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Sample records for 1st order autocorrelation

  1. Distributions of Autocorrelated First-Order Kinetic Outcomes: Illness Severity.

    PubMed

    Englehardt, James D

    2015-01-01

    Many complex systems produce outcomes having recurring, power law-like distributions over wide ranges. However, the form necessarily breaks down at extremes, whereas the Weibull distribution has been demonstrated over the full observed range. Here the Weibull distribution is derived as the asymptotic distribution of generalized first-order kinetic processes, with convergence driven by autocorrelation, and entropy maximization subject to finite positive mean, of the incremental compounding rates. Process increments represent multiplicative causes. In particular, illness severities are modeled as such, occurring in proportion to products of, e.g., chronic toxicant fractions passed by organs along a pathway, or rates of interacting oncogenic mutations. The Weibull form is also argued theoretically and by simulation to be robust to the onset of saturation kinetics. The Weibull exponential parameter is shown to indicate the number and widths of the first-order compounding increments, the extent of rate autocorrelation, and the degree to which process increments are distributed exponential. In contrast with the Gaussian result in linear independent systems, the form is driven not by independence and multiplicity of process increments, but by increment autocorrelation and entropy. In some physical systems the form may be attracting, due to multiplicative evolution of outcome magnitudes towards extreme values potentially much larger and smaller than control mechanisms can contain. The Weibull distribution is demonstrated in preference to the lognormal and Pareto I for illness severities versus (a) toxicokinetic models, (b) biologically-based network models, (c) scholastic and psychological test score data for children with prenatal mercury exposure, and (d) time-to-tumor data of the ED01 study. PMID:26061263

  2. Distributions of Autocorrelated First-Order Kinetic Outcomes: Illness Severity

    PubMed Central

    Englehardt, James D.

    2015-01-01

    Many complex systems produce outcomes having recurring, power law-like distributions over wide ranges. However, the form necessarily breaks down at extremes, whereas the Weibull distribution has been demonstrated over the full observed range. Here the Weibull distribution is derived as the asymptotic distribution of generalized first-order kinetic processes, with convergence driven by autocorrelation, and entropy maximization subject to finite positive mean, of the incremental compounding rates. Process increments represent multiplicative causes. In particular, illness severities are modeled as such, occurring in proportion to products of, e.g., chronic toxicant fractions passed by organs along a pathway, or rates of interacting oncogenic mutations. The Weibull form is also argued theoretically and by simulation to be robust to the onset of saturation kinetics. The Weibull exponential parameter is shown to indicate the number and widths of the first-order compounding increments, the extent of rate autocorrelation, and the degree to which process increments are distributed exponential. In contrast with the Gaussian result in linear independent systems, the form is driven not by independence and multiplicity of process increments, but by increment autocorrelation and entropy. In some physical systems the form may be attracting, due to multiplicative evolution of outcome magnitudes towards extreme values potentially much larger and smaller than control mechanisms can contain. The Weibull distribution is demonstrated in preference to the lognormal and Pareto I for illness severities versus (a) toxicokinetic models, (b) biologically-based network models, (c) scholastic and psychological test score data for children with prenatal mercury exposure, and (d) time-to-tumor data of the ED01 study. PMID:26061263

  3. 1st- and 2nd-order motion and texture resolution in central and peripheral vision

    NASA Technical Reports Server (NTRS)

    Solomon, J. A.; Sperling, G.

    1995-01-01

    STIMULI. The 1st-order stimuli are moving sine gratings. The 2nd-order stimuli are fields of static visual texture, whose contrasts are modulated by moving sine gratings. Neither the spatial slant (orientation) nor the direction of motion of these 2nd-order (microbalanced) stimuli can be detected by a Fourier analysis; they are invisible to Reichardt and motion-energy detectors. METHOD. For these dynamic stimuli, when presented both centrally and in an annular window extending from 8 to 10 deg in eccentricity, we measured the highest spatial frequency for which discrimination between +/- 45 deg texture slants and discrimination between opposite directions of motion were each possible. RESULTS. For sufficiently low spatial frequencies, slant and direction can be discriminated in both central and peripheral vision, for both 1st- and for 2nd-order stimuli. For both 1st- and 2nd-order stimuli, at both retinal locations, slant discrimination is possible at higher spatial frequencies than direction discrimination. For both 1st- and 2nd-order stimuli, motion resolution decreases 2-3 times more rapidly with eccentricity than does texture resolution. CONCLUSIONS. (1) 1st- and 2nd-order motion scale similarly with eccentricity. (2) 1st- and 2nd-order texture scale similarly with eccentricity. (3) The central/peripheral resolution fall-off is 2-3 times greater for motion than for texture.

  4. 26. Photograph of original Fresnel lens a 1st order fixed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Photograph of original Fresnel lens a 1st order fixed white light. (Installed 1874 and first illuminated Feb. 1, 1875. This is the only known photograph of this lens - - removed in 1929.)ca. 1918. - Block Island Southeast Light, Spring Street & Mohegan Trail at Mohegan Bluffs, New Shoreham, Washington County, RI

  5. Magnetic field induced 1st order transitions: Recent studies, and some new concepts

    NASA Astrophysics Data System (ADS)

    Chaddah, P.

    2015-05-01

    Phase transitions are caused by varying temperature, or pressure, or magnetic field. The observation of 1st order magneto-structural transitions has created application possibilities based on magnetoresistance, magnetocaloric effect, magnetic shape memory effect, and magneto-dielectric effect. Magnetic field induced transitions, and phase coexistence of competing magnetic phases down to the lowest temperature, gained prominence over a decade ago with theoretical models suggesting that the ground state is not homogeneous. Researchers at Indore pushed an alternative view that this phase coexistence could be due to glasslike "kinetic arrest" of a disorder-broadened first-order magnetic transition between two states with long-range magnetic order, resulting in phase coexistence down to the lowest temperatures. The CHUF (cooling and heating in unequal field) protocol created at Indore allows the observation of `devitrification', followed by `melting'. I show examples of measurements establishing kinetic arrest in various materials, emphasizing that glasslike arrest of 1st order magnetic transitions may be as ubiquitous as glass formation following the arrest of 1st order structural transitions.

  6. Four-dimensional investigation of the 2nd order volume autocorrelation technique

    NASA Astrophysics Data System (ADS)

    Faucher, O.; Tzallas, P.; Benis, E. P.; Kruse, J.; Peralta Conde, A.; Kalpouzos, C.; Charalambidis, D.

    2009-10-01

    The 2nd order volume autocorrelation technique, widely utilized in directly measuring ultra-short light pulses durations, is examined in detail via model calculations that include three-dimensional integration over a large ionization volume, temporal delay and spatial displacement of the two beams of the autocorrelator at the focus. The effects of the inherent displacement to the 2nd order autocorrelation technique are demonstrated for short and long pulses, elucidating the appropriate implementation of the technique in tight focusing conditions. Based on the above investigations, a high accuracy 2nd order volume autocorrelation measurement of the duration of the 5th harmonic of a 50 fs long laser pulse, including the measurement of the carrier wavelength oscillation, is presented.

  7. Dimensionality dependence of aging in kinetics of diffusive phase separation: Behavior of order-parameter autocorrelation

    NASA Astrophysics Data System (ADS)

    Midya, Jiarul; Majumder, Suman; Das, Subir K.

    2015-08-01

    Behavior of two-time autocorrelation during the phase separation in solid binary mixtures is studied via numerical solutions of the Cahn-Hilliard equation as well as Monte Carlo simulations of the Ising model. Results are analyzed via state-of-the-art methods, including the finite-size scaling technique. Full forms of the autocorrelation in space dimensions 2 and 3 are obtained empirically. The long-time behavior is found to be power law, with exponents unexpectedly higher than the ones for the ferromagnetic ordering. Both Cahn-Hilliard and Ising models provide consistent results.

  8. Dimensionality dependence of aging in kinetics of diffusive phase separation: Behavior of order-parameter autocorrelation.

    PubMed

    Midya, Jiarul; Majumder, Suman; Das, Subir K

    2015-08-01

    Behavior of two-time autocorrelation during the phase separation in solid binary mixtures is studied via numerical solutions of the Cahn-Hilliard equation as well as Monte Carlo simulations of the Ising model. Results are analyzed via state-of-the-art methods, including the finite-size scaling technique. Full forms of the autocorrelation in space dimensions 2 and 3 are obtained empirically. The long-time behavior is found to be power law, with exponents unexpectedly higher than the ones for the ferromagnetic ordering. Both Cahn-Hilliard and Ising models provide consistent results. PMID:26382361

  9. Fifth-order intensity autocorrelations based on six-wave mixing of femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Gaižauskas, Eugenijus; Steponkevičius, KÈ©stutis; Vaičaitis, Virgilijus

    2016-02-01

    It is shown both experimentally and by numerical simulations that fifth-order intensity autocorrelations of femtosecond laser pulses can be obtained from two-beam noncollinear six-wave mixing in air. A numerical analysis of competing direct and six-wave-assisted third-harmonic-generation pathways showed that these measurements are suitable for the background-free temporal characterization of laser pulses. Reshaping of the pulse and 10 fs subpulse formation during the primary stages of light filamentation were observed using the proposed method.

  10. Euclidean Dynamical Triangulation revisited: is the phase transition really 1st order?

    NASA Astrophysics Data System (ADS)

    Rindlisbacher, Tobias; de Forcrand, Philippe

    2015-05-01

    The transition between the two phases of 4D Euclidean Dynamical Triangulation [1] was long believed to be of second order until in 1996 first order behavior was found for sufficiently large systems [5, 9]. However, one may wonder if this finding was affected by the numerical methods used: to control volume fluctuations, in both studies [5, 9] an artificial harmonic potential was added to the action and in [9] measurements were taken after a fixed number of accepted instead of attempted moves which introduces an additional error. Finally the simulations suffer from strong critical slowing down which may have been underestimated.

  11. Polymer desorption under pulling a 1st - order phase transition without phase coexistence

    NASA Astrophysics Data System (ADS)

    Milchev, A.; Rostiashvili, V. G.; Bhattacharya, S.; Vilgis, T. A.

    2010-02-01

    We show that when a self-avoiding polymer chain is pulled off a sticky surface by force applied to the end segment, it undergoes a first-order thermodynamic phase transition albeit without phase coexistence. This unusual feature is demonstrated analytically by means of a Grand Canonical Ensemble (GCE) description of adsorbed macromolecules as well as by Monte Carlo simulations of an off-lattice bead-spring model of a polymer chain. Theoretical treatment and computer experiment can be carried out both in the constant force statistical ensembl whereby at fixed pulling force f one measures the mean height < h > of the chain end above the adsorbing plane, and in the constant-height ensemble where for a given height h one monitors the resulting force < f > applied at the last segment. We find that the force-assisted desorption undergoes a first-order dichotomic phase transition whereby phase coexistence between adsorbed and desorbed states does not exist. In the f-ensemble the order parameter (the fraction of chain contacts with the surface) is characterized by huge fluctuations when the pulling force attains a critical value fD. In the h-ensemble, in contrast, fluctuations are always finite at the critical height hD. The derived analytical expressions for the probability distributions of the basic structural units of an adsorbed polymer, such as loops, trains and tails, in terms of the adhesive potential and f, or h, provide a full description of the polymer structure and behavior upon force-assisted detachment. In addition, one finds that the hitherto controversial value of the universal critical adsorption exponent ϕ depends essentially on the extent of interaction between the loops adsorbed chain so that ϕ may vary within the limits 0.34 ≤ ϕ ≤ 0.59.

  12. 1st Order Modeling of a SAW Delay Line using MathCAD(Registered)

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2007-01-01

    To aid in the development of SAW sensors for Integrated Vehicle Health Monitoring applications, a first order model of a SAW Delay line has been created using MathCadA. The model implements the Impulse Response method to calculate the frequency response, impedance, and insertion loss. This paper presents the model and the results from the model for a SAW delay line design. Integrated Vehicle Health Monitoring (IVHM) of aerospace vehicles requires rugged sensors having reduced volume, mass, and power that can be used to measure a variety of phenomena. Wireless systems are preferred when retro-fitting sensors onto existing vehicles [1]. Surface Acoustic Wave (SAW) devices are capable of sensing: temperature, pressure, strain, chemical species, mass loading, acceleration, and shear stress. SAW technology is low cost, rugged, lightweight, and extremely low power. Passive wireless sensors have been developed using SAW technology. For these reasons new SAW sensors are being investigated for aerospace applications.

  13. A Comparison of In-Channel Dead Zone and Hyporheic Zone Transient Storage Parameter Estimates Between a 1st and 5th Order Stream

    NASA Astrophysics Data System (ADS)

    Briggs, M.; Gooseff, M.; Morkeski, K.; Wollheim, W.; Hopkinson, C.; Peterson, B.; Vorosmarty, C.

    2007-12-01

    A major enhancement to our understanding of how watersheds function would be the ability to discriminate between in-channel dead zone ( DZ) and hyporheic zone ( HZ) transient storage, and an evaluation of how these properties scale across stream orders. The nature of DZ storage is to display faster exchange rates with the main channel and less overall sediment contact time than HZ storage. These differences have great significance to many in-stream processes such as nutrient cycling. The combination of high slope, coarse bed material and fluvial structure endemic to many 1st order streams can provide greater forcing of hyporheic flow paths than occurs within the lower gradient 5th order streams. Conversely many 5th order reaches exhibit large side pool and back eddy DZ areas not common along 1st order streams. This study builds on existing methods to delineate the DZ and HZ from the integrated signal of a conservative solute's breakthrough curve ( BTC). Data for this comparison were collected over the summer of 2007 within the Ipswich River watershed, a basin which drains into Plum Island Sound on the north shore of Massachusetts, USA. The conservative solute NaCl was injected into both a 1st order medium gradient stream and a 5th order low gradient stream. The BTCs collected in thalwegs from the NaCl injections were simulated using a version of the solute transport model OTIS containing two zones of transient storage. Hydrometric measurements of stream velocity were used to estimate average main channel cross sectional area ( A) and DZ cross sectional area ( ASDZ) for each reach to constrain parameter estimates and avoid model equifinality between the storage zones. Initial values for the exchange rate between main channel flow and DZ storage ( αDZ) were estimated from DZ BTCs. Our results indicate that although the overall storage zone is much larger in proportion to the main channel for the 1st order reach than for the 5th order reach, the percentage of median

  14. Nonlinear random motion analysis of coupled heave-pitch motions of a spar platform considering 1st-order and 2nd-order wave loads

    NASA Astrophysics Data System (ADS)

    Liu, Shuxiao; Tang, Yougang; Li, Wei

    2016-06-01

    In this study, we consider first- and second-order random wave loads and the effects of time-varying displacement volume and transient wave elevation to establish motion equations of the Spar platform's coupled heave-pitch. We generated random wave loads based on frequency-domain wave load transfer functions and the Joint North Sea Wave Project (JONSWAP) wave spectrum, designed program codes to solve the motion equations, and then simulated the coupled heave-pitch motion responses of the platform in the time domain. We then calculated and compared the motion responses in different sea conditions and separately investigated the effects of second-order random wave loads and transient wave elevation. The results show that the coupled heave-pitch motion responses of the platform are primarily dominated by wave height and the characteristic wave period, the latter of which has a greater impact. Second-order mean wave loads mainly affect the average heave value. The platform's pitch increases after the second-order low frequency wave loads are taken into account. The platform's heave is underestimated if the transient wave elevation term in the motion equations is neglected.

  15. Parallel auto-correlative statistics with VTK.

    SciTech Connect

    Pebay, Philippe Pierre; Bennett, Janine Camille

    2013-08-01

    This report summarizes existing statistical engines in VTK and presents both the serial and parallel auto-correlative statistics engines. It is a sequel to [PT08, BPRT09b, PT09, BPT09, PT10] which studied the parallel descriptive, correlative, multi-correlative, principal component analysis, contingency, k-means, and order statistics engines. The ease of use of the new parallel auto-correlative statistics engine is illustrated by the means of C++ code snippets and algorithm verification is provided. This report justifies the design of the statistics engines with parallel scalability in mind, and provides scalability and speed-up analysis results for the autocorrelative statistics engine.

  16. Semiclassical description of autocorrelations in nuclear masses

    SciTech Connect

    Garcia-Garcia, Antonio M.; Hirsch, Jorge G.; Frank, Alejandro

    2006-08-15

    Nuclear mass autocorrelations are investigated as a function of the number of nucleons. The fluctuating part of these autocorrelations is modeled by a parameter free model in which the nucleons are confined in a rigid sphere. Explicit results are obtained by using periodic orbit theory. Despite the simplicity of the model we have found a remarkable quantitative agreement of the mass autocorrelations for all nuclei in the nuclear data chart. In order to achieve a similar degree of agreement for the nuclear masses themselves it is necessary to consider additional variables such as multipolar corrections to the spherical shape and an effective number of nucleons. Our findings suggest that higher order effects like nuclear deformations or residual interactions have little relevance in the description of the fluctuations of the nuclear autocorrelations.

  17. Impact of Autocorrelation on Functional Connectivity

    PubMed Central

    Arbabshirani, Mohammad R.; Damaraju, Eswar; Phlypo, Ronald; Plis, Sergey; Allen, Elena; Ma, Sai; Mathalon, Daniel; Preda, Adrian; Vaidya, Jatin G.; Adali, Tülay; Calhoun, Vince D.

    2014-01-01

    Although the impact of serial correlation (autocorrelation) in residuals of general linear models for fMRI time-series has been studied extensively, the effect of autocorrelation on functional connectivity studies has been largely neglected until recently. Some recent studies based on results from economics have questioned the conventional estimation of functional connectivity and argue that not correcting for autocorrelation in fMRI time-series results in “spurious” correlation coefficients. In this paper, first we assess the effect of autocorrelation on Pearson correlation coefficient through theoretical approximation and simulation. Then we present this effect on real fMRI data. To our knowledge this is the first work comprehensively investigating the effect of autocorrelation on functional connectivity estimates. Our results show that although FC values are altered, even following correction for autocorrelation, results of hypothesis testing on FC values remain very similar to those before correction. In real data we show this is true for main effects and also for group difference testing between healthy controls and schizophrenia patients. We further discuss model order selection in the context of autoregressive processes, effects of frequency filtering and propose a preprocessing pipeline for connectivity studies. PMID:25072392

  18. Low autocorrelation binary sequences

    NASA Astrophysics Data System (ADS)

    Packebusch, Tom; Mertens, Stephan

    2016-04-01

    Binary sequences with minimal autocorrelations have applications in communication engineering, mathematics and computer science. In statistical physics they appear as groundstates of the Bernasconi model. Finding these sequences is a notoriously hard problem, that so far can be solved only by exhaustive search. We review recent algorithms and present a new algorithm that finds optimal sequences of length N in time O(N {1.73}N). We computed all optimal sequences for N≤slant 66 and all optimal skewsymmetric sequences for N≤slant 119.

  19. "Hard Science" for Gifted 1st Graders

    ERIC Educational Resources Information Center

    DeGennaro, April

    2006-01-01

    "Hard Science" is designed to teach 1st grade gifted students accurate and high level science concepts. It is based upon their experience of the world and attempts to build a foundation for continued love and enjoyment of science. "Hard Science" provides field experiences and opportunities for hands-on discovery working beside experts in the field…

  20. Velocity and stress autocorrelation decay in isothermal dissipative particle dynamics

    NASA Astrophysics Data System (ADS)

    Chaudhri, Anuj; Lukes, Jennifer R.

    2010-02-01

    The velocity and stress autocorrelation decay in a dissipative particle dynamics ideal fluid model is analyzed in this paper. The autocorrelation functions are calculated at three different friction parameters and three different time steps using the well-known Groot/Warren algorithm and newer algorithms including self-consistent leap-frog, self-consistent velocity Verlet and Shardlow first and second order integrators. At low friction values, the velocity autocorrelation function decays exponentially at short times, shows slower-than exponential decay at intermediate times, and approaches zero at long times for all five integrators. As friction value increases, the deviation from exponential behavior occurs earlier and is more pronounced. At small time steps, all the integrators give identical decay profiles. As time step increases, there are qualitative and quantitative differences between the integrators. The stress correlation behavior is markedly different for the algorithms. The self-consistent velocity Verlet and the Shardlow algorithms show very similar stress autocorrelation decay with change in friction parameter, whereas the Groot/Warren and leap-frog schemes show variations at higher friction factors. Diffusion coefficients and shear viscosities are calculated using Green-Kubo integration of the velocity and stress autocorrelation functions. The diffusion coefficients match well-known theoretical results at low friction limits. Although the stress autocorrelation function is different for each integrator, fluctuates rapidly, and gives poor statistics for most of the cases, the calculated shear viscosities still fall within range of theoretical predictions and nonequilibrium studies.

  1. Integrated autocorrelator based on superconducting nanowires.

    PubMed

    Sahin, Döndü; Gaggero, Alessandro; Hoang, Thang Ba; Frucci, Giulia; Mattioli, Francesco; Leoni, Roberto; Beetz, Johannes; Lermer, Matthias; Kamp, Martin; Höfling, Sven; Fiore, Andrea

    2013-05-01

    We demonstrate an integrated autocorrelator based on two superconducting single-photon detectors patterned on top of a GaAs ridge waveguide. This device enables the on-chip measurement of the second-order intensity correlation function g(2)(τ). A polarization-independent device quantum efficiency in the 1% range is reported, with a timing jitter of 88 ps at 1300 nm. g(2)(τ) measurements of continuous-wave and pulsed laser excitations are demonstrated with no measurable crosstalk within our measurement accuracy. PMID:23669973

  2. Lock No. 1 St. Lucie Canal. Sector gates, internal struts ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Lock No. 1- St. Lucie Canal. Sector gates, internal struts- nose beams. - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL

  3. Sources of variation in Landsat autocorrelation

    NASA Technical Reports Server (NTRS)

    Craig, R. G.; Labovitz, M. L.

    1980-01-01

    Analysis of sixty-four scan lines representing diverse conditions across satellites, channels, scanners, locations and cloud cover confirms that Landsat data are autocorrelated and consistently follow an Arima (1,0,1) pattern. The AR parameter varies significantly with location and the MA coefficient with cloud cover. Maximum likelihood classification functions are considerably in error unless this autocorrelation is compensated for in sampling.

  4. A simple method to estimate interwell autocorrelation

    SciTech Connect

    Pizarro, J.O.S.; Lake, L.W.

    1997-08-01

    The estimation of autocorrelation in the lateral or interwell direction is important when performing reservoir characterization studies using stochastic modeling. This paper presents a new method to estimate the interwell autocorrelation based on parameters, such as the vertical range and the variance, that can be estimated with commonly available data. We used synthetic fields that were generated from stochastic simulations to provide data to construct the estimation charts. These charts relate the ratio of areal to vertical variance and the autocorrelation range (expressed variously) in two directions. Three different semivariogram models were considered: spherical, exponential and truncated fractal. The overall procedure is demonstrated using field data. We find that the approach gives the most self-consistent results when it is applied to previously identified facies. Moreover, the autocorrelation trends follow the depositional pattern of the reservoir, which gives confidence in the validity of the approach.

  5. Bayesian Estimates of Autocorrelations in Single-Case Designs

    ERIC Educational Resources Information Center

    Shadish, William R.; Rindskopf, David M.; Hedges, Larry V.; Sullivan, Kristynn J.

    2012-01-01

    Researchers in the single-case design tradition have debated the size and importance of the observed autocorrelations in those designs. All of the past estimates of the autocorrelation in that literature have taken the observed autocorrelation estimates as the data to be used in the debate. However, estimates of the autocorrelation are subject to…

  6. Droplet model for autocorrelation functions in an Ising ferromagnet

    NASA Technical Reports Server (NTRS)

    Tang, Chao; Nakanishi, Hiizu; Langer, J. S.

    1989-01-01

    The autocorrelation function of Ising spins in an ordered phase is studied via a droplet model. Only noninteracting spherical droplets are considered. The Langevin equation which describes fluctuations in the radius of a single droplet is studied in detail. A general description of the transformation to a Fokker-Planck equations and the ways in which a spectral analysis of that equation can be used to compute the autocorrelation function is given. It is shown that the eigenvalues of the Fokker-Planck operator form (1) a continuous spectrum of relaxation rates starting from zero for d = 2, (2) a continuous spectrum with a finite gap for d = 3, and (3) a discrete spectrum for d greater than 4, where d is the spatial dimensionality. Detailed solutions for various cases are presented.

  7. Photoacoustic Doppler flowmetry of carbon particles flow using an autocorrelation method

    NASA Astrophysics Data System (ADS)

    Lu, Tao

    2014-11-01

    In order to measure the axial flowing velocity of carbon particle suspension with particle diameter of tens of micrometers, the photoacoustic Doppler (PAD) frequency shift is calculated based on a series of individual A scans using an autocorrelation method. A 532 nm pulsed laser with repetition rate of 20 Hz is used as a pumping source to generate photoacoustic signal. The photoacoustic signals are detected using a focused piezoelectric (PZT) ultrasound transducer with central frequency of 5 MHz. The suspension of carbon particles is driven by a syringe pump. The complex photoacoustic signal is calculated by the Hilbert transformation from time-domain photoacoustic signal, and then it is autocorrelated to calculate the Doppler frequency shift. The photoacoustic Doppler frequency shift is calculated by averaging the autocorrelation results of some individual A scans. The advantage of the autocorrelation method is that the time delay in autocorrelation can be defined by user, and the requirement of high pulse repetition rate is avoided. The feasibility of the proposed autocorrelation method is preliminarily demonstrated by quantifying the motion of a carbon particle suspension with flow velocity from 5 mm/s to 60 mm/s. The experimental results show that there is an approximately linear relation between the autocorrelation result and the setting velocity.

  8. An Overdetermined System for Improved Autocorrelation Based Spectral Moment Estimator Performance

    NASA Technical Reports Server (NTRS)

    Keel, Byron M.

    1996-01-01

    Autocorrelation based spectral moment estimators are typically derived using the Fourier transform relationship between the power spectrum and the autocorrelation function along with using either an assumed form of the autocorrelation function, e.g., Gaussian, or a generic complex form and applying properties of the characteristic function. Passarelli has used a series expansion of the general complex autocorrelation function and has expressed the coefficients in terms of central moments of the power spectrum. A truncation of this series will produce a closed system of equations which can be solved for the central moments of interest. The autocorrelation function at various lags is estimated from samples of the random process under observation. These estimates themselves are random variables and exhibit a bias and variance that is a function of the number of samples used in the estimates and the operational signal-to-noise ratio. This contributes to a degradation in performance of the moment estimators. This dissertation investigates the use autocorrelation function estimates at higher order lags to reduce the bias and standard deviation in spectral moment estimates. In particular, Passarelli's series expansion is cast in terms of an overdetermined system to form a framework under which the application of additional autocorrelation function estimates at higher order lags can be defined and assessed. The solution of the overdetermined system is the least squares solution. Furthermore, an overdetermined system can be solved for any moment or moments of interest and is not tied to a particular form of the power spectrum or corresponding autocorrelation function. As an application of this approach, autocorrelation based variance estimators are defined by a truncation of Passarelli's series expansion and applied to simulated Doppler weather radar returns which are characterized by a Gaussian shaped power spectrum. The performance of the variance estimators determined

  9. Spatial Autocorrelation Analysis of Migration and Selection

    PubMed Central

    Sokal, R. R.; Jacquez, G. M.; Wooten, M. C.

    1989-01-01

    We test various assumptions necessary for the interpretation of spatial autocorrelation analysis of gene frequency surfaces, using simulations of Wright's isolation-by-distance model with migration or selection superimposed. Increasing neighborhood size enhances spatial autocorrelation, which is reduced again for the largest neighborhood sizes. Spatial correlograms are independent of the mean gene frequency of the surface. Migration affects surfaces and correlograms when immigrant gene frequency differentials are substantial. Multiple directions of migration are reflected in the correlograms. Selection gradients yield clinal correlograms; other selection patterns are less clearly reflected in their correlograms. Sequential migration from different directions and at different gene frequencies can be disaggregated into component migration vectors by means of principal components analysis. This encourages analysis by such methods of gene frequency surfaces in nature. The empirical results of these findings lend support to the inference structure developed earlier for spatial autocorrelation analysis. PMID:2721935

  10. ISS Update: 1st Annual ISS R&D Conference

    NASA Video Gallery

    NASA Public Affairs Officer Kelly Humphries talks by phone on Wednesday with Julie Robinson, ISS Program Scientist, about the 1st Annual International Space Station Research and Development Confere...

  11. EMSL Quarterly Highlights Report: 1st Quarter, Fiscal Year 2009

    SciTech Connect

    Showalter, Mary Ann; Kathmann, Loel E.; Manke, Kristin L.

    2009-02-02

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2008 - December 2008) of Fiscal Year 2009.

  12. Electronic Health Records Place 1st at Indy 500

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues EHR Electronic Health Records Place 1st at Indy 500 Past ... last May's Indy 500 had thousands of personal Electronic Health Records on hand for those attending—and ...

  13. 1st HPV Test for Use with Preservative Fluid

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159789.html 1st HPV Test for Use With Preservative Fluid Human papillomavirus ... Food and Drug Administration has approved Roche's cobas HPV Test -- the first diagnostic to be used with ...

  14. EMSL Quarterly Highlights Report: 1st Quarter, FY08

    SciTech Connect

    Showalter, Mary Ann

    2008-01-28

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2007 - December 2007) of Fiscal Year 2008.

  15. Constant-Envelope Waveform Design for Optimal Target-Detection and Autocorrelation Performances

    SciTech Connect

    Sen, Satyabrata

    2013-01-01

    We propose an algorithm to directly synthesize in time-domain a constant-envelope transmit waveform that achieves the optimal performance in detecting an extended target in the presence of signal-dependent interference. This approach is in contrast to the traditional indirect methods that synthesize the transmit signal following the computation of the optimal energy spectral density. Additionally, we aim to maintain a good autocorrelation property of the designed signal. Therefore, our waveform design technique solves a bi-objective optimization problem in order to simultaneously improve the detection and autocorrelation performances, which are in general conflicting in nature. We demonstrate this compromising characteristics of the detection and autocorrelation performances with numerical examples. Furthermore, in the absence of the autocorrelation criterion, our designed signal is shown to achieve a near-optimum detection performance.

  16. Spectra of empirical autocorrelation matrices: A random-matrix-theory-inspired perspective

    NASA Astrophysics Data System (ADS)

    Jamali, Tayeb; Jafari, G. R.

    2015-07-01

    We construct an autocorrelation matrix of a time series and analyze it based on the random-matrix theory (RMT) approach. The autocorrelation matrix is capable of extracting information which is not easily accessible by the direct analysis of the autocorrelation function. In order to provide a precise conclusion based on the information extracted from the autocorrelation matrix, the results must be first evaluated. In other words they need to be compared with some sort of criterion to provide a basis for the most suitable and applicable conclusions. In the context of the present study, the criterion is selected to be the well-known fractional Gaussian noise (fGn). We illustrate the applicability of our method in the context of stock markets. For the former, despite the non-Gaussianity in returns of the stock markets, a remarkable agreement with the fGn is achieved.

  17. Spatial Autocorrelation in Mass Spectrometry Imaging.

    PubMed

    Cassese, Alberto; Ellis, Shane R; Ogrinc Potočnik, Nina; Burgermeister, Elke; Ebert, Matthias; Walch, Axel; van den Maagdenberg, Arn M J M; McDonnell, Liam A; Heeren, Ron M A; Balluff, Benjamin

    2016-06-01

    Mass spectrometry imaging (MSI) is a powerful molecular imaging technique. In microprobe MSI, images are created through a grid-wise interrogation of individual spots by mass spectrometry across a surface. Classical statistical tests for within-sample comparisons fail as close-by measurement spots violate the assumption of independence of these tests, which can lead to an increased false-discovery rate. For spatial data, this effect is referred to as spatial autocorrelation. In this study, we investigated spatial autocorrelation in three different matrix-assisted laser desorption/ionization MSI data sets. These data sets cover different molecular classes (metabolites/drugs, lipids, and proteins) and different spatial resolutions ranging from 20 to 100 μm. Significant spatial autocorrelation was detected in all three data sets and found to increase with decreasing pixel size. To enable statistical testing for differences in mass signal intensities between regions of interest within MSI data sets, we propose the use of Conditional Autoregressive (CAR) models. We show that, by accounting for spatial autocorrelation, discovery rates (i.e., the ratio between the features identified and the total number of features) could be reduced between 21% and 69%. The reliability of this approach was validated by control mass signals based on prior knowledge. In light of the advent of larger MSI data sets based on either an increased spatial resolution or 3D data sets, accounting for effects due to spatial autocorrelation becomes even more indispensable. Here, we propose a generic and easily applicable workflow to enable within-sample statistical comparisons. PMID:27180608

  18. Design and construction of the 1st proton CT scanner

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Bashkirov, V.; Hurley, F.; Johnson, R.; Rykalin, V.; Sadrozinski, H.; Schulte, R.

    2013-04-01

    This paper discusses the design and operation of the 1st proton CT scanner for 3D imaging. Reduction of proton range uncertainties and improved dose accuracy in the patient for treatment planning are central goals. A central CT slice acquired by reconstruction of 134 million proton tracks through a 14 cm spherical polystyrene phantom with high and low density inserts is presented.

  19. Lag-One Autocorrelation in Short Series: Estimation and Hypotheses Testing

    ERIC Educational Resources Information Center

    Solanas, Antonio; Manolov, Rumen; Sierra, Vicenta

    2010-01-01

    In the first part of the study, nine estimators of the first-order autoregressive parameter are reviewed and a new estimator is proposed. The relationships and discrepancies between the estimators are discussed in order to achieve a clear differentiation. In the second part of the study, the precision in the estimation of autocorrelation is…

  20. Idaho National Laboratory Quarterly Performance Analysis - 1st Quarter FY2015

    SciTech Connect

    Mitchell, Lisbeth A.

    2015-03-01

    This report is published quarterly by the Idaho National Laboratory (INL) Quality and Performance Management Organization. The Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS), as prescribed in DOE Order 232.2, “Occurrence Reporting and Processing of Operations Information,” requires a quarterly analysis of events, both reportable and not reportable, for the previous 12 months. This report is the analysis of 73 reportable events (27 from the 1St Qtr FY-15 and 46 from the prior three reporting quarters), as well as 38 other issue reports (including nine not reportable events and Significant Category A and B conditions reported during the1st Qtr FY-15) identified at INL during the past 12 months.

  1. Complex singularities of the fluid velocity autocorrelation function

    NASA Astrophysics Data System (ADS)

    Chtchelkatchev, N. M.; Ryltsev, R. E.

    2015-11-01

    There are intensive debates regarding the nature of supercritical fluids: if their evolution from liquid-like to gas-like behavior is a continuous multistage process or there is a sharp well-defined crossover. Velocity auto-correlation function Z is the established detector of evolution of fluid particles dynamics. Usually, complex singularities of correlation functions give more information. For this reason, we investigate Z in complex plane of frequencies using numerical analytic continuation. We have found that naive picture with few isolated poles fails describing Z(ω) of one-component Lennard-Jones (LJ) fluid. Instead, we see the singularity manifold forming branch cuts extending approximately parallel to the real frequency axis. That suggests LJ velocity autocorrelation function is a multivalued function of complex frequency. The branch cuts are separated from the real axis by the well-defined "gap" whose width corresponds to an important time scale of a fluid characterizing crossover of system dynamics from kinetic to hydrodynamic regime. Our working hypothesis is that the branch cut origin is related to competition between one-particle dynamics and hydrodynamics. The observed analytic structure of Z is very stable under changes in the temperature; it survives at temperatures two orders of magnitude higher than the critical one.

  2. Spatial Autocorrelation Approaches to Testing Residuals from Least Squares Regression

    PubMed Central

    Chen, Yanguang

    2016-01-01

    In geo-statistics, the Durbin-Watson test is frequently employed to detect the presence of residual serial correlation from least squares regression analyses. However, the Durbin-Watson statistic is only suitable for ordered time or spatial series. If the variables comprise cross-sectional data coming from spatial random sampling, the test will be ineffectual because the value of Durbin-Watson’s statistic depends on the sequence of data points. This paper develops two new statistics for testing serial correlation of residuals from least squares regression based on spatial samples. By analogy with the new form of Moran’s index, an autocorrelation coefficient is defined with a standardized residual vector and a normalized spatial weight matrix. Then by analogy with the Durbin-Watson statistic, two types of new serial correlation indices are constructed. As a case study, the two newly presented statistics are applied to a spatial sample of 29 China’s regions. These results show that the new spatial autocorrelation models can be used to test the serial correlation of residuals from regression analysis. In practice, the new statistics can make up for the deficiencies of the Durbin-Watson test. PMID:26800271

  3. Record breaking properties for typical autocorrelation structures

    NASA Astrophysics Data System (ADS)

    Anagnostopoulou, Eirini; Galani, Andriani; Dimas, Panagiotis; Karanasios, Alexandros; Mastrotheodoros, Theodoros; Michaelidi, Eleni-Maria; Nikolopoulos, Dionisios; Pontikos, Stamatis; Sourla, Fani; Chazapi, Anna; Papalexiou, Simon Michael; Koutsoyiannis, Demetris

    2013-04-01

    Record-breaking occurrences in hydrometeorological processes are often used particularly in communicating information to the public and their analysis offers the possibility of better comprehending extreme events. However, the typical comprehension depends on prototypes characterized by pure randomness. In fact the occurrence of record breaking depends on the marginal distribution and the autocorrelation function of the process as well the length of available record. Here we study the influence of the process autocorrelation structure on the statistics of record-breaking occurrences giving emphasis on the differences with those of a purely random process. The particular stochastic processes, which we examine, are the AR(1), AR(2) and ARMA(1,1), as well as the Hurst-Kolmogorov process. The necessary properties are calculated using either analytical methods when possible or Monte Carlo simulation. We also compare the model results with observed hydrometeorological time series. Acknowledgement: This research is conducted within the frame of the undergraduate course "Stochastic Methods in Water Resources" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students in the Assembly.

  4. [Granuloma Gravidarum in a 37-year-old 1st Gravida, 1st Para--A Case Report].

    PubMed

    Findeklee, S

    2015-10-01

    The granuloma gravidarum is a rare benign tumour with gingival origin. It occurs in circa 0.2% of pregnancies. Mostly we see an asymptomatic course of disease terminated by hormonal changes after delivery. If the granuloma is associated with complaints of the pregnant woman, for example masticational pain or recurrent bleedings, therapeutic options are conservative therapy, surgery or delivery. We report the case of a 37-year-old 1st gravida, 1st para who had an induced delivery in the 39+2 gestational week because of a symptomatic granuloma gravidarum. We saw a spontaneous remission of the granuloma within 3 months post partum. The case report underlines the importance of suitable information for pregnant women about oral hygiene and the necessity of regular dental controls during pregnancy for prophylaxis of granuloma gravidarum. PMID:26402852

  5. Photoacoustic Doppler flowmetry of carbon particles flow using an autocorrelation method

    NASA Astrophysics Data System (ADS)

    Lu, Tao

    2014-09-01

    In order to measure the axial flowing velocity of a suspension carbon particles of tens of micometer-scale, the photoacoustic doppler frequency shift was calculated from a series of individual A scans using a autocorrelation method. A 532nm pulsed laser with the repetition rate of 20Hz was used as a pumping source to generate photoacoustic signal. The photoacoustic signals were detected using a focused PZT ultrasound transducer with central frequency of 5MHz. The suspension of carbon particles was driven by a syringe pump. Firstly, the complex photoacoustic signal was calculated by the Hilbert transformation from time-domain photoacoustic signal. The complex photoacoustic signal was then autocorrelated to calculate doppler frequency shift. The flow velocity was calculated by averaging the autocorrelation results of individual A scans. In comparison , the previously reported data processing methods using cross-correlation method in time domain or frequency domain require high sequential scanning rate or high laser repetition rate up to several kHz to avoid aliasing or uncorrelation between sequential waveform pairs. But it is difficult to get several kHz repetition rate for a single pulsed laser and the correlation between waveform pairs of sequential A scans were also limited by the laser repetition rate. To solve the problem, we used the autocorrelation method of individual A scans to calculated Doppler frequency shift. The time delay can be user defined to avoid aliasing. The feasibility of the proposed autocorrelation method was preliminarily demonstrated by quantifying the motion of a carbon particles suspension flow from 5 to 60 mm/s. The experimental results showed that the autocorrelation result approximately agreed with the setting velocity linearly.

  6. Adaptive non-collinear autocorrelation of few-cycle pulses with an angular tunable bi-mirror

    NASA Astrophysics Data System (ADS)

    Treffer, A.; Brunne, J.; Bock, M.; König, S.; Wallrabe, U.; Grunwald, R.

    2016-02-01

    Adaptive autocorrelation with an angular tunable micro-electro-mechanical system is reported. A piezo-actuated Fresnel bi-mirror structure was applied to measure the second order autocorrelation of near-infrared few-cycle laser pulses in a non-collinear setup at tunable superposition angles. Because of enabling measurements with variable scaling and minimizing the influence of distortions by adaptive self-reconstruction, the approach extends the capability of autocorrelators. Flexible scaling and robustness against localized amplitude obscurations are demonstrated. The adaptive reconstruction of temporal frequency information by the Fourier analysis of autocorrelation data is shown. Experimental results and numerical simulations of the beam propagation and interference are compared for variable angles.

  7. ["1st Therapeutic Red Cross Hospital" during the civil war].

    PubMed

    Simonenko, V B; Abashin, V G

    2014-04-01

    The article presents the documentary information about the founding, the establishment and early years of the 1st Therapeutic Red Cross Hospital - in the future - Mandryka Central Military Clinical Hospital of the Ministry of Defence of the Russian Federation. Presented the work of the Hospital during the dificult period of the Civil War, typhus epidemic, famine and devastation. Specified its staffing structure, command, medical and administrative staff, travel and accommodation till the moment of the deployment in the Silver Lane in Moscow. PMID:25051792

  8. The 1st All-Russian Workshop on Archaeoastronomy

    NASA Astrophysics Data System (ADS)

    Bochkarev, Nikolai G.

    2007-08-01

    The 1st All-Russia Workshop on Archaeoastronomy “Astronomical and World-Outlook Meaning of the Archaeological Monuments of South Ural” was held on June 19-25, 2006, at the ground of the archaeological center “Arkaim” (Chelyabinsk Region). Besides about 30 talks, astronomical measurements were performed at two archaeological objects under intensive study: Arkaim Site (Bronze Epoch, XVIII-XVI c. B.C.) and tumuli “with whiskers” complex Kondurovsky (V-VIII c. A.D.). The promising character of the megalithic complex on the Vera Island (Lake Turgoyak) was stated.

  9. ASSESSMENT OF SPATIAL AUTOCORRELATION IN EMPIRICAL MODELS IN ECOLOGY

    EPA Science Inventory

    Statistically assessing ecological models is inherently difficult because data are autocorrelated and this autocorrelation varies in an unknown fashion. At a simple level, the linking of a single species to a habitat type is a straightforward analysis. With some investigation int...

  10. Low power, CMOS digital autocorrelator spectrometer for spaceborne applications

    NASA Technical Reports Server (NTRS)

    Chandra, Kumar; Wilson, William J.

    1992-01-01

    A 128-channel digital autocorrelator spectrometer using four 32 channel low power CMOS correlator chips was built and tested. The CMOS correlator chip uses a 2-bit multiplication algorithm and a full-custom CMOS VLSI design to achieve low DC power consumption. The digital autocorrelator spectrometer has a 20 MHz band width, and the total DC power requirement is 6 Watts.

  11. Inference for local autocorrelations in locally stationary models

    PubMed Central

    Zhao, Zhibiao

    2014-01-01

    For non-stationary processes, the time-varying correlation structure provides useful insights into the underlying model dynamics. We study estimation and inferences for local autocorrelation process in locally stationary time series. Our constructed simultaneous confidence band can be used to address important hypothesis testing problems, such as whether the local autocorrelation process is indeed time-varying and whether the local autocorrelation is zero. In particular, our result provides an important generalization of the R function acf() to locally stationary Gaussian processes. Simulation studies and two empirical applications are developed. For the global temperature series, we find that the local autocorrelations are time-varying and have a “V” shape during 1910–1960. For the S&P 500 index, we conclude that the returns satisfy the efficient-market hypothesis whereas the magnitudes of returns show significant local autocorrelations. PMID:26097285

  12. Crustal thickness in central Europe from single-station seismic noise autocorrelation analysis

    NASA Astrophysics Data System (ADS)

    Becker, Gesa; Knapmeyer-Endrun, Brigitte

    2016-04-01

    The InSight mission to Mars will place a single three-component seismometer on the planet's surface, requiring the application of single-station methods. In addition, seismicity on Mars is likely less abundant than on Earth, making it important to also use the available seismic noise. For these reasons different approaches of seismic noise autocorrelation have been tested with broadband three-component datasets from 12 stations across central Europe. These stations cover varying Moho depths of ca. 25-50 km depth. With the help of the autocorrelations, reflected body waves are extracted in order to estimate the crustal thickness at each station. This is of special relevance for Mars, where average crustal thickness is uncertain by a factor of two. The different approaches used are waterlevel normalized autocorrelation, with and without application of a short-term and long-term average filter to the spectrum of the data prior to autocorrelation, and phase autocorrelation. These approaches are compared and analyzed. Estimates for the Moho depths are made from the lag times of the reflected P-waves and compared to available Moho depth values at the stations. Due to the availability of three-component data these estimates can be cross-validated and in some cases not only P-wave reflections, but also possible S-wave and multiple reflections can be identified. The estimates compare well with the general trend of Moho depth expected for these stations. The consistency of results is further investigated by comparing different stations of the GERES array (aperture 2 km), which also allows to examine results for closely located broad-band and short-period stations side by side.

  13. A compact nonlinear fiber-based optical autocorrelation peak discriminator.

    PubMed

    Fok, M P; Deng, Y; Prucnal, P R

    2009-06-01

    We experimentally demonstrate a nonlinear fiber-based optical autocorrelation peak discriminator. The approach exploits four-wave mixing in a 37-cm highly-nonlinear bismuth-oxide fiber that provides a passive and compact means for rejecting cross-correlation peaks. The autocorrelation peak discriminator plays an important role in improving the detection of optical CDMA signals. Eye diagrams and bit-error rates are measured at different power ratios. Significant receiver sensitivity improvements are obtained and error-floors are removed. The experimental results show that the autocorrelation peak discriminator works well even when the amplitudes of individual cross-correlation peaks are higher than that of the autocorrelation peak. PMID:19506641

  14. Mode Analysis with Autocorrelation Method (Single Time Series) in Tokamak

    NASA Astrophysics Data System (ADS)

    Saadat, Shervin; Salem, Mohammad K.; Goranneviss, Mahmoud; Khorshid, Pejman

    2010-08-01

    In this paper plasma mode analyzed with statistical method that designated Autocorrelation function. Auto correlation function used from one time series, so for this purpose we need one Minov coil. After autocorrelation analysis on mirnov coil data, spectral density diagram is plotted. Spectral density diagram from symmetries and trends can analyzed plasma mode. RHF fields effects with this method ate investigated in IR-T1 tokamak and results corresponded with multichannel methods such as SVD and FFT.

  15. A Method for Detecting Positive Growth Autocorrelation without Marking Individuals

    PubMed Central

    Brooks, Mollie E.; McCoy, Michael W.; Bolker, Benjamin M.

