Science.gov

Sample records for iv large time

  1. Time in Physics IV: Aristotle's reductionistic vision in four movements

    NASA Astrophysics Data System (ADS)

    Roark, Anthony Phillip

    Aristotle's definition of time in Physics IV.11 as ``a number of motion with respect to the before and after'' is often claimed to be viciously circular, since it is thought that `before' and `after' are terms that cannot be explicated independently of temporal concepts. My project in this dissertation is to defend Aristotle's theory against this charge of circularity and, further, to argue that it succeeds where some modern theories of time fail. The centerpiece of my interpretation is an explication of theoretical entities that Aristotle calls `the before and after in motion', entities that I have dubbed `kinetic positions'. Kinetic positions are instantaneous happenings within a movement that can be specified as functions of a moving object's actual spatial location and the telos, or end, of the movement. On Aristotle's view, time is an aspect of motion, and kinetic positions are the lower-level metaphysical counterparts of instants. It is in this sense that Aristotle's account is reductionistic: time derives its existence and structure from that of motion, and motion derives its existence and structure from that of spatial magnitudes. The success of my project requires that I: (i)establish that Aristotle's kinetic theory can be explicated independently of temporal concepts; (ii)explain how the asymmetrically-ordered kinetic continuum derives from the symmetrically-ordered spatial continuum; (iii)show that my interpretation of kinetic positions is consistent with Aristotle's claim in Physics VI that motion in an instant is impossible; (iv)explain the significance of Aristotle's placement of time within the genus number; (v)justify Aristotle's claim in IV.14 that time would not exist if there were no perceptive souls; (vi)how that Aristotle's account integrates temporal passage, the ``flow'' of time, in such a way as to be immune from devastating arguments, devised by McTaggart and others, against its possibility. I conclude that Aristotle ultimately conceives

  2. Large numbers hypothesis. IV - The cosmological constant and quantum physics

    NASA Technical Reports Server (NTRS)

    Adams, P. J.

    1983-01-01

    In standard physics quantum field theory is based on a flat vacuum space-time. This quantum field theory predicts a nonzero cosmological constant. Hence the gravitational field equations do not admit a flat vacuum space-time. This dilemma is resolved using the units covariant gravitational field equations. This paper shows that the field equations admit a flat vacuum space-time with nonzero cosmological constant if and only if the canonical LNH is valid. This allows an interpretation of the LNH phenomena in terms of a time-dependent vacuum state. If this is correct then the cosmological constant must be positive.

  3. OGLE-IV Real-Time Transient Search

    NASA Astrophysics Data System (ADS)

    Wyrzykowski, Ł.; Kostrzewa-Rutkowska, Z.; Kozłowski, S.; Udalski, A.; Poleski, R.; Skowron, J.; Blagorodnova, N.; Kubiak, M.; Szymański, M. K.; Pietrzyński, G.; Soszyński, I.; Ulaczyk, K.; Pietrukowicz, P.; Mróz, P.

    2014-09-01

    We present the design and first results of a real-time search for transients within the 650 sq. deg. area around the Magellanic Clouds, conducted as part of the OGLE-IV project and aimed at detecting supernovae, novae and other events. The average sampling of about four days from September to May, yielded a detection of 238 transients in 2012/2013 and 2013/2014 seasons. The superb photometric and astrometric quality of the OGLE data allows for numerous applications of the discovered transients. We use this sample to prepare and train a Machine Learning-based automated classifier for early light curves, which distinguishes major classes of transients with more than 80% of correct answers. Spectroscopically classified 49 supernovae Type Ia are used to construct a Hubble Diagram with statistical scatter of about 0.3 mag and fill the least populated region of the redshifts range in the Union sample. We investigate the influence of host galaxy environments on supernovae statistics and find the mean host extinction of AI=0.19±0.10 mag and AV=0.39±0.21 mag based on a subsample of supernovae Type Ia. We show that the positional accuracy of the survey is of the order of 0.5 pixels (0.13'') and that the OGLE-IV Transient Detection System is capable of detecting transients within the nuclei of galaxies. We present a few interesting cases of nuclear transients of unknown type. All data on the OGLE transients are made publicly available to the astronomical community via the OGLE website.

  4. Combination Chemo, Rituximab, and Bevacizumab in Older Patients With Stage II-IV Diffuse Large B-Cell Lymphoma

    ClinicalTrials.gov

    2014-05-06

    Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma

  5. Information Collected on Nonapplied Time, Engaged Time, Nonengaged Time and Applied Time. Comparative Studies of Phase IV IGE Evaluation Project. Phase IV, Project Paper 80-5.

    ERIC Educational Resources Information Center

    Webb, Norman L.; Nerenz, Anne G.

    This is one of a series of reports which provide definitions of and descriptive data on the variables used in the Comparative Study of Phase IV of the Individually Guided Education (IEG) Evaluation Project. Phase IV investigated three curriculum programs specifically designed to be compatible with instructional programming for the individual…

  6. Non-existence of perfect dark energy fluid in Bianchi type-IV space time

    NASA Astrophysics Data System (ADS)

    Mishra, B.; Sahoo, P. K.; Suresh, Srikanth

    2015-07-01

    In this paper, non-diagonal Bianchi type-IV space-time is investigated in Einstein general theory of relativity. The matter field is considered in the form of perfect dark energy fluid. It is interesting to observe that in this case, Bianchi type IV perfect dark energy fluid cosmological model does not exist. The space-time reduces to Minkowskian geometry.

  7. Rates of DSM-IV psychiatric disorders among adolescents in a large metropolitan area.

    PubMed

    Roberts, Robert E; Roberts, Catherine Ramsay; Xing, Yun

    2007-12-01

    We present prevalence data for adolescents in a large metropolitan area in the US and the association of DSM-IV diagnoses to functional impairment and selected demographic correlates. We sampled 4175 youths aged 11-17 years from households enrolled in large health maintenance organizations. Data were collected using questionnaires and the Diagnostic Interview Schedule for Children, Version IV (DISC-IV). Impairment was measured using the Child Global Assessment Scale and diagnostic specific impairment in the DISC-IV. 17.1% of the sample met DSM-IV criteria for one or more disorders in the past year; 11% when only DISC impairment was considered and 5.3% only using the CGAS. The most prevalent disorders were anxiety (6.9%), disruptive (6.5%), and substance use (5.3%) disorders. The most prevalent specific disorders were agoraphobia, conduct and marijuana abuse/dependence, then alcohol use and oppositional defiant disorder. Younger youths and females had lower odds for any disorder, as did youths from two parent homes. There was increased odds associated with lower family income. Females had greater odds of mood and anxiety disorders, males of disruptive and substance use disorders. There were greater odds of mood and disruptive disorders for older youths. Prevalences were highly comparable to recent studies using similar methods in diverse non-metropolitan populations. We found associations with age, gender, and to a lesser extent, socioeconomic status reported in previous studies. The inclusion of both diagnosis-specific impairment and global impairment reduced prevalence rates significantly. Our results suggest commonality of prevalences and associated factors in diverse study settings, including urban and rural areas. PMID:17107689

  8. Large-scale vertical motion calculations in the AVE IV Experiment. [of atmospheric wind velocity

    NASA Technical Reports Server (NTRS)

    Wilson, G. S.

    1976-01-01

    Using 3- and 6-h consecutive rawinsonde and surface data from NASA's AVE IV Experiment, synoptic-scale vertical motion calculations are made using an adiabatic technique and three variations of the kinematic technique. Both subjective and objective comparisons in space and time between the sign and magnitude of the computed vertical velocities and precipitation intensities are made. These comparisons are conducted to determine which method would consistently produce realistic magnitudes, patterns, and vertical profiles of vertical velocity essential to the diagnostic study of the relationship between severe convective storms and their environment in AVE IV. The kinematic method, adjusted to the adiabatic value at 100 mb, proved to produce the best overall vertical velocities.

  9. 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.

  10. Oblimersen Sodium and Combination Chemotherapy in Treating Patients With Newly Diagnosed Stage I, Stage II, Stage III, or Stage IV Diffuse Large B-Cell Lymphoma

    ClinicalTrials.gov

    2012-10-11

    Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma

  11. Real time interrupt handling using FORTRAN IV plus under RSX-11M

    SciTech Connect

    Schultz, D.E.

    1981-01-01

    A real-time data acquisition application for a linear accelerator is described. The important programming features of this application are use of connect to interrupt, a shared library, map to I/O page, and a shared data area. How you can provide rapid interrupt handling using these tools from FORTRAN IV PLUS is explained.

  12. Timing Characteristics of Large Area Picosecond Photodetectors

    SciTech Connect

    Adams, Bernhard W.; Elagin, Andrey L.; Frisch, H.; Obaid, Razib; Oberla, E; Vostrikov, Alexander; Wagner, Robert G.; Wang, Jingbo; Wetstein, Matthew J.; Northrop, R

    2015-09-21

    The LAPPD Collaboration was formed to develop ultralast large-area imaging photodetectors based on new methods for fabricating microchannel plates (MCPs). In this paper we characterize the time response using a pulsed, sub picosecond laser. We observe single photoelectron time resolutions of a 20 cm x 20 cm MCP consistently below 70 ps, spatial resolutions of roughly 500 pm, and median gains higher than 10(7). The RMS measured at one particular point on an LAPPD detector is 58 ps, with in of 47 ps. The differential time resolution between the signal reaching the two ends of the delay line anode is measured to be 5.1 ps for large signals, with an asymptotic limit falling below 2 ps as noise-over-signal approaches zero.

  13. Timing characteristics of Large Area Picosecond Photodetectors

    NASA Astrophysics Data System (ADS)

    Adams, B. W.; Elagin, A.; Frisch, H. J.; Obaid, R.; Oberla, E.; Vostrikov, A.; Wagner, R. G.; Wang, J.; Wetstein, M.

    2015-09-01

    The LAPPD Collaboration was formed to develop ultrafast large-area imaging photodetectors based on new methods for fabricating microchannel plates (MCPs). In this paper we characterize the time response using a pulsed, sub-picosecond laser. We observe single-photoelectron time resolutions of a 20 cm × 20 cm MCP consistently below 70 ps, spatial resolutions of roughly 500 μm, and median gains higher than 107. The RMS measured at one particular point on an LAPPD detector is 58 ps, with ± 1σ of 47 ps. The differential time resolution between the signal reaching the two ends of the delay line anode is measured to be 5.1 ps for large signals, with an asymptotic limit falling below 2 ps as noise-over-signal approaches zero.

  14. Construct Validity of the WISC-IV[superscript UK] with a Large Referred Irish Sample

    ERIC Educational Resources Information Center

    Watkins, Marley W.; Canivez, Gary L.; James, Trevor; James, Kate; Good, Rebecca

    2013-01-01

    Irish educational psychologists frequently use the Wechsler Intelligence Scale for Children-Fourth U.K. Edition (WISC-IV[superscript UK]) in clinical assessments of children with learning difficulties. Unfortunately, reliability and validity studies of the WISC-IV[superscript UK] have not yet been reported. This study examined the construct…

  15. Vorinostat, Rituximab, and Combination Chemotherapy in Treating Patients With Newly Diagnosed Stage II, Stage III, or Stage IV Diffuse Large B-Cell Lymphoma

    ClinicalTrials.gov

    2016-06-20

    Stage II Contiguous Adult Diffuse Large Cell Lymphoma; Stage II Non-Contiguous Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma

  16. Real-Time Series Resistance Monitoring in PV Systems Without the Need for IV Curves

    SciTech Connect

    Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-06-14

    We apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting IV curves or constructing full series-resistance-free IV curves. RTSR is most readily deployable at the module level on micro-inverters or module-integrated electronics, but it can also be extended to full strings. Automated detection of series resistance increases can provide early warnings of some of the most common reliability issues, which also pose fire risks, including broken ribbons, broken solder bonds, and contact problems in the junction or combiner box. We describe the method in detail and describe a sample application to data collected from modules operating in the field.

  17. Titanium(IV) in the organic-structure-directing-agent-free synthesis of hydrophobic and large-pore molecular sieves as redox catalysts.

    PubMed

    Wang, Jingui; Yokoi, Toshiyuki; Kondo, Junko N; Tatsumi, Takashi; Zhao, Yanli

    2015-08-10

    Titanium(IV) incorporated into the framework of molecular sieves can be used as a highly active and sustainable catalyst for the oxidation of industrially important organic molecules. Unfortunately, the current process for the incorporation of titanium(IV) requires a large amount of expensive organic molecules used as organic-structure-directing agents (OSDAs), and this significantly increases the production costs and causes environmental problems owing to the removal of OSDAs by pyrolysis. Herein, an OSDA-free process was developed to incorporate titanium(IV) into BEA-type molecular sieves for the first time. More importantly, the hydrophobic environment and the robust, 3 D, and large pore structure of the titanium(IV)-incorporated molecular sieves fabricated from the OSDA-free process created a catalyst that was extremely active and selective for the epoxidation of bulky cyclooctene in comparison to Ti-incorporated BEA-type molecular sieves synthesized with OSDAs and commercial titanosilicate TS-1. PMID:26073555

  18. Rapid detection of lineage IV peste des petits ruminants virus by real-time RT-PCR.

    PubMed

    Li, Lin; Wu, Xiaodong; Liu, Fuxiao; Wang, Zhiliang; Liu, Chunju; Wang, Qinghua; Bao, Jingyue

    2016-09-01

    Peste des petits ruminants virus (PPRV) is the cause agent of peste des petitis ruminants (PPR). A novel lineage IV PPRV has reemerged in China in 2013 and 2014. Mass vaccination was implemented in most provinces in China. In order to detect lineage IV PPRV in clinical samples and to distinguish rapidly it from the other lineages PPRVs, a real-time RT-PCR assay was developed. This assay showed high sensitivity, specificity and efficiency in differentiating the lineage IV PPRV from others. The performance of this assay was evaluated by positive clinical samples of lineage IV viruses. This new real-time RT-PCR assay will facilitate epidemiological investigations and rapid differentiatial diagnosis in areas where lineage IV viruses are circulating. PMID:27260657

  19. Time Filtering in Large Eddy Simulations

    NASA Technical Reports Server (NTRS)

    Carati, Daniele; Wray, Alan A.

    2000-01-01

    An explicit time filter is applied to the Navier-Stokes equation prior to a space filter. The time filter is supposed to be smooth, and an exact expansion depending on the time derivatives of the velocity is derived for the associated stress tensor. On the contrary, the effect of the space filter is treated as usual and an eddy viscosity model is introduced in the LES equation. The total stress is thus represented using a new class of mixed models combining time and space derivatives of the LES field.

  20. Simulating stochastic dynamics using large time steps.

    PubMed

    Corradini, O; Faccioli, P; Orland, H

    2009-12-01

    We present an approach to investigate the long-time stochastic dynamics of multidimensional classical systems, in contact with a heat bath. When the potential energy landscape is rugged, the kinetics displays a decoupling of short- and long-time scales and both molecular dynamics or Monte Carlo (MC) simulations are generally inefficient. Using a field theoretic approach, we perform analytically the average over the short-time stochastic fluctuations. This way, we obtain an effective theory, which generates the same long-time dynamics of the original theory, but has a lower time-resolution power. Such an approach is used to develop an improved version of the MC algorithm, which is particularly suitable to investigate the dynamics of rare conformational transitions. In the specific case of molecular systems at room temperature, we show that elementary integration time steps used to simulate the effective theory can be chosen a factor approximately 100 larger than those used in the original theory. Our results are illustrated and tested on a simple system, characterized by a rugged energy landscape. PMID:20365123

  1. High lying configurations in the spectrum of three times ionized indium (In IV)

    NASA Astrophysics Data System (ADS)

    Ryabtsev, A. N.; Kononov, E. Ya.

    2016-01-01

    Using the high resolution vacuum normal and grazing incidence spectrographs the spectrum of three times ionized indium has been studied in the wavelength region 250-700 Å. Previously unknown transitions 4d95s-4d85s5p and 4d95p-4d98s were investigated resulting in the identification of 146 spectral lines and location of 55 levels of the 4d85s5p configuration and all four levels of the 4d98s configuration. The number of identified lines involving the 4d97s, 4d96p, 4d97p, 4d96d, 4d94f and 4d95f configurations was significantly increased. Previously found levels of these configurations were confirmed except two 4d96d levels which were corrected. Overall 210 new lines were identified in In IV.

  2. Nonparametric, nonnegative deconvolution of large time series

    NASA Astrophysics Data System (ADS)

    Cirpka, O. A.

    2006-12-01

    There is a long tradition of characterizing hydrologic systems by linear models, in which the response of the system to a time-varying stimulus is computed by convolution of a system-specific transfer function with the input signal. Despite its limitations, the transfer-function concept has been shown valuable for many situations such as the precipitation/run-off relationships of catchments and solute transport in agricultural soils and aquifers. A practical difficulty lies in the identification of the transfer function. A common approach is to fit a parametric function, enforcing a particular shape of the transfer function, which may be in contradiction to the real behavior (e.g., multimodal transfer functions, long tails, etc.). In our nonparametric deconvolution, the transfer function is assumed an auto-correlated random time function, which is conditioned on the data by a Bayesian approach. Nonnegativity, which is a vital constraint for solute-transport applications, is enforced by the method of Lagrange multipliers. This makes the inverse problem nonlinear. In nonparametric deconvolution, identifying the auto-correlation parameters is crucial. Enforcing too much smoothness prohibits the identification of important features, whereas insufficient smoothing leads to physically meaningless transfer functions, mapping noise components in the two data series onto each other. We identify optimal smoothness parameters by the expectation-maximization method, which requires the repeated generation of many conditional realizations. The overall approach, however, is still significantly faster than Markov-Chain Monte-Carlo methods presented recently. We apply our approach to electric-conductivity time series measured in a river and monitoring wells in the adjacent aquifer. The data cover 1.5 years with a temporal resolution of 1h. The identified transfer functions have lengths of up to 60 days, making up 1440 parameters. We believe that nonparametric deconvolution is an

  3. Effect of Intravenous (IV) Assistive Device (VeinViewer) on IV Access Attempts, Procedural Time, and Patient and Nurse Satisfaction.

    PubMed

    Ramer, Lois; Hunt, Pauline; Ortega, Erin; Knowlton, Jessica; Briggs, Raymond; Hirokawa, Shinichi

    2016-07-01

    This study evaluated the effectiveness of VeinViewer for peripheral vascular accessing a pediatric hematology oncology clinic. After obtaining consent, 53 patients were randomly assigned to either the VeinViewer group (n = 27) or standard methods group (n = 26). Data on number of attempts, procedural time, access complications, and patient and nurse satisfaction were collected. Patients randomized to the VeinViewer group required significantly less time to access a vein as compared with the standard methods group (P ≤ .05). Additionally, these patients rated nurses as having significantly more skill than nurses who did not use VeinViewer (P ≤ .05) and assigned significantly higher scores for "overall experience"(P ≤ .05). Responses by nurses using VeinViewer overall saw the device in a positive light. PMID:26510643

  4. Real-time application of PASSER IV: Project summary and guidelines. Research report, September 1994--August 1997

    SciTech Connect

    Chaudhary, N.A.

    1997-10-01

    PASSER IV is a program for timing traffic signals in networks based on progression bandwidth optimization. It is capable of optimizing signals timings for arterials as well as multi-arterial closed-loop networks. This report presents a summary of work conducted under a three-year research project funded by TxDOT. It provides guidelines for using PASSER IV as a 1.5 generation real-time traffic control system using a test-bed from the city of Richardson, Texas. In addition, the report addresses the issue of signal timing transition and provides the description of a preliminary algorithm for finding the cost of transition. Finally, the report provides new PASSER IV developments and describes new features.

  5. Profiling the metabolism of astragaloside IV by ultra performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry.

    PubMed

    Cheng, Xu-Dong; Wei, Ming-Gang

    2014-01-01

    Astragaloside IV is a compound isolated from the Traditional Chinese Medicine Astragalus membranaceus, that has been reported to have bioactivities against cardiovascular disease and kidney disease. There is limited information on the metabolism of astragaloside IV, which impedes comprehension of its biological actions and pharmacology. In the present study, an ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS)-based approach was developed to profile the metabolites of astragaloside IV in rat plasma, bile, urine and feces samples. Twenty-two major metabolites were detected. The major components found in plasma, bile, urine and feces included the parent chemical and phases I and II metabolites. The major metabolic reactions of astragaloside IV were hydrolysis, glucuronidation, sulfation and dehydrogenation. These results will help to improve understanding the metabolism and reveal the biotransformation profiling of astragaloside IV in vivo. The metabolic information obtained from our study will guide studies into the pharmacological activity and clinical safety of astragaloside IV. PMID:25407723

  6. Topology of large-scale structure. IV - Topology in two dimensions

    NASA Technical Reports Server (NTRS)

    Melott, Adrian L.; Cohen, Alexander P.; Hamilton, Andrew J. S.; Gott, J. Richard, III; Weinberg, David H.

    1989-01-01

    In a recent series of papers, an algorithm was developed for quantitatively measuring the topology of the large-scale structure of the universe and this algorithm was applied to numerical models and to three-dimensional observational data sets. In this paper, it is shown that topological information can be derived from a two-dimensional cross section of a density field, and analytic expressions are given for a Gaussian random field. The application of a two-dimensional numerical algorithm for measuring topology to cross sections of three-dimensional models is demonstrated.

  7. Reionization on Large Scales. IV. Predictions for the 21 cm Signal Incorporating the Light Cone Effect

    NASA Astrophysics Data System (ADS)

    La Plante, P.; Battaglia, N.; Natarajan, A.; Peterson, J. B.; Trac, H.; Cen, R.; Loeb, A.

    2014-07-01

    We present predictions for the 21 cm brightness temperature power spectrum during the Epoch of Reionization (EoR). We discuss the implications of the "light cone" effect, which incorporates evolution of the neutral hydrogen fraction and 21 cm brightness temperature along the line of sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model the neutral hydrogen density field and 21 cm signal in large volumes (L = 2 Gpc h -1). The inclusion of the light cone effect leads to a relative decrease of about 50% in the 21 cm power spectrum on all scales. We also find that the effect is more prominent at the midpoint of reionization and later. The light cone effect can also introduce an anisotropy along the line of sight. By decomposing the 3D power spectrum into components perpendicular to and along the line of sight, we find that in our fiducial reionization model, there is no significant anisotropy. However, parallel modes can contribute up to 40% more power for shorter reionization scenarios. The scales on which the light cone effect is relevant are comparable to scales where one measures the baryon acoustic oscillation. We argue that due to its large comoving scale and introduction of anisotropy, the light cone effect is important when considering redshift space distortions and future application to the Alcock-Paczyński test for the determination of cosmological parameters.

  8. Reionization on large scales. IV. Predictions for the 21 cm signal incorporating the light cone effect

    SciTech Connect

    La Plante, P.; Battaglia, N.; Natarajan, A.; Peterson, J. B.; Trac, H.; Cen, R.; Loeb, A.

    2014-07-01

    We present predictions for the 21 cm brightness temperature power spectrum during the Epoch of Reionization (EoR). We discuss the implications of the 'light cone' effect, which incorporates evolution of the neutral hydrogen fraction and 21 cm brightness temperature along the line of sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model the neutral hydrogen density field and 21 cm signal in large volumes (L = 2 Gpc h {sup –1}). The inclusion of the light cone effect leads to a relative decrease of about 50% in the 21 cm power spectrum on all scales. We also find that the effect is more prominent at the midpoint of reionization and later. The light cone effect can also introduce an anisotropy along the line of sight. By decomposing the 3D power spectrum into components perpendicular to and along the line of sight, we find that in our fiducial reionization model, there is no significant anisotropy. However, parallel modes can contribute up to 40% more power for shorter reionization scenarios. The scales on which the light cone effect is relevant are comparable to scales where one measures the baryon acoustic oscillation. We argue that due to its large comoving scale and introduction of anisotropy, the light cone effect is important when considering redshift space distortions and future application to the Alcock-Paczyński test for the determination of cosmological parameters.

  9. STT Doubles with Large DM – Part IV: Ophiuchus and Hercules

    NASA Astrophysics Data System (ADS)

    Knapp, Wilfried; Nanson, John

    2016-04-01

    The results of visual double star observing sessions suggested a pattern for STT doubles with large DM of being harder to resolve than would be expected based on the WDS catalog data. It was felt this might be a problem with expectations on one hand, and on the other might be an indication of a need for new precise measurements, so we decided to take a closer look at a selected sample of STT doubles and do some research. We found that like in the other constellations covered so far (Gem, Leo, UMa, etc.) at least several of the selected objects in Ophiuchus and Hercules show parameters quite different from the current WDS data.

  10. The dynamics and control of large flexible space structures-IV

    NASA Technical Reports Server (NTRS)

    Bainum, P. M.; Kumar, V. K.; Krishna, R.; Reddy, A. S. S. R.

    1981-01-01

    The effects of solar radiation pressure as the main environmental disturbance torque were incorporated into the model of the rigid orbiting shallow shell and computer simulation results indicate that within the linear range the rigid modal amplitudes are excited in proportion to the area to mass ratio. The effect of higher order terms in the gravity-gradient torque expressions previously neglected was evaluated and found to be negligible for the size structures under consideration. A graph theory approach was employed for calculating the eigenvalues of a large flexible system by reducing the system (stiffness) matrix to lower ordered submatrices. The related reachability matrix and term rank concepts are used to verify controllability and can be more effective than the alternate numerical rank tests. Control laws were developed for the shape and orientation control of the orbiting flexible shallow shell and numerical results presented.

  11. The Gould's Belt Very Large Array Survey. IV. The Taurus-Auriga Complex

    NASA Astrophysics Data System (ADS)

    Dzib, Sergio A.; Loinard, Laurent; Rodríguez, Luis F.; Mioduszewski, Amy J.; Ortiz-León, Gisela N.; Kounkel, Marina A.; Pech, Gerardo; Rivera, Juana L.; Torres, Rosa M.; Boden, Andrew F.; Hartmann, Lee; Evans, Neal J., II; Briceño, Cesar; Tobin, John

    2015-03-01

    We present a multi-epoch radio study of the Taurus-Auriga star-forming complex made with the Karl G. Jansky Very Large Array at frequencies of 4.5 GHz and 7.5 GHz. We detect a total of 610 sources, 59 of which are related to young stellar objects (YSOs) and 18 to field stars. The properties of 56% of the young stars are compatible with non-thermal radio emission. We also show that the radio emission of more evolved YSOs tends to be more non-thermal in origin and, in general, that their radio properties are compatible with those found in other star-forming regions. By comparing our results with previously reported X-ray observations, we notice that YSOs in Taurus-Auriga follow a Güdel-Benz relation with κ = 0.03, as we previously suggested for other regions of star formation. In general, YSOs in Taurus-Auriga and in all the previous studied regions seem to follow this relation with a dispersion of ~1 dex. Finally, we propose that most of the remaining sources are related with extragalactic objects but provide a list of 46 unidentified radio sources whose radio properties are compatible with a YSO nature.

  12. RAGBEEF: a FORTRAN IV implementation of a time-dependent model for radionuclide contamination of beef

    SciTech Connect

    Pleasant, J C; McDowell-Boyer, L M; Killough, G G

    1982-06-01

    RAGBEEF is a FORTRAN IV program that calculates radionuclide concentrations in beef as a result of ingestion of contaminated feeds, pasture, and pasture soil by beef cattle. The model implemented by RAGBEEF is dynamic in nature, allowing the user to consider age- and season-dependent aspects of beef cattle management in estimating concentrations in beef. It serves as an auxiliary code to RAGTIME, previously documented by the authors, which calculates radionuclide concentrations in agricultural crops in a dynamic manner, but evaluates concentrations in beef for steady-state conditions only. The time-dependent concentrations in feeds, pasture, and pasture soil generated by RAGTIME are used as input to the RAGBEEF code. RAGBEEF, as presently implemented, calculates radionuclide concentrations in the muscle of age-based cohorts in a beef cattle herd. Concentrations in the milk of lactating cows are also calculated, but are assumed age-dependent as in RAGTIME. Radionuclide concentrations in beef and milk are described in RAGBEEF by a system of ordinary linear differential equations in which the transfer rate of radioactivity between compartments is proportional to the inventory of radioactivity in the source compartment. This system is solved by use of the GEAR package for solution of systems of ordinary differential equations. The accuracy of this solution is monitored at various check points by comparison with explicit solutions of Bateman-type equations. This report describes the age- and season-dependent considerations making up the RAGBEEF model, as well as presenting the equations which describe the model and a documentation of the associated computer code. Listings of the RAGBEEF and updated RAGTIME codes are provided in appendices, as are the results of a sample run of RAGBEEF and a description of recent modifications to RAGTIME.

  13. Quantum Coherence Times Enhancement in Vanadium(IV)-based Potential Molecular Qubits: the Key Role of the Vanadyl Moiety.

    PubMed

    Atzori, Matteo; Morra, Elena; Tesi, Lorenzo; Albino, Andrea; Chiesa, Mario; Sorace, Lorenzo; Sessoli, Roberta

    2016-09-01

    In the search for long-lived quantum coherence in spin systems, vanadium(IV) complexes have shown record phase memory times among molecular systems. When nuclear spin-free ligands are employed, vanadium(IV) complexes can show at low temperature sufficiently long quantum coherence times, Tm, to perform quantum operations, but their use in real devices operating at room temperature is still hampered by the rapid decrease of T1 caused by the efficient spin-phonon coupling. In this work we have investigated the effect of different coordination environments on the magnetization dynamics and the quantum coherence of two vanadium(IV)-based potential molecular spin qubits in the solid state by introducing a unique structural difference, i.e., an oxovanadium(IV) in a square pyramidal versus a vanadium(IV) in an octahedral environment featuring the same coordinating ligand, namely, the 1,3-dithiole-2-thione-4,5-dithiolate. This investigation, performed by a combined approach of alternate current (ac) susceptibility measurements and continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) spectroscopies revealed that the effectiveness of the vanadyl moiety in enhancing quantum coherence up to room temperature is related to a less effective mechanism of spin-lattice relaxation that can be quantitatively evaluated by the exponent n (ca. 3) of the temperature dependence of the relaxation rate. A more rapid collapse is observed for the non-oxo counterpart (n = 4) hampering the observation of quantum coherence at room temperature. Record coherence time at room temperature (1.04 μs) and Rabi oscillations are also observed for the vanadyl derivative in a very high concentrated material (5 ± 1%) as a result of the additional benefit provided by the use of a nuclear spin-free ligand. PMID:27517709

  14. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages.

    PubMed

    Campisi, Edmondo; Rinaudo, C Daniela; Donati, Claudio; Barucco, Mara; Torricelli, Giulia; Edwards, Morven S; Baker, Carol J; Margarit, Imma; Rosini, Roberto

    2016-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV. PMID:27411639

  15. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages

    PubMed Central

    Campisi, Edmondo; Rinaudo, C. Daniela; Donati, Claudio; Barucco, Mara; Torricelli, Giulia; Edwards, Morven S.; Baker, Carol J.; Margarit, Imma; Rosini, Roberto

    2016-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV. PMID:27411639

  16. Data on Log Allocated Time for 11 Reading and 8 Math Schools. Comparative Study of Phase IV IGE Evaluation Project. Phase IV, Project Paper 80-4.

    ERIC Educational Resources Information Center

    Nerenz, Anne G.; Webb, Norman L.

    This is one of a series of reports which provide definitions of and descriptive data on the variables used in the Comparative Study of Phase IV of the Individually Guided Education (IEG) Evaluation Project. Phase IV investigated three curriculum programs specifically designed to be compatible with instructional programming for the individual…

  17. Real-Time Series Resistance Monitoring in PV Systems Without the Need for I-V Curves

    SciTech Connect

    Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-10-01

    We apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting I-V curves or constructing full series resistance-free I-V curves. RTSR is most readily deployable at the module level on microinverters or module-integrated electronics, but it can also be extended to full strings. We found that automated detection of series resistance increases can provide early warnings of some of the most common reliability issues, which also pose fire risks, including broken ribbons, broken solder bonds, and contact problems in the junction or combiner box. We also describe the method in detail and describe a sample application to data collected from modules operating in the field.

  18. Characteristics of microbial communities in steppe paleosols buried under kurgans of the Sarmatian time (I-IV centuries AD)

    NASA Astrophysics Data System (ADS)

    Demkina, T. S.; Khomutova, T. E.; Kashirskaya, N. N.; Stretovich, I. V.; Demkin, V. A.

    2009-07-01

    Microbiological studies of paleosols buried under steppe kurgans of different ages of the Middle (I-II centuries AD) and Late Sarmatian (II-IV centuries AD) time in different regions of the Lower Volga steppes were carried out. The regularities of the soil microbial communities’ development were determined in the I-IV centuries AD by the climate dynamics and the replacement of the relatively humid conditions (the I century to the first half of the II century) by dry (the second half of the II century to the first half of the III century) and then again by humid (the end of the III century to the IV century) conditions. In the humid climatic periods, the active biomass of the microorganisms and its portion in the total microbial biomass and the Corg of the soil increased, the portion of microorganisms consuming plant residues increased in the ecological-trophic structure of the microbial community, and the index of oligotrophy decreased. These changes had an opposite direction in the arid climatic periods. The variations of the microbiological parameters relative to the century-long dynamics of the climate over the historical time were synchronous and unidirectional, though the studied soils were found in different soil-geographical zones (dry and desert steppe), natural regions (the Privolzhskaya and Ergeni uplands and the Caspian Lowland), and landforms (watersheds, river terraces, marine plains).

  19. Dwell time calculation for computer controlled large tool

    NASA Astrophysics Data System (ADS)

    Fan, Bin; Burge, James H.; Martin, Hubert; Zeng, Zhige; Li, Xiaojin; Zhou, Jiabin

    2012-09-01

    The Computer-controlled Large-tool such as the stressed-lap which firstly developed in the Steward Observatory Mirror Lab (SOML) [1]and the Computer controlled active lap which developed in the IOE (Institute of Optics and Electronics, Chinese Academy of Science), those large tools are controlled by computer to manufacturing large optics, especially for grinding with loose abrasive and polishing with slurry. Comparing the fixed orbital lap, computer-controlled largetool can bend its lap surface timely to match the local sub-aperture, so it always strike the high area preferentially, due to its large diameter , computer-controlled large-tool possess highly remove efficiency and generate less middle-frequency and high-frequency errors comparing some small tools such as computer controlled optical surface (CCOS), but on the other hand how to calculate the dwell time for those computer-controlled large-tool becomes a challenge comparing those small tools. Based on the mathematical removal equation for computer controlled active lap we have none negative least square algorithm to calculate the dwell time, after the simulation, a optimized algorithm based on none negative least square is provided, the dwell time calculated by this optimized algorithm meet the wanted removal volume with little residual errors.

