Science.gov

Sample records for absolute time scale

  1. Absolute flux scale for radioastronomy

    SciTech Connect

    Ivanov, V.P.; Stankevich, K.S.

    1986-07-01

    The authors propose and provide support for a new absolute flux scale for radio astronomy, which is not encumbered with the inadequacies of the previous scales. In constructing it the method of relative spectra was used (a powerful tool for choosing reference spectra). A review is given of previous flux scales. The authors compare the AIS scale with the scale they propose. Both scales are based on absolute measurements by the ''artificial moon'' method, and they are practically coincident in the range from 0.96 to 6 GHz. At frequencies above 6 GHz, 0.96 GHz, the AIS scale is overestimated because of incorrect extrapolation of the spectra of the primary and secondary standards. The major results which have emerged from this review of absolute scales in radio astronomy are summarized.

  2. Combined Use of Absolute and Differential Seismic Arrival Time Data to Improve Absolute Event Location

    NASA Astrophysics Data System (ADS)

    Myers, S.; Johannesson, G.

    2012-12-01

    Arrival time measurements based on waveform cross correlation are becoming more common as advanced signal processing methods are applied to seismic data archives and real-time data streams. Waveform correlation can precisely measure the time difference between the arrival of two phases, and differential time data can be used to constrain relative location of events. Absolute locations are needed for many applications, which generally requires the use of absolute time data. Current methods for measuring absolute time data are approximately two orders of magnitude less precise than differential time measurements. To exploit the strengths of both absolute and differential time data, we extend our multiple-event location method Bayesloc, which previously used absolute time data only, to include the use of differential time measurements that are based on waveform cross correlation. Fundamentally, Bayesloc is a formulation of the joint probability over all parameters comprising the multiple event location system. The Markov-Chain Monte Carlo method is used to sample from the joint probability distribution given arrival data sets. The differential time component of Bayesloc includes scaling a stochastic estimate of differential time measurement precision based the waveform correlation coefficient for each datum. For a regional-distance synthetic data set with absolute and differential time measurement error of 0.25 seconds and 0.01 second, respectively, epicenter location accuracy is improved from and average of 1.05 km when solely absolute time data are used to 0.28 km when absolute and differential time data are used jointly (73% improvement). The improvement in absolute location accuracy is the result of conditionally limiting absolute location probability regions based on the precise relative position with respect to neighboring events. Bayesloc estimates of data precision are found to be accurate for the synthetic test, with absolute and differential time measurement

  3. Clock time is absolute and universal

    NASA Astrophysics Data System (ADS)

    Shen, Xinhang

    2015-09-01

    A critical error is found in the Special Theory of Relativity (STR): mixing up the concepts of the STR abstract time of a reference frame and the displayed time of a physical clock, which leads to use the properties of the abstract time to predict time dilation on physical clocks and all other physical processes. Actually, a clock can never directly measure the abstract time, but can only record the result of a physical process during a period of the abstract time such as the number of cycles of oscillation which is the multiplication of the abstract time and the frequency of oscillation. After Lorentz Transformation, the abstract time of a reference frame expands by a factor gamma, but the frequency of a clock decreases by the same factor gamma, and the resulting multiplication i.e. the displayed time of a moving clock remains unchanged. That is, the displayed time of any physical clock is an invariant of Lorentz Transformation. The Lorentz invariance of the displayed times of clocks can further prove within the framework of STR our earth based standard physical time is absolute, universal and independent of inertial reference frames as confirmed by both the physical fact of the universal synchronization of clocks on the GPS satellites and clocks on the earth, and the theoretical existence of the absolute and universal Galilean time in STR which has proved that time dilation and space contraction are pure illusions of STR. The existence of the absolute and universal time in STR has directly denied that the reference frame dependent abstract time of STR is the physical time, and therefore, STR is wrong and all its predictions can never happen in the physical world.

  4. The Study of the Tether Motion with Time-Varying Length Using the Absolute Nodal Coordinate Formulation with Multiple Nonlinear Time Scales

    NASA Astrophysics Data System (ADS)

    Kawaguti, Keisuke; Terumichi, Yoshiaki; Takehara, Shoichiro; Kaczmarczyk, Stefan; Sogabe, Kiyoshi

    In this study, the modeling and formulation for tether motion with time-varying length, large rotation, large displacement and large deformation are proposed. A tether or cable is an important element in lift systems, construction machines for transportation and often is used with a time-varying length. In some cases, these systems are large and the tether has a long length, large deformation and large displacement. The dynamic behavior of a tether in extension and retraction using the proposed method is discussed in this paper. In the passage through resonance, significant tether motions with large rotation and large deformation result. In the analysis of this phenomenon, the transient fluctuations of the motion amplitudes are examined and compared with the corresponding steady state motions. The accuracy and the cost of the calculations are also verified by comparison with the experimental results.

  5. An absolute scale for measuring the utility of money

    NASA Astrophysics Data System (ADS)

    Thomas, P. J.

    2010-07-01

    Measurement of the utility of money is essential in the insurance industry, for prioritising public spending schemes and for the evaluation of decisions on protection systems in high-hazard industries. Up to this time, however, there has been no universally agreed measure for the utility of money, with many utility functions being in common use. In this paper, we shall derive a single family of utility functions, which have risk-aversion as the only free parameter. The fact that they return a utility of zero at their low, reference datum, either the utility of no money or of one unit of money, irrespective of the value of risk-aversion used, qualifies them to be regarded as absolute scales for the utility of money. Evidence of validation for the concept will be offered based on inferential measurements of risk-aversion, using diverse measurement data.

  6. Mid-infrared absolute spectral responsivity scale based on an absolute cryogenic radiometer and an optical parametric oscillator laser

    NASA Astrophysics Data System (ADS)

    Zhao, Kun; Shi, Xueshun; Chen, Haidong; Liu, Yulong; Liu, Changming; Chen, Kunfeng; Li, Ligong; Gan, Haiyong; Ma, Chong

    2016-06-01

    We are reporting on a laser-based absolute spectral responsivity scale in the mid-infrared spectral range. By using a mid-infrared tunable optical parametric oscillator as the laser source, the absolute responsivity scale has been established by calibrating thin-film thermopile detectors against an absolute cryogenic radiometer. The thin-film thermopile detectors can be then used as transfer standard detectors. The extended uncertainty of the absolute spectral responsivity measurement has been analyzed to be 0.58%–0.68% (k  =  2).

  7. Mid-infrared absolute spectral responsivity scale based on an absolute cryogenic radiometer and an optical parametric oscillator laser

    NASA Astrophysics Data System (ADS)

    Zhao, Kun; Shi, Xueshun; Chen, Haidong; Liu, Yulong; Liu, Changming; Chen, Kunfeng; Li, Ligong; Gan, Haiyong; Ma, Chong

    2016-06-01

    We are reporting on a laser-based absolute spectral responsivity scale in the mid-infrared spectral range. By using a mid-infrared tunable optical parametric oscillator as the laser source, the absolute responsivity scale has been established by calibrating thin-film thermopile detectors against an absolute cryogenic radiometer. The thin-film thermopile detectors can be then used as transfer standard detectors. The extended uncertainty of the absolute spectral responsivity measurement has been analyzed to be 0.58%-0.68% (k  =  2).

  8. Communication: The absolute shielding scales of oxygen and sulfur revisited

    SciTech Connect

    Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Ruud, Kenneth; Gauss, Jürgen

    2015-03-07

    We present an updated semi-experimental absolute shielding scale for the {sup 17}O and {sup 33}S nuclei. These new shielding scales are based on accurate rotational microwave data for the spin–rotation constants of H{sub 2}{sup 17}O [Puzzarini et al., J. Chem. Phys. 131, 234304 (2009)], C{sup 17}O [Cazzoli et al., Phys. Chem. Chem. Phys. 4, 3575 (2002)], and H{sub 2}{sup 33}S [Helgaker et al., J. Chem. Phys. 139, 244308 (2013)] corrected both for vibrational and temperature effects estimated at the CCSD(T) level of theory as well as for the relativistic corrections to the relation between the spin–rotation constant and the absolute shielding constant. Our best estimate for the oxygen shielding constants of H{sub 2}{sup 17}O is 328.4(3) ppm and for C{sup 17}O −59.05(59) ppm. The relativistic correction for the sulfur shielding of H{sub 2}{sup 33}S amounts to 3.3%, and the new sulfur shielding constant for this molecule is 742.9(4.6) ppm.

  9. Absolute Timing of the Crab Pulsar with RXTE

    NASA Technical Reports Server (NTRS)

    Rots, Arnold H.; Jahoda, Keith; Lyne, Andrew G.

    2004-01-01

    We have monitored the phase of the main X-ray pulse of the Crab pulsar with the Rossi X-ray Timing Explorer (RXTE) for almost eight years, since the start of the mission in January 1996. The absolute time of RXTE's clock is sufficiently accurate to allow this phase to be compared directly with the radio profile. Our monitoring observations of the pulsar took place bi-weekly (during the periods when it was at least 30 degrees from the Sun) and we correlated the data with radio timing ephemerides derived from observations made at Jodrell Bank. We have determined the phase of the X-ray main pulse for each observation with a typical error in the individual data points of 50 microseconds. The total ensemble is consistent with a phase that is constant over the monitoring period, with the X-ray pulse leading the radio pulse by 0.01025 plus or minus 0.00120 period in phase, or 344 plus or minus 40 microseconds in time. The error estimate is dominated by a systematic error of 40 microseconds, most likely constant, arising from uncertainties in the instrumental calibration of the radio data. The statistical error is 0.00015 period, or 5 microseconds. The separation of the main pulse and interpulse appears to be unchanging at time scales of a year or less, with an average value of 0.4001 plus or minus 0.0002 period. There is no apparent variation in these values with energy over the 2-30 keV range. The lag between the radio and X-ray pulses ma be constant in phase (i.e., rotational in nature) or constant in time (i.e., due to a pathlength difference). We are not (yet) able to distinguish between these two interpretations.

  10. Henry More and the development of absolute time.

    PubMed

    Thomas, Emily

    2015-12-01

    This paper explores the nature, development and influence of the first English account of absolute time, put forward in the mid-seventeenth century by the 'Cambridge Platonist' Henry More. Against claims in the literature that More does not have an account of time, this paper sets out More's evolving account and shows that it reveals the lasting influence of Plotinus. Further, this paper argues that More developed his views on time in response to his adoption of Descartes' vortex cosmology and cosmogony, providing new evidence of More's wider project to absorb Cartesian natural philosophy into his Platonic metaphysics. Finally, this paper argues that More should be added to the list of sources that later English thinkers - including Newton and Samuel Clarke - drew on in constructing their absolute accounts of time. PMID:26568082

  11. An absolute interval scale of order for point patterns

    PubMed Central

    Protonotarios, Emmanouil D.; Baum, Buzz; Johnston, Alan; Hunter, Ginger L.; Griffin, Lewis D.

    2014-01-01

    Human observers readily make judgements about the degree of order in planar arrangements of points (point patterns). Here, based on pairwise ranking of 20 point patterns by degree of order, we have been able to show that judgements of order are highly consistent across individuals and the dimension of order has an interval scale structure spanning roughly 10 just-notable-differences (jnd) between disorder and order. We describe a geometric algorithm that estimates order to an accuracy of half a jnd by quantifying the variability of the size and shape of spaces between points. The algorithm is 70% more accurate than the best available measures. By anchoring the output of the algorithm so that Poisson point processes score on average 0, perfect lattices score 10 and unit steps correspond closely to jnds, we construct an absolute interval scale of order. We demonstrate its utility in biology by using this scale to quantify order during the development of the pattern of bristles on the dorsal thorax of the fruit fly. PMID:25079866

  12. Occupational Cohort Time Scales

    PubMed Central

    Roth, H. Daniel

    2015-01-01

    Purpose: This study explores how highly correlated time variables (occupational cohort time scales) contribute to confounding and ambiguity of interpretation. Methods: Occupational cohort time scales were identified and organized through simple equations of three time scales (relational triads) and the connections between these triads (time scale web). The behavior of the time scales was examined when constraints were imposed on variable ranges and interrelationships. Results: Constraints on a time scale in a triad create high correlations between the other two time scales. These correlations combine with the connections between relational triads to produce association paths. High correlation between time scales leads to ambiguity of interpretation. Conclusions: Understanding the properties of occupational cohort time scales, their relational triads, and the time scale web is helpful in understanding the origins of otherwise obscure confounding bias and ambiguity of interpretation. PMID:25647318

  13. Strong thermal leptogenesis and the absolute neutrino mass scale

    SciTech Connect

    Bari, Pasquale Di; King, Sophie E.; Fiorentin, Michele Re E-mail: sk1806@soton.ac.uk

    2014-03-01

    We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass m{sub 1}∼>10 meV for normal ordering (NO) and m{sub 1}∼>3 meV for inverted ordering (IO) for models with orthogonal matrix entries respecting |Ω{sub ij}{sup 2}|∼<2. We show analytically why lower values of m{sub 1} require a higher level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint exists thanks to the measured values of the neutrino mixing angles and could be tightened by a future determination of the Dirac phase. Our analysis also allows us to place a more stringent constraint for a specific model or class of models, such as SO(10)-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of m{sub 1}. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing m{sub 1}. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.

  14. Extension of the absolute flux density scale to 22.285 GHz. [radio astronomy

    NASA Technical Reports Server (NTRS)

    Janssen, M. A.; Golden, L. M.; Welch, W. J.

    1974-01-01

    Extending the absolute flux density scale at microwave wavelengths, the absolute flux densities at 22.285 GHz of several standard sources were determined using the absolute calibrations of the 6.1 meter antenna of the Hat Creek Observatory. Interpolation formulas for each nonthermal standard source have been derived by combining these data with those determined at lower frequencies. The suitability of employing the standard sources for calibrating other antennas is discussed.

  15. Time-resolved Absolute Velocity Quantification with Projections

    PubMed Central

    Langham, Michael C.; Jain, Varsha; Magland, Jeremy F.; Wehrli, Felix W.

    2010-01-01

    Quantitative information on time-resolved blood velocity along the femoral/popliteal artery can provide clinical information on peripheral arterial disease and complement MR angiography since not all stenoses are hemodynamically significant. The key disadvantages of the most widely used approach to time-resolve pulsatile blood flow by cardiac-gated velocity-encoded gradient-echo imaging are gating errors and long acquisition time. Here we demonstrate a rapid non-triggered method that quantifies absolute velocity on the basis of phase difference between successive velocity-encoded projections after selectively removing the background static tissue signal via a reference image. The tissue signal from the reference image’s center k-space line is isolated by masking out the vessels in the image domain. The performance of the technique, in terms of reproducibility and agreement with results obtained with conventional phase contrast (PC)-MRI was evaluated at 3T field strength with a variable-flow rate phantom and in vivo of the triphasic velocity waveforms at several segments along the femoral and popliteal arteries. Additionally, time-resolved flow velocity was quantified in five healthy subjects and compared against gated PC-MRI results. To illustrate clinical feasibility the proposed method was shown to be able to identify hemodynamic abnormalities and impaired reactivity in a diseased femoral artery. For both phantom and in vivo studies, velocity measurements were within 1.5 cm/s and the coefficient of variation was less than 5% in an in vivo reproducibility study. In five healthy subjects, the average differences in mean peak velocities and their temporal locations were within 1 cm/s and 10 ms compared to gated PC-MRI. In conclusion, the proposed method provides temporally-resolved arterial velocity with a temporal resolution of 20 ms with minimal post-processing. PMID:20677235

  16. Improved Strategies and Optimization of Calibration Models for Real-time PCR Absolute Quantification

    EPA Science Inventory

    Real-time PCR absolute quantification applications rely on the use of standard curves to make estimates of DNA target concentrations in unknown samples. Traditional absolute quantification approaches dictate that a standard curve must accompany each experimental run. However, t...

  17. Ensemble Pulsar Time Scale

    NASA Astrophysics Data System (ADS)

    Yin, D. S.; Gao, Y. P.; Zhao, S. H.

    2016-05-01

    Millisecond pulsars can generate another type of time scale that is totally independent of the atomic time scale, because the physical mechanisms of the pulsar time scale and the atomic time scale are quite different from each other. Usually the pulsar timing observational data are not evenly sampled, and the internals between data points range from several hours to more than half a month. What's more, these data sets are sparse. And all these make it difficult to generate an ensemble pulsar time scale. Hence, a new algorithm to calculate the ensemble pulsar time scale is proposed. Firstly, we use cubic spline interpolation to densify the data set, and make the intervals between data points even. Then, we employ the Vondrak filter to smooth the data set, and get rid of high-frequency noise, finally adopt the weighted average method to generate the ensemble pulsar time scale. The pulsar timing residuals represent clock difference between the pulsar time and atomic time, and the high precision pulsar timing data mean the clock difference measurement between the pulsar time and atomic time with a high signal to noise ratio, which is fundamental to generate pulsar time. We use the latest released NANOGRAV (North American Nanohertz Observatory for Gravitational Waves) 9-year data set to generate the ensemble pulsar time scale. This data set is from the newest NANOGRAV data release, which includes 9-year observational data of 37 millisecond pulsars using the 100-meter Green Bank telescope and 305-meter Arecibo telescope. We find that the algorithm used in this paper can lower the influence caused by noises in timing residuals, and improve long-term stability of pulsar time. Results show that the long-term (> 1 yr) frequency stability of the pulsar time is better than 3.4×10-15.

  18. Kelvin Absolute Temperature Scale Identified as Length Scale and Related to de Broglie Thermal Wavelength

    NASA Astrophysics Data System (ADS)

    Sohrab, Siavash

    Thermodynamic equilibrium between matter and radiation leads to de Broglie wavelength λdβ = h /mβvrβ and frequency νdβ = k /mβvrβ of matter waves and stochastic definitions of Planck h =hk =mk <λrk > c and Boltzmann k =kk =mk <νrk > c constants, λrkνrk = c , that respectively relate to spatial (λ) and temporal (ν) aspects of vacuum fluctuations. Photon massmk =√{ hk /c3 } , amu =√{ hkc } = 1 /No , and universal gas constant Ro =No k =√{ k / hc } result in internal Uk = Nhνrk = Nmkc2 = 3 Nmkvmpk2 = 3 NkT and potential pV = uN\\vcirc / 3 = N\\ucirc / 3 = NkT energy of photon gas in Casimir vacuum such that H = TS = 4 NkT . Therefore, Kelvin absolute thermodynamic temperature scale [degree K] is identified as length scale [meter] and related to most probable wavelength and de Broglie thermal wavelength as Tβ =λmpβ =λdβ / 3 . Parallel to Wien displacement law obtained from Planck distribution, the displacement law λwS T =c2 /√{ 3} is obtained from Maxwell -Boltzmann distribution of speed of ``photon clusters''. The propagation speeds of sound waves in ideal gas versus light waves in photon gas are described in terms of vrβ in harmony with perceptions of Huygens. Newton formula for speed of long waves in canals √{ p / ρ } is modified to √{ gh } =√{ γp / ρ } in accordance with adiabatic theory of Laplace.

  19. Absolute and Relative Reliability of Percentage of Syllables Stuttered and Severity Rating Scales

    ERIC Educational Resources Information Center

    Karimi, Hamid; O'Brian, Sue; Onslow, Mark; Jones, Mark

    2014-01-01

    Purpose: Percentage of syllables stuttered (%SS) and severity rating (SR) scales are measures in common use to quantify stuttering severity and its changes during basic and clinical research conditions. However, their reliability has not been assessed with indices measuring both relative and absolute reliability. This study was designed to provide…

  20. Global-Scale Location and Distance Estimates: Common Representations and Strategies in Absolute and Relative Judgments

    ERIC Educational Resources Information Center

    Friedman, Alinda; Montello, Daniel R.

    2006-01-01

    The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although…

  1. Energy dispersive X-ray analysis on an absolute scale in scanning transmission electron microscopy.

    PubMed

    Chen, Z; D'Alfonso, A J; Weyland, M; Taplin, D J; Allen, L J; Findlay, S D

    2015-10-01

    We demonstrate absolute scale agreement between the number of X-ray counts in energy dispersive X-ray spectroscopy using an atomic-scale coherent electron probe and first-principles simulations. Scan-averaged spectra were collected across a range of thicknesses with precisely determined and controlled microscope parameters. Ionization cross-sections were calculated using the quantum excitation of phonons model, incorporating dynamical (multiple) electron scattering, which is seen to be important even for very thin specimens.

  2. Absolute shielding scale for 31P from gas-phase NMR studies

    NASA Astrophysics Data System (ADS)

    Jameson, Cynthia J.; De Dios, Angel; Keith Jameson, A.

    1990-04-01

    Differences in the 31P nuclear shielding in the zero-pressure limit have been measured in seven compounds. An absolute 31P shielding scale based on the PH 3 molecular beam data is established and the absolute shielding of the standard liquid reference (85% aqueous H 3PO 4) is found to be 328.35 ppm, based on PH 3 being 594.45 ± 0.63 ppm. Comparisons with ab initio calculations show that calculations using local origins (the IGLO method) are in good agreement with experiment.

  3. A California statewide three-dimensional seismic velocity model from both absolute and differential times

    USGS Publications Warehouse

    Lin, G.; Thurber, C.H.; Zhang, H.; Hauksson, E.; Shearer, P.M.; Waldhauser, F.; Brocher, T.M.; Hardebeck, J.

    2010-01-01

    We obtain a seismic velocity model of the California crust and uppermost mantle using a regional-scale double-difference tomography algorithm. We begin by using absolute arrival-time picks to solve for a coarse three-dimensional (3D) P velocity (VP) model with a uniform 30 km horizontal node spacing, which we then use as the starting model for a finer-scale inversion using double-difference tomography applied to absolute and differential pick times. For computational reasons, we split the state into 5 subregions with a grid spacing of 10 to 20 km and assemble our final statewide VP model by stitching together these local models. We also solve for a statewide S-wave model using S picks from both the Southern California Seismic Network and USArray, assuming a starting model based on the VP results and a VP=VS ratio of 1.732. Our new model has improved areal coverage compared with previous models, extending 570 km in the SW-NE directionand 1320 km in the NW-SE direction. It also extends to greater depth due to the inclusion of substantial data at large epicentral distances. Our VP model generally agrees with previous separate regional models for northern and southern California, but we also observe some new features, such as high-velocity anomalies at shallow depths in the Klamath Mountains and Mount Shasta area, somewhat slow velocities in the northern Coast Ranges, and slow anomalies beneath the Sierra Nevada at midcrustal and greater depths. This model can be applied to a variety of regional-scale studies in California, such as developing a unified statewide earthquake location catalog and performing regional waveform modeling.

  4. The possibility of constructing the hydrogen scale of the absolute atomic masses of the elements

    NASA Astrophysics Data System (ADS)

    Kuz'min, I. I.

    2009-12-01

    The paper presents a scheme for the experimental-empirical construction of the existing chemical, physical, and carbon scales of the relative nonintegral atomic masses of the elements. The quantitative interrelation between the nonintegral relative atomic masses, their minimized fractional positive and negative natural deviations from integral numbers, and their integral parts are reproduced mathematically. Nonisotopic fractional deviations are shown to be a consequence of methodological side effects of the scheme for theoretical processing of the data of thorough physical and chemical measurements performed by Stas and Aston in constructing scales of relative atomic masses. In conformity with the Prout hypothesis, the absolute atomic mass unit and the corresponding Avogadro’s number value are suggested for the construction of the hydrogen scale of absolute atomic masses of nonisotopic elements, individual isotopes, and isotope-containing elements.

  5. Multi-channel data acquisition system with absolute time synchronization

    NASA Astrophysics Data System (ADS)

    Włodarczyk, Przemysław; Pustelny, Szymon; Budker, Dmitry; Lipiński, Marcin

    2014-11-01

    We present a low-cost, stand-alone global-time-synchronized data acquisition system. Our prototype allows recording up to four analog signals with a 16-bit resolution in variable ranges and a maximum sampling rate of 1000 S/s. The system simultaneously acquires readouts of external sensors e.g. magnetometer or thermometer. A complete data set, including a header containing timestamp, is stored on a Secure Digital (SD) card or transmitted to a computer using Universal Serial Bus (USB). The estimated time accuracy of the data acquisition is better than ±200 ns. The device is intended for use in a global network of optical magnetometers (the Global Network of Optical Magnetometers for Exotic physics - GNOME), which aims to search for signals heralding physics beyond the Standard Model, that can be generated by ordinary spin coupling to exotic particles or anomalous spin interactions.

  6. Absolute GPS Time Event Generation and Capture for Remote Locations

    NASA Astrophysics Data System (ADS)

    HIRES Collaboration

    The HiRes experiment operates fixed location and portable lasers at remote desert locations to generate calibration events. One physics goal of HiRes is to search for unusual showers. These may appear similar to upward or horizontally pointing laser tracks used for atmospheric calibration. It is therefore necessary to remove all of these calibration events from the HiRes detector data stream in a physics blind manner. A robust and convenient "tagging" method is to generate the calibration events at precisely known times. To facilitate this tagging method we have developed the GPSY (Global Positioning System YAG) module. It uses a GPS receiver, an embedded processor and additional timing logic to generate laser triggers at arbitrary programmed times and frequencies with better than 100nS accuracy. The GPSY module has two trigger outputs (one microsecond resolution) to trigger the laser flash-lamp and Q-switch and one event capture input (25nS resolution). The GPSY module can be programmed either by a front panel menu based interface or by a host computer via an RS232 serial interface. The latter also allows for computer logging of generated and captured event times. Details of the design and the implementation of these devices will be presented. 1 Motivation Air Showers represent a small fraction, much less than a percent, of the total High Resolution Fly's Eye data sample. The bulk of the sample is calibration data. Most of this calibration data is generated by two types of systems that use lasers. One type sends light directly to the detectors via optical fibers to monitor detector gains (Girard 2001). The other sends a beam of light into the sky and the scattered light that reaches the detectors is used to monitor atmospheric effects (Wiencke 1998). It is important that these calibration events be cleanly separated from the rest of the sample both to provide a complete set of monitoring information, and more

  7. Absolute Calibration of the Radio Astronomy Flux Density Scale at 22 to 43 GHz Using Planck

    NASA Astrophysics Data System (ADS)

    Partridge, B.; López-Caniego, M.; Perley, R. A.; Stevens, J.; Butler, B. J.; Rocha, G.; Walter, B.; Zacchei, A.

    2016-04-01

    The Planck mission detected thousands of extragalactic radio sources at frequencies from 28 to 857 GHz. Planck's calibration is absolute (in the sense that it is based on the satellite’s annual motion around the Sun and the temperature of the cosmic microwave background), and its beams are well characterized at sub-percent levels. Thus, Planck's flux density measurements of compact sources are absolute in the same sense. We have made coordinated Very Large Array (VLA) and Australia Telescope Compact Array (ATCA) observations of 65 strong, unresolved Planck sources in order to transfer Planck's calibration to ground-based instruments at 22, 28, and 43 GHz. The results are compared to microwave flux density scales currently based on planetary observations. Despite the scatter introduced by the variability of many of the sources, the flux density scales are determined to 1%-2% accuracy. At 28 GHz, the flux density scale used by the VLA runs 2%-3% ± 1.0% below Planck values with an uncertainty of +/- 1.0%; at 43 GHz, the discrepancy increases to 5%-6% ± 1.4% for both ATCA and the VLA.

  8. Supercontinent cycles and the calculation of absolute palaeolongitude in deep time.

    PubMed

    Mitchell, Ross N; Kilian, Taylor M; Evans, David A D

    2012-02-08

    Traditional models of the supercontinent cycle predict that the next supercontinent--'Amasia'--will form either where Pangaea rifted (the 'introversion' model) or on the opposite side of the world (the 'extroversion' models). Here, by contrast, we develop an 'orthoversion' model whereby a succeeding supercontinent forms 90° away, within the great circle of subduction encircling its relict predecessor. A supercontinent aggregates over a mantle downwelling but then influences global-scale mantle convection to create an upwelling under the landmass. We calculate the minimum moment of inertia about which oscillatory true polar wander occurs owing to the prolate shape of the non-hydrostatic Earth. By fitting great circles to each supercontinent's true polar wander legacy, we determine that the arc distances between successive supercontinent centres (the axes of the respective minimum moments of inertia) are 88° for Nuna to Rodinia and 87° for Rodinia to Pangaea--as predicted by the orthoversion model. Supercontinent centres can be located back into Precambrian time, providing fixed points for the calculation of absolute palaeolongitude over billion-year timescales. Palaeogeographic reconstructions additionally constrained in palaeolongitude will provide increasingly accurate estimates of ancient plate motions and palaeobiogeographic affinities.

  9. Supercontinent cycles and the calculation of absolute palaeolongitude in deep time.

    PubMed

    Mitchell, Ross N; Kilian, Taylor M; Evans, David A D

    2012-02-01

    Traditional models of the supercontinent cycle predict that the next supercontinent--'Amasia'--will form either where Pangaea rifted (the 'introversion' model) or on the opposite side of the world (the 'extroversion' models). Here, by contrast, we develop an 'orthoversion' model whereby a succeeding supercontinent forms 90° away, within the great circle of subduction encircling its relict predecessor. A supercontinent aggregates over a mantle downwelling but then influences global-scale mantle convection to create an upwelling under the landmass. We calculate the minimum moment of inertia about which oscillatory true polar wander occurs owing to the prolate shape of the non-hydrostatic Earth. By fitting great circles to each supercontinent's true polar wander legacy, we determine that the arc distances between successive supercontinent centres (the axes of the respective minimum moments of inertia) are 88° for Nuna to Rodinia and 87° for Rodinia to Pangaea--as predicted by the orthoversion model. Supercontinent centres can be located back into Precambrian time, providing fixed points for the calculation of absolute palaeolongitude over billion-year timescales. Palaeogeographic reconstructions additionally constrained in palaeolongitude will provide increasingly accurate estimates of ancient plate motions and palaeobiogeographic affinities. PMID:22318605

  10. Geologic time scale bookmark

    USGS Publications Warehouse

    ,

    2012-01-01

    This bookmark, designed for use with U.S. Geological Survey activities at the 2nd USA Science and Engineering Festival (April 26–29, 2012), is adapted from the more detailed Fact Sheet 2010–3059 "Divisions of Geologic Time." The information that it presents is widely sought by educators and students.

  11. Absolute frequency measurement at 10-16 level based on the international atomic time

    NASA Astrophysics Data System (ADS)

    Hachisu, H.; Fujieda, M.; Kumagai, M.; Ido, T.

    2016-06-01

    Referring to International Atomic Time (TAI), we measured the absolute frequency of the 87Sr lattice clock with its uncertainty of 1.1 x 10-15. Unless an optical clock is continuously operated for the five days of the TAI grid, it is required to evaluate dead time uncertainty in order to use the available five-day average of the local frequency reference. We homogeneously distributed intermittent measurements over the five-day grid of TAI, by which the dead time uncertainty was reduced to low 10-16 level. Three campaigns of the five (or four)-day consecutive measurements have resulted in the absolute frequency of the 87Sr clock transition of 429 228 004 229 872.85 (47) Hz, where the systematic uncertainty of the 87Sr optical frequency standard amounts to 8.6 x 10-17.

  12. A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Bell, Cameron P. M.; Mamajek, Eric E.; Naylor, Tim

    2015-11-01

    We present a self-consistent, absolute isochronal age scale for young ( ≲ 200 Myr), nearby ( ≲ 100 pc) moving groups in the solar neighbourhood based on homogeneous fitting of semi-empirical pre-main-sequence model isochrones using the τ2 maximum-likelihood fitting statistic of Naylor & Jeffries in the MV, V - J colour-magnitude diagram. The final adopted ages for the groups are as follows: 149^{+51}_{-19} {Myr} for the AB Dor moving group, 24 ± 3 Myr for the β Pic moving group (BPMG), 45^{+11}_{-7} {Myr} for the Carina association, 42^{+6}_{-4} {Myr} for the Columba association, 11 ± 3 Myr for the η Cha cluster, 45 ± 4 Myr for the Tucana-Horologium moving group (Tuc-Hor), 10 ± 3 Myr for the TW Hya association and 22^{+4}_{-3} {Myr} for the 32 Ori group. At this stage we are uncomfortable assigning a final, unambiguous age to the Argus association as our membership list for the association appears to suffer from a high level of contamination, and therefore it remains unclear whether these stars represent a single population of coeval stars. Our isochronal ages for both the BPMG and Tuc-Hor are consistent with recent lithium depletion boundary (LDB) ages, which unlike isochronal ages, are relatively insensitive to the choice of low-mass evolutionary models. This consistency between the isochronal and LDB ages instils confidence that our self-consistent, absolute age scale for young, nearby moving groups is robust, and hence we suggest that these ages be adopted for future studies of these groups. Software implementing the methods described in this study is available from http://www.astro.ex.ac.uk/people/timn/tau-squared/.

  13. Global-scale location and distance estimates: common representations and strategies in absolute and relative judgments.

    PubMed

    Friedman, Alinda; Montello, Daniel R

    2006-03-01

    The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latitude estimates revealed the presence of psychologically based regions with large gaps between them and a tendency to stretch North America southward toward the equator. The distance estimates revealed the same properties in the representation recovered via multidimensional scaling. Though the aggregated within- and between-regions distance estimates were fitted by Stevens's law (S. S. Stevens, 1957), this was an averaging artifact: The appropriateness of a power function to describe distance estimates depended on the regional membership of the cities. The authors conclude that plausible reasoning strategies, combined with regionalized representations and beliefs about the location of these relative to global landmarks, underlie global-scale latitude and distance judgments.

  14. Absolute value optimization to estimate phase properties of stochastic time series

    NASA Technical Reports Server (NTRS)

    Scargle, J. D.

    1977-01-01

    Most existing deconvolution techniques are incapable of determining phase properties of wavelets from time series data; to assure a unique solution, minimum phase is usually assumed. It is demonstrated, for moving average processes of order one, that deconvolution filtering using the absolute value norm provides an estimate of the wavelet shape that has the correct phase character when the random driving process is nonnormal. Numerical tests show that this result probably applies to more general processes.

  15. A Concurrent Mixed Methods Approach to Examining the Quantitative and Qualitative Meaningfulness of Absolute Magnitude Estimation Scales in Survey Research

    ERIC Educational Resources Information Center

    Koskey, Kristin L. K.; Stewart, Victoria C.

    2014-01-01

    This small "n" observational study used a concurrent mixed methods approach to address a void in the literature with regard to the qualitative meaningfulness of the data yielded by absolute magnitude estimation scaling (MES) used to rate subjective stimuli. We investigated whether respondents' scales progressed from less to more and…

  16. White-light scanning interferometer for absolute nano-scale gap thickness measurement.

    PubMed

    Xu, Zhiguang; Shilpiekandula, Vijay; Youcef-toumi, Kamal; Yoon, Soon Fatt

    2009-08-17

    A special configuration of white-light scanning interferometer is described for measuring the absolute air gap thickness between two planar plates brought into close proximity. The measured gap is not located in any interference arm of the interferometer, but acts as an amplitude-and-phase modulator of the light source. Compared with the common white-light interferometer our approach avoids the influence of the chromatic dispersion of the planar plates on the gap thickness quantification. It covers a large measurement range of from approximate contact to tens of microns with a high resolution of 0.1 nm. Detailed analytical models are presented and signal-processing algorithms based on convolution and correlation techniques are developed. Practical measurements are carried out and the experimental results match well with the analysis and simulation. Short-time and long-time repeatabilities are both tested to prove the high performance of our method.

  17. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; /more authors..

    2012-09-20

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between {approx}6 and {approx}13 GeV with an estimated uncertainty of {approx}2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  18. NMR absolute shielding scale and nuclear magnetic dipole moment of (207)Pb.

    PubMed

    Adrjan, Bożena; Makulski, Włodzimierz; Jackowski, Karol; Demissie, Taye B; Ruud, Kenneth; Antušek, Andrej; Jaszuński, Michał

    2016-06-28

    An absolute shielding scale is proposed for (207)Pb nuclear magnetic resonance (NMR) spectroscopy. It is based on ab initio calculations performed on an isolated tetramethyllead Pb(CH3)4 molecule and the assignment of the experimental resonance frequency from the gas-phase NMR spectra of Pb(CH3)4, extrapolated to zero density of the buffer gas to obtain the result for an isolated molecule. The computed (207)Pb shielding constant is 10 790 ppm for the isolated molecule, leading to a shielding of 10799.7 ppm for liquid Pb(CH3)4 which is the accepted reference standard for (207)Pb NMR spectra. The new experimental and theoretical data are used to determine μ((207)Pb), the nuclear magnetic dipole moment of (207)Pb, by applying the standard relationship between NMR frequencies, shielding constants and nuclear moments of two nuclei in the same external magnetic field. Using the gas-phase (207)Pb and (reference) proton results and the theoretical value of the Pb shielding in Pb(CH3)4, we find μ((207)Pb) = 0.59064 μN. The analysis of new experimental and theoretical data obtained for the Pb(2+) ion in water solutions provides similar values of μ((207)Pb), in the range of 0.59000-0.59131 μN. PMID:27265668

  19. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbielini, G; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B,; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Gehrels, N.; Hays, E.; McEnery, J. E.; Thompson, D. J.; Troja, E. J.

    2012-01-01

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron- plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between approx. 6 and approx. 13 GeV with an estimated uncertainty of approx. 2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  20. Time scales of Magmatic Processes

    NASA Astrophysics Data System (ADS)

    Hawkesworth, C. J.

    2002-05-01

    Knowledge of the rates of natural processes is critical to the development of physically realistic models. For magmatic processes, rates are increasingly well determined from short lived isotopes, and from diffusion modified element profiles, on time scales that vary from 10s of 1000s of years to a few years. Our understanding of the melting processes beneath MOR have been revolutionised by the application of U-series isotopes, because they include isotopes with half lives similar to the time scales of melt generation and extraction. For island arcs there is much discussion of how to incorporate suggestions that Ra and Ba are transferred from the slab in a few 1000 years, and yet significantly more time is required to generate the excess Pa isotopes. Once in the crust, crystallisation and differentiation may be driven by cooling, degassing and decompression, and these should be characterised by different time scales. Crystals preserve rich high-resolution records of changing magma compositions, but the time scales of those changes are difficult to establish. Isotope studies have shown that more evolved rock types tend to contain more old crystals that may be 10s of 1000s of years old at the time of eruption. Whether these are xenocrysts, or evidence for long term crystallisation histories remains controversial. Moreover, diffusion modified element profiles, and crystal size distributions, suggest that crystals are often less than a 100 years old. An alternative approach is to consider U-series isotope ratios in the magma, and how these may change with degree of magma evolution. These suggest that differentiation time scales may be up to 200 ky for magmas at the base of the crust, but for magmas that crystallise at shallower levels the time scales are much shorter. In some cases these are in weeks and months, and crystallisation is likely to be due to decompression and degassing. One consequence of the short crystallisation times, is that there may be insufficient

  1. Comparison of different standards for real-time PCR-based absolute quantification.

    PubMed

    Dhanasekaran, S; Doherty, T Mark; Kenneth, John

    2010-03-31

    Quantitative real-time PCR (qPCR) is a powerful tool used for both research and diagnostic, which has the advantage, compared to relative quantification, of providing an absolute copy number for a particular target. However, reliable standards are essential for qPCR. In this study, we have compared four types of commonly-used standards--PCR products (with and without purification) and cloned target sequences (circular and linear plasmid) for their stability during storage (using percentage of variance in copy numbers, PCR efficiency and regression curve correlation coefficient (R(2))) using hydrolysis probe (TaqMan) chemistry. Results, expressed as copy numbers/microl, are presented from a sample human system in which absolute levels of HuPO (reference gene) and the cytokine gene IFN-gamma were measured. To ensure the suitability and stability of the four standards, the experiments were performed at 0, 7 and 14 day intervals and repeated 6 times. We have found that the copy numbers vary (due to degradation of standards) over the period of time during storage at 4 degrees C and -20 degrees C, which affected PCR efficiency significantly. The cloned target sequences were noticeably more stable than the PCR product, which could lead to substantial variance in results using standards constructed by different routes. Standard quality and stability should be routinely tested for assays using qPCR.

  2. Evaluation of absolute quantitation by nonlinear regression in probe-based real-time PCR

    PubMed Central

    Goll, Rasmus; Olsen, Trine; Cui, Guanglin; Florholmen, Jon

    2006-01-01

    Background In real-time PCR data analysis, the cycle threshold (CT) method is currently the gold standard. This method is based on an assumption of equal PCR efficiency in all reactions, and precision may suffer if this condition is not met. Nonlinear regression analysis (NLR) or curve fitting has therefore been suggested as an alternative to the cycle threshold method for absolute quantitation. The advantages of NLR are that the individual sample efficiency is simulated by the model and that absolute quantitation is possible without a standard curve, releasing reaction wells for unknown samples. However, the calculation method has not been evaluated systematically and has not previously been applied to a TaqMan platform. Aim: To develop and evaluate an automated NLR algorithm capable of generating batch production regression analysis. Results Total RNA samples extracted from human gastric mucosa were reverse transcribed and analysed for TNFA, IL18 and ACTB by TaqMan real-time PCR. Fluorescence data were analysed by the regular CT method with a standard curve, and by NLR with a positive control for conversion of fluorescence intensity to copy number, and for this purpose an automated algorithm was written in SPSS syntax. Eleven separate regression models were tested, and the output data was subjected to Altman-Bland analysis. The Altman-Bland analysis showed that the best regression model yielded quantitative data with an intra-assay variation of 58% vs. 24% for the CT derived copy numbers, and with a mean inter-method deviation of × 0.8. Conclusion NLR can be automated for batch production analysis, but the CT method is more precise for absolute quantitation in the present setting. The observed inter-method deviation is an indication that assessment of the fluorescence conversion factor used in the regression method can be improved. However, the versatility depends on the level of precision required, and in some settings the increased cost effectiveness of NLR

  3. Time dependent corrections to absolute gravity determinations in the establishment of modern gravity control

    NASA Astrophysics Data System (ADS)

    Dykowski, Przemyslaw; Krynski, Jan

    2015-04-01

    The establishment of modern gravity control with the use of exclusively absolute method of gravity determination has significant advantages as compared to the one established mostly with relative gravity measurements (e.g. accuracy, time efficiency). The newly modernized gravity control in Poland consists of 28 fundamental stations (laboratory) and 168 base stations (PBOG14 - located in the field). Gravity at the fundamental stations was surveyed with the FG5-230 gravimeter of the Warsaw University of Technology, and at the base stations - with the A10-020 gravimeter of the Institute of Geodesy and Cartography, Warsaw. This work concerns absolute gravity determinations at the base stations. Although free of common relative measurement errors (e.g. instrumental drift) and effects of network adjustment, absolute gravity determinations for the establishment of gravity control require advanced corrections due to time dependent factors, i.e. tidal and ocean loading corrections, atmospheric corrections and hydrological corrections that were not taken into account when establishing the previous gravity control in Poland. Currently available services and software allow to determine high accuracy and high temporal resolution corrections for atmospheric (based on digital weather models, e.g. ECMWF) and hydrological (based on hydrological models, e.g. GLDAS/Noah) gravitational and loading effects. These corrections are mostly used for processing observations with Superconducting Gravimeters in the Global Geodynamics Project. For the area of Poland the atmospheric correction based on weather models can differ from standard atmospheric correction by even ±2 µGal. The hydrological model shows the annual variability of ±8 µGal. In addition the standard tidal correction may differ from the one obtained from the local tidal model (based on tidal observations). Such difference at Borowa Gora Observatory reaches the level of ±1.5 µGal. Overall the sum of atmospheric and

  4. Time-series modeling and prediction of global monthly absolute temperature for environmental decision making

    NASA Astrophysics Data System (ADS)

    Ye, Liming; Yang, Guixia; Van Ranst, Eric; Tang, Huajun

    2013-03-01

    A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochastic combined (DSC) approach. Although the development of the framework was based on the characterization of the variation patterns of a global dataset, the methodology could be applied to any monthly absolute temperature record. Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal, involving polynomial functions and the Fourier method, respectively, while stochastic processes were employed to account for any remaining patterns in the temperature signal, involving seasonal autoregressive integrated moving average (SARIMA) models. A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years. The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors, suggesting that DSC models, when coupled with other ecoenvironmental models, can be used as a supplemental tool for short-term (˜10-year) environmental planning and decision making.

  5. Calculation of Retention Time Tolerance Windows with Absolute Confidence from Shared Liquid Chromatographic Retention Data

    PubMed Central

    Boswell, Paul G.; Abate-Pella, Daniel; Hewitt, Joshua T.

    2015-01-01

    Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user’s system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called “retention projection” was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously. PMID:26292624

  6. Time scales in cognitive neuroscience

    PubMed Central

    Papo, David

    2013-01-01

    Cognitive neuroscience boils down to describing the ways in which cognitive function results from brain activity. In turn, brain activity shows complex fluctuations, with structure at many spatio-temporal scales. Exactly how cognitive function inherits the physical dimensions of neural activity, though, is highly non-trivial, and so are generally the corresponding dimensions of cognitive phenomena. As for any physical phenomenon, when studying cognitive function, the first conceptual step should be that of establishing its dimensions. Here, we provide a systematic presentation of the temporal aspects of task-related brain activity, from the smallest scale of the brain imaging technique's resolution, to the observation time of a given experiment, through the characteristic time scales of the process under study. We first review some standard assumptions on the temporal scales of cognitive function. In spite of their general use, these assumptions hold true to a high degree of approximation for many cognitive (viz. fast perceptual) processes, but have their limitations for other ones (e.g., thinking or reasoning). We define in a rigorous way the temporal quantifiers of cognition at all scales, and illustrate how they qualitatively vary as a function of the properties of the cognitive process under study. We propose that each phenomenon should be approached with its own set of theoretical, methodological and analytical tools. In particular, we show that when treating cognitive processes such as thinking or reasoning, complex properties of ongoing brain activity, which can be drastically simplified when considering fast (e.g., perceptual) processes, start playing a major role, and not only characterize the temporal properties of task-related brain activity, but also determine the conditions for proper observation of the phenomena. Finally, some implications on the design of experiments, data analyses, and the choice of recording parameters are discussed. PMID:23626578

  7. The Question of Absolute Space and Time Directions in Relation to Molecular Chirality, Parity Violation, and Biomolecular Homochirality

    SciTech Connect

    Quack, Martin

    2001-03-21

    The questions of the absolute directions of space and time or the “observability” of absolute time direction as well as absolute handedness-left or right- are related to the fundamental symmetries of physics C, P, T as well as their combinations, in particular CPT, and their violations, such as parity violation. At the same time there is a relation to certain still open questions in chemistry concerning the fundamental physical- chemical principles of molecular chirality and in biochemistry concerning the selection of homochirality in evolution. In the lecture we shall introduce the concepts and then report new theoretical results from our work on parity violation in chiral molecules, showing order of magnitude increases with respect to previously accepted values. We discus as well our current experimental efforts. We shall briefly mention the construction of an absolute molecular clock.

  8. The Question of Absolute Space and Time Directions in Relation to Molecular Chirality, Parity Violation, and Biomolecular Homochirality

    SciTech Connect

    Quack, Martin

    2001-03-21

    The questions of the absolute directions of space and time or the 'observability' of absolute time direction as well as absolute handedness - left or right - are related to the fundamental symmetries of physics C, P, T as well as their combinations, in particular CPT, and their violations, such as parity violation. At the same time there is a relation to certain still open questions in chemistry concerning the fundamental physical-chemical principles of molecular chirality and in biochemistry concerning the selection of homochirality in evolution. In the lecture we shall introduce the concepts and then report new theoretical results from our work on parity violation in chiral molecules, showing order of magnitude increases with respect to previously accepted values. We discuss as well our current experimental efforts. We shall briefly mention the construction of an absolute molecular clock.

  9. Toward an absolute NMR shielding scale using the spin-rotation tensor within a relativistic framework.

    PubMed

    Aucar, I Agustín; Gomez, Sergio S; Giribet, Claudia G; Aucar, Gustavo A

    2016-08-24

    One of the most influential articles showing the best way to get the absolute values of NMR magnetic shieldings, σ (non-measurables) from both accurate measurements and theoretical calculations, was published a long time ago by Flygare. His model was shown to break down when heavy atoms are involved. This fact motivated the development of new theories of nuclear spin-rotation (SR) tensors, which consider electronic relativistic effects. One was published recently by some of us. In this article we take another step further and propose three different models that generalize Flygare's model. All of them are written using four-component relativistic expressions, though the two-component relativistic SO-S term also appears in one. The first clues for these developments were built from the relationship among σ and the SR tensors within the two-component relativistic LRESC model. Besides, we had to introduce a few other well defined assumptions: (i) relativistic corrections must be included in a way to best reproduce the relationship among the (e-e) term (called "paramagnetic" within the non-relativistic domain) of σ and its equivalent part of the SR tensor, (ii) as happens in Flygare's rule, the shielding of free atoms shall be included to improve accuracy. In the highest accurate model, a new term known as Spin-orbit due to spin, SO-S (in this mechanism the spin-Zeeman Hamiltonian replaces the orbital-Zeeman Hamiltonian), is included. We show the results of the application of those models to halogen containing linear molecules. PMID:27506822

  10. Toward an absolute NMR shielding scale using the spin-rotation tensor within a relativistic framework.

    PubMed

    Aucar, I Agustín; Gomez, Sergio S; Giribet, Claudia G; Aucar, Gustavo A

    2016-08-24

    One of the most influential articles showing the best way to get the absolute values of NMR magnetic shieldings, σ (non-measurables) from both accurate measurements and theoretical calculations, was published a long time ago by Flygare. His model was shown to break down when heavy atoms are involved. This fact motivated the development of new theories of nuclear spin-rotation (SR) tensors, which consider electronic relativistic effects. One was published recently by some of us. In this article we take another step further and propose three different models that generalize Flygare's model. All of them are written using four-component relativistic expressions, though the two-component relativistic SO-S term also appears in one. The first clues for these developments were built from the relationship among σ and the SR tensors within the two-component relativistic LRESC model. Besides, we had to introduce a few other well defined assumptions: (i) relativistic corrections must be included in a way to best reproduce the relationship among the (e-e) term (called "paramagnetic" within the non-relativistic domain) of σ and its equivalent part of the SR tensor, (ii) as happens in Flygare's rule, the shielding of free atoms shall be included to improve accuracy. In the highest accurate model, a new term known as Spin-orbit due to spin, SO-S (in this mechanism the spin-Zeeman Hamiltonian replaces the orbital-Zeeman Hamiltonian), is included. We show the results of the application of those models to halogen containing linear molecules.

  11. Alignment between seafloor spreading directions and absolute plate motions through time

    NASA Astrophysics Data System (ADS)

    Williams, Simon E.; Flament, Nicolas; Müller, R. Dietmar

    2016-02-01

    The history of seafloor spreading in the ocean basins provides a detailed record of relative motions between Earth's tectonic plates since Pangea breakup. Determining how tectonic plates have moved relative to the Earth's deep interior is more challenging. Recent studies of contemporary plate motions have demonstrated links between relative plate motion and absolute plate motion (APM), and with seismic anisotropy in the upper mantle. Here we explore the link between spreading directions and APM since the Early Cretaceous. We find a significant alignment between APM and spreading directions at mid-ocean ridges; however, the degree of alignment is influenced by geodynamic setting, and is strongest for mid-Atlantic spreading ridges between plates that are not directly influenced by time-varying slab pull. In the Pacific, significant mismatches between spreading and APM direction may relate to a major plate-mantle reorganization. We conclude that spreading fabric can be used to improve models of APM.

  12. An Integrated Model of Choices and Response Times in Absolute Identification

    ERIC Educational Resources Information Center

    Brown, Scott D.; Marley, A. A. J.; Donkin, Christopher; Heathcote, Andrew

    2008-01-01

    Recent theoretical developments in the field of absolute identification have stressed differences between relative and absolute processes, that is, whether stimulus magnitudes are judged relative to a shorter term context provided by recently presented stimuli or a longer term context provided by the entire set of stimuli. The authors developed a…

  13. Investigation of Absolute and Relative Scaling Conceptions of Students in Introductory College Chemistry Courses

    ERIC Educational Resources Information Center

    Gerlach, Karrie; Trate, Jaclyn; Blecking, Anja; Geissinger, Peter; Murphy, Kristen

    2014-01-01

    Scale as a theme in science instruction is not a new idea. As early as the mid-1980s, scale was identified as an important component of a student's overall science literacy. However, the study of scale and the scale literacy of students in varying levels of education have received less attention than other science-literacy components.…

  14. Model-based evaluation of microbial mass fractions: effect of absolute anaerobic reaction time on microbial mass fractions.

    PubMed

    Tunçal, Tolga

    2010-04-14

    Although enhanced biological phosphorus removal processes (EBPR) are popular methods for nutrient control, unstable treatment performances of full-scale systems are still not well understood. In this study, the interaction between electron acceptors present at the start of the anaerobic phase of an EBPR system and the amount of organic acids generated from simple substrate (rbsCOD) was investigated in a full-scale wastewater treatment plant. Quantification of microbial groups including phosphorus-accumulating microorganisms (PAOs), denitrifying PAOs (DPAOs), glycogen-accumulating microorganisms (GAOs) and ordinary heterotrophic microorganisms (OHOs) was based on a modified dynamic model. The intracellular phosphorus content of PAOs was also determined by the execution of mass balances for the biological stages of the plant. The EBPR activities observed in the plant and in batch tests (under idealized conditions) were compared with each other statistically as well. Modelling efforts indicated that the use of absolute anaerobic reaction (eta1) instead of nominal anaerobic reaction time (eta), to estimate the amount of available substrate for PAOs, significantly improved model accuracy. Another interesting result of the study was the differences in EBPR characteristics observed in idealized and real conditions. PMID:20480829

  15. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  16. Symbolic Formulation of Large-scale Open-loop Multibody Systems for Vibration Analysis Using Absolute Joint Coordinates

    NASA Astrophysics Data System (ADS)

    Jiang, Wei; Chen, Xuedong; Luo, Xin; Huang, Qingjiu

    A novel symbolic formulation is presented to model dynamics of large-scale open-loop holonomic multibody systems, by using absolute joint coordinates and via matrix transformation, instead of solving constraint equations. The resulting minimal set of second-order linear ordinary differential equations (ODEs) can be used for linear vibration analysis and control directly. The ODEs are generated in three steps. Firstly, a set of linearized ODEs are formulated in terms of absolute coordinates without considering any constraint. Secondly, an overall transform matrix representing constraint topology for the entire constrained system is generated. Finally, matrices for a minimal set of ODEs for the open-loop holonomic multibody system are obtained via matrix transformation. The correctness and efficiency of the presented algorithm are verified by numerical experiments on various cases of holonomic multibody systems with different open-loop topologies, including chain topology and tree topology. It is indicated that the proposed method can significantly improve efficiency without losing computational accuracy.

  17. Absolute dominance of hydrogenotrophic methanogens in full-scale anaerobic sewage sludge digesters.

    PubMed

    Kim, Jaai; Kim, Woong; Lee, Changsoo

    2013-11-01

    Anaerobic digestion (AD) is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Despite extensive efforts, AD microbial ecology is still limitedly understood, especially due to the lack of quantitative information on the structures and dynamics of AD microbial communities. Such knowledge gap is particularly pronounced in sewage sludge AD processes although treating sewage sludge is among the major practical applications of AD. Therefore, we examined the microbial communities in three full-scale sewage sludge digesters using qualitative and quantitative molecular techniques in combination: denaturing gradient gel electrophoresis (DGGE) and real-time polymerase chain reaction (PCR). Eight out of eleven bacterial sequences retrieved from the DGGE analysis were not affiliated to any known species while all eleven archaeal sequences were assigned to known methanogen species. Quantitative real-time PCR analysis revealed that, based on the 16S rRNA gene abundance, the hydrogenotrophic order Methanomicrobiales is the most dominant methanogen group (> 94% of the total methanogen population) in all digesters. This corresponds well to the prevailing occurrence of the DGGE bands related to Methanolinea and Methanospirillum, both belonging to the order Methanomicrobiales, in all sludge samples. It is therefore suggested that hydrogenotrophic methanogens, especially Methanomicrobiales strains, are likely the major players responsible for biogas production in the digesters studied. Our observation is contrary to the conventional understanding that aceticlastic methanogens generally dominate methanogen communities in stable AD environments, suggesting the need for further studies on the dominance relationship in various AD systems.

  18. Gas-phase NMR measurements, absolute shielding scales, and magnetic dipole moments of 29Si and 73Ge nuclei.

    PubMed

    Makulski, W; Jackowski, K; Antusek, A; Jaszuński, M

    2006-10-12

    New gas-phase NMR measurements of the shielding constants of 29Si, 73Ge, and 1H nuclei in SiH4 and GeH4 are reported. The results, extrapolated to zero density, provide accurate isolated molecule values, best suited for comparison with theoretical calculations. Using the recent ab initio results for these molecules and the measured chemical shifts, we determine the absolute shielding scales for 29Si and 73Ge. This allows us to provide new values of the nuclear magnetic dipole moments for these two nuclei; in addition, we examine the dipole moments of 13C and 119Sn.

  19. Music Proficiency and Quantification of Absolute Pitch: A Large-Scale Study among Brazilian Musicians

    PubMed Central

    Leite, Raphael B. C.; Mota-Rolim, Sergio A.; Queiroz, Claudio M. T.

    2016-01-01

    Absolute pitch (AP) is the ability to identify and name the pitch of a sound without external reference. Often, accuracy and speed at naming isolated musical pitches are correlated with demographic, biological, and acoustical parameters to gain insight into the genesis and evolution of this ability in specific cohorts. However, the majority of those studies were conducted in North America, Europe, or Asia. To fill this gap, here we investigated the pitch-naming performance in a large population of Brazilian conservatory musicians (N = 200). As previously shown, we found that the population performance was rather a continuum than an “all-or-none” ability. By comparing the observed distribution of correct responses to a theoretical binomial distribution, we estimated the prevalence of AP as being 18% amongst regular music students. High accuracy thresholds (e.g., 85% of correct responses) yielded a prevalence of 4%, suggesting that AP might have been underestimated in previous reports. Irrespective of the threshold used, AP prevalence was higher in musicians who started their musical practice and formal musical education early in life. Finally, we compared the performance of those music students (average proficiency group) with another group of students selected to take part in the conservatory orchestra (high proficiency group, N = 30). Interestingly, the prevalence of AP was higher in the latter in comparison to the former group. In addition, even when the response was incorrect, the mean absolute deviation from the correct response was smaller in the high proficiency group compared to the average proficiency group (Glass's Δ: 0.5). Taken together, our results show that the prevalence of AP in Brazilian students is similar to other non-tonal language populations, although this measure is highly dependent on the scoring threshold used. Despite corroborating that early involvement with musical practice and formal education can foster AP ability, the present data

  20. A BAYESIAN METHOD FOR CALCULATING REAL-TIME QUANTITATIVE PCR CALIBRATION CURVES USING ABSOLUTE PLASMID DNA STANDARDS

    EPA Science Inventory

    In real-time quantitative PCR studies using absolute plasmid DNA standards, a calibration curve is developed to estimate an unknown DNA concentration. However, potential differences in the amplification performance of plasmid DNA compared to genomic DNA standards are often ignore...

  1. Advances in time-scale algorithms

    NASA Technical Reports Server (NTRS)

    Stein, S. R.

    1993-01-01

    The term clock is usually used to refer to a device that counts a nearly periodic signal. A group of clocks, called an ensemble, is often used for time keeping in mission critical applications that cannot tolerate loss of time due to the failure of a single clock. The time generated by the ensemble of clocks is called a time scale. The question arises how to combine the times of the individual clocks to form the time scale. One might naively be tempted to suggest the expedient of averaging the times of the individual clocks, but a simple thought experiment demonstrates the inadequacy of this approach. Suppose a time scale is composed of two noiseless clocks having equal and opposite frequencies. The mean time scale has zero frequency. However if either clock fails, the time-scale frequency immediately changes to the frequency of the remaining clock. This performance is generally unacceptable and simple mean time scales are not used. First, previous time-scale developments are reviewed and then some new methods that result in enhanced performance are presented. The historical perspective is based upon several time scales: the AT1 and TA time scales of the National Institute of Standards and Technology (NIST), the A.1(MEAN) time scale of the US Naval observatory (USNO), the TAI time scale of the Bureau International des Poids et Measures (BIPM), and the KAS-1 time scale of the Naval Research laboratory (NRL). The new method was incorporated in the KAS-2 time scale recently developed by Timing Solutions Corporation. The goal is to present time-scale concepts in a nonmathematical form with as few equations as possible. Many other papers and texts discuss the details of the optimal estimation techniques that may be used to implement these concepts.

  2. The Dynamics of Scaling: A Memory-Based Anchor Model of Category Rating and Absolute Identification

    ERIC Educational Resources Information Center

    Petrov, Alexander A.; Anderson, John R.

    2005-01-01

    A memory-based scaling model--ANCHOR--is proposed and tested. The perceived magnitude of the target stimulus is compared with a set of anchors in memory. Anchor selection is probabilistic and sensitive to similarity, base-level strength, and recency. The winning anchor provides a reference point near the target and thereby converts the global…

  3. Stability of Rasch Scales over Time

    ERIC Educational Resources Information Center

    Taylor, Catherine S.; Lee, Yoonsun

    2010-01-01

    Item response theory (IRT) methods are generally used to create score scales for large-scale tests. Research has shown that IRT scales are stable across groups and over time. Most studies have focused on items that are dichotomously scored. Now Rasch and other IRT models are used to create scales for tests that include polytomously scored items.…

  4. Energy Decomposition Analysis Based on Absolutely Localized Molecular Orbitals for Large-Scale Density Functional Theory Calculations in Drug Design.

    PubMed

    Phipps, M J S; Fox, T; Tautermann, C S; Skylaris, C-K

    2016-07-12

    We report the development and implementation of an energy decomposition analysis (EDA) scheme in the ONETEP linear-scaling electronic structure package. Our approach is hybrid as it combines the localized molecular orbital EDA (Su, P.; Li, H. J. Chem. Phys., 2009, 131, 014102) and the absolutely localized molecular orbital EDA (Khaliullin, R. Z.; et al. J. Phys. Chem. A, 2007, 111, 8753-8765) to partition the intermolecular interaction energy into chemically distinct components (electrostatic, exchange, correlation, Pauli repulsion, polarization, and charge transfer). Limitations shared in EDA approaches such as the issue of basis set dependence in polarization and charge transfer are discussed, and a remedy to this problem is proposed that exploits the strictly localized property of the ONETEP orbitals. Our method is validated on a range of complexes with interactions relevant to drug design. We demonstrate the capabilities for large-scale calculations with our approach on complexes of thrombin with an inhibitor comprised of up to 4975 atoms. Given the capability of ONETEP for large-scale calculations, such as on entire proteins, we expect that our EDA scheme can be applied in a large range of biomolecular problems, especially in the context of drug design.

  5. Length scales in alloy dissolution and measurement of absolute interfacial free energy.

    PubMed

    Rugolo, J; Erlebacher, J; Sieradzki, K

    2006-12-01

    De-alloying is the selective dissolution of one or more of the elemental components of an alloy. In binary alloys that exhibit complete solid solubility, de-alloying of the less noble component results in the formation of nanoporous metals, a materials class that has attracted attention for applications such as catalysis, sensing and actuation. In addition, the occurrence of de-alloying in metallic alloy systems under stress is known to result in stress-corrosion cracking, a key failure mechanism in fossil fuel and nuclear plants, ageing aircraft, and also an important concern in the design of nuclear-waste storage containers. Central to the design of corrosion-resistant alloys is the identification of a composition-dependent electrochemical critical potential, Vcrit, above which the current rises dramatically with potential, signalling the onset of bulk de-alloying. Below Vcrit, the surface is passivated by the accumulation of up to several monolayers of the more noble component. The current understanding of the processes that control Vcrit is incomplete. Here, we report on de-alloying results of Ag/Au superlattices that clarify the role of pre-existing length scales in alloy dissolution. Our data motivated us to re-analyse existing data on critical potentials of Ag-Au alloys and develop a simple unifying picture that accounts for the compositional dependence of solid-solution alloy critical potentials.

  6. Review of time scales. [Universal Time-Ephemeris Time-International Atomic Time

    NASA Technical Reports Server (NTRS)

    Guinot, B.

    1974-01-01

    The basic time scales are presented: International Atomic Time, Universal Time, and Universal Time (Coordinated). These scales must be maintained in order to satisfy specific requirements. It is shown how they are obtained and made available at a very high level of precision.

  7. Time scale in quasifission reactions

    SciTech Connect

    Back, B.B.; Paul, P.; Nestler, J.

    1995-08-01

    The quasifission process arises from the hindrance of the complete fusion process when heavy-ion beams are used. The strong dissipation in the system tends to prevent fusion and lead the system towards reseparation into two final products of similar mass reminiscent of a fission process. This dissipation slows down the mass transfer and shape transformation and allows for the emission of high energy {gamma}-rays during the process, albeit with a low probability. Giant Dipole {gamma} rays emitted during this time have a characteristic spectral shape and may thus be discerned in the presence of a background of {gamma} rays emitted from the final fission-like fragments. Since the rate of GDR {gamma} emission is very well established, the strength of this component may therefore be used to measure the timescale of the quasifission process. In this experiment we studied the reaction between 368-MeV {sup 58}Ni and a {sup 165}Ho target, where deep inelastic scattering and quasifission processes are dominant. Coincidences between fission fragments (detected in four position-sensitive avalanche detectors) and high energy {gamma} rays (measured in a 10{close_quotes} x 10{close_quotes} actively shielded NaI detector) were registered. Beams were provided by the Stony Brook Superconducting Linac. The {gamma}-ray spectrum associated with deep inelastic scattering events is well reproduced by statistical cooling of projectile and target-like fragments with close to equal initial excitation energy sharing. The y spectrum associated with quasifission events is well described by statistical emission from the fission fragments alone, with only weak evidence for GDR emission from the mono-nucleus. A 1{sigma} limit of t{sub ss} < 11 x 10{sup -21} s is obtained for the mono-nucleus lifetime, which is consistent with the lifetime obtained from quasifission fragment angular distributions. A manuscript was accepted for publication.

  8. Multiple time scale methods in tokamak magnetohydrodynamics

    SciTech Connect

    Jardin, S.C.

    1984-01-01

    Several methods are discussed for integrating the magnetohydrodynamic (MHD) equations in tokamak systems on other than the fastest time scale. The dynamical grid method for simulating ideal MHD instabilities utilizes a natural nonorthogonal time-dependent coordinate transformation based on the magnetic field lines. The coordinate transformation is chosen to be free of the fast time scale motion itself, and to yield a relatively simple scalar equation for the total pressure, P = p + B/sup 2//2..mu../sub 0/, which can be integrated implicitly to average over the fast time scale oscillations. Two methods are described for the resistive time scale. The zero-mass method uses a reduced set of two-fluid transport equations obtained by expanding in the inverse magnetic Reynolds number, and in the small ratio of perpendicular to parallel mobilities and thermal conductivities. The momentum equation becomes a constraint equation that forces the pressure and magnetic fields and currents to remain in force balance equilibrium as they evolve. The large mass method artificially scales up the ion mass and viscosity, thereby reducing the severe time scale disparity between wavelike and diffusionlike phenomena, but not changing the resistive time scale behavior. Other methods addressing the intermediate time scales are discussed.

  9. Kalman plus weights: a time scale algorithm

    NASA Technical Reports Server (NTRS)

    Greenhall, C. A.

    2001-01-01

    KPW is a time scale algorithm that combines Kalman filtering with the basic time scale equation (BTSE). A single Kalman filter that estimates all clocks simultaneously is used to generate the BTSE frequency estimates, while the BTSE weights are inversely proportional to the white FM variances of the clocks. Results from simulated clock ensembles are compared to previous simulation results from other algorithms.

  10. Time-dependent corona models - Scaling laws

    NASA Technical Reports Server (NTRS)

    Korevaar, P.; Martens, P. C. H.

    1989-01-01

    Scaling laws are derived for the one-dimensional time-dependent Euler equations that describe the evolution of a spherically symmetric stellar atmosphere. With these scaling laws the results of the time-dependent calculations by Korevaar (1989) obtained for one star are applicable over the whole Hertzsprung-Russell diagram and even to elliptic galaxies. The scaling is exact for stars with the same M/R-ratio and a good approximation for stars with a different M/R-ratio. The global relaxation oscillation found by Korevaar (1989) is scaled to main sequence stars, a solar coronal hole, cool giants and elliptic galaxies.

  11. Absolute calibration method for nanosecond-resolved, time-streaked, fiber optic light collection, spectroscopy systems

    NASA Astrophysics Data System (ADS)

    Johnston, Mark D.; Oliver, Bryan V.; Droemer, Darryl W.; Frogget, Brent; Crain, Marlon D.; Maron, Yitzhak

    2012-08-01

    This paper describes a convenient and accurate method to calibrate fast (<1 ns resolution) streaked, fiber optic light collection, spectroscopy systems. Such systems are inherently difficult to calibrate due to the lack of sufficiently intense, calibrated light sources. Such a system is used to collect spectral data on plasmas generated in electron beam diodes fielded on the RITS-6 accelerator (8-12MV, 140-200kA) at Sandia National Laboratories. On RITS, plasma light is collected through a small diameter (200 μm) optical fiber and recorded on a fast streak camera at the output of a 1 meter Czerny-Turner monochromator. For this paper, a 300 W xenon short arc lamp (Oriel Model 6258) was used as the calibration source. Since the radiance of the xenon arc varies from cathode to anode, just the area around the tip of the cathode ("hotspot") was imaged onto the fiber, to produce the highest intensity output. To compensate for chromatic aberrations, the signal was optimized at each wavelength measured. Output power was measured using 10 nm bandpass interference filters and a calibrated photodetector. These measurements give power at discrete wavelengths across the spectrum, and when linearly interpolated, provide a calibration curve for the lamp. The shape of the spectrum is determined by the collective response of the optics, monochromator, and streak tube across the spectral region of interest. The ratio of the spectral curve to the measured bandpass filter curve at each wavelength produces a correction factor (Q) curve. This curve is then applied to the experimental data and the resultant spectra are given in absolute intensity units (photons/sec/cm2/steradian/nm). Error analysis shows this method to be accurate to within +/- 20%, which represents a high level of accuracy for this type of measurement.

  12. Absolute calibration method for nanosecond-resolved, time-streaked, fiber optic light collection, spectroscopy systems.

    PubMed

    Johnston, Mark D; Oliver, Bryan V; Droemer, Darryl W; Frogget, Brent; Crain, Marlon D; Maron, Yitzhak

    2012-08-01

    This paper describes a convenient and accurate method to calibrate fast (<1 ns resolution) streaked, fiber optic light collection, spectroscopy systems. Such systems are inherently difficult to calibrate due to the lack of sufficiently intense, calibrated light sources. Such a system is used to collect spectral data on plasmas generated in electron beam diodes fielded on the RITS-6 accelerator (8-12MV, 140-200kA) at Sandia National Laboratories. On RITS, plasma light is collected through a small diameter (200 μm) optical fiber and recorded on a fast streak camera at the output of a 1 meter Czerny-Turner monochromator. For this paper, a 300 W xenon short arc lamp (Oriel Model 6258) was used as the calibration source. Since the radiance of the xenon arc varies from cathode to anode, just the area around the tip of the cathode ("hotspot") was imaged onto the fiber, to produce the highest intensity output. To compensate for chromatic aberrations, the signal was optimized at each wavelength measured. Output power was measured using 10 nm bandpass interference filters and a calibrated photodetector. These measurements give power at discrete wavelengths across the spectrum, and when linearly interpolated, provide a calibration curve for the lamp. The shape of the spectrum is determined by the collective response of the optics, monochromator, and streak tube across the spectral region of interest. The ratio of the spectral curve to the measured bandpass filter curve at each wavelength produces a correction factor (Q) curve. This curve is then applied to the experimental data and the resultant spectra are given in absolute intensity units (photons/sec/cm(2)/steradian/nm). Error analysis shows this method to be accurate to within +∕- 20%, which represents a high level of accuracy for this type of measurement. PMID:22938275

  13. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  14. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  15. DAQ Software Contributions, Absolute Scale Energy Calibration and Background Evaluation for the NOvA Experiment at Fermilab

    SciTech Connect

    Flumerfelt, Eric Lewis

    2015-08-01

    The NOvA (NuMI Off-axis ve [nu_e] Appearance) Experiment is a long-baseline accelerator neutrino experiment currently in its second year of operations. NOvA uses the Neutrinos from the Main Injector (NuMI) beam at Fermilab, and there are two main off-axis detectors: a Near Detector at Fermilab and a Far Detector 810 km away at Ash River, MN. The work reported herein is in support of the NOvA Experiment, through contributions to the development of data acquisition software, providing an accurate, absolute-scale energy calibration for electromagnetic showers in NOvA detector elements, crucial to the primary electron neutrino search, and through an initial evaluation of the cosmic background rate in the NOvA Far Detector, which is situated on the surface without significant overburden. Additional support work for the NOvA Experiment is also detailed, including DAQ Server Administration duties and a study of NOvA’s sensitivity to neutrino oscillations into a “sterile” state.

  16. Absolute pitch among students at the Shanghai Conservatory of Music: a large-scale direct-test study.

    PubMed

    Deutsch, Diana; Li, Xiaonuo; Shen, Jing

    2013-11-01

    This paper reports a large-scale direct-test study of absolute pitch (AP) in students at the Shanghai Conservatory of Music. Overall note-naming scores were very high, with high scores correlating positively with early onset of musical training. Students who had begun training at age ≤5 yr scored 83% correct not allowing for semitone errors and 90% correct allowing for semitone errors. Performance levels were higher for white key pitches than for black key pitches. This effect was greater for orchestral performers than for pianists, indicating that it cannot be attributed to early training on the piano. Rather, accuracy in identifying notes of different names (C, C#, D, etc.) correlated with their frequency of occurrence in a large sample of music taken from the Western tonal repertoire. There was also an effect of pitch range, so that performance on tones in the two-octave range beginning on Middle C was higher than on tones in the octave below Middle C. In addition, semitone errors tended to be on the sharp side. The evidence also ran counter to the hypothesis, previously advanced by others, that the note A plays a special role in pitch identification judgments.

  17. Mouse Activity across Time Scales: Fractal Scenarios

    PubMed Central

    Lima, G. Z. dos Santos; Lobão-Soares, B.; do Nascimento, G. C.; França, Arthur S. C.; Muratori, L.; Ribeiro, S.; Corso, G.

    2014-01-01

    In this work we devise a classification of mouse activity patterns based on accelerometer data using Detrended Fluctuation Analysis. We use two characteristic mouse behavioural states as benchmarks in this study: waking in free activity and slow-wave sleep (SWS). In both situations we find roughly the same pattern: for short time intervals we observe high correlation in activity - a typical 1/f complex pattern - while for large time intervals there is anti-correlation. High correlation of short intervals ( to : waking state and to : SWS) is related to highly coordinated muscle activity. In the waking state we associate high correlation both to muscle activity and to mouse stereotyped movements (grooming, waking, etc.). On the other side, the observed anti-correlation over large time scales ( to : waking state and to : SWS) during SWS appears related to a feedback autonomic response. The transition from correlated regime at short scales to an anti-correlated regime at large scales during SWS is given by the respiratory cycle interval, while during the waking state this transition occurs at the time scale corresponding to the duration of the stereotyped mouse movements. Furthermore, we find that the waking state is characterized by longer time scales than SWS and by a softer transition from correlation to anti-correlation. Moreover, this soft transition in the waking state encompass a behavioural time scale window that gives rise to a multifractal pattern. We believe that the observed multifractality in mouse activity is formed by the integration of several stereotyped movements each one with a characteristic time correlation. Finally, we compare scaling properties of body acceleration fluctuation time series during sleep and wake periods for healthy mice. Interestingly, differences between sleep and wake in the scaling exponents are comparable to previous works regarding human heartbeat. Complementarily, the nature of these sleep-wake dynamics could lead to a better

  18. Characteristic Time Scales of Characteristic Magmatic Processes and Systems

    NASA Astrophysics Data System (ADS)

    Marsh, B. D.