    2013-01-01

    In most ecological studies, within-group variation is a nuisance that obscures patterns of interest and reduces statistical power. However, patterns of within-group variability often contain information about ecological processes. In particular, such patterns can be used to detect positive growth autocorrelation (consistent variation in growth rates among individuals in a cohort across time), even in samples of unmarked individuals. Previous methods for detecting autocorrelated growth required data from marked individuals. We propose a method that requires only estimates of within-cohort variance through time, using maximum likelihood methods to obtain point estimates and confidence intervals of the correlation parameter. We test our method on simulated data sets and determine the loss in statistical power due to the inability to identify individuals. We show how to accommodate nonlinear growth trajectories and test the effects of size-dependent mortality on our method's accuracy. The method can detect significant growth autocorrelation at moderate levels of autocorrelation with moderate-sized cohorts (for example, statistical power of 80% to detect growth autocorrelation ρ2 = 0.5 in a cohort of 100 individuals measured on 16 occasions). We present a case study of growth in the red-eyed tree frog. Better quantification of the processes driving size variation will help ecologists improve predictions of population dynamics. This work will help researchers to detect growth autocorrelation in cases where marking is logistically infeasible or causes unacceptable decreases in the fitness of marked individuals. PMID:24204620

  16. A method for detecting positive growth autocorrelation without marking individuals.

    PubMed

    Brooks, Mollie E; McCoy, Michael W; Bolker, Benjamin M

    2013-01-01

    In most ecological studies, within-group variation is a nuisance that obscures patterns of interest and reduces statistical power. However, patterns of within-group variability often contain information about ecological processes. In particular, such patterns can be used to detect positive growth autocorrelation (consistent variation in growth rates among individuals in a cohort across time), even in samples of unmarked individuals. Previous methods for detecting autocorrelated growth required data from marked individuals. We propose a method that requires only estimates of within-cohort variance through time, using maximum likelihood methods to obtain point estimates and confidence intervals of the correlation parameter. We test our method on simulated data sets and determine the loss in statistical power due to the inability to identify individuals. We show how to accommodate nonlinear growth trajectories and test the effects of size-dependent mortality on our method's accuracy. The method can detect significant growth autocorrelation at moderate levels of autocorrelation with moderate-sized cohorts (for example, statistical power of 80% to detect growth autocorrelation ρ (2) = 0.5 in a cohort of 100 individuals measured on 16 occasions). We present a case study of growth in the red-eyed tree frog. Better quantification of the processes driving size variation will help ecologists improve predictions of population dynamics. This work will help researchers to detect growth autocorrelation in cases where marking is logistically infeasible or causes unacceptable decreases in the fitness of marked individuals. PMID:24204620

  17. Use of autocorrelation of wavelet coefficients for fault diagnosis

    NASA Astrophysics Data System (ADS)

    Rafiee, J.; Tse, P. W.

    2009-07-01

    This paper presents a novel time-frequency-based feature recognition system for gear fault diagnosis using autocorrelation of continuous wavelet coefficients (CWC). Furthermore, it introduces an original mathematical approximation of gearbox vibration signals which approximates sinusoidal components of noisy vibration signals generated from gearboxes, including incipient and serious gear failures using autocorrelation of CWC. First, the drawbacks of the continuous wavelet transform (CWT) have been eliminated using autocorrelation function. Secondly, the autocorrelation of CWC is introduced as an original pattern for fault identification in machine condition monitoring. Thirdly, a sinusoidal summation function consisting of eight terms was used to approximate the periodic waveforms generated by autocorrelation of CWC for normal gearboxes (NGs) as well as occurrences of incipient and severe gear fault (e.g. slight-worn, medium-worn, and broken-tooth gears). In other words, the size of vibration signals can be reduced with minimal loss of significant frequency content by means of the sinusoidal approximation of generated autocorrelation waveforms of CWC as reported in this paper.

  18. Performance of signal-to-noise ratio estimation for scanning electron microscope using autocorrelation Levinson-Durbin recursion model.

    PubMed

    Sim, K S; Lim, M S; Yeap, Z X

    2016-07-01

    A new technique to quantify signal-to-noise ratio (SNR) value of the scanning electron microscope (SEM) images is proposed. This technique is known as autocorrelation Levinson-Durbin recursion (ACLDR) model. To test the performance of this technique, the SEM image is corrupted with noise. The autocorrelation function of the original image and the noisy image are formed. The signal spectrum based on the autocorrelation function of image is formed. ACLDR is then used as an SNR estimator to quantify the signal spectrum of noisy image. The SNR values of the original image and the quantified image are calculated. The ACLDR is then compared with the three existing techniques, which are nearest neighbourhood, first-order linear interpolation and nearest neighbourhood combined with first-order linear interpolation. It is shown that ACLDR model is able to achieve higher accuracy in SNR estimation. PMID:26871742

  19. 1st Advanced Marine Renewable Energy Instrumentation Experts Workshop

    SciTech Connect

    none,

    2011-10-01

    The U.S. marine energy industry is actively pursuing development of offshore wind and marine hydrokinetic (MHK) energy systems. Experience in the wind energy sector demonstrates that new technology development requires thorough measurement and characterization of the environmental conditions prevalent at installation sites and of technology operating in the field. Presently, there are no turn-key instrumentation system solutions that meet the measurement needs of the marine energy industry. The 1st Advanced Marine Renewable Energy Instrumentation Experts Workshop brought together technical experts from government laboratories, academia, and industry representatives from marine energy, wind, offshore oil and gas, and instrumentation developers to present and discuss the instrumentation needs of the marine energy industry. The goals of the meeting were to: 1. Share the latest relevant knowledge among technical experts; 2. Review relevant state-of-the-art field measurement technologies and methods; 3. Review lessons learned from recent field deployments; 4. Identify synergies across different industries; 5. Identify gaps between existing and needed instrumentation capabilities; 6. Understand who are the leading experts; 7. Provide a forum where stakeholders from the marine energy industry could provide substantive input in the development of new marine energy field deployable instrumentation packages.

  20. THEOS: The1st Thailand EO System and

    NASA Astrophysics Data System (ADS)

    Peanvijarnpong, Chanchai

    Thailand has engaged in remote sensing satellite technological and scientific development many years since early 1980s. Thailand Landsat Station was established as a regional center of data processing and dissemination for Thai scientists for data applications. Over the years, GISTDA and Thai user community have been gaining technical experience and expertise in satellite data applications around the country such natural resources and environmental management, forest inventory, forest change detections, soil mapping, land-use and land cover mapping, crop type mapping, coastal shrimp farming, flood zone mapping, base mapping, water and drought management. The Government of Thailand realizes that remote sensing satellite technology is an important mechanism for social and economic development of the country. So the 1st Thailand Earth Observation System (THEOS) development program was approved by the Government since 2003. THEOS system is sub-synchronous satellite orbiting around the earth at 822 km. altitude same as SPOT satellites. It carries two imaging instruments; 2-m Panchromatic telescope with 22 km. swath width and 15-m resolution camera with four-multi-spectral band and 90-km swath wide. THEOS is scheduled to launch around March 2008. A number of technological and scientific activities has been implementing for Thailand and international scientific user community. Therefore THEOS is strong endorsement from the Government of Thailand on the value of remote sensing technology. This paper presents Thailand EO activities including THEOS System and its plans.

  1. VIEW WEST, 1ST FLOOR, EAST ROOM, HYDRAULIC COTTON PRESS, DETAIL, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW WEST, 1ST FLOOR, EAST ROOM, HYDRAULIC COTTON PRESS, DETAIL, CONTINENTAL GIN COMPANY HYDRAULIC TANK - Magnolia Plantation, Cotton Gins & Presses, LA Route 119, Natchitoches, Natchitoches Parish, LA

  2. 94. DETAIL, SAME BEAN AS ABOVE, MARKED 'PATENTED DEC. 1ST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    94. DETAIL, SAME BEAN AS ABOVE, MARKED 'PATENTED DEC. 1ST 1857' - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  3. Evaluation of estimation, prediction and inference for autocorrelated latent variable modeling of binary data-a simulation study.

    PubMed

    Hutmacher, Matthew M

    2016-06-01

    Longitudinal models of binary or ordered categorical data are often evaluated for adequacy by the ability of these to characterize the transition frequency and type between response states. Drug development decisions are often concerned with accurate prediction and inference of the probability of response by time and dose. A question arises on whether the transition probabilities need to be characterized adequately to ensure accurate response prediction probabilities unconditional on the previous response state. To address this, a simulation study was conducted to assess bias in estimation, prediction and inferences of autocorrelated latent variable models (ALVMs) when the transition probabilities are misspecified due to ill-posed random effects structures, inadequate likelihood approximation or omission of the autocorrelation component. The results may be surprising in that these suggest that characterizing autocorrelation in ALVMs is not as important as specifying a suitably rich random effects structure. PMID:27007275

  4. Investigations of Passive Seismic Body-Wave Interferometry Using Noise Auto-correlations for Crustal and Upper Mantle Structure

    NASA Astrophysics Data System (ADS)

    Oren, C.; Nowack, R. L.

    2015-12-01

    It is known that the positive lags of the auto-correlation for the seismic transmission response of a layered medium correspond to the reflection seismogram (Claerbout, 1968). In this study, we investigate the use of ambient seismic noise recorded at selected broadband USArray EarthScope Transportable Array (TA) stations to obtain effective reflection seismograms for frequencies up to 1 Hz. The goal is to determine the most suitable parameters used for the processing of ambient seismic noise for the identification of crustal and upper mantle reflections and to minimize unwanted artifacts in the noise correlations. In order to best retrieve the body-wave components of the Green's function beneath a station, a number of processing steps are required. We first remove the instrument response and apply a temporal normalization to remove the effects of the most energetic sources. Next we implement spectral whitening. We test several operators for the spectral whitening where the undulations of the power spectrum are related to the strengths of later arrivals in the auto-correlation. Different filters are then applied to the auto-correlation functions, including Gaussian and zero phase Butterworth filters, in order to reduce the effect of side lobes. Hourly auto-correlations are then stacked for up to one year. On the final stack, Automatic Gain Control (AGC) is applied to equalize the correlation amplitudes in the time domain. The robustness of the resulting ambient noise auto-correlation is first tested on selected TA stations in Nevada, where we are able to identify PmP and SmS arrivals similar to those found by Tibuleac and von Seggern (2012). We then investigate noise auto-correlations applied to selected USArray TA stations in the central US.

  5. The resemblance of an autocorrelation function to a power spectrum density for a spike train of an auditory model

    NASA Astrophysics Data System (ADS)

    Ushakov, Y. V.; Dubkov, A. A.; Spagnolo, B.

    2013-01-01

    In this work we develop an analytical approach for calculation of the all-order interspike interval density (AOISID), show its connection with the autocorrelation function, and try to explain the discovered resemblance of AOISID to the power spectrum of the same spike train.

  6. The impact of temporal auto-correlation mismatch on the assimilation of satellite-derived surface soil moisture retrievals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Satellite-based surface soil moisture retrievals are commonly assimilated into eco-hydrological models in order to obtain improved profile soil moisture estimates. However, differences in temporal auto-correlation structure between these retrievals and comparable model-based predictions can potentia...

  7. Kindergarten to 1st Grade: Classroom Characteristics and the Stability and Change of Children's Classroom Experiences

    ERIC Educational Resources Information Center

    La Paro, Karen M.; Rimm-Kaufman, Sara E.; Pianta, Robert C.

    2006-01-01

    This study examines the classroom experiences of 192 children followed longitudinally from kindergarten to 1st grade. Time-sampled observations of children were conducted to compare learning formats, teaching activities, and children's engagement in activities between kindergarten and 1st grade. Classroom observations also were conducted to…

  8. Autocorrelation of location estimates and the analysis of radiotracking data

    USGS Publications Warehouse

    Otis, D.L.; White, Gary C.

    1999-01-01

    The wildlife literature has been contradictory about the importance of autocorrelation in radiotracking data used for home range estimation and hypothesis tests of habitat selection. By definition, the concept of a home range involves autocorrelated movements, but estimates or hypothesis tests based on sampling designs that predefine a time frame of interest, and that generate representative samples of an animal's movement during this time frame, should not be affected by length of the sampling interval and autocorrelation. Intensive sampling of the individual's home range and habitat use during the time frame of the study leads to improved estimates for the individual, but use of location estimates as the sample unit to compare across animals is pseudoreplication. We therefore recommend against use of habitat selection analysis techniques that use locations instead of individuals as the sample unit. We offer a general outline for sampling designs for radiotracking studies.

  9. Data Analysis Methods for Synthetic Polymer Mass Spectrometry: Autocorrelation

    PubMed Central

    Wallace, William E.; Guttman, Charles M.

    2002-01-01

    Autocorrelation is shown to be useful in describing the periodic patterns found in high- resolution mass spectra of synthetic polymers. Examples of this usefulness are described for a simple linear homopolymer to demonstrate the method fundamentals, a condensation polymer to demonstrate its utility in understanding complex spectra with multiple repeating patterns on different mass scales, and a condensation copolymer to demonstrate how it can elegantly and efficiently reveal unexpected phenomena. It is shown that using autocorrelation to determine where the signal devolves into noise can be useful in determining molecular mass distributions of synthetic polymers, a primary focus of the NIST synthetic polymer mass spectrometry effort. The appendices describe some of the effects of transformation from time to mass space when time-of-flight mass separation is used, as well as the effects of non-trivial baselines on the autocorrelation function.

  10. Monitoring autocorrelated process: A geometric Brownian motion process approach

    NASA Astrophysics Data System (ADS)

    Li, Lee Siaw; Djauhari, Maman A.

    2013-09-01

    Autocorrelated process control is common in today's modern industrial process control practice. The current practice of autocorrelated process control is to eliminate the autocorrelation by using an appropriate model such as Box-Jenkins models or other models and then to conduct process control operation based on the residuals. In this paper we show that many time series are governed by a geometric Brownian motion (GBM) process. Therefore, in this case, by using the properties of a GBM process, we only need an appropriate transformation and model the transformed data to come up with the condition needs in traditional process control. An industrial example of cocoa powder production process in a Malaysian company will be presented and discussed to illustrate the advantages of the GBM approach.

  11. An autocorrelation method for three-dimensional strain analysis

    NASA Astrophysics Data System (ADS)

    Thissen, Christopher J.; Brandon, Mark T.

    2015-12-01

    We present a method of finite-strain estimation using the autocorrelation properties of deformed rock. Autocorrelation is the correlation of an image with itself as a function of an offset or lag. In two and three dimensions, the lag has both distance and direction. Many geologic materials are initially isotropic, which means that the autocorrelation function (ACF) will be initially isotropic as well. Deformation imposes an anisotropic distortion, which can be measured using the Ramsay and Fry strain methods for example, but can also be estimated from the ACF. X-ray tomography now provides a rapid way to measure the three-dimensional ACF of a geologic sample. Strain parameters are estimated by using a non-linear, best-fit method to minimize the anisotropy in the ACF. The ACF method works best for materials where the objects are internally uniform and contrast strongly with the matrix and other grains.

  12. Proceedings of the 1st Puerto Rico Biobanking Workshop

    PubMed Central

    Mora, Edna; Robb, James A.; Stefanoff, Gustavo; Mellado, Robert Hunter; Coppola, Domenico; Muñoz-Antonia, Teresita; Flores, Idhaliz

    2015-01-01

    The 1st Puerto Rico Biobanking Workshop took place on August 20th, 2014 in the Auditorium of the Comprehensive Cancer Center of the University of Puerto Rico, Medical Sciences Campus in San Juan Puerto Rico. The program for this 1-day, live workshop included lectures by three biobanking experts, followed by presentations from existing biobanks in Puerto Rico and audience discussion. The need for increasing biobanking expertise in Puerto Rico stems from the fact that Hispanics in general are underrepresented in the biobanks in existence in the US, which limits the research conducted specifically to understand the molecular differences in cancer cells compared to other better studied populations. In turn, this lack of information impairs the development of better diagnostic and therapeutic approaches for our population. Dr. James Robb, M.D., F.C.A.P., consulting pathologist to the National Cancer Institute (NCI) and the Office of Biorepositories and Biospecimen Research (OBBR), opened the workshop with a discussion on the basic aspects of the science of biobanking (e.g., what is a biobank; its goals and objectives; protocols and procedures) in his talk addressing the importance of banking tissues for advancing biomedical research. Next, Dr. Gustavo Stefanoff, from the Cancer Institutes Network of Latin America (RINC by its name in Spanish), explained the mission, objectives, and structure of the Network of Latin-American and Caribbean Biobanks (REBLAC by its name in Spanish), which despite limited resources and many challenges, currently accrue high quality human tissue specimens and data to support cancer research in the region. Dr. Robert Hunter-Mellado, Professor of Internal Medicine, Universidad Central del Caribe, followed with an examination of the ethical and regulatory aspects of biobanking tissues for future research, including informed consent of subjects; protection of human subjects rights; and balancing risks and benefit ratios. In the afternoon, the

  13. Proceedings of the 1st Puerto Rico Biobanking Workshop.

    PubMed

    Mora, Edna; Robb, James A; Stefanoff, Gustavo; Mellado, Robert Hunter; Coppola, Domenico; Muñoz-Antonia, Teresita; Flores, Idhaliz

    2014-01-01

    The 1st Puerto Rico Biobanking Workshop took place on August 20st, 2014 in the Auditorium of the Comprehensive Cancer Center of the University of Puerto Rico, Medical Sciences Campus in San Juan Puerto Rico. The program for this 1-day, live workshop included lectures by three biobanking experts, followed by presentations from existing biobanks in Puerto Rico and audience discussion. The need for increasing biobanking expertise in Puerto Rico stems from the fact that Hispanics in general are underrepresented in the biobanks in existence in the US, which limits the research conducted specifically to understand the molecular differences in cancer cells compared to other better studied populations. In turn, this lack of information impairs the development of better diagnostic and therapeutic approaches for our population. Dr. James Robb, M.D., F.C.A.P., consulting pathologist to the National Cancer Institute (NCI) and the Office of Biorepositories and Biospecimen Research (OBBR), opened the workshop with a discussion on the basic aspects of the science of biobanking (e.g., what is a biobank; its goals and objectives; protocols and procedures) in his talk addressing the importance of banking tissues for advancing biomedical research. Next, Dr. Gustavo Stefanoff, from the Cancer Institutes Network of Latin America (RINC by its name in Spanish), explained the mission, objectives, and structure of the Network of Latin-American and Caribbean Biobanks (REBLAC by its name in Spanish), which despite limited resources and many challenges, currently accrue high quality human tissue specimens and data to support cancer research in the region. Dr. Robert Hunter-Mellado, Professor of Internal Medicine, Universidad Central del Caribe, followed with an examination of the ethical and regulatory aspects of biobanking tissues for future research, including informed consent of subjects; protection of human subjects rights; and balancing risks and benefit ratios. In the afternoon, the

  14. Interferometric autocorrelation of an attosecond pulse train calculated using feasible formulae

    NASA Astrophysics Data System (ADS)

    Nabekawa, Y.; Midorikawa, K.

    2008-02-01

    The autocorrelation trace of an attosecond pulse train (APT) directly revealed the pulse envelope in our recent experiment on measuring the two-photon Coulomb explosion of a nitrogen molecule as a correlation signal. Although the spatial overlap of the two replicas of the APT in the correlation measurement was only achieved near the focal region owing to the spatial split of the measured APT field, which is a situation quite different from that of the correlation measurement using a Michelson interferometer, the interference fringes clearly appeared on the correlation envelope and provedthe odd symmetry of the electric field to the time translation with a half-period of the driving laser field. In this paper, we show a simple and practical analysis for the propagation and the nonlinear interaction of an APT to simulate the experimental result of the interferometric autocorrelation of the spatially split APT. The spatial convolution of the focused electric field is essential for obtaining the fringes. We also discuss how the autocorrelation should be described in the context of the second-order perturbation theory within a dipole approximation.

  15. Autocorrelation method for measuring the transfer function of optical systems

    NASA Astrophysics Data System (ADS)

    Grover, C. P.; van Driel, H. M.

    1980-03-01

    An unconventional autocorrelation method is described for measuring the transfer function of optical systems. The interference takes place between the scattered waves obtained from two laterally sheared correlated partial diffusers. The output of a detector responding only to an extremely narrowband of spatial frequencies is proportional to the autocorrelation of the system pupil function. An automatic display of the transfer function is obtained by continuously varying the shear between the diffusers. The theory and some experimental results of this simple and inexpensive device are presented. A study of various parameters affecting the performance of the instrument is also given.

  16. Variance of size-age curves: Bootstrapping with autocorrelation

    USGS Publications Warehouse

    Bullock, S.H.; Turner, R.M.; Hastings, J.R.; Escoto-Rodriguez, M.; Lopez, Z.R.A.; Rodrigues-Navarro, J. L.

    2004-01-01

    We modify a method of estimating size-age relations from a minimal set of individual increment data, recognizing that growth depends not only on size but also varies greatly among individuals and is consistent within an individual for several to many time intervals. The method is exemplified with data from a long-lived desert plant and a range of autocorrelation factors encompassing field-measured values. The results suggest that age estimates based on size and growth rates with only moderate autocorrelation are subject to large variation, which raises major problems for prediction or hindcasting for ecological analysis or management.

  17. Analgesic Effects of 1st Generation Anti-histamines in Mice.

    PubMed

    Takahashi, Mebae; Shima, Kazuhiro; Tsuchiya, Masahiro; Hagiwara, Yoshihiro; Mizoguchi, Hirokazu; Sakurada, Shinobu; Sugawara, Shunji; Fujita, Takuo; Tadano, Takeshi; Watanabe, Makoto; Fukumoto, Satoshi; Endo, Yasuo

    2016-01-01

    Pain is sensed, transmitted, and modified by a variety of mediators and receptors. Histamine is a well-known mediator of pain. In addition to their anti-histaminic effects, the classical, or 1st generation, anti-histamines (1st AHs) possess, to various degrees, anti-muscarinic, anti-serotonergic, anti-adrenergic, and other pharmacologic effects. Although there have been attempts to use 1st AHs as analgesics and/or analgesic adjuvants, the advent of non-steroidal anti-inflammatory drugs (NSAIDs) discouraged such trials. We previously reported that in patients with temporomandibular disorders, osteoporosis, and/or osteoarthritis, the analgesic effects of certain 1st AHs (chlorpheniramine and diphenhydramine) are superior to those of the NSAIDs flurbiprofen and indomethacin. Here, we compared analgesic effects among 1st AHs and NSAIDs against responses shown by mice to intraperitoneally injected 0.7% acetic acid. Since 1st AHs are water soluble, we selected water-soluble NSAIDs. For direct comparison, drugs were intravenously injected 30 min before the above tests. Histamine-H1-receptor-deficient (H1R-KO) mice were used for evaluating H1-receptor-independent effects. The tested 1st AHs (especially cyproheptadine) displayed or tended to display analgesic effects comparable to those of NSAIDs in normal and H1R-KO mice. Our data suggest that the anti-serotonergic and/or anti-adrenergic effects of 1st AHs make important contributions to their analgesic effects. Moreover, combination of a 1st AH with an NSAID (cyclooxygenase-1 inhibitor) produced remarkably potent analgesic effects. We propose that a 1st AH, by itself or in combination with a cyclooxygenase-1 inhibitor, should undergo testing to evaluate its usefulness in analgesia. PMID:27040636

  18. The Effect of Foot Structure on 1st Metatarsophalangeal Joint Flexibility and Hallucal Loading

    PubMed Central

    Rao, Smita; Song, Jinsup; Kraszewski, Andrew; Backus, Sherry; Ellis, Scott J.; Deland, Jonathan T.; Hillstrom, Howard J.

    2011-01-01

    The purpose of our study was to examine 1st metatarsophalangeal (MTP) joint motion and flexibility and plantar loads in individuals with high, normal and low arch foot structure. Asymptomatic individuals (n=61), with high, normal and low arches participated in this study. Foot structure was quantified using malleolar valgus index (MVI) and arch height index (AHI). First MTP joint flexibility was measured using a specially constructed jig. Peak pressure under the hallux, 1st and 2nd metatarsals during walking was assessed using a pedobarograph. A one-way ANOVA with Bonferroni-adjusted post-hoc comparisons was used to assess between-group differences in MVI, AHI, Early and Late 1st MTP joint flexibility in sitting and standing, peak dorsiflexion (DF), and peak pressure under the hallux, 1st and 2nd metatarsals. Stepwise linear regression was used to identify predictors of hallucal loading. Significant between-group differences were found in MVI (F2,56=15.4, p<0.01), 1st MTP late flexibility in sitting (F2,57=3.7, p=0.03), and standing (F2,57=3.7, p=0.03). Post-hoc comparisons demonstrated that 1st MTP late flexibility in sitting was significantly higher in individuals with low arch compared to high arch structure, and that 1st MTP late flexibility in standing was significantly higher in individuals with low arch compared to normal arch structure. Stepwise regression analysis indicated that MVI and 1st MTP joint early flexibility in sitting explain about 20% of the variance in hallucal peak pressure. Our results provide objective evidence indicating that individuals with low arches show increased 1st MTP joint late flexibility compared to individuals with normal arch structure, and that hindfoot alignment and 1st MTP joint flexibility affect hallucal loading. PMID:21536440

  19. Autocorrelation of rainfall and streamflow minimums

    USGS Publications Warehouse

    Matalas, N.C.

    1963-01-01

    Hydrologic time series of annual minimum mean monthly rainfall and annual minimum 1-day and 7-day discharge, considered as drought indices, were used to study the distribution of droughts with respect to time. The rainfall data were found to be nearly random. The discharge data, however, were found to be nonrandomly distributed in time and generated by a first-order Markov process. The expected value of the variance for a time series generated by a first-order Markov process was compared with the expected value of the variance for a random time series. This comparison showed that the expected value of the variance for a nonrandom time series converged to the population variance with an increase in sample size at a slower rate than for a random time series.

  20. Macroscopic lithotype characterisation of the 1st Middle-Polish (1st Lusatian) Lignite Seam in the Miocene of central Poland

    NASA Astrophysics Data System (ADS)

    Widera, Marek

    2012-03-01

    The 1st Middle-Polish (1st Lusatian) Lignite Seam is exploited in open-cast mines in central Poland. A large number of lignite lithotypes, grouped in four lithotype associations, are distinguished: xylitic, detritic, xylo-detritic and detro-xylitic lithotype associations, which show various structures. Each lithotype association was produced under specific peat-forming environmental conditions. In the case of the lignite seams under study they represent all the main environments that are known from Neogene mires, i.e.: fen or open water, bush moor, wet forest swamp and dry forest swamp. For a simple and practical description in the field of both the lignite sections and borehole cores, a new codification for lignite lithotypes is proposed. It is based on the codification of clastic deposits (lithofacies). The practical value of the new lignite lithotype codification is examined in three vertical sections of the 1st Middle-Polish Lignite Seam.

  1. Velocity Autocorrelation Functions and Diffusion of Dusty Plasma

    SciTech Connect

    Ramazanov, T. S.; Dzhumagulova, K. N.; Daniyarov, T. T.; Dosbolayev, M. K.; Jumabekov, A. N.

    2008-09-07

    The velocity autocorrelation functions and square displacements were calculated on the basis of experimental data obtained on experimental setup with dc discharge. Computer simulation of the system of dust particles by the method of the Langevin dynamics was performed. The comparisons of experimental and theoretical results are given.

  2. Autocorrelation and Dominance Ratio in Monte Carlo Criticality Calculations

    SciTech Connect

    Ueki, Taro; Brown, Forrest B.; Parsons, D. Kent; Kornreich, Drew E.

    2003-11-15

    The cycle-to-cycle correlation (autocorrelation) in Monte Carlo criticality calculations is analyzed concerning the dominance ratio of fission kernels. The mathematical analysis focuses on how the eigenfunctions of a fission kernel decay if operated on by the cycle-to-cycle error propagation operator of the Monte Carlo stationary source distribution. The analytical results obtained can be summarized as follows: When the dominance ratio of a fission kernel is close to unity, autocorrelation of the k-effective tallies is weak and may be negligible, while the autocorrelation of the source distribution is strong and decays slowly. The practical implication is that when one analyzes a critical reactor with a large dominance ratio by Monte Carlo methods, the confidence interval estimation of the fission rate and other quantities at individual locations must account for the strong autocorrelation. Numerical results are presented for sample problems with a dominance ratio of 0.85-0.99, where Shannon and relative entropies are utilized to exclude the influence of initial nonstationarity.

  3. New approaches for calculating Moran's index of spatial autocorrelation.

    PubMed

    Chen, Yanguang

    2013-01-01

    Spatial autocorrelation plays an important role in geographical analysis; however, there is still room for improvement of this method. The formula for Moran's index is complicated, and several basic problems remain to be solved. Therefore, I will reconstruct its mathematical framework using mathematical derivation based on linear algebra and present four simple approaches to calculating Moran's index. Moran's scatterplot will be ameliorated, and new test methods will be proposed. The relationship between the global Moran's index and Geary's coefficient will be discussed from two different vantage points: spatial population and spatial sample. The sphere of applications for both Moran's index and Geary's coefficient will be clarified and defined. One of theoretical findings is that Moran's index is a characteristic parameter of spatial weight matrices, so the selection of weight functions is very significant for autocorrelation analysis of geographical systems. A case study of 29 Chinese cities in 2000 will be employed to validate the innovatory models and methods. This work is a methodological study, which will simplify the process of autocorrelation analysis. The results of this study will lay the foundation for the scaling analysis of spatial autocorrelation. PMID:23874592

  4. Cross- and auto-correlation in early vision

    PubMed Central

    Barlow, Horace; Berry, David L.

    2011-01-01

    Neurons that respond selectively to the orientation of visual stimuli were discovered in V1 more than 50 years ago, but it is still not fully understood how or why this is brought about. We report experiments planned to show whether human observers use cross-correlation or auto-correlation to detect oriented streaks in arrays of randomly positioned dots, expecting that this would help us to understand what David Marr called the ‘computational goal’ of V1. The streaks were generated by two different methods: either by sinusoidal spatial modulation of the local mean dot density, or by introducing coherent pairs of dots to create moiré patterns, as Leon Glass did. A wide range of dot numbers was used in the randomly positioned arrays, because dot density affects cross- and auto-correlation differently, enabling us to infer which method was used. This difference stems from the fact that the cross-correlation task is limited by random fluctuations in the local mean density of individual dots in the noisy array, whereas the auto-correlation task is limited by fluctuations in the numbers of randomly occurring spurious pairs having the same separation and orientation as the deliberately introduced coherent pairs. After developing a new method using graded dot luminances, we were able to extend the range of dot densities that could be used by a large factor, and convincing results were obtained indicating that the streaks generated by amplitude modulation were discriminated by cross-correlation, while those generated as moiré patterns were discriminated by auto-correlation. Though our current results only apply to orientation selectivity, it is important to know that early vision can do more than simple filtering, for evaluating auto-correlations opens the way to more interesting possibilities, such as the detection of symmetries and suspicious coincidences. PMID:21147803

  5. Field test of an autocorrelation technique for determining grain size using a digital camera

    NASA Astrophysics Data System (ADS)

    Barnard, P. L.; Rubin, D. M.; Harney, J.; Mustain, N.

    2007-12-01

    autocorrelation technique is roughly 2 orders of magnitude faster than traditional grain- size analysis, saving time and money, without sacrificing accuracy in measuring average grain size; however, the technique may not be as accurate in measuring the fine and coarse tails of a size distribution.

  6. PROPAGATION AND EVOLUTION OF THE JUNE 1st 2008 CME IN THE INTERPLANETARY MEDIUM

    NASA Astrophysics Data System (ADS)

    Nieves-Chinchilla, T.; Lamb, D. A.; Davila, J. M.; Vinas, A. F.; Moestl, C.; Hidalgo, M. A.; Farrugia, C. J.; Malandraki, O.; Dresing, N.; Gómez-Herrero, R.

    2009-12-01

    In this work we present a study of the coronal mass ejection (CME) of June 1st of 2008 in the interplanetary medium. This event has been extensively studied by others because of its favorable geometry and the possible consequences of its peculiar initiation for space weather forecasting. We show an analysis of the evolution of the CME in the interplanetary medium in order to shed some light on the propagation mechanism of the ICME. We have determined the typical shock associated characteristics of the ICME in order to understand the propagation properties. Using two different non force-free models of the magnetic cloud allows us to incorporate expansion of the cloud. We use in-situ measurements from STEREO B/IMPACT to characterize the ICME. In addition, we use images from STEREO A/SECCHI-HI to analyze the propagation and visual evolution of the associated flux rope in the interplanetary medium. We compare and contrast these observations with the results of the analytical models.

  7. VIEW SOUTH/SOUTHEAST LOOKING DOWN ON 2ND AQUEDUCT AND 1ST AQUEDUCT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW SOUTH/SOUTHEAST LOOKING DOWN ON 2ND AQUEDUCT AND 1ST AQUEDUCT CASCADES TOWARDS FILTRATION PLANT AND LOS ANGELES RESERVOIR - Los Angeles Aqueduct, Cascades Structures, Los Angeles, Los Angeles County, CA

  8. MAGAZINE E30. VIEW FROM BETWEEN 1ST AND 2ND BLAST WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MAGAZINE E-30. VIEW FROM BETWEEN 1ST AND 2ND BLAST WALL LOOKING TO THE REAR OF THE MAGAZINE. - Naval Magazine Lualualei, Waikele Branch, Tunnel Magazine Type, Waikakalaua & Kipapa Gulches, Pearl City, Honolulu County, HI

  9. 14. Building 105, Facilities Engineering Building, 1830, interior, 1st floor, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Building 105, Facilities Engineering Building, 1830, interior, 1st floor, crib area of building, showing electrical and plumbing cribs, wall and ceiling detail, looking S. - Watervliet Arsenal, Building 105, South Broadway, on Hudson River, Watervliet, Albany County, NY

  10. 4. VIEW WEST, WEST SIDE, SHOWING CHANNELS 1ST AND 2ND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW WEST, WEST SIDE, SHOWING CHANNELS 1ST AND 2ND VERTICAL BRACED DOUBLE ANGLES, DIAGONAL BRACING AND CROSS BRACED RAILING - Thirty-Sixth Street Bridge, Spanning Rabbit River, Hamilton, Allegan County, MI

  11. 62. Neg. No. F75A, Jun 18, 1930, INTERIORWAREHOUSE, 1ST FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. Neg. No. F-75A, Jun 18, 1930, INTERIOR-WAREHOUSE, 1ST FLOOR, STORAGE OF AUTOMOBILE COMPONENTS - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  12. 1st International consensus guidelines for advanced breast cancer (ABC 1).

    PubMed

    Cardoso, F; Costa, A; Norton, L; Cameron, D; Cufer, T; Fallowfield, L; Francis, P; Gligorov, J; Kyriakides, S; Lin, N; Pagani, O; Senkus, E; Thomssen, C; Aapro, M; Bergh, J; Di Leo, A; El Saghir, N; Ganz, P A; Gelmon, K; Goldhirsch, A; Harbeck, N; Houssami, N; Hudis, C; Kaufman, B; Leadbeater, M; Mayer, M; Rodger, A; Rugo, H; Sacchini, V; Sledge, G; van't Veer, L; Viale, G; Krop, I; Winer, E

    2012-06-01

    The 1st international Consensus Conference for Advanced Breast Cancer (ABC 1) took place on November 2011, in Lisbon. Consensus guidelines for the management of this disease were developed. This manuscript summarizes these international consensus guidelines. PMID:22425534

  13. 19. Detail of brick courses 116, back side, between 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Detail of brick courses 1-16, back side, between 1st and 2nd windows from the right - Oklahoma State University, Boys Dormitory, Northwest corner of Hester Street & Athletic Avenue, Stillwater, Payne County, OK

  14. 20. Detail of brick courses 4675, back side, between 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Detail of brick courses 46-75, back side, between 1st and 2nd windows from the right - Oklahoma State University, Boys Dormitory, Northwest corner of Hester Street & Athletic Avenue, Stillwater, Payne County, OK

  15. 45. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Turn span from SE. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  16. 46. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Overall view, from S. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  17. 28. ENGINE CLUSTER OF 1ST STAGE OF A SATURN I ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. ENGINE CLUSTER OF 1ST STAGE OF A SATURN I ROCKET ENGINE LOCATED ON NORTH SIDE OF STATIC TEST STAND. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

  18. BLOEDNER MONUMENT (32ND INDIANA, 1ST GERMAN MONUMENT), SECTION C, FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BLOEDNER MONUMENT (32ND INDIANA, 1ST GERMAN MONUMENT), SECTION C, FRONT ELEVATION DETAIL OF GERMAN TEXT. VIEW TO NORTHEAST. - Cave Hill National Cemetery, 701 Baxter Avenue, Louisville, Jefferson County, KY

  19. Transverse flowmetry of carbon particles based on photoacoustic Doppler standard deviation using an auto-correlation method

    NASA Astrophysics Data System (ADS)

    Lu, Tao; Sun, Li-jun

    2015-05-01

    In order to measure the flow velocity of carbon particle suspension perpendicular to the receiving axis of ultrasound transducer, the standard deviation of photoacoustic Doppler frequency spectrum is used to estimate the bandwidth broadening, and the spectrum standard deviation is calculated by an auto-correlation method. A 532 nm pulsed laser with the repetition rate of 20 Hz is used as a pumping source to generate photoacoustic signal. The photoacoustic signals are detected using a focused PZT ultrasound transducer with the central frequency of 10 MHz. The suspension of carbon particles is driven by a syringe pump. The complex photoacoustic signal is calculated by Hilbert transformation from time domain signal before auto-correlation. The standard deviation of the Doppler bandwidth broadening is calculated by averaging the auto-correlation results of several individual A scans. The feasibility of the proposed method is demonstrated by measuring the spectrum standard deviation of the transversal carbon particle flow from 5.0 mm/s to 8.4 mm/s. The experimental results show that the auto-correlation result is approximately linearly distributed within the measuring range.

  20. Evaluation of terrain complexity by autocorrelation. [geomorphology and geobotany

    NASA Technical Reports Server (NTRS)

    Craig, R. G.

    1982-01-01

    The topographic complexity of various sections of the Ozark, Appalachian, and Interior Low Plateaus, as well as of the New England, Piedmont, Blue Ridge, Ouachita, and Valley and Ridge Provinces of the Eastern United States were characterized. The variability of autocorrelation within a small area (7 1/2-ft quadrangle) to the variability at widely separated and diverse areas within the same physiographic region was compared to measure the degree of uniformity of the processes which can be expected to be encountered within a given physiographic province. The variability of autocorrelation across the eight geomorphic regions was compared and contrasted. The total study area was partitioned into subareas homogeneous in terrain complexity. The relation between the complexity measured, the geomorphic process mix implied, and the way in which geobotanical information is modified into a more or less recognizable entity is demonstrated. Sampling strategy is described.

  1. A Meta-Analysis of the Autocorrelation in Single Case Designs

    ERIC Educational Resources Information Center

    Boyajian, Jonathan

    2011-01-01

    This conference presentation reviews the authors' work on autocorrelations in single-case designs. The bias-corrected autocorrelation is computed, results are meta-analyzed with 5-level multilevel analysis in SAS Proc Mixed. Results suggest autocorrelations are normally distributed, and that taking into account nesting in outcomes and articles…

  2. Genetic spatial autocorrelation can readily detect sex-biased dispersal.

    PubMed

    Banks, Sam C; Peakall, Rod

    2012-05-01

    Sex-biased dispersal is expected to generate differences in the fine-scale genetic structure of males and females. Therefore, spatial analyses of multilocus genotypes may offer a powerful approach for detecting sex-biased dispersal in natural populations. However, the effects of sex-biased dispersal on fine-scale genetic structure have not been explored. We used simulations and multilocus spatial autocorrelation analysis to investigate how sex-biased dispersal influences fine-scale genetic structure. We evaluated three statistical tests for detecting sex-biased dispersal: bootstrap confidence intervals about autocorrelation r values and recently developed heterogeneity tests at the distance class and whole correlogram levels. Even modest sex bias in dispersal resulted in significantly different fine-scale spatial autocorrelation patterns between the sexes. This was particularly evident when dispersal was strongly restricted in the less-dispersing sex (mean distance <200 m), when differences between the sexes were readily detected over short distances. All tests had high power to detect sex-biased dispersal with large sample sizes (n ≥ 250). However, there was variation in type I error rates among the tests, for which we offer specific recommendations. We found congruence between simulation predictions and empirical data from the agile antechinus, a species that exhibits male-biased dispersal, confirming the power of individual-based genetic analysis to provide insights into asymmetries in male and female dispersal. Our key recommendations for using multilocus spatial autocorrelation analyses to test for sex-biased dispersal are: (i) maximize sample size, not locus number; (ii) concentrate sampling within the scale of positive structure; (iii) evaluate several distance class sizes; (iv) use appropriate methods when combining data from multiple populations; (v) compare the appropriate groups of individuals. PMID:22335562

  3. [Struggle against typhus in the Caucasian front during the 1st World War].

    PubMed

    Karatepe, Mustafa

    2002-01-01

    As an infectious disease, typhus has triggered many epidemics during the course of wars and caused thousands of death all through the ages. The French physician Charles Nicolle (1886-1936) defined its agent as a louse transferring the disease from man to man in 1909 and was awarded the Nobel Prize in 1928. Many cases were reported during the 1st World War both in the European and the Ottoman armies; and one of the most severe epidemics broke in the Caucasian front; a great number of civilians and soldiers died at winter in 1914 and 1915. Lice had to be destroyed in order to prevent the epidemic, but etuves in the Caucasian front was too few to achieve it. Clothes were cleansed in ovens by means of a method proposed by Dr. Abdülkadir Noyan (1886-1977). On March 28, 1915 the first typhus vaccination, obtained from the infected blood of the patients, was applied by Dr. Tevfik Salim (Saklam) (1882-1963). In 1916 Dr. Ahmet Fikri Tüzer discovered a disinfection apparatus called "buğu sandiği" (vapour box) which was widely used in the Caucasian front after 1917. This apparatus was highly useful in controlling the typhus epidemics. 164 health officers lost their lifes in the Caucasian front between 1914-1918, in addition, 7310 military casualties were recorded from 1915 to the end of the war. PMID:17152154

  4. Spatial autocorrelation analysis of hyperspectral imagery for feature selection

    SciTech Connect

    Warner, T.A.; Shank, M.C.

    1997-04-01

    The spatial information in a single spectral image can be estimated from the spatial autocorrelation, which is a measure of how the local variation compares with the overall variance in a scene. In images of random noise, the local variation tends to be similar to the overall variance. In contrast, scenes in which large features can be discerned have clusters of pixels with similar values, which cause the local variation to be much smaller on average than the overall scene variance. Feature selection is the process of finding a subset of the original bands that provides an optimal trade-off between probability of error and classification cost. Three feature selection problems are addressed in this paper: (1) narrow band feature selection, which is the selection of a subset of individual bands; (2) broad band feature selection, in which groups of adjacent bands are selected, and (3) nonadjacent multiple band feature selection, in which selection of the groups of bands is not limited to adjacent bands. Spatial autocorrelation is useful in all three feature selection problems. Tests with simulated data indicate that the spatial autocorrelation based methods consistently identify the best bands or groups of bands. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data of eastern Washington state are used to illustrate the technique on real data.

  5. A Statistical Approach to Autocorrelation Detection of Low Frequency Earthquakes

    NASA Astrophysics Data System (ADS)

    Aguiar, A. C.; Beroza, G. C.

    2012-12-01

    We have analyzed tremor data during the April, 2006 tremor episode in the Nankai Trough in SW Japan using the auto-correlation approach of Brown et al. (2008), which detects low frequency earthquakes (LFEs) based on pair-wise matching. We have found that the statistical behavior of the autocorrelations of each station is different and for this reason we have based our LFE detection method on the autocorrelation of each station individually. Analyzing one station at a time assures that the detection threshold will only depend on the station being analyzed. Once detections are found on each station individually, using a low detection threshold based on a Gaussian distribution of the correlation coefficients, the results are compared within stations and declared a detection if they are found in a statistically significant number of the stations, following multinomial statistics. We have compared our detections using the single station method to the detections found by Shelly et al. (2007) for the 2006 April 16 events and find a significant number of similar detections as well as many new detections that were not found using templates from known LFEs. We are working towards developing a sound statistical basis for event detection. This approach should improve our ability to detect LFEs within weak tremor signals where they are not already identified, and should be applicable to earthquake swarms and sequences in general.

  6. Estimating the variation, autocorrelation, and environmental sensitivity of phenotypic selection.

    PubMed

    Chevin, Luis-Miguel; Visser, Marcel E; Tufto, Jarle

    2015-09-01

    Despite considerable interest in temporal and spatial variation of phenotypic selection, very few methods allow quantifying this variation while correctly accounting for the error variance of each individual estimate. Furthermore, the available methods do not estimate the autocorrelation of phenotypic selection, which is a major determinant of eco-evolutionary dynamics in changing environments. We introduce a new method for measuring variable phenotypic selection using random regression. We rely on model selection to assess the support for stabilizing selection, and for a moving optimum that may include a trend plus (possibly autocorrelated) fluctuations. The environmental sensitivity of selection also can be estimated by including an environmental covariate. After testing our method on extensive simulations, we apply it to breeding time in a great tit population in the Netherlands. Our analysis finds support for an optimum that is well predicted by spring temperature, and occurs about 33 days before a peak in food biomass, consistent with what is known from the biology of this species. We also detect autocorrelated fluctuations in the optimum, beyond those caused by temperature and the food peak. Because our approach directly estimates parameters that appear in theoretical models, it should be particularly useful for predicting eco-evolutionary responses to environmental change. PMID:26227394

  7. World commercial aircraft accidents: 1st edition, 1946--1991

    SciTech Connect

    Kimura, C.Y.

    1992-02-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. This report is organized into six chapters. The first chapter is the introduction. The second chapter contains the compilation of accidents involving world commercial jet aircraft from 1952 to 1991. The third chapter presents a compilation of accidents involving world commercial turboprop aircraft from 1952 to 1991. The fourth chapter presents a compilation of accidents involving world commercial pistonprop aircraft with four or more engines from 1946 to 1991. Each accident compilation or database in chapters two, three and four is presented in chronological order. Each accident is presented with information the following categories: date of accident, airline or operator and its flight number (if known), type of flight, type of aircraft and model, aircraft registration number, construction number/manufacturers serial number, aircraft damage resulting from accident, accident flight phase, accident location, number of fatalities, number of occupants, references used to compile the information, and finally cause, remarks, or description (brief) of the accident. The fifth chapter presents a list of all commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities. Chapter six presents the commercial aircraft accidents for all aircraft types by flight phase. Future editions of this report will have additional follow-on chapters which will present other studies still in preparation at the time this edition was being prepared.

  8. INL FY2014 1st Quarterly Performance Analysis

    SciTech Connect

    Loran Kinghorn

    2014-07-01

    This report is published quarterly by the Idaho National Laboratory (INL) Performance Assurance Organization. The Department of Energy Occurrence Reporting and Processing System (ORPS), as prescribed in DOE Order 232.2 “Occurrence Reporting and Processing of Operations Information,” requires a quarterly analysis of events, both reportable and not reportable, for the previous 12 months. This report is the analysis of 76 occurrence reports and over 16 other deficiency reports (including not reportable events) identified at the INL during the period of October 2013 through December 2013. Battelle Energy Alliance (BEA) operates the INL under contract DE AC 07 051D14517

  9. When should orthostatic blood pressure changes be evaluated in elderly: 1st, 3rd or 5th minute?

    PubMed

    Soysal, Pinar; Aydin, Ali Ekrem; Koc Okudur, Saadet; Isik, Ahmet Turan

    2016-01-01

    Detection of orthostatic hypotension (OH) is very important in geriatric practice, since OH is associated with mortality, ischemic stroke, falls, cognitive failure and depression. It was aimed to determine the most appropriate time for measuring blood pressure in transition from supine to upright position in order to diagnose OH in elderly. Comprehensive geriatric assessment (CGA) including Head up Tilt Table (HUT) test was performed in 407 geriatric patients. Orthostatic changes were assessed separately for the 1st, 3rd and 5th minutes (HUT1, HUT3 and HUT5, respectively) taking the data in supine position as the basis. The mean age, recurrent falls, presence of dementia and Parkinson's disease, number of drugs, alpha-blocker and anti-dementia drug use, and fasting blood glucose levels were significantly higher in the patients with versus without OH; whereas, albumin and 25-hydroxy vitamin D levels were significantly lower (p<0.05). However, different from HUT3 and HUT5, Charlson Comorbidity Index and the prevalence of diabetes mellitus were higher, the use of antidiabetics, antipsychotics, benzodiazepine, opioid and levodopa were more common (p<0.05). Statistical significance of the number of drugs and fasting blood glucose level was prominent in HUT1 as compared to HUT3 (p<0.01, p<0.05). Comparison of the patients that had OH only in HUT1, HUT3or HUT5 revealed no difference in terms of CGA parameters. These results suggests that orthostatic blood pressure changes determined at the 1st minute might be more important for geriatric practice. Moreover, 1st minute measurement might be more convenient in the elderly as it requires shorter time in practice. PMID:27077324

  10. National Institute for Rocket Propulsion Systems 1st Annual Workshop

    NASA Technical Reports Server (NTRS)

    Doreswamy, Rajiv; Fry, Emma; Swindell, Tina

    2012-01-01

    The National Institute for Rocket Propulsion Systems (NIRPS) is a Government -wide initiative that seeks to ensure the resiliency of the Nation fs rocket propulsion community in order for the enterprise to remain vibrant and capable of providing reliable and affordable propulsion systems for the nation fs defense, civil and commercial needs. Recognizing that rocket propulsion is a multi-use technology that ensures the nation fs leadership in aerospace, the Government has a vested interest in maintaining this strategic capability through coordinated and synchronized acquisition programs and continual investments in research and development. NIRPS is a resource for collaboration and integration between all sectors of the U.S. propulsion enterprise, supporting policy development options, identifying technology requirements, and offering solutions that maximize national resources while ensuring that capability exists to meet future demand. NIRPS functions as a multi ]agency organization that our nation fs decision makers can look to for comprehensive information regarding all issues concerning the propulsion enterprise.