  20. Predictors of Local Recurrence After Rituximab-Based Chemotherapy Alone in Stage III and IV Diffuse Large B-Cell Lymphoma: Guiding Decisions for Consolidative Radiation

    SciTech Connect

    Jegadeesh, Naresh; Rajpara, Raj; Esiashvili, Natia; Shi, Zheng; Liu, Yuan; Okwan-Duodu, Derrick; Flowers, Christopher R.; Khan, Mohammad K.

    2015-05-01

    Purpose: The role of consolidative radiation therapy (RT) for stage III and IV diffuse large B-cell lymphoma (DLBCL) in the era of rituximab is not well defined. There is evidence that some patients with bulky disease may benefit, but patient selection criteria are not well established. We sought to identify a subset of patients who experienced a high local failure rate after receiving rituximab-based chemotherapy alone and hence may benefit from the addition of consolidative RT. Methods and Materials: Two hundred eleven patients with stage III and IV DLBCL treated between August 1999 and January 2012 were reviewed. Of these, 89 had a complete response to systemic therapy including rituximab and received no initial RT. Kaplan-Meier analysis and Cox proportional hazards regression were performed, with local recurrence (LR) as the primary outcome. Results: The median follow-up time was 43.9 months. Fifty percent of patients experienced LR at 5 years. In multivariate analysis, tumor ≥5 cm and stage III disease were associated with increased risk of LR. The 5-year LR-free survival was 47.4% for patients with ≥5-cm lesions versus 74.7% for patients with <5-cm lesions (P=.01). In patients with <5-cm tumors, the maximum standardized uptake value (SUVmax) was ≥15 in all patients with LR. The 5-year LR-free survival was 100% in SUV<15 versus 68.8% in SUV≥15 (P=.10). Conclusions: Advanced-stage DLBCL patients with stage III disease or with disease ≥5 cm appear to be at an increased risk for LR. Patients with <5-cm disease and SUVmax ≥15 may be at higher risk for LR. These patients may benefit from consolidative RT after chemoimmunotherapy.

  1. Ovarian Cancer Stage IV

    MedlinePlus

    ... hyphen, e.g. -historical Searches are case-insensitive Ovarian Cancer Stage IV Add to My Pictures View /Download : ... 1200x1335 View Download Large: 2400x2670 View Download Title: Ovarian Cancer Stage IV Description: Drawing of stage IV shows ...

  2. Atypical depression: useful concept, but it's time to revise the DSM-IV criteria.

    PubMed

    Thase, Michael E

    2009-12-01

    Stewart et al (2009) have outlined the evidence in support of the validity of the DSM-IV definition of the 'With Atypical Features' episode specifier. Although recognizing the historical significance and clinical utility of the concept of atypical depression, this article takes issue with the DSM-IV criteria. It is concluded that mood reactivity, the A or obligative criterion, is neither significantly associated with the other symptomatic criteria nor useful to diagnose atypical depression, and thus should be eliminated. Problems with operationalization, specification, and reliability of ratings of the diagnostic criteria further limit validity. Despite these limitations in classification, many of the features associated with atypical depression are linked to an early onset of affective illness, including trait-like interpersonal sensitivity, comorbid social anxiety and agoraphobia, a history of childhood physical or sexual trauma, and indicators of the 'soft' side of the bipolar spectrum. Neurophysiologic studies also suggest that chronic, early-onset atypical depressions differ from both melancholia and normality. Re-analyses of the Columbia group's seminal studies suggest that preferential response to phenelzine vs imipramine--arguably the strongest validator of atypical depression--similarly appears to be limited to patients with chronic, early-onset syndromes. The criteria for atypical depression need to be revised in DSM-V, including sharpening the operational definitions for the specific symptoms. The importance of age of onset and comorbid anxiety warrant further study. Research examining the validity of a subform of atypical depression characterized by trait-like interpersonal sensitivity and a chronic, early-onset course may further enhance the clinical utility of the DSM-V classification. PMID:19741592

  3. Large Time Asymptotics for the Kadomtsev-Petviashvili Equation

    NASA Astrophysics Data System (ADS)

    Hayashi, Nakao; Naumkin, Pavel I.

    2014-08-01

    We study the large time asymptotic behavior of solutions to the Kadomtsev-Petviashvili equations ut + u_{xxx} + σ partialx^{-1}u_{yy} = -partialxu2, quad quad (x, y) in {R}2, t in {R},\\ u(0, x, y) = u0( x, y), quad quad qquad qquad (x, y) in {R}2, where σ = ±1 and {partialx^{-1} = int_{-infty}xdx^' } . We prove that the large time asymptotics of the derivative u x of the solution has a quasilinear character.

  4. Generation IV nuclear energy system initiative. Large GFR core subassemblydesign for the Gas-Cooled Fast Reactor.

    SciTech Connect

    Hoffman, E. A.; Kulak, R. F.; Therios, I. U.; Wei, T. Y. C.

    2006-07-31

    Gas-cooled fast reactor (GFR) designs are being developed to meet Gen IV goals of sustainability, economics, safety and reliability, and proliferation resistance and physical protection as part of an International Generation IV Nuclear Energy System Research Initiative effort. Different organizations are involved in the development of a variety of GFR design concepts. The current analysis has focused on the evaluation of low-pressure drop, pin-core designs with favorable passive cooling properties. Initial evaluation of the passive cooling safety case for the GFR during depressurized decay heat removal accidents with concurrent loss of electric power have resulted in requirements for a reduction of core power density to the 100 w/cc level and a low core pressure drop of 0.5 bars. Additional design constraints and the implementation of their constraints are evaluated in this study to enhance and passive cooling properties of the reactor. Passive cooling is made easier by a flat radial distribution of the decay heat. One goal of this study was to evaluate the radial power distribution and determine to what extent it can be flattened, since the decay heat is nearly proportional to the fission power at shutdown. In line with this investigation of the radial power profile, an assessment was also made of the control rod configuration. The layout provided a large number of control rod locations with a fixed area provided for control rods. The number of control rods was consistent with other fast reactor designs. The adequacy of the available control rod locations was evaluated. Future studies will be needed to optimize the control rod designs and evaluate the shutdown system. The case for low pressure drop core can be improved by the minimization of pressure drop sources such as the number of required fuel spacers in the subassembly design and by the details of the fuel pin design. The fuel pin design is determined by a number of neutronic, thermal-hydraulic (gas dynamics

  5. High-resolution spectroscopy for Cepheids distance determination. IV. Time series of Hα line profiles

    NASA Astrophysics Data System (ADS)

    Nardetto, N.; Groh, J. H.; Kraus, S.; Millour, F.; Gillet, D.

    2008-10-01

    Context: In recent years, infrared interferometry has revealed the presence of faint dusty circumstellar envelopes (CSE) around Cepheids. However the size, shape, chemical nature, and the interaction of the CSE with the star itself are still under investigation. The presence of a CSE might have an effect on the angular diameter estimates used in the interferometric Baade-Wesselink and surface-brightness methods of determining the distance of Cepheids. Aims: By studying Hα profiles as a function of the period, we investigate the permanent mass loss and the CSE around Cepheids. Our high spectral- and time-resolution data, combined with a very good S/N, will be useful in constraining future hydrodynamical models of Cepheids atmosphere and their close environment. Methods: We present HARPS (High Accuracy Radial velocity Planetary Search project developed by the European Southern Observatory.) high-resolution spectroscopy (R = 120 000) of eight galactic Cepheids: R Tra, S Cru, Y Sgr, β Dor, zeta Gem, RZ Vel, ell Car, and RS Pup, providing a good period sampling (P = 3.39 d to P = 41.52 d). The Hα line profiles are described for all stars using a 2D (wavelength versus pulsation phase) representation. For each star, an average spectral line profile is derived, together with its first moment (γ-velocity) and its asymmetry (γ-asymmetry). Results: Short-period Cepheids show Hα line profiles following the pulsating envelope of the star, while long-period Cepheids show very complex line profiles and, in particular, large asymmetries. We find a new relationship between the period of Cepheids and their γ-velocities and -asymmetries. These results may be related to the dynamical structure of the atmosphere and to a permanent mass loss of Cepheids. In particular, we confirm for ell Car a dominant absorption component whose velocity is constant and nearly of zero km s-1 in the stellar rest frame. This component is attributed to the presence of circumstellar envelope

  6. I-V and noise performance in MWIR to VLWIR large area Hg1-xCdxTe photodiodes

    NASA Astrophysics Data System (ADS)

    D'Souza, A. I.; Stapelbroek, M. G.; Dolan, P. N.; Wijewarnasuriya, P. S.; Boehmer, E.; Smith, D. S.; Ehlert, J. C.; Andrews, J. E.

    2005-05-01

    , diffusion current limited photodiodes having values of αdark in the mid 10-6 range. All of the 850 μm diameter, λc ~ 15.5 μm photodiodes measured have excess low frequency noise, with the best performers having in(f = 100 Hz, Vd =-60 mV , Δf = 1 Hz) ~ 2 x 10-11 A/Hz1/2 and the best photodiode αdark = 3.92 x 10-6. I-V measurements, noise, and visual inspections are performed at several steps in the photodiodes manufacturing process. It was observed, following FPM fabrication, photodiode dark current and noise had increased from the initial pre-mounting leadless chip carrier (LCC) measurements for some of the nine photodiodes. The performance degradation observed led to an investigation into the cause (baking at elevated temperatures, mechanical handling, electrical stress etc.) of photodiode degradation that occurred between LCC and FPM testing. Correlations between I-V, noise and surface visual defects have been performed on some λc ~ 15.5 mm photodiodes. This paper outlines the results of the study, correlating the electrical performance observed to visual defects on the surface and to defects seen following cross sectioning of degraded photodiodes. In addition, other lessons learned and the corrective actions implemented that led to the successful manufacture of SWIR, MWIR and LWIR large photodiodes from the material growth to insertion into and successful demonstration of flight FPMs for the CrIS program are described.

  7. The Time of Our Lives: A Perspective from the Keystone IV Conference.

    PubMed

    Loxterkamp, David

    2016-01-01

    We often experience time as a commodity-in excess for those who suffer; in scarcity for those who minister to them. But it is also a teacher, a tool, and a generous yardstick for measuring one's career-if we take the time to reflect on it. This is an essay about time and timing as a doctor negotiates the practice of medicine. PMID:27387161

  8. Time simulation of flutter with large stiffness changes

    NASA Technical Reports Server (NTRS)

    Karpel, Mordechay; Wieseman, Carol D.

    1992-01-01

    Time simulation of flutter, involving large local structural changes, is formulated with a state-space model that is based on a relatively small number of generalized coordinates. Free-free vibration modes are first calculated for a nominal finite-element model with relatively large fictitious masses located at the area of structural changes. A low-frequency subset of these modes is then transformed into a set of structural modal coordinates with which the entire simulation is performed. These generalized coordinates and the associated oscillatory aerodynamic force coefficient matrices are used to construct an efficient time-domain, state-space model for a basic aeroelastic case. The time simulation can then be performed by simply changing the mass, stiffness, and damping coupling terms when structural changes occur. It is shown that the size of the aeroelastic model required for time simulation with large structural changes at a few apriori known locations is similar to that required for direct analysis of a single structural case. The method is applied to the simulation of an aeroelastic wind-tunnel model. The diverging oscillations are followed by the activation of a tip-ballast decoupling mechanism that stabilizes the system but may cause significant transient overshoots.

  9. Time simulation of flutter with large stiffness changes

    NASA Technical Reports Server (NTRS)

    Karpel, M.; Wieseman, C. D.

    1992-01-01

    Time simulation of flutter, involving large local structural changes, is formulated with a state-space model that is based on a relatively small number of generalized coordinates. Free-free vibration modes are first calculated for a nominal finite-element model with relatively large fictitious masses located at the area of structural changes. A low-frequency subset of these modes is then transformed into a set of structural modal coordinates with which the entire simulation is performed. These generalized coordinates and the associated oscillatory aerodynamic force coefficient matrices are used to construct an efficient time-domain, state-space model for basic aeroelastic case. The time simulation can then be performed by simply changing the mass, stiffness and damping coupling terms when structural changes occur. It is shown that the size of the aeroelastic model required for time simulation with large structural changes at a few a priori known locations is similar to that required for direct analysis of a single structural case. The method is applied to the simulation of an aeroelastic wind-tunnel model. The diverging oscillations are followed by the activation of a tip-ballast decoupling mechanism that stabilizes the system but may cause significant transient overshoots.

  10. Recurrence time distributions of large earthquakes in conceptual model studies

    NASA Astrophysics Data System (ADS)

    Zoeller, G.; Hainzl, S.

    2007-12-01

    The recurrence time distribution of large earthquakes in seismically active regions is a crucial ingredient for seismic hazard assessment. However, due to sparse observational data and a lack of knowledge on the precise mechanisms controlling seismicity, this distribution is unknown. In many practical applications of seismic hazard assessment, the Brownian passage time (BPT) distribution (or a different distribution) is fitted to a small number of observational recurrence times. Here, we study various aspects of recurrence time distributions in conceptual models of individual faults and fault networks: First, the dependence of the recurrence time distribution on the fault interaction is investigated by means of a network of Brownian relaxation oscillators. Second, the Brownian relaxation oscillator is modified towards a model for large earthquakes, taking into account also the statistics of intermediate events in a more appropriate way. This model simulates seismicity in a fault zone consisting of a major fault and some surrounding smaller faults with Gutenberg-Richter type seismicity. This model can be used for more realistic and robust estimations of the real recurrence time distribution in seismic hazard assessment.

  11. Global existence and large time behavior of the asymmetric fluids

    NASA Astrophysics Data System (ADS)

    Tan, Zhong; Tong, Leilei

    2016-06-01

    In this paper, we consider the asymptotic stability of the steady state with the constant equilibrium state. Under the assumptions that the {H^3} norm of the initial data is small, but its higher-order derivatives could be large, we prove the global existence to the Cauchy problem for the asymmetric fluids in {{R}^3}. Moreover, we obtain the time decay rates of the solutions and their higher-order spatial derivatives by introducing the negative Sobolev and Besov spaces.

  12. FTSPlot: Fast Time Series Visualization for Large Datasets

    PubMed Central

    Riss, Michael

    2014-01-01

    The analysis of electrophysiological recordings often involves visual inspection of time series data to locate specific experiment epochs, mask artifacts, and verify the results of signal processing steps, such as filtering or spike detection. Long-term experiments with continuous data acquisition generate large amounts of data. Rapid browsing through these massive datasets poses a challenge to conventional data plotting software because the plotting time increases proportionately to the increase in the volume of data. This paper presents FTSPlot, which is a visualization concept for large-scale time series datasets using techniques from the field of high performance computer graphics, such as hierarchic level of detail and out-of-core data handling. In a preprocessing step, time series data, event, and interval annotations are converted into an optimized data format, which then permits fast, interactive visualization. The preprocessing step has a computational complexity of ; the visualization itself can be done with a complexity of and is therefore independent of the amount of data. A demonstration prototype has been implemented and benchmarks show that the technology is capable of displaying large amounts of time series data, event, and interval annotations lag-free with ms. The current 64-bit implementation theoretically supports datasets with up to bytes, on the x86_64 architecture currently up to bytes are supported, and benchmarks have been conducted with bytes/1 TiB or double precision samples. The presented software is freely available and can be included as a Qt GUI component in future software projects, providing a standard visualization method for long-term electrophysiological experiments. PMID:24732865

  13. Visual Data Mining of Large, Multivariate Space-Time Data

    NASA Astrophysics Data System (ADS)

    Cook, D.

    2001-12-01

    Interest in understanding global climate change is generating monitoring efforts that yield a huge amount of multivariate space-time data. While analytical methods for univariate space-time data may be mature and substantial, methods for multivariate space-time data analysis are still in their infancy. The urgency of understanding climate change on a global scale begs for input from data analysts, and to work effectively they need new tools to explore multivariate aspects of climate. This talk describes interactive and dynamic visual tools for mining information from multivariate space-time data. Methods for small amounts of data will be discussed, followed by approaches to scaling up methods for large quantities of data. We focus on the ``multiple views'' approach for viewing multivariate data, and how these extend to include space-time contextual information. We also will describe dynamic graphics methods such as tours in the space-time context. Data mining is the current terminology for exploratory analyses of data, typically associated with large databases. Exploratory analysis has a goal of finding anomalies, quirks and deviations from a trend, and basically extracting unexpected information from data. It oft-times emphasizes model-free methods, although model-based approaches are also integral components to the analysis process. Visual data mining concentrates on the use of visual tools in the exploratory process. As such it often involves highly interactive and dynamic graphics environments which facilitate quick queries and visual responses. Visual methods are especially important in exploratory analysis because they provide an interface for using the human eye to digest complex information. A good plot can convey far more information than a numerical summary. Visual tools enhance the chances of discovering the unexpected, and detecting the anomalous events.

  14. Time-Domain Filtering for Spatial Large-Eddy Simulation

    NASA Technical Reports Server (NTRS)

    Pruett, C. David

    1997-01-01

    An approach to large-eddy simulation (LES) is developed whose subgrid-scale model incorporates filtering in the time domain, in contrast to conventional approaches, which exploit spatial filtering. The method is demonstrated in the simulation of a heated, compressible, axisymmetric jet, and results are compared with those obtained from fully resolved direct numerical simulation. The present approach was, in fact, motivated by the jet-flow problem and the desire to manipulate the flow by localized (point) sources for the purposes of noise suppression. Time-domain filtering appears to be more consistent with the modeling of point sources; moreover, time-domain filtering may resolve some fundamental inconsistencies associated with conventional space-filtered LES approaches.

  15. Experimental occlusion of the central artery of the retina. IV: Retinal tolerance time to acute ischaemia.

    PubMed Central

    Hayreh, S. S.; Weingeist, T. A.

    1980-01-01

    Ophthalmoscopic, fluorescein angiographic, electrophysiological, and morphological studies on 63 eyes of rhesus monkeys with acute transient experimental occlusion of the central artery of the retina (OCAR) showed that the retina suffered irreparable damage after ischaemia of 105 minutes but recovered well after ischaemia of 97-98 minutes. The tolerance time of the brain to acute transient ischaemia is many times shorter than that of the retina. The metabolism of ischaemic neurones (in the retina and brain) is discussed with a view to explaining this difference, and also the various factors possibly responsible for the retina's longer tolerance to ischaemia, as compared to the brain. PMID:7426553

  16. Real-time distributed map building in large environments

    NASA Astrophysics Data System (ADS)

    Julier, Simon J.; Uhlmann, Jeffrey K.

    2000-10-01

    Many of the future missions for mobile robots demand multi- robot systems which are capable of operating in large environments for long periods of time. One of the most critical capabilities is the ability to localize- a mobile robot must be able to estimate its own position and to consistently transmit this information to other robots and control sites. Although state-of-the-art GPS is capable of yielding unmatched performance over large areas, it is not applicable in many environments (such as within city streets, under water, indoors, beneath foliage or extra- terrestrial robotic missions) where mobile robots are likely to become commonplace. A widely researched alternative is Simultaneous Localization and Map Building (SLAM): the vehicle constructs a map and, concurrently, estimates its own position. However, most approaches are non-scalable (the storage and computational costs vary quadratically and cubically with the number of beacons in the map) and can only be used with multiple robotic vehicles with a great degree of difficulty. In this paper, we describe the development of a scalable, multiple-vehicle SLAM system. This system, based on the Covariance Intersection algorithm, is scalable- its storage and computational costs are linearly proportional to the number of beacons in the map. Furthermore, it is scalable to multiple robots- each has complete freedom to exchange partial or full map information with any other robot at any other time step. We demonstrate the real-time performance of this system in a scenario of 15,000 beacons.

  17. Galactic cannibalism. IV. The evidence-correlations between dynamical time scales and Bautz-Morgan type

    SciTech Connect

    McGlynn, T.A.; Ostriker, J.P.

    1980-11-01

    If the luminosity of supergiant cD galaxies in particular, and the Bautz-Morgan sequence of galaxy types in general, is produced by dynamical evolutionary processes, then one expects to find a correlation between dynamical times and ..delta..M/sub 12/, the magnitude difference between first and second brightest cluster members.

  18. How To Dance through Time. Volume IV: The Elegance of Baroque Social Dance. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This 45-minute VHS videotape is the fourth in a series of "How To Dance Through Time" videos. It shows how to dance the most influential social dances of the French Baroque Court. The ceremonious Minuet is the most famous of the 18th century dance invention. The Allemande is the pivotal bridge linking to the 19th century. The Contredance has…

  19. Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models

    SciTech Connect

    Fabrycky, Daniel C.; Ford, Eric B.; Steffen, Jason H.; Rowe, Jason F.; Carter, Joshua A.; Moorhead, Althea V.; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Buchhave, Lars A.; Christiansen, Jessie L.; /SETI Inst., Mtn. View /NASA, Ames /Caltech

    2012-01-01

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present 4 sets of lightcurves from the Kepler spacecraft, which each show multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems architectures, even in cases for which high-precision Doppler follow-up is impractical.

  20. Large area spark counter with fine time and position resolution

    SciTech Connect

    Ogawa, A.; Fujiwara, N.; Pestov, Yu.N.; Sugahara, R.

    1984-03-01

    The key properties of spark counters include their capability of precision timing (at the sub 100 ps level) and of measuring the position of the charged particle to high accuracy. At SLAC we have undertaken a program to develop these devices for use in high energy physics experiments involving large detectors. A spark counter of size 1.2 m x 0.1 m has been constructed and has been operating continuously in our test setup for several months. Some details of its construction and its properties as a particle detector are reported. 14 references. (WHK)

  1. Studies in astronomical time series analysis. IV - Modeling chaotic and random processes with linear filters

    NASA Technical Reports Server (NTRS)

    Scargle, Jeffrey D.

    1990-01-01

    While chaos arises only in nonlinear systems, standard linear time series models are nevertheless useful for analyzing data from chaotic processes. This paper introduces such a model, the chaotic moving average. This time-domain model is based on the theorem that any chaotic process can be represented as the convolution of a linear filter with an uncorrelated process called the chaotic innovation. A technique, minimum phase-volume deconvolution, is introduced to estimate the filter and innovation. The algorithm measures the quality of a model using the volume covered by the phase-portrait of the innovation process. Experiments on synthetic data demonstrate that the algorithm accurately recovers the parameters of simple chaotic processes. Though tailored for chaos, the algorithm can detect both chaos and randomness, distinguish them from each other, and separate them if both are present. It can also recover nonminimum-delay pulse shapes in non-Gaussian processes, both random and chaotic.

  2. NIHAO - IV: core creation and destruction in dark matter density profiles across cosmic time

    NASA Astrophysics Data System (ADS)

    Tollet, Edouard; Macciò, Andrea V.; Dutton, Aaron A.; Stinson, Greg S.; Wang, Liang; Penzo, Camilla; Gutcke, Thales A.; Buck, Tobias; Kang, Xi; Brook, Chris; Di Cintio, Arianna; Keller, Ben W.; Wadsley, James

    2016-03-01

    We use the NIHAO (Numerical Investigation of Hundred Astrophysical Objects) cosmological simulations to investigate the effects of baryonic physics on the time evolution of dark matter central density profiles. The sample is made of ≈70 independent high-resolution hydrodynamical simulations of galaxy formation and covers a wide mass range: 1010 ≲ Mhalo/M⊙ ≲ 1012, i.e. from dwarfs to L⋆. We confirm previous results on the dependence of the inner dark matter density slope, α, on the ratio between stellar-to-halo mass, Mstar/Mhalo. We show that this relation holds approximately at all redshifts (with an intrinsic scatter of ˜0.18 in α measured between 1 and 2 per cent of the virial radius). This implies that in practically all haloes the shape of their inner density profile changes quite substantially over cosmic time, as they grow in stellar and total mass. Thus, depending on their final Mstar/Mhalo ratio, haloes can either form and keep a substantial density core (Rcore ˜ 1 kpc), or form and then destroy the core and recontract the halo, going back to a cuspy profile, which is even steeper than cold-dark-matter predictions for massive galaxies (1012 M⊙). We show that results from the NIHAO suite are in good agreement with recent observational measurements of α in dwarf galaxies. Overall our results suggest that the notion of a universal density profile for dark matter haloes is no longer valid in the presence of galaxy formation.

  3. Irregular Morphing for Real-Time Rendering of Large Terrain

    NASA Astrophysics Data System (ADS)

    Kalem, Sid'Ali; Kourgli, Assia

    2016-06-01

    The following paper proposes an alternative approach to the real-time adaptive triangulation problem. A new region-based multi-resolution approach for terrain rendering is described which improves on-the-fly the distribution of the density of triangles inside the tile after selecting appropriate Level-Of-Detail by an adaptive sampling. This proposed approach organizes the heightmap into a QuadTree of tiles that are processed independently. This technique combines the benefits of both Triangular Irregular Network approach and region-based multi-resolution approach by improving the distribution of the density of triangles inside the tile. Our technique morphs the initial regular grid of the tile to deformed grid in order to minimize approximation error. The proposed technique strives to combine large tile size and real-time processing while guaranteeing an upper bound on the screen space error. Thus, this approach adapts terrain rendering process to local surface characteristics and enables on-the-fly handling of large amount of terrain data. Morphing is based-on the multi-resolution wavelet analysis. The use of the D2WT multi-resolution analysis of the terrain height-map speeds up processing and permits to satisfy an interactive terrain rendering. Tests and experiments demonstrate that Haar B-Spline wavelet, well known for its properties of localization and its compact support, is suitable for fast and accurate redistribution. Such technique could be exploited in client-server architecture for supporting interactive high-quality remote visualization of very large terrain.

  4. Overview of real-time computer systems technical analysis of the Modcomp implementation of a proprietary system MAX IV'' and real-time UNIX system REAL/IX''

    SciTech Connect

    Cummings, J.

    1990-10-01

    There many applications throughout industry and government requiring real-time computing. Any application that monitors and/or controls a process would fit into this category. Some examples are: Nuclear power plants, Steel mills, Space program, etc. General Atomics uses eight real-time computer systems for control and high speed data acquisition required to run the nuclear fusion experiments. Real-Time computing can be defined as the ability to respond to asynchronous external events in a predictable (preferably fast) time frame. Real-Time computer systems are similar to other computers in many ways and may by used for general computing requirements such as Time-Sharing. However special hardware, operating systems and software had to be developed to meet the requirement for real-time computing. Traditionally, real-time computing has been a realm of proprietary operating systems with real-time applications written in FORTRAN and assembly language. In the past, these systems adequately served the needs of the real-time world. Many of these systems that were developed 15 years ago are still being used today. However the real-time world is now changing, demanding new systems to be developed. This paper gives a description of general real-time computer systems and how they differ from other systems. However, the main purpose of this paper is to give a detailed technical description of the hardware and operating systems of an existing proprietary system and a real-time UNIX system. The two real-time computer systems described in detail are Modcomp Classic III/95 with the MAX IV operating system and Modcomp TRI-D 9750 with the REAL/IX.2 operating system.

  5. Temporal weighting functions for interaural time and level differences. IV. Effects of carrier frequency

    PubMed Central

    Stecker, G. Christopher

    2014-01-01

    Temporal variation in listeners' sensitivity to interaural time and level differences (ITD and ILD, respectively) was measured for sounds of different carrier frequency using the temporal weighting function (TWF) paradigm [Stecker and Hafter (2002) J. Acoust. Soc. Am. 112,1046–1057]. Listeners made lateralization judgments following brief trains of filtered impulses (Gabor clicks) presented over headphones with overall ITD and/or ILD ranging from ±500 μs ITD and/or ±5 dB ILD across trials. Individual clicks within each train varied by an additional ±100 μs ITD or ±2 dB ILD to allow TWF calculation by multiple regression. In separate conditions, TWFs were measured for carrier frequencies of 1, 2, 4, and 8 kHz. Consistent with past studies, TWFs demonstrated high weight on the first click for stimuli with short interclick interval (ICI = 2 ms), but flatter weighting for longer ICI (5–10 ms). Some conditions additionally demonstrated greater weight for clicks near the offset than near the middle of the train. Results support a primary role of the auditory periphery in emphasizing onset and offset cues in rapidly modulated low-frequency sounds. For slower modulations, sensitivity to ongoing high-frequency ILD and low-frequency ITD cues appears subject to recency effects consistent with the effects of leaky temporal integration of binaural information. PMID:25480069

  6. Response time of large-scale electrochromic devices

    SciTech Connect

    Randin, J.P.

    1990-12-31

    The studies related to electrochromic phenomena performed in the seventies were mainly aimed at the development of information displays. Such applications require small electrode sizes, i.e. with active surface areas of between about 0.01 to 10 cm{sup 2}. The development of large information devices and chiefly smart windows require much larger switching areas. This paper deals with the influence of increasing the active surface area on the response time. The latter depends on both properties of the cell components (transparent conducting layer, electrochromic film, electrolyte and counter electrode) and structure of the cell (size, shape, gap, resistivity of the busbar). Experimental devices were constructed with given components and cell geometry. The effect of a series resistance arisen mainly from the cell size was investigated and explained by the effect of the additional series resistance on the response time of a diffusion-controlled process. The study indicates that the scaling-up of WO{sub 3} devices will be limited by an increase of the response time with increasing active area.

  7. Teleoperation with large time delay using a prevision system

    NASA Astrophysics Data System (ADS)

    Bergamasco, Massimo; De Paolis, Lucio; Ciancio, Stefano; Pinna, Sebastiano

    1997-12-01

    In teleoperation technology various techniques have been proposed in order to alleviate the effects of time delayed communication and to avoid the instability of the system. This paper describes a different approach to robotic teleoperation with large-time delay and a teleoperation system, based on teleprogramming paradigm, has been developed with the intent to improve the slave autonomy and to decrease the amount of information exchanged between master and slave system. The goal concept, specific of AI, has been used. In order to minimize the total task completion time has been introduced a prevision system, called Merlino, able to know in advance the slave's choices taking into account both the operator's actions and the information about the remote environment. The prevision system allows, in case of environment changes, to understand if the slave can solve the goal. Otherwise, Merlino is able to signal a 'fail situation.' Some experiments have been carried out by means of an advanced human-machine interface with force feedback, designed at PERCRO Laboratory of Scuola Superiore S. Anna, which gives a better sensation of presence in the remote environment.

  8. Real-time radiography of Titan IV Solid Rocket Motor Upgrade (SRMU) static firing test QM-2

    SciTech Connect

    Dolan, K.W.; Curnow, G.M.; Perkins, D.E.; Schneberk, D.J.; Costerus, B.W.; La Chapell, M.J.; Turner, D.E.; Wallace, P.W.

    1994-03-08

    Real-time radiography was successfully applied to the Titan-IV Solid Rocket Motor Upgrade (SRMU) static firing test QM-2 conducted February 22, 1993 at Phillips Laboratory, Edwards AFB, CA. The real-time video data obtained in this test gave the first incontrovertible evidence that the molten slag pool is low (less than 5 to 6 inches in depth referenced to the bottom of the aft dome cavity) before T + 55 seconds, builds fairly linearly from this point in time reaching a quasi-equilibrium depth of 16 to 17 inches at about T + 97 seconds, which is well below the top of the vectored nozzle, and maintains that level until T + 125 near the end motor burn. From T + 125 seconds to motor burn-out at T + 140 seconds the slag pool builds to a maximum depth of about 20 to 21 inches, still well below the top of the nozzle. The molten slag pool was observed to interact with motions of the vectored nozzle, and exhibit slosh and wave mode oscillations. A few slag ejection events were also observed.

  9. Large introns in the 3' end of the gene for the pro. cap alpha. 1(IV) chain of human basement membrane collagen

    SciTech Connect

    Soininen, R.; Tikka, L.; Chow, L.; Pihlajaniemi, T.; Kurkinen, M.; Prockop, D.J.; Boyd, C.D.; Tryggvason, K.

    1986-03-01

    Using a recently characterized cDNA clone (HT-21) coding for the pro..cap alpha..1(IV) chain of human type IV procollagen, the authors have isolated three clones from a bacteriophage lambda Charon 4A library of human genomic DNA. The intron/exon structure of the pro..cap alpha..1(IV) genomic clones was analyzed by heteroduplex electron microscopy and nucleotide sequencing. The analysis showed that the introns separating exons 2-9 are large and have a total length of over 12,000 base pairs (bp). Six of seven exons at the 3' end of the gene coded for -Gly-Xaa-Yaa-repeats of the collagenous part of the chain. Five of the -Gly-Xaa-Yaa-coding exons (numbers 5-9) varied in size between 72 bp and 134 bp, and none of them were 54 bp or multiples thereof. A sixth exon (exon 4) was a junction exon containing 71 bp coding for-Gly-Xaa-Yaa-sequences and 142 bp coding for the carboxyl-terminal noncollagenous domain (NC-1). The seventh exon (exon 3, 178 bp) coded for sequences of the NC-1 domain. Five of the six-Gly-Xaa-Yaa- coding exons began with the second base coding for glycine, and only one exon began with a complete glycine codon at the 5' end. The results (i) suggest that the gene for the pro..cap alpha..1(IV) chain of human basement membrane collagen is significantly larger than the genes for fibrillar collagens and (ii) show that it lacks the 54-bp exon repeats characteristic of fibrillar collagen genes.

  10. Parallel Rendering of Large Time-Varying Volume Data

    NASA Technical Reports Server (NTRS)

    Garbutt, Alexander E.