    2004-05-01

    Every specific magmatic process, regardless of spatial scale, has an associated characteristic time scale. Time scales associated with crystals alone are rates of growth, dissolution, settling, aggregation, annealing, and nucleation, among others. At the other extreme are the time scales associated with the dynamics of the entire magmatic system. These can be separated into two groups: those associated with system genetics (e.g., the production and transport of magma, establishment of the magmatic system) and those due to physical characteristics of the established system (e.g., wall rock failure, solidification front propagation and instability, porous flow). The detailed geometry of a specific magmatic system is particularly important to appreciate; although generic systems are useful, care must be taken to make model systems as absolutely realistic as possible. Fuzzy models produce fuzzy science. Knowledge of specific time scales is not necessarily useful or meaningful unless the hierarchical context of the time scales for a realistic magmatic system is appreciated. The age of a specific phenocryst or ensemble of phenocrysts, as determined from isotopic or CSD studies, is not meaningful unless something can be ascertained of the provenance of the crystals. For example, crystal size multiplied by growth rate gives a meaningful crystal age only if it is from a part of the system that has experienced semi-monotonic cooling prior to chilling; crystals entrained from a long-standing cumulate bed that were mechanically sorted in ascending magma may not reveal this history. Ragged old crystals rolling about in the system for untold numbers of flushing times record specious process times, telling more about the noise in the system than the life of typical, first generation crystallization processes. The most helpful process-related time scales are those that are known well and that bound or define the temporal style of the system. Perhaps the most valuable of these

  19. Solid-state track recorder dosimetry device to measure absolute reaction rates and neutron fluence as a function of time

    DOEpatents

    Gold, Raymond; Roberts, James H.

    1989-01-01

    A solid state track recording type dosimeter is disclosed to measure the time dependence of the absolute fission rates of nuclides or neutron fluence over a period of time. In a primary species an inner recording drum is rotatably contained within an exterior housing drum that defines a series of collimating slit apertures overlying windows defined in the stationary drum through which radiation can enter. Film type solid state track recorders are positioned circumferentially about the surface of the internal recording drum to record such radiation or its secondary products during relative rotation of the two elements. In another species both the recording element and the aperture element assume the configuration of adjacent disks. Based on slit size of apertures and relative rotational velocity of the inner drum, radiation parameters within a test area may be measured as a function of time and spectra deduced therefrom.

  20. Effects of knowledge of results (KR) frequency in the learning of a timing skill: absolute versus relative KR frequency.

    PubMed

    Vieira, Márcio M; Ugrinowitsch, Herbert; Oliveira, Fernanda S; Gallo, Lívia G; Benda, Rodolfo N

    2012-10-01

    The interaction between the amount of practice and frequency of Knowledge of Results (KR) was investigated in a timing skill. In the acquisition phase the task involved 90 trials of releasing a knob and transporting three tennis balls from three near recipients to three far ones in a specific sequence and target time. The retention test performed 24 hr. later had the same sequence of transport but a new target time was required. In both phases, absolute error and standard deviation plus constant error was measured. The five groups differed in relation to frequency of KR and amount of practice. The results showed that intermediate frequencies as well as higher frequencies of KR elicited better performance during the retention test. PMID:23265002

  1. Effects of knowledge of results (KR) frequency in the learning of a timing skill: absolute versus relative KR frequency.

    PubMed

    Vieira, Márcio M; Ugrinowitsch, Herbert; Oliveira, Fernanda S; Gallo, Lívia G; Benda, Rodolfo N

    2012-10-01

    The interaction between the amount of practice and frequency of Knowledge of Results (KR) was investigated in a timing skill. In the acquisition phase the task involved 90 trials of releasing a knob and transporting three tennis balls from three near recipients to three far ones in a specific sequence and target time. The retention test performed 24 hr. later had the same sequence of transport but a new target time was required. In both phases, absolute error and standard deviation plus constant error was measured. The five groups differed in relation to frequency of KR and amount of practice. The results showed that intermediate frequencies as well as higher frequencies of KR elicited better performance during the retention test.

  2. Absolute perfusion measurements and associated iodinated contrast agent time course in brain metastasis: a study for contrast-enhanced radiotherapy.

    PubMed

    Obeid, Layal; Deman, Pierre; Tessier, Alexandre; Balosso, Jacques; Estève, François; Adam, Jean-François

    2014-04-01

    Contrast-enhanced radiotherapy is an innovative treatment that combines the selective accumulation of heavy elements in tumors with stereotactic irradiations using medium energy X-rays. The radiation dose enhancement depends on the absolute amount of iodine reached in the tumor and its time course. Quantitative, postinfusion iodine biodistribution and associated brain perfusion parameters were studied in human brain metastasis as key parameters for treatment feasibility and quality. Twelve patients received an intravenous bolus of iodinated contrast agent (CA) (40 mL, 4 mL/s), followed by a steady-state infusion (160 mL, 0.5 mL/s) to ensure stable intratumoral amounts of iodine during the treatment. Absolute iodine concentrations and quantitative perfusion maps were derived from 40 multislice dynamic computed tomography (CT) images of the brain. The postinfusion mean intratumoral iodine concentration (over 30 minutes) reached 1.94 ± 0.12 mg/mL. Reasonable correlations were obtained between these concentrations and the permeability surface area product and the cerebral blood volume. To our knowledge, this is the first quantitative study of CA biodistribution versus time in brain metastasis. The study shows that suitable and stable amounts of iodine can be reached for contrast-enhanced radiotherapy. Moreover, the associated perfusion measurements provide useful information for the patient recruitment and management processes.

  3. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements.

    PubMed

    Sigaud, L; de Jesus, V L B; Ferreira, Natalia; Montenegro, E C

    2016-08-01

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell-to study ionization of atoms and molecules by electron impact-is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed. PMID:27587105

  4. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements.

    PubMed

    Sigaud, L; de Jesus, V L B; Ferreira, Natalia; Montenegro, E C

    2016-08-01

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell-to study ionization of atoms and molecules by electron impact-is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed.

  5. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements

    NASA Astrophysics Data System (ADS)

    Sigaud, L.; de Jesus, V. L. B.; Ferreira, Natalia; Montenegro, E. C.

    2016-08-01

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell—to study ionization of atoms and molecules by electron impact—is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed.

  6. ABSOLUTE TIMING OF THE CRAB PULSAR WITH THE INTEGRAL/SPI TELESCOPE

    SciTech Connect

    Molkov, S.; Jourdain, E.; Roques, J. P.

    2010-01-01

    We have investigated the pulse shape evolution of the Crab pulsar emission in the hard X-ray domain of the electromagnetic spectrum. In particular, we have studied the alignment of the Crab pulsar phase profiles measured in the hard X-rays and in other wavebands. To obtain the hard X-ray pulse profiles, we have used six years (2003-2009, with a total exposure of about 4 Ms) of publicly available data of the SPI telescope on-board the International Gamma-Ray Astrophysics Laboratory observatory, folded with the pulsar time solution derived from the Jodrell Bank Crab Pulsar Monthly Ephemeris. We found that the main pulse in the hard X-ray 20-100 keV energy band leads the radio one by 8.18 +- 0.46 milliperiods in phase, or 275 +- 15 mus in time. Quoted errors represent only statistical uncertainties. Our systematic error is estimated to be approx40 mus and is mainly caused by the radio measurement uncertainties. In hard X-rays, the average distance between the main pulse and interpulse on the phase plane is 0.3989 +- 0.0009. To compare our findings in hard X-rays with the soft 2-20 keV X-ray band, we have used data of quasi-simultaneous Crab observations with the proportional counter array monitor on-board the Rossi X-Ray Timing Explorer mission. The time lag and the pulses separation values measured in the 3-20 keV band are 0.00933 +- 0.00016 (corresponding to 310 +- 6 mus) and 0.40016 +- 0.00028 parts of the cycle, respectively. While the pulse separation values measured in soft X-rays and hard X-rays agree, the time lags are statistically different. Additional analysis show that the delay between the radio and X-ray signals varies with energy in the 2-300 keV energy range. We explain such a behavior as due to the superposition of two independent components responsible for the Crab pulsed emission in this energy band.

  7. Mouse activity across time scales: fractal scenarios.

    PubMed

    Lima, G Z dos Santos; Lobão-Soares, B; do Nascimento, G C; França, Arthur S C; Muratori, L; Ribeiro, S; Corso, G

    2014-01-01

    In this work we devise a classification of mouse activity patterns based on accelerometer data using Detrended Fluctuation Analysis. We use two characteristic mouse behavioural states as benchmarks in this study: waking in free activity and slowwave sleep (SWS). In both situations we find roughly the same pattern: for short time intervals we observe high correlation in activity--a typical 1/f complex pattern--while for large time intervals there is anti-correlation. High correlation of short intervals (0.01 s to 2 s: waking state and 0.01 s to 0.1 s: SWS) is related to highly coordinated muscle activity. In the waking state we associate high correlation both to muscle activity and to mouse stereotyped movements (grooming, waking, etc.). On the other side, the observed anti-correlation over large time scales (30 s to 300 s: waking state and 0.3 s to 5 s: SWS) during SWS appears related to a feedback autonomic response. The transition from correlated regime at short scales to an anti-correlated regime at large scales during SWS is given by the respiratory cycle interval, while during the waking state this transition occurs at the time scale corresponding to the duration of the stereotyped mouse movements. Furthermore, we find that the waking state is characterized by longer time scales than SWS and by a softer transition from correlation to anticorrelation. Moreover, this soft transition in the waking state encompass a behavioural time scale window that gives rise to a multifractal pattern. We believe that the observed multifractality in mouse activity is formed by the integration of several stereotyped movements each one with a characteristic time correlation. Finally, we compare scaling properties of body acceleration fluctuation time series during sleep and wake periods for healthy mice. Interestingly, differences between sleep and wake in the scaling exponents are comparable to previous works regarding human heartbeat. Complementarily, the nature of these sleep

  8. Neither One-Time Negative Screening Tests nor Negative Colposcopy Provides Absolute Reassurance against Cervical Cancer

    PubMed Central

    Castle, Philip E.; Rodríguez, Ana C.; Burk, Robert D.; Herrero, Rolando; Hildesheim, Allan; Solomon, Diane; Sherman, Mark E.; Jeronimo, Jose; Alfaro, Mario; Morales, Jorge; Guillén, Diego; Hutchinson, Martha L.; Wacholder, Sholom; Schiffman, Mark

    2009-01-01

    A population sample of 10,049 women living in Guanacaste, Costa Rica was recruited into a natural history of human papillomavirus (HPV) and cervical neoplasia study in 1993–4. At the enrollment visit, we applied multiple state-of-the-art cervical cancer screening methods to detect prevalent cervical cancer and to prevent subsequent cervical cancers by the timely detection and treatment of precancerous lesions. Women were screened at enrollment with 3 kinds of cytology (often reviewed by more than one pathologist), visual inspection, and Cervicography. Any positive screening test led to colposcopic referral and biopsy and/or excisional treatment of CIN2 or worse. We retrospectively tested stored specimens with an early HPV test (Hybrid Capture Tube Test) and for >40 HPV genotypes using a research PCR assay. We followed women typically 5–7 years and some up to 11 years. Nonetheless, sixteen cases of invasive cervical cancer were diagnosed during follow-up. Six cancer cases were failures at enrollment to detect abnormalities by cytology screening; three of the six were also negative at enrollment by sensitive HPV DNA testing. Seven cancers represent failures of colposcopy to diagnose cancer or a precancerous lesion in screen-positive women. Finally, three cases arose despite attempted excisional treatment of precancerous lesions. Based on this evidence, we suggest that no current secondary cervical cancer prevention technologies applied once in a previously under-screened population is likely to be 100% efficacious in preventing incident diagnoses of invasive cervical cancer. PMID:19569231

  9. Global scale precipitation from monthly to centennial scales: empirical space-time scaling analysis, anthropogenic effects

    NASA Astrophysics Data System (ADS)

    de Lima, Isabel; Lovejoy, Shaun

    2016-04-01

    The characterization of precipitation scaling regimes represents a key contribution to the improved understanding of space-time precipitation variability, which is the focus here. We conduct space-time scaling analyses of spectra and Haar fluctuations in precipitation, using three global scale precipitation products (one instrument based, one reanalysis based, one satellite and gauge based), from monthly to centennial scales and planetary down to several hundred kilometers in spatial scale. Results show the presence - similarly to other atmospheric fields - of an intermediate "macroweather" regime between the familiar weather and climate regimes: we characterize systematically the macroweather precipitation temporal and spatial, and joint space-time statistics and variability, and the outer scale limit of temporal scaling. These regimes qualitatively and quantitatively alternate in the way fluctuations vary with scale. In the macroweather regime, the fluctuations diminish with time scale (this is important for seasonal, annual, and decadal forecasts) while anthropogenic effects increase with time scale. Our approach determines the time scale at which the anthropogenic signal can be detected above the natural variability noise: the critical scale is about 20 - 40 yrs (depending on the product, on the spatial scale). This explains for example why studies that use data covering only a few decades do not easily give evidence of anthropogenic changes in precipitation, as a consequence of warming: the period is too short. Overall, while showing that precipitation can be modeled with space-time scaling processes, our results clarify the different precipitation scaling regimes and further allow us to quantify the agreement (and lack of agreement) of the precipitation products as a function of space and time scales. Moreover, this work contributes to clarify a basic problem in hydro-climatology, which is to measure precipitation trends at decadal and longer scales and to

  10. The hippocampus, time, and memory across scales.

    PubMed

    Howard, Marc W; Eichenbaum, Howard

    2013-11-01

    A wealth of experimental studies with animals have offered insights about how neural networks within the hippocampus support the temporal organization of memories. These studies have revealed the existence of "time cells" that encode moments in time, much as the well-known "place cells" map locations in space. Another line of work inspired by human behavioral studies suggests that episodic memories are mediated by a state of temporal context that changes gradually over long time scales, up to at least a few thousand seconds. In this view, the "mental time travel" hypothesized to support the experience of episodic memory corresponds to a "jump back in time" in which a previous state of temporal context is recovered. We suggest that these 2 sets of findings could be different facets of a representation of temporal history that maintains a record at the last few thousand seconds of experience. The ability to represent long time scales comes at the cost of discarding precise information about when a stimulus was experienced--this uncertainty becomes greater for events further in the past. We review recent computational work that describes a mechanism that could construct such a scale-invariant representation. Taken as a whole, this suggests the hippocampus plays its role in multiple aspects of cognition by representing events embedded in a general spatiotemporal context. The representation of internal time can be useful across nonhippocampal memory systems.

  11. Absolute rate constant determinations for the deactivation of O/1D/ by time resolved decay of O/1D/ yields O/3P/ emission

    NASA Technical Reports Server (NTRS)

    Davidson, J. A.; Sadowski, C. M.; Schiff, H. I.; Howard, C. J.; Schmeltekopf, A. L.; Jennings, D. A.; Streit, G. E.

    1976-01-01

    Absolute rate constants for the deactivation of O(1D) atoms by some atmospheric gases have been determined by observing the time-resolved emission of O(1D) at 630 nm. O(1D) atoms were produced by the dissociation of ozone via repetitive laser pulses at 266 nm. Absolute rate constants for the relaxation of O(1D) at 298 K are reported for N2, O2, CO2, O3, H2, D2, CH4, HCl, NH3, H2O, N2O, and Ne. The results obtained are compared with previous relative and absolute measurements reported in the literature.

  12. Multiple time scales is well named.

    PubMed

    Gibbon, J

    1999-03-01

    Staddon and Higa's article is a critique of scalar expectancy theory, and a proposed alternative, multiple time scales. The critique is generally flawed, both factually and logically. The alternative is bewildering in its flexibility, opaque in its quantitative description, and never addressed to real data.

  13. Structure of Student Time Management Scale (STMS)

    ERIC Educational Resources Information Center

    Balamurugan, M.

    2013-01-01

    With the aim of constructing a Student Time Management Scale (STMS), the initial version was administered and data were collected from 523 standard eleventh students. (Mean age = 15.64). The data obtained were subjected to Reliability and Factor analysis using PASW Statistical software version 18. From 42 items 14 were dropped, resulting in the…

  14. Leptin in whales: validation and measurement of mRNA expression by absolute quantitative real-time PCR.

    PubMed

    Ball, Hope C; Holmes, Robert K; Londraville, Richard L; Thewissen, Johannes G M; Duff, Robert Joel

    2013-01-01

    Leptin is the primary hormone in mammals that regulates adipose stores. Arctic adapted cetaceans maintain enormous adipose depots, suggesting possible modifications of leptin or receptor function. Determining expression of these genes is the first step to understanding the extreme physiology of these animals, and the uniqueness of these animals presents special challenges in estimating and comparing expression levels of mRNA transcripts. Here, we compare expression of two model genes, leptin and leptin-receptor gene-related product (OB-RGRP), using two quantitative real-time PCR (qPCR) methods: "relative" and "absolute". To assess the expression of leptin and OB-RGRP in cetacean tissues, we first examined how relative expression of those genes might differ when normalized to four common endogenous control genes. We performed relative expression qPCR assays measuring the amplification of these two model target genes relative to amplification of 18S ribosomal RNA (18S), ubiquitously expressed transcript (Uxt), ribosomal protein 9 (Rs9) and ribosomal protein 15 (Rs15) endogenous controls. Results demonstrated significant differences in the expression of both genes when different control genes were employed; emphasizing a limitation of relative qPCR assays, especially in studies where differences in physiology and/or a lack of knowledge regarding levels and patterns of expression of common control genes may possibly affect data interpretation. To validate the absolute quantitative qPCR methods, we evaluated the effects of plasmid structure, the purity of the plasmid standard preparation and the influence of type of qPCR "background" material on qPCR amplification efficiencies and copy number determination of both model genes, in multiple tissues from one male bowhead whale. Results indicate that linear plasmids are more reliable than circular plasmid standards, no significant differences in copy number estimation based upon background material used, and that the use of

  15. Lunch-time food choices in preschoolers: Relationships between absolute and relative intakes of different food categories, and appetitive characteristics and weight.

    PubMed

    Carnell, S; Pryor, K; Mais, L A; Warkentin, S; Benson, L; Cheng, R

    2016-08-01

    Children's appetitive characteristics measured by parent-report questionnaires are reliably associated with body weight, as well as behavioral tests of appetite, but relatively little is known about relationships with food choice. As part of a larger preloading study, we served 4-5year olds from primary school classes five school lunches at which they were presented with the same standardized multi-item meal. Parents completed Child Eating Behavior Questionnaire (CEBQ) sub-scales assessing satiety responsiveness (CEBQ-SR), food responsiveness (CEBQ-FR) and enjoyment of food (CEBQ-EF), and children were weighed and measured. Despite differing preload conditions, children showed remarkable consistency of intake patterns across all five meals with day-to-day intra-class correlations in absolute and percentage intake of each food category ranging from 0.78 to 0.91. Higher CEBQ-SR was associated with lower mean intake of all food categories across all five meals, with the weakest association apparent for snack foods. Higher CEBQ-FR was associated with higher intake of white bread and fruits and vegetables, and higher CEBQ-EF was associated with greater intake of all categories, with the strongest association apparent for white bread. Analyses of intake of each food group as a percentage of total intake, treated here as an index of the child's choice to consume relatively more or relatively less of each different food category when composing their total lunch-time meal, further suggested that children who were higher in CEBQ-SR ate relatively more snack foods and relatively less fruits and vegetables, while children with higher CEBQ-EF ate relatively less snack foods and relatively more white bread. Higher absolute intakes of white bread and snack foods were associated with higher BMI z score. CEBQ sub-scale associations with food intake variables were largely unchanged by controlling for daily metabolic needs. However, descriptive comparisons of lunch intakes with

  16. Accuracy metrics for judging time scale algorithms

    NASA Technical Reports Server (NTRS)

    Douglas, R. J.; Boulanger, J.-S.; Jacques, C.

    1994-01-01

    Time scales have been constructed in different ways to meet the many demands placed upon them for time accuracy, frequency accuracy, long-term stability, and robustness. Usually, no single time scale is optimum for all purposes. In the context of the impending availability of high-accuracy intermittently-operated cesium fountains, we reconsider the question of evaluating the accuracy of time scales which use an algorithm to span interruptions of the primary standard. We consider a broad class of calibration algorithms that can be evaluated and compared quantitatively for their accuracy in the presence of frequency drift and a full noise model (a mixture of white PM, flicker PM, white FM, flicker FM, and random walk FM noise). We present the analytic techniques for computing the standard uncertainty for the full noise model and this class of calibration algorithms. The simplest algorithm is evaluated to find the average-frequency uncertainty arising from the noise of the cesium fountain's local oscillator and from the noise of a hydrogen maser transfer-standard. This algorithm and known noise sources are shown to permit interlaboratory frequency transfer with a standard uncertainty of less than 10(exp -15) for periods of 30-100 days.

  17. A comment on the use of flushing time, residence time, and age as transport time scales

    USGS Publications Warehouse

    Monsen, N.E.; Cloern, J.E.; Lucas, L.V.; Monismith, Stephen G.

    2002-01-01

    Applications of transport time scales are pervasive in biological, hydrologic, and geochemical studies yet these times scales are not consistently defined and applied with rigor in the literature. We compare three transport time scales (flushing time, age, and residence time) commonly used to measure the retention of water or scalar quantities transported with water. We identify the underlying assumptions associated with each time scale, describe procedures for computing these time scales in idealized cases, and identify pitfalls when real-world systems deviate from these idealizations. We then apply the time scale definitions to a shallow 378 ha tidal lake to illustrate how deviations between real water bodies and the idealized examples can result from: (1) non-steady flow; (2) spatial variability in bathymetry, circulation, and transport time scales; and (3) tides that introduce complexities not accounted for in the idealized cases. These examples illustrate that no single transport time scale is valid for all time periods, locations, and constituents, and no one time scale describes all transport processes. We encourage aquatic scientists to rigorously define the transport time scale when it is applied, identify the underlying assumptions in the application of that concept, and ask if those assumptions are valid in the application of that approach for computing transport time scales in real systems.

  18. Hemispheric Asymmetries in Substorm Recovery Time Scales

    NASA Technical Reports Server (NTRS)

    Fillingim, M. O.; Chua, D H.; Germany, G. A.; Spann, James F.

    2009-01-01

    Previous statistical observations have shown that the recovery time scales of substorms occurring in the winter and near equinox (when the nighttime auroral zone was in darkness) are roughly twice as long as the recovery time scales for substorms occurring in the summer (when the nighttime auroral region was sunlit). This suggests that auroral substorms in the northern and southern hemispheres develop asymmetrically during solstice conditions with substorms lasting longer in the winter (dark) hemisphere than in the summer (sunlit) hemisphere. Additionally, this implies that more energy is deposited by electron precipitation in the winter hemisphere than in the summer one during substorms. This result, coupled with previous observations that have shown that auroral activity is more common when the ionosphere is in darkness and is suppressed when the ionosphere is in daylight, strongly suggests that the ionospheric conductivity plays an important role governing how magnetospheric energy is transferred to the ionosphere during substorms. Therefore, the ionosphere itself may dictate how much energy it will accept from the magnetosphere during substorms rather than this being an externally imposed quantity. Here, we extend our earlier work by statistically analyzing the recovery time scales for a large number of substorms observed in the conjugate hemispheres simultaneously by two orbiting global auroral imagers: Polar UVI and IMAGE FUV. Our current results are consistent with previous observations. The recovery time scales are observed to be longer in the winter (dark) hemisphere while the auroral activity has a shorter duration in the summer (sunlit) hemisphere. This leads to an asymmetric energy input from the magnetosphere to the ionosphere with more energy being deposited in the winter hemisphere than in the summer hemisphere.

  19. Current relaxation time scales in toroidal plasmas

    SciTech Connect

    Mikkelsen, D.R.

    1987-02-01

    An approximate normal mode analysis of plasma current diffusion in tokamaks is presented. The work is based on numerical solutions of the current diffusion equation in cylindrical geometry. Eigenvalues and eigenfunctions are shown for a broad range of plasma conductivity profile shapes. Three classes of solutions are considered which correspond to three types of tokamak operation. Convenient approximations to the three lowest eigenvalues in each class are presented and simple formulae for the current relaxation time scales are given.

  20. Scaling of light and dark time intervals.

    PubMed

    Marinova, J

    1978-01-01

    Scaling of light and dark time intervals of 0.1 to 1.1 s is performed by the mehtod of magnitude estimation with respect to a given standard. The standards differ in duration and type (light and dark). The light intervals are subjectively estimated as longer than the dark ones. The relation between the mean interval estimations and their magnitude is linear for both light and dark intervals.

  1. Liquidity crises on different time scales.

    PubMed

    Corradi, Francesco; Zaccaria, Andrea; Pietronero, Luciano

    2015-12-01

    We present an empirical analysis of the microstructure of financial markets and, in particular, of the static and dynamic properties of liquidity. We find that on relatively large time scales (15 min) large price fluctuations are connected to the failure of the subtle mechanism of compensation between the flows of market and limit orders: in other words, the missed revelation of the latent order book breaks the dynamical equilibrium between the flows, triggering the large price jumps. On smaller time scales (30 s), instead, the static depletion of the limit order book is an indicator of an intrinsic fragility of the system, which is related to a strongly nonlinear enhancement of the response. In order to quantify this phenomenon we introduce a measure of the liquidity imbalance present in the book and we show that it is correlated to both the sign and the magnitude of the next price movement. These findings provide a quantitative definition of the effective liquidity, which proves to be strongly dependent on the considered time scales.

  2. Liquidity crises on different time scales

    NASA Astrophysics Data System (ADS)

    Corradi, Francesco; Zaccaria, Andrea; Pietronero, Luciano

    2015-12-01

    We present an empirical analysis of the microstructure of financial markets and, in particular, of the static and dynamic properties of liquidity. We find that on relatively large time scales (15 min) large price fluctuations are connected to the failure of the subtle mechanism of compensation between the flows of market and limit orders: in other words, the missed revelation of the latent order book breaks the dynamical equilibrium between the flows, triggering the large price jumps. On smaller time scales (30 s), instead, the static depletion of the limit order book is an indicator of an intrinsic fragility of the system, which is related to a strongly nonlinear enhancement of the response. In order to quantify this phenomenon we introduce a measure of the liquidity imbalance present in the book and we show that it is correlated to both the sign and the magnitude of the next price movement. These findings provide a quantitative definition of the effective liquidity, which proves to be strongly dependent on the considered time scales.

  3. Multidimensional scaling of musical time estimations.

    PubMed

    Cocenas-Silva, Raquel; Bueno, José Lino Oliveira; Molin, Paul; Bigand, Emmanuel

    2011-06-01

    The aim of this study was to identify the psycho-musical factors that govern time evaluation in Western music from baroque, classic, romantic, and modern repertoires. The excerpts were previously found to represent variability in musical properties and to induce four main categories of emotions. 48 participants (musicians and nonmusicians) freely listened to 16 musical excerpts (lasting 20 sec. each) and grouped those that seemed to have the same duration. Then, participants associated each group of excerpts to one of a set of sine wave tones varying in duration from 16 to 24 sec. Multidimensional scaling analysis generated a two-dimensional solution for these time judgments. Musical excerpts with high arousal produced an overestimation of time, and affective valence had little influence on time perception. The duration was also overestimated when tempo and loudness were higher, and to a lesser extent, timbre density. In contrast, musical tension had little influence. PMID:21853763

  4. Various time-scales of relaxation

    NASA Astrophysics Data System (ADS)

    Ali-Akbari, M.; Charmchi, F.; Ebrahim, H.; Shahkarami, L.

    2016-08-01

    Via gauge-gravity duality, relaxation of far-from-equilibrium initial states in a strongly coupled gauge theory has been investigated. In the system we consider in this paper there are two ways where the state under study can deviate from its equilibrium: anisotropic pressure and time-dependent expectation value of a scalar operator with Δ =3 . In the gravity theory, this system corresponds to Einstein's general relativity with a nontrivial metric, including the anisotropy function, coupled to a massive scalar matter field. We study the effect of different initial configurations for the scalar field and anisotropy function on physical processes such as thermalization, i.e., time evolution of an event horizon; equilibration of the expectation value of a scalar operator; and isotropization. We also discuss time ordering of these time-scales.

  5. Short-time scale behavior modeling within long-time scale fuel cycle evaluations

    SciTech Connect

    Johnson, M.; Tsvetkov, P.; Lucas, S.

    2012-07-01

    Typically, short-time and long-time scales in nuclear energy system behavior are accounted for with entirely separate models. However, long-term changes in system characteristics do affect short-term transients through material variations. This paper presents an approach to consistently account for short-time scales within a nuclear system lifespan. The reported findings and developments are of significant importance for small modular reactors and other nuclear energy systems operating in autonomous modes. It is necessary to simulate the short time-scale kinetic behavior of the reactor as well as the long time-scale dynamics that occur with fuel burnup. The former is modeled using the point kinetics equations, while the latter is modeled by the Bateman equations. (authors)

  6. South Atlantic Spreading Velocities and Time Scales

    NASA Astrophysics Data System (ADS)

    Clark, S. R.; Smethurst, M. A.; Bianchi, M. C.

    2013-12-01

    Plate reconstructions based on hierarchical spherical rotations have been around for many years. For the breakup of Pangea and Gondwana, these reconstructions are based on two major sources: magnetic isochrons and geological evidence for the onset of rifting and the tightness of the fit between continents. These reconstructions imply spreading velocities and it is the changes in velocities that can be used to probe questions of the forces moving plates around. In order to calculate the velocities correctly though, the importance of the choice of geologic time scale is often ignored. In this talk, we focus on the South Atlantic and calculate the spreading velocity errors implied by the choice of time scale for three major epochs: the Cenozoic and Late Mesozoic, the Cretaceous Quiet Zone and the Late Cretaceous to the Early Jurassic. In addition, we report the spreading velocities implied through these phases by various available magnetic isochron-derived reconstructions and the geological fits for South America and Africa used by large scale global reconstruction as well as in recent papers. Finally, we will highlight the implications for the choice of the mantle reference frame on African plate velocities.

  7. Detection and absolute quantitation of Tomato torrado virus (ToTV) by real time RT-PCR.

    PubMed

    Herrera-Vásquez, José Angel; Rubio, Luis; Alfaro-Fernández, Ana; Debreczeni, Diana Elvira; Font-San-Ambrosio, Isabel; Falk, Bryce W; Ferriol, Inmaculada

    2015-09-01

    Tomato torrado virus (ToTV) causes serious damage to the tomato industry and significant economic losses. A quantitative real-time reverse-transcription polymerase chain reaction (RT-qPCR) method using primers and a specific TaqMan(®) MGB probe for ToTV was developed for sensitive detection and quantitation of different ToTV isolates. A standard curve using RNA transcripts enabled absolute quantitation, with a dynamic range from 10(4) to 10(10) ToTV RNA copies/ng of total RNA. The specificity of the RT-qPCR was tested with twenty-three ToTV isolates from tomato (Solanum lycopersicum L.), and black nightshade (Solanum nigrum L.) collected in Spain, Australia, Hungary and France, which covered the genetic variation range of this virus. This new RT-qPCR assay enables a reproducible, sensitive and specific detection and quantitation of ToTV, which can be a valuable tool in disease management programs and epidemiological studies.

  8. Deciphering Time Scale Hierarchy in Reaction Networks.

    PubMed

    Nagahata, Yutaka; Maeda, Satoshi; Teramoto, Hiroshi; Horiyama, Takashi; Taketsugu, Tetsuya; Komatsuzaki, Tamiki

    2016-03-01

    Markovian dynamics on complex reaction networks are one of the most intriguing subjects in a wide range of research fields including chemical reactions, biological physics, and ecology. To represent the global kinetics from one node (corresponding to a basin on an energy landscape) to another requires information on multiple pathways that directly or indirectly connect these two nodes through the entire network. In this paper we present a scheme to extract a hierarchical set of global transition states (TSs) over a discrete-time Markov chain derived from first-order rate equations. The TSs can naturally take into account the multiple pathways connecting any pair of nodes. We also propose a new type of disconnectivity graph (DG) to capture the hierarchical organization of different time scales of reactions that can capture changes in the network due to changes in the time scale of observation. The crux is the introduction of the minimum conductance cut (MCC) in graph clustering, corresponding to the dividing surface across the network having the "smallest" transition probability between two disjoint subnetworks (superbasins on the energy landscape) in the network. We present a new combinatorial search algorithm for finding this MCC. We apply our method to a reaction network of Claisen rearrangement of allyl vinyl ether that consists of 23 nodes and 66 links (saddles on the energy landscape) connecting them. We compare the kinetic properties of our DG to those of the transition matrix of the rate equations and show that our graph can properly reveal the hierarchical organization of time scales in a network. PMID:26641663

  9. Scaling laws from geomagnetic time series

    USGS Publications Warehouse

    Voros, Z.; Kovacs, P.; Juhasz, A.; Kormendi, A.; Green, A.W.

    1998-01-01

    The notion of extended self-similarity (ESS) is applied here for the X - component time series of geomagnetic field fluctuations. Plotting nth order structure functions against the fourth order structure function we show that low-frequency geomagnetic fluctuations up to the order n = 10 follow the same scaling laws as MHD fluctuations in solar wind, however, for higher frequencies (f > l/5[h]) a clear departure from the expected universality is observed for n > 6. ESS does not allow to make an unambiguous statement about the non triviality of scaling laws in "geomagnetic" turbulence. However, we suggest to use higher order moments as promising diagnostic tools for mapping the contributions of various remote magnetospheric sources to local observatory data. Copyright 1998 by the American Geophysical Union.

  10. Absolute measurement of subnanometer scale vibration of cochlear partition of an excised guinea pig cochlea using spectral-domain phase-sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Subhash, Hrebesh M.; Choudhury, Niloy; Jacques, Steven L.; Wang, Ruikang K.; Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L.

    2012-01-01

    Direct measurement of absolute vibration parameters from different locations within the mammalian organ of Corti is crucial for understanding the hearing mechanics such as how sound propagates through the cochlea and how sound stimulates the vibration of various structures of the cochlea, namely, basilar membrane (BM), recticular lamina, outer hair cells and tectorial membrane (TM). In this study we demonstrate the feasibility a modified phase-sensitive spectral domain optical coherence tomography system to provide subnanometer scale vibration information from multiple angles within the imaging beam. The system has the potential to provide depth resolved absolute vibration measurement of tissue microstructures from each of the delay-encoded vibration images with a noise floor of ~0.3nm at 200Hz.

  11. Native American Students' Understanding of Geologic Time Scale: 4th-8th Grade Ojibwe Students' Understanding of Earth's Geologic History

    ERIC Educational Resources Information Center

    Nam, Younkyeong; Karahan, Engin; Roehrig, Gillian

    2016-01-01

    Geologic time scale is a very important concept for understanding long-term earth system events such as climate change. This study examines forty-three 4th-8th grade Native American--particularly Ojibwe tribe--students' understanding of relative ordering and absolute time of Earth's significant geological and biological events. This study also…

  12. Toward an objective Phanerozoic time scale

    NASA Astrophysics Data System (ADS)

    Carr, Paul F.; Jones, Brian G.; Quinn, Barry G.; Wright, Anthony J.

    1984-05-01

    Previous age estimations of period, series, and stage boundaries for the Phanerozoic have usually relied on a subjective approach, in which visual inspection was used to determine each time interval. This subjectivity can be eliminated partially by fitting a piecewise linear regression model of radiometric age on a variable calculated from the biostratigraphic data, enabling the computation of estimates of, and confidence limits for, various boundaries of interest. This method is illustrated by calculating the duration of each Phanerozoic system and thus the quantitative age of all the system boundaries. The method can be extended to investigate any part of the Phanerozoic time scale in more detail, provided sufficient biostratigraphically well-controlled isotopic age data are available, as for example, for the Cenozoic and the Eocene. *Present address: University of Queensland, St. Lucia, Queensland, Australia 4067

  13. Parametric instabilities in picosecond time scales

    SciTech Connect

    Baldis, H.A.; Rozmus, W.; Labaune, C.; Mounaix, Ph.; Pesme, D.; Baton, S.; Tikhonchuk, V.T.

    1993-03-01

    The coupling of intense laser light with plasmas is a rich field of plasma physics, with many applications. Among these are inertial confinement fusion (ICF), x-ray lasers, particle acceleration, and x-ray sources. Parametric instabilities have been studied for many years because of their importance to ICF; with laser pulses with duration of approximately a nanosecond, and laser intensities in the range 10{sup 14}--10{sup 15}W/cm{sup 2} these instabilities are of crucial concern because of a number of detrimental effects. Although the laser pulse duration of interest for these studies are relatively long, it has been evident in the past years that to reach an understanding of these instabilities requires their characterization and analysis in picosecond time scales. At the laser intensities of interest, the growth rate for stimulated Brillouin scattering (SBS) is of the order of picoseconds, and of an order of magnitude shorter for stimulated Raman scattering (SRS). In this paper the authors discuss SBS and SRS in the context of their evolution in picosecond time scales. They describe the fundamental concepts associated with their growth and saturation, and recent work on the nonlinear treatment required for the modeling of these instabilities at high laser intensities.

  14. Interference peak detection based on FPGA for real-time absolute distance ranging with dual-comb lasers

    NASA Astrophysics Data System (ADS)

    Ni, Kai; Dong, Hao; Zhou, Qian; Xu, Mingfei; Li, Xinghui; Wu, Guanhao

    2015-08-01

    Absolute distance measurement using dual femtosecond comb lasers can achieve higher accuracy and faster measurement speed, which makes it more and more attractive. The data processing flow consists of four steps: interference peak detection, fast Fourier transform (FFT), phase fitting and compensation of index of refraction. A realtime data processing system based on Field-Programmable Gate Array (FPGA) for dual-comb ranging has been newly developed. The design and implementation of the interference peak detection algorithm by FPGA and Verilog language is introduced in this paper, which is viewed as the most complicated part and an important guarantee for system precision and reliability. An adaptive sliding window for scanning is used to detect peaks. In the process of detection, the algorithm stores 16 sample data as a detection unit and calculates the average of each unit. The average result is used to determine the vertical center height of the sliding window. The algorithm estimates the noise intensity of each detection unit, and then calculates the average of the noise strength of successive 128 units. The noise average is used to calculate the signal to noise ratio of the current working environment, which is used to adjust the height of the sliding window. This adaptive sliding window helps to eliminate fake peaks caused by noise. The whole design is based on the way of pipeline, which can improves the real-time throughput of the overall peak detection module. Its execution speed is up to 140MHz in the FPGA, and the peak can be detected in 16 clock cycle when it appears.

  15. Leptin in Whales: Validation and Measurement of mRNA Expression by Absolute Quantitative Real-Time PCR

    PubMed Central

    Ball, Hope C.; Holmes, Robert K.; Londraville, Richard L.; Thewissen, Johannes G. M.; Duff, Robert Joel

    2013-01-01

    Leptin is the primary hormone in mammals that regulates adipose stores. Arctic adapted cetaceans maintain enormous adipose depots, suggesting possible modifications of leptin or receptor function. Determining expression of these genes is the first step to understanding the extreme physiology of these animals, and the uniqueness of these animals presents special challenges in estimating and comparing expression levels of mRNA transcripts. Here, we compare expression of two model genes, leptin and leptin-receptor gene-related product (OB-RGRP), using two quantitative real-time PCR (qPCR) methods: “relative” and “absolute”. To assess the expression of leptin and OB-RGRP in cetacean tissues, we first examined how relative expression of those genes might differ when normalized to four common endogenous control genes. We performed relative expression qPCR assays measuring the amplification of these two model target genes relative to amplification of 18S ribosomal RNA (18S), ubiquitously expressed transcript (Uxt), ribosomal protein 9 (Rs9) and ribosomal protein 15 (Rs15) endogenous controls. Results demonstrated significant differences in the expression of both genes when different control genes were employed; emphasizing a limitation of relative qPCR assays, especially in studies where differences in physiology and/or a lack of knowledge regarding levels and patterns of expression of common control genes may possibly affect data interpretation. To validate the absolute quantitative qPCR methods, we evaluated the effects of plasmid structure, the purity of the plasmid standard preparation and the influence of type of qPCR “background” material on qPCR amplification efficiencies and copy number determination of both model genes, in multiple tissues from one male bowhead whale. Results indicate that linear plasmids are more reliable than circular plasmid standards, no significant differences in copy number estimation based upon background material used, and

  16. Measurement of the Absolute Magnitude and Time Courses of Mitochondrial Membrane Potential in Primary and Clonal Pancreatic Beta-Cells.

    PubMed

    Gerencser, Akos A; Mookerjee, Shona A; Jastroch, Martin; Brand, Martin D

    2016-01-01

    The aim of this study was to simplify, improve and validate quantitative measurement of the mitochondrial membrane potential (ΔψM) in pancreatic β-cells. This built on our previously introduced calculation of the absolute magnitude of ΔψM in intact cells, using time-lapse imaging of the non-quench mode fluorescence of tetramethylrhodamine methyl ester and a bis-oxonol plasma membrane potential (ΔψP) indicator. ΔψM is a central mediator of glucose-stimulated insulin secretion in pancreatic β-cells. ΔψM is at the crossroads of cellular energy production and demand, therefore precise assay of its magnitude is a valuable tool to study how these processes interplay in insulin secretion. Dispersed islet cell cultures allowed cell type-specific, single-cell observations of cell-to-cell heterogeneity of ΔψM and ΔψP. Glucose addition caused hyperpolarization of ΔψM and depolarization of ΔψP. The hyperpolarization was a monophasic step increase, even in cells where the ΔψP depolarization was biphasic. The biphasic response of ΔψP was associated with a larger hyperpolarization of ΔψM than the monophasic response. Analysis of the relationships between ΔψP and ΔψM revealed that primary dispersed β-cells responded to glucose heterogeneously, driven by variable activation of energy metabolism. Sensitivity analysis of the calibration was consistent with β-cells having substantial cell-to-cell variations in amounts of mitochondria, and this was predicted not to impair the accuracy of determinations of relative changes in ΔψM and ΔψP. Finally, we demonstrate a significant problem with using an alternative ΔψM probe, rhodamine 123. In glucose-stimulated and oligomycin-inhibited β-cells the principles of the rhodamine 123 assay were breached, resulting in misleading conclusions.

  17. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  18. Calibration of diffuse correlation spectroscopy with a time-resolved near-infrared technique to yield absolute cerebral blood flow measurements

    PubMed Central

    Diop, Mamadou; Verdecchia, Kyle; Lee, Ting-Yim; St Lawrence, Keith

    2011-01-01

    A primary focus of neurointensive care is the prevention of secondary brain injury, mainly caused by ischemia. A noninvasive bedside technique for continuous monitoring of cerebral blood flow (CBF) could improve patient management by detecting ischemia before brain injury occurs. A promising technique for this purpose is diffuse correlation spectroscopy (DCS) since it can continuously monitor relative perfusion changes in deep tissue. In this study, DCS was combined with a time-resolved near-infrared technique (TR-NIR) that can directly measure CBF using indocyanine green as a flow tracer. With this combination, the TR-NIR technique can be used to convert DCS data into absolute CBF measurements. The agreement between the two techniques was assessed by concurrent measurements of CBF changes in piglets. A strong correlation between CBF changes measured by TR-NIR and changes in the scaled diffusion coefficient measured by DCS was observed (R2 = 0.93) with a slope of 1.05 ± 0.06 and an intercept of 6.4 ± 4.3% (mean ± standard error). PMID:21750781

  19. The Impact of Strategy Instruction and Timing of Estimates on Low and High Working-Memory Capacity Readers' Absolute Monitoring Accuracy

    ERIC Educational Resources Information Center

    Linderholm, Tracy; Zhao, Qin

    2008-01-01

    Working-memory capacity, strategy instruction, and timing of estimates were investigated for their effects on absolute monitoring accuracy, which is the difference between estimated and actual reading comprehension test performance. Participants read two expository texts under one of two randomly assigned reading strategy instruction conditions…

  20. EDITORIAL: Special issue on time scale algorithms

    NASA Astrophysics Data System (ADS)

    Matsakis, Demetrios; Tavella, Patrizia

    2008-12-01

    This special issue of Metrologia presents selected papers from the Fifth International Time Scale Algorithm Symposium (VITSAS), including some of the tutorials presented on the first day. The symposium was attended by 76 persons, from every continent except Antarctica, by students as well as senior scientists, and hosted by the Real Instituto y Observatorio de la Armada (ROA) in San Fernando, Spain, whose staff further enhanced their nation's high reputation for hospitality. Although a timescale can be simply defined as a weighted average of clocks, whose purpose is to measure time better than any individual clock, timescale theory has long been and continues to be a vibrant field of research that has both followed and helped to create advances in the art of timekeeping. There is no perfect timescale algorithm, because every one embodies a compromise involving user needs. Some users wish to generate a constant frequency, perhaps not necessarily one that is well-defined with respect to the definition of a second. Other users might want a clock which is as close to UTC or a particular reference clock as possible, or perhaps wish to minimize the maximum variation from that standard. In contrast to the steered timescales that would be required by those users, other users may need free-running timescales, which are independent of external information. While no algorithm can meet all these needs, every algorithm can benefit from some form of tuning. The optimal tuning, and even the optimal algorithm, can depend on the noise characteristics of the frequency standards, or of their comparison systems, the most precise and accurate of which are currently Two Way Satellite Time and Frequency Transfer (TWSTFT) and GPS carrier phase time transfer. The interest in time scale algorithms and its associated statistical methodology began around 40 years ago when the Allan variance appeared and when the metrological institutions started realizing ensemble atomic time using more than

  1. EDITORIAL: Special issue on time scale algorithms

    NASA Astrophysics Data System (ADS)

    Matsakis, Demetrios; Tavella, Patrizia

    2008-12-01

    This special issue of Metrologia presents selected papers from the Fifth International Time Scale Algorithm Symposium (VITSAS), including some of the tutorials presented on the first day. The symposium was attended by 76 persons, from every continent except Antarctica, by students as well as senior scientists, and hosted by the Real Instituto y Observatorio de la Armada (ROA) in San Fernando, Spain, whose staff further enhanced their nation's high reputation for hospitality. Although a timescale can be simply defined as a weighted average of clocks, whose purpose is to measure time better than any individual clock, timescale theory has long been and continues to be a vibrant field of research that has both followed and helped to create advances in the art of timekeeping. There is no perfect timescale algorithm, because every one embodies a compromise involving user needs. Some users wish to generate a constant frequency, perhaps not necessarily one that is well-defined with respect to the definition of a second. Other users might want a clock which is as close to UTC or a particular reference clock as possible, or perhaps wish to minimize the maximum variation from that standard. In contrast to the steered timescales that would be required by those users, other users may need free-running timescales, which are independent of external information. While no algorithm can meet all these needs, every algorithm can benefit from some form of tuning. The optimal tuning, and even the optimal algorithm, can depend on the noise characteristics of the frequency standards, or of their comparison systems, the most precise and accurate of which are currently Two Way Satellite Time and Frequency Transfer (TWSTFT) and GPS carrier phase time transfer. The interest in time scale algorithms and its associated statistical methodology began around 40 years ago when the Allan variance appeared and when the metrological institutions started realizing ensemble atomic time using more than

  2. Consistent scaling of persistence time in metapopulations.

    PubMed

    Yaari, Gur; Ben-Zion, Yossi; Shnerb, Nadav M; Vasseur, David A

    2012-05-01

    Recent theory and experimental work in metapopulations and metacommunities demonstrates that long-term persistence is maximized when the rate at which individuals disperse among patches within the system is intermediate; if too low, local extinctions are more frequent than recolonizations, increasing the chance of regional-scale extinctions, and if too high, dynamics exhibit region-wide synchrony, and local extinctions occur in near unison across the region. Although common, little is known about how the size and topology of the metapopulation (metacommunity) affect this bell-shaped relationship between dispersal rate and regional persistence time. Using a suite of mathematical models, we examined the effects of dispersal, patch number, and topology on the regional persistence time when local populations are subject to demographic stochasticity. We found that the form of the relationship between regional persistence time and the number of patches is consistent across all models studied; however, the form of the relationship is distinctly different among low, intermediate, and high dispersal rates. Under low and intermediate dispersal rates, regional persistence times increase logarithmically and exponentially (respectively) with increasing numbers of patches, whereas under high dispersal, the form of the relationship depends on local dynamics. Furthermore, we demonstrate that the forms of these relationships, which give rise to the bell-shaped relationship between dispersal rate and persistence time, are a product of recolonization and the region-wide synchronization (or lack thereof) of population dynamics. Identifying such metapopulation attributes that impact extinction risk is of utmost importance for managing and conserving the earth's evermore fragmented populations.

  3. Time Horizon and Social Scale in Communication

    NASA Astrophysics Data System (ADS)

    Krantz, D. H.

    2010-12-01

    In 2009 our center (CRED) published a first version of The Psychology of Climate Change Communication. In it, we attempted to summarize facts and concepts from psychological research that could help guide communication. While this work focused on climate change, most of the ideas are at least partly applicable for communication about a variety of natural hazards. Of the many examples in this guide, I mention three. Single-action bias is the human tendency to stop considering further actions that might be needed to deal with a given hazard, once a single action has been taken. Another example is the importance of group affiliation in motivating voluntary contributions to joint action. A third concerns the finding that group participation enhances understanding of probabilistic concepts and promotes action in the face of uncertainty. One current research direction, which goes beyond those included in the above publication, focuses on how time horizons arise in the thinking of individuals and groups, and how these time horizons might influence hazard preparedness. On the one hand, individuals sometimes appear impatient, organizations look for immediate results, and officials fail to look beyond the next election cycle. Yet under some laboratory conditions and in some subcultures, a longer time horizon is adopted. We are interested in how time horizon is influenced by group identity and by the very architecture of planning and decision making. Institutional changes, involving long-term contractual relationships among communities, developers, insurers, and governments, could greatly increase resilience in the face of natural hazards. Communication about hazards, in the context of such long-term contractual relationships might look very different from communication that is first initiated by immediate threat. Another new direction concerns the social scale of institutions and of communication about hazards. Traditionally, insurance contracts share risk among a large

  4. Measurement of the Absolute Magnitude and Time Courses of Mitochondrial Membrane Potential in Primary and Clonal Pancreatic Beta-Cells.

    PubMed

    Gerencser, Akos A; Mookerjee, Shona A; Jastroch, Martin; Brand, Martin D

    2016-01-01

    The aim of this study was to simplify, improve and validate quantitative measurement of the mitochondrial membrane potential (ΔψM) in pancreatic β-cells. This built on our previously introduced calculation of the absolute magnitude of ΔψM in intact cells, using time-lapse imaging of the non-quench mode fluorescence of tetramethylrhodamine methyl ester and a bis-oxonol plasma membrane potential (ΔψP) indicator. ΔψM is a central mediator of glucose-stimulated insulin secretion in pancreatic β-cells. ΔψM is at the crossroads of cellular energy production and demand, therefore precise assay of its magnitude is a valuable tool to study how these processes interplay in insulin secretion. Dispersed islet cell cultures allowed cell type-specific, single-cell observations of cell-to-cell heterogeneity of ΔψM and ΔψP. Glucose addition caused hyperpolarization of ΔψM and depolarization of ΔψP. The hyperpolarization was a monophasic step increase, even in cells where the ΔψP depolarization was biphasic. The biphasic response of ΔψP was associated with a larger hyperpolarization of ΔψM than the monophasic response. Analysis of the relationships between ΔψP and ΔψM revealed that primary dispersed β-cells responded to glucose heterogeneously, driven by variable activation of energy metabolism. Sensitivity analysis of the calibration was consistent with β-cells having substantial cell-to-cell variations in amounts of mitochondria, and this was predicted not to impair the accuracy of determinations of relative changes in ΔψM and ΔψP. Finally, we demonstrate a significant problem with using an alternative ΔψM probe, rhodamine 123. In glucose-stimulated and oligomycin-inhibited β-cells the principles of the rhodamine 123 assay were breached, resulting in misleading conclusions. PMID:27404273

  5. Measurement of the Absolute Magnitude and Time Courses of Mitochondrial Membrane Potential in Primary and Clonal Pancreatic Beta-Cells

    PubMed Central

    Gerencser, Akos A.; Mookerjee, Shona A.; Jastroch, Martin; Brand, Martin D.

    2016-01-01

    The aim of this study was to simplify, improve and validate quantitative measurement of the mitochondrial membrane potential (ΔψM) in pancreatic β-cells. This built on our previously introduced calculation of the absolute magnitude of ΔψM in intact cells, using time-lapse imaging of the non-quench mode fluorescence of tetramethylrhodamine methyl ester and a bis-oxonol plasma membrane potential (ΔψP) indicator. ΔψM is a central mediator of glucose-stimulated insulin secretion in pancreatic β-cells. ΔψM is at the crossroads of cellular energy production and demand, therefore precise assay of its magnitude is a valuable tool to study how these processes interplay in insulin secretion. Dispersed islet cell cultures allowed cell type-specific, single-cell observations of cell-to-cell heterogeneity of ΔψM and ΔψP. Glucose addition caused hyperpolarization of ΔψM and depolarization of ΔψP. The hyperpolarization was a monophasic step increase, even in cells where the ΔψP depolarization was biphasic. The biphasic response of ΔψP was associated with a larger hyperpolarization of ΔψM than the monophasic response. Analysis of the relationships between ΔψP and ΔψM revealed that primary dispersed β-cells responded to glucose heterogeneously, driven by variable activation of energy metabolism. Sensitivity analysis of the calibration was consistent with β-cells having substantial cell-to-cell variations in amounts of mitochondria, and this was predicted not to impair the accuracy of determinations of relative changes in ΔψM and ΔψP. Finally, we demonstrate a significant problem with using an alternative ΔψM probe, rhodamine 123. In glucose-stimulated and oligomycin-inhibited β-cells the principles of the rhodamine 123 assay were breached, resulting in misleading conclusions. PMID:27404273

  6. Time lapse imaging of water content with geoelectrical methods: on the interest of working with absolute water content data

    NASA Astrophysics Data System (ADS)

    Dumont, Gaël; Pilawski, Tamara; Robert, Tanguy; Hermans, Thomas; Garré, Sarah; Nguyen, Frederic

    2016-04-01

    The electrical resistivity tomography is a suitable method to estimate the water content of a waste material and detect changes in water content. Various ERT profiles, both static data and time-lapse, where acquired on a landfill during the Minerve project. In the literature, the relative change of resistivity (Δρ/ρ) is generally computed. For saline or heat tracer tests in the saturated zone, the Δρ/ρ can be easily translated into pore water conductivity or underground temperature changes (provided that the initial salinity or temperature condition is homogeneous over the ERT panel extension). For water content changes in the vadose zone resulting of an infiltration event or injection experiment, many authors also work with the Δρ/ρ or relative changes of water content Δθ/θ (linked to the change of resistivity through one single parameter: the Archie's law exponent "m"). This parameter is not influenced by the underground temperature and pore fluid conductivity (ρ¬w) condition but is influenced by the initial water content distribution. Therefore, you never know if the loss of Δθ/θ signal is representative of the limit of the infiltration front or more humid initial condition. Another approach for the understanding of the infiltration process is the assessment of the absolute change of water content (Δθ). This requires the direct computation of the water content of the waste from the resistivity data. For that purpose, we used petrophysical laws calibrated with laboratory experiments and our knowledge of the in situ temperature and pore fluid conductivity parameters. Then, we investigated water content changes in the waste material after a rainfall event (Δθ= Δθ/θ* θ). This new observation is really representatives of the quantity of water infiltrated in the waste material. However, the uncertainty in the pore fluid conductivity value may influence the computed water changes (Δθ=k*m√(ρw) ; where "m" is the Archie's law exponent

  7. Absolutely calibrated, time-resolved measurements of soft x rays using transmission grating spectrometers at the Nike Laser Facility

    NASA Astrophysics Data System (ADS)

    Weaver, J. L.; Feldman, U.; Seely, J. F.; Holland, G.; Serlin, V.; Klapisch, M.; Columbant, D.; Mostovych, A.

    2001-12-01

    Accurate simulation of pellet implosions for direct drive inertial confinement fusion requires benchmarking the codes with experimental data. The Naval Research Laboratory (NRL) has begun to measure the absolute intensity of radiation from laser irradiated targets to provide critical information for the radiatively preheated pellet designs developed by the Nike laser group. Two main diagnostics for this effort are two spectrometers incorporating three detection systems. While both spectrometers use 2500 lines/mm transmission gratings, one instrument is coupled to a soft x-ray streak camera and the other is coupled to both an absolutely calibrated Si photodiode array and a charge coupled device (CCD) camera. Absolute calibration of spectrometer components has been undertaken at the National Synchrotron Light Source at Brookhaven National Laboratories. Currently, the system has been used to measure the spatially integrated soft x-ray flux as a function of target material, laser power, and laser spot size. A comparison between measured and calculated flux for Au and CH targets shows reasonable agreement to one-dimensional modeling for two laser power densities.

  8. Time Scales, Bedforms and Bedload Transport

    NASA Astrophysics Data System (ADS)

    Dhont, B.

    2015-12-01

    Bedload transport rates in mountain streams may exhibit wide fluctuations even under constant flow conditions. A better understanding of bedload pulses is key to predict natural hazards induced by torrential activity and sediment issues in mountainous areas. Several processes such as bedforms migration, grain sorting and random particles' trajectories are evoked as the driving agents of pulse formation and development. Quantifying the effects of these processes is a difficult task. This work aims to investigate the interactions between bedload transport and bedform dynamics in steep gravel-bed rivers. Experiments are carried out in a 17-m long 60-cm wide flume inclined at an angle of 2.7%. The bed is initially flat and made of homogenous natural gravel with a mean diameter of 6 mm. We imposed 200 identical hydrographs (of 1 hr duration) at the flume inlet (the bed surface was not flattened out during these cycling floods). The input hydrograph and the input sediment discharge are nearly triangular. Bed topography is measured after each flood using ultrasound sensors while the bedload transport rate is steadily monitored at the outlet using accelerometers (accelerometers fixed on metallic plates record the impacts of the grains flowing out of the flume). For the sake of comparison, a similar experiment consisting of 19 floods of 10 hours is carried out under constant supply conditions. We show that accelerometers are a cost effective technique to obtain high-frequency bedload discharge data. Spectral analysis of the bedload timeseries is used to highlight the different time scales corresponding to different bedload transport processes. We show that long timeseries are necessary to capture the different processes that drive bedload transport, including the resilience time after a perturbation of the bed. The alternate bars that develop and migrate along the flume are found to significantly influence bedload transport rate fluctuations.

  9. An optimal modification of a Kalman filter for time scales

    NASA Technical Reports Server (NTRS)

    Greenhall, C. A.

    2003-01-01

    The Kalman filter in question, which was implemented in the time scale algorithm TA(NIST), produces time scales with poor short-term stability. A simple modification of the error covariance matrix allows the filter to produce time scales with good stability at all averaging times, as verified by simulations of clock ensembles.

  10. Two-probe optical encoder for absolute positioning of precision stages by using an improved scale grating.

    PubMed

    Li, Xinghui; Wang, Huanhuan; Ni, Kai; Zhou, Qian; Mao, Xinyu; Zeng, Lijiang; Wang, Xiaohao; Xiao, Xiang

    2016-09-19

    In this paper, a novel optical encoder enabling the simultaneous measurement of displacement and the position of precision stages is presented. The encoder is composed of an improved single-track scale grating and a compact two-probe reading head. In the scale grating, multiple reference codes are physically superimposed onto the incremental grooves, in contrast to conventional designs, where an additional track is necessary. The distribution of the reference codes follows a specific mathematical algorithm. For the reading head, a two-probe structure is designed to identify the discrete reference codes by means of the superimposition of the codes with a stationary mask and to read the continuous incremental grooves by means of a grating interferometry, respectively. A prototype encoder was designed, constructed and evaluated, and experimental results show that the distance code precision achieved is 0.5 μm, while the linearity error of the linear displacement measurement is less than 0.06%. PMID:27661879

  11. Teaching about time by understanding Geologic Time Scales: The Geological Society of America Geologic Time Scale and its history

    NASA Astrophysics Data System (ADS)

    Geissman, J. W.; Walker, J. D.

    2012-12-01

    Geologic time scales, of one form or another, are used in most undergraduate geosciences courses, even including introductory physical geology or equivalent. However, satisfactory discussions of how geologic time scales originated, and how they have evolved to modern versions, are far too often conveniently or inconveniently left out of classroom discussions. Yet it is these kinds of discussions that have the potential of solidifying student appreciation of deep time and rates of geologic processes. We use the history and development of the Geological Society of America Geologic Time Scale, which reflects major developments in the fields of stratigraphy, geochronology, magnetic polarity stratigraphy, astrochronology, and chemostratigraphy, as a focus of how specific details of time scales can be used to teach about time. Advances in all of these fields have allowed many parts of the time scale to be calibrated to precisions approaching less than 0.05 %. Notable time intervals for which collaborative, multifaceted efforts have led to dramatic improvements in our understanding of the character and temporal resolution of key evolutionary events, in both marine and terrestrial environments, include the Triassic-Jurassic, Permo-Triassic, and Neoproterozoic-Phanerozoic boundaries (or transitions). Many of the details, but certainly not all, can be incorporated in discussions of how we know about geologic time in the classroom. For example, we presently understand that both the end-Permian ecological crisis and the biostratigraphic Permian-Triassic boundary, as calibrated by conodonts, lie within a ca. 700 ka long normal polarity chron. The reverse to normal polarity transition at the beginning of this chron is ca. 100 ka earlier than the ecological crisis and thus slightly older than the current estimate, based on high precision U-Pb zircon age determinations, of ca. 252.4 Ma for the Permian-Triassic boundary. This polarity transition occurred during the early part of

  12. Detection of crossover time scales in multifractal detrended fluctuation analysis

    NASA Astrophysics Data System (ADS)

    Ge, Erjia; Leung, Yee

    2013-04-01

    Fractal is employed in this paper as a scale-based method for the identification of the scaling behavior of time series. Many spatial and temporal processes exhibiting complex multi(mono)-scaling behaviors are fractals. One of the important concepts in fractals is crossover time scale(s) that separates distinct regimes having different fractal scaling behaviors. A common method is multifractal detrended fluctuation analysis (MF-DFA). The detection of crossover time scale(s) is, however, relatively subjective since it has been made without rigorous statistical procedures and has generally been determined by eye balling or subjective observation. Crossover time scales such determined may be spurious and problematic. It may not reflect the genuine underlying scaling behavior of a time series. The purpose of this paper is to propose a statistical procedure to model complex fractal scaling behaviors and reliably identify the crossover time scales under MF-DFA. The scaling-identification regression model, grounded on a solid statistical foundation, is first proposed to describe multi-scaling behaviors of fractals. Through the regression analysis and statistical inference, we can (1) identify the crossover time scales that cannot be detected by eye-balling observation, (2) determine the number and locations of the genuine crossover time scales, (3) give confidence intervals for the crossover time scales, and (4) establish the statistically significant regression model depicting the underlying scaling behavior of a time series. To substantive our argument, the regression model is applied to analyze the multi-scaling behaviors of avian-influenza outbreaks, water consumption, daily mean temperature, and rainfall of Hong Kong. Through the proposed model, we can have a deeper understanding of fractals in general and a statistical approach to identify multi-scaling behavior under MF-DFA in particular.

  13. Elasticity of MgO to 11 GPa with an independent absolute pressure scale: Implications for pressure calibration

    SciTech Connect

    Li, B.; Woody, K; Kung, J

    2006-01-01

    P and S wave velocities and unit cell parameters (density) of MgO are measured simultaneously up to 11 GPa using combined ultrasonic interferometry and in situ X-ray diffraction techniques. The elastic bulk and shear moduli as well as their pressure derivatives are obtained by fitting the measured velocity and density data to the third-order finite strain equations, yielding K0S = 163.5(11) GPa, K'0S = 4.20(10), G0 = 129.8(6) GPa, and G'0 = 2.42(6), independent of pressure. These properties are subsequently used in a Birch-Murnaghan equation of state to determine the sample pressures at the observed strains. Comparison of the 300K isothermal compression of MgO indicates that current pressure scales from recent studies are in better than 1.5% agreement. We find that pressures derived from secondary pressure standards (NaCl, ruby fluorescence) at 300K are lower than those from current MgO scales by 5-8% ({approx}6% on average) in the entire pressure range of the current experiment. If this is taken into account, discrepancy in previous static compression studies on MgO at 300K can be reconciled, and a better agreement with the present study can be achieved.

  14. Time scales in Galveston Bay: An unsteady estuary

    NASA Astrophysics Data System (ADS)

    Rayson, Matthew D.; Gross, Edward S.; Hetland, Robert D.; Fringer, Oliver B.

    2016-04-01

    Estuarine time scales including the turnover, particle e-folding time, the age (calculated with a passive tracer), and residence time (calculated with Lagrangian particles) were computed using a three-dimensional hydrodynamic model of Galveston Bay, a low-flow, partially stratified estuary. Time scales were computed during a time period when river flow varied by several orders of magnitude and all time scales therefore exhibited significant temporal variability because of the unsteadiness of the system. The spatial distributions of age and residence time were qualitatively similar and increased from 15 days in a shipping channel to >45 days in the upper estuary. Volume-averaged age and residence time decreased during high-flow conditions. Bulk time scales, including the freshwater and salinity turnover times, were far more variable due to the changing river discharge and salt flux through the estuary mouth. A criterion for calculating a suitable averaging time is discussed to satisfy a steady state assumption and to estimate a more representative bulk time scale. When scaled with a freshwater advective time, all time scales were approximately equal to the advective time scale during high-flow conditions and many times higher during low-flow conditions. The mean age, Lagrangian residence, and flushing times exhibited a relationship that was weakly dependent on the freshwater advective time scale demonstrating predictability even in an unsteady, realistic estuary.

  15. Absolute fragmentation cross sections in atom-molecule collisions: Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

    SciTech Connect

    Chen, T.; Gatchell, M.; Stockett, M. H.; Alexander, J. D.; Schmidt, H. T.; Cederquist, H.; Zettergren, H.; Zhang, Y.; Rousseau, P.; Maclot, S.; Delaunay, R.; Adoui, L.; Domaracka, A.; Huber, B. A.

    2014-06-14

    We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH{sup +}) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH{sup +} + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C{sub 6}H{sub 5}). Thus nonstatistical fragmentation may be an effective initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures.

  16. A Quaternary Geomagnetic Instability Time Scale

    NASA Astrophysics Data System (ADS)

    Singer, B. S.

    2013-12-01

    Reversals and excursions of Earth's geomagnetic field create marker horizons that are readily detected in sedimentary and volcanic rocks worldwide. An accurate and precise chronology of these geomagnetic field instabilities is fundamental to understanding several aspects of Quaternary climate, dynamo processes, and surface processes. For example, stratigraphic correlation between marine sediment and polar ice records of climate change across the cryospheres benefits from a highly resolved record of reversals and excursions. The temporal patterns of dynamo behavior may reflect physical interactions between the molten outer core and the solid inner core or lowermost mantle. These interactions may control reversal frequency and shape the weak magnetic fields that arise during successive dynamo instabilities. Moreover, weakening of the axial dipole during reversals and excursions enhances the production of cosmogenic isotopes that are used in sediment and ice core stratigraphy and surface exposure dating. The Geomagnetic Instability Time Scale (GITS) is based on the direct dating of transitional polarity states recorded by lava flows using the 40Ar/39Ar method, in parallel with astrochronologic age models of marine sediments in which O isotope and magnetic records have been obtained. A review of data from Quaternary lava flows and sediments yields a GITS comprising 10 polarity reversals and 27 excursions during the past 2.6 million years. Nine of the ten reversals bounding chrons and subchrons are associated with 40Ar/39Ar ages of transitionally-magnetized lava flows. The tenth, the Guass-Matuyama chron boundary, is tightly bracketed by 40Ar/39Ar dated ash deposits. Of the 27 well-documented excursions, 14 occurred during the Matuyama chron and 13 during the Brunhes chron; 19 have been dated directly using the 40Ar/39Ar method on transitionally-magnetized volcanic rocks and form the backbone of the GITS. Excursions are clearly not the rare phenomena once thought

  17. Scaling relation between earthquake magnitude and the departure time from P wave similar growth

    NASA Astrophysics Data System (ADS)

    Noda, Shunta; Ellsworth, William L.

    2016-09-01

    We introduce a new scaling relation between earthquake magnitude (M) and a characteristic of initial P wave displacement. By examining Japanese K-NET data averaged in bins partitioned by Mw and hypocentral distance, we demonstrate that the P wave displacement briefly displays similar growth at the onset of rupture and that the departure time (Tdp), which is defined as the time of departure from similarity of the absolute displacement after applying a band-pass filter, correlates with the final M in a range of 4.5 ≤ Mw ≤ 7. The scaling relation between Mw and Tdp implies that useful information on the final M can be derived while the event is still in progress because Tdp occurs before the completion of rupture. We conclude that the scaling relation is important not only for earthquake early warning but also for the source physics of earthquakes.

  18. Scaling relation between earthquake magnitude and the departure time from P wave similar growth

    USGS Publications Warehouse

    Noda, Shunta; Ellsworth, William L.

    2016-01-01

    We introduce a new scaling relation between earthquake magnitude (M) and a characteristic of initial P wave displacement. By examining Japanese K-NET data averaged in bins partitioned by Mw and hypocentral distance, we demonstrate that the P wave displacement briefly displays similar growth at the onset of rupture and that the departure time (Tdp), which is defined as the time of departure from similarity of the absolute displacement after applying a band-pass filter, correlates with the final M in a range of 4.5 ≤ Mw ≤ 7. The scaling relation between Mw and Tdp implies that useful information on the final M can be derived while the event is still in progress because Tdp occurs before the completion of rupture. We conclude that the scaling relation is important not only for earthquake early warning but also for the source physics of earthquakes.

  19. Categorical scaling of time: implications for clock-counter models.

    PubMed

    Fetterman, J G; Killeen, P R

    1995-01-01

    Pigeons partitioned time into three intervals. Responses to one key could be reinforced after a short time, to a second key after an intermediate time, and to a third key after a long time. The values of the short, intermediate, and long times and the proportion of trials ending with reinforcement were varied. Absolute and relative response rates on each key were an orderly function of time and showed approximately proportional changes with changes in the interval values, consistent with Weber's law, Gibbon's (1977) scalar expectancy theory, and Killeen and Fetterman's (1988) behavioral theory of timing (BeT). Standard deviations of the times at which subjects switched between successive keys increased more slowly within a condition than across conditions, as predicted by BeT. Increases and decreases in reinforcement probability produced both transient and longer lasting changes in timing behavior, once again, in accord with predictions of BeT.

  20. On time scales and time synchronization using LORAN-C as a time reference signal

    NASA Technical Reports Server (NTRS)

    Chi, A. R.

    1974-01-01

    The long term performance of the eight LORAN-C chains is presented in terms of the Coordinated Universal Time (UTC) of the U.S. Naval Observatory (USNO); and the use of the LORAN-C navigation system for maintaining the user's clock to a UTC scale is described. The atomic time scale and the UTC of several national laboratories and observatories relative to the international atomic time are reported. Typical performance of several NASA tracking station clocks, relative to the USNO master clock, is also presented.

  1. Relative time scales reveal multiple origins of parallel disjunct distributions of African caecilian amphibians.

    PubMed

    Loader, Simon P; Pisani, Davide; Cotton, James A; Gower, David J; Day, Julia J; Wilkinson, Mark

    2007-10-22

    Parallel patterns of distribution in different lineages suggest a common cause. Explanations in terms of a single biogeographic event often imply contemporaneous diversifications. Phylogenies with absolute time scales provide the most obvious means of testing temporal components of biogeographic hypotheses but, in their absence, the sequence of diversification events and whether any could have been contemporaneous can be tested with relative date estimates. Tests using relative time scales have been largely overlooked, but because they do not require the calibration upon which absolute time scales depend, they make a large amount of existing molecular data of use to historical biogeography and may also be helpful when calibration is possible but uncertain. We illustrate the use of relative dating by testing the hypothesis that parallel, disjunct east/west distributions in three independent lineages of African caecilians have a common cause. We demonstrate that at least two biogeographic events are implied by molecular data. Relative dating analysis reveals the potential complexity of causes of parallel distributions and cautions against inferring common cause from common spatial patterns without considering the temporal dimension.

  2. Relative time scales reveal multiple origins of parallel disjunct distributions of African caecilian amphibians.

    PubMed

    Loader, Simon P; Pisani, Davide; Cotton, James A; Gower, David J; Day, Julia J; Wilkinson, Mark

    2007-10-22

    Parallel patterns of distribution in different lineages suggest a common cause. Explanations in terms of a single biogeographic event often imply contemporaneous diversifications. Phylogenies with absolute time scales provide the most obvious means of testing temporal components of biogeographic hypotheses but, in their absence, the sequence of diversification events and whether any could have been contemporaneous can be tested with relative date estimates. Tests using relative time scales have been largely overlooked, but because they do not require the calibration upon which absolute time scales depend, they make a large amount of existing molecular data of use to historical biogeography and may also be helpful when calibration is possible but uncertain. We illustrate the use of relative dating by testing the hypothesis that parallel, disjunct east/west distributions in three independent lineages of African caecilians have a common cause. We demonstrate that at least two biogeographic events are implied by molecular data. Relative dating analysis reveals the potential complexity of causes of parallel distributions and cautions against inferring common cause from common spatial patterns without considering the temporal dimension. PMID:17609171

  3. Standardization of Gene Expression Quantification by Absolute Real-Time qRT-PCR System Using a Single Standard for Marker and Reference Genes.

    PubMed

    Zhou, Yi-Hong; Raj, Vinay R; Siegel, Eric; Yu, Liping

    2010-08-16

    In the last decade, genome-wide gene expression data has been collected from a large number of cancer specimens. In many studies utilizing either microarray-based or knowledge-based gene expression profiling, both the validation of candidate genes and the identification and inclusion of biomarkers in prognosis-modeling has employed real-time quantitative PCR on reverse transcribed mRNA (qRT-PCR) because of its inherent sensitivity and quantitative nature. In qRT-PCR data analysis, an internal reference gene is used to normalize the variation in input sample quantity. The relative quantification method used in current real-time qRT-PCR analysis fails to ensure data comparability pivotal in identification of prognostic biomarkers. By employing an absolute qRT-PCR system that uses a single standard for marker and reference genes (SSMR) to achieve absolute quantification, we showed that the normalized gene expression data is comparable and independent of variations in the quantities of sample as well as the standard used for generating standard curves. We compared two sets of normalized gene expression data with same histological diagnosis of brain tumor from two labs using relative and absolute real-time qRT-PCR. Base-10 logarithms of the gene expression ratio relative to ACTB were evaluated for statistical equivalence between tumors processed by two different labs. The results showed an approximate comparability for normalized gene expression quantified using a SSMR-based qRT-PCR. Incomparable results were seen for the gene expression data using relative real-time qRT-PCR, due to inequality in molar concentration of two standards for marker and reference genes. Overall results show that SSMR-based real-time qRT-PCR ensures comparability of gene expression data much needed in establishment of prognostic/predictive models for cancer patients-a process that requires large sample sizes by combining independent sets of data.