  11. Using auto-correlations from seismic ambient noise to monitor velocity changes at Villarrica Volcano, Chile

    NASA Astrophysics Data System (ADS)

    McKee, K. F.; Waite, G. P.; Richardson, J. P.

    2012-12-01

    We used the Green's functions from auto-correlations and cross-correlations of seismic ambient noise to monitor temporal velocity changes in the subsurface at Villarrica Volcano in the Southern Andes of Chile. Campaigns were conducted from March to October 2010 and February to April 2011 with 8 broadband and 6 short-period stations, respectively. We prepared the data by removing the instrument response, normalizing with a root-mean-square method, whitening the spectra, and filtering from 1 to 10 Hz. This frequency band was chosen based on the relatively high background noise level in that range. Hour-long auto- and cross-correlations were computed and the Green's functions stacked by day and total time. To track the temporal velocity changes we stretched a 24 hour moving window of correlation functions from 90% to 110% of the original and cross correlated them with the total stack. The average increase in velocity gleaned from the auto-correlations during the 2010 array was 0.13%, as seen in the figure. Cross-correlations from station V01, near the summit, to the other stations show comparable increases in velocity. We attribute this change to the closing of cracks in the subsurface due either to seasonal snow loading or regional tectonics. In addition to the common increase in velocity across the stations, there are excursions in velocity on the same order lasting several days. Amplitude decreases as the station's distance from the vent increases suggesting these excursions may be attributed to changes within the volcanic edifice. Two occurrences are highlighted in the figure in which it is seen that the amplitudes at stations V06 and V07, the stations farthest from the vent, are smaller. Similar short temporal excursions were seen in the auto-correlations from 2011, however, there was little to no increase in the overall velocity.ercent change in velocity at Villarrica Volcano, Chile from March to October 2010 (stations offset by 0.2%)

  12. Performance indicators for 1st quarter CY 1993

    SciTech Connect

    Not Available

    1993-08-01

    The Department of Energy (DOE) has established a Department-wide Performance Indicator (PI) Program for trending and analysis of operational data as directed by DOE Order 5480.26. The PI Program was established to provide a means for monitoring the environment, safety, and health (ES&H) performance of the DOE at the Secretary and other management levels. This is the ninth in a series of quarterly reports generated for the Department of Energy Field Office, Idaho (DOE-ID) by EG&G Idaho, Inc. to meet the requirements of the PI Program as directed by the DOE Standard. DOE-STD-1048-92 identifies four general areas of PIs. They are: Personnel Safety, Operational Incidents, Environment and Management. These four areas have been subdivided into 26 performance indicators. Approximately 115 performance indicator control and distribution charts comprise the body of this report A brief summary of PIs contained in each of these general areas is provided in the following pages. The four EG&G facilities whose performance is charted herein are as follows: (1) The Advanced Test Reactor (ATR); (2) The Radioactive Waste Management Complex (RWMC); (3) The Waste Experimental Reduction Facility (WERF) and (4) The Test Reactor Area (TRA) Hot Cells.

  13. Study of trabecular bone microstructure using spatial autocorrelation analysis

    NASA Astrophysics Data System (ADS)

    Wald, Michael J.; Vasilic, Branimir; Saha, Punam K.; Wehrli, Felix W.

    2005-04-01

    The spatial autocorrelation analysis method represents a powerful, new approach to quantitative characterization of structurally quasi-periodic anisotropic materials such as trabecular bone (TB). The method is applicable to grayscale images and thus does not require any preprocessing, such as segmentation which is difficult to achieve in the limited resolution regime of in vivo imaging. The 3D autocorrelation function (ACF) can be efficiently calculated using the Fourier transform. The resulting trabecular thickness and spacing measurements are robust to the presence of noise and produce values within the expected range as determined by other methods from μCT and μMRI datasets. TB features found from the ACF are shown to correlate well with those determined by the Fuzzy Distance transform (FDT) in the transverse plane, i.e. the plane orthogonal to bone"s major axis. The method is further shown to be applicable to in-vivo μMRI data. Using the ACF, we examine data acquired in a previous study aimed at evaluating the structural implications of male hypogonadism characterized by testosterone deficiency and reduced bone mass. Specifically, we consider the hypothesis that eugonadal and hypogonadal men differ in the anisotropy of their trabecular networks. The analysis indicates a significant difference in trabecular bone thickness and longitudinal spacing between the control group and the testosterone deficient group. We conclude that spatial autocorrelation analysis is able to characterize the 3D structure and anisotropy of trabecular bone and provides new insight into the structural changes associated with osteoporotic trabecular bone loss.

  14. Influence of autocorrelation on the topology of the climate network

    NASA Astrophysics Data System (ADS)

    Guez, Oded C.; Gozolchiani, Avi; Havlin, Shlomo

    2014-12-01

    Different definitions of links in climate networks may lead to considerably different network topologies. We construct a network from climate records of surface level atmospheric temperature in different geographical sites around the globe using two commonly used definitions of links. Utilizing detrended fluctuation analysis, shuffled surrogates, and separation analysis of maritime and continental records, we find that one of the major influences on the structure of climate networks is due to the autocorrelation in the records, which may introduce spurious links. This may explain why different methods could lead to different climate network topologies.

  15. Autocorrelation Analysis of Meteorological Data from a RASS Sodar.

    NASA Astrophysics Data System (ADS)

    Pérez, Isidro A.; Ángeles García, M.; Sánchez, M. Luisa; de Torre, Beatriz

    2004-08-01

    Autocorrelation analysis is necessary in persistence studies and identification of cyclical processes. In this paper, autocorrelations of available wind speed and temperature data from a radio acoustic sounding system (RASS) sodar were calculated. This device was placed on flat terrain, and the measuring campaign extended over April 2001. Ten-minute averages were considered from 40 to 500 m in 20-m levels. The direction frequency rose indicated clear, prevailing directions in the east-northeast west-southwest axis. Analysis of median temperatures revealed that east-northeast advections were 5°C colder than those from the west-southwest. A defined pattern was obtained for both autocorrelations, comprising deterministic and random parts. Noise became more relevant at the higher levels. The deterministic part could be considered as an initial fast-decaying term with the addition of two harmonic functions. The initial decay, linked to fast changes, increased with height for wind speed and decreased for temperature. A diurnal cycle was relevant at intermediate levels for wind speed and at lower temperature levels. The absence of the surface influence added to the horizontal movement associated with the stable night stratification and diurnal convection produced a sharp daily contrast in wind speed at intermediate levels. The influence of the surface decreased with height for temperature. The second cycle was linked to changes in the synoptic pattern and had a 5 6-day period. It was more relevant at lower levels for wind speed, and its amplitude decreased with height. For temperature, this second cycle was less significant. Following these assumptions, a model for the autocorrelation function was proposed and its coefficients are calculated by means of a simple method—a multiple linear regression beyond the first day and a simple linear regression for the first 12-h residuals. This model proved satisfactory, especially below 300 m. A rough height parameterization has

  16. Broadband short pulse measurement by autocorrelation with a sum-frequency generation set-up

    SciTech Connect

    Glotin, F.; Jaroszynski, D.; Marcouille, O.

    1995-12-31

    Previous spectral and laser pulse length measurements carried out on the CLIO FEL at wavelength {lambda}=8.5 {mu}m suggested that very short light pulses could be generated, about 500 fs wide (FWHM). For these measurements a Michelson interferometer with a Te crystal, as a non-linear detector, was used as a second order autocorrelation device. More recent measurements in similar conditions have confirmed that the laser pulses observed are indeed single: they are not followed by other pulses distant by the slippage length N{lambda}. As the single micropulse length is likely to depend on the slippage, more measurements at different wavelengths would be useful. This is not directly possible with our actual interferometer set-up, based on a phase-matched non-linear crystal. However, we can use the broadband non-linear medium provided by one of our users` experiments: Sum-Frequency Generation over surfaces. With such autocorrelation set-up, interference fringes are no more visible, but this is largely compensated by the frequency range provided. First tests at 8 {mu}m have already been performed to validate the technic, leading to results similar to those obtained with our previous Michelson set-up.

  17. Autocorrelation in ultraviolet radiation measured at ground level using detrended fluctuation analysis

    NASA Astrophysics Data System (ADS)

    da Silva Filho, Paulo Cavalcante; da Silva, Francisco Raimundo; Corso, Gilberto

    2016-07-01

    In this study, we analyzed the autocorrelation among four ultraviolet (UV) radiation data sets obtained at 305 nm, 320 nm, 340 nm, and 380 nm. The data were recorded at ground level at the INPE climate station in Natal, RN, Brazil, which is a site close to the equator. The autocorrelations were computed by detrended fluctuation analysis (DFA) to estimate the index α. We found that the ​fluctuations in the UV radiation data were fractal, with scale-free behavior at a DFA index α ≃ 0.7. In addition, we performed a power law spectral analysis, which showed that the power spectrum exhibited a power law behavior with an exponent of β ≃ 0.45. Given that the theoretical result is β = 2 α - 1, these two results are in good agreement. Moreover, the application of the DFA ​method to the UV radiation data required detrending using a polynomial with an order of at least eight, which was related to the complex daily solar radiation curve obtained at ground level in a tropical region. The results indicated that the α exponent of UV radiation is similar to other climatic records such as air temperature, wind, or rain, but not solar activity.

  18. Autocorrelation-based time synchronous averaging for condition monitoring of planetary gearboxes in wind turbines

    NASA Astrophysics Data System (ADS)

    Ha, Jong M.; Youn, Byeng D.; Oh, Hyunseok; Han, Bongtae; Jung, Yoongho; Park, Jungho

    2016-03-01

    We propose autocorrelation-based time synchronous averaging (ATSA) to cope with the challenges associated with the current practice of time synchronous averaging (TSA) for planet gears in planetary gearboxes of wind turbine (WT). An autocorrelation function that represents physical interactions between the ring, sun, and planet gears in the gearbox is utilized to define the optimal shape and range of the window function for TSA using actual kinetic responses. The proposed ATSA offers two distinctive features: (1) data-efficient TSA processing and (2) prevention of signal distortion during the TSA process. It is thus expected that an order analysis with the ATSA signals significantly improves the efficiency and accuracy in fault diagnostics of planet gears in planetary gearboxes. Two case studies are presented to demonstrate the effectiveness of the proposed method: an analytical signal from a simulation and a signal measured from a 2 kW WT testbed. It can be concluded from the results that the proposed method outperforms conventional TSA methods in condition monitoring of the planetary gearbox when the amount of available stationary data is limited.

  19. Smoothing localized directional cyclic autocorrelation and application in oil-film instability analysis

    NASA Astrophysics Data System (ADS)

    Liu, Xiaofeng; Bo, Lin; Luo, Honglin

    2016-04-01

    In this paper, smoothing localized directional cyclic autocorrelation (SLDCA) is proposed as a novel time-frequency distribution to analyze the vibration signal of rotor-bearing system in oil-film instability. Based on the cyclostationarity of real-valued signal, directional cyclic autocorrelation (DCA) is defined for the complex-valued signal. In order to suppress the cross-term interferences, the DCA is localized and filtered with two-dimensional time-frequency window which allows the smoothing kernel function to adapt to the signal time-frequency-varying characteristics. And then the localized DCA is smoothed by the localized optimal radially Gaussian kernel and cascaded to produce the SLDCA with high time-frequency resolution and less susceptibility to cross-term interferences. The application of SLDCA in the oil-film instability analysis verifies that the SLDCA can not only precisely detect the instantaneous frequency information in the time-frequency distribution with high resolution and robustness to the noises and cross-terms, but also provide the phase coupling information of rotor instantaneous planar motion by which the directivity and shape of the planar motion can be determined.

  20. Minimally Invasive Arthrodesis of 1st Metatarsophalangeal Joint for Hallux Rigidus.

    PubMed

    Sott, A H

    2016-09-01

    First metatarsophalangeal joint arthrodesis plays a significant role in the management of symptomatic hallux rigidus/osteoarthritis of the 1st metatarsophalangeal joint. Several open and few percutaneous techniques have been described in the literature. This article describes and discusses a percutaneous technique that has been successfully used to achieve a pain-free stable and functional 1st metatarsophalangeal joint. All aspects of surgical indication and operative technique and details of patient-reported outcomes are presented with a referenced discussion. PMID:27524706

  1. Monitoring North Korea Explosions: Status and Result of 1st and 2nd Tests (Invited)

    NASA Astrophysics Data System (ADS)

    Chi, H.; Lee, H.; Shin, J.; Park, J.; Sheen, D.; Kim, G.; Che, I.; Lim, I.; Kim, T.

    2009-12-01

    Through data exchanging with China, Russia and Japan, KIGAM could monitor North Korea explosion tests in near real time with azimuthal full coverage from the test site. Except for the East Sea (Japan Sea) side, the seismic stations are distributed uniformly along the boundaries of North Korea and adjacent countries, and only stations with the distance of 200 to 550 Km from the test site were considered. Irrespective of azimuthal directions of stations from the test site, the conventional discrimination, Pn/Lg spectral ratio clearly showed that both tests were explosion. But mb-Ms discrimination did not show apparently the known pattern of explosion for both tests. Body wave magnitude, mb(Pn) of 2nd test, which was evaluated as 4.5 by KIGAM, varies with directional location of stations widely from 4.1 to 5.2. The magnitude obtained from Lg, mb(Lg), showed narrow variation between 4.3 to 4.7 with the average of 4.5. In the case of 1st test, both mb(Pn) and mb(Lg) showed equivalently large variation with directional station location. The error ellipses of epicentral determination of test site for 1st and 2nd tests showed almost identical pattern if they were separately calculated with the same configuration of stations. But the combined use of 1st and 2nd test data showed that 2nd test site was moved approximately 2 Km westward from 1st site. The cut-off frequencies of P wave of 1st and 2nd tests showed no or negligible difference even though the estimated yield of 2nd test were much larger than that of 1st one. The ratio of 1st and 2nd P-wave amplitudes showed from 2 to 3.1 times. Correspondingly the estimated energy or yield were ranged from 4 to roughly 10 times. KIGAM evaluated the yield of 2nd test were 8 times in the average larger than that of 1st one.

  2. The autocorrelation function of the North Pole dust

    NASA Technical Reports Server (NTRS)

    Knude, Jens

    1989-01-01

    The angular scales on which local interstellar dust is distributed are so far rather unknown as are the geometrical shapes of the dust features. From the about 5000 color excesses resulting from a north polar survey with 4 to 5 stars per square degree the two-point autocorrelation function is derived for separations ranging from 10 min to 3 deg. For intercloud lines of sight, -0.020 is less than E(b - y) is less than -0.010 mag, the average cross products (E sub 1 x E sub 2)(sub theta) show no variation with separation theta(1,2) whereas products of cloud column densities, 0.030 is less than E(b - y) is less than 0.040 mag, seem to prefer discrete separations either less than 20 min, around 75 min, or finally at about 150 min. Surprisingly the two point autocorrelation function omega(sub E) = E(sub 1) x E(sub 2)/E squared - 1 equals 0 except for any separation except theta = 0. Omega(sub E)(theta)'s absence of variation is unexpected because omega(sub H)(theta) is known to vary exponentially above b = 40 deg for separations less than 3 deg. Atomic hydrogen and dust may thus not be entirely mixed or the moments (E sub 1 x E sub 2)(sub theta) may not characterize the dust distribution.

  3. How Many Attempts Until Success in Some Core 1st. Year Disciplines?

    ERIC Educational Resources Information Center

    Fernandes, Graça Leão; Andrade e Silva, João; Lopes, Margarida Chagas

    2012-01-01

    Due to a general development in education brought about by democracy, Portugal has witnessed tremendous development in Higher Education (HE) since the beginning of the 1980s. Nevertheless, the percentage of graduates among the Portuguese population still ranks far below most European countries. This is why academic performance in HE 1st cycle…

  4. 130. Post1911. Photograph labeled, 'SEASON 1913. CAPTAIN, 1st MATE, SUPT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    130. Post-1911. Photograph labeled, 'SEASON 1913. CAPTAIN, 1st MATE, SUPT AND STOREKEEPER, A.P. ASS'N CANNERY, SHIP STAR OF ALASKA.' View forward from mizzenmast, post side. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

  5. First-Generation College Students' 1st-Year College Experiences: Challenges Attending a Private University

    ERIC Educational Resources Information Center

    Reid, Josephine

    2013-01-01

    First-generation college students (FGCS) face challenges when switching from high school to college and during their 1st-year in college. Additionally, FGCS may have difficulty understanding the steps required to prepare for and enroll in postsecondary education. The social capital theory examines support of social, academic, and cultural networks…

  6. 25. PRIMARY POWER TRANSMISSION BELT HOLES IN 1st FLOOR MILL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. PRIMARY POWER TRANSMISSION BELT HOLES IN 1st FLOOR MILL NO. 1 CEILING. WATER-POWERED MACHINERY LOCATED IN BASEMENT RAN LEATHER BELTS THROUGH THESE HOLES. POWER WAS THEN TRANSMITTED TO SHAFTS AND PULLEYS TO RUN MACHINERY ON MILL FLOORS. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  7. 77 FR 22574 - Filing Dates for the Washington Special Election In the 1st Congressional District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Filing Dates for the Washington Special Election In the 1st Congressional District AGENCY: Federal Election Commission. ACTION: Notice of filing dates for special election. SUMMARY: Washington has...

  8. 76 FR 51366 - Filing Dates for the Oregon Special Election in the 1st Congressional District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-18

    ... information on these requirements, see Federal Register Notice 2009-03, 74 FR 7285 (February 17, 2009... November 8, 2011, and January 31, 2012, to fill the U.S. House seat in the 1st Congressional District... forms: One form to cover 2011 activity, labeled as the Year-End Report; and the other form to cover...

  9. Perceptual Narrowing of Linguistic Sign Occurs in the 1st Year of Life

    ERIC Educational Resources Information Center

    Palmer, Stephanie Baker; Fais, Laurel; Golinkoff, Roberta Michnick; Werker, Janet F.

    2012-01-01

    Over their 1st year of life, infants' "universal" perception of the sounds of language narrows to encompass only those contrasts made in their native language (J. F. Werker & R. C. Tees, 1984). This research tested 40 infants in an eyetracking paradigm and showed that this pattern also holds for infants exposed to seen language--American Sign…

  10. Highlights of the 1st Student Symposium of the ISCB RSG UK

    PubMed Central

    Rahman, Farzana; Farmer, Rohit; Das, Sayoni; Vayani, Fatima; Hassan, Mehedi

    2015-01-01

    This short report summarises the scientific content and activities of a student-led event, the 1st student symposium by the UK Regional Student Group of the International Society for Computational Biology. The event took place on the 8th of October 2014. PMID:26998223

  11. 48. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms Latching mechanism, E end of turn span, view from N. Sarcone Photography, Columbus, MS. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  12. 42. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Copy of postcard ca. 1900. Copy owned and made by Jack Donnell, Columbus, Ms. Shows two-span steel truss, built by Phoenix Bridge Co. in 1878. Negative copied by: Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  13. 49. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Top of pier and underside of w end of turn span. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  14. 47. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Latching mechanism, E end of turn span, viewed from W. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  15. The Course of Psychological Disorders in the 1st Year After Cancer Diagnosis

    ERIC Educational Resources Information Center

    Kangas, Maria; Henry, Jane L.; Bryant, Richard A.

    2005-01-01

    This study investigated the relationship between acute stress disorder (ASD) and posttraumatic stress disorder (PTSD) and comorbid anxiety, depressive, and substance use disorders over the first 12-month period following a cancer diagnosis. Individuals recently diagnosed with 1st onset head and neck or lung malignancy were assessed for ASD within…

  16. The role of fluctuating modes of autocorrelation in crude oil prices

    NASA Astrophysics Data System (ADS)

    An, Haizhong; Gao, Xiangyun; Fang, Wei; Huang, Xuan; Ding, Yinghui

    2014-01-01

    Autocorrelation exists in the crude oil price due to price inertia, the cobweb theorem, model errors, etc. Many researchers have studied the fluctuation of the crude oil price, but few have focused on the autocorrelation fluctuation in crude oil prices. Exploring the fluctuating rules of autocorrelation can aid in understanding the fluctuating mechanism of crude oil prices. To study the role of fluctuating modes of autocorrelation in crude oil prices, which have time series characteristics, this study selected international crude oil spot prices as sample data to employ the methods of statistical physics. The fluctuating modes of autocorrelation were defined by the autocorrelation coefficient, symbolization, and a coarse-graining process. We set the modes as nodes and the transformation between modes as edges; the fluctuating mode weight network of autocorrelation was then built. Thus, the study of autocorrelation fluctuation was transformed to a network study. Then, certain aspects, such as the statistical properties, the “small-world” behavior, and the transmission medium in the network, could be analyzed using complex network theory and analytical methods. The periodicity of the fluctuation was calculated using a spectral analysis method. This study not only describes the fluctuation of the time series more precisely than other methods but also provides ideas for methods of studying the fluctuation of univariate autocorrelations.

  17. A two-photon fluorescence autocorrelator for a Nd:YLF modelocked laser

    SciTech Connect

    Kner, P.A.

    1991-05-01

    In this thesis, I discuss the design and implementation of an autocorrelator for an actively modelocked ND:YLF laser at wavelength 1.054{mu}m. A dye is used to generate a broadband two-photon fluorescence (TPF) signal at 570nm which is the autocorrelation of the laser pulses. Two different techniques are discussed. A colliding pulse scheme can be used to generate a TPF autocorrelation signal as a function of distance, or an interferometer technique can be used to generate an autocorrelation signal as a function of the delay in an interferometer arm. Experimental results are discussed, but they are inconclusive because of difficulties in interpreting the signal.

  18. Receiver structure from teleseisms: Autocorrelation and cross correlation

    NASA Astrophysics Data System (ADS)

    Sun, Weijia; Kennett, B. L. N.

    2016-06-01

    We present a way of characterizing the structure beneath a seismic station, by exploiting stacked correlograms of three-component records from teleseismic events. This seismic daylight imaging approach exploits the extraction of reflection and conversion information from teleseismic coda via tensor autocorrelation. The approach is illustrated for a number of Australian stations in a variety of tectonic environments using hundreds of teleseismic events, to extract P and S reflectivity and converted Ps and Sp information. The results show a very good agreement with prior knowledge across Australia. Compared with the classical receiver function, the broader-frequency band of 0.5-4.0 Hz provides additional information on finer-scale structure.

  19. A linear regression solution to the spatial autocorrelation problem

    NASA Astrophysics Data System (ADS)

    Griffith, Daniel A.

    The Moran Coefficient spatial autocorrelation index can be decomposed into orthogonal map pattern components. This decomposition relates it directly to standard linear regression, in which corresponding eigenvectors can be used as predictors. This paper reports comparative results between these linear regressions and their auto-Gaussian counterparts for the following georeferenced data sets: Columbus (Ohio) crime, Ottawa-Hull median family income, Toronto population density, southwest Ohio unemployment, Syracuse pediatric lead poisoning, and Glasgow standard mortality rates, and a small remotely sensed image of the High Peak district. This methodology is extended to auto-logistic and auto-Poisson situations, with selected data analyses including percentage of urban population across Puerto Rico, and the frequency of SIDs cases across North Carolina. These data analytic results suggest that this approach to georeferenced data analysis offers considerable promise.

  20. Fractal analysis of multiscale spatial autocorrelation among point data

    USGS Publications Warehouse

    De Cola, L.

    1991-01-01

    The analysis of spatial autocorrelation among point-data quadrats is a well-developed technique that has made limited but intriguing use of the multiscale aspects of pattern. In this paper are presented theoretical and algorithmic approaches to the analysis of aggregations of quadrats at or above a given density, in which these sets are treated as multifractal regions whose fractal dimension, D, may vary with phenomenon intensity, scale, and location. The technique is illustrated with Matui's quadrat house-count data, which yield measurements consistent with a nonautocorrelated simulated Poisson process but not with an orthogonal unit-step random walk. The paper concludes with a discussion of the implications of such analysis for multiscale geographic analysis systems. -Author

  1. An autocorrelation method to detect low frequency earthquakes within tremor

    USGS Publications Warehouse

    Brown, J.R.; Beroza, G.C.; Shelly, D.R.

    2008-01-01

    Recent studies have shown that deep tremor in the Nankai Trough under western Shikoku consists of a swarm of low frequency earthquakes (LFEs) that occur as slow shear slip on the down-dip extension of the primary seismogenic zone of the plate interface. The similarity of tremor in other locations suggests a similar mechanism, but the absence of cataloged low frequency earthquakes prevents a similar analysis. In this study, we develop a method for identifying LFEs within tremor. The method employs a matched-filter algorithm, similar to the technique used to infer that tremor in parts of Shikoku is comprised of LFEs; however, in this case we do not assume the origin times or locations of any LFEs a priori. We search for LFEs using the running autocorrelation of tremor waveforms for 6 Hi-Net stations in the vicinity of the tremor source. Time lags showing strong similarity in the autocorrelation represent either repeats, or near repeats, of LFEs within the tremor. We test the method on an hour of Hi-Net recordings of tremor and demonstrates that it extracts both known and previously unidentified LFEs. Once identified, we cross correlate waveforms to measure relative arrival times and locate the LFEs. The results are able to explain most of the tremor as a swarm of LFEs and the locations of newly identified events appear to fill a gap in the spatial distribution of known LFEs. This method should allow us to extend the analysis of Shelly et al. (2007a) to parts of the Nankai Trough in Shikoku that have sparse LFE coverage, and may also allow us to extend our analysis to other regions that experience deep tremor, but where LFEs have not yet been identified. Copyright 2008 by the American Geophysical Union.

  2. Regional Observations of North Korea Explosions: 1st and 2nd Tests

    NASA Astrophysics Data System (ADS)

    Chi, Heon Cheol; Shin, Jin Soo; Lee, Hee-Il; Park, Jung Ho; Sheen, Dong-Hoon; Kim, Geunyoung; Kim, Tea Sung; Che, Il-Young; Lim, In-Seub

    2010-05-01

    Through data exchanging with China, Russia and Japan, KIGAM could monitor North Korea explosion tests in near real time with azimuthally full coverage from the test site. Except for the East Sea (Japan Sea) side, the seismic stations are distributed uniformly along the boundaries of North Korea and adjacent countries. The error ellipses of epicentral determination of test site for 1st and 2nd tests showed almost identical pattern if they were separately calculated with the same configuration of stations. But the combined use of the 1st and the 2nd test data showed that the 2nd test site was moved approximately 2 Km westward from 1st site. The Pn/Lg spectral ratio clearly discriminate these events from two nearby natural earthquakes above 4 Hz. Full moment tensor inversion also indicate the 2nd test had a very large isotropic component. But mb-Ms discrimination, which has been considered one of the most reliable discriminants for separating explosions and earthquakes, did not show apparently the known pattern of explosion for both tests. Body wave magnitude, mb(Pn) of the 2nd test, which was evaluated as 4.5 by KIGAM, varies with directional location of stations widely from 4.1 to 5.2. The magnitude obtained from Lg, mb(Lg), showed narrow variation between 4.3 to 4.7 with the average of 4.5. In the case of both 1st and 2nd tests, both mb(Pn) and mb(Lg) showed equivalently large variation with directional station location. These variations are mainly due to lateral variation of crustal structures surrounding the test site. Remarkably mb(Lg) showed very linear relationship with mb(Pn). By considering attenuation characteristics according to the propagation path, the variations could be effectively reduced. The cut-off frequencies of P wave of both tests showed no or negligible difference even though the estimated yield of the 2nd test were much larger than that of the 1st one. The ratio of P-wave amplitudes of two tests showed from 2 to 3.1 times. Correspondingly the

  3. Seismic ambient noise H/V spectral ratio using the ACA (autocorrelations of coda of autocorrelations) approach

    NASA Astrophysics Data System (ADS)

    Sanchez-Sesma, F. J.; Piña, J.; Campillo, M.; Luzón, F.; García-Jerez, A.; Albarello, D.; Lunedei, E.

    2012-12-01

    The seismic ambient noise horizontal-to-vertical spectral ratios (NHVSR) are valuable for microzonation, and seismic prospecting. This is particularly true for low-cost dense spatial sampling projects. Arai and Tokimatsu (2004) proposed to use average energy densities to compose the ratios. It means that H/V comes from the square root of the ratio of averages. On the other hand, a popular approach makes the average of spectral ratios. For ergodic processes peak values are usually the same using these two approaches. Sometimes however, the observations are insufficient and computed values for low frequencies display large variability and the corresponding H/V estimates may be inaccurate. The bias caused by localized sources may be the source of errors in the estimates. In this work we propose to compute the NHVSR using the Autocorrelations of Coda of Autocorrelations. This ACA approach is inspired in the work by Stehly et al. (2008). They used the Correlations of Coda of Correlations (C3) to isotropize the field. In our ACA approach the whole time series, say of 30 minutes, for each component is autocorrelated and the averages of the spectral density of selected windows (late coda windows are eliminated) are then improved estimates of directional energy densities. The computation of NHVSR using ACA appears more stable and free of transient effects. It remains to establish how this may be accounted for in forward calculation of H/V spectral ratios for models like a layered medium (e.g. Sánchez-Sesma et al., 2011; Albarello and Lunedei, 2011). This will require further scrutiny. References. Albarello, D. & E. Lunedei (2011). Structure of ambient vibration wavefield in the frequency range of engineering interest ([0.5, 20] Hz): insights from numerical modelling. Near Surface Geophysics 9, 543-559. Arai, H. & K. Tokimatsu (2004). S-wave velocity profiling by inversion of microtremor H/V spectrum, Bull. Seismol. Soc. Am. 94, 53-63. Sánchez-Sesma, F. J., M. Rodr

  4. 46. NORTH END OF MILL NO. 2, 1st FLOOR, BELOW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. NORTH END OF MILL NO. 2, 1st FLOOR, BELOW PICKER AND CLOTH ROOM AREA. FUNCTION OF THIS SPACE UNKNOWN AT PRESENT. NOTE THAT EYE BEAM REPLACES ORIGINAL WALL OF 1892 PICKER HOUSE. CENTER (OR LEFT) DOOR IS ENTRY TO MILL NO. 2. RIGHT DOOR IS ENTRY TO 1892 NAPPER ROOM. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  5. 1st Central and Eastern European Proteomic Conference and 3rd Czech Proteomic Conference.

    PubMed

    Kovarova, Hana; Gadher, Suresh Jivan; Archakov, Alexander

    2008-02-01

    The 1st Central and Eastern European Proteomic Conference was organized together with the 3rd Czech Proteomic Conference in the TOP Hotel, Prague in the Czech Republic from the 29th to the 31st October, 2007. The aim was to strengthen links with scientists from Central and Eastern Europe including Russia, which until now have been weak or nonexistent, and to highlight the emergence of excellent proteomic studies from various countries, which until now were not visible. PMID:18282121

  6. 7. Photographic copy of original construction drawing, ELECTRICAL 1ST AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photographic copy of original construction drawing, ELECTRICAL 1ST AND 2ND FLOOR PLANS, SHEET 10 of 11, DRAWING NO. 35-03-05 SF 5/1677, U.S. Army Engineer District, Detroit, Corps of Engineers, 9 June, 1959, on file Selfridge Base Museum. - Selfridge Field, Building No. 1041, West of E Street, north of D Street, Mount Clemens, Macomb County, MI

  7. Ruthenium indenylidene “1st generation” olefin metathesis catalysts containing triisopropyl phosphite

    PubMed Central

    Guidone, Stefano; Nahra, Fady; Slawin, Alexandra M Z

    2015-01-01

    Summary The reaction of triisopropyl phosphite with phosphine-based indenylidene pre-catalysts affords “1st generation” cis-complexes. These have been used in olefin metathesis reactions. The cis-Ru species exhibit noticeable differences with the trans-Ru parent complexes in terms of structure, thermal stability and reactivity. Experimental data underline the importance of synergistic effects between phosphites and L-type ligands. PMID:26425210

  8. 1st International Symposium on Stress-Associated RNA Granules in Human Disease and Viral Infection

    PubMed Central

    Banfield, Bruce W.; Mouland, Andrew J.; McCormick, Craig

    2014-01-01

    In recent years, important linkages have been made between RNA granules and human disease processes. On June 8-10 of this year, we hosted a new symposium, dubbed the 1st International Symposium on Stress-Associated RNA Granules in Human Disease and Viral Infection. This symposium brought together experts from diverse research disciplines ranging from cancer and neuroscience to infectious disease. This report summarizes speaker presentations and highlights current challenges in the field. PMID:25256393

  9. 43. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Copy of photo 1900. Shows 1878 M&O RR bridge. The steamboat, 'Gopher,' in foreground, was an archeological survey vessel from the Franklin Institute in Philadelphia. Published in Art in Mississippi (1901). Credit: Copied from print in Lowndes Co. Public Library by Sarcone Photography, Columbus, Ms. 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  10. 44. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Detail from Camille Drie's map: A Bird's Eye View of Columbus, Mississippi ca. 1875-76. Shows M&O RR bridge before the Phoenix Bridge Co. erected iron truss spans in 1878. Credit: Photostat of map in Lowndes Co. Public Library Sarcone Photography, Columbus, Ms. 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  11. MATLAB-Based Program for Teaching Autocorrelation Function and Noise Concepts

    ERIC Educational Resources Information Center

    Jovanovic Dolecek, G.

    2012-01-01

    An attractive MATLAB-based tool for teaching the basics of autocorrelation function and noise concepts is presented in this paper. This tool enhances traditional in-classroom lecturing. The demonstrations of the tool described here highlight the description of the autocorrelation function (ACF) in a general case for wide-sense stationary (WSS)…

  12. Comparison of joint versus postprocessor approaches for hydrological uncertainty estimation accounting for error autocorrelation and heteroscedasticity

    NASA Astrophysics Data System (ADS)

    Evin, Guillaume; Thyer, Mark; Kavetski, Dmitri; McInerney, David; Kuczera, George

    2014-03-01

    The paper appraises two approaches for the treatment of heteroscedasticity and autocorrelation in residual errors of hydrological models. Both approaches use weighted least squares (WLS), with heteroscedasticity modeled as a linear function of predicted flows and autocorrelation represented using an AR(1) process. In the first approach, heteroscedasticity and autocorrelation parameters are inferred jointly with hydrological model parameters. The second approach is a two-stage "postprocessor" scheme, where Stage 1 infers the hydrological parameters ignoring autocorrelation and Stage 2 conditionally infers the heteroscedasticity and autocorrelation parameters. These approaches are compared to a WLS scheme that ignores autocorrelation. Empirical analysis is carried out using daily data from 12 US catchments from the MOPEX set using two conceptual rainfall-runoff models, GR4J, and HBV. Under synthetic conditions, the postprocessor and joint approaches provide similar predictive performance, though the postprocessor approach tends to underestimate parameter uncertainty. However, the MOPEX results indicate that the joint approach can be nonrobust. In particular, when applied to GR4J, it often produces poor predictions due to strong multiway interactions between a hydrological water balance parameter and the error model parameters. The postprocessor approach is more robust precisely because it ignores these interactions. Practical benefits of accounting for error autocorrelation are demonstrated by analyzing streamflow predictions aggregated to a monthly scale (where ignoring daily-scale error autocorrelation leads to significantly underestimated predictive uncertainty), and by analyzing one-day-ahead predictions (where accounting for the error autocorrelation produces clearly higher precision and better tracking of observed data). Including autocorrelation into the residual error model also significantly affects calibrated parameter values and uncertainty estimates. The

  13. Palm Tree Detection Using Circular Autocorrelation of Polar Shape Matrix

    NASA Astrophysics Data System (ADS)

    Manandhar, A.; Hoegner, L.; Stilla, U.

    2016-06-01

    Palm trees play an important role as they are widely used in a variety of products including oil and bio-fuel. Increasing demand and growing cultivation have created a necessity in planned farming and the monitoring different aspects like inventory keeping, health, size etc. The large cultivation regions of palm trees motivate the use of remote sensing to produce such data. This study proposes an object detection methodology on the aerial images, using shape feature for detecting and counting palm trees, which can support an inventory. The study uses circular autocorrelation of the polar shape matrix representation of an image, as the shape feature, and the linear support vector machine to standardize and reduce dimensions of the feature. Finally, the study uses local maximum detection algorithm on the spatial distribution of standardized feature to detect palm trees. The method was applied to 8 images chosen from different tough scenarios and it performed on average with an accuracy of 84% and 76.1%, despite being subjected to different challenging conditions in the chosen test images.

  14. On the statistics of SuperDARN autocorrelation function estimates

    NASA Astrophysics Data System (ADS)

    Reimer, A. S.; Hussey, G. C.; Dueck, S. R.

    2016-06-01

    Time domain signal processing techniques are employed by the Super Dual Auroral Radar Network (SuperDARN) to obtain bulk measurements of the velocity and spectral width of F region ionospheric plasma irregularities. The measurements are obtained by fitting estimates of the mean autocorrelation function (ACF) of the radar target. To accurately and consistently extract target parameters from the mean unnormalized ACF, it is necessary to utilize error-weighted fitting algorithms with a weight given by the variance of the ACF. Currently implemented weights are ad hoc, and a detailed description of the statistical characterization of SuperDARN ACFs is needed. Following the discussions in Farley (1969) and Woodman and Hagfors (1969), which describe the variance for the mean normalized ACF used with incoherent scatter radars, we present analytic expressions for obtaining the variance of the real and imaginary components of the mean unnormalized SuperDARN ACF. These expressions are based on models by André et al. (1999) and Moorcroft (2004) of the voltage signal received by SuperDARN radars but may be used for other soft target radar systems. An algorithm for obtaining the variance of both the magnitude and phase of the mean ACF is also presented. The results of this study may be directly integrated into existing SuperDARN data analysis software and other pulse-Doppler radar systems that utilize estimates of the mean unnormalized ACF.

  15. Design and construction of a femtosecond pulse autocorrelator using two-photon absorption in a luminescent diode

    NASA Astrophysics Data System (ADS)

    Arthur, M. A. G.; Rojo, R. R.; Jamasbi, N.; Mohebi, M.

    2003-06-01

    In this work, we present the design and construction of a femtosecond laser pulse autocorrelator, based on the two-photon absorption process in a light emitting diode (LED). Compared with traditional autocorrelators based on nonlinear crystals, this autocorrelator has the advantages of lower cost and greater ease of alignment. The intensity and interferometric autocorrelation traces obtained with this device for a titanium-sapphire laser with pulses that are less than 100 fs long, are also presented.

  16. The 1st October 2009 Messina debris flows: first analysis for a susceptibility model

    NASA Astrophysics Data System (ADS)

    Agnesi, Valerio; Cappadonia, Chiara; Conoscenti, Christian; Costanzo, Dario; Pino, Paolo; Puglisi, Claudio; Rotigliano, Edoardo

    2010-05-01

    In the evening of the 1st of October 2009, a sector of the Messina district (Sicily, Italy) was struck by a number of debris flows, triggered by extraordinary intense rainfall that, from 2 pm to 10 pm, discharged an amount of more than 160 mm and that followed the ones of September 23-24 (more than 200 mm in 10 hours). A number of villages (Altolia, Briga, Giampilieri, Guidomandri, Itala, Molino, Pezzolo, Scaletta), suffered for severe damages, including the destruction of houses and small buildings and more of 30 deaths. The area is located South from the city of Messina and mainly includes five short fluvial basins, that from the Peloritanian chain drain south-eastward for some kilometres to the Ionian sea. The area is characterized by the outcropping of metamorphic rocks and, due to the closeness of the chain (ranging up to 1200 meters a.s.l.) to the sea, the steepness of the slopes is typically very high. The debris flows involved the shallow layer made up of colluvial/eluvial and landslide deposits, having a thickness of some decimetres; both pure debris flow and debris slide movements have been inferred at the initiation zones, in light of the morphologic features of the source area (scarps). Also, according to the specific patterns recognized for the flow track zone, four typologies have been distinguished: ribbon-shaped, triangular, arch-shaped and multi-lobed debris flow. The landslides moved fast, as single or multiple/successive confluent style, so that already at the medium sector of the slopes, where the villages are, huge volumes of the debris flowed. Due to the shallowness of the failure zone, the high water content and velocity, the tracks of the debris flows have been highly controlled by hydrography, reaching, where no obstacles were present, the valley floor, with kilometric run-out distances. To each of the 379 recognized debris flows, which produced a total landslide area of about 7 km2, a landslide identification point (LIP) has been assigned

  17. Spatial autocorrelation and the scaling of species-environment relationships.

    PubMed

    De Knegt, H J; van Langevelde, F; Coughenour, M B; Skidmore, A K; de Boer, W F; Heitkönig, I M A; Knox, N M; Slotow, R; van der Waal, C; Prins, H H T

    2010-08-01

    Issues of residual spatial autocorrelation (RSA) and spatial scale are critical to the study of species-environment relationships, because RSA invalidates many statistical procedures, while the scale of analysis affects the quantification of these relationships. Although these issues independently are widely covered in the literature, only sparse attention is given to their integration. This paper focuses on the interplay between RSA and the spatial scaling of species-environment relationships. Using a hypothetical species in an artificial landscape, we show that a mismatch between the scale of analysis and the scale of a species' response to its environment leads to a decrease in the portion of variation explained by environmental predictors. Moreover, it results in RSA and biased regression coefficients. This bias stems from error-predictor dependencies due to the scale mismatch, the magnitude of which depends on the interaction between the scale of landscape heterogeneity and the scale of a species' response to this heterogeneity. We show that explicitly considering scale effects on RSA can reveal the characteristic scale of a species' response to its environment. This is important, because the estimation of species-environment relationships using spatial regression methods proves to be erroneous in case of a scale mismatch, leading to spurious conclusions when scaling issues are not explicitly considered. The findings presented here highlight the importance of examining the appropriateness of the spatial scales used in analyses, since scale mismatches affect the rigor of statistical analyses and thereby the ability to understand the processes underlying spatial patterning in ecological phenomena. PMID:20836467

  18. TDR Using Autocorrelation and Varying-Duration Pulses

    NASA Technical Reports Server (NTRS)

    Lucena, Angel; Mullinex, Pam; Huang, PoTien; Santiago, Josephine; Mata, Carlos; Zavala, Carlos; Lane, John

    2008-01-01

    In an alternative to a prior technique of time-domain-reflectometry (TDR) in which very short excitation pulses are used, the pulses have very short rise and fall times and the pulse duration is varied continuously between a minimum and a maximum value. In both the present and prior techniques, the basic idea is to (1) measure the times between the generation of excitation pulses and the reception of reflections of the pulses as indications of the locations of one or more defects along a cable and (2) measure the amplitudes of the reflections as indication of the magnitudes of the defects. In general, an excitation pulse has a duration T. Each leading and trailing edge of an excitation pulse generates a reflection from a defect, so that a unique pair of reflections is associated with each defect. In the present alternative technique, the processing of the measured reflection signal includes computation of the autocorrelation function R(tau) identical with fx(t)x(t-tau)dt where t is time, x(t) is the measured reflection signal at time t, and taus is the correlation interval. The integration is performed over a measurement time interval short enough to enable identification and location of a defect within the corresponding spatial interval along the cable. Typically, where there is a defect, R(tau) exhibits a negative peak having maximum magnitude for tau in the vicinity of T. This peak can be used as a means of identifying a leading-edge/trailing-edge reflection pair. For a given spatial interval, measurements are made and R(tau) computed, as described above, for pulse durations T ranging from the minimum to the maximum value. The advantage of doing this is that the effective signal-to-noise ratio may be significantly increased over that attainable by use of a fixed pulse duration T.

  19. The Human Auditory System Modeled as AN Autocorrelator.

    NASA Astrophysics Data System (ADS)

    Martin, Mark Aaron

    This thesis is intended to investigate a new strategy for interpreting the human auditory physiology and assess the impact this knowledge might have on engineering applications such as speech encoding, word recognition, and speaker verification. The new interpretation is based around the signal processing properties associated with the autocorrelation function and has been developed from a strong foundation of literature that has been compiled over the last 50 years. A distilation of the pertinent literature includes the phylogenetic development of audition, a detailed description of the anatomy of the inner ear, and the well-recognized inconsistencies involved with traditional interpretations of physiology and psychoacoustic experiments. These issues are discussed and reinterpreted to support a new philosophy on the signal processing functionality of the inner ear. From this conceptual model, a mathematical description and a partly phenomenological computer model are developed. The responses of the new model to test stimuli show qualitative similarity to the results of important psychoacoustic experiments, demonstrating that the new philosophy represents a more unified theory on audition than any proposed so far. In particular the new model predicts the effects known as "pitch", "the second filter", and some other phenomena that are not specifically recognized in the literature. The knowledge gained in this effort is applied to techniques for speech encoding by real zeros, specifically, the reconstruction of signals that have been infinitely clipped. Finally, the concept is extended to include speculation on neural processes at the level of the cochlear nucleus in the brain. At this level an investigation is made to explore the power with which the new model can characterize phoneme signals generated by several different speakers. The results are shown to possess the historically accepted techniques for phoneme characterization as a subset of a dimensionally

  20. Dipolar interactions and hydrogen bonding in supramolecular aggregates: understanding cooperative phenomena for 1st hyperpolarizability.

    PubMed

    Datta, Ayan; Pati, Swapan K

    2006-12-01

    Weak intermolecular forces like dipolar interactions and hydrogen-bonding lead to a variety of different packing arrangements of molecules in crystals and self-assemblies. Such differences in the arrangements change the extent of excitonic splitting and excitation spectra in the multichromophore aggregates. In this tutorial review, the role of such interactions in fine tuning the linear and 1st non-linear optical (NLO) responses in molecular aggregates are discussed. The non-additivity of these optical properties arise specifically due to such cooperative interactions. Calculations performed on dimers, trimers and higher aggregates for model systems provide insights into the interaction mechanisms and strategies to enhance the 1st hyperpolarizabilities of pi-conjugated molecular assemblies. Flexible dipole orientations in the alkane bridged chromophores show odd-even variations in their second-harmonic responses that are explained through their dipolar interactions in different conformations. Parameters for the optical applications of molecules arranged in constrained geometry, like in Calix[n]arene, have been elucidated. We also highlight the recent developments in this field of research together with their future prospects. PMID:17225890

  1. Autopsy as a tool for learning gross anatomy during 1st year MBBS

    PubMed Central

    Goyal, Parmod Kumar; Gupta, Monika; Kaur, Jaswinder

    2016-01-01

    Introduction: Embalmed cadavers are the primary tool for teaching anatomy. However, difficulties are encountered due to changed color/texture of organs, hardening of tissues, and smell of formaldehyde. To overcome these difficulties, dissections on a fresh human body were shown to the 1st year MBBS students, and their perception was noted. Materials and Methods: After taking universal precautionary measures, postmortem dissections were shown to students on voluntary donated bodies in the dissection hall, in addition to the traditional teaching on embalmed cadavers. Feedback was taken from students and faculty regarding the utility of these sessions. Results: Better appreciation of texture, orientation, location, and relations of organs in fresh body, integration of teaching, awareness of the process and laws related to body donations were the outcomes of the study. However, the smell and sight of blood was felt to be nauseating by some students, and some students were worried about the spread of infectious diseases. Conclusions: Visualizing single fresh body dissection during 1st year professional MBBS is recommended either on medicolegal autopsy or on voluntarily-donated bodies. PMID:27563594

  2. A broadly tunable autocorrelator for ultra-short, ultra-high power infrared optical pulses

    SciTech Connect

    Szarmes, E.B.; Madey, J.M.J.

    1995-12-31

    We describe the design of a crossed-beam, optical autocorrelator that uses an uncoated, birefringent beamsplitter to split a linearly polarized incident pulse into two orthogonally polarized pulses, and a Type II, SHG crystal to generate the intensity autocorrelation function. The uncoated beamsplitter accommodates extremely broad tunability while precluding any temporal distortion of ultrashort optical pulses at the dielectric interface, and the specific design provides efficient operation between 1 {mu}m and 4 {mu}m. Furthermore, the use of Type II SHG completely eliminates any single-beam doubling, so the autocorrelator can be operated at very shallow crossed-beam angles without generating a background pedestal. The autocorrelator has been constructed and installed in the Mark III laboratory at Duke University as a broadband diagnostic for ongoing compression experiments on the chirped-pulse FEL.