    2005-01-01

    Interactive visualization of large time-varying 3D volume datasets has been and still is a great challenge to the modem computational world. It stretches the limits of the memory capacity, the disk space, the network bandwidth and the CPU speed of a conventional computer. In this SURF project, we propose to develop a parallel volume rendering program on SGI's Prism, a cluster computer equipped with state-of-the-art graphic hardware. The proposed program combines both parallel computing and hardware rendering in order to achieve an interactive rendering rate. We use 3D texture mapping and a hardware shader to implement 3D volume rendering on each workstation. We use SGI's VisServer to enable remote rendering using Prism's graphic hardware. And last, we will integrate this new program with ParVox, a parallel distributed visualization system developed at JPL. At the end of the project, we Will demonstrate remote interactive visualization using this new hardware volume renderer on JPL's Prism System using a time-varying dataset from selected JPL applications.

  11. TIME-SETTLEMENT BEHAVIOR OF PROCESSED REFUSE. PART IV: CONSOLIDATION OF MILLED REFUSE, VOLUME 1, VOLUME 2-APPENDIX

    EPA Science Inventory

    A previously developed mathematical model for the prediction of the time-settlement behavior of a sanitary landfill of milled refuse, taking into account the effects of finite deformations, large creep strains, and biological and chemical decomposition of the material with accomp...

  12. Large Time Projection Chambers for Rare Event Detection

    SciTech Connect

    Heffner, M

    2009-11-03

    The Time Projection Chamber (TPC) concept [add ref to TPC section] has been applied to many projects outside of particle physics and the accelerator based experiments where it was initially developed. TPCs in non-accelerator particle physics experiments are principally focused on rare event detection (e.g. neutrino and darkmater experiments) and the physics of these experiments can place dramatically different constraints on the TPC design (only extensions to the traditional TPCs are discussed here). The drift gas, or liquid, is usually the target or matter under observation and due to very low signal rates a TPC with the largest active mass is desired. The large mass complicates particle tracking of short and sometimes very low energy particles. Other special design issues include, efficient light collection, background rejection, internal triggering and optimal energy resolution. Backgrounds from gamma-rays and neutrons are significant design issues in the construction of these TPCs. They are generally placed deep underground to shield from cosmogenic particles and surrounded with shielding to reduce radiation from the local surroundings. The construction materials have to be carefully screened for radiopurity as they are in close contact with the active mass and can be a signification source of background events. The TPC excels in reducing this internal background because the mass inside the fieldcage forms one monolithic volume from which fiducial cuts can be made ex post facto to isolate quiet drift mass, and can be circulated and purified to a very high level. Self shielding in these large mass systems can be significant and the effect improves with density. The liquid phase TPC can obtain a high density at low pressure which results in very good self-shielding and compact installation with a lightweight containment. The down sides are the need for cryogenics, slower charge drift, tracks shorter than the typical electron diffusion, lower energy resolution (e

  13. Impact of Consolidation Radiation Therapy in Stage III-IV Diffuse Large B-cell Lymphoma With Negative Post-Chemotherapy Radiologic Imaging

    SciTech Connect

    Dorth, Jennifer A.; Prosnitz, Leonard R.; Broadwater, Gloria; Diehl, Louis F.; Beaven, Anne W.; Coleman, R. Edward; Kelsey, Chris R.

    2012-11-01

    Purpose: While consolidation radiation therapy (i.e., RT administered after chemotherapy) is routine treatment for patients with early-stage diffuse large B-cell lymphoma (DLBCL), the role of consolidation RT in stage III-IV DLBCL is controversial. Methods and Materials: Cases of patients with stage III-IV DLBCL treated from 1991 to 2009 at Duke University, who achieved a complete response to chemotherapy were reviewed. Clinical outcomes were calculated using the Kaplan-Meier method and were compared between patients who did and did not receive RT, using the log-rank test. A multivariate analysis was performed using Cox proportional hazards model. Results: Seventy-nine patients were identified. Chemotherapy (median, 6 cycles) consisted of anti-CD20 antibody rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 65%); cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP; 22%); or other (13%). Post-chemotherapy imaging consisted of positron emission tomography (PET)/computed tomography (CT) (73%); gallium with CT (14%); or CT only (13%). Consolidation RT (median, 25 Gy) was given to involved sites of disease in 38 (48%) patients. Receipt of consolidation RT was associated with improved in-field control (92% vs. 69%, respectively, p = 0.028) and event-free survival (85% vs. 65%, respectively, p = 0.014) but no difference in overall survival (85% vs. 78%, respectively, p = 0.15) when compared to patients who did not receive consolidation RT. On multivariate analysis, no RT was predictive of increased risk of in-field failure (hazard ratio [HR], 8.01, p = 0.014) and worse event-free survival (HR, 4.3, p = 0.014). Conclusions: Patients with stage III-IV DLBCL who achieve negative post-chemotherapy imaging have improved in-field control and event-free survival with low-dose consolidation RT.

  14. Large seals fabricated from small segments reduce procurement lead time

    NASA Technical Reports Server (NTRS)

    Daniels, C. M.; Hanes, V. D.

    1966-01-01

    Large diameter seals are fabricated from narrow strip stock welded in segments to form a complete ring. This technique could be used to reduce the cost of critical, large diameter seals in the heating and ventilating industry, petrochemical industry, and marine fabrication industry.

  15. Nonuniform steam generator U-tube flow distribution during natural circulation tests in ROSA-IV large scale test facility

    SciTech Connect

    Kukita, Y.; Nakamura, H.; Tasaka, K. ); Chauliac, C. )

    1988-08-01

    Natural circulation experiments were conducted in a large-scale (1/48 scale in volume) full-height simulator of a Westinghouse-type pressurized water reactor. This facility has two steam generators each containing 141 full-size U-tubes of 9 different heights. Transition of the natural circulation mode was observed in the experiments as the primary of side mass inventory was decreased. Three major circulation modes were observed: single-phase liquid natural circulation, two-phase natural circulation, and reflux condensation. For all these circulation modes, and during the transitions between the modes, the mass flow distribution among the steam generator U-tubes was significantly nonuniform. The longer U-tubes indicated reversed flow at higher primary side mass inventories and also tended to empty earlier than the shorter U-tubes when the primary side mass inventory was decreased.

  16. VAC Therapy in Large Infected Sacral Pressure Ulcer Grade IV-Can Be an Alternative to Flap Reconstruction?

    PubMed

    Batra, R K; Aseeja, Veena

    2014-04-01

    Vacuum-assisted closure (VAC) therapy is a new entrant in wound care after growth factors and alginate or hydrocolloid dressing, in the treatment of pressure ulcers. We have been using this technique for diabetic foot ulcers. A young nondiabetic man presented with a large sacral bed sore after high doses of ionotropes in an intensive care unit for treating severe hypotension. His wound was debrided, and instead of flap surgery in such infected wound, he was treated with VAC therapy. The complete wound healing was achieved in 6 weeks and at half the cost of flap surgery. Moreover, the chances of flap failure and its related complications were eliminated. PMID:24891788

  17. A new class of large band gap quantum spin hall insulators: 2D fluorinated group-IV binary compounds

    PubMed Central

    Padilha, J. E.; Pontes, R. B.; Schmidt, T. M.; Miwa, R. H.; Fazzio, A.

    2016-01-01

    We predict a new class of large band gap quantum spin Hall insulators, the fluorinated PbX (X = C, Si, Ge and Sn) compounds, that are mechanically stable two-dimensional materials. Based on first principles calculations we find that, while the PbX systems are not topological insulators, all fluorinated PbX (PbXF2) compounds are 2D topological insulators. The quantum spin Hall insulating phase was confirmed by the explicitly calculation of the Z2 invariant. In addition we performed a thorough investigation of the role played by the (i) fluorine saturation, (ii) crystal field, and (iii) spin-orbital coupling in PbXF2. By considering nanoribbon structures, we verify the appearance of a pair of topologically protected Dirac-like edge states connecting the conduction and valence bands. The insulating phase which is a result of the spin orbit interaction, reveals that this new class of two dimensional materials present exceptional nontrivial band gaps, reaching values up to 0.99 eV at the Γ point, and an indirect band gap of 0.77 eV. The topological phase is arisen without any external field, making this system promising for nanoscale applications, using topological properties. PMID:27212604

  18. A new class of large band gap quantum spin hall insulators: 2D fluorinated group-IV binary compounds.

    PubMed

    Padilha, J E; Pontes, R B; Schmidt, T M; Miwa, R H; Fazzio, A

    2016-01-01

    We predict a new class of large band gap quantum spin Hall insulators, the fluorinated PbX (X = C, Si, Ge and Sn) compounds, that are mechanically stable two-dimensional materials. Based on first principles calculations we find that, while the PbX systems are not topological insulators, all fluorinated PbX (PbXF2) compounds are 2D topological insulators. The quantum spin Hall insulating phase was confirmed by the explicitly calculation of the Z2 invariant. In addition we performed a thorough investigation of the role played by the (i) fluorine saturation, (ii) crystal field, and (iii) spin-orbital coupling in PbXF2. By considering nanoribbon structures, we verify the appearance of a pair of topologically protected Dirac-like edge states connecting the conduction and valence bands. The insulating phase which is a result of the spin orbit interaction, reveals that this new class of two dimensional materials present exceptional nontrivial band gaps, reaching values up to 0.99 eV at the Γ point, and an indirect band gap of 0.77 eV. The topological phase is arisen without any external field, making this system promising for nanoscale applications, using topological properties. PMID:27212604

  19. A new class of large band gap quantum spin hall insulators: 2D fluorinated group-IV binary compounds

    NASA Astrophysics Data System (ADS)

    Padilha, J. E.; Pontes, R. B.; Schmidt, T. M.; Miwa, R. H.; Fazzio, A.

    2016-05-01

    We predict a new class of large band gap quantum spin Hall insulators, the fluorinated PbX (X = C, Si, Ge and Sn) compounds, that are mechanically stable two-dimensional materials. Based on first principles calculations we find that, while the PbX systems are not topological insulators, all fluorinated PbX (PbXF2) compounds are 2D topological insulators. The quantum spin Hall insulating phase was confirmed by the explicitly calculation of the Z2 invariant. In addition we performed a thorough investigation of the role played by the (i) fluorine saturation, (ii) crystal field, and (iii) spin-orbital coupling in PbXF2. By considering nanoribbon structures, we verify the appearance of a pair of topologically protected Dirac-like edge states connecting the conduction and valence bands. The insulating phase which is a result of the spin orbit interaction, reveals that this new class of two dimensional materials present exceptional nontrivial band gaps, reaching values up to 0.99 eV at the Γ point, and an indirect band gap of 0.77 eV. The topological phase is arisen without any external field, making this system promising for nanoscale applications, using topological properties.

  20. Damped Lyman-alpha absorption by disk galaxies with large redshifts. IV - More intermediate-resolution spectroscopy

    NASA Technical Reports Server (NTRS)

    Wolfe, Arthur M.; Turnshek, David A.; Lanzetta, Kenneth M.; Lu, Limin

    1993-01-01

    Intermediate-resolution spectra of six QSOs exhibiting seven Ly-alpha absorption troughs that are candidates for damped Ly-alpha absorption lines are presented. The metal content of the confirmed damped systems is investigated by examining the metal-line velocity profiles, and by performing curve-of-growth analyses for four of the six confirmed damped systems. The low-ionization lines associated with the z(metals) = 2.0399 damped system toward Q0458-020 have velocity widths up to 10 times wider than the width of the 21-cm absorption feature found at the same redshift. Since the 21-cm absorption arises in a low velocity dispersion layer of H I that extends more than 8/h kpc transverse to the line of sight, the H I absorption cannot arise from the same clouds responsible for the bulk of the metal-line absorption. This is strong evidence for a two-component model consisting of high column density 'quiescent' gas which gives rise to damped Ly-alpha and 21-cm absorption, and low column density 'turbulent' gas which dominates equivalent widths of saturated metal lines.

  1. Research on the timing sequence control in large laser facility

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaolu; Wang, Lingfang; Wang, Chao; Tang, Ling; Chen, Ji; Zhang, Xin

    2015-11-01

    The timing sequence, between different pulses in SG-III laser facility, is controlled with three arbitrary waveform generators. The external clock and trigger are used to inhibit the timing jitter, which is provided by the synchronization system. Close-loop monitoring is used to make sure that the temporal phase can be recovered after reboot of the arbitrary waveform generator. The verification experiment shows that the three arbitrary waveform generators can work synchronously , which ensures the synchronization error control of the SG-III laser facility.

  2. Large-memory real-time multichannel multiplexed pattern recognition

    NASA Technical Reports Server (NTRS)

    Gregory, D. A.; Liu, H. K.

    1984-01-01

    The principle and experimental design of a real-time multichannel multiplexed optical pattern recognition system via use of a 25-focus dichromated gelatin holographic lens (hololens) are described. Each of the 25 foci of the hololens may have a storage and matched filtering capability approaching that of a single-lens correlator. If the space-bandwidth product of an input image is limited, as is true in most practical cases, the 25-focus hololens system has 25 times the capability of a single lens. Experimental results have shown that the interfilter noise is not serious. The system has already demonstrated the storage and recognition of over 70 matched filters - which is a larger capacity than any optical pattern recognition system reported to date.

  3. The PLATO IV Architecture.

    ERIC Educational Resources Information Center

    Stifle, Jack

    The PLATO IV computer-based instructional system consists of a large scale centrally located CDC 6400 computer and a large number of remote student terminals. This is a brief and general description of the proposed input/output hardware necessary to interface the student terminals with the computer's central processing unit (CPU) using available…

  4. Large-time evolution of an electron in photon bath

    SciTech Connect

    Kazakov, Kirill A.; Nikitin, Vladimir V.

    2012-12-15

    The problem of infrared divergence of the effective electromagnetic field produced by elementary charges is revisited using the model of an electron freely evolving in a photon bath. It is shown that for any finite travel time, the effective field of the electron is infrared-finite, and that at each order of perturbation theory the radiative contributions grow unboundedly with time. Using the Schwinger-Keldysh formalism, factorization of divergent contributions in multi-loop diagrams is proved, and summation of the resulting infinite series is performed. It is found that despite the unbounded growth of individual contributions to the effective field, their sum is bounded, tending to zero in the limit of infinite travel time. It is concluded that the physical meaning of infrared singularity in the effective field is the existence of a peculiar irreversible spreading of electric charges, caused by their interaction with the electromagnetic field. This spreading originates from the quantum electromagnetic fluctuations, rather than the electron-photon scattering, and exists in vacuum as well as at finite temperatures. It shows itself in a damping of the off-diagonal elements of the momentum-space density matrix of electron, but does not affect its momentum probability distribution. This effect is discussed in terms of thermalization of the electron state, and the asymptotic growth of its quantum entropy is determined. Relationship of the obtained results to the Bloch-Nordsieck theorem is established and considered from the standpoint of measurability of the electromagnetic field. The effect of irreversible spreading on the electron diffraction in the classic two-slit experiment is determined, and is shown to be detectable in principle by modern devices already at room temperature. - Highlights: Black-Right-Pointing-Pointer Infrared finiteness of the effective electromagnetic field of a free electron is proved. Black-Right-Pointing-Pointer Quantum radiative effects

  5. Asteroids IV

    NASA Astrophysics Data System (ADS)

    Michel, Patrick; DeMeo, Francesca E.; Bottke, William F.

    . Asteroids, like planets, are driven by a great variety of both dynamical and physical mechanisms. In fact, images sent back by space missions show a collection of small worlds whose characteristics seem designed to overthrow our preconceived notions. Given their wide range of sizes and surface compositions, it is clear that many formed in very different places and at different times within the solar nebula. These characteristics make them an exciting challenge for researchers who crave complex problems. The return of samples from these bodies may ultimately be needed to provide us with solutions. In the book Asteroids IV, the editors and authors have taken major strides in the long journey toward a much deeper understanding of our fascinating planetary ancestors. This book reviews major advances in 43 chapters that have been written and reviewed by a team of more than 200 international authorities in asteroids. It is aimed to be as comprehensive as possible while also remaining accessible to students and researchers who are interested in learning about these small but nonetheless important worlds. We hope this volume will serve as a leading reference on the topic of asteroids for the decade to come. We are deeply indebted to the many authors and referees for their tremendous efforts in helping us create Asteroids IV. We also thank the members of the Asteroids IV scientific organizing committee for helping us shape the structure and content of the book. The conference associated with the book, "Asteroids Comets Meteors 2014" held June 30-July 4, 2014, in Helsinki, Finland, did an outstanding job of demonstrating how much progress we have made in the field over the last decade. We are extremely grateful to our host Karri Muinonnen and his team. The editors are also grateful to the Asteroids IV production staff, namely Renée Dotson and her colleagues at the Lunar and Planetary Institute, for their efforts, their invaluable assistance, and their enthusiasm; they made life as

  6. Asteroids IV

    NASA Astrophysics Data System (ADS)

    Michel, Patrick; DeMeo, Francesca E.; Bottke, William F.

    . Asteroids, like planets, are driven by a great variety of both dynamical and physical mechanisms. In fact, images sent back by space missions show a collection of small worlds whose characteristics seem designed to overthrow our preconceived notions. Given their wide range of sizes and surface compositions, it is clear that many formed in very different places and at different times within the solar nebula. These characteristics make them an exciting challenge for researchers who crave complex problems. The return of samples from these bodies may ultimately be needed to provide us with solutions. In the book Asteroids IV, the editors and authors have taken major strides in the long journey toward a much deeper understanding of our fascinating planetary ancestors. This book reviews major advances in 43 chapters that have been written and reviewed by a team of more than 200 international authorities in asteroids. It is aimed to be as comprehensive as possible while also remaining accessible to students and researchers who are interested in learning about these small but nonetheless important worlds. We hope this volume will serve as a leading reference on the topic of asteroids for the decade to come. We are deeply indebted to the many authors and referees for their tremendous efforts in helping us create Asteroids IV. We also thank the members of the Asteroids IV scientific organizing committee for helping us shape the structure and content of the book. The conference associated with the book, "Asteroids Comets Meteors 2014" held June 30-July 4, 2014, in Helsinki, Finland, did an outstanding job of demonstrating how much progress we have made in the field over the last decade. We are extremely grateful to our host Karri Muinonnen and his team. The editors are also grateful to the Asteroids IV production staff, namely Renée Dotson and her colleagues at the Lunar and Planetary Institute, for their efforts, their invaluable assistance, and their enthusiasm; they made life as

  7. Time-dependent recovery of passive neutrophils after large deformation.

    PubMed Central

    Tran-Son-Tay, R; Needham, D; Yeung, A; Hochmuth, R M

    1991-01-01

    Experiments are performed in which a passive human neutrophil is deformed into an elongated "sausage" shape by aspirating it into a small glass pipette. When expelled from the pipette the neutrophil recovers its natural spherical shape in approximately 1 minute. This recovery process is analyzed according to a Newtonian, liquid-drop model in which a variational method is used to simultaneously solve the hydrodynamic equations for low Reynolds-number flow and the equations for membrane equilibrium with a constant membrane tension. The theoretical model gives a good fit to the experimental data for a ratio of membrane cortical tension to cytoplasmic viscosity of approximately 1.7 x 10(-5) cm/s (0.17 micron/s). However, when the cell is held in the pipette for only a short time period of 5 s or less, and then expelled, the cell undergoes an initial, rapid elastic rebound suggesting that the cell behaves in this instance as a Maxwell viscoelastic liquid rather than a Newtonian liquid with constant cortical tension. PMID:1742456

  8. Observation of W IV-W VII line emissions in wavelength range of 495-1475 Å in the large helical device

    NASA Astrophysics Data System (ADS)

    Oishi, Tetsutarou; Morita, Shigeru; Huang, Xianli; Zhang, Hongming; Goto, Motoshi; the LHD Experiment Group

    2016-02-01

    Vacuum ultraviolet spectra of line emissions from tungsten ions at lower ionization stages have been measured in the large helical device (LHD) using a high-resolution 3 m normal incidence spectrometer in the wavelength range of 495-1475 Å. Tungsten was introduced in the LHD plasma by injecting a coaxial tungsten impurity pellet. Many tungsten lines of W IV-W VII were successfully observed in low-temperature plasmas just after the tungsten pellet injection. It is found that some W VI lines are emitted with extremely high intensity and entirely isolated from other intrinsic impurity lines, in particular, W VI at 605.926 Å (5d-6p), 639.683 Å (5d-6p), 677.722 Å (5d-6p), 1168.151 Å (6s-6p) and 1467.959 Å (6s-6p). The result strongly suggests that those lines may be useful for the spectroscopic study in ITER and other magnetic fusion devices with tungsten materials as the plasma facing component. The ion temperature was also measured from Doppler broadening of W V and W VI lines. The result indicates that the measured ion temperature is clearly higher than the ionization energy of such ions. The reason is discussed with regarding to the pellet injection.

  9. Association between i.v. thrombolysis volume and door-to-needle times in acute ischemic stroke.

    PubMed

    Groot, Adrien E; van Schaik, Ivo N; Visser, Marieke C; Nederkoorn, Paul J; Limburg, Martien; Aramideh, Majid; de Beer, Frank; Zwetsloot, Caspar P; Halkes, Patricia; de Kruijk, Jelle; Kruyt, Nyika D; van der Meulen, Willem; Spaander, Fianne; van der Ree, Taco; Kwa, Vincent I H; Van den Berg-Vos, Renske M; Roos, Yvo B; Coutinho, Jonathan M

    2016-04-01

    Centralization of intravenous thrombolysis (IVT) for acute ischemic stroke in high-volume centers is believed to improve the door-to-needle times (DNT), but limited data support this assumption. We examined the association between DNT and IVT volume in a large Dutch province. We identified consecutive patients treated with IVT between January 2009 and 2013. Based on annualized IVT volume, hospitals were categorized as low-volume (≤ 24), medium-volume (25-49) or high-volume (≥ 50). In logistic regression analysis, low-volume hospitals were used as reference category. Of 17,332 stroke patients from 11 participating hospitals, 1962 received IVT (11.3 %). We excluded 140 patients because of unknown DNT (n = 86) or in-hospital stroke (n = 54). There were two low-volume (total 101 patients), five medium-volume (747 patients) and four high-volume hospitals (974 patients). Median DNT was shorter in high-volume hospitals (30 min) than in medium-volume (42 min, p < 0.001) and low-volume hospitals (38 min, p < 0.001). Patients admitted to high-volume hospitals had a higher chance of DNT < 30 min (adjusted OR 3.13, 95 % CI 1.70-5.75), lower risk of symptomatic intracerebral hemorrhage (adjusted OR 0.39, 95 % CI 0.16-0.92), and a lower mortality risk (adjusted OR 0.45, 95 % CI 0.21-1.01), compared to low-volume centers. There was no difference in DNT between low- and medium-volume hospitals. Onset-to-needle times (ONT) did not differ between the groups. Hospitals in this Dutch province generally achieved short DNTs. Despite this overall good performance, higher IVT volumes were associated with shorter DNTs and lower complication risks. The ONT was not associated with IVT volume. PMID:26946499

  10. Welding IV.

    ERIC Educational Resources Information Center

    Allegheny County Community Coll., Pittsburgh, PA.

    Instructional objectives and performance requirements are outlined in this course guide for Welding IV, a competency-based course in advanced arc welding offered at the Community College of Allegheny County to provide students with proficiency in: (1) single vee groove welding using code specifications established by the American Welding Society…

  11. Use of a large time-compensated scintillation detector in neutron time-of-flight measurements

    DOEpatents

    Goodman, Charles D.

    1979-01-01

    A scintillator for neutron time-of-flight measurements is positioned at a desired angle with respect to the neutron beam, and as a function of the energy thereof, such that the sum of the transit times of the neutrons and photons in the scintillator are substantially independent of the points of scintillations within the scintillator. Extrapolated zero timing is employed rather than the usual constant fraction timing. As a result, a substantially larger scintillator can be employed that substantially increases the data rate and shortens the experiment time.

  12. IVS Organization

    NASA Technical Reports Server (NTRS)

    2004-01-01

    International VLBI Service (IVS) is an international collaboration of organizations which operate or support Very Long Baseline Interferometry (VLBI) components. The goals are: To provide a service to support geodetic, geophysical and astrometric research and operational activities. To promote research and development activities in all aspects of the geodetic and astrometric VLBI technique. To interact with the community of users of VLBI products and to integrate VLBI into a global Earth observing system.

  13. [The Project on a Large Scale in its first times: time for a recall].

    PubMed

    Bassinello, Greicelene Aparecida Hespanhol; Bagnato, Maria Helena Salgado

    2009-01-01

    In this work we rebuilt the first attempts on the creation of the Program of Formation on a Large Scale of Elementary and High School people for basic health services. We examined the Program of Formation on a Large Scale from its beginning, being supported by documentary sources, such as Izabel dos Santos's interview, which filled in all the meanings of this experience. In the investigations, we went trough the purpose and the procedures of the proposal on a national scale. According to our point of view, this experience acquired a wider meaning of qualification: in which the focal point of the work, as a condition to workers' formation process, constituted as a methodological-pedagogical purpose of qualification at the work environment in order to obtain a critical professional. PMID:19768343

  14. The Effect of Radiation Timing on Patients With High-Risk Features of Parameningeal Rhabdomyosarcoma: An Analysis of IRS-IV and D9803

    SciTech Connect

    Spalding, Aaron C.; Hawkins, Douglas S.; Anderson, James R.; Lyden, Elizabeth; Laurie, Fran; Wolden, Suzanne L.; Arndt, Carola A.S.; Michalski, Jeff M.

    2013-11-01

    Purpose: Radiation therapy remains an essential treatment for patients with parameningeal rhabdomyosarcoma (PMRMS), and early radiation therapy may improve local control for patients with intracranial extension (ICE). Methods and Materials: To address the role of radiation therapy timing in PMRMS in the current era, we reviewed the outcome from 2 recent clinical trials for intermediate-risk RMS: Intergroup Rhabdomyosarcoma Study (IRS)-IV and Children's Oncology Group (COG) D9803. The PMRMS patients on IRS-IV with any high-risk features (cranial nerve palsy [CNP], cranial base bony erosion [CBBE], or ICE) were treated immediately at day 0, and PMRMS patients without any of these 3 features received week 6-9 radiation therapy. The D9803 PMRMS patients with ICE received day 0 X-Ray Therapy (XRT) as well; however, those with either CNP or CBBE had XRT at week 12. Results: Compared with the 198 PMRMS patients from IRS-IV, the 192 PMRMS patients from D9803 had no difference (P<.05) in 5-year local failure (19% vs 19%), failure-free-survival (70% vs 67%), or overall survival (75% vs 73%) in aggregate. The 5-year local failure rates by subset did not differ when patients were classified as having no risk features (None, 15% vs 19%, P=.25), cranial nerve palsy/cranial base of skull erosion (CNP/CBBE, 15% vs 28%, P=.22), or intracranial extension (ICE, 21% vs 15%, P=.27). The D9083 patients were more likely to have received initial staging by magnetic resonance imaging (71% vs 53%). Conclusions: These data support that a delay in radiation therapy for high-risk PMRMS features of CNP/CBBE does not compromise clinical outcomes.

  15. Bibliographic Automation of Large Library Operations Using a Time-Sharing System: Phase I. Final Report.

    ERIC Educational Resources Information Center

    Epstein, A. H.; And Others

    The first phase of an ongoing library automation project at Stanford University is described. Project BALLOTS (Bibliographic Automation of Large Library Operations Using a Time-Sharing System) seeks to automate the acquisition and cataloging functions of a large library using an on-line time-sharing computer. The main objectives are to control…

  16. Kepler eclipsing binary stars. IV. Precise eclipse times for close binaries and identification of candidate three-body systems

    SciTech Connect

    Conroy, Kyle E.; Stassun, Keivan G.; Prša, Andrej; Orosz, Jerome A.; Welsh, William F.; Fabrycky, Daniel C.

    2014-02-01

    We present a catalog of precise eclipse times and analysis of third-body signals among 1279 close binaries in the latest Kepler Eclipsing Binary Catalog. For these short-period binaries, Kepler's 30 minute exposure time causes significant smearing of light curves. In addition, common astrophysical phenomena such as chromospheric activity, as well as imperfections in the light curve detrending process, can create systematic artifacts that may produce fictitious signals in the eclipse timings. We present a method to measure precise eclipse times in the presence of distorted light curves, such as in contact and near-contact binaries which exhibit continuously changing light levels in and out of eclipse. We identify 236 systems for which we find a timing variation signal compatible with the presence of a third body. These are modeled for the light travel time effect and the basic properties of the third body are derived. This study complements J. A. Orosz et al. (in preparation), which focuses on eclipse timing variations of longer period binaries with flat out-of-eclipse regions. Together, these two papers provide comprehensive eclipse timings for all binaries in the Kepler Eclipsing Binary Catalog, as an ongoing resource freely accessible online to the community.

  17. A Nationwide Survey on the Daily Screen Time of Iranian Children and Adolescents: The CASPIAN - IV Study

    PubMed Central

    Jari, Mohsen; Qorbani, Mostafa; Motlagh, Mohammad Esmaeil; Heshmat, Ramin; Ardalan, Gelayol; Kelishadi, Roya

    2014-01-01

    Background: Leisure time activity is an important life-style habit. This study aims to determine the screen time of a nationally representative sample of Iranian children and adolescents. Methods: This nationwide cross-sectional study was conducted as part of the fourth survey of a surveillance system. The participants consisted of 14880 students, with aged range from 6 to 18 years, living in 30 provinces in Iran. Screen time, i.e. the time spent on watching television (TV)/video and computer games during leisure time, was assessed by using the questionnaire of the Globasl Student Health Survey of the World Health Organization. Results: The study participants were 13486 school students (participation rate of 90.6%) with a mean age of 12. 47 (3.36) years. Overall, 75.6% of students were from urban and 24.4% from rural areas and 50.8% were boys respectively. Overall, 33.4% and 53% of students watched TV/video more than 2 h a day in their leisure time during school days and holidays, respectively. Likewise, 6.3% and 10.9% of students used computer more than 2 h a day in their leisure time during the school days and holidays, respectively. Overall, 47.1% of urban students and 24.2% of rural students used personal computer in their leisure time during the school days. The corresponding figures were 50.8% and 27.2% in weekends and holidays, respectively. Conclusions: The time spent on screen activities is long in a considerably high number of Iranian children and adolescents. It should be reduced by increasing the public awareness and by providing facilities for regular daily physic activity for students’ leisure times. PMID:24627751

  18. Interplanetary Type IV Bursts

    NASA Astrophysics Data System (ADS)

    Hillaris, A.; Bouratzis, C.; Nindos, A.

    2016-08-01

    We study the characteristics of moving type IV radio bursts that extend to hectometric wavelengths (interplanetary type IV or type {IV}_{{IP}} bursts) and their relationship with energetic phenomena on the Sun. Our dataset comprises 48 interplanetary type IV bursts observed with the Radio and Plasma Wave Investigation (WAVES) instrument onboard Wind in the 13.825 MHz - 20 kHz frequency range. The dynamic spectra of the Radio Solar Telescope Network (RSTN), the Nançay Decametric Array (DAM), the Appareil de Routine pour le Traitement et l' Enregistrement Magnetique de l' Information Spectral (ARTEMIS-IV), the Culgoora, Hiraso, and the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) Radio Spectrographs were used to track the evolution of the events in the low corona. These were supplemented with soft X-ray (SXR) flux-measurements from the Geostationary Operational Environmental Satellite (GOES) and coronal mass ejections (CME) data from the Large Angle and Spectroscopic Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). Positional information of the coronal bursts was obtained by the Nançay Radioheliograph (NRH). We examined the relationship of the type IV events with coronal radio bursts, CMEs, and SXR flares. The majority of the events (45) were characterized as compact, their duration was on average 106 minutes. This type of events was, mostly, associated with M- and X-class flares (40 out of 45) and fast CMEs, 32 of these events had CMEs faster than 1000 km s^{-1}. Furthermore, in 43 compact events the CME was possibly subjected to reduced aerodynamic drag as it was propagating in the wake of a previous CME. A minority (three) of long-lived type {IV}_{{IP}} bursts was detected, with durations from 960 minutes to 115 hours. These events are referred to as extended or long duration and appear to replenish their energetic electron content, possibly from electrons escaping from the corresponding coronal

  19. EVALUATION OF THE PILLS IV

    EPA Science Inventory

    The report gives results of theoretical and experimental investigations of the operating characteristics of the PILLS IV (Particulate Instrumentation by Laser Light Scattering) in situ particle sizing instrument. Results of both investigations show large errors in sizing particle...

  20. AN EXPERIMENT IN BASIC AIRBORNE ELECTRONICS TRAINING, PART IV-- EFFECT OF REDUCTION IN TRAINING TIME ON FLEET PERFORMANCE. FINAL REPORT.

    ERIC Educational Resources Information Center

    BALDWIN, ROBERT O.; AND OTHERS

    THREE PRECEDING REPORTS PRESENTED THE EFFECTS OF SHORTENING TRAINING TIME IN AVIONICS FUNDAMENTALS AND AVIATION ELECTRONICS TECHNICIAN (RADAR) TRAINING UPON THE FINAL COMPREHENSIVE EXAMINATION IN THESE COURSES AND UPON PERFORMANCE IN A SUBSEQUENT EQUIPMENT COURSE. THIS REPORT COMPARES THE ON THE JOB PERFORMANCE OF GRADUATES FROM FOUR GROUPS…

  1. TRANSIT TIMING OBSERVATIONS FROM KEPLER. IV. CONFIRMATION OF FOUR MULTIPLE-PLANET SYSTEMS BY SIMPLE PHYSICAL MODELS

    SciTech Connect

    Fabrycky, Daniel C.; Ford, Eric B.; Moorhead, Althea V.; Steffen, Jason H.; Rowe, Jason F.; Christiansen, Jessie L.; Carter, Joshua A.; Fressin, Francois; Geary, John; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Haas, Michael R.; Buchhave, Lars A.; Ciardi, David R.; Fanelli, Michael N.; Hall, Jennifer R. [Orbital Sciences Corporation and others

    2012-05-10

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present four sets of light curves from the Kepler spacecraft, each which of shows multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates that the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets' masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems' architectures, even in cases for which high-precision Doppler follow-up is impractical.