  4. Real-Time Determination of Absolute Frequency in Continuous-Wave Terahertz Radiation with a Photocarrier Terahertz Frequency Comb Induced by an Unstabilized Femtosecond Laser

    NASA Astrophysics Data System (ADS)

    Minamikawa, Takeo; Hayashi, Kenta; Mizuguchi, Tatsuya; Hsieh, Yi-Da; Abdelsalam, Dahi Ghareab; Mizutani, Yasuhiro; Yamamoto, Hirotsugu; Iwata, Tetsuo; Yasui, Takeshi

    2016-05-01

    A practical method for the absolute frequency measurement of continuous-wave terahertz (CW-THz) radiation uses a photocarrier terahertz frequency comb (PC-THz comb) because of its ability to realize real-time, precise measurement without the need for cryogenic cooling. However, the requirement for precise stabilization of the repetition frequency ( f rep) and/or use of dual femtosecond lasers hinders its practical use. In this article, based on the fact that an equal interval between PC-THz comb modes is always maintained regardless of the fluctuation in f rep, the PC-THz comb induced by an unstabilized laser was used to determine the absolute frequency f THz of CW-THz radiation. Using an f rep-free-running PC-THz comb, the f THz of the frequency-fixed or frequency-fluctuated active frequency multiplier chain CW-THz source was determined at a measurement rate of 10 Hz with a relative accuracy of 8.2 × 10-13 and a relative precision of 8.8 × 10-12 to a rubidium frequency standard. Furthermore, f THz was correctly determined even when fluctuating over a range of 20 GHz. The proposed method enables the use of any commercial femtosecond laser for the absolute frequency measurement of CW-THz radiation.

  5. Cluster-continuum quasichemical theory calculation of the lithium ion solvation in water, acetonitrile and dimethyl sulfoxide: an absolute single-ion solvation free energy scale.

    PubMed

    Carvalho, Nathalia F; Pliego, Josefredo R

    2015-10-28

    Absolute single-ion solvation free energy is a very useful property for understanding solution phase chemistry. The real solvation free energy of an ion depends on its interaction with the solvent molecules and on the net potential inside the solute cavity. The tetraphenyl arsonium-tetraphenyl borate (TATB) assumption as well as the cluster-continuum quasichemical theory (CC-QCT) approach for Li(+) solvation allows access to a solvation scale excluding the net potential. We have determined this free energy scale investigating the solvation of the lithium ion in water (H2O), acetonitrile (CH3CN) and dimethyl sulfoxide (DMSO) solvents via the CC-QCT approach. Our calculations at the MP2 and MP4 levels with basis sets up to the QZVPP+diff quality, and including solvation of the clusters and solvent molecules by the dielectric continuum SMD method, predict the solvation free energy of Li(+) as -116.1, -120.6 and -123.6 kcal mol(-1) in H2O, CH3CN and DMSO solvents, respectively (1 mol L(-1) standard state). These values are compatible with the solvation free energy of the proton of -253.4, -253.2 and -261.1 kcal mol(-1) in H2O, CH3CN and DMSO solvents, respectively. Deviations from the experimental TATB scale are only 1.3 kcal mol(-1) in H2O and 1.8 kcal mol(-1) in DMSO solvents. However, in the case of CH3CN, the deviation reaches a value of 9.2 kcal mol(-1). The present study suggests that the experimental TATB scale is inconsistent for CH3CN. A total of 125 values of the solvation free energy of ions in these three solvents were obtained. These new data should be useful for the development of theoretical solvation models.

  6. On the Uncertainty of the Annular Mode Time Scale

    NASA Astrophysics Data System (ADS)

    Kim, Junsu; Reichler, Thomas

    2015-04-01

    The proper simulation of the annular mode (AM) time scale may be regarded as an important benchmark for climate models. Previous research demonstrated that climate models systematically overestimate this time scale. As suggested by the fluctuation-dissipation theorem, this may imply that models are overly sensitive to external forcings. Previous research also made it clear that calculating the AM time scale is a slowly converging process, necessitating relatively long time series and casting doubts on the usefulness of the historical reanalysis record to constrain climate models in terms of the AM time scale. Here, we use a 4000-year-long control simulation with the GFDL climate model CM2.1 to study the effects of internal atmospheric variability on the stability of the AM time scale. In particular, we ask whether a model's AM time scale and climate sensitivity can be constrained from the 50-year-long reanalysis record. We find that internal variability attaches large uncertainty to the AM time scale when diagnosed from decadal records. Even under fixed forcing conditions, at least 100 years of data are required in order to keep the uncertainty in the AM time scale of the Northern Hemisphere to 10%; over the Southern Hemisphere the required length increases to 200 years. If nature's AM time scale is similarly variable, there is no guarantee that the historical reanalysis record is a fully representative target for model evaluation. We further use the model simulation to investigate the dynamical coupling between the stratosphere and the troposphere from the perspective of the AM time scale. Over the Northern Hemisphere we find only weak indication for influences from stratosphere-troposphere coupling on the AM time scale. The situation is very different over the Southern Hemisphere, where we find robust connections between the AM time scale in the stratosphere and that in the troposphere, confirming and extending earlier results of influences of stratospheric

  7. Scale-dependent intrinsic entropies of complex time series.

    PubMed

    Yeh, Jia-Rong; Peng, Chung-Kang; Huang, Norden E

    2016-04-13

    Multi-scale entropy (MSE) was developed as a measure of complexity for complex time series, and it has been applied widely in recent years. The MSE algorithm is based on the assumption that biological systems possess the ability to adapt and function in an ever-changing environment, and these systems need to operate across multiple temporal and spatial scales, such that their complexity is also multi-scale and hierarchical. Here, we present a systematic approach to apply the empirical mode decomposition algorithm, which can detrend time series on various time scales, prior to analysing a signal's complexity by measuring the irregularity of its dynamics on multiple time scales. Simulated time series of fractal Gaussian noise and human heartbeat time series were used to study the performance of this new approach. We show that our method can successfully quantify the fractal properties of the simulated time series and can accurately distinguish modulations in human heartbeat time series in health and disease.

  8. Timing signatures of large scale solar eruptions

    NASA Astrophysics Data System (ADS)

    Balasubramaniam, K. S.; Hock-Mysliwiec, Rachel; Henry, Timothy; Kirk, Michael S.

    2016-05-01

    We examine the timing signatures of large solar eruptions resulting in flares, CMEs and Solar Energetic Particle events. We probe solar active regions from the chromosphere through the corona, using data from space and ground-based observations, including ISOON, SDO, GONG, and GOES. Our studies include a number of flares and CMEs of mostly the M- and X-strengths as categorized by GOES. We find that the chromospheric signatures of these large eruptions occur 5-30 minutes in advance of coronal high temperature signatures. These timing measurements are then used as inputs to models and reconstruct the eruptive nature of these systems, and explore their utility in forecasts.

  9. The analysis of space-time structure in QCD vacuum II: Dynamics of polarization and absolute X-distribution

    NASA Astrophysics Data System (ADS)

    Alexandru, Andrei; Draper, Terrence; Horváth, Ivan; Streuer, Thomas

    2011-08-01

    We propose a framework for quantitative evaluation of dynamical tendency for polarization in an arbitrary random variable that can be decomposed into a pair of orthogonal subspaces. The method uses measures based on comparisons of given dynamics to its counterpart with statistically independent components. The formalism of previously considered X-distributions is used to express the aforementioned comparisons, in effect putting the former approach on solid footing. Our analysis leads to the definition of a suitable correlation coefficient with clear statistical meaning. We apply the method to the dynamics induced by pure-glue lattice QCD in local left-right components of overlap Dirac eigenmodes. It is found that, in finite physical volume, there exists a non-zero physical scale in the spectrum of eigenvalues such that eigenmodes at smaller (fixed) eigenvalues exhibit convex X-distribution (positive correlation), while at larger eigenvalues the distribution is concave (negative correlation). This chiral polarization scale thus separates a regime where dynamics enhances chirality relative to statistical independence from a regime where it suppresses it, and gives an objective definition to the notion of "low" and "high" Dirac eigenmode. We propose to investigate whether the polarization scale remains non-zero in the infinite volume limit, in which case it would represent a new kind of low energy scale in QCD.

  10. Modeling orbital changes on tectonic time scales

    NASA Technical Reports Server (NTRS)

    Crowley, Thomas J.

    1992-01-01

    Geologic time series indicate significant 100 ka and 400 ka pre-Pleistocene climate fluctuations, prior to the time of such fluctuations in Pleistocene ice sheets. The origin of these fluctuations must therefore depend on phenomena other than the ice sheets. In a previous set of experiments, we tested the sensitivity of an energy balance model to orbital insolation forcing, specifically focusing on the filtering effect of the Earth's geography. We found that in equatorial areas, the twice-yearly passage of the sun across the equator interacts with the precession index to generate 100 ka and 400 ka power in our modeled time series. The effect is proportional to the magnitude of land in equatorial regions. We suggest that such changes may reflect monsoonal variations in the real climate system, and the subsequent wind and weathering changes may transfer some of this signal to the marine record. A comparison with observed fluctuations of Triassic lake levels is quite favorable. A number of problems remain to be studied or clarified: (1) the EBM experiments need to be followed up by a limited number of GCM experiments; (2) the sensitivity to secular changes in orbital forcing needs to be examined; (3) the possible modifying role of sedimentary processes on geologic time series warrants considerably more study; (4) the effect of tectonic changes on Earth's rotation rate needs to be studied; and (5) astronomers need to make explicit which of their predictions are robust and geologists and astronomers have to agree on which of the predictions are most testable in the geologic record.

  11. Objective quality measurement for audio time-scale modification

    NASA Astrophysics Data System (ADS)

    Liu, Fang; Lee, Jae-Joon; Kuo, C. C. J.

    2003-11-01

    The recent ITU-T Recommendation P.862, known as the Perceptual Evaluation of Speech Quality (PESQ) is an objective end-to-end speech quality assessment method for telephone networks and speech codecs through the measurement of received audio quality. To ensure that certain network distortions will not affect the estimated subjective measurement determined by PESQ, the algorithm takes into account packet loss, short-term and long-term time warping resulted from delay variation. However, PESQ does not work well for time-scale audio modification or temporal clipping. We investigated the factors that impact the perceived quality when time-scale modification is involved. An objective measurement of time-scale modification is proposed in this research, where the cross-correlation values obtained from time-scale modification synchronization are used to evaluate the quality of a time-scaled audio sequence. This proposed objective measure has been verified by a subjective test.

  12. Rapid evaluation of time scale using an optical clock

    NASA Astrophysics Data System (ADS)

    Ido, T.; Hachisu, H.; Nakagawa, F.; Hanado, Y.

    2016-06-01

    Feasibility of steering a time scale using an optical clock is investigated. Since the high stability of optical frequency standards enables rapid evaluation of the scale interval, the requirement for the continuous operation is mitigated. Numerical simulations with the input of real calibration data by a 87Sr lattice clock indicated that the calibrations once in two weeks maintain the time scale within 5 ns level using a currently available hydrogen maser at NICT. “Optical” steering of a time scale by the intermittent calibrations frees an optical frequency standard from being dedicated to the steering, enabling other applications using the same apparatus.

  13. Small angle neutron scattering on an absolute intensity scale and the internal surface of diatom frustules from three species of differing morphologies.

    PubMed

    Garvey, C J; Strobl, M; Percot, A; Saroun, J; Haug, J; Vyverman, W; Chepurnov, V A; Ferris, J M

    2013-05-01

    The internal nanostructure of the diatoms Cyclotella meneghiniana, Seminavis robusta and Achnanthes subsessilis was investigated using small angle neutron scattering (SANS) to examine thin biosilica samples, consisting of isotropic (powder) from their isolated cell walls. The interpretation of SANS data was assisted by several other measurements. The N2 adsorption, interpreted within the Branuer-Emmet-Teller isotherm, yielded the specific surface area of the material. Fourier transform infrared (FTIR) and Raman spectroscopy indicates that the isolated material is amorphous silica with small amounts of organic cell wall materials acting as a filling material between the silica particles. A two-phase (air and amorphous silica) model was used to interpret small angle neutron scattering data. After correction for instrumental resolution, the measurements on two SANS instruments covered an extended range of scattering vectors 0.0011 nm(-1) < q < 5.6 nm(-1), giving an almost continuous SANS curve over a range of scattering vectors, q, on an absolute scale of intensity for each sample. Each of the samples gave a characteristic scattering curve where log (intensity) versus log (q) has a -4 dependence, with other features superimposed. In the high-q regime, departure from this behaviour was observed at a length-scales equivalent to the proposed unitary silica particle. The limiting Porod scattering law was used to determine the specific area per unit of volume of each sample illuminated by the neutron beam. The Porod behaviour, and divergence from this behaviour, is discussed in terms of various structural features and the proposed mechanisms for the bio-assembly of unitary silica particles in frustules.

  14. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors.

    PubMed

    Waugh, C J; Rosenberg, M J; Zylstra, A B; Frenje, J A; Séguin, F H; Petrasso, R D; Glebov, V Yu; Sangster, T C; Stoeckl, C

    2015-05-01

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule. PMID:26026524

  15. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    SciTech Connect

    Waugh, C. J. Zylstra, A. B.; Frenje, J. A.; Séguin, F. H.; Petrasso, R. D.; Rosenberg, M. J.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-15

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

  16. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    DOE PAGES

    Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-27

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition,more » comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.« less

  17. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    SciTech Connect

    Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-27

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

  18. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  19. Multiple time scales in multi-state models.

    PubMed

    Iacobelli, Simona; Carstensen, Bendix

    2013-12-30

    In multi-state models, it has been the tradition to model all transition intensities on one time scale, usually the time since entry into the study ('clock-forward' approach). The effect of time since an intermediate event has been accommodated either by changing the time scale to time since entry to the new state ('clock-back' approach) or by including the time at entry to the new state as a covariate. In this paper, we argue that the choice of time scale for the various transitions in a multi-state model should be dealt with as an empirical question, as also the question of whether a single time scale is sufficient. We illustrate that these questions are best addressed by using parametric models for the transition rates, as opposed to the traditional Cox-model-based approaches. Specific advantages are that dependence of failure rates on multiple time scales can be made explicit and described in informative graphical displays. Using a single common time scale for all transitions greatly facilitates computations of probabilities of being in a particular state at a given time, because the machinery from the theory of Markov chains can be applied. However, a realistic model for transition rates is preferable, especially when the focus is not on prediction of final outcomes from start but on the analysis of instantaneous risk or on dynamic prediction. We illustrate the various approaches using a data set from stem cell transplant in leukemia and provide supplementary online material in R. PMID:24027131

  20. Sub-micron absolute distance measurements in sub-millisecond times with dual free-running femtosecond Er fiber-lasers.

    PubMed

    Liu, Tze-An; Newbury, Nathan R; Coddington, Ian

    2011-09-12

    We demonstrate a simplified dual-comb LIDAR setup for precision absolute ranging that can achieve a ranging precision of 2 μm in 140 μs acquisition time. With averaging, the precision drops below 1 μm at 0.8 ms and below 200 nm at 20 ms. The system can measure the distance to multiple targets with negligible dead zones and a ranging ambiguity of 1 meter. The system is much simpler than a previous coherent dual-comb LIDAR because the two combs are replaced by free-running, saturable-absorber-based femtosecond Er fiber lasers, rather than tightly phase-locked combs, with the entire time base provided by a single 10-digit frequency counter. Despite the simpler design, the system provides a factor of three improved performance over the previous coherent dual comb LIDAR system.

  1. Sub-micron absolute distance measurements in sub-millisecond times with dual free-running femtosecond Er fiber-lasers.

    PubMed

    Liu, Tze-An; Newbury, Nathan R; Coddington, Ian

    2011-09-12

    We demonstrate a simplified dual-comb LIDAR setup for precision absolute ranging that can achieve a ranging precision of 2 μm in 140 μs acquisition time. With averaging, the precision drops below 1 μm at 0.8 ms and below 200 nm at 20 ms. The system can measure the distance to multiple targets with negligible dead zones and a ranging ambiguity of 1 meter. The system is much simpler than a previous coherent dual-comb LIDAR because the two combs are replaced by free-running, saturable-absorber-based femtosecond Er fiber lasers, rather than tightly phase-locked combs, with the entire time base provided by a single 10-digit frequency counter. Despite the simpler design, the system provides a factor of three improved performance over the previous coherent dual comb LIDAR system. PMID:21935219

  2. Comprehensive panel of real-time TaqMan polymerase chain reaction assays for detection and absolute quantification of filoviruses, arenaviruses, and New World hantaviruses.

    PubMed

    Trombley, Adrienne R; Wachter, Leslie; Garrison, Jeffrey; Buckley-Beason, Valerie A; Jahrling, Jordan; Hensley, Lisa E; Schoepp, Randal J; Norwood, David A; Goba, Augustine; Fair, Joseph N; Kulesh, David A

    2010-05-01

    Viral hemorrhagic fever is caused by a diverse group of single-stranded, negative-sense or positive-sense RNA viruses belonging to the families Filoviridae (Ebola and Marburg), Arenaviridae (Lassa, Junin, Machupo, Sabia, and Guanarito), and Bunyaviridae (hantavirus). Disease characteristics in these families mark each with the potential to be used as a biological threat agent. Because other diseases have similar clinical symptoms, specific laboratory diagnostic tests are necessary to provide the differential diagnosis during outbreaks and for instituting acceptable quarantine procedures. We designed 48 TaqMan-based polymerase chain reaction (PCR) assays for specific and absolute quantitative detection of multiple hemorrhagic fever viruses. Forty-six assays were determined to be virus-specific, and two were designated as pan assays for Marburg virus. The limit of detection for the assays ranged from 10 to 0.001 plaque-forming units (PFU)/PCR. Although these real-time hemorrhagic fever virus assays are qualitative (presence of target), they are also quantitative (measure a single DNA/RNA target sequence in an unknown sample and express the final results as an absolute value (e.g., viral load, PFUs, or copies/mL) on the basis of concentration of standard samples and can be used in viral load, vaccine, and antiviral drug studies.

  3. Computational Modeling of Semiconductor Dynamics at Femtosecond Time Scales

    NASA Technical Reports Server (NTRS)

    Agrawal, Govind P.; Goorjian, Peter M.

    1998-01-01

    The main objective of the Joint-Research Interchange NCC2-5149 was to develop computer codes for accurate simulation of femtosecond pulse propagation in semiconductor lasers and semiconductor amplifiers [I]. The code should take into account all relevant processes such as the interband and intraband carrier relaxation mechanisms and the many-body effects arising from the Coulomb interaction among charge carriers [2]. This objective was fully accomplished. We made use of a previously developed algorithm developed at NASA Ames [3]-[5]. The new algorithm was tested on several problems of practical importance. One such problem was related to the amplification of femtosecond optical pulses in semiconductors. These results were presented in several international conferences over a period of three years. With the help of a postdoctoral fellow, we also investigated the origin of instabilities that can lead to the formation of femtosecond pulses in different kinds of lasers. We analyzed the occurrence of absolute instabilities in lasers that contain a dispersive host material with third-order nonlinearities. Starting from the Maxwell-Bloch equations, we derived general multimode equations to distinguish between convective and absolute instabilities. We find that both self-phase modulation and intensity-dependent absorption can dramatically affect the absolute stability of such lasers. In particular, the self-pulsing threshold (the so-called second laser threshold) can occur at few times the first laser threshold even in good-cavity lasers for which no self-pulsing occurs in the absence of intensity-dependent absorption. These results were presented in an international conference and published in the form of two papers.

  4. Local and Catchment-Scale Water Storage Changes in Northern Benin Deduced from Gravity Monitoring at Various Time-Scales

    NASA Astrophysics Data System (ADS)

    Hinderer, J.; Hector, B.; Séguis, L.; Descloitres, M.; Cohard, J.; Boy, J.; Calvo, M.; Rosat, S.; Riccardi, U.; Galle, S.

    2013-12-01

    Water storage changes (WSC) are investigated by the mean of gravity monitoring in Djougou, northern Benin, in the frame of the GHYRAF (Gravity and Hydrology in Africa) project. In this area, WSC are 1) part of the control system for evapotranspiration (ET) processes, a key variable of the West-African monsoon cycle and 2) the state variable for resource management, a critical issue in storage-poor hard rock basement contexts such as in northern Benin. We show the advantages of gravity monitoring for analyzing different processes in the water cycle involved at various time and space scales, using the main gravity sensors available today (FG5 absolute gravimeter, superconducting gravimeter -SG- and CG5 micro-gravimeter). The study area is also part of the long-term observing system AMMA-Catch, and thus under intense hydro-meteorological monitoring (rain, soil moisture, water table level, ET ...). Gravity-derived WSC are compared at all frequencies to hydrological data and to hydrological models calibrated on these data. Discrepancies are analyzed to discuss the pros and cons of each approach. Fast gravity changes (a few hours) are significant when rain events occur, and involve different contributions: rainfall itself, runoff, fast subsurface water redistribution, screening effect of the gravimeter building and local topography. We investigate these effects and present the statistical results of a set of rain events recorded with the SG installed in Djougou since July 2010. The intermediate time scale of gravity changes (a few days) is caused by ET and both vertical and horizontal water redistribution. The integrative nature of gravity measurements does not allow to separate these different contributions, and the screening from the shelter reduces our ability to retrieve ET values. Also, atmospheric corrections are critical at such frequencies, and deserve some specific attention. However, a quick analysis of gravity changes following rain events shows that the

  5. Multiple time scale complexity analysis of resting state FMRI.

    PubMed

    Smith, Robert X; Yan, Lirong; Wang, Danny J J

    2014-06-01

    The present study explored multi-scale entropy (MSE) analysis to investigate the entropy of resting state fMRI signals across multiple time scales. MSE analysis was developed to distinguish random noise from complex signals since the entropy of the former decreases with longer time scales while the latter signal maintains its entropy due to a "self-resemblance" across time scales. A long resting state BOLD fMRI (rs-fMRI) scan with 1000 data points was performed on five healthy young volunteers to investigate the spatial and temporal characteristics of entropy across multiple time scales. A shorter rs-fMRI scan with 240 data points was performed on a cohort of subjects consisting of healthy young (age 23 ± 2 years, n = 8) and aged volunteers (age 66 ± 3 years, n = 8) to investigate the effect of healthy aging on the entropy of rs-fMRI. The results showed that MSE of gray matter, rather than white matter, resembles closely that of f (-1) noise over multiple time scales. By filtering out high frequency random fluctuations, MSE analysis is able to reveal enhanced contrast in entropy between gray and white matter, as well as between age groups at longer time scales. Our data support the use of MSE analysis as a validation metric for quantifying the complexity of rs-fMRI signals.

  6. Liquidity spillover in international stock markets through distinct time scales.

    PubMed

    Righi, Marcelo Brutti; Vieira, Kelmara Mendes

    2014-01-01

    This paper identifies liquidity spillovers through different time scales based on a wavelet multiscaling method. We decompose daily data from U.S., British, Brazilian and Hong Kong stock markets indices in order to calculate the scale correlation between their illiquidities. The sample is divided in order to consider non-crisis, sub-prime crisis and Eurozone crisis. We find that there are changes in correlations of distinct scales and different periods. Association in finest scales is smaller than in coarse scales. There is a rise on associations in periods of crisis. In frequencies, there is predominance for significant distinctions involving the coarsest scale, while for crises periods there is predominance for distinctions on the finest scale.

  7. Liquidity Spillover in International Stock Markets through Distinct Time Scales

    PubMed Central

    Righi, Marcelo Brutti; Vieira, Kelmara Mendes

    2014-01-01

    This paper identifies liquidity spillovers through different time scales based on a wavelet multiscaling method. We decompose daily data from U.S., British, Brazilian and Hong Kong stock markets indices in order to calculate the scale correlation between their illiquidities. The sample is divided in order to consider non-crisis, sub-prime crisis and Eurozone crisis. We find that there are changes in correlations of distinct scales and different periods. Association in finest scales is smaller than in coarse scales. There is a rise on associations in periods of crisis. In frequencies, there is predominance for significant distinctions involving the coarsest scale, while for crises periods there is predominance for distinctions on the finest scale. PMID:24465918

  8. Scaling features of texts, images and time series

    NASA Astrophysics Data System (ADS)

    Pavlov, Alexey N.; Ebeling, Werner; Molgedey, Lutz; Ziganshin, Amir R.; Anishchenko, Vadim S.

    2001-11-01

    In the given paper, we consider the scaling features of long letter sequences like human writings, discretized images and discretized financial data. Using several approaches we show that the symbolic strings and time series being analyzed have a complex multiscale structure and demonstrate different scalings for large and small fluctuations. We discuss complex phenomena in the scaling behavior of partition functions in the case of high frequency DAX-future data.

  9. Extreme reaction times determine fluctuation scaling in human color vision

    NASA Astrophysics Data System (ADS)

    Medina, José M.; Díaz, José A.

    2016-11-01

    In modern mental chronometry, human reaction time defines the time elapsed from stimulus presentation until a response occurs and represents a reference paradigm for investigating stochastic latency mechanisms in color vision. Here we examine the statistical properties of extreme reaction times and whether they support fluctuation scaling in the skewness-kurtosis plane. Reaction times were measured for visual stimuli across the cardinal directions of the color space. For all subjects, the results show that very large reaction times deviate from the right tail of reaction time distributions suggesting the existence of dragon-kings events. The results also indicate that extreme reaction times are correlated and shape fluctuation scaling over a wide range of stimulus conditions. The scaling exponent was higher for achromatic than isoluminant stimuli, suggesting distinct generative mechanisms. Our findings open a new perspective for studying failure modes in sensory-motor communications and in complex networks.

  10. Absolute concentrations of highly vibrationally excited OH(υ = 9 + 8) in the mesopause region derived from the TIMED/SABER instrument

    NASA Astrophysics Data System (ADS)

    Mast, Jeffrey; Mlynczak, Martin G.; Hunt, Linda A.; Marshall, B. Thomas; Mertens, Christoper J.; Russell, James M.; Thompson, R. Earl; Gordley, Larry L.