  3. Effects of autocorrelation upon LANDSAT classification accuracy. [Richmond, Virginia and Denver, Colorado

    NASA Technical Reports Server (NTRS)

    Craig, R. G. (Principal Investigator)

    1983-01-01

    Richmond, Virginia and Denver, Colorado were study sites in an effort to determine the effect of autocorrelation on the accuracy of a parallelopiped classifier of LANDSAT digital data. The autocorrelation was assumed to decay to insignificant levels when sampled at distances of at least ten pixels. Spectral themes developed using blocks of adjacent pixels, and using groups of pixels spaced at least 10 pixels apart were used. Effects of geometric distortions were minimized by using only pixels from the interiors of land cover sections. Accuracy was evaluated for three classes; agriculture, residential and "all other"; both type 1 and type 2 errors were evaluated by means of overall classification accuracy. All classes give comparable results. Accuracy is approximately the same in both techniques; however, the variance in accuracy is significantly higher using the themes developed from autocorrelated data. The vectors of mean spectral response were nearly identical regardless of sampling method used. The estimated variances were much larger when using autocorrelated pixels.

  4. EFFICIENCY OF LEAST SQUARES ESTIMATORS IN THE PRESENCE OF SPATIAL AUTOCORRELATION

    EPA Science Inventory

    The authors consider the effect of spatial autocorrelation on inferences made using ordinary least squares estimation. it is found, in some cares, that ordinary least squares estimators provide a reasonable alternative to the estimated ' generalized least squares estimators recom...

  5. Properties of even length Barker codes and specific polyphase codes with Barker type autocorrelation functions

    NASA Astrophysics Data System (ADS)

    Gabbay, S.

    1982-07-01

    Properties of even-length Barker codes, if they exist, are derived. The analysis leads to the analysis of polyphase codes. Similar properties are derived for specific types of polyphase codes, with Barker type autocorrelation functions. The analysis is done in the time and frequency domains (including linear algebra and Z transform treatments), and suggests a procedure to search for codes with Barker type autocorrelation functions. The search problem is reduced by using the properties of such codes.

  6. Diffuse correlation spectroscopy with a fast Fourier transform-based software autocorrelator

    NASA Astrophysics Data System (ADS)

    Dong, Jing; Bi, Renzhe; Ho, Jun Hui; Thong, Patricia S. P.; Soo, Khee-Chee; Lee, Kijoon

    2012-09-01

    Diffuse correlation spectroscopy (DCS) is an emerging noninvasive technique that probes the deep tissue blood flow, by using the time-averaged intensity autocorrelation function of the fluctuating diffuse reflectance signal. We present a fast Fourier transform (FFT)-based software autocorrelator that utilizes the graphical programming language LabVIEW (National Instruments) to complete data acquisition, recording, and processing tasks. The validation and evaluation experiments were conducted on an in-house flow phantom, human forearm, and photodynamic therapy (PDT) on mouse tumors under the acquisition rate of ˜400 kHz. The software autocorrelator in general has certain advantages, such as flexibility in raw photon count data preprocessing and low cost. In addition to that, our FFT-based software autocorrelator offers smoother starting and ending plateaus when compared to a hardware correlator, which could directly benefit the fitting results without too much sacrifice in speed. We show that the blood flow index (BFI) obtained by using a software autocorrelator exhibits better linear behavior in a phantom control experiment when compared to a hardware one. The results indicate that an FFT-based software autocorrelator can be an alternative solution to the conventional hardware ones in DCS systems with considerable benefits.

  7. Diffuse correlation spectroscopy with a fast Fourier transform-based software autocorrelator.

    PubMed

    Dong, Jing; Bi, Renzhe; Ho, Jun Hui; Thong, Patricia S P; Soo, Khee-Chee; Lee, Kijoon

    2012-09-01

    Diffuse correlation spectroscopy (DCS) is an emerging noninvasive technique that probes the deep tissue blood flow, by using the time-averaged intensity autocorrelation function of the fluctuating diffuse reflectance signal. We present a fast Fourier transform (FFT)-based software autocorrelator that utilizes the graphical programming language LabVIEW (National Instruments) to complete data acquisition, recording, and processing tasks. The validation and evaluation experiments were conducted on an in-house flow phantom, human forearm, and photodynamic therapy (PDT) on mouse tumors under the acquisition rate of ∼400  kHz. The software autocorrelator in general has certain advantages, such as flexibility in raw photon count data preprocessing and low cost. In addition to that, our FFT-based software autocorrelator offers smoother starting and ending plateaus when compared to a hardware correlator, which could directly benefit the fitting results without too much sacrifice in speed. We show that the blood flow index (BFI) obtained by using a software autocorrelator exhibits better linear behavior in a phantom control experiment when compared to a hardware one. The results indicate that an FFT-based software autocorrelator can be an alternative solution to the conventional hardware ones in DCS systems with considerable benefits. PMID:23085922

  8. Temporal autocorrelation in host density increases establishment success of parasitoids in an experimental system

    PubMed Central

    Vercken, Elodie; Fauvergue, Xavier; Ris, Nicolas; Crochard, Didier; Mailleret, Ludovic

    2015-01-01

    Environmental variation is classically expected to affect negatively population growth and to increase extinction risk, and it has been identified as a major determinant of establishment failures in the field. Yet, recent theoretical investigations have shown that the structure of environmental variation and more precisely the presence of positive temporal autocorrelation might alter this prediction. This is particularly likely to affect the establishment dynamics of biological control agents in the field, as host–parasitoid interactions are expected to induce temporal autocorrelation in host abundance. In the case where parasitoid populations display overcompensatory dynamics, the presence of such positive temporal autocorrelation should increase their establishment success in a variable environment. We tested this prediction in laboratory microcosms by introducing parasitoids to hosts whose abundances were manipulated to simulate uncorrelated or positively autocorrelated variations in carrying capacity. We found that environmental variability decreased population size and increased parasitoid population variance, which is classically expected to extinction risk. However, although exposed to significant environmental variation, we found that parasitoid populations experiencing positive temporal autocorrelation in host abundance were more likely to persist than populations exposed to uncorrelated variation. These results confirm that environmental variation is a key determinant of extinction dynamics that can have counterintuitive effects depending on its autocorrelation structure. PMID:26257880

  9. A learning skills course for the 1st year medical students: an experience at a Saudi medical school

    PubMed Central

    Siddiqui, Imran A; Bin Abdulrahman, Khalid A; Alsultan, Mohammed A

    2015-01-01

    Background Every year nearly 1,500 students enter into medical program after passing high school and national aptitude exams. However, many students experience frustration, failure, and psychological morbidities like stress, depression, and anxiety because they are not aware of their learning styles or do not have effective learning skills and strategies. The College of Medicine of Al-Imam Muhammad ibn Saud Islamic University has adopted the outcome based, community oriented, Spiral Curriculum. Although the curriculum is innovative, on the other hand, it is very demanding. Objective The purpose of this paper is to share educational structure and evaluation results of the course on effective learning and study skills for the 1st year medical students. Methods To prepare our students in order to cope with this demanding but promising curriculum, we conducted an effective and comprehensive learning skills course for 16 weeks in the first semester of year 1 in the medical program. Performance of each student was assessed and the course evaluation was done by students at the end of the course. Results The attendance of the students throughout the course was over 90%. The average performance of students in the summative assessment was 78% and the course was generally liked by the students. Discussion Students overall had a positive attitude toward the learning skills course. Majority of the students showed interest in attending the sessions regularly and realized the significance of this course to improve their learning skills. PMID:25848332

  10. Local slope, hillslope length and upslope unstable area as 1st order controls on co-seismic landslide hazard.

    NASA Astrophysics Data System (ADS)

    Milledge, D.; Densmore, A. L.; Petley, D. N.; Bellugi, D. G.; Li, G.

    2015-12-01

    Many communities in mountainous areas have limited access to and/or understanding of co-seismic landslide hazard maps. Furthermore these maps rarely provide the information that a community seeks: Where is safest? How big could the landslide be? Geomorphic intuition suggests that: 1) on the ridges one is less likely to be hit by a landslide than elsewhere in the landscape; 2) hazard increases with the amount of upslope unstable area; 3) longer slopes contain more candidate landslides and are also capable of producing larger landslides thus they constitute a more severe hazard. These observations could help communities in siting infrastructure or making earthquake plans but have not, to our knowledge, been tested against past landslide inventories. Co-seismic landslide models make no attempt to predict landslide size and focus on initiation, ignoring the runout which is critical in the slope length control on hazard. Here we test our intuitive hypotheses using an inventory of co-seismic landslides from the 2008 Wenchuan earthquake. The inventory is mapped from high-resolution remote imagery using an automated algorithm and manual delineation and does not distinguish between source and runout zones. Discretizing the study area into 30 m cells we define landslide hazard as the probability that a cell is within a mapped landslide polygon (p(ls)). We find that p(ls) increases rapidly with increasing slope and upslope area. Locations with low local slope (<10˚) or upslope area (<900 m2/m) have p(ls) less than one third of the areal average. The joint p(ls) conditional on local slope and upslope area identifies long steep slopes as particularly hazardous and ridges (where slope and upslope area are both low) as particularly low hazard. Examining the slope lengths associated with each landslide in the inventory we find that hillslope length sets an upper limit on landslide size but that its influence on the detailed size distribution is more difficult to untangle. Finally, we combine local slope and upslope unstable area in a simple mechanistic rule-based model of landslide runout hazard and test its ability to predict p(ls). Our findings support the intuitive view that long steep slopes are among the most hazardous locations while ridges are the least hazardous locations in terms of co-seismic landslides.

  11. Detecting Anomaly Regions in Satellite Image Time Series Based on Sesaonal Autocorrelation Analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Z.-G.; Tang, P.; Zhou, M.

    2016-06-01

    Anomaly regions in satellite images can reflect unexpected changes of land cover caused by flood, fire, landslide, etc. Detecting anomaly regions in satellite image time series is important for studying the dynamic processes of land cover changes as well as for disaster monitoring. Although several methods have been developed to detect land cover changes using satellite image time series, they are generally designed for detecting inter-annual or abrupt land cover changes, but are not focusing on detecting spatial-temporal changes in continuous images. In order to identify spatial-temporal dynamic processes of unexpected changes of land cover, this study proposes a method for detecting anomaly regions in each image of satellite image time series based on seasonal autocorrelation analysis. The method was validated with a case study to detect spatial-temporal processes of a severe flooding using Terra/MODIS image time series. Experiments demonstrated the advantages of the method that (1) it can effectively detect anomaly regions in each of satellite image time series, showing spatial-temporal varying process of anomaly regions, (2) it is flexible to meet some requirement (e.g., z-value or significance level) of detection accuracies with overall accuracy being up to 89% and precision above than 90%, and (3) it does not need time series smoothing and can detect anomaly regions in noisy satellite images with a high reliability.

  12. Parametric optical surface roughness measurement by means of polychromatic speckle autocorrelation

    NASA Astrophysics Data System (ADS)

    Patzelt, Stefan; Ciossek, Andreas; Lehmann, Peter; Schoene, Armin

    1998-10-01

    A method for determining surface roughness of engineering surfaces that is applicable to in-process measurements under harsh circumstances of industrial production plants (e.g. vibrations, humidity) is introduced. The rough surface is illuminated with polychromatic laser light. The angular distribution of scattered light intensities, i.e. a polychromatic speckle pattern, is the result of an incoherent superposition of monochromatic speckle intensities. The angular dispersion leads to increasing speckle widths with an increasing distance to the optical axis an effect called speckle elongation. This gives rise to a radial structure of the speckle pattern. However, with increasing surface roughness the radial structure vanishes because of a decreasing similarity of the monochromatic speckle patterns of the different wavelengths. The markedness of this effect is analyzed by digital image processing algorithms, e.g. the procedure of polychromatic speckle autocorrelation. The latest approach to an in-process roughness measurement device was made by the use of singlemode fiber-pigtailed laser diodes in order to supply a trichromatic, temporally partially coherent laser beam. A brief introduction to the theoretical background is followed by the presentation of the experimental setup. The image processing algorithms for calculating an optical roughness measure from digitalized speckle patterns are explained, and first results of surface roughness determination are presented.

  13. EDITORIAL: The 1st International Conference on Nanomanufacturing (NanoMan2008) The 1st International Conference on Nanomanufacturing (NanoMan2008)

    NASA Astrophysics Data System (ADS)

    Luo, Jack Jiqui; Fang, Fengzhou

    2009-05-01

    Nanomanufacturing is an emerging technology in the field of synthesis of nanomaterials, manufacture of nanodevices, nanosystems and the relevant characterization technologies, and will greatly impact our society and environment: speeding up scientific discovery, technological development, improving healthcare and living standards and slowing down the exhaustion of energy resources, to name but few. The 1st International Conference on Nanomanufacturing (NanoMan2008) was held on the 13-16 July 2008 in Singapore in conjunction with ThinFilm2008 (The 4th International Conference on Technological Advances of Thin Films & Surface Coatings). Approximately 140 delegates from all over the world have participated in the conference and presented their latest discoveries and technological developments. The main focuses of the conference were modern nanomanufacturing by laser machining, focused ion beam fabrication, nano/micro-molding/imprinting, nanomaterial synthesis and characterization, nanometrology and nano/microsystems fabrication and characterization. There was also great interest in applications of nanomanufacturing technologies in traditional areas such as free form machining, polishing and grinding with nano-scale precision and the smoothness of surfaces of objects, and applications in space exploration, military and medicine. This special issue is devoted to NanoMan2008 with a collection of 9 invited talks presented at the conference, covering all the topics of nanomanufacturing technology and development. These papers have been upgraded by the authors with new results and discoveries since the preparation of the conference manuscripts, hence presenting the latest developments. We would like to take this opportunity to thank all the delegates who attended the conference and made the conference successful, and to the authors who contributed papers to this special issue. Thanks also go to the conference committee for their efforts and devotion to the conference. We

  14. Correlates and Phenomenology of 1st and 3rd Person Memories

    PubMed Central

    Sutin, Angelina R.; Robins, Richard W.

    2010-01-01

    The present research addressed fundamental questions about the visual perspective of autobiographical memories: Are stable personality characteristics associated with visual perspective? Does visual perspective influence the memory's phenomenological qualities? Participants in Study 1 (N = 1,684) completed individual-difference measures and indicated the perspective from which they generally retrieve memories. Participants in Study 2 (N = 706) retrieved a memory from their natural or manipulated perspective, rated its phenomenology, and completed the same individual-difference measures. Dissociation and anxiety were associated with 3rd person retrieval style; the Big Five personality traits were primarily unrelated to perspective. Compared to 3rd person memories, naturally-occurring 1st person memories were higher on Vividness, Coherence, Accessibility, Sensory Detail, Emotional Intensity, and Time Perspective and lower on Distancing; manipulating perspective eliminated these differences. Visual perspective is associated with clinically-relevant constructs and, although associated with the memory's phenomenology, perspective does not shape it. PMID:20665336

  15. Meeting report for the 1st skin microbiota workshop, boulder, CO October 15-16 2012

    PubMed Central

    2014-01-01

    This report details the outcome of the 1st Skin Microbiota Workshop, Boulder, CO, held on October 15th-16th 2012. The workshop was arranged to bring Department of Defense personnel together with experts in microbial ecology, human skin physiology and anatomy, and computational techniques for interrogating the microbiome to define research frontiers at the intersection of these important areas. The workshop outlined a series of questions and created several working groups to address those questions, specifically to promote interdisciplinary activity and potential future collaboration. The US Army provided generous grant support and the meeting was organized and hosted by the University of Colorado at Boulder. A primary forward vision of the meeting was the importance of understanding skin microbial communities to improve the health and stealth of US Army warfighters.

  16. Statistical Ring Opening Metathesis Copolymerization of Norbornene and Cyclopentene by Grubbs' 1st-Generation Catalyst.

    PubMed

    Nikovia, Christiana; Maroudas, Andreas-Philippos; Goulis, Panagiotis; Tzimis, Dionysios; Paraskevopoulou, Patrina; Pitsikalis, Marinos

    2015-01-01

    Statistical copolymers of norbornene (NBE) with cyclopentene (CP) were prepared by ring-opening metathesis polymerization, employing the 1st-generation Grubbs' catalyst, in the presence or absence of triphenylphosphine, PPh₃. The reactivity ratios were estimated using the Finemann-Ross, inverted Finemann-Ross, and Kelen-Tüdos graphical methods, along with the computer program COPOINT, which evaluates the parameters of binary copolymerizations from comonomer/copolymer composition data by integrating a given copolymerization equation in its differential form. Structural parameters of the copolymers were obtained by calculating the dyad sequence fractions and the mean sequence length, which were derived using the monomer reactivity ratios. The kinetics of thermal decomposition of the copolymers along with the respective homopolymers was studied by thermogravimetric analysis within the framework of the Ozawa-Flynn-Wall and Kissinger methodologies. Finally, the effect of triphenylphosphine on the kinetics of copolymerization, the reactivity ratios, and the kinetics of thermal decomposition were examined. PMID:26343620

  17. Assessment of drug-induced arrhythmic risk using limit cycle and autocorrelation analysis of human iPSC-cardiomyocyte contractility.

    PubMed

    Kirby, R Jason; Qi, Feng; Phatak, Sharangdhar; Smith, Layton H; Malany, Siobhan

    2016-08-15

    Cardiac safety assays incorporating label-free detection of human stem-cell derived cardiomyocyte contractility provide human relevance and medium throughput screening to assess compound-induced cardiotoxicity. In an effort to provide quantitative analysis of the large kinetic datasets resulting from these real-time studies, we applied bioinformatic approaches based on nonlinear dynamical system analysis, including limit cycle analysis and autocorrelation function, to systematically assess beat irregularity. The algorithms were integrated into a software program to seamlessly generate results for 96-well impedance-based data. Our approach was validated by analyzing dose- and time-dependent changes in beat patterns induced by known proarrhythmic compounds and screening a cardiotoxicity library to rank order compounds based on their proarrhythmic potential. We demonstrate a strong correlation for dose-dependent beat irregularity monitored by electrical impedance and quantified by autocorrelation analysis to traditional manual patch clamp potency values for hERG blockers. In addition, our platform identifies non-hERG blockers known to cause clinical arrhythmia. Our method provides a novel suite of medium-throughput quantitative tools for assessing compound effects on cardiac contractility and predicting compounds with potential proarrhythmia and may be applied to in vitro paradigms for pre-clinical cardiac safety evaluation. PMID:27343406

  18. Global Autocorrelation Scales of the Partial Pressure of Oceanic CO2

    NASA Technical Reports Server (NTRS)

    Li, Zhen; Adamec, David; Takahashi, Taro; Sutherland, Stewart C.

    2004-01-01

    A global database of approximately 1.7 million observations of the partial pressure of carbon dioxide in surface ocean waters (pCO2) collected between 1970 and 2003 is used to estimate its spatial autocorrelation structure. The patterns of the lag distance where the autocorrelation exceeds 0.8 is similar to patterns in the spatial distribution of the first baroclinic Rossby radius of deformation indicating that ocean circulation processes play a significant role in determining the spatial variability of pCO2. For example, the global maximum of the distance at which autocorrelations exceed 0.8 averages about 140 km in the equatorial Pacific. Also, the lag distance at which the autocorrelation exceed 0.8 is greater in the vicinity of the Gulf Stream than it is near the Kuroshio, approximately 50 km near the Gulf Stream as opposed to 20 km near the Kuroshio. Separate calculations for times when the sun is north and south of the equator revealed no obvious seasonal dependence of the spatial autocorrelation scales. The pCO2 measurements at Ocean Weather Station (OWS) 'P', in the eastern subarctic Pacific (50 N, 145 W) is the only fixed location where an uninterrupted time series of sufficient length exists to calculate a meaningful temporal autocorrelation function for lags greater than a few days. The estimated temporal autocorrelation function at OWS 'P', is highly variable. A spectral analysis of the longest four pCO2 time series indicates a high level of variability occurring over periods from the atmospheric synoptic to the maximum length of the time series, in this case 42 days. It is likely that a relative peak in variability with a period of 3-6 days is related to atmospheric synoptic period variability and ocean mixing events due to wind stirring. However, the short length of available time series makes identifying temporal relationships between pCO2 and atmospheric or ocean processes problematic.

  19. New Features Using Robust MVDR Spectrum of Filtered Autocorrelation Sequence for Robust Speech Recognition

    PubMed Central

    Gazor, Saeed

    2013-01-01

    This paper presents a novel noise-robust feature extraction method for speech recognition using the robust perceptual minimum variance distortionless response (MVDR) spectrum of temporally filtered autocorrelation sequence. The perceptual MVDR spectrum of the filtered short-time autocorrelation sequence can reduce the effects of residue of the nonstationary additive noise which remains after filtering the autocorrelation. To achieve a more robust front-end, we also modify the robust distortionless constraint of the MVDR spectral estimation method via revised weighting of the subband power spectrum values based on the sub-band signal to noise ratios (SNRs), which adjusts it to the new proposed approach. This new function allows the components of the input signal at the frequencies least affected by noise to pass with larger weights and attenuates more effectively the noisy and undesired components. This modification results in reduction of the noise residuals of the estimated spectrum from the filtered autocorrelation sequence, thereby leading to a more robust algorithm. Our proposed method, when evaluated on Aurora 2 task for recognition purposes, outperformed all Mel frequency cepstral coefficients (MFCC) as the baseline, relative autocorrelation sequence MFCC (RAS-MFCC), and the MVDR-based features in several different noisy conditions. PMID:24501584

  20. Rigorous home range estimation with movement data: a new autocorrelated kernel density estimator.

    PubMed

    Fleming, C H; Fagan, W F; Mueller, T; Olson, K A; Leimgruber, P; Calabrese, J M

    2015-05-01

    Quantifying animals' home ranges is a key problem in ecology and has important conservation and wildlife management applications. Kernel density estimation (KDE) is a workhorse technique for range delineation problems that is both statistically efficient and nonparametric. KDE assumes that the data are independent and identically distributed (IID). However, animal tracking data, which are routinely used as inputs to KDEs, are inherently autocorrelated and violate this key assumption. As we demonstrate, using realistically autocorrelated data in conventional KDEs results in grossly underestimated home ranges. We further show that the performance of conventional KDEs actually degrades as data quality improves, because autocorrelation strength increases as movement paths become more finely resolved. To remedy these flaws with the traditional KDE method, we derive an autocorrelated KDE (AKDE) from first principles to use autocorrelated data, making it perfectly suited for movement data sets. We illustrate the vastly improved performance of AKDE using analytical arguments, relocation data from Mongolian gazelles, and simulations based upon the gazelle's observed movement process. By yielding better minimum area estimates for threatened wildlife populations, we believe that future widespread use of AKDE will have significant impact on ecology and conservation biology. PMID:26236833

  1. Deprivation and mortality: the implications of spatial autocorrelation for health resources allocation.

    PubMed

    Lorant, V; Thomas, I; Deliège, D; Tonglet, R

    2001-12-01

    This paper aims at investigating whether the relationship between mortality and socio-economic deprivation is affected by the spatial autocorrelation of ecological data. A simple model is used in which mortality (all-ages and premature) is the dependent variable, and deprivation, morbidity and other socio-economic indicators are the explanatory variables. Deprivation is measured by the Townsend index; the other socio-economic variables are the median income, unequal income distribution (Gini coefficient) and population density. Morbidity is estimated on the basis of hospital admission rates and overweight prevalence. Spatial autocorrelation is measured by the Moran's I coefficient. All mortality and morbidity variables have significant, positive, and moderate-to-high spatial autocorrelation. Two multivariate models are explored: a weighted least-squares model ignoring spatial autocorrelation and a simultaneous autoregressive model. The paper concludes that spatial autocorrelation has a significant impact on the relationship between mortality and socio-economic variables. Future ecological models intended to inform health resources allocation need to pay greater attention to the spatial dimension of the data used. PMID:11762895

  2. PREFACE: 1st European Conference on Gas Micro Flows (GasMems 2012)

    NASA Astrophysics Data System (ADS)

    Frijns, Arjan; Valougeorgis, Dimitris; Colin, Stéphane; Baldas, Lucien

    2012-05-01

    The aim of the 1st European Conference on Gas Micro Flows is to advance research in Europe and worldwide in the field of gas micro flows as well as to improve global fundamental knowledge and to enable technological applications. Gas flows in microsystems are of great importance and touch almost every industrial field (e.g. fluidic microactuators for active control of aerodynamic flows, vacuum generators for extracting biological samples, mass flow and temperature micro-sensors, pressure gauges, micro heat-exchangers for the cooling of electronic components or for chemical applications, and micro gas analyzers or separators). The main characteristic of gas microflows is their rarefaction, which for device design often requires modelling and simulation both by continuous and molecular approaches. In such flows various non-equilibrium transport phenomena appear, while the role played by the interaction between the gas and the solid device surfaces becomes essential. The proposed models of boundary conditions often need an empirical adjustment strongly dependent on the micro manufacturing technique. The 1st European Conference on Gas Micro Flows is organized under the umbrella of the recently established GASMEMS network (www.gasmems.eu/) consisting of 13 participants and six associate members. The main objectives of the network are to structure research and train researchers in the fields of micro gas dynamics, measurement techniques for gaseous flows in micro experimental setups, microstructure design and micro manufacturing with applications in lab and industry. The conference takes place on June 6-8 2012, at the Skiathos Palace Hotel, on the beautiful island of Skiathos, Greece. The conference has received funding from the European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement ITN GASMEMS no. 215504. It owes its success to many people. We would like to acknowledge the support of all members of the Scientific Committee and of all

  3. PREFACE: 1st International Conference on Rheology and Modeling of Materials

    NASA Astrophysics Data System (ADS)

    Gömze, László A.

    2015-04-01

    Understanding the rheological properties of materials and their rheological behaviors during their manufacturing processes and in their applications in many cases can help to increase the efficiency and competitiveness not only of the finished goods and products but the organizations and societies also. The more scientific supported and prepared organizations develop more competitive products with better thermal, mechanical, physical, chemical and biological properties and the leading companies apply more competitive knowledge, materials, equipment and technology processes. The idea to organize in Hungary the 1st International Conference on Rheology and Modeling of Materials we have received from prospective scientists, physicists, chemists, mathematicians and engineers from Asia, Europe, North and South America including India, Korea, Russia, Turkey, Estonia, France, Italy, United Kingdom, Chile, Mexico and USA. The goals of ic-rmm1 the 1st International Conference on Rheology and Modeling of Materials are the following: • Promote new methods and results of scientific research in the fields of modeling and measurements of rheological properties and behavior of materials under processing and applications. • Change information between the theoretical and applied sciences as well as technical and technological implantations. • Promote the communication between the scientists of different disciplines, nations, countries and continents. The international conference ic-rmm1 provides a platform among the leading international scientists, researchers, PhD students and engineers for discussing recent achievements in measurement, modeling and application of rheology in materials technology and materials science of liquids, melts, solids, crystals and amorphous structures. Among the major fields of interest are the influences of material structures, mechanical stresses temperature and deformation speeds on rheological and physical properties, phase transformation of

  4. Spatial Autocorrelation Analysis of Chinese Inter-Provincial Industrial Chemical Oxygen Demand Discharge

    PubMed Central

    Zhao, Xiaofeng; Huang, Xianjin; Liu, Yibo

    2012-01-01

    A spatial autocorrelation analysis method is adopted to process the spatial dynamic change of industrial Chemical Oxygen Demand (COD) discharge in China over the past 15 years. Studies show that amount and intensity of industrial COD discharges are on a decrease, and the tendency is more remarkable for discharge intensity. There are large differences between inter-provincial discharge amount and intensity, and with different spatial differentiation features. Global spatial autocorrelation analysis reveals that Global Moran’s I of discharge amount and intensity is on the decrease. In space, there is an evolution from an agglomeration pattern to a discretization pattern. Local spatial autocorrelation analysis shows that the agglomeration area of industrial COD discharge amount and intensity varies greatly in space with time. Stringent environmental regulations and increased funding for environmental protections are the crucial factors to cut down industrial COD discharge amount and intensity. PMID:22829788

  5. A CD adaptive monitoring and compensation method based on the average of the autocorrelation matrix eigenvalue

    NASA Astrophysics Data System (ADS)

    Lei, Yu; Lei, Jianming; Guo, Junhui; Zou, Xuecheng; Li, Bin; Lu, Li

    2014-02-01

    A new autocorrelation matrix eigenvalue based digital signal processing (DSP) chromatic dispersion (CD) adaptive monitoring and compensation method is proposed. It employs the average of the autocorrelation matrix eigenvalue instead of eigenvalue spread to be the metric of scanning. The average calculation has been effective in relieving the degradation of performance caused by the fluctuation of autocorrelation matrix eigenvalue. Compare with the eigenvalue spread scanning algorithm, this method reduces the monitoring errors to below 10 ps/nm from more than 200 ps/nm, while not increasing its computation complexity. Simulation results show that in 100 Gbit/s polarization division multiplexing (PDM) quadrature phase shift keying (QPSK) coherent optical transmission system, this method improves the bit error rate (BER) performance and the system robustness against the amplified-spontaneous-emission noise.

  6. Assessing the Significance of Global and Local Correlations under Spatial Autocorrelation; a Nonparametric Approach

    PubMed Central

    Mazumder, Rahul; McInturff, Alex; McCauley, Douglas J.; Hastie, Trevor

    2014-01-01

    Summary We propose a method to test the correlation of two random fields when they are both spatially auto-correlated. In this scenario, the assumption of independence for the pair of observations in the standard test does not hold, and as a result we reject in many cases where there is no effect (the precision of the null distribution is overestimated). Our method recovers the null distribution taking into account the autocorrelation. It uses Monte-Carlo methods, and focuses on permuting, and then smoothing and scaling one of the variables to destroy the correlation with the other, while maintaining at the same time the initial autocorrelation. With this simulation model, any test based on the independence of two (or more) random fields can be constructed. This research was motivated by a project in biodiversity and conservation in the Biology Department at Stanford University. PMID:24571609

  7. Assessing the significance of global and local correlations under spatial autocorrelation: a nonparametric approach.

    PubMed

    Viladomat, Júlia; Mazumder, Rahul; McInturff, Alex; McCauley, Douglas J; Hastie, Trevor

    2014-06-01

    We propose a method to test the correlation of two random fields when they are both spatially autocorrelated. In this scenario, the assumption of independence for the pair of observations in the standard test does not hold, and as a result we reject in many cases where there is no effect (the precision of the null distribution is overestimated). Our method recovers the null distribution taking into account the autocorrelation. It uses Monte-Carlo methods, and focuses on permuting, and then smoothing and scaling one of the variables to destroy the correlation with the other, while maintaining at the same time the initial autocorrelation. With this simulation model, any test based on the independence of two (or more) random fields can be constructed. This research was motivated by a project in biodiversity and conservation in the Biology Department at Stanford University. PMID:24571609

  8. Testing Pairwise Association between Spatially Autocorrelated Variables: A New Approach Using Surrogate Lattice Data

    PubMed Central

    Deblauwe, Vincent; Kennel, Pol; Couteron, Pierre

    2012-01-01

    Background Independence between observations is a standard prerequisite of traditional statistical tests of association. This condition is, however, violated when autocorrelation is present within the data. In the case of variables that are regularly sampled in space (i.e. lattice data or images), such as those provided by remote-sensing or geographical databases, this problem is particularly acute. Because analytic derivation of the null probability distribution of the test statistic (e.g. Pearson's r) is not always possible when autocorrelation is present, we propose instead the use of a Monte Carlo simulation with surrogate data. Methodology/Principal Findings The null hypothesis that two observed mapped variables are the result of independent pattern generating processes is tested here by generating sets of random image data while preserving the autocorrelation function of the original images. Surrogates are generated by matching the dual-tree complex wavelet spectra (and hence the autocorrelation functions) of white noise images with the spectra of the original images. The generated images can then be used to build the probability distribution function of any statistic of association under the null hypothesis. We demonstrate the validity of a statistical test of association based on these surrogates with both actual and synthetic data and compare it with a corrected parametric test and three existing methods that generate surrogates (randomization, random rotations and shifts, and iterative amplitude adjusted Fourier transform). Type I error control was excellent, even with strong and long-range autocorrelation, which is not the case for alternative methods. Conclusions/Significance The wavelet-based surrogates are particularly appropriate in cases where autocorrelation appears at all scales or is direction-dependent (anisotropy). We explore the potential of the method for association tests involving a lattice of binary data and discuss its potential for

  9. A spatial and nondegenerative autocorrelation function to reveal the inner similarity structure of irregular sets

    NASA Astrophysics Data System (ADS)

    Li, Jun; Nekka, Fahima

    2012-07-01

    When applied to signals defined on fractal sets, the classical autocorrelation function has generally been exploited through its power law properties, the main hypothesis being that the exponent involved in this power law is uniquely defined. In this paper, we show that different power laws can likely be retrieved for the same signal. This non uniqueness turns out to be associated to the uncertainty in determination of the exponent value. To avoid such degeneracy, we propose to use a generalized form of the autocorrelation function, a version of which we have previously introduced in the context of characterization of fractal sets.

  10. Study of terahertz intensity dependence on time resolved dynamic fringes in the interferometric autocorrelation setup

    NASA Astrophysics Data System (ADS)

    Venkatesh, M.; Chaudhary, A. K.

    2014-10-01

    Terahertz signal is generated from Low temperature gallium arsenide photoconductive dipole antennas (gap = 5μm, length = 20μm) by focusing 15 fs laser pulses and applying 12V DC across it. Terahertz intensity is detected by Pyroelectric detector (THZ1.5MB-USB). The collinear autocorrelation arrangement provides dynamic fringes which are allowed to be incident on photoconductive antennas to study the variation in terahertz intensity with respect to delay between laser pulses. Interestingly, the profile of THz intensity variation was similar to interferometric autocorrelation signal of laser pulses. The THz power attenuation with its propagation distance in atmosphere was measured.

  11. Suppression of image autocorrelation artefacts in spectral domain optical coherence tomography and multiwave digital holography

    NASA Astrophysics Data System (ADS)

    Gelikonov, V. M.; Gelikonov, G. V.; Terpelov, D. A.; Shabanov, D. V.; Shilyagin, P. A.

    2012-05-01

    An improved method for suppressing image artefacts in spectral domain optical coherence tomography (SD OCT) and multiwave digital holography, caused by the influence of coherent noise in the course of successive registration of an autocorrelation component and informative signal is reported. The method allows complete suppression of all types of coherent noises, provided that the sample of values used to record the autocorrelation component satisfies the conditions of Kotelnikov's theorem: in SD OCT — for the transverse structure of the studied medium, in multiwave digital holography — for the envelop function of the radiation source frequency tuning spectrum.

  12. Dynamic Composition Determination in Heterogeneous Ensembles using Angular Autocorrelation Functions as Signatures

    SciTech Connect

    Li, Dongsheng; Xu, Zhijie; Ahzi, Said

    2013-06-04

    Signatures of heterogeneous ensembles composed of multiple types of random oriented particles are represented by the angular autocorrelation functions of the systems. These signatures are retrieved by averaging oversampled angular correlation functions calculated from high throughput X-ray diffraction patterns. Using a component signature matrix, the composition of the heterogeneous system will be directly calculated from the signature of the ensemble. This is the first attempt to determine dynamic composition of a heterogeneous ensemble by fluctuation X-ray scattering using the angular autocorrelation functions as signatures.

  13. Suppression of image autocorrelation artefacts in spectral domain optical coherence tomography and multiwave digital holography

    SciTech Connect

    Gelikonov, V M; Gelikonov, G V; Terpelov, D A; Shabanov, D V; Shilyagin, P A

    2012-05-31

    An improved method for suppressing image artefacts in spectral domain optical coherence tomography (SD OCT) and multiwave digital holography, caused by the influence of coherent noise in the course of successive registration of an autocorrelation component and informative signal is reported. The method allows complete suppression of all types of coherent noises, provided that the sample of values used to record the autocorrelation component satisfies the conditions of Kotelnikov's theorem: in SD OCT - for the transverse structure of the studied medium, in multiwave digital holography - for the envelop function of the radiation source frequency tuning spectrum.

  14. 1st Advanced Marine Renewable Energy Instrumentation Experts Workshop: April 5-7, 2011

    SciTech Connect

    Not Available

    2011-10-01

    The U.S. marine energy industry is actively pursuing development of offshore wind and marine hydrokinetic (MHK) energy systems. Experience in the wind energy sector demonstrates that new technology development requires thorough measurement and characterization of the environmental conditions prevalent at installation sites and of technology operating in the field. Presently, there are no turn-key instrumentation system solutions that meet the measurement needs of the marine energy industry. The 1st Advanced Marine Renewable Energy Instrumentation Experts Workshop brought together technical experts from government laboratories, academia, and industry representatives from marine energy, wind, offshore oil and gas, and instrumentation developers to present and discuss the instrumentation needs of the marine energy industry. The goals of the meeting were to: (1) Share the latest relevant knowledge among technical experts; (2) Review relevant state-of-the-art field measurement technologies and methods; (3) Review lessons learned from recent field deployments; (4) Identify synergies across different industries; (5) Identify gaps between existing and needed instrumentation capabilities; (6) Understand who are the leading experts; (7) Provide a forum where stakeholders from the marine energy industry could provide substantive input in the development of new marine energy field deployable instrumentation packages.

  15. Wind-US Results for the AIAA 1st Propulsion Aerodynamics Workshop

    NASA Technical Reports Server (NTRS)

    Yoder, Dennis; Dippold, Vance, III; Georgiadis, Nicholas

    2012-01-01

    This presentation contains Wind-US results presented at the 1st Propulsion Aerodynamics Workshop. The The workshop was organized by the American Institute of Aeronautics and Astronautics, Air Breathing Propulsion Propulsion Systems Integration Technical Committee with the purpose of assessing the accuracy of computational computational fluid dynamics for air breathing propulsion applications. Attendees included representatives from representatives from government, industry, academia, and commercial software companies. Participants were were encouraged to explore and discuss all aspects of the simulation process including the effects of mesh type and mesh type and refinement, solver numerical schemes, and turbulence modeling. The first set of challenge cases involved computing the thrust and discharge coefficients for a series of convergent convergent nozzles for a range of nozzle pressure ratios between 1.4 and 7.0. These configurations included a included a reference axisymmetric nozzle as well as 15deg , 25deg , and 40deg conical nozzles. Participants were also asked also asked to examine the plume shock structure for two cases where the 25deg conical nozzle was bifurcated by a bifurcated by a solid plate. The final test case was a serpentine inlet diffuser with an outlet to inlet area ratio of 1.52 ratio of 1.52 and an offset of 1.34 times the inlet diameter. Boundary layer profiles, wall static pressure, and total and total pressure at downstream rake locations were examined.

  16. 1st paleomagnetic investigation of Nubia Sandstone at Kalabsha, south Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Mostafa, R.; Khashaba, A.; El-Hemaly, I. A.; Takla, E. M.; Abdel Aal, E.; Odah, H.

    2016-06-01

    Two profiles have been sampled from the Nubia Sandstone at Aswan, south Western Desert: the 1st profile has been taken from Abu Aggag Formation and the 2nd one was from Sabaya Formation (23.25 °N, 32.75 °E). 136 oriented cores (from 9 sites) have been sampled. Abu Aggag Formation is of Late Cretaceous (Turonian) and Sabaya Formation is of early Cretaceous (Albian-Cenomanian). The studied rocks are subjected to rock magnetic measurements as well as demagnetization treatment. It has been found that hematite is the main magnetic mineral in both formations. Four profile sections from Abu Aggag Formation, yielded a magnetic component with D = 352.7°, I = 36.6° with α95 = 5.2° and the corresponding pole lies at Lat. = 82.8 °N and Long. = 283.1 °E. Five profile sections from Sabaya Formation, yielded a magnetic component with D = 348.6°, I = 33.3° with α95 = 5.8° and the corresponding pole lies at Lat. = 78.3 °N and Long. = 280.4 °E. The obtained paleopole for the two formations lies at Lat. = 80.5 °N and Long. = 281.7 °E. The obtaind magnetic components are considered primary and the corresponding paleopole reflects the age of Nubia Sandstone when compared with the previously obtained Cretaceous poles for Egypt.

  17. Identifying 1st instar larvae for three forensically important blowfly species using "fingerprint" cuticular hydrocarbon analysis.

    PubMed

    Moore, Hannah E; Adam, Craig D; Drijfhout, Falko P

    2014-07-01

    Calliphoridae are known to be the most forensically important insects when it comes to establishing the minimum post mortem interval (PMImin) in criminal investigations. The first step in calculating the PMImin is to identify the larvae present to species level. Accurate identification which is conventionally carried out by morphological analysis is crucial because different insects have different life stage timings. Rapid identification in the immature larvae stages would drastically cut time in criminal investigations as it would eliminate the need to rear larvae to adult flies to determine the species. Cuticular hydrocarbon analysis on 1st instar larvae has been applied to three forensically important blowflies; Lucilia sericata, Calliphora vicina and Calliphora vomitoria, using gas chromatography-mass spectrometry (GC-MS) and principal component analysis (PCA). The results show that each species holds a distinct "fingerprint" hydrocarbon profile, allowing for accurate identification to be established in 1-day old larvae, when it can be challenging to apply morphological criteria. Consequently, this GC-MS based technique could accelerate and strengthen the identification process, not only for forensically important species, but also for other entomological samples which are hard to identify using morphological features. PMID:24815992

  18. [POPIN Advisory Committee, 1st session. Geneva, March 22-25, 1982: report].

    PubMed

    1982-09-01

    A report of the POPIN, (International Population Information Network), Advisory Committee on its 1st session. The chairman presented a progress report on the activities of the Network in general and the POPIN coordinating unit in particular. More active participation by the developing countries was stressed to share information. The working group reported the efforts made by various groups for the translation of the population multilingual thesaurus into other languages. It also reviewed the draft manuscript on inventory and evaluation of training materials to identify gaps and make suggestions for improvement. The advisory committee suggested the development of a series of shorter guides which would deal with specific subjects. The development of a common classification scheme was considered of utmost importance since it would facilitate the processing, retrieval and exchange of information. A proposed work plan for 1983 and 1984 was discussed. This included publication of the POPIN Bulletin and newsletter, preparation of documentations for the sessions of the Advisory Committee, publication of the specific guides and a directory of POPIN members. Recommendations of the committee included measures for expansion of membership, publication of Popline multilingual thesaurus and guides for specific subjects. The committee considered and adopted the recommendations. Annexes include, 1) list of participants, documents and agenda, 2) recommendations of the POPIN working group on the management of the population multilingual thesaurus, and 3) recommendations on the inventory and evaluation of teaching materials for population information services. PMID:12279381

  19. The relation between 1st grade grey matter volume and 2nd grade math competence.

    PubMed

    Price, Gavin R; Wilkey, Eric D; Yeo, Darren J; Cutting, Laurie E

    2016-01-01

    Mathematical and numerical competence is a critical foundation for individual success in modern society yet the neurobiological sources of individual differences in math competence are poorly understood. Neuroimaging research over the last decade suggests that neural mechanisms in the parietal lobe, particularly the intraparietal sulcus (IPS) are structurally aberrant in individuals with mathematical learning disabilities. However, whether those same brain regions underlie individual differences in math performance across the full range of math abilities is unknown. Furthermore, previous studies have been exclusively cross-sectional, making it unclear whether variations in the structure of the IPS are caused by or consequences of the development of math skills. The present study investigates the relation between grey matter volume across the whole brain and math competence longitudinally in a representative sample of 50 elementary school children. Results show that grey matter volume in the left IPS at the end of 1st grade relates to math competence a year later at the end of 2nd grade. Grey matter volume in this region did not change over that year, and was still correlated with math competence at the end of 2nd grade. These findings support the hypothesis that the IPS and its associated functions represent a critical foundation for the acquisition of mathematical competence. PMID:26334946

  20. Jordanian Kindergarten and 1st-Grade Teachers' Beliefs about Child-Based Dimensions of School Readiness

    ERIC Educational Resources Information Center

    Fayez, Merfat; Ahmad, Jamal Fathi; Oliemat, Enass

    2016-01-01

    The purpose of this study was to explore the beliefs of Jordanian kindergarten and 1st-grade teachers regarding six child-based dimensions of school readiness: academic knowledge, basic thinking skills, socioemotional maturity, physical well-being and motor development, self-discipline, and communication skills. Questionnaires were used to collect…

  1. Laying a Foundation for Lifelong Learning: Case Studies of E-Assessment in Large 1st-Year Classes

    ERIC Educational Resources Information Center

    Nicol, David

    2007-01-01

    Concerns about noncompletion and the quality of the 1st-year student experience have been linked to recent changes in higher education such as modularisation, increased class sizes, greater diversity in the student intake and reduced resources. Improving formative assessment and feedback processes is seen as one way of addressing academic failure,…

  2. 78 FR 7781 - Filing Dates for the South Carolina Special Elections in the 1st Congressional District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Filing Dates for the South Carolina Special Elections in the 1st Congressional District AGENCY: Federal Election Commission. ACTION: Notice of filing dates for special elections. SUMMARY: South Carolina...