  2. Resolution of Large Azygos Vein Aneurysm Following Stent-Graft Shunt Placement in a Patient with Ehlers-Danlos Syndrome Type IV

    SciTech Connect

    D'Souza, Estelle S.; Williams, David M.; Deeb, G.M.; Cwikiel, Wojciech

    2006-10-15

    Ehlers-Danlos syndrome (EDS) type IV is a rare connective tissue disorder associated with thin-walled, friable arteries and veins predisposing patients to aneurysm formation, dissection, fistula formation, and vessel rupture. Azygos vein aneurysm is an extremely rare condition which has not been reported in association with EDS in the literature. We present a patient with EDS type IV and interrupted inferior vena cava (IVC) with azygos continuation who developed an azygos vein aneurysm. In order to decrease flow through the azygos vein and reduce the risk of aneurysm rupture, a stent-graft shunt was created from the right hepatic vein to the azygos vein via a transhepatic, retroperitoneal route. At 6 month follow-up the shunt was open and the azygos vein aneurysm had resolved.

  3. Axially symmetric two-body problem in general relativity. IV. Boundary conditions, time scales, and the quadrupole formula

    SciTech Connect

    Cooperstock, F.I.

    1982-06-15

    The analysis of the field equations and the conservation laws is extended into the skin boundary region which maintains the initially static configuration of the two fluid spheres. Although this leads to a correction of the gravitational-radiation energy-loss rate from a dependence of Eapprox...cap alpha../sup -4/rho/sub 0/ /sup -4/ to ..cap alpha../sup -6/rho/sub 0/ /sup -2/, the importance of the nonlinear structure-dependent terms remain and the essential conclusion, that the quadrupole formula does not apply to this problem, is unaltered. The hydrodynamic, stress-breaking, and free-fall time scales are considered. It is shown that insofar as the quadrupole-formula comparison for free-fall is concerned, only the contribution from bulk motion of the fluid spheres need be considered since tidal quadrupole deformation contributes negligibly to the quadrupole formula. With reference to our problem, it is shown that a recent derivation of the quadrupole formula for free-fall is incorrect and it is suggested that certain other derivations may be applicable only to the radiation damping of a single body.

  4. Photocytotoxicity and DNA cleavage activity of L-arg and L-lys Schiff base oxovanadium(IV) complexes having phenanthroline bases.

    PubMed

    Sasmal, Pijus K; Majumdar, Ritankar; Dighe, Rajan R; Chakravarty, Akhil R

    2010-08-14

    Oxovanadium(IV) complexes [VO(sal-argH)(B)]Cl (1-3) and [VO(sal-lysH)(B)]Cl (4-6), where sal-argH2 and sal-lysH2 are N-salicylidene-L-arginine and N-salicylidene-L-lysine Schiff bases and B is a phenanthroline base, viz. 1,10-phenanthroline (phen in 1 and 4); dipyrido[3,2-d:2',3'-f]quinoxaline (dpq in 2 and 5) and dipyrido[3,2-a:2',3'-c]phenazine (dppz in 3 and 6), have been prepared, characterized and their DNA photocleavage activity studied. Complex 1, characterized by X-ray crystallography, shows the presence of a vanadyl group in V(IV)O3N3 coordination geometry with a tridentate Schiff base having a pendant guanidinium moiety and bidentate phen ligand. The complexes exhibit a d-d band at 715 nm in 20% DMF-Tris-HCl buffer. The complexes are redox active showing cathodic and anodic responses near -1.0 V and 0.85 V (vs. SCE) for the V(IV)-V(III) and V(V)-V(IV) couples, respectively, in DMF-Tris-HCl buffer. The complexes bind to calf thymus DNA giving Kb values in the range of 3.8 x 10(4) to 1.6 x 10(5) M(-1). Thermal denaturation and viscosity data suggest DNA groove binding nature of the complexes. The complexes do not show any "chemical nuclease" activity in dark in the presence of 3-mercaptopropionic acid or H2O2. The dpq and dppz complexes are efficient photocleavers of plasmid DNA in UV-A (365 nm) and red light (676 nm) via singlet oxygen pathway. The dppz complexes exhibit photocytotoxicity in HeLa cancer cells giving IC50 values of 15.4 microM for 3 and 17.5 microM for 6 in visible light while being non-toxic in dark giving IC50 values of >100 microM. PMID:20563340

  5. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    NASA Astrophysics Data System (ADS)

    Milnes, J. S.; Horsfield, C. J.; Conneely, T. M.; Howorth, J.

    2014-11-01

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  6. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    SciTech Connect

    Milnes, J. S. Conneely, T. M.; Howorth, J.; Horsfield, C. J.

    2014-11-15

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  7. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics.

    PubMed

    Milnes, J S; Horsfield, C J; Conneely, T M; Howorth, J

    2014-11-01

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year. PMID:25430347

  8. Exploration of PBPK Model-Calculation of Drug Time Course in Tissue Using IV Bolus Drug Plasma Concentration-Time Profile and the Physiological Parameters of the Organ.

    PubMed

    Berezhkovskiy, Leonid M

    2016-08-01

    An uncommon innovative consideration of the well-stirred linear physiologically based pharmacokinetic model and the drug plasma concentration-time profile, which is measured in routine intravenous bolus pharmacokinetic study, was applied for the calculation of the drug time course in human tissues. This cannot be obtained in the in vivo pharmacokinetic study. The physiological parameters of the organ such as organ tissue volume, organ blood flow rate, and its vascular volume were used in the calculation. The considered method was applied to calculate the time course of midazolam, alprazolam, quinidine, and diclofenac in human organs or tissues. The suggested method might be applied for the prediction of drug concentration-time profile in tissues and consequently the drug concentration level in the targeted tissue, as well as the possible undesirable toxic levels in other tissues. PMID:27290628

  9. Large-time behavior for the Vlasov/compressible Navier-Stokes equations

    NASA Astrophysics Data System (ADS)

    Choi, Young-Pil

    2016-07-01

    We establish the large-time behavior for the coupled kinetic-fluid equations. More precisely, we consider the Vlasov equation coupled to the compressible isentropic Navier-Stokes equations through a drag forcing term. For this system, the large-time behavior shows the exponential alignment between particles and fluid velocities as time evolves. This improves the previous result by Bae et al. [Discrete Contin. Dyn. Syst. 34, 4419-4458 (2014)] in which they considered the Vlasov/Navier-Stokes equations with nonlocal velocity alignment forces for particles. Employing a new Lyapunov functional measuring the fluctuations of momentum and mass from the averaged quantities, we refine assumptions for the large-time behavior of the solutions to that system.

  10. Large time behavior of the isentropic compressible Navier-Stokes-Maxwell system

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Li, Fucai; Zhang, Zhipeng

    2016-08-01

    In this paper, we study the large time behavior of the isentropic compressible Navier-Stokes-Maxwell system introduced by Jiang and Li (Nonlinearity 25(6):1735-1752, 2012) in the whole space {{{R}}^3} when the initial data are a small perturbation of some given constant state. We obtain the desired result through taking the refined analysis on the time decay property and Green's function of the linearized system. Moreover, we also obtain the optimal time rate of the solution.

  11. Large-alphabet time-frequency entangled quantum key distribution by means of time-to-frequency conversion

    NASA Astrophysics Data System (ADS)

    Nunn, J.; Wright, L. J.; Söller, C.; Zhang, L.; Walmsley, I. A.; Smith, B. J.

    2013-07-01

    We introduce a novel time-frequency quantum key distribution (TFQKD) scheme based on photon pairs entangled in these two conjugate degrees of freedom. The scheme uses spectral detection and phase modulation to enable measurements in the temporal basis by means of time-to-frequency conversion. This allows large-alphabet encoding to be implemented with realistic components. A general security analysis for TFQKD with binned measurements reveals a close connection with finite-dimensional QKD protocols and enables analysis of the effects of dark counts on the secure key size.

  12. Large lateral photovoltaic effect with ultrafast relaxation time in SnSe/Si junction

    NASA Astrophysics Data System (ADS)

    Wang, Xianjie; Zhao, Xiaofeng; Hu, Chang; Zhang, Yang; Song, Bingqian; Zhang, Lingli; Liu, Weilong; Lv, Zhe; Zhang, Yu; Tang, Jinke; Sui, Yu; Song, Bo

    2016-07-01

    In this paper, we report a large lateral photovoltaic effect (LPE) with ultrafast relaxation time in SnSe/p-Si junctions. The LPE shows a linear dependence on the position of the laser spot, and the position sensitivity is as high as 250 mV mm-1. The optical response time and the relaxation time of the LPE are about 100 ns and 2 μs, respectively. The current-voltage curve on the surface of the SnSe film indicates the formation of an inversion layer at the SnSe/p-Si interface. Our results clearly suggest that most of the excited-electrons diffuse laterally in the inversion layer at the SnSe/p-Si interface, which results in a large LPE with ultrafast relaxation time. The high positional sensitivity and ultrafast relaxation time of the LPE make the SnSe/p-Si junction a promising candidate for a wide range of optoelectronic applications.

  13. Non-Linear Dynamics and Stability of Circular Cylindrical Shells Containing Flowing Fluid. Part Iv: Large-Amplitude Vibrations with Flow

    NASA Astrophysics Data System (ADS)

    AMABILI, M.; PELLICANO, F.; PAÏDOUSSIS, M. P.

    2000-11-01

    The response of a shell conveying fluid to harmonic excitation, in the spectral neighbourhood of one of the lowest natural frequencies, is investigated for different flow velocities. The theoretical model has already been presented in Part I of the present study. Non-linearities due to moderately large-amplitude shell motion are considered by using Donnell's non-linear shallow-shell theory. Linear potential flow theory is applied to describe the fluid-structure interaction by using the model proposed by Paı̈doussis and Denise. For different amplitudes and frequencies of the excitation and for different flow velocities, the following are investigated numerically: (1) periodic response of the system; (2) unsteady and stochastic motion; (3) loss of stability by jumps to bifurcated branches. The effect of the flow velocity on the non-linear periodic response of the system has also been investigated. Poincaré maps and bifurcation diagrams are used to study the unsteady and stochastic dynamics of the system. Amplitude modulated motions, multi-periodic solutions, chaotic responses, cascades of bifurcations as the route to chaos and the so-called “blue sky catastrophe” phenomenon have all been observed for different values of the system parameters; the latter two have been predicted here probably for the first time for the dynamics of circular cylindrical shells.

  14. Effects of Eddy Viscosity on Time Correlations in Large Eddy Simulation

    NASA Technical Reports Server (NTRS)

    He, Guowei; Rubinstein, R.; Wang, Lian-Ping; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    Subgrid-scale (SGS) models for large. eddy simulation (LES) have generally been evaluated by their ability to predict single-time statistics of turbulent flows such as kinetic energy and Reynolds stresses. Recent application- of large eddy simulation to the evaluation of sound sources in turbulent flows, a problem in which time, correlations determine the frequency distribution of acoustic radiation, suggest that subgrid models should also be evaluated by their ability to predict time correlations in turbulent flows. This paper compares the two-point, two-time Eulerian velocity correlation evaluated from direct numerical simulation (DNS) with that evaluated from LES, using a spectral eddy viscosity, for isotropic homogeneous turbulence. It is found that the LES fields are too coherent, in the sense that their time correlations decay more slowly than the corresponding time. correlations in the DNS fields. This observation is confirmed by theoretical estimates of time correlations using the Taylor expansion technique. Tile reason for the slower decay is that the eddy viscosity does not include the random backscatter, which decorrelates fluid motion at large scales. An effective eddy viscosity associated with time correlations is formulated, to which the eddy viscosity associated with energy transfer is a leading order approximation.

  15. ECLIPSE TIMINGS OF THE TRANSIENT LOW-MASS X-RAY BINARY EXO 0748-676. IV. THE ROSSI X-RAY TIMING EXPLORER ECLIPSES

    SciTech Connect

    Wolff, Michael T.; Ray, Paul S.; Wood, Kent S.; Hertz, Paul L. E-mail: Paul.Ray@nrl.navy.mil E-mail: Paul.Hertz@nasa.gov

    2009-07-01

    We report our complete database of X-ray eclipse timings of the low-mass X-ray binary EXO 0748-676 observed by the Rossi X-Ray Timing Explorer (RXTE) satellite. As of this writing we have accumulated 443 full X-ray eclipses, 392 of which have been observed with the Proportional Counter Array on RXTE. These include both observations where an eclipse was specifically targeted and those eclipses found in the RXTE data archive. Eclipse cycle count has been maintained since the discovery of the EXO 0748-676 system in 1985 February. We describe our observing and analysis techniques for each eclipse and describe improvements we have made since the last compilation by Wolff et al. The principal result of this paper is the database containing the timing results from a seven-parameter fit to the X-ray light curve for each observed eclipse along with the associated errors in the fitted parameters. Based on the standard O - C analysis, EXO 0748-676 has undergone four distinct orbital period epochs since its discovery. In addition, EXO 0748-676 shows small-scale events in the O - C curve that are likely due to short-lived changes in the secondary star.

  16. A robust and high-performance queue management controller for large round trip time networks

    NASA Astrophysics Data System (ADS)

    Khoshnevisan, Ladan; Salmasi, Farzad R.

    2016-05-01

    Congestion management for transmission control protocol is of utmost importance to prevent packet loss within a network. This necessitates strategies for active queue management. The most applied active queue management strategies have their inherent disadvantages which lead to suboptimal performance and even instability in the case of large round trip time and/or external disturbance. This paper presents an internal model control robust queue management scheme with two degrees of freedom in order to restrict the undesired effects of large and small round trip time and parameter variations in the queue management. Conventional approaches such as proportional integral and random early detection procedures lead to unstable behaviour due to large delay. Moreover, internal model control-Smith scheme suffers from large oscillations due to the large round trip time. On the other hand, other schemes such as internal model control-proportional integral and derivative show excessive sluggish performance for small round trip time values. To overcome these shortcomings, we introduce a system entailing two individual controllers for queue management and disturbance rejection, simultaneously. Simulation results based on Matlab/Simulink and also Network Simulator 2 (NS2) demonstrate the effectiveness of the procedure and verify the analytical approach.

  17. The Space-Time Conservative Schemes for Large-Scale, Time-Accurate Flow Simulations with Tetrahedral Meshes

    NASA Technical Reports Server (NTRS)

    Venkatachari, Balaji Shankar; Streett, Craig L.; Chang, Chau-Lyan; Friedlander, David J.; Wang, Xiao-Yen; Chang, Sin-Chung

    2016-01-01

    Despite decades of development of unstructured mesh methods, high-fidelity time-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-time 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-time conservation element solution element (CESE) numerical and software framework under the Revolutionary Computational Aerosciences (RCA) project. Solution accuracy and large-scale parallel performance of the numerical framework is assessed with the goal of providing a viable paradigm for future high-fidelity flow physics simulations.

  18. Large volume recycling of oceanic lithosphere over short time scales: geochemical constraints from the Caribbean Large Igneous Province

    NASA Astrophysics Data System (ADS)

    Hauff, F.; Hoernle, K.; Tilton, G.; Graham, D. W.; Kerr, A. C.

    2000-01-01

    Oceanic flood basalts are poorly understood, short-term expressions of highly increased heat flux and mass flow within the convecting mantle. The uniqueness of the Caribbean Large Igneous Province (CLIP, 92-74 Ma) with respect to other Cretaceous oceanic plateaus is its extensive sub-aerial exposures, providing an excellent basis to investigate the temporal and compositional relationships within a starting plume head. We present major element, trace element and initial Sr-Nd-Pb isotope composition of 40 extrusive rocks from the Caribbean Plateau, including onland sections in Costa Rica, Colombia and Curaçao as well as DSDP Sites in the Central Caribbean. Even though the lavas were erupted over an area of ˜3×10 6 km 2, the majority have strikingly uniform incompatible element patterns (La/Yb=0.96±0.16, n=64 out of 79 samples, 2σ) and initial Nd-Pb isotopic compositions (e.g. 143Nd/ 144Nd in=0.51291±3, ɛNdi=7.3±0.6, 206Pb/ 204Pb in=18.86±0.12, n=54 out of 66, 2σ). Lavas with endmember compositions have only been sampled at the DSDP Sites, Gorgona Island (Colombia) and the 65-60 Ma accreted Quepos and Osa igneous complexes (Costa Rica) of the subsequent hotspot track. Despite the relatively uniform composition of most lavas, linear correlations exist between isotope ratios and between isotope and highly incompatible trace element ratios. The Sr-Nd-Pb isotope and trace element signatures of the chemically enriched lavas are compatible with derivation from recycled oceanic crust, while the depleted lavas are derived from a highly residual source. This source could represent either oceanic lithospheric mantle left after ocean crust formation or gabbros with interlayered ultramafic cumulates of the lower oceanic crust. High 3He/ 4He in olivines of enriched picrites at Quepos are ˜12 times higher than the atmospheric ratio suggesting that the enriched component may have once resided in the lower mantle. Evaluation of the Sm-Nd and U-Pb isotope systematics on

  19. An Efficient Format for Nearly Constant-Time Access to Arbitrary Time Intervals in Large Trace Files

    DOE PAGESBeta

    Chan, Anthony; Gropp, William; Lusk, Ewing

    2008-01-01

    A powerful method to aid in understanding the performance of parallel applications uses log or trace files containing time-stamped events and states (pairs of events). These trace files can be very large, often hundreds or even thousands of megabytes. Because of the cost of accessing and displaying such files, other methods are often used that reduce the size of the tracefiles at the cost of sacrificing detail or other information. This paper describes a hierarchical trace file format that provides for display of an arbitrary time window in a time independent of the total size of the file andmore » roughly proportional to the number of events within the time window. This format eliminates the need to sacrifice data to achieve a smaller trace file size (since storage is inexpensive, it is necessary only to make efficient use of bandwidth to that storage). The format can be used to organize a trace file or to create a separate file of annotations that may be used with conventional trace files. We present an analysis of the time to access all of the events relevant to an interval of time and we describe experiments demonstrating the performance of this file format.« less

  20. A Stochastic, Resonance-Free Multiple Time-Step Algorithm for Polarizable Models That Permits Very Large Time Steps.

    PubMed

    Margul, Daniel T; Tuckerman, Mark E

    2016-05-10

    the polarizable AMOEBA water model. As was seen with fixed-charge models, we are able to obtain large time steps exceeding 100 fs, allowing calculations to be performed 10 to 20 times faster than standard thermostated molecular dynamics. PMID:27054809

  1. Asymptotic behavior of dispersive waves in a spiral structure at large times

    NASA Astrophysics Data System (ADS)

    Kiselev, V. V.

    2016-04-01

    In the framework of the sine-Gordon integrable model for spiral magnetic structures, we investigate the behavior at large times of a weakly nonlinear dispersive wave field generated by a spatially local initial excitation of the structure. The method used is based on a direct asymptotic analysis of the corresponding matrix of the Riemann problem on the torus.

  2. Managing the Editing Function on Large Publication Tasks with Short Flow Times.

    ERIC Educational Resources Information Center

    Santa, Terry M. Dalla

    Large publication tasks with short flow times require that several editors be assigned to work together as part of a larger publication team that includes management, engineer-writers, publishing logistics personnel, word processor operators, illustrators, and printers. Team-edited publications have special problems, and the technical editing and…

  3. Efficiency and large deviations in time-asymmetric stochastic heat engines

    SciTech Connect

    Gingrich, Todd R.; Rotskoff, Grant M.; Vaikuntanathan, Suriyanarayanan; Geissler, Phillip L.

    2014-10-24

    In a stochastic heat engine driven by a cyclic non-equilibrium protocol, fluctuations in work and heat give rise to a fluctuating efficiency. Using computer simulations and tools from large deviation theory, we have examined these fluctuations in detail for a model two-state engine. We find in general that the form of efficiency probability distributions is similar to those described by Verley et al (2014 Nat. Commun. 5 4721), in particular featuring a local minimum in the long-time limit. In contrast to the time-symmetric engine protocols studied previously, however, this minimum need not occur at the value characteristic of a reversible Carnot engine. Furthermore, while the local minimum may reside at the global minimum of a large deviation rate function, it does not generally correspond to the least likely efficiency measured over finite time. Lastly, we introduce a general approximation for the finite-time efficiency distribution, $P(\\eta )$, based on large deviation statistics of work and heat, that remains very accurate even when $P(\\eta )$ deviates significantly from its large deviation form.

  4. Numerical Estimation of the Lyapunov Exponents of Chaotic Time Series Corrupted by Noises of Large Amplitude

    NASA Astrophysics Data System (ADS)

    Mera, M. Eugenia; Morán, Manuel

    2009-09-01

    We show that the Lyapunov spectrum of chaotic vector time series corrupted by noises with a noise-to-signal ratio of up to 100% in one of the coordinates can be estimated using the output of a noise reduction algorithm designed to deal with noises of large amplitude.

  5. Efficiency and large deviations in time-asymmetric stochastic heat engines

    DOE PAGESBeta

    Gingrich, Todd R.; Rotskoff, Grant M.; Vaikuntanathan, Suriyanarayanan; Geissler, Phillip L.

    2014-10-24

    In a stochastic heat engine driven by a cyclic non-equilibrium protocol, fluctuations in work and heat give rise to a fluctuating efficiency. Using computer simulations and tools from large deviation theory, we have examined these fluctuations in detail for a model two-state engine. We find in general that the form of efficiency probability distributions is similar to those described by Verley et al (2014 Nat. Commun. 5 4721), in particular featuring a local minimum in the long-time limit. In contrast to the time-symmetric engine protocols studied previously, however, this minimum need not occur at the value characteristic of a reversible Carnot engine. Furthermore, while the local minimum may reside at the global minimum of a large deviation rate function, it does not generally correspond to the least likely efficiency measured over finite time. Lastly, we introduce a general approximation for the finite-time efficiency distribution,more » $$P(\\eta )$$, based on large deviation statistics of work and heat, that remains very accurate even when $$P(\\eta )$$ deviates significantly from its large deviation form.« less

  6. A time of day analysis of crashes involving large trucks in urban areas.

    PubMed

    Pahukula, Jasmine; Hernandez, Salvador; Unnikrishnan, Avinash

    2015-02-01

    Previous studies have looked at different factors that contribute to large truck-involved crashes, however a detailed analysis considering the specific effects of time of day is lacking. Using the Crash Records Information System (CRIS) database in Texas, large truck-involved crashes occurring on urban freeways between 2006 and 2010 were separated into five time periods (i.e., early morning, morning, mid-day, afternoon and evening). A series of log likelihood ratio tests were conducted to validate that five separate random parameters logit models by time of day were warranted. The outcomes of each time of day model show major differences in both the combination of variables included in each model and the magnitude of impact of those variables. These differences show that the different time periods do in fact have different contributing factors to each injury severity further highlighting the importance of examining crashes based on time of day. Traffic flow, light conditions, surface conditions, time of year and percentage of trucks on the road were found as key differences between the time periods. PMID:25481540

  7. Precursory measure of interoccurrence time associated with large earthquakes in the Burridge-Knopoff model

    SciTech Connect

    Hasumi, Tomohiro

    2008-11-13

    We studied the statistical properties of interoccurrence time i.e., time intervals between successive earthquakes in the two-dimensional (2D) Burridge-Knopoff (BK) model, and have found that these statistics can be classified into three types: the subcritical state, the critical state, and the supercritical state. The survivor function of interoccurrence time is well fitted by the Zipf-Mandelbrot type power law in the subcritical regime. However, the fitting accuracy of this distribution tends to be worse as the system changes from the subcritical state to the supercritical state. Because the critical phase of a fault system in nature changes from the subcritical state to the supercritical state prior to a forthcoming large earthquake, we suggest that the fitting accuracy of the survivor distribution can be another precursory measure associated with large earthquakes.

  8. Design verification of large time constant thermal shields for optical reference cavities.

    PubMed

    Zhang, J; Wu, W; Shi, X H; Zeng, X Y; Deng, K; Lu, Z H

    2016-02-01

    In order to achieve high frequency stability in ultra-stable lasers, the Fabry-Pérot reference cavities shall be put inside vacuum chambers with large thermal time constants to reduce the sensitivity to external temperature fluctuations. Currently, the determination of thermal time constants of vacuum chambers is based either on theoretical calculation or time-consuming experiments. The first method can only apply to simple system, while the second method will take a lot of time to try out different designs. To overcome these limitations, we present thermal time constant simulation using finite element analysis (FEA) based on complete vacuum chamber models and verify the results with measured time constants. We measure the thermal time constants using ultrastable laser systems and a frequency comb. The thermal expansion coefficients of optical reference cavities are precisely measured to reduce the measurement error of time constants. The simulation results and the experimental results agree very well. With this knowledge, we simulate several simplified design models using FEA to obtain larger vacuum thermal time constants at room temperature, taking into account vacuum pressure, shielding layers, and support structure. We adopt the Taguchi method for shielding layer optimization and demonstrate that layer material and layer number dominate the contributions to the thermal time constant, compared with layer thickness and layer spacing. PMID:26931831

  9. Probabilistic model of waiting times between large failures in sheared media

    NASA Astrophysics Data System (ADS)

    Brinkman, Braden A. W.; LeBlanc, Michael P.; Uhl, Jonathan T.; Ben-Zion, Yehuda; Dahmen, Karin A.

    2016-01-01

    Using a probabilistic approximation of a mean-field mechanistic model of sheared systems, we analytically calculate the statistical properties of large failures under slow shear loading. For general shear F (t ) , the distribution of waiting times between large system-spanning failures is a generalized exponential distribution, ρT(t ) =λ ( F (t ) ) P ( F (t ) ) exp[-∫0td τ λ ( F (τ ) ) P ( F (τ ) ) ] , where λ ( F (t )) is the rate of small event occurrences at stress F (t ) and P ( F (t )) is the probability that a small event triggers a large failure. We study the behavior of this distribution as a function of fault properties, such as heterogeneity or shear rate. Because the probabilistic model accommodates any stress loading F (t ) , it is particularly useful for modeling experiments designed to understand how different forms of shear loading or stress perturbations impact the waiting-time statistics of large failures. As examples, we study how periodic perturbations or fluctuations on top of a linear shear stress increase impact the waiting-time distribution.

  10. Large-scale study of the interactions between proteins involved in type IV pilus biology in Neisseria meningitidis: characterization of a subcomplex involved in pilus assembly.

    PubMed

    Georgiadou, Michaella; Castagnini, Marta; Karimova, Gouzel; Ladant, Daniel; Pelicic, Vladimir

    2012-06-01

    The functionally versatile type IV pili (Tfp) are one of the most widespread virulence factors in bacteria. However, despite generating much research interest for decades, the molecular mechanisms underpinning the various aspects of Tfp biology remain poorly understood, mainly because of the complexity of the system. In the human pathogen Neisseria meningitidis for example, 23 proteins are dedicated to Tfp biology, 15 of which are essential for pilus biogenesis. One of the important gaps in our knowledge concerns the topology of this multiprotein machinery. Here we have used a bacterial two-hybrid system to identify and quantify the interactions between 11 Pil proteins from N. meningitidis. We identified 20 different binary interactions, many of which are novel. This represents the most complex interaction network between Pil proteins reported to date and indicates, among other things, that PilE, PilM, PilN and PilO, which are involved in pilus assembly, indeed interact. We focused our efforts on this subset of proteins and used a battery of assays to determine the membrane topology of PilN and PilO, map the interaction domains between PilE, PilM, PilN and PilO, and show that a widely conserved N-terminal motif in PilN is essential for both PilM-PilN interactions and pilus assembly. Finally, we show that PilP (another protein involved in pilus assembly) forms a complex with PilM, PilN and PilO. Taken together, these findings have numerous implications for understanding Tfp biology and provide a useful blueprint for future studies. PMID:22486968

  11. The large discretization step method for time-dependent partial differential equations

    NASA Technical Reports Server (NTRS)

    Haras, Zigo; Taasan, Shlomo

    1995-01-01

    A new method for the acceleration of linear and nonlinear time dependent calculations is presented. It is based on the Large Discretization Step (LDS) approximation, defined in this work, which employs an extended system of low accuracy schemes to approximate a high accuracy discrete approximation to a time dependent differential operator. Error bounds on such approximations are derived. These approximations are efficiently implemented in the LDS methods for linear and nonlinear hyperbolic equations, presented here. In these algorithms the high and low accuracy schemes are interpreted as the same discretization of a time dependent operator on fine and coarse grids, respectively. Thus, a system of correction terms and corresponding equations are derived and solved on the coarse grid to yield the fine grid accuracy. These terms are initialized by visiting the fine grid once in many coarse grid time steps. The resulting methods are very general, simple to implement and may be used to accelerate many existing time marching schemes.

  12. TIME DISTRIBUTIONS OF LARGE AND SMALL SUNSPOT GROUPS OVER FOUR SOLAR CYCLES

    SciTech Connect

    Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Cao, W.; Ozguc, A.; Rozelot, J. P.

    2011-04-10

    Here we analyze solar activity by focusing on time variations of the number of sunspot groups (SGs) as a function of their modified Zurich class. We analyzed data for solar cycles 20-23 by using Rome (cycles 20 and 21) and Learmonth Solar Observatory (cycles 22 and 23) SG numbers. All SGs recorded during these time intervals were separated into two groups. The first group includes small SGs (A, B, C, H, and J classes by Zurich classification), and the second group consists of large SGs (D, E, F, and G classes). We then calculated small and large SG numbers from their daily mean numbers as observed on the solar disk during a given month. We report that the time variations of small and large SG numbers are asymmetric except for solar cycle 22. In general, large SG numbers appear to reach their maximum in the middle of the solar cycle (phases 0.45-0.5), while the international sunspot numbers and the small SG numbers generally peak much earlier (solar cycle phases 0.29-0.35). Moreover, the 10.7 cm solar radio flux, the facular area, and the maximum coronal mass ejection speed show better agreement with the large SG numbers than they do with the small SG numbers. Our results suggest that the large SG numbers are more likely to shed light on solar activity and its geophysical implications. Our findings may also influence our understanding of long-term variations of the total solar irradiance, which is thought to be an important factor in the Sun-Earth climate relationship.

  13. Subsurface Supergranular Vertical Flows as Measured Using Large Distance Separations in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L., Jr.; Hanasoge, S. M.

    2012-01-01

    As large-distance rays (say, 10 - 24deg) approach the solar surface approximately vertically, travel times measured from surface pairs for these large separations are mostly sensitive to vertical flows, at least for shallow flows within a few Mm of the solar surface. All previous analyses of supergranulation have used smaller separations and have been hampered by the difficulty of separating the horizontal and vertical flow components. We find that the large-separation travel times associated with supergranulation cannot be studied using the standard phase-speed filters of time-distance helioseismology. These filters, whose use is based upon a refractive model of the perturbations, reduce the resultant travel time signal by at least an order of magnitude at some distances. More effective filters are derived. Modeling suggests that the center-annulus travel-time difference [outward-going time minus inward-going time] in the separation range delta= 10 - 24deg is insensitive to the horizontally diverging flow from the centers of the supergranules and should lead to a constant signal from the vertical flow. Our measurement of this quantity, 5.1+/-0.1 seconds, is constant over the distance range. This magnitude of the signal cannot be caused by the level of upflow at cell centers seen at the photosphere of 10 ms(exp-1) extended in depth. It requires the vertical flow to increase with depth. A simple Gaussian model of the increase with depth implies a peak upward flow of 240 ms(exp-1) at a depth of 2.3 Mm and a peak horizontal flow of 700 ms(exp-1) at a depth of 1.6 Mm.

  14. Bifurcation analysis on a turning system with large and state-dependent time delay

    NASA Astrophysics Data System (ADS)

    Kim, Pilkee; Bae, Sanghyun; Seok, Jongwon

    2012-12-01

    Stability and bifurcation analyses were performed in this study on the turning process with a state-dependent and large time delay using the method of multiple scales (MMS). The turning system tool was modeled as an oscillator with two degrees of freedom, and both the cubic nonlinear stiffness and the nonlinear cutting force were considered. The nonlinear cutting force was appropriately expanded in a Taylor series considering the state-dependency of the time delay. The time delay and parameters were scaled through the proper ordering process to reflect the large delay effect on an asymptotic formulation of the MMS. Asymptotic solutions were then obtained by the MMS in the large delay regime and used to calculate the linear stability boundaries (i.e., Hopf bifurcation points) and coexisting one-period periodic solutions (i.e., limit cycles) of the turning system. To investigate the local and global behaviors of the tool chatter, bifurcation diagrams were obtained at various workpiece rotating speeds. The validity of the results was examined by comparison with those obtained through the method of harmonic balance and direct numerical integration. Additionally, using the bifurcation diagrams, the effects of the state-dependent time delay and nonlinear stiffness on the chatter vibration behaviors were examined.

  15. Large-Strain Time-Temperature Equivalence and Adiabatic Heating of Polyethylene

    SciTech Connect

    Furmanski, Jevan; Brown, Eric; Cady, Carl M.

    2012-06-06

    Time-temperature equivalence is a well-known phenomenon in time-dependent material response, where rapid events at a moderate temperature are indistinguishable from some occurring at modest rates but elevated temperatures. However, there is as-yet little elucidation of how well this equivalence holds for substantial plastic strains. In this work, we demonstrate time-temperature equivalence over a large range in a previously studied high-density polyethylene formulation (HDPE). At strain-rates exceeding 0.1/s, adiabatic heating confounds the comparison of nominally isothermal material response, apparently violating time-temperature equivalence. Strain-rate jumps can be employed to access the instantaneous true strain rate without heating. Adiabatic heating effects were isolated by comparing a locus of isothermal instantaneous flow stress measurements from strain-rate jumps up to 1/s with the predicted equivalent states at 0.01/s and 0.001/s in compression. Excellent agreement between the isothermal jump condition locus and the quasi-static tests was observed up to 50% strain, yielding one effective isothermal plastic response for each material for a given time-temperature equivalent state. These results imply that time-temperature equivalence can be effectively used to predict the deformation response of polymers during extreme mechanical events (large strain and high strain-rate) from measurements taken at reduced temperatures and nominal strain-rates in the laboratory.

  16. Observation of quantum particles on a large space-time scale

    NASA Astrophysics Data System (ADS)

    Landau, L. J.