    2013-02-01

    Abstract <span class="hlt">Absolute</span> concentrations (cm-3) of highly vibrationally excited hydroxyl (OH) are derived from measurements of the volume emission rate of the υ = 9 + 8 states of the OH radical made by the SABER instrument on the <span class="hlt">TIMED</span> satellite. SABER has exceptionally sensitive measurement precision that corresponds to an ability to detect changes in volume emission rate on the order of ~5 excited OH molecules per cm3. Peak zonal annual mean concentrations observed by SABER exceed 1000 cm-3 at night and 225 cm-3 during the day. Measurements since 2002 show an apparent altitude-dependent variation of the night OH(υ = 9 + 8) concentrations with the 11 year solar cycle, with concentrations decreasing below ~ 95 km from 2002 to 2008. These observations provide a global database for evaluating photochemical model computations of OH abundance, reaction kinetics, and rates and mechanisms responsible for maintaining vibrationally excited OH in the mesopause region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812195W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812195W"><span id="translatedtitle">Continuous Gravity Monitoring in South America with Superconducting and <span class="hlt">Absolute</span> Gravimeters: More than 12 years <span class="hlt">time</span> series at station TIGO/Concepcion (Chile)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wziontek, Hartmut; Falk, Reinhard; Hase, Hayo; Armin, Böer; Andreas, Güntner; Rongjiang, Wang</p> <p>2016-04-01</p> <p>As part of the Transportable Integrated Geodetic Observatory (TIGO) of BKG, the superconducting gravimeter SG 038 was set up in December 2002 at station Concepcion / Chile to record temporal gravity variations with highest precision. Since May 2006 the <span class="hlt">time</span> series was supported by weekly observations with the <span class="hlt">absolute</span> gravimeter FG5-227, proving the large seasonal variations of up to 30 μGal and establishing a gravity reference station in South America. With the move of the whole observatory to the new location near to La Plata / Argentina the series was terminated. Results of almost continuously monitoring gravity variations for more than 12 years are presented. Seasonal variations are interpreted with respect of global and local water storage changes and the impact of the 8.8 Maule Earthquake in February 2010 is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17847309','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17847309"><span id="translatedtitle">Carbon-14 <span class="hlt">time</span> <span class="hlt">scale</span> extended: comparison of chronologies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grootes, P M</p> <p>1978-04-01</p> <p>Thermal diffusion isotopic enrichment of carbon-14 has extended the radiocarbon dating range to about 75,000 years ago. Twenty-eight samples obtained up to June 1976, mainly from northwest Europe, were dated. Consideration of the basic assumptions of carbon-14 dating and of the sources of contamination indicates that the ages are generally reliable. Together with the pollen analytic and stratigraphic the dates yield a more detailed radiocarbon <span class="hlt">time</span> <span class="hlt">scale</span> for climatic variations in northwest Europe, showing three early glacial interstades. The radiocarbon <span class="hlt">time</span> <span class="hlt">scale</span> agrees with the Camp Century chronology and with the thorium-230 ages of corals representing high sea level stands on New Guinea. Ther is a discrepancy between the radiocarbon <span class="hlt">time</span> <span class="hlt">scale</span> and the deep-sea chronology, which may be due to correlation errors. With a modified interpretation of the correlation, all four <span class="hlt">time</span> <span class="hlt">scales</span> agree within the estimated experimental uncertainties of the dating techniques used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.youtube.com/watch?v=Ao7gfoW4wkA','SCIGOVIMAGE-NASA'); return false;" href="http://www.youtube.com/watch?v=Ao7gfoW4wkA"><span id="translatedtitle">NEA Scout Solar Sail: Half-<span class="hlt">scale</span> Fold <span class="hlt">Time</span> Lapse</span></a></p> <p><a target="_blank" href="http://www.nasa.gov/multimedia/videogallery/index.html">NASA Video Gallery</a></p> <p></p> <p></p> <p>In this <span class="hlt">time</span> lapse, the Near-Earth Asteroid Scout (NEA Scout) CubeSat team rolls a half-<span class="hlt">scale</span> prototype of the small satellite's solar sail in preparation for a deployment test. During its mission,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ASPC..503..233C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ASPC..503..233C"><span id="translatedtitle">SkyProbe: Real-<span class="hlt">Time</span> Precision Monitoring in the Optical of the <span class="hlt">Absolute</span> Atmospheric Absorption on the Telescope Science and Calibration Fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cuillandre, J.-C.; Magnier, E.; Sabin, D.; Mahoney, B.</p> <p>2016-05-01</p> <p>Mauna Kea is known for its pristine seeing conditions but sky transparency can be an issue for science operations since at least 25% of the observable (i.e. open dome) nights are not photometric, an effect mostly due to high-altitude cirrus. Since 2001, the original single channel SkyProbe mounted in parallel on the Canada-France-Hawaii Telescope (CFHT) has gathered one V-band exposure every minute during each observing night using a small CCD camera offering a very wide field of view (35 sq. deg.) encompassing the region pointed by the telescope for science operations, and exposures long enough (40 seconds) to capture at least 100 stars of Hipparcos' Tycho catalog at high galactic latitudes (and up to 600 stars at low galactic latitudes). The measurement of the true atmospheric absorption is achieved within 2%, a key advantage over all-sky direct thermal infrared imaging detection of clouds. The <span class="hlt">absolute</span> measurement of the true atmospheric absorption by clouds and particulates affecting the data being gathered by the telescope's main science instrument has proven crucial for decision making in the CFHT queued service observing (QSO) representing today all of the telescope <span class="hlt">time</span>. Also, science exposures taken in non-photometric conditions are automatically registered for a new observation at a later date at 1/10th of the original exposure <span class="hlt">time</span> in photometric conditions to ensure a proper final <span class="hlt">absolute</span> photometric calibration. Photometric standards are observed only when conditions are reported as being perfectly stable by SkyProbe. The more recent dual color system (simultaneous B & V bands) will offer a better characterization of the sky properties above Mauna Kea and should enable a better detection of the thinnest cirrus (absorption down to 0.01 mag., or 1%).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26132165','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26132165"><span id="translatedtitle">Using a Novel <span class="hlt">Absolute</span> Ontogenetic Age Determination Technique to Calculate the <span class="hlt">Timing</span> of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wysocki, M Aleksander; Feranec, Robert S; Tseng, Zhijie Jack; Bjornsson, Christopher S</p> <p>2015-01-01</p> <p>Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates <span class="hlt">absolute</span> ontogenetic age ranges of tooth development and eruption in S. fatalis. The <span class="hlt">timing</span> of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for <span class="hlt">absolute</span> ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the <span class="hlt">timing</span> of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4489498','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4489498"><span id="translatedtitle">Using a Novel <span class="hlt">Absolute</span> Ontogenetic Age Determination Technique to Calculate the <span class="hlt">Timing</span> of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wysocki, M. Aleksander; Feranec, Robert S.; Tseng, Zhijie Jack; Bjornsson, Christopher S.</p> <p>2015-01-01</p> <p>Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates <span class="hlt">absolute</span> ontogenetic age ranges of tooth development and eruption in S. fatalis. The <span class="hlt">timing</span> of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for <span class="hlt">absolute</span> ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the <span class="hlt">timing</span> of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation. PMID:26132165</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030014976','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030014976"><span id="translatedtitle">Diffusion <span class="hlt">Time-Scale</span> of Porous Pressure-Sensitive Paint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liu, Tianshu; Teduka, Norikazu; Kameda, Masaharu; Asai, Keisuke</p> <p>2001-01-01</p> <p>Pressure-sensitive paint (PSP) is an optical pressure sensor that utilizes the oxygen quenching of luminescence. PSP measurements in unsteady aerodynamic flows require fast <span class="hlt">time</span> response of the paint. There are two characteristic <span class="hlt">time-scales</span> that are related to the <span class="hlt">time</span> response of PSP. One is the luminescent lifetime representing an intrinsic physical limit for the achievable temporal resolution of PSP. Another is the <span class="hlt">time-scale</span> of oxygen diffusion across the PSP layer. When the <span class="hlt">time-scale</span> of oxygen diffusion is much larger than the luminescent lifetime, the <span class="hlt">time</span> response of PSP is controlled by oxygen diffusion. In a thin homogenous polymer layer where diffusion is Fickian, the oxygen concentration 1021 can be described by the diffusion equation in one-dimension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21175685','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21175685"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> for point-defect equilibration in nanostructures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Millett, Paul C.; Wolf, Dieter; Desai, Tapan; Yamakov, Vesselin</p> <p>2008-10-20</p> <p>Molecular dynamics simulations of high-temperature annealing are performed on nanostructured materials enabling direct observation of vacancy emission from planar defects (i.e., grain boundaries and free surfaces) to populate the initially vacancy-free grain interiors on a subnanosecond <span class="hlt">time</span> <span class="hlt">scale</span>. We demonstrate a universal <span class="hlt">time</span>-length <span class="hlt">scale</span> correlation that governs these re-equilibration processes, suggesting that nanostructures are particularly stable against perturbations in their point-defect concentrations, caused for example by particle irradiation or temperature fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NJPh...12h3021N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NJPh...12h3021N"><span id="translatedtitle">Multi-<span class="hlt">scale</span> description and prediction of financial <span class="hlt">time</span> series</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nawroth, A. P.; Friedrich, R.; Peinke, J.</p> <p>2010-08-01</p> <p>A new method is proposed that allows a reconstruction of <span class="hlt">time</span> series based on higher order multi-<span class="hlt">scale</span> statistics given by a hierarchical process. This method is able to model financial <span class="hlt">time</span> series not only on a specific <span class="hlt">scale</span> but for a range of <span class="hlt">scales</span>. The method itself is based on the general n-<span class="hlt">scale</span> joint probability density, which can be extracted directly from given data. It is shown how based on this n-<span class="hlt">scale</span> statistics, general n-point probabilities can be estimated from which predictions can be achieved. Exemplary results are shown for the German DAX index. The ability to model correctly the behaviour of the original process for different <span class="hlt">scales</span> simultaneously and in <span class="hlt">time</span> is demonstrated. As a main result it is shown that this method is able to reproduce the known volatility cluster, although the model contains no explicit <span class="hlt">time</span> dependence. Thus a new mechanism is shown how, in a stationary multi-<span class="hlt">scale</span> process, volatility clustering can emerge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940026174','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940026174"><span id="translatedtitle">Russian national <span class="hlt">time</span> <span class="hlt">scale</span> long-term stability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Alshina, A. P.; Gaigerov, B. A.; Koshelyaevsky, N. B.; Pushkin, S. B.</p> <p>1994-01-01</p> <p>The Institute of Metrology for <span class="hlt">Time</span> and Space NPO 'VNIIFTRI' generates the National <span class="hlt">Time</span> <span class="hlt">Scale</span> (NTS) of Russia -- one of the most stable <span class="hlt">time</span> <span class="hlt">scales</span> in the world. Its striking feature is that it is based on a free ensemble of H-masers only. During last two years the estimations of NTS longterm stability based only on H-maser intercomparison data gives a flicker floor of about (2 to 3) x 10(exp -15) for averaging <span class="hlt">times</span> from 1 day to 1 month. Perhaps the most significant feature for a <span class="hlt">time</span> laboratory is an extremely low possible frequency drift -- it is too difficult to estimate it reliably. The other estimations, free from possible inside the ensemble correlation phenomena, are available based on the <span class="hlt">time</span> comparison of NTS relative to the stable enough <span class="hlt">time</span> <span class="hlt">scale</span> of outer laboratories. The data on NTS comparison relative to the <span class="hlt">time</span> <span class="hlt">scale</span> of secondary <span class="hlt">time</span> and frequency standards at Golitzino and Irkutsk in Russia and relative to NIST, PTB and USNO using GLONASS and GPS <span class="hlt">time</span> transfer links gives stability estimations which are close to that based on H-maser intercomparisons.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...766...96I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...766...96I"><span id="translatedtitle"><span class="hlt">Time</span>-average-based Methods for Multi-angular <span class="hlt">Scale</span> Analysis of Cosmic-Ray Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iuppa, R.; Di Sciascio, G.</p> <p>2013-04-01</p> <p>Over the past decade, a number of experiments dealt with the problem of measuring the arrival direction distribution of cosmic rays, looking for information on the propagation mechanisms and the identification of their sources. Any deviation from the isotropy may be regarded to as a signature of unforeseen or unknown phenomena, mostly if well localized in the sky and occurring at low rigidity. It induced experimenters to search for excesses down to angular <span class="hlt">scales</span> as narrow as 10°, disclosing the issue of properly filtering contributions from wider structures. A solution commonly envisaged was based on <span class="hlt">time</span>-average methods to determine the reference value of cosmic-ray flux. Such techniques are nearly insensitive to signals wider than the <span class="hlt">time</span> window in use, thus allowing us to focus the analysis on medium- and small-<span class="hlt">scale</span> signals. Nonetheless, the signal often cannot be excluded in the calculation of the reference value, which induces systematic errors. The use of <span class="hlt">time</span>-average methods recently revealed important discoveries about the medium-<span class="hlt">scale</span> cosmic-ray anisotropy, present both in the northern and southern hemispheres. It is known that the excess (or deficit) is observed as less intense than in reality and that fake deficit zones are rendered around true excesses because of the <span class="hlt">absolute</span> lack of knowledge a priori of which signal is true and which is not. This work is an attempt to critically review the use of <span class="hlt">time</span>-average-based methods for observing extended features in the cosmic-ray arrival distribution pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/003649.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/003649.htm"><span id="translatedtitle">Eosinophil count - <span class="hlt">absolute</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Eosinophils; <span class="hlt">Absolute</span> eosinophil count ... the white blood cell count to give the <span class="hlt">absolute</span> eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CNSNS..39..252O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CNSNS..39..252O"><span id="translatedtitle">Exponentials and Laplace transforms on nonuniform <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortigueira, Manuel D.; Torres, Delfim F. M.; Trujillo, Juan J.</p> <p>2016-10-01</p> <p>We formulate a coherent approach to signals and systems theory on <span class="hlt">time</span> <span class="hlt">scales</span>. The two derivatives from the <span class="hlt">time-scale</span> calculus are used, i.e., nabla (forward) and delta (backward), and the corresponding eigenfunctions, the so-called nabla and delta exponentials, computed. With these exponentials, two generalised discrete-<span class="hlt">time</span> Laplace transforms are deduced and their properties studied. These transforms are compatible with the standard Laplace and Z transforms. They are used to study discrete-<span class="hlt">time</span> linear systems defined by difference equations. These equations mimic the usual continuous-<span class="hlt">time</span> equations that are uniformly approximated when the sampling interval becomes small. Impulse response and transfer function notions are introduced. This implies a unified mathematical framework that allows us to approximate the classic continuous-<span class="hlt">time</span> case when the sampling rate is high or to obtain the standard discrete-<span class="hlt">time</span> case, based on difference equations, when the <span class="hlt">time</span> grid becomes uniform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJMPC..2750138G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJMPC..2750138G"><span id="translatedtitle">The <span class="hlt">scaling</span> of <span class="hlt">time</span> series size towards detrended fluctuation analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Xiaolei; Ren, Liwei; Shang, Pengjian; Feng, Guochen</p> <p>2016-06-01</p> <p>In this paper, we introduce a modification of detrended fluctuation analysis (DFA), called multivariate DFA (MNDFA) method, based on the <span class="hlt">scaling</span> of <span class="hlt">time</span> series size N. In traditional DFA method, we obtained the influence of the sequence segmentation interval s, and it inspires us to propose a new model MNDFA to discuss the <span class="hlt">scaling</span> of <span class="hlt">time</span> series size towards DFA. The effectiveness of the procedure is verified by numerical experiments with both artificial and stock returns series. Results show that the proposed MNDFA method contains more significant information of series compared to traditional DFA method. The <span class="hlt">scaling</span> of <span class="hlt">time</span> series size has an influence on the auto-correlation (AC) in <span class="hlt">time</span> series. For certain series, we obtain an exponential relationship, and also calculate the slope through the fitting function. Our analysis and finite-size effect test demonstrate that an appropriate choice of the <span class="hlt">time</span> series size can avoid unnecessary influences, and also make the testing results more accurate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..94c2316P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..94c2316P"><span id="translatedtitle">Controllability of multiplex, multi-<span class="hlt">time-scale</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pósfai, Márton; Gao, Jianxi; Cornelius, Sean P.; Barabási, Albert-László; D'Souza, Raissa M.</p> <p>2016-09-01</p> <p>The paradigm of layered networks is used to describe many real-world systems, from biological networks to social organizations and transportation systems. While recently there has been much progress in understanding the general properties of multilayer networks, our understanding of how to control such systems remains limited. One fundamental aspect that makes this endeavor challenging is that each layer can operate at a different <span class="hlt">time</span> <span class="hlt">scale</span>; thus, we cannot directly apply standard ideas from structural control theory of individual networks. Here we address the problem of controlling multilayer and multi-<span class="hlt">time-scale</span> networks focusing on two-layer multiplex networks with one-to-one interlayer coupling. We investigate the practically relevant case when the control signal is applied to the nodes of one layer. We develop a theory based on disjoint path covers to determine the minimum number of inputs (Ni) necessary for full control. We show that if both layers operate on the same <span class="hlt">time</span> <span class="hlt">scale</span>, then the network structure of both layers equally affect controllability. In the presence of <span class="hlt">time-scale</span> separation, controllability is enhanced if the controller interacts with the faster layer: Ni decreases as the <span class="hlt">time-scale</span> difference increases up to a critical <span class="hlt">time-scale</span> difference, above which Ni remains constant and is completely determined by the faster layer. We show that the critical <span class="hlt">time-scale</span> difference is large if layer I is easy and layer II is hard to control in isolation. In contrast, control becomes increasingly difficult if the controller interacts with the layer operating on the slower <span class="hlt">time</span> <span class="hlt">scale</span> and increasing <span class="hlt">time-scale</span> separation leads to increased Ni, again up to a critical value, above which Ni still depends on the structure of both layers. This critical value is largely determined by the longest path in the faster layer that does not involve cycles. By identifying the underlying mechanisms that connect <span class="hlt">time-scale</span> difference and controllability for a simplified</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGP42A..01M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGP42A..01M"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> construction from multiple sources of information (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malinverno, A.</p> <p>2013-12-01</p> <p>Geological age estimates are provided by diverse chronometers, such as radiometric measurements, astrochronology, and the spacing of magnetic anomalies recorded on mid-ocean ridges by seafloor spreading. These age estimates are affected by errors that can be systematic (e.g., biased radiometric dates due to imperfect assumptions) or random (e.g., imprecise recording of astronomical cycles in sedimentary records). Whereas systematic errors can be reduced by improvements in technique and calibration, uncertainties due to random errors will always be present and need to be dealt with. A Bayesian framework can be used to construct an integrated <span class="hlt">time</span> <span class="hlt">scale</span> that is based on several uncertain sources of information. In this framework, each piece of data and the final <span class="hlt">time</span> <span class="hlt">scale</span> have an associated probability distribution that describes their uncertainty. The key calculation is to determine the uncertainty in the <span class="hlt">time</span> <span class="hlt">scale</span> from the uncertain data that constrain it. In practice, this calculation can be performed by Monte Carlo sampling. In Markov chain Monte Carlo algorithms, the <span class="hlt">time</span> <span class="hlt">scale</span> is iteratively perturbed and the perturbed <span class="hlt">time</span> <span class="hlt">scale</span> is accepted or rejected depending on how closely it fits the data. The final result is a large ensemble of possible <span class="hlt">time</span> <span class="hlt">scales</span> that are consistent with all the uncertain data; while the average of this ensemble defines a 'best' <span class="hlt">time</span> <span class="hlt">scale</span>, the ensemble variability quantifies the <span class="hlt">time</span> <span class="hlt">scale</span> uncertainty. An example of this approach is the M-sequence (Late Jurassic-Early Cretaceous, ~160-120 Ma) MHTC12 geomagnetic polarity <span class="hlt">time</span> <span class="hlt">scale</span> (GPTS) of Malinverno et al. (2012, J. Geophys. Res., B06104, doi:10.1029/2012JB009260). Previous GPTSs were constructed by interpolating between dated marine magnetic anomalies while assuming constant or smoothly varying spreading rates. These GPTSs were typically based on magnetic lineations from one or a few selected spreading centers, and an undesirable result is that they imply larger spreading rate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhPl....8..321Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhPl....8..321Z"><span id="translatedtitle">Slow-<span class="hlt">time-scale</span> magnetic fields driven by fast-<span class="hlt">time-scale</span> waves in an underdense relativistic Vlasov plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Shao-ping; He, X. T.; Zheng, C. Y.</p> <p>2001-01-01</p> <p>Slow-<span class="hlt">time-scale</span> magnetic fields driven by fast-<span class="hlt">time-scale</span> electromagnetic waves or plasma waves are examined from the perspective of the Vlasov-Maxwell equations for a relativistic Vlasov plasma. An equation for slow-<span class="hlt">time-scale</span> magnetic field is obtained. The field proposed in the present paper is a result of wave-wave beating which drives a solenoidal current. The magnitude of the slow-<span class="hlt">time-scale</span> magnetic field proposed here can be as high as 20 MG at the critical surface for a laser intensity I=1018W/cm2 at wavelength λ0=1.05 μm. The predicted magnetic field is observed in two-dimensional particle simulations presented here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040089217&hterms=analysis+gait&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Danalysis%2Bgait','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040089217&hterms=analysis+gait&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Danalysis%2Bgait"><span id="translatedtitle">Multiple-<span class="hlt">time</span> <span class="hlt">scales</span> analysis of physiological <span class="hlt">time</span> series under neural control</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peng, C. K.; Hausdorff, J. M.; Havlin, S.; Mietus, J. E.; Stanley, H. E.; Goldberger, A. L.</p> <p>1998-01-01</p> <p>We discuss multiple-<span class="hlt">time</span> <span class="hlt">scale</span> properties of neurophysiological control mechanisms, using heart rate and gait regulation as model systems. We find that <span class="hlt">scaling</span> exponents can be used as prognostic indicators. Furthermore, detection of more subtle degradation of <span class="hlt">scaling</span> properties may provide a novel early warning system in subjects with a variety of pathologies including those at high risk of sudden death.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFMSA41A1834M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFMSA41A1834M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Absolute</span> Populations of Highly Vibrationally Excited OH(υ=8 + υ=9) in the Night Mesopause Region Derived from the <span class="hlt">TIMED</span>/SABER Instrument from 2002 to 2010</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mast, J. C.; Mlynczak, M. G.; Marshall, B. T.; Thompson, R. E.; Mertens, C. J.; Hunt, L. A.; Russell, J. M.; Gordley, L. L.</p> <p>2011-12-01</p> <p>We present global distributions of v = 9 + v = 8 nighttime vibrationally excited hydroxyl concentrations as measured by the SABER instrument on board the <span class="hlt">TIMED</span> spacecraft. These states are formed directly by the reaction of atomic hydrogen and ozone in the terrestrial mesopause region. SABER measures the limb radiance from the delta-v = 2 transitions in a channel centered near 2.0 um, specifically the sum of the 9 -> 7 and 8 -> 6 transitions. The limb radiances are inverted to yield the volume emission rates from the sum of the v = 8 and 9 states of the hydroxyl molecule. The Einstein coefficients for spontaneous emission for these two transitions are essentially identical. Thus dividing the derived volume emission rate by the Einstein coefficient yields the <span class="hlt">absolute</span> populations of these states (molecules per cubic cm). Nine full years of data are presented in this paper. Over this <span class="hlt">time</span> the globally averaged OH(v = 8 + v = 9) populations have varied relative to the nine year mean by only a few percent. We conclude that despite substantial solar variability over this <span class="hlt">time</span> period, the apparently small variation of the highly vibrationally excited hydroxyl populations implies that atomic hydrogen, atomic oxygen, temperature, and density adjust in such a way so as to keep the product of the atomic hydrogen concentration, the ozone concentration, and the rate coefficient for their reaction essentially constant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5052011','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5052011"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> bias in erosion rates of glaciated landscapes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ganti, Vamsi; von Hagke, Christoph; Scherler, Dirk; Lamb, Michael P.; Fischer, Woodward W.; Avouac, Jean-Philippe</p> <p>2016-01-01</p> <p>Deciphering erosion rates over geologic <span class="hlt">time</span> is fundamental for understanding the interplay between climate, tectonic, and erosional processes. Existing techniques integrate erosion over different <span class="hlt">time</span> <span class="hlt">scales</span>, and direct comparison of such rates is routinely done in earth science. On the basis of a global compilation, we show that erosion rate estimates in glaciated landscapes may be affected by a systematic averaging bias that produces higher estimated erosion rates toward the present, which do not reflect straightforward changes in erosion rates through <span class="hlt">time</span>. This trend can result from a heavy-tailed distribution of erosional hiatuses (that is, <span class="hlt">time</span> periods where no or relatively slow erosion occurs). We argue that such a distribution can result from the intermittency of erosional processes in glaciated landscapes that are tightly coupled to climate variability from decadal to millennial <span class="hlt">time</span> <span class="hlt">scales</span>. In contrast, we find no evidence for a <span class="hlt">time</span> <span class="hlt">scale</span> bias in spatially averaged erosion rates of landscapes dominated by river incision. We discuss the implications of our findings in the context of the proposed coupling between climate and tectonics, and interpreting erosion rate estimates with different averaging <span class="hlt">time</span> <span class="hlt">scales</span> through geologic <span class="hlt">time</span>. PMID:27713925</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/147864','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/147864"><span id="translatedtitle">Multiple <span class="hlt">time</span> <span class="hlt">scales</span> in the microwave ionization of Rydberg atoms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Buchleitner, A.; Delande, D.; Zakrzewski, J.; Mantegna, R.N.; Arndt, M.; Walther, H. ||||</p> <p>1995-11-20</p> <p>We investigate the <span class="hlt">time</span> dependence of the ionization probability of Rydberg atoms driven by microwave fields, both numerically and experimentally. Our exact quantum results provide evidence for an algebraic decay law on suitably chosen <span class="hlt">time</span> <span class="hlt">scales</span>, a phenomenon that is considered to be the signature of nonhyperbolic scattering in unbounded classically chaotic motion. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014RMxAC..43...29A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014RMxAC..43...29A"><span id="translatedtitle">Atomic <span class="hlt">Time</span> <span class="hlt">Scales</span> for the 21st Century</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arias, E. F.</p> <p>2014-06-01</p> <p>The International Bureau of Weights and Measures, in coordination with international organizations and national institutes, maintains and disseminates Coordinated Universal <span class="hlt">Time</span> (UTC). Other timescales exist for different purposes. This article describes the state-of-the-art in the elaboration of these <span class="hlt">time</span> <span class="hlt">scales</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020067784&hterms=equinox&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dequinox','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020067784&hterms=equinox&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dequinox"><span id="translatedtitle">Auroral Substorm <span class="hlt">Time</span> <span class="hlt">Scales</span>: Seasonal and IMF Variations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chua, D.; Parks, G. K.; Brittnacher, M.; Germany, G. A.; Spann, J. F.; Six, N. Frank (Technical Monitor)</p> <p>2002-01-01</p> <p>The <span class="hlt">time</span> <span class="hlt">scales</span> and phases of auroral substorm, activity are quantied in this study using the hemispheric power computed from Polar Ultraviolet Imager (UVI) images. We have applied this technique to several hundred substorm events and we are able to quantify how the characterist act, of substorms vary with season and IMF Bz orientation. We show that substorm <span class="hlt">time</span> <span class="hlt">scales</span> vary more strongly with season than with IMF Bz orientation. The recovery <span class="hlt">time</span> for substorm. activity is well ordered by whether or not the nightside oral zone is sunlit. The recovery <span class="hlt">time</span> <span class="hlt">scales</span> for substorms occurring in the winter and equinox periods are similar and are both roughly a factor of two longer than in summer when the auroral oval is sunlit. Our results support the hypothesis that the ionosphere plays an active role in governing the dynamics of the aurora.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=millimeter&pg=3&id=ED056088','ERIC'); return false;" href="http://eric.ed.gov/?q=millimeter&pg=3&id=ED056088"><span id="translatedtitle">Millimeter <span class="hlt">Scale</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Harvill, Leo M.</p> <p></p> <p>This <span class="hlt">absolute</span> <span class="hlt">scale</span> contains nine <span class="hlt">times</span>, each of which consists of a 100 millimeter vertical line with small division marks every 25 millimeters with the words "high" at the top and "low" at the bottom of the line. Above each of the vertical lines is a word or phrase. For the second grade <span class="hlt">scale</span> these words are: arithmetic, counting, adding,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24391935','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24391935"><span id="translatedtitle">Thermodynamics constrains allometric <span class="hlt">scaling</span> of optimal development <span class="hlt">time</span> in insects.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dillon, Michael E; Frazier, Melanie R</p> <p>2013-01-01</p> <p>Development <span class="hlt">time</span> is a critical life-history trait that has profound effects on organism fitness and on population growth rates. For ectotherms, development <span class="hlt">time</span> is strongly influenced by temperature and is predicted to <span class="hlt">scale</span> with body mass to the quarter power based on 1) the ontogenetic growth model of the metabolic theory of ecology which describes a bioenergetic balance between tissue maintenance and growth given the <span class="hlt">scaling</span> relationship between metabolism and body size, and 2) numerous studies, primarily of vertebrate endotherms, that largely support this prediction. However, few studies have investigated the allometry of development <span class="hlt">time</span> among invertebrates, including insects. Abundant data on development of diverse insects provides an ideal opportunity to better understand the <span class="hlt">scaling</span> of development <span class="hlt">time</span> in this ecologically and economically important group. Insects develop more quickly at warmer temperatures until reaching a minimum development <span class="hlt">time</span> at some optimal temperature, after which development slows. We evaluated the allometry of insect development <span class="hlt">time</span> by compiling estimates of minimum development <span class="hlt">time</span> and optimal developmental temperature for 361 insect species from 16 orders with body mass varying over nearly 6 orders of magnitude. Allometric <span class="hlt">scaling</span> exponents varied with the statistical approach: standardized major axis regression supported the predicted quarter-power <span class="hlt">scaling</span> relationship, but ordinary and phylogenetic generalized least squares did not. Regardless of the statistical approach, body size alone explained less than 28% of the variation in development <span class="hlt">time</span>. Models that also included optimal temperature explained over 50% of the variation in development <span class="hlt">time</span>. Warm-adapted insects developed more quickly, regardless of body size, supporting the "hotter is better" hypothesis that posits that ectotherms have a limited ability to evolutionarily compensate for the depressing effects of low temperatures on rates of biological processes. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3877264','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3877264"><span id="translatedtitle">Thermodynamics Constrains Allometric <span class="hlt">Scaling</span> of Optimal Development <span class="hlt">Time</span> in Insects</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dillon, Michael E.; Frazier, Melanie R.</p> <p>2013-01-01</p> <p>Development <span class="hlt">time</span> is a critical life-history trait that has profound effects on organism fitness and on population growth rates. For ectotherms, development <span class="hlt">time</span> is strongly influenced by temperature and is predicted to <span class="hlt">scale</span> with body mass to the quarter power based on 1) the ontogenetic growth model of the metabolic theory of ecology which describes a bioenergetic balance between tissue maintenance and growth given the <span class="hlt">scaling</span> relationship between metabolism and body size, and 2) numerous studies, primarily of vertebrate endotherms, that largely support this prediction. However, few studies have investigated the allometry of development <span class="hlt">time</span> among invertebrates, including insects. Abundant data on development of diverse insects provides an ideal opportunity to better understand the <span class="hlt">scaling</span> of development <span class="hlt">time</span> in this ecologically and economically important group. Insects develop more quickly at warmer temperatures until reaching a minimum development <span class="hlt">time</span> at some optimal temperature, after which development slows. We evaluated the allometry of insect development <span class="hlt">time</span> by compiling estimates of minimum development <span class="hlt">time</span> and optimal developmental temperature for 361 insect species from 16 orders with body mass varying over nearly 6 orders of magnitude. Allometric <span class="hlt">scaling</span> exponents varied with the statistical approach: standardized major axis regression supported the predicted quarter-power <span class="hlt">scaling</span> relationship, but ordinary and phylogenetic generalized least squares did not. Regardless of the statistical approach, body size alone explained less than 28% of the variation in development <span class="hlt">time</span>. Models that also included optimal temperature explained over 50% of the variation in development <span class="hlt">time</span>. Warm-adapted insects developed more quickly, regardless of body size, supporting the “hotter is better” hypothesis that posits that ectotherms have a limited ability to evolutionarily compensate for the depressing effects of low temperatures on rates of biological processes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040089149&hterms=Congestive+heart+failure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DCongestive%2Bheart%2Bfailure','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040089149&hterms=Congestive+heart+failure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DCongestive%2Bheart%2Bfailure"><span id="translatedtitle">Deviations from uniform power law <span class="hlt">scaling</span> in nonstationary <span class="hlt">time</span> series</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Viswanathan, G. M.; Peng, C. K.; Stanley, H. E.; Goldberger, A. L.</p> <p>1997-01-01</p> <p>A classic problem in physics is the analysis of highly nonstationary <span class="hlt">time</span> series that typically exhibit long-range correlations. Here we test the hypothesis that the <span class="hlt">scaling</span> properties of the dynamics of healthy physiological systems are more stable than those of pathological systems by studying beat-to-beat fluctuations in the human heart rate. We develop techniques based on the Fano factor and Allan factor functions, as well as on detrended fluctuation analysis, for quantifying deviations from uniform power-law <span class="hlt">scaling</span> in nonstationary <span class="hlt">time</span> series. By analyzing extremely long data sets of up to N = 10(5) beats for 11 healthy subjects, we find that the fluctuations in the heart rate <span class="hlt">scale</span> approximately uniformly over several temporal orders of magnitude. By contrast, we find that in data sets of comparable length for 14 subjects with heart disease, the fluctuations grow erratically, indicating a loss of <span class="hlt">scaling</span> stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhLA..377.1606B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhLA..377.1606B"><span id="translatedtitle">Physics in space-<span class="hlt">time</span> with <span class="hlt">scale</span>-dependent metrics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balankin, Alexander S.</p> <p>2013-10-01</p> <p>We construct three-dimensional space Rγ3 with the <span class="hlt">scale</span>-dependent metric and the corresponding Minkowski space-<span class="hlt">time</span> Mγ,β4 with the <span class="hlt">scale</span>-dependent fractal (DH) and spectral (DS) dimensions. The local derivatives based on <span class="hlt">scale</span>-dependent metrics are defined and differential vector calculus in Rγ3 is developed. We state that Mγ,β4 provides a unified phenomenological framework for dimensional flow observed in quite different models of quantum gravity. Nevertheless, the main attention is focused on the special case of flat space-<span class="hlt">time</span> M1/3,14 with the <span class="hlt">scale</span>-dependent Cantor-dust-like distribution of admissible states, such that DH increases from DH=2 on the <span class="hlt">scale</span> ≪ℓ0 to DH=4 in the infrared limit ≫ℓ0, where ℓ0 is the characteristic length (e.g. the Planck length, or characteristic size of multi-fractal features in heterogeneous medium), whereas DS≡4 in all <span class="hlt">scales</span>. Possible applications of approach based on the <span class="hlt">scale</span>-dependent metric to systems of different nature are briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8015S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8015S"><span id="translatedtitle">Segregation <span class="hlt">time-scales</span> in model granular flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Staron, Lydie; Phillips, Jeremy C.</p> <p>2016-04-01</p> <p>Segregation patterns in natural granular systems offer a singular picture of the systems evolution. In many cases, understanding segregation dynamics may help understanding the system's history as well as its future evolution. Among the key questions, one concerns the typical <span class="hlt">time-scales</span> at which segregation occurs. In this contribution, we present model granular flows simulated by means of the discrete Contact Dynamics method. The granular flows are bi-disperse, namely exhibiting two grain sizes. The flow composition and its dynamics are systematically varied, and the segregation dynamics carefully analyzed. We propose a physical model for the segregation that gives account of the observed dependence of segregation <span class="hlt">time</span> <span class="hlt">scales</span> on composition and dynamics. References L. Staron and J. C. Phillips, Stress partition and micro-structure in size-segregating granular flows, Phys. Rev. E 92 022210 (2015) L. Staron and J. C. Phillips, Segregation <span class="hlt">time-scales</span> in bi-disperse granular flows, Phys. Fluids 26 (3), 033302 (2014)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940026163','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940026163"><span id="translatedtitle">An algorithm for the Italian atomic <span class="hlt">time</span> <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cordara, F.; Vizio, G.; Tavella, P.; Pettiti, V.</p> <p>1994-01-01</p> <p>During the past twenty years, the <span class="hlt">time</span> <span class="hlt">scale</span> at the IEN has been realized by a commercial cesium clock, selected from an ensemble of five, whose rate has been continuously steered towards UTC to maintain a long term agreement within 3 x 10(exp -13). A <span class="hlt">time</span> <span class="hlt">scale</span> algorithm, suitable for a small clock ensemble and capable of improving the medium and long term stability of the IEN <span class="hlt">time</span> <span class="hlt">scale</span>, has been recently designed taking care of reducing the effects of the seasonal variations and the sudden frequency anomalies of the single cesium clocks. The new <span class="hlt">time</span> <span class="hlt">scale</span>, TA(IEN), is obtained as a weighted average of the clock ensemble computed once a day from the <span class="hlt">time</span> comparisons between the local reference UTC(IEN) and the single clocks. It is foreseen to include in the computation also ten cesium clocks maintained in other Italian laboratories to further improve its reliability and its long term stability. To implement this algorithm, a personal computer program in Quick Basic has been prepared and it has been tested at the IEN <span class="hlt">time</span> and frequency laboratory. Results obtained using this algorithm on the real clocks data relative to a period of about two years are presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4280174','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4280174"><span id="translatedtitle">Evaluation of <span class="hlt">Scaling</span> Invariance Embedded in Short <span class="hlt">Time</span> Series</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pan, Xue; Hou, Lei; Stephen, Mutua; Yang, Huijie; Zhu, Chenping</p> <p>2014-01-01</p> <p><span class="hlt">Scaling</span> invariance of <span class="hlt">time</span> series has been making great contributions in diverse research fields. But how to evaluate <span class="hlt">scaling</span> exponent from a real-world series is still an open problem. Finite length of <span class="hlt">time</span> series may induce unacceptable fluctuation and bias to statistical quantities and consequent invalidation of currently used standard methods. In this paper a new concept called correlation-dependent balanced estimation of diffusion entropy is developed to evaluate <span class="hlt">scale</span>-invariance in very short <span class="hlt">time</span> series with length . Calculations with specified Hurst exponent values of show that by using the standard central moving average de-trending procedure this method can evaluate the <span class="hlt">scaling</span> exponents for short <span class="hlt">time</span> series with ignorable bias () and sharp confidential interval (standard deviation ). Considering the stride series from ten volunteers along an approximate oval path of a specified length, we observe that though the averages and deviations of <span class="hlt">scaling</span> exponents are close, their evolutionary behaviors display rich patterns. It has potential use in analyzing physiological signals, detecting early warning signals, and so on. As an emphasis, the our core contribution is that by means of the proposed method one can estimate precisely shannon entropy from limited records. PMID:25549356</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25549356','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25549356"><span id="translatedtitle">Evaluation of <span class="hlt">scaling</span> invariance embedded in short <span class="hlt">time</span> series.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pan, Xue; Hou, Lei; Stephen, Mutua; Yang, Huijie; Zhu, Chenping</p> <p>2014-01-01</p> <p><span class="hlt">Scaling</span> invariance of <span class="hlt">time</span> series has been making great contributions in diverse research fields. But how to evaluate <span class="hlt">scaling</span> exponent from a real-world series is still an open problem. Finite length of <span class="hlt">time</span> series may induce unacceptable fluctuation and bias to statistical quantities and consequent invalidation of currently used standard methods. In this paper a new concept called correlation-dependent balanced estimation of diffusion entropy is developed to evaluate <span class="hlt">scale</span>-invariance in very short <span class="hlt">time</span> series with length ~10(2). Calculations with specified Hurst exponent values of 0.2,0.3,...,0.9 show that by using the standard central moving average de-trending procedure this method can evaluate the <span class="hlt">scaling</span> exponents for short <span class="hlt">time</span> series with ignorable bias (≤0.03) and sharp confidential interval (standard deviation ≤0.05). Considering the stride series from ten volunteers along an approximate oval path of a specified length, we observe that though the averages and deviations of <span class="hlt">scaling</span> exponents are close, their evolutionary behaviors display rich patterns. It has potential use in analyzing physiological signals, detecting early warning signals, and so on. As an emphasis, the our core contribution is that by means of the proposed method one can estimate precisely shannon entropy from limited records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.C4001G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.C4001G"><span id="translatedtitle">Going up in <span class="hlt">time</span> and length <span class="hlt">scales</span> in modeling polymers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grest, Gary S.</p> <p></p> <p>Polymer properties depend on a wide range of coupled length and <span class="hlt">time</span> <span class="hlt">scales</span>, with unique macroscopic viscoelastic behavior stemming from interactions at the atomistic level. The need to probe polymers across <span class="hlt">time</span> and length <span class="hlt">scales</span> and particularly computational modeling is inherently challenging. Here new paths to probing long <span class="hlt">time</span> and length <span class="hlt">scales</span> including introducing interactions into traditional bead-spring models and coarse graining of atomistic simulations will be compared and discussed. Using linear polyethylene as a model system, the degree of coarse graining with two to six methylene groups per coarse-grained bead derived from a fully atomistic melt simulation were probed. We show that the degree of coarse graining affects the measured dynamic. Using these models we were successful in probing highly entangled melts and were able reach the long-<span class="hlt">time</span> diffusive regime which is computationally inaccessible using atomistic simulations. We simulated the relaxation modulus and shear viscosity of well-entangled polyethylene melts for <span class="hlt">scaled</span> <span class="hlt">times</span> of 500 µs. Results for plateau modulus are in good agreement with experiment. The long <span class="hlt">time</span> and length <span class="hlt">scale</span> is coupled to the macroscopic viscoelasticity where the degree of coarse graining sets the minimum length <span class="hlt">scale</span> instrumental in defining polymer properties and dynamics. Results will be compared to those obtained from simple bead-spring models to demonstrate the additional insight that can be gained from atomistically inspired coarse grained models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3717360','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3717360"><span id="translatedtitle">Primary motor cortex reports efferent control of vibrissa motion on multiple <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hill, Daniel N.; Curtis, John C.; Moore, Jeffrey D.; Kleinfeld, David</p> <p>2011-01-01</p> <p>Exploratory whisking in rat is an example of self-generated movement on multiple <span class="hlt">time</span> <span class="hlt">scales</span>, from slow variations in the envelope of whisking to the rapid sequence of muscle contractions during a single whisk cycle. We find that, as a population, spike trains of single units in primary vibrissa motor cortex report the <span class="hlt">absolute</span> angle of vibrissa position. This representation persists after sensory nerve transection, indicating an efferent source. About two-thirds of the units are modulated by slow variations in the envelope of whisking while relatively few units report rapid changes in position within the whisk cycle. The combined results from this study and past measurements, which show that primary sensory cortex codes the whisking envelope as a motor copy signal, imply that signals present in both sensory and motor cortices are necessary to compute coordinates based on vibrissa touch. PMID:22017992</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19760052971&hterms=Reaction+time&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DReaction%2Btime','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19760052971&hterms=Reaction+time&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DReaction%2Btime"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scales</span> for molecule formation by ion-molecule reactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Langer, W. D.; Glassgold, A. E.</p> <p>1976-01-01</p> <p>Analytical solutions are obtained for nonlinear differential equations governing the <span class="hlt">time</span>-dependence of molecular abundances in interstellar clouds. Three gas-phase reaction schemes are considered separately for the regions where each dominates. The particular case of CO, and closely related members of the Oh and CH families of molecules, is studied for given values of temperature, density, and the radiation field. Nonlinear effects and couplings with particular ions are found to be important. The <span class="hlt">time</span> <span class="hlt">scales</span> for CO formation range from 100,000 to a few million years, depending on the chemistry and regime. The <span class="hlt">time</span> required for essentially complete conversion of C(+) to CO in the region where the H3(+) chemistry dominates is several million years. Because this <span class="hlt">time</span> is longer than or comparable to dynamical <span class="hlt">time</span> <span class="hlt">scales</span> for dense interstellar clouds, steady-state abundances may not be observed in such clouds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyA..428..295S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyA..428..295S"><span id="translatedtitle">Memory on multiple <span class="hlt">time-scales</span> in an Abelian sandpile</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sokolov, Andrey; Melatos, Andrew; Kieu, Tien; Webster, Rachel</p> <p>2015-06-01</p> <p>We report results of a numerical analysis of the memory effects in two-dimensional Abelian sandpiles. It is found that a sandpile forgets its instantaneous configuration in two distinct stages: a fast stage and a slow stage, whose durations roughly <span class="hlt">scale</span> as N and N2 respectively, where N is the linear size of the sandpile. We confirm the presence of the longer <span class="hlt">time-scale</span> by an independent diagnostic based on analysing emission probabilities of a hidden Markov model applied to a <span class="hlt">time</span>-averaged sequence of avalanche sizes. The application of hidden Markov modelling to the output of sandpiles is novel. It discriminates effectively between a sandpile <span class="hlt">time</span> series and a shuffled control <span class="hlt">time</span> series with the same <span class="hlt">time</span>-averaged event statistics and hence deserves further development as a pattern-recognition tool for Abelian sandpiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AAS...21544105R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AAS...21544105R"><span id="translatedtitle">The Galaxy Viewed at Very Short <span class="hlt">Time-Scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Radnia, Navid; Siegmund, O.; Welsh, B.; Mcphate, J.; Rogers, D.; Charles, P.; Buckley, D.</p> <p>2010-01-01</p> <p>We present high <span class="hlt">time</span>-resolution astronomical observations recorded with the Berkeley Visible Image Tube (BVIT) photon counting detector mounted on the 10m South African Large Telescope (SALT). Relative B and V-band photometric fluxes were obtained as a function of <span class="hlt">time</span> for targets that included Polar-type cataclysmic variables (UZ For, OY Car, V1033Cen), low-mass X-ray binaries (GX 339-4, UY Vol), pulsars (PSR 0540-69), dMe flare stars (CN Leo) and active galactic nucleii (Mkn 618). These observations, which were recorded during several nights of engineering <span class="hlt">time</span> at SALT in early 2009, indicate that there are many types of astrophysical processes operating over very short <span class="hlt">time-scales</span> in a wide variety of astronomical objects. The high-<span class="hlt">time</span> resolution capability of the BVIT detector allowed emission features occurring on <span class="hlt">time-scales</span> as short as tens of milli-seconds to be revealed. In particular, we have measured the optical period of the PSR 0540-69 pulsar to be 0.05065018808s and we have also detected several quasi-periodic oscillations operating on <span class="hlt">time-scales</span> of < 0.5 s in the emitted flux from the X-ray transient source, GX 339-4. These preliminary data indicate that the new field of high <span class="hlt">time</span>-resolution astronomy is providing important new insights into the transient nature of the Universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27300902','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27300902"><span id="translatedtitle">Renormalized <span class="hlt">time</span> <span class="hlt">scale</span> for anticipating and lagging synchronization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hayashi, Yoshikatsu; Nasuto, Slawomir J; Eberle, Henry</p> <p>2016-05-01</p> <p>Anticipating synchronization has been recently proposed as a mechanism of interaction in dynamical systems which are able to bring about predictions of future states of a driver system. We suggest that an interesting insight into anticipating synchronization can be obtained by the renormalization of the <span class="hlt">time</span> <span class="hlt">scale</span> in the driven system. Our approach directly links the feedback delay of the driven system with the renormalized <span class="hlt">time</span> <span class="hlt">scale</span> of the driven system, identifying the main component in the anticipating synchronization paradigm and suggesting an alternative method to generate anticipating and lagging synchronization. PMID:27300902</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22250779','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22250779"><span id="translatedtitle">Dynamics symmetries of Hamiltonian system on <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Peng, Keke Luo, Yiping</p> <p>2014-04-15</p> <p>In this paper, the dynamics symmetries of Hamiltonian system on <span class="hlt">time</span> <span class="hlt">scales</span> are studied. We study the symmetries and quantities based on the calculation of variation and Lie transformation group. Particular focus lies in: the Noether symmetry leads to the Noether conserved quantity and the Lie symmetry leads to the Noether conserved quantity if the infinitesimal transformations satisfy the structure equation. As the new application of result, at end of the article, we give a simple example of Noether symmetry and Lie symmetry on <span class="hlt">time</span> <span class="hlt">scales</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARY23011H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARY23011H"><span id="translatedtitle">Temperature sensing and real-<span class="hlt">time</span> two-dimensional mapping at the micro-<span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huo, Xiaoye; Li, Gang; Wang, Zhenhai; Mao, Xinyu; Xu, Shengyong</p> <p></p> <p>To sense temperature at micro/nano <span class="hlt">scales</span> and obtain its detailed distribution in space and in <span class="hlt">time</span> remains a technical challenge in many cases. We observed an unexpected thermoelectric size effect, where the <span class="hlt">absolute</span> Seebeck coefficient of metallic thin film stripes (e.g. Ni, Cr, Pd, W, Bi, Sc, etc.) decreased with the stripe width from 100 μm down to 100nm. This phenomenon was utilized in micro/nano-stripe-based thin film temperature sensors. By using an array of such sensors, two-dimensional temperature distribution at the micro-<span class="hlt">scale</span> could be precisely mapped. Small temperature sensors with a total width less than 1 μm and a sensitivity of 0.5-2.2 μV/K were fabricated, showing a potential for monitoring temperatures at submicro-<span class="hlt">scales</span>. By using a special multiplexer and software, nearly real-<span class="hlt">time</span> 2D temperature mapping was performed, demonstrating 2D thermal history of target surface with a delay of less than one minute. These thin film sensors were also fabricated on flexible Parylene-C substrates for application in flexible electronic devices, temperature monitoring of cell culturing, and heat transfer between Au nanoparticles and metallic stripes due to plasmonic excitation under laser radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27475291','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27475291"><span id="translatedtitle">Midfrontal theta tracks action monitoring over multiple interactive <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cohen, Michael X</p> <p>2016-11-01</p> <p>Quickly detecting and correcting mistakes is a crucial brain function. EEG studies have identified an idiosyncratic electrophysiological signature of online error correction, termed midfrontal theta. Midfrontal theta has so far been investigated over the fast <span class="hlt">time-scale</span> of a few hundred milliseconds. But several aspects of behavior and brain activity unfold over multiple <span class="hlt">time</span> <span class="hlt">scales</span>, displaying "<span class="hlt">scale</span>-free" dynamics that have been linked to criticality and optimal flexibility when responding to changing environmental demands. Here we used a novel line-tracking task to demonstrate that midfrontal theta is a transient yet non-phase-locked response that is modulated by task performance over at least three <span class="hlt">time</span> <span class="hlt">scales</span>: a few hundred milliseconds at the onset of a mistake, task performance over a fixed window of the previous 5s, and <span class="hlt">scale</span>-free-like fluctuations over many tens of seconds. These findings provide novel evidence for a role of midfrontal theta in online behavioral adaptation, and suggest new approaches for linking EEG signatures of human executive functioning to its neurobiological underpinnings. PMID:27475291</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27475291','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27475291"><span id="translatedtitle">Midfrontal theta tracks action monitoring over multiple interactive <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cohen, Michael X</p> <p>2016-11-01</p> <p>Quickly detecting and correcting mistakes is a crucial brain function. EEG studies have identified an idiosyncratic electrophysiological signature of online error correction, termed midfrontal theta. Midfrontal theta has so far been investigated over the fast <span class="hlt">time-scale</span> of a few hundred milliseconds. But several aspects of behavior and brain activity unfold over multiple <span class="hlt">time</span> <span class="hlt">scales</span>, displaying "<span class="hlt">scale</span>-free" dynamics that have been linked to criticality and optimal flexibility when responding to changing environmental demands. Here we used a novel line-tracking task to demonstrate that midfrontal theta is a transient yet non-phase-locked response that is modulated by task performance over at least three <span class="hlt">time</span> <span class="hlt">scales</span>: a few hundred milliseconds at the onset of a mistake, task performance over a fixed window of the previous 5s, and <span class="hlt">scale</span>-free-like fluctuations over many tens of seconds. These findings provide novel evidence for a role of midfrontal theta in online behavioral adaptation, and suggest new approaches for linking EEG signatures of human executive functioning to its neurobiological underpinnings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T13A2965T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T13A2965T"><span id="translatedtitle">The Application of Optimisation Methods to Constrain <span class="hlt">Absolute</span> Plate Motions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tetley, M. G.; Williams, S.; Hardy, S.; Müller, D.</p> <p>2015-12-01</p> <p>Plate tectonic reconstructions are an excellent tool for understanding the configuration and behaviour of continents through <span class="hlt">time</span> on both global and regional <span class="hlt">scales</span>, and are relatively well understood back to ~200 Ma. However, many of these models represent only relative motions between continents, providing little information of <span class="hlt">absolute</span> tectonic motions and their relationship with the deep Earth. Significant issues exist in solving this problem, including how to combine constraints from multiple, diverse data into a unified model of <span class="hlt">absolute</span> plate motions; and how to address uncertainties both in the available data, and in the assumptions involved in this process (e.g. hotspot motion, true polar wander). In deep <span class="hlt">time</span> (pre-Pangea breakup), plate reconstructions rely more heavily on paleomagnetism, but these data often imply plate velocities much larger than those observed since the breakup of the supercontinent Pangea where plate velocities are constrained by the seafloor spreading record. Here we present two complementary techniques to address these issues, applying parallelized numerical methods to quantitatively investigate <span class="hlt">absolute</span> plate motions through <span class="hlt">time</span>. Firstly, we develop a data-fit optimized global <span class="hlt">absolute</span> reference frame constrained by kinematic reconstruction data, hotspot-trail observations, and trench migration statistics. Secondly we calculate optimized paleomagnetic data-derived apparent polar wander paths (APWPs) for both the Phanerozoic and Precambrian. Paths are generated from raw pole data with optimal spatial and temporal pole configurations calculated using all known uncertainties and quality criteria to produce velocity-optimized <span class="hlt">absolute</span> motion paths through deep <span class="hlt">time</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27314723','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27314723"><span id="translatedtitle">Separation of <span class="hlt">Time</span> <span class="hlt">Scales</span> in a Quantum Newton's Cradle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van den Berg, R; Wouters, B; Eliëns, S; De Nardis, J; Konik, R M; Caux, J-S</p> <p>2016-06-01</p> <p>We provide detailed modeling of the Bragg pulse used in quantum Newton's-cradle-like settings or in Bragg spectroscopy experiments for strongly repulsive bosons in one dimension. We reconstruct the postpulse <span class="hlt">time</span> evolution and study the <span class="hlt">time</span>-dependent local density profile and momentum distribution by a combination of exact techniques. We further provide a variety of results for finite interaction strengths using a <span class="hlt">time</span>-dependent Hartree-Fock analysis and bosonization-refermionization techniques. Our results display a clear separation of <span class="hlt">time</span> <span class="hlt">scales</span> between rapid and trap-insensitive relaxation immediately after the pulse, followed by slow in-trap periodic behavior. PMID:27314723</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4225W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4225W"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">Scale</span> Calculus - a new perspectives for synthetic seismogram calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waskiewicz, Kamil; Debski, Wojciech</p> <p>2013-04-01</p> <p>Synthetic, numerically generated seismograms are one of the key factors of any interpretation of recorded seismic data. At the early stage of development, calculation of full seismic waveforms was impossible due to a limited computational resource so we were forced to used only some selected characteristics of seismic waves relatively easy for numerical calculations like first arrival <span class="hlt">times</span>, maximum amplitude, approximate source spectra, to name a few. Continues development of computational resources as well as progress in numerical techniques has opened possibilities of generation the full, 3-component seismograms incorporating many physically important elements like wave attenuation, anisotropy or randomness of the media. Although achieved results are impressive we still need new numerical methods to tackle existing problems with the synthetic seismogram generation. In this contribution we present a novel approach to discretization of the wave equation which brings together continues and discrete numerical analysis of the seismic waves. The foundations of this new technique, called <span class="hlt">Time</span> <span class="hlt">Scale</span> Calculus, have been formulated by Hilger in late eighties and is very dynamically developing. The <span class="hlt">Time</span> <span class="hlt">scale</span> calculus, due to its universality seems to have a great potential when practical applications are considered. Thus we have decided to bring the <span class="hlt">Time</span> <span class="hlt">Scale</span> calculus concept closer to geophysical, or more precisely to seismological applications. This presentation is intend as a basic introduction to the <span class="hlt">time</span> <span class="hlt">scales</span> calculus considered from seismological point of view. We shortly present and discuss the possibility of using the <span class="hlt">Time</span> <span class="hlt">Scales</span> (TS) technique for solving the simplest acoustic 2D wave equation keeping in mind its particular applications for mining induced seismicity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AcGeo..62.1127N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AcGeo..62.1127N"><span id="translatedtitle">Separation of <span class="hlt">time</span> <span class="hlt">scales</span> in the HCA model for sand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niemunis, Andrzej; Wichtmann, Torsten</p> <p>2014-10-01</p> <p>Separation of <span class="hlt">time</span> <span class="hlt">scales</span> is used in a high cycle accumulation (HCA) model for sand. An important difficulty of the model is the limited applicability of the Miner's rule to multiaxial cyclic loadings applied simultaneously or in a combination with monotonic loading. Another problem is the lack of simplified objective HCA formulas for geotechnical settlement problems. Possible solutions of these problems are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=compensation&id=EJ1034629','ERIC'); return false;" href="http://eric.ed.gov/?q=compensation&id=EJ1034629"><span id="translatedtitle">Speech Compensation for <span class="hlt">Time-Scale</span>-Modified Auditory Feedback</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ogane, Rintaro; Honda, Masaaki</p> <p>2014-01-01</p> <p>Purpose: The purpose of this study was to examine speech compensation in response to <span class="hlt">time-scale</span>-modified auditory feedback during the transition of the semivowel for a target utterance of /ija/. Method: Each utterance session consisted of 10 control trials in the normal feedback condition followed by 20 perturbed trials in the modified auditory…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JMAA..331..913S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JMAA..331..913S"><span id="translatedtitle">Maximum principles for second order dynamic equations on <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stehlik, Petr; Thompson, Bevan</p> <p>2007-07-01</p> <p>This paper establishes some new maximum principles for second order dynamic equations on <span class="hlt">time</span> <span class="hlt">scales</span>, including: a strong maximum principle; a generalized maximum principle; and a boundary point lemma. The new results include, as special cases, well-known ideas for ordinary differential equations and difference equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhRvL..84.1074B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhRvL..84.1074B"><span id="translatedtitle">Gott <span class="hlt">Time</span> Machines, BTZ Black Hole Formation, and Choptuik <span class="hlt">Scaling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Birmingham, Danny; Sen, Siddhartha</p> <p>2000-02-01</p> <p>We study the formation of Bañados-Teitelboim-Zanelli black holes by the collision of point particles. It is shown that the Gott <span class="hlt">time</span> machine, originally constructed for the case of vanishing cosmological constant, provides a precise mechanism for black hole formation. As a result, one obtains an exact analytic understanding of the Choptuik <span class="hlt">scaling</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910016453&hterms=definition+time&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddefinition%2Btime','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910016453&hterms=definition+time&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddefinition%2Btime"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> algorithm: Definition of ensemble <span class="hlt">time</span> and possible uses of the Kalman filter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tavella, Patrizia; Thomas, Claudine</p> <p>1990-01-01</p> <p>The comparative study of two <span class="hlt">time</span> <span class="hlt">scale</span> algorithms, devised to satisfy different but related requirements, is presented. They are ALGOS(BIPM), producing the international reference TAI at the Bureau International des Poids et Mesures, and AT1(NIST), generating the real-<span class="hlt">time</span> <span class="hlt">time</span> <span class="hlt">scale</span> AT1 at the National Institute of Standards and Technology. In each case, the <span class="hlt">time</span> <span class="hlt">scale</span> is a weighted average of clock readings, but the weight determination and the frequency prediction are different because they are adapted to different purposes. The possibility of using a mathematical tool, such as the Kalman filter, together with the definition of the <span class="hlt">time</span> <span class="hlt">scale</span> as a weighted average, is also analyzed. Results obtained by simulation are presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3982793','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3982793"><span id="translatedtitle">THEORETICAL REVIEW The Hippocampus, <span class="hlt">Time</span>, and Memory Across <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Howard, Marc W.; Eichenbaum, Howard</p> <p>2014-01-01</p> <p>A wealth of experimental studies with animals have offered insights about how neural networks within the hippocampus support the temporal organization of memories. These studies have revealed the existence of “<span class="hlt">time</span> cells” that encode moments in <span class="hlt">time</span>, much as the well-known “place cells” map locations in space. Another line of work inspired by human behavioral studies suggests that episodic memories are mediated by a state of temporal context that changes gradually over long <span class="hlt">time</span> <span class="hlt">scales</span>, up to at least a few thousand seconds. In this view, the “mental <span class="hlt">time</span> travel” hypothesized to support the experience of episodic memory corresponds to a “jump back in time” in which a previous state of temporal context is recovered. We suggest that these 2 sets of findings could be different facets of a representation of temporal history that maintains a record at the last few thousand seconds of experience. The ability to represent long <span class="hlt">time</span> <span class="hlt">scales</span> comes at the cost of discarding precise information about when a stimulus was experienced—this uncertainty becomes greater for events further in the past. We review recent computational work that describes a mechanism that could construct such a <span class="hlt">scale</span>-invariant representation. Taken as a whole, this suggests the hippocampus plays its role in multiple aspects of cognition by representing events embedded in a general spatiotemporal context. The representation of internal <span class="hlt">time</span> can be useful across nonhippocampal memory systems. PMID:23915126</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511365B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511365B"><span id="translatedtitle">Characterization of a binary karst aquifer using process <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Birk, Steffen; Wagner, Thomas</p> <p>2013-04-01</p> <p>Within "a theoretical framework for the interpretation of karst spring signals" (Covington, EGU2012-853-1) process length <span class="hlt">scales</span> that characterize the travel distances required for damping pulses of physicochemical parameters of spring waters such as electrical conductivity and temperature were derived (Covington et al., J. Geophys. Res., 2012). These length <span class="hlt">scales</span> can be converted to corresponding process <span class="hlt">time</span> <span class="hlt">scales</span> characterizing the travel <span class="hlt">times</span> needed for damping the pulses. This is particularly convenient if the travel distance is unknown. In this case the <span class="hlt">time</span> lag between the increase of spring discharge and subsequent physicochemical responses at the spring may provide an estimate of the travel <span class="hlt">time</span>. In binary karst aquifers with localized recharge from a sinking stream, the recharge pulse can be directly observed and thus travel <span class="hlt">times</span> are readily obtained from the <span class="hlt">time</span> delay of the physicochemical spring responses. If the spring response is strongly damped travel <span class="hlt">times</span> can be inferred from artificial tracer testing. In this work, <span class="hlt">time</span> <span class="hlt">scales</span> for carbonate dissolution and heat transport were used for characterizing the binary Lurbach-Tanneben karst aquifer (Austria). This aquifer receives allogenic recharge from the sinking stream Lurbach and is drained by two springs, namely the Hammerbach and the Schmelzbach. The two springs show different thermal responses to two recharge events in December 2008: Whereas the temperature of the Schmelzbach responds within one day after the flood pulse in the Lurbach, the temperature signal is strongly damped at the Hammerbach. The evaluation based on the thermal <span class="hlt">time</span> <span class="hlt">scale</span> thus suggests that the Schmelzbach spring is fed by conduits with hydraulic diameters at least in the order of decimetres. In contrast, the damping of the thermal responses at the Hammerbach may be due to lower hydraulic diameters and/or longer residence <span class="hlt">times</span>. Interestingly, the Hammerbach did show thermal responses in the <span class="hlt">time</span> before a flood event in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMEP52A..05D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMEP52A..05D"><span id="translatedtitle">Placing <span class="hlt">Absolute</span> <span class="hlt">Timing</span> on Basin Incision Adjacent to the Colorado Front Range: Results from Meteoric and in Situ 10BE Dating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duehnforth, M.; Anderson, R. S.; Ward, D.</p> <p>2010-12-01</p> <p>A sequence of six levels of gravel-capped surfaces, mapped as Pliocene to Holocene in age, are cut into Cretaceous shale in the northwestern part of the Denver Basin immediately adjacent to the Colorado Front Range (CFR). The existing relative age constraints and terrace correlations suggest that the incision of the Denver Basin occurred at a steady and uniform rate of 0.1 mm yr-1 since the Pliocene. As <span class="hlt">absolute</span> ages in this landscape are rare, they have the potential to test the reliability of the existing chronology, and to illuminate the detailed history of incision. We explore the <span class="hlt">timing</span> of basin incision and the variability of geomorphic process rates through <span class="hlt">time</span> by dating the three highest surfaces at the northwestern edge of the Denver Basin using both in situ and meteoric 10Be concentrations. As the tectonic conditions have not changed since the Pliocene, much of the variability of generation and abandonment of alluvial surfaces likely reflects the influence of glacial-interglacial climate variations. We selected Gunbarrel Hill (mapped as pre-Rocky Flats (Pliocene)), Table Mountain (mapped as Rocky Flats (early Pleistocene)), and the Pioneer surface (mapped as Verdos (Pleistocene, ~640 ka)) as sample locations. We took two amalgamated clast samples on the Gunbarrel Hill surface, and dated depth profiles using meteoric and in situ 10Be on the Table Mountain and Pioneer surfaces. In addition, we measured the in situ 10Be concentrations of 6 boulder samples from the Table Mountain surface. We find that all three surfaces are significantly younger than expected and that in situ and meteoric age measurements largely agree with each other. The samples from the pre-Rocky Flats site (Gunbarrel Hill) show ages of 250 and 310 ka, ignoring post-depositional surface erosion. The ages of the Table Mountain and Pioneer sites fall within the 120 to 150 ka window. These <span class="hlt">absolute</span> ages overlap with the <span class="hlt">timing</span> of the penultimate glaciation during marine isotope stage (MIS) 6</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012Metro..49..706S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012Metro..49..706S"><span id="translatedtitle">Frequency-domain analysis of <span class="hlt">absolute</span> gravimeters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Svitlov, S.</p> <p>2012-12-01</p> <p>An <span class="hlt">absolute</span> gravimeter is analysed as a linear <span class="hlt">time</span>-invariant system in the frequency domain. Frequency responses of <span class="hlt">absolute</span> gravimeters are derived analytically based on the propagation of the complex exponential signal through their linear measurement functions. Depending on the model of motion and the number of <span class="hlt">time</span>-distance coordinates, an <span class="hlt">absolute</span> gravimeter is considered as a second-order (three-level scheme) or third-order (multiple-level scheme) low-pass filter. It is shown that the behaviour of an atom <span class="hlt">absolute</span> gravimeter in the frequency domain corresponds to that of the three-level corner-cube <span class="hlt">absolute</span> gravimeter. Theoretical results are applied for evaluation of random and systematic measurement errors and optimization of an experiment. The developed theory agrees with known results of an <span class="hlt">absolute</span> gravimeter analysis in the <span class="hlt">time</span> and frequency domains and can be used for measurement uncertainty analyses, building of vibration-isolation systems and synthesis of digital filtering algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.cienciasdaterra.com/index.php/vol/article/view/278','USGSPUBS'); return false;" href="http://www.cienciasdaterra.com/index.php/vol/article/view/278"><span id="translatedtitle">Updating the planetary <span class="hlt">time</span> <span class="hlt">scale</span>: focus on Mars</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Tanaka, Kenneth L.; Quantin-Nataf, Cathy</p> <p>2013-01-01</p> <p>Formal stratigraphic systems have been developed for the surface materials of the Moon, Mars, Mercury, and the Galilean satellite Ganymede. These systems are based on geologic mapping, which establishes relative ages of surfaces delineated by superposition, morphology, impact crater densities, and other relations and features. Referent units selected from the mapping determine <span class="hlt">time</span>-stratigraphic bases and/or representative materials characteristic of events and periods for definition of chronologic units. <span class="hlt">Absolute</span> ages of these units in some cases can be estimated using crater size-frequency data. For the Moon, the chronologic units and cratering record are calibrated by radiometric ages measured from samples collected from the lunar surface. Model ages for other cratered planetary surfaces are constructed primarily by estimating cratering rates relative to that of the Moon. Other cratered bodies with estimated surface ages include Venus and the Galilean satellites of Jupiter. New global geologic mapping and crater dating studies of Mars are resulting in more accurate and detailed reconstructions of its geologic history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26ES...39a2050L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26ES...39a2050L"><span id="translatedtitle">Real-<span class="hlt">time</span> simulation of large-<span class="hlt">scale</span> floods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Q.; Qin, Y.; Li, G. D.; Liu, Z.; Cheng, D. J.; Zhao, Y. H.</p> <p>2016-08-01</p> <p>According to the complex real-<span class="hlt">time</span> water situation, the real-<span class="hlt">time</span> simulation of large-<span class="hlt">scale</span> floods is very important for flood prevention practice. Model robustness and running efficiency are two critical factors in successful real-<span class="hlt">time</span> flood simulation. This paper proposed a robust, two-dimensional, shallow water model based on the unstructured Godunov- type finite volume method. A robust wet/dry front method is used to enhance the numerical stability. An adaptive method is proposed to improve the running efficiency. The proposed model is used for large-<span class="hlt">scale</span> flood simulation on real topography. Results compared to those of MIKE21 show the strong performance of the proposed model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994PhDT.......152H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PhDT.......152H"><span id="translatedtitle">Characterizing Complex <span class="hlt">Time</span> Series from the <span class="hlt">Scaling</span> of Prediction Error.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hinrichs, Brant Eric</p> <p></p> <p>This thesis concerns characterizing complex <span class="hlt">time</span> series from the <span class="hlt">scaling</span> of prediction error. We use the global modeling technique of radial basis function approximation to build models from a state-space reconstruction of a <span class="hlt">time</span> series that otherwise appears complicated or random (i.e. aperiodic, irregular). Prediction error as a function of prediction horizon is obtained from the model using the direct method. The relationship between the underlying dynamics of the <span class="hlt">time</span> series and the logarithmic <span class="hlt">scaling</span> of prediction error as a function of prediction horizon is investigated. We use this relationship to characterize the dynamics of both a model chaotic system and physical data from the optic tectum of an attentive pigeon exhibiting the important phenomena of nonstationary neuronal oscillations in response to visual stimuli.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Orme&pg=2&id=EJ852921','ERIC'); return false;" href="http://eric.ed.gov/?q=Orme&pg=2&id=EJ852921"><span id="translatedtitle">The Available <span class="hlt">Time</span> <span class="hlt">Scale</span>: Measuring Foster Parents' Available <span class="hlt">Time</span> to Foster</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Cherry, Donna J.; Orme, John G.; Rhodes, Kathryn W.</p> <p>2009-01-01</p> <p>This article presents a new measure of available <span class="hlt">time</span> specific to fostering, the Available <span class="hlt">Time</span> <span class="hlt">Scale</span> (ATS). It was tested with a national sample of 304 foster mothers and is designed to measure the amount of <span class="hlt">time</span> foster parents are able to devote to fostering activities. The ATS has excellent reliability, and good support exists for its validity.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27431524','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27431524"><span id="translatedtitle">Energy and <span class="hlt">time</span> determine <span class="hlt">scaling</span> in biological and computer designs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moses, Melanie; Bezerra, George; Edwards, Benjamin; Brown, James; Forrest, Stephanie</p> <p>2016-08-19</p> <p>Metabolic rate in animals and power consumption in computers are analogous quantities that <span class="hlt">scale</span> similarly with size. We analyse vascular systems of mammals and on-chip networks of microprocessors, where natural selection and human engineering, respectively, have produced systems that minimize both energy dissipation and delivery <span class="hlt">times</span>. Using a simple network model that simultaneously minimizes energy and <span class="hlt">time</span>, our analysis explains empirically observed trends in the <span class="hlt">scaling</span> of metabolic rate in mammals and power consumption and performance in microprocessors across several orders of magnitude in size. Just as the evolutionary transitions from unicellular to multicellular animals in biology are associated with shifts in metabolic <span class="hlt">scaling</span>, our model suggests that the <span class="hlt">scaling</span> of power and performance will change as computer designs transition to decentralized multi-core and distributed cyber-physical systems. More generally, a single energy-<span class="hlt">time</span> minimization principle may govern the design of many complex systems that process energy, materials and information.This article is part of the themed issue 'The major synthetic evolutionary transitions'. PMID:27431524</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6407194','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6407194"><span id="translatedtitle">Revised magnetic polarity <span class="hlt">time</span> <span class="hlt">scale</span> for the Paleocene and early Eocene and implications for Pacific plate motion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Butler, R.F.; Coney, P.J.</p> <p>1981-04-01</p> <p>Magnetostratiographic studies of a continental sedimentary sequence in the Clark's Fork Basin, Wyoming and a marine sedimentary sequence at Gubbio, Italy indicate that the Paleocene--Eocene boundary occurs just stratigraphically above normal polarity zones correlative with magnetic anomaly 25 chron. These data indicate that the older boundary of anomaly 24 chron is 52.5 Ma. This age is younger than the late Paleocene age assigned by LaBrecque et al. (1977) and also younger than the basal Eocene age assigned by Ness et al. (1980). A revised magnetic polarity <span class="hlt">time</span> <span class="hlt">scale</span> for the Paleocene and early Eocene is presented in this paper. Several changes in the relative motion system between the Pacific plate and neighboring plates occurred in the interval between anomaly 24 and anomaly 21. A major change in <span class="hlt">absolute</span> motion of the Pacific plate is indicated by the bend in the Hawaiian--Emperor Seamount chain at approx.43 Ma. The revised magnetic polarity <span class="hlt">time</span> <span class="hlt">scale</span> indicates that the <span class="hlt">absolute</span> motion change lags the relative motion changes by only approx.3--5 m.y. rather than by >10 m.y. as indicated by previous polarity <span class="hlt">time</span> <span class="hlt">scales</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70025069','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70025069"><span id="translatedtitle"><span class="hlt">Absolute</span> irradiance of the Moon for on-orbit calibration</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stone, T.C.; Kieffer, H.H.; ,</p> <p>2002-01-01</p> <p>The recognized need for on-orbit calibration of remote sensing imaging instruments drives the ROLO project effort to characterize the Moon for use as an <span class="hlt">absolute</span> radiance source. For over 5 years the ground-based ROLO telescopes have acquired spatially-resolved lunar images in 23 VNIR (Moon diameter ???500 pixels) and 9 SWIR (???250 pixels) passbands at phase angles within ??90 degrees. A numerical model for lunar irradiance has been developed which fits hundreds of ROLO images in each band, corrected for atmospheric extinction and calibrated to <span class="hlt">absolute</span> radiance, then integrated to irradiance. The band-coupled extinction algorithm uses absorption spectra of several gases and aerosols derived from MODTRAN to fit <span class="hlt">time</span>-dependent component abundances to nightly observations of standard stars. The <span class="hlt">absolute</span> radiance <span class="hlt">scale</span> is based upon independent telescopic measurements of the star Vega. The fitting process yields uncertainties in lunar relative irradiance over small ranges of phase angle and the full range of lunar libration well under 0.5%. A larger source of uncertainty enters in the <span class="hlt">absolute</span> solar spectral irradiance, especially in the SWIR, where solar models disagree by up to 6%. Results of ROLO model direct comparisons to spacecraft observations demonstrate the ability of the technique to track sensor responsivity drifts to sub-percent precision. Intercomparisons among instruments provide key insights into both calibration issues and the <span class="hlt">absolute</span> <span class="hlt">scale</span> for lunar irradiance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22493540','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22493540"><span id="translatedtitle"><span class="hlt">Absolute</span> shielding <span class="hlt">scales</span> for Al, Ga, and In and revised nuclear magnetic dipole moments of {sup 27}Al, {sup 69}Ga, {sup 71}Ga, {sup 113}In, and {sup 115}In nuclei</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Antušek, A. Holka, F.</p> <p>2015-08-21</p> <p>We present coupled cluster calculations of NMR shielding constants of aluminum, gallium, and indium in water-ion clusters. In addition, relativistic and dynamical corrections and the influence of the second solvation shell are evaluated. The final NMR shielding constants define new <span class="hlt">absolute</span> shielding <span class="hlt">scales</span>, 600.0 ± 4.1 ppm, 2044.4 ± 31.4 ppm, and 4507.7 ± 63.7 ppm for aluminum, gallium, and indium, respectively. The nuclear magnetic dipole moments for {sup 27}Al, {sup 69}Ga, {sup 71}Ga, {sup 113}In, and {sup 115}In isotopes are corrected by combining the computed shielding constants with experimental NMR frequencies. The <span class="hlt">absolute</span> magnitude of the correction increases along the series and for indium isotopes it reaches approximately −8.0 × 10{sup −3} of the nuclear magneton.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16241691','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16241691"><span id="translatedtitle">Anomalous multiphoton photoelectric effect in ultrashort <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kupersztych, J; Raynaud, M</p> <p>2005-09-30</p> <p>In a multiphoton photoelectric process, an electron needs to absorb a given number of photons to escape the surface of a metal. It is shown for the first <span class="hlt">time</span> that this number is not a constant depending only on the characteristics of the metal and light, but varies with the interaction duration in ultrashort <span class="hlt">time</span> <span class="hlt">scales</span>. The phenomenon occurs when electromagnetic energy is transferred, via ultrafast excitation of electron collective modes, to conduction electrons in a duration less than the electron energy damping <span class="hlt">time</span>. It manifests itself through a dramatic increase of electron production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhRvE..72d6120M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhRvE..72d6120M"><span id="translatedtitle">Wavelet analysis and <span class="hlt">scaling</span> properties of <span class="hlt">time</span> series</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manimaran, P.; Panigrahi, Prasanta K.; Parikh, Jitendra C.</p> <p>2005-10-01</p> <p>We propose a wavelet based method for the characterization of the <span class="hlt">scaling</span> behavior of nonstationary <span class="hlt">time</span> series. It makes use of the built-in ability of the wavelets for capturing the trends in a data set, in variable window sizes. Discrete wavelets from the Daubechies family are used to illustrate the efficacy of this procedure. After studying binomial multifractal <span class="hlt">time</span> series with the present and earlier approaches of detrending for comparison, we analyze the <span class="hlt">time</span> series of averaged spin density in the 2D Ising model at the critical temperature, along with several experimental data sets possessing multifractal behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMSM13A0346P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMSM13A0346P"><span id="translatedtitle">Single Particle-Photon Imaging Detector With 4-Dimensional Output: <span class="hlt">Absolute</span> <span class="hlt">Time</span>-of-hit, X-Y Position, and PHA: Applications in Space Science Instruments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paschalidis, N. P.; Mitchell, D. G.; Brandt, P. C.</p> <p>2006-12-01</p> <p>A detector that can simultaneously measure <span class="hlt">time</span>, position, and pulse high analysis (PHA) of single particle/photons with high resolutions and speeds, is a strong enabling technology for many space science instruments such as: energetic neutral atom imagers, low energy neutrals, energetic particle spectrometers, ion/electron plasma analyzers, UV spectrographs, mass spectrometers, laser range finding imagers, X-ray imagers. This presentation describes one such 4-dimentional detector based on micro-channel plates (MCPs), delay line anodes, and precise <span class="hlt">time</span> of flight, and charge integration electronics for PHA. More specifically the detector includes: a) An MCP in 2-stack or Z-stack configuration for the particle/photon detection. b) Option for a thin foil or photo-cathode in front of the MCP to increase the detection efficiency of particles or photons respectively. c) Novel 1D or 2D delay line anode adaptable to almost any geometry and physical size of common instruments mentioned above. d) Fast <span class="hlt">time</span> of flight (TOF) electronics for the <span class="hlt">absolute</span> <span class="hlt">time</span> of hit and the X-Y position determination. e) Fast charge integration electronics for PHA of the total charge released by the MCP. Under certain circumstances the PHA gives information about the particle mass such as for protons, He and Oxygen, cross calibrated against UV light which typically gives a single electron distribution. f) FPGA electronics for digital data acquisition and handling. e) Standard mat lab SW for data analysis and visualization in a stand alone application. The detector achieves <span class="hlt">time</span> of hit accuracy <50ps, X-Y position resolution <20um in a field of 2048 x 2048 pixels (2048 for 1D) and adjustable speeds of: 10MHz at 256 x 256 pixels to 1MHz at 2048 x 2048 pixels. The total-charge analysis is at 10-bits. The detector can be used in its full 4D configuration such as in TOF imaging particle analyzer (i.e ENA), or in a reduced configuration such as in a UV spectrograph with X-Y position only. Typical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12952039','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12952039"><span id="translatedtitle">Parametric <span class="hlt">scaling</span> from species relative abundances to <span class="hlt">absolute</span> abundances in the computation of biological diversity: a first proposal using Shannon's entropy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ricotta, Carlo</p> <p>2003-01-01</p> <p>Traditional diversity measures such as the Shannon entropy are generally computed from the species' relative abundance vector of a given community to the exclusion of species' <span class="hlt">absolute</span> abundances. In this paper, I first mention some examples where the total information content associated with a given community may be more adequate than Shannon's average information content for a better understanding of ecosystem functioning. Next, I propose a parametric measure of statistical information that contains both Shannon's entropy and total information content as special cases of this more general function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AGUFM.H54B..05Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AGUFM.H54B..05Y&link_type=ABSTRACT"><span id="translatedtitle">Accuracy Assessment in rainfall upscaling in multiple <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, H.; Wang, C.; Lin, Y.</p> <p>2008-12-01</p> <p>Long-term hydrologic parameters, e.g. annual precipitations, are usually used to represent the general hydrologic characteristics in a region. Recently, the analysis of the impact of climate change to hydrological patterns primarily relies on the measurement and/or the estimations in long <span class="hlt">time</span> <span class="hlt">scales</span>, e.g. year. Under the general condition of the prevalence of short-term measurements, therefore, it is important to understand the accuracy of upscaling for the long-term estimations of hydrologic parameters. This study applies spatiotemporal geostatistical method to analyze and discuss the accuracy of precipitation upscaling in Taiwan under the different <span class="hlt">time</span> <span class="hlt">scales</span>, and also quantifies the uncertainty in the upscaled long-term precipitations. In this study, two space-<span class="hlt">time</span> upscaling approaches developed by Bayesian Maximum Entropy method (BME) are presented 1) UM1: data aggregation followed by BME estimation and 2) UM2: BME estimation followed by aggregation. The investigation and comparison are also implemented to assess the performance of the rainfall estimations in multiple <span class="hlt">time</span> <span class="hlt">scales</span> in Taiwan by the two upscaling. Keywords: upscaling, geostatistics, BME, uncertainty analysis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E1664K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E1664K"><span id="translatedtitle">Reconstructions of solar irradiance on centennial <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krivova, Natalie; Solanki, Sami K.; Dasi Espuig, Maria; Kok Leng, Yeo</p> <p></p> <p>Solar irradiance is the main external source of energy to Earth's climate system. The record of direct measurements covering less than 40 years is too short to study solar influence on Earth's climate, which calls for reconstructions of solar irradiance into the past with the help of appropriate models. An obvious requirement to a competitive model is its ability to reproduce observed irradiance changes, and a successful example of such a model is presented by the SATIRE family of models. As most state-of-the-art models, SATIRE assumes that irradiance changes on <span class="hlt">time</span> <span class="hlt">scales</span> longer than approximately a day are caused by the evolving distribution of dark and bright magnetic features on the solar surface. The surface coverage by such features as a function of <span class="hlt">time</span> is derived from solar observations. The choice of these depends on the <span class="hlt">time</span> <span class="hlt">scale</span> in question. Most accurate is the version of the model that employs full-disc spatially-resolved solar magnetograms and reproduces over 90% of the measured irradiance variation, including the overall decreasing trend in the total solar irradiance over the last four cycles. Since such magnetograms are only available for about four decades, reconstructions on <span class="hlt">time</span> <span class="hlt">scales</span> of centuries have to rely on disc-integrated proxies of solar magnetic activity, such as sunspot areas and numbers. Employing a surface flux transport model and sunspot observations as input, we have being able to produce synthetic magnetograms since 1700. This improves the temporal resolution of the irradiance reconstructions on centennial <span class="hlt">time</span> <span class="hlt">scales</span>. The most critical aspect of such reconstructions remains the uncertainty in the magnitude of the secular change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ams..book..145K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ams..book..145K"><span id="translatedtitle"><span class="hlt">Absolute</span> High-Precision Localisation of an Unmanned Ground Vehicle by Using Real-<span class="hlt">Time</span> Aerial Video Imagery for Geo-referenced Orthophoto Registration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuhnert, Lars; Ax, Markus; Langer, Matthias; Nguyen van, Duong; Kuhnert, Klaus-Dieter</p> <p></p> <p>This paper describes an <span class="hlt">absolute</span> localisation method for an unmanned ground vehicle (UGV) if GPS is unavailable for the vehicle. The basic idea is to combine an unmanned aerial vehicle (UAV) to the ground vehicle and use it as an external sensor platform to achieve an <span class="hlt">absolute</span> localisation of the robotic team. Beside the discussion of the rather naive method directly using the GPS position of the aerial robot to deduce the ground robot's position the main focus of this paper lies on the indirect usage of the telemetry data of the aerial robot combined with live video images of an onboard camera to realise a registration of local video images with apriori registered orthophotos. This yields to a precise driftless <span class="hlt">absolute</span> localisation of the unmanned ground vehicle. Experiments with our robotic team (AMOR and PSYCHE) successfully verify this approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014JPhA...47q3001H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014JPhA...47q3001H&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> of diffusion in molecular and cellular biology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holcman, D.; Schuss, Z.