  3. Addressing the Effects of Reciprocal Teaching on the Receptive and Expressive Vocabulary of 1st-Grade Students

    ERIC Educational Resources Information Center

    Mandel, Eliana; Osana, Helena P.; Venkatesh, Vivek

    2013-01-01

    This study evaluated the effects of Adapted Reciprocal Teaching (ART) on the receptive and expressive flight-word vocabulary of 1st-grade students. During ART, classroom interactions produced narrative contexts within which students assumed responsibility for applying new flight words in personally meaningful ways. Students in the control group…

  4. Exploring the effects of spatial autocorrelation when identifying key drivers of wildlife crop-raiding

    PubMed Central

    Songhurst, Anna; Coulson, Tim

    2014-01-01

    Few universal trends in spatial patterns of wildlife crop-raiding have been found. Variations in wildlife ecology and movements, and human spatial use have been identified as causes of this apparent unpredictability. However, varying spatial patterns of spatial autocorrelation (SA) in human–wildlife conflict (HWC) data could also contribute. We explicitly explore the effects of SA on wildlife crop-raiding data in order to facilitate the design of future HWC studies. We conducted a comparative survey of raided and nonraided fields to determine key drivers of crop-raiding. Data were subsampled at different spatial scales to select independent raiding data points. The model derived from all data was fitted to subsample data sets. Model parameters from these models were compared to determine the effect of SA. Most methods used to account for SA in data attempt to correct for the change in P-values; yet, by subsampling data at broader spatial scales, we identified changes in regression estimates. We consequently advocate reporting both model parameters across a range of spatial scales to help biological interpretation. Patterns of SA vary spatially in our crop-raiding data. Spatial distribution of fields should therefore be considered when choosing the spatial scale for analyses of HWC studies. Robust key drivers of elephant crop-raiding included raiding history of a field and distance of field to a main elephant pathway. Understanding spatial patterns and determining reliable socio-ecological drivers of wildlife crop-raiding is paramount for designing mitigation and land-use planning strategies to reduce HWC. Spatial patterns of HWC are complex, determined by multiple factors acting at more than one scale; therefore, studies need to be designed with an understanding of the effects of SA. Our methods are accessible to a variety of practitioners to assess the effects of SA, thereby improving the reliability of conservation management actions. PMID:25035800

  5. Exploring the effects of spatial autocorrelation when identifying key drivers of wildlife crop-raiding.

    PubMed

    Songhurst, Anna; Coulson, Tim

    2014-03-01

    Few universal trends in spatial patterns of wildlife crop-raiding have been found. Variations in wildlife ecology and movements, and human spatial use have been identified as causes of this apparent unpredictability. However, varying spatial patterns of spatial autocorrelation (SA) in human-wildlife conflict (HWC) data could also contribute. We explicitly explore the effects of SA on wildlife crop-raiding data in order to facilitate the design of future HWC studies. We conducted a comparative survey of raided and nonraided fields to determine key drivers of crop-raiding. Data were subsampled at different spatial scales to select independent raiding data points. The model derived from all data was fitted to subsample data sets. Model parameters from these models were compared to determine the effect of SA. Most methods used to account for SA in data attempt to correct for the change in P-values; yet, by subsampling data at broader spatial scales, we identified changes in regression estimates. We consequently advocate reporting both model parameters across a range of spatial scales to help biological interpretation. Patterns of SA vary spatially in our crop-raiding data. Spatial distribution of fields should therefore be considered when choosing the spatial scale for analyses of HWC studies. Robust key drivers of elephant crop-raiding included raiding history of a field and distance of field to a main elephant pathway. Understanding spatial patterns and determining reliable socio-ecological drivers of wildlife crop-raiding is paramount for designing mitigation and land-use planning strategies to reduce HWC. Spatial patterns of HWC are complex, determined by multiple factors acting at more than one scale; therefore, studies need to be designed with an understanding of the effects of SA. Our methods are accessible to a variety of practitioners to assess the effects of SA, thereby improving the reliability of conservation management actions. PMID:25035800

  6. Statistical mapping of speckle autocorrelation for visualization of hyperaemic responses to cortical stimulation.

    PubMed

    Paul, Joseph S; Al Nashash, Hasan; Luft, Andreas R; Le, Thinh M

    2006-07-01

    Statistically mapped speckle autocorrelation images (SAR) were used to track the hemodynamically active perfusion regions in the rat cortex during and following DC current stimulation with high transverse spatial resolution (38 um). The SAR images provided a spatio-temporal information about the net activation patterns of Cerebral Blood Flow (CBF) changes over a period of time as against those changes for each frame interval estimated using spatial contrasts derived from the first order spatial statistics. Thus the information about the relative maxima of perfusion during a Transient Hyperaemic Episode (THE) across different regions in the imaging window could be identified without the need for actually having to estimate the spatial contrast maps of the imaged region for each frame contained in the time window of observation. With the application of DC stimulation, the regions with a high correlation in the temporal fluctuations were representative of the areas that underwent least changes in activation. By varying the intensity of stimulation, THEs were observed for stimulation current densities in the range 0.1-3.8 mA/mm2 using both the derived speckle contrast maps and concurrently on a Laser Doppler Flow meter, with its probe positioned 1 mm from the site of stimulation. For current densities below the lower threshold of stimulation, the SAR images revealed an unprecedented reduction in the surge amplitude at sites distal to the region of stimulation. This was accompanied by an increase in pixel areas representing minimally active regions of perfusion ("perfusion islets") with no identifiable peak in the hemodynamic responses estimated from speckle contrast variations. The SAR images can be a useful tool for visualization of slow wave perfusion dynamics during cortical stimulation. PMID:16786397

  7. Evaluating multi-exposure speckle imaging estimates of absolute autocorrelation times.

    PubMed

    Kazmi, S M Shams; Wu, Rebecca K; Dunn, Andrew K

    2015-08-01

    Multi-exposure speckle imaging (MESI) is a camera-based flow-imaging technique for quantitative blood-flow monitoring by mapping the speckle-contrast dependence on camera exposure duration. The ability of laser speckle contrast imaging to measure the temporal dynamics of backscattered and interfering coherent fields, in terms of the accuracy of autocorrelation measurements, is a major unresolved issue in quantitative speckle flowmetry. MESI fits for a number of parameters including an estimate of the electric field autocorrelation decay time from the imaged speckles. We compare the MESI-determined correlation times in vitro and in vivo with accepted true values from direct temporal measurements acquired with a photon-counting photon-multiplier tube and an autocorrelator board. The correlation times estimated by MESI in vivo remain on average within 14±11% of those obtained from direct temporal autocorrelation measurements, demonstrating that MESI yields highly comparable statistics of the time-varying fields that can be useful for applications seeking not only quantitative blood flow dynamics but also absolute perfusion. PMID:26258378

  8. Temporal autocorrelation functions for movement rates from global positioning system radiotelemetry data

    PubMed Central

    Boyce, Mark S.; Pitt, Justin; Northrup, Joseph M.; Morehouse, Andrea T.; Knopff, Kyle H.; Cristescu, Bogdan; Stenhouse, Gordon B.

    2010-01-01

    Autocorrelation has been viewed as a problem in telemetry studies because sequential observations are not independent in time or space, therefore violating assumptions for statistical inference. Yet nearly all ecological and behavioural data are autocorrelated in both space and time. We argue that there is much to learn about the structure of ecological and behavioural data from patterns of autocorrelation. Such patterns include periodicity in movement and patchiness in spatial data, which can be characterized by an autocorrelogram, semivariogram or spectrum. We illustrate the utility of temporal autocorrelation functions (ACFs) for analysing step-length data from GPS telemetry of wolves (Canis lupus), cougars (Puma concolor), grizzly bears (Ursus arctos) and elk (Cervus elaphus) in western Alberta. ACFs often differ by season, reflecting differences in foraging behaviour. In wilderness landscapes, step-length ACFs for predators decay slowly to apparently random patterns, but sometimes display strong daily rhythms in areas of human disturbance. In contrast, step lengths of elk are consistently periodic, reflecting crepuscular activity. PMID:20566498

  9. Multi-scale autocorrelation via morphological wavelet slices for rolling element bearing fault diagnosis

    NASA Astrophysics Data System (ADS)

    Li, Chuan; Liang, Ming; Zhang, Yi; Hou, Shumin

    2012-08-01

    Fault features of rolling element bearings can be reflected by geometrical structures of the bearing vibration signals. These symptoms, however, often spread over various morphological scales without a known pattern. For this reason, we propose a multi-scale autocorrelation via morphological wavelet slices (MAMWS) approach to detect bearing fault signatures. The vibration measurement of a bearing is decomposed using morphological stationary wavelet with different resolutions of structuring elements. The extracted temporal components are then transformed to form a frequency-domain view of morphological slices by the Fourier transform. Although this three-dimensional representation is more intuitive in terms of fault diagnosis, the existence of the noise may reduce its readability. Hence the autocorrelation function is exploited to produce a multi-scale autocorrelation spectrogram from which the maximal autocorrelation values of all frequencies are aggregated into an ichnographical spectral representation. Accordingly the fault signature is highlighted for easy diagnosis of bearing faults. The effectiveness of the proposed approach has been demonstrated by both the simulation and experimental signal analyses.

  10. Controlling for localised spatio-temporal autocorrelation in long-term air pollution and health studies

    PubMed Central

    Mitchell, Richard

    2014-01-01

    Estimating the long-term health impact of air pollution using an ecological spatio-temporal study design is a challenging task, due to the presence of residual spatio-temporal autocorrelation in the health counts after adjusting for the covariate effects. This autocorrelation is commonly modelled by a set of random effects represented by a Gaussian Markov random field (GMRF) prior distribution, as part of a hierarchical Bayesian model. However, GMRF models typically assume the random effects are globally smooth in space and time, and thus are likely to be collinear to any spatially and temporally smooth covariates such as air pollution. Such collinearity leads to poor estimation performance of the estimated fixed effects, and motivated by this epidemiological problem, this paper proposes new GMRF methodology to allow for localised spatio-temporal smoothing. This means random effects that are either geographically or temporally adjacent are allowed to be autocorrelated or conditionally independent, which allows more flexible autocorrelation structures to be represented. This increased flexibility results in improved fixed effects estimation compared with global smoothing models, which is evidenced by our simulation study. The methodology is then applied to the motivating study investigating the long-term effects of air pollution on respiratory ill health in Greater Glasgow, Scotland between 2007 and 2011. PMID:24648100

  11. A method to simulate synthetic aperture sonar images with parameterized autocorrelation functions

    NASA Astrophysics Data System (ADS)

    Cobb, J. Tory; Slatton, K. Clint; Principe, Jose

    2010-04-01

    An approach to simulate synthetic aperture sonar (SAS) images with known autocorrelation functions (ACF) and single-point statistics is presented. ACF models for generating textures with and without periodicities are defined and explained. Simulated textures of these models are compared visually with real SAS image textures. Distortion and degradation of the synthetic textures are examined for various simulation parameter choices.

  12. The temporal autocorrelation in FCS: a single-molecule detection nano-biotechnology

    NASA Astrophysics Data System (ADS)

    Kao, Lie-Jane

    2005-11-01

    The fluorescence correlation spectroscopy (FCS) has become a powerful tool that entails the information about molecules at very minute concentrations in the biological system. With the advances in the laser technology and confocal microscopy, the applications of FCS have been extended to the studies of protein dynamics in living cells as well as drug-screening. Two assumptions are made in FCS: the biological system under study is in its equilibrium state and the molecules diffuse within the system freely according to Brownian motions. Fluorescence intensity fluctuations occur when the fluorescent molecule moving in and out of the confocal microscopy defined detection volume in which bursts of photons are emitted. Based on the assumptions above, the statistical-physics-based autocorrelation function of the fluorescence intensity fluctuations was formulated by Aragon and Pecora, which provides the information about the dynamics of the fluorescent macromolecules in the system. However, in this manuscript, we demonstrate that the temporal autocorrelation function of Aragon and Pecora was inadequately derived due to the fact that the process of the positions of a molecule in the system over time is not a stationary Gaussian process. Efforts are made here to derive a new version of the autocorrelation function of the temporal fluorescence intensity fluctuation. The fit of the new autocorrelation function will be compared with that of Aragon and Pecora.

  13. Negligible influence of spatial autocorrelation in the assessment of fire effects in a mixed conifer forest

    USGS Publications Warehouse

    van Mantgem, P.J.; Schwilk, D.W.

    2009-01-01

    Fire is an important feature of many forest ecosystems, although the quantification of its effects is compromised by the large scale at which fire occurs and its inherent unpredictability. A recurring problem is the use of subsamples collected within individual burns, potentially resulting in spatially autocorrelated data. Using subsamples from six different fires (and three unburned control areas) we show little evidence for strong spatial autocorrelation either before or after burning for eight measures of forest conditions (both fuels and vegetation). Additionally, including a term for spatially autocorrelated errors provided little improvement for simple linear models contrasting the effects of early versus late season burning. While the effects of spatial autocorrelation should always be examined, it may not always greatly influence assessments of fire effects. If high patch scale variability is common in Sierra Nevada mixed conifer forests, even following more than a century of fire exclusion, treatments designed to encourage further heterogeneity in forest conditions prior to the reintroduction of fire will likely be unnecessary.

  14. Foreword to Selected presentations from the 1st European Hip Sport Meeting.

    PubMed

    Dallari, Dante; Ribas, Manuel

    2016-05-14

    Recent years have witnessed a growing number of people practising sports both at professional and amateur level. This trend led to a progressive rise in the incidence and prevalence of acute and chronic hip damage. The treatment of hip disease in subjects practising sports is a major challenge for the orthopaedic surgeon. The evaluation of patients, in particular those of young age with high functional demands, is inevitably complex and should be performed with a multidisciplinary approach; from a surgical point of view, it is essential to carefully assess whether the indication is towards conservative surgery or hip replacement surgery. The advent of arthroscopic surgery in recent years has allowed us to improve our knowledge of hip joint diseases, such as femoroacetabular impingement that is typical of sports and overuse activity. A correct and early diagnosis of the disease can direct the patient promptly to a conservative surgical treatment that could reduce the progression of degenerative pathology. However, when the joint is permanently damaged, the only reliable solution remains prosthetic surgery, leading to a series of issues that the orthopaedic surgeon should be able to master, leading to a thoughtful decision on, for example, which implant to use, which biomaterials, which surgical approach or which sport to practise after surgery. This supplement contains selected contributions stemming from the work performed by internationally recognised experts in the field and presented during the 1st European Hip Sport Meeting held in Bologna on May 19th, 20th, 2016 that we had the honour to co-chair. We hope that these contributions will help the orthopaedic surgeon, the sports physician and physiotherapist in their day-to-day practice, and will help in fulfilling our ultimate aim to improve the knowledge of the hip pathology related to sports and overuse activities. PMID:27174057

  15. PREFACE: 1st Conference on Light and Particle Beams in Materials Science 2013 (LPBMS2013)

    NASA Astrophysics Data System (ADS)

    Kumai, Reiji; Murakami, Youichi

    2014-04-01

    From 29-31 August 2013, the 1st International Conference on Light and Particle Beams in Materials Science, LPBMS 2013, took place in the Tsukuba International Congress Center in the city of Tsukuba, Japan. The conference was a continuation of the international series Synchrotron Radiation in Materials Science (SRMS), which started in 1994. The last one, SRMS-7, was held in Oxford UK 11-14 July 2010, where the International Advisory Committee (IAC) recommended the conference be enlarged to incorporate Materials Research from Neutron, Muon, and Slow Positron Sources, as well as the science emerging from Synchrotron Light Sources. The conference brought together contributions from academics and industrial researchers with a diverse background and experience from the physics, chemistry and engineering communities. The topics covered in the LPBMS2013 include strongly correlated electron systems, magnetism and magnetic materials, soft matter, interface and surface defects, catalysts, biomaterials, and ceramics. In the 3-day scientific program, the conference consisted of 9 plenary talks, 33 invited talks, 20 oral presentations, and 126 poster presentations. We are pleased to publish the proceedings of the LPBMS2013 in this volume of Journal of Physics: Conference Series. This volume contains 58 papers representing the work that was presented and discussed at the conference. We hope that this volume will promote further development of this interdisciplinary materials research emerging from synchrotron light, neutron, muon, and slow positron sciences. Finally, we would like to thank the International Advisory Committee (Chair: Professor G N Greaves), sponsors, all the participants and contributors for making possible this international meeting of researchers. Reiji Kumai & Youichi Murakami Conference photograph Details of the program and organizing committees are available in the pdf

  16. Computational Simulations of Convergent Nozzles for the AIAA 1st Propulsion Aerodynamics Workshop

    NASA Technical Reports Server (NTRS)

    Dippold, Vance F., III

    2014-01-01

    Computational Fluid Dynamics (CFD) simulations were completed for a series of convergent nozzles in participation of the American Institute of Aeronautics and Astronautics (AIAA) 1st Propulsion Aerodynamics Workshop. The simulations were performed using the Wind-US flow solver. Discharge and thrust coefficients were computed for four axisymmetric nozzles with nozzle pressure ratios (NPR) ranging from 1.4 to 7.0. The computed discharge coefficients showed excellent agreement with available experimental data; the computed thrust coefficients captured trends observed in the experimental data, but over-predicted the thrust coefficient by 0.25 to 1.0 percent. Sonic lines were computed for cases with NPR >= 2.0 and agreed well with experimental data for NPR >= 2.5. Simulations were also performed for a 25 deg. conic nozzle bifurcated by a flat plate at NPR = 4.0. The jet plume shock structure was compared with and without the splitter plate to the experimental data. The Wind-US simulations predicted the shock structure well, though lack of grid resolution in the plume reduced the sharpness of the shock waves. Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations and Detached Eddy Simulations (DES) were performed at NPR = 1.6 for the 25 deg conic nozzle with splitter plate. The simulations predicted vortex shedding from the trailing edge of the splitter plate. However, the vortices of URANS and DES solutions appeared to dissipate earlier than observed experimentally. It is believed that a lack of grid resolution in the region of the vortex shedding may have caused the vortices to break down too soon

  17. Patterns of Irregular Burials in Western Europe (1st-5th Century A.D.)

    PubMed Central

    Milella, Marco; Mariotti, Valentina; Belcastro, Maria Giovanna; Knüsel, Christopher J.

    2015-01-01

    Background Irregular burials (IB—burials showing features that contrast with the majority of others in their geographic and chronological context) have been the focus of archaeological study because of their relative rarity and enigmatic appearance. Interpretations of IB often refer to supposed fear of the dead or to social processes taking place in time-specific contexts. However, a comprehensive and quantitative analysis of IB for various geographical contexts is still lacking, a fact that hampers any discussion of these burials on a larger scale. Methods Here, we collected a bibliographic dataset of 375 IB from both Britain and Continental Europe, altogether spanning a time period from the 1st to the 5th century AD. Each burial has been coded according to ten dichotomous variables, further analyzed by means of chi-squared tests on absolute frequencies, non-metric multidimensional scaling, and cluster analysis. Results Even acknowledging the limits of this study, and in particular the bias represented by the available literature, our results point to interesting patterns. Geographically, IB show a contrast between Britain and Continental Europe, possibly related to historical processes specific to these regions. Different types of IB (especially prone depositions and depositions with the cephalic extremity displaced) present a series of characteristics and associations between features that permit a more detailed conceptualization of these occurrences from a socio-cultural perspective that aids to elucidate their funerary meaning. Conclusions and Significance Altogether, the present work stresses the variability of IB, and the need to contextualize them in a proper archaeological and historical context. It contributes to the discussion of IB by providing a specific geographic and chronological frame of reference that supports a series of hypotheses about the cultural processes possibly underlying their occurrence. PMID:26115408

  18. Analysis and study of the in situ observation of the June 1st 2008 CME by STEREO

    NASA Astrophysics Data System (ADS)

    Nieves-Chinchilla, T.; Gómez-Herrero, R.; Viñas, A. F.; Malandraki, O.; Dresing, N.; Hidalgo, M. A.; Opitz, A.; Sauvaud, J.-A.; Lavraud, B.; Davila, J. M.

    2011-07-01

    In this work we present a combined study of the counterpart of the coronal mass ejection (CME) of June 1st of 2008 in the interplanetary medium. This event has been largely studied because of its peculiar initiation and its possible forecasting consequences for space weather. We show an in situ analysis (on days June 6th-7th of 2008) of the CME in the interplanetary medium in order to shed some light on the propagation and evolution mechanisms of the interplanetary CME (ICME). The goals of this work are twofold: gathering the whole in situ data from PLASTIC and IMPACT onboard STEREO B in order to provide a complete characterization of the ICME, and to present a model where the thermal plasma pressure is included. The isolated ICME features show a clear forward shock which we identify as an oblique forward fast shock accelerating ions to a few-hundred keV during its passage. Following the shock, a flux rope is easily defined as a magnetic cloud (MC) by the magnetic field components and magnitude, and the low proton plasma-β. During the spacecraft passage through the MC, the energetic ion intensity shows a pronounced decrease, suggesting a closed magnetic topology, and the suprathermal electron population shows a density and temperature increase, demonstrating the importance of the electrons in the MC description. The in situ evidence suggests that there is no direct magnetic connection between the forward shock and the MC, and the characteristics of the reverse shock determined suggest that the shock pair is a consequence of the propagation of the ICME in the interplanetary medium. The energetic ions measured by the SEPT instrument suggest that their enhancement is not related to any solar event, but is solely due to the interplanetary shock consistent with the fact that no flares are observed on the Sun. The changes in the polarity of the interplanetary magnetic field in the vicinity of the ICME observed by electron PADs from SWEA are in accordance with the idea

  19. Autocorrelation and regularization in digital images. II - Simple image models

    NASA Technical Reports Server (NTRS)

    Jupp, David L. B.; Strahler, Alan H.; Woodcock, Curtis E.

    1989-01-01

    The variogram function used in geostatistical analysis is a useful statistic in the analysis of remotely sensed images. Using the results derived by Jupp et al. (1988), the basic second-order, or covariance, properties of scenes modeled by simple disks of varying size and spacing after imaging into disk-shaped pixels are analyzed to explore the relationship betwee image variograms and discrete object scene structure. The models provide insight into the nature of real images of the earth's surface and the tools for a complete analysis of the more complex case of three-dimensional illuminated discrete-object images.

  20. Global autocorrelation scales of the partial pressure of oceanic CO2

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Adamec, David; Takahashi, Taro; Sutherland, Stewart C.

    2005-08-01

    A global database of approximately 1.7 million observations of the partial pressure of carbon dioxide in surface ocean waters (pCO2) collected between 1970 and 2003 is used to estimate its spatial autocorrelation structure. The patterns of the lag distance where the autocorrelation exceeds 0.8 is similar to patterns in the spatial distribution of the first baroclinic Rossby radius of deformation indicating that ocean circulation processes play a significant role in determining the spatial variability of pCO2. Separate calculations for times when the Sun is north and south of the equator revealed no obvious seasonal dependence of the spatial autocorrelation scales. The pCO2 measurements at Ocean Weather Station (OWS) "P" in the eastern subarctic Pacific (50°N, 145°W) is the only fixed location where an uninterrupted time series of sufficient length exists to calculate a meaningful temporal autocorrelation function for lags greater than a few days. The estimated temporal autocorrelation function at OWS "P" is highly variable. A spectral analysis of the longest four pCO2 time series indicates a high level of variability occurring over periods from the atmospheric synoptic to the maximum length of the time series, in this case 42 days. It is likely that a relative peak in variability with a period of 3-6 days is related to atmospheric synoptic period variability and ocean mixing events due to wind stirring. However, the short length of available time series makes identifying temporal relationships between pCO2 and atmospheric or ocean processes problematic.

  1. Cobble cam: Grain-size measurements of sand to boulder from digital photographs and autocorrelation analyses

    USGS Publications Warehouse

    Warrick, J.A.; Rubin, D.M.; Ruggiero, P.; Harney, J.N.; Draut, A.E.; Buscombe, D.

    2009-01-01

    A new application of the autocorrelation grain size analysis technique for mixed to coarse sediment settings has been investigated. Photographs of sand- to boulder-sized sediment along the Elwha River delta beach were taken from approximately 1??2 m above the ground surface, and detailed grain size measurements were made from 32 of these sites for calibration and validation. Digital photographs were found to provide accurate estimates of the long and intermediate axes of the surface sediment (r2 > 0??98), but poor estimates of the short axes (r2 = 0??68), suggesting that these short axes were naturally oriented in the vertical dimension. The autocorrelation method was successfully applied resulting in total irreducible error of 14% over a range of mean grain sizes of 1 to 200 mm. Compared with reported edge and object-detection results, it is noted that the autocorrelation method presented here has lower error and can be applied to a much broader range of mean grain sizes without altering the physical set-up of the camera (~200-fold versus ~6-fold). The approach is considerably less sensitive to lighting conditions than object-detection methods, although autocorrelation estimates do improve when measures are taken to shade sediments from direct sunlight. The effects of wet and dry conditions are also evaluated and discussed. The technique provides an estimate of grain size sorting from the easily calculated autocorrelation standard error, which is correlated with the graphical standard deviation at an r2 of 0??69. The technique is transferable to other sites when calibrated with linear corrections based on photo-based measurements, as shown by excellent grain-size analysis results (r2 = 0??97, irreducible error = 16%) from samples from the mixed grain size beaches of Kachemak Bay, Alaska. Thus, a method has been developed to measure mean grain size and sorting properties of coarse sediments. ?? 2009 John Wiley & Sons, Ltd.

  2. An integrated approach of auto-correlation functions and wavelet analysis applied to the wind meandering phenomenon

    NASA Astrophysics Data System (ADS)

    Mortarini, Luca; Cava, Daniela; Giostra, Umberto; Anfossi, Domenico

    2016-04-01

    Meandering is generally defined in terms of large 
variation of the wind direction due to a complex mix of motions on scales between the main turbulent eddies and the smallest mesoscale motions. There is not a general consensus on the physical causes of the motions responsible of the wind meandering during low-wind speed conditions. They include internal gravity waves, quasi-2D pancake motions, cold air drainage, solitons, vortices with either a horizontal axis or a vertical axis. In this work we present the analysis of wind and temperature data measured with two sonic anemometers in a low-wind stably stratified night observed during the Urban Turbulent Project (Torino, Italy). An original approach to estimate the meandering time scales of the wind velocity and temperature using two complementary methodologies is proposed. In the literature the meandering time-scale is evaluated fitting the Eulerian auto-correlation functions of the wind velocity with an oscillating theoretical behaviour on hourly datasets. First we extend this method considering the dependence of the time-scale on the dataset length considering longer datasets (1, 2, 3, 4 hours) and then we compare these results with a wavelet analysis. The continuous wavelet transform based on the Morlet basis is used to detect and characterize the time-scale of the wavelike oscillations both in the wind velocity and in the temperature signals. Moreover cross-wavelet spectra are used to identify the nature of the wavy patterns in order to discriminate the presence of gravity waves. The wavelet analysis corroborates the results obtained with the auto-correlation functions and opens new promising perspectives for the study of the meandering phenomenon.

  3. 78 FR 39255 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Advance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-01

    ... Countervailing Duty Orders; Policy Bulletin, 63 FR 18871 (April 16, 1998). The Notice of Initiation of Five-Year... Magnets from Jennifer Moats China (A-570-922) (1st (202) 482-5047 Review). Raw Flexible Magnets from David... Magnets from Jennifer Moats China (C-570-923) (1st (202) 482-5047 Review). Suspended Investigations...

  4. Adaptive and Effortful Control and Academic Self-Efficacy Beliefs on Achievement: A Longitudinal Study of 1st through 3rd Graders

    ERIC Educational Resources Information Center

    Liew, Jeffrey; McTigue, Erin M.; Barrois, Lisa; Hughes, Jan N.

    2008-01-01

    The linkages between self-regulatory processes and achievement were examined across 3 years in 733 children beginning at 1st grade (M = 6.57 years, S.D. = 0.39 at 1st grade) who were identified as lower achieving in literacy. Accounting for consistencies in measures (from 1 year prior) and for influences of child's age, gender, IQ, ethnicity and…

  5. Effects of the April 1st, 2014 GLONASS Outage on GNSS Receivers

    NASA Astrophysics Data System (ADS)

    Blume, F.; Berglund, H. T.; Romero, I.; D'Anastasio, E.

    2014-12-01

    The use of multi-constellation GNSS receivers has been assumed as a way to increase system integrity both by increased coverage during normal operations and failover redundancy in the event of a constellation failure. At approximately 21:00 UTC on April 1st the entire GLONASS constellation was disrupted as illegal ephemeris uploaded to each satellite took effect simultaneously. The outage continued for more than 10 hours. While ephemeris were incorrect, pseudoranges were correctly broadcast on both L1 and L2 and carrier phases were not affected; in the best case, GNSS receivers could be expected to continue to track all signals including GLONASS and at the worst to continue to track GPS and other constellations. It became clear to operators of the GeoNet network in New Zealand that the majority of their 79 GLONASS-enabled receivers experienced total tracking failures. Further detailed analysis of data from these and 315 additional GLONASS-enabled stations worldwide showed that receiver tracking behavior was affected for most receiver brands and models, both for GLONASS and GPS. Findings regarding the impacts of the GLONASS outage on receiver behavior will be highlighted. We use data recorded by GLONASS enabled global sites for the days during, preceding and following the outage to evaluate the impact of the outage on tracking and positioning performance. We observe that for some receiver types the onboard receiver autonomous integrity monitoring (RAIM) failed to ignore the incorrect messages, resulting in degraded GLONASS and GPS tracking and in some cases complete tracking failures and significant data loss. In addition, many of the receivers with clock steering enabled showed outliers in their receiver clock bias estimates that also coincided with the outage. Our results show in detail how different brands, configurations, and distributions of receivers were affected to varying extents, but no common factors are apparent. This event shows that many manufacturers

  6. PREFACE: 1st International Conference on Mechanical Engineering Research 2011 (ICMER2011)

    NASA Astrophysics Data System (ADS)

    Abu Bakar, Rosli

    2012-09-01

    The year 2010 represented a significant milestone in the history of the Mechanical Engineering community with the organization of the first and second national level conferences (National Conference in Mechanical Engineering for Research, 1st and 2nd NCMER) at Universiti Malaysia Pahang on 26-27 May and 3-4 December 2010. The conferences attracted a large number of delegates from different premier academic and research institutions in the country to participate and share their research experiences at the conference. The International Conference on Mechanical Engineering Research (ICMER 2011) followed on from the first and second conferences due to good support from researchers. The ICMER 2011 is a good platform for researchers and postgraduate students to present their latest finding in research. The conference covers a wide range of topics including the internal combustion engine, machining processes, heat and mass transfer, fuel, biomechanical analysis, aerodynamic analysis, thermal comfort, computational techniques, design and simulation, automotive transmission, optimization techniques, hybrid electric vehicles, engine vibration, heat exchangers, finite element analysis, computational fluid dynamics, green energy, vehicle dynamics renewable energy, combustion, design, product development, advanced experimentation techniques, to name but a few. The international conference has helped to bridge the gap between researchers working at different institutions and in different countries to share their knowledge and has helped to motivate young scientists with their research. This has also given some clear direction for further research from the deliberations of the conference. Several people have contributed in different ways to the success of the conference. We thank the keynote speakers and all authors of the contributed papers, for the cooperation rendered to us in the publication of the CD conference proceedings. In particular, we would like to place on record our

  7. PREFACE: 1st International Conference on Sensing for Industry, Control, Communication & Security Technologies

    NASA Astrophysics Data System (ADS)

    Shuja Syed, Ahmed

    2013-12-01

    The 1st International Conference on Sensing for Industry, Control, Communication & Security Technologies (ICSICCST-2013), took place in Karachi, Pakistan, from 24-26 June 2013. It was organized by Indus University, Karachi, in collaboration with HEJ Research Institute of Chemistry, University of Karachi, Karachi. More than 80 abstracts were submitted to the conference and were double blind-reviewed by an international scientific committee. The topics of the Conference were: Video, Image & Voice Sensing Sensing for Industry, Environment, and Health Automation and Controls Laser Sensors and Systems Displays for Innovative Applications Emerging Technologies Unmanned, Robotic, and Layered Systems Sensing for Defense, Homeland Security, and Law Enforcement The title of the conference, 'Sensing for Industry, Control, Communication & Security Technologies' is very apt in capturing the main issues facing the industry of Pakistan and the world. We believe the sensing industry, particularly in Pakistan, is currently at a critical juncture of its development. The future of the industry will depend on how the industry players choose to respond to the challenge of global competition and opportunities arising from strong growth in the Asian region for which we are pleased to note that the conference covered a comprehensive spectrum of issues with an international perspective. This will certainly assist industry players to make informed decisions in shaping the future of the industry. The conference gathered qualified researchers from developed countries like USA, UK, Sweden, Saudi Arabia, China, South Korea and Malaysia etc whose expertise resulting from the research can be drawn upon to build an exploitable area of new technology that has potential Defense, Homeland Security, and Military applicability. More than 250 researchers/students attended the event and made the event great success as the turnout was 100%. An exceptional line-up of speakers spoke at the occasion. We want

  8. PREFACE: 1st-2nd Young Researchers Meetings in Rome - Proceedings

    NASA Astrophysics Data System (ADS)

    YRMR Organizing Committee; Cannuccia, E.; Mazzaferro, L.; Migliaccio, M.; Pietrobon, D.; Stellato, F.; Veneziani, M.

    2011-03-01

    Students in science, particularly in physics, face a fascinating and challenging future. Scientists have proposed very interesting theories, which describe the microscopic and macroscopic world fairly well, trying to match the quantum regime with cosmological scales. Between the extremes of this scenario, biological phenomena in all their complexity take place, challenging the laws we observe in the atomic and sub-atomic world. More and more accurate and complex experiments have been devised and these are now going to test the paradigms of physics. Notable experiments include: the Large Hadronic Collider (LHC), which is going to shed light on the physics of the Standard Model of Particles and its extensions; the Planck-Herschel satellites, which target a very precise measurement of the properties of our Universe; and the Free Electron Lasers facilities, which produce high-brilliance, ultrafast X-ray pulses, allowing the investigation of the fundamental processes of solid state physics, chemistry, and biology. These projects are the result of huge collaborations spread across the world, involving scientists belonging to different and complementary research fields: physicists, chemists, biologists and others, keen to make the best of these extraordinary laboratories. Even though each branch of science is experiencing a process of growing specialization, it is very important to keep an eye on the global picture, remaining aware of the deep interconnections between inherent fields. This is even more crucial for students who are beginning their research careers. These considerations motivated PhD students and young post-docs connected to the Roman scientific research area to organize a conference, to establish the background and the network for interactions and collaborations. This resulted in the 1st and 2nd Young Researchers Meetings in Rome (http://ryrm.roma2.infn.it), one day conferences aimed primarily at graduate students and post-docs, working in physics in Italy

  9. Teachers' Spatial Anxiety Relates to 1st-and 2nd-Graders' Spatial Learning

    ERIC Educational Resources Information Center

    Gunderson, Elizabeth A.; Ramirez, Gerardo; Beilock, Sian L.; Levine, Susan C.

    2013-01-01

    Teachers' anxiety about an academic domain, such as math, can impact students' learning in that domain. We asked whether this relation held in the domain of spatial skill, given the importance of spatial skill for success in math and science and its malleability at a young age. We measured 1st-and 2nd-grade teachers' spatial anxiety…

  10. Gene-Environment Interaction Effects on the Development of Immune Responses in the 1st Year of Life

    PubMed Central

    Hoffjan, Sabine; Nicolae, Dan; Ostrovnaya, Irina; Roberg, Kathy; Evans, Michael; Mirel, Daniel B.; Steiner, Lori; Walker, Karen; Shult, Peter; Gangnon, Ronald E.; Gern, James E.; Martinez, Fernando D.; Lemanske, Robert F.; Ober, Carole

    2005-01-01

    Asthma is a common disease that results from both genetic and environmental risk factors. Children attending day care in the 1st year of life have lower risks for developing asthma, although the mechanism for this “day care” effect is largely unknown. We investigated the interactions between day care exposure in the 1st 6 mo of life and genotypes for 72 polymorphisms at 45 candidate loci and their effects on cytokine response profiles and on the development of atopic phenotypes in the 1st year of life in the Childhood Onset of Asthma (COAST) cohort of children. Six interactions (at four polymorphisms in three loci) with “day care” that had an effect on early-life immune phenotypes were significant at P<.001. The estimated false-discovery rate was 33%, indicating that an estimated four P values correspond to true associations. Moreover, the “day care” effect at some loci was accounted for by the increased number of viral infections among COAST children attending day care, whereas interactions at other loci were independent of the number of viral infections, indicating the presence of additional risk factors associated with day care environment. This study identified significant gene-environment interactions influencing the early patterning of the immune system and the subsequent development of asthma and highlights the importance of considering environmental risk factors in genetic analyses. PMID:15726497

  11. The theoretical simulation on electrostatic distribution of 1st proximity region in proximity focusing low-light-level image intensifier

    NASA Astrophysics Data System (ADS)

    Zhang, Liandong; Bai, Xiaofeng; Song, De; Fu, Shencheng; Li, Ye; Duanmu, Qingduo

    2015-03-01

    Low-light-level night vision technology is magnifying low light level signal large enough to be seen by naked eye, which uses the photons - photoelectron as information carrier. Until the micro-channel plate was invented, it has been possibility for the realization of high performance and miniaturization of low-light-level night vision device. The device is double-proximity focusing low-light-level image intensifier which places a micro-channel plate close to photocathode and phosphor screen. The advantages of proximity focusing low-light-level night vision are small size, light weight, small power consumption, no distortion, fast response speed, wide dynamic range and so on. It is placed parallel to each other for Micro-channel plate (both sides of it with metal electrode), the photocathode and the phosphor screen are placed parallel to each other. The voltage is applied between photocathode and the input of micro-channel plate when image intensifier works. The emission electron excited by photo on the photocathode move towards to micro-channel plate under the electric field in 1st proximity focusing region, and then it is multiplied through the micro-channel. The movement locus of emission electrons can be calculated and simulated when the distributions of electrostatic field equipotential lines are determined in the 1st proximity focusing region. Furthermore the resolution of image tube can be determined. However the distributions of electrostatic fields and equipotential lines are complex due to a lot of micro-channel existing in the micro channel plate. This paper simulates electrostatic distribution of 1st proximity region in double-proximity focusing low-light-level image intensifier with the finite element simulation analysis software Ansoft maxwell 3D. The electrostatic field distributions of 1st proximity region are compared when the micro-channel plates' pore size, spacing and inclination angle ranged. We believe that the electron beam movement

  12. Simulation of autocorrelation function and photon counting distribution in fluorescence fluctuation spectroscopy.

    PubMed

    Shingaryov, Igor P; Skakun, Victor V; Apanasovich, Vladimir V

    2014-01-01

    In modern fluorescence fluctuation spectroscopy, the autocorrelation function and photon counting distribution are two widely used statistical characteristics of the measured fluctuating fluorescence intensity signal. Applying special analysis methods such as fluorescence correlation spectroscopy (FCS) and photon counting histogram (PCH) to these properties, it is possible to recover values of different parameters of fluorescent molecules such as the concentration, diffusion coefficient, molecular brightness, and kinetic rate constants. The development of new analysis methods is senseless without testing their validity, accuracy, and robustness. The most appropriate check of a method is its application to experimental data. However, sometimes it is more convenient and easier to verify a method on simulated data. Simulation is also useful for better understanding the processes that were modeled during the development of analysis methods. Here, we present two simulation models providing an autocorrelation function and photon counting distribution of a sequence of photon arrival times detected in fluorescence fluctuation spectroscopy. PMID:24108653

  13. Full-field velocity imaging of red blood cells in capillaries with spatiotemporal demodulation autocorrelation

    NASA Astrophysics Data System (ADS)

    Wang, Mingyi; Zeng, Yaguang; Dong, Nannan; Liao, Riwei; Yang, Guojian

    2016-03-01

    We propose a full-field optical method for the label-free and quantitative mapping of the velocities of red blood cells (RBCs) in capillaries. It integrates spatiotemporal demodulation and an autocorrelation algorithm, and measures RBC velocity according to the ratio of RBC length to lag time. Conventionally, RBC length is assumed to be a constant and lag time is taken as a variable, while our method treats both of them as variables. We use temporal demodulation and the Butterworth spatial filter to separate RBC signal from background signal, based on which we obtain the RBC length by image segmentation and lag time by autocorrelation analysis. The RBC velocity calculated now is more accurate. The validity of our method is verified by an in vivo experiment on a mouse ear. Owing to its higher image signal-to-noise ratio, our method can be used for mapping RBC velocity in the turbid tissue case.

  14. Simultaneous measurement of the root-mean-square roughness and autocorrelation length by optical method

    NASA Astrophysics Data System (ADS)

    Kim, Dalwoo; Oh, Ki-Jang; Lim, Choong-Soo

    1998-12-01

    We developed an on-line measurement system for the simultaneous measurement of the root-mean-square roughness and autocorrelation length which are the parameters of surface roughness. The measurement is based on the scattering theory of light on the rough surface. Computer simulation shows that the measurement range depends on the wavelength of the light source, and this is verified with the experiment. We installed the measurement system at the finishing line of a cold-rolling steel work, and measured the two parameters in situ. The rms roughness and autocorrelation length are measured and transformed in the average surface roughness and then umber of peaks per inch, respectively. The measured data for both of the parameters are compared with those of stylus method, an the optical method is well coincided with the conventional stylus method.

  15. Characterization of a broadband interferometric autocorrelator for visible light with ultrashort blue laser pulses

    NASA Astrophysics Data System (ADS)

    Zürch, M.; Hoffmann, A.; Gräfe, M.; Landgraf, B.; Riediger, M.; Spielmann, Ch.

    2014-06-01

    We present a compact interferometric autocorrelator that allows the characterization of ultrashort laser pulses in the visible light domain (370-740 nm). The presented device uses a GaN photodiode with corresponding two-photon absorption. Different GaN and AlGaN photodiodes were characterized for this purpose. Despite AlGaN diodes have a better matched bandgap for this application, we have found that only the GaN diodes show sufficient nonlinear behavior. Using the autocorrelator we were able to characterize ultrashort frequency doubled Ti:Sapphire laser pulses with a pulse duration down to 18 fs in the second harmonic having just a few hundred nanojoules of pulse energy. The broadband behavior and extension towards the UV along with the need for only low energetic pulses are the novelties of this device.

  16. Phase II monitoring of auto-correlated linear profiles using linear mixed model

    NASA Astrophysics Data System (ADS)

    Narvand, A.; Soleimani, P.; Raissi, Sadigh

    2013-05-01

    In many circumstances, the quality of a process or product is best characterized by a given mathematical function between a response variable and one or more explanatory variables that is typically referred to as profile. There are some investigations to monitor auto-correlated linear and nonlinear profiles in recent years. In the present paper, we use the linear mixed models to account autocorrelation within observations which is gathered on phase II of the monitoring process. We undertake that the structure of correlated linear profiles simultaneously has both random and fixed effects. The work enhanced a Hotelling's T 2 statistic, a multivariate exponential weighted moving average (MEWMA), and a multivariate cumulative sum (MCUSUM) control charts to monitor process. We also compared their performances, in terms of average run length criterion, and designated that the proposed control charts schemes could effectively act in detecting shifts in process parameters. Finally, the results are applied on a real case study in an agricultural field.

  17. Crustal imaging across the North Anatolian Fault Zone from the autocorrelation of ambient seismic noise

    NASA Astrophysics Data System (ADS)

    Taylor, George; Rost, Sebastian; Houseman, Gregory

    2016-03-01

    Seismic images of active fault zones can be used to examine the structure of faults throughout the crust and upper mantle and give clues as to whether the associated deformation occurs within a narrow shear zone or is broadly distributed through the lower crust. Limitations on seismic resolution within the crust and difficulties imaging shallow structures such as the crust-mantle boundary (Moho) place constraints on the interpretation of seismic images. In this study we retrieve body wave reflections from autocorrelations of ambient seismic noise. The instantaneous phase coherence autocorrelations allow unprecedented ambient noise images of the North Anatolian Fault Zone (NAFZ). Our reflection profiles show a Moho reflected P wave and additional structure within the crust and upper mantle. We image a distinct vertical offset of the Moho associated with the northern branch of the NAFZ indicating that deformation related to the fault remains narrow in the upper mantle.

  18. Detection of Burn Area and Severity with MODIS Satellite Images and Spatial Autocorrelation Techniques

    NASA Astrophysics Data System (ADS)

    Kaya, S.; Kavzoglu, T.; Tonbul, H.

    2014-12-01

    Effects of forest fires and implications are one of the most important natural disasters all over the world. Statistical data observed that forest fires had a variable structure in the last century in Turkey, but correspondingly the population growth amount of forest fires and burn area increase widely in recent years. Depending on this, erosion, landslides, desertification and mass loss come into existence. In addition; after forest fires, renewal of forests and vegetation are very important for land management. Classic methods used for detection of burn area and severity requires a long and challenging process due to time and cost factors. Thanks to advanced techniques used in the field of Remote Sensing, burn area and severity can be determined with high detail and precision. The purpose of this study based on blending MODIS (Moderate Resolution Imaging Spectradiometer) satellite images and spatial autocorrelation techniques together, thus detect burn area and severity absolutely. In this context, spatial autocorrelation statistics like Moran's I and Get is-Ord Local Gi indexes were used to measure and analyze to burned area characteristics. Prefire and postfire satellite images were used to determine fire severity depending on spectral indexes corresponding to biomass loss and carbon emissivity intensities. Satellite images have used for identification of fire damages and risks in terms of fire management for a long time. This study was performed using prefire and postfire satellite images and spatial autocorrelation techniques to determining and analyzing forest fires in Antalya, Turkey region which serious fires occurred. In this context, this approach enables the characterization of distinctive texture of burned area and helps forecasting more precisely. Finally, it is observed that mapping of burned area and severity could be performed from local scale to national scale. Key Words: Spatial autocorrelation, MODIS, Fire, Burn Severity

  19. PREFACE: PAGES 1st Young Scientists Meeting (YSM) - 'Retrospective views on our planet's future'

    NASA Astrophysics Data System (ADS)

    Margrethe Basse, Ellen

    2010-03-01

    more recent pollution. The concept and format of the 1st PAGES YSM worked very well, and

  20. What Autocorrelation Tells Us about Motor Variability: Insights from Dart Throwing

    PubMed Central

    van Beers, Robert J.; van der Meer, Yor; Veerman, Richard M.

    2013-01-01

    In sports such as golf and darts it is important that one can produce ballistic movements of an object towards a goal location with as little variability as possible. A factor that influences this variability is the extent to which motor planning is updated from movement to movement based on observed errors. Previous work has shown that for reaching movements, our motor system uses the learning rate (the proportion of an error that is corrected for in the planning of the next movement) that is optimal for minimizing the endpoint variability. Here we examined whether the learning rate is hard-wired and therefore automatically optimal, or whether it is optimized through experience. We compared the performance of experienced dart players and beginners in a dart task. A hallmark of the optimal learning rate is that the lag-1 autocorrelation of movement endpoints is zero. We found that the lag-1 autocorrelation of experienced dart players was near zero, implying a near-optimal learning rate, whereas it was negative for beginners, suggesting a larger than optimal learning rate. We conclude that learning rates for trial-by-trial motor learning are optimized through experience. This study also highlights the usefulness of the lag-1 autocorrelation as an index of performance in studying motor-skill learning. PMID:23691199

  1. What autocorrelation tells us about motor variability: insights from dart throwing.

    PubMed

    van Beers, Robert J; van der Meer, Yor; Veerman, Richard M

    2013-01-01

    In sports such as golf and darts it is important that one can produce ballistic movements of an object towards a goal location with as little variability as possible. A factor that influences this variability is the extent to which motor planning is updated from movement to movement based on observed errors. Previous work has shown that for reaching movements, our motor system uses the learning rate (the proportion of an error that is corrected for in the planning of the next movement) that is optimal for minimizing the endpoint variability. Here we examined whether the learning rate is hard-wired and therefore automatically optimal, or whether it is optimized through experience. We compared the performance of experienced dart players and beginners in a dart task. A hallmark of the optimal learning rate is that the lag-1 autocorrelation of movement endpoints is zero. We found that the lag-1 autocorrelation of experienced dart players was near zero, implying a near-optimal learning rate, whereas it was negative for beginners, suggesting a larger than optimal learning rate. We conclude that learning rates for trial-by-trial motor learning are optimized through experience. This study also highlights the usefulness of the lag-1 autocorrelation as an index of performance in studying motor-skill learning. PMID:23691199

  2. Spatial autocorrelation of radiation measured by the Earth Radiation Budget Experiment: Scene inhomogeneity and reciprocity violation

    NASA Technical Reports Server (NTRS)

    Davies, Roger

    1994-01-01

    The spatial autocorrelation functions of broad-band longwave and shortwave radiances measured by the Earth Radiation Budget Experiment (ERBE) are analyzed as a function of view angle in an investigation of the general effects of scene inhomogeneity on radiation. For nadir views, the correlation distance of the autocorrelation function is about 900 km for longwave radiance and about 500 km for shortwave radiance, consistent with higher degrees of freedom in shortwave reflection. Both functions rise monotonically with view angle, but there is a substantial difference in the relative angular dependence of the shortwave and longwave functions, especially for view angles less than 50 deg. In this range, the increase with angle of the longwave functions is found to depend only on the expansion of pixel area with angle, whereas the shortwave functions show an additional dependence on angle that is attributed to the occlusion of inhomogeneities by cloud height variations. Beyond a view angle of about 50 deg, both longwave and shortwave functions appear to be affected by cloud sides. The shortwave autocorrelation functions do not satisfy the principle of directional reciprocity, thereby proving that the average scene is horizontally inhomogeneous over the scale of an ERBE pixel (1500 sq km). Coarse stratification of the measurements by cloud amount, however, indicates that the average cloud-free scene does satisfy directional reciprocity on this scale.

  3. Adaptive Bessel-autocorrelation of ultrashort pulses with phase-only spatial light modulators

    NASA Astrophysics Data System (ADS)

    Huferath-von Luepke, Silke; Bock, Martin; Grunwald, Ruediger

    2009-06-01

    Recently, we proposed a new approach of a noncollinear correlation technique for ultrashort-pulsed coherent optical signals which was referred to as Bessel-autocorrelator (BAC). The BAC-principle combines the advantages of Bessellike nondiffracting beams like stable propagation, angular robustness and self-reconstruction with the principle of temporal autocorrelation. In comparison to other phase-sensitive measuring techniques, autocorrelation is most straightforward and time-effective because of non-iterative data processing. The analysis of nonlinearly converted fringe patterns of pulsed Bessel-like beams reveals their temporal signature from details of fringe envelopes. By splitting the beams with axicon arrays into multiple sub-beams, transversal resolution is approximated. Here we report on adaptive implementations of BACs with improved phase resolution realized by phase-only liquid-crystal-on-silicon spatial light modulators (LCoS-SLMs). Programming microaxicon phase functions in gray value maps enables for a flexible variation of phase and geometry. Experiments on the diagnostics of few-cycle pulses emitted by a mode-locked Ti:sapphire laser oscillator at wavelengths around 800 nm with 2D-BAC and angular tuned BAC were performed. All-optical phase shift BAC and fringe free BAC approaches are discussed.