    1994-10-01

    A quantum particle observed on a sufficiently large space-time scale can be described by means of classical particle trajectories. The joint distribution for large-scale multiple-time position and momentum measurements on a nonrelativistic quantum particle moving freely in R v is given by straight-line trajectories with probabilities determined by the initial momentum-space wavefunction. For large-scale toroidal and rectangular regions the trajectories are geodesics. In a uniform gravitational field the trajectories are parabolas. A quantum counting process on free particles is also considered and shown to converge in the large-space-time limit to a classical counting process for particles with straight-line trajectories. If the quantum particle interacts weakly with its environment, the classical particle trajectories may undergo random jumps. In the random potential model considered here, the quantum particle evolves according to a reversible unitary one-parameter group describing elastic scattering off static randomly distributed impurities (a quantum Lorentz gas). In the large-space-time weak-coupling limit a classical stochastic process is obtained with probability one and describes a classical particle moving with constant speed in straight lines between random jumps in direction. The process depends only on the ensemble value of the covariance of the random field and not on the sample field. The probability density in phase space associated with the classical stochastic process satisfies the linear Boltzmann equation for the classical Lorentz gas, which, in the limit h→0, goes over to the linear Landau equation. Our study of the quantum Lorentz gas is based on a perturbative expansion and, as in other studies of this system, the series can be controlled only for small values of the rescaled time and for Gaussian random fields. The discussion of classical particle trajectories for nonrelativistic particles on a macroscopic spacetime scale applies also to

  17. Asymptotic behavior of solutions of the Korteweg-de Vries equation for large times

    SciTech Connect

    Buslaev, V.S.; Sukhanov, V.V.

    1986-09-10

    For the KdV equation a complete asymptotic expansion of the dispersive tail for large times is described, and generalized wave operators are introduced. The asymptotics for large times of the spectral Schroedinger equation with a potential of the type of a solution of the KdV equation is studied. It is shown that the KdV equation is connected in a specific manner with the structure of the asymptotics of solutions of the spectral equation. As a corollary, known explicit formulas for the leading terms of the asymptotics of solutions of the KdV equation in terms of spectral data corresponding to the initial conditions are obtained. A plan for justifying the results listed is outlined.

  18. Tail probabilities of extinction time in a large number of experimental populations.

    PubMed

    Drake, John M

    2014-05-01

    Determining the distribution of population extinction times is a fundamental problem in theoretical population biology. In particular, the tail properties, patterns in the probability of long-term persistence, have not been studied. Further, until now there have been no experimental or observational data sets with which to empirically test the "rare event" predictions of the standard stochastic theory of extinction, which holds that extinction times should be exponentially distributed. I performed an experimental study of extinction in a large number of replicate (n = 1076) laboratory populations of the waterflea Daphnia pulicaria. Observed extinction time ranged from 1 to 1239 days. Statistical models supported the hypothesis of a power-law distribution over the exponential distribution and other alternatives. This pattern contradicts the notion that population extinction time has an exponential tail, questioning its ubiquitous use in theoretical ecology. It is also a rare instance of a data set that exhibits power-law scaling under appropriate statistical criteria. PMID:25000743

  19. Organizing the Extremely Large LSST Database forReal-Time Astronomical Processing

    SciTech Connect

    Becla, Jacek; Lim, Kian-Tat; Monkewitz, Serge; Nieto-Santisteban, Maria; Thakar, Ani; /Johns Hopkins U.

    2007-11-07

    The Large Synoptic Survey Telescope (LSST) will catalog billions of astronomical objects and trillions of sources, all of which will be stored and managed by a database management system. One of the main challenges is real-time alert generation. To generate alerts, up to 100K new difference detections have to be cross-correlated with the huge historical catalogs, and then further processed to prune false alerts. This paper explains the challenges, the implementation of the LSST Association Pipeline and the database organization strategies we are planning to use to meet the real-time requirements, including data partitioning, parallelization, and pre-loading.

  20. Time-sliced perturbation theory for large scale structure I: general formalism

    NASA Astrophysics Data System (ADS)

    Blas, Diego; Garny, Mathias; Ivanov, Mikhail M.; Sibiryakov, Sergey

    2016-07-01

    We present a new analytic approach to describe large scale structure formation in the mildly non-linear regime. The central object of the method is the time-dependent probability distribution function generating correlators of the cosmological observables at a given moment of time. 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 time playing the role of an external parameter. For the physically relevant case of cold dark matter in an Einstein-de Sitter universe, the time evolution of the distribution function can be found exactly and is encapsulated by a time-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 scale structure formation. We also argue that the approach proposed here provides a natural framework to account for the influence of short-scale dynamics on larger scales along the lines of effective field theory.

  1. Fast Estimate of Rupture Process of Large Earthquakes via Real Time Hi-net Data

    NASA Astrophysics Data System (ADS)

    Wang, D.; Kawakatsu, H.; Mori, J. J.

    2014-12-01

    We developed a real time system based on Hi-net seismic array that can offer fast and reliable source information, for example, source extent and rupture velocity, for earthquakes that occur at distance of roughly 30°- 85°with respect to the array center. We perform continuous grid search on a Hi-net real time data stream to identify possible source locations (following Nishida, K., Kawakatsu, H., and S. Obara, 2008). Earthquakes that occurred off the bright area of the array (30°- 85°with respect to the array center) will be ignored. Once a large seismic event is identified successfully, back-projection will be implemented to trace the source propagation and energy radiation. Results from extended global GRiD-MT and real time W phase inversion will be combined for the better identification of large seismic events. The time required is mainly due to the travel time from the epicenter to the array stations, so we can get the results between 6 to 13 min depending on the epicenter distances. This system can offer fast and robust estimates of earthquake source information, which will be useful for disaster mitigation, such as tsunami evacuation, emergency rescue, and aftershock hazard evaluation.

  2. Numerical methods for large-scale, time-dependent partial differential equations

    NASA Technical Reports Server (NTRS)

    Turkel, E.

    1979-01-01

    A survey of numerical methods for time dependent partial differential equations is presented. The emphasis is on practical applications to large scale problems. A discussion of new developments in high order methods and moving grids is given. The importance of boundary conditions is stressed for both internal and external flows. A description of implicit methods is presented including generalizations to multidimensions. Shocks, aerodynamics, meteorology, plasma physics and combustion applications are also briefly described.

  3. Flashover of vacuum interfaces with many stages and large transit times

    SciTech Connect

    Smith, I.D.

    1997-04-01

    Methods are developed to calculate the effective breakdown levels and reliabilities of vacuum interfaces with many stages and (where applicable) large transit times. The method assumes that a breakdown equation like that of Martin describes the flashover of individual stages. The Nike and Saturn tubes are used to illustrate the results. Uncertainties in the single insulator breakdown equation are discussed, as are the implications of experience with Saturn and the two AIRIX injectors.

  4. Integrating real-time digital signal processing capability into a large research and development facility

    NASA Astrophysics Data System (ADS)

    Manges, W. W.; Mallinak-Glassell, J. T.; Breeding, J. E.; Jansen, J. M., Jr.; Tate, R. M.; Bentz, R. R.

    The Instrumentation and Controls Division at Oak Ridge National Laboratory recently developed and installed a large scale, real-time measurement system for the world's largest pressurized water tunnel. This water tunnel, the Large Cavitation Channel (LCC) provides a research and development facility for the study of acoustic phenomena to aid in model testing of new naval ship and submarine designs. The LCC design required the development of a near-field beamformer in addition to extending the range of real-time processing capability to frequencies unavailable at other facilities. The beamformer acquires and processes time-domain acoustic data at 9.5 MB/s from up to 45 hydrophones while performing 200 million floating-point operations per second, producing a time-integrated, spatially filtered, frequency-domain data set with improved signal-to-noise ratio. The acoustic processing software provides for the real-time analysis of acoustic data. Up to 128 facility sensors are sampled, time stamped, and stored at 600 kB/s. The system generates information for acoustic phenomena and facility measurements in real-time so that the operator can make facility adjustments to control the running equipment. This real-time control of facility conditions requires that the measurement system integrate facility and acoustic data for simultaneous display to the operator in engineering units via high-end workstations. A dual-host minicomputer configuration with high-end workstations connected via an Ethernet networking cluster controls and integrates measurement and display subsystems. The hardware and software architecture is described in this paper.

  5. Automatic location of L/H transition times for physical studies with a large statistical basis

    NASA Astrophysics Data System (ADS)

    González, S.; Vega, J.; Murari, A.; Pereira, A.; Dormido-Canto, S.; Ramírez, J. M.; contributors, JET-EFDA

    2012-06-01

    Completely automatic techniques to estimate and validate L/H transition times can be essential in L/H transition analyses. The generation of databases with hundreds of transition times and without human intervention is an important step to accomplish (a) L/H transition physics analysis, (b) validation of L/H theoretical models and (c) creation of L/H scaling laws. An entirely unattended methodology is presented in this paper to build large databases of transition times in JET using time series. The proposed technique has been applied to a dataset of 551 JET discharges between campaigns C21 and C26. A prediction with discharges that show a clear signature in time series is made through the locating properties of the wavelet transform. It is an accurate prediction and the uncertainty interval is ±3.2 ms. The discharges with a non-clear pattern in the time series use an L/H mode classifier based on discharges with a clear signature. In this case, the estimation error shows a distribution with mean and standard deviation of 27.9 ms and 37.62 ms, respectively. Two different regression methods have been applied to the measurements acquired at the transition times identified by the automatic system. The obtained scaling laws for the threshold power are not significantly different from those obtained using the data at the transition times determined manually by the experts. The automatic methods allow performing physical studies with a large number of discharges, showing, for example, that there are statistically different types of transitions characterized by different scaling laws.

  6. Incipient multiple fault diagnosis in real time with applications to large-scale systems

    SciTech Connect

    Chung, H.Y.; Bien, Z.; Park, J.H.; Seon, P.H. . Dept. of Electrical Engineering)

    1994-08-01

    By using a modified signed directed graph (SDG) together with the distributed artificial neutral networks and a knowledge-based system, a method of incipient multi-fault diagnosis is presented for large-scale physical systems with complex pipes and instrumentations such as valves, actuators, sensors, and controllers. The proposed method is designed so as to (1) make a real-time incipient fault diagnosis possible for large-scale systems, (2) perform the fault diagnosis not only in the steady-state case but also in the transient case as well by using a concept of fault propagation time, which is newly adopted in the SDG model, (3) provide with highly reliable diagnosis results and explanation capability of faults diagnosed as in an expert system, and (4) diagnose the pipe damage such as leaking, break, or throttling. This method is applied for diagnosis of a pressurizer in the Kori Nuclear Power Plant (NPP) unit 2 in Korea under a transient condition, and its result is reported to show satisfactory performance of the method for the incipient multi-fault diagnosis of such a large-scale system in a real-time manner.

  7. Real-time visualization of large volume datasets on standard PC hardware.

    PubMed

    Xie, Kai; Yang, Jie; Zhu, Y M

    2008-05-01

    In medical area, interactive three-dimensional volume visualization of large volume datasets is a challenging task. One of the major challenges in graphics processing unit (GPU)-based volume rendering algorithms is the limited size of texture memory imposed by current GPU architecture. We attempt to overcome this limitation by rendering only visible parts of large CT datasets. In this paper, we present an efficient, high-quality volume rendering algorithm using GPUs for rendering large CT datasets at interactive frame rates on standard PC hardware. We subdivide the volume dataset into uniform sized blocks and take advantage of combinations of early ray termination, empty-space skipping and visibility culling to accelerate the whole rendering process and render visible parts of volume data. We have implemented our volume rendering algorithm for a large volume data of 512 x 304 x 1878 dimensions (visible female), and achieved real-time performance (i.e., 3-4 frames per second) on a Pentium 4 2.4GHz PC equipped with NVIDIA Geforce 6600 graphics card ( 256 MB video memory). This method can be used as a 3D visualization tool of large CT datasets for doctors or radiologists. PMID:18243401

  8. Molecular Genetics of Growth and Development in Populus. IV. Mapping Qtls with Large Effects on Growth, Form, and Phenology Traits in a Forest Tree

    PubMed Central

    Bradshaw-Jr, H. D.; Stettler, R. F.

    1995-01-01

    We have mapped quantitative trait loci (QTLs) for commercially important traits (stem growth and form) and an adaptive trait (spring leaf flush) in a Populus F(2) generation derived from a cross between interspecific F(1) hybrids (P. trichocarpa X P. deltoides). Phenotypic data were collected over a 2-year period from a replicated clonal trial containing ramets of the parental, F(1), and F(2) trees. Contrary to the assumptions of simple polygenic models of quantitative trait inheritance, 1-5 QTLs of large effect are responsible for a large portion of the genetic variance in each of the traits measured. For example, 44.7% of the genetic variance in stem volume after 2 years of growth is controlled by just two QTLs. QTLs governing stem basal area were found clustered with QTLs for sylleptic branch leaf area, sharing similar chromosomal position and mode of action and suggesting a pleiotropic effect of QTLs ultimately responsible for stem diameter growth. PMID:7713445

  9. Subsurface Supergranular Vertical Flows as Measured Using Large Distance Separations in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.; Hanasoge, S. M.

    2012-01-01

    As large-distance rays (say, 10-24 deg) approach the solar surface approximately vertically, travel times measured from surface pairs for these large separations are mostly sensitive to vertical flows, at least for shallow flows within a few Mm of the solar surface. All previous analyses of supergranulation have used smaller separations and have been hampered by the difficulty of separating the horizontal and vertical flow components. We find that the large separation travel times associated with upergranulation cannot be studied using the standard phase-speed filters of time-distance helioseismology. These filters, whose use is based upon a refractive model of the perturbations,reduce the resultant travel time signal by at least an order of magnitude at some distances. More effective filters are derived. Modeling suggests that the center-annulus travel time difference in the separation range 10-24 deg is insensitive to the horizontally diverging flow from the centers of the supergranules and should lead to a constant signal from the vertical flow. Our measurement of this quantity for the average supergranule, 5.1 s, is constant over the distance range. This magnitude of signal cannot be caused by the level of upflow at cell centers seen at the photosphere of 10 m/s extended in depth. It requires the vertical flow to increase with depth. A simple Gaussian model of the increase with depth implies a peak upward flow of 240 m/s at a depth of 2.3 Mm and a peak horizontal flow of 700 m/s at a depth of 1.6 Mm.

  10. TIMESERIESSTREAMING.VI: LabVIEW program for reliable data streaming of large analog time series

    NASA Astrophysics Data System (ADS)

    Czerwinski, Fabian; Oddershede, Lene B.

    2011-02-01

    With modern data acquisition devices that work fast and very precise, scientists often face the task of dealing with huge amounts of data. These need to be rapidly processed and stored onto a hard disk. We present a LabVIEW program which reliably streams analog time series of MHz sampling. Its run time has virtually no limitation. We explicitly show how to use the program to extract time series from two experiments: For a photodiode detection system that tracks the position of an optically trapped particle and for a measurement of ionic current through a glass capillary. The program is easy to use and versatile as the input can be any type of analog signal. Also, the data streaming software is simple, highly reliable, and can be easily customized to include, e.g., real-time power spectral analysis and Allan variance noise quantification. Program summaryProgram title: TimeSeriesStreaming.VI Catalogue identifier: AEHT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 250 No. of bytes in distributed program, including test data, etc.: 63 259 Distribution format: tar.gz Programming language: LabVIEW ( http://www.ni.com/labview/) Computer: Any machine running LabVIEW 8.6 or higher Operating system: Windows XP and Windows 7 RAM: 60-360 Mbyte Classification: 3 Nature of problem: For numerous scientific and engineering applications, it is highly desirable to have an efficient, reliable, and flexible program to perform data streaming of time series sampled with high frequencies and possibly for long time intervals. This type of data acquisition often produces very large amounts of data not easily streamed onto a computer hard disk using standard methods. Solution method: This LabVIEW program is developed to directly

  11. Time-dependent large aspect-ratio thermal convection in the earth's mantle

    NASA Astrophysics Data System (ADS)

    Weinstein, Stuart A.; Olson, Peter L.; Yuen, David A.

    Numerical simulations of two-dimensional time-dependent thermal convection in a Boussinesq, isoviscous, infinite Prandtl number fluid with isothermal, stress-free boundaries have been performed in large aspect-ratio configurations, in which the fluid is heated from below as well as internally. The value of the basal heated Rayleigh number ranged from 16000 to 800 000 and the Rayleigh number based on internal heat generation was varied from zero to 4 500 000. Large aspect-ratio cells are found to exist, however, they are time-dependent even at small values of the Rayleigh number. In the absence of internal heating, the onset of time-dependence occurs as a regular oscillation in the flow characteristics (Nusselt number, kinetic energy), and is accompanied by the presence of boundary layer instabilities (BLI) which exist within a large aspect-ratio circulation. At high values of the Rayleigh number the BLI are powerful features which leave the confines of the boundary layer and strongly perturb the large aspect-ratio circulation giving the flow a multi-scale character. Convective mixing of these powerful BLI results in heterogeneity in the cell interior which plays a role in the excitation of new BLI and establishes a negative temperature gradient in the cell interior. We have developed a fluid loop model which gives a qualitative explanation for the variation of the onset of time-dependence with aspect-ratio. The addition of internal heating tends to destabilize the large aspect-ratio cell configuration. Multi-cellular states last longer and occur more frequently with increasing amounts of internal heating. These calculations shed new light on a variety of time-dependent phenomena in geodynamics such as subduction, back-arc spreading, intraplate deformation, and the average geotherm. Recently, Jeanloz and Morris proposed that the seismic inhomogeneity parameter () can be used to measure the importance of internal heating in mantle convection. However, our

  12. A sputnik IV saga

    NASA Astrophysics Data System (ADS)

    Lundquist, Charles A.

    2009-12-01

    The Sputnik IV launch occurred on May 15, 1960. On May 19, an attempt to deorbit a 'space cabin' failed and the cabin went into a higher orbit. The orbit of the cabin was monitored and Moonwatch volunteer satellite tracking teams were alerted to watch for the vehicle demise. On September 5, 1962, several team members from Milwaukee, Wisconsin made observations starting at 4:49 a.m. of a fireball following the predicted orbit of Sputnik IV. Requests went out to report any objects found under the fireball path. An early morning police patrol in Manitowoc had noticed a metal object on a street and had moved it to the curb. Later the officers recovered the object and had it dropped off at the Milwaukee Journal. The Moonwarch team got the object and reported the situation to Moonwatch Headquarters at the Smithsonian Astrophysical Observatory. A team member flew to Cambridge with the object. It was a solid, 9.49 kg piece of steel with a slag-like layer attached to it. Subsequent analyses showed that it contained radioactive nuclei produced by cosmic ray exposure in space. The scientists at the Observatory quickly recognized that measurements of its induced radioactivity could serve as a calibration for similar measurements of recently fallen nickel-iron meteorites. Concurrently, the Observatory directorate informed government agencies that a fragment from Sputnik IV had been recovered. Coincidently, a debate in the UN Committee on Peaceful Uses of Outer Space involved the issue of liability for damage caused by falling satellite fragments. On September 12, the Observatory delivered the bulk of the fragment to the US Delegation to the UN. Two days later, the fragment was used by US Ambassador Francis Plimpton as an exhibit that the time had come to agree on liability for damage from satellite debris. He offered the Sputnik IV fragment to USSR Ambassador P.D. Morozov, who refused the offer. On October 23, Drs. Alla Massevitch and E.K. Federov of the USSR visited the

  13. Physics of the environment: possible Sumatra Tsunami warning times for large animals in Sri Lanka

    NASA Astrophysics Data System (ADS)

    Browning, David G.; Scheifele, Peter M.; Vonwinkle, William A.

    2005-04-01

    There has previously been significant anecdotal evidence that animals can anticipate or sense seismic events. It is known that large animals, specifically elephants, sense and utilize low frequency sound. The object of this paper is to estimate the possible warning times that large animals in Sri Lanka could have had of the Sumatra Tsunami, assuming they could sense low frequency wave transmission from the initial earthquake arriving by either atmospheric, ocean, or bottom paths. The atmospheric path appears to be the least efficient due to relatively high attenuation and poor coupling to the source. It would also give the shortest warning time: approximately 30 minutes. The ocean path via the deep sound channel, which has been shown by a previous Bermuda experiment to be an efficient means of coupling seismic energy to an island, would give a warning time of more than 1.5 hours. The bottom path(s), which gave strong received signals at a Sri Lanka seismic station, would give a warning time of about 2 hours. These estimates should provide a context for animal behavior reports.

  14. Time and Amplitude Characteristics of Large Scintillation Detectors with SiPM

    NASA Astrophysics Data System (ADS)

    Kaplin, V. A.; Makliaev, E. F.; Melikyan, Yu. A.; Naumov, P. P.; Naumov, P. Yu.; Runtso, M. F.

    A large plastic scintillation detector system with silicon photomultiplier (SiPM) readout has been developed as a prototype for future astroparticle experiments' detectors. A set of SiPM connected in parallel was used in order to enlarge the light collection effective area and thus enhance the detector's amplitude and timing performance. Here we report on the values of time resolution and scintillation detection efficiency of such a system for different types of SiPM as a function of the distance between the scintillation strip edge with photomultipliers attached to it, and the penetrating particle. Results of a special simulation study of the system's amplitude and timing performance as a function of the SiPM radiation aging are also presented.

  15. Software features of a DBMS kernel in large real-time EMS systems

    SciTech Connect

    Schwab, B.C.; Sackett, S.A.; Lawrence, G.M.; Davis, R.N.; Daine, D.N.; Hemmaplardh, K.

    1986-01-01

    A number of performance improvement features were designed and implemented in a database management system (DBMS). The performance oriented DBMS is of the relational model. The DBMS was specifically developed for real-time energy management and control systems (EMS) for electric utilities. Previous analysis had shown that commercially available DBMSs could not meet the performance requirements for the application. This paper describes the performance improvement software features. The description focuses on the performance improvement features and the dual database concept for coordinated updates. The description of the performance improvement features deals with task structuring, buffer usage, active file restructuring, and pre-resolving access routes. Some of these features are applicable to other real-time systems with large databases shared by many application programs. A brief description of extending the DBMS design for use in a hierarchical real-time system is given.

  16. Some Uniform Estimates and Large-Time Behavior of Solutions to One-Dimensional Compressible Navier-Stokes System in Unbounded Domains with Large Data

    NASA Astrophysics Data System (ADS)

    Li, Jing; Liang, Zhilei

    2016-06-01

    We study the large-time behavior of solutions to the initial and initial boundary value problems with large initial data for the compressible Navier-Stokes system describing the one-dimensional motion of a viscous heat-conducting perfect polytropic gas in unbounded domains. The temperature is proved to be bounded from below and above, independent of both time and space. Moreover, it is shown that the global solution is asymptotically stable as time tends to infinity. Note that the initial data can be arbitrarily large. This result is proved by using elementary energy methods.

  17. Large domains of apparent delayed replication timing associated with triplet repeat expansion at FRAXA and FRAXE.

    PubMed Central

    Subramanian, P. S.; Nelson, D. L.; Chinault, A. C.

    1996-01-01

    Trinucleotide repeat expansions have been implicated in the causation of a number of neurodegenerative disorders. In the case of fragile X syndrome, full expansion of the FMR1 repeat element (CGG)n has also been correlated with replication timing delay of the locus and proximal flanking sequences in male lymphoblasts. To define more extensively this altered region of DNA replication, as well as to extend these studies to female cells containing premutant and mutant alleles, study of the replication timing properties of a >2-Mb zone in the FRAXA region (Xq27.3-q28) was undertaken by using a FISH technique. In this assay, relative times of replication of specific loci are inferred from the ratios of singlet and doublet hybridization signals in interphase nuclei. In all individuals with a full expansion of the trinucleotide repeat, a large (1-1.2-Mb) region of delayed timing was observed; the apparent timing of the earlier-replicating allele in female cells in this region was intermediate between normal and affected alleles in males, which is in accordance with expectations of a mixed population of cells resulting from random X inactivation. In addition, expansion of the nearby FRAXE locus also was found to correlate with replication timing delay, although the extent of the altered region was somewhat less. Trinucleotide repeat expansion thus may be acting in the Xq27.3-q28 region to alter long-range chromatin structure that could influence transcription of gene sequences within the affected domain. PMID:8755928

  18. Large Observatory For X-ray Timing (LOFT-P): A Probe-Class Mission Concept

    NASA Astrophysics Data System (ADS)

    Wilson-Hodge, Colleen A.; Ray, Paul S.; Chakrabarty, Deepto; Feroci, Marco

    2016-04-01

    LOFT-P is a mission concept for a NASA Astrophysics Probe-Class (<$1B) X-ray timing mission, based on the LOFT M-class concept originally proposed to ESA’s M3 and M4 calls. LOFT-P requires very large collecting area, high time resolution, good spectral resolution,broadband spectral coverage (2-30 keV), highly flexible scheduling, and an ability to detect and respond promptly to time-critical targets of opportunity. It addresses science questions such as: What is the equation of state of ultra dense matter? What are the effects of strong gravity on matter spiraling into black holes? It would be optimized for sub-millisecond timing of bright Galactic X-ray sources including X-ray bursters, black hole binaries, and magnetars to study phenomena at the natural timescales of neutron star surfaces and black hole event horizons and to measure mass and spin of black holes. These measurements are synergistic to imaging and high-resolution spectroscopy instruments, addressing much smaller distance scales than are possible without very long baseline X-ray interferometry, and using complementary techniques to address the geometry and dynamics of emission regions. LOFT-P would have an effective area of >6 m2, >10x that of the highly successful Rossi X-ray Timing Explorer (RXTE). A sky monitor (~2-50 keV) acts as a trigger for pointed observations, providing high duty cycle, high time resolution monitoring of the X-ray sky with ~20 times the sensitivity of the RXTE All-Sky Monitor, enabling multi-wavelength and multi-messenger studies. A probe-class mission concept would employ lightweight collimator technology and large-area solid-state detectors, segmented into pixels or strips, technologies which have been recently greatly advanced during the ESA M-3 Phase A study of LOFT. Given the large community interested in LOFT (>800 supporters), the scientific productivity of this mission is expected to be very high, similar to or greater than RXTE (~2000 refereed publications.) In

  19. Very Large Inflammatory Odontogenic Cyst with Origin on a Single Long Time Traumatized Lower Incisor

    PubMed Central

    Freitas, Filipe; Andre, Saudade; Moreira, Andre; Carames, Joao

    2015-01-01

    One of the consequences of traumatic injuries is the chance of aseptic pulp necrosis to occur which in time may became infected and give origin to periapical pathosis. Although the apical granulomas and cysts are a common condition, there appearance as an extremely large radiolucent image is a rare finding. Differential diagnosis with other radiographic-like pathologies, such as keratocystic odontogenic tumour or unicystic ameloblastoma, is mandatory. The purpose of this paper is to report a very large radicular cyst caused by a single mandibular incisor traumatized long back, in a 60-year-old male. Medical and clinical histories were obtained, radiographic and cone beam CT examinations performed and an initial incisional biopsy was done. The final decision was to perform a surgical enucleation of a lesion, 51.4 mm in length. The enucleated tissue biopsy analysis was able to render the diagnosis as an inflammatory odontogenic cyst. A 2 year follow-up showed complete bone recovery. PMID:26393219

  20. Seemingly unrelated intervention time series models for effectiveness evaluation of large scale environmental remediation.

    PubMed

    Ip, Ryan H L; Li, W K; Leung, Kenneth M Y

    2013-09-15

    Large scale environmental remediation projects applied to sea water always involve large amount of capital investments. Rigorous effectiveness evaluations of such projects are, therefore, necessary and essential for policy review and future planning. This study aims at investigating effectiveness of environmental remediation using three different Seemingly Unrelated Regression (SUR) time series models with intervention effects, including Model (1) assuming no correlation within and across variables, Model (2) assuming no correlation across variable but allowing correlations within variable across different sites, and Model (3) allowing all possible correlations among variables (i.e., an unrestricted model). The results suggested that the unrestricted SUR model is the most reliable one, consistently having smallest variations of the estimated model parameters. We discussed our results with reference to marine water quality management in Hong Kong while bringing managerial issues into consideration. PMID:23932418

  1. Time-of-flight detection of monoatomic ions generated by femtosecond laser ablation from large molecules

    NASA Astrophysics Data System (ADS)

    Kato, Toshiyuki; Kobayashi, Tohru; Kurata-Nishimura, Mizuki; Okamura-Oho, Yuko; Sano, Takuma; Oyama, Rieko; Matsumura, Yonehiro; Yamamoto, Hiroshi; Hayashizaki, Yoshihide; Matsuo, Yukari; Kawai, Jun

    2008-03-01

    Single-shot femtosecond laser ablation (fsLA) was applied to large molecules to analyze elemental composition through out wide range of mass-to-charge ratio. Molecular samples such as Eu-DNA and cosmetic powders were atomized and ionized simultaneously by the single-shot fsLA and positive atomic ions were detected using a reflectron time-of-flight (TOF) mass spectrometer. The ratios among the signal intensity of the detected stable isotopes including 151,153Eu and 182-184,186W were consistent with the respective natural abundances of the isotopes. The results demonstrate the feasibility of the fsLA-TOF method as a high-throughput analytical technique for elemental microanalysis of large molecular samples in small quantities.

  2. The effect of access time on online quiz performance in large biology lecture courses.

    PubMed

    Metz, Anneke M

    2008-05-01

    To better understand the dynamics of online student test taking, including the likelihood of cheating by large numbers of students, we examined test-taking patterns and outcomes of weekly online quizzes in two large undergraduate biology lecture courses. Students taking a quiz late in a 1-3-day quiz access period performed 10-15% worse on quizzes than the students who completed the quiz early. Quiz access time was also negatively correlated with performance in other course components and course grades. These patterns suggest that academic dishonesty was not a determinant in unsupervised online quiz performance. Students generally completed quizzes in late afternoon or evening hours, but students who completed quizzes between midnight and 8 a.m. had significantly lower quiz grades than their peers. In addition, upper-division students were more likely to characterize weekly online quizzes as more helpful for their learning than the lower-division students. PMID:21591191

  3. Hybrid coarse-graining approach for lipid bilayers at large length and time scales.

    PubMed

    Ayton, Gary S; Voth, Gregory A

    2009-04-01

    A hybrid analytic-systematic (HAS) coarse-grained (CG) lipid model is developed and employed in a large-scale simulation of a liposome. The methodology is termed hybrid analytic-systematic because one component of the interaction between CG sites is variationally determined from the multiscale coarse-graining (MS-CG) methodology, whereas the remaining component utilizes an analytic potential. The systematic component models the in-plane center-of-mass interaction of the lipids as determined from an atomistic-level MD simulation of a bilayer. The analytic component is based on the well-known Gay-Berne ellipsoid-of-revolution liquid-crystal model and is designed to model the highly anisotropic interactions at a highly coarse-grained level. The HAS CG approach is the first step in an "aggressive" CG methodology designed to model multicomponent biological membranes at very large length and time scales. PMID:19281167

  4. Timing of Formal Phase Safety Reviews for Large-Scale Integrated Hazard Analysis

    NASA Technical Reports Server (NTRS)

    Massie, Michael J.; Morris, A. Terry

    2010-01-01

    Integrated hazard analysis (IHA) is a process used to identify and control unacceptable risk. As such, it does not occur in a vacuum. IHA approaches must be tailored to fit the system being analyzed. Physical, resource, organizational and temporal constraints on large-scale integrated systems impose additional direct or derived requirements on the IHA. The timing and interaction between engineering and safety organizations can provide either benefits or hindrances to the overall end product. The traditional approach for formal phase safety review timing and content, which generally works well for small- to moderate-scale systems, does not work well for very large-scale integrated systems. This paper proposes a modified approach to timing and content of formal phase safety reviews for IHA. Details of the tailoring process for IHA will describe how to avoid temporary disconnects in major milestone reviews and how to maintain a cohesive end-to-end integration story particularly for systems where the integrator inherently has little to no insight into lower level systems. The proposal has the advantage of allowing the hazard analysis development process to occur as technical data normally matures.

  5. A class of large time step Godunov schemes for hyperbolic conservation laws and applications

    NASA Astrophysics Data System (ADS)

    Qian, ZhanSen; Lee, Chun-Hian

    2011-08-01

    A large time step (LTS) Godunov scheme firstly proposed by LeVeque is further developed in the present work and applied to Euler equations. Based on the analysis of the computational performances of LeVeque's linear approximation on wave interactions, a multi-wave approximation on rarefaction fan is proposed to avoid the occurrences of rarefaction shocks in computations. The developed LTS scheme is validated using 1-D test cases, manifesting high resolution for discontinuities and the capability of maintaining computational stability when large CFL numbers are imposed. The scheme is then extended to multidimensional problems using dimensional splitting technique; the treatment of boundary condition for this multidimensional LTS scheme is also proposed. As for demonstration problems, inviscid flows over NACA0012 airfoil and ONERA M6 wing with given swept angle are simulated using the developed LTS scheme. The numerical results reveal the high resolution nature of the scheme, where the shock can be captured within 1-2 grid points. The resolution of the scheme would improve gradually along with the increasing of CFL number under an upper bound where the solution becomes severely oscillating across the shock. Computational efficiency comparisons show that the developed scheme is capable of reducing the computational time effectively with increasing the time step (CFL number).

  6. Incorporating Real-time Earthquake Information into Large Enrollment Natural Disaster Course Learning

    NASA Astrophysics Data System (ADS)

    Furlong, K. P.; Benz, H.; Hayes, G. P.; Villasenor, A.

    2010-12-01

    Although most would agree that the occurrence of natural disaster events such as earthquakes, volcanic eruptions, and floods can provide effective learning opportunities for natural hazards-based courses, implementing compelling materials into the large-enrollment classroom environment can be difficult. These natural hazard events derive much of their learning potential from their real-time nature, and in the modern 24/7 news-cycle where all but the most devastating events are quickly out of the public eye, the shelf life for an event is quite limited. To maximize the learning potential of these events requires that both authoritative information be available and course materials be generated as the event unfolds. Although many events such as hurricanes, flooding, and volcanic eruptions provide some precursory warnings, and thus one can prepare background materials to place the main event into context, earthquakes present a particularly confounding situation of providing no warning, but where context is critical to student learning. Attempting to implement real-time materials into large enrollment classes faces the additional hindrance of limited internet access (for students) in most lecture classrooms. In Earth 101 Natural Disasters: Hollywood vs Reality, taught as a large enrollment (150+ students) general education course at Penn State, we are collaborating with the USGS’s National Earthquake Information Center (NEIC) to develop efficient means to incorporate their real-time products into learning activities in the lecture hall environment. Over time (and numerous events) we have developed a template for presenting USGS-produced real-time information in lecture mode. The event-specific materials can be quickly incorporated and updated, along with key contextual materials, to provide students with up-to-the-minute current information. In addition, we have also developed in-class activities, such as student determination of population exposure to severe ground

  7. Large time-step stability of explicit one-dimensional advection schemes

    NASA Technical Reports Server (NTRS)

    Leonard, B. P.