</p> <p>2014-05-01</p> <p>Diffusion is the driver of critical biological processes in cellular and molecular biology. The diverse temporal <span class="hlt">scales</span> of cellular function are determined by vastly diverse spatial <span class="hlt">scales</span> in most biophysical processes. The latter are due, among others, to small binding sites inside or on the cell membrane or to narrow passages between large cellular compartments. The great disparity in <span class="hlt">scales</span> is at the root of the difficulty in quantifying cell function from molecular dynamics and from simulations. The coarse-grained <span class="hlt">time</span> <span class="hlt">scale</span> of cellular function is determined from molecular diffusion by the mean first passage <span class="hlt">time</span> of molecular Brownian motion to a small targets or through narrow passages. The narrow escape theory (NET) concerns this issue. The NET is ubiquitous in molecular and cellular biology and is manifested, among others, in chemical reactions, in the calculation of the effective diffusion coefficient of receptors diffusing on a neuronal cell membrane strewn with obstacles, in the quantification of the early steps of viral trafficking, in the regulation of diffusion between the mother and daughter cells during cell division, and many other cases. Brownian trajectories can represent the motion of a molecule, a protein, an ion in solution, a receptor in a cell or on its membrane, and many other biochemical processes. The small target can represent a binding site or an ionic channel, a hidden active site embedded in a complex protein structure, a receptor for a neurotransmitter on the membrane of a neuron, and so on. The mean <span class="hlt">time</span> to attach to a receptor or activator determines diffusion fluxes that are key regulators of cell function. This review describes physical models of various subcellular microdomains, in which the NET coarse-grains the molecular <span class="hlt">scale</span> to a higher cellular-level, thus clarifying the role of cell geometry in determining subcellular function.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22415997','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22415997"><span id="translatedtitle">Sublinear <span class="hlt">scaling</span> for <span class="hlt">time</span>-dependent stochastic density functional theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gao, Yi; Neuhauser, Daniel; Baer, Roi; Rabani, Eran</p> <p>2015-01-21</p> <p>A stochastic approach to <span class="hlt">time</span>-dependent density functional theory is developed for computing the absorption cross section and the random phase approximation (RPA) correlation energy. The core idea of the approach involves <span class="hlt">time</span>-propagation of a small set of stochastic orbitals which are first projected on the occupied space and then propagated in <span class="hlt">time</span> according to the <span class="hlt">time</span>-dependent Kohn-Sham equations. The evolving electron density is exactly represented when the number of random orbitals is infinite, but even a small number (≈16) of such orbitals is enough to obtain meaningful results for absorption spectrum and the RPA correlation energy per electron. We implement the approach for silicon nanocrystals using real-space grids and find that the overall <span class="hlt">scaling</span> of the algorithm is sublinear with computational <span class="hlt">time</span> and memory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5911499','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5911499"><span id="translatedtitle">Thermal lens measurements in liquids on a submicrosecond <span class="hlt">time</span> <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Isak, S. J.; Komorowski, S. J.; Merrow, C. N.; Poston, P. E.; Eyring, E. M.</p> <p>1989-03-01</p> <p>The use of the thermal lens method is shown to be quite suitable for kinetic studies of quenching on a submicrosecond <span class="hlt">time</span> <span class="hlt">scale</span>. The lower limit of <span class="hlt">time</span> resolution that can be achieved is determined by the acoustic transit <span class="hlt">time</span>, /tau//sub /ital a//, in the medium. A thermal lens signal with a 100-ns <span class="hlt">time</span> constant due to the quenched triplet state of benzophenone is readily measured. The thermal lens method is superior to the photoacoustic (PA) method in the breadth of the accessible <span class="hlt">time</span> range, and in the significantly fewer measurements required to obtain accurate data, including no requirement for a reference sample; it is also less sensitive to geometrical and laser power requirements than is the PA method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22167504','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22167504"><span id="translatedtitle"><span class="hlt">TIME</span>-AVERAGE-BASED METHODS FOR MULTI-ANGULAR <span class="hlt">SCALE</span> ANALYSIS OF COSMIC-RAY DATA</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Iuppa, R.; Di Sciascio, G. E-mail: giuseppe.disciascio@roma2.infn.it</p> <p>2013-04-01</p> <p>Over the past decade, a number of experiments dealt with the problem of measuring the arrival direction distribution of cosmic rays, looking for information on the propagation mechanisms and the identification of their sources. Any deviation from the isotropy may be regarded to as a signature of unforeseen or unknown phenomena, mostly if well localized in the sky and occurring at low rigidity. It induced experimenters to search for excesses down to angular <span class="hlt">scales</span> as narrow as 10 Degree-Sign , disclosing the issue of properly filtering contributions from wider structures. A solution commonly envisaged was based on <span class="hlt">time</span>-average methods to determine the reference value of cosmic-ray flux. Such techniques are nearly insensitive to signals wider than the <span class="hlt">time</span> window in use, thus allowing us to focus the analysis on medium- and small-<span class="hlt">scale</span> signals. Nonetheless, the signal often cannot be excluded in the calculation of the reference value, which induces systematic errors. The use of <span class="hlt">time</span>-average methods recently revealed important discoveries about the medium-<span class="hlt">scale</span> cosmic-ray anisotropy, present both in the northern and southern hemispheres. It is known that the excess (or deficit) is observed as less intense than in reality and that fake deficit zones are rendered around true excesses because of the <span class="hlt">absolute</span> lack of knowledge a priori of which signal is true and which is not. This work is an attempt to critically review the use of <span class="hlt">time</span>-average-based methods for observing extended features in the cosmic-ray arrival distribution pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013CliPD...9.6635W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013CliPD...9.6635W"><span id="translatedtitle">Orbitally tuned <span class="hlt">time</span> <span class="hlt">scale</span> and astronomical forcing in the middle Eocene to early Oligocene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Westerhold, T.; Röhl, U.; Pälike, H.; Wilkens, R.; Wilson, P. A.; Acton, G.</p> <p>2013-12-01</p> <p>Deciphering the driving mechanisms of Earth system processes, including the climate dynamics expressed as paleoceanographic events, requires a complete, continuous, and high-resolution stratigraphy that is very accurately dated. In this study, we construct a robust astronomically calibrated age model for the middle Eocene to early Oligocene interval (31-43 Ma) in order to permit more detailed study of the exceptional climatic events that occurred during this <span class="hlt">time</span>, including the Middle Eocene Climate Optimum and the Eocene/Oligocene transition. A goal of this effort is to accurately date the middle Eocene to early Oligocene composite section cored during the Pacific Equatorial Age Transect (PEAT, IODP Exp. 320/321). The stratigraphic framework for the new <span class="hlt">time</span> <span class="hlt">scale</span> is based on the identification of the stable long eccentricity cycle in published and new high-resolution records encompassing bulk and benthic stable isotope, calibrated XRF core scanning, and magnetostratigraphic data from ODP Sites 171B-1052, 189-1172, 199-1218, and 207-1260 as well as IODP Sites 320-U1333, and -U1334 spanning magnetic polarity Chrons C12n to C20n. Subsequently we applied orbital tuning of the records to the La2011 orbital solution. The resulting new <span class="hlt">time</span> <span class="hlt">scale</span> revises and refines the existing orbitally tuned age model and the Geomagnetic Polarity <span class="hlt">Time</span> <span class="hlt">Scale</span> from 31 to 43 Ma. Our newly defined <span class="hlt">absolute</span> age for the Eocene/Oligocene boundary validates the astronomical tuned age of 33.89 Ma identified at the Massignano (Italy) global stratotype section and point. Our compilation of geochemical records of climate-controlled variability in sedimentation through the middle-to-late Eocene and early Oligocene demonstrates strong power in the eccentricity band that is readily tuned to the latest astronomical solution. Obliquity driven cyclicity is only apparent during very long eccentricity cycle minima around 35.5, 38.3 and 40.1 Ma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvL.117g0601W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvL.117g0601W"><span id="translatedtitle">Entropy Production of Nanosystems with <span class="hlt">Time</span> <span class="hlt">Scale</span> Separation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Shou-Wen; Kawaguchi, Kyogo; Sasa, Shin-ichi; Tang, Lei-Han</p> <p>2016-08-01</p> <p>Energy flows in biomolecular motors and machines are vital to their function. Yet experimental observations are often limited to a small subset of variables that participate in energy transport and dissipation. Here we show, through a solvable Langevin model, that the seemingly hidden entropy production is measurable through the violation spectrum of the fluctuation-response relation of a slow observable. For general Markov systems with <span class="hlt">time</span> <span class="hlt">scale</span> separation, we prove that the violation spectrum exhibits a characteristic plateau in the intermediate frequency region. Despite its vanishing height, the plateau can account for energy dissipation over a broad <span class="hlt">time</span> <span class="hlt">scale</span>. Our findings suggest a general possibility to probe hidden entropy production in nanosystems without direct observation of fast variables.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27563943','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27563943"><span id="translatedtitle">Entropy Production of Nanosystems with <span class="hlt">Time</span> <span class="hlt">Scale</span> Separation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Shou-Wen; Kawaguchi, Kyogo; Sasa, Shin-Ichi; Tang, Lei-Han</p> <p>2016-08-12</p> <p>Energy flows in biomolecular motors and machines are vital to their function. Yet experimental observations are often limited to a small subset of variables that participate in energy transport and dissipation. Here we show, through a solvable Langevin model, that the seemingly hidden entropy production is measurable through the violation spectrum of the fluctuation-response relation of a slow observable. For general Markov systems with <span class="hlt">time</span> <span class="hlt">scale</span> separation, we prove that the violation spectrum exhibits a characteristic plateau in the intermediate frequency region. Despite its vanishing height, the plateau can account for energy dissipation over a broad <span class="hlt">time</span> <span class="hlt">scale</span>. Our findings suggest a general possibility to probe hidden entropy production in nanosystems without direct observation of fast variables. PMID:27563943</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840019567','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840019567"><span id="translatedtitle">Solar Irradiance Variations on Active Region <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Labonte, B. J. (Editor); Chapman, G. A. (Editor); Hudson, H. S. (Editor); Willson, R. C. (Editor)</p> <p>1984-01-01</p> <p>The variations of the total solar irradiance is an important tool for studying the Sun, thanks to the development of very precise sensors such as the ACRIM instrument on board the Solar Maximum Mission. The largest variations of the total irradiance occur on <span class="hlt">time</span> <span class="hlt">scales</span> of a few days are caused by solar active regions, especially sunspots. Efforts were made to describe the active region effects on total and spectral irradiance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/980040','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/980040"><span id="translatedtitle">Biogenic Calcium Phosphate Transformation in Soils over Millennium <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sato, S.; Neves, E; Solomon, D; Liang, B; Lehmann, J</p> <p>2009-01-01</p> <p>Changes in bioavailability of phosphorus (P) during pedogenesis and ecosystem development have been shown for geogenic calcium phosphate (Ca-P). However, very little is known about long-term changes of biogenic Ca-P in soil. Long-term transformation characteristics of biogenic Ca-P were examined using anthropogenic soils along a chronosequence from centennial to millennial <span class="hlt">time</span> <span class="hlt">scales</span>. Phosphorus fractionation of Anthrosols resulted in overall consistency with the Walker and Syers model of geogenic Ca-P transformation during pedogenesis. The biogenic Ca-P (e.g., animal and fish bones) disappeared to 3% of total P within the first ca. 2,000 years of soil development. This change concurred with increases in P adsorbed on metal-oxides surfaces, organic P, and occluded P at different pedogenic <span class="hlt">time</span>. Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy revealed that the crystalline and therefore thermodynamically most stable biogenic Ca-P was transformed into more soluble forms of Ca-P over <span class="hlt">time</span>. While crystalline hydroxyapatite (34% of total P) dominated Ca-P species after about 600-1,000 years, {Beta}-tricalcium phosphate increased to 16% of total P after 900-1,100 years, after which both Ca-P species disappeared. Iron-associated P was observable concurrently with Ca-P disappearance. Soluble P and organic P determined by XANES maintained relatively constant (58-65%) across the <span class="hlt">time</span> <span class="hlt">scale</span> studied. Conclusions - Disappearance of crystalline biogenic Ca-P on a <span class="hlt">time</span> <span class="hlt">scale</span> of a few thousand years appears to be ten <span class="hlt">times</span> faster than that of geogenic Ca-P.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12366207','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12366207"><span id="translatedtitle"><span class="hlt">Scaling</span> detection in <span class="hlt">time</span> series: diffusion entropy analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scafetta, Nicola; Grigolini, Paolo</p> <p>2002-09-01</p> <p>The methods currently used to determine the <span class="hlt">scaling</span> exponent of a complex dynamic process described by a <span class="hlt">time</span> series are based on the numerical evaluation of variance. This means that all of them can be safely applied only to the case where ordinary statistical properties hold true even if strange kinetics are involved. We illustrate a method of statistical analysis based on the Shannon entropy of the diffusion process generated by the <span class="hlt">time</span> series, called diffusion entropy analysis (DEA). We adopt artificial Gauss and Lévy <span class="hlt">time</span> series, as prototypes of ordinary and anomalous statistics, respectively, and we analyze them with the DEA and four ordinary methods of analysis, some of which are very popular. We show that the DEA determines the correct <span class="hlt">scaling</span> exponent even when the statistical properties, as well as the dynamic properties, are anomalous. The other four methods produce correct results in the Gauss case but fail to detect the correct <span class="hlt">scaling</span> in the case of Lévy statistics. PMID:12366207</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....51.6988S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....51.6988S"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> interactions and the coevolution of humans and water</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sivapalan, Murugesu; Blöschl, Günter</p> <p>2015-09-01</p> <p>We present a coevolutionary view of hydrologic systems, revolving around feedbacks between environmental and social processes operating across different <span class="hlt">time</span> <span class="hlt">scales</span>. This brings to the fore an emphasis on emergent phenomena in changing water systems, such as the levee effect, adaptation to change, system lock-in, and system collapse due to resource depletion. Changing human values play a key role in the emergence of these phenomena and should therefore be considered as internal to the system. Guidance is provided for the framing and modeling of these phenomena to test alternative hypotheses about how they arose. A plurality of coevolutionary models, from stylized to comprehensive system-of-system models, may assist strategic water management for long <span class="hlt">time</span> <span class="hlt">scales</span> through facilitating stakeholder participation, exploring the possibility space of alternative futures, and helping to synthesize the observed dynamics in a wide range of case studies. Future research opportunities lie in exploring emergent phenomena arising from <span class="hlt">time</span> <span class="hlt">scale</span> interactions through historical, comparative, and process studies of human-water feedbacks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24183025','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24183025"><span id="translatedtitle"><span class="hlt">Scaling</span> brain size, keeping <span class="hlt">timing</span>: evolutionary preservation of brain rhythms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buzsáki, György; Logothetis, Nikos; Singer, Wolf</p> <p>2013-10-30</p> <p>Despite the several-thousand-fold increase of brain volume during the course of mammalian evolution, the hierarchy of brain oscillations remains remarkably preserved, allowing for multiple-<span class="hlt">time-scale</span> communication within and across neuronal networks at approximately the same speed, irrespective of brain size. Deployment of large-diameter axons of long-range neurons could be a key factor in the preserved <span class="hlt">time</span> management in growing brains. We discuss the consequences of such preserved network constellation in mental disease, drug discovery, and interventional therapies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4009705','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4009705"><span id="translatedtitle"><span class="hlt">Scaling</span> Brain Size, Keeping <span class="hlt">Timing</span>: Evolutionary Preservation of Brain Rhythms</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Buzsáki, György; Logothetis, Nikos; Singer, Wolf</p> <p>2014-01-01</p> <p>Despite the several-thousand-fold increase of brain volume during the course of mammalian evolution, the hierarchy of brain oscillations remains remarkably preserved, allowing for multiple-<span class="hlt">time-scale</span> communication within and across neuronal networks at approximately the same speed, irrespective of brain size. Deployment of large-diameter axons of long-range neurons could be a key factor in the preserved <span class="hlt">time</span> management in growing brains. We discuss the consequences of such preserved network constellation in mental disease, drug discovery, and interventional therapies. PMID:24183025</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhyA..414..378R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhyA..414..378R"><span id="translatedtitle"><span class="hlt">Scale</span> and <span class="hlt">time</span> dependence of serial correlations in word-length <span class="hlt">time</span> series of written texts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodriguez, E.; Aguilar-Cornejo, M.; Femat, R.; Alvarez-Ramirez, J.</p> <p>2014-11-01</p> <p>This work considered the quantitative analysis of large written texts. To this end, the text was converted into a <span class="hlt">time</span> series by taking the sequence of word lengths. The detrended fluctuation analysis (DFA) was used for characterizing long-range serial correlations of the <span class="hlt">time</span> series. To this end, the DFA was implemented within a rolling window framework for estimating the variations of correlations, quantified in terms of the <span class="hlt">scaling</span> exponent, strength along the text. Also, a filtering derivative was used to compute the dependence of the <span class="hlt">scaling</span> exponent relative to the <span class="hlt">scale</span>. The analysis was applied to three famous English-written literary narrations; namely, Alice in Wonderland (by Lewis Carrol), Dracula (by Bram Stoker) and Sense and Sensibility (by Jane Austen). The results showed that high correlations appear for <span class="hlt">scales</span> of about 50-200 words, suggesting that at these <span class="hlt">scales</span> the text contains the stronger coherence. The <span class="hlt">scaling</span> exponent was not constant along the text, showing important variations with apparent cyclical behavior. An interesting coincidence between the <span class="hlt">scaling</span> exponent variations and changes in narrative units (e.g., chapters) was found. This suggests that the <span class="hlt">scaling</span> exponent obtained from the DFA is able to detect changes in narration structure as expressed by the usage of words of different lengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvE..89a2724X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvE..89a2724X"><span id="translatedtitle">Two-<span class="hlt">time-scale</span> population evolution on a singular landscape</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Song; Jiao, Shuyun; Jiang, Pengyao; Ao, Ping</p> <p>2014-01-01</p> <p>Under the effect of strong genetic drift, it is highly probable to observe gene fixation or gene loss in a population, shown by singular peaks on a potential landscape. The genetic drift-induced noise gives rise to two-<span class="hlt">time-scale</span> diffusion dynamics on the bipeaked landscape. We find that the logarithmically divergent (singular) peaks do not necessarily imply infinite escape <span class="hlt">times</span> or biological fixations by iterating the Wright-Fisher model and approximating the average escape <span class="hlt">time</span>. Our analytical results under weak mutation and weak selection extend Kramers's escape <span class="hlt">time</span> formula to models with B (Beta) function-like equilibrium distributions and overcome constraints in previous methods. The constructed landscape provides a coherent description for the bistable system, supports the quantitative analysis of bipeaked dynamics, and generates mathematical insights for understanding the boundary behaviors of the diffusion model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005AAS...20714101F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005AAS...20714101F&link_type=ABSTRACT"><span id="translatedtitle">Variability Trends in QSOs Over Monthly <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fleming, B. T.; Kennefick, J.</p> <p>2005-12-01</p> <p>Variation in quasar magnitude from night to night can reveal long term variability trends as well as have a greater chance of detecting sudden luminosity changes than a typical long-term variability survey. In this study, five quasars with a range of properties were observed approximately every other night over 40 days using the 24" NFO webscope in Silver City, NM. Three 200 second exposure images were taken in both the R and V color filters each observation. Two passbands were used so that the data could be correlated to support findings. The images were stacked and processed using IRAF and SExtractor. Differential photometry using field stars was utilized. The five quasars were selected so that as large a range of redshift and <span class="hlt">absolute</span> magnitude observable by the NFO webscope was represented. They are: (1) MRK 0877 with z=0.1124, (2) 3C-334 a RQQ with z=0.5551, (3) HS 1603+3820 a very luminous, very distant QSO with z=2.51, and two quasars from the QUEST survey (J1507-0202 and J1507-0207) which were selected because they both showed evidence of magnitude variations during the QUEST1 survey. Two of the observed quasars showed no significant variability. 3C-334 displayed a sudden apparent magnitude jump in both passbands, with Δ mR = 0.5602 ± 0.0474, corresponding to an increase of 6.62E+11 solar luminosities on June 21st. The magnitude returned to previous levels by the next observation. QUEST 1507-0202 and MRK 0877 suggested evidence of small long term variability over the 40 day study. Future observations revealing significant changes in magnitude corresponding to these trends may lead to the conclusion that these slow long-term variations can be detected over a 40 day <span class="hlt">time</span> period with frequent observations. Funding was provided through an Arkansas Space Center grant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25833580','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25833580"><span id="translatedtitle">The hyperfine structure in the rotational spectra of D2(17)O and HD(17)O: Confirmation of the <span class="hlt">absolute</span> nuclear magnetic shielding <span class="hlt">scale</span> for oxygen.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Puzzarini, Cristina; Cazzoli, Gabriele; Harding, Michael E; Vázquez, Juana; Gauss, Jürgen</p> <p>2015-03-28</p> <p>Guided by theoretical predictions, the hyperfine structures of the rotational spectra of mono- and bideuterated-water containing (17)O have been experimentally investigated. To reach sub-Doppler resolution, required to resolve the hyperfine structure due to deuterium quadrupole coupling as well as to spin-rotation (SR) and dipolar spin-spin couplings, the Lamb-dip technique has been employed. The experimental investigation and in particular, the spectral analysis have been supported by high-level quantum-chemical computations employing coupled-cluster techniques and, for the first <span class="hlt">time</span>, a complete experimental determination of the hyperfine parameters involved was possible. The experimentally determined (17)O spin-rotation constants of D2 (17)O and HD(17)O were used to derive the paramagnetic part of the corresponding nuclear magnetic shielding constants. Together with the computed diamagnetic contributions as well as the vibrational and temperature corrections, the latter constants have been employed to confirm the oxygen nuclear magnetic shielding <span class="hlt">scale</span>, recently established on the basis of spin-rotation data for H2 (17)O [Puzzarini et al., J. Chem. Phys. 131, 234304 (2009)].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21980278','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21980278"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> hierarchies in the functional organization of complex behaviors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perdikis, Dionysios; Huys, Raoul; Jirsa, Viktor K</p> <p>2011-09-01</p> <p>Traditional approaches to cognitive modelling generally portray cognitive events in terms of 'discrete' states (point attractor dynamics) rather than in terms of processes, thereby neglecting the <span class="hlt">time</span> structure of cognition. In contrast, more recent approaches explicitly address this temporal dimension, but typically provide no entry points into cognitive categorization of events and experiences. With the aim to incorporate both these aspects, we propose a framework for functional architectures. Our approach is grounded in the notion that arbitrary complex (human) behaviour is decomposable into functional modes (elementary units), which we conceptualize as low-dimensional dynamical objects (structured flows on manifolds). The ensemble of modes at an agent's disposal constitutes his/her functional repertoire. The modes may be subjected to additional dynamics (termed operational signals), in particular, instantaneous inputs, and a mechanism that sequentially selects a mode so that it temporarily dominates the functional dynamics. The inputs and selection mechanisms act on faster and slower <span class="hlt">time</span> <span class="hlt">scales</span> then that inherent to the modes, respectively. The dynamics across the three <span class="hlt">time</span> <span class="hlt">scales</span> are coupled via feedback, rendering the entire architecture autonomous. We illustrate the functional architecture in the context of serial behaviour, namely cursive handwriting. Subsequently, we investigate the possibility of recovering the contributions of functional modes and operational signals from the output, which appears to be possible only when examining the output phase flow (i.e., not from trajectories in phase space or <span class="hlt">time</span>). PMID:21980278</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810961P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810961P"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scaling</span> of tree rings cell production in Siberia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Popkova, Margarita; Babushkina, Elena; Tychkov, Ivan; Shishov, Vladimir; Vaganov, Eugene</p> <p>2016-04-01</p> <p>It is assumed that an annual tree-ring growth is adequately determined by a linear function of local or regional precipitation and temperature with a set of coefficients that are temporally invariant. But often that relations are non-linear. The process-based tree-ring VS-model can be used to resolve the critical processes linking climate variables to tree-ring formation. This work describes a new block of VS-model which allows to estimate a cell production in tree rings and transfer it into <span class="hlt">time</span> <span class="hlt">scale</span> based on the simulated integral growth rates of the model. In the algorithm of <span class="hlt">time</span> identification for cell production we used a integral growth rates simulated by the VS-model for each growing season. The obtained detailed approach with a calculation of the <span class="hlt">time</span> of each cell formation improves significantly the date accuracy of new cell formation in growing season. As a result for each cell in the tree-ring we estimate the temporal moment of the cell production corresponded to the seasonal growth rate in the same <span class="hlt">time</span> <span class="hlt">scale</span>. The approach was applied and tested for the cell measurements obtained for Scots pine (Pinus sylvestris) for the period 1964-2013 in Malaya Minusa river (Khakassia, South Siberia). The work was supported by the Russian Science Foundation (RSF # 14-14-00219)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2568860','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2568860"><span id="translatedtitle">A Hierarchy of <span class="hlt">Time-Scales</span> and the Brain</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kiebel, Stefan J.; Daunizeau, Jean; Friston, Karl J.</p> <p>2008-01-01</p> <p>In this paper, we suggest that cortical anatomy recapitulates the temporal hierarchy that is inherent in the dynamics of environmental states. Many aspects of brain function can be understood in terms of a hierarchy of temporal <span class="hlt">scales</span> at which representations of the environment evolve. The lowest level of this hierarchy corresponds to fast fluctuations associated with sensory processing, whereas the highest levels encode slow contextual changes in the environment, under which faster representations unfold. First, we describe a mathematical model that exploits the temporal structure of fast sensory input to track the slower trajectories of their underlying causes. This model of sensory encoding or perceptual inference establishes a proof of concept that slowly changing neuronal states can encode the paths or trajectories of faster sensory states. We then review empirical evidence that suggests that a temporal hierarchy is recapitulated in the macroscopic organization of the cortex. This anatomic-temporal hierarchy provides a comprehensive framework for understanding cortical function: the specific <span class="hlt">time-scale</span> that engages a cortical area can be inferred by its location along a rostro-caudal gradient, which reflects the anatomical distance from primary sensory areas. This is most evident in the prefrontal cortex, where complex functions can be explained as operations on representations of the environment that change slowly. The framework provides predictions about, and principled constraints on, cortical structure–function relationships, which can be tested by manipulating the <span class="hlt">time-scales</span> of sensory input. PMID:19008936</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4434B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4434B"><span id="translatedtitle">The Role of <span class="hlt">Time-Scales</span> in Socio-hydrology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blöschl, Günter; Sivapalan, Murugesu</p> <p>2016-04-01</p> <p>Much of the interest in hydrological modeling in the past decades revolved around resolving spatial variability. With the rapid changes brought about by human impacts on the hydrologic cycle, there is now an increasing need to refocus on <span class="hlt">time</span> dependency. We present a co-evolutionary view of hydrologic systems, in which every part of the system including human systems, co-evolve, albeit at different rates. The resulting coupled human-nature system is framed as a dynamical system, characterized by interactions of fast and slow <span class="hlt">time</span> <span class="hlt">scales</span> and feedbacks between environmental and social processes. This gives rise to emergent phenomena such as the levee effect, adaptation to change and system collapse due to resource depletion. Changing human values play a key role in the emergence of these phenomena and should therefore be considered as internal to the system in a dynamic way. The co-evolutionary approach differs from the traditional view of water resource systems analysis as it allows for path dependence, multiple equilibria, lock-in situations and emergent phenomena. The approach may assist strategic water management for long <span class="hlt">time</span> <span class="hlt">scales</span> through facilitating stakeholder participation, exploring the possibility space of alternative futures, and helping to synthesise the observed dynamics of different case studies. Future research opportunities include the study of how changes in human values are connected to human-water interactions, historical analyses of trajectories of system co-evolution in individual places and comparative analyses of contrasting human-water systems in different climate and socio-economic settings. Reference Sivapalan, M. and G. Blöschl (2015) <span class="hlt">Time</span> <span class="hlt">scale</span> interactions and the coevolution of humans and water. Water Resour. Res., 51, 6988-7022, doi:10.1002/2015WR017896.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20120010653&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528sea%2Blevel%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20120010653&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528sea%2Blevel%2529"><span id="translatedtitle">Terrestrial Waters and Sea Level Variations on Interannual <span class="hlt">Time</span> <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Llovel, W.; Becker, M.; Cazenave, A.; Jevrejeva, S.; Alkama, R.; Decharme, B.; Douville, H.; Ablain, M.; Beckley, B.</p> <p>2011-01-01</p> <p>On decadal to multi-decadal <span class="hlt">time</span> <span class="hlt">scales</span>, thermal expansion of sea waters and land ice loss are the main contributors to sea level variations. However, modification of the terrestrial water cycle due to climate variability and direct anthropogenic forcing may also affect sea level. For the past decades, variations in land water storage and corresponding effects on sea level cannot be directly estimated from observations because these are almost non-existent at global continental <span class="hlt">scale</span>. However, global hydrological models developed for atmospheric and climatic studies can be used for estimating total water storage. For the recent years (since mid-2002), terrestrial water storage change can be directly estimated from observations of the GRACE space gravimetry mission. In this study, we analyse the interannual variability of total land water storage, and investigate its contribution to mean sea level variability at interannual <span class="hlt">time</span> <span class="hlt">scale</span>. We consider three different periods that, each, depend on data availability: (1) GRACE era (2003-2009), (2) 1993-2003 and (3) 1955-1995. For the GRACE era (period 1), change in land water storage is estimated using different GRACE products over the 33 largest river basins worldwide. For periods 2 and 3, we use outputs from the ISBA-TRIP (Interactions between Soil, Biosphere, and Atmosphere-Total Runoff Integrating Pathways) global hydrological model. For each <span class="hlt">time</span> span, we compare change in land water storage (expressed in sea level equivalent) to observed mean sea level, either from satellite altimetry (periods 1 and 2) or tide gauge records (period 3). For each data set and each <span class="hlt">time</span> span, a trend has been removed as we focus on the interannual variability. We show that whatever the period considered, interannual variability of the mean sea level is essentially explained by interannual fluctuations in land water storage, with the largest contributions arising from tropical river basins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/674862','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/674862"><span id="translatedtitle">Decay of surface nanostructures via long-<span class="hlt">time-scale</span> dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Voter, A.F.; Stanciu, N.</p> <p>1998-11-01</p> <p>This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors have developed a new approach for extending the <span class="hlt">time</span> <span class="hlt">scale</span> of molecular dynamics simulations. For infrequent-event systems, the category that includes most diffusive events in the solid phase, this hyperdynamics method can extend the simulation <span class="hlt">time</span> by a few orders of magnitude compared to direct molecular dynamics. The trajectory is run on a potential surface that has been biased to raise the energy in the potential basins without affecting the transition state region. The method is described and applied to surface and bulk diffusion processes, achieving microsecond and millisecond simulation <span class="hlt">times</span>. The authors have also developed a new parallel computing method that is efficient for small system sizes. The combination of the hyperdynamics with this parallel replica dynamics looks promising as a general materials simulation tool.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140006576','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140006576"><span id="translatedtitle">Optimal Control Modification for <span class="hlt">Time-Scale</span> Separated Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nguyen, Nhan T.</p> <p>2012-01-01</p> <p>Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a <span class="hlt">time</span> <span class="hlt">scale</span> separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow <span class="hlt">time</span>. A model matching conditions in the transformed <span class="hlt">time</span> coordinate results in an increase in the actuator command that effectively compensate for the slow actuator dynamics. Simulations demonstrate effectiveness of the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21413490','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21413490"><span id="translatedtitle">Multiple-<span class="hlt">Time</span> <span class="hlt">Scaling</span> and Universal Behavior of the Earthquake Interevent <span class="hlt">Time</span> Distribution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bottiglieri, M.; Godano, C.; Lippiello, E.; Arcangelis, L. de</p> <p>2010-04-16</p> <p>The interevent <span class="hlt">time</span> distribution characterizes the temporal occurrence in seismic catalogs. Universal <span class="hlt">scaling</span> properties of this distribution have been evidenced for entire catalogs and seismic sequences. Recently, these universal features have been questioned and some criticisms have been raised. We investigate the existence of universal <span class="hlt">scaling</span> properties by analyzing a Californian catalog and by means of numerical simulations of an epidemic-type model. We show that the interevent <span class="hlt">time</span> distribution exhibits a universal behavior over the entire temporal range if four characteristic <span class="hlt">times</span> are taken into account. The above analysis allows us to identify the <span class="hlt">scaling</span> form leading to universal behavior and explains the observed deviations. Furthermore, it provides a tool to identify the dependence on the mainshock magnitude of the c parameter that fixes the onset of the power law decay in the Omori law.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23586876','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23586876"><span id="translatedtitle"><span class="hlt">Absolute</span> biological needs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McLeod, Stephen</p> <p>2014-07-01</p> <p><span class="hlt">Absolute</span> needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended <span class="hlt">absolute</span> needs on the grounds that the verb 'need' has instrumental and <span class="hlt">absolute</span> senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are <span class="hlt">absolute</span> biological needs. The <span class="hlt">absolute</span> nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of <span class="hlt">absolute</span> need is not inherently normative in either of the first two senses. PMID:23586876</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23586876','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23586876"><span id="translatedtitle"><span class="hlt">Absolute</span> biological needs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McLeod, Stephen</p> <p>2014-07-01</p> <p><span class="hlt">Absolute</span> needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended <span class="hlt">absolute</span> needs on the grounds that the verb 'need' has instrumental and <span class="hlt">absolute</span> senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are <span class="hlt">absolute</span> biological needs. The <span class="hlt">absolute</span> nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of <span class="hlt">absolute</span> need is not inherently normative in either of the first two senses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PSST...25d5013B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PSST...25d5013B"><span id="translatedtitle"><span class="hlt">Absolute</span> OH and O radical densities in effluent of a He/H2O micro-<span class="hlt">scaled</span> atmospheric pressure plasma jet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benedikt, J.; Schröder, D.; Schneider, S.; Willems, G.; Pajdarová, A.; Vlček, J.; Schulz-von der Gathen, V.</p> <p>2016-08-01</p> <p>The effluent of a micro-<span class="hlt">scaled</span> atmospheric pressure plasma jet (μ-APPJ) operated in helium with admixtures of water vapor (≲ {{10}4} ppm) has been analyzed by means of cavity ring-down laser absorption spectroscopy and molecular beam mass spectrometry to measure hydroxyl (OH) radical densities, and by two-photon absorption laser-induced fluorescence spectroscopy to measure atomic oxygen (O) densities. Additionally, the performance of the bubbler as a source of water vapor in the helium feed gas has been carefully characterized and calibrated. The largest OH and O densities in the effluent of 2× {{10}14}~\\text{c}{{\\text{m}}-3} and 3.2× {{10}13}~\\text{c}{{\\text{m}}-3} , respectively, have been measured at around 6000 ppm. The highest selectivity is reached around 1500 ppm, where the OH density is at  ∼63% of its maximum value and is 14 <span class="hlt">times</span> larger than the O density. The measured density profiles and distance variations are compared to the results of a 2D axially symmetric fluid model of species transport and reaction kinetics in the plasma effluent. It is shown that the main loss of OH radicals in the effluent is their mutual reaction. In the case of O, reactions with other species than OH also have to be considered to explain the density decay in the effluent. The results presented here provide additional information for understanding the plasma-chemical processes in non-equilibrium atmospheric pressure plasmas. They also open the way to applying μ-APPJ with He/H2O as a selective source of OH radicals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811468M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811468M"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">Scale</span> Optimization and the Hunt for Astronomical Cycles in Deep <span class="hlt">Time</span> Strata</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meyers, Stephen R.</p> <p>2016-04-01</p> <p>A valuable attribute of astrochronology is the direct link between chronometer and climate change, providing a remarkable opportunity to constrain the evolution of the surficial Earth System. Consequently, the hunt for astronomical cycles in strata has spurred the development of a rich conceptual framework for climatic/oceanographic change, and has allowed exploration of the geologic record with unprecedented temporal resolution. Accompanying these successes, however, has been a persistent skepticism about appropriate astrochronologic testing and circular reasoning: how does one reliably test for astronomical cycles in stratigraphic data, especially when <span class="hlt">time</span> is poorly constrained? From this perspective, it would seem that the merits and promise of astrochronology (e.g., a geologic <span class="hlt">time</span> <span class="hlt">scale</span> measured in ≤400 kyr increments) also serves as its Achilles heel, if the confirmation of such short rhythms defies rigorous statistical testing. To address these statistical challenges in astrochronologic testing, a new approach has been developed that (1) explicitly evaluates <span class="hlt">time</span> <span class="hlt">scale</span> uncertainty, (2) is resilient to common problems associated with spectrum confidence level assessment and 'multiple testing', and (3) achieves high statistical power under a wide range of conditions (it can identify astronomical cycles when present in data). Designated <span class="hlt">Time</span>Opt (for "<span class="hlt">time</span> <span class="hlt">scale</span> optimization"; Meyers 2015), the method employs a probabilistic linear regression model framework to investigate amplitude modulation and frequency ratios (bundling) in stratigraphic data, while simultaneously determining the optimal <span class="hlt">time</span> <span class="hlt">scale</span>. This presentation will review the <span class="hlt">Time</span>Opt method, and demonstrate how the flexible statistical framework can be further extended to evaluate (and optimize upon) complex sedimentation rate models, enhancing the statistical power of the approach, and addressing the challenge of unsteady sedimentation. Meyers, S. R. (2015), The evaluation of eccentricity</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25955500','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25955500"><span id="translatedtitle">Role of relaxation <span class="hlt">time</span> <span class="hlt">scale</span> in noisy signal transduction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maity, Alok Kumar; Chaudhury, Pinaki; Banik, Suman K</p> <p>2015-01-01</p> <p>Intra-cellular fluctuations, mainly triggered by gene expression, are an inevitable phenomenon observed in living cells. It influences generation of phenotypic diversity in genetically identical cells. Such variation of cellular components is beneficial in some contexts but detrimental in others. To quantify the fluctuations in a gene product, we undertake an analytical scheme for studying few naturally abundant linear as well as branched chain network motifs. We solve the Langevin equations associated with each motif under the purview of linear noise approximation and derive the expressions for Fano factor and mutual information in close analytical form. Both quantifiable expressions exclusively depend on the relaxation <span class="hlt">time</span> (decay rate constant) and steady state population of the network components. We investigate the effect of relaxation <span class="hlt">time</span> constraints on Fano factor and mutual information to indentify a <span class="hlt">time</span> <span class="hlt">scale</span> domain where a network can recognize the fluctuations associated with the input signal more reliably. We also show how input population affects both quantities. We extend our calculation to long chain linear motif and show that with increasing chain length, the Fano factor value increases but the mutual information processing capability decreases. In this type of motif, the intermediate components act as a noise filter that tune up input fluctuations and maintain optimum fluctuations in the output. For branched chain motifs, both quantities vary within a large <span class="hlt">scale</span> due to their network architecture and facilitate survival of living system in diverse environmental conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940006526&hterms=Atomic+clocks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528Atomic%2Bclocks%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940006526&hterms=Atomic+clocks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528Atomic%2Bclocks%2529"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> algorithms for an inhomogeneous group of atomic clocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jacques, C.; Boulanger, J.-S.; Douglas, R. J.; Morris, D.; Cundy, S.; Lam, H. F.</p> <p>1993-01-01</p> <p>Through the past 17 years, the <span class="hlt">time</span> <span class="hlt">scale</span> requirements at the National Research Council (NRC) have been met by the unsteered output of its primary laboratory cesium clocks, supplemented by hydrogen masers when short-term stability better than 2 x 10(exp -12)tau(sup -1/2) has been required. NRC now operates three primary laboratory cesium clocks, three hydrogen masers, and two commercial cesium clocks. NRC has been using ensemble averages for internal purposes for the past several years, and has a realtime algorithm operating on the outputs of its high-resolution (2 x 10(exp -13) s at 1 s) phase comparators. The slow frequency drift of the hydrogen masers has presented difficulties in incorporating their short-term stability into the ensemble average, while retaining the long-term stability of the laboratory cesium frequency standards. We report on this work on algorithms for an inhomogeneous ensemble of atomic clocks, and on our initial work on <span class="hlt">time</span> <span class="hlt">scale</span> algorithms that could incorporate frequency calibrations at NRC from the next generation of Zacharias fountain cesium frequency standards having frequency accuracies that might surpass 10(exp -15), or from single-trapped-ion frequency standards (Ba+, Sr+,...) with even higher potential accuracies. The requirements for redundancy in all the elements (including the algorithms) of an inhomogeneous ensemble that would give a robust real-<span class="hlt">time</span> output of the algorithms are presented and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21930569','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21930569"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scales</span> in the context of general relativity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guinot, Bernard</p> <p>2011-10-28</p> <p>Towards 1967, the accuracy of caesium frequency standards reached such a level that the relativistic effect could not be ignored anymore. Corrections began to be applied for the gravitational frequency shift and for distant <span class="hlt">time</span> comparisons. However, these corrections were not applied to an explicit theoretical framework. Only in 1991 did the International Astronomical Union provide metrics (then improved in 2000) for a definition of space-<span class="hlt">time</span> coordinates in reference systems centred at the barycentre of the Solar System and at the centre of mass of the Earth. In these systems, the temporal coordinates (coordinate <span class="hlt">times</span>) can be realized on the basis of one of them, the International Atomic <span class="hlt">Time</span> (TAI), which is itself a realized <span class="hlt">time</span> <span class="hlt">scale</span>. The definition and the role of TAI in this context will be recalled. There remain controversies regarding the name to be given to the unit of coordinate <span class="hlt">times</span> and to other quantities appearing in the theory. However, the idea that astrometry and celestial mechanics should adopt the usual metrological rules is progressing, together with the use of the International System of Units, among astronomers. PMID:21930569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21930569','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21930569"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scales</span> in the context of general relativity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guinot, Bernard</p> <p>2011-10-28</p> <p>Towards 1967, the accuracy of caesium frequency standards reached such a level that the relativistic effect could not be ignored anymore. Corrections began to be applied for the gravitational frequency shift and for distant <span class="hlt">time</span> comparisons. However, these corrections were not applied to an explicit theoretical framework. Only in 1991 did the International Astronomical Union provide metrics (then improved in 2000) for a definition of space-<span class="hlt">time</span> coordinates in reference systems centred at the barycentre of the Solar System and at the centre of mass of the Earth. In these systems, the temporal coordinates (coordinate <span class="hlt">times</span>) can be realized on the basis of one of them, the International Atomic <span class="hlt">Time</span> (TAI), which is itself a realized <span class="hlt">time</span> <span class="hlt">scale</span>. The definition and the role of TAI in this context will be recalled. There remain controversies regarding the name to be given to the unit of coordinate <span class="hlt">times</span> and to other quantities appearing in the theory. However, the idea that astrometry and celestial mechanics should adopt the usual metrological rules is progressing, together with the use of the International System of Units, among astronomers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16877564','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16877564"><span id="translatedtitle"><span class="hlt">Scale</span>-space analysis of <span class="hlt">time</span> series in circulatory research.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mortensen, Kim Erlend; Godtliebsen, Fred; Revhaug, Arthur</p> <p>2006-12-01</p> <p>Statistical analysis of <span class="hlt">time</span> series is still inadequate within circulation research. With the advent of increasing computational power and real-<span class="hlt">time</span> recordings from hemodynamic studies, one is increasingly dealing with vast amounts of data in <span class="hlt">time</span> series. This paper aims to illustrate how statistical analysis using the significant nonstationarities (SiNoS) method may complement traditional repeated-measures ANOVA and linear mixed models. We applied these methods on a dataset of local hepatic and systemic circulatory changes induced by aortoportal shunting and graded liver resection. We found SiNoS analysis more comprehensive when compared with traditional statistical analysis in the following four ways: 1) the method allows better signal-to-noise detection; 2) including all data points from real <span class="hlt">time</span> recordings in a statistical analysis permits better detection of significant features in the data; 3) analysis with multiple <span class="hlt">scales</span> of resolution facilitates a more differentiated observation of the material; and 4) the method affords excellent visual presentation by combining group differences, <span class="hlt">time</span> trends, and multiscale statistical analysis allowing the observer to quickly view and evaluate the material. It is our opinion that SiNoS analysis of <span class="hlt">time</span> series is a very powerful statistical tool that may be used to complement conventional statistical methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6127215','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6127215"><span id="translatedtitle">Multiple <span class="hlt">time-scale</span> methods in particle simulations of plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cohen, B.I.</p> <p>1985-02-14</p> <p>This paper surveys recent advances in the application of multiple <span class="hlt">time-scale</span> methods to particle simulation of collective phenomena in plasmas. These methods dramatically improve the efficiency of simulating low-frequency kinetic behavior by allowing the use of a large timestep, while retaining accuracy. The numerical schemes surveyed provide selective damping of unwanted high-frequency waves and preserve numerical stability in a variety of physics models: electrostatic, magneto-inductive, Darwin and fully electromagnetic. The paper reviews hybrid simulation models, the implicitmoment-equation method, the direct implicit method, orbit averaging, and subcycling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000IJMPC..11.1209D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000IJMPC..11.1209D"><span id="translatedtitle"><span class="hlt">Scaling</span> in a Continuous <span class="hlt">Time</span> Model for Biological Aging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Almeida, R. M. C.; Thomas, G. L.</p> <p></p> <p>In this paper, we consider a generalization to the asexual version of Penna model for biological aging, where we take a continuous <span class="hlt">time</span> limit. The genotype associated to each individual is an interval of real numbers over which Dirac δ-functions are defined, representing genetically programmed diseases to be switched on at defined ages of the individual life. We discuss two different continuous limits for the evolution equation and two different mutation protocols, to be implemented during reproduction. Exact stationary solutions are obtained and <span class="hlt">scaling</span> properties are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNG33B3843R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNG33B3843R"><span id="translatedtitle"><span class="hlt">Time</span>-Dependent Earthquake Forecasts on a Global <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rundle, J. B.; Holliday, J. R.; Turcotte, D. L.; Graves, W. R.</p> <p>2014-12-01</p> <p>We develop and implement a new type of global earthquake forecast. Our forecast is a perturbation on a smoothed seismicity (Relative Intensity) spatial forecast combined with a temporal <span class="hlt">time</span>-averaged ("Poisson") forecast. A variety of statistical and fault-system models have been discussed for use in computing forecast probabilities. An example is the Working Group on California Earthquake Probabilities, which has been using fault-based models to compute conditional probabilities in California since 1988. An example of a forecast is the Epidemic-Type Aftershock Sequence (ETAS), which is based on the Gutenberg-Richter (GR) magnitude-frequency law, the Omori aftershock law, and Poisson statistics. The method discussed in this talk is based on the observation that GR statistics characterize seismicity for all space and <span class="hlt">time</span>. Small magnitude event counts (quake counts) are used as "markers" for the approach of large events. More specifically, if the GR b-value = 1, then for every 1000 M>3 earthquakes, one expects 1 M>6 earthquake. So if ~1000 M>3 events have occurred in a spatial region since the last M>6 earthquake, another M>6 earthquake should be expected soon. In physics, event count models have been called natural <span class="hlt">time</span> models, since counts of small events represent a physical or natural <span class="hlt">time</span> <span class="hlt">scale</span> characterizing the system dynamics. In a previous research, we used conditional Weibull statistics to convert event counts into a temporal probability for a given fixed region. In the present paper, we move belyond a fixed region, and develop a method to compute these Natural <span class="hlt">Time</span> Weibull (NTW) forecasts on a global <span class="hlt">scale</span>, using an internally consistent method, in regions of arbitrary shape and size. We develop and implement these methods on a modern web-service computing platform, which can be found at www.openhazards.com and www.quakesim.org. We also discuss constraints on the User Interface (UI) that follow from practical considerations of site usability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006cosp...36.1762C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006cosp...36.1762C"><span id="translatedtitle"><span class="hlt">Scale</span> analysis of pre- and post-midnight ESF bubbles at storm <span class="hlt">time</span> and quiet <span class="hlt">time</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, K. Y.; Su, S. Y.; Yeh, H. C.; Liu, C. H.</p> <p></p> <p>This paper investigates intermediate <span class="hlt">scale</span> plasma structures observed by ROCSAT-1 in the equatorial F region The empirical mode decomposition EMD method of Hilbert-Huang transform HHT technique is utilized to develop a procedure of <span class="hlt">scale</span> analysis that allows the mutually correlated components in velocity density and relative density gradient to be identified and extracted Comparing the three data sets good match in wave form is found for velocity and density in <span class="hlt">scales</span> between kilometers and hundred meters It implies that there are electric fields proportional to density fluctuation -- delta N N in the form similar to what is expected for the Rayleigh Taylor instability In smaller <span class="hlt">scales</span> velocity and density don t correlate to each other more the good match is then found in velocity and density gradient This is the manifestation of the Boltzmann relation By studying the cases in post-midnight and pre-midnight under storm <span class="hlt">time</span> and quiet <span class="hlt">time</span> we find the one-to-one match hold although it is known that ESF bubbles can be driven by different mechanisms under different conditions In other words the spatial structures of electric field in the intermediate <span class="hlt">scale</span> will always be correlated to the density structures in a manner of delta E sim - delta N N independent of the mechanisms driving the ESF bubbles It is interesting to note that the relation delta V z quad sim delta N N for irregularities in <span class="hlt">scale</span> of kilometers holds only for ESF occurs within -5 dip latitude while the Boltzmann relation delta</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T24C..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T24C..01S"><span id="translatedtitle">Cross-<span class="hlt">Scale</span> Modelling of Subduction from Minute to Million of Years <span class="hlt">Time</span> <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sobolev, S. V.; Muldashev, I. A.</p> <p>2015-12-01</p> <p>Subduction is an essentially multi-<span class="hlt">scale</span> process with <span class="hlt">time-scales</span> spanning from geological to earthquake <span class="hlt">scale</span> with the seismic cycle in-between. Modelling of such process constitutes one of the largest challenges in geodynamic modelling today.Here we present a cross-<span class="hlt">scale</span> thermomechanical model capable of simulating the entire subduction process from rupture (1 min) to geological <span class="hlt">time</span> (millions of years) that employs elasticity, mineral-physics-constrained non-linear transient viscous rheology and rate-and-state friction plasticity. The model generates spontaneous earthquake sequences. The adaptive <span class="hlt">time</span>-step algorithm recognizes moment of instability and drops the integration <span class="hlt">time</span> step to its minimum value of 40 sec during the earthquake. The <span class="hlt">time</span> step is then gradually increased to its maximal value of 5 yr, following decreasing displacement rates during the postseismic relaxation. Efficient implementation of numerical techniques allows long-term simulations with total <span class="hlt">time</span> of millions of years. This technique allows to follow in details deformation process during the entire seismic cycle and multiple seismic cycles. We observe various deformation patterns during modelled seismic cycle that are consistent with surface GPS observations and demonstrate that, contrary to the conventional ideas, the postseismic deformation may be controlled by viscoelastic relaxation in the mantle wedge, starting within only a few hours after the great (M>9) earthquakes. Interestingly, in our model an average slip velocity at the fault closely follows hyperbolic decay law. In natural observations, such deformation is interpreted as an afterslip, while in our model it is caused by the viscoelastic relaxation of mantle wedge with viscosity strongly varying with <span class="hlt">time</span>. We demonstrate that our results are consistent with the postseismic surface displacement after the Great Tohoku Earthquake for the day-to-year <span class="hlt">time</span> range. We will also present results of the modeling of deformation of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNCS.5690..675L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNCS.5690..675L"><span id="translatedtitle">Alignment of Noisy and Uniformly <span class="hlt">Scaled</span> <span class="hlt">Time</span> Series</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lipowsky, Constanze; Dranischnikow, Egor; Göttler, Herbert; Gottron, Thomas; Kemeter, Mathias; Schömer, Elmar</p> <p></p> <p>The alignment of noisy and uniformly <span class="hlt">scaled</span> <span class="hlt">time</span> series is an important but difficult task. Given two <span class="hlt">time</span> series, one of which is a uniformly stretched subsequence of the other, we want to determine the stretching factor and the offset of the second <span class="hlt">time</span> series within the first one. We adapted and enhanced different methods to address this problem: classical FFT-based approaches to determine the offset combined with a naïve search for the stretching factor or its direct computation in the frequency domain, bounded dynamic <span class="hlt">time</span> warping and a new approach called shotgun analysis, which is inspired by sequencing and reassembling of genomes in bioinformatics. We thoroughly examined the strengths and weaknesses of the different methods on synthetic and real data sets. The FFT-based approaches are very accurate on high quality data, the shotgun approach is especially suitable for data with outliers. Dynamic <span class="hlt">time</span> warping is a candidate for non-linear stretching or compression. We successfully applied the presented methods to identify steel coils via their thickness profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OcDyn..64..797T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OcDyn..64..797T"><span id="translatedtitle">Estimating ventilation <span class="hlt">time</span> <span class="hlt">scales</span> using overturning stream functions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thompson, Bijoy; Nycander, Jonas; Nilsson, Johan; Jakobsson, Martin; Döös, Kristofer</p> <p>2014-06-01</p> <p>A simple method for estimating ventilation <span class="hlt">time</span> <span class="hlt">scales</span> from overturning stream functions is proposed. The stream function may be computed using either geometric coordinates or a generalized vertical coordinate, such as potential density (salinity in our study). The method is tested with a three-dimensional circulation model describing an idealized semi-enclosed ocean basin ventilated through a narrow strait over a sill, and the result is compared to age estimates obtained from a passive numerical age tracer. The best result is obtained when using the stream function in salinity coordinates. In this case, the reservoir-averaged advection <span class="hlt">time</span> obtained from the overturning stream function in salinity coordinates agrees rather well with the mean age of the age tracer, and the corresponding maximum ages agree very well.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JChPh.141d4109L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JChPh.141d4109L"><span id="translatedtitle">Exact dynamical coarse-graining without <span class="hlt">time-scale</span> separation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Jianfeng; Vanden-Eijnden, Eric</p> <p>2014-07-01</p> <p>A family of collective variables is proposed to perform exact dynamical coarse-graining even in systems without <span class="hlt">time</span> <span class="hlt">scale</span> separation. More precisely, it is shown that these variables are not slow in general, yet satisfy an overdamped Langevin equation that statistically preserves the sequence in which any regions in collective variable space are visited and permits to calculate exactly the mean first passage <span class="hlt">times</span> from any such region to another. The role of the free energy and diffusion coefficient in this overdamped Langevin equation is discussed, along with the way they transform under any change of variable in collective variable space. These results apply both to systems with and without inertia, and they can be generalized to using several collective variables simultaneously. The view they offer on what makes collective variables and reaction coordinates optimal breaks from the standard notion that good collective variable must be slow variable, and it suggests new ways to interpret data from molecular dynamics simulations and experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMAE31A0272L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMAE31A0272L"><span id="translatedtitle">Infrasonic Observations of Thunderstorms at High Latitudes: <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liszka, L. J.</p> <p>2008-12-01</p> <p>The present work summarizes some results of infrasonic observations of thunderstorms recorded in the Northern Scandinavia by the Swedish-Finnish Infrasound Network (SIN). A lightning in the atmosphere is a source of cylindrical shock waves. When the distance from the source increases, more and more energy is transferred into the low-frequency range through the same mechanism as for shock waves from supersonic aircraft. Frequently, semi-regular sequences of lightning with similar orientation and nearly constant repetition frequency are observed. For that reason the spectrum of <span class="hlt">time</span> delays between individual strokes is studied. It has been found that the apparent random occurrence of strokes seems be a result of superposition of several processes with slowly varying <span class="hlt">time</span> <span class="hlt">scales</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000067661','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000067661"><span id="translatedtitle">Reusable Launch Vehicle Control In Multiple <span class="hlt">Time</span> <span class="hlt">Scale</span> Sliding Modes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shtessel, Yuri; Hall, Charles; Jackson, Mark</p> <p>2000-01-01</p> <p>A reusable launch vehicle control problem during ascent is addressed via multiple-<span class="hlt">time</span> <span class="hlt">scaled</span> continuous sliding mode control. The proposed sliding mode controller utilizes a two-loop structure and provides robust, de-coupled tracking of both orientation angle command profiles and angular rate command profiles in the presence of bounded external disturbances and plant uncertainties. Sliding mode control causes the angular rate and orientation angle tracking error dynamics to be constrained to linear, de-coupled, homogeneous, and vector valued differential equations with desired eigenvalues placement. Overall stability of a two-loop control system is addressed. An optimal control allocation algorithm is designed that allocates torque commands into end-effector deflection commands, which are executed by the actuators. The dual-<span class="hlt">time</span> <span class="hlt">scale</span> sliding mode controller was designed for the X-33 technology demonstration sub-orbital launch vehicle in the launch mode. Simulation results show that the designed controller provides robust, accurate, de-coupled tracking of the orientation angle command profiles in presence of external disturbances and vehicle inertia uncertainties. This is a significant advancement in performance over that achieved with linear, gain scheduled control systems currently being used for launch vehicles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030020733&hterms=analysis+floods&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Danalysis%2Bfloods','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030020733&hterms=analysis+floods&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Danalysis%2Bfloods"><span id="translatedtitle">Global Precipitation Analyses at Monthly to 3-HR <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adler, Robert F.; Huffman, George; Curtis, Scott; Bolvin, David; Nelkin, Eric</p> <p>2002-01-01</p> <p>Global precipitation analysis covering the last few decades and the impact of the new TRMM precipitation observations are discussed. The 20+ year, monthly, globally complete precipitation analysis of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP) is used to explore global and regional variations and trends and is compared to the much shorter TRMM(Tropica1 Rainfall Measuring Mission) tropical data set. A trend pattern that is a combination of both El Nino and La Nina precipitation features is evident in the 20-year data set. This pattern is related to an increase with <span class="hlt">time</span> in the number of combined months of El Nino and La Nina during the 20 year period. Monthly anomalies of precipitation are related to ENSO variations with clear signals extending into middle and high latitudes of both hemispheres. The GPCP daily, 1deg latitude-longitude analysis, which is available from January 1997 to the present is described and the evolution of precipitation patterns on this <span class="hlt">time</span> <span class="hlt">scale</span> related to El Nino and La Nina is described. Finally, a TRMM-based 3-hr analysis is described that uses TRMM to calibrate polar-orbit microwave observations from SSM/I and geosynchronous IR observations and merges the various calibrated observations into a final, 3-hr resolution map. This TRMM standard product will soon be available for the entire TRMM period (January 1998- present). A real-<span class="hlt">time</span> version of this merged product is being produced and is available at 0.25deg latitude-longitude resolution over the latitude range from 50degN-50degS. Images from this data set can be seen at the U.S. TRMM web site (trmm.gsfc.nasa.gov). Examples will be shown, including its use in monitoring flood conditions and relating weather-<span class="hlt">scale</span> events to climate variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFMOS71A0261S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFMOS71A0261S"><span id="translatedtitle">Modelling <span class="hlt">Time</span> and Length <span class="hlt">Scales</span> of Scour Around a Pipeline</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, H. D.; Foster, D. L.</p> <p>2002-12-01</p> <p>The scour and burial of submarine objects is an area of interest for engineers, oceanographers and military personnel. Given the limited availability of field observations, there exists a need to accurately describe the hydrodynamics and sediment response around an obstacle using numerical models. In this presentation, we will compare observations of submarine pipeline scour with model predictions. The research presented here uses the computational fluid dynamics (CFD) model FLOW-3D. FLOW-3D, developed by Flow Science in Santa Fe, NM, is a 3-dimensional finite-difference model that solves the Navier-Stokes and continuity equations. Using the Volume of Fluid (VOF) technique, FLOW-3D is able to resolve fluid-fluid and fluid-air interfaces. The FAVOR technique allows for complex geometry to be resolved with rectangular grids. FLOW-3D uses a bulk transport method to describe sediment transport and feedback to the hydrodynamic solver is accomplished by morphology evolution and fluid viscosity due to sediment suspension. Previous investigations by the authors have shown FLOW-3D to well-predict the hydrodynamics around five static scoured bed profiles and a stationary pipeline (``Modelling of Flow Around a Cylinder Over a Scoured Bed,'' submit to Journal of Waterway, Port, Coastal, and Ocean Engineering). Following experiments performed by Mao (1986, Dissertation, Technical University of Denmark), we will be performing model-data comparisons of length and <span class="hlt">time</span> <span class="hlt">scales</span> for scour around a pipeline. Preliminary investigations with LES and k-ɛ closure schemes have shown that the model predicts shorter <span class="hlt">time</span> <span class="hlt">scales</span> in scour hole development than that observed by Mao. Predicted <span class="hlt">time</span> and length <span class="hlt">scales</span> of scour hole development are shown to be a function of turbulence closure scheme, grain size, and hydrodynamic forcing. Subsequent investigations consider variable wave-current flow regimes and object burial. This investigation will allow us to identify different regimes for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26486804','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26486804"><span id="translatedtitle">Continent-<span class="hlt">scale</span> global change attribution in European birds - combining annual and decadal <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jørgensen, Peter Søgaard; Böhning-Gaese, Katrin; Thorup, Kasper; Tøttrup, Anders P; Chylarecki, Przemysław; Jiguet, Frédéric; Lehikoinen, Aleksi; Noble, David G; Reif, Jiri; Schmid, Hans; van Turnhout, Chris; Burfield, Ian J; Foppen, Ruud; Voříšek, Petr; van Strien, Arco; Gregory, Richard D; Rahbek, Carsten</p> <p>2016-02-01</p> <p>Species attributes are commonly used to infer impacts of environmental change on multiyear species trends, e.g. decadal changes in population size. However, by themselves attributes are of limited value in global change attribution since they do not measure the changing environment. A broader foundation for attributing species responses to global change may be achieved by complementing an attributes-based approach by one estimating the relationship between repeated measures of organismal and environmental changes over short <span class="hlt">time</span> <span class="hlt">scales</span>. To assess the benefit of this multiscale perspective, we investigate the recent impact of multiple environmental changes on European farmland birds, here focusing on climate change and land use change. We analyze more than 800 <span class="hlt">time</span> series from 18 countries spanning the past two decades. Analysis of long-term population growth rates documents simultaneous responses that can be attributed to both climate change and land-use change, including long-term increases in populations of hot-dwelling species and declines in long-distance migrants and farmland specialists. In contrast, analysis of annual growth rates yield novel insights into the potential mechanisms driving long-term climate induced change. In particular, we find that birds are affected by winter, spring, and summer conditions depending on the distinct breeding phenology that corresponds to their migratory strategy. Birds in general benefit from higher temperatures or higher primary productivity early on or in the peak of the breeding season with the largest effect sizes observed in cooler parts of species' climatic ranges. Our results document the potential of combining <span class="hlt">time</span> <span class="hlt">scales</span> and integrating both species attributes and environmental variables for global change attribution. We suggest such an approach will be of general use when high-resolution <span class="hlt">time</span> series are available in large-<span class="hlt">scale</span> biodiversity surveys. PMID:26486804</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26486804','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26486804"><span id="translatedtitle">Continent-<span class="hlt">scale</span> global change attribution in European birds - combining annual and decadal <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jørgensen, Peter Søgaard; Böhning-Gaese, Katrin; Thorup, Kasper; Tøttrup, Anders P; Chylarecki, Przemysław; Jiguet, Frédéric; Lehikoinen, Aleksi; Noble, David G; Reif, Jiri; Schmid, Hans; van Turnhout, Chris; Burfield, Ian J; Foppen, Ruud; Voříšek, Petr; van Strien, Arco; Gregory, Richard D; Rahbek, Carsten</p> <p>2016-02-01</p> <p>Species attributes are commonly used to infer impacts of environmental change on multiyear species trends, e.g. decadal changes in population size. However, by themselves attributes are of limited value in global change attribution since they do not measure the changing environment. A broader foundation for attributing species responses to global change may be achieved by complementing an attributes-based approach by one estimating the relationship between repeated measures of organismal and environmental changes over short <span class="hlt">time</span> <span class="hlt">scales</span>. To assess the benefit of this multiscale perspective, we investigate the recent impact of multiple environmental changes on European farmland birds, here focusing on climate change and land use change. We analyze more than 800 <span class="hlt">time</span> series from 18 countries spanning the past two decades. Analysis of long-term population growth rates documents simultaneous responses that can be attributed to both climate change and land-use change, including long-term increases in populations of hot-dwelling species and declines in long-distance migrants and farmland specialists. In contrast, analysis of annual growth rates yield novel insights into the potential mechanisms driving long-term climate induced change. In particular, we find that birds are affected by winter, spring, and summer conditions depending on the distinct breeding phenology that corresponds to their migratory strategy. Birds in general benefit from higher temperatures or higher primary productivity early on or in the peak of the breeding season with the largest effect sizes observed in cooler parts of species' climatic ranges. Our results document the potential of combining <span class="hlt">time</span> <span class="hlt">scales</span> and integrating both species attributes and environmental variables for global change attribution. We suggest such an approach will be of general use when high-resolution <span class="hlt">time</span> series are available in large-<span class="hlt">scale</span> biodiversity surveys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1231575-absolute-path-command','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1231575-absolute-path-command"><span id="translatedtitle">The <span class="hlt">absolute</span> path command</span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p>2012-05-11</p> <p>The ap command traveres all symlinks in a given file, directory, or executable name to identify the final <span class="hlt">absolute</span> path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the <span class="hlt">absolute</span> path to a relative directory from the current working directory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1231575','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1231575"><span id="translatedtitle">The <span class="hlt">absolute</span> path command</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moody, A.</p> <p>2012-05-11</p> <p>The ap command traveres all symlinks in a given file, directory, or executable name to identify the final <span class="hlt">absolute</span> path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the <span class="hlt">absolute</span> path to a relative directory from the current working directory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27300941','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27300941"><span id="translatedtitle">Rotational relaxation <span class="hlt">time</span> as unifying <span class="hlt">time</span> <span class="hlt">scale</span> for polymer and fiber drag reduction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boelens, A M P; Muthukumar, M</p> <p>2016-05-01</p> <p>Using hybrid direct numerical simulation plus Langevin dynamics, a comparison is performed between polymer and fiber stress tensors in turbulent flow. The stress tensors are found to be similar, suggesting a common drag reducing mechanism in the onset regime for both flexible polymers and rigid fibers. Since fibers do not have an elastic backbone, this must be a viscous effect. Analysis of the viscosity tensor reveals that all terms are negligible, except the off-diagonal shear viscosity associated with rotation. Based on this analysis, we identify the rotational orientation <span class="hlt">time</span> as the unifying <span class="hlt">time</span> <span class="hlt">scale</span> setting a new <span class="hlt">time</span> criterion for drag reduction by both flexible polymers and rigid fibers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.7149E..17D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.7149E..17D"><span id="translatedtitle">A study of predictability of SST at different <span class="hlt">time</span> <span class="hlt">scales</span> based on satellite <span class="hlt">time</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Youzhuan; Fu, Dongyang; Wei, Zhihui; He, Xianqiang; Huang, Haiqing; Pan, Delu</p> <p>2008-12-01</p> <p>Sea surface temperature (SST) is both an important variable for weather and ocean forecasting, but also a key indicator of climate change. Predicting future SST at different <span class="hlt">time</span> <span class="hlt">scales</span> constitutes an important scientific problem. The traditional approach to prediction is achieved through numerical simulation, but it is difficult to obtain a detailed knowledge of ocean initial conditions and forcing. This paper proposes a improved prediction system based on SOFT proposed by Alvarez et al and studies the predictability of SST at different <span class="hlt">time</span> <span class="hlt">scales</span>, i.e., 5 day, 10 day, 15 day, 20 day and month ahead. This method is used to forecast the SST in the Yangtze River estuary and its adjacent areas. The period of <span class="hlt">time</span> ranging from Jan 1st 2000 to Dec 31st 2005 is employed to build the prediction system and the period of <span class="hlt">time</span> ranging from Jan 1st 2006 to Dec 31st 2007 is employed to validate the performance of this prediction system. Results indicate: The prediction errors of 5 day,10 day,15 day, 20 day and monthly ahead are 0.78°C,0.86°C,0.90°C,1.00°C and 1.45°C respectively. The longer of <span class="hlt">time</span> <span class="hlt">scales</span> prediction, the worse of prediction capability. Compared with the SOFT system proposed by Alvarez et al, the improved prediction system is more robust. Merging more satellite data and trying to better reflect the real state of ocean variables, we can greatly improve the predictive precision of long <span class="hlt">time</span> <span class="hlt">scale</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930031964&hterms=1083&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231083','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930031964&hterms=1083&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231083"><span id="translatedtitle">Variations in solar Lyman alpha irradiance on short <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pap, J. M.</p> <p>1992-01-01</p> <p>Variations in solar UV irradiance at Lyman alpha are studied on short <span class="hlt">time</span> <span class="hlt">scales</span> (from days to months) after removing the long-term changes over the solar cycle. The SME/Lyman alpha irradiance is estimated from various solar indices using linear regression analysis. In order to study the nonlinear effects, Lyman alpha irradiance is modeled with a 5th-degree polynomial as well. It is shown that the full-disk equivalent width of the He line at 1083 nm, which is used as a proxy for the plages and active network, can best reproduce the changes observed in Lyman alpha. Approximately 72 percent of the solar-activity-related changes in Lyman alpha irradiance arise from plages and the network. The network contribution is estimated by the correlation analysis to be about 19 percent. It is shown that significant variability remains in Lyman alpha irradiance, with periods around 300, 27, and 13.5d, which is not explained by the solar activity indices. It is shown that the nonlinear effects cannot account for a significant part of the unexplained variation in Lyman alpha irradiance. Therefore, additional events (e.g., large-<span class="hlt">scale</span> motions and/or a systematic difference in the area and intensity of the plages and network observed in the lines of Ca-K, He 1083, and Lyman alpha) may explain the discrepancies found between the observed and estimated irradiance values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27679569','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27679569"><span id="translatedtitle">Neural Computations in a Dynamical System with Multiple <span class="hlt">Time</span> <span class="hlt">Scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mi, Yuanyuan; Lin, Xiaohan; Wu, Si</p> <p>2016-01-01</p> <p>Neural systems display rich short-term dynamics at various levels, e.g., spike-frequency adaptation (SFA) at the single-neuron level, and short-term facilitation (STF) and depression (STD) at the synapse level. These dynamical features typically cover a broad range of <span class="hlt">time</span> <span class="hlt">scales</span> and exhibit large diversity in different brain regions. It remains unclear what is the computational benefit for the brain to have such variability in short-term dynamics. In this study, we propose that the brain can exploit such dynamical features to implement multiple seemingly contradictory computations in a single neural circuit. To demonstrate this idea, we use continuous attractor neural network (CANN) as a working model and include STF, SFA and STD with increasing <span class="hlt">time</span> constants in its dynamics. Three computational tasks are considered, which are persistent activity, adaptation, and anticipative tracking. These tasks require conflicting neural mechanisms, and hence cannot be implemented by a single dynamical feature or any combination with similar <span class="hlt">time</span> constants. However, with properly coordinated STF, SFA and STD, we show that the network is able to implement the three computational tasks concurrently. We hope this study will shed light on the understanding of how the brain orchestrates its rich dynamics at various levels to realize diverse cognitive functions. PMID:27679569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5020071','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5020071"><span id="translatedtitle">Neural Computations in a Dynamical System with Multiple <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mi, Yuanyuan; Lin, Xiaohan; Wu, Si</p> <p>2016-01-01</p> <p>Neural systems display rich short-term dynamics at various levels, e.g., spike-frequency adaptation (SFA) at the single-neuron level, and short-term facilitation (STF) and depression (STD) at the synapse level. These dynamical features typically cover a broad range of <span class="hlt">time</span> <span class="hlt">scales</span> and exhibit large diversity in different brain regions. It remains unclear what is the computational benefit for the brain to have such variability in short-term dynamics. In this study, we propose that the brain can exploit such dynamical features to implement multiple seemingly contradictory computations in a single neural circuit. To demonstrate this idea, we use continuous attractor neural network (CANN) as a working model and include STF, SFA and STD with increasing <span class="hlt">time</span> constants in its dynamics. Three computational tasks are considered, which are persistent activity, adaptation, and anticipative tracking. These tasks require conflicting neural mechanisms, and hence cannot be implemented by a single dynamical feature or any combination with similar <span class="hlt">time</span> constants. However, with properly coordinated STF, SFA and STD, we show that the network is able to implement the three computational tasks concurrently. We hope this study will shed light on the understanding of how the brain orchestrates its rich dynamics at various levels to realize diverse cognitive functions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5020071','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5020071"><span id="translatedtitle">Neural Computations in a Dynamical System with Multiple <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mi, Yuanyuan; Lin, Xiaohan; Wu, Si</p> <p>2016-01-01</p> <p>Neural systems display rich short-term dynamics at various levels, e.g., spike-frequency adaptation (SFA) at the single-neuron level, and short-term facilitation (STF) and depression (STD) at the synapse level. These dynamical features typically cover a broad range of <span class="hlt">time</span> <span class="hlt">scales</span> and exhibit large diversity in different brain regions. It remains unclear what is the computational benefit for the brain to have such variability in short-term dynamics. In this study, we propose that the brain can exploit such dynamical features to implement multiple seemingly contradictory computations in a single neural circuit. To demonstrate this idea, we use continuous attractor neural network (CANN) as a working model and include STF, SFA and STD with increasing <span class="hlt">time</span> constants in its dynamics. Three computational tasks are considered, which are persistent activity, adaptation, and anticipative tracking. These tasks require conflicting neural mechanisms, and hence cannot be implemented by a single dynamical feature or any combination with similar <span class="hlt">time</span> constants. However, with properly coordinated STF, SFA and STD, we show that the network is able to implement the three computational tasks concurrently. We hope this study will shed light on the understanding of how the brain orchestrates its rich dynamics at various levels to realize diverse cognitive functions. PMID:27679569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.7208W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.7208W"><span id="translatedtitle">Multi-<span class="hlt">scale</span> gravity field modeling in space and <span class="hlt">time</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Shuo; Panet, Isabelle; Ramillien, Guillaume; Guilloux, Frédéric</p> <p>2016-04-01</p> <p>The Earth constantly deforms as it undergoes dynamic phenomena, such as earthquakes, post-glacial rebound and water displacement in its fluid envelopes. These processes have different spatial and temporal <span class="hlt">scales</span> and are accompanied by mass displacements, which create temporal variations of the gravity field. Since 2002, the GRACE satellite missions provide an unprecedented view of the gravity field spatial and temporal variations. Gravity models built from these satellite data are essential to study the Earth's dynamic processes (Tapley et al., 2004). Up to present, <span class="hlt">time</span> variations of the gravity field are often modelled using spatial spherical harmonics functions averaged over a fixed period, as 10 days or 1 month. This approach is well suited for modeling global phenomena. To better estimate gravity related to local and/or transient processes, such as earthquakes or floods, and adapt the temporal resolution of the model to its spatial resolution, we propose to model the gravity field using localized functions in space and <span class="hlt">time</span>. For that, we build a model of the gravity field in space and <span class="hlt">time</span> with a four-dimensional wavelet basis, well localized in space and <span class="hlt">time</span>. First we design the 4D basis, then, we study the inverse problem to model the gravity field from the potential differences between the twin GRACE satellites, and its regularization using prior knowledge on the water cycle. Our demonstration of surface water mass signals decomposition in <span class="hlt">time</span> and space is based on the use of synthetic along-track gravitational potential data. We test the developed approach on one year of 4D gravity modeling and compare the reconstructed water heights to those of the input hydrological model. Perspectives of this work is to apply the approach on real GRACE data, addressing the challenge of a realistic noise, to better describe and understand physical processus with high temporal resolution/low spatial resolution or the contrary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JCoAM.232..594E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JCoAM.232..594E"><span id="translatedtitle">Nonoscillation for second order sublinear dynamic equations on <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Erbe, Lynn; Baoguo, Jia; Peterson, Allan</p> <p>2009-10-01</p> <p>Consider the Emden-Fowler sublinear dynamic equation x[Delta][Delta](t)+p(t)f(x([sigma](t)))=0, where , is a <span class="hlt">time</span> <span class="hlt">scale</span>, , where ai>0, 0<[beta]i<1, with [beta]i the quotient of odd positive integers, 1<=i<=m. When m=1, and , (0.1) is the usual sublinear Emden-Fowler equation which has attracted the attention of many researchers. In this paper, we allow the coefficient function p(t) to be negative for arbitrarily large values of t. We extend a nonoscillation result of Wong for the second order sublinear Emden-Fowler equation in the continuous case to the dynamic equation (0.1). As applications, we show that the sublinear difference equation has a nonoscillatory solution, for b>0, c>[alpha], and the sublinear q-difference equation has a nonoscillatory solution, for , q>1, b>0, c>1+[alpha].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26918994','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26918994"><span id="translatedtitle">Dynamic Leidenfrost Effect: Relevant <span class="hlt">Time</span> and Length <span class="hlt">Scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shirota, Minori; van Limbeek, Michiel A J; Sun, Chao; Prosperetti, Andrea; Lohse, Detlef</p> <p>2016-02-12</p> <p>When a liquid droplet impacts a hot solid surface, enough vapor may be generated under it to prevent its contact with the solid. The minimum solid temperature for this so-called Leidenfrost effect to occur is termed the Leidenfrost temperature, or the dynamic Leidenfrost temperature when the droplet velocity is non-negligible. We observe the wetting or drying and the levitation dynamics of the droplet impacting on an (isothermal) smooth sapphire surface using high-speed total internal reflection imaging, which enables us to observe the droplet base up to about 100 nm above the substrate surface. By this method we are able to reveal the processes responsible for the transitional regime between the fully wetting and the fully levitated droplet as the solid temperature increases, thus shedding light on the characteristic <span class="hlt">time</span> and length <span class="hlt">scales</span> setting the dynamic Leidenfrost temperature for droplet impact on an isothermal substrate. PMID:26918994</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23978849','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23978849"><span id="translatedtitle">The effect of photosynthesis <span class="hlt">time</span> <span class="hlt">scales</span> on microalgae productivity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hartmann, Philipp; Béchet, Quentin; Bernard, Olivier</p> <p>2014-01-01</p> <p>Microalgae are often seen as a potential biofuel producer. In order to predict achievable productivities in the so called raceway culturing system, the dynamics of photosynthesis has to be taken into account. In particular, the dynamical effect of inhibition by an excess of light (photoinhibition) must be represented. We propose a model considering both photosynthesis and growth dynamics. This model involves three different <span class="hlt">time</span> <span class="hlt">scales</span>. We study the response of this model to fluctuating light with different frequencies by slow/fast approximations. Therefore, we identify three different regimes for which a simplified expression for the model can be derived. These expressions give a hint on productivity improvement which can be expected by stimulating photosynthesis with a faster hydrodynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770012044','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770012044"><span id="translatedtitle">X-ray signatures: New <span class="hlt">time</span> <span class="hlt">scales</span> and spectral features</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boldt, E. A.</p> <p>1977-01-01</p> <p>The millisecond bursts from Cyg X-1 are investigated and the overall chaotic variability for the bulk of the Cyg X-1 emission is compared to that of Sco X-1, showing that the essential character is remarkably similar (i.e. shot noise) although the fundamental <span class="hlt">time</span> <span class="hlt">scales</span> involved differ widely, from a fraction of a second (for Cyg X-1) to a fraction of a day (for Sco X-1). Recent OSO-8 observations of spectra features attributable to iron are reviewed. In particular, line emission is discussed within the context of a model for thermal radiation by a hot evolved gas in systems as different as supernova remnants and clusters of galaxies. Newly observed spectral structure in the emission from the X-ray pulsar Her X-1 is reported.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007EPJB...59...75L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007EPJB...59...75L"><span id="translatedtitle">Large-<span class="hlt">scale</span> structure of <span class="hlt">time</span> evolving citation networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leicht, E. A.; Clarkson, G.; Shedden, K.; Newman, M. E. J.</p> <p>2007-09-01</p> <p>In this paper we examine a number of methods for probing and understanding the large-<span class="hlt">scale</span> structure of networks that evolve over <span class="hlt">time</span>. We focus in particular on citation networks, networks of references between documents such as papers, patents, or court cases. We describe three different methods of analysis, one based on an expectation-maximization algorithm, one based on modularity optimization, and one based on eigenvector centrality. Using the network of citations between opinions of the United States Supreme Court as an example, we demonstrate how each of these methods can reveal significant structural divisions in the network and how, ultimately, the combination of all three can help us develop a coherent overall picture of the network's shape.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H23B0934L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H23B0934L"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">Scale</span> Dependent SGD due to the Sea Level Change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, K.; Lee, E.; Hyun, Y.</p> <p>2009-12-01</p> <p>Submarine groundwater discharge (SGD) is defined as the groundwater outflux across the ocean-land interface. In this study, the variation of amount of SGD due to the sea level change is investigated by means of numerical simulation. Numerical code FEFLOW (Diersh et al., 2005) is used to conduct the simulation and the effect of sea level change on the variation of SGD with different <span class="hlt">time</span> <span class="hlt">scales</span> from diurnal cycle to glacial cycle is evaluated. The simulation results indicate that generally, the increase of amplitude of sea level leads to the increase of SGD while the increase of period of sea level change cause more complicated pattern of the variation of SGD. These variations are changed with the aquifer properties, especially, hydraulic conductivity. The simulation results show that the sea level change with different period and amplitude leads to the variation of total SGD and it may explain the unknown source of the unexpectedly high amount of SGD.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11006301','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11006301"><span id="translatedtitle">Water relations and leaf expansion: importance of <span class="hlt">time</span> <span class="hlt">scale</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Munns, R; Passioura, J B; Guo, J; Chazen, O; Cramer, G R</p> <p>2000-09-01</p> <p>The role of leaf water relations in controlling cell expansion in leaves of water-stressed maize and barley depends on <span class="hlt">time</span> <span class="hlt">scale</span>. Sudden changes in leaf water status, induced by sudden changes in humidity, light and soil salinity, greatly affect leaf elongation rate, but often only transiently. With sufficiently large changes in salinity, leaf elongation rates are persistently reduced. When plants are kept fully turgid throughout such sudden environmental changes, by placing their roots in a pressure chamber and raising the pressure so that the leaf xylem sap is maintained at atmospheric pressure, both the transient and persistent changes in leaf elongation rate disappear. All these responses show that water relations are responsible for the sudden changes in leaf elongation rate resulting from sudden changes in water stress and putative root signals play no part. However, at a <span class="hlt">time</span> <span class="hlt">scale</span> of days, pressurization fails to maintain high rates of leaf elongation of plants in either saline or drying soil, indicating that root signals are overriding water relations effects. In both saline and drying soil, pressurization does raise the growth rate during the light period, but a subsequent decrease during the dark results in no net effect on leaf growth over a 24 h period. When transpirational demand is very high, however, growth-promoting effects of pressurization during the light period outweigh any reductions in the dark, resulting in a net increase in growth of pressurized plants over 24 h. Thus leaf water status can limit leaf expansion rates during periods of high transpiration despite the control exercised by hormonal effects on a 24 h basis. PMID:11006301</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5802H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5802H"><span id="translatedtitle">Towards a stable numerical <span class="hlt">time</span> <span class="hlt">scale</span> for the early Paleogene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hilgen, Frederik; Kuiper, Klaudia; Sierro, Francisco J.; Wotzlaw, Jorn; Schaltegger, Urs; Sahy, Diana; Condon, Daniel</p> <p>2014-05-01</p> <p>The construction of an astronomical <span class="hlt">time</span> <span class="hlt">scale</span> for the early Paleogene is hampered by ambiguities in the number, correlation and tuning of 405-kyr eccentricity related cycles in deep marine records from ODP cores and land-based sections. The two most competing age models result in astronomical ages for the K/Pg boundary that differ by ~750 kyr (~66.0 Ma of Vandenberghe et al. (2012) versus 65.25 Ma of Westerhold et al. (2012); these ages in turn are consistent with proposed ages for the Fish Canyon sanidine (FCs) that differ by ~300 kyr (28.201 Ma of Kuiper et al. (2008) versus 27.89 Ma of Westerhold et al. (2012)); an even older age of 28.294 Ma is proposed based on a statistical optimization model (Renne et al., 2011). The astronomically calibrated FCs age of 28.201 ± 0.046 Ma of Kuiper et al. (2008), which is consistent with the astronomical age of ~66.0 Ma for the K/Pg boundary, is currently adopted in the standard geological <span class="hlt">time</span> <span class="hlt">scale</span> (GTS2012). Here we combine new and published data in an attempt to solve the controversy and arrive at a stable nuemrical <span class="hlt">time</span> <span class="hlt">scale</span> for the early Paleogene. Supporting their younger age model, Westerhold et al. (2012) argue that the tuning of Miocene sections in the Mediterranean, which underlie the older FCs age of Kuiper et al. (2008) and, hence, the coupled older early Paleogene age model of Vandenberghe et al. (2012), might be too old by three precession cycles. We thoroughly rechecked this tuning; distinctive cycle patterns related to eccentricity and precession-obliquity interference make a younger tuning that would be consistent with the younger astronomical age of 27.89 Ma for the FCs of Westerhold et al. (2012) challenging. Next we compared youngest U/Pb zircon and astronomical ages for a number of ash beds in the tuned Miocene section of Monte dei Corvi. These ages are indistinguishable, indicating that the two independent dating methods yield the same age when the same event is dated. This is consistent with results</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26093508','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26093508"><span id="translatedtitle">Using Laplace Regression to Model and Predict Percentiles of Age at Death When Age Is the Primary <span class="hlt">Time</span> <span class="hlt">Scale</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bellavia, Andrea; Discacciati, Andrea; Bottai, Matteo; Wolk, Alicja; Orsini, Nicola</p> <p>2015-08-01</p> <p>Increasingly often in epidemiologic research, associations between survival <span class="hlt">time</span> and predictors of interest are measured by differences between distribution functions rather than hazard functions. For example, differences in percentiles of survival <span class="hlt">time</span>, expressed in <span class="hlt">absolute</span> <span class="hlt">time</span> units (e.g., weeks), may complement the popular risk ratios, which are unitless measures. When analyzing <span class="hlt">time</span> to an event of interest (e.g., death) in prospective cohort studies, the <span class="hlt">time</span> <span class="hlt">scale</span> can be set to start at birth or at study entry. The advantages of one <span class="hlt">time</span> origin over the other have been thoroughly explored for the estimation of risks but not for the estimation of survival percentiles. In this paper, we analyze the use of different <span class="hlt">time</span> <span class="hlt">scales</span> in the estimation of survival percentiles with Laplace regression. Using this regression method, investigators can estimate percentiles of survival <span class="hlt">time</span> over levels of an exposure of interest while adjusting for potential confounders. Our findings may help to improve modeling strategies and ease interpretation in the estimation of survival percentiles in prospective cohort studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27197958','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27197958"><span id="translatedtitle">Large-<span class="hlt">scale</span> multiplex <span class="hlt">absolute</span> protein quantification of drug-metabolizing enzymes and transporters in human intestine, liver, and kidney microsomes by SWATH-MS: Comparison with MRM/SRM and HR-MRM/PRM.