  4. Effect of the spatial autocorrelation of empty sites on the evolution of cooperation

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Wang, Li; Hou, Dongshuang

    2016-02-01

    An evolutionary game model is constructed to investigate the spatial autocorrelation of empty sites on the evolution of cooperation. Each individual is assumed to imitate the strategy of the one who scores the highest in its neighborhood including itself. Simulation results illustrate that the evolutionary dynamics based on the Prisoner's Dilemma game (PD) depends severely on the initial conditions, while the Snowdrift game (SD) is hardly affected by that. A high degree of autocorrelation of empty sites is beneficial for the evolution of cooperation in the PD, whereas it shows diversification effects depending on the parameter of temptation to defect in the SD. Moreover, for the repeated game with three strategies, 'always defect' (ALLD), 'tit-for-tat' (TFT), and 'always cooperate' (ALLC), simulations reveal that an amazing evolutionary diversity appears for varying of parameters of the temptation to defect and the probability of playing in the next round of the game. The spatial autocorrelation of empty sites can have profound effects on evolutionary dynamics (equilibrium and oscillation) and spatial distribution.

  5. Two Point Autocorrelation Analysis of Auger Highest Energy Events Backtracked in Galactic Magnetic Field

    NASA Astrophysics Data System (ADS)

    Petrov, Yevgeniy

    2009-10-01

    Searches for sources of the highest-energy cosmic rays traditionally have included looking for clusters of event arrival directions on the sky. The smallest cluster is a pair of events falling within some angular window. In contrast to the standard two point (2-pt) autocorrelation analysis, this work takes into account influence of the galactic magnetic field (GMF). The highest energy events, those above 50EeV, collected by the surface detector of the Pierre Auger Observatory between January 1, 2004 and May 31, 2009 are used in the analysis. Having assumed protons as primaries, events are backtracked through BSS/S, BSS/A, ASS/S and ASS/A versions of Harari-Mollerach-Roulet (HMR) model of the GMF. For each version of the model, a 2-pt autocorrelation analysis is applied to the backtracked events and to 105 isotropic Monte Carlo realizations weighted by the Auger exposure. Scans in energy, separation angular window and different model parameters reveal clustering at different angular scales. Small angle clustering at 2-3 deg is particularly interesting and it is compared between different field scenarios. The strength of the autocorrelation signal at those angular scales differs between BSS and ASS versions of the HMR model. The BSS versions of the model tend to defocus protons as they arrive to Earth whereas for the ASS, in contrary, it is more likely to focus them.

  6. A new radial strain and strain rate estimation method using autocorrelation for carotid artery

    NASA Astrophysics Data System (ADS)

    Ye, Jihui; Kim, Hoonmin; Park, Jongho; Yeo, Sunmi; Shim, Hwan; Lim, Hyungjoon; Yoo, Yangmo

    2014-03-01

    Atherosclerosis is a leading cause of cardiovascular disease. The early diagnosis of atherosclerosis is of clinical interest since it can prevent any adverse effects of atherosclerotic vascular diseases. In this paper, a new carotid artery radial strain estimation method based on autocorrelation is presented. In the proposed method, the strain is first estimated by the autocorrelation of two complex signals from the consecutive frames. Then, the angular phase from autocorrelation is converted to strain and strain rate and they are analyzed over time. In addition, a 2D strain image over region of interest in a carotid artery can be displayed. To evaluate the feasibility of the proposed radial strain estimation method, radiofrequency (RF) data of 408 frames in the carotid artery of a volunteer were acquired by a commercial ultrasound system equipped with a research package (V10, Samsung Medison, Korea) by using a L5-13IS linear array transducer. From in vivo carotid artery data, the mean strain estimate was -0.1372 while its minimum and maximum values were -2.961 and 0.909, respectively. Moreover, the overall strain estimates are highly correlated with the reconstructed M-mode trace. Similar results were obtained from the estimation of the strain rate change over time. These results indicate that the proposed carotid artery radial strain estimation method is useful for assessing the arterial wall's stiffness noninvasively without increasing the computational complexity.

  7. The secret assumption of transfer functions: problems with spatial autocorrelation in evaluating model performance

    NASA Astrophysics Data System (ADS)

    Telford, R. J.; Birks, H. J. B.

    2005-11-01

    The estimation of the predictive power of transfer functions assumes that the test sites are independent of the modelling sites. Cross-validation in the presence of spatial autocorrelation seriously violates this assumption. This assumption and the consequences of its violation have not been discussed before. We show, by simulation, that the expected r2 of a transfer function model from an autocorrelated environment can be high, and is not near zero as commonly assumed. We investigate a foraminiferal sea surface temperature training set for the North Atlantic, for which, with cross-validation, the modern analogue technique (MAT) and artificial neural networks (ANN) outperform transfer function methods based on a unimodal species-environment response model. However, when a spatially independent test set, the South Atlantic, is used, all models have a similar predictive power. We show that there is a spatial structure in the foraminiferal assemblages even after accounting for temperature, presumably due to autocorrelations in other environmental variables. Since the residuals from MAT show little spatial structure, in contrast to the residuals of unimodal response models, we contend that MAT has inappropriately internalized the non-temperature spatial structure to improve its performance. We argue that most, if not all, estimates of the predictive power of MAT and ANN models for sea surface temperatures hitherto published are over-optimistic and misleading.

  8. Using PPI network autocorrelation in hierarchical multi-label classification trees for gene function prediction

    PubMed Central

    2013-01-01

    Background Ontologies and catalogs of gene functions, such as the Gene Ontology (GO) and MIPS-FUN, assume that functional classes are organized hierarchically, that is, general functions include more specific ones. This has recently motivated the development of several machine learning algorithms for gene function prediction that leverages on this hierarchical organization where instances may belong to multiple classes. In addition, it is possible to exploit relationships among examples, since it is plausible that related genes tend to share functional annotations. Although these relationships have been identified and extensively studied in the area of protein-protein interaction (PPI) networks, they have not received much attention in hierarchical and multi-class gene function prediction. Relations between genes introduce autocorrelation in functional annotations and violate the assumption that instances are independently and identically distributed (i.i.d.), which underlines most machine learning algorithms. Although the explicit consideration of these relations brings additional complexity to the learning process, we expect substantial benefits in predictive accuracy of learned classifiers. Results This article demonstrates the benefits (in terms of predictive accuracy) of considering autocorrelation in multi-class gene function prediction. We develop a tree-based algorithm for considering network autocorrelation in the setting of Hierarchical Multi-label Classification (HMC). We empirically evaluate the proposed algorithm, called NHMC (Network Hierarchical Multi-label Classification), on 12 yeast datasets using each of the MIPS-FUN and GO annotation schemes and exploiting 2 different PPI networks. The results clearly show that taking autocorrelation into account improves the predictive performance of the learned models for predicting gene function. Conclusions Our newly developed method for HMC takes into account network information in the learning phase: When

  9. PREFACE: PAGES 1st Young Scientists Meeting (YSM) - 'Retrospective views on our planet's future'

    NASA Astrophysics Data System (ADS)

    Cléroux, Caroline; Fehrenbacher, Jennifer; Phipps, Steven; Rupper, Summer; Williams, Branwen; Kiefer, Thorsten

    2010-03-01

    more recent pollution. The concept and format of the 1st PAGES YSM worked very well, and created a high degree of enthusiasm and stimulation among the participants (as is demonstrated by this special issue). The 2nd YSM is therefore firmly planned to take place in 2013, back-to-back with the 4th PAGES OSM. Crucial and gratefully acknowledged contributions to the success of the YSM were made by the numerous co-sponsors (see logos below), who provided the financial basis for the YSM and supported the attendance of many early-career researchers from various parts of the world. Furthermore, we cordially thank all reviewers for shaping this proceeding issue with their insightful and helpful reviews. Conference photograph

  10. Educational impact of a clinical anatomy workshop on 1st-year orthopedic and rheumatology fellows in Mexico City.

    PubMed

    Saavedra, M A; Villaseñor-Ovies, P; Harfush, L A; Navarro-Zarza, J E; Canoso, J J; Cruz-Domínguez, P; Vargas, A; Hernández-Díaz, C; Chiapas-Gasca, K; Camacho-Galindo, J; Alvarez-Nemegyei, J; Kalish, R A

    2016-05-01

    We aim to study the educational impact of a clinical anatomy workshop in 1st-year orthopedic and rheumatology fellows. First-year rheumatology fellows (N = 17) and a convenience sample of 1st-year orthopedic fellows (N = 14) from Mexico City in the 9th month of training participated in the study. The pre- and the post- workshop tests included the same 20 questions that had to be answered by identification or demonstration of relevant anatomical items. The questions, arranged by anatomical regions, were asked in five dynamic stations. Overall, the 31 participants showed an increase of correct answers, from a median of 6 (range 1 to 12) in the pre-workshop test, to a median of 14 (range 7 to 19) in the post-workshop test. In the pre-workshop test, the correct median answers were 7 (range 2 to 12) in the orthopedic fellows and 5 (range 1 to 10) in the rheumatology fellows (p = 0.297). Corresponding scores in the post-workshop were 15 (range 10 to 19) and 12 (range 7 to 18) (p = 0.026) showing a significant difference favoring the orthopedic group. Our clinical anatomy workshop was efficacious, in the short term, as a teaching instrument for 1st-year orthopedic and rheumatology fellows. The post-workshop scores, although significantly improved in both groups, particularly in the orthopedic fellows, were still suboptimal. Further refinements of our workshop might yield better results. PMID:26400643

  11. A Predictive Risk Model for A(H7N9) Human Infections Based on Spatial-Temporal Autocorrelation and Risk Factors: China, 2013-2014.

    PubMed

    Dong, Wen; Yang, Kun; Xu, Quan-Li; Yang, Yu-Lian

    2015-12-01

    This study investigated the spatial distribution, spatial autocorrelation, temporal cluster, spatial-temporal autocorrelation and probable risk factors of H7N9 outbreaks in humans from March 2013 to December 2014 in China. The results showed that the epidemic spread with significant spatial-temporal autocorrelation. In order to describe the spatial-temporal autocorrelation of H7N9, an improved model was developed by introducing a spatial-temporal factor in this paper. Logistic regression analyses were utilized to investigate the risk factors associated with their distribution, and nine risk factors were significantly associated with the occurrence of A(H7N9) human infections: the spatial-temporal factor φ (OR = 2546669.382, p < 0.001), migration route (OR = 0.993, p < 0.01), river (OR = 0.861, p < 0.001), lake(OR = 0.992, p < 0.001), road (OR = 0.906, p < 0.001), railway (OR = 0.980, p < 0.001), temperature (OR = 1.170, p < 0.01), precipitation (OR = 0.615, p < 0.001) and relative humidity (OR = 1.337, p < 0.001). The improved model obtained a better prediction performance and a higher fitting accuracy than the traditional model: in the improved model 90.1% (91/101) of the cases during February 2014 occurred in the high risk areas (the predictive risk > 0.70) of the predictive risk map, whereas 44.6% (45/101) of which overlaid on the high risk areas (the predictive risk > 0.70) for the traditional model, and the fitting accuracy of the improved model was 91.6% which was superior to the traditional model (86.1%). The predictive risk map generated based on the improved model revealed that the east and southeast of China were the high risk areas of A(H7N9) human infections in February 2014. These results provided baseline data for the control and prevention of future human infections. PMID:26633446

  12. A Predictive Risk Model for A(H7N9) Human Infections Based on Spatial-Temporal Autocorrelation and Risk Factors: China, 2013–2014

    PubMed Central

    Dong, Wen; Yang, Kun; Xu, Quan-Li; Yang, Yu-Lian

    2015-01-01

    This study investigated the spatial distribution, spatial autocorrelation, temporal cluster, spatial-temporal autocorrelation and probable risk factors of H7N9 outbreaks in humans from March 2013 to December 2014 in China. The results showed that the epidemic spread with significant spatial-temporal autocorrelation. In order to describe the spatial-temporal autocorrelation of H7N9, an improved model was developed by introducing a spatial-temporal factor in this paper. Logistic regression analyses were utilized to investigate the risk factors associated with their distribution, and nine risk factors were significantly associated with the occurrence of A(H7N9) human infections: the spatial-temporal factor φ (OR = 2546669.382, p < 0.001), migration route (OR = 0.993, p < 0.01), river (OR = 0.861, p < 0.001), lake(OR = 0.992, p < 0.001), road (OR = 0.906, p < 0.001), railway (OR = 0.980, p < 0.001), temperature (OR = 1.170, p < 0.01), precipitation (OR = 0.615, p < 0.001) and relative humidity (OR = 1.337, p < 0.001). The improved model obtained a better prediction performance and a higher fitting accuracy than the traditional model: in the improved model 90.1% (91/101) of the cases during February 2014 occurred in the high risk areas (the predictive risk > 0.70) of the predictive risk map, whereas 44.6% (45/101) of which overlaid on the high risk areas (the predictive risk > 0.70) for the traditional model, and the fitting accuracy of the improved model was 91.6% which was superior to the traditional model (86.1%). The predictive risk map generated based on the improved model revealed that the east and southeast of China were the high risk areas of A(H7N9) human infections in February 2014. These results provided baseline data for the control and prevention of future human infections. PMID:26633446

  13. Positron-electron autocorrelation function study of E-center in silicon

    NASA Astrophysics Data System (ADS)

    Ho, K. F.; Ching, H. M.; Beling, C. D.; Fung, S.; Ng, K. P.; Biasini, M.; Ferro, G.; Gong, M.

    2003-11-01

    Two-dimensional angular correlation of annihilation radiation (2D-ACAR) spectra have been taken for 1019cm-3 phosphorus-doped Si in the as-grown state after having been subjected to 1.8 MeV electron fluences of 1×1018 and 2×1018 cm-2. Positron annihilation lifetime spectroscopy confirms, in accordance with previous works, that positrons are saturation trapping into (VSi:P) pair defect (E-center) monovacancy sites in the electron irradiated samples. In the as-grown case, the positron-electron autocorrelation functions along the [111] and [1-10] directions, obtained through Fourier transformation of the 2D-ACAR data, reveal zero-crossings that deviate only slightly from the lattice points, in a manner consistent with positron-electron correlation effects. Conversely, in the spectra of the irradiated samples, the zero-crossing points are observed to move outward further by between 0.15 and 0.50 Å. This displacement is associated with positron annihilation with electrons in localized orbitals at the defect site. An attempt is made to extract just the component of the defect's positron-electron autocorrelation function that relates to the localized defect orbitals. In doing this features are found that correspond to the expected atomic positions at the vacancy defect site suggesting that this real-space function may provide a convenient means for obtaining a mapping of localized orbitals. The observed approximate separability of positron and electron wave-function autocorrelates leads to an estimate of 0.22 eV for the positron binding energy to the E-center.

  14. Structure of the North Anatolian Fault Zone from the Autocorrelation of Ambient Seismic Noise

    NASA Astrophysics Data System (ADS)

    Taylor, George; Rost, Sebastian; Houseman, Gregory

    2016-04-01

    In recent years the technique of cross-correlating the ambient seismic noise wavefield at two seismometers to reconstruct empirical Green's Functions for the determination of Earth structure has been a powerful tool to study the Earth's interior without earthquakes or man-made sources. However, far less attention has been paid to using auto-correlations of seismic noise to reveal body wave reflections from interfaces in the subsurface. In principle, the Green's functions thus derived should be comparable to the Earth's impulse response to a co-located source and receiver. We use data from a dense seismic array (Dense Array for Northern Anatolia - DANA) deployed across the northern branch of the North Anatolian Fault Zone (NAFZ) in the region of the 1999 magnitude 7.6 Izmit earthquake in western Turkey. The NAFZ is a major strike-slip system that extends ~1200 km across northern Turkey and continues to pose a high level of seismic hazard, in particular to the mega-city of Istanbul. We construct body wave images for the entire crust and the shallow upper mantle over the ~35 km by 70 km footprint of the 70-station DANA array. Using autocorrelations of the vertical component of ground motion, P-wave reflections can be retrieved from the wavefield to constrain crustal structure. We show that clear P-wave reflections from the crust-mantle boundary (Moho) can be retrieved using the autocorrelation technique, indicating topography on the Moho on horizontal scales of less than 10 km. Offsets in crustal structure can be identified that seem to be correlated with the surface expression of the northern branch of the fault zone, indicating that the NAFZ reaches the upper mantle as a narrow structure. The southern branch has a less clear effect on crustal structure. We also see evidence of several discontinuities in the mid-crust in addition to an upper mantle reflector that we interpret to represent the Hales discontinuity.

  15. Evaluation of an Extended Autocorrelation Phase Estimator for Ultrasonic Velocity Profiles Using Nondestructive Testing Systems.

    PubMed

    Ofuchi, César Yutaka; Coutinho, Fabio Rizental; Neves, Flávio; de Arruda, Lucia Valéria Ramos; Morales, Rigoberto Eleazar Melgarejo

    2016-01-01

    In this paper the extended autocorrelation velocity estimator is evaluated and compared using a nondestructive ultrasonic device. For this purpose, three velocity estimators are evaluated and compared. The autocorrelation method (ACM) is the most used and well established in current ultrasonic velocity profiler technology, however, the technique suffers with phase aliasing (also known as the Nyquist limit) at higher velocities. The cross-correlation method (CCM) is also well known and does not suffer with phase aliasing as it relies on time shift measurements between emissions. The problem of this method is the large computational burden due to several required mathematical operations. Recently, an extended autocorrelation method (EAM) which combines both ACM and CCM was developed. The technique is not well known within the fluid engineering community, but it can measure velocities beyond the Nyquist limit without the ACM phase aliasing issues and with a lower computational cost than CCM. In this work, all three velocity estimation methods are used to measure a uniform flow of the liquid inside a controlled rotating cylinder. The root-mean-square deviation variation coefficient (CVRMSD) of the velocity estimate and the reference cylinder velocity was used to evaluate the three different methods. Results show that EAM correctly measures velocities below the Nyquist limit with less than 2% CVRMSD. Velocities beyond the Nyquist limit are only measured well by EAM and CCM, with the advantage of the former of being computationally 15 times faster. Furthermore, the maximum value of measurable velocity is also investigated considering the number of times the velocity surpasses the Nyquist limit. The combination of number of pulses and number of samples, which highly affects the results, are also studied in this work. Velocities up to six times the Nyquist limit could be measurable with CCM and EAM using a set of parameters as suggested in this work. The results validate

  16. Identification and Characterization of Zebrafish SULT1 ST9, SULT3 ST4, and SULT3 ST5

    PubMed Central

    Mohammed, Yasir I.; Kurogi, Katsuhisa; Shaban, Amani Al; Xu, Zheng; Liu, Ming-Yih; Williams, Frederick E.; Sakakibara, Yoichi; Suiko, Masahito; Bhuiyan, Shakhawat; Liu, Ming-Cheh

    2012-01-01

    By searching the GenBank database, we identified sequences encoding three new zebrafish cytosolic sulfotransferases (SULTs). These three new zebrafish SULTs, designated SULT1 ST9, SULT3 ST4, and SULT3 ST5, were cloned, expressed, purified, and characterized. SULT1 ST9 appeared to be mostly involved in the metabolism and detoxification of xenobiotics such as β-naphthol, β-naphthylamine, caffeic acid and gallic acid. SULT3 ST4 showed strong activity toward endogenous compound such as dehydroepiandrosterone (DHEA), pregnenolone, and 17β-estradiol. SULT3 ST5 showed weaker, but significant, activities toward endogenous compounds such as DHEA and corticosterone, as well as xenobiotics including mestranol, β-naphthylamine, β-naphthol, and butylated hydroxyl anisole (BHA). pH-dependency and kinetic constants of these three enzymes were determined with DHEA, β-naphthol, and 17β-estradiol as substrates. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to examine the expression of these three new zebrafish SULTs at different developmental stages during embryogenesis, through larval development, and on to maturity. PMID:22360938

  17. Attitudes towards General Practice: a comparative cross-sectional survey of 1st and 5th year medical students

    PubMed Central

    Kruschinski, Carsten; Wiese, Birgitt; Hummers-Pradier, Eva

    2012-01-01

    Objective: Positive attitudes towards General Practice can be understood as a prerequisite for becoming a General Practitioner (GP) and for collaboration with GPs later on. This study aimed to assess attitudes of medical students at the beginning and the end of medical school. Methods: A total of 160 1st year students at Hannover Medical School were surveyed. Their attitudes were compared to those of 287 5th year students. Descriptive, bi- and multivariate analyses were performed to investigate influences of year of study and gender. Results: Year of study and gender both were associated with the attitudes towards General Practice. The interest in General Practice and patient-orientation (communication, care of older patients with chronic diseases) was higher in 1st year students compared to more advanced students. Female students valued such requirements more than male students, the differences in attitudes between the years of study being more pronounced in male students. Conclusion: Despite some limitations caused by the cross-sectional design, the attitudes towards General Practice competencies changed to their disadvantage during medical school. This suggests a formative influence of the strategies used in medical education. Educational strategies, however, could be used to bring about a change of attitudes in the other direction. PMID:23255966

  18. BMI differences in 1st and 2nd generation immigrants of Asian and European origin to Australia.

    PubMed

    Hauck, Katharina; Hollingsworth, Bruce; Morgan, Lawrie

    2011-01-01

    We estimate assimilation of immigrants' body mass index (BMI) to the host population of Australia over one generation, conducting separate analyses for immigrants from 7 regions of Europe and Asia. We use quantile regressions to allow for differing impact of generational status across 19 quantiles of BMI from under-weight to morbidly obese individuals. We find that 1st generation South European immigrants have higher, and South and East Asian immigrants have lower BMI than Australians, but have assimilated to the BMI of their hosts in the 2nd generation. There are no or only small BMI differences between Australians and 1st and 2nd generation immigrants from East Europe, North-West Europe, Middle East and Pacific regions. We conclude that both upward and downward assimilation in some immigrant groups is most likely caused by factors which can change over one generation (such as acculturation), and not factors which would take longer to change (such as genetics). Our results suggest that public health policies targeting the lifestyles of well educated Asian immigrants may be effective in preventing BMI increase in this subgroup. PMID:20869292

  19. Blending vocal music with a given sound field due to the characteristics of the running autocorrelation function of singing voices

    NASA Astrophysics Data System (ADS)

    Kato, Kosuke; Fujii, Kenji; Kawai, Keiji; Ando, Yoichi; Yano, Takashi

    2001-05-01

    This is a study to meet music and the opera house acoustics. It is said that singers adjust their interpretation style according to the acoustical condition of the sound field in a room. However, this mechanism of blending of musical performance with the sound field is unknown. In order to obtain a method of performance blending of opera house acoustics, we attempted to develop evaluation criteria for a singing voice in terms of the minimum value of the effective duration of the running autocorrelation function (r-ACF), (te)min, of sound source signals. This temporal factor has shown to have close correlation with the subjective response of both listeners and performers to sound fields [Y. Ando, Architectural Acoustics (AIP Press/Springer-Verlag, New York, 1998)]. As example for the control of (te)min due to performing style, effects of singing style, kind of vowel, relative pitch, vibrato extent, and intonation on the values of (te)min are demonstrated. In addition, the fine structure of the r-ACF is discussed with regard to the identification of vowels of singing voice. a)Now at 1-10-27 Yamanokami, Kumamoto, Japan.

  20. Sign reversals of the output autocorrelation function for the stochastic Bernoulli-Verhulst equation

    SciTech Connect

    Lumi, N. Mankin, R.

    2015-10-28

    We consider a stochastic Bernoulli-Verhulst equation as a model for population growth processes. The effect of fluctuating environment on the carrying capacity of a population is modeled as colored dichotomous noise. Relying on the composite master equation an explicit expression for the stationary autocorrelation function (ACF) of population sizes is found. On the basis of this expression a nonmonotonic decay of the ACF by increasing lag-time is shown. Moreover, in a certain regime of the noise parameters the ACF demonstrates anticorrelation as well as related sign reversals at some values of the lag-time. The conditions for the appearance of this highly unexpected effect are also discussed.

  1. New autocorrelation technique for the IR FEL optical pulse width measurements

    SciTech Connect

    Amirmadhi, F.; Brau, K.A.; Becker, C.

    1995-12-31

    We have developed a new technique for the autocorrelation measurement of optical pulse width at the Vanderbilt University FEL center. This method is based on nonlinear absorption and transmission characteristics of semiconductors such as Ge, Te and InAs suitable for the wavelength range from 2 to over 6 microns. This approach, aside being simple and low cost, removes the phase matching condition that is generally required for the standard frequency doubling technique and covers a greater wavelength range per nonlinear material. In this paper we will describe the apparatus, explain the principal mechanism involved and compare data which have been acquired with both frequency doubling and two-photon absorption.

  2. Autocorrelation and Error Structure of Rainfall Derived from NEXRAD in Central and South Florida

    NASA Astrophysics Data System (ADS)

    Pathak, C. S.; Vieux, B. E.

    2007-12-01

    Motivation for this study comes from the South Florida Water Management District (District) who is responsible for managing water resources in 16-counties over a 46,439-square kilometer (17,930 square-mile) area. Near-real- time rainfall data are used in operation of approximately 3,000 kilometers (~1,800 miles) of canals, 22 major pump stations and 200 water control structures. The spatial extent of the District extends from Orlando to Key West and from the Gulf Coast to the Atlantic Ocean and contains major water features including Lake Okeechobee and the Everglades wetlands. Rainfall is a key factor in the water management decisions made by the District in real-time and through studies that rely on archival rainfall data derived from radar and rain gauge observations. Rainfall measurements are obtained from a combination of four NEXRAD radars and a rain gauge network that comprises 280 active rain gauge stations located in the more populated areas. Four NEXRAD (Next Generation Weather Radar) sites operated by the National Weather Service cover the region. Rain gauges are used for frequency analysis and for adjustment of the radar rainfall products. An optimization study of the rain gauge network is accomplished by removing gauges in areas of excess coverage, and by adding or moving rain gauges to gain a more even spatial distribution over the District. Rainfall fields measured at daily and hourly timesteps exhibit autocorrelation which can affect the network design subject to optimality constraints. This presentation will describe the autocorrelation and error structure found in rainfall measurements derived from rain gage and NEXRAD data. The data used in the analysis includes rain gage data and the NEXRAD rainfall data that was collected during 1995-2005 at 2 x 2 km resolution. A set of clusters of rain gages and a regular array of analysis blocks that were 20 x 20 km in size for the NEXRAD data were used to account for variability of the rainfall processes

  3. Autocorrelation Analysis of Hipparcos Photometry of Short-Period Be Stars

    NASA Astrophysics Data System (ADS)

    Percy, John R.; Hosick, JoAnne; Kincaide, Heather; Pang, Ceci

    2002-05-01

    We have used Hipparcos epoch photometry and a form of autocorrelation analysis to investigate the amplitude and timescale of the short-period variability of 82 Be stars, including 46 Be stars that were analyzed by Hubert & Floquet using Fourier and CLEAN analysis and 36 other Be stars that were suspected of short-period variability. Our method has given useful information for about 84% of these stars; for the rest, the time distribution of the Hipparcos epoch photometry limits the capability of our technique.

  4. Microfluidic volumetric flow determination using optical coherence tomography speckle: An autocorrelation approach

    NASA Astrophysics Data System (ADS)

    De Pretto, Lucas R.; Nogueira, Gesse E. C.; Freitas, Anderson Z.

    2016-04-01

    Functional modalities of Optical Coherence Tomography (OCT) based on speckle analysis are emerging in the literature. We propose a simple approach to the autocorrelation of OCT signal to enable volumetric flow rate differentiation, based on decorrelation time. Our results show that this technique could distinguish flows separated by 3 μl/min, limited by the acquisition speed of the system. We further perform a B-scan of gradient flow inside a microchannel, enabling the visualization of the drag effect on the walls.

  5. Bit corruption correlation and autocorrelation in a stochastic binary nano-bit system

    NASA Astrophysics Data System (ADS)

    Sa-nguansin, Suchittra

    2014-10-01

    The corruption process of a binary nano-bit model resulting from an interaction with N stochastically-independent Brownian agents (BAs) is studied with the help of Monte-Carlo simulations and analytic continuum theory to investigate the data corruption process through the measurement of the spatial two-point correlation and the autocorrelation of bit corruption at the origin. By taking into account a more realistic correlation between bits, this work will contribute to the understanding of the soft error or the corruption of data stored in nano-scale devices.

  6. 77 FR 39215 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Advance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... Countervailing Duty Orders; Policy Bulletin, 63 FR 18871 (April 16, 1998). The Notice of Initiation of Five-Year... Investigations Lemon Juice from Argentina (A-357-818) (1st Sally Gannon Review). (202) 482-0162 Lemon Juice...

  7. 77 FR 5485 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Advance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... Five-Year Sunset Reviews. Antidumping Duty Proceedings Activated Carbon From China (A-570-904) (1st... Countervailing Duty Orders; Policy Bulletin, 63 FR 18871 (April 16, 1998). The Notice of Initiation of...

  8. 78 FR 46575 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Advance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... (``Sunset'') Reviews of Antidumping and Countervailing Duty Orders; Policy Bulletin, 63 FR 18871 (April 16... Garment Hangers Jennifer Moats (202) 482-5047. from China (A-570-918) (1st Review). Countervailing...

  9. The efficiency of second order orientation coherence detection.

    PubMed

    Baldwin, Alex S; Husk, Jesse S; Edwards, Lauren; Hess, Robert F

    2015-04-01

    Neurons in early visual cortex respond to both luminance- (1st order) and contrast-modulated (2nd order) local features in the visual field. In later extra-striate areas neurons with larger receptive fields integrate information across the visual field. For example, local luminance-defined features can be integrated into contours and shapes. Evidence for the global integration of features defined by contrast-modulation is less well established. While good performance in some shape tasks has been demonstrated with 2nd order stimuli, the integration of contours fails with 2nd order elements. Recently we developed a global orientation coherence task that is more basic than contour integration, bearing similarity to the well-established global motion coherence task. Similar to our previous 1st order result for this task, we find 2nd order coherence detection to be scale-invariant. There was a small but significant threshold elevation for 2nd order relative to 1st order. We used a noise masking approach to compare the efficiency of orientation integration for the 1st and 2nd order. We find a significant deficit for 2nd order detection at both the local and global level, however the small size of this effect stands in stark contrast against previous results from contour-integration experiments, which are almost impossible with 2nd order stimuli. PMID:25749675

  10. A Robust Spectrum Sensing Method Based on Maximum Cyclic Autocorrelation Selection for Dynamic Spectrum Access

    NASA Astrophysics Data System (ADS)

    Muraoka, Kazushi; Ariyoshi, Masayuki; Fujii, Takeo

    Spectrum sensing is an important function for dynamic spectrum access (DSA) type cognitive radio systems to detect opportunities for sharing the spectrum with a primary system. The key requirements for spectrum sensing are stability in controlling the probability of false alarm as well as detection performance of the primary signals. However, false alarms can be triggered by noise uncertainty at the secondary devices or unknown interference signals from other secondary systems in realistic radio environments. This paper proposes a robust spectrum sensing method against such uncertainties; it is a kind of cyclostationary feature detection (CFD) approaches. Our proposed method, referred to as maximum cyclic autocorrelation selection (MCAS), compares the peak and non-peak values of the cyclic autocorrelation function (CAF) to detect primary signals, where the non-peak value is the CAF value calculated at cyclic frequencies between the peaks. In MCAS, the desired probability of false alarm can be obtained by setting the number of the non-peak values. In addition, the multiple peak values are combined in MCAS to obtain noise reduction effect and coherent combining gain. Through computer simulations, we show that MCAS can control the probability of false alarm under the condition of noise uncertainty and interference. Furthermore, our method achieves better performance with much less computational complexity in comparison to conventional CFD methods.

  11. Application of a Modified Self-Organizing Map Incorporating Auto-Correlated Data for Hydrochemical Analyses

    NASA Astrophysics Data System (ADS)

    Pearce, A. R.; Watzin, M. C.; Rizzo, D. M.

    2008-12-01

    We modified a self-organizing map (SOM), a clustering artificial neural network, using variogram analyses to incorporate the spatial and temporal auto-correlation that exists in many surface and subsurface environmental datasets. The SOM reduces the dimensionality and clusters the data. The SOM is particularly effective with multiple data types (e.g. continuous, discrete and categorical variables). The standard SOM algorithm iteratively updates connection weights between the input parameters and the two-dimensional output mapping over a specified region of the estimation field. The method accounts for the anisotropy found in geologic and hydrologic datasets. The algorithm is tested on a unique dataset collected from a slab of Berea sandstone (1 m by 0.4 m). Air permeability, electrical resistivity and compressional wave velocity were measured on a 3 mm rectangular grid. Sparse testing data were drawn randomly from this exhaustive dataset for validating the new computational methods. We apply the method using biogeochemical data collected along a transect between the Vermont and New York shorelines of Lake Champlain, to demonstrate the ability to discriminate between different functional zones in the lake. This clustering method could be applied to a variety of terrestrial, aquatic, or subsurface biogeochemical or geophysical problems. Considering spatial auto-correlation in delineating regions or zones in environmental systems creates more accurate estimations.

  12. Spatial Pattern Analysis of Heavy Metals in Beijing Agricultural Soils Based on Spatial Autocorrelation Statistics

    PubMed Central

    Huo, Xiao-Ni; Zhang, Wei-Wei; Sun, Dan-Feng; Li, Hong; Zhou, Lian-Di; Li, Bao-Guo

    2011-01-01

    This study explored the spatial pattern of heavy metals in Beijing agricultural soils using Moran’s I statistic of spatial autocorrelation. The global Moran’s I result showed that the spatial dependence of Cr, Ni, Zn, and Hg changed with different spatial weight matrixes, and they had significant and positive global spatial correlations based on distance weight. The spatial dependence of the four metals was scale-dependent on distance, but these scale effects existed within a threshold distance of 13 km, 32 km, 50 km, and 29 km, respectively for Cr, Ni, Zn, and Hg. The maximal spatial positive correlation range was 57 km, 70 km, 57 km, and 55 km for Cr, Ni, Zn, and Hg, respectively and these were not affected by sampling density. Local spatial autocorrelation analysis detected the locations of spatial clusters and spatial outliers and revealed that the pollution of these four metals occurred in significant High-high spatial clusters, Low-high, or even High-low spatial outliers. Thus, three major areas were identified and should be receiving more attention: the first was the northeast region of Beijing, where Cr, Zn, Ni, and Hg had significant increases. The second was the southeast region of Beijing where wastewater irrigation had strongly changed the content of metals, particularly of Cr and Zn, in soils. The third area was the urban fringe around city, where Hg showed a significant increase. PMID:21776217

  13. Comparison of Kasai Autocorrelation and Maximum Likelihood Estimators for Doppler Optical Coherence Tomography

    PubMed Central

    Chan, Aaron C.; Srinivasan, Vivek J.

    2013-01-01

    In optical coherence tomography (OCT) and ultrasound, unbiased Doppler frequency estimators with low variance are desirable for blood velocity estimation. Hardware improvements in OCT mean that ever higher acquisition rates are possible, which should also, in principle, improve estimation performance. Paradoxically, however, the widely used Kasai autocorrelation estimator’s performance worsens with increasing acquisition rate. We propose that parametric estimators based on accurate models of noise statistics can offer better performance. We derive a maximum likelihood estimator (MLE) based on a simple additive white Gaussian noise model, and show that it can outperform the Kasai autocorrelation estimator. In addition, we also derive the Cramer Rao lower bound (CRLB), and show that the variance of the MLE approaches the CRLB for moderate data lengths and noise levels. We note that the MLE performance improves with longer acquisition time, and remains constant or improves with higher acquisition rates. These qualities may make it a preferred technique as OCT imaging speed continues to improve. Finally, our work motivates the development of more general parametric estimators based on statistical models of decorrelation noise. PMID:23446044

  14. Dispersal leads to spatial autocorrelation in species distributions: A simulation model

    USGS Publications Warehouse

    Bahn, V.; Krohn, W.B.; O'Connor, R.J.

    2008-01-01

    Compared to population growth regulated by local conditions, dispersal has been underappreciated as a central process shaping the spatial distribution of populations. This paper asks: (a) which conditions increase the importance of dispersers relative to local recruits in determining population sizes? and (b) how does dispersal influence the spatial distribution patterns of abundances among connected populations? We approached these questions with a simulation model of populations on a coupled lattice with cells of continuously varying habitat quality expressed as carrying capacities. Each cell contained a population with the basic dynamics of density-regulated growth, and was connected to other populations by immigration and emigration. The degree to which dispersal influenced the distribution of population sizes depended most strongly on the absolute amount of dispersal, and then on the potential population growth rate. Dispersal decaying in intensity with distance left close neighbours more alike in population size than distant populations, leading to an increase in spatial autocorrelation. The spatial distribution of species with low potential growth rates is more dependent on dispersal than that of species with high growth rates; therefore, distribution modelling for species with low growth rates requires particular attention to autocorrelation, and conservation management of these species requires attention to factors curtailing dispersal, such as fragmentation and dispersal barriers. ?? 2007 Elsevier B.V. All rights reserved.

  15. Autocorrelation based denoising of manatee vocalizations using the undecimated discrete wavelet transform.

    PubMed

    Gur, Berke M; Niezrecki, Christopher

    2007-07-01

    Recent interest in the West Indian manatee (Trichechus manatus latirostris) vocalizations has been primarily induced by an effort to reduce manatee mortality rates due to watercraft collisions. A warning system based on passive acoustic detection of manatee vocalizations is desired. The success and feasibility of such a system depends on effective denoising of the vocalizations in the presence of high levels of background noise. In the last decade, simple and effective wavelet domain nonlinear denoising methods have emerged as an alternative to linear estimation methods. However, the denoising performances of these methods degrades considerably with decreasing signal-to-noise ratio (SNR) and therefore are not suited for denoising manatee vocalizations in which the typical SNR is below 0 dB. Manatee vocalizations possess a strong harmonic content and a slow decaying autocorrelation function. In this paper, an efficient denoising scheme that exploits both the autocorrelation function of manatee vocalizations and effectiveness of the nonlinear wavelet transform based denoising algorithms is introduced. The suggested wavelet-based denoising algorithm is shown to outperform linear filtering methods, extending the detection range of vocalizations. PMID:17614478

  16. Impact of volcanic eruptions on the climate of the 1st millennium AD in a comprehensive climate simulation

    NASA Astrophysics Data System (ADS)

    Wagner, Sebastian; Zorita, Eduardo

    2015-04-01

    The climate of the 1st millennium AD shows some remarkable differences compared to the last millennium concerning variation in external forcings. Together with an orbitally induced increased solar insolation during the northern hemisphere summer season and a general lack of strong solar minima, the frequency and intensity of large tropical and extratropical eruptions is decreased. Here we present results of a new climate simulation carried out with the comprehensive Earth System Model MPI-ESM-P forced with variations in orbital, solar, volcanic and greenhouse gas variations and land use changes for the last 2,100 years. The atmospheric model has a horizontal resolution of T63 (approx. 125x125 km) and therefore also allows investigations of regional-to-continental scale climatic phenomena. The volcanic forcing was reconstructed based on a publication by Sigl et al. (2013) using the sulfate records of the NEEM and WAIS ice cores. To obtain information on the aerosol optical depth (AOD) these sulfate records were scaled to an established reconstruction from Crowley and Unterman (2010), which is also a standard forcing in the framework of CMIP5/PMIP3. A comparison between the newly created data set with the Crowley and Unterman dataset reveals that the new reconstruction shows in general weaker intensities, especially of the large tropical outbreaks and fewer northern hemispheric small-to-medium scale eruptions. However, the general pattern in the overlapping period is similar. A hypothesis that can be tested with the simulation is whether the reduced volcanic intensity of the 1st millennium AD contributed to the elevated temperature levels over Europe, evident within a new proxy-based reconstruction. On the other hand, the few but large volcanic eruptions, e.g. the 528 AD event, also induced negative decadal-scale temperature anomalies. Another interesting result of the simulation relates to the 79 AD eruption of the Vesuvius, which caused the collapse of the city of

  17. Plasma properties from the multi-wavelength analysis of the November 1st 2003 CME/shock event

    PubMed Central

    Benna, Carlo; Mancuso, Salvatore; Giordano, Silvio; Gioannini, Lorenzo

    2012-01-01

    The analysis of the spectral properties and dynamic evolution of a CME/shock event observed on November 1st 2003 in white-light by the LASCO coronagraph and in the ultraviolet by the UVCS instrument operating aboard SOHO, has been performed to compute the properties of some important plasma parameters in the middle corona below about 2R⊙. Simultaneous observations obtained with the MLSO/Mk4 white-light coronagraph, providing both the early evolution of the CME expansion in the corona and the pre-shock electron density profile along the CME front, were also used to study this event. By combining the above information with the analysis of the metric type II radio emission detected by ground-based radio spectrographs, we finally derive estimates of the values of the local Alfvén speed and magnetic field strength in the solar corona. PMID:25685432

  18. Seismic Interferometry and the Spatial Auto-Correlation Method on the Regional Coda of the Non-Proliferation Experiment

    NASA Astrophysics Data System (ADS)

    de Ridder, S.; Prieto, G. A.

    2008-12-01

    A seismic recording of the non-proliferation experiment (NPE), made by a petroleum-exploration company in Railroad Valley (Nevada), contains the first break of the regional P phases followed by a three minute long coda. The transverse orientation and sign-bit recording of the array, renders distinguishing phase arrival times difficult. This motivates the use of seismic interferometry. The geometry does not permit recovering the Green's function from the first break arrival times using the stationary phase theorem, however the coda contains sufficiently equipartitioned energy. We study the result of seismic interferometry in the frequency-domain. This procedure is analogous to the spatial auto-correlation (SPAC) method, devised for studying microtremors by Aki in 1957. Cross-correlating two receiver stations retrieves, under favorable circumstances, an approximation of the Green's function between these two stations. To first order, this Green's function consists of a direct event traveling between the receivers. In the frequency domain, the lowest mode in the Green's function is a weighted and scaled zero-order Bessel function of the first kind, J0. We fit the frequency-domain of the recovered Green's functions to damped J0 functions. to recover phase velocity and estimates of the attenuation coefficients. Only energy between 1-4 Hz can be fitted unambiguously with J0 functions, because higher frequencies contain too much spurious energy. This result shows the equivalence of the SPAC method and seismic interferometry for the lowest mode in the Green's function. This study also shows how the coda of a regional event, seemingly unfavorably positioned, can contains energy useful for seismic interferometry.

  19. Levels of innate immune factors in preterm and term mothers' breast milk during the 1st month postpartum.

    PubMed

    Trend, Stephanie; Strunk, Tobias; Lloyd, Megan L; Kok, Chooi Heen; Metcalfe, Jessica; Geddes, Donna T; Lai, Ching Tat; Richmond, Peter; Doherty, Dorota A; Simmer, Karen; Currie, Andrew

    2016-04-14

    There is a paucity of data on the effect of preterm birth on the immunological composition of breast milk throughout the different stages of lactation. We aimed to characterise the effects of preterm birth on the levels of immune factors in milk during the 1st month postpartum, to determine whether preterm milk is deficient in antimicrobial factors. Colostrum (days 2-5 postpartum), transitional milk (days 8-12) and mature milk (days 26-30) were collected from mothers of extremely preterm (<28 weeks of gestation, n 15), very preterm (28-<32 weeks of gestation, n 15), moderately preterm (32-<37 weeks of gestation, n 15) and term infants (37-41 weeks of gestation, n 15). Total protein, lactoferrin, secretory IgA, soluble CD14 receptor (sCD14), transforming growth factor-β2 (TGF-β2), α defensin 5 (HD5), β defensins 1 (HBD1) and 2, IL-6, IL-10, IL-13, interferon-γ, TNF-α and lysozyme (LZ) were quantified in milk. We examined the effects of lactation stage, gestational age, volume of milk expressed, mode of delivery, parity and maternal infection on milk immune factor concentrations using repeated-measures regression analysis. The concentrations of all factors except LZ and HD5 decreased over the 1st month postpartum. Extremely preterm mothers had significantly higher concentrations of HBD1 and TGF-β2 in colostrum than term mothers did. After controlling for other variables in regression analyses, preterm birth was associated with higher concentrations of HBD1, LZ and sCD14 in milk samples. In conclusion, preterm breast milk contains significantly higher concentrations of some immune proteins than term breast milk. PMID:26891901

  20. A decadal gridded hyperspectral infrared record for climate Sep 1st 2002--Aug 31st 2012

    NASA Astrophysics Data System (ADS)

    Chapman, David Raymond

    We present a gridded Fundamental Decadal Data Record (FDDR) of Brightness Temperatures (BT) from the NASA Atmospheric Infrared Sounder (AIRS) from ten years of hyperspectral Infrared Radiances onboard the NASA EOS Aqua satellite. Although global surface temperature data records are available for over 130 years, it was not until 1978 when the Microwave Sounding Unit (MSU) was the first instrument series to reliably monitor long-term trends of the upper atmosphere. AIRS, operational on September 1, 2002 is the first successful hyperspectral satellite weather instrument of more than 1 year, and provides a 10 year global hyperspectral IR radiance data record. Our contribution was to prepare a gridded decadal data record of climate resolution from the AIRS Outgoing Longwave Spectrum (OLS). In order to do this, we developed a robust software infrastructure "Gridderama" using large multivariate array storage to facilitate this multi-terabyte parallel data processing task while ensuring integrity, tracking provenance, logging errors, and providing extensive visualization. All of our data, code, logs and visualizations are freely available online and browsable via a real-time "Data Catalog" interface. We show that these global all-sky trends are consistent with the expected radiative forcings from an increase in greenhouse gasses. We have also measured high global correlations with the GISS global surface air temperatures as well as high regional anticorrelations with the NOAA ONI index of El Niño phase. In addition, we have performed inter-annual inter-comparisons with the Moderate Resolution Spectro-radiometer (MODIS) on the same Aqua satellite to examine the relative consistency of their calibrations. The comparisons of the two instruments for the 4µ spectral channels (between 3.9µ and 4.1µ) indicate an inter-annual warming of 0.13K per decade of AIRS more than MODIS. This decadal relative drift is small compared to inter-annual variability but on the order of

  1. Compact first and second order polarization mode dispersion emulator

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Li, Shiguang; Yang, Changxi

    2005-08-01

    We propose a 1st and 2nd order polarization mode dispersion emulator (PMDE) with one variable differential group delay (DGD) element using birefringence crystals and four polarization controllers (PCs). Monte Carlo simulations demonstrate that the output 1st and 2nd order polarization mode dispersion (PMD) generated by the PMDE consists with statistic theory. Compared with former PMDEs, this design is tunable, lower-cost, and more integrated for fabrication, which shows response time of 150 ?s, response frequency of 3.8 kHz, working wavelength of 1550 nm, total power consumption of less than 3 W, working range of 0---84 ps and 0---3600 ps2 for 1st and 2nd order PMD emulation, respectively. Also, it is programmable and can be controlled by either singlechip or computer. It can be applied to study the outage probability of optical communication systems due to PMD effect and the effectiveness of PMD compensation.

  2. [Spatial autocorrelation of genetic structure of Prunus padus population in broadleaved Korean pine forest of Changbai Mountains].

    PubMed

    Niu, Xiao-Min; Shi, Shuai; Wang, Zheng-Feng; Ye, Wan-Hui; Hao, Zhan-Qing

    2014-02-01

    All 396 Prunus padus individuals of the population with DBH (diameter at breast height) > or = 1 cm were sampled in a 25 hm2 broadleaved Korean pine forest plot of Changbai Mountains and divided into three DBH classes: 1-3 cm, 3-10 cm, and >10 cm. They were then genotyped using microsatellite loci. The spatial autocorrelation of their genetic structure was analyzed at different distance classes and life stages. The results showed that positive autocorrelation mainly occurred at scales less than 70 m, while negative autocorrelation occurred at scales larger than 110 m. The spatial genetic structure (SGS) at different life stages was similar due to limited pollen/seed dispersal and asexual reproduction. No significant self-thinning occurred in the studied population. PMID:24830226

  3. Social and moral norm differences among Portuguese 1st and 6th year medical students towards their intention to comply with hand hygiene.