    1993-01-01

    There is a wide-spread belief that most explicit one-dimensional advection schemes need to satisfy the so-called 'CFL condition' - that the Courant number, c = udelta(t)/delta(x), must be less than or equal to one, for stability in the von Neumann sense. This puts severe limitations on the time-step in high-speed, fine-grid calculations and is an impetus for the development of implicit schemes, which often require less restrictive time-step conditions for stability, but are more expensive per time-step. However, it turns out that, at least in one dimension, if explicit schemes are formulated in a consistent flux-based conservative finite-volume form, von Neumann stability analysis does not place any restriction on the allowable Courant number. Any explicit scheme that is stable for c is less than 1, with a complex amplitude ratio, G(c), can be easily extended to arbitrarily large c. The complex amplitude ratio is then given by exp(- (Iota)(Nu)(Theta)) G(delta(c)), where N is the integer part of c, and delta(c) = c - N (less than 1); this is clearly stable. The CFL condition is, in fact, not a stability condition at all, but, rather, a 'range restriction' on the 'pieces' in a piece-wise polynomial interpolation. When a global view is taken of the interpolation, the need for a CFL condition evaporates. A number of well-known explicit advection schemes are considered and thus extended to large delta(t). The analysis also includes a simple interpretation of (large delta(t)) total-variation-diminishing (TVD) constraints.

  8. Intelligent Virtual Station (IVS)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intelligent Virtual Station (IVS) is enabling the integration of design, training, and operations capabilities into an intelligent virtual station for the International Space Station (ISS). A viewgraph of the IVS Remote Server is presented.

  9. Near minimum-time maneuvers of large space structures using parameter optimization

    NASA Technical Reports Server (NTRS)

    Carter, M. T.; Vadali, S. R.; Singh, T.

    1993-01-01

    Near minimum-time attitude maneuvers for large, inherently-flexible space structures with finite fuel supplies are investigated. The open loop maneuver is determined with the Sequential Quadratic Programming (SQP) algorithm, which optimizes a bang-off-bang control parameter set for the given maneuver. Torque smoothing is used to prevent discontinuities in the control which would excite the flexible structure. Additional system dynamics such as thruster inefficiency, spring forces and pressure leaks are identified from preliminary experiments on the ASTREX test article.

  10. On Large Time Behavior and Selection Principle for a Diffusive Carr-Penrose Model

    NASA Astrophysics Data System (ADS)

    Conlon, Joseph G.; Dabkowski, Michael; Wu, Jingchen

    2016-04-01

    This paper is concerned with the study of a diffusive perturbation of the linear LSW model introduced by Carr and Penrose. A main subject of interest is to understand how the presence of diffusion acts as a selection principle, which singles out a particular self-similar solution of the linear LSW model as determining the large time behavior of the diffusive model. A selection principle is rigorously proven for a model which is a semiclassical approximation to the diffusive model. Upper bounds on the rate of coarsening are also obtained for the full diffusive model.

  11. Space-Time Controls on Carbon Sequestration Over Large-Scale Amazon Basin

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Cooper, Harry J.; Gu, Jiujing; Grose, Andrew; Norman, John; daRocha, Humberto R.; Starr, David O. (Technical Monitor)

    2002-01-01

    A major research focus of the LBA Ecology Program is an assessment of the carbon budget and the carbon sequestering capacity of the large scale forest-pasture system that dominates the Amazonia landscape, and its time-space heterogeneity manifest in carbon fluxes across the large scale Amazon basin ecosystem. Quantification of these processes requires a combination of in situ measurements, remotely sensed measurements from space, and a realistically forced hydrometeorological model coupled to a carbon assimilation model, capable of simulating details within the surface energy and water budgets along with the principle modes of photosynthesis and respiration. Here we describe the results of an investigation concerning the space-time controls of carbon sources and sinks distributed over the large scale Amazon basin. The results are derived from a carbon-water-energy budget retrieval system for the large scale Amazon basin, which uses a coupled carbon assimilation-hydrometeorological model as an integrating system, forced by both in situ meteorological measurements and remotely sensed radiation fluxes and precipitation retrieval retrieved from a combination of GOES, SSM/I, TOMS, and TRMM satellite measurements. Brief discussion concerning validation of (a) retrieved surface radiation fluxes and precipitation based on 30-min averaged surface measurements taken at Ji-Parana in Rondonia and Manaus in Amazonas, and (b) modeled carbon fluxes based on tower CO2 flux measurements taken at Reserva Jaru, Manaus and Fazenda Nossa Senhora. The space-time controls on carbon sequestration are partitioned into sets of factors classified by: (1) above canopy meteorology, (2) incoming surface radiation, (3) precipitation interception, and (4) indigenous stomatal processes varied over the different land covers of pristine rainforest, partially, and fully logged rainforests, and pasture lands. These are the principle meteorological, thermodynamical, hydrological, and biophysical

  12. Demonstration of a large-size real-time full-color three-dimensional display.

    PubMed

    Sang, Xinzhu; Fan, Frank C; Jiang, C C; Choi, Sam; Dou, Wenhua; Yu, Chongxiu; Xu, Daxiong

    2009-12-15

    A large-size and full-color three-dimensional (3D) display system without the need for special eyeglasses is demonstrated. With a specially fabricated holographic functional screen with a size of 1.8x1.3 m(2), the system including optimally designed camera-projector arrays and a video server can display the fully continuous, natural 3D scene with more than 1 m image depth in real time. We explain the operating principle and present experimental results. PMID:20016619

  13. Visible-light-induced electron transport from small to large nanoparticles in bimodal gold nanoparticle-loaded titanium(IV) oxide.

    PubMed

    Naya, Shin-Ichi; Niwa, Tadahiro; Kume, Takahiro; Tada, Hiroaki

    2014-07-01

    A key to realizing the sustainable society is to develop highly active photocatalysts for selective organic synthesis effectively using sunlight as the energy source. Recently, metal-oxide-supported gold nanoparticles (NPs) have emerged as a new type of visible-light photocatalysts driven by the excitation of localized surface plasmon resonance of Au NPs. Here we show that visible-light irradiation (λ>430 nm) of TiO2 -supported Au NPs with a bimodal size distribution (BM-Au/TiO2 ) gives rise to the long-range (>40 nm) electron transport from about 14 small (ca. 2 nm) Au NPs to one large (ca. 9 nm) Au NP through the conduction band of TiO2 . As a result of the enhancement of charge separation, BM-Au/TiO2 exhibits a high level of visible-light activity for the one-step synthesis of azobenzenes from nitrobenzenes at 25 °C with a yield greater than 95 % and a selectivity greater than 99 %, whereas unimodal Au/TiO2 (UM-Au/TiO2 ) is photocatalytically inactive. PMID:24863051

  14. Large Eddy Simulation of an URBAN 2000 Experiment with Various Time-Dependent Forcing

    SciTech Connect

    Chan, S T; Leach, M J

    2004-06-15

    Under the sponsorship of the U.S. DOE and DHS, we have developed a Computational Fluid Dynamics (CFD) model for simulating airflow and dispersion of chemical/biological agents released in the urban environment. Our model, FEM3MP, is based on solving the three-dimensional, time-dependent, incompressible Navier-Stokes equations on massively parallel computer platforms. The numerical algorithm uses the finite element method for accurate representation of complex building shapes and variable terrain, together with a semi-implicit projection method and modern iterative solvers for efficient time integration (Gresho and Chan, 1998). Physical processes treated in our code include turbulence modeling via the RANS (Reynolds Averaged Navier-Stokes) and LES (Large Eddy Simulation) approaches, atmospheric stability, aerosols, UV radiation decay, surface energy budget, and vegetative canopies, etc.

  15. Bose-Einstein condensation in large time-averaged optical ring potentials

    NASA Astrophysics Data System (ADS)

    Bell, Thomas A.; Glidden, Jake A. P.; Humbert, Leif; Bromley, Michael W. J.; Haine, Simon A.; Davis, Matthew J.; Neely, Tyler W.; Baker, Mark A.; Rubinsztein-Dunlop, Halina

    2016-03-01

    Interferometric measurements with matter waves are established techniques for sensitive gravimetry, rotation sensing, and measurement of surface interactions, but compact interferometers will require techniques based on trapped geometries. In a step towards the realisation of matter wave interferometers in toroidal geometries, we produce a large, smooth ring trap for Bose-Einstein condensates using rapidly scanned time-averaged dipole potentials. The trap potential is smoothed by using the atom distribution as input to an optical intensity correction algorithm. Smooth rings with a diameter up to 300 μm are demonstrated. We experimentally observe and simulate the dispersion of condensed atoms in the resulting potential, with good agreement serving as an indication of trap smoothness. Under time of flight expansion we observe low energy excitations in the ring, which serves to constrain the lower frequency limit of the scanned potential technique. The resulting ring potential will have applications as a waveguide for atom interferometry and studies of superfluidity.

  16. A large-area time-of-flight system for a colliding beam machine

    NASA Astrophysics Data System (ADS)

    Basile, M.; Cara Romeo, G.; Cifarelli, L.; D'Ali, G.; Di Cesare, P.; Giusti, P.; Massam, T.; Palmonari, F.; Sartorelli, G.; Valenti, G.; Contin, A.; Favale, L.; Zichichi, A.; Esposito, B.

    1981-02-01

    We describe the performance of a large solid-angle (2 sr) time-of-flight system used in conjunction with the Split Field Magnet spectrometer of the CERN Intersecting Storage Rings (ISR). The system consists of a hodoscope of 67 scintillator counters, at a distance of about 5 m from the beam intersection. The ISR being a coasting beam machine, contrary to the tightly bunched e +e - machines, the event time is unknown and therefore a special analysis procedure for particle identification is required. We illustrate a powerful statistical method which allows the identification, with more than 90% efficiency, of pions up to about 1 GeV/c, kaons up to about 1.4 GeV/c, and protons up to about 2 GeV/c.

  17. One-Way Markov Process Approach to Repeat Times of Large Earthquakes in Faults

    NASA Astrophysics Data System (ADS)

    Tejedor, Alejandro; Gomez, Javier B.; Pacheco, Amalio F.

    2012-11-01

    One of the uses of Markov Chains is the simulation of the seismic cycle in a fault, i.e. as a renewal model for the repetition of its characteristic earthquakes. This representation is consistent with Reid's elastic rebound theory. We propose a general one-way Markovian model in which the waiting time distribution, its first moments, coefficient of variation, and functions of error and alarm (related to the predictability of the model) can be obtained analytically. The fact that in any one-way Markov cycle the coefficient of variation of the corresponding distribution of cycle lengths is always lower than one concurs with observations of large earthquakes in seismic faults. The waiting time distribution of one of the limits of this model is the negative binomial distribution; as an application, we use it to fit the Parkfield earthquake series in the San Andreas fault, California.

  18. Virtual Testing of Large Composite Structures: A Multiple Length/Time-Scale Framework

    NASA Astrophysics Data System (ADS)

    Gigliotti, Luigi; Pinho, Silvestre T.

    2015-12-01

    This paper illustrates a multiple length/time-scale 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-scales 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) scales and the computational cost required to calculate the homogenised to be used in the higher-scales 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/time-scale framework are demonstrated through the analysis of a real-sized aeronautical composite component.

  19. Large Scale GPS Processing at ESOC for LEO, GNSS and Real-Time Applications

    NASA Astrophysics Data System (ADS)

    Boomkamp, H.; Dow, J.

    2003-12-01

    Most POD systems that are used in GPS data analysis, for instance in routine IGS processing, are large FORTRAN programs that have evolved from early generation systems over many years of use. These systems do not exploit the advantages of modern software engineering technology, and their limited processing efficiency constrains their application to emerging large-scale GPS processes, like real-time GPS, high-rate data processing or combined solutions for LEO + MEO constellations. In support of such high-performance applications, the ESOC IGS Analysis Centre is developing a new POD system based on the latest software engineering methods. This system is optimised in its use of both CPU and memory, following fundamental rules of minimum information containment that are more commonly found in internet search engines or artificial intelligence applications. Although this new system still has an experimental status it is expected to augment the GPS data processing capacity at ESOC by at least one order of magnitude. Some innovative concepts behind the system will be presented, together with first examples of GPS processes that until now were prohibitively large or slow.

  20. Asymptotics for Large Time of Global Solutions to the Generalized Kadomtsev-Petviashvili Equation

    NASA Astrophysics Data System (ADS)

    Hayashi, Nakao; Naumkin, Pavel I.; Saut, Jean-Claude

    We study the large time asymptotic behavior of solutions to the generalized Kadomtsev-Petviashvili (KP) equations where σ= 1 or σ=- 1. When ρ= 2 and σ=- 1, (KP) is known as the KPI equation, while ρ= 2, σ=+ 1 corresponds to the KPII equation. The KP equation models the propagation along the x-axis of nonlinear dispersive long waves on the surface of a fluid, when the variation along the y-axis proceeds slowly [10]. The case ρ= 3, σ=- 1 has been found in the modeling of sound waves in antiferromagnetics [15]. We prove that if ρ>= 3 is an integer and the initial data are sufficiently small, then the solution u of (KP) satisfies the following estimates: for all t∈R, where κ= 1 if ρ= 3 and κ= 0 if ρ>= 4. We also find the large time asymptotics for the solution.

  1. Real-time evolution of a large-scale relativistic jet

    NASA Astrophysics Data System (ADS)

    Martí, Josep; Luque-Escamilla, Pedro L.; Romero, Gustavo E.; Sánchez-Sutil, Juan R.; Muñoz-Arjonilla, Álvaro J.

    2015-06-01

    Context. Astrophysical jets are ubiquitous in the Universe on all scales, but their large-scale dynamics and evolution in time are hard to observe since they usually develop at a very slow pace. Aims: We aim to obtain the first observational proof of the expected large-scale evolution and interaction with the environment in an astrophysical jet. Only jets from microquasars offer a chance to witness the real-time, full-jet evolution within a human lifetime, since they combine a "short", few parsec length with relativistic velocities. Methods: The methodology of this work is based on a systematic recalibraton of interferometric radio observations of microquasars available in public archives. In particular, radio observations of the microquasar GRS 1758-258 over less than two decades have provided the most striking results. Results: Significant morphological variations in the extended jet structure of GRS 1758-258 are reported here that were previously missed. Its northern radio lobe underwent a major morphological variation that rendered the hotspot undetectable in 2001 and reappeared again in the following years. The reported changes confirm the Galactic nature of the source. We tentatively interpret them in terms of the growth of instabilities in the jet flow. There is also evidence of surrounding cocoon. These results can provide a testbed for models accounting for the evolution of jets and their interaction with the environment.

  2. Real time identification of large space structures. Ph.D. Thesis - MIT

    NASA Technical Reports Server (NTRS)

    Voss, Janice E.

    1987-01-01

    Identification of frequencies, damping ratios, and mode shapes of large space structures (LSSs) are examined in real time. Real time processing allows for quick updates of model processing after a reconfiguration of structural failure. Recursive lattice least squares (RLLS) was selected as the baseline algorithm for the identification. Simulation results on a one dimensional LSS demonstrated that it provides good estimates, was not ill-conditioned in the presence of under-excited modes, allowed activity by a supervisory control system which prevented damage to the LSS or excessive drift, and was capable of real-time processing for typical LSS models. A suboptimal version of RLLS, which is equivalent to simulated parallel processing, was derived. A NASTRAN model of the dual keel U.S. space station was used to demonstrate the input/identification algorithm package in a more realistic simulation. Because the first eight flexible modes were very close together, the identification was much more difficult than in the simple examples. Even so, the model was accurately identified in real time.

  3. Associations between motor timing, music practice, and intelligence studied in a large sample of twins.

    PubMed

    Ullén, Fredrik; Mosing, Miriam A; Madison, Guy

    2015-03-01

    Music performance depends critically on precise processing of time. A common model behavior in studies of motor timing is isochronous serial interval production (ISIP), that is, hand/finger movements with a regular beat. ISIP accuracy is related to both music practice and intelligence. Here we present a study of these associations in a large twin cohort, demonstrating that the effects of music practice and intelligence on motor timing are additive, with no significant multiplicative (interaction) effect. Furthermore, the association between music practice and motor timing was analyzed with the use of a co-twin control design using intrapair differences. These analyses revealed that the phenotypic association disappeared when all genetic and common environmental factors were controlled. This suggests that the observed association may not reflect a causal effect of music practice on ISIP performance but rather reflect common influences (e.g., genetic effects) on both outcomes. The relevance of these findings for models of practice and expert performance is discussed. PMID:25773626

  4. Characterization of Caramel Colour IV.

    PubMed

    Licht, B H; Shaw, K; Smith, C; Mendoza, M; Orr, J; Myers, D V

    1992-05-01

    A large number of commercial Caramel Colour IV samples were characterized in order to assess the uniformity of the class and to provide data to be used in specifications development. Owing to the chemical and physical complexity of caramel colour it was not feasible to perform detailed analysis of all constituents for assessment of uniformity. Instead, selected parameters were evaluated and judgements were made with respect to compositional uniformity based on the similarities of these parameters among the various samples. As Caramel Colour IV is required by the food industry in a range of colour intensities, there must be a range of properties that differ from sample to sample, but that are sufficiently similar for the material to still be considered as part of the Caramel Colour IV class. Fractions as well as whole caramel were analysed using selected spectrophotometric, chromatographic and chemical techniques. Samples were fractionated based on molecular weight and polarity. The data presented here provide evidence for the uniformity in composition of Caramel Colour IV with respect to molecular weight distribution, to nitrogen and sulphur content and their distribution throughout the fractions, to absorbance properties and to specific low molecular weight compounds. Thus, it can be concluded that Caramel Colour IV exhibits compositional uniformity within the range of colour intensity required by the food industry worldwide. PMID:1644377

  5. Globular Cluster Abundances from High-resolution, Integrated-light Spectroscopy. IV. The Large Magellanic Cloud: α, Fe-peak, Light, and Heavy Elements

    NASA Astrophysics Data System (ADS)

    Colucci, Janet E.; Bernstein, Rebecca A.; Cameron, Scott A.; McWilliam, Andrew

    2012-02-01

    We present detailed chemical abundances in eight clusters in the Large Magellanic Cloud (LMC). We measure abundances of 22 elements for clusters spanning a range in age of 0.05-12 Gyr, providing a comprehensive picture of the chemical enrichment and star formation history of the LMC. The abundances were obtained from individual absorption lines using a new method for analysis of high-resolution (R ~ 25,000), integrated-light (IL) spectra of star clusters. This method was developed and presented in Papers I, II, and III of this series. In this paper, we develop an additional IL χ2-minimization spectral synthesis technique to facilitate measurement of weak (~15 mÅ) spectral lines and abundances in low signal-to-noise ratio data (S/N ~ 30). Additionally, we supplement the IL abundance measurements with detailed abundances that we measure for individual stars in the youngest clusters (age < 2 Gyr) in our sample. In both the IL and stellar abundances we find evolution of [α/Fe] with [Fe/H] and age. Fe-peak abundance ratios are similar to those in the Milky Way (MW), with the exception of [Cu/Fe] and [Mn/Fe], which are sub-solar at high metallicities. The heavy elements Ba, La, Nd, Sm, and Eu are significantly enhanced in the youngest clusters. Also, the heavy to light s-process ratio is elevated relative to the MW ([Ba/Y] >+0.5) and increases with decreasing age, indicating a strong contribution of low-metallicity asymptotic giant branch star ejecta to the interstellar medium throughout the later history of the LMC. We also find a correlation of IL Na and Al abundances with cluster mass in the sense that more massive, older clusters are enriched in the light elements Na and Al with respect to Fe, which implies that these clusters harbor star-to-star abundance variations as is common in the MW. Lower mass, intermediate-age, and young clusters have Na and Al abundances that are lower and more consistent with LMC field stars. Our results can be used to constrain both

  6. GLOBULAR CLUSTER ABUNDANCES FROM HIGH-RESOLUTION, INTEGRATED-LIGHT SPECTROSCOPY. IV. THE LARGE MAGELLANIC CLOUD: {alpha}, Fe-PEAK, LIGHT, AND HEAVY ELEMENTS

    SciTech Connect

    Colucci, Janet E.; Bernstein, Rebecca A.; McWilliam, Andrew E-mail: rab@ucolick.org E-mail: andy@ociw.edu

    2012-02-10

    We present detailed chemical abundances in eight clusters in the Large Magellanic Cloud (LMC). We measure abundances of 22 elements for clusters spanning a range in age of 0.05-12 Gyr, providing a comprehensive picture of the chemical enrichment and star formation history of the LMC. The abundances were obtained from individual absorption lines using a new method for analysis of high-resolution (R {approx} 25,000), integrated-light (IL) spectra of star clusters. This method was developed and presented in Papers I, II, and III of this series. In this paper, we develop an additional IL {chi}{sup 2}-minimization spectral synthesis technique to facilitate measurement of weak ({approx}15 mA) spectral lines and abundances in low signal-to-noise ratio data (S/N {approx} 30). Additionally, we supplement the IL abundance measurements with detailed abundances that we measure for individual stars in the youngest clusters (age < 2 Gyr) in our sample. In both the IL and stellar abundances we find evolution of [{alpha}/Fe] with [Fe/H] and age. Fe-peak abundance ratios are similar to those in the Milky Way (MW), with the exception of [Cu/Fe] and [Mn/Fe], which are sub-solar at high metallicities. The heavy elements Ba, La, Nd, Sm, and Eu are significantly enhanced in the youngest clusters. Also, the heavy to light s-process ratio is elevated relative to the MW ([Ba/Y] >+0.5) and increases with decreasing age, indicating a strong contribution of low-metallicity asymptotic giant branch star ejecta to the interstellar medium throughout the later history of the LMC. We also find a correlation of IL Na and Al abundances with cluster mass in the sense that more massive, older clusters are enriched in the light elements Na and Al with respect to Fe, which implies that these clusters harbor star-to-star abundance variations as is common in the MW. Lower mass, intermediate-age, and young clusters have Na and Al abundances that are lower and more consistent with LMC field stars. Our

  7. Backward-in-time methods to simulate large-scale transport and mixing in the ocean

    NASA Astrophysics Data System (ADS)

    Prants, S. V.

    2015-06-01

    In oceanography and meteorology, it is important to know not only where water or air masses are headed for, but also where they came from as well. For example, it is important to find unknown sources of oil spills in the ocean and of dangerous substance plumes in the atmosphere. It is impossible with the help of conventional ocean and atmospheric numerical circulation models to extrapolate backward from the observed plumes to find the source because those models cannot be reversed in time. We review here recently elaborated backward-in-time numerical methods to identify and study mesoscale eddies in the ocean and to compute where those waters came from to a given area. The area under study is populated with a large number of artificial tracers that are advected backward in time in a given velocity field that is supposed to be known analytically or numerically, or from satellite and radar measurements. After integrating advection equations, one gets positions of each tracer on a fixed day in the past and can identify from known destinations a particle positions at earlier times. The results provided show that the method is efficient, for example, in estimating probabilities to find increased concentrations of radionuclides and other pollutants in oceanic mesoscale eddies. The backward-in-time methods are illustrated in this paper with a few examples. Backward-in-time Lagrangian maps are applied to identify eddies in satellite-derived and numerically generated velocity fields and to document the pathways by which they exchange water with their surroundings. Backward-in-time trapping maps are used to identify mesoscale eddies in the altimetric velocity field with a risk to be contaminated by Fukushima-derived radionuclides. The results of simulations are compared with in situ mesurement of caesium concentration in sea water samples collected in a recent research vessel cruise in the area to the east of Japan. Backward-in-time latitudinal maps and the corresponding

  8. Large-scale Shear Velocities Beneath Hotspot Locations: New Observations and Travel Time Synthesis

    NASA Astrophysics Data System (ADS)

    An, Y.; Gu, Y. J.; Sacchi, M. D.

    2007-12-01

    The existence, lateral dimension, and depth of mantle plumes beneath hotspots have been issues of contentious debate in the past two decades. To a large extent, the difficulty lies in the insufficient data resolution in the transition region (400-1000 km) between the upper and lower mantle beneath major hotspot locations. In this study, we report a new type of observation, the ray parameter variation of SS precursors, to image large-scale mantle shear velocities from the surface down to 1200 km beneath 17 major hotspots. We significantly improve the resolution by a High-resolution Radon transform method that utilizes time-domain inversions to simultaneously constrain differential times and ray parameters. Perturbations of S410S-SS ray parameters present the most revealing observations of hot thermal anomalies in this study. We identify both positive and negative jumps in travel time curves (hence ray parameters) for rays bottoming beneath the majority of the hotspot locations; these anomalous jumps are not observed at non-hotspot locations. Through careful modeling of the observed ray parameter jumps using 2-D finite-difference ray tracing, and accounting for depth, width, sign and strength of the velocity columns, we are able to unequivocally categorize the mantle beneath the aforementioned 17 hotspots to have low seismic velocities at depth 1) comparable to transition zone (400-670 km) depths, or 2) down to 900-1200 km or more. While our data and modeling strategies do not enable us to probe the source of hotspots beyond 1200-km depth, they do have major implications for the discussion of shallow vs. deep-rooted hotspots around the world. For example, the Hawaii and Macdonald hotspots exhibit strong type 1 characteristics, while the Azores and Canary hotspots are describable by type 2 mantle velocity variations.

  9. Variations of characteristic time scales in rotating stratified turbulence using a large parametric numerical study.

    PubMed

    Rosenberg, D; Marino, R; Herbert, C; Pouquet, A

    2016-01-01

    We study rotating stratified turbulence (RST) making use of numerical data stemming from a large parametric study varying the Reynolds, Froude and Rossby numbers, Re, Fr and Ro in a broad range of values. The computations are performed using periodic boundary conditions on grids of 1024(3) points, with no modeling of the small scales, no forcing and with large-scale random initial conditions for the velocity field only, and there are altogether 65 runs analyzed in this paper. The buoyancy Reynolds number defined as R(B) = ReFr2 varies from negligible values to ≈ 10(5), approaching atmospheric or oceanic regimes. This preliminary analysis deals with the variation of characteristic time scales of RST with dimensionless parameters, focusing on the role played by the partition of energy between the kinetic and potential modes, as a key ingredient for modeling the dynamics of such flows. We find that neither rotation nor the ratio of the Brunt-Väisälä frequency to the inertial frequency seem to play a major role in the absence of forcing in the global dynamics of the small-scale kinetic and potential modes. Specifically, in these computations, mostly in regimes of wave turbulence, characteristic times based on the ratio of energy to dissipation of the velocity and temperature fluctuations, T(V) and T(P), vary substantially with parameters. Their ratio γ=T(V)/T(P) follows roughly a bell-shaped curve in terms of Richardson number Ri. It reaches a plateau - on which time scales become comparable, γ≈0.6 - when the turbulence has significantly strengthened, leading to numerous destabilization events together with a tendency towards an isotropization of the flow. PMID:26830757

  10. Large field of view real-time three-dimensional imaging for ports

    NASA Astrophysics Data System (ADS)

    Gao, Meijing; Wu, Weilong; Gu, Haihua; Bi, Weihong

    2011-06-01

    With the acceleration of globalization and regionalization of the world economy, port is playing an increasingly important role for that it is an international transportation hub port interface and the support of the international trade platform. How to effectively reduce labor costs, improve the working environment, stable productivity, reduce the production cuts caused by human intervention and improve the management of real-time monitoring of all the major ports has become a common issue faced. In order to achieve the automatically stacking and reclaiming process of Stacker-Reclaimer in the bulk material yard, the source of its control is expected to identify the stockpile in the bulk yard, including length, width, height, the starting address, destination address, as well as Three-dimensional shape of the stockpile, since in the operation process, stockpile changes the shape dynamically. As a result, the real-time three-dimensional shape and coordinate of piles should be achieved. Based on the existing Stacker-Reclaimer in Qinhuangdao Port coal, we study the large field of view real-time three-dimensional laser scanning imaging theory and technology. The overall system design to achieving the three-dimensional laser scanning image is presented. The working principle of the three-dimensional laser scanning imaging system is analysised. Moreover, the parameter designation, the technical parameters and the composition of the whole system are all given. The research of the thesis is also used for other large-scale three-dimensional modeling of piles and the volume computing. In a world, the method has wide application prospect.

  11. Stage IV work hardening in cubic metals

    SciTech Connect

    Rollett, A.D.; Kocks, U.F.; Doherty, R.D.

    1986-01-01

    The work hardening of fcc metals at large strains is discussed with reference to the linear stress-strain behavior often observed at large strains and known as Stage IV. The experimental evidence shows that Stage IV is a work hardening phenomenon that is found quite generally, even in pure fcc metals subjected to homogeneous deformation. A simple model for Stage IV in pure metals is presented, based on the accumulation of dislocation debris. Experiments are described for large strain torsion tests on four aluminum alloys. The level and extent of Stage IV scaled with the saturation stress that would represent the end of Stage III in the absence of a Stage IV. Reversing the torsion after large prestrains produced transient reductions in the work hardening. The strain rate sensitivity was also measured before and during the transient and found not to vary significantly. The microstructure observed at large strains in an Mg alloy suggest that Stage IV can occur in the absence of microband formation. Previous proposals for the cause of Stage IV are reviewed and found to be not supported by recent experimental data.

  12. European river flow regimes: assessing space-time dynamics and links to large-scale climate

    NASA Astrophysics Data System (ADS)

    Hannah, D. M.; Kingston, D. G.; Laize, C.; Lavers, D. A.; Wilson, D.

    2011-12-01

    Given heightened concerns about climate change/ variability and human impacts on hydrology, there is a pressing need for research to quantify temporal variability and spatial structure in river flow regimes, and to establish hydroclimatological (climate-flow) associations as a basis for predicting future water stress. This paper draws together findings from studies undertaken at the UK and pan-European scale (using datasets of >100 stations with time series >25 years) and aims: (1) to demonstrate the utility of classification schemes for identifying space-time patterns in river flow regimes and (2) to explore the hydroclimatological relationships between large-scale atmospheric circulation and river flow response. Often, classification is undertaken prior to detailed analysis of large-scale patterns in river flow. In this paper, a suite of novel cluster analysis based methods are presented that identify hydrological regions as well as inter-annual river flow regime variation within regions. Statistical characteristics of the emergent classifications are analysed including geographical expression, teleconnections and presence of time-series trends. Results show that classification provides a useful general organising framework for large-scale hydrological research and facilitates systematic testing of hypotheses about drivers of hydrological variation across wide spatial domains. To investigate climate controls on space-time river flow variation, three methods for characterising atmospheric influences are considered: air-mass types, large-scale climate indices and gridded re-analyses (ECMWF ERA-40). A new air-mass classification for Europe (Spatial Synoptic Classification 2) is presented that classifies daily air-masses. Data are pooled by long-term flow regime regions to assess air-mass - flow regime (shape and magnitude) class associations across Europe; and multiple discriminant function analysis (MDFA) is used to model links between the categorical data. The

  13. Quadratic Time-Frequency Analysis of Hydroacoustic Signals as Applied to Acoustic Emissions of Large Whales

    NASA Astrophysics Data System (ADS)

    Le Bras, Ronan; Victor, Sucic; Damir, Malnar; Götz, Bokelmann

    2014-05-01

    In order to enrich the set of attributes in setting up a large database of whale signals, as envisioned in the Baleakanta project, we investigate methods of time-frequency analysis. The purpose of establishing the database is to increase and refine knowledge of the emitted signal and of its propagation characteristics, leading to a better understanding of the animal migrations in a non-invasive manner and to characterize acoustic propagation in oceanic media. The higher resolution for signal extraction and a better separation from other signals and noise will be used for various purposes, including improved signal detection and individual animal identification. The quadratic class of time-frequency distributions (TFDs) is the most popular set of time-frequency tools for analysis and processing of non-stationary signals. Two best known and most studied members of this class are the spectrogram and the Wigner-Ville distribution. However, to be used efficiently, i.e. to have highly concentrated signal components while significantly suppressing interference and noise simultaneously, TFDs need to be optimized first. The optimization method used in this paper is based on the Cross-Wigner-Ville distribution, and unlike similar approaches it does not require prior information on the analysed signal. The method is applied to whale signals, which, just like the majority of other real-life signals, can generally be classified as multicomponent non-stationary signals, and hence time-frequency techniques are a natural choice for their representation, analysis, and processing. We present processed data from a set containing hundreds of individual calls. The TFD optimization method results into a high resolution time-frequency representation of the signals. It allows for a simple extraction of signal components from the TFD's dominant ridges. The local peaks of those ridges can then be used for the signal components instantaneous frequency estimation, which in turn can be used as

  14. Real-time data assimilation for large-scale systems: The spectral Kalman filter

    NASA Astrophysics Data System (ADS)

    Ghorbanidehno, Hojat; Kokkinaki, Amalia; Li, Judith Yue; Darve, Eric; Kitanidis, Peter K.

    2015-12-01

    The Kalman Filter (KF) is a data assimilation method that has been widely used for estimating spatially varying unknown states evolving in time. Recently, KF methods have shown potential for tracking CO2 plumes injected in deep geologic formations. Such real-time estimation would serve as an early warning system for leakage incidents. However, for the large number of unknowns of such large systems, KF methods are impractical, because updating the huge state covariance matrix is computationally expensive. Low rank approximation methods have been devised to overcome this problem; these methods assume a low rank of the covariance matrix, which they approximate by smaller matrices. The approximation error is small for smooth functions, but may be larger for more complex physical problems, potentially leading to filter divergence and inaccurate state estimates. We present the Spectral Kalman Filter (SpecKF), a new algorithm that utilizes the exact covariance matrix. Thus it avoids the approximation error and does so in a computationally efficient way, which is specially important for systems with large numbers of unknowns. The computational speed-up of the SpecKF is achieved by updating cross-covariance matrices instead of the larger covariance matrices. The benefit can be considerable, especially in large systems, because the computational complexity of the SpecKF scales with the number of measurements, as opposed to the effective rank of the covariance matrix in low-rank KFs or the number of ensemble members in ensemble methods. We investigate the accuracy and performance of the SpecKF for a diffusion problem with random perturbations, and for a more complex case of CO2 injection in a homogeneous two-dimensional domain. Our results show that the SpecKF reduces greatly the computational cost compared to the original KF algorithm, and that it can provide higher accuracy than the Ensemble Kalman Filter (EnKF) with the same or even smaller computational cost. Finally, we

  15. Timing of occurrence of large submarine landslides on the Atlantic Ocean margin

    USGS Publications Warehouse

    Lee, H.J.