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakamura, Kenji; Hirayama-Kurogi, Mio; Ito, Shingo; Kuno, Takuya; Yoneyama, Toshihiro; Obuchi, Wataru; Terasaki, Tetsuya; Ohtsuki, Sumio</p> <p>2016-08-01</p> <p>The purpose of the present study was to examine simultaneously the <span class="hlt">absolute</span> protein amounts of 152 membrane and membrane-associated proteins, including 30 metabolizing enzymes and 107 transporters, in pooled microsomal fractions of human liver, kidney, and intestine by means of SWATH-MS with stable isotope-labeled internal standard peptides, and to compare the results with those obtained by MRM/SRM and high resolution (HR)-MRM/PRM. The protein expression levels of 27 metabolizing enzymes, 54 transporters, and six other membrane proteins were quantitated by SWATH-MS; other targets were below the lower limits of quantitation. Most of the values determined by SWATH-MS differed by less than 50% from those obtained by MRM/SRM or HR-MRM/PRM. Various metabolizing enzymes were expressed in liver microsomes more abundantly than in other microsomes. Ten, 13, and eight transporters listed as important for drugs by International Transporter Consortium were quantified in liver, kidney, and intestinal microsomes, respectively. Our results indicate that SWATH-MS enables large-<span class="hlt">scale</span> multiplex <span class="hlt">absolute</span> protein quantification while retaining similar quantitative capability to MRM/SRM or HR-MRM/PRM. SWATH-MS is expected to be useful methodology in the context of drug development for elucidating the molecular mechanisms of drug absorption, metabolism, and excretion in the human body based on protein profile information.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMED13A0719S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMED13A0719S"><span id="translatedtitle">Use of a Walk Through <span class="hlt">Time</span> to Facilitate Student Understandings of the Geological <span class="hlt">Time</span> <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shipman, H. L.</p> <p>2004-12-01</p> <p>Students often have difficulties in appreciating just how old the earth and the universe are. While they can simply memorize a number, they really do not understand just how big that number really is, in comparison with other, more familiar student referents like the length of a human lifetime or how long it takes to eat a pizza. (See, e.g., R.D. Trend 2001, J. Research in Science Teaching 38(2): 191-221) Students, and members of the general public, also display such well-known misconceptions as the "Flintstone chronology" of believing that human beings and dinosaurs walked the earth at the same <span class="hlt">time</span>. (In the classic American cartoon "The Flintstones," human beings used dinosaurs as draft animals. As scientists we know this is fiction, but not all members of the public understand that.) In an interdisciplinary undergraduate college class that dealt with astronomy, cosmology, and biological evolution, I used a familiar activity to try to improve student understanding of the concept of <span class="hlt">time</span>'s vastness. Students walked through a pre-determined 600-step path which provided a spatial analogy to the geological <span class="hlt">time</span> <span class="hlt">scale</span>. They stopped at various points and engaged in some pre-determined discussions and debates. This activity is as old as the hills, but reports of its effectiveness or lack thereof are quite scarce. This paper demonstrates that this activity was effective for a general-audience, college student population in the U.S. The growth of student understandings of the geological <span class="hlt">time</span> <span class="hlt">scale</span> was significant as a result of this activity. Students did develop an understanding of <span class="hlt">time</span>'s vastness and were able to articulate this understanding in various ways. This growth was monitored through keeping track of several exam questions and through pre- and post- analysis of student writings. In the pre-writings, students often stated that they had "no idea" about how to illustrate the size of the geological <span class="hlt">time</span> <span class="hlt">scale</span> to someone else. While some post-<span class="hlt">time</span> walk responses</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E.467D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E.467D"><span id="translatedtitle">Forecasting decadal and shorter <span class="hlt">time-scale</span> solar cycle features</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dikpati, Mausumi</p> <p>2016-07-01</p> <p>Solar energetic particles and magnetic fields reach the Earth through the interplanetary medium and affect it in various ways, producing beautiful aurorae, but also electrical blackouts and damage to our technology-dependent economy. The root of energetic solar outputs is the solar activity cycle, which is most likely caused by dynamo processes inside the Sun. It is a formidable task to accurately predict the amplitude, onset and peak <span class="hlt">timings</span> of a solar cycle. After reviewing all solar cycle prediction methods, including empirical as well as physical model-based schemes, I will describe what we have learned from both validation and nonvalidation of cycle 24 forecasts, and how to refine the model-based schemes for upcoming cycle 25 forecasts. Recent observations indicate that within a solar cycle there are shorter <span class="hlt">time-scale</span> 'space weather' features, such as bursts of various forms of activity with approximately one year periodicity. I will demonstrate how global tachocline dynamics could play a crucial role in producing such space weather. The National Center for Atmospheric Research is sponsored by the National Science Foundation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4861..163L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4861..163L"><span id="translatedtitle">Quality Enhancement of Packet Audio with <span class="hlt">Time-Scale</span> Modification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Fang; Kuo, C.-C. Jay</p> <p>2002-12-01</p> <p>In traditional packet voice or the emerging 2.5G and 3G wireless data services, smooth and <span class="hlt">timely</span> delivery of audio is an essential requirement in Quality of Service (QoS) provision. It has been shown in our previous work that, by adapting <span class="hlt">time-scale</span> modification to audio signals, an adaptive play-out algorithm can be designed to minimize packet dropping at the receiver end. By stretching the audio frame duration up and down, the proposed algorithm could adapt quickly to accommodate fluctuating delays including delay spikes. In this paper, we will address the packet audio QoS with emphasis on end-to-end delay, packet loss, and delay jitter. The characteristics of delay and loss will be discussed. Adaptive playback will enhance the audio quality by adapting to the transmission delay jitter and delay spike. Coupled with Forward Error Correction (FEC) schemes, the proposed delay and loss concealment algorithm achieves less overall application loss rate without sacrificing on the average end-to-end delay. The optimal solution of such algorithms will be discussed. We also investigate the stretching-ratio transition effect on perceived audio quality by measuring the objective Perceptual Evaluation of Speech Quality (PESQ) Mean Opinion Score (MOS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP21G..08B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP21G..08B"><span id="translatedtitle">Halogens: From Annual To a Millennial <span class="hlt">Time</span> <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barbante, C.; Spolaor, A.; Vallelonga, P. T.; Schoenhardt, A.; Gabrieli, J.; Plane, J. M. C.; Curran, M. A.; Bjorkman, M. P.</p> <p>2014-12-01</p> <p>The role of sea ice in the Earth climate system is poorly defined, although its influence albedo, ocean circulation and atmosphere-ocean heat and gas exchange, in particular there is lack of information about its behaviour in the past. Different approaches have been proposed and used for the past reconstruction of sea ice. Attention has been given to sediment core in which measurement of diatomean assemblage has been discovered to respond to sea ice fluctuations. Recently a class of compounds, the highly branched isoprenoids (in particular the IP25) have been proposed as possible tracers for past sea ice extension. Other strategies have been used to evaluate the sea ice changes, for example multy-proxy approach (Kinnard et al. 2011) but for ice cores the question is still open. Sodium (Na) and Methanesulphonic acid (MSA) are now suggested as possible proxy. Sodium reflects glacial-interglacial sea ice variability but on shorter timescales is strongly influenced by meteorology (Levine et al. 2014). Methanesulphonic Acid, correlates with satellite observations of sea ice extent off the East Antarctic coast, but is reactive and remobilized in ice cores over centennial <span class="hlt">time</span> <span class="hlt">scales</span> (Curran, et al. 2003; Rothlisberger et al. 2010). In parallel we propose iodine and bromine, as a possible tracers for past sea ice changes. Bromine is actively involved in destruction chemistry of polar ozone via auto-catalyzed reactions called "Bromine explosions", which occur above seasonal sea ice and causing an excess of bromine in the snow deposition compared to the sea water ratio. Iodine is emitted from algal communities growing under sea ice and then, percolating up to the sea ice surface, it is emitted into the polar atmosphere. We investigate the halogens signal in different sites and with different <span class="hlt">time</span> coverage; measurements have been carried out in Greenland, Svalbard and Antarctica. We first investigate the conservation of the climate signal in the recent depositions (~3 years</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC43B0900C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC43B0900C"><span id="translatedtitle">Evaluating the uncertainty of predicting future climate <span class="hlt">time</span> series at the hourly <span class="hlt">time</span> <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caporali, E.; Fatichi, S.; Ivanov, V. Y.</p> <p>2011-12-01</p> <p>A stochastic downscaling methodology is developed to generate hourly, point-<span class="hlt">scale</span> <span class="hlt">time</span> series for several meteorological variables, such as precipitation, cloud cover, shortwave radiation, air temperature, relative humidity, wind speed, and atmospheric pressure. The methodology uses multi-model General Circulation Model (GCM) realizations and an hourly weather generator, AWE-GEN. Probabilistic descriptions of factors of change (a measure of climate change with respect to historic conditions) are computed for several climate statistics and different aggregation <span class="hlt">times</span> using a Bayesian approach that weights the individual GCM contributions. The Monte Carlo method is applied to sample the factors of change from their respective distributions thereby permitting the generation of <span class="hlt">time</span> series in an ensemble fashion, which reflects the uncertainty of climate projections of future as well as the uncertainty of the downscaling procedure. Applications of the methodology and probabilistic expressions of certainty in reproducing future climates for the periods, 2000 - 2009, 2046 - 2065 and 2081 - 2100, using the 1962 - 1992 period as the baseline, are discussed for the location of Firenze (Italy). The climate predictions for the period of 2000 - 2009 are tested against observations permitting to assess the reliability and uncertainties of the methodology in reproducing statistics of meteorological variables at different <span class="hlt">time</span> <span class="hlt">scales</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/931845','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/931845"><span id="translatedtitle">Detonation initiation on the microsecond <span class="hlt">time</span> <span class="hlt">scale</span>: DDTs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kuehn, Jeffery A; Kassoy, Dr. David R; Nabity, Mr. Matthew W.; Clarke, Dr. John F.</p> <p>2006-01-01</p> <p>Spatially resolved, thermal power deposition of limited duration into a finite volume of reactive gas is the initiator for a deflagration-to-detonation transition (DDT) on the microsecond <span class="hlt">time</span> <span class="hlt">scale</span>. The reactive Euler equations with one-step Arrhenius kinetics are used to derive novel formulas for velocity and temperature variation that describe the physical phenomena characteristic of DDTs. A nonlinear transformation of the variables is shown to yield a canonical equation system, independent of the activation energy. Numerical solutions of the reactive Euler equations are used to describe the detailed sequence of reactive gas dynamic processes leading to an overdriven planar detonation far from the power deposition location. Results are presented for deposition into a region isolated from the planar boundary of the reactive gas as well as for that adjacent to the boundary. The role of compressions and shocks reflected from the boundary into the partially reacted hot gas is described. The quantitative dependences of DDT evolution on the magnitude of thermal power deposition and activation energy are identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1004650','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1004650"><span id="translatedtitle">Detonation initiation on the microsecond <span class="hlt">time</span> <span class="hlt">scale</span>: DDTs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kassoy, Dr. David R; Kuehn, Jeffery A; Nabity, Mr. Matthew W.; Clarke, Dr. John F.</p> <p>2008-01-01</p> <p>Spatially resolved, thermal power deposition of limited duration into a finite volume of reactive gas is the initiator for a deflagration-to-detonation transition (DDT) on the microsecond <span class="hlt">time</span> <span class="hlt">scale</span>. The reactive Euler equations with one-step Arrhenius kinetics are used to derive novel formulas for velocity and temperature variation that describe the physical phenomena characteristic of DDTs. A transformation of the variables is shown to yield a canonical equation system, independent of the activation energy. Numerical solutions of the reactive Euler equations are used to describe the detailed sequence of reactive gasdynamic processes leading to an overdriven planar detonation far from the power deposition location. Results are presented for deposition into a region isolated from the planar boundary of the reactive gas as well as for that adjacent to the boundary. The role of compressions and shocks reflected from the boundary into the partially reacted hot gas is described. The quantitative dependences of DDT evolution on the magnitude of thermal power deposition and activation energy are identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27301704','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27301704"><span id="translatedtitle"><span class="hlt">Time</span>-resolved <span class="hlt">absolute</span> measurements by electro-optic effect of giant electromagnetic pulses due to laser-plasma interaction in nanosecond regime.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Consoli, F; De Angelis, R; Duvillaret, L; Andreoli, P L; Cipriani, M; Cristofari, G; Di Giorgio, G; Ingenito, F; Verona, C</p> <p>2016-01-01</p> <p>We describe the first electro-optical <span class="hlt">absolute</span> measurements of electromagnetic pulses (EMPs) generated by laser-plasma interaction in nanosecond regime. Laser intensities are inertial-confinement-fusion (ICF) relevant and wavelength is 1054 nm. These are the first direct EMP amplitude measurements with the detector rather close and in direct view of the plasma. A maximum field of 261 kV/m was measured, two orders of magnitude higher than previous measurements by conductive probes on nanosecond regime lasers with much higher energy. The analysis of measurements and of particle-in-cell simulations indicates that signals match the emission of charged particles detected in the same experiment, and suggests that anisotropic particle emission from target, X-ray photoionization and charge implantation on surfaces directly exposed to plasma, could be important EMP contributions. Significant information achieved on EMP features and sources is crucial for future plants of laser-plasma acceleration and inertial-confinement-fusion and for the use as effective plasma diagnostics. It also opens to remarkable applications of laser-plasma interaction as intense source of RF-microwaves for studies on materials and devices, EMP-radiation-hardening and electromagnetic compatibility. The demonstrated extreme effectivity of electric-fields detection in laser-plasma context by electro-optic effect, leads to great potential for characterization of laser-plasma interaction and generated Terahertz radiation. PMID:27301704</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4908660','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4908660"><span id="translatedtitle"><span class="hlt">Time</span>-resolved <span class="hlt">absolute</span> measurements by electro-optic effect of giant electromagnetic pulses due to laser-plasma interaction in nanosecond regime</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Consoli, F.; De Angelis, R.; Duvillaret, L.; Andreoli, P. L.; Cipriani, M.; Cristofari, G.; Di Giorgio, G.; Ingenito, F.; Verona, C.</p> <p>2016-01-01</p> <p>We describe the first electro-optical <span class="hlt">absolute</span> measurements of electromagnetic pulses (EMPs) generated by laser-plasma interaction in nanosecond regime. Laser intensities are inertial-confinement-fusion (ICF) relevant and wavelength is 1054 nm. These are the first direct EMP amplitude measurements with the detector rather close and in direct view of the plasma. A maximum field of 261 kV/m was measured, two orders of magnitude higher than previous measurements by conductive probes on nanosecond regime lasers with much higher energy. The analysis of measurements and of particle-in-cell simulations indicates that signals match the emission of charged particles detected in the same experiment, and suggests that anisotropic particle emission from target, X-ray photoionization and charge implantation on surfaces directly exposed to plasma, could be important EMP contributions. Significant information achieved on EMP features and sources is crucial for future plants of laser-plasma acceleration and inertial-confinement-fusion and for the use as effective plasma diagnostics. It also opens to remarkable applications of laser-plasma interaction as intense source of RF-microwaves for studies on materials and devices, EMP-radiation-hardening and electromagnetic compatibility. The demonstrated extreme effectivity of electric-fields detection in laser-plasma context by electro-optic effect, leads to great potential for characterization of laser-plasma interaction and generated Terahertz radiation. PMID:27301704</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...627889C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...627889C"><span id="translatedtitle"><span class="hlt">Time</span>-resolved <span class="hlt">absolute</span> measurements by electro-optic effect of giant electromagnetic pulses due to laser-plasma interaction in nanosecond regime</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Consoli, F.; de Angelis, R.; Duvillaret, L.; Andreoli, P. L.; Cipriani, M.; Cristofari, G.; di Giorgio, G.; Ingenito, F.; Verona, C.</p> <p>2016-06-01</p> <p>We describe the first electro-optical <span class="hlt">absolute</span> measurements of electromagnetic pulses (EMPs) generated by laser-plasma interaction in nanosecond regime. Laser intensities are inertial-confinement-fusion (ICF) relevant and wavelength is 1054 nm. These are the first direct EMP amplitude measurements with the detector rather close and in direct view of the plasma. A maximum field of 261 kV/m was measured, two orders of magnitude higher than previous measurements by conductive probes on nanosecond regime lasers with much higher energy. The analysis of measurements and of particle-in-cell simulations indicates that signals match the emission of charged particles detected in the same experiment, and suggests that anisotropic particle emission from target, X-ray photoionization and charge implantation on surfaces directly exposed to plasma, could be important EMP contributions. Significant information achieved on EMP features and sources is crucial for future plants of laser-plasma acceleration and inertial-confinement-fusion and for the use as effective plasma diagnostics. It also opens to remarkable applications of laser-plasma interaction as intense source of RF-microwaves for studies on materials and devices, EMP-radiation-hardening and electromagnetic compatibility. The demonstrated extreme effectivity of electric-fields detection in laser-plasma context by electro-optic effect, leads to great potential for characterization of laser-plasma interaction and generated Terahertz radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27301704','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27301704"><span id="translatedtitle"><span class="hlt">Time</span>-resolved <span class="hlt">absolute</span> measurements by electro-optic effect of giant electromagnetic pulses due to laser-plasma interaction in nanosecond regime.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Consoli, F; De Angelis, R; Duvillaret, L; Andreoli, P L; Cipriani, M; Cristofari, G; Di Giorgio, G; Ingenito, F; Verona, C</p> <p>2016-06-15</p> <p>We describe the first electro-optical <span class="hlt">absolute</span> measurements of electromagnetic pulses (EMPs) generated by laser-plasma interaction in nanosecond regime. Laser intensities are inertial-confinement-fusion (ICF) relevant and wavelength is 1054 nm. These are the first direct EMP amplitude measurements with the detector rather close and in direct view of the plasma. A maximum field of 261 kV/m was measured, two orders of magnitude higher than previous measurements by conductive probes on nanosecond regime lasers with much higher energy. The analysis of measurements and of particle-in-cell simulations indicates that signals match the emission of charged particles detected in the same experiment, and suggests that anisotropic particle emission from target, X-ray photoionization and charge implantation on surfaces directly exposed to plasma, could be important EMP contributions. Significant information achieved on EMP features and sources is crucial for future plants of laser-plasma acceleration and inertial-confinement-fusion and for the use as effective plasma diagnostics. It also opens to remarkable applications of laser-plasma interaction as intense source of RF-microwaves for studies on materials and devices, EMP-radiation-hardening and electromagnetic compatibility. The demonstrated extreme effectivity of electric-fields detection in laser-plasma context by electro-optic effect, leads to great potential for characterization of laser-plasma interaction and generated Terahertz radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MSMSE..22e5002C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MSMSE..22e5002C"><span id="translatedtitle">EON: software for long <span class="hlt">time</span> simulations of atomic <span class="hlt">scale</span> systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chill, Samuel T.; Welborn, Matthew; Terrell, Rye; Zhang, Liang; Berthet, Jean-Claude; Pedersen, Andreas; Jónsson, Hannes; Henkelman, Graeme</p> <p>2014-07-01</p> <p>The EON software is designed for simulations of the state-to-state evolution of atomic <span class="hlt">scale</span> systems over timescales greatly exceeding that of direct classical dynamics. States are defined as collections of atomic configurations from which a minimization of the potential energy gives the same inherent structure. The <span class="hlt">time</span> evolution is assumed to be governed by rare events, where transitions between states are uncorrelated and infrequent compared with the timescale of atomic vibrations. Several methods for calculating the state-to-state evolution have been implemented in EON, including parallel replica dynamics, hyperdynamics and adaptive kinetic Monte Carlo. Global optimization methods, including simulated annealing, basin hopping and minima hopping are also implemented. The software has a client/server architecture where the computationally intensive evaluations of the interatomic interactions are calculated on the client-side and the state-to-state evolution is managed by the server. The client supports optimization for different computer architectures to maximize computational efficiency. The server is written in Python so that developers have access to the high-level functionality without delving into the computationally intensive components. Communication between the server and clients is abstracted so that calculations can be deployed on a single machine, clusters using a queuing system, large parallel computers using a message passing interface, or within a distributed computing environment. A generic interface to the evaluation of the interatomic interactions is defined so that empirical potentials, such as in LAMMPS, and density functional theory as implemented in VASP and GPAW can be used interchangeably. Examples are given to demonstrate the range of systems that can be modeled, including surface diffusion and island ripening of adsorbed atoms on metal surfaces, molecular diffusion on the surface of ice and global structural optimization of nanoparticles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=J+A+Rock&pg=3&id=EJ651239','ERIC'); return false;" href="http://eric.ed.gov/?q=J+A+Rock&pg=3&id=EJ651239"><span id="translatedtitle">A Group Simulation of the Development of the Geologic <span class="hlt">Time</span> <span class="hlt">Scale</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bennington, J. Bret</p> <p>2000-01-01</p> <p>Explains how to demonstrate to students that the relative dating of rock layers is redundant. Uses two column diagrams to simulate stratigraphic sequences from two different geological <span class="hlt">time</span> <span class="hlt">scales</span> and asks students to complete the <span class="hlt">time</span> <span class="hlt">scale</span>. (YDS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27475064','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27475064"><span id="translatedtitle">Attractors of relaxation discrete-<span class="hlt">time</span> systems with chaotic dynamics on a fast <span class="hlt">time</span> <span class="hlt">scale</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maslennikov, Oleg V; Nekorkin, Vladimir I</p> <p>2016-07-01</p> <p>In this work, a new type of relaxation systems is considered. Their prominent feature is that they comprise two distinct epochs, one is slow regular motion and another is fast chaotic motion. Unlike traditionally studied slow-fast systems that have smooth manifolds of slow motions in the phase space and fast trajectories between them, in this new type one observes, apart the same geometric objects, areas of transient chaos. Alternating periods of slow regular motions and fast chaotic ones as well as transitions between them result in a specific chaotic attractor with chaos on a fast <span class="hlt">time</span> <span class="hlt">scale</span>. We formulate basic properties of such attractors in the framework of discrete-<span class="hlt">time</span> systems and consider several examples. Finally, we provide an important application of such systems, the neuronal electrical activity in the form of chaotic spike-burst oscillations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGP41E..01G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGP41E..01G"><span id="translatedtitle">Advances in the Geomagnetic Polarity <span class="hlt">Time</span> <span class="hlt">Scale</span>--Developments and Integration with the Geologic <span class="hlt">Time</span> <span class="hlt">Scale</span> and Future Directions (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geissman, J. W.</p> <p>2013-12-01</p> <p>We celebrate the 50th anniversary of the publication of the Vine-Matthews/Morley-Larochelle hypothesis (Vine and Matthews, Nature, 1963, v. 199, #4897, p. 947-949), which integrated marine magnetic anomaly data with a rapidly evolving terrestrial-based geomagnetic polarity <span class="hlt">time</span> <span class="hlt">scale</span> (GPTS). The five decades of research since 1963 have witnessed the expansion and refinement of the GPTS, to the point where ages of magnetochron boundaries, in particular in the Cenozoic, can be estimated with uncertainties better than 0.1%. This has come about by integrating high precision geochronology, cyclostratigraphy at different <span class="hlt">time</span> <span class="hlt">scales</span>, and magnetic polarity data of increased quality, allowing extension of the GPTS back into the Paleozoic. The definition of a high resolution GPTS across <span class="hlt">time</span> intervals of major events in Earth history has been of particular interest, as a specific magnetochron boundary correlated across several localities represents a singular global datum. A prime example is the end Permian, when some 80 percent of genus-level extinctions and a range of 75 to 96 percent species- level extinctions took place in the marine environment, depending upon clade. Much our understanding of the Permian-Triassic boundary (PTB) is based on relatively slowly deposited marine sequences in Europe and Asia, yet a growing body of observations from continental sequences demonstrates a similar extinction event and new polarity data from some of these sequences are critical to refining the GPTS across the PTB and testing synchronicity of marine and terrestrial events. The data show that the end-Permian ecological crisis and the conodont calibrated biostratigraphic PTB both followed a key polarity reversal between a short interval (subchron) of reverse polarity to a considerably longer (chron) of normal polarity. Central European Basin strata (continental Permian and epicontinental Triassic) yield high-quality magnetic polarity stratigraphic records (Szurlies et al., 2003</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9384619','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9384619"><span id="translatedtitle">Multiple <span class="hlt">time</span> <span class="hlt">scales</span> and the lifetime coefficient of variation: engineering applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kordonsky, K B; Gertsbakh, I</p> <p>1997-01-01</p> <p>We consider linear combinations of "natural" <span class="hlt">time</span> <span class="hlt">scales</span> and choose the "best" one which provides the minimum coefficient of variation of the lifetime. Our <span class="hlt">time</span> <span class="hlt">scale</span> is in fact a generalized Miner <span class="hlt">time</span> <span class="hlt">scale</span> because the latter is based on an appropriate weighting of the <span class="hlt">times</span> spent on low and high level loadings. The suggested modus operandi for finding the "best" <span class="hlt">time</span> <span class="hlt">scale</span> has many features in common with the approach suggested by Farewell and Cox (1979) and Oakes (1995) which is devoted to multiple <span class="hlt">time</span> <span class="hlt">scales</span> in survival analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/921934','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/921934"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> POLARIMETRY AT RHIC.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.</p> <p>2007-09-10</p> <p>Precise and <span class="hlt">absolute</span> beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The <span class="hlt">absolute</span> polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..717D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..717D"><span id="translatedtitle"><span class="hlt">Absolute</span> magnitudes of trans-neptunian objects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duffard, R.; Alvarez-candal, A.; Pinilla-Alonso, N.; Ortiz, J. L.; Morales, N.; Santos-Sanz, P.; Thirouin, A.</p> <p>2015-10-01</p> <p>Accurate measurements of diameters of trans- Neptunian objects are extremely complicated to obtain. Radiomatric techniques applied to thermal measurements can provide good results, but precise <span class="hlt">absolute</span> magnitudes are needed to constrain diameters and albedos. Our objective is to measure accurate <span class="hlt">absolute</span> magnitudes for a sample of trans- Neptunian objects, many of which have been observed, and modelled, by the "TNOs are cool" team, one of Herschel Space Observatory key projects grantes with ~ 400 hours of observing <span class="hlt">time</span>. We observed 56 objects in filters V and R, if possible. These data, along with data available in the literature, was used to obtain phase curves and to measure <span class="hlt">absolute</span> magnitudes by assuming a linear trend of the phase curves and considering magnitude variability due to rotational light-curve. In total we obtained 234 new magnitudes for the 56 objects, 6 of them with no reported previous measurements. Including the data from the literature we report a total of 109 <span class="hlt">absolute</span> magnitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1030789','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1030789"><span id="translatedtitle">Probing the <span class="hlt">Absolute</span> Mass <span class="hlt">Scale</span> of Neutrinos</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Prof. Joseph A. Formaggio</p> <p>2011-10-12</p> <p>The experimental efforts of the Neutrino Physics Group at MIT center primarily around the exploration of neutrino mass and its significance within the context of nuclear physics, particle physics, and cosmology. The group has played a prominent role in the Sudbury Neutrino Observatory, a neutrino experiment dedicated to measure neutrino oscillations from 8B neutrinos created in the sun. The group is now focusing its efforts in the measurement of the neutrino mass directly via the use of tritium beta decay. The MIT group has primary responsibilities in the Karlsruhe Tritium Neutrino mass experiment, expected to begin data taking by 2013. Specifically, the MIT group is responsible for the design and development of the global Monte Carlo framework to be used by the KATRIN collaboration, as well as responsibilities directly associated with the construction of the focal plane detector. In addition, the MIT group is sponsoring a new research endeavor for neutrino mass measurements, known as Project 8, to push beyond the limitations of current neutrino mass experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850031741&hterms=input+output&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dinput%2Boutput','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850031741&hterms=input+output&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dinput%2Boutput"><span id="translatedtitle">Input-output description of linear systems with multiple <span class="hlt">time-scales</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Madriz, R. S.; Sastry, S. S.</p> <p>1984-01-01</p> <p>It is pointed out that the study of systems evolving at multiple <span class="hlt">time-scales</span> is simplified by studying reduced-order models of these systems valid at specific <span class="hlt">time-scales</span>. The present investigation is concerned with an extension of results on the <span class="hlt">time-scale</span> decomposition of autonomous systems to that of input-output systems. The results are employed to study conditions under which positive realness of a transfer function is preserved under singular perturbation. Attention is given to the perturbation theory for linear operators, the multiple <span class="hlt">time-scale</span> structure of autonomous linear systems, the input-output description of two <span class="hlt">time-scale</span> linear systems, the positive realness of two <span class="hlt">time-scale</span> systems, and multiple <span class="hlt">time-scale</span> linear systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040110742','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040110742"><span id="translatedtitle"><span class="hlt">Absolute</span> Equilibrium Entropy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shebalin, John V.</p> <p>1997-01-01</p> <p>The entropy associated with <span class="hlt">absolute</span> equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850027731','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850027731"><span id="translatedtitle">Investigation of cosmic rays in very short <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peltonen, J.; Valtonen, E.; Torsti, J. J.; Arvela, H.; Lumme, M.; Nieminen, M.; Vainikka, E.</p> <p>1985-01-01</p> <p>A fast databuffer system, where cosmic ray events in the Turku hadron spectrometer, including particle arrival <span class="hlt">times</span> are recorded with <span class="hlt">time</span> resolution of 100 ns was constructed. The databuffer can be read continuously by a microprocessor, which preanalyzes the data and transfers it to the main computer. The <span class="hlt">time</span> span, that can be analyzed in every detail, is a few seconds. The high <span class="hlt">time</span> resolution enables a study of <span class="hlt">time</span> correlated groups of high energy particles. In addition the operational characteristics of the spectrometer can be monitored in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25106404','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25106404"><span id="translatedtitle">Monitoring <span class="hlt">scale</span> scores over <span class="hlt">time</span> via quality control charts, model-based approaches, and <span class="hlt">time</span> series techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Yi-Hsuan; von Davier, Alina A</p> <p>2013-07-01</p> <p>Maintaining a stable score <span class="hlt">scale</span> over <span class="hlt">time</span> is critical for all standardized educational assessments. Traditional quality control tools and approaches for assessing <span class="hlt">scale</span> drift either require special equating designs, or may be too <span class="hlt">time</span>-consuming to be considered on a regular basis with an operational test that has a short <span class="hlt">time</span> window between an administration and its score reporting. Thus, the traditional methods are not sufficient to catch unusual testing outcomes in a <span class="hlt">timely</span> manner. This paper presents a new approach for score monitoring and assessment of <span class="hlt">scale</span> drift. It involves quality control charts, model-based approaches, and <span class="hlt">time</span> series techniques to accommodate the following needs of monitoring <span class="hlt">scale</span> scores: continuous monitoring, adjustment of customary variations, identification of abrupt shifts, and assessment of autocorrelation. Performance of the methodologies is evaluated using manipulated data based on real responses from 71 administrations of a large-<span class="hlt">scale</span> high-stakes language assessment. PMID:25106404</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/397383','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/397383"><span id="translatedtitle">Fractal <span class="hlt">scaling</span> properties in nonstationary heartbeat <span class="hlt">time</span> series</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Peng, C. |; Havlin, S. |; Stanley, H.E.; Goldberger, A.L. |</p> <p>1996-06-01</p> <p>Under healthy conditions, the normal cardiac (sinus) interbeat interval fluctuates in a complex manner. Quantitative analysis using techniques adapted from statistical physics reveals the presence of long-range power-law correlations extending over thousands of heartbeats. This <span class="hlt">scale</span>-invariant (fractal) behavior suggests that the regulatory system generating these fluctuations is operating far from equilibrium. In contrast, we find that for subjects at high risk of sudden death (e.g. congestive heart failure patients) these long-range correlations break down. Application of fractal <span class="hlt">scaling</span> analysis and related techniques provides new approaches to assessing cardiac risk and forecasting sudden cardiac death, as well as motivating development of novel physiological models of systems that appear to be {open_quote}{open_quote}hetero-dynamic{close_quote}{close_quote} rather than {open_quote}{open_quote}homeo-static.{close_quote}{close_quote} {copyright} {ital 1996 American Institute of Physics.}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/527485','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/527485"><span id="translatedtitle">Global terrestrial biogeochemistry: Perturbations, interactions, and <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Braswell, B.H. Jr.</p> <p>1996-12-01</p> <p>Global biogeochemical processes are being perturbed by human activity, principally that which is associated with industrial activity and expansion of urban and agricultural complexes. Perturbations have manifested themselves at least since the beginning of the 19th Century, and include emissions of CO{sub 2} and other pollutants from fossil fuel combustion, agricultural emissions of reactive nitrogen, and direct disruption of ecosystem function through land conversion. These perturbations yield local impacts, but there are also global consequences that are the sum of local-<span class="hlt">scale</span> influences. Several approaches to understanding the global-<span class="hlt">scale</span> implications of chemical perturbations to the Earth system are discussed. The lifetime of anthropogenic CO{sub 2} in the atmosphere is an important concept for understanding the current and future commitment to an altered atmospheric heat budget. The importance of the terrestrial biogeochemistry relative to the lifetime of excess CO{sub 2} is demonstrated using dynamic, aggregated models of the global carbon cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996AIPC..375..615P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996AIPC..375..615P"><span id="translatedtitle">Fractal <span class="hlt">scaling</span> properties in nonstationary heartbeat <span class="hlt">time</span> series</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peng, C.-K.; Havlin, S.; Stanley, H. E.; Goldberger, A. L.</p> <p>1996-06-01</p> <p>Under healthy conditions, the normal cardiac (sinus) interbeat interval fluctuates in a complex manner. Quantitative analysis using techniques adapted from statistical physics reveals the presence of long-range power-law correlations extending over thousands of heartbeats. This <span class="hlt">scale</span>-invariant (fractal) behavior suggests that the regulatory system generating these fluctuations is operating far from equilibrium. In contrast, we find that for subjects at high risk of sudden death (e.g. congestive heart failure patients) these long-range correlations break down. Application of fractal <span class="hlt">scaling</span> analysis and related techniques provides new approaches to assessing cardiac risk and forecasting sudden cardiac death, as well as motivating development of novel physiological models of systems that appear to be ``hetero-dynamic'' rather than ``homeo-static.''</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26478959','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26478959"><span id="translatedtitle">Stimulus probability effects in <span class="hlt">absolute</span> identification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kent, Christopher; Lamberts, Koen</p> <p>2016-05-01</p> <p>This study investigated the effect of stimulus presentation probability on accuracy and response <span class="hlt">times</span> in an <span class="hlt">absolute</span> identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of presentation probability on both proportion correct and response <span class="hlt">times</span>. The effects were moderated by the ubiquitous stimulus position effect. The accuracy and response <span class="hlt">time</span> data were predicted by an exemplar-based model of perceptual cognition (Kent & Lamberts, 2005). The bow in discriminability was also attenuated when presentation probability for middle items was relatively high, an effect that will constrain future model development. The study provides evidence for item-specific learning in <span class="hlt">absolute</span> identification. Implications for other theories of <span class="hlt">absolute</span> identification are discussed. (PsycINFO Database Record</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8654E..05X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8654E..05X"><span id="translatedtitle">Exploring large <span class="hlt">scale</span> <span class="hlt">time</span>-series data using nested timelines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Zaixian; Ward, Matthew O.; Rundensteiner, Elke A.</p> <p>2013-01-01</p> <p>When data analysts study <span class="hlt">time</span>-series data, an important task is to discover how data patterns change over <span class="hlt">time</span>. If the dataset is very large, this task becomes challenging. Researchers have developed many visualization techniques to help address this problem. However, little work has been done regarding the changes of multivariate patterns, such as linear trends and clusters, on <span class="hlt">time</span>-series data. In this paper, we describe a set of history views to fill this gap. This technique works under two modes: merge and non-merge. For the merge mode, merge algorithms were applied to selected <span class="hlt">time</span> windows to generate a change-based hierarchy. Contiguous <span class="hlt">time</span> windows having similar patterns are merged first. Users can choose different levels of merging with the tradeoff between more details in the data and less visual clutter in the visualizations. In the non-merge mode, the framework can use natural hierarchical <span class="hlt">time</span> units or one defined by domain experts to represent timelines. This can help users navigate across long <span class="hlt">time</span> periods. Gridbased views were designed to provide a compact overview for the history data. In addition, MDS pattern starfields and distance maps were developed to enable users to quickly investigate the degree of pattern similarity among different <span class="hlt">time</span> periods. The usability evaluation demonstrated that most participants could understand the concepts of the history views correctly and finished assigned tasks with a high accuracy and relatively fast response <span class="hlt">time</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016MNRAS.tmp.1268T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016MNRAS.tmp.1268T&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Time</span> Evolution of Galaxy <span class="hlt">Scaling</span> Relations in Cosmological Simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, Philip; Kobayashi, Chiaki</p> <p>2016-08-01</p> <p>We predict the evolution of galaxy <span class="hlt">scaling</span> relationships from cosmological, hydrodynamical simulations, that reproduce the <span class="hlt">scaling</span> relations of present-day galaxies. Although we do not assume co-evolution between galaxies and black holes a priori, we are able to reproduce the black hole mass-velocity dispersion relation. This relation does not evolve, and black holes actually grow along the relation from significantly less massive seeds than have previously been used. AGN feedback does not very much affect the chemical evolution of our galaxies. In our predictions, the stellar mass-metallicity relation does not change its shape, but the metallicity significantly increases from z ˜ 2 to z ˜ 1, while the gas-phase mass-metallicity relation does change shape, having a steeper slope at higher redshifts (z ≲ 3). Furthermore, AGN feedback is required to reproduce observations of the most massive galaxies at z ≲ 1, specifically their positions on the star formation main sequence and galaxy mass-size relation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890000284&hterms=Hilbert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHilbert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890000284&hterms=Hilbert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHilbert"><span id="translatedtitle"><span class="hlt">Absolute</span> Stability And Hyperstability In Hilbert Space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wen, John Ting-Yung</p> <p>1989-01-01</p> <p>Theorems on stabilities of feedback control systems proved. Paper presents recent developments regarding theorems of <span class="hlt">absolute</span> stability and hyperstability of feedforward-and-feedback control system. Theorems applied in analysis of nonlinear, adaptive, and robust control. Extended to provide sufficient conditions for stability in system including nonlinear feedback subsystem and linear <span class="hlt">time</span>-invariant (LTI) feedforward subsystem, state space of which is Hilbert space, and input and output spaces having finite numbers of dimensions. (In case of <span class="hlt">absolute</span> stability, feedback subsystem memoryless and possibly <span class="hlt">time</span> varying. For hyperstability, feedback system dynamical system.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25592045','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25592045"><span id="translatedtitle">Rating depression over brief <span class="hlt">time</span> intervals with the Hamilton Depression Rating <span class="hlt">Scale</span>: standard vs. abbreviated <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luckenbaugh, David A; Ameli, Rezvan; Brutsche, Nancy E; Zarate, Carlos A</p> <p>2015-02-01</p> <p>Although antidepressant trials typically use weekly ratings to examine changes in symptoms over six to 12 weeks, antidepressant treatments may improve symptoms more quickly. Thus, rating <span class="hlt">scales</span> must be adapted to capture changes over shorter intervals. We examined the use of the 17-item Hamilton Depression Rating <span class="hlt">Scale</span> (HDRS) to evaluate more rapid changes. Data were examined from 58 patients with major depressive disorder or bipolar disorder enrolled in double-blind, placebo-controlled, crossover studies who received a single infusion of ketamine (0.5 mg/kg) or placebo over 40 min then crossed over to the other condition. HDRS subscales, a single HDRS Depressed mood item, and a visual analogue <span class="hlt">scale</span> were used at baseline, after a brief interval (230 min), and one week post-infusion. Effect sizes for the ketamine-placebo difference were moderate (d > 0.50), but one and two-item HDRS subscales had the smallest effects. Response rates on active drug were lowest for the complete HDRS (43%); the remaining <span class="hlt">scales</span> had higher response rates to active drug, but the shortest subscales had higher response rates to placebo. Correlations between the changes from baseline to 230 min post-ketamine across scores were similar for most subscales (r = 0.82-0.97), but correlations using the single items were lower (r < 0.74). Overall, effect sizes for drug-placebo differences and correlations between changes were lower for one- and two-item measures. Response rates were lower with the full HDRS <span class="hlt">scale</span>. The data suggest that, to best identify rapid antidepressant effects, a <span class="hlt">scale</span> should have more than two items, but fewer items than a full <span class="hlt">scale</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhR...307....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhR...307....1S"><span id="translatedtitle">The <span class="hlt">time</span> <span class="hlt">scale</span> test for Ω: the inverse Hubble constant compared with the age of the universe.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandage, A.; Tammann, G. A.; Saha, A.</p> <p>1998-12-01</p> <p>The status of the HST program to calibrate the <span class="hlt">absolute</span> magnitude at maximum of non-peculiar Type Ia supernovae is reviewed. Assuming, in first approximation, that SNe Ia are perfect standard candles gives an interim calibration, based on seven SNe Ia in six galaxies for which one has Cepheid distances, of >MB(max)< = -19.52±0.07, >MV(max)< = -19.48±0.07. Applying these calibrations to the Hubble diagram of 52 fiducial SNe Ia with good photometric data, and using a correction of 0.08 mag to an earlier adopted Cepheid period-luminosity relation gives H0 = 55±5 km s-1Mpc-1. Three other methods (via the Virgo cluster distance tied to the global expansion frame, the luminosity function of field spirals calibrated via Cepheids, and the physical methods using gravitational lenses, the Sunyaev-Zel'dovich effect, and expanding SN envelopes) confirm the long distance <span class="hlt">scale</span> that is implied by this value. Second-parameter corrections to the supernovae method depending on decay rate affect this solution for H0 by, at most, 5%. A critique is given of the "Key Project" result that H0 > 70 (Freedman et al., 1998). Disagreements with their precepts are discussed. The Key Project results, reduced to the Virgo cluster distance of 21.5 Mpc, gives H0 = 55 km s-1Mpc-1. Adopting 13.5 Gyr for the <span class="hlt">time</span> since the beginning of the expansion gives a <span class="hlt">timing</span> test value of Ω(total) = 0.44 (-0.37,+1.16). This shows that the <span class="hlt">timing</span> test for Omega, although powerful in principle because it measures the total mass, is presently impotent because the errors in H0 and Tu are too large. The principal result is that there is no <span class="hlt">time</span> <span class="hlt">scale</span> crisis in Big Bang cosmology, sans cosmological constant, because H0-1 > Tu decisively, using the long distance <span class="hlt">scale</span> derived here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3640655','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3640655"><span id="translatedtitle"><span class="hlt">Time-scale</span> invariance as an emergent property in a perceptron with realistic, noisy neurons</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Buhusi, Catalin V.; Oprisan, Sorinel A.</p> <p>2013-01-01</p> <p>In most species, interval <span class="hlt">timing</span> is <span class="hlt">time-scale</span> invariant: errors in <span class="hlt">time</span> estimation <span class="hlt">scale</span> up linearly with the estimated duration. In mammals, <span class="hlt">time-scale</span> invariance is ubiquitous over behavioral, lesion, and pharmacological manipulations. For example, dopaminergic drugs induce an immediate, whereas cholinergic drugs induce a gradual, scalar change in <span class="hlt">timing</span>. Behavioral theories posit that <span class="hlt">time-scale</span> invariance derives from particular computations, rules, or coding schemes. In contrast, we discuss a simple neural circuit, the perceptron, whose output neurons fire in a clockwise fashion (interval <span class="hlt">timing</span>) based on the pattern of coincidental activation of its input neurons. We show numerically that <span class="hlt">time-scale</span> invariance emerges spontaneously in a perceptron with realistic neurons, in the presence of noise. Under the assumption that dopaminergic drugs modulate the firing of input neurons, and that cholinergic drugs modulate the memory representation of the criterion <span class="hlt">time</span>, we show that a perceptron with realistic neurons reproduces the pharmacological clock and memory patterns, and their <span class="hlt">time-scale</span> invariance, in the presence of noise. These results suggest that rather than being a signature of higher-order cognitive processes or specific computations related to <span class="hlt">timing</span>, <span class="hlt">time-scale</span> invariance may spontaneously emerge in a massively-connected brain from the intrinsic noise of neurons and circuits, thus providing the simplest explanation for the ubiquity of <span class="hlt">scale</span> invariance of interval <span class="hlt">timing</span>. PMID:23518297</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70024269','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70024269"><span id="translatedtitle"><span class="hlt">Absolute</span> <span class="hlt">timing</span> of sulfide and gold mineralization: A comparison of Re-Os molybdenite and Ar-Ar mica methods from the Tintina Gold Belt, Alaska</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Selby, D.; Creaser, R.A.; Hart, C.J.R.; Rombach, C.S.; Thompson, J.F.H.; Smith, M.T.; Bakke, A.A.; Goldfarb, R.J.</p> <p>2002-01-01</p> <p>New Re-Os molybdenite dates from two lode gold deposits of the Tintina Gold Belt, Alaska, provide direct <span class="hlt">timing</span> constraints for sulfide and gold mineralization. At Fort Knox, the Re-Os molybdenite date is identical to the U-Pb zircon age for the host intrusion, supporting an intrusive-related origin for the deposit. However, 40Ar/39Ar dates from hydrothermal and igneous mica are considerably younger. At the Pogo deposit, Re-Os molybdenite dates are also much older than 40Ar/39Ar dates from hydrothermal mica, but dissimilar to the age of local granites. These age relationships indicate that the Re-Os molybdenite method records the <span class="hlt">timing</span> of sulfide and gold mineralization, whereas much younger 40Ar/39Ar dates are affected by post-ore thermal events, slow cooling, and/or systemic analytical effects. The results of this study complement a growing body of evidence to indicate that the Re-Os chronometer in molybdenite can be an accurate and robust tool for establishing <span class="hlt">timing</span> relations in ore systems.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21611867','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21611867"><span id="translatedtitle"><span class="hlt">Absolute</span> neutrino mass measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wolf, Joachim</p> <p>2011-10-06</p> <p>The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the <span class="hlt">absolute</span> neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5513869','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5513869"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scales</span> of variability associated with Nordeste precipitation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sperber, K.R. ); Hameed, S. . Inst. for Terrestrial and Planetary Atmospheres)</p> <p>1991-06-01</p> <p>The Northeast section of Brazil, called the Nordeste, experiences flood and drought regimes as the norm rather than the exception. This region receives its principal dose of precipitation during March--April, subsequent to regions to the west and north due to its proximity to the southern Atlantic subtropical high. A weakening of this anticyclone and strengthening of its counterpart in the northern Atlantic during this season results in the farthest southward penetration of the ITCZ and the Nordeste rainy season. Fluctuations in the large-<span class="hlt">scale</span> circulation of the atmosphere, such as ENSO, modulate the track of the ITCZ causing the interannual drought or flood conditions that plague this region. Empirical studies have shown that Nordeste rainfall is related to the sea-surface temperature (SST) in the tropical Atlantic Ocean. 16 refs., 4 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005Geo....33..909P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005Geo....33..909P"><span id="translatedtitle">Deposition of playa windblown dust over geologic <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pelletier, Jon D.; Cook, Joseph P.</p> <p>2005-11-01</p> <p>Thick eolian deposits are commonly observed beneath desert pavements downwind of dust-emitting playas. These deposits play an important role in piedmont-surface evolution, controlling surface hydrologic conductivity and rates of pedogenesis. To better understand the factors controlling the spatial distribution of eolian deposition, we developed a numerical model that treats deposition from spatially distributed playa sources using analytic point-source solutions for deposition from a Gaussian plume. The model also accounts for complex downwind topography. As a test case, model predictions were compared to eolian deposit thicknesses on Eagle Mountain piedmont, southern Amargosa Valley, California, which receives dust from nearby Franklin Lake playa. The close relationship between the model predictions and mapped thicknesses suggests that eolian transport and deposition can be modeled from basin to regional <span class="hlt">scales</span> within this framework. These results have important implications for hydrologic, pedogenic, and air-quality problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4397594','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4397594"><span id="translatedtitle">Microsecond-<span class="hlt">Scale</span> <span class="hlt">Timing</span> Precision in Rodent Trigeminal Primary Afferents</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bale, Michael R.; Campagner, Dario; Erskine, Andrew</p> <p>2015-01-01</p> <p>Communication in the nervous system occurs by spikes: the <span class="hlt">timing</span> precision with which spikes are fired is a fundamental limit on neural information processing. In sensory systems, spike-<span class="hlt">timing</span> precision is constrained by first-order neurons. We found that spike-<span class="hlt">timing</span> precision of trigeminal primary afferents in rats and mice is limited both by stimulus speed and by electrophysiological sampling rate. High-speed video of behaving mice revealed whisker velocities of at least 17,000°/s, so we delivered an ultrafast “ping” (>50,000°/s) to single whiskers and sampled primary afferent activity at 500 kHz. Median spike jitter was 17.4 μs; 29% of neurons had spike jitter < 10 μs. These results indicate that the input stage of the trigeminal pathway has extraordinary spike-<span class="hlt">timing</span> precision and very high potential information capacity. This <span class="hlt">timing</span> precision ranks among the highest in biology. PMID:25878266</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27575136','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27575136"><span id="translatedtitle">Clustering of <span class="hlt">time</span>-evolving <span class="hlt">scaling</span> dynamics in a complex signal.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saghir, Hamidreza; Chau, Tom; Kushki, Azadeh</p> <p>2016-07-01</p> <p>Complex <span class="hlt">time</span> series are widespread in physics and physiology. Multifractal analysis provides a tool to study the <span class="hlt">scaling</span> dynamics of such <span class="hlt">time</span> series. However, the temporal evolution of <span class="hlt">scaling</span> dynamics has been ignored by traditional tools such as the multifractal spectrum. We present <span class="hlt">scaling</span> maps that add the <span class="hlt">time</span> dimension to the study of <span class="hlt">scaling</span> dynamics. This is particularly important in cases in which the dynamics of the underlying processes change in <span class="hlt">time</span> or in applications that necessitate real-<span class="hlt">time</span> detection of <span class="hlt">scaling</span> dynamics. In addition, we present a methodology for automatic clustering of existing <span class="hlt">scaling</span> regimes in a signal. We demonstrate the methodology on <span class="hlt">time</span>-evolving correlated and uncorrelated noise and the output of a physiological control system (i.e., cardiac interbeat intervals) in healthy and pathological states. PMID:27575136</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..94a2220S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..94a2220S"><span id="translatedtitle">Clustering of <span class="hlt">time</span>-evolving <span class="hlt">scaling</span> dynamics in a complex signal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saghir, Hamidreza; Chau, Tom; Kushki, Azadeh</p> <p>2016-07-01</p> <p>Complex <span class="hlt">time</span> series are widespread in physics and physiology. Multifractal analysis provides a tool to study the <span class="hlt">scaling</span> dynamics of such <span class="hlt">time</span> series. However, the temporal evolution of <span class="hlt">scaling</span> dynamics has been ignored by traditional tools such as the multifractal spectrum. We present <span class="hlt">scaling</span> maps that add the <span class="hlt">time</span> dimension to the study of <span class="hlt">scaling</span> dynamics. This is particularly important in cases in which the dynamics of the underlying processes change in <span class="hlt">time</span> or in applications that necessitate real-<span class="hlt">time</span> detection of <span class="hlt">scaling</span> dynamics. In addition, we present a methodology for automatic clustering of existing <span class="hlt">scaling</span> regimes in a signal. We demonstrate the methodology on <span class="hlt">time</span>-evolving correlated and uncorrelated noise and the output of a physiological control system (i.e., cardiac interbeat intervals) in healthy and pathological states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890042911&hterms=Cenozoic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DCenozoic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890042911&hterms=Cenozoic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DCenozoic"><span id="translatedtitle">Structure and dating errors in the geologic <span class="hlt">time</span> <span class="hlt">scale</span> and periodicity in mass extinctions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stothers, Richard B.</p> <p>1989-01-01</p> <p>Structure in the geologic <span class="hlt">time</span> <span class="hlt">scale</span> reflects a partly paleontological origin. As a result, ages of Cenozoic and Mesozoic stage boundaries exhibit a weak 28-Myr periodicity that is similar to the strong 26-Myr periodicity detected in mass extinctions of marine life by Raup and Sepkoski. Radiometric dating errors in the geologic <span class="hlt">time</span> <span class="hlt">scale</span>, to which the mass extinctions are stratigraphically tied, do not necessarily lessen the likelihood of a significant periodicity in mass extinctions, but do spread the acceptable values of the period over the range 25-27 Myr for the Harland et al. <span class="hlt">time</span> <span class="hlt">scale</span> or 25-30 Myr for the DNAG <span class="hlt">time</span> <span class="hlt">scale</span>. If the Odin <span class="hlt">time</span> <span class="hlt">scale</span> is adopted, acceptable periods fall between 24 and 33 Myr, but are not robust against dating errors. Some indirect evidence from independently-dated flood-basalt volcanic horizons tends to favor the Odin <span class="hlt">time</span> <span class="hlt">scale</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JPhD...41u5404S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JPhD...41u5404S"><span id="translatedtitle">Nonlinear acoustic <span class="hlt">time</span> reversal imaging using the <span class="hlt">scaling</span> subtraction method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scalerandi, M.; Gliozzi, A. S.; Bruno, C. L. E.; Van Den Abeele, K.</p> <p>2008-11-01</p> <p>Lab experiments have shown that the imaging of nonlinear scatterers using <span class="hlt">time</span> reversal acoustics can be a very promising tool for early stage damage detection. The potential applications are however limited by the need for an extremely accurate acquisition system. In order to let nonlinear features emerge from the background noise it is necessary to enhance the signal-to-noise ratio as much as possible. A comprehensive analysis to determine the nonlinear components in a recorded <span class="hlt">time</span> signal, an alternative to those usually adopted (e.g. fast Fourier), is proposed here. The method is based on the nonlinear physical properties of the solution of the wave equation and takes advantage of the deficient system response scalability with the excitation amplitude. In this contribution, we outline the adopted procedure and apply it to a nonlinear <span class="hlt">time</span> reversal imaging simulation to highlight the advantages with respect to traditional imaging based on a fast Fourier analysis of the recorded signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARH35012H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARH35012H"><span id="translatedtitle"><span class="hlt">Scaling</span> of expected survival <span class="hlt">time</span> in a stochastic harvesting model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hastings, Harold; Radin, Michael; Wiandt, Tamas</p> <p></p> <p>We explore the dynamics of modified version of a standard fishery model (Gordon-Schafer-Munro), with additive and multiplicative noise, under a quota-based harvest. A harvest quota induces an effective strong Allee effect (a positive unstable steady state population level, below which populations die out), with expected survival <span class="hlt">time</span> following generalized Ornstein-Uhlenbeck dynamics. In particular, for additive noise, the expected survival <span class="hlt">time</span> is exponential in s3/σ2, where s is the difference between stable and unstable steady state populations and σ the noise level. Thus survival <span class="hlt">time</span> depends sensitively upon harvest quota (which determines steady state population), perhaps a warning to avoid future collapses such as that of the Atlantic cod fishery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23518297','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23518297"><span id="translatedtitle"><span class="hlt">Time-scale</span> invariance as an emergent property in a perceptron with realistic, noisy neurons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buhusi, Catalin V; Oprisan, Sorinel A</p> <p>2013-05-01</p> <p>In most species, interval <span class="hlt">timing</span> is <span class="hlt">time-scale</span> invariant: errors in <span class="hlt">time</span> estimation <span class="hlt">scale</span> up linearly with the estimated duration. In mammals, <span class="hlt">time-scale</span> invariance is ubiquitous over behavioral, lesion, and pharmacological manipulations. For example, dopaminergic drugs induce an immediate, whereas cholinergic drugs induce a gradual, scalar change in <span class="hlt">timing</span>. Behavioral theories posit that <span class="hlt">time-scale</span> invariance derives from particular computations, rules, or coding schemes. In contrast, we discuss a simple neural circuit, the perceptron, whose output neurons fire in a clockwise fashion based on the pattern of coincidental activation of its input neurons. We show numerically that <span class="hlt">time-scale</span> invariance emerges spontaneously in a perceptron with realistic neurons, in the presence of noise. Under the assumption that dopaminergic drugs modulate the firing of input neurons, and that cholinergic drugs modulate the memory representation of the criterion <span class="hlt">time</span>, we show that a perceptron with realistic neurons reproduces the pharmacological clock and memory patterns, and their <span class="hlt">time-scale</span> invariance, in the presence of noise. These results suggest that rather than being a signature of higher order cognitive processes or specific computations related to <span class="hlt">timing</span>, <span class="hlt">time-scale</span> invariance may spontaneously emerge in a massively connected brain from the intrinsic noise of neurons and circuits, thus providing the simplest explanation for the ubiquity of <span class="hlt">scale</span> invariance of interval <span class="hlt">timing</span>. PMID:23518297</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1227359','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1227359"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay using count distribution (LAMBDA) space</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2015-12-01</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous <span class="hlt">time</span>-evolving sequence of event-counts by spreading the fission chain distribution in <span class="hlt">time</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1055713','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1055713"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay using count distribution (LAMBDA) space</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2012-06-05</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous <span class="hlt">time</span>-evolving sequence of event-counts by spreading the fission chain distribution in <span class="hlt">time</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21550281','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21550281"><span id="translatedtitle">Probing Single-Photon Ionization on the Attosecond <span class="hlt">Time</span> <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kluender, K.; Dahlstroem, J. M.; Gisselbrecht, M.; Fordell, T.; Swoboda, M.; Guenot, D.; Johnsson, P.; Mauritsson, J.; L'Huillier, A.; Caillat, J.; Maquet, A.; Taieeb, R.</p> <p>2011-04-08</p> <p>We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. We measure the difference in <span class="hlt">time</span> delays between electrons emitted from the 3s{sup 2} and from the 3p{sup 6} shell, at different excitation energies ranging from 32 to 42 eV. The determination of photoemission <span class="hlt">time</span> delays requires taking into account the measurement process, involving the interaction with a probing infrared field. This contribution can be estimated using a universal formula and is found to account for a substantial fraction of the measured delay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=biology+AND+sleep&pg=6&id=EJ379095','ERIC'); return false;" href="http://eric.ed.gov/?q=biology+AND+sleep&pg=6&id=EJ379095"><span id="translatedtitle">Computer Response <span class="hlt">Time</span> Measurements of Mood, Fatigue and Symptom <span class="hlt">Scale</span> Items: Implications for <span class="hlt">Scale</span> Response <span class="hlt">Time</span> Uses.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ryman, David H.; And Others</p> <p>1988-01-01</p> <p>Describes study conducted with U.S. Marine Corps enlisted personnel to measure response <span class="hlt">time</span> to computer-administered questionnaire items, and to evaluate how measurement of response <span class="hlt">time</span> might be useful in various research areas. Topics addressed include mood states; the occurrence of straight lining; and experimental effects of sleep loss and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140001056','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140001056"><span id="translatedtitle">Evaluation of the <span class="hlt">Absolute</span> Regional Temperature Potential</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shindell, D. T.</p> <p>2012-01-01</p> <p>The <span class="hlt">Absolute</span> Regional Temperature Potential (ARTP) is one of the few climate metrics that provides estimates of impacts at a sub-global <span class="hlt">scale</span>. The ARTP presented here gives the <span class="hlt">time</span>-dependent temperature response in four latitude bands (90-28degS, 28degS-28degN, 28-60degN and 60-90degN) as a function of emissions based on the forcing in those bands caused by the emissions. It is based on a large set of simulations performed with a single atmosphere-ocean climate model to derive regional forcing/response relationships. Here I evaluate the robustness of those relationships using the forcing/response portion of the ARTP to estimate regional temperature responses to the historic aerosol forcing in three independent climate models. These ARTP results are in good accord with the actual responses in those models. Nearly all ARTP estimates fall within +/-20%of the actual responses, though there are some exceptions for 90-28degS and the Arctic, and in the latter the ARTP may vary with forcing agent. However, for the tropics and the Northern Hemisphere mid-latitudes in particular, the +/-20% range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 39-45% and 9-39% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-<span class="hlt">scale</span> latitude bands and land areas within those bands to inhomogeneous radiative forcing and thus potentially to emissions as well. Hence this metric could allow rapid evaluation of the effects of emissions policies at a finer <span class="hlt">scale</span> than global metrics without requiring use of a full climate model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1854932','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1854932"><span id="translatedtitle">Brain connectivity at different <span class="hlt">time-scales</span> measured with EEG</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Koenig, T; Studer, D; Hubl, D; Melie, L; Strik, W.K</p> <p>2005-01-01</p> <p>We present an overview of different methods for decomposing a multichannel spontaneous electroencephalogram (EEG) into sets of temporal patterns and topographic distributions. All of the methods presented here consider the scalp electric field as the basic analysis entity in space. In <span class="hlt">time</span>, the resolution of the methods is between milliseconds (<span class="hlt">time</span>-domain analysis), subseconds (<span class="hlt">time</span>- and frequency-domain analysis) and seconds (frequency-domain analysis). For any of these methods, we show that large parts of the data can be explained by a small number of topographic distributions. Physically, this implies that the brain regions that generated one of those topographies must have been active with a common phase. If several brain regions are producing EEG signals at the same <span class="hlt">time</span> and frequency, they have a strong tendency to do this in a synchronized mode. This view is illustrated by several examples (including combined EEG and functional magnetic resonance imaging (fMRI)) and a selective review of the literature. The findings are discussed in terms of short-lasting binding between different brain regions through synchronized oscillations, which could constitute a mechanism to form transient, functional neurocognitive networks. PMID:16087445</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060034656&hterms=definition+time&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddefinition%2Btime','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060034656&hterms=definition+time&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddefinition%2Btime"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">Scales</span> in the JPL and CfA Ephemerides</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Standish, E. M.</p> <p>1998-01-01</p> <p>Over the past decades, the IAU has repeatedly attempted to correct its definition of the basic fundamental argument used in the emphemerides. Finally, they have defined a <span class="hlt">time</span> system which is physically possible, according to the accepted standard theory of gravitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920034874&hterms=weinberg&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dweinberg','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920034874&hterms=weinberg&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dweinberg"><span id="translatedtitle"><span class="hlt">Scaling</span> properties of induction <span class="hlt">times</span> in heterogeneous nucleation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shneidman, Vitaly A.; Weinberg, Michael C.</p> <p>1991-01-01</p> <p>The heterogeneous-to-homogeneous induction <span class="hlt">time</span> ratio is obtained as a function of the contact angle in the asymptotic limit of a high nucleation barrier. Model-dependent corrections to t(ind) are investigated, particularly in cases of the Turnbull-Fisher model used in numerical simulations by Greer et al. (1990).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18632378','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18632378"><span id="translatedtitle">Hamilton-Jacobi-Bellman equations and approximate dynamic programming on <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Seiffertt, John; Sanyal, Suman; Wunsch, Donald C</p> <p>2008-08-01</p> <p>The <span class="hlt">time</span> <span class="hlt">scales</span> calculus is a key emerging area of mathematics due to its potential use in a wide variety of multidisciplinary applications. We extend this calculus to approximate dynamic programming (ADP). The core backward induction algorithm of dynamic programming is extended from its traditional discrete case to all isolated <span class="hlt">time</span> <span class="hlt">scales</span>. Hamilton-Jacobi-Bellman equations, the solution of which is the fundamental problem in the field of dynamic programming, are motivated and proven on <span class="hlt">time</span> <span class="hlt">scales</span>. By drawing together the calculus of <span class="hlt">time</span> <span class="hlt">scales</span> and the applied area of stochastic control via ADP, we have connected two major fields of research. PMID:18632378</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006QSRv...25..657R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006QSRv...25..657R&link_type=ABSTRACT"><span id="translatedtitle">What is the <span class="hlt">timing</span> of orbital-<span class="hlt">scale</span> monsoon changes?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruddiman, William F.</p> <p>2006-04-01</p> <p>A major (but little noted) divergence of opinion has developed among climate scientists over the orbital-<span class="hlt">scale</span> periodicity and phasing of tropical monsoon variations. Kutzbach (1981. Monsoon climate of the early Holocene: climate experiment with Earth's orbital parameters for 9000 years ago. Science 214, 59-61) proposed that monsoons are driven by northern summer insolation at the precession period, but Clemens and Prell (1990. Late Pleistocene variability of Arabian Sea summer monsoon winds and continental aridity: eolian records from the lithogenic component of deep-sea sediments. Paleoceanography 5, 109-145; 2003. A 350,000-year summer-monsoon multi-proxy stack from the Owen Ridge, Northern Arabian Sea. Marine Geology 201, 35-51) inferred a more complicated response tied to latent heat transfer from the Southern Hemisphere. Because tropical monsoons affect climate over a vast area, resolving this divergence is an important task for the climate community. The purpose of this note is to highlight definitive evidence from high-resolution dating of speleothem calcite that provides unambiguous support for the Kutzbach hypothesis.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22047190','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22047190"><span id="translatedtitle"><span class="hlt">Absolute</span> photoionization cross-section of the propargyl radical</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Savee, John D.; Welz, Oliver; Taatjes, Craig A.; Osborn, David L.; Soorkia, Satchin; Selby, Talitha M.</p> <p>2012-04-07</p> <p>Using synchrotron-generated vacuum-ultraviolet radiation and multiplexed <span class="hlt">time</span>-resolved photoionization mass spectrometry we have measured the <span class="hlt">absolute</span> photoionization cross-section for the propargyl (C{sub 3}H{sub 3}) radical, {sigma}{sub propargyl}{sup ion}(E), relative to the known <span class="hlt">absolute</span> cross-section of the methyl (CH{sub 3}) radical. We generated a stoichiometric 1:1 ratio of C{sub 3}H{sub 3} : CH{sub 3} from 193 nm photolysis of two different C{sub 4}H{sub 6} isomers (1-butyne and 1,3-butadiene). Photolysis of 1-butyne yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(26.1{+-}4.2) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(23.4{+-}3.2) Mb, whereas photolysis of 1,3-butadiene yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(23.6{+-}3.6) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(25.1{+-}3.5) Mb. These measurements place our relative photoionization cross-section spectrum for propargyl on an <span class="hlt">absolute</span> <span class="hlt">scale</span> between 8.6 and 10.5 eV. The cross-section derived from our results is approximately a factor of three larger than previous determinations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1017214','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1017214"><span id="translatedtitle">Bi-Plasma Interactions on Femtosecond <span class="hlt">Time-Scales</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>2011-06-22</p> <p>Ultrafast THz radiation has important applications in materials science studies, such as characterizing transport properties, studying the vibrational response of materials, and in recent years, controlling materials and elucidating their response in intense electromagnetic fields. THz fields can be generated in a lab setting using various plasma-based techniques. This study seeks to examine the interaction of two plasmas in order to better understand the fundamental physics associated with femtosecond filamentation processes and to achieve more efficient THz generation in a lab setting. The intensity of fluorescence in the region of overlap was measured as a function of polarization, power, and relative <span class="hlt">time</span> delay of the two plasma-generating laser beams. Results of <span class="hlt">time</span> dependent intensity studies indicate strikingly similar behaviors across polarizations and power levels; a sudden intensity spike was observed at <span class="hlt">time</span>-zero, followed by a secondary maxima and subsequent decay to the initial plasma intensity. Dependence of the intensity on the power through either beam arm was also observed. Spectral studies of the enhanced emission were also carried out. Although this physical phenomenon is still not fully understood, future studies, including further spectral analysis of the fluorescence overlap, could yield new insight into the ultrafast processes occurring at the intersection of femtosecond filaments, and would provide a better understanding of the mechanisms for enhanced THz production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H53A1644R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H53A1644R"><span id="translatedtitle">Sub-Daily Runoff Simulations with Parameters Inferred at the Daily <span class="hlt">Time</span> <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reynolds, J. E.; Xu, C. Y.; Seibert, J.; Halldin, S.</p> <p>2015-12-01</p> <p>Concentration <span class="hlt">times</span> in small and medium-sized watersheds (~100-1000 km2) are commonly less than 24 hours. Flood-forecasting models then require data at sub-daily <span class="hlt">time</span> <span class="hlt">scales</span>, but <span class="hlt">time</span>-series of input and runoff data with sufficient lengths are often only available at the daily <span class="hlt">time</span> <span class="hlt">scale</span>, especially in developing countries. This has led to a search for <span class="hlt">time-scale</span> relationships to infer parameter values at the <span class="hlt">time</span> <span class="hlt">scales</span> where they are needed from the <span class="hlt">time</span> <span class="hlt">scales</span> where they are available. In this study, <span class="hlt">time-scale</span> dependencies in the HBV-light conceptual hydrological model were assessed within the generalized likelihood uncertainty estimation (GLUE) approach. It was hypothesised that the existence of such dependencies is a result of the numerical method or <span class="hlt">time</span>-stepping scheme used in the models rather than a real <span class="hlt">time-scale</span>-data dependence. Parameter values inferred showed a clear dependence on <span class="hlt">time</span> <span class="hlt">scale</span> when the explicit Euler method was used for modelling at the same <span class="hlt">time</span> steps as the <span class="hlt">time</span> <span class="hlt">scale</span> of the input data (1 to 24 h). However, the dependence almost fully disappeared when the explicit Euler method was used for modelling in 1-hour <span class="hlt">time</span> steps internally irrespectively of the <span class="hlt">time</span> <span class="hlt">scale</span> of the input data. In other words, it was found that when an adequate <span class="hlt">time</span>-stepping scheme was implemented, parameter sets inferred at one <span class="hlt">time</span> <span class="hlt">scale</span> (e.g., daily) could be used directly for runoff simulations at other <span class="hlt">time</span> <span class="hlt">scales</span> (e.g., 3 h or 6 h) without any <span class="hlt">time</span> <span class="hlt">scaling</span> and this approach only resulted in a small (if any) model performance decrease, in terms of Nash-Sutcliffe and volume-error efficiencies. The overall results of this study indicated that as soon as sub-daily driving data can be secured, flood forecasting in watersheds with sub-daily concentration <span class="hlt">times</span> is possible with model parameter values inferred from long <span class="hlt">time</span> series of daily data, as long as an appropriate numerical method is used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004APS..MAR.D7001Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004APS..MAR.D7001Y&link_type=ABSTRACT"><span id="translatedtitle">A Cool Business: Trapping Intermediates on the submillisecond <span class="hlt">time</span> <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yeh, Syun-Ru</p> <p>2004-03-01</p> <p>The freeze-quenching technique is extremely useful for trapping meta-stable intermediates populated during fast chemical or biochemical reactions. The application of this technique, however, is limited by the long mixing <span class="hlt">time</span> of conventional solution mixers and the slow freezing <span class="hlt">time</span> of cryogenic fluids. To overcome these problems, we have designed and tested a novel microfluidic silicon mixer equipped with a new freeze-quenching device, with which reactions can be followed down to 50 microseconds. In the microfluidic silicon mixer, seven vertical pillars with 10 micrometer diameter are arranged perpendicular to the flow direction and in a staggered fashion in the 450 picoliter mixing chamber to enhance turbulent mixing. The mixed solution jet, with a cross-section of 10 micrometer by 100 micrometer, exits from the microfluidic silicon mixer with a linear flow velocity of 20 m/sec. It instantaneously freezes on one of two rotating copper wheels maintained at 77 K and is subsequently ground into an ultra-fine powder. The ultra-fine frozen powder exhibits excellent spectral quality, high packing factor and can be readily transferred between spectroscopic observation cells. The microfluidic mixer was tested by the reaction between azide and myoglobin at pH 5.0. It was found that complete mixing was achieved within the mixing dead-<span class="hlt">time</span> of the mixer (20 microseconds) and the first observable point for this coupled device was determined to be 50 microseconds, which is approximately two orders of magnitude faster than commercially available instruments. Several new applications of this device in ultra-fast biological reactions will be presented. Acknowledgements: This work is done in collaboration with Dr. Denis Rousseau and is supported by the NIH Grants HL65465 to S.-R.Y. and GM67814 to D.L.R.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JHyd..420..245K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JHyd..420..245K"><span id="translatedtitle">Identification of varying <span class="hlt">time</span> <span class="hlt">scales</span> in sediment transport using the Hilbert-Huang Transform method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuai, Ken Z.; Tsai, Christina W.</p> <p>2012-02-01</p> <p>SummarySediment transport processes vary at a variety of <span class="hlt">time</span> <span class="hlt">scales</span> - from seconds, hours, days to months and years. Multiple <span class="hlt">time</span> <span class="hlt">scales</span> exist in the system of flow, sediment transport and bed elevation change processes. As such, identification and selection of appropriate <span class="hlt">time</span> <span class="hlt">scales</span> for flow and sediment processes can assist in formulating a system of flow and sediment governing equations representative of the dynamic interaction of flow and particles at the desired details. Recognizing the importance of different varying <span class="hlt">time</span> <span class="hlt">scales</span> in the fluvial processes of sediment transport, we introduce the Hilbert-Huang Transform method (HHT) to the field of sediment transport for the <span class="hlt">time</span> <span class="hlt">scale</span> analysis. The HHT uses the Empirical Mode Decomposition (EMD) method to decompose a <span class="hlt">time</span> series into a collection of the Intrinsic Mode Functions (IMFs), and uses the Hilbert Spectral Analysis (HSA) to obtain instantaneous frequency data. The EMD extracts the variability of data with different <span class="hlt">time</span> <span class="hlt">scales</span>, and improves the analysis of data series. The HSA can display the succession of <span class="hlt">time</span> varying <span class="hlt">time</span> <span class="hlt">scales</span>, which cannot be captured by the often-used Fast Fourier Transform (FFT) method. This study is one of the earlier attempts to introduce the state-of-the-art technique for the multiple <span class="hlt">time</span> sales analysis of sediment transport processes. Three practical applications of the HHT method for data analysis of both suspended sediment and bedload transport <span class="hlt">time</span> series are presented. The analysis results show the strong impact of flood waves on the variations of flow and sediment <span class="hlt">time</span> <span class="hlt">scales</span> at a large sampling <span class="hlt">time</span> <span class="hlt">scale</span>, as well as the impact of flow turbulence on those <span class="hlt">time</span> <span class="hlt">scales</span> at a smaller sampling <span class="hlt">time</span> <span class="hlt">scale</span>. Our analysis reveals that the existence of multiple <span class="hlt">time</span> <span class="hlt">scales</span> in sediment transport processes may be attributed to the fractal nature in sediment transport. It can be demonstrated by the HHT analysis that the bedload motion <span class="hlt">time</span> <span class="hlt">scale</span> is better represented by the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.6678H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.6678H"><span id="translatedtitle">Simultaneous storm <span class="hlt">time</span> equatorward and poleward large-<span class="hlt">scale</span> TIDs on a global <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habarulema, John Bosco; Katamzi, Zama Thobeka; Yizengaw, Endawoke; Yamazaki, Yosuke; Seemala, Gopi</p> <p>2016-07-01</p> <p>We report on the first simultaneous observations of poleward and equatorward traveling ionospheric disturbances (TIDs) during the same geomagnetic storm period on a global <span class="hlt">scale</span>. While poleward propagating TIDs originate from the geomagnetic equator region, equatorward propagating TIDs are launched from the auroral regions. On a global <span class="hlt">scale</span>, we use total electron content observations from the Global Navigation Satellite Systems to show that these TIDs existed over South American, African, and Asian sectors. The American and African sectors exhibited predominantly strong poleward TIDs, while the Asian sector recorded mostly equatorward TIDs which crossed the geomagnetic equator to either hemisphere on 9 March 2012. However, both poleward and equatorward TIDs are simultaneously present in all three sectors. Using a combination of ground-based magnetometer observations and available low-latitude radar (JULIA) data, we have established and confirmed that poleward TIDs of geomagnetic equator origin are due to ionospheric electrodynamics, specifically changes in E × B vertical drift after the storm onset.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ClDy...47..637K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ClDy...47..637K"><span id="translatedtitle">Quantifying the uncertainty of the annular mode <span class="hlt">time</span> <span class="hlt">scale</span> and the role of the stratosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Junsu; Reichler, Thomas</p> <p>2016-07-01</p> <p>The proper simulation of the annular mode <span class="hlt">time</span> <span class="hlt">scale</span> may be regarded as an important benchmark for climate models. Previous research demonstrated that this <span class="hlt">time</span> <span class="hlt">scale</span> is systematically overestimated by climate models. As suggested by the fluctuation-dissipation theorem, this may imply that climate models are overly sensitive to external forcings. Previous research also made it clear that calculating the AM <span class="hlt">time</span> <span class="hlt">scale</span> is a slowly converging process, necessitating relatively long <span class="hlt">time</span> series and casting doubts on the usefulness of the historical reanalysis record to constrain climate models in terms of the annular mode <span class="hlt">time</span> <span class="hlt">scale</span>. Here, we use long control simulations with the coupled and uncoupled version of the GFDL climate model, CM2.1 and AM2.1, respectively, to study the effects of internal atmospheric variability and forcing from the lower boundary on the stability of the annular mode <span class="hlt">time</span> <span class="hlt">scale</span>. In particular, we ask whether a model's annular mode <span class="hlt">time</span> <span class="hlt">scale</span> and dynamical sensitivity can be constrained from the 50-year-long reanalysis record. We find that internal variability attaches large uncertainty to the annular mode <span class="hlt">time</span> <span class="hlt">scale</span> when diagnosed from decadal records. Even under the fixed forcing conditions of our long control run at least 100 years of data are required in order to keep the uncertainty in the annular mode <span class="hlt">time</span> <span class="hlt">scale</span> of the Northern Hemisphere to 10 %; over the Southern Hemisphere, the required length increases to 200 years. If nature's annular mode <span class="hlt">time</span> <span class="hlt">scale</span> over the Northern Hemisphere is similarly variable, there is no guarantee that the historical reanalysis record is a fully representative target for model evaluation. Over the Southern Hemisphere, however, the discrepancies between model and reanalysis are sufficiently large to conclude that the model is unable to reproduce the observed <span class="hlt">time</span> <span class="hlt">scale</span> structure correctly. The effects of ocean coupling lead to a considerable increase in <span class="hlt">time</span> <span class="hlt">scale</span> and uncertainty in <span class="hlt">time</span> <span class="hlt">scale</span>, effects which</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JChPh.113..883D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JChPh.113..883D"><span id="translatedtitle">Chain length <span class="hlt">scaling</span> of protein folding <span class="hlt">time</span>: Beta sheet structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dimitrievski, K.; Kasemo, B.; Zhdanov, V. P.</p> <p>2000-07-01</p> <p>We present comprehensive 3D lattice Monte Carlo simulations of the folding kinetics of two-turn antiparallel β sheets. The model employed takes into account isotropic nonspecific interactions as in previous flexible heteropolymer models and also orientation-dependent monomer-monomer interactions, mimicking the formation of hydrogen bonds and chain rigidity. The chain length is varied from N=15 to 33. For each chain length, we calculate the fastest folding temperature, Tfast, folding temperature, Tfold, and glass-transition temperature, Tg. The <span class="hlt">time</span>-averaged occupation probability of the native state is found to be nearly independent of N at all temperatures. The dependence of Tfast and Tfold on N is accordingly relatively weak. The temperature interval where the folding is fast rapidly decreases with increasing N. For the chain lengths chosen, Tfold slightly exceeds Tg. The dependence of the folding <span class="hlt">time</span> τf on N is well fitted by using the power law, τf∝Nλ. The exponent λ is found to depend on temperature and on the distribution of nonspecific interactions in the chain. In particular, λ=2.7-4.0 at T=Tfast and 5.2 at T slightly below Tfold. Evaluating τf in real units at T near Tfold yields physically reasonable results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMGP21A0775S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMGP21A0775S"><span id="translatedtitle">Geomagnetic Instability <span class="hlt">Time</span> <span class="hlt">Scale</span> 2008 (GITS-08) and dynamo processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singer, B. S.; Hoffman, K. A.</p> <p>2008-12-01</p> <p>During the past 2.6 million years Earth's outer core geodynamo has produced at least 18 geomagnetic excursions and 5 full polarity reversals. This record has been compiled from terrestrial volcanic rocks, including mainly basaltic lava flow sequences, but also two silicic ash beds, that have been analyzed using modern paleomagnetic techniques and dated using the 40Ar/39Ar method. Several brief periods of field instability associated with excursions correlate with lows in paleointensity or directional changes recorded in marine sediments, for example in the SINT2000 or GLOPIS75 composite records, or the more detailed records found at ODP site 919, that are dated using astronomically-forced oxygen isotope signals or ice layer counting. However, the lack of correlation of several excursions between marine and terrestrial records indicates that neither sediments, nor lava flows, are ideal recording media. Another factor complicating correlation is that some excursions may be geographically localized and not expressed globally. Despite decades of observation, these records remain fragmentary, especially when periods of millions of years are considered. Recent 40Ar/39Ar dating in our laboratory, that includes age determinations for the Mono Lake, Laschamp, Blake, Pringle Falls, Big Lost, West Eifel, and Agua Nova excursions, as well as the Halawa (C2r.2r-1) cryptochron, prompt us to critically review the terrestrial record of geodynamo instability and propose a GITS for the entire Quaternary period. Both the ca. 4:1 ratio of excursions to reversals during the past 2.6 Ma as well as the temporal pattern of occurrence of these events provide fundamental input as to the long-term behavior and, possibly, the structure of the core dynamo. On the one hand, intervals of significant temporal clustering of excursions have highlighted a relatively stable period of high field strength lasting >250 ka in the middle of the Brunhes chron during which <span class="hlt">time</span> few, or no, excursions took</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=effect&pg=3&id=EJ1099263','ERIC'); return false;" href="http://eric.ed.gov/?q=effect&pg=3&id=EJ1099263"><span id="translatedtitle">Stimulus Probability Effects in <span class="hlt">Absolute</span> Identification</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kent, Christopher; Lamberts, Koen</p> <p>2016-01-01</p> <p>This study investigated the effect of stimulus presentation probability on accuracy and response <span class="hlt">times</span> in an <span class="hlt">absolute</span> identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NPGeo..20...19V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NPGeo..20...19V"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scale</span> of the largest imaginable magnetic storm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasyliūnas, V. M.</p> <p>2013-01-01</p> <p>The depression of the horizontal magnetic field at Earth's equator for the largest imaginable magnetic storm has been estimated (Vasyliūnas, 2011a) as -Dst ~ 2500 nT, from the assumption that the total pressure in the magnetosphere (plasma plus magnetic field perturbation) is limited, in order of magnitude, by the minimum pressure of Earth's dipole field at the location of each flux tube. The obvious related question is how long it would take the solar wind to supply the energy content of this largest storm. The maximum rate of energy input from the solar wind to the magnetosphere can be evaluated on the basis either of magnetotail stress balance or of polar cap potential saturation, giving an estimate of the <span class="hlt">time</span> required to build up the largest storm, which (for solar-wind and magnetospheric parameter values typical of observed superstorms) is roughly between ~2 and ~6 h.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=serial+AND+position+AND+effect&id=EJ735377','ERIC'); return false;" href="http://eric.ed.gov/?q=serial+AND+position+AND+effect&id=EJ735377"><span id="translatedtitle"><span class="hlt">Absolute</span> Identification by Relative Judgment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stewart, Neil; Brown, Gordon D. A.; Chater, Nick</p> <p>2005-01-01</p> <p>In unidimensional <span class="hlt">absolute</span> identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of <span class="hlt">absolute</span> magnitudes. The authors propose an alternative…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&id=EJ765743','ERIC'); return false;" href="http://eric.ed.gov/?q=VALUE+AND+ABSOLUTE&id=EJ765743"><span id="translatedtitle">Be Resolute about <span class="hlt">Absolute</span> Value</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kidd, Margaret L.