    PubMed

    Roberto, Magda S; Mearns, Kathryn; Silva, Silvia A

    2012-01-01

    This study examines social and moral norms towards the intention to comply with hand hygiene among Portuguese medical students from 1st and 6th years (N = 175; 121 from the 1st year, 54 from the 6th year). The study extended the theory of planned behaviour theoretical principles and hypothesised that both subjective and moral norms will be the best predictors of 1st and 6th year medical students' intention to comply with hand hygiene; however, these predictors ability to explain intention variance will change according to medical students' school year. Results indicated that the subjective norm, whose referent focuses on professors, is a relevant predictor of 1st year medical students' intention, while the subjective norm that emphasises the relevance of colleagues predicts the intentions of medical students from the 6th year. In terms of the moral norm, 6th year students' intention is better predicted by a norm that interferes with compliance; whereas intentions from 1st year students are better predicted by a norm that favours compliance. Implications of the findings highlight the importance of role models and mentors as key factors in teaching hand hygiene in medical undergraduate curricula. PMID:22111788

  4. Experience from the 1st Year running a Massive High Quality Videoconferencing Service for the LHC

    NASA Astrophysics Data System (ADS)

    Fernandes, Joao; Baron, Thomas; Bompastor, Bruno

    2014-06-01

    In the last few years, we have witnessed an explosion of visual collaboration initiatives in the industry. Several advances in video services and also in their underlying infrastructure are currently improving the way people collaborate globally. These advances are creating new usage paradigms: any device in any network can be used to collaborate, in most cases with an overall high quality. To keep apace with this technology progression, the CERN IT Department launched a service based on the Vidyo product. This new service architecture introduces Adaptive Video Layering, which dynamically optimizes the video for each endpoint by leveraging the H.264 Scalable Video Coding (SVC)-based compression technology. It combines intelligent AV routing techniques with the flexibility of H.264 SVC video compression, in order to achieve resilient video collaboration over the Internet, 3G and WiFi. We present an overview of the results that have been achieved after this major change. In particular, the first year of operation of the CERN Vidyo service will be described in terms of performance and scale: The service became part of the daily activity of the LHC collaborations, reaching a monthly usage of more than 3200 meetings with a peak of 750 simultaneous connections. We also present some key features such as the integration with CERN Indico. LHC users can now join a Vidyo meeting either from their personal computer or a CERN videoconference room simply from an Indico event page, with the ease of a single click. The roadmap for future improvements, service extensions and core infrastructure tendencies such as cloud based services and virtualization of system components will also be discussed. Vidyo's strengths allowed us to build a universal service (it is accessible from PCs, but also videoconference rooms, traditional phones, tablets and smartphones), developed with 3 key ideas in mind: ease of use, full integration and high quality.

  5. Cloud 3D Effects Evidenced in Landsat Power Spectra and Autocorrelation Functions

    NASA Technical Reports Server (NTRS)

    Oreopoulos, Lazaros; Marshak, Alexander; Cahalan, Robert F.; Wen, Guoyong

    1999-01-01

    An analysis of nadir reflectivity Fourier spatial power spectra and autocorrelation functions at solar wavelengths and for cloudy conditions has been carried out. The data come from Landsat Thematic Mapper (TM) observations, while Monte Carlo (MC) simulations are used to aid the interpretation of the Landsat results. We show that radiative processes produce consistent signatures on power spectra and autocorrelation functions. The former take a variety of forms not shown or explained in previous observational studies. We demonstrate that the TM spectra can potentially be affected by both radiative "roughening" at intermediate scales (approx. 1 -5 km), being more prevalent at large solar zenith angles, and the already documented radiative "smoothing" at small scales (less than 1 km). These processes are wavelength dependent, as shown by systematic differences between conservative (for cloud droplets) TM band 4 (approx. 0.8 microns) and absorbing band 7 (approx. 2.2 microns): band 7 exhibits more roughening and less smoothing. This is confirmed quantitatively by comparing least-squared fitted power spectral slopes for the two bands. It is also corroborated by a slower decrease with distance of autocorrelation function values for band 4 compared to band 7. The appearance of roughening at large solar zenith angles is a result of side illumination and shadowing and adds an additional complexity to the power spectra. MC spectra are useful in illustrating that scale invariant optical depth fields can produce complex power spectra that take a variety of shapes under different conditions. We show that radiative roughening increases with the decrease of single scattering albedo and with the increase of solar zenith angle (as in the observations). For high Sun there is also a clear shift of the radiative smoothing scale to smaller values as droplet absorption increases. The shape of the power spectrum is sensitive to the magnitude and type of cloud top height variability, with

  6. First- and second-order contrast sensitivity functions reveal disrupted visual processing following mild traumatic brain injury.

    PubMed

    Spiegel, Daniel P; Reynaud, Alexandre; Ruiz, Tatiana; Laguë-Beauvais, Maude; Hess, Robert; Farivar, Reza

    2016-05-01

    Vision is disrupted by traumatic brain injury (TBI), with vision-related complaints being amongst the most common in this population. Based on the neural responses of early visual cortical areas, injury to the visual cortex would be predicted to affect both 1(st) order and 2(nd) order contrast sensitivity functions (CSFs)-the height and/or the cut-off of the CSF are expected to be affected by TBI. Previous studies have reported disruptions only in 2(nd) order contrast sensitivity, but using a narrow range of parameters and divergent methodologies-no study has characterized the effect of TBI on the full CSF for both 1(st) and 2(nd) order stimuli. Such information is needed to properly understand the effect of TBI on contrast perception, which underlies all visual processing. Using a unified framework based on the quick contrast sensitivity function, we measured full CSFs for static and dynamic 1(st) and 2(nd) order stimuli. Our results provide a unique dataset showing alterations in sensitivity for both 1(st) and 2(nd) order visual stimuli. In particular, we show that TBI patients have increased sensitivity for 1(st) order motion stimuli and decreased sensitivity to orientation-defined and contrast-defined 2(nd) order stimuli. In addition, our data suggest that TBI patients' sensitivity for both 1(st) order stimuli and 2(nd) order contrast-defined stimuli is shifted towards higher spatial frequencies. PMID:27036098

  7. About temporary autocorrelation function of fluctuations of the scattered radiation of the focused laser beam (0.63 mm) in the surface atmosphere in rain, drizzle and fog

    NASA Astrophysics Data System (ADS)

    Vostretsov, N. A.; Zhukov, A. F.

    2015-11-01

    Measured temporal autocorrelation function the fluctuations of the scattered radiation of the focused laser beam (0.63 μm) in the surface atmosphere in rain, drizzle and fog on the highway with a length of 130 m. Found that the time correlation of the fluctuations of the scattered radiation of the focused laser beam in the rain and drizzle decreases with increasing perpendicular component to the path the wind speed is at close to atmospheric conditions (with close values of optical depth and particle size of atmospheric precipitation). The time correlation in the fog more, than the time correlation in the drizzle. It is an order of magnitude or more greater than in the rain.

  8. A simple autocorrelation algorithm for determining grain size from digital images of sediment

    USGS Publications Warehouse

    Rubin, D.M.

    2004-01-01

    Autocorrelation between pixels in digital images of sediment can be used to measure average grain size of sediment on the bed, grain-size distribution of bed sediment, and vertical profiles in grain size in a cross-sectional image through a bed. The technique is less sensitive than traditional laboratory analyses to tails of a grain-size distribution, but it offers substantial other advantages: it is 100 times as fast; it is ideal for sampling surficial sediment (the part that interacts with a flow); it can determine vertical profiles in grain size on a scale finer than can be sampled physically; and it can be used in the field to provide almost real-time grain-size analysis. The technique can be applied to digital images obtained using any source with sufficient resolution, including digital cameras, digital video, or underwater digital microscopes (for real-time grain-size mapping of the bed). ?? 2004, SEPM (Society for Sedimentary Geology).

  9. Autocorrelation spectra of an air-fluidized granular system measured by NMR

    NASA Astrophysics Data System (ADS)

    Lasic, S.; Stepisnik, J.; Mohoric, A.; Sersa, I.; Planinsic, G.

    2006-09-01

    A novel insight into the dynamics of a fluidized granular system is given by a nuclear magnetic resonance method that yields the spin-echo attenuation proportional to the spectrum of the grain positional fluctuation. Measurements of the air-fluidized oil-filled spheres and mustard seeds at different degrees of fluidization and grain volume fractions provide the velocity autocorrelation that differs from the commonly anticipated exponential Enskog decay. An empiric formula, which corresponds to the model of grain caging at collisions with adjacent beads, fits well to the experimental data. Its parameters are the characteristic collision time, the free path between collisions and the cage-breaking rate or the diffusion-like constant, which decreases with increasing grain volume fraction. Mean-squared displacements calculated from the correlation spectrum clearly show transitions from ballistic, through sub-diffusion and into diffusion regimes of grain motion.

  10. Evidence of partial temporal coherence effects in the linear autocorrelation of extreme ultraviolet laser pulses.

    PubMed

    Le Marec, Andréa; Guilbaud, Olivier; Larroche, Olivier; Klisnick, Annie

    2016-07-15

    We study how the degree of temporal coherence of plasma-based extreme ultraviolet lasers operated in the amplification of the spontaneous emission mode is encoded in the shape of the linear autocorrelation function, which is obtained from the variation of the fringe visibility while varying the delay in a variable path-difference interferometer. We discuss the implications of this effect when the technique is used to infer the spectral properties of the source. Our numerical simulations, based on a partial coherence model developed by other authors for x-ray free electron lasers, are in good agreement with previously reported sets of measurements, illustrating similar statistical properties for both sources. PMID:27420542

  11. Artificial fingerprint recognition by using optical coherence tomography with autocorrelation analysis.

    PubMed

    Cheng, Yezeng; Larin, Kirill V

    2006-12-20

    Fingerprint recognition is one of the most widely used methods of biometrics. This method relies on the surface topography of a finger and, thus, is potentially vulnerable for spoofing by artificial dummies with embedded fingerprints. In this study, we applied the optical coherence tomography (OCT) technique to distinguish artificial materials commonly used for spoofing fingerprint scanning systems from the real skin. Several artificial fingerprint dummies made from household cement and liquid silicone rubber were prepared and tested using a commercial fingerprint reader and an OCT system. While the artificial fingerprints easily spoofed the commercial fingerprint reader, OCT images revealed the presence of them at all times. We also demonstrated that an autocorrelation analysis of the OCT images could be potentially used in automatic recognition systems. PMID:17151765

  12. Long-Time Autocorrelation Function of ECG Signal for Healthy versus Diseased Human Heart

    NASA Astrophysics Data System (ADS)

    Kulessa, B.; Srokowski, T.; Drozdz, S.

    2003-01-01

    Long-time ECG time series for healthy subjects and diseased patients are analysed. In the first case, the power spectrum has the 1/f shape in a broad frequency range. However, its behaviour for very low and very high frequency is different and the entire spectrum is integrable. For patients with post-ictal heart rate oscillation in partial epilepsy the 1/f noise is not present. We determine the power spectrum by evaluating the Fourier transform of the signal in both cases and calculate the signal autocorrelation function. It falls with time faster for diseased patients then for healthy people. The presented method can serve as a diagnostic tool of some heart diseases.

  13. Reconstruction of thermally symmetrized quantum autocorrelation functions from imaginary-time data.

    PubMed

    Predescu, Cristian

    2004-12-01

    In this paper, I propose a technique for recovering quantum dynamical information from imaginary-time data via the resolution of a one-dimensional Hamburger moment problem. It is shown that the quantum autocorrelation functions are uniquely determined by and can be reconstructed from their sequence of derivatives at origin. A general class of reconstruction algorithms is then identified, according to Theorem 3. The technique is advocated as especially effective for a certain class of quantum problems in continuum space, for which only a few moments are necessary. For such problems, it is argued that the derivatives at origin can be evaluated by Monte Carlo simulations via estimators of finite variances in the limit of an infinite number of path variables. Finally, a maximum entropy inversion algorithm for the Hamburger moment problem is utilized to compute the quantum rate of reaction for a one-dimensional symmetric Eckart barrier. PMID:15697551

  14. Amplitude autocorrelation of femtosecond laser pulses using linear photogalvanic effect in sillenite crystals

    NASA Astrophysics Data System (ADS)

    Grachev, A. I.; Romashko, R. V.; Kulchin, Yu. N.; Golik, S. S.; Nippolainen, E.; Kamshilin, A. A.

    2012-06-01

    We demonstrate excitation of the linear photogalvanic current in a Bi12TiO20 crystal by two orthogonally polarized femtosecond laser pulses with detecting the electrical current via charge accumulation on the sample electrodes. Such a setup was used to implement an interferometric autocorrelation technique for characterization of ultrashort light pulses. Integration of the detected current in femtosecond time domain leads to vanishing of a bipolar component of the photogalvanic current which arises due to a pulse chirping. The advantage of the proposed technique is that it produces the electric field correlation function directly without the need for data processing using a compact, robust, and non-expensive detector in the form of a photoconductive cell of a non-centrosymmetric crystal.

  15. Autocorrelation measurement of an ultra-short optical pulse using an electrically focus-tunable lens

    NASA Astrophysics Data System (ADS)

    Serna, Juan; Hamad, Abdullatif; Rueda, Edgar; Garcia, Hernando

    2015-10-01

    In this communication, a novel technique to measure the temporal width of an ultra-short optical pulse using an electrically focus-tunable lens (EFTL) is proposed and implemented (no need for a mechanical translation stage). The principle is based on the time delay experienced by the pulse when it passes through the deformed membrane of the EFTL as the focal length changes by an applied current. The resolution of the system is approximately 0.23 fs, with a total time delay of 0.69 ps. A typical autocorrelation can be performed in less than 5 s with an excellent Signal to Noise Ratio. The same technique can be implemented to study ultrafast phenomena like electronic relaxation or ultrafast fluorescence in a pump-probe configuration.

  16. Autocorrelations from the transfer-matrix density-matrix renormalization-group method

    NASA Astrophysics Data System (ADS)

    Naef, F.; Wang, X.; Zotos, X.; von der Linden, W.

    1999-07-01

    Extending the transfer-matrix density-matrix renormalization-group algorithm, we are able to calculate imaginary time spin autocorrelations with high accuracy (absolute error <10-6) over a wide temperature range (0<βJ<20). After analytic continuation using the rules of probability theory along with the entropic prior (MaxEnt), we obtain real frequency spectra for the XY model, the isotropic Heisenberg, and the gapped Heisenberg-Ising model. Available exact results in some limits allow for a critical evaluation of the quality of answers expected from this procedure. We find that high-precision data are still insufficient for resolving specific line shapes such as low-frequency divergences. However, the method is appropriate for identifying low-temperature gaps and peak positions.

  17. Velocity autocorrelation spectra in molten polymers measured by NMR modulated gradient spin-echo

    NASA Astrophysics Data System (ADS)

    Stepišnik, Janez; Mohorič, Aleš; Mattea, Carlos; Stapf, Siegfried; Serša, Igor

    2014-04-01

    The segmental dynamics in molten linear polymers is studied by the NMR method of modulated gradient spin-echo, which directly probes a spectrum of molecular velocity autocorrelation function. Diffusion spectra of mono-disperse poly(isoprene-1.4) with different molecular masses, measured in the frequency range 0.1-10 kHz at a temperature of 26\\ ^{\\circ}\\text{C} , have a form similar to the spectrum of Rouse chain dynamics, which implicates the tube-Rouse motion as the dominant dynamic process in this frequency range. The scaling of the center-of-mass diffusion coefficient, given from the fitting parameters, changes from N^{-1} into N^{-2.4} at around N \\approx 3\\text{-}5 Kuhn steps, which is less than predicted by theory and simulations, while the correlation times of the tube-Rouse mode do not follow the anticipated scaling.

  18. Autocorrelation function of channel matrix in few-mode fibers with strong mode coupling.

    PubMed

    Hu, Qian; Shieh, William

    2013-09-23

    Channel matrix plays a critical role in receiver design and ultimate channel performance. To fully describe the channel matrix of a few-mode fiber (FMF), we choose the generalized high-dimensional Gell-Mann matrices, an equivalent of the 2-dimensional Pauli matrices used for a single-mode fiber (SMF), as the basis for the channel matrix decomposition. The frequency dependence of channel matrix can be studied in terms of the autocorrelation function (ACF), showing how fast channel changes in frequency domain. In this paper, we derive a canonical stochastic differential equation (SDE) for the FMF channel matrix in the regime of strong coupling. With the SDE, we develop an analytical form for the ACF of FMF channel matrix, from which the channel correlation bandwidth is obtained. PMID:24104107

  19. Adaptive and Effortful Control and Academic Self-efficacy Beliefs on Achievement: A Longitudinal Study of 1st through 3rd Graders

    PubMed Central

    Liew, Jeffrey; McTigue, Erin; Barrois, Lisa; Hughes, Jan

    2009-01-01

    The linkages between self-regulatory processes and achievement were examined across three years in 733 children beginning at 1st grade (M = 6.57 years, SD = .39 at 1st grade) who were identified as lower achieving in literacy. Accounting for consistencies in measures (from one year prior) and for influences of child’s age, gender, IQ, ethnicity and economic adversity on achievement, results indicate that adaptive/effortful control at 1st grade contributed to both academic self-efficacy beliefs at 2nd grade, and reading (but not math) achievement at 3rd grade. Although academic self-efficacy did not partially mediate the linkage between adaptive/effortful control and achievement, academic self-efficacy beliefs were positively correlated with reading and math. Results support the notion that early efforts to promote children’s self-regulatory skills would enhance future academic self-beliefs and achievement, particularly in literacy. PMID:19169387

  20. Extension of the spatial autocorrelation (SPAC) method to mixed-component correlations of surface waves

    USGS Publications Warehouse

    Haney, Matthew M.; Mikesell, T. Dylan; van Wijk, Kasper; Nakahara, Hisashi

    2012-01-01

    Using ambient seismic noise for imaging subsurface structure dates back to the development of the spatial autocorrelation (SPAC) method in the 1950s. We present a theoretical analysis of the SPAC method for multicomponent recordings of surface waves to determine the complete 3 × 3 matrix of correlations between all pairs of three-component motions, called the correlation matrix. In the case of isotropic incidence, when either Rayleigh or Love waves arrive from all directions with equal power, the only non-zero off-diagonal terms in the matrix are the vertical–radial (ZR) and radial–vertical (RZ) correlations in the presence of Rayleigh waves. Such combinations were not considered in the development of the SPAC method. The method originally addressed the vertical–vertical (ZZ), RR and TT correlations, hence the name spatial autocorrelation. The theoretical expressions we derive for the ZR and RZ correlations offer additional ways to measure Rayleigh wave dispersion within the SPAC framework. Expanding on the results for isotropic incidence, we derive the complete correlation matrix in the case of generally anisotropic incidence. We show that the ZR and RZ correlations have advantageous properties in the presence of an out-of-plane directional wavefield compared to ZZ and RR correlations. We apply the results for mixed-component correlations to a data set from Akutan Volcano, Alaska and find consistent estimates of Rayleigh wave phase velocity from ZR compared to ZZ correlations. This work together with the recently discovered connections between the SPAC method and time-domain correlations of ambient noise provide further insights into the retrieval of surface wave Green’s functions from seismic noise.

  1. Determining the spatial autocorrelation of dengue vector populations: influences of mosquito sampling method, covariables, and vector control.

    PubMed

    Azil, Aishah H; Bruce, David; Williams, Craig R

    2014-06-01

    We investigated spatial autocorrelation of female Aedes aegypti L. mosquito abundance from BG-Sentinel trap and sticky ovitrap collections in Cairns, north Queensland, Australia. BG-Sentinel trap collections in 2010 show a significant spatial autocorrelation across the study site and over a smaller spatial extent, while sticky ovitrap collections only indicate a non-significant, weak spatial autocorrelation. The BG-Sentinel trap collections were suitable for spatial interpolation using ordinary kriging and cokriging techniques. The uses of Premise Condition Index and potential breeding container data have helped improve our prediction of vector abundance. Semiovariograms and prediction maps indicate that the spatial autocorrelation of mosquito abundance determined by BG-Sentinel traps extends farther compared to sticky ovitrap collections. Based on our data, fewer BG-Sentinel traps are required to represent vector abundance at a series of houses compared to sticky ovitraps. A lack of spatial structure was observed following vector control treatment in the area. This finding has implications for the design and costs of dengue vector surveillance programs. PMID:24820568

  2. Stochastic systems with delay: Perturbation theory for second order statistics

    NASA Astrophysics Data System (ADS)

    Frank, T. D.

    2016-03-01

    Within the framework of delay Fokker-Planck equations, a perturbation theoretical method is developed to determine second-order statistical quantities such as autocorrelation functions for stochastic systems with delay. Two variants of the perturbation theoretical approach are presented. The first variant is based on a non-local Fokker-Planck operator. The second variant requires to solve a Fokker-Planck equation with source term. It is shown that the two variants yield consistent results. The perturbation theoretical approaches are applied to study negative autocorrelations that are induced by feedback delays and mediated by the strength of the fluctuating forces that act on the feedback systems.

  3. Field test comparison of an autocorrelation technique for determining grain size using a digital 'beachball' camera versus traditional methods

    USGS Publications Warehouse

    Barnard, P.L.; Rubin, D.M.; Harney, J.; Mustain, N.

    2007-01-01

    This extensive field test of an autocorrelation technique for determining grain size from digital images was conducted using a digital bed-sediment camera, or 'beachball' camera. Using 205 sediment samples and >1200 images from a variety of beaches on the west coast of the US, grain size ranging from sand to granules was measured from field samples using both the autocorrelation technique developed by Rubin [Rubin, D.M., 2004. A simple autocorrelation algorithm for determining grain size from digital images of sediment. Journal of Sedimentary Research, 74(1): 160-165.] and traditional methods (i.e. settling tube analysis, sieving, and point counts). To test the accuracy of the digital-image grain size algorithm, we compared results with manual point counts of an extensive image data set in the Santa Barbara littoral cell. Grain sizes calculated using the autocorrelation algorithm were highly correlated with the point counts of the same images (r2 = 0.93; n = 79) and had an error of only 1%. Comparisons of calculated grain sizes and grain sizes measured from grab samples demonstrated that the autocorrelation technique works well on high-energy dissipative beaches with well-sorted sediment such as in the Pacific Northwest (r2 ??? 0.92; n = 115). On less dissipative, more poorly sorted beaches such as Ocean Beach in San Francisco, results were not as good (r2 ??? 0.70; n = 67; within 3% accuracy). Because the algorithm works well compared with point counts of the same image, the poorer correlation with grab samples must be a result of actual spatial and vertical variability of sediment in the field; closer agreement between grain size in the images and grain size of grab samples can be achieved by increasing the sampling volume of the images (taking more images, distributed over a volume comparable to that of a grab sample). In all field tests the autocorrelation method was able to predict the mean and median grain size with ???96% accuracy, which is more than

  4. Case Study of Severe Lightning Activity Prior to and During the Outbreak of the June 1st Greenbelt Tornado

    NASA Astrophysics Data System (ADS)

    Barnum, B. H.; Badesha, S.; Shishineh, A.; Adams, N. H.

    2012-12-01

    Surges in lightning activity have been known to be associated with the outbreak of tornado activity. We present a case study of a tornado that touched down near Greenbelt Maryland during the evening of June 1st 2012. Preceding the tornado touchdown, two single point lightning detection systems, a Boltek LD-250 and Vaisala SA20, recorded very high lightning activity rates. An electric field mill (EFM) was also making measurements and recorded large, rapid amplitude oscillations in the vertical electric fields. These electric field oscillations quickly subsided after the initial tornado touchdown. The lightning activity also generated significant RF interference in the S-band dish antenna operated at the Applied Physics Laboratory. It was somewhat surprising that the lightning activity produced enough radiation at these frequencies to cause measured levels of interference which could potentially impair satellite communications. Our interpretation of the EFM data is that intensive vertical forcing and rotation in the thunderstorm during the tornado formation caused the observed rapid electric field oscillations. At the same time, the vertical mixing in the storm caused a surge in lightning activity rates recorded by the Boltek and Vaisala sensors. Following the tornado touchdown, there was a rapid decrease in the lightning rates from the sensors. The EFM oscillations also abruptly ceased and went to a more normal slow-varying pattern typically observed during other thunderstorms without associated tornado activity. It is suggested that a network of field mills could provide realtime warning of imminent tornado activity.

  5. Synthesis of nanomagnetic fluids and their UV spectrophotometric response with aliphatic organic acids and 1st tier dendrimers

    NASA Astrophysics Data System (ADS)

    Pandya, Shivani R.; Singh, Man

    2016-04-01

    Synthesis of Magnetic nanoparticles were made using coprecipitation method on mixing Fe+3 and Fe+2 in 2:1 ratio with aqueous 8M NaOH which on heating at 90°C for 2 h has yielded 85% magnetic (Fe3O4) nanoparticles (MNPs), characterized by XRD, VSM, SEM, and HR-TEM. The formic acid (FA), oxalic acid (OA) and citric acid (CA), the series of aliphatic organic acids along with Trimesoyl 1, 3, 5 tridimethyl malonate (TTDMM), trimesoyl 1, 3, 5 tridiethyl malonate (TTDEM), trimesoyl 1, 3, 5 tridipropyl malonate (TTDPM), trimesoyl 1, 3, 5 tridibutyl malonate (TTDBM) and trimesoyl 1, 3, 5 tridihexyl malonate (TTDHM) 1st tier dendrimers were used separately for preparing nanomagnetic fluid. From 25 to 150 µM MNPs at an interval of 25 µM were dispersed in 150 µM of acids and dendrimers separately with DMSO. UV-VIS spectrophotometry showed a maximum MNPs dispersion with TTDMM against others and found to be most stable nanomagnetic fluid on account of capping type mechanism of acids.

  6. Stem Cell Gene Therapy for Fanconi Anemia: Report from the 1st International Fanconi Anemia Gene Therapy Working Group Meeting

    PubMed Central

    Tolar, Jakub; Adair, Jennifer E; Antoniou, Michael; Bartholomae, Cynthia C; Becker, Pamela S; Blazar, Bruce R; Bueren, Juan; Carroll, Thomas; Cavazzana-Calvo, Marina; Clapp, D Wade; Dalgleish, Robert; Galy, Anne; Gaspar, H Bobby; Hanenberg, Helmut; Von Kalle, Christof; Kiem, Hans-Peter; Lindeman, Dirk; Naldini, Luigi; Navarro, Susana; Renella, Raffaele; Rio, Paula; Sevilla, Julián; Schmidt, Manfred; Verhoeyen, Els; Wagner, John E; Williams, David A; Thrasher, Adrian J

    2011-01-01

    Survival rates after allogeneic hematopoietic cell transplantation (HCT) for Fanconi anemia (FA) have increased dramatically since 2000. However, the use of autologous stem cell gene therapy, whereby the patient's own blood stem cells are modified to express the wild-type gene product, could potentially avoid the early and late complications of allogeneic HCT. Over the last decades, gene therapy has experienced a high degree of optimism interrupted by periods of diminished expectation. Optimism stems from recent examples of successful gene correction in several congenital immunodeficiencies, whereas diminished expectations come from the realization that gene therapy will not be free of side effects. The goal of the 1st International Fanconi Anemia Gene Therapy Working Group Meeting was to determine the optimal strategy for moving stem cell gene therapy into clinical trials for individuals with FA. To this end, key investigators examined vector design, transduction method, criteria for large-scale clinical-grade vector manufacture, hematopoietic cell preparation, and eligibility criteria for FA patients most likely to benefit. The report summarizes the roadmap for the development of gene therapy for FA. PMID:21540837

  7. Child gender and weight status moderate the relation of maternal feeding practices to body esteem in 1st grade children.

    PubMed

    Shriver, Lenka H; Hubbs-Tait, Laura; Harrist, Amanda W; Topham, Glade; Page, Melanie

    2015-06-01

    Prevention of body dissatisfaction development is critical for minimizing adverse effects of poor body esteem on eating behaviors, self-esteem, and overall health. Research has examined body esteem and its correlates largely in pre-adolescents and adolescents; however, important questions remain about factors influencing body esteem of younger children. The main purpose of this study was to test moderation by children's gender and weight status of the relation of maternal controlling feeding practices to 1st graders' body esteem. The Body Esteem Scale (BES) and anthropometric measurements were completed during one-on-one child interviews at school. Mothers completed the Child Feeding Questionnaire (restriction, monitoring, concern, self-assessed maternal weight). A total of 410 mother/child dyads (202 girls) participated. Percent of children classified as overweight (BMI-for-age ≥85th) was: girls - 29%; boys - 27%. Gender moderated the relation between restriction and body esteem (β = -.140, p = .05), with maternal restriction predicting body esteem in girls but not boys. The hypothesized three-way interaction among gender, child weight status, and monitoring was confirmed. Monitoring was significantly inversely related to body esteem only for overweight/obese girls (b = -1.630). The moderating influence of gender or gender and weight status on the link between maternal feeding practices and body esteem suggests the importance of body esteem interventions for girls as early as first grade. PMID:25624022

  8. Frontline nilotinib in patients with chronic myeloid leukemia in chronic phase: results from the European ENEST1st study.

    PubMed

    Hochhaus, A; Rosti, G; Cross, N C P; Steegmann, J L; le Coutre, P; Ossenkoppele, G; Petrov, L; Masszi, T; Hellmann, A; Griskevicius, L; Wiktor-Jedrzejczak, W; Rea, D; Coriu, D; Brümmendorf, T H; Porkka, K; Saglio, G; Gastl, G; Müller, M C; Schuld, P; Di Matteo, P; Pellegrino, A; Dezzani, L; Mahon, F-X; Baccarani, M; Giles, F J

    2016-01-01

    The Evaluating Nilotinib Efficacy and Safety in Clinical Trials as First-Line Treatment (ENEST1st) study included 1089 patients with newly diagnosed chronic myeloid leukemia in chronic phase. The rate of deep molecular response (MR(4) (BCR-ABL1⩽0.01% on the International Scale or undetectable BCR-ABL1 with ⩾10,000 ABL1 transcripts)) at 18 months was evaluated as the primary end point, with molecular responses monitored by the European Treatment and Outcome Study network of standardized laboratories. This analysis was conducted after all patients had completed 24 months of study treatment (80.9% of patients) or discontinued early. In patients with typical BCR-ABL1 transcripts and ⩽3 months of prior imatinib therapy, 38.4% (404/1052) achieved MR(4) at 18 months. Six patients (0.6%) developed accelerated or blastic phase, and 13 (1.2%) died. The safety profile of nilotinib was consistent with that of previous studies, although the frequencies of some nilotinib-associated adverse events were lower (for example, rash, 21.4%). Ischemic cardiovascular events occurred in 6.0% of patients. Routine monitoring of lipid and glucose levels was not mandated in the protocol. These results support the use of frontline nilotinib, particularly when achievement of a deep molecular response (a prerequisite for attempting treatment-free remission in clinical trials) is a treatment goal. PMID:26437782

  9. Frontline nilotinib in patients with chronic myeloid leukemia in chronic phase: results from the European ENEST1st study

    PubMed Central

    Hochhaus, A; Rosti, G; Cross, N C P; Steegmann, J L; le Coutre, P; Ossenkoppele, G; Petrov, L; Masszi, T; Hellmann, A; Griskevicius, L; Wiktor-Jedrzejczak, W; Rea, D; Coriu, D; Brümmendorf, T H; Porkka, K; Saglio, G; Gastl, G; Müller, M C; Schuld, P; Di Matteo, P; Pellegrino, A; Dezzani, L; Mahon, F-X; Baccarani, M; Giles, F J

    2016-01-01

    The Evaluating Nilotinib Efficacy and Safety in Clinical Trials as First-Line Treatment (ENEST1st) study included 1089 patients with newly diagnosed chronic myeloid leukemia in chronic phase. The rate of deep molecular response (MR4 (BCR-ABL1⩽0.01% on the International Scale or undetectable BCR-ABL1 with ⩾10 000 ABL1 transcripts)) at 18 months was evaluated as the primary end point, with molecular responses monitored by the European Treatment and Outcome Study network of standardized laboratories. This analysis was conducted after all patients had completed 24 months of study treatment (80.9% of patients) or discontinued early. In patients with typical BCR-ABL1 transcripts and ⩽3 months of prior imatinib therapy, 38.4% (404/1052) achieved MR4 at 18 months. Six patients (0.6%) developed accelerated or blastic phase, and 13 (1.2%) died. The safety profile of nilotinib was consistent with that of previous studies, although the frequencies of some nilotinib-associated adverse events were lower (for example, rash, 21.4%). Ischemic cardiovascular events occurred in 6.0% of patients. Routine monitoring of lipid and glucose levels was not mandated in the protocol. These results support the use of frontline nilotinib, particularly when achievement of a deep molecular response (a prerequisite for attempting treatment-free remission in clinical trials) is a treatment goal. PMID:26437782

  10. 1st Quarter Transportation Report FY 2015: Radioactive Waste Shipments to and from the Nevada National Security Site (NNSS)

    SciTech Connect

    Gregory, Louis

    2015-02-20

    This report satisfies the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary report of radioactive waste shipments to and from the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) at Area 5. There were no shipments sent for offsite treatment and returned to the NNSS this quarter. This report summarizes the 1st quarter of Fiscal Year (FY) 2015 low-level radioactive waste (LLW) and mixed low-level radioactive waste (MLLW) shipments. Tabular summaries are provided which include the following: Sources of and carriers for LLW and MLLW shipments to and from the NNSS; Number and external volume of LLW and MLLW shipments; Highway routes used by carriers; and Incident/accident data applicable to LLW and MLLW shipments. In this report shipments are accounted for upon arrival at the NNSS, while disposal volumes are accounted for upon waste burial. The disposal volumes presented in this report include minor volumes of non-radioactive classified waste/material that were approved for disposal (non-radioactive classified or nonradioactive classified hazardous). Volume reports showing cubic feet generated using the Low-Level Waste Information System may vary slightly due to rounding conventions for volumetric conversions from cubic meters to cubic feet.

  11. Embryonic development of chicken (Gallus Gallus Domesticus) from 1st to 19th day-ectodermal structures.

    PubMed

    Toledo Fonseca, Erika; De Oliveira Silva, Fernanda Menezes; Alcântara, Dayane; Carvalho Cardoso, Rafael; Luís Franciolli, André; Sarmento, Carlos Alberto Palmeira; Fratini, Paula; José Piantino Ferreira, Antônio; Miglino, Maria Angélica

    2013-12-01

    Birds occupy a prominent place in the Brazilian economy not only in the poultry industry but also as an animal model in many areas of scientific research. Thus the aim of this study was to provide a description of macro and microscopic aspects of the ectoderm-derived structures in chicken embryos / fetuses poultry (Gallus gallus domesticus) from 1st to 19th day of incubation. 40 fertilized eggs, from a strain of domestic chickens, with an incubation period of 2-19 days were subjected to macroscopic description, biometrics, light, and scanning microscopy. All changes observed during the development were described. The nervous system, skin and appendages and organs related to vision and hearing began to be identified, both macro and microscopically, from the second day of incubation. The vesicles from the primitive central nervous system-forebrain, midbrain, and hindbrain-were identified on the third day of incubation. On the sixth day of incubation, there was a clear vascularization of the skin. The optic vesicle was first observed fourth day of development and on the fifth day there was the beginning of the lens formation. Although embryonic development is influenced by animal line as well as external factors such as incubation temperature, this paper provides a chronological description for chicken (Gallus gallus domesticus) during its embryonic development. PMID:24019213

  12. PROCEEDINGS: JOINT SYMPOSIUM ON DRY SO2 AND SIMULTANEOUS SO2/NOX CONTROL TECHNOLOGIES (1ST). VOLUME 1. FUNDAMENTAL RESEARCH AND PROCESS DEVELOPMENT

    EPA Science Inventory

    Forty six papers describing recent advances in dry sorbent injection technologies for SO2 control were presented at the 1st Joint Symposium on Dry SO2 and Simultaneous SO2/NOx Control Technologies. These papers covered the following topics: fundamental research; pilot-scale devel...

  13. The Impact of Gender-Fair versus Gender-Stereotyped Basal Readers on 1st-Grade Children's Gender Stereotypes: A Natural Experiment

    ERIC Educational Resources Information Center

    Karniol, Rachel; Gal-Disegni, Michal

    2009-01-01

    Israeli 1st-grade children in two different schools in the same neighborhood who were using either a gender-stereotyped or a gender-fair basal reader were asked to judge for a series of female-stereotyped, male-stereotyped, and gender-neutral activities whether they were characteristic of females, of males, or of both. Children using the…

  14. Moving beyond the Lone Scientist: Helping 1st-Grade Students Appreciate the Social Context of Scientific Work Using Stories about Scientists

    ERIC Educational Resources Information Center

    Sharkawy, Azza

    2009-01-01

    While several studies have documented young children's (K-2) stereotypic views of scientists and scientific work, few have examined students' views of the social nature of scientific work and the strategies effective in broadening these views. The purpose of this study is to examine how stories about scientists influence 1st-grade students' views…

  15. Diagnostic Online Assessment of Basic IT Skills in 1st-Year Undergraduates in the Medical Sciences Division, University of Oxford

    ERIC Educational Resources Information Center

    Sieber, Vivien

    2009-01-01

    Attitude, experience and competence (broadly covered by the European Computer Driving Licence syllabus) in information technology (IT) were assessed in 846 1st-year Medical Sciences Division undergraduates (2003-06) at the start of their first term. Online assessments delivered during induction workshops were presented as an opportunity for…

  16. Characterization of Forested Landscapes From Remotely Sensed Data Using Fractals and Spatial Autocorrelation

    NASA Technical Reports Server (NTRS)

    Al-Hamdan, Mohammad Z.; Cruise, James F.; Rickman, Douglas L.; Quattrochi, Dale A.

    2007-01-01

    The characterization of forested areas is frequently required in resource management practice. Passive remotely sensed data, which are much more accessible and cost effective than are active data, have rarely, if ever, been used to characterize forest structure directly, but rather they usually focus on the estimation of indirect measurement of biomass or canopy coverage. In this study, some spatial analysis techniques are presented that might be employed with Landsat TM data to analyze forest structure characteristics. A case study is presented wherein fractal dimensions, along with a simple spatial autocorrelation technique (Moran s I), were related to stand density parameters of the Oakmulgee National Forest located in the southeastern United States (Alabama). The results of the case study presented herein have shown that as the percentage of smaller diameter trees becomes greater, and particularly if it exceeds 50%, then the canopy image obtained from Landsat TM data becomes sufficiently homogeneous so that the spatial indices reach their lower limits and thus are no longer determinative. It also appears, at least for the Oakmulgee forest, that the relationships between the spatial indices and forest class percentages within the boundaries can reasonably be considered linear. The linear relationship is much more pronounced in the sawtimber and saplings cases than in samples dominated by medium sized trees (poletimber). In addition, it also appears that, at least for the Oakmulgee forest, the relationships between the spatial indices and forest species groups (Hardwood and Softwood) percentages can reasonably be considered linear. The linear relationship is more pronounced in the forest species groups cases than in the forest classes cases. These results appear to indicate that both fractal dimensions and spatial autocorrelation indices hold promise as means of estimating forest stand characteristics from remotely sensed images. However, additional work is

  17. Time dependence of the velocity autocorrelation function of a fluid: An eigenmode analysis of dynamical processes.

    PubMed

    Bellissima, S; Neumann, M; Guarini, E; Bafile, U; Barocchi, F

    2015-10-01

    The velocity autocorrelation function (VAF), a key quantity in the atomic-scale dynamics of fluids, has been the first paradigmatic example of a long-time tail phenomenon, and much work has been devoted to detecting such long-lasting correlations and understanding their nature. There is, however, much more to the VAF than simply the evidence of this long-time dynamics. A unified description of the VAF from very short to long times, and of the way it changes with varying density, is still missing. Here we show that an approach based on very general principles makes such a study possible and opens the way to a detailed quantitative characterization of the dynamical processes involved at all time scales. From the analysis of molecular dynamics simulations for a slightly supercritical Lennard-Jones fluid at various densities, we are able to evidence the presence of distinct fast and slow decay channels for the velocity correlation on the time scale set by the collision rate. The density evolution of these decay processes is also highlighted. The method presented here is very general, and its application to the VAF can be considered as an important example. PMID:26565227

  18. Snow Pack and Lake Ice Pack Remote Sensing using Wideband Autocorrelation Radiometry

    NASA Astrophysics Data System (ADS)

    Mousavi, S.; De Roo, R. D.; Sarabandi, K.; England, A. W.

    2015-12-01

    A novel microwave radiometric technique, wideband autocorrelation radiometry (WiBAR), offers a deterministic method of remotely sensing the propagation time τdelay of microwaves through low loss layers at the bottom of the atmosphere. Terrestrial examples are the snow and lake ice packs. This technique is based on the Planck radiation from the surface beneath the pack which travels upwards through the pack towards the radiometer; such a signal we call a direct signal. On the other hand, part of this radiation reflects back from the pack's upper interface then from its lower interface, before traveling towards the radiometer's antenna. Thus, there are two signals received by the radiometer, the direct signal and a delayed copy of it. The microwave propagation time τdelay through the pack yields a measure of its vertical extent. We report a time series of measurements of the ice pack on Lake Superior from February to April 2014 to demonstrate this technique. The observations are done at frequencies from 7 to 10 GHz. At these frequencies, the volume and surface scattering are small in the ice pack. This technique is inherently low-power since there is no transmitter as opposed to active remote sensing techniques. The results of this paper is to present the WiBAR technique and show that the microwave travel time within a dry snow pack and lake ice pack can be deterministically measured for different thicknesses using this technique.

  19. Single-shot electron bunch length measurements using a spatial electro-optical autocorrelation interferometer

    NASA Astrophysics Data System (ADS)

    Sütterlin, Daniel; Erni, Daniel; Schlott, Volker; Sigg, Hans; Jäckel, Heinz; Murk, Axel

    2010-10-01

    A spatial, electro-optical autocorrelation (EOA) interferometer using the vertically polarized lobes of coherent transition radiation (CTR) has been developed as a single-shot electron bunch length monitor at an optical beam port downstream the 100 MeV preinjector LINAC of the Swiss Light Source. This EOA monitor combines the advantages of step-scan interferometers (high temporal resolution) [D. Mihalcea et al., Phys. Rev. ST Accel. Beams 9, 082801 (2006) and T. Takahashi and K. Takami, Infrared Phys. Technol. 51, 363 (2008)] and terahertz-gating technologies [U. Schmidhammer et al., Appl. Phys. B: Lasers Opt. 94, 95 (2009) and B. Steffen et al., Phys. Rev. ST Accel. Beams 12, 032802 (2009)] (fast response), providing the possibility to tune the accelerator with an online bunch length diagnostics. While a proof of principle of the spatial interferometer was achieved by step-scan measurements with far-infrared detectors, the single-shot capability of the monitor has been demonstrated by electro-optical correlation of the spatial CTR interference pattern with fairly long (500 ps) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulses in a ZnTe crystal. In single-shot operation, variations of the bunch length between 1.5 and 4 ps due to different phase settings of the LINAC bunching cavities have been measured with subpicosecond time resolution.

  20. Estimating where and how animals travel: an optimal framework for path reconstruction from autocorrelated tracking data.

    PubMed

    Fleming, C H; Fagan, W F; Mueller, T; Olson, K A; Leimgruber, P; Calabrese, J M

    2016-03-01

    An animal's trajectory is a fundamental object of interest in movement ecology, as it directly informs a range of topics from resource selection to energy expenditure and behavioral states. Optimally inferring the mostly unobserved movement path and its dynamics from a limited sample of telemetry observations is a key unsolved problem, however. The field of geostatistics has focused significant attention on a mathematically analogous problem that has a statistically optimal solution coined after its inventor, Krige. Kriging revolutionized geostatistics and is now the gold standard for interpolating between a limited number of autocorrelated spatial point observations. Here we translate Kriging for use with animal movement data. Our Kriging formalism encompasses previous methods to estimate animal's trajectories--the Brownian bridge and continuous-time correlated random walk library--as special cases, informs users as to when these previous methods are appropriate, and provides a more general method when they are not. We demonstrate the capabilities of Kriging on a case study with Mongolian gazelles where, compared to the Brownian bridge, Kriging with a more optimal model was 10% more precise in interpolating locations and 500% more precise in estimating occurrence areas. PMID:27197385

  1. Single-shot electron bunch length measurements using a spatial electro-optical autocorrelation interferometer

    SciTech Connect

    Suetterlin, Daniel; Erni, Daniel; Schlott, Volker; Sigg, Hans; Jaeckel, Heinz; Murk, Axel

    2010-10-15

    A spatial, electro-optical autocorrelation (EOA) interferometer using the vertically polarized lobes of coherent transition radiation (CTR) has been developed as a single-shot electron bunch length monitor at an optical beam port downstream the 100 MeV preinjector LINAC of the Swiss Light Source. This EOA monitor combines the advantages of step-scan interferometers (high temporal resolution) [D. Mihalcea et al., Phys. Rev. ST Accel. Beams 9, 082801 (2006) and T. Takahashi and K. Takami, Infrared Phys. Technol. 51, 363 (2008)] and terahertz-gating technologies [U. Schmidhammer et al., Appl. Phys. B: Lasers Opt. 94, 95 (2009) and B. Steffen et al., Phys. Rev. ST Accel. Beams 12, 032802 (2009)] (fast response), providing the possibility to tune the accelerator with an online bunch length diagnostics. While a proof of principle of the spatial interferometer was achieved by step-scan measurements with far-infrared detectors, the single-shot capability of the monitor has been demonstrated by electro-optical correlation of the spatial CTR interference pattern with fairly long (500 ps) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulses in a ZnTe crystal. In single-shot operation, variations of the bunch length between 1.5 and 4 ps due to different phase settings of the LINAC bunching cavities have been measured with subpicosecond time resolution.

  2. Shear-stress relaxation and ensemble transformation of shear-stress autocorrelation functions.

    PubMed

    Wittmer, J P; Xu, H; Baschnagel, J

    2015-02-01

    We revisit the relation between the shear-stress relaxation modulus G(t), computed at finite shear strain 0<γ≪1, and the shear-stress autocorrelation functions C(t)|(γ) and C(t)|(τ) computed, respectively, at imposed strain γ and mean stress τ. Focusing on permanent isotropic spring networks it is shown theoretically and computationally that in general G(t)=C(t)|(τ)=C(t)|(γ)+G(eq) for t>0 with G(eq) being the static equilibrium shear modulus. G(t) and C(t)|(γ) thus must become different for solids and it is impossible to obtain G(eq) alone from C(t)|(γ) as often assumed. We comment briefly on self-assembled transient networks where G(eq)(f) must vanish for a finite scission-recombination frequency f. We argue that G(t)=C(t)|(τ)=C(t)|(γ) should reveal an intermediate plateau set by the shear modulus G(eq)(f=0) of the quenched network. PMID:25768458

  3. EARLY-TIME VELOCITY AUTOCORRELATION FOR CHARGED PARTICLES DIFFUSION AND DRIFT IN STATIC MAGNETIC TURBULENCE

    SciTech Connect

    Fraschetti, F.; Giacalone, J.

    2012-08-20

    Using test-particle simulations, we investigate the temporal dependence of the two-point velocity correlation function for charged particles scattering in a time-independent spatially fluctuating magnetic field derived from a three-dimensional isotropic turbulence power spectrum. Such a correlation function allowed us to compute the spatial coefficients of diffusion both parallel and perpendicular to the average magnetic field. Our simulations confirm the dependence of the perpendicular diffusion coefficient on turbulence energy density and particle energy predicted previously by a model for early-time charged particle transport. Using the computed diffusion coefficients, we exploit the particle velocity autocorrelation to investigate the timescale over which the particles 'decorrelate' from the solution to the unperturbed equation of motion. Decorrelation timescales are evaluated for parallel and perpendicular motions, including the drift of the particles from the local magnetic field line. The regimes of strong and weak magnetic turbulence are compared for various values of the ratio of the particle gyroradius to the correlation length of the magnetic turbulence. Our simulation parameters can be applied to energetic particles in the interplanetary space, cosmic rays at the supernova shocks, and cosmic-rays transport in the intergalactic medium.

  4. Equatorial anisotropy in the inner part of Earth's inner core from autocorrelation of earthquake coda

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Song, Xiaodong; Xia, Han H.

    2015-03-01

    The Earth's solid inner core exhibits strong anisotropy, with wave velocity dependent on the direction of propagation due to the preferential alignment of iron crystals. Variations in the anisotropic structure, laterally and with depth, provide markers for measuring inner-core rotation and offer clues into the formation and dynamics of the inner core. Previous anisotropy models of the inner core have assumed a cylindrical anisotropy in which the symmetry axis is parallel to the Earth's spin axis. An inner part of the inner core with a distinct form of anisotropy has been suggested, but there is considerable uncertainty regarding its existence and characteristics. Here we analyse the autocorrelation of earthquake coda measured by global broadband seismic arrays between 1992 and 2012, and find that the differential travel times of two types of core-penetrating waves vary at low latitudes by up to 10 s. Our findings are consistent with seismic anisotropy in the innermost inner core that has a fast axis near the equatorial plane through Central America and Southeast Asia, in contrast to the north-south alignment of anisotropy in the outer inner core. The different orientations and forms of anisotropy may represent a shift in the evolution of the inner core.