    2009-01-01

    Submarine landslides are distributed unevenly both in space and time. Spatially, they occur most commonly in fjords, active river deltas, submarine canyon-fan systems, the open continental slope and on the flanks of oceanic volcanic islands. Temporally, they are influenced by the size, location, and sedimentology of migrating depocenters, changes in seafloor pressures and temperatures, variations in seismicity and volcanic activity, and changes in groundwater flow conditions. The dominant factor influencing the timing of submarine landslide occurrence is glaciation. A review of known ages of submarine landslides along the margins of the Atlantic Ocean, augmented by a few ages from other submarine locations shows a relatively even distribution of large landslides with time from the last glacial maximum until about five thousand years after the end of glaciation. During the past 5000??yr, the frequency of occurrence is less by a factor of 1.7 to 3.5 than during or shortly after the last glacial/deglaciation period. Such an association likely exists because of the formation of thick deposits of sediment on the upper continental slope during glacial periods and increased seismicity caused by isostatic readjustment during and following deglaciation. Hydrate dissociation may play a role, as suggested previously in the literature, but the connection is unclear.

  16. Real-time modulated nanoparticle separation with an ultra-large dynamic range.

    PubMed

    Zeming, Kerwin Kwek; Thakor, Nitish V; Zhang, Yong; Chen, Chia-Hung

    2016-01-01

    Nanoparticles exhibit size-dependent properties which make size-selective purification of proteins, DNA or synthetic nanoparticles essential for bio-analytics, clinical medicine, nano-plasmonics and nano-material sciences. Current purification methods of centrifugation, column chromatography and continuous-flow techniques suffer from particle aggregation, multi-stage process, complex setups and necessary nanofabrication. These increase process costs and time, reduce efficiency and limit dynamic range. Here, we achieve an unprecedented real-time nanoparticle separation (51-1500 nm) using a large-pore (2 μm) deterministic lateral displacement (DLD) device. No external force fields or nanofabrication are required. Instead, we investigated innate long-range electrostatic influences on nanoparticles within a fluid medium at different NaCl ionic concentrations. In this study we account for the electrostatic forces beyond Debye length and showed that they cannot be assumed as negligible especially for precise nanoparticle separation methods such as DLD. Our findings have enabled us to develop a model to simultaneously quantify and modulate the electrostatic force interactions between nanoparticle and micropore. By simply controlling buffer solutions, we achieve dynamic nanoparticle size separation on a single device with a rapid response time (<20 s) and an enlarged dynamic range (>1200%), outperforming standard benchtop centrifuge systems. This novel method and model combines device simplicity, isolation precision and dynamic flexibility, opening opportunities for high-throughput applications in nano-separation for industrial and biological applications. PMID:26575003

  17. A real-time, large area, high space resolution particle radiography system

    NASA Astrophysics Data System (ADS)

    Lo Presti, D.; Bonanno, D.; Longhitano, F.; Pugliatti, C.; Aiello, S.; Cirrone, G. A. P.; Giordano, V.; Leonora, E.; Randazzo, N.; Romano, F.; Russo, G. V.; Sipala, V.; Stancampiano, C.; Ventura, C.

    2014-06-01

    In this paper we describe a new detection system for the high resolution measurement of the residual range of charged particles, designed and developed with the aim of achieving real-time data acquisition and large detection areas. A prototype of the residual range detector, with a sensitive area of about 4 × 4 cm2, consisting of a stack of sixty ribbons of scintillating fibers (Sci-Fi) has been designed and tested. Each layer is read-out by two wavelength shifter (WLS) fibers and a position sensitive photomultiplier (PSPM). The Bragg peak shape is calculated real-time by the time over a suitable threshold for each channel. The results of the measurements taken using the prototype and a 62 MeV proton beam and a comparison with the GEANT4 simulations of the detector are presented. The main concepts on which the prototype is based have been used to demonstrate the technique patented by the INFN. The next step will be to design and validate the final detector which will have 30 × 30 cm2 FOV and cover the 250 MeV proton range with about 150 micron range resolution. These performances are suitable for almost all medical imaging applications.

  18. Testing a time-domain regional momtent tensor inversion program for large worldwide earthquakes

    NASA Astrophysics Data System (ADS)

    Richter, G.; Hoffmann, M.; Hanka, W.; Saul, J.

    2009-04-01

    After gaining an accurate source location and magnitude estimate of large earthquakes the direction of plate movement is the next important information for reliable hazard assessment. For this purpose rapid moment tensor inversions are necessary. In this study the time-domain moment tensor inversion program by Dreger (2001) is tested. This program for regional moment tensor solutions is applied to seismic data from regional stations of the GEOFON net and international cooperating partner networks (InaTEWS, IRIS, GEOFON Extended Virtual Network) to obtain moment tensor solutions for large earthquakes worldwide. The motivation of the study is to have rapid information on the plate motion direction for the verification of tsunami generation hazard by earthquakes. A special interest lies on the application in the Indonesian archipelago to integrate the program in German-Indonesian Tsunami Early Warning System (GITEWS). Performing the inversion on a single CPU of a normal PC most solutions are achieved within half an hour after origin time. The program starts automatically for large earthquakes detected by the seismic analysis tool SeisComP3 (Hanka et al, 2008). The data from seismic stations in the distance range up to 2000 km are selected, prepared and quality controlled. First the program searches the best automatic solution by varying the source depth. Testing different stations combinations for the inversion enables to identify the stability of the solution. For further optimization of the solution the interactive selection of available stations is facilitated. The results of over 200 events are compared to centroid moment tensor solutions from the Global CMT-Project, from MedNet/INGV and NEID to evaluate the accuracy of the results. The inversion in the time-domain is sensitive to uncertainties in the velocity model and in the source location. These resolution limits are visible in the waveform fits. Another reason for misfits are strong structural inhomogeneities

  19. Parallel computation of unsteady, three-dimensional, chemically reacting, nonequilibrium flow using a time-split finite-volume method on the Illiac IV

    NASA Technical Reports Server (NTRS)

    Reinhardt, W. A.

    1977-01-01

    A description is presented of the split finite-volume method which is a viable numerical procedure for performing with the aid of a modern special purpose vector computer numerical simulation studies of complicated flow fields, including chemical reactions, about geometrically complex bodies. Such numerical studies are needed for the development of atmospheric entry vehicles such as the space shuttle. The equations which are approximated are quite general and can be used in studies of combustion, pollution, and other chemically reacting flow phenomena, where convective transport effects dominate the influence of radiative, viscous, and other transport mechanisms. The shock perturbed flow about a shuttle orbiter flying at a large angle of attack during atmospheric entry is illustrated. The method uses a time splitting of the convection differencing operator to achieve efficient data management.

  20. Time scales for the decay of induced large-scale magnetic fields in the Venus ionosphere

    NASA Astrophysics Data System (ADS)

    Luhmann, J. G.; Russell, C. T.; Elphic, R. C.

    1984-01-01

    Observations made with the aid of a magnetometer on the Pioneer Venus Orbiter have shown large-scale horizontal magnetic fields in the dayside ionosphere of Venus. According to Cloutier and Daniell (1981), the observed magnetic structures may be quasi-steady features produced by an ionospheric current system driven by solar wind interaction. Russell et al. (1983) have suggested that the altitude profiles of the horizontal field on different orbits exhibit a pattern which can be interpreted as phases in the temporal evolution of an initial state in which the ionosphere was permeated with magnetosheath-like fields. The present investigation is concerned with the argument in favor of a temporal versus spatial explanation for some of the observed field structure. A calculation indicates that the diffusion time for ionospheric fields is long enough to justify attributing the observed fields to the 'memory' of the Venus ionosphere in certain regions.

  1. Spatial, temporal, and hybrid decompositions for large-scale vehicle routing with time windows

    SciTech Connect

    Bent, Russell W

    2010-01-01

    This paper studies the use of decomposition techniques to quickly find high-quality solutions to large-scale vehicle routing problems with time windows. It considers an adaptive decomposition scheme which iteratively decouples a routing problem based on the current solution. Earlier work considered vehicle-based decompositions that partitions the vehicles across the subproblems. The subproblems can then be optimized independently and merged easily. This paper argues that vehicle-based decompositions, although very effective on various problem classes also have limitations. In particular, they do not accommodate temporal decompositions and may produce spatial decompositions that are not focused enough. This paper then proposes customer-based decompositions which generalize vehicle-based decouplings and allows for focused spatial and temporal decompositions. Experimental results on class R2 of the extended Solomon benchmarks demonstrates the benefits of the customer-based adaptive decomposition scheme and its spatial, temporal, and hybrid instantiations. In particular, they show that customer-based decompositions bring significant benefits over large neighborhood search in contrast to vehicle-based decompositions.

  2. A New Paradigm for Supergranulation Derived from Large-Distance Time-Distance Helioseismology: Pancakes

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L.; Hanasoge, Shravan M.

    2012-01-01

    With large separations (10-24 deg heliocentric), it has proven possible to cleanly separate the horizontal and vertical components of supergranular flow with time-distance helioseismology. These measurements require very broad filters in the k-$\\omega$ power spectrum as apparently supergranulation scatters waves over a large area of the power spectrum. By picking locations of supergranulation as peaks in the horizontal divergence signal derived from f-mode waves, it is possible to simultaneously obtain average properties of supergranules and a high signal/noise ratio by averaging over many cells. By comparing ray-theory forward modeling with HMI measurements, an average supergranule model with a peak upflow of 240 m/s at cell center at a depth of 2.3 Mm and a peak horizontal outflow of 700 m/s at a depth of 1.6 Mm. This upflow is a factor of 20 larger than the measured photospheric upflow. These results may not be consistent with earlier measurements using much shorter separations (<5 deg heliocentric). With a 30 Mm horizontal extent and a few Mm in depth, the cells might be characterized as thick pancakes.

  3. Time-space Kriging to address the spatiotemporal misalignment in the large datasets.

    PubMed

    Liang, Dong; Kumar, Naresh

    2013-06-01

    This paper presents a Bayesian hierarchical spatiotemporal method of interpolation, termed as Markov Cube Kriging (MCK). The classical Kriging methods become computationally prohibitive, especially for large datasets due to the O(n(3)) matrix decomposition. MCK offers novel and computationally efficient solutions to address spatiotemporal misalignment, mismatch in the spatiotemporal scales and missing values across space and time in large spatiotemporal datasets. MCK is flexible in that it allows for non-separable spatiotemporal structure and nonstationary covariance at the hierarchical spatiotemporal scales. Employing MCK we developed estimates of daily concentration of fine particulates matter ≤2.5 μm in aerodynamic diameter (PM2.5) at 2.5 km spatial grid for the Cleveland Metropolitan Statistical Area, 2000 to 2009. Our validation and cross-validation suggest that MCK achieved robust prediction of spatiotemporal random effects and underlying hierarchical and nonstationary spatiotemporal structure in air pollution data. MCK has important implications for environmental epidemiology and environmental sciences for exposure quantification and collocation of data from different sources, available at different spatiotemporal scales. PMID:24039539

  4. The Australia Telescope Large Area Survey: Measuring the AGN contribution to galaxies over cosmic time

    NASA Astrophysics Data System (ADS)

    Chow, Kate

    2014-07-01

    The Australia Telescope Large Area Survey (ATLAS) is the widest deep radio survey ever attempted, covering ~7deg2 across its two fields, the Chandra Deep Field South (CDFS) and the European Large Area ISO Survey South 1 Region (ELAIS-S1). ATLAS has extensive multiwavelength data, including optical, infrared and X-ray, to complement its ~15μJy rms 1.4 GHz radio data. At these faint radio flux densities, the proportion of AGN to star-forming galaxies (SFGs) is high, and there are likely many composite objects, which have both an AGN and ongoing star formation. In ATLAS, we estimate that the number of AGN is approximately 50%, and this proportion will change with decreasing flux density. To understand the relationship between the AGN and the host galaxy, we need to measure the contribution of the AGN to the total luminosity, and determine how this varies with the evolutionary stage of the galaxy. Here I present results exploring the AGN contribution to galaxies over cosmic time, through the use of different multiwavelength discriminants.

  5. Time-space Kriging to address the spatiotemporal misalignment in the large datasets

    PubMed Central

    Liang, Dong; Kumar, Naresh

    2013-01-01

    This paper presents a Bayesian hierarchical spatiotemporal method of interpolation, termed as Markov Cube Kriging (MCK). The classical Kriging methods become computationally prohibitive, especially for large datasets due to the O(n3) matrix decomposition. MCK offers novel and computationally efficient solutions to address spatiotemporal misalignment, mismatch in the spatiotemporal scales and missing values across space and time in large spatiotemporal datasets. MCK is flexible in that it allows for non-separable spatiotemporal structure and nonstationary covariance at the hierarchical spatiotemporal scales. Employing MCK we developed estimates of daily concentration of fine particulates matter ≤2.5 μm in aerodynamic diameter (PM2.5) at 2.5 km spatial grid for the Cleveland Metropolitan Statistical Area, 2000 to 2009. Our validation and cross-validation suggest that MCK achieved robust prediction of spatiotemporal random effects and underlying hierarchical and nonstationary spatiotemporal structure in air pollution data. MCK has important implications for environmental epidemiology and environmental sciences for exposure quantification and collocation of data from different sources, available at different spatiotemporal scales. PMID:24039539

  6. Time-space Kriging to address the spatiotemporal misalignment in the large datasets

    NASA Astrophysics Data System (ADS)

    Liang, Dong; Kumar, Naresh

    2013-06-01

    This paper presents a Bayesian hierarchical spatiotemporal method of interpolation, termed as Markov Cube Kriging (MCK). The classical Kriging methods become computationally prohibitive, especially for large datasets due to the O(n3) matrix decomposition. MCK offers novel and computationally efficient solutions to address spatiotemporal misalignment, mismatch in the spatiotemporal scales and missing values across space and time in large spatiotemporal datasets. MCK is flexible in that it allows for non-separable spatiotemporal structure and nonstationary covariance at the hierarchical spatiotemporal scales. Employing MCK we developed estimates of daily concentration of fine particulates matter ≤2.5 μm in aerodynamic diameter (PM2.5) at 2.5 km spatial grid for the Cleveland Metropolitan Statistical Area, 2000 to 2009. Our validation and cross-validation suggest that MCK achieved robust prediction of spatiotemporal random effects and underlying hierarchical and nonstationary spatiotemporal structure in air pollution data. MCK has important implications for environmental epidemiology and environmental sciences for exposure quantification and collocation of data from different sources, available at different spatiotemporal scales.

  7. Detrending Algorithms in Large Time Series: Application to TFRM-PSES Data

    NASA Astrophysics Data System (ADS)

    del Ser, D.; Fors, O.; Núñez, J.; Voss, H.; Rosich, A.; Kouprianov, V.

    2015-07-01

    Certain instrumental effects and data reduction anomalies introduce systematic errors in photometric time series. Detrending algorithms such as the Trend Filtering Algorithm (TFA; Kovács et al. 2004) have played a key role in minimizing the effects caused by these systematics. Here we present the results obtained after applying the TFA, Savitzky & Golay (1964) detrending algorithms, and the Box Least Square phase-folding algorithm (Kovács et al. 2002) to the TFRM-PSES data (Fors et al. 2013). Tests performed on these data show that by applying these two filtering methods together the photometric RMS is on average improved by a factor of 3-4, with better efficiency towards brighter magnitudes, while applying TFA alone yields an improvement of a factor 1-2. As a result of this improvement, we are able to detect and analyze a large number of stars per TFRM-PSES field which present some kind of variability. Also, after porting these algorithms to Python and parallelizing them, we have improved, even for large data samples, the computational performance of the overall detrending+BLS algorithm by a factor of ˜10 with respect to Kovács et al. (2004).

  8. Geographic variation in marine invasions among large estuaries: effects of ships and time.

    PubMed

    Ruiz, Gregory M; Fofonoff, Paul W; Ashton, Gail; Minton, Mark S; Miller, A Whitman

    2013-03-01

    Coastal regions exhibit strong geographic patterns of nonnative species richness. Most invasions in marine ecosystems are known from bays and estuaries, where ship-mediated transfers (on hulls or in ballasted materials) have been a dominant vector of species introductions. Conspicuous spatial differences in nonnative species richness exist among bays, but the quantitative relationship between invasion magnitude and shipping activity across sites is largely unexplored. Using data on marine invasions (for invertebrates and algae) and commercial shipping across 16 large bays in the United States, we estimated (1) geographic variation in nonnative species richness attributed to ships, controlling for effects of salinity and other vectors, (2) changes through time in geographic variation of these ship-mediated invasions, and (3) effects of commercial ship traffic and ballast water discharge magnitude on nonnative species richness. For all nonnative species together (regardless of vector, salinity, or time period), species richness differed among U.S. coasts, being significantly greater for Pacific Coast bays than Atlantic or Gulf Coast bays. This difference also existed when considering only species attributed to shipping (or ballast water), controlling for time and salinity. Variation in nonnative species richness among Pacific Coast bays was strongly affected by these same criteria. San Francisco Bay, California, had over 200 documented nonnative species, more than twice that reported for other bays, but many species were associated with other (non-shipping) vectors or the extensive low-salinity habitats (unavailable in some bays). When considering only ship- or ballast-mediated introductions in high-salinity waters, the rate of newly detected invasions in San Francisco Bay has converged increasingly through time on that for other Pacific Coast bays, appearing no different since 1982. Considering all 16 bays together, there was no relationship between either (1

  9. The biotic effects of large bolide impacts: size versus time and place

    NASA Astrophysics Data System (ADS)

    Walkden, Gordon; Parker, Julian

    2008-10-01

    In estimating the biotic effects of large terrestrial impacts we are reliant upon apparent crater diameter as a proxy for impact magnitude. This underlies the ‘kill-curve’ approach which graphs crater diameter directly against likely percentage losses of taxa. However, crater diameter is a complex product of syn- and post-impact processes that can be site-dependent. Furthermore, location (global positioning) and timing (moment in geological history) also strongly influence biotic effects. We examine four of our largest and best-documented Phanerozoic impacts to explore this more holistic size time place relationship. Only the c. 180 km end-Cretaceous Chicxulub crater (Mexico) links to any substantial immediate extinction and some of the worst effects stem from where it struck the planet (a continental margin carbonate platform site) and when (a time of high regional and global biodiversity). Both the c. 100 km late Triassic Manicouagan crater in NE Canada (arid continental interior, low regional and world biodiversity) and the c. 35 Ma 100 km Popigai crater, Siberia (continental arctic desert) provide much less damaging scenarios. However the c. 90 km Chesapeake Bay crater, Eastern USA (also c. 35 Ma) marks a far more sensitive (Chicxulub-like) site but it also proved relatively benign. Here the rheologically varied shallow marine target site produced an anomalously broad crater, and the scale of the impact has evidently been overestimated. We offer a new approach to the graphical prediction of biotic risk in which both crater diameter and a generalised time/place factor we term ‘vulnerability’ are variables.

  10. Thermal motion in proteins: Large effects on the time-averaged interaction energies

    NASA Astrophysics Data System (ADS)

    Goethe, Martin; Fita, Ignacio; Rubi, J. Miguel

    2016-03-01

    As a consequence of thermal motion, inter-atomic distances in proteins fluctuate strongly around their average values, and hence, also interaction energies (i.e. the pair-potentials evaluated at the fluctuating distances) are not constant in time but exhibit pronounced fluctuations. These fluctuations cause that time-averaged interaction energies do generally not coincide with the energy values obtained by evaluating the pair-potentials at the average distances. More precisely, time-averaged interaction energies behave typically smoother in terms of the average distance than the corresponding pair-potentials. This averaging effect is referred to as the thermal smoothing effect. Here, we estimate the strength of the thermal smoothing effect on the Lennard-Jones pair-potential for globular proteins at ambient conditions using x-ray diffraction and simulation data of a representative set of proteins. For specific atom species, we find a significant smoothing effect where the time-averaged interaction energy of a single atom pair can differ by various tens of cal/mol from the Lennard-Jones potential at the average distance. Importantly, we observe a dependency of the effect on the local environment of the involved atoms. The effect is typically weaker for bulky backbone atoms in beta sheets than for side-chain atoms belonging to other secondary structure on the surface of the protein. The results of this work have important practical implications for protein software relying on free energy expressions. We show that the accuracy of free energy expressions can largely be increased by introducing environment specific Lennard-Jones parameters accounting for the fact that the typical thermal motion of protein atoms depends strongly on their local environment.

  11. Large Area Flat Panel Imaging Detectors for Astronomy and Night Time Sensing

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

    2013-09-01

    Sealed tube photo-sensing detectors for optical/IR detection have applications in astronomy, nighttime remote reconnaissance, and airborne/space situational awareness. The potential development of large area photon counting, imaging, timing detectors has significance for these applications and a number of other areas (High energy particle detection (RICH), biological single-molecule fluorescence lifetime imaging microscopy, neutron imaging, time of flight mass spectroscopy, diffraction imaging). We will present details of progress towards the development of a 20 cm sealed tube optical detector with nanoengineered microchannel plates for photon counting, imaging and sub-ns event time stamping. In the operational scheme of the photodetector incoming light passes through an entrance window and interacts with a semitransparent photocathode on the inside of the window. The photoelectrons emitted are accelerated across a proximity gap and are detected by an MCP pair. The pair of novel borosilicate substrate MCPs are functionalized by atomic layer deposition (ALD), and amplify the signal and the resulting electron cloud is detected by a conductive strip line anode for determination of the event positions and the time of arrival. The physical package is ~ 25 x 25 cm but only 1.5 cm thick. Development of such a device in a square 20 cm format presents challenges: hermetic sealing to a large entrance window, a 20 cm semitransparent photocathode with good efficiency and uniformity, 20 cm MCPs with reasonable cost and performance, robust construction to preserve high vacuum and withstand an atmosphere pressure differential. We will discuss the schemes developed to address these issues and present the results for the first test devices. The novel microchannel plates employing borosilicate micro-capillary arrays provide many performance characteristics typical of conventional MCPs, but have been made in sizes up to 20 cm, have low intrinsic background (0.08 events cm2 s-1) and

  12. Solar Wind and IMF Control of Large-Scale Ionospheric Currents and Their Time Variations

    NASA Astrophysics Data System (ADS)

    Juusola, L.; Kauristie, K.; Tanskanen, E.; Partamies, N.; Viljanen, A.; Andréeová, K.; van de Kamp, M.; Vanhamäki, H.; Milan, S. E.; Lester, M.; Grocott, A.; Imber, S. M.

    2014-12-01

    Patterns of high-latitude ionospheric currents are a manifestation of the solar wind-magnetosphere-ionosphere coupling. Rapid variations of the currents are associated with geomagnetically induced currents (GIC) in technological conductor systems and displays of bright, diverse auroras. One advantage of a ground-based magnetometer network over a low-orbit satellite is the possibility to distinguish between temporal and spatial variations in the data. Although ground magnetic field data can only yield distributions of ionospheric equivalent currents instead of the full horizontal and field-aligned current density, estimates for these can be obtained, under certain assumptions. We use data (1994-2013) from the ground-based IMAGE magnetometer network to derive statistical distributions of the large-scale ionospheric equivalent current density and its time-derivative as well as estimates for the field-aligned current density. These are compared with and validated against horizontal and field-aligned current density distributions obtained from low-orbit CHAMP satellite magnetic field data (2000-2010) and convection maps obtained from SuperDARN radar data (2000-2010). The ground-based distributions reveal a strong dependence of the dayside variations on radial interplanetary magnetic field (IMF) orientation and solar wind speed. The spatial distribution of enhanced nightside activity agrees with that of the average substorm bulge and depends on solar wind energy input into the magnetosphere. The most intense time variation events are related to substorm activity and occur on the nightside.

  13. Real-World-Time Simulation of Memory Consolidation in a Large-Scale Cerebellar Model.

    PubMed

    Gosui, Masato; Yamazaki, Tadashi

    2016-01-01

    We report development of a large-scale spiking network model of the cerebellum composed of more than 1 million neurons. The model is implemented on graphics processing units (GPUs), which are dedicated hardware for parallel computing. Using 4 GPUs simultaneously, we achieve realtime simulation, in which computer simulation of cerebellar activity for 1 s completes within 1 s in the real-world time, with temporal resolution of 1 ms. This allows us to carry out a very long-term computer simulation of cerebellar activity in a practical time with millisecond temporal resolution. Using the model, we carry out computer simulation of long-term gain adaptation of optokinetic response (OKR) eye movements for 5 days aimed to study the neural mechanisms of posttraining memory consolidation. The simulation results are consistent with animal experiments and our theory of posttraining memory consolidation. These results suggest that realtime computing provides a useful means to study a very slow neural process such as memory consolidation in the brain. PMID:26973472

  14. A web-based modular framework for real-time monitoring of large scale sensor networks

    NASA Astrophysics Data System (ADS)

    Newman, R. L.; Lindquist, K. G.; Vernon, F. L.

    2007-12-01

    The Antelope Real Time System (ARTS) is an integrated combination of protocols, acquisition systems and applications designed for real-time data collection and analysis from an array of deployed field sensors. Historically these were seismic sensors, however the open architecture of the ARTS facilitated development of acquisition protocols for a diverse group of sensors, including data streams from hf radar, meteorological instrumentation and cameras. In parallel with the expansion of data-type ingestion, a web-based interface to the ARTS was developed in PHP, a popular HTML embedded scripting language. The application-driven development of web-based software to Antelope-stored data has risen exponentially over the last four years, from simple database interactions to web-based AJAX applications similar in look and feel to desktop software. As the web-based applications have grown in complexity, the architecture around their development has matured into an extensible framework with "plug'n'play" capabilities. Their modular design has allowed multiple institutions to deploy the same web-based applications, tailored for their specific requirements. Examples include the NSF Earthscope USArray Transportable Array, ROADNet's Realtime Imagebank, the broadband seismic network monitoring of the University of Nevada Reno and University of California San Diego, and monitoring of the downhole arrays maintained by the University of California Santa Barbara. The success of these deployments suggest that such a framework could be applicable to other large scale sensor networks, including the developing Ocean Observatories project.

  15. Global Static Indexing for Real-Time Exploration of Very Large Regular Grids

    SciTech Connect

    Pascucci, V; Frank, R

    2001-07-23

    In this paper we introduce a new indexing scheme for progressive traversal and visualization of large regular grids. We demonstrate the potential of our approach by providing a tool that displays at interactive rates planar slices of scalar field data with very modest computing resources. We obtain unprecedented results both in terms of absolute performance and, more importantly, in terms of scalability. On a laptop computer we provide real time interaction with a 2048{sup 3} grid (8 Giga-nodes) using only 20MB of memory. On an SGI Onyx we slice interactively an 8192{sup 3} grid (1/2 tera-nodes) using only 60MB of memory. The scheme relies simply on the determination of an appropriate reordering of the rectilinear grid data and a progressive construction of the output slice. The reordering minimizes the amount of I/O performed during the out-of-core computation. The progressive and asynchronous computation of the output provides flexible quality/speed tradeoffs and a time-critical and interruptible user interface.

  16. Real-World-Time Simulation of Memory Consolidation in a Large-Scale Cerebellar Model

    PubMed Central

    Gosui, Masato; Yamazaki, Tadashi

    2016-01-01

    We report development of a large-scale spiking network model of the cerebellum composed of more than 1 million neurons. The model is implemented on graphics processing units (GPUs), which are dedicated hardware for parallel computing. Using 4 GPUs simultaneously, we achieve realtime simulation, in which computer simulation of cerebellar activity for 1 s completes within 1 s in the real-world time, with temporal resolution of 1 ms. This allows us to carry out a very long-term computer simulation of cerebellar activity in a practical time with millisecond temporal resolution. Using the model, we carry out computer simulation of long-term gain adaptation of optokinetic response (OKR) eye movements for 5 days aimed to study the neural mechanisms of posttraining memory consolidation. The simulation results are consistent with animal experiments and our theory of posttraining memory consolidation. These results suggest that realtime computing provides a useful means to study a very slow neural process such as memory consolidation in the brain. PMID:26973472

  17. Heritability of longevity in Large White and Landrace sows using continuous time and grouped data models

    PubMed Central

    2010-01-01

    Background Using conventional measurements of lifetime, it is not possible to differentiate between productive and non-productive days during a sow's lifetime and this can lead to estimated breeding values favoring less productive animals. By rescaling the time axis from continuous to several discrete classes, grouped survival data (discrete survival time) models can be used instead. Methods The productive life length of 12319 Large White and 9833 Landrace sows was analyzed with continuous scale and grouped data models. Random effect of herd*year, fixed effects of interaction between parity and relative number of piglets, age at first farrowing and annual herd size change were included in the analysis. The genetic component was estimated from sire, sire-maternal grandsire, sire-dam, sire-maternal grandsire and animal models, and the heritabilities computed for each model type in both breeds. Results If age at first farrowing was under 43 weeks or above 60 weeks, the risk of culling sows increased. An interaction between parity and relative litter size was observed, expressed by limited culling during first parity and severe risk increase of culling sows having small litters later in life. In the Landrace breed, heritabilities ranged between 0.05 and 0.08 (s.e. 0.014-0.020) for the continuous and between 0.07 and 0.11 (s.e. 0.016-0.023) for the grouped data models, and in the Large White breed, they ranged between 0.08 and 0.14 (s.e. 0.012-0.026) for the continuous and between 0.08 and 0.13 (s.e. 0.012-0.025) for the grouped data models. Conclusions Heritabilities for length of productive life were similar with continuous time and grouped data models in both breeds. Based on these results and because grouped data models better reflect the economical needs in meat animals, we conclude that grouped data models are more appropriate in pig. PMID:20465803

  18. Determination of paleoseismic activity over a large time-scale: Fault scarp dating with 36Cl

    NASA Astrophysics Data System (ADS)

    Mozafari Amiri, Nasim; Tikhomirov, Dmitry; Sümer, Ökmen; Özkaymak, Çaǧlar; Uzel, Bora; Ivy-Ochs, Susan; Vockenhuber, Christof; Sözbilir, Hasan; Akçar, Naki

    2016-04-01

    Bedrock fault scarps are the most direct evidence of past earthquakes to reconstruct seismic activity in a large time-scale using cosmogenic 36Cl dating if built in carbonates. For this method, a surface along the fault scarp with a minimum amount of erosion is required to be chosen as an ideal target point. The section of the fault selected for sampling should cover at least two meters of the fault surface from the lower part of the scarp, where intersects with colluvium wedge. Ideally, sampling should be performed on a continuous strip along the direction of the fault slip direction. First, samples of 10 cm high and 15 cm wide are marked on the fault surface. Then, they are collected using cutters, hammer and chisel in a thickness of 3 cm. The main geometrical factors of scarp dip, scarp height, top surface dip and colluvium dip are also measured. Topographic shielding in the sampling spot is important to be estimated as well. Moreover, density of the fault scarp and colluvium are calculated. The physical and chemical preparations are carried in laboratory for AMS and chemical analysis of the samples. A Matlab® code is used for modelling of seismically active periods based on increasing production rate of 36Cl following each rupture, when a buried section of a fault is exposed. Therefore, by measuring the amount of cosmogenic 36Cl versus height, the timing of major ruptures and their offsets are determined. In our study, Manastır, Mugırtepe and Rahmiye faults in Gediz graben, Priene-Sazlı, Kalafat and Yavansu faults in Büyük Menderes graben and Ören fault in Gökava half-graben have been examined in the seismically active region of Western Turkey. Our results reconstruct at least five periods of high seismic activity during the Holocene time, three of which reveal seismic ruptures beyond the historical pre-existing data.

  19. Energy levels and lifetimes of Nd IV, Pm IV, Sm IV, and Eu IV

    SciTech Connect

    Dzuba, V. A.; Safronova, U. I.; Johnson, W. R.

    2003-09-01

    To address the shortage of experimental data for electron spectra of triply ionized rare-earth elements we have calculated energy levels and lifetimes of 4f{sup n+1} and 4f{sup n}5d configurations of Nd IV (n=2), Pm IV (n=3), Sm IV (n=4), and Eu IV (n=5) using Hartree-Fock and configuration-interaction methods. To control the accuracy of our calculations we also performed similar calculations for Pr III, Nd III, and Sm III, for which experimental data are available. The results are important, in particular, for physics of magnetic garnets.

  20. Decentralised H∞ finite-time control equation of large-scale switched systems using robust performance minimisation

    NASA Astrophysics Data System (ADS)

    Han, Lu; Xiao, Jian; Qiu, Cunyong; Huang, Jingchun

    2016-07-01

    Many actual engineering applications can be modelled as large-scale switched system, while switching behaviours often occur in some short finite time intervals; thus, it is significant to ensure the finite-time boundedness of large-scale switched system in practical terms. In this paper, the problems of finite-time stability analysis and stabilisation for large-scale switched system are addressed. First, considering different switching signals for subsystems, the concepts of decentralised finite-time boundedness (DFTB) and decentralised finite-time H∞ controllers are introduced, which focus on the dynamical transient behaviour of large-scale switched system during finite intervals. Under these concepts, several sufficient conditions are given to ensure a class of large-scale systems decentralised finite-time stable based on the decentralised average dwell times, and then the results are extended to H∞ finite-time boundedness of large-scale switched system. Finally, based on the results on DFTB, optimal decentralised H∞ controllers and average dwell times are designed under the minimum value of H∞ performance. Numerical examples are given to illustrate the effectiveness of the proposed approaches in this paper.