</p> <p>2007-01-01</p> <p>This article explores how conceptualization of <span class="hlt">absolute</span> value can start long before it is introduced. The manner in which <span class="hlt">absolute</span> value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22063785','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22063785"><span id="translatedtitle">Invited Review Article: The statistical modeling of atomic clocks and the design of <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Levine, Judah</p> <p>2012-02-15</p> <p>I will show how the statistical models that are used to describe the performance of atomic clocks are derived from their internal design. These statistical models form the basis for <span class="hlt">time</span> <span class="hlt">scales</span>, which are used to define international <span class="hlt">time</span> <span class="hlt">scales</span> such as International Atomic <span class="hlt">Time</span> and Coordinated Universal <span class="hlt">Time</span>. These international <span class="hlt">time</span> <span class="hlt">scales</span> are realized by ensembles of clocks at national laboratories such as the National Institute of Standards and Technology, and I will describe how ensembles of atomic clocks are characterized and managed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22380071','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22380071"><span id="translatedtitle">Invited review article: The statistical modeling of atomic clocks and the design of <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Levine, Judah; Ibarra-Manzano, O</p> <p>2012-02-01</p> <p>I will show how the statistical models that are used to describe the performance of atomic clocks are derived from their internal design. These statistical models form the basis for <span class="hlt">time</span> <span class="hlt">scales</span>, which are used to define international <span class="hlt">time</span> <span class="hlt">scales</span> such as International Atomic <span class="hlt">Time</span> and Coordinated Universal <span class="hlt">Time</span>. These international <span class="hlt">time</span> <span class="hlt">scales</span> are realized by ensembles of clocks at national laboratories such as the National Institute of Standards and Technology, and I will describe how ensembles of atomic clocks are characterized and managed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22380071','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22380071"><span id="translatedtitle">Invited review article: The statistical modeling of atomic clocks and the design of <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Levine, Judah; Ibarra-Manzano, O</p> <p>2012-02-01</p> <p>I will show how the statistical models that are used to describe the performance of atomic clocks are derived from their internal design. These statistical models form the basis for <span class="hlt">time</span> <span class="hlt">scales</span>, which are used to define international <span class="hlt">time</span> <span class="hlt">scales</span> such as International Atomic <span class="hlt">Time</span> and Coordinated Universal <span class="hlt">Time</span>. These international <span class="hlt">time</span> <span class="hlt">scales</span> are realized by ensembles of clocks at national laboratories such as the National Institute of Standards and Technology, and I will describe how ensembles of atomic clocks are characterized and managed. PMID:22380071</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22413237','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22413237"><span id="translatedtitle">On the <span class="hlt">time</span> <span class="hlt">scale</span> associated with Monte Carlo simulations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bal, Kristof M. Neyts, Erik C.</p> <p>2014-11-28</p> <p>Uniform-acceptance force-bias Monte Carlo (fbMC) methods have been shown to be a powerful technique to access longer timescales in atomistic simulations allowing, for example, phase transitions and growth. Recently, a new fbMC method, the <span class="hlt">time</span>-stamped force-bias Monte Carlo (tfMC) method, was derived with inclusion of an estimated effective timescale; this timescale, however, does not seem able to explain some of the successes the method. In this contribution, we therefore explicitly quantify the effective timescale tfMC is able to access for a variety of systems, namely a simple single-particle, one-dimensional model system, the Lennard-Jones liquid, an adatom on the Cu(100) surface, a silicon crystal with point defects and a highly defected graphene sheet, in order to gain new insights into the mechanisms by which tfMC operates. It is found that considerable boosts, up to three orders of magnitude compared to molecular dynamics, can be achieved for solid state systems by lowering of the apparent activation barrier of occurring processes, while not requiring any system-specific input or modifications of the method. We furthermore address the pitfalls of using the method as a replacement or complement of molecular dynamics simulations, its ability to explicitly describe correct dynamics and reaction mechanisms, and the association of timescales to MC simulations in general.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JChPh.141t4104B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JChPh.141t4104B"><span id="translatedtitle">On the <span class="hlt">time</span> <span class="hlt">scale</span> associated with Monte Carlo simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bal, Kristof M.; Neyts, Erik C.</p> <p>2014-11-01</p> <p>Uniform-acceptance force-bias Monte Carlo (fbMC) methods have been shown to be a powerful technique to access longer timescales in atomistic simulations allowing, for example, phase transitions and growth. Recently, a new fbMC method, the <span class="hlt">time</span>-stamped force-bias Monte Carlo (tfMC) method, was derived with inclusion of an estimated effective timescale; this timescale, however, does not seem able to explain some of the successes the method. In this contribution, we therefore explicitly quantify the effective timescale tfMC is able to access for a variety of systems, namely a simple single-particle, one-dimensional model system, the Lennard-Jones liquid, an adatom on the Cu(100) surface, a silicon crystal with point defects and a highly defected graphene sheet, in order to gain new insights into the mechanisms by which tfMC operates. It is found that considerable boosts, up to three orders of magnitude compared to molecular dynamics, can be achieved for solid state systems by lowering of the apparent activation barrier of occurring processes, while not requiring any system-specific input or modifications of the method. We furthermore address the pitfalls of using the method as a replacement or complement of molecular dynamics simulations, its ability to explicitly describe correct dynamics and reaction mechanisms, and the association of timescales to MC simulations in general.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012BVol...74.1777M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012BVol...74.1777M"><span id="translatedtitle">Probabilistic eruption forecasting at short and long <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marzocchi, Warner; Bebbington, Mark S.</p> <p>2012-10-01</p> <p>Any effective volcanic risk mitigation strategy requires a scientific assessment of the future evolution of a volcanic system and its eruptive behavior. Some consider the onus should be on volcanologists to provide simple but emphatic deterministic forecasts. This traditional way of thinking, however, does not deal with the implications of inherent uncertainties, both aleatoric and epistemic, that are inevitably present in observations, monitoring data, and interpretation of any natural system. In contrast to deterministic predictions, probabilistic eruption forecasting attempts to quantify these inherent uncertainties utilizing all available information to the extent that it can be relied upon and is informative. As with many other natural hazards, probabilistic eruption forecasting is becoming established as the primary scientific basis for planning rational risk mitigation actions: at short-term (hours to weeks or months), it allows decision-makers to prioritize actions in a crisis; and at long-term (years to decades), it is the basic component for land use and emergency planning. Probabilistic eruption forecasting consists of estimating the probability of an eruption event and where it sits in a complex multidimensional <span class="hlt">time</span>-space-magnitude framework. In this review, we discuss the key developments and features of models that have been used to address the problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980237704','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980237704"><span id="translatedtitle">Computational Modeling of Semiconductor Dynamics at Femtosecond <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Agrawal, Govind P.; Goorjian, Peter M.</p> <p>1998-01-01</p> <p>The Interchange No. NCC2-5149 deals with the emerging technology of photonic (or optoelectronic) integrated circuits (PICs or OEICs). In PICs, optical and electronic components are grown together on the same chip. To build such devices and subsystems, one needs to model the entire chip. PICs are useful for building components for integrated optical transmitters, integrated optical receivers, optical data storage systems, optical interconnects, and optical computers. For example, the current commercial rate for optical data transmission is 2.5 gigabits per second, whereas the use of shorter pulses to improve optical transmission rates would yield an increase of 400 to 1000 <span class="hlt">times</span>. The improved optical data transmitters would be used in telecommunications networks and computer local-area networks. Also, these components can be applied to activities in space, such as satellite to satellite communications, when the data transmissions are made at optical frequencies. The research project consisted of developing accurate computer modeling of electromagnetic wave propagation in semiconductors. Such modeling is necessary for the successful development of PICs. More specifically, these computer codes would enable the modeling of such devices, including their subsystems, such as semiconductor lasers and semiconductor amplifiers in which there is femtosecond pulse propagation. Presently, there are no computer codes that could provide this modeling. Current codes do not solve the full vector, nonlinear, Maxwell's equations, which are required for these short pulses and also current codes do not solve the semiconductor Bloch equations, which are required to accurately describe the material's interaction with femtosecond pulses. The research performed under NCC2-5149 solves the combined Maxwell's and Bloch's equations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26461957','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26461957"><span id="translatedtitle"><span class="hlt">Scale</span> (in)variance in a unified diffusion model of decision making and <span class="hlt">timing</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Simen, Patrick; Vlasov, Ksenia; Papadakis, Samantha</p> <p>2016-03-01</p> <p>Weber's law is the canonical <span class="hlt">scale</span>-invariance law in psychology: when the intensities of 2 stimuli are <span class="hlt">scaled</span> by any value k, the just-noticeable-difference between them also <span class="hlt">scales</span> by k. A diffusion model that approximates a spike-counting process accounts for Weber's law (Link, 1992), but there exist surprising corollaries of this account that have not yet been described or tested. We show that (a) this spike-counting diffusion model predicts <span class="hlt">time-scale</span> invariant decision <span class="hlt">time</span> distributions in perceptual decision making, and <span class="hlt">time-scale</span> invariant response <span class="hlt">time</span> (RT) distributions in interval <span class="hlt">timing</span>; (b) for 2-choice perceptual decisions, the model predicts equal accuracy but faster responding for stimulus pairs with equally <span class="hlt">scaled</span>-up intensities; (c) the coefficient of variation (CV) of decision <span class="hlt">times</span> should remain constant across average intensity <span class="hlt">scales</span>, but should otherwise decrease as a specific function of stimulus discriminability and speed-accuracy trade-off; and (d) for <span class="hlt">timing</span> tasks, RT CVs should be constant for all durations, and RT skewness should always equal 3 <span class="hlt">times</span> the CV. We tested these predictions using visual, auditory and vibrotactile decision tasks and visual interval <span class="hlt">timing</span> tasks in humans. The data conformed closely to the predictions in all modalities. These results support a unified theory of decision making and <span class="hlt">timing</span> in terms of a common, underlying spike-counting process, compactly represented as a diffusion process. PMID:26461957</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21405931','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21405931"><span id="translatedtitle">Ring intermittency near the boundary of the synchronous <span class="hlt">time</span> <span class="hlt">scales</span> of chaotic oscillators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhuravlev, Maxim O; Koronovskii, Alexey A; Moskalenko, Olga I; Ovchinnikov, Alexey A; Hramov, Alexander E</p> <p>2011-02-01</p> <p>In this Brief Report we study both experimentally and numerically the intermittent behavior taking place near the boundary of the synchronous <span class="hlt">time</span> <span class="hlt">scales</span> of chaotic oscillators being in the regime of <span class="hlt">time</span> <span class="hlt">scale</span> synchronization. We have shown that the observed type of the intermittent behavior should be classified as the ring intermittency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H31A0585A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H31A0585A"><span id="translatedtitle">Salinization of aquifers at the regional <span class="hlt">scale</span> by marine transgression: <span class="hlt">Time</span> <span class="hlt">scales</span> and processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Armandine Les Landes, A.; Davy, P.; Aquilina, L.</p> <p>2014-12-01</p> <p>Saline fluids with moderate concentrations have been sampled and reported in the Armorican basement at the regional <span class="hlt">scale</span> (northwestern France). The horizontal and vertical distributions of high chloride concentrations (60-1400mg/L) at the regional <span class="hlt">scale</span> support the marine origin and provide constraints on the age of these saline fluids. The current distribution of fresh and "saline" groundwater at depth is the result mostly of processes occurring at geological timescales - seawater intrusion processes followed by fresh groundwater flushing -, and only slightly of recent anthropogenic activities. In this study, we focus on seawater intrusion mechanisms in continental aquifers. We argue that one of the most efficient processes in macrotidal environments is the gravity-driven downconing instability below coastal salinized rivers. 2-D numerical experiments have been used to quantify this process according to four main parameter types: (1) the groundwater system permeability, (2) the salinity degree of the river, (3) the river width and slope, and (4) the tidal amplitude. A general expression of the salinity inflow rates have been derived, which has been used to estimate groundwater salinization rates in Brittany, given the geomorphological and environmental characteristics (drainage basin area, river widths and slopes, tidal range, aquifer permeability). We found that downconing below coastal rivers entail very high saline rates, indicating that this process play a major role in the salinization of regional aquifers. This is also likely to be an issue in the context of climate change, where sea-level rise is expected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H13I..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H13I..05R"><span id="translatedtitle">Abrupt changes in soil water content variability for various <span class="hlt">time</span> <span class="hlt">scales</span> and at different depths at the catchment <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosenbaum, U.; Herbst, M.; Huisman, J. A.; Weuthen, A.; Petersen, T. J.; Western, A. W.; Vereecken, H.; Bogena, H. R.</p> <p>2010-12-01</p> <p>A current challenge in hydrology is to observe, explain and model soil water content (SWC) patterns across multiple space-<span class="hlt">time</span> <span class="hlt">scales</span>. A promising technique for the assessment of SWC patterns at the catchment <span class="hlt">scale</span> is the wireless sensor network. This technique has the potential to continuously monitor three-dimensional SWC fields with high spatial and temporal resolution, i.e. to detect abrupt changes in SWC patterns. The objective of this study was to analyze the dynamics of SWC patterns at the TERENO forest hydrologic observatory Wüstebach (0.27 km2) for different depths (surface and subsurface soil) and various <span class="hlt">time</span> <span class="hlt">scales</span> (annual, seasonal <span class="hlt">scale</span> and wetting and drying periods). We used the SoilNet wireless network system developed at Forschungszentrum Jülich. SWC measurements were taken every 15 minutes in three depths (5, 20, 50 cm) at 150 locations using EC-5 and 5TE sensors (Decagon Devices). This particular analysis is based on hourly aggregated SWC data measured from 1st of August 2009 to 31st of July 2010. Descriptive statistics and geostatistics were used to investigate the data set depending on soil depth and <span class="hlt">time</span> <span class="hlt">scale</span>. We analyzed the mean SWC, standard deviation, coefficient of variation and geostatististical parameters (nugget, sill and range) as a function of <span class="hlt">time</span> and mean SWC. We found that the dynamics of SWC variability depended on depth, mean soil moisture status, <span class="hlt">time</span> <span class="hlt">scale</span> and wetting versus drying period. The magnitude and the variability of the mean SWC, standard deviation, coefficient of variation, and the range decreased with depth depending on soil moisture status. As already observed by others, the standard deviation peaked at medium (critical) SWC, which means that during wetting the standard deviation increased for mean SWC below the critical SWC and decreased above the mean SWC (and vice versa for drying). In addition, we observed that the standard deviation was higher during wetting periods than during drying periods in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJB...88..320C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJB...88..320C"><span id="translatedtitle">Empirical study on structural properties in temporal networks under different <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Duanbing</p> <p>2015-12-01</p> <p>Many network analyzing methods are usually based on static networks. However, temporal networks should be considered so as to investigate real complex systems deeply since some dynamics on these systems cannot be described by static networks accurately. In this paper, four structural properties in temporal networks are empirically studied, including degree, clustering coefficient, adjacent correlation, and connected component. Three real temporal networks with different <span class="hlt">time</span> <span class="hlt">scales</span> are analyzed in this paper, including short message, telephone, and router networks. Moreover, structural properties of these temporal networks are compared with that of corresponding static aggregation networks in the whole <span class="hlt">time</span> window. Some essential differences of structural properties between temporal and static networks are achieved through empirical analysis. Finally, the effect of structural properties on spreading dynamics under different <span class="hlt">time</span> <span class="hlt">scales</span> is investigated. Some interesting results such as turning point of structure evolving <span class="hlt">time</span> <span class="hlt">scale</span> corresponding to certain spreading dynamics <span class="hlt">time</span> <span class="hlt">scale</span> from the point of view of infected <span class="hlt">scale</span> are achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17144687','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17144687"><span id="translatedtitle">Reduction and solution of the chemical master equation using <span class="hlt">time</span> <span class="hlt">scale</span> separation and finite state projection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peles, Slaven; Munsky, Brian; Khammash, Mustafa</p> <p>2006-11-28</p> <p>The dynamics of chemical reaction networks often takes place on widely differing <span class="hlt">time</span> <span class="hlt">scales</span>--from the order of nanoseconds to the order of several days. This is particularly true for gene regulatory networks, which are modeled by chemical kinetics. Multiple <span class="hlt">time</span> <span class="hlt">scales</span> in mathematical models often lead to serious computational difficulties, such as numerical stiffness in the case of differential equations or excessively redundant Monte Carlo simulations in the case of stochastic processes. We present a model reduction method for study of stochastic chemical kinetic systems that takes advantage of multiple <span class="hlt">time</span> <span class="hlt">scales</span>. The method applies to finite projections of the chemical master equation and allows for effective <span class="hlt">time</span> <span class="hlt">scale</span> separation of the system dynamics. We implement this method in a novel numerical algorithm that exploits the <span class="hlt">time</span> <span class="hlt">scale</span> separation to achieve model order reductions while enabling error checking and control. We illustrate the efficiency of our method in several examples motivated by recent developments in gene regulatory networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005AGUFM.H32C..05L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005AGUFM.H32C..05L&link_type=ABSTRACT"><span id="translatedtitle">Modeling the uncertainty associated with the observation <span class="hlt">scale</span> of space/<span class="hlt">time</span> natural processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, S.; Serre, M.</p> <p>2005-12-01</p> <p>In many mapping applications of spatiotemporally distributed hydrological processes, the traditional space/<span class="hlt">time</span> Geostatistics approaches have played a significant role to estimate a variable of interest at unsampled locations. Measured values are usually sparsely located over space and <span class="hlt">time</span> due to the difficulty and cost of obtaining data. In some cases, the data for the hydrological variable of interest may have been collected at different temporal or spatial observation <span class="hlt">scales</span>. Even though mixing data measured at different space/<span class="hlt">time</span> <span class="hlt">scales</span> may alleviate the problem of the sparsity of the data available, it essentially disregards the <span class="hlt">scale</span> effect of estimation results. The importance of the <span class="hlt">scale</span> effect must be recognized since a variable displays different physical properties depending on the spatial or temporal <span class="hlt">scale</span> at which it is observed. In this study we develop a mathematical framework to derive the conditional Probability Density Function (PDF) of a variable at the local <span class="hlt">scale</span> given an observation of that variable at a larger spatial or temporal <span class="hlt">scale</span>, which properly models the uncertainty associated with the different observations <span class="hlt">scales</span> of space/<span class="hlt">time</span> natural processes. The developed framework allows to efficiently mix data observed at a variety of <span class="hlt">scales</span> by accounting for data uncertainty associated with each observation <span class="hlt">scale</span> present, and therefore generates soft data rigorously assimilated in the Bayesian Maximum Entropy (BME) method of modern Geostatistics to increase the mapping accuracy of the map at the <span class="hlt">scale</span> of interest. We investigate the proposed approach with synthetic case studies involving observations of a space/<span class="hlt">time</span> process at a variety of temporal and spatial <span class="hlt">scales</span>. These case studies demonstrate the power of the proposed approach by leading to a set of maps with a noticeable increase of mapping accuracy over classical approaches not accounting for the <span class="hlt">scale</span> effects. Hence the proposed approach will be useful for a wide variety of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27468397','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27468397"><span id="translatedtitle">Existence and exponential stability of positive almost periodic solution for Nicholson's blowflies models on <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yongkun; Li, Bing</p> <p>2016-01-01</p> <p>In this paper, we first give a new definition of almost periodic <span class="hlt">time</span> <span class="hlt">scales</span>, two new definitions of almost periodic functions on <span class="hlt">time</span> <span class="hlt">scales</span> and investigate some basic properties of them. Then, as an application, by using a fixed point theorem in Banach space and the <span class="hlt">time</span> <span class="hlt">scale</span> calculus theory, we obtain some sufficient conditions for the existence and exponential stability of positive almost periodic solutions for a class of Nicholson's blowflies models on <span class="hlt">time</span> <span class="hlt">scales</span>. Finally, we present an illustrative example to show the effectiveness of obtained results. Our results show that under a simple condition the continuous-<span class="hlt">time</span> Nicholson's blowflies model and its discrete-<span class="hlt">time</span> analogue have the same dynamical behaviors. PMID:27468397</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EL.....9268006H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EL.....9268006H"><span id="translatedtitle">Evolution in <span class="hlt">time</span> and <span class="hlt">scales</span> of the stability of heart interbeat rate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernández-Pérez, R.; Guzmán-Vargas, L.; Reyes-Ramírez, I.; Angulo-Brown, F.</p> <p>2010-12-01</p> <p>We approach heart interbeat rate by observing the evolution of its stability on <span class="hlt">scales</span> and <span class="hlt">time</span>, using tools for the analysis of frequency standards. In particular, we employ the dynamic Allan variance, which is used to characterize the <span class="hlt">time</span>-varying stability of an atomic clock, to analyze heart interbeat <span class="hlt">time</span> series for normal subjects and patients with congestive heart failure (CHF). Our stability analysis shows that healthy dynamics is characterized by at least two stability regions along different <span class="hlt">scales</span>. In contrast, diseased patients exhibit at least three different stability regions; over short <span class="hlt">scales</span> the fluctuations resembled white-noise behavior whereas for large <span class="hlt">scales</span> a drift is observed. The inflection points delimiting the first two stability regions for both groups are located around the same <span class="hlt">scales</span>. Moreover, we find that CHF patients show lower variation of the stability in <span class="hlt">time</span> than healthy subjects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7355967','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7355967"><span id="translatedtitle">Sonar fetal cephalometry: comparison of bistable with gray <span class="hlt">scale</span> and real-<span class="hlt">time</span> techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santos-Ramos, R; Duenhoelter, J H; Reisch, J S</p> <p>1980-03-15</p> <p>The fetal biparietal diameter was measured simultaneously with B-scan bistable and gray <span class="hlt">scale</span> techniques and subsequently with real-<span class="hlt">time</span> ultrasonography. Measurements were made from outer table to outer table with the bistable technique, which has been proven to be accurate and reliable. With the gray <span class="hlt">scale</span> and real-<span class="hlt">time</span> modalities, distances were measured between several landmarks from the same image. Off all measurements taken from gray <span class="hlt">scale</span> and realtime images, those between the centers of each band outlining the fetal skull showed the best correlation and the closest values to measurements using the standard bistable technique. Discrepancies exceeded 2 mm in only 5% with the gray <span class="hlt">scale</span> and in 2% with the real-<span class="hlt">time</span> technique. Using the measurement between outer and inner aspects of the cephalic band, the percentages of discrepancies exceeding 2 mm were 7% with gray <span class="hlt">scale</span> and 6% with real <span class="hlt">time</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJBC...2540024A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJBC...2540024A"><span id="translatedtitle">Li-Yorke Chaos in Hybrid Systems on a <span class="hlt">Time</span> <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akhmet, Marat; Fen, Mehmet Onur</p> <p>2015-12-01</p> <p>By using the reduction technique to impulsive differential equations [Akhmet & Turan, 2006], we rigorously prove the presence of chaos in dynamic equations on <span class="hlt">time</span> <span class="hlt">scales</span> (DETS). The results of the present study are based on the Li-Yorke definition of chaos. This is the first <span class="hlt">time</span> in the literature that chaos is obtained for DETS. An illustrative example is presented by means of a Duffing equation on a <span class="hlt">time</span> <span class="hlt">scale</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20465249','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20465249"><span id="translatedtitle">Studying the <span class="hlt">time</span> <span class="hlt">scale</span> dependence of environmental variables predictability using fractal analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yuval; Broday, David M</p> <p>2010-06-15</p> <p>Prediction of meteorological and air quality variables motivates a lot of research in the atmospheric sciences and exposure assessment communities. An interesting related issue regards the relative predictive power that can be expected at different <span class="hlt">time</span> <span class="hlt">scales</span>, and whether it vanishes altogether at certain ranges. An improved understanding of our predictive powers enables better environmental management and more efficient decision making processes. Fractal analysis is commonly used to characterize the self-affinity of <span class="hlt">time</span> series. This work introduces the Continuous Wavelet Transform (CWT) fractal analysis method as a tool for assessing environmental <span class="hlt">time</span> series predictability. The high temporal <span class="hlt">scale</span> resolution of the CWT enables detailed information about the Hurst parameter, a common temporal fractality measure, and thus about <span class="hlt">time</span> <span class="hlt">scale</span> variations in predictability. We analyzed a few years records of half-hourly air pollution and meteorological <span class="hlt">time</span> series from which the trivial seasonal and daily cycles were removed. We encountered a general trend of decreasing Hurst values from about 1.4 (good autocorrelation and predictability), in the sub-daily <span class="hlt">time</span> <span class="hlt">scale</span> to 0.5 (which implies complete randomness) in the monthly to seasonal <span class="hlt">scales</span>. The air pollutants predictability follows that of the meteorological variables in the short <span class="hlt">time</span> <span class="hlt">scales</span> but is better at longer <span class="hlt">scales</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25423049','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25423049"><span id="translatedtitle">Probing <span class="hlt">absolute</span> spin polarization at the nanoscale.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Eltschka, Matthias; Jäck, Berthold; Assig, Maximilian; Kondrashov, Oleg V; Skvortsov, Mikhail A; Etzkorn, Markus; Ast, Christian R; Kern, Klaus</p> <p>2014-12-10</p> <p>Probing <span class="hlt">absolute</span> values of spin polarization at the nanoscale offers insight into the fundamental mechanisms of spin-dependent transport. Employing the Zeeman splitting in superconducting tips (Meservey-Tedrow-Fulde effect), we introduce a novel spin-polarized scanning tunneling microscopy that combines the probing capability of the <span class="hlt">absolute</span> values of spin polarization with precise control at the atomic <span class="hlt">scale</span>. We utilize our novel approach to measure the locally resolved spin polarization of magnetic Co nanoislands on Cu(111). We find that the spin polarization is enhanced by 65% when increasing the width of the tunnel barrier by only 2.3 Å due to the different decay of the electron orbitals into vacuum. PMID:25423049</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720059878&hterms=rights+author&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Drights%2Bauthor','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720059878&hterms=rights+author&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Drights%2Bauthor"><span id="translatedtitle">Singular perturbation of <span class="hlt">absolute</span> stability.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siljak, D. D.</p> <p>1972-01-01</p> <p>It was previously shown (author, 1969) that the regions of <span class="hlt">absolute</span> stability in the parameter space can be determined when the parameters appear on the right-hand side of the system equations, i.e., the regular case. Here, the effect on <span class="hlt">absolute</span> stability of a small parameter attached to higher derivatives in the equations (the singular case) is studied. The Lur'e-Postnikov class of nonlinear systems is considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26737821','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26737821"><span id="translatedtitle">Estimation of the reaction <span class="hlt">times</span> in tasks of varying difficulty from the phase coherence of the auditory steady-state response using the least <span class="hlt">absolute</span> shrinkage and selection operator analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yokota, Yusuke; Igarashi, Yasuhiko; Okada, Masato; Naruse, Yasushi</p> <p>2015-01-01</p> <p>Quantitative estimation of the workload in the brain is an important factor for helping to predict the behavior of humans. The reaction <span class="hlt">time</span> when performing a difficult task is longer than that when performing an easy task. Thus, the reaction <span class="hlt">time</span> reflects the workload in the brain. In this study, we employed an N-back task in order to regulate the degree of difficulty of the tasks, and then estimated the reaction <span class="hlt">times</span> from the brain activity. The brain activity that we used to estimate the reaction <span class="hlt">time</span> was the auditory steady-state response (ASSR) evoked by a 40-Hz click sound. Fifteen healthy participants participated in the present study and magnetoencephalogram (MEG) responses were recorded using a 148-channel magnetometer system. The least <span class="hlt">absolute</span> shrinkage and selection operator (LASSO), which is a type of sparse modeling, was employed to estimate the reaction <span class="hlt">times</span> from the ASSR recorded by MEG. The LASSO showed higher estimation accuracy than the least squares method. This result indicates that LASSO overcame the over-fitting to the learning data. Furthermore, the LASSO selected channels in not only the parietal region, but also in the frontal and occipital regions. Since the ASSR is evoked by auditory stimuli, it is usually large in the parietal region. However, since LASSO also selected channels in regions outside the parietal region, this suggests that workload-related neural activity occurs in many brain regions. In the real world, it is more practical to use a wearable electroencephalography device with a limited number of channels than to use MEG. Therefore, determining which brain areas should be measured is essential. The channels selected by the sparse modeling method are informative for determining which brain areas to measure. PMID:26737821</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Chaos..26i4810D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Chaos..26i4810D"><span id="translatedtitle">Super-transient <span class="hlt">scaling</span> in <span class="hlt">time</span>-delay autonomous Boolean network motifs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Huys, Otti; Lohmann, Johannes; Haynes, Nicholas D.; Gauthier, Daniel J.</p> <p>2016-09-01</p> <p>Autonomous Boolean networks are commonly used to model the dynamics of gene regulatory networks and allow for the prediction of stable dynamical attractors. However, most models do not account for <span class="hlt">time</span> delays along the network links and noise, which are crucial features of real biological systems. Concentrating on two paradigmatic motifs, the toggle switch and the repressilator, we develop an experimental testbed that explicitly includes both inter-node <span class="hlt">time</span> delays and noise using digital logic elements on field-programmable gate arrays. We observe transients that last millions to billions of characteristic <span class="hlt">time</span> <span class="hlt">scales</span> and <span class="hlt">scale</span> exponentially with the amount of <span class="hlt">time</span> delays between nodes, a phenomenon known as super-transient <span class="hlt">scaling</span>. We develop a hybrid model that includes <span class="hlt">time</span> delays along network links and allows for stochastic variation in the delays. Using this model, we explain the observed super-transient <span class="hlt">scaling</span> of both motifs and recreate the experimentally measured transient distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/980889','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/980889"><span id="translatedtitle">Using Focused Regression for Accurate <span class="hlt">Time</span>-Constrained <span class="hlt">Scaling</span> of Scientific Applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barnes, B; Garren, J; Lowenthal, D; Reeves, J; de Supinski, B; Schulz, M; Rountree, B</p> <p>2010-01-28</p> <p>Many large-<span class="hlt">scale</span> clusters now have hundreds of thousands of processors, and processor counts will be over one million within a few years. Computational scientists must <span class="hlt">scale</span> their applications to exploit these new clusters. <span class="hlt">Time</span>-constrained <span class="hlt">scaling</span>, which is often used, tries to hold total execution <span class="hlt">time</span> constant while increasing the problem size along with the processor count. However, complex interactions between parameters, the processor count, and execution <span class="hlt">time</span> complicate determining the input parameters that achieve this goal. In this paper we develop a novel gray-box, focused median prediction errors are less than 13%. regression-based approach that assists the computational scientist with maintaining constant run <span class="hlt">time</span> on increasing processor counts. Combining application-level information from a small set of training runs, our approach allows prediction of the input parameters that result in similar per-processor execution <span class="hlt">time</span> at larger <span class="hlt">scales</span>. Our experimental validation across seven applications showed that median prediction errors are less than 13%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/945365','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/945365"><span id="translatedtitle"><span class="hlt">Scaling</span> Behavior of the First Arrival <span class="hlt">Time</span> of a Random-Walking Magnetic Domain</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Im, M.-Y.; Lee, S.-H.; Kim, D.-H.; Fischer, P.; Shin, S.-C.</p> <p>2008-02-04</p> <p>We report a universal <span class="hlt">scaling</span> behavior of the first arrival <span class="hlt">time</span> of a traveling magnetic domain wall into a finite space-<span class="hlt">time</span> observation window of a magneto-optical microscope enabling direct visualization of a Barkhausen avalanche in real <span class="hlt">time</span>. The first arrival <span class="hlt">time</span> of the traveling magnetic domain wall exhibits a nontrivial fluctuation and its statistical distribution is described by universal power-law <span class="hlt">scaling</span> with <span class="hlt">scaling</span> exponents of 1.34 {+-} 0.07 for CoCr and CoCrPt films, despite their quite different domain evolution patterns. Numerical simulation of the first arrival <span class="hlt">time</span> with an assumption that the magnetic domain wall traveled as a random walker well matches our experimentally observed <span class="hlt">scaling</span> behavior, providing an experimental support for the random-walking model of traveling magnetic domain walls.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyA..436..338B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyA..436..338B"><span id="translatedtitle">A wavelet based approach to measure and manage contagion at different <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berger, Theo</p> <p>2015-10-01</p> <p>We decompose financial return series of US stocks into different <span class="hlt">time</span> <span class="hlt">scales</span> with respect to different market regimes. First, we examine dependence structure of decomposed financial return series and analyze the impact of the current financial crisis on contagion and changing interdependencies as well as upper and lower tail dependence for different <span class="hlt">time</span> <span class="hlt">scales</span>. Second, we demonstrate to which extent the information of different <span class="hlt">time</span> <span class="hlt">scales</span> can be used in the context of portfolio management. As a result, minimizing the variance of short-run noise outperforms a portfolio that minimizes the variance of the return series.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhRvE..84f1914A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhRvE..84f1914A"><span id="translatedtitle">Correlation transfer in stochastically driven neural oscillators over long and short <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abouzeid, Aushra; Ermentrout, Bard</p> <p>2011-12-01</p> <p>In the absence of synaptic coupling, two or more neural oscillators may become synchronized by virtue of the statistical correlations in their noisy input streams. Recent work has shown that the degree of correlation transfer from input currents to output spikes depends not only on intrinsic oscillator dynamics, but also on the length of the observation window over which the correlation is calculated. In this paper we use stochastic phase reduction and regular perturbations to derive the correlation of the total phase elapsed over long <span class="hlt">time</span> <span class="hlt">scales</span>, a quantity that provides a convenient proxy for the spike count correlation. Over short <span class="hlt">time</span> <span class="hlt">scales</span>, we derive the spike count correlation directly using straightforward probabilistic reasoning applied to the density of the phase difference. Our approximations show that output correlation <span class="hlt">scales</span> with the autocorrelation of the phase resetting curve over long <span class="hlt">time</span> <span class="hlt">scales</span>. We also find a concise expression for the influence of the shape of the phase resetting curve on the initial slope of the output correlation over short <span class="hlt">time</span> <span class="hlt">scales</span>. These analytic results together with numerical simulations provide new intuitions for the recent counterintuitive finding that type I oscillators transfer correlations more faithfully than do type II over long <span class="hlt">time</span> <span class="hlt">scales</span>, while the reverse holds true for the better understood case of short <span class="hlt">time</span> <span class="hlt">scales</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1045983','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1045983"><span id="translatedtitle">Mastering Uncertainty and Risk at Multiple <span class="hlt">Time</span> <span class="hlt">Scales</span> in the Future Electrical Grid</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chertkov, Michael; Bent, Russell W.; Backhaus, Scott N.</p> <p>2012-07-10</p> <p>Today's electrical grids enjoy a relatively clean separation of spatio-temporal <span class="hlt">scales</span> yielding a compartmentalization of grid design, optimization, control and risk assessment allowing for the use of conventional mathematical tools within each area. In contrast, the future grid will incorporate <span class="hlt">time</span>-intermittent renewable generation, operate via faster electrical markets, and tap the latent control capability at finer grid modeling <span class="hlt">scales</span>; creating a fundamentally new set of couplings across spatiotemporal <span class="hlt">scales</span> and requiring revolutionary advances in mathematics techniques to bridge these <span class="hlt">scales</span>. One example is found in decade-<span class="hlt">scale</span> grid expansion planning in which today's algorithms assume accurate load forecasts and well-controlled generation. Incorporating intermittent renewable generation creates fluctuating network flows at the hourly <span class="hlt">time</span> <span class="hlt">scale</span>, inherently linking the ability of a transmission line to deliver electrical power to hourly operational decisions. New operations-based planning algorithms are required, creating new mathematical challenges. Spatio-temporal <span class="hlt">scales</span> are also crossed when the future grid's minute-<span class="hlt">scale</span> fluctuations in network flows (due to intermittent generation) create a disordered state upon which second-<span class="hlt">scale</span> transient grid dynamics propagate effectively invalidating today's on-line dynamic stability analyses. Addressing this challenge requires new on-line algorithms that use large data streams from new grid sensing technologies to physically aggregate across many spatial <span class="hlt">scales</span> to create responsive, data-driven dynamic models. Here, we sketch the mathematical foundations of these problems and potential solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=acls&pg=4&id=EJ175384','ERIC'); return false;" href="http://eric.ed.gov/?q=acls&pg=4&id=EJ175384"><span id="translatedtitle">Factor Structure and <span class="hlt">Scale</span> Reliabilities of the Adjective Check List Across <span class="hlt">Time</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Miller, Stephen H.; And Others</p> <p>1978-01-01</p> <p>Investigated factor structure and <span class="hlt">scale</span> reliabilities of Gough's Adjective Check List (ACL) and their stability over <span class="hlt">time</span>. Employees in a community mental health center completed the ACL twice, separated by a one-year interval. After each administration, separate factor analyses were computed. All <span class="hlt">scales</span> had highly significant test-retest…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70142152','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70142152"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scales</span> of porphyry Cu deposit formation: insights from titanium diffusion in quartz</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mercer, Celestine N.; Reed, Mark H.; Mercer, Cameron M.</p> <p>2015-01-01</p> <p>Porphyry dikes and hydrothermal veins from the porphyry Cu-Mo deposit at Butte, Montana, contain multiple generations of quartz that are distinct in scanning electron microscope-cathodoluminescence (SEM-CL) images and in Ti concentrations. A comparison of microprobe trace element profiles and maps to SEM-CL images shows that the concentration of Ti in quartz correlates positively with CL brightness but Al, K, and Fe do not. After calibrating CL brightness in relation to Ti concentration, we use the brightness gradient between different quartz generations as a proxy for Ti gradients that we model to determine <span class="hlt">time</span> <span class="hlt">scales</span> of quartz formation and cooling. Model results indicate that <span class="hlt">time</span> <span class="hlt">scales</span> of porphyry magma residence are ~1,000s of years and <span class="hlt">time</span> <span class="hlt">scales</span> from porphyry quartz phenocryst rim formation to porphyry dike injection and cooling are ~10s of years. <span class="hlt">Time</span> <span class="hlt">scales</span> for the formation and cooling of various generations of hydrothermal vein quartz range from 10s to 10,000s of years. These <span class="hlt">time</span> <span class="hlt">scales</span> are considerably shorter than the ~0.6 m.y. overall <span class="hlt">time</span> frame for each porphyry-style mineralization pulse determined from isotopic studies at Butte, Montana. Simple heat conduction models provide a temporal reference point to compare chemical diffusion <span class="hlt">time</span> <span class="hlt">scales</span>, and we find that they support short dike and vein formation <span class="hlt">time</span> <span class="hlt">scales</span>. We interpret these relatively short <span class="hlt">time</span> <span class="hlt">scales</span> to indicate that the Butte porphyry deposit formed by short-lived episodes of hydrofracturing, dike injection, and vein formation, each with discrete thermal pulses, which repeated over the ~3 m.y. generation of the deposit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=311125&keyword=Weather&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68460992&CFTOKEN=73316500','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=311125&keyword=Weather&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68460992&CFTOKEN=73316500"><span id="translatedtitle">A Dynamically Computed Convective <span class="hlt">Time</span> <span class="hlt">Scale</span> for the Kain–Fritsch Convective Parameterization Scheme</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Many convective parameterization schemes define a convective adjustment <span class="hlt">time</span> <span class="hlt">scale</span> τ as the <span class="hlt">time</span> allowed for dissipation of convective available potential energy (CAPE). The Kain–Fritsch scheme defines τ based on an estimate of the advective <span class="hlt">time</span> period for deep con...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27627369','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27627369"><span id="translatedtitle">Insights from inside the spinodal: Bridging thermalization <span class="hlt">time</span> <span class="hlt">scales</span> with smoothed particle hydrodynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pütz, Martin; Nielaba, Peter</p> <p>2016-08-01</p> <p>We report the influence of the strength of heat bath coupling on the demixing behavior in spinodal decomposing one component liquid-vapor systems. The smoothed particle hydrodynamics (SPH) method with a van der Waals equation of state is used for the simulation. A thermostat for SPH is introduced that is based on the Berendsen thermostat. It controls the strength of heat bath coupling and allows for quenches with exponential temperature decay at a certain thermalization <span class="hlt">time</span> <span class="hlt">scale</span>. The present method allows us to bridge several orders of magnitude in the thermalization <span class="hlt">time</span> <span class="hlt">scale</span>. The early stage is highly affected by the choice of <span class="hlt">time</span> <span class="hlt">scale</span>. A transition from exponential growth to a 1/2 ordinary power law <span class="hlt">scaling</span> in the characteristic lengths is observed. At high initial temperatures the growth is logarithmic. The comparison with pure thermal simulations reveals latent heat to raise the mean system temperature. Large thermalization <span class="hlt">time</span> <span class="hlt">scales</span> and thermal conductivity are figured out to affect a stagnation of heating, which is explained with convective processes. Furthermore, large thermalization <span class="hlt">time</span> <span class="hlt">scales</span> are responsible for a stagnation of growth of domains, which is temporally embedded between early and late stage of phase separation. Therefore, it is considered as an intermediate stage. We present an aspect concerning this stage, namely that choosing larger thermalization <span class="hlt">time</span> <span class="hlt">scales</span> increases the duration. Moreover, it is observed that diffuse interfaces are formed during this stage, provided that the stage is apparent. We show that the differences in the evolution between pure thermal simulations and simulations with an instantaneously <span class="hlt">scaled</span> mean temperature can be explained by the thermalization process, since a variation of the <span class="hlt">time</span> <span class="hlt">scale</span> allows for the bridging between these cases of limit. PMID:27627369</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..94b2616P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..94b2616P"><span id="translatedtitle">Insights from inside the spinodal: Bridging thermalization <span class="hlt">time</span> <span class="hlt">scales</span> with smoothed particle hydrodynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pütz, Martin; Nielaba, Peter</p> <p>2016-08-01</p> <p>We report the influence of the strength of heat bath coupling on the demixing behavior in spinodal decomposing one component liquid-vapor systems. The smoothed particle hydrodynamics (SPH) method with a van der Waals equation of state is used for the simulation. A thermostat for SPH is introduced that is based on the Berendsen thermostat. It controls the strength of heat bath coupling and allows for quenches with exponential temperature decay at a certain thermalization <span class="hlt">time</span> <span class="hlt">scale</span>. The present method allows us to bridge several orders of magnitude in the thermalization <span class="hlt">time</span> <span class="hlt">scale</span>. The early stage is highly affected by the choice of <span class="hlt">time</span> <span class="hlt">scale</span>. A transition from exponential growth to a 1 /2 ordinary power law <span class="hlt">scaling</span> in the characteristic lengths is observed. At high initial temperatures the growth is logarithmic. The comparison with pure thermal simulations reveals latent heat to raise the mean system temperature. Large thermalization <span class="hlt">time</span> <span class="hlt">scales</span> and thermal conductivity are figured out to affect a stagnation of heating, which is explained with convective processes. Furthermore, large thermalization <span class="hlt">time</span> <span class="hlt">scales</span> are responsible for a stagnation of growth of domains, which is temporally embedded between early and late stage of phase separation. Therefore, it is considered as an intermediate stage. We present an aspect concerning this stage, namely that choosing larger thermalization <span class="hlt">time</span> <span class="hlt">scales</span> increases the duration. Moreover, it is observed that diffuse interfaces are formed during this stage, provided that the stage is apparent. We show that the differences in the evolution between pure thermal simulations and simulations with an instantaneously <span class="hlt">scaled</span> mean temperature can be explained by the thermalization process, since a variation of the <span class="hlt">time</span> <span class="hlt">scale</span> allows for the bridging between these cases of limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27627369','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27627369"><span id="translatedtitle">Insights from inside the spinodal: Bridging thermalization <span class="hlt">time</span> <span class="hlt">scales</span> with smoothed particle hydrodynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pütz, Martin; Nielaba, Peter</p> <p>2016-08-01</p> <p>We report the influence of the strength of heat bath coupling on the demixing behavior in spinodal decomposing one component liquid-vapor systems. The smoothed particle hydrodynamics (SPH) method with a van der Waals equation of state is used for the simulation. A thermostat for SPH is introduced that is based on the Berendsen thermostat. It controls the strength of heat bath coupling and allows for quenches with exponential temperature decay at a certain thermalization <span class="hlt">time</span> <span class="hlt">scale</span>. The present method allows us to bridge several orders of magnitude in the thermalization <span class="hlt">time</span> <span class="hlt">scale</span>. The early stage is highly affected by the choice of <span class="hlt">time</span> <span class="hlt">scale</span>. A transition from exponential growth to a 1/2 ordinary power law <span class="hlt">scaling</span> in the characteristic lengths is observed. At high initial temperatures the growth is logarithmic. The comparison with pure thermal simulations reveals latent heat to raise the mean system temperature. Large thermalization <span class="hlt">time</span> <span class="hlt">scales</span> and thermal conductivity are figured out to affect a stagnation of heating, which is explained with convective processes. Furthermore, large thermalization <span class="hlt">time</span> <span class="hlt">scales</span> are responsible for a stagnation of growth of domains, which is temporally embedded between early and late stage of phase separation. Therefore, it is considered as an intermediate stage. We present an aspect concerning this stage, namely that choosing larger thermalization <span class="hlt">time</span> <span class="hlt">scales</span> increases the duration. Moreover, it is observed that diffuse interfaces are formed during this stage, provided that the stage is apparent. We show that the differences in the evolution between pure thermal simulations and simulations with an instantaneously <span class="hlt">scaled</span> mean temperature can be explained by the thermalization process, since a variation of the <span class="hlt">time</span> <span class="hlt">scale</span> allows for the bridging between these cases of limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27450249','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27450249"><span id="translatedtitle">Combined use of meteorological drought indices at multi-<span class="hlt">time</span> <span class="hlt">scales</span> for improving hydrological drought detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Ye; Wang, Wen; Singh, Vijay P; Liu, Yi</p> <p>2016-11-15</p> <p>Prediction of hydrological drought in the absence of hydrological records is of great significance for water resources management and risk assessment. In this study, two meteorological drought indices, including standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) calculated at different <span class="hlt">time</span> <span class="hlt">scales</span> (1 to 12months), were analyzed for their capabilities in detecting hydrological droughts. The predictive skills of meteorological drought indices were assessed through correlation analysis, and two skill scores, i.e. probability of detection (POD) and false alarm rate (FAR). When used independently, indices of short <span class="hlt">time</span> <span class="hlt">scales</span> generally performed better than did those of long <span class="hlt">time</span> <span class="hlt">scales</span>. However, at least 31% of hydrological droughts were still missed in view of the peak POD score (0.69) of a single meteorological drought index. Considering the distinguished roles of different <span class="hlt">time</span> <span class="hlt">scales</span> in explaining hydrological droughts with disparate features, an optimization approach of blending SPI/SPEI at multiple <span class="hlt">time</span> <span class="hlt">scales</span> was proposed. To examine the robustness of the proposed method, data of 1964-1990 was used to establish the multiscalar index, then validate during 2000-2010. Results showed that POD exhibited a significant increase when more than two <span class="hlt">time</span> <span class="hlt">scales</span> were used, and the best performances were found when blending 8 <span class="hlt">time</span> <span class="hlt">scales</span> of SPI and 9 for SPEI, with the corresponding values of 0.82 and 0.85 for POD, 0.205 and 0.21 for FAR, in the calibration period, and even better performance in the validation period. These results far exceeded the performance of any single meteorological drought index. This suggests that when there is lack of streamflow measurements, blending climatic information of multiple <span class="hlt">time</span> <span class="hlt">scales</span> to jointly monitor hydrological droughts could be an alternative solution. PMID:27450249</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27450249','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27450249"><span id="translatedtitle">Combined use of meteorological drought indices at multi-<span class="hlt">time</span> <span class="hlt">scales</span> for improving hydrological drought detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Ye; Wang, Wen; Singh, Vijay P; Liu, Yi</p> <p>2016-11-15</p> <p>Prediction of hydrological drought in the absence of hydrological records is of great significance for water resources management and risk assessment. In this study, two meteorological drought indices, including standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) calculated at different <span class="hlt">time</span> <span class="hlt">scales</span> (1 to 12months), were analyzed for their capabilities in detecting hydrological droughts. The predictive skills of meteorological drought indices were assessed through correlation analysis, and two skill scores, i.e. probability of detection (POD) and false alarm rate (FAR). When used independently, indices of short <span class="hlt">time</span> <span class="hlt">scales</span> generally performed better than did those of long <span class="hlt">time</span> <span class="hlt">scales</span>. However, at least 31% of hydrological droughts were still missed in view of the peak POD score (0.69) of a single meteorological drought index. Considering the distinguished roles of different <span class="hlt">time</span> <span class="hlt">scales</span> in explaining hydrological droughts with disparate features, an optimization approach of blending SPI/SPEI at multiple <span class="hlt">time</span> <span class="hlt">scales</span> was proposed. To examine the robustness of the proposed method, data of 1964-1990 was used to establish the multiscalar index, then validate during 2000-2010. Results showed that POD exhibited a significant increase when more than two <span class="hlt">time</span> <span class="hlt">scales</span> were used, and the best performances were found when blending 8 <span class="hlt">time</span> <span class="hlt">scales</span> of SPI and 9 for SPEI, with the corresponding values of 0.82 and 0.85 for POD, 0.205 and 0.21 for FAR, in the calibration period, and even better performance in the validation period. These results far exceeded the performance of any single meteorological drought index. This suggests that when there is lack of streamflow measurements, blending climatic information of multiple <span class="hlt">time</span> <span class="hlt">scales</span> to jointly monitor hydrological droughts could be an alternative solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T31C2900P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T31C2900P"><span id="translatedtitle"><span class="hlt">Time</span>-frequency <span class="hlt">scale</span> decomposition of tectonic tremor signals for space-<span class="hlt">time</span> reconstruction of tectonic tremor sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poiata, N.; Satriano, C.; Vilotte, J. P.; Bernard, P.; Obara, K.</p> <p>2015-12-01</p> <p>Seismic radiation associated with transient deformations along the faults and subduction interfaces encompasses a variety of events, i.e., tectonic tremors, low-frequency earthquakes (LFE), very low-frequency earthquakes (VLFs), and slow-slip events (SSE), with a wide range of seismic moment and characteristic durations. Characterizing in space and <span class="hlt">time</span> the complex sources of these slow earthquakes, and their relationship with background seismicity and large earthquakes generation, is of great importance for understanding the physics and mechanics of the processes of active deformations along the plate interfaces. We present here first developments towards a methodology for: (1) extracting the different frequency and <span class="hlt">scale</span> components of observed tectonic tremor signal, using advanced <span class="hlt">time</span>-frequency and <span class="hlt">time-scale</span> signal representation such as Gabor transform scheme based on, e.g. Wilson bases or Modified Discrete Cosine Transform (MDCT) bases; (2) reconstructing their corresponding potential sources in space and <span class="hlt">time</span>, using the array method of Poiata et al. (2015). The methodology is assessed using a dataset of tectonic tremor episodes from Shikoku, Japan, recorded by the Hi-net seismic network operated by NIED. We illustrate its performance and potential in providing activity maps - associated to different <span class="hlt">scale</span>-components of tectonic tremors - that can be analyzed statistically to improve our understanding of tremor sources and <span class="hlt">scaling</span>, as well as their relation with the background seismicity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMOS51B1305S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMOS51B1305S"><span id="translatedtitle">Alongshore Shear-Dispersion of Surfzone Drifters: The Effect of a Finite Lagrangian <span class="hlt">Time-Scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spydell, M. S.; Feddersen, F.</p> <p>2010-12-01</p> <p>GPS-tracked surfzone drifters were used to investigate surfzone dispersion. For the 2006 Huntington Beach (HB06) data, the alongshore diffusivity is related to the magnitude of the mean alongshore current V0 [Spydell et al. JGR 2009]. In particular the asymptotic alongshore diffusivity κyy was approximately consistent with a "shear dispersion" <span class="hlt">scaling</span> [e.g., Taylor 1953] κyy = K V02 τD, where K is a constant, and τD=Ls2/κxx is the cross-shore diffusion <span class="hlt">time</span> for surfzone width Ls and cross-shore diffusivity κxx. However, the value of the constant K obtained from the in-situ data is more than three <span class="hlt">times</span> that expected for the classic Taylor shear dispersion model that assumes uncorrelated Lagrangian velocities at all <span class="hlt">times</span>. Lagrangian velocities in the surfzone are correlated and eventually become decorrelated at <span class="hlt">times</span> longer than the Lagrangian <span class="hlt">time-scale</span> τL. A theory for shear-dispersion that includes the effect of a finite Lagrangian <span class="hlt">time-scale</span> is presented. The shear-enhanced alongshore diffusivity for this model has a different <span class="hlt">scaling</span> κyy ˜ C V02(τDτL)1/2 where C is a constant given by the theory. This <span class="hlt">scaling</span> better explains the HB06 data than the classic shear dispersion <span class="hlt">scaling</span>. This new theory may have application in other geophysical fluid dynamics settings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMuMo...650008G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMuMo...650008G"><span id="translatedtitle">Virtual Testing of Large Composite Structures: A Multiple Length/<span class="hlt">Time-Scale</span> Framework</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gigliotti, Luigi; Pinho, Silvestre T.</p> <p>2015-12-01</p> <p>This paper illustrates a multiple length/<span class="hlt">time-scale</span> framework for the virtual testing of large composite structures. Such framework hinges upon a Mesh Superposition Technique (MST) for the coupling between areas of the structure modelled at different length-<span class="hlt">scales</span> and upon an efficient solid-to-shell numerical homogenization which exploits the internal symmetries of Unit Cells (UCs). Using this framework, it is possible to minimize the areas of the structure modelled at the lowest- (and computationally demanding) <span class="hlt">scales</span> and the computational cost required to calculate the homogenised to be used in the higher-<span class="hlt">scales</span> subdomains of multiscale FE models, as well as to simulate the mechanical response of different parts of the structure using different solvers, depending on where they are expected to provide the most computationally efficient solution. The relevance and key-aspects of the multiple length/<span class="hlt">time-scale</span> framework are demonstrated through the analysis of a real-sized aeronautical composite component.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080005158','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080005158"><span id="translatedtitle">Method and apparatus for two-dimensional <span class="hlt">absolute</span> optical encoding</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Leviton, Douglas B. (Inventor)</p> <p>2004-01-01</p> <p>This invention presents a two-dimensional <span class="hlt">absolute</span> optical encoder and a method for determining position of an object in accordance with information from the encoder. The encoder of the present invention comprises a <span class="hlt">scale</span> having a pattern being predetermined to indicate an <span class="hlt">absolute</span> location on the <span class="hlt">scale</span>, means for illuminating the <span class="hlt">scale</span>, means for forming an image of the pattern; and detector means for outputting signals derived from the portion of the image of the pattern which lies within a field of view of the detector means, the field of view defining an image reference coordinate system, and analyzing means, receiving the signals from the detector means, for determining the <span class="hlt">absolute</span> location of the object. There are two types of <span class="hlt">scale</span> patterns presented in this invention: grid type and starfield type.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003EAEJA....11518R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003EAEJA....11518R&link_type=ABSTRACT"><span id="translatedtitle">Topographic and meteorological influences on space-<span class="hlt">time</span> <span class="hlt">scaling</span> of heavy convective rainfall in mountainous regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rubert Godoy, A.; Nykanen, D.</p> <p>2003-04-01</p> <p>Characterizing the space-<span class="hlt">time</span> <span class="hlt">scaling</span> and dynamics of convective precipitation in mountainous terrain and the development of downscaling methods to transfer precipitation fields from one <span class="hlt">scale</span> to another is the overall motivation for this research. Subtantiing a space-<span class="hlt">time</span> statistical downscaling model for orographic convective precipitation based on the interplay between meteorological forcings and topographic influences on the <span class="hlt">scale</span>-invariant properties of precipitation will be assessed.al progress has been made on characterizing the space-<span class="hlt">time</span> organization of mid-western convective systems and tropical rainfall, which has lead to the development of statistical/dynamical downscaling models. Space-<span class="hlt">time</span> analysis and downscaling of orographic precipitation has received much less attention due to the complexities of topographic influences. This study uses multi-<span class="hlt">scale</span> statistical analysis to investigate the space-<span class="hlt">time</span> <span class="hlt">scaling</span> of organized thunderstorms that produced heavy rainfall and catastrophic flooding in mountainous regions. Focus is placed on the eastern and western slopes of the Appalachian region and the Front Range of the Rocky Mountains. Parameter estimates are analyzed over <span class="hlt">time</span> and focus is placed on linking changes in the multi-<span class="hlt">scale</span> parameters with meteorological forcings and orographic influences on the rainfall. Influences of geographic region (e.g., western versus eastern United States) and predominant orographic controls (e.g., windward versus leeward forcing)on trends in multi-<span class="hlt">scale</span> properties of precipitation are investigated. Spatial resolutions from 1 km to 50 km and temporal integrations from 5 minutes to 3 hours ae considered. This range of space-<span class="hlt">time</span> <span class="hlt">scales</span> is needed to bridge typical <span class="hlt">scale</span> gaps between distributed hydrologic models and numerical weather prediction (NWP) forecasts and attempts to address the open research problem of <span class="hlt">scaling</span> organized thunderstorms and convection in mountainous terrain down to 1-4 km <span class="hlt">scales</span>. The potential for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120012063','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120012063"><span id="translatedtitle">Orion <span class="hlt">Absolute</span> Navigation System Progress and Challenge</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Holt, Greg N.; D'Souza, Christopher</p> <p>2012-01-01</p> <p>The <span class="hlt">absolute</span> navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a <span class="hlt">timely</span> and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, <span class="hlt">scale</span> factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26785541','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26785541"><span id="translatedtitle">[Stormflow hydrochemical characteristics at different <span class="hlt">time</span> <span class="hlt">scales</span> in a typical karst catchment of northwest Guangxi, China].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Chun; Yang, Jing; Nie, Yun-peng; Chen, Hong-song; Fu, Zhi-yong</p> <p>2015-09-01</p> <p>Through in situ observation and indoor tests, the hydrochemical characteristics of a typical karst watershed at three different <span class="hlt">time</span> <span class="hlt">scales</span> (diurnal, single storm, and seasonal <span class="hlt">scales</span>) from June 2013 to March 2014 were investigated, and their influencing factors were analyzed. The results showed that the diurnal variations of the hydrochemistry exhibited a regular changing pattern resulting from the shifting of the main vegetation physiological activity from photosynthesis in the day to respiration in the night. At single storm <span class="hlt">scale</span>, however, the hydrochemical processes were mainly determined by the number of consecutive rainless days and rainfall intensity, while the diurnal <span class="hlt">scale</span> effect was weakened. As to the seasonal <span class="hlt">scale</span>, the overall hydrochemical processes showed quick responses to rainfall events although they responded more quickly in the rainy season than in the dry season. The temperature and the yearly rainfall distribution regime were the two main influencing factors at this <span class="hlt">scale</span>. PMID:26785541</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22300358','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22300358"><span id="translatedtitle">A hybrid procedure for MSW generation forecasting at multiple <span class="hlt">time</span> <span class="hlt">scales</span> in Xiamen City, China</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xu, Lilai; Gao, Peiqing; Cui, Shenghui; Liu, Chun</p> <p>2013-06-15</p> <p>Highlights: ► We propose a hybrid model that combines seasonal SARIMA model and grey system theory. ► The model is robust at multiple <span class="hlt">time</span> <span class="hlt">scales</span> with the anticipated accuracy. ► At month-<span class="hlt">scale</span>, the SARIMA model shows good representation for monthly MSW generation. ► At medium-term <span class="hlt">time</span> <span class="hlt">scale</span>, grey relational analysis could yield the MSW generation. ► At long-term <span class="hlt">time</span> <span class="hlt">scale</span>, GM (1, 1) provides a basic scenario of MSW generation. - Abstract: Accurate forecasting of municipal solid waste (MSW) generation is crucial and fundamental for the planning, operation and optimization of any MSW management system. Comprehensive information on waste generation for month-<span class="hlt">scale</span>, medium-term and long-term <span class="hlt">time</span> <span class="hlt">scales</span> is especially needed, considering the necessity of MSW management upgrade facing many developing countries. Several existing models are available but of little use in forecasting MSW generation at multiple <span class="hlt">time</span> <span class="hlt">scales</span>. The goal of this study is to propose a hybrid model that combines the seasonal autoregressive integrated moving average (SARIMA) model and grey system theory to forecast MSW generation at multiple <span class="hlt">time</span> <span class="hlt">scales</span> without needing to consider other variables such as demographics and socioeconomic factors. To demonstrate its applicability, a case study of Xiamen City, China was performed. Results show that the model is robust enough to fit and forecast seasonal and annual dynamics of MSW generation at month-<span class="hlt">scale</span>, medium- and long-term <span class="hlt">time</span> <span class="hlt">scales</span> with the desired accuracy. In the month-<span class="hlt">scale</span>, MSW generation in Xiamen City will peak at 132.2 thousand tonnes in July 2015 – 1.5 <span class="hlt">times</span> the volume in July 2010. In the medium term, annual MSW generation will increase to 1518.1 thousand tonnes by 2015 at an average growth rate of 10%. In the long term, a large volume of MSW will be output annually and will increase to 2486.3 thousand tonnes by 2020 – 2.5 <span class="hlt">times</span> the value for 2010. The hybrid model proposed in this paper can enable decision makers to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004AIPC..708..462P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004AIPC..708..462P&link_type=ABSTRACT"><span id="translatedtitle">The stability of the critical <span class="hlt">scaling</span> against the <span class="hlt">time</span>-dependent perturbation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Heungsik; Park, Hyunggyu</p> <p>2004-04-01</p> <p>We study the stability of critical <span class="hlt">scaling</span> against the <span class="hlt">time</span>-dependent perturbation in the contact process(CP) model. The critical probability of the particle varies asp = p0 + ct-α. we perform the static Monte Carlo simulation using the finite size <span class="hlt">scaling</span> theory in the steady state. For the α > 1/v∥, the <span class="hlt">time</span> dependent perturbation is irrelevant, therefore , the critical exponents β/v∥,β/v⊥ have the DP value. For the α = 1/v∥, β/v∥ is DP value but β/v⊥ is varied with perturbation strength c. For the α < 1/v∥, the particle density is decayed with ρ ˜ tαβ in thermodynamic limit. However, for the all case, z have DP value. To study the stability of critical <span class="hlt">scaling</span>, we introduce the <span class="hlt">time</span>-dependent perturbation and know that critical <span class="hlt">scaling</span> function is satisfied in all cases. Numerical simulations confirm our predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EL....10918002S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EL....10918002S"><span id="translatedtitle">Change ΔS of the entropy in natural <span class="hlt">time</span> under <span class="hlt">time</span> reversal: Complexity measures upon change of <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarlis, N. V.; Christopoulos, S.-R. G.; Bemplidaki, M. M.</p> <p>2015-01-01</p> <p>The entropy S in natural <span class="hlt">time</span> as well as the entropy in natural <span class="hlt">time</span> under <span class="hlt">time</span> reversal S- have already found useful applications in the physics of complex systems, e.g., in the analysis of electrocardiograms (ECGs). Here, we focus on the complexity measures Λl which result upon considering how the statistics of the <span class="hlt">time</span> series Δ S≤ft[\\equiv S- S-\\right] changes upon varying the <span class="hlt">scale</span> l. These <span class="hlt">scale</span>-specific measures are ratios of the standard deviations σ(Δ S_l) and hence independent of the mean value and the standard deviation of the data. They focus on the different dynamics that appear on different <span class="hlt">scales</span>. For this reason, they can be considered complementary to other standard measures of heart rate variability in ECG, like SDNN, as well as other complexity measures already defined in natural <span class="hlt">time</span>. An application to the analysis of ECG —when solely using NN intervals— is presented: We show how Λl can be used to separate ECG of healthy individuals from those suffering from congestive heart failure and sudden cardiac death.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ClDy...45.2001A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ClDy...45.2001A"><span id="translatedtitle">Increasing temperature forcing reduces the Greenland Ice Sheet's response <span class="hlt">time</span> <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Applegate, Patrick J.; Parizek, Byron R.; Nicholas, Robert E.; Alley, Richard B.; Keller, Klaus</p> <p>2015-10-01</p> <p>Damages from sea level rise, as well as strategies to manage the associated risk, hinge critically on the <span class="hlt">time</span> <span class="hlt">scale</span> and eventual magnitude of sea level rise. Satellite observations and paleo-data suggest that the Greenland Ice Sheet (GIS) loses mass in response to increased temperatures, and may thus contribute substantially to sea level rise as anthropogenic climate change progresses. The <span class="hlt">time</span> <span class="hlt">scale</span> of GIS mass loss and sea level rise are deeply uncertain, and are often assumed to be constant. However, previous ice sheet modeling studies have shown that the <span class="hlt">time</span> <span class="hlt">scale</span> of GIS response likely decreases strongly with increasing temperature anomaly. Here, we map the relationship between temperature anomaly and the <span class="hlt">time</span> <span class="hlt">scale</span> of GIS response, by perturbing a calibrated, three-dimensional model of GIS behavior. Additional simulations with a profile, higher-order, ice sheet model yield <span class="hlt">time</span> <span class="hlt">scales</span> that are broadly consistent with those obtained using the three-dimensional model, and shed light on the feedbacks in the ice sheet system that cause the <span class="hlt">time</span> <span class="hlt">scale</span> shortening. Semi-empirical modeling studies that assume a constant <span class="hlt">time</span> <span class="hlt">scale</span> of sea level adjustment, and are calibrated to small preanthropogenic temperature and sea level changes, may underestimate future sea level rise. Our analysis suggests that the benefits of reducing greenhouse gas emissions, in terms of avoided sea level rise from the GIS, may be greatest if emissions reductions begin before large temperature increases have been realized. Reducing anthropogenic climate change may also allow more <span class="hlt">time</span> for design and deployment of risk management strategies by slowing sea level contributions from the GIS.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/975437','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/975437"><span id="translatedtitle"><span class="hlt">Absolute</span> photoionization cross-section of the methyl radical.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Taatjes, C. A.; Osborn, D. L.; Selby, T.; Meloni, G.; Fan, H.; Pratt, S. T.; Chemical Sciences and Engineering Division; SNL</p> <p>2008-01-01</p> <p>The <span class="hlt">absolute</span> photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH{sub 3} photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed laser-photolysis/<span class="hlt">time</span>-resolved synchrotron photoionization mass spectrometry method. The <span class="hlt">time</span>-resolved depletion of the acetone or methyl vinyl ketone precursor and the production of methyl radicals following 193 nm photolysis are monitored simultaneously by using <span class="hlt">time</span>-resolved synchrotron photoionization mass spectrometry. Comparison of the initial methyl signal with the decrease in precursor signal, in combination with previously measured <span class="hlt">absolute</span> photoionization cross-sections of the precursors, yields the <span class="hlt">absolute</span> photoionization cross-section of the methyl radical; {sigma}{sub CH}(10.2 eV) = (5.7 {+-} 0.9) x 10{sup -18} cm{sup 2} and {sigma}{sub CH{sub 3}}(11.0 eV) = (6.0 {+-} 2.0) x 10{sup -18} cm{sup 2}. The photoionization cross-section for vinyl radical determined by photolysis of methyl vinyl ketone is in good agreement with previous measurements. The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison of ionization signals from CH{sub 3} and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. These measurements gave a cross-section of (5.4 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.460 eV, (5.5 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.466 eV, and (4.9 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.471 eV. The measurements allow relative photoionization efficiency spectra of methyl radical to be placed on an <span class="hlt">absolute</span> <span class="hlt">scale</span> and will facilitate quantitative measurements of methyl concentrations by photoionization mass spectrometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22493160','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22493160"><span id="translatedtitle"><span class="hlt">Absolute</span> NMR shielding <span class="hlt">scales</span> and nuclear spin–rotation constants in {sup 175}LuX and {sup 197}AuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br and {sup 127}I)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Demissie, Taye B. Komorovsky, Stanislav; Repisky, Michal; Ruud, Kenneth; Jaszuński, Michał</p> <p>2015-10-28</p> <p>We present nuclear spin–rotation constants, <span class="hlt">absolute</span> nuclear magnetic resonance (NMR) shielding constants, and shielding spans of all the nuclei in {sup 175}LuX and {sup 197}AuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br, {sup 127}I), calculated using coupled-cluster singles-and-doubles with a perturbative triples (CCSD(T)) correction theory, four-component relativistic density functional theory (relativistic DFT), and non-relativistic DFT. The total nuclear spin–rotation constants determined by adding the relativistic corrections obtained from DFT calculations to the CCSD(T) values are in general in agreement with available experimental data, indicating that the computational approach followed in this study allows us to predict reliable results for the unknown spin–rotation constants in these molecules. The total NMR <span class="hlt">absolute</span> shielding constants are determined for all the nuclei following the same approach as that applied for the nuclear spin–rotation constants. In most of the molecules, relativistic effects significantly change the computed shielding constants, demonstrating that straightforward application of the non-relativistic formula relating the electronic contribution to the nuclear spin–rotation constants and the paramagnetic contribution to the shielding constants does not yield correct results. We also analyze the origin of the unusually large <span class="hlt">absolute</span> shielding constant and its relativistic correction of gold in AuF compared to the other gold monohalides.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JChPh.143p4311D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JChPh.143p4311D"><span id="translatedtitle"><span class="hlt">Absolute</span> NMR shielding <span class="hlt">scales</span> and nuclear spin-rotation constants in 175LuX and 197AuX (X = 19F, 35Cl, 79Br and 127I)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demissie, Taye B.; Jaszuński, Michał; Komorovsky, Stanislav; Repisky, Michal; Ruud, Kenneth</p> <p>2015-10-01</p> <p>We present nuclear spin-rotation constants, <span class="hlt">absolute</span> nuclear magnetic resonance (NMR) shielding constants, and shielding spans of all the nuclei in 175LuX and 197AuX (X = 19F, 35Cl, 79Br, 127I), calculated using coupled-cluster singles-and-doubles with a perturbative triples (CCSD(T)) correction theory, four-component relativistic density functional theory (relativistic DFT), and non-relativistic DFT. The total nuclear spin-rotation constants determined by adding the relativistic corrections obtained from DFT calculations to the CCSD(T) values are in general in agreement with available experimental data, indicating that the computational approach followed in this study allows us to predict reliable results for the unknown spin-rotation constants in these molecules. The total NMR <span class="hlt">absolute</span> shielding constants are determined for all the nuclei following the same approach as that applied for the nuclear spin-rotation constants. In most of the molecules, relativistic effects significantly change the computed shielding constants, demonstrating that straightforward application of the non-relativistic formula relating the electronic contribution to the nuclear spin-rotation constants and the paramagnetic contribution to the shielding constants does not yield correct results. We also analyze the origin of the unusually large <span class="hlt">absolute</span> shielding constant and its relativistic correction of gold in AuF compared to the other gold monohalides.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997A%26A...319..881G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997A%26A...319..881G"><span id="translatedtitle"><span class="hlt">Absolute</span> magnitudes and kinematics of barium stars.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gomez, A. E.; Luri, X.; Grenier, S.; Prevot, L.; Mennessier, M. O.; Figueras, F.; Torra, J.</p> <p>1997-03-01</p> <p>The <span class="hlt">absolute</span> magnitude of barium stars has been obtained from kinematical data using a new algorithm based on the maximum-likelihood principle. The method allows to separate a sample into groups characterized by different mean <span class="hlt">absolute</span> magnitudes, kinematics and z-<span class="hlt">scale</span> heights. It also takes into account, simultaneously, the censorship in the sample and the errors on the observables. The method has been applied to a sample of 318 barium stars. Four groups have been detected. Three of them show a kinematical behaviour corresponding to disk population stars. The fourth group contains stars with halo kinematics. The luminosities of the disk population groups spread a large range. The intrinsically brightest one (M_v_=-1.5mag, σ_M_=0.5mag) seems to be an inhomogeneous group containing barium binaries as well as AGB single stars. The most numerous group (about 150 stars) has a mean <span class="hlt">absolute</span> magnitude corresponding to stars in the red giant branch (M_v_=0.9mag, σ_M_=0.8mag). The third group contains barium dwarfs, the obtained mean <span class="hlt">absolute</span> magnitude is characteristic of stars on the main sequence or on the subgiant branch (M_v_=3.3mag, σ_M_=0.5mag). The obtained mean luminosities as well as the kinematical results are compatible with an evolutionary link between barium dwarfs and classical barium giants. The highly luminous group is not linked with these last two groups. More high-resolution spectroscopic data will be necessary in order to better discriminate between barium and non-barium stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H24F..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H24F..01S"><span id="translatedtitle"><span class="hlt">Absolute</span> Humidity and the Seasonality of Influenza (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shaman, J. L.; Pitzer, V.; Viboud, C.; Grenfell, B.; Goldstein, E.; Lipsitch, M.</p> <p>2010-12-01</p> <p>Much of the observed wintertime increase of mortality in temperate regions is attributed to seasonal influenza. A recent re-analysis of laboratory experiments indicates that <span class="hlt">absolute</span> humidity strongly modulates the airborne survival and transmission of the influenza virus. Here we show that the onset of increased wintertime influenza-related mortality in the United States is associated with anomalously low <span class="hlt">absolute</span> humidity levels during the prior weeks. We then use an epidemiological model, in which observed <span class="hlt">absolute</span> humidity conditions temper influenza transmission rates, to successfully simulate the seasonal cycle of observed influenza-related mortality. The model results indicate that direct modulation of influenza transmissibility by <span class="hlt">absolute</span> humidity alone is sufficient to produce this observed seasonality. These findings provide epidemiological support for the hypothesis that <span class="hlt">absolute</span> humidity drives seasonal variations of influenza transmission in temperate regions. In addition, we show that variations of the basic and effective reproductive numbers for influenza, caused by seasonal changes in <span class="hlt">absolute</span> humidity, are consistent with the general <span class="hlt">timing</span> of pandemic influenza outbreaks observed for 2009 A/H1N1 in temperate regions. Indeed, <span class="hlt">absolute</span> humidity conditions correctly identify the region of the United States vulnerable to a third, wintertime wave of pandemic influenza. These findings suggest that the <span class="hlt">timing</span> of pandemic influenza outbreaks is controlled by a combination of <span class="hlt">absolute</span> humidity conditions, levels of susceptibility and changes in population mixing and contact rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27000526','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27000526"><span id="translatedtitle">Putting <span class="hlt">scales</span> into evolutionary <span class="hlt">time</span>: the divergence of major <span class="hlt">scale</span> insect lineages (Hemiptera) predates the radiation of modern angiosperm hosts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vea, Isabelle M; Grimaldi, David A</p> <p>2016-03-22</p> <p>The radiation of flowering plants in the mid-Cretaceous transformed landscapes and is widely believed to have fuelled the radiations of major groups of phytophagous insects. An excellent group to test this assertion is the <span class="hlt">scale</span> insects (Coccomorpha: Hemiptera), with some 8,000 described Recent species and probably the most diverse fossil record of any phytophagous insect group preserved in amber. We used here a total-evidence approach (by tip-dating) employing 174 morphological characters of 73 Recent and 43 fossil taxa (48 families) and DNA sequences of three gene regions, to obtain divergence <span class="hlt">time</span> estimates and compare the chronology of the most diverse lineage of <span class="hlt">scale</span> insects, the neococcoid families, with the <span class="hlt">timing</span> of the main angiosperm radiation. An estimated origin of the Coccomorpha occurred at the beginning of the Triassic, about 245 Ma [228-273], and of the neococcoids 60 million years later [210-165 Ma]. A total-evidence approach allows the integration of extinct <span class="hlt">scale</span> insects into a phylogenetic framework, resulting in slightly younger median estimates than analyses using Recent taxa, calibrated with fossil ages only. From these estimates, we hypothesise that most major lineages of coccoids shifted from gymnosperms onto angiosperms when the latter became diverse and abundant in the mid- to Late Cretaceous.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4802209','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4802209"><span id="translatedtitle">Putting <span class="hlt">scales</span> into evolutionary <span class="hlt">time</span>: the divergence of major <span class="hlt">scale</span> insect lineages (Hemiptera) predates the radiation of modern angiosperm hosts</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vea, Isabelle M.; Grimaldi, David A.</p> <p>2016-01-01</p> <p>The radiation of flowering plants in the mid-Cretaceous transformed landscapes and is widely believed to have fuelled the radiations of major groups of phytophagous insects. An excellent group to test this assertion is the <span class="hlt">scale</span> insects (Coccomorpha: Hemiptera), with some 8,000 described Recent species and probably the most diverse fossil record of any phytophagous insect group preserved in amber. We used here a total-evidence approach (by tip-dating) employing 174 morphological characters of 73 Recent and 43 fossil taxa (48 families) and DNA sequences of three gene regions, to obtain divergence <span class="hlt">time</span> estimates and compare the chronology of the most diverse lineage of <span class="hlt">scale</span> insects, the neococcoid families, with the <span class="hlt">timing</span> of the main angiosperm radiation. An estimated origin of the Coccomorpha occurred at the beginning of the Triassic, about 245 Ma [228–273], and of the neococcoids 60 million years later [210–165 Ma]. A total-evidence approach allows the integration of extinct <span class="hlt">scale</span> insects into a phylogenetic framework, resulting in slightly younger median estimates than analyses using Recent taxa, calibrated with fossil ages only. From these estimates, we hypothesise that most major lineages of coccoids shifted from gymnosperms onto angiosperms when the latter became diverse and abundant in the mid- to Late Cretaceous. PMID:27000526</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AtmEn.133...34A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AtmEn.133...34A"><span id="translatedtitle">Analytical expression for gas-particle equilibration <span class="hlt">time</span> <span class="hlt">scale</span> and its numerical evaluation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anttila, Tatu; Lehtinen, Kari E. J.; Dal Maso, Miikka</p> <p>2016-05-01</p> <p>We have derived a <span class="hlt">time</span> <span class="hlt">scale</span> τeq that describes the characteristic <span class="hlt">time</span> for a single compound i with a saturation vapour concentration Ceff,i to reach thermodynamic equilibrium between the gas and particle phases. The equilibration process was assumed to take place via gas-phase diffusion and absorption into a liquid-like phase present in the particles. It was further shown that τeq combines two previously derived and often applied <span class="hlt">time</span> <span class="hlt">scales</span> τa and τs that account for the changes in the gas and particle phase concentrations of i resulting from the equilibration, respectively. The validity of τeq was tested by comparing its predictions against results from a numerical model that explicitly simulates the transfer of i between the gas and particle phases. By conducting a large number of simulations where the values of the key input parameters were varied randomly, it was found out that τeq yields highly accurate results when i is a semi-volatile compound in the sense that the ratio of total (gas and particle phases) concentration of i to the saturation vapour concentration of i, μ, is below unity. On the other hand, the comparison of analytical and numerical <span class="hlt">time</span> <span class="hlt">scales</span> revealed that using τa or τs alone to calculate the equilibration <span class="hlt">time</span> <span class="hlt">scale</span> may lead to considerable errors. It was further shown that τeq tends to overpredict the equilibration <span class="hlt">time</span> when i behaves as a non-volatile compound in a sense that μ > 1. Despite its simplicity, the <span class="hlt">time</span> <span class="hlt">scale</span> derived here has useful applications. First, it can be used to assess if semi-volatile compounds reach thermodynamic equilibrium during dynamic experiments that involve changes in the compound volatility. Second, the <span class="hlt">time</span> <span class="hlt">scale</span> can be used in modeling of secondary organic aerosol (SOA) to check whether SOA forming compounds equilibrate over a certain <span class="hlt">time</span> interval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27056478','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27056478"><span id="translatedtitle">Monitoring forest dynamics with multi-<span class="hlt">scale</span> and <span class="hlt">time</span> series imagery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Chunbo; Zhou, Zhixiang; Wang, Di; Dian, Yuanyong</p> <p>2016-05-01</p> <p>To learn the forest dynamics and evaluate the ecosystem services of forest effectively, a <span class="hlt">timely</span> acquisition of spatial and quantitative information of forestland is very necessary. Here, a new method was proposed for mapping forest cover changes by combining multi-<span class="hlt">scale</span> satellite remote-sensing imagery with <span class="hlt">time</span> series data. Using <span class="hlt">time</span> series Normalized Difference Vegetation Index products derived from the Moderate Resolution Imaging Spectroradiometer images (MODIS-NDVI) and Landsat Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM+) images as data source, a hierarchy stepwise analysis from coarse <span class="hlt">scale</span> to fine <span class="hlt">scale</span> was developed for detecting the forest change area. At the coarse <span class="hlt">scale</span>, MODIS-NDVI data with 1-km resolution were used to detect the changes in land cover types and a land cover change map was constructed using NDVI values at vegetation growing seasons. At the fine <span class="hlt">scale</span>, based on the results at the coarse <span class="hlt">scale</span>, Landsat TM/ETM+ data with 30-m resolution were used to precisely detect the forest change location and forest change trend by analyzing <span class="hlt">time</span> series forest vegetation indices (IFZ). The method was tested using the data for Hubei Province, China. The MODIS-NDVI data from 2001 to 2012 were used to detect the land cover changes, and the overall accuracy was 94.02 % at the coarse <span class="hlt">scale</span>. At the fine <span class="hlt">scale</span>, the available TM/ETM+ images at vegetation growing seasons between 2001 and 2012 were used to locate and verify forest changes in the Three Gorges Reservoir Area, and the overall accuracy was 94.53 %. The accuracy of the two layer hierarchical monitoring results indicated that the multi-<span class="hlt">scale</span> monitoring method is feasible and reliable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27056478','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27056478"><span id="translatedtitle">Monitoring forest dynamics with multi-<span class="hlt">scale</span> and <span class="hlt">time</span> series imagery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Chunbo; Zhou, Zhixiang; Wang, Di; Dian, Yuanyong</p> <p>2016-05-01</p> <p>To learn the forest dynamics and evaluate the ecosystem services of forest effectively, a <span class="hlt">timely</span> acquisition of spatial and quantitative information of forestland is very necessary. Here, a new method was proposed for mapping forest cover changes by combining multi-<span class="hlt">scale</span> satellite remote-sensing imagery with <span class="hlt">time</span> series data. Using <span class="hlt">time</span> series Normalized Difference Vegetation Index products derived from the Moderate Resolution Imaging Spectroradiometer images (MODIS-NDVI) and Landsat Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM+) images as data source, a hierarchy stepwise analysis from coarse <span class="hlt">scale</span> to fine <span class="hlt">scale</span> was developed for detecting the forest change area. At the coarse <span class="hlt">scale</span>, MODIS-NDVI data with 1-km resolution were used to detect the changes in land cover types and a land cover change map was constructed using NDVI values at vegetation growing seasons. At the fine <span class="hlt">scale</span>, based on the results at the coarse <span class="hlt">scale</span>, Landsat TM/ETM+ data with 30-m resolution were used to precisely detect the forest change location and forest change trend by analyzing <span class="hlt">time</span> series forest vegetation indices (IFZ). The method was tested using the data for Hubei Province, China. The MODIS-NDVI data from 2001 to 2012 were used to detect the land cover changes, and the overall accuracy was 94.02 % at the coarse <span class="hlt">scale</span>. At the fine <span class="hlt">scale</span>, the available TM/ETM+ images at vegetation growing seasons between 2001 and 2012 were used to locate and verify forest changes in the Three Gorges Reservoir Area, and the overall accuracy was 94.53 %. The accuracy of the two layer hierarchical monitoring results indicated that the multi-<span class="hlt">scale</span> monitoring method is feasible and reliable. PMID:27056478</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006APS..DPPBO1012G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006APS..DPPBO1012G"><span id="translatedtitle">Micro- and nano- second <span class="hlt">time</span> <span class="hlt">scale</span>, high power electrical wire explosions in water.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grinenko, Alon; Efimov, Sergey; Sayapin, Arkadii; Fedotov, Alexander; Gurovich, Viktor; Krasik, Yakov</p> <p>2006-10-01</p> <p>Experimental and magneto-hydro-dynamic simulation results of micro- and nanosecond <span class="hlt">time</span> <span class="hlt">scale</span> underwater electrical Al, Cu and W wires explosions are presented. A capacitor bank with stored energy up to 6 kJ (discharge current up to 80 kA with 2.5 μs quarter period) was used in microsecond <span class="hlt">time</span> <span class="hlt">scale</span> experiments and water forming line generator with current amplitude up to 100 kA and pulse duration of 100 ns were used in nanosecond <span class="hlt">time</span> <span class="hlt">scale</span> experiments. Extremely high energy deposition of up to 60 <span class="hlt">times</span> the atomization enthalpy was registered in nanosecond <span class="hlt">time</span> <span class="hlt">scale</span> explosions. A discharge channel evolution and surface temperature were analyzed by streak shadow imaging and using fast photo-diode with a set of interference filters, respectively. Microsecond <span class="hlt">time</span> <span class="hlt">scale</span> electrical explosion of cylindrical wire array showed extremely high pressure of converging shock waves at the axis, up to 0.2 MBar. A 1D and 2D magneto-hydro-dynamic simulation demonstrated good agreement with such experimental parameters as discharge channel current, voltage, radius, and temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED097019.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED097019.pdf"><span id="translatedtitle">Disk File Management in a Medium-<span class="hlt">Scale</span> <span class="hlt">Time</span>-Sharing System.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Fitzhugh, Robert J.; Pethia, Richard D.</p> <p></p> <p>The paper descibes a compact and highly efficient disk file management system responsible for the management and allocation of space on moving head disk drives in a medium-<span class="hlt">scale</span> <span class="hlt">time</span>-sharing system. The disk file management system is a major component of the Experimental <span class="hlt">Time</span>-Sharing System (ETSS) developed at the Learning Research and Development…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21562090','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21562090"><span id="translatedtitle">Acoustic Emission Monitoring of the Syracuse Athena Temple: <span class="hlt">Scale</span> Invariance in the <span class="hlt">Timing</span> of Ruptures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Niccolini, G.; Carpinteri, A.; Lacidogna, G.; Manuello, A.