  1. Large-deviation joint statistics of the finite-time Lyapunov spectrum in isotropic turbulence

    NASA Astrophysics Data System (ADS)

    Johnson, Perry L.; Meneveau, Charles

    2015-08-01

    One of the hallmarks of turbulent flows is the chaotic behavior of fluid particle paths with exponentially growing separation among them while their distance does not exceed the viscous range. The maximal (positive) Lyapunov exponent represents the average strength of the exponential growth rate, while fluctuations in the rate of growth are characterized by the finite-time Lyapunov exponents (FTLEs). In the last decade or so, the notion of Lagrangian coherent structures (which are often computed using FTLEs) has gained attention as a tool for visualizing coherent trajectory patterns in a flow and distinguishing regions of the flow with different mixing properties. A quantitative statistical characterization of FTLEs can be accomplished using the statistical theory of large deviations, based on the so-called Cramér function. To obtain the Cramér function from data, we use both the method based on measuring moments and measuring histograms and introduce a finite-size correction to the histogram-based method. We generalize the existing univariate formalism to the joint distributions of the two FTLEs needed to fully specify the Lyapunov spectrum in 3D flows. The joint Cramér function of turbulence is measured from two direct numerical simulation datasets of isotropic turbulence. Results are compared with joint statistics of FTLEs computed using only the symmetric part of the velocity gradient tensor, as well as with joint statistics of instantaneous strain-rate eigenvalues. When using only the strain contribution of the velocity gradient, the maximal FTLE nearly doubles in magnitude, highlighting the role of rotation in de-correlating the fluid deformations along particle paths. We also extend the large-deviation theory to study the statistics of the ratio of FTLEs. The most likely ratio of the FTLEs λ1 : λ2 : λ3 is shown to be about 4:1:-5, compared to about 8:3:-11 when using only the strain-rate tensor for calculating fluid volume deformations. The results

  2. Large-deviation joint statistics of the finite-time Lyapunov spectrum in isotropic turbulence

    SciTech Connect

    Johnson, Perry L. Meneveau, Charles

    2015-08-15

    One of the hallmarks of turbulent flows is the chaotic behavior of fluid particle paths with exponentially growing separation among them while their distance does not exceed the viscous range. The maximal (positive) Lyapunov exponent represents the average strength of the exponential growth rate, while fluctuations in the rate of growth are characterized by the finite-time Lyapunov exponents (FTLEs). In the last decade or so, the notion of Lagrangian coherent structures (which are often computed using FTLEs) has gained attention as a tool for visualizing coherent trajectory patterns in a flow and distinguishing regions of the flow with different mixing properties. A quantitative statistical characterization of FTLEs can be accomplished using the statistical theory of large deviations, based on the so-called Cramér function. To obtain the Cramér function from data, we use both the method based on measuring moments and measuring histograms and introduce a finite-size correction to the histogram-based method. We generalize the existing univariate formalism to the joint distributions of the two FTLEs needed to fully specify the Lyapunov spectrum in 3D flows. The joint Cramér function of turbulence is measured from two direct numerical simulation datasets of isotropic turbulence. Results are compared with joint statistics of FTLEs computed using only the symmetric part of the velocity gradient tensor, as well as with joint statistics of instantaneous strain-rate eigenvalues. When using only the strain contribution of the velocity gradient, the maximal FTLE nearly doubles in magnitude, highlighting the role of rotation in de-correlating the fluid deformations along particle paths. We also extend the large-deviation theory to study the statistics of the ratio of FTLEs. The most likely ratio of the FTLEs λ{sub 1} : λ{sub 2} : λ{sub 3} is shown to be about 4:1:−5, compared to about 8:3:−11 when using only the strain-rate tensor for calculating fluid volume

  3. Leisure Time Physical Activity of Moderate to Vigorous Intensity and Mortality: A Large Pooled Cohort Analysis

    PubMed Central

    Moore, Steven C.; Patel, Alpa V.; Matthews, Charles E.; Berrington de Gonzalez, Amy; Park, Yikyung; Katki, Hormuzd A.; Linet, Martha S.; Weiderpass, Elisabete; Visvanathan, Kala; Helzlsouer, Kathy J.; Thun, Michael; Gapstur, Susan M.; Hartge, Patricia; Lee, I-Min

    2012-01-01

    Background Leisure time physical activity reduces the risk of premature mortality, but the years of life expectancy gained at different levels remains unclear. Our objective was to determine the years of life gained after age 40 associated with various levels of physical activity, both overall and according to body mass index (BMI) groups, in a large pooled analysis. Methods and Findings We examined the association of leisure time physical activity with mortality during follow-up in pooled data from six prospective cohort studies in the National Cancer Institute Cohort Consortium, comprising 654,827 individuals, 21–90 y of age. Physical activity was categorized by metabolic equivalent hours per week (MET-h/wk). Life expectancies and years of life gained/lost were calculated using direct adjusted survival curves (for participants 40+ years of age), with 95% confidence intervals (CIs) derived by bootstrap. The study includes a median 10 y of follow-up and 82,465 deaths. A physical activity level of 0.1–3.74 MET-h/wk, equivalent to brisk walking for up to 75 min/wk, was associated with a gain of 1.8 (95% CI: 1.6–2.0) y in life expectancy relative to no leisure time activity (0 MET-h/wk). Higher levels of physical activity were associated with greater gains in life expectancy, with a gain of 4.5 (95% CI: 4.3–4.7) y at the highest level (22.5+ MET-h/wk, equivalent to brisk walking for 450+ min/wk). Substantial gains were also observed in each BMI group. In joint analyses, being active (7.5+ MET-h/wk) and normal weight (BMI 18.5–24.9) was associated with a gain of 7.2 (95% CI: 6.5–7.9) y of life compared to being inactive (0 MET-h/wk) and obese (BMI 35.0+). A limitation was that physical activity and BMI were ascertained by self report. Conclusions More leisure time physical activity was associated with longer life expectancy across a range of activity levels and BMI groups. Please see later in the article for the Editors' Summary PMID:23139642

  4. Blind-blind prediction by RELAP5/MOD1 for a 0. 1% very small cold-leg break experiment at ROSA-IV large-scale test facility

    SciTech Connect

    Koizumi, Y.; Kumamaru, H.; Kukita, Y.; Kawaji, M.; Osakabe, M.; Schultz, R.R.; Tanaka, M.; Tasaka, K.

    1986-06-01

    The large-scale test facility (LSTF) of the Rig of Safety Assessment No. 4 (ROSA-IV) program is a volumetrically scaled (1/48) pressurized water reactor (PWR) system with an electrically heated core used for integral simulation of small break loss-of-coolant accidents (LOCAs) and operational transients. The 0.1% very small cold-leg break experiment was conducted as the first integral experiment at the LSTF. The test provided a good opportunity to truly assess the state-of-the-art predictability of the safety analysis code RELAP5/MODI CY18 through a blind-blind prediction of the experiment since there was no prior experience in analyzing the experimental data with the code; furthermore, detailed operational characteristics of LSTF were not yet known. The LOCA transient was mitigated by high-pressure charging pump injection to the primary system and bleed and feed operation of the secondary system. The simulated reactor system was safely placed in hot standby condition by engineered safety features similar to those on a PWR. Natural circulation flow was established to effectively remove the decay heat generated in the core. No cladding surface temperature excursion was observed. The RELAP5 code showed good capability to predict thermal-hydraulic phenomena during the very small break LOCA transient. Although all the information needed for the analysis by the RELAP5 code was obtained solely from the engineering drawings for fabrication and the operational specifications, the code predicted key phenomena satisfactorily.

  5. Precipitation-snowmelt timing and snowmelt augmentation of large peak flow events, western Cascades, Oregon

    NASA Astrophysics Data System (ADS)

    Jennings, Keith; Jones, Julia A.

    2015-09-01

    This study tested multiple hydrologic mechanisms to explain snowpack dynamics in extreme rain-on-snow floods, which occur widely in the temperate and polar regions. We examined 26, 10 day large storm events over the period 1992-2012 in the H.J. Andrews Experimental Forest in western Oregon, using statistical analyses (regression, ANOVA, and wavelet coherence) of hourly snowmelt lysimeter, air and dewpoint temperature, wind speed, precipitation, and discharge data. All events involved snowpack outflow, but only seven events had continuous net snowpack outflow, including three of the five top-ranked peak discharge events. Peak discharge was not related to precipitation rate, but it was related to the 10 day sum of precipitation and net snowpack outflow, indicating an increased flood response to continuously melting snowpacks. The two largest peak discharge events in the study had significant wavelet coherence at multiple time scales over several days; a distribution of phase differences between precipitation and net snowpack outflow at the 12-32 h time scale with a sharp peak at π/2 radians; and strongly correlated snowpack outflow among lysimeters representing 42% of basin area. The recipe for an extreme rain-on-snow event includes persistent, slow melt within the snowpack, which appears to produce a near-saturated zone within the snowpack throughout the landscape, such that the snowpack may transmit pressure waves of precipitation directly to streams, and this process is synchronized across the landscape. Further work is needed to understand the internal dynamics of a melting snowpack throughout a snow-covered landscape and its contribution to extreme rain-on-snow floods.

  6. Multifrequency time-harmonic elastography for the measurement of liver viscoelasticity in large tissue windows.

    PubMed

    Tzschätzsch, Heiko; Ipek-Ugay, Selcan; Trong, Manh Nguyen; Guo, Jing; Eggers, Jonathan; Gentz, Enno; Fischer, Thomas; Schultz, Michael; Braun, Jürgen; Sack, Ingolf

    2015-03-01

    Elastography of the liver for the non-invasive diagnosis of hepatic fibrosis is an established method. However, investigations of obese patients or patients with ascites are often limited by small and superficial elastographic windows. Therefore, multifrequency time-harmonic elastography (THE) based on time-resolved A-line ultrasound has recently been developed for measuring liver viscoelasticity in wide soft tissue windows and at greater depths. In this study, THE was integrated into a clinical B-mode scanner connected to a dedicated actuator bed driven by superimposed vibrations of 30- to 60-Hz frequencies. The resulting shear waves in the liver were captured along multiple profiles 7 to 14 cm in width and automatically processed for reconstruction of mean efficient shear wave speed and shear wave dispersion slope. This new modality was tested in healthy volunteers and 22 patients with clinically proven cirrhosis. Patients could be separated from controls by higher shear wave speeds (3.11 ± 0.64 m/s, 2.14-4.81 m/s, vs. 1.74 ± 0.10 m/s, 1.60-1.91 m/s) without significant degradation of data by high body mass index or ascites. Furthermore, the wave speed dispersion slope was significantly (p = 0.0025) lower in controls (5.2 ± 1.8 m/s/kHz) than in patients (39.1 ± 32.2 m/s/kHz). In conclusion, THE is useful for the diagnosis of cirrhosis in large tissue windows. PMID:25638319

  7. Storm-time Large-Scale Birkeland Currents: Salient Dynamics in Grand Challenge Events

    NASA Astrophysics Data System (ADS)

    Korth, H.; Anderson, B. J.; Waters, C. L.; Barnes, R. J.

    2015-12-01

    The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) provides continuous global observations of Birkeland currents on a 10 minute cadence. During geomagnetic storms, currents intensify to over 15 MA, are dynamic both in intensity and distribution, and exhibit features not discernible in statistical analyses. For all of the subject grand challenge storms, AMPERE data reveal a number of novel phenomena illustrating the profound dynamics of the storm-time system. Storm-time onsets associated with shock arrivals are often very prompt and lead to dramatic surges in total current from 1 MA to over 5 MA in less than 20 minutes. The current surges occur predominantly on the dayside at high latitudes prior to any ring current or auroral expansions, indicating that neutral density upwelling is often driven independently of ring current or auroral zone intensifications. Rapid reconfigurations of the currents with IMF BY reversals within the sheath structures of coronal mass ejections (CMEs) are also common. This implies that convection of ionospheric density patches over the polar cap may be quite complex, particularly during the early phase of geomagnetic storms related to the CME sheath passage. The 3 September 2012 storm exhibited intense driving with classic quasi-stable Region 1 and 2 currents spanning 55 to 70 degrees magnetic latitude for over 10 hours at the beginning of the day, corresponding to stable southward IMF prior to shock arrival at noon on that day. The shock arrival and IMF southward intensification led to further expansion of the currents below 50 degrees magnetic latitude and to episodic surges in currents on the nightside, which is unique to storms. The resulting current structure showed multiple large-scale alternations in downward-upward-downward-upward direction that often occurs during intense, sustained driving during strong storms.

  8. "Tools For Analysis and Visualization of Large Time- Varying CFD Data Sets"

    NASA Technical Reports Server (NTRS)

    Wilhelms, Jane; vanGelder, Allen

    1999-01-01

    During the four years of this grant (including the one year extension), we have explored many aspects of the visualization of large CFD (Computational Fluid Dynamics) datasets. These have included new direct volume rendering approaches, hierarchical methods, volume decimation, error metrics, parallelization, hardware texture mapping, and methods for analyzing and comparing images. First, we implemented an extremely general direct volume rendering approach that can be used to render rectilinear, curvilinear, or tetrahedral grids, including overlapping multiple zone grids, and time-varying grids. Next, we developed techniques for associating the sample data with a k-d tree, a simple hierarchial data model to approximate samples in the regions covered by each node of the tree, and an error metric for the accuracy of the model. We also explored a new method for determining the accuracy of approximate models based on the light field method described at ACM SIGGRAPH (Association for Computing Machinery Special Interest Group on Computer Graphics) '96. In our initial implementation, we automatically image the volume from 32 approximately evenly distributed positions on the surface of an enclosing tessellated sphere. We then calculate differences between these images under different conditions of volume approximation or decimation.

  9. A timing constraint on the (total) mass of the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Peñarrubia, Jorge; Gómez, Facundo A.; Besla, Gurtina; Erkal, Denis; Ma, Yin-Zhe

    2016-02-01

    This paper explores the effect of the Large Magellanic Cloud (LMC) on the mass estimates obtained from the timing argument. We show that accounting for the presence of the LMC systematically lowers the Local Group mass (MLG) derived from the relative motion of the Milky Way-Andromeda pair. Motivated by this result, we apply a Bayesian technique devised by Peñarrubia et al. to simultaneously fit (i) distances and velocities of galaxies within 3 Mpc and (ii) the relative motion between the Milky Way and Andromeda derived from HST observations, with the LMC mass (MLMC) as a free parameter. Our analysis returns a Local Group mass M_LG=2.64^{+0.42}_{-0.38}× 10^{12} M_{⊙} at a 68 per cent confidence level. The masses of the Milky Way, M_MW=1.04_{-0.23}^{+0.26}× 10^{12} M_{⊙}, and Andromeda, M_{M31}=1.33_{-0.33}^{+0.39}× 10^{12} M_{⊙}, are consistent with previous estimates that neglect the impact of the LMC on the observed Hubble flow. We find a (total) LMC mass M_LMC=0.25_{-0.08}^{+0.09}× 10^{12} M_{⊙}, which is indicative of an extended dark matter halo and supports the scenario where this galaxy is just past its first pericentric approach. Consequently, these results suggest that the LMC may induce significant perturbations on the Galactic potential.

  10. Near linear time algorithm to detect community structures in large-scale networks

    NASA Astrophysics Data System (ADS)

    Raghavan, Usha Nandini; Albert, Réka; Kumara, Soundar

    2007-09-01

    Community detection and analysis is an important methodology for understanding the organization of various real-world networks and has applications in problems as diverse as consensus formation in social communities or the identification of functional modules in biochemical networks. Currently used algorithms that identify the community structures in large-scale real-world networks require a priori information such as the number and sizes of communities or are computationally expensive. In this paper we investigate a simple label propagation algorithm that uses the network structure alone as its guide and requires neither optimization of a predefined objective function nor prior information about the communities. In our algorithm every node is initialized with a unique label and at every step each node adopts the label that most of its neighbors currently have. In this iterative process densely connected groups of nodes form a consensus on a unique label to form communities. We validate the algorithm by applying it to networks whose community structures are known. We also demonstrate that the algorithm takes an almost linear time and hence it is computationally less expensive than what was possible so far.

  11. On the problem of earthquake correlation in space and time over large distances

    NASA Astrophysics Data System (ADS)

    Georgoulas, G.; Konstantaras, A.; Maravelakis, E.; Katsifarakis, E.; Stylios, C. D.

    2012-04-01

    A quick examination of geographical maps with the epicenters of earthquakes marked on them reveals a strong tendency of these points to form compact clusters of irregular shapes and various sizes often traversing with other clusters. According to [Saleur et al. 1996] "earthquakes are correlated in space and time over large distances". This implies that seismic sequences are not formatted randomly but they follow a spatial pattern with consequent triggering of events. Seismic cluster formation is believed to be due to underlying geological natural hazards, which: a) act as the energy storage elements of the phenomenon, and b) tend to form a complex network of numerous interacting faults [Vallianatos and Tzanis, 1998]. Therefore it is imperative to "isolate" meaningful structures (clusters) in order to mine information regarding the underlying mechanism and at a second stage to test the causality effect implied by what is known as the Domino theory [Burgman, 2009]. Ongoing work by Konstantaras et al. 2011 and Katsifarakis et al. 2011 on clustering seismic sequences in the area of the Southern Hellenic Arc and progressively throughout the Greek vicinity and the entire Mediterranean region based on an explicit segmentation of the data based both on their temporal and spatial stamp, following modelling assumptions proposed by Dobrovolsky et al. 1989 and Drakatos et al. 2001, managed to identify geologically validated seismic clusters. These results suggest that that the time component should be included as a dimension during the clustering process as seismic cluster formation is dynamic and the emerging clusters propagate in time. Another issue that has not been investigated yet explicitly is the role of the magnitude of each seismic event. In other words the major seismic event should be treated differently compared to pre or post seismic sequences. Moreover the sometimes irregular and elongated shapes that appear on geophysical maps means that clustering algorithms

  12. IV treatment at home

    MedlinePlus

    ... 24 hours a day. If there is a problem with the IV, you can call your home health care agency for help. If the IV comes out of ... bleeding stops. Then call the home health care agency or the doctor right away.

  13. Using PLATO IV.

    ERIC Educational Resources Information Center

    Meller, David V.

    This beginning reference manual describes PLATO IV hardware for prospective users and provides an introduction to PLATO for new authors. The PLATO terminal is described in detail in Chapter 1. Chapter 2 provides a block diagram of the PLATO IV system. Procedures for getting on line are described in Chapter 3, and Chapter 4 provides references to…

  14. Comparing two fish sampling standards over time: largely congruent results but with caveats

    USGS Publications Warehouse

    Yule, Daniel L.; Evrard, Lori M.; Cachera, Sébastien; Colon, Michel; Guillard, Jean

    2013-01-01

    1. We sampled Lake Bourget (surface area = 44 km2) using CEN standard gillnet and provisional standard acoustic survey methods over 3 years (2005, 2010 and 2011) as the fish community responded to re-oligotrophication. A total of 16 species were caught in benthic gillnets and three species in pelagic gillnets. 2. Lake Bourget results were consistent with a recent study (Emmrich et al., Freshwater Biology, 57, 2012, 2436) showing strong correspondence between average biomass-per-unit-effort (BPUE) in standard benthic gillnets and average acoustic volume backscattering when smaller lakes (0.25–5.45 km2) were treated as sample units. 3. The BPUE of whitefish (Coregonus lavaretus), perch (Perca fluviatilis) and roach (Rutilus rutilus) measured by benthic gillnets all declined significantly with increasing bathymetric depth; 93% of nets set at depths >50 m caught zero fish. 4. Pelagic gillnetting indicated that small (20 m) increased significantly after 2005. 5. Both surveys showed whitefish biomass increased significantly during the study, but whitefish ≥25 cm were poorly represented in benthic gillnet catches. Contrary to the acoustic findings, the BPUE of perch and roach in benthic gillnets did not vary significantly over time. This metric is insensitive to changes in size structure in that a high catch of small fish and a low catch of large fish in different years can provide similar average BPUE estimates. 6. We examined correlations between BPUE in benthic gillnets and acoustic methods at fine spatial scales by averaging acoustic backscattering measurements encompassed by buffers of varying size (250–2000 m) around individual gillnets and by averaging samples collected from lake quadrants. Correlations at fines scales were generally poor, and only in 1 year was the quadrant correlation significant. The lack of correlation can be explained, in part, by the two gears sampling different components of the fish community. Conversely, in pelagic habitat, where the

  15. Tools for Analysis and Visualization of Large Time-Varying CFD Data Sets

    NASA Technical Reports Server (NTRS)

    Wilhelms, Jane; VanGelder, Allen

    1997-01-01

    In the second year, we continued to built upon and improve our scanline-based direct volume renderer that we developed in the first year of this grant. This extremely general rendering approach can handle regular or irregular grids, including overlapping multiple grids, and polygon mesh surfaces. It runs in parallel on multi-processors. It can also be used in conjunction with a k-d tree hierarchy, where approximate models and error terms are stored in the nodes of the tree, and approximate fast renderings can be created. We have extended our software to handle time-varying data where the data changes but the grid does not. We are now working on extending it to handle more general time-varying data. We have also developed a new extension of our direct volume renderer that uses automatic decimation of the 3D grid, as opposed to an explicit hierarchy. We explored this alternative approach as being more appropriate for very large data sets, where the extra expense of a tree may be unacceptable. We also describe a new approach to direct volume rendering using hardware 3D textures and incorporates lighting effects. Volume rendering using hardware 3D textures is extremely fast, and machines capable of using this technique are becoming more moderately priced. While this technique, at present, is limited to use with regular grids, we are pursuing possible algorithms extending the approach to more general grid types. We have also begun to explore a new method for determining the accuracy of approximate models based on the light field method described at ACM SIGGRAPH '96. In our initial implementation, we automatically image the volume from 32 equi-distant positions on the surface of an enclosing tessellated sphere. We then calculate differences between these images under different conditions of volume approximation or decimation. We are studying whether this will give a quantitative measure of the effects of approximation. We have created new tools for exploring the

  16. How the timing of weather events influences early development in a large mammal.

    PubMed

    Hendrichsen, D K; Tyler, N J C

    2014-07-01

    Capturing components of the weather that drive environment-animal interactions is a perennial problem in ecology. Identifying biologically significant elements of weather conditions in sensible statistics suitable for analysis of life history variation and population dynamics is central. Meteorological variables such as temperature, precipitation, and wind modulate rates of heat loss in animals, but analysis of their effects on endothermic species is complicated by the fact that their influence on energy balance is not invariably linear, even across the thermoneutral range. Rather, the thermal load imposed by a given set of weather conditions is a function of organisms' metabolic requirement, which, crucially, may vary spontaneously both seasonally and across different life phases. We propose that the endogenous component of variation in metabolic demand introduces a temporal dimension and that, as a consequence, the specific effect of meteorological variables on energy balance and attendant life history parameters is a function of the timing of weather events with respect to the organism's metabolic rhythm(s). To test this, we examined how a spontaneous increase in metabolic demand influenced the effect of weather on early development in a large mammal. Specifically, we examined interaction between the exponential rise in the energy requirements of pregnancy and depth of snow, which restricts dams' access to forage, on the body mass of reindeer calves (Rangifer tarandus) at weaning. As expected, we detected a significant temporal component: the specific negative effect of snow on weaning mass was not constant, but increased across pregnancy. The life history response was therefore better predicted by interaction between the magnitude and the timing of weather events than by their magnitude alone. To our knowledge, this is the first demonstration of the influence of an endogenous metabolic dynamic on the impact of weather on a life history trait in a free

  17. The Potential of Time Series Based Earth Observation for the Monitoring of Large River Deltas

    NASA Astrophysics Data System (ADS)

    Kuenzer, C.; Leinenkugel, P.; Huth, J.; Ottinger, M.; Renaud, F.; Foufoula-Georgiou, E.; Vo Khac, T.; Trinh Thi, L.; Dech, S.; Koch, P.; Le Tissier, M.

    2015-12-01

    Although river deltas only contribute 5% to the overall land surface, nearly six hundred million people live in these complex social-ecological environments, which combine a variety of appealing locational advantages. In many countries deltas provide the major national contribution to agricultural and industrial production. At the same time these already very dynamic environments are exposed to a variety of threats, including the disturbance and replacement of valuable ecosystems, increasing water, soil, and air pollution, human induced land subsidence, sea level rise, as well upstream developments impacting water and sediment supplies. A constant monitoring of delta systems is thus of utmost relevance for understanding past and current land surface change and anticipating possible future developments. We present the potential of Earth Observation based analyses and derived novel information products that can play a key role in this context. Along with the current trend of opening up numerous satellite data archives go increasing capabilities to explore big data. Whereas in past decades remote sensing data were analysed based on the spectral-reflectance-defined 'finger print' of individual surfaces, we mainly exploit the 'temporal fingerprints' of our land surface in novel pathways of data analyses at differing spatial-, and temporally-dense scales. Following our results on an Earth Observation based characterization of large deltas globally, we present in depth results from the Mekong Delta in Vietnam, the Yellow River Delta in China, the Niger Delta in Nigeria, as well as additional deltas, focussing on the assessment of river delta flood and inundation dynamics, river delta coastline dynamics, delta morphology dynamics including the quantification of erosion and accretion processes, river delta land use change and trends, as well as the monitoring of compliance to environmental regulations.

  18. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV

    SciTech Connect

    Lupone, S.; Damoy, S.; Husseen, A.; Briand, N.; Debiossac, M.; Tall, S.; Roncin, P.

    2015-12-15

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  19. Students' Understanding of Large Numbers as a Key Factor in Their Understanding of Geologic Time

    ERIC Educational Resources Information Center

    Cheek, Kim A.

    2012-01-01

    An understanding of geologic time is comprised of 2 facets. Events in Earth's history can be placed in relative and absolute temporal succession on a vast timescale. Rates of geologic processes vary widely, and some occur over time periods well outside human experience. Several factors likely contribute to an understanding of geologic time, one of…

  20. IV treatment at home

    MedlinePlus

    ... home; PICC line - home; Infusion therapy - home; Home health care - IV treatment ... Often, home health care nurses will come to your home to give you the medicine. Sometimes, a family member, a friend, or ...

  1. GCF Mark IV development

    NASA Technical Reports Server (NTRS)

    Mortensen, L. O.

    1982-01-01

    The Mark IV ground communication facility (GCF) as it is implemented to support the network consolidation program is reviewed. Changes in the GCF are made in the area of increased capacity. Common carrier circuits are the medium for data transfer. The message multiplexing in the Mark IV era differs from the Mark III era, in that all multiplexing is done in a GCF computer under GCF software control, which is similar to the multiplexing currently done in the high speed data subsystem.

  2. Visual analytics techniques for large multi-attribute time series data

    NASA Astrophysics Data System (ADS)

    Hao, Ming C.; Dayal, Umeshwar; Keim, Daniel A.

    2008-01-01

    Time series data commonly occur when variables are monitored over time. Many real-world applications involve the comparison of long time series across multiple variables (multi-attributes). Often business people want to compare this year's monthly sales with last year's sales to make decisions. Data warehouse administrators (DBAs) want to know their daily data loading job performance. DBAs need to detect the outliers early enough to act upon them. In this paper, two new visual analytic techniques are introduced: The color cell-based Visual Time Series Line Charts and Maps highlight significant changes over time in a long time series data and the new Visual Content Query facilitates finding the contents and histories of interesting patterns and anomalies, which leads to root cause identification. We have applied both methods to two real-world applications to mine enterprise data warehouse and customer credit card fraud data to illustrate the wide applicability and usefulness of these techniques.

  3. Synthesis procedure for linear time-varying feedback systems with large parameter ignorance

    NASA Technical Reports Server (NTRS)

    Mcdonald, T. E., Jr.

    1972-01-01

    The development of synthesis procedures for linear time-varying feedback systems is considered. It is assumed that the plant can be described by linear differential equations with time-varying coefficients; however, ignorance is associated with the plant in that only the range of the time-variations are known instead of exact functional relationships. As a result of this plant ignorance the use of time-varying compensation is ineffective so that only time-invariant compensation is employed. In addition, there is a noise source at the plant output which feeds noise through the feedback elements to the plant input. Because of this noise source the gain of the feedback elements must be as small as possible. No attempt is made to develop a stability criterion for time-varying systems in this work.

  4. Real-Time Large Scale 3d Reconstruction by Fusing Kinect and Imu Data

    NASA Astrophysics Data System (ADS)

    Huai, J.; Zhang, Y.; Yilmaz, A.

    2015-08-01

    Kinect-style RGB-D cameras have been used to build large scale dense 3D maps for indoor environments. These maps can serve many purposes such as robot navigation, and augmented reality. However, to generate dense 3D maps of large scale environments is still very challenging. In this paper, we present a mapping system for 3D reconstruction that fuses measurements from a Kinect and an inertial measurement unit (IMU) to estimate motion. Our major achievements include: (i) Large scale consistent 3D reconstruction is realized by volume shifting and loop closure; (ii) The coarse-to-fine iterative closest point (ICP) algorithm, the SIFT odometry, and IMU odometry are combined to robustly and precisely estimate pose. In particular, ICP runs routinely to track the Kinect motion. If ICP fails in planar areas, the SIFT odometry provides incremental motion estimate. If both ICP and the SIFT odometry fail, e.g., upon abrupt motion or inadequate features, the incremental motion is estimated by the IMU. Additionally, the IMU also observes the roll and pitch angles which can reduce long-term drift of the sensor assembly. In experiments on a consumer laptop, our system estimates motion at 8Hz on average while integrating color images to the local map and saving volumes of meshes concurrently. Moreover, it is immune to tracking failures, and has smaller drift than the state-of-the-art systems in large scale reconstruction.

  5. Hard X-ray time profiles and acceleration processes in large solar flares

    NASA Technical Reports Server (NTRS)

    Bai, T.; Ramaty, R.

    1979-01-01

    The hard X-ray time profiles of the (1972) August 4 and 7 flares are investigated, taking into account a comparison of the time profiles of different energy channels. It is shown that for these flares the temporal features of the intensity profiles of higher energy channels are delayed with respect to those of channel 1. The delay time gradually increases to approximately 5 sec as the channel number increases from 1 to 5, and it jumps to approximately 15 sec for channels 6 and 7. A description is presented of a model in which the delay and other characteristics of the observed time profiles in channels 1-5 are self-consistently explained by the increase of the electron energy loss time with electron energy.

  6. GSFC IVS Technology Development Center Report

    NASA Technical Reports Server (NTRS)

    Himwich, Ed; Vandenberg, Nancy; Clark, Tom

    2001-01-01

    This report summarizes the activities of the Goddard Space Flight Center's (GSFC's) International Very Long Base Interferometry (VLBI) Service (IVS)Technology Development Center from the establishment of IVS to the end of 2000. The report forecasts activities planned for the year 2001. The GSFC IVS Technology Development Center (TDC) develops station software including the Field System (FS), scheduling software (SKED), hardware including tools for station timing and meteorology, scheduling algorithms, operational procedures, and provides a pool of individuals to assist with station implementation, check-out, upgrades, and training.

  7. Decentralised robust stabilisation of uncertain large-scale interconnected time-delay systems with unknown upper bounds of uncertainties

    NASA Astrophysics Data System (ADS)

    Wu, Hansheng

    2016-09-01

    The problem of decentralised robust stabilisation is considered for a class of uncertain large-scale time-delay interconnected dynamical systems. In the paper, the upper bounds of delayed state perturbations, uncertainties, interconnection terms, and external disturbances are assumed to be completely unknown, and the delays are assumed to be any non-negative constants. For such a class of uncertain large-scale time-delay interconnected systems, a new method is presented whereby a class of adaptation-free decentralised local robust state feedback controllers can be constructed. In addition, it is also shown that the solutions of uncertain large-scale time-delay interconnected systems can be guaranteed to be uniformly ultimately bounded. Finally, as an application to the practical mechanical systems, some simulations of a numerical example are provided to demonstrate the validity of the theoretical results.

  8. Design for the correction system of the real time nonuniformity of large area-array CCD image

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Li, Chunmei; Lei, Ning

    2012-10-01

    With the robust thriving of aviation cameras and remote sensing technology, the linear-array CCD (charge-coupled device) and area CCD have developed toward large area CCD, which has a broad coverage and avoids the difficulty in jointing small area CCDs in addition to improving time resolution. However, due to the high amount of pixels and channels of large area CCD, photo-response non-uniformity (PRNU) is severe. In this paper, a real time non-uniformity correction system is introduced for a sort of large area full frame transfer CCD. First, the correction algorithm is elaborated according to CCD's working principle. Secondly, due to the high number of pixels and correction coefficient, ordinary chip memory cannot meet the requirement. The combination of external flash memory and DDR described in the paper satisfies large capacity memory and rapid real time correction. The methods and measurement steps for obtaining correction factors are provided simultaneously. At the end, an imaging test is made. The non-uniformity of the image is reduced to 0.38 % from the pre-correction 2.96 %, achieving an obvious reduction of non-uniformity. The result shows that the real time non-uniformity correction system can meet the demands of large area-array CCD.

  9. A Hybrid Coarse-graining Approach for Lipid Bilayers at Large Length and Time Scales

    PubMed Central

    Ayton, Gary S.; Voth, Gregory A.

    2009-01-01

    A hybrid analytic-systematic (HAS) coarse-grained (CG) lipid model is developed and employed in a large-scale simulation of a liposome. The methodology is termed hybrid analyticsystematic as one component of the interaction between CG sites is variationally determined from the multiscale coarse-graining (MS-CG) methodology, while the remaining component utilizes an analytic potential. The systematic component models the in-plane center of mass interaction of the lipids as determined from an atomistic-level MD simulation of a bilayer. The analytic component is based on the well known Gay-Berne ellipsoid of revolution liquid crystal model, and is designed to model the highly anisotropic interactions at a highly coarse-grained level. The HAS CG approach is the first step in an “aggressive” CG methodology designed to model multi-component biological membranes at very large length and timescales. PMID:19281167

  10. Implications of cosmic strings with time-varying tension on the CMB and large scale structure

    SciTech Connect

    Ichikawa, Kazuhide; Takahashi, Tomo; Yamaguchi, Masahide

    2006-09-15

    We investigate cosmological evolution and implications of cosmic strings with time-dependent tension. We derive basic equations of time development of the correlation length and the velocity of such strings, based on the one-scale model. Then, we find that, in the case where the tension depends on some power of the cosmic time, cosmic strings with time-dependent tension goes into the scaling 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.