</p> <p>2011-03-11</p> <p>We perform a comparative statistical analysis between the acoustic-emission <span class="hlt">time</span> series from the ancient Greek Athena temple in Syracuse and the sequence of nearby earthquakes. We find an apparent association between acoustic-emission bursts and the earthquake occurrence. The waiting-<span class="hlt">time</span> distributions for acoustic-emission and earthquake <span class="hlt">time</span> series are described by a unique <span class="hlt">scaling</span> law indicating self-similarity over a wide range of magnitude <span class="hlt">scales</span>. This evidence suggests a correlation between the aging process of the temple and the local seismic activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4309122','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4309122"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">scales</span> of the stick–slip dynamics of the peeling of an adhesive tape</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mishra, Nachiketa; Parida, Nigam Chandra; Raha, Soumyendu</p> <p>2015-01-01</p> <p>The stick–slip dynamics of the peeling of an adhesive tape is characterized by bifurcations that have been experimentally well studied. In this work, we investigate the <span class="hlt">time</span> <span class="hlt">scale</span> in which the the stick–slips happen leading to the bifurcations. This is fundamental to understanding the triboluminescence and acoustic emissions associated with the bifurcations. We establish a relationship between the <span class="hlt">time</span> <span class="hlt">scale</span> of the bifurcations and the inherent mathematical structure of the peeling dynamics by studying a characteristic <span class="hlt">time</span> quantity associated with the dynamics. PMID:25663802</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EL....10268005R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EL....10268005R&link_type=ABSTRACT"><span id="translatedtitle">Coevolution of strategy-selection <span class="hlt">time</span> <span class="hlt">scale</span> and cooperation in spatial prisoner's dilemma game</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rong, Zhihai; Wu, Zhi-Xi; Chen, Guanrong</p> <p>2013-06-01</p> <p>In this paper, we investigate a networked prisoner's dilemma game where individuals' strategy-selection <span class="hlt">time</span> <span class="hlt">scale</span> evolves based on their historical learning information. We show that the more <span class="hlt">times</span> the current strategy of an individual is learnt by his neighbors, the longer <span class="hlt">time</span> he will stick on the successful behavior by adaptively adjusting the lifetime of the adopted strategy. Through characterizing the extent of success of the individuals with normalized payoffs, we show that properly using the learned information can form a positive feedback mechanism between cooperative behavior and its lifetime, which can boost cooperation on square lattices and <span class="hlt">scale</span>-free networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6918501','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6918501"><span id="translatedtitle">Calibration of the geologic <span class="hlt">time</span> <span class="hlt">scale</span>: Cenozoic and Late Cretaceous glauconite and nonglauconite dates compared</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Craig, L.E.; Smith, A.G. ); Armstrong, R.L. )</p> <p>1989-09-01</p> <p>Revision of the 1982 <span class="hlt">time</span> <span class="hlt">scale</span> of Harland et al. has led to the compilation of 377 isotopic dates for calibration of the Cenozoic to Cretaceous <span class="hlt">time</span> interval. The results show that the ages of stage boundaries based on glauconite dates are on average about 2 m.y. younger than those based on nonglauconite dates, but for many Cenozoic and Late Cretaceous stages the differences are too small to require special consideration of glauconite dates. Future work may reveal an irreducible systematic difference between glauconite and nonglauconite <span class="hlt">time</span> <span class="hlt">scales</span>, but the progress made so far in recognizing those glauconites likely to yield reliable dates for the Cenozoic to Late Cretaceous interval may continue to provide useful <span class="hlt">time-scale</span> calibration points.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011APS..MAR.H7001C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011APS..MAR.H7001C&link_type=ABSTRACT"><span id="translatedtitle">Energy Landscapes Encoding Function in Enzymes Investigated Over Broad <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Callender, Robert</p> <p>2011-03-01</p> <p>The operating hypothesis of much of our current work is that atomic motion, over broad <span class="hlt">time</span> <span class="hlt">scales</span> (femtoseconds to milliseconds, the latter being the <span class="hlt">time</span> <span class="hlt">scale</span> of most enzyme catalyzed reactions), contributes to enzymic catalysis in proteins. It is clear from our work that specific types of motions are important in binding of ligands to proteins and transition state formation in enzymatic catalysis. Since new experimental and theoretical approaches are needed to understand the dynamical nature of proteins broadly and enzymatic catalysis specifically, we have employed <span class="hlt">time</span>-resolved ``pump-probe'' spectroscopic techniques because of the sensitivity of these type of approaches to all relevant <span class="hlt">time</span> <span class="hlt">scales</span>. And we have also developed and applied new theoretical methods. The talk will focus on how lactate dehydrogenase brings about catalysis based on current experimental and theoretical studies. Work supported by NIH Grant P01GM068036.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhLA..255..331M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhLA..255..331M"><span id="translatedtitle">Long-<span class="hlt">time</span> <span class="hlt">scale</span> spectral diffusion in PMMA: Beyond the TLS model?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller, J.; Haarer, D.; Khodykin, O. V.; Kharlamov, B. M.</p> <p>1999-05-01</p> <p>Spectral diffusion (SD) in PMMA doped with H 2-TPP is investigated at 4.2 K on a <span class="hlt">time</span> <span class="hlt">scale</span> of 3 ÷ 10 6 s via optical hole burning. Two contradictory (in frames of the TLS model) results are obtained. The first is the absence of aging effects which put the upper limit for the TLS relaxation <span class="hlt">times</span> to tens of minutes. The second is an intensive superlogarithmic SD on the whole <span class="hlt">time</span> <span class="hlt">scale</span> of the experiment, which evidences the presence of very slow relaxations, independent of the sample history on the <span class="hlt">time</span> <span class="hlt">scale</span> of up to 2 months. The presented results provide the clear evidence of the deviation of SD behavior from the TLS model predictions at moderately low temperatures. The concept of structural relaxations is applied for a qualitative interpretation of the experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhyA..407...15O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhyA..407...15O"><span id="translatedtitle">An <span class="hlt">absolute</span> measure for a key currency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito</p> <p></p> <p>It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no <span class="hlt">absolute</span> general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an <span class="hlt">absolute</span> measure for a key currency based on the strength of the periodicity. Moreover, we analyze the <span class="hlt">time</span> evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Absolutism&pg=3&id=EJ265369','ERIC'); return false;" href="http://eric.ed.gov/?q=Absolutism&pg=3&id=EJ265369"><span id="translatedtitle">Relativistic <span class="hlt">Absolutism</span> in Moral Education.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Vogt, W. Paul</p> <p>1982-01-01</p> <p>Discusses Emile Durkheim's "Moral Education: A Study in the Theory and Application of the Sociology of Education," which holds that morally healthy societies may vary in culture and organization but must possess <span class="hlt">absolute</span> rules of moral behavior. Compares this moral theory with current theory and practice of American educators. (MJL)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=Phosphorus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhosphorus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=Phosphorus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhosphorus"><span id="translatedtitle"><span class="hlt">Absolute</span> transition probabilities of phosphorus.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, M. H.; Roig, R. A.; Bengtson, R. D.</p> <p>1971-01-01</p> <p>Use of a gas-driven shock tube to measure the <span class="hlt">absolute</span> strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70029539','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70029539"><span id="translatedtitle">The role of topography on catchment-<span class="hlt">scale</span> water residence <span class="hlt">time</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McGuire, K.J.; McDonnell, Jeffery J.; Weiler, M.; Kendall, C.; McGlynn, B.L.; Welker, J.M.; Seibert, J.</p> <p>2005-01-01</p> <p>The age, or residence <span class="hlt">time</span>, of water is a fundamental descriptor of catchment hydrology, revealing information about the storage, flow pathways, and source of water in a single integrated measure. While there has been tremendous recent interest in residence <span class="hlt">time</span> estimation to characterize watersheds, there are relatively few studies that have quantified residence <span class="hlt">time</span> at the watershed <span class="hlt">scale</span>, and fewer still that have extended those results beyond single catchments to larger landscape <span class="hlt">scales</span>. We examined-topographic controls on residence <span class="hlt">time</span> for seven catchments (0.085-62.4 km2) that represent diverse geologic and geomorphic conditions in the western Cascade Mountains of Oregon. Our primary objective was to determine the dominant physical controls on catchment-<span class="hlt">scale</span>, water residence <span class="hlt">time</span> and specifically test the hypothesis that residence <span class="hlt">time</span> is related to the size of the basin. Residence <span class="hlt">times</span> were estimated by simple convolution models that described the transfer of precipitation isotopic composition to the stream network. We found that base flow mean residence <span class="hlt">times</span> for exponential distributions ranged from 0.8 to 3.3 years. Mean residence <span class="hlt">time</span> showed no correlation to basin area (r2 < 0.01) but instead was correlated (r2 =-0:91) to catchment terrain indices representing the flow path distance and flow path gradient to the stream network. These results illustrate that landscape organization (i.e., topography) rather than basin area controls catchment-<span class="hlt">scale</span> transport. Results from this study may provide a framework for describing <span class="hlt">scale</span>-invariant transport across climatic and geologic conditions, whereby the internal form and structure of the basin defines the first-order control on base flow residence <span class="hlt">time</span>. Copyright 2005 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93b4103H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93b4103H"><span id="translatedtitle">Kibble-Zurek mechanism beyond adiabaticity: Finite-<span class="hlt">time</span> <span class="hlt">scaling</span> with critical initial slip</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Yingyi; Yin, Shuai; Hu, Qijun; Zhong, Fan</p> <p>2016-01-01</p> <p>The Kibble-Zurek mechanism demands an initial adiabatic stage before an impulse stage to have a frozen correlation length that generates topological defects in a cooling phase transition. Here we study such a driven critical dynamics but with an initial condition that is near the critical point and that is far away from equilibrium. In this case, there is no initial adiabatic stage at all and thus adiabaticity is broken. However, we show that there again exists a finite length <span class="hlt">scale</span> arising from the driving that divides the evolution into three stages. A relaxation-finite-<span class="hlt">time-scaling</span>-adiabatic scenario is then proposed in place of the adiabatic-impulse-adiabatic scenario of the original Kibble-Zurek mechanism. A unified <span class="hlt">scaling</span> theory, which combines finite-<span class="hlt">time</span> <span class="hlt">scaling</span> with critical initial slip, is developed to describe the universal behavior and is confirmed with numerical simulations of a two-dimensional classical Ising model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/5211052','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/5211052"><span id="translatedtitle">Space and <span class="hlt">time</span> <span class="hlt">scales</span> of shoreline change at Cape Cod National Seashore, MA, USA</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Allen, J.R.; LaBash, C.L.; List, J.H.; Kraus, Nicholas C.; McDougal, William G.</p> <p>1999-01-01</p> <p>Different processes cause patterns of shoreline change which are exhibited at different magnitudes and nested into different spatial and <span class="hlt">time</span> <span class="hlt">scale</span> hierarchies. The 77-km outer beach at Cape Cod National Seashore offers one of the few U.S. federally owned portions of beach to study shoreline change within the full range of sediment source and sink relationships, and barely affected by human intervention. 'Mean trends' of shoreline changes are best observed at long <span class="hlt">time</span> <span class="hlt">scales</span> but contain much spatial variation thus many sites are not equal in response. Long-term, earlier-noted trends are confirmed but the added quantification and resolution improves greatly the understanding of appropriate spatial and <span class="hlt">time</span> <span class="hlt">scales</span> of those processes driving bluff retreat and barrier island changes in both north and south depocenters. Shorter timescales allow for comparison of trends and uncertainty in shoreline change at local <span class="hlt">scales</span> but are dependent upon some measure of storm intensity and seasonal frequency. Single-event shoreline survey results for one storm at daily intervals after the erosional phase suggest a recovery <span class="hlt">time</span> for the system of six days, identifies three sites with abnormally large change, and that responses at these sites are spatially coherent for now unknown reasons. Areas near inlets are the most variable at all <span class="hlt">time</span> <span class="hlt">scales</span>. Hierarchies in both process and form are suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.450.4323S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.450.4323S"><span id="translatedtitle"><span class="hlt">Time-scales</span> of close-in exoplanet radio emission variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>See, V.; Jardine, M.; Fares, R.; Donati, J.-F.; Moutou, C.</p> <p>2015-07-01</p> <p>We investigate the variability of exoplanetary radio emission using stellar magnetic maps and 3D field extrapolation techniques. We use a sample of hot Jupiter hosting stars, focusing on the HD 179949, HD 189733 and τ Boo systems. Our results indicate two <span class="hlt">time-scales</span> over which radio emission variability may occur at magnetized hot Jupiters. The first is the synodic period of the star-planet system. The origin of variability on this <span class="hlt">time-scale</span> is the relative motion between the planet and the interplanetary plasma that is corotating with the host star. The second <span class="hlt">time-scale</span> is the length of the magnetic cycle. Variability on this <span class="hlt">time-scale</span> is caused by evolution of the stellar field. At these systems, the magnitude of planetary radio emission is anticorrelated with the angular separation between the subplanetary point and the nearest magnetic pole. For the special case of τ Boo b, whose orbital period is tidally locked to the rotation period of its host star, variability only occurs on the <span class="hlt">time-scale</span> of the magnetic cycle. The lack of radio variability on the synodic period at τ Boo b is not predicted by previous radio emission models, which do not account for the co-rotation of the interplanetary plasma at small distances from the star.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhRvE..69c6121B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhRvE..69c6121B"><span id="translatedtitle">Crossover from antipersistent to persistent behavior in <span class="hlt">time</span> series possessing the generalyzed dynamic <span class="hlt">scaling</span> law</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balankin, Alexander S.; Morales Matamoros, Oswaldo; Gálvez M., Ernesto; Pérez A., Alfonso</p> <p>2004-03-01</p> <p>The behavior of crude oil price volatility is analyzed within a conceptual framework of kinetic roughening of growing interfaces. We find that the persistent long-horizon volatilities satisfy the Family-Viscek dynamic <span class="hlt">scaling</span> ansatz, whereas the mean-reverting in <span class="hlt">time</span> short horizon volatilities obey the generalized <span class="hlt">scaling</span> law with continuously varying <span class="hlt">scaling</span> exponents. Furthermore we find that the crossover from antipersistent to persistent behavior is accompanied by a change in the type of volatility distribution. These phenomena are attributed to the complex avalanche dynamics of crude oil markets and so a similar behavior may be observed in a wide variety of physical systems governed by avalanche dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22400522','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22400522"><span id="translatedtitle"><span class="hlt">Scaling</span> of Langevin and molecular dynamics persistence <span class="hlt">times</span> of nonhomogeneous fluids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Olivares-Rivas, Wilmer; Colmenares, Pedro J</p> <p>2012-01-01</p> <p>The existing solution for the Langevin equation of an anisotropic fluid allowed the evaluation of the position-dependent perpendicular and parallel diffusion coefficients, using molecular dynamics data. However, the <span class="hlt">time</span> <span class="hlt">scale</span> of the Langevin dynamics and molecular dynamics are different and an ansatz for the persistence probability relaxation <span class="hlt">time</span> was needed. Here we show how the solution for the average persistence probability obtained from the backward Smoluchowski-Fokker-Planck equation (SE), associated to the Langevin dynamics, <span class="hlt">scales</span> with the corresponding molecular dynamics quantity. Our SE perpendicular persistence <span class="hlt">time</span> is evaluated in terms of simple integrals over the equilibrium local density. When properly <span class="hlt">scaled</span> by the perpendicular diffusion coefficient, it gives a good match with that obtained from molecular dynamics. PMID:22400522</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120008714','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120008714"><span id="translatedtitle">Predicting Regional Drought on Sub-Seasonal to Decadal <span class="hlt">Time</span> <span class="hlt">Scales</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schubert, Siegfried; Wang, Hailan; Suarez, Max; Koster, Randal</p> <p>2011-01-01</p> <p>Drought occurs on a wide range of <span class="hlt">time</span> <span class="hlt">scales</span>, and within a variety of different types of regional climates. It is driven foremost by an extended period of reduced precipitation, but it is the impacts on such quantities as soil moisture, streamflow and crop yields that are often most important from a users perspective. While recognizing that different users have different needs for drought information, it is nevertheless important to understand that progress in predicting drought and satisfying such user needs, largely hinges on our ability to improve predictions of precipitation. This talk reviews our current understanding of the physical mechanisms that drive precipitation variations on subseasonal to decadal <span class="hlt">time</span> <span class="hlt">scales</span>, and the implications for predictability and prediction skill. Examples are given highlighting the phenomena and mechanisms controlling precipitation on monthly (e.g., stationary Rossby waves, soil moisture), seasonal (ENSO) and decadal <span class="hlt">time</span> <span class="hlt">scales</span> (PD and AMO).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22400522','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22400522"><span id="translatedtitle"><span class="hlt">Scaling</span> of Langevin and molecular dynamics persistence <span class="hlt">times</span> of nonhomogeneous fluids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Olivares-Rivas, Wilmer; Colmenares, Pedro J</p> <p>2012-01-01</p> <p>The existing solution for the Langevin equation of an anisotropic fluid allowed the evaluation of the position-dependent perpendicular and parallel diffusion coefficients, using molecular dynamics data. However, the <span class="hlt">time</span> <span class="hlt">scale</span> of the Langevin dynamics and molecular dynamics are different and an ansatz for the persistence probability relaxation <span class="hlt">time</span> was needed. Here we show how the solution for the average persistence probability obtained from the backward Smoluchowski-Fokker-Planck equation (SE), associated to the Langevin dynamics, <span class="hlt">scales</span> with the corresponding molecular dynamics quantity. Our SE perpendicular persistence <span class="hlt">time</span> is evaluated in terms of simple integrals over the equilibrium local density. When properly <span class="hlt">scaled</span> by the perpendicular diffusion coefficient, it gives a good match with that obtained from molecular dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP13D3550S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP13D3550S"><span id="translatedtitle">Reconciling Changes to the Geologic <span class="hlt">Time</span> <span class="hlt">Scale</span>, in the U.S. Geologic Names Lexicon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Soller, D. R.; Stamm, N. R.</p> <p>2014-12-01</p> <p>The U.S. Geologic Names Lexicon ("Geolex", http://ngmdb.usgs.gov/Geolex/), is a standard reference for the Nation's stratigraphic nomenclature. Geolex's content is drawn from the literature published since the late 1800's. Since that <span class="hlt">time</span>, modifications to the geologic <span class="hlt">time</span> <span class="hlt">scale</span> have been significant, particularly in recent decades (e.g., the Ordovician, Carboniferous, Permian, and Quaternary), owing in part to more precise biostratigraphic zonations and advances in isotopic dating techniques. Because the definitions of geologic <span class="hlt">time</span> intervals have been modified as more information is gathered, interpreted, and published, the geologic age of a unit as stated in a report published in, for example, 1950, may be different according to today's <span class="hlt">time</span> <span class="hlt">scale</span>. In order to ensure that people can search Geolex for geologic units according to today's <span class="hlt">time</span> <span class="hlt">scale</span>, we have updated to the modern <span class="hlt">time</span> <span class="hlt">scale</span> the age estimates for many geologic units. These updated age estimates are shown in Geolex's "Unit Summary" pages; the ages as originally determined are preserved in the synopsis for each publication. This presentation will focus on our methodology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PNAS..110...52V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PNAS..110...52V"><span id="translatedtitle">Response of vegetation to drought <span class="hlt">time-scales</span> across global land biomes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vicente-Serrano, Sergio M.; Gouveia, Célia; Julio Camarero, Jesús; Beguería, Santiago; Trigo, Ricardo; López-Moreno, Juan I.; Azorín-Molina, César; Pasho, Edmond; Lorenzo-Lacruz, Jorge; Revuelto, Jesús; Morán-Tejeda, Enrique; Sanchez-Lorenzo, Arturo</p> <p>2013-01-01</p> <p>We evaluated the response of the Earth land biomes to drought by correlating a drought index with three global indicators of vegetation activity and growth: vegetation indices from satellite imagery, tree-ring growth series, and Aboveground Net Primary Production (ANPP) records. Arid and humid biomes are both affected by drought, and we suggest that the persistence of the water deficit (i.e., the drought <span class="hlt">time-scale</span>) could be playing a key role in determining the sensitivity of land biomes to drought. We found that arid biomes respond to drought at short <span class="hlt">time-scales</span>; that is, there is a rapid vegetation reaction as soon as water deficits below normal conditions occur. This may be due to the fact that plant species of arid regions have mechanisms allowing them to rapidly adapt to changing water availability. Humid biomes also respond to drought at short <span class="hlt">time-scales</span>, but in this case the physiological mechanisms likely differ from those operating in arid biomes, as plants usually have a poor adaptability to water shortage. On the contrary, semiarid and subhumid biomes respond to drought at long <span class="hlt">time-scales</span>, probably because plants are able to withstand water deficits, but they lack the rapid response of arid biomes to drought. These results are consistent among three vegetation parameters analyzed and across different land biomes, showing that the response of vegetation to drought depends on characteristic drought <span class="hlt">time-scales</span> for each biome. Understanding the dominant <span class="hlt">time-scales</span> at which drought most influences vegetation might help assessing the resistance and resilience of vegetation and improving our knowledge of vegetation vulnerability to climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3538253','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3538253"><span id="translatedtitle">Response of vegetation to drought <span class="hlt">time-scales</span> across global land biomes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vicente-Serrano, Sergio M.; Gouveia, Célia; Camarero, Jesús Julio; Beguería, Santiago; Trigo, Ricardo; López-Moreno, Juan I.; Azorín-Molina, César; Pasho, Edmond; Lorenzo-Lacruz, Jorge; Revuelto, Jesús; Morán-Tejeda, Enrique; Sanchez-Lorenzo, Arturo</p> <p>2013-01-01</p> <p>We evaluated the response of the Earth land biomes to drought by correlating a drought index with three global indicators of vegetation activity and growth: vegetation indices from satellite imagery, tree-ring growth series, and Aboveground Net Primary Production (ANPP) records. Arid and humid biomes are both affected by drought, and we suggest that the persistence of the water deficit (i.e., the drought <span class="hlt">time-scale</span>) could be playing a key role in determining the sensitivity of land biomes to drought. We found that arid biomes respond to drought at short <span class="hlt">time-scales</span>; that is, there is a rapid vegetation reaction as soon as water deficits below normal conditions occur. This may be due to the fact that plant species of arid regions have mechanisms allowing them to rapidly adapt to changing water availability. Humid biomes also respond to drought at short <span class="hlt">time-scales</span>, but in this case the physiological mechanisms likely differ from those operating in arid biomes, as plants usually have a poor adaptability to water shortage. On the contrary, semiarid and subhumid biomes respond to drought at long <span class="hlt">time-scales</span>, probably because plants are able to withstand water deficits, but they lack the rapid response of arid biomes to drought. These results are consistent among three vegetation parameters analyzed and across different land biomes, showing that the response of vegetation to drought depends on characteristic drought <span class="hlt">time-scales</span> for each biome. Understanding the dominant <span class="hlt">time-scales</span> at which drought most influences vegetation might help assessing the resistance and resilience of vegetation and improving our knowledge of vegetation vulnerability to climate change. PMID:23248309</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GBioC..29..583C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GBioC..29..583C"><span id="translatedtitle">The <span class="hlt">time</span> <span class="hlt">scale</span> of the silicate weathering negative feedback on atmospheric CO2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colbourn, G.; Ridgwell, A.; Lenton, T. M.</p> <p>2015-05-01</p> <p>The ultimate fate of CO2 added to the ocean-atmosphere system is chemical reaction with silicate minerals and burial as marine carbonates. The <span class="hlt">time</span> <span class="hlt">scale</span> of this silicate weathering negative feedback on atmospheric pCO2 will determine the duration of perturbations to the carbon cycle, be they geological release events or the current anthropogenic perturbation. However, there has been little previous work on quantifying the <span class="hlt">time</span> <span class="hlt">scale</span> of the silicate weathering feedback, with the primary estimate of 300-400 kyr being traceable to an early box model study by Sundquist (1991). Here we employ a representation of terrestrial rock weathering in conjunction with the "GENIE" (Grid ENabled Integrated Earth system) model to elucidate the different <span class="hlt">time</span> <span class="hlt">scales</span> of atmospheric CO2 regulation while including the main climate feedbacks on CO2 uptake by the ocean. In this coupled model, the main dependencies of weathering—runoff, temperature, and biological productivity—were driven from an energy-moisture balance atmosphere model and parameterized plant productivity. Long-term projections (1 Myr) were conducted for idealized scenarios of 1000 and 5000 PgC fossil fuel emissions and their sensitivity to different model parameters was tested. By fitting model output to a series of exponentials we determined the e-folding <span class="hlt">time</span> <span class="hlt">scale</span> for atmospheric CO2 drawdown by silicate weathering to be ˜240 kyr (range 170-380 kyr), significantly less than existing quantifications. Although the <span class="hlt">time</span> <span class="hlt">scales</span> for reequilibration of global surface temperature and surface ocean pH are similar to that for CO2, a much greater proportion of the peak temperature anomaly persists on this longest <span class="hlt">time</span> <span class="hlt">scale</span>; ˜21% compared to ˜10% for CO2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23248309','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23248309"><span id="translatedtitle">Response of vegetation to drought <span class="hlt">time-scales</span> across global land biomes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vicente-Serrano, Sergio M; Gouveia, Célia; Camarero, Jesús Julio; Beguería, Santiago; Trigo, Ricardo; López-Moreno, Juan I; Azorín-Molina, César; Pasho, Edmond; Lorenzo-Lacruz, Jorge; Revuelto, Jesús; Morán-Tejeda, Enrique; Sanchez-Lorenzo, Arturo</p> <p>2013-01-01</p> <p>We evaluated the response of the Earth land biomes to drought by correlating a drought index with three global indicators of vegetation activity and growth: vegetation indices from satellite imagery, tree-ring growth series, and Aboveground Net Primary Production (ANPP) records. Arid and humid biomes are both affected by drought, and we suggest that the persistence of the water deficit (i.e., the drought <span class="hlt">time-scale</span>) could be playing a key role in determining the sensitivity of land biomes to drought. We found that arid biomes respond to drought at short <span class="hlt">time-scales</span>; that is, there is a rapid vegetation reaction as soon as water deficits below normal conditions occur. This may be due to the fact that plant species of arid regions have mechanisms allowing them to rapidly adapt to changing water availability. Humid biomes also respond to drought at short <span class="hlt">time-scales</span>, but in this case the physiological mechanisms likely differ from those operating in arid biomes, as plants usually have a poor adaptability to water shortage. On the contrary, semiarid and subhumid biomes respond to drought at long <span class="hlt">time-scales</span>, probably because plants are able to withstand water deficits, but they lack the rapid response of arid biomes to drought. These results are consistent among three vegetation parameters analyzed and across different land biomes, showing that the response of vegetation to drought depends on characteristic drought <span class="hlt">time-scales</span> for each biome. Understanding the dominant <span class="hlt">time-scales</span> at which drought most influences vegetation might help assessing the resistance and resilience of vegetation and improving our knowledge of vegetation vulnerability to climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150016315','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150016315"><span id="translatedtitle">Computational Fluid Dynamics Study on the Effects of RATO <span class="hlt">Timing</span> on the <span class="hlt">Scale</span> Model Acoustic Test</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nielsen, Tanner; Williams, B.; West, Jeff</p> <p>2015-01-01</p> <p>The <span class="hlt">Scale</span> Model Acoustic Test (SMAT) is a 5% <span class="hlt">scale</span> test of the Space Launch System (SLS), which is currently being designed at Marshall Space Flight Center (MSFC). The purpose of this test is to characterize and understand a variety of acoustic phenomena that occur during the early portions of lift off, one being the overpressure environment that develops shortly after booster ignition. The SLS lift off configuration consists of four RS-25 liquid thrusters on the core stage, with two solid boosters connected to each side. Past experience with <span class="hlt">scale</span> model testing at MSFC (in ER42), has shown that there is a delay in the ignition of the Rocket Assisted Take Off (RATO) motor, which is used as the 5% <span class="hlt">scale</span> analog of the solid boosters, after the signal to ignite is given. This delay can range from 0 to 16.5ms. While this small of a delay maybe insignificant in the case of the full <span class="hlt">scale</span> SLS, it can significantly alter the data obtained during the SMAT due to the much smaller geometry. The speed of sound of the air and combustion gas constituents is not <span class="hlt">scaled</span>, and therefore the SMAT pressure waves propagate at approximately the same speed as occurs during full <span class="hlt">scale</span>. However, the SMAT geometry is much smaller allowing the pressure waves to move down the exhaust duct, through the trench, and impact the vehicle model much faster than occurs at full <span class="hlt">scale</span>. To better understand the effect of the RATO <span class="hlt">timing</span> simultaneity on the SMAT IOP test data, a computational fluid dynamics (CFD) analysis was performed using the Loci/CHEM CFD software program. Five different <span class="hlt">timing</span> offsets, based on RATO ignition delay statistics, were simulated. A variety of results and comparisons will be given, assessing the overall effect of RATO <span class="hlt">timing</span> simultaneity on the SMAT overpressure environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.V41E..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.V41E..01S"><span id="translatedtitle">A Methodology for <span class="hlt">Absolute</span> Isotope Composition Measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, J. J.; Lee, D.; Liang, W.</p> <p>2007-12-01</p> <p>Double spike technique was a well defined method for isotope composition measurement by TIMS of samples which have natural mass fractionation effect, but it is still a problem to define the isotope composition for double spike itself. In this study, we modified the old double spike technique and found that we could use the modified technique to solve the ¡§true¡¨ isotope composition of double spike itself. According the true isotope composition of double spike, we can measure the <span class="hlt">absolute</span> isotope composition if the sample has natural fractionation effect. A new vector analytical method has been developed in order to obtain the true isotopic composition of a 42Ca-48Ca double spike, and this is achieved by using two different sample-spike mixtures combined with the double spike and the natural Ca data. Because the natural sample, the two mixtures, and the spike should all lie on a single mixing line, we are able to constrain the true isotopic composition of our double spike using this new approach. This method not only can be used in Ca system but also in Ti, Cr, Fe, Ni, Zn, Mo, Ba and Pb systems. The <span class="hlt">absolute</span> double spike isotopic ratio is important, which can save a lot of <span class="hlt">time</span> to check different reference standards. Especially for Pb, radiogenic isotope system, the decay systems embodied in three of four naturally occurring isotopes induce difficult to obtain true isotopic ratios for <span class="hlt">absolute</span> dating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AdWR...45...58R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AdWR...45...58R"><span id="translatedtitle">Doubly stochastic Poisson process models for precipitation at fine <span class="hlt">time-scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramesh, Nadarajah I.; Onof, Christian; Xie, Dichao</p> <p>2012-09-01</p> <p>This paper considers a class of stochastic point process models, based on doubly stochastic Poisson processes, in the modelling of rainfall. We examine the application of this class of models, a neglected alternative to the widely-known Poisson cluster models, in the analysis of fine <span class="hlt">time-scale</span> rainfall intensity. These models are mainly used to analyse tipping-bucket raingauge data from a single site but an extension to multiple sites is illustrated which reveals the potential of this class of models to study the temporal and spatial variability of precipitation at fine <span class="hlt">time-scales</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6431181','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6431181"><span id="translatedtitle">Search for UHE point-source emission over various <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1993-01-01</p> <p>A method has been developed to search for pulsed and/or unpulsed ultra high energy (UHE) emission from point sources over a range of <span class="hlt">time</span> <span class="hlt">scales</span>. This method has been applied to data accumulated with the CYGNUS extensive air-shower array for events associated with the directions of Cyg X-3, Her X-1, the Crab nebula, and a collection of 48 secondary source candidates. An examination of <span class="hlt">time</span> <span class="hlt">scales</span> ranging from minutes to years has yielded results consistent with background fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10157297','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10157297"><span id="translatedtitle">Search for UHE point-source emission over various <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>The CYGNUS Collaboration</p> <p>1993-05-01</p> <p>A method has been developed to search for pulsed and/or unpulsed ultra high energy (UHE) emission from point sources over a range of <span class="hlt">time</span> <span class="hlt">scales</span>. This method has been applied to data accumulated with the CYGNUS extensive air-shower array for events associated with the directions of Cyg X-3, Her X-1, the Crab nebula, and a collection of 48 secondary source candidates. An examination of <span class="hlt">time</span> <span class="hlt">scales</span> ranging from minutes to years has yielded results consistent with background fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26280315','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26280315"><span id="translatedtitle">Relative errors can cue <span class="hlt">absolute</span> visuomotor mappings.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Dam, Loes C J; Ernst, Marc O</p> <p>2015-12-01</p> <p>When repeatedly switching between two visuomotor mappings, e.g. in a reaching or pointing task, adaptation tends to speed up over <span class="hlt">time</span>. That is, when the error in the feedback corresponds to a mapping switch, fast adaptation occurs. Yet, what is learned, the relative error or the <span class="hlt">absolute</span> mappings? When switching between mappings, errors with a size corresponding to the relative difference between the mappings will occur more often than other large errors. Thus, we could learn to correct more for errors with this familiar size (Error Learning). On the other hand, it has been shown that the human visuomotor system can store several <span class="hlt">absolute</span> visuomotor mappings (Mapping Learning) and can use associated contextual cues to retrieve them. Thus, when contextual information is present, no error feedback is needed to switch between mappings. Using a rapid pointing task, we investigated how these two types of learning may each contribute when repeatedly switching between mappings in the absence of task-irrelevant contextual cues. After training, we examined how participants changed their behaviour when a single error probe indicated either the often-experienced error (Error Learning) or one of the previously experienced <span class="hlt">absolute</span> mappings (Mapping Learning). Results were consistent with Mapping Learning despite the relative nature of the error information in the feedback. This shows that errors in the feedback can have a double role in visuomotor behaviour: they drive the general adaptation process by making corrections possible on subsequent movements, as well as serve as contextual cues that can signal a learned <span class="hlt">absolute</span> mapping. PMID:26280315</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SCPMA..56.1017C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SCPMA..56.1017C"><span id="translatedtitle">Noether symmetries of the nonconservative and nonholonomic systems on <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, PingPing; Fu, JingLi; Guo, YongXin</p> <p>2013-05-01</p> <p>In this paper we give a new method to investigate Noether symmetries and conservation laws of nonconservative and nonholonomic mechanical systems on <span class="hlt">time</span> <span class="hlt">scales</span> {T}, which unifies the Noether's theories of the two cases for the continuous and the discrete nonconservative and nonholonomic systems. Firstly, the exchanging relationships between the isochronous variation and the delta derivatives as well as the relationships between the isochronous variation and the total variation on <span class="hlt">time</span> <span class="hlt">scales</span> are obtained. Secondly, using the exchanging relationships, the Hamilton's principle is presented for nonconservative systems with delta derivatives and then the Lagrange equations of the systems are obtained. Thirdly, based on the quasi-invariance of Hamiltonian action of the systems under the infinitesimal transformations with respect to the <span class="hlt">time</span> and generalized coordinates, the Noether's theorem and the conservation laws for nonconservative systems on <span class="hlt">time</span> <span class="hlt">scales</span> are given. Fourthly, the d'Alembert-Lagrange principle with delta derivatives is presented, and the Lagrange equations of nonholonomic systems with delta derivatives are obtained. In addition, the Noether's theorems and the conservation laws for nonholonomic systems on <span class="hlt">time</span> <span class="hlt">scales</span> are also obtained. Lastly, we present a new version of Noether's theorems for discrete systems. Several examples are given to illustrate the application of our results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JCAP...07..052B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JCAP...07..052B"><span id="translatedtitle"><span class="hlt">Time</span>-sliced perturbation theory for large <span class="hlt">scale</span> structure I: general formalism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blas, Diego; Garny, Mathias; Ivanov, Mikhail M.; Sibiryakov, Sergey</p> <p>2016-07-01</p> <p>We present a new analytic approach to describe large <span class="hlt">scale</span> structure formation in the mildly non-linear regime. The central object of the method is the <span class="hlt">time</span>-dependent probability distribution function generating correlators of the cosmological observables at a given moment of <span class="hlt">time</span>. Expanding the distribution function around the Gaussian weight we formulate a perturbative technique to calculate non-linear corrections to cosmological correlators, similar to the diagrammatic expansion in a three-dimensional Euclidean quantum field theory, with <span class="hlt">time</span> playing the role of an external parameter. For the physically relevant case of cold dark matter in an Einstein-de Sitter universe, the <span class="hlt">time</span> evolution of the distribution function can be found exactly and is encapsulated by a <span class="hlt">time</span>-dependent coupling constant controlling the perturbative expansion. We show that all building blocks of the expansion are free from spurious infrared enhanced contributions that plague the standard cosmological perturbation theory. This paves the way towards the systematic resummation of infrared effects in large <span class="hlt">scale</span> structure formation. We also argue that the approach proposed here provides a natural framework to account for the influence of short-<span class="hlt">scale</span> dynamics on larger <span class="hlt">scales</span> along the lines of effective field theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.B34A..06M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.B34A..06M"><span id="translatedtitle">Systematic Land-Surface-Model Performance Evaluation on different <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mahecha, M. D.; Jung, M.; Reichstein, M.; Beer, C.; Braakhekke, M.; Carvalhais, N.; Lange, H.; Lasslop, G.; Le Maire, G.; Seneviratne, S. I.; Vetter, M.</p> <p>2008-12-01</p> <p>Keeping track of the space--<span class="hlt">time</span> evolution of CO2--, and H2O--fluxes between the terrestrial biosphere and atmosphere is essential to our understanding of current climate. Monitoring fluxes at site level is one option to characterize the temporal development of ecosystem--atmosphere interactions. Nevertheless, many aspects of ecosystem--atmosphere fluxes become meaningful only when interpreted in <span class="hlt">time</span> over larger geographical regions. Empirical and process based models play a key role in spatial and temporal upscaling exercises. In this context, comparative model performance evaluations at site level are indispensable. We present a model evaluation scheme which investigates the model-data agreement separately on different <span class="hlt">time</span> <span class="hlt">scales</span>. Observed and modeled <span class="hlt">time</span> series were decomposed by essentially non parametric techniques into subsignals (<span class="hlt">time</span> <span class="hlt">scales</span>) of characteristic fluctuations. By evaluating the extracted subsignals of observed and modeled C--fluxes (gross and net ecosystem exchange, GEE and NEE, and terrestrial ecosystem respiration, TER) separately, we obtain <span class="hlt">scale</span>--dependent performances for the different evaluation measures. Our diagnostic model comparison allows uncovering <span class="hlt">time</span> <span class="hlt">scales</span> of model-data agreement and fundamental mismatch. We focus on the systematic evaluation of three land--surface models: Biome--BGC, ORCHIDEE, and LPJ. For the first <span class="hlt">time</span> all models were driven by consistent site meteorology and compared to respective Eddy-Covariance flux observations. The results show that correct net C--fluxes may result from systematic (simultaneous) biases in TER and GEE on specific <span class="hlt">time</span> <span class="hlt">scales</span> of variation. We localize significant model-data mismatches of the annual-seasonal cycles in <span class="hlt">time</span> and illustrate the recurrence characteristics of such problems. For example LPJ underestimates GEE during winter months and over estimates it in early summer at specific sites. Contrary, ORCHIDEE over-estimates the flux from July to September at these sites. Finally</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvA..94a3808D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PhRvA..94a3808D&link_type=ABSTRACT"><span id="translatedtitle">Optomechanics for <span class="hlt">absolute</span> rotation detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davuluri, Sankar</p> <p>2016-07-01</p> <p>In this article, we present an application of optomechanical cavity for the <span class="hlt">absolute</span> rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of <span class="hlt">absolute</span> rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11262641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11262641"><span id="translatedtitle">Moral <span class="hlt">absolutism</span> and ectopic pregnancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaczor, C</p> <p>2001-02-01</p> <p>If one accepts a version of <span class="hlt">absolutism</span> that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the <span class="hlt">absolutism</span> mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11262641','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11262641"><span id="translatedtitle">Moral <span class="hlt">absolutism</span> and ectopic pregnancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaczor, C</p> <p>2001-02-01</p> <p>If one accepts a version of <span class="hlt">absolutism</span> that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the <span class="hlt">absolutism</span> mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate. PMID:11262641</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp"><span id="translatedtitle">The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kogut, A. J.</p> <p>2010-01-01</p> <p>The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP) is an Explorer-class mission to map the <span class="hlt">absolute</span> intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15831074','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15831074"><span id="translatedtitle">Classification images predict <span class="hlt">absolute</span> efficiency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Murray, Richard F; Bennett, Patrick J; Sekuler, Allison B</p> <p>2005-02-24</p> <p>How well do classification images characterize human observers' strategies in perceptual tasks? We show mathematically that from the classification image of a noisy linear observer, it is possible to recover the observer's <span class="hlt">absolute</span> efficiency. If we could similarly predict human observers' performance from their classification images, this would suggest that the linear model that underlies use of the classification image method is adequate over the small range of stimuli typically encountered in a classification image experiment, and that a classification image captures most important aspects of human observers' performance over this range. In a contrast discrimination task and in a shape discrimination task, we found that observers' <span class="hlt">absolute</span> efficiencies were generally well predicted by their classification images, although consistently slightly (approximately 13%) higher than predicted. We consider whether a number of plausible nonlinearities can account for the slight under prediction, and of these we find that only a form of phase uncertainty can account for the discrepancy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175308','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175308"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of optical flats</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sommargren, Gary E.</p> <p>2005-04-05</p> <p>The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of <span class="hlt">absolute</span> flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the <span class="hlt">absolute</span> phase error of the optical flat is obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNS41B1671H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNS41B1671H"><span id="translatedtitle">Rainfall impact on gravity at annual and rapid <span class="hlt">time</span> <span class="hlt">scales</span> from a superconducting gravimeter record in Benin, West-Africa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hector, B.; Hinderer, J.; Séguis, L.; Boy, J.; Calvo, M.; Descloitres, M.; Rosat, S.; Riccardi, U.; Littel, F.</p> <p>2012-12-01</p> <p>A superconducting gravimeter (SG) has been installed since 2010 in Nalohou, northern Benin, within the framework of the GHYRAF (Gravity and Hydrology in Africa) project. This site was chosen to monitor the strong annual monsoon signal with both local and non-local hydrological contributions within the humid sudanian zone of West-Africa. The area is also part of the long-term observing system AMMA-Catch, and thus under intense hydrological monitoring. We present here the results of the first two years relative gravity monitoring. The signal includes predominantly solid earth tides, ocean loading, polar motion, atmospheric pressure effects, drift and water storage changes (WSC). Retrieving WSC needs thorough corrections of other components, and detailed tide and barometric analysis are thus undertaken. Pressure effects are of major concern in the equatorial band, because they are governed by S1 and S2 thermal pressure waves. These waves dominate both the local Newtonian effect (an increase in local pressure decreases the gravity) and the smaller non-local loading effect (an increase in regional pressure decreases the gravity by a subsidence effect of the elastic earth) because of their coherency at the regional <span class="hlt">scale</span>. FG5 <span class="hlt">absolute</span> gravity data are used for calibration and drift estimate of the SG. Residuals clearly show interesting WSC behaviors at two predominant frequencies for which different accuracies are involved: the seasonal and the rainfall event <span class="hlt">time-scales</span>. The weathered hard rock shallow aquifer of the site is known to produce WSC only in the 0-7m depth range (7m being the lowest interannual level of the water table within our record). WSC are coming both from soil moisture and water table variations. These are monitored 1) by weekly neutronic measurements over the whole vertical profile (every 50cm) in a borehole close to the SG, and 2) by water table level observations for the saturated zone only. The contribution to gravity of the latter is evaluated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ClDy..tmp..312D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ClDy..tmp..312D"><span id="translatedtitle">Synchrony between reanalysis-driven RCM simulations and observations: variation with <span class="hlt">time</span> <span class="hlt">scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Elía, Ramón; Laprise, René; Biner, Sébastien; Merleau, James</p> <p>2016-06-01</p> <p>Unlike coupled global climate models (CGCMs) that run in a stand-alone mode, nested regional climate models (RCMs) are driven by either a CGCM or a reanalysis dataset. This feature makes high correlations between the RCM simulation and its driver possible. When the driving dataset is a reanalysis, <span class="hlt">time</span> correlations between RCM output and observations are also common and to be expected. In certain situations <span class="hlt">time</span> correlation between driver and driven RCM is of particular interest and techniques have been developed to increase it (e.g. large-<span class="hlt">scale</span> spectral nudging). For such cases, a question that remains open is whether aggregating in <span class="hlt">time</span> increases the correlation between RCM output and observations. That is, although the RCM may be unable to reproduce a given daily event, whether it will still be able to satisfactorily simulate an anomaly on a monthly or annual basis. This is a preconception that the authors of this work and others in the community have held, perhaps as a natural extension of the properties of upscaling or aggregating other statistics such as the mean squared error. Here we explore analytically four particular cases that help us partially answer this question. In addition, we use observations datasets and RCM-simulated data to illustrate our findings. Results indicate that <span class="hlt">time</span> upscaling does not necessarily increase <span class="hlt">time</span> correlations, and that those interested in achieving high monthly or annual <span class="hlt">time</span> correlations between RCM output and observations may have to do so by increasing correlation as much as possible at the shortest <span class="hlt">time</span> <span class="hlt">scale</span>. This may indicate that even when only concerned with <span class="hlt">time</span> correlations at large temporal <span class="hlt">scale</span>, large-<span class="hlt">scale</span> spectral nudging acting at the <span class="hlt">time</span>-step level may have to be used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160007725','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160007725"><span id="translatedtitle">The Space-<span class="hlt">Time</span> Conservative Schemes for Large-<span class="hlt">Scale</span>, <span class="hlt">Time</span>-Accurate Flow Simulations with Tetrahedral Meshes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Venkatachari, Balaji Shankar; Streett, Craig L.; Chang, Chau-Lyan; Friedlander, David J.; Wang, Xiao-Yen; Chang, Sin-Chung</p> <p>2016-01-01</p> <p>Despite decades of development of unstructured mesh methods, high-fidelity <span class="hlt">time</span>-accurate simulations are still predominantly carried out on structured, or unstructured hexahedral meshes by using high-order finite-difference, weighted essentially non-oscillatory (WENO), or hybrid schemes formed by their combinations. In this work, the space-<span class="hlt">time</span> conservation element solution element (CESE) method is used to simulate several flow problems including supersonic jet/shock interaction and its impact on launch vehicle acoustics, and direct numerical simulations of turbulent flows using tetrahedral meshes. This paper provides a status report for the continuing development of the space-<span class="hlt">time</span> conservation element solution element (CESE) numerical and software framework under the Revolutionary Computational Aerosciences (RCA) project. Solution accuracy and large-<span class="hlt">scale</span> parallel performance of the numerical framework is assessed with the goal of providing a viable paradigm for future high-fidelity flow physics simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93m4506W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93m4506W"><span id="translatedtitle">Linear-<span class="hlt">scaling</span> source-sink algorithm for simulating <span class="hlt">time</span>-resolved quantum transport and superconductivity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weston, Joseph; Waintal, Xavier</p> <p>2016-04-01</p> <p>We report on a "source-sink" algorithm which allows one to calculate <span class="hlt">time</span>-resolved physical quantities from a general nanoelectronic quantum system (described by an arbitrary <span class="hlt">time</span>-dependent quadratic Hamiltonian) connected to infinite electrodes. Although mathematically equivalent to the nonequilibrium Green's function formalism, the approach is based on the scattering wave functions of the system. It amounts to solving a set of generalized Schrödinger equations that include an additional "source" term (coming from the <span class="hlt">time</span>-dependent perturbation) and an absorbing "sink" term (the electrodes). The algorithm execution <span class="hlt">time</span> <span class="hlt">scales</span> linearly with both system size and simulation <span class="hlt">time</span>, allowing one to simulate large systems (currently around 106 degrees of freedom) and/or large <span class="hlt">times</span> (currently around 105 <span class="hlt">times</span> the smallest <span class="hlt">time</span> <span class="hlt">scale</span> of the system). As an application we calculate the current-voltage characteristics of a Josephson junction for both short and long junctions, and recover the multiple Andreev reflection physics. We also discuss two intrinsically <span class="hlt">time</span>-dependent situations: the relaxation <span class="hlt">time</span> of a Josephson junction after a quench of the voltage bias, and the propagation of voltage pulses through a Josephson junction. In the case of a ballistic, long Josephson junction, we predict that a fast voltage pulse creates an oscillatory current whose frequency is controlled by the Thouless energy of the normal part. A similar effect is found for short junctions; a voltage pulse produces an oscillating current which, in the absence of electromagnetic environment, does not relax.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..94b2311S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..94b2311S"><span id="translatedtitle"><span class="hlt">Time-scale</span> effects on the gain-loss asymmetry in stock indices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sándor, Bulcsú; Simonsen, Ingve; Nagy, Bálint Zsolt; Néda, Zoltán</p> <p>2016-08-01</p> <p>The gain-loss asymmetry, observed in the inverse statistics of stock indices is present for logarithmic return levels that are over 2 % , and it is the result of the non-Pearson-type autocorrelations in the index. These non-Pearson-type correlations can be viewed also as functionally dependent daily volatilities, extending for a finite <span class="hlt">time</span> interval. A generalized <span class="hlt">time</span>-window shuffling method is used to show the existence of such autocorrelations. Their characteristic <span class="hlt">time</span> <span class="hlt">scale</span> proves to be smaller (less than 25 trading days) than what was previously believed. It is also found that this characteristic <span class="hlt">time</span> <span class="hlt">scale</span> has decreased with the appearance of program trading in the stock market transactions. Connections with the leverage effect are also established.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27627321','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27627321"><span id="translatedtitle"><span class="hlt">Time-scale</span> effects on the gain-loss asymmetry in stock indices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sándor, Bulcsú; Simonsen, Ingve; Nagy, Bálint Zsolt; Néda, Zoltán</p> <p>2016-08-01</p> <p>The gain-loss asymmetry, observed in the inverse statistics of stock indices is present for logarithmic return levels that are over 2%, and it is the result of the non-Pearson-type autocorrelations in the index. These non-Pearson-type correlations can be viewed also as functionally dependent daily volatilities, extending for a finite <span class="hlt">time</span> interval. A generalized <span class="hlt">time</span>-window shuffling method is used to show the existence of such autocorrelations. Their characteristic <span class="hlt">time</span> <span class="hlt">scale</span> proves to be smaller (less than 25 trading days) than what was previously believed. It is also found that this characteristic <span class="hlt">time</span> <span class="hlt">scale</span> has decreased with the appearance of program trading in the stock market transactions. Connections with the leverage effect are also established. PMID:27627321</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8679M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8679M"><span id="translatedtitle">Linking <span class="hlt">Time</span> and Space <span class="hlt">Scales</span> in Distributed Hydrological Modelling - a case study for the VIC model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melsen, Lieke; Teuling, Adriaan; Torfs, Paul; Zappa, Massimiliano; Mizukami, Naoki; Clark, Martyn; Uijlenhoet, Remko</p> <p>2015-04-01</p> <p>One of the famous paradoxes of the Greek philosopher Zeno of Elea (~450 BC) is the one with the arrow: If one shoots an arrow, and cuts its motion into such small <span class="hlt">time</span> steps that at every step the arrow is standing still, the arrow is motionless, because a concatenation of non-moving parts does not create motion. Nowadays, this reasoning can be refuted easily, because we know that motion is a change in space over <span class="hlt">time</span>, which thus by definition depends on both <span class="hlt">time</span> and space. If one disregards <span class="hlt">time</span> by cutting it into infinite small steps, motion is also excluded. This example shows that <span class="hlt">time</span> and space are linked and therefore hard to evaluate separately. As hydrologists we want to understand and predict the motion of water, which means we have to look both in space and in <span class="hlt">time</span>. In hydrological models we can account for space by using spatially explicit models. With increasing computational power and increased data availability from e.g. satellites, it has become easier to apply models at a higher spatial resolution. Increasing the resolution of hydrological models is also labelled as one of the 'Grand Challenges' in hydrology by Wood et al. (2011) and Bierkens et al. (2014), who call for global modelling at hyperresolution (~1 km and smaller). A literature survey on 242 peer-viewed articles in which the Variable Infiltration Capacity (VIC) model was used, showed that the spatial resolution at which the model is applied has decreased over the past 17 years: From 0.5 to 2 degrees when the model was just developed, to 1/8 and even 1/32 degree nowadays. On the other hand the literature survey showed that the <span class="hlt">time</span> step at which the model is calibrated and/or validated remained the same over the last 17 years; mainly daily or monthly. Klemeš (1983) stresses the fact that space and <span class="hlt">time</span> <span class="hlt">scales</span> are connected, and therefore downscaling the spatial <span class="hlt">scale</span> would also imply downscaling of the temporal <span class="hlt">scale</span>. Is it worth the effort of downscaling your model from 1 degree to 1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27627321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27627321"><span id="translatedtitle"><span class="hlt">Time-scale</span> effects on the gain-loss asymmetry in stock indices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sándor, Bulcsú; Simonsen, Ingve; Nagy, Bálint Zsolt; Néda, Zoltán</p> <p>2016-08-01</p> <p>The gain-loss asymmetry, observed in the inverse statistics of stock indices is present for logarithmic return levels that are over 2%, and it is the result of the non-Pearson-type autocorrelations in the index. These non-Pearson-type correlations can be viewed also as functionally dependent daily volatilities, extending for a finite <span class="hlt">time</span> interval. A generalized <span class="hlt">time</span>-window shuffling method is used to show the existence of such autocorrelations. Their characteristic <span class="hlt">time</span> <span class="hlt">scale</span> proves to be smaller (less than 25 trading days) than what was previously believed. It is also found that this characteristic <span class="hlt">time</span> <span class="hlt">scale</span> has decreased with the appearance of program trading in the stock market transactions. Connections with the leverage effect are also established.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20871200','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20871200"><span id="translatedtitle">Implications of cosmic strings with <span class="hlt">time</span>-varying tension on the CMB and large <span class="hlt">scale</span> structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ichikawa, Kazuhide; Takahashi, Tomo; Yamaguchi, Masahide</p> <p>2006-09-15</p> <p>We investigate cosmological evolution and implications of cosmic strings with <span class="hlt">time</span>-dependent tension. We derive basic equations of <span class="hlt">time</span> development of the correlation length and the velocity of such strings, based on the one-<span class="hlt">scale</span> model. Then, we find that, in the case where the tension depends on some power of the cosmic <span class="hlt">time</span>, cosmic strings with <span class="hlt">time</span>-dependent tension goes into the <span class="hlt">scaling</span> solution if the power is lower than a critical value. We also discuss cosmic microwave background anisotropy and matter power spectra produced by these strings. The constraints on their tensions from the Wilkinson microwave anisotropy probe (WMAP) 3 yr data and Sloan digital sky survey (SDSS) data are also given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EL....10368002W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EL....10368002W"><span id="translatedtitle">Transitions in effective <span class="hlt">scaling</span> behavior of accelerometric <span class="hlt">time</span> series across sleep and wake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wohlfahrt, Patrick; Kantelhardt, Jan W.; Zinkhan, Melanie; Schumann, Aicko Y.; Penzel, Thomas; Fietze, Ingo; Pillmann, Frank; Stang, Andreas</p> <p>2013-09-01</p> <p>We study the effective <span class="hlt">scaling</span> behavior of high-resolution accelerometric <span class="hlt">time</span> series recorded at the wrists and hips of 100 subjects during sleep and wake. Using spectral analysis and detrended fluctuation analysis we find long-term correlated fluctuations with a spectral exponent \\beta \\approx 1.0 (1/f noise). On short <span class="hlt">time</span> <span class="hlt">scales</span>, β is larger during wake (\\approx 1.4 ) and smaller during sleep (\\approx 0.6 ). In addition, characteristic peaks at 0.2-0.3 Hz (due to respiration) and 4-10 Hz (probably due to physiological tremor) are observed in periods of weak activity. Because of these peaks, spectral analysis is superior in characterizing effective <span class="hlt">scaling</span> during sleep, while detrending analysis performs well during wake. Our findings can be exploited to detect sleep-wake transitions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/775024','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/775024"><span id="translatedtitle"><span class="hlt">Time</span> <span class="hlt">Scaling</span> of the Rates of Produced Fluids in Laboratory Displacements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Laroche, Catherine; Chen, Min; Yortsos, Yanis C.; Kamath, Jairam</p> <p>2001-02-27</p> <p>In this report, the use of an asymptotic method, based on the <span class="hlt">time</span> <span class="hlt">scaling</span> of the ratio of produced fluids, to infer the relative permeability exponent of the displaced phase near its residual saturation, for immiscible displacements in laboratory cores was proposed. Sufficiently large injection rates, the existence of a power law can be detected, and its exponent inferred, by plotting in an appropriate plot the ratio of the flow rates of the two fluids at the effluent for some <span class="hlt">time</span> after breakthrough.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011Metro..48S.125B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011Metro..48S.125B&link_type=ABSTRACT"><span id="translatedtitle">Role of the ITU-R in <span class="hlt">time</span> <span class="hlt">scale</span> definition and dissemination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beard, Ronald L.</p> <p>2011-08-01</p> <p>The International Telecommunications Union (ITU) is the leading United Nations agency for Radio and Telecommunications coordination worldwide. The process of managing overall frequency spectrum utilization is through Worldwide Radio Conferences, associated radiocommunication conferences and the activities of the Radiocommunication Study Groups. These Study Groups and their Working Parties, devoted to specialized technical areas, provide the mechanism for Member Nations to participate, study and recommend standards and practices to ensure equitable utilization and interference-free operation within the radio spectrum. An important underlying aspect of spectrum utilization is the facilitation of the determination and coordination of the international <span class="hlt">time</span> <span class="hlt">scale</span>. The international <span class="hlt">time</span> <span class="hlt">scale</span> is an atomic <span class="hlt">time</span> <span class="hlt">scale</span> used by broadcast services throughout the world known as Coordinated Universal <span class="hlt">Time</span> (UTC). UTC is defined by the International Telecommunication Union (ITU-R) and is maintained by the International Bureau of Weights and Measures (BIPM) in cooperation with the International Earth reference and Rotation Service (IERS). Contributed measurements from <span class="hlt">timing</span> centres around the world are used in the determination of UTC, which is adjusted to within 0.9 s of Earth rotation <span class="hlt">time</span> (UT1) by IERS-determined values of the Earth rotation. The adjustments, made in one second steps known as leap seconds, were implemented in 1972 to permit UT1 to be recovered from broadcast values of UTC for celestial navigation. Current telecommunications and navigation systems utilize continuous <span class="hlt">timing</span> for their data transmissions; consequently, deliberations have been ongoing within the ITU-R on the issue of modifying the definition of UTC to a continuous <span class="hlt">time</span> <span class="hlt">scale</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22415565','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22415565"><span id="translatedtitle">The hyperfine structure in the rotational spectra of D{sub 2}{sup 17}O and HD{sup 17}O: Confirmation of the <span class="hlt">absolute</span> nuclear magnetic shielding <span class="hlt">scale</span> for oxygen</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Puzzarini, Cristina Cazzoli, Gabriele; Harding, Michael E.; Vázquez, Juana; Gauss, Jürgen</p> <p>2015-03-28</p> <p>Guided by theoretical predictions, the hyperfine structures of the rotational spectra of mono- and bideuterated-water containing {sup 17}O have been experimentally investigated. To reach sub-Doppler resolution, required to resolve the hyperfine structure due to deuterium quadrupole coupling as well as to spin-rotation (SR) and dipolar spin-spin couplings, the Lamb-dip technique has been employed. The experimental investigation and in particular, the spectral analysis have been supported by high-level quantum-chemical computations employing coupled-cluster techniques and, for the first <span class="hlt">time</span>, a complete experimental determination of the hyperfine parameters involved was possible. The experimentally determined {sup 17}O spin-rotation constants of D{sub 2}{sup 17}O and HD{sup 17}O were used to derive the paramagnetic part of the corresponding nuclear magnetic shielding constants. Together with the computed diamagnetic contributions as well as the vibrational and temperature corrections, the latter constants have been employed to confirm the oxygen nuclear magnetic shielding <span class="hlt">scale</span>, recently established on the basis of spin-rotation data for H{sub 2}{sup 17}O [Puzzarini et al., J. Chem. Phys. 131, 234304 (2009)].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFMEP51A0964H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFMEP51A0964H&link_type=ABSTRACT"><span id="translatedtitle">Landscape behaviour at storm and millennial <span class="hlt">time</span> <span class="hlt">scales</span>: How good are landscape evolution models at prediction?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hancock, G. R.; Coulthard, T. J.; Lowry, J.</p> <p>2012-12-01</p> <p>Landscape evolution models theoretically provide the ability to examine both short and long-term evolution processes. The hydrology and sediment transport components of these models have been largely based on physical principals and well understood theory yet they have not been fully assessed or employed across all environments. They have been recognised as valuable tools with which to explore the short and long-term erosional behaviour of both natural and anthropogenic landscapes. Of particular interest are anthropogenic landscapes (i.e. post-mining landscapes) which often have steeper slopes, unconsolidated materials and a higher erodibility than the undisturbed surface where these models have been used to examine the long-term erosional behaviour usually at millennial <span class="hlt">scales</span>. Further, such landscapes often have to contain potential contaminants (i.e. radionuclides, acid generating materials) that need to be contained over geological timescales. Here two landscape evolution models (SIBERIA and CAESAR) are used to examine a proposed rehabilitation design for the ERA Ranger mine in the Northern Territory, Australia. The SIBERIA model has been developed to operate at annual timescales and has been calibrated for surface conditions at the site. CAESAR operates at sub-hourly <span class="hlt">time</span> <span class="hlt">scales</span> and employs hydrology and sediment characteristics in its calibration. The results demonstrate that despite the different modelling approaches, both SIBERIA and CAESAR produce similar spatial and temporal outcomes with erosion patterns (i.e. gullying) and rates very comparable. As a result of SIBERIA using annual <span class="hlt">time</span> <span class="hlt">scales</span> the model run <span class="hlt">time</span> is significantly quicker than CAESAR however CAESAR can provide important information at the storm <span class="hlt">scale</span>. Significantly, both models are sensitive to parameterisation with soils evolution (pedogenesis) and vegetation having significant influences on erosion rates. The findings demonstrate the usefulness of landscape evolution models to explore</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..92e2702C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..92e2702C"><span id="translatedtitle">First-passage <span class="hlt">times</span> in multiscale random walks: The impact of movement <span class="hlt">scales</span> on search efficiency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Campos, Daniel; Bartumeus, Frederic; Raposo, E. P.; Méndez, Vicenç</p> <p>2015-11-01</p> <p>An efficient searcher needs to balance properly the trade-off between the exploration of new spatial areas and the exploitation of nearby resources, an idea which is at the core of <span class="hlt">scale</span>-free Lévy search strategies. Here we study multiscale random walks as an approximation to the <span class="hlt">scale</span>-free case and derive the exact expressions for their mean-first-passage <span class="hlt">times</span> in a one-dimensional finite domain. This allows us to provide a complete analytical description of the dynamics driving the situation in which both nearby and faraway targets are available to the searcher, so the exploration-exploitation trade-off does not have a trivial solution. For this situation, we prove that the combination of only two movement <span class="hlt">scales</span> is able to outperform both ballistic and Lévy strategies. This two-<span class="hlt">scale</span> strategy involves an optimal discrimination between the nearby and faraway targets which is only possible by adjusting the range of values of the two movement <span class="hlt">scales</span> to the typical distances between encounters. So, this optimization necessarily requires some prior information (albeit crude) about target distances or distributions. Furthermore, we found that the incorporation of additional (three, four, …) movement <span class="hlt">scales</span> and its adjustment to target distances does not improve further the search efficiency. This allows us to claim that optimal random search strategies arise through the informed combination of only two walk <span class="hlt">scales</span> (related to the exploitative and the explorative <span class="hlt">scales</span>, respectively), expanding on the well-known result that optimal strategies in strictly uninformed scenarios are achieved through Lévy paths (or, equivalently, through a hierarchical combination of multiple <span class="hlt">scales</span>).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPhCS.268a2009H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPhCS.268a2009H"><span id="translatedtitle">Mass action realizations of reaction kinetic system models on various <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hangos, K. M.; Szederkényi, G.</p> <p>2011-01-01</p> <p>Complex chemical reaction networks often exhibit different dynamic behaviour on different <span class="hlt">time</span> <span class="hlt">scales</span>. A combined approach is proposed in this work for determining physically meaningful mass action realizations of complex chemical reaction networks that describe its dynamic behaviour on different <span class="hlt">time</span> <span class="hlt">scales</span>. This is achieved by appropriately reducing the detailed overall mass action kinetic scheme using quasi steady state assumptions fit to the particular <span class="hlt">time</span> <span class="hlt">scale</span>, and then searching for an optimal realization using mixed integer linear programing. Furthermore, the relationship between the properties (reversibility, deficiency, stability) of the obtained realizations of the same system on different <span class="hlt">time</span> <span class="hlt">scales</span> are also investigated and related to the same properties of the detailed overall model. It is shown that the reduced models obtained by quasi steady state assumptions may show exotic nonlinear behaviour, such as oscillations, when the original detailed is globally asymptotically stable. The proposed methods are illustrated by using a simple Michaelis-Menten type reaction kinetic example. The simplified versions of the well known Brusselator model have also been investigated and presented as a case study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5004814','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5004814"><span id="translatedtitle">Short <span class="hlt">Time-Scale</span> Sensory Coding in S1 during Discrimination of Whisker Vibrotactile Sequences</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Miyashita, Toshio; Lee, Daniel J.; Smith, Katherine A.; Feldman, Daniel E.</p> <p>2016-01-01</p> <p>Rodent whisker input consists of dense microvibration sequences that are often temporally integrated for perceptual discrimination. Whether primary somatosensory cortex (S1) participates in temporal integration is unknown. We trained rats to discriminate whisker impulse sequences that varied in single-impulse kinematics (5–20-ms <span class="hlt">time</span> <span class="hlt">scale</span>) and mean speed (150-ms <span class="hlt">time</span> <span class="hlt">scale</span>). Rats appeared to use the integrated feature, mean speed, to guide discrimination in this task, consistent with similar prior studies. Despite this, 52% of S1 units, including 73% of units in L4 and L2/3, encoded sequences at fast <span class="hlt">time</span> <span class="hlt">scales</span> (≤20 ms, mostly 5–10 ms), accurately reflecting single impulse kinematics. 17% of units, mostly in L5, showed weaker impulse responses and a slow firing rate increase during sequences. However, these units did not effectively integrate whisker impulses, but instead combined weak impulse responses with a distinct, slow signal correlated to behavioral choice. A neural decoder could identify sequences from fast unit spike trains and behavioral choice from slow units. Thus, S1 encoded fast <span class="hlt">time</span> <span class="hlt">scale</span> whisker input without substantial temporal integration across whisker impulses. PMID:27574970</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=exercise&pg=7&id=EJ826565','ERIC'); return false;" href="http://eric.ed.gov/?q=exercise&pg=7&id=EJ826565"><span id="translatedtitle">Development and Preliminary Validation of the <span class="hlt">Time</span> Management for Exercise <span class="hlt">Scale</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hellsten, Laurie-ann M.; Rogers, W. Todd</p> <p>2009-01-01</p> <p>The purpose of this study was to collect preliminary validity evidence for a <span class="hlt">time</span> management <span class="hlt">scale</span> for exercise. An initial pool of 91 items was developed from existing literature. Ten exercise/health psychologists evaluated each of the items in terms of relevance and representativeness. Forty-nine items met all criteria. Exploratory factor…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=128574','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=128574"><span id="translatedtitle">Natural variability of atmospheric temperatures and geomagnetic intensity over a wide range of <span class="hlt">time</span> <span class="hlt">scales</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pelletier, Jon D.</p> <p>2002-01-01</p> <p>The majority of numerical models in climatology and geomagnetism rely on deterministic finite-difference techniques and attempt to include as many empirical constraints on the many processes and boundary conditions applicable to their very complex systems. Despite their sophistication, many of these models are unable to reproduce basic aspects of climatic or geomagnetic dynamics. We show that a simple stochastic model, which treats the flux of heat energy in the atmosphere by convective instabilities with random advection and diffusive mixing, does a remarkable job at matching the observed power spectrum of historical and proxy records for atmospheric temperatures from <span class="hlt">time</span> <span class="hlt">scales</span> of one day to one million years (Myr). With this approach distinct changes in the power-spectral form can be associated with characteristic <span class="hlt">time</span> <span class="hlt">scales</span> of ocean mixing and radiative damping. Similarly, a simple model of the diffusion of magnetic intensity in Earth's core coupled with amplification and destruction of the local intensity can reproduce the observed 1/f noise behavior of Earth's geomagnetic intensity from <span class="hlt">time</span> <span class="hlt">scales</span> of 1 (Myr) to 100 yr. In addition, the statistics of the fluctuations in the polarity reversal rate from <span class="hlt">time</span> <span class="hlt">scales</span> of 1 Myr to 100 Myr are consistent with the hypothesis that reversals are the result of variations in 1/f noise geomagnetic intensity above a certain threshold, suggesting that reversals may be associated with internal fluctuations rather than changes in mantle thermal or magnetic boundary conditions. PMID:11875208</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..94c2407Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..94c2407Z"><span id="translatedtitle">Fixation of competing strategies when interacting agents differ in the <span class="hlt">time</span> <span class="hlt">scale</span> of strategy updating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Jianlei; Weissing, Franz J.; Cao, Ming</p> <p>2016-09-01</p> <p>A commonly used assumption in evolutionary game theory is that natural selection acts on individuals in the same <span class="hlt">time</span> <span class="hlt">scale</span>; e.g., players use the same frequency to update their strategies. Variation in learning rates within populations suggests that evolutionary game theory may not necessarily be restricted to uniform <span class="hlt">time</span> <span class="hlt">scales</span> associated with the game interaction and strategy adaption evolution. In this study, we remove this restricting assumption by dividing the population into fast and slow groups according to the players' strategy updating frequencies and investigate how different strategy compositions of one group influence the evolutionary outcome of the other's fixation probabilities of strategies within its own group. Analytical analysis and numerical calculations are performed to study the evolutionary dynamics of strategies in typical classes of two-player games (prisoner's dilemma game, snowdrift game, and stag-hunt game). The introduction of the heterogeneity in strategy-update <span class="hlt">time</span> <span class="hlt">scales</span> leads to substantial changes in the evolution dynamics of strategies. We provide an approximation formula for the fixation probability of mutant types in finite populations and study the outcome of strategy evolution under the weak selection. We find that although heterogeneity in <span class="hlt">time</span> <span class="hlt">scales</span> makes the collective evolutionary dynamics more complicated, the possible long-run evolutionary outcome can be effectively predicted under technical assumptions when knowing the population composition and payoff parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27574970','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27574970"><span id="translatedtitle">Short <span class="hlt">Time-Scale</span> Sensory Coding in S1 during Discrimination of Whisker Vibrotactile Sequences.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McGuire, Leah M; Telian, Gregory; Laboy-Juárez, Keven J; Miyashita, Toshio; Lee, Daniel J; Smith, Katherine A; Feldman, Daniel E</p> <p>2016-08-01</p> <p>Rodent whisker input consists of dense microvibration sequences that are often temporally integrated for perceptual discrimination. Whether primary somatosensory cortex (S1) participates in temporal integration is unknown. We trained rats to discriminate whisker impulse sequences that varied in single-impulse kinematics (5-20-ms <span class="hlt">time</span> <span class="hlt">scale</span>) and mean speed (150-ms <span class="hlt">time</span> <span class="hlt">scale</span>). Rats appeared to use the integrated feature, mean speed, to guide discrimination in this task, consistent with similar prior studies. Despite this, 52% of S1 units, including 73% of units in L4 and L2/3, encoded sequences at fast <span class="hlt">time</span> <span class="hlt">scales</span> (≤20 ms, mostly 5-10 ms), accurately reflecting single impulse kinematics. 17% of units, mostly in L5, showed weaker impulse responses and a slow firing rate increase during sequences. However, these units did not effectively integrate whisker impulses, but instead combined weak impulse responses with a distinct, slow signal correlated to behavioral choice. A neural decoder could identify sequences from fast unit spike trains and behavioral choice from slow units. Thus, S1 encoded fast <span class="hlt">time</span> <span class="hlt">scale</span> whisker input without substantial temporal integration across whisker impulses. PMID:27574970</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1171120','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1171120"><span id="translatedtitle">Improving Building Performance at Urban <span class="hlt">Scale</span> with a Framework for Real-<span class="hlt">time</span> Data Sharing</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pang, Xiufeng; Hong, Tianzhen; Piette, Mary Ann</p> <p>2013-06-03</p> <p>This paper describes work in progress toward an urban-<span class="hlt">scale</span> system aiming to reduce energy use in neighboring buildings by providing three components: a database for accessing past and present weather data from high quality weather stations; a network for communicating energy-saving strategies between building owners; and a set of modeling tools for real-<span class="hlt">time</span> building energy simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11875208','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11875208"><span id="translatedtitle">Natural variability of atmospheric temperatures and geomagnetic intensity over a wide range of <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pelletier, Jon D</p> <p>2002-02-19</p> <p>The majority of numerical models in climatology and geomagnetism rely on deterministic finite-difference techniques and attempt to include as many empirical constraints on the many processes and boundary conditions applicable to their very complex systems. Despite their sophistication, many of these models are unable to reproduce basic aspects of climatic or geomagnetic dynamics. We show that a simple stochastic model, which treats the flux of heat energy in the atmosphere by convective instabilities with random advection and diffusive mixing, does a remarkable job at matching the observed power spectrum of historical and proxy records for atmospheric temperatures from <span class="hlt">time</span> <span class="hlt">scales</span> of one day to one million years (Myr). With this approach distinct changes in the power-spectral form can be associated with characteristic <span class="hlt">time</span> <span class="hlt">scales</span> of ocean mixing and radiative damping. Similarly, a simple model of the diffusion of magnetic intensity in Earth's core coupled with amplification and destruction of the local intensity can reproduce the observed 1/f noise behavior of Earth's geomagnetic intensity from <span class="hlt">time</span> <span class="hlt">scales</span> of 1 (Myr) to 100 yr. In addition, the statistics of the fluctuations in the polarity reversal rate from <span class="hlt">time</span> <span class="hlt">scales</span> of 1 Myr to 100 Myr are consistent with the hypothesis that reversals are the result of variations in 1/f noise geomagnetic intensity above a certain threshold, suggesting that reversals may be associated with internal fluctuations rather than changes in mantle thermal or magnetic boundary conditions. PMID:11875208</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860016584','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860016584"><span id="translatedtitle">Two <span class="hlt">time</span> <span class="hlt">scale</span> output feedback regulation for ill-conditioned systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Calise, A. J.; Moerder, D. D.</p> <p>1986-01-01</p> <p>Issues pertaining to the well-posedness of a two <span class="hlt">time</span> <span class="hlt">scale</span> approach to the output feedback regulator design problem are examined. An approximate quadratic performance index which reflects a two <span class="hlt">time</span> <span class="hlt">scale</span> decomposition of the system dynamics is developed. It is shown that, under mild assumptions, minimization of this cost leads to feedback gains providing a second-order approximation of optimal full system performance. A simplified approach to two <span class="hlt">time</span> <span class="hlt">scale</span> feedback design is also developed, in which gains are separately calculated to stabilize the slow and fast subsystem models. By exploiting the notion of combined control and observation spillover suppression, conditions are derived assuring that these gains will stabilize the full-order system. A sequential numerical algorithm is described which obtains output feedback gains minimizing a broad class of performance indices, including the standard LQ case. It is shown that the algorithm converges to a local minimum under nonrestrictive assumptions. This procedure is adapted to and demonstrated for the two <span class="hlt">time</span> <span class="hlt">scale</span> design formulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16819798','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16819798"><span id="translatedtitle">Inference of <span class="hlt">scale</span>-free networks from gene expression <span class="hlt">time</span> series.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Daisuke, Tominaga; Horton, Paul</p> <p>2006-04-01</p> <p>Quantitative <span class="hlt">time</span>-series observation of gene expression is becoming possible, for example by cell array technology. However, there are no practical methods with which to infer network structures using only observed <span class="hlt">time</span>-series data. As most computational models of biological networks for continuous <span class="hlt">time</span>-series data have a high degree of freedom, it is almost impossible to infer the correct structures. On the other hand, it has been reported that some kinds of biological networks, such as gene networks and metabolic pathways, may have <span class="hlt">scale</span>-free properties. We hypothesize that the architecture of inferred biological network models can be restricted to <span class="hlt">scale</span>-free networks. We developed an inference algorithm for biological networks using only <span class="hlt">time</span>-series data by introducing such a restriction. We adopt the S-system as the network model, and a distributed genetic algorithm to optimize models to fit its simulated results to observed <span class="hlt">time</span> series data. We have tested our algorithm on a case study (simulated data). We compared optimization under no restriction, which allows for a fully connected network, and under the restriction that the total number of links must equal that expected from a <span class="hlt">scale</span> free network. The restriction reduced both false positive and false negative estimation of the links and also the differences between model simulation and the given <span class="hlt">time</span>-series data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP53A3640L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP53A3640L"><span id="translatedtitle">Comparing <span class="hlt">Time</span>-Dependent Geomagnetic and Atmospheric Effects on Cosmogenic Nuclide Production Rate <span class="hlt">Scaling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lifton, N. A.</p> <p>2014-12-01</p> <p>A recently published cosmogenic nuclide production rate <span class="hlt">scaling</span> model based on analytical fits to Monte Carlo simulations of atmospheric cosmic ray flux spectra (both of which agree well with measured spectra) (Lifton et al., 2014, Earth Planet. Sci. Lett. 386, 149-160: termed the LSD model) provides two main advantages over previous <span class="hlt">scaling</span> models: identification and quantification of potential sources of bias in the earlier models, and the ability to generate nuclide-specific <span class="hlt">scaling</span> factors easily for a wide range of input parameters. The new model also provides a flexible framework for exploring the implications of advances in model inputs. In this work, the <span class="hlt">scaling</span> implications of two recent <span class="hlt">time</span>-dependent spherical harmonic geomagnetic models spanning the Holocene will be explored. Korte and Constable (2011, Phys. Earth Planet. Int. 188, 247-259) and Korte et al. (2011, Earth Planet. Sci. Lett. 312, 497-505) recently updated earlier spherical harmonic paleomagnetic models used by Lifton et al. (2014) with paleomagnetic measurements from sediment cores in addition to archeomagnetic and volcanic data. These updated models offer improved accuracy over the previous versions, in part to due to increased temporal and spatial data coverage. With the new models as input, trajectory-traced estimates of effective vertical cutoff rigidity (RC- the standard method for ordering cosmic ray data) yield significantly different <span class="hlt">time</span>-integrated <span class="hlt">scaling</span> predictions when compared to the earlier models. These results will be compared to <span class="hlt">scaling</span> predictions using another recent <span class="hlt">time</span>-dependent spherical harmonic model of the Holocene geomagnetic field by Pavón-Carrasco et al. (2014, Earth Planet. Sci. Lett. 388, 98-109), based solely on archeomagnetic and volcanic paleomagnetic data, but extending to 14 ka. In addition, the potential effects of <span class="hlt">time</span>-dependent atmospheric models on LSD <span class="hlt">scaling</span> predictions will be presented. Given the typical dominance of altitudinal over</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSP...164..438R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSP...164..438R"><span id="translatedtitle">Discretization of Continuous <span class="hlt">Time</span> Discrete <span class="hlt">Scale</span> Invariant Processes: Estimation and Spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rezakhah, Saeid; Maleki, Yasaman</p> <p>2016-07-01</p> <p>Imposing some flexible sampling scheme we provide some discretization of continuous <span class="hlt">time</span> discrete <span class="hlt">scale</span> invariant (DSI) processes which is a subsidiary discrete <span class="hlt">time</span> DSI process. Then by introducing some simple random measure we provide a second continuous <span class="hlt">time</span> DSI process which provides a proper approximation of the first one. This enables us to provide a bilateral relation between covariance functions of the subsidiary process and the new continuous <span class="hlt">time</span> processes. The <span class="hlt">time</span> varying spectral representation of such continuous <span class="hlt">time</span> DSI process is characterized, and its spectrum is estimated. Also, a new method for estimation <span class="hlt">time</span> dependent Hurst parameter of such processes is provided which gives a more accurate estimation. The performance of this estimation method is studied via simulation. Finally this method is applied to the real data of S & P500 and Dow Jones indices for some special periods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3945107','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3945107"><span id="translatedtitle">Temporal Dynamics of Microbial Rhodopsin Fluorescence Reports <span class="hlt">Absolute</span> Membrane Voltage</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hou, Jennifer H.; Venkatachalam, Veena; Cohen, Adam E.</p> <p>2014-01-01</p> <p>Plasma membrane voltage is a fundamentally important property of a living cell; its value is tightly coupled to membrane transport, the dynamics of transmembrane proteins, and to intercellular communication. Accurate measurement of the membrane voltage could elucidate subtle changes in cellular physiology, but existing genetically encoded fluorescent voltage reporters are better at reporting relative changes than <span class="hlt">absolute</span> numbers. We developed an Archaerhodopsin-based fluorescent voltage sensor whose <span class="hlt">time</span>-domain response to a stepwise change in illumination encodes the <span class="hlt">absolute</span> membrane voltage. We validated this sensor in human embryonic kidney cells. Measurements were robust to variation in imaging parameters and in gene expression levels, and reported voltage with an <span class="hlt">absolute</span> accuracy of 10 mV. With further improvements in membrane trafficking and signal amplitude, <span class="hlt">time</span>-domain encoding of <span class="hlt">absolute</span> voltage could be applied to investigate many important and previously intractable bioelectric phenomena. PMID:24507604</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20809591','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20809591"><span id="translatedtitle">Evolution of equilibrium Pickering emulsions--a matter of <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kraft, Daniela J; Luigjes, Bob; de Folter, Julius W J; Philipse, Albert P; Kegel, Willem K</p> <p>2010-09-30</p> <p>A new class of equilibrium solid-stabilized oil-in-water emulsions harbors a competition of two processes on disparate <span class="hlt">time</span> <span class="hlt">scales</span> that affect the equilibrium droplet size in opposing ways. The aim of this work is to elucidate the molecular origins of these two <span class="hlt">time</span> <span class="hlt">scales</span> and demonstrate their effects on the evolution of the emulsion droplet size. First, spontaneous emulsification into particle-covered droplets occurs through in situ generation of surface-active molecules by hydrolysis of molecules of the oil phase. We show that surface tensions of the oil-water interfaces in the absence of stabilizing colloidal particles are connected to the concentration of these surface-active molecules, and hence also to the equilibrium droplet size in the presence of colloids. As a consequence, the hydrolysis process sets the <span class="hlt">time</span> <span class="hlt">scale</span> of formation of these solid-stabilized emulsions. A second <span class="hlt">time</span> <span class="hlt">scale</span> is governing the ultimate fate of the solid-stabilized equilibrium emulsions: by condensation of the in situ generated amphiphilic molecules onto the colloidal particles, their wetting properties change, leading to a gradual transfer from the aqueous to the oil phase via growth of the emulsion droplets. This migration is observed macroscopically by a color change of the water and oil phases, as well as by electron microscopy after polymerization of the oil phase in a phase separated sample. Surprisingly, the relative oil volume sets the <span class="hlt">time</span> <span class="hlt">scale</span> of particle transfer. Phase separation into an aqueous phase and an oil phase containing colloidal particles is influenced by sedimentation of the emulsion droplets. The two processes of formation of surface-active molecules through hydrolysis and condensation thereof on the colloidal surface have an opposite influence on the droplet size. By their interplay, a dynamic equilibrium is created where the droplet size always adjusts to the thermodynamically stable state. PMID:20809591</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20809591','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20809591"><span id="translatedtitle">Evolution of equilibrium Pickering emulsions--a matter of <span class="hlt">time</span> <span class="hlt">scales</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kraft, Daniela J; Luigjes, Bob; de Folter, Julius W J; Philipse, Albert P; Kegel, Willem K</p> <p>2010-09-30</p> <p>A new class of equilibrium solid-stabilized oil-in-water emulsions harbors a competition of two processes on disparate <span class="hlt">time</span> <span class="hlt">scales</span> that affect the equilibrium droplet size in opposing ways. The aim of this work is to elucidate the molecular origins of these two <span class="hlt">time</span> <span class="hlt">scales</span> and demonstrate their effects on the evolution of the emulsion droplet size. First, spontaneous emulsification into particle-covered droplets occurs through in situ generation of surface-active molecules by hydrolysis of molecules of the oil phase. We show that surface tensions of the oil-water interfaces in the absence of stabilizing colloidal particles are connected to the concentration of these surface-active molecules, and hence also to the equilibrium droplet size in the presence of colloids. As a consequence, the hydrolysis process sets the <span class="hlt">time</span> <span class="hlt">scale</span> of formation of these solid-stabilized emulsions. A second <span class="hlt">time</span> <span class="hlt">scale</span> is governing the ultimate fate of the solid-stabilized equilibrium emulsions: by condensation of the in situ generated amphiphilic molecules onto the colloidal particles, their wetting properties change, leading to a gradual transfer from the aqueous to the oil phase via growth of the emulsion droplets. This migration is observed macroscopically by a color change of the water and oil phases, as well as by electron microscopy after polymerization of the oil phase in a phase separated sample. Surprisingly, the relative oil volume sets the <span class="hlt">time</span> <span class="hlt">scale</span> of particle transfer. Phase separation into an aqueous phase and an oil phase containing colloidal particles is influenced by sedimentation of the emulsion droplets. The two processes of formation of surface-active molecules through hydrolysis and condensation thereof on the colloidal surface have an opposite influence on the droplet size. By their interplay, a dynamic equilibrium is created where the droplet size always adjusts to the thermodynamically stable state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9301E..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9301E..04L"><span id="translatedtitle">A real-<span class="hlt">time</span> multi-<span class="hlt">scale</span> 2D Gaussian filter based on FPGA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, Haibo; Gai, Xingqin; Chang, Zheng; Hui, Bin</p> <p>2014-11-01</p> <p>Multi-<span class="hlt">scale</span> 2-D Gaussian filter has been widely used in feature extraction (e.g. SIFT, edge etc.), image segmentation, image enhancement, image noise removing, multi-<span class="hlt">scale</span> shape description etc. However, their computational complexity remains an issue for real-<span class="hlt">time</span> image processing systems. Aimed at this problem, we propose a framework of multi-<span class="hlt">scale</span> 2-D Gaussian filter based on FPGA in this paper. Firstly, a full-hardware architecture based on parallel pipeline was designed to achieve high throughput rate. Secondly, in order to save some multiplier, the 2-D convolution is separated into two 1-D convolutions. Thirdly, a dedicate first in first out memory named as CAFIFO (Column Addressing FIFO) was designed to avoid the error propagating induced by spark on clock. Finally, a shared memory framework was designed to reduce memory costs. As a demonstration, we realized a 3 <span class="hlt">scales</span> 2-D Gaussian filter on a single ALTERA Cyclone III FPGA chip. Experimental results show that, the proposed framework can computing a Multi-<span class="hlt">scales</span> 2-D Gaussian filtering within one pixel clock period, is further suitable for real-<span class="hlt">time</span> image processing. Moreover, the main principle can be popularized to the other operators based on convolution, such as Gabor filter, Sobel operator and so on.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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