  5. Seismic Spatial Autocorrelation as a Technique to Track Changes in the Permafrost Active Layer

    NASA Astrophysics Data System (ADS)

    Abbott, R. E.

    2013-12-01

    We present preliminary results from an effort to continuously track freezing and thawing of the permafrost active layer using a small-aperture seismic array. The 7-element array of three-component posthole seismometers is installed on permafrost at Poker Flat Research Range, near Fairbanks, Alaska. The array is configured in two three-station circles with 75 and 25 meter radii that share a common center station. This configuration is designed to resolve omnidirectional, high-frequency seismic microtremor (i.e. ambient noise). Microtremor is continuously monitored and the data are processed using the spatial autocorrelation (SPAC) method. The resulting SPAC coefficients are then inverted for shear-wave velocity structure versus depth. Thawed active-layer soils have a much slower seismic velocity than frozen soils, allowing us to track the depth and intensity of thawing. Persistent monitoring on a permanent array would allow for a way to investigate year-to-year changes without costly site visits. Results from the seismic array will compared to, and correlated with, other measurement techniques, such as physical probing and remote sensing methods. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  6. Ultrasound modulated light blood flow measurement using intensity autocorrelation function: a Monte-Carlo simulation

    NASA Astrophysics Data System (ADS)

    Tsalach, A.; Metzger, Y.; Breskin, I.; Zeitak, R.; Shechter, R.

    2014-03-01

    Development of techniques for continuous measurement of regional blood flow, and in particular cerebral blood flow (CBF), is essential for monitoring critical care patients. Recently, a novel technique, based on ultrasound modulation of light was developed for non-invasive, continuous CBF monitoring (termed ultrasound-tagged light (UTL or UT-NIRS)), and shown to correlate with readings of 133 Xe SPECT1 and laser Doppler2. Coherent light is introduced into the tissue concurrently with an Ultrasound (US) field. Displacement of scattering centers within the sampled volume induced by Brownian motion, blood flow and the US field affects the photons' temporal correlation. Hence, the temporal fluctuations of the obtained speckle pattern provide dynamic information about the blood flow. We developed a comprehensive simulation, combining the effects of Brownian motion, US and flow on the obtained speckle pattern. Photons trajectories within the tissue are generated using a Monte-Carlo based model. Then, the temporal changes in the optical path due to displacement of scattering centers are determined, and the corresponding interference pattern over time is derived. Finally, the light intensity autocorrelation function of a single speckle is calculated, from which the tissue decorrelation time is determined. The simulation's results are compared with in-vitro experiments, using a digital correlator, demonstrating decorrelation time prediction within the 95% confidence interval. This model may assist in the development of optical based methods for blood flow measurements and particularly, in methods using the acousto-optic effect.

  7. High-Responsivity Graphene-Boron Nitride Photodetector and Autocorrelator in a Silicon Photonic Integrated Circuit.

    PubMed

    Shiue, Ren-Jye; Gao, Yuanda; Wang, Yifei; Peng, Cheng; Robertson, Alexander D; Efetov, Dmitri K; Assefa, Solomon; Koppens, Frank H L; Hone, James; Englund, Dirk

    2015-11-11

    Graphene and other two-dimensional (2D) materials have emerged as promising materials for broadband and ultrafast photodetection and optical modulation. These optoelectronic capabilities can augment complementary metal-oxide-semiconductor (CMOS) devices for high-speed and low-power optical interconnects. Here, we demonstrate an on-chip ultrafast photodetector based on a two-dimensional heterostructure consisting of high-quality graphene encapsulated in hexagonal boron nitride. Coupled to the optical mode of a silicon waveguide, this 2D heterostructure-based photodetector exhibits a maximum responsivity of 0.36 A/W and high-speed operation with a 3 dB cutoff at 42 GHz. From photocurrent measurements as a function of the top-gate and source-drain voltages, we conclude that the photoresponse is consistent with hot electron mediated effects. At moderate peak powers above 50 mW, we observe a saturating photocurrent consistent with the mechanisms of electron-phonon supercollision cooling. This nonlinear photoresponse enables optical on-chip autocorrelation measurements with picosecond-scale timing resolution and exceptionally low peak powers. PMID:26372880

  8. Cognitive-based approach in teaching 1st year Physics for Life Sciences, including Atmospheric Physics and Climate Change components

    NASA Astrophysics Data System (ADS)

    Petelina, S. V.

    2009-12-01

    Most 1st year students who take the service course in Physics - Physics for Life Sciences - in Australia encounter numerous problems caused by such factors as no previous experience with this subject; general perception that Physics is hard and only very gifted people are able to understand it; lack of knowledge of elementary mathematics; difficulties encountered by lecturers in teaching university level Physics to a class of nearly 200 students with no prior experience, diverse and sometime disadvantageous backgrounds, different majoring areas, and different learning abilities. As a result, many students either drop, or fail the subject. In addition, many of those who pass develop a huge dislike towards Physics, consider the whole experience as time wasted, and spread this opinion among their peers and friends. The above issues were addressed by introducing numerous changes to the curriculum and modifying strategies and approaches in teaching Physics for Life Sciences. Instead of a conventional approach - teaching Physics from simple to complicated, topic after topic, the students were placed in the world of Physics in the same way as a newborn child is introduced to this world - everything is seen all the time and everywhere. That created a unique environment where a bigger picture and all details were always present and interrelated. Numerous concepts of classical and modern physics were discussed, compared, and interconnected all the time with “Light” being a key component. Our primary field of research is Atmospheric Physics, in particular studying the atmospheric composition and structure using various satellite and ground-based data. With this expertise and also inspired by an increasing importance of training a scientifically educated generation who understands the challenges of the modern society and responsibilities that come with wealth, a new section on environmental physics has been developed. It included atmospheric processes and the greenhouse

  9. Small airway dysfunction by impulse oscillometry in asthmatic patients with normal forced expiratory volume in the 1st second values.

    PubMed

    Pisi, Roberta; Tzani, Panagiota; Aiello, Marina; Martinelli, Enrico; Marangio, Emilio; Nicolini, Gabriele; Olivieri, Dario; Chetta, Alfredo

    2013-01-01

    Small airways are relevant to the pathophysiology of asthma. We investigated whether in asthmatic patients with normal forced expiratory volume in the 1st second (FEV(1)) values, impulse oscillometry system (IOS), as a measure of small airway function, contributed additional information to spirometry either at baseline or after bronchodilator, and whether it was related to the disease control. The fall in resistance from 5 to 20 Hz (R5-R20) and reactance at 5 Hz (X5) by IOS and spirometry measures of small airway function (forced expiratory flow at 25-75% [FEF(25-75)] and forced vital capacity/slow inspiratory vital capacity [FVC/SVC]) at baseline and after 400 micrograms of salbutamol were prospectively measured in 33 asthmatic patients (18 women; age range, 18-66 years). Disease control was assessed by the Asthma Control Test (ACT). R5-R20 but not X5 values were significantly related to FEF(25-75) and FVC/SVC values (p < 0.05 for both correlations). When the bronchodilator response was assessed, no correlation was found among IOS and spirometry changes. ACT scores were related to R5-R20, FEF(25-75), and FVC/SVC values (p < 0.01 for all correlations). In asthmatic patients with normal FEV(1) values, R5-R20 values were related to spirometry measures of small airway function. However, when the bronchodilator response was assessed, IOS and spirometry provided quite different results. Moreover, small airway dysfunction, as assessed by IOS and spirometry, was associated with poor disease control and history of asthma exacerbations. The results of this study confirm the value of IOS, as an investigative tool, and suggest that in asthmatic patients with normal FEV(1) values and poor disease control, small airway function should be investigated. PMID:23406931

  10. New approaches for improving the production of the 1st and 2nd generation ethanol by yeast.

    PubMed

    Kurylenko, Olena; Semkiv, Marta; Ruchala, Justyna; Hryniv, Orest; Kshanovska, Barbara; Abbas, Charles; Dmytruk, Kostyantyn; Sibirny, Andriy

    2016-01-01

    Increase in the production of 1st generation ethanol from glucose is possible by the reduction in the production of ethanol co-products, especially biomass. We have developed a method to reduce biomass accumulation of Saccharomyces cerevisiae by the manipulation of the intracellular ATP level due to overexpression of genes of alkaline phosphatase, apyrase or enzymes involved in futile cycles. The strains constructed accumulated up to 10% more ethanol on a cornmeal hydrolysate medium. Similar increase in ethanol accumulation was observed in the mutants resistant to the toxic inhibitors of glycolysis like 3-bromopyruvate and others. Substantial increase in fuel ethanol production will be obtained by the development of new strains of yeasts that ferment sugars of the abundant lignocellulosic feedstocks, especially xylose, a pentose sugar. We have found that xylose can be fermented under elevated temperatures by the thermotolerant yeast, Hansenula polymorpha. We combined protein engineering of the gene coding for xylose reductase (XYL1) along with overexpression of the other two genes responsible for xylose metabolism in yeast (XYL2, XYL3) and the deletion of the global transcriptional activator CAT8, with the selection of mutants defective in utilizing ethanol as a carbon source using the anticancer drug, 3-bromopyruvate. Resulted strains accumulated 20-25 times more ethanol from xylose at the elevated temperature of 45°C with up to 12.5 g L(-1) produced. Increase in ethanol yield and productivity from xylose was also achieved by overexpression of genes coding for the peroxisomal enzymes: transketolase (DAS1) and transaldolase (TAL2), and deletion of the ATG13 gene. PMID:26619255

  11. Ichnological analysis of the Upper Miocene in the ANH-Tumaco-1-ST-P well: assessing paleoenvironmental conditions at the Tumaco Basin, in the Colombian Pacific

    NASA Astrophysics Data System (ADS)

    Giraldo-Villegas, Carlos A.; Celis, Sergio A.; Rodríguez-Tovar, Francisco J.; Pardo-Trujillo, Andrés; Vallejo-Hincapié, Diego F.; Trejos-Tamayo, Raúl A.

    2016-11-01

    Tumaco is a frontier basin located on the SW Colombian Pacific coast. It is composed of a thick siliciclastic sequence up to reach 10,000 m-thick. In recent years, the National Hydrocarbon Agency-ANH has promoted new exploration wells in order to understand the sedimentary dynamic and its relationship with petroleum systems. One of them, the ANH-Tumaco-1-ST-P well has ∼3000 m (12,000 feet). We carried out sedimentological, geochemical, and micropaleontological detailed analyses with special attention to the ichnology on a 55 m-cored interval (from 1695.3 to 1640.4 m = 5563-5382 ft) in order to assess paleoenvironmental conditions. Beds are composed of green and gray mudrocks interbedded with lithic sandstones and fine-grained tuffs. Calcareous microfossil assemblages defined by the recovery of Uvigerina carapitana, Uvigerina laviculata, Uvigerina pigmaea, Globigerina woodi,Globigerionoides obliquus, Discoaster bellus gr., Catinaster coalitus, Reticulofenestra pseudoumbilicus and Sphenolithus abies indicated a Tortonian age, between CN6/CN7 biozones. Six sedimentary facies were identified: (1, 2) massive and laminated mudrocks, (3, 4) massive and normal-graded sandstones, (5) heterolithic beds, and in some cases (6) sandstones with soft-deformation structures. These rocks were accumulated in a shallowing platform-prodelta environment with continuous volcanic influence. Ichnotaxonomic analysis, conducted for the first time in the Colombian Pacific, allowed the identification of eighteen ichnogenera: Alcyonidiopsis, Asterosoma, Chondrites, Conichnus, Cylindrichnus, Diplocraterion, Ophiomorpha, Palaeophycus, Phycosiphon, Planolites, Rhyzocorallium, Schaubcylindrichnus, Scolicia, Siphonichnus, Taeinidum, Teichichnus, Thalassinoides, and Zoophycos. The ichnological association belongs to the archetypal Cruziana ichnofacies and its "distal" expression. By integrating lithofacies and ichnological results, two segments have been distinguished: 1) the lower one (1695

  12. Power-law decay of the velocity autocorrelation function of a granular fluid in the homogeneous cooling state.

    PubMed

    Brey, J Javier; Ruiz-Montero, M J

    2015-01-01

    The hydrodynamic part of the velocity autocorrelation function of a granular fluid in the homogeneous cooling state has been calculated by using mode-coupling theory for a finite system with periodic boundary conditions. The existence of the shearing instability, leading to a divergent behavior of the velocity flow fluctuations, is taken into account. A time region in which the velocity autocorrelation function exhibits a power-law decay, when time is measured by the number of collisions per particle, has been been identified. Also the explicit form of the exponential asymptotic long time decay has been obtained. The theoretical prediction for the power-law decay is compared with molecular dynamics simulation results, and a good agreement is found, after taking into account finite size corrections. The effects of approaching the shearing instability are also explored. PMID:25679614

  13. The influence of autocorrelation in signature extraction: An example from a geobotanical investigation of Cotter Basin, Montana

    NASA Technical Reports Server (NTRS)

    Labovitz, M. L.; Masuoka, E. J. (Principal Investigator)

    1981-01-01

    The presence of positive serial correlation (autocorrelation) in remotely sensed data results in an underestimate of the variance-covariance matrix when calculated using contiguous pixels. This underestimate produces an inflation in F statistics. For a set of Thematic Mapper Simulator data (TMS), used to test the ability to discriminate a known geobotanical anomaly from its background, the inflation in F statistics related to serial correlation is between 7 and 70 times. This means that significance tests of means of the spectral bands initially appear to suggest that the anomalous site is very different in spectral reflectance and emittance from its background sites. However, this difference often disappears and is always dramatically reduced when compared to frequency distributions of test statistics produced by the comparison of simulated training sets possessing equal means, but which are composed of autocorrelated observations.

  14. Usage Autocorrelation Function in the Capacity of Indicator Shape of the Signal in Acoustic Emission Testing of Intricate Castings

    NASA Astrophysics Data System (ADS)

    Popkov, Artem

    2016-01-01

    The article contains information about acoustic emission signals analysing using autocorrelation function. Operation factors were analysed, such as shape of signal, the origins time and carrier frequency. The purpose of work is estimating the validity of correlations methods analysing signals. Acoustic emission signal consist of different types of waves, which propagate on different trajectories in object of control. Acoustic emission signal is amplitude-, phase- and frequency-modeling signal. It was described by carrier frequency at a given point of time. Period of signal make up 12.5 microseconds and carrier frequency make up 80 kHz for analysing signal. Usage autocorrelation function like indicator the origin time of acoustic emission signal raises validity localization of emitters.

  15. Velocity autocorrelation function of a dispersion of heavy particles in a turbulent flow: on the effect of interparticle collisions

    NASA Astrophysics Data System (ADS)

    Avila, R.; Rodriguez-Meza, M. A.

    2004-04-01

    The effect of particle-to-particle interactions on the dispersion and on the velocity auto-correlation function of heavy particles in a turbulent flow, is presented. The inter-particle collision process is based on a direct numerical simulation approach, which requires that all the particles be simultaneously tracked through the flow field. In the first part of the paper, the turbulent characteristics of the velocity of non-colliding heavy particles which disperse in a vertical, nearly isotropic, grid generated decaying turbulence air flow, are presented. In the second part of this investigation, the solid particles are allowed to collide. The numerical predictions confirm the fact that the inter-particle collisions promote a decrease of the lateral particle dispersion, the particle velocity autocorrelation function and the mean lateral velocity of the particles.

  16. The influence of autocorrelation in signature extraction - An example from a geobotanical investigation of Cotter Basin, Montana

    NASA Technical Reports Server (NTRS)

    Labovitz, M. L.; Masuoka, E. J.

    1984-01-01

    The presence of positive serial correlation (autocorrelation) in remotely sensed data results in an underestimate of the variance-covariance matrix when calculated using contiguous pixels. This underestimate produces an inflation in F statistics. For a set of Thematic Mapper Simulator data (TMS), used to test the ability to discriminate a known geobotanical anomaly from its background, the inflation in F statistics related to serial correlation is between 7 and 70 times. This means that significance tests of means of the spectal bands initially appear to suggest that the anomalous site is very different in spectral reflectance and emittance from its background sites. However, this difference often disappears and is always dramatically reduced when compared to frequency distributions of test statistics produced by the comparison of simulated training sets possessing equal means, but which are composed of autocorrelated observations.

  17. Mean-field approximation for a limit order driven market model.

    PubMed

    Slanina, F

    2001-11-01

    A mean-field variant of the model of limit order driven market introduced recently by Maslov is formulated and solved. The agents do not have any strategies and the memory of the system is kept within the order book. We show that the evolution of the order book is governed by a matrix multiplicative process. The resulting stationary distribution of step-to-step price changes is calculated. It exhibits a power-law tail with exponent 2. We obtain also the price autocorrelation function, which agrees qualitatively with the experimentally observed negative autocorrelation for short times. PMID:11736043

  18. On the Use of the Sparse Property of the Cyclic Autocorrelation Function to Blindly Estimate the Cyclostationarity

    NASA Astrophysics Data System (ADS)

    Khalaf, Ziad; Palicot, Jacques

    2012-09-01

    Based on the sparse property of the Cyclic Autocorrelation Function (CAF) in the cyclic frequency domain, we propose in this paper a new blind estimator using compressed sensing, which better estimates the Cyclic Autocorrelation Function at a given delay compared to the classical non blind estimator when using the same number of samples. Two metrics are used to evaluate this estimation: the Mean Square Error of type one and that of type two (MSE1 and MSE2). The first metric compares the estimated Cyclic Autocorrelation Vector (CAV) which is a particular vector of the CAF for a fixed delay τ, with the theoretical reference vector obtained using the CAF. The second metric compares the value of the estimated cyclic frequency with the theoretical one. Simulation results show lower (MSE1 and MSE2 for the new proposed estimator compared to the classical one under the same conditions, from the simplest scenario to the more realistic one that uses a filter at the transmission side, a reception noise, and fading channel.

  19. On the Use of the Sparse Property of the Cyclic Autocorrelation Function to Blindly Estimate the Cyclostationarity

    NASA Astrophysics Data System (ADS)

    Khalaf, Ziad; Palicot, Jacques

    2012-09-01

    Based on the sparse property of the Cyclic Autocorrelation Function (CAF) in the cyclic frequency domain, we propose in this paper a new blind estimator using compressed sensing, which better estimates the Cyclic Autocorrelation Function at a given delay compared to the classical non blind estimator when using the same number of samples. Two metrics are used to evaluate this estimation: the Mean Square Error of type one and that of type two (MSE1 andMSE2). The first metric compares the estimated Cyclic Autocorrelation Vector (CAV) which is a particular vector of the CAF for a fixed delayτ, with the theoretical reference vector obtained using the CAF. The second metric compares the value of the estimated cyclic frequency with the theoretical one. Simulation results show lower (MSE1 andMSE2 for the new proposed estimator compared to the classical one under the same conditions, from the simplest scenario to the more realistic one that uses a filter at the transmission side, a reception noise, and fading channel.

  20. Explaining Local-Scale Species Distributions: Relative Contributions of Spatial Autocorrelation and Landscape Heterogeneity for an Avian Assemblage

    PubMed Central

    Mattsson, Brady J.; Zipkin, Elise F.; Gardner, Beth; Blank, Peter J.; Sauer, John R.; Royle, J. Andrew

    2013-01-01

    Understanding interactions between mobile species distributions and landcover characteristics remains an outstanding challenge in ecology. Multiple factors could explain species distributions including endogenous evolutionary traits leading to conspecific clustering and endogenous habitat features that support life history requirements. Birds are a useful taxon for examining hypotheses about the relative importance of these factors among species in a community. We developed a hierarchical Bayes approach to model the relationships between bird species occupancy and local landcover variables accounting for spatial autocorrelation, species similarities, and partial observability. We fit alternative occupancy models to detections of 90 bird species observed during repeat visits to 316 point-counts forming a 400-m grid throughout the Patuxent Wildlife Research Refuge in Maryland, USA. Models with landcover variables performed significantly better than our autologistic and null models, supporting the hypothesis that local landcover heterogeneity is important as an exogenous driver for species distributions. Conspecific clustering alone was a comparatively poor descriptor of local community composition, but there was evidence for spatial autocorrelation in all species. Considerable uncertainty remains whether landcover combined with spatial autocorrelation is most parsimonious for describing bird species distributions at a local scale. Spatial structuring may be weaker at intermediate scales within which dispersal is less frequent, information flows are localized, and landcover types become spatially diversified and therefore exhibit little aggregation. Examining such hypotheses across species assemblages contributes to our understanding of community-level associations with conspecifics and landscape composition. PMID:23393564

  1. The analysis of trend variations of reference evapotranspiration via eliminating the significance effect of all autocorrelation coefficients

    NASA Astrophysics Data System (ADS)

    Amirataee, Babak; Montaseri, Majid; Sanikhani, Hadi

    2015-07-01

    Reference evapotranspiration (ET0) is considered a key parameter for evaluating the climatic changes as well as spatial and temporal patterns of parameters influencing the eco-hydrological processes. The analysis of trend variations of this index can be used to determine appropriate strategies in planning and management of water resources. In this paper, the trend variations of monthly and annual ET0 in Urmia Lake basin, located in the northwest of Iran, have been analyzed using data from 14 synoptic stations in the study area. Regarding the significant effect of autocorrelation coefficients with different lags on trend variations of ET0, this paper has resorted to modified Mann-Kendall test via eliminating the significance effect of autocorrelation coefficients with different lags to analyze the trend variations. Furthermore, Theil-Sen estimator has been used to determine the slope of trend line of ET0. The results indicated an increasing trend in ET0 values at all the studied stations. Having used the modified Mann-Kendall test, the values of significant increasing (positive) trend, which were estimated using common Mann-Kendall test, dramatically decreased. As such, the values of only 7 stations have been significant at 95 % level. The results confirmed the need for eliminating the significance effect of autocorrelation coefficients with different lags to determine and evaluate the trend of hydrological variables.

  2. The gated integration technique for the accurate measurement of the autocorrelation function of speckle intensities scattered from random phase screens

    NASA Astrophysics Data System (ADS)

    Zhang, Ningyu; Cheng, Chuanfu; Teng, Shuyun; Chen, Xiaoyi; Xu, Zhizhan

    2007-09-01

    A new approach based on the gated integration technique is proposed for the accurate measurement of the autocorrelation function of speckle intensities scattered from a random phase screen. The Boxcar used for this technique in the acquisition of the speckle intensity data integrates the photoelectric signal during its sampling gate open, and it repeats the sampling by a preset number, m. The average analog of the m samplings output by the Boxcar enhances the signal-to-noise ratio by √{m}, because the repeated sampling and the average make the useful speckle signals stable, while the randomly varied photoelectric noise is suppressed by 1/√{m}. In the experiment, we use an analog-to-digital converter module to synchronize all the actions such as the stepped movement of the phase screen, the repeated sampling, the readout of the averaged output of the Boxcar, etc. The experimental results show that speckle signals are better recovered from contaminated signals, and the autocorrelation function with the secondary maximum is obtained, indicating that the accuracy of the measurement of the autocorrelation function is greatly improved by the gated integration technique.

  3. PREFACE: 1st International School and Conference "Saint Petersburg OPEN 2014" on Optoelectronics, Photonics, Engineering and Nanostructures

    NASA Astrophysics Data System (ADS)

    2014-09-01

    Dear Colleagues, 1st International School and Conference "Saint Petersburg OPEN 2014" on Optoelectronics, Photonics, Engineering and Nanostructures was held on March 25 - 27, 2014 at St. Petersburg Academic University - Nanotechnology Research and Education Centre of the Russian Academy of Sciences. The School and Conference included a series of invited talks given by leading professors with the aim to introduce young scientists with actual problems and major advances in physics and technology. The keynote speakers were: Mikhail Glazov (Ioffe Physico-Technical Institute RAS, Russia) Vladimir Dubrovskii (Saint Petersburg Academic University RAS, Russia) Alexey Kavokin (University of Southampton, United Kingdom and St. Petersburg State University, Russia) Vladimir Korenev (Ioffe Physico-Technical Institute RAS, Russia) Sergey Kukushkin (Institute of Problems of Mechanical Engineering RAS, Russia) Nikita Pikhtin (Ioffe Physico-Technical Institute RAS, Russia and "Elfolum" Ltd., Russia) Dmitry Firsov (Saint Petersburg State Polytechnical University, Russia) During the poster session all undergraduate and graduate students attending the conference presented their works. Sufficiently large number of participants with more than 160 student attendees from all over the world allowed the Conference to provide a fertile ground for the fruitful discussions between the young scientists as well as to become a perfect platform for the valuable discussions between student authors and highly experienced scientists. The best student papers, which were selected by the Program Committee and by the invited speakers basing on the theses and their poster presentation, were awarded with diplomas of the conference - see the photos. This year's School and Conference is supported by SPIE (The International Society for Optics and Photonics), OSA (The Optical Society), St. Petersburg State Polytechnical University and by Skolkovo Foundation. It is a continuation of the annual schools and

  4. Creating Research-Rich Learning Experiences and Quantitative Skills in a 1st Year Earth Systems Course

    NASA Astrophysics Data System (ADS)

    King, P. L.; Eggins, S.; Jones, S.

    2014-12-01

    We are creating a 1st year Earth Systems course at the Australian National University that is built around research-rich learning experiences and quantitative skills. The course has top students including ≤20% indigenous/foreign students; nonetheless, students' backgrounds in math and science vary considerably posing challenges for learning. We are addressing this issue and aiming to improve knowledge retention and deep learning by changing our teaching approach. In 2013-2014, we modified the weekly course structure to a 1hr lecture; a 2hr workshop with hands-on activities; a 2hr lab; an assessment piece covering all face-to-face activities; and a 1hr tutorial. Our new approach was aimed at: 1) building student confidence with data analysis and quantitative skills through increasingly difficult tasks in science, math, physics, chemistry, climate science and biology; 2) creating effective learning groups using name tags and a classroom with 8-person tiered tables; 3) requiring students to apply new knowledge to new situations in group activities, two 1-day field trips and assessment items; 4) using pre-lab and pre-workshop exercises to promote prior engagement with key concepts; 5) adding open-ended experiments to foster structured 'scientific play' or enquiry and creativity; and 6) aligning the assessment with the learning outcomes and ensuring that it contains authentic and challenging southern hemisphere problems. Students were asked to design their own ocean current experiment in the lab and we were astounded by their ingenuity: they simulated the ocean currents off Antarctica; varied water density to verify an equation; and examined the effect of wind and seafloor topography on currents. To evaluate changes in student learning, we conducted surveys in 2013 and 2014. In 2014, we found higher levels of student engagement with the course: >~80% attendance rates and >~70% satisfaction (20% neutral). The 2014 cohort felt that they were more competent in writing

  5. Viscosity and stress autocorrelation function in supercooled water: a molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Guo, Guang-Jun; Zhang, Yi-Gang; Refson, Keith; Zhao, Ya-Juan

    Following GUO, G.-J., and ZHANG, Y.-G., 2001, Molec. Phys. , 99 , 283, which calculates the bulk and shear viscosities of SPC/E water at 30°C and 0.999gcm -3 , further molecular dynamics simulations have been performed at state points of 0°C,-20°C,-40°C, and -60°C along an approximate isobar with the previous state point. SACF and BACF (stress autocorrelation functions related to shear and bulk viscosities, respectively) of high precision have been obtained and compared for their similarities and differences. Shear and bulk viscosities calculated from them showed an increased deviation from real water with decreasing temperature. These correlation functions were then fitted using a uniform two-step relaxation function including a fast oscillatory Kohlrausch law and a slow straightforward Kohlrausch law. The fitting parameters of SACF and BACF have been analysed in detail, and several interesting dynamic phenomena were observed. (1) The oscillation frequency of SACF (44 ~ 48ps -1 ) for short time intervals agrees with the stretching mode of hydrogen bonds, while that of BACF (7 ~ 12ps -1 ) agrees with the bending mode of hydrogen bonds. (2) With decreasing temperature, the slow relaxation fraction of the BACF increases, while that of the SACF remains constant. (3) The exponents βin the Kohlrausch laws with values greater than 1 are obtained for BACF at ambient temperatures. (4) With regard to both shear and bulk viscosities, the slow relaxation time largely increases with decreasing temperature, while the fast relaxation time slightly decreases. These phenomena are qualitatively explained and discussed.

  6. ROTATION PERIODS OF 34,030 KEPLER MAIN-SEQUENCE STARS: THE FULL AUTOCORRELATION SAMPLE

    SciTech Connect

    McQuillan, A.; Mazeh, T.; Aigrain, S.

    2014-04-01

    We analyzed three years of data from the Kepler space mission to derive rotation periods of main-sequence stars below 6500 K. Our automated autocorrelation-based method detected rotation periods between 0.2 and 70 days for 34,030 (25.6%) of the 133,030 main-sequence Kepler targets (excluding known eclipsing binaries and Kepler Objects of Interest), making this the largest sample of stellar rotation periods to date. In this paper we consider the detailed features of the now well-populated period-temperature distribution and demonstrate that the period bimodality, first seen by McQuillan et al. in the M-dwarf sample, persists to higher masses, becoming less visible above 0.6 M {sub ☉}. We show that these results are globally consistent with the existing ground-based rotation-period data and find that the upper envelope of the period distribution is broadly consistent with a gyrochronological age of 4.5 Gyr, based on the isochrones of Barnes, Mamajek, and Hillenbrand and Meibom et al. We also performed a detailed comparison of our results to those of Reinhold et al. and Nielsen et al., who measured rotation periods of field stars observed by Kepler. We examined the amplitude of periodic variability for the stars with detection rotation periods, and found a typical range between ∼950 ppm (5th percentile) and ∼22,700 ppm (95th percentile), with a median of ∼5600 ppm. We found typically higher amplitudes for shorter periods and lower effective temperatures, with an excess of low-amplitude stars above ∼5400 K.

  7. New speckle analysis method for optical coherence tomography signal based on autocorrelation

    NASA Astrophysics Data System (ADS)

    De Pretto, Lucas R.; Nogueira, Gesse E. C.; Freitas, Anderson Z.

    2015-06-01

    Optical Coherence Tomography (OCT) is a noninvasive imaging technique with high resolution widely used for in vivo applications. Nonetheless, OCT is prone to speckle, a granular noise that degrades the OCT signal. Speckle statistics may, nevertheless, reveal information regarding the scatterers from which it originates. This fact is exploited by techniques such as Speckle Variance-OCT (SVOCT). SVOCT, however, doesn't provide quantitative information, which is a major drawback for the use of speckle based techniques on OCT. In the present work we attack this problem, proposing a new method for analysis of speckle in OCT signal, based on autocorrelation. We associate the changes in decorrelation time of the signal with the changes in flow velocity. It is expected that greater velocities result in lower decorrelation times. To verify that, milk was pumped through a microchannel at different velocities, and the decorrelation time was computed for a single point in the center of the microchannel, sampled at 8 kHz rate. Our results suggest that for flows rates greater than 1 μl/min it is possible to associate decorrelation time with flow velocity, while velocities below that value are not distinguishable, supposedly due to the Brownian motion. For flow rates above 50 μl/min our acquisition rate doesn't get enough sampling information, as the decorrelation time gets too low. These results indicate that Speckle based techniques may be used to get quantitative information of flow in OCT samples, which can be used to assist in many diagnostics modalities, as well as map such flow regions.

  8. Autocorrelation descriptor improvements for QSAR: 2DA_Sign and 3DA_Sign.

    PubMed

    Sliwoski, Gregory; Mendenhall, Jeffrey; Meiler, Jens

    2016-03-01

    Quantitative structure-activity relationship (QSAR) is a branch of computer aided drug discovery that relates chemical structures to biological activity. Two well established and related QSAR descriptors are two- and three-dimensional autocorrelation (2DA and 3DA). These descriptors encode the relative position of atoms or atom properties by calculating the separation between atom pairs in terms of number of bonds (2DA) or Euclidean distance (3DA). The sums of all values computed for a given small molecule are collected in a histogram. Atom properties can be added with a coefficient that is the product of atom properties for each pair. This procedure can lead to information loss when signed atom properties are considered such as partial charge. For example, the product of two positive charges is indistinguishable from the product of two equivalent negative charges. In this paper, we present variations of 2DA and 3DA called 2DA_Sign and 3DA_Sign that avoid information loss by splitting unique sign pairs into individual histograms. We evaluate these variations with models trained on nine datasets spanning a range of drug target classes. Both 2DA_Sign and 3DA_Sign significantly increase model performance across all datasets when compared with traditional 2DA and 3DA. Lastly, we find that limiting 3DA_Sign to maximum atom pair distances of 6 Å instead of 12 Å further increases model performance, suggesting that conformational flexibility may hinder performance with longer 3DA descriptors. Consistent with this finding, limiting the number of bonds in 2DA_Sign from 11 to 5 fails to improve performance. PMID:26721261

  9. Equatorial anisotropy of the Earth's inner inner core from autocorrelations of earthquake coda

    NASA Astrophysics Data System (ADS)

    Wang, T.; Song, X.; Xia, H.

    2014-12-01

    The anisotropic structure of the inner core seems complex with significant depth and lateral variations. An innermost inner core has been suggested with a distinct form of anisotropy, but it has considerable uncertainties in its form, size, or even existence. All the previous inner-core anisotropy models have assumed a cylindrical anisotropy with the symmetry axis parallel (or nearly parallel) to the Earth's spin axis. In this study, we obtain inner-core phases, PKIIKP2 and PKIKP2 (the round-trip phases between the station and its antipode that passes straight through the center of the Earth and that is reflected from the inner-core boundary, respectively), from stackings of autocorrelations of earthquake coda at seismic station clusters around the world. The differential travel times PKIIKP2 - PKIKP2, which are sensitive to inner-core structure, show fast arrivals at high latitudes. However, we also observed large variations of up to 10 s along equatorial paths. These observations can be explained by a cylindrical anisotropy in the inner inner core (IIC) (with a radius of slightly less than half the inner core radius) that has a fast axis aligned near the equator and a cylindrical anisotropy in the outer inner core (OIC) that has a fast axis along the north-south direction. The equatorial fast axis of the IIC is near the Central America and the Southeast Asia. The form of the anisotropy in the IIC is distinctly different from that in the OIC and the anisotropy amplitude in the IIC is about 70% stronger than in the OIC. The different forms of anisotropy may be explained by a two-phase system of iron in the inner core (hcp in the OIC and bcc in the IIC). These results may suggest a major shift of the tectonics of the inner core during its formation and growth.

  10. PREFACE: 1st Nano-IBCT Conference 2011 - Radiation Damage of Biomolecular Systems: Nanoscale Insights into Ion Beam Cancer Therapy

    NASA Astrophysics Data System (ADS)

    Huber, Bernd A.; Malot, Christiane; Domaracka, Alicja; Solov'yov, Andrey V.

    2012-07-01

    The 1st Nano-IBCT Conference entitled 'Radiation Damage in Biomolecular Systems: Nanoscale Insights into Ion Beam Cancer Therapy' was held in Caen, France, in October 2011. The Meeting was organised in the framework of the COST Action MP1002 (Nano-IBCT) which was launched in December 2010 (http://fias.uni-frankfurt.de/nano-ibct). This action aims to promote the understanding of mechanisms and processes underlying the radiation damage of biomolecular systems at the molecular and nanoscopic level and to use the findings to improve the strategy of Ion Beam Cancer Therapy. In the hope of achieving this, participants from different disciplines were invited to represent the fields of physics, biology, medicine and chemistry, and also included those from industry and the operators of hadron therapy centres. Ion beam therapy offers the possibility of excellent dose localization for treatment of malignant tumours, minimizing radiation damage in normal healthy tissue, while maximizing cell killing within the tumour. Several ion beam cancer therapy clinical centres are now operating in Europe and elsewhere. However, the full potential of such therapy can only be exploited by better understanding the physical, chemical and biological mechanisms that lead to cell death under ion irradiation. Considering a range of spatio-temporal scales, the proposed action therefore aims to combine the unique experimental and theoretical expertise available within Europe to acquire greater insight at the nanoscopic and molecular level into radiation damage induced by ion impact. Success in this endeavour will be both an important scientific breakthrough and give great impetus to the practical improvement of this innovative therapeutic technique. Ion therapy potentially provides an important advance in cancer therapy and the COST action MP1002 will be very significant in ensuring Europe's leadership in this field, providing the scientific background, required data and mechanistic insight which

  11. Auto-correlation of journal impact factor for consensus research reporting statements: a cohort study.

    PubMed

    Shanahan, Daniel R

    2016-01-01

    journal in which a reporting statement was published was shown to influence the number of citations that statement will gather over time. Similarly, the number of article accesses also influenced the number of citations, although to a lesser extent than the impact factor. This demonstrates that citation counts are not purely a reflection of scientific merit and the impact factor is, in fact, auto-correlated. PMID:27069817

  12. Auto-correlation of journal impact factor for consensus research reporting statements: a cohort study

    PubMed Central

    2016-01-01

    factor of the journal in which a reporting statement was published was shown to influence the number of citations that statement will gather over time. Similarly, the number of article accesses also influenced the number of citations, although to a lesser extent than the impact factor. This demonstrates that citation counts are not purely a reflection of scientific merit and the impact factor is, in fact, auto-correlated. PMID:27069817

  13. Near surface velocity structure of Pacaya volcano using spatial autocorrelation method

    NASA Astrophysics Data System (ADS)

    Kenyon, L. M.; Waite, G. P.; Manzoni, P.

    2011-12-01

    Pacaya Volcano, Guatemala is a basaltic volcano in the Central American arc characterized by persistent degassing and nearly continuous nonharmonic tremor, coupled at times with lava effusion and/or coincident strombolian-style explosions. A moderate (VEI 2-3) eruption on 27 May 2010 destroyed part of the edifice and was followed by the opening of a new vent ~1.6 km south-southeast of the edifice. This change in activity prompted a field campaign, highlighted by the deployment of a small-aperture array of seismometers 1.1 km west of the summit in January 2011. The semi-circular array consisted of 11 short-period three-component seismometers with an aperture of 300 m and irregular radii of about 70 m and 150 m. During the deployment, we recorded primarily narrow-band tremor of volcanic and anthropogenic origin. We used the spatial auto-correlation (SPAC) method to generate band-limited dispersion curves from the tremor data and then inverted the dispersion curves for a velocity model. From 23 - 24 January we identified 16 segments of 300 s each using spectrograms, within which there were no events defined as LP, VLP or VT earthquakes. These were also periods during which there was little narrow-band tremor. The lack of directional dependence on the correlations confirms that there were no strong localized tremor sources. Because the station spacing was not ideal for SPAC analysis, we combined results for seven different radii, with a minimum of 3 station pairs each. The number of station pairs for each radius is given in parentheses after the distance: 73 (6), 82 (3), 100 (4), 133 (4), 145 (4), 153 (4) and 212 m (4). There are a total of 29 pairs of stations. The dispersion curve model found using only the vertical component shows Rayleigh wave velocities ranging from 1200 m/s at 1.5 Hz to 250 m/s at 8 Hz. The observed dispersion curve velocity range is consistent with other previously studied volcanoes where low velocities are found in the top 300 m. An analysis of

  14. Generalized Bond Order Parameters to Characterize Transient Crystals

    NASA Astrophysics Data System (ADS)

    Isobe, Masaharu; Alder, Berni

    2013-03-01

    Higher order parameters in the hard disk fluid are computed to investigate the number, the life time and size of transient crystal nuclei in the pre-freezing phase. The methodology introduces further neighbor shells bond orientational order parameters and coarse-grains the correlation functions needed for the evaluation of the stress autocorrelation function for the viscosity. We successfully reproduce results by the previous collision method for the pair orientational correlation function, but some two orders of magnitude faster. This speed-up allows calculating the time dependent four body orientational correlation between two different pairs of particles as a function of their separation, needed to characterize the size of the transient crystals. The result is that the slow decay of the stress autocorrelation function near freezing is due to a large number of rather small crystal nuclei lasting long enough to lead to the molasses tail.

  15. Generalized bond order parameters to characterize transient crystals

    NASA Astrophysics Data System (ADS)

    Isobe, M.; Alder, B. J.

    2012-11-01

    Higher order parameters in the hard disk fluid are computed to investigate the number, the lifetime, and size of transient crystal nuclei in the pre-freezing phase. The methodology introduces further neighbor shells bond orientational order parameters and coarse-grains the correlation functions needed for the evaluation of the stress autocorrelation function for the viscosity. We successfully reproduce results by the previous collision method for the pair orientational correlation function, but some two orders of magnitude faster. This speed-up allows calculating the time dependent four body orientational correlation between two different pairs of particles as a function of their separation, needed to characterize the size of the transient crystals. The result is that the slow decay of the stress autocorrelation function near freezing is due to a large number of rather small crystal nuclei lasting long enough to lead to the molasses tail.

  16. Shared spatial effects on quantitative genetic parameters: accounting for spatial autocorrelation and home range overlap reduces estimates of heritability in wild red deer.

    PubMed

    Stopher, Katie V; Walling, Craig A; Morris, Alison; Guinness, Fiona E; Clutton-Brock, Tim H; Pemberton, Josephine M; Nussey, Daniel H

    2012-08-01

    Social structure, limited dispersal, and spatial heterogeneity in resources are ubiquitous in wild vertebrate populations. As a result, relatives share environments as well as genes, and environmental and genetic sources of similarity between individuals are potentially confounded. Quantitative genetic studies in the wild therefore typically account for easily captured shared environmental effects (e.g., parent, nest, or region). Fine-scale spatial effects are likely to be just as important in wild vertebrates, but have been largely ignored. We used data from wild red deer to build "animal models" to estimate additive genetic variance and heritability in four female traits (spring and rut home range size, offspring birth weight, and lifetime breeding success). We then, separately, incorporated spatial autocorrelation and a matrix of home range overlap into these models to estimate the effect of location or shared habitat on phenotypic variation. These terms explained a substantial amount of variation in all traits and their inclusion resulted in reductions in heritability estimates, up to an order of magnitude up for home range size. Our results highlight the potential of multiple covariance matrices to dissect environmental, social, and genetic contributions to phenotypic variation, and the importance of considering fine-scale spatial processes in quantitative genetic studies. PMID:22834741

  17. Three-dimensional analysis of the distal movement of maxillary 1st molars in patients fitted with mini-implant-aided trans-palatal arches

    PubMed Central

    Miresmaeili, Amirfarhang; Sajedi, Ahmad; Moghimbeigi, Abbas

    2015-01-01

    Objective The aim of this study was to investigate three-dimensional molar displacement after distalization via miniscrews and a horizontal modification of the trans-palatal-arch (TPA). Methods The subjects in this clinical trial were 26 Class II patients. After the preparation of a complete set of diagnostic records, miniscrews were inserted between the maxillary 2nd premolar and 1st molar on the palatal side. Elastic modules connected to the TPA exerting an average force of 150-200 g/side parallel to the occlusal plane were applied. Cone-beam computed tomography was utilized to evaluate the position of the miniscrews relative to the adjacent teeth and maxillary sinus, and the direction of force relative to molar furcation. The distances from the central point of the incisive papilla to the mesiopalatal cusps of the 1st maxillary molars and the distances between the mesiopalatal cusps of the left and right molars were measured to evaluate displacement of the maxillary molars on the horizontal plane. Interocclusal space was used to evaluate vertical changes. Results Mean maxillary 1st molar distalization was 2.3 ± 1.1 mm, at a rate of 0.4 ± 0.2 mm/month, and rotation was not significant. Intermolar width increased by 2.9 ± 1.8 mm. Molars were intruded relative to the neighboring teeth, from 0.1 to 0.8 mm. Conclusions Distalization of molars was possible without extrusion, using the appliance investigated. The intrusive component of force reduced the rate of distal movement. PMID:26445718

  18. Moral Judgment and Its Relation to Second-Order Theory of Mind

    ERIC Educational Resources Information Center

    Fu, Genyue; Xiao, Wen S.; Killen, Melanie; Lee, Kang

    2014-01-01

    Recent research indicates that moral judgment and 1st-order theory of mind abilities are related. What is not known, however, is how 2nd-order theory of mind is related to moral judgment. In the present study, we extended previous findings by administering a morally relevant theory of mind task (an accidental transgressor) to 4- to 7-year-old…

  19. [Influence of hypocaloric diet with addition of a vitamin-mineral complex on status of patients with obesity 1st and 2nd degrees].

    PubMed

    Sharafetdinov, Kh Kh; Plotnikova, O A; Zykina, V V; Mal'tsev, G Iu; Sokol'nikov, A A; Kaganov, B S

    2011-01-01

    Addition of a vitamin-mineral complex (VMC) to a standard hypocaloric diet leads to a positive dynamics of antropometric characteristics in patients with obesity 1st and 2nd degrees which is comparable to effectiveness of standard dietotherapy (dietary treatment) traditionally used in complex treatment of obesity. Addition of 1,8 mg of vitamin B2 as part of VMC to a hypocaloric diet is shown to be inadequate in eradication of marginal provision of riboflavin when using diets reduced in calories. PMID:22232885

  20. The Earth Microbiome Project: The Meeting Report for the 1st International Earth Microbiome Project Conference, Shenzhen, China, June 13th-15th 2011

    PubMed Central

    Gilbert, Jack A.; Bailey, Mark; Field, Dawn; Fierer, Noah; Fuhrman, Jed A.; Hu, Bin; Jansson, Janet; Knight, Rob; Kowalchuk, George A.; Kyrpides, Nikos C.; Meyer, Folker; Stevens, Rick

    2011-01-01

    This report details the outcome of the 1st International Earth Microbiome Project Conference. The 2-day conference was held at the Kingkey Palace Hotel, Shenzhen, China, on the 14th-15th June 2011, and was hosted by BGI (formally the Beijing Genomics Institute). The conference was arranged as a formal launch for the Earth Microbiome Project, to highlight some of the exciting research projects, results of the preliminary pilot studies, and to provide a discussion forum for the types of technology and experimental approaches that will come to define the standard operating procedures of this project.

  1. Autocorrelation measurement of femtosecond laser pulses based on two-photon absorption in GaP photodiode

    SciTech Connect

    Chong, E. Z.; Watson, T. F.; Festy, F.

    2014-08-11

    Semiconductor materials which exhibit two-photon absorption characteristic within a spectral region of interest can be useful in building an ultra-compact interferometric autocorrelator. In this paper, we report on the evidence of a nonlinear absorption process in GaP photodiodes which was exploited to measure the temporal profile of femtosecond Ti:sapphire laser pulses with a tunable peak wavelength above 680 nm. The two-photon mediated conductivity measurements were performed at an average laser power of less than a few tenths of milliwatts. Its suitability as a single detector in a broadband autocorrelator setup was assessed by investigating the nonlinear spectral sensitivity bandwidth of a GaP photodiode. The highly favourable nonlinear response was found to cover the entire tuning range of our Ti:sapphire laser and can potentially be extended to wavelengths below 680 nm. We also demonstrated the flexibility of GaP in determining the optimum compensation value of the group delay dispersion required to restore the positively chirped pulses inherent in our experimental optical system to the shortest pulse width possible. With the rise in the popularity of nonlinear microscopy, the broad two-photon response of GaP and the simplicity of this technique can provide an alternative way of measuring the excitation laser pulse duration at the focal point of any microscopy systems.

  2. A Mixed Model to Disentangle Variance and Serial Autocorrelation in Affective Instability Using Ecological Momentary Assessment Data.

    PubMed

    Vansteelandt, Kristof; Verbeke, Geert

    2016-01-01

    Affective instability, the tendency to experience emotions that fluctuate frequently and intensively over time, is a core feature of several mental disorders including borderline personality disorder. Currently, affect is often measured with Ecological Momentary Assessment protocols, which yield the possibility to quantify the instability of affect over time. A number of linear mixed models are proposed to examine (diagnostic) group differences in affective instability. The models contribute to the existing literature by estimating simultaneously both the variance and serial dependency component of affective instability when observations are unequally spaced in time with the serial autocorrelation (or emotional inertia) declining as a function of the time interval between observations. In addition, the models can eliminate systematic trends, take between subject differences into account and test for (diagnostic) group differences in serial autocorrelation, short-term as well as long-term affective variability. The usefulness of the models is illustrated in a study on diagnostic group differences in affective instability in the domain of eating disorders. Limitations of the model are that they pertain to group (and not individual) differences and do not focus explicitly on circadian rhythms or cycles in affect. PMID:27191204

  3. Clinical Performance of the 1st American Academy of Orthopaedic Surgeons Clinical Guideline on Prevention of Symptomatic Pulmonary Embolism after Total Knee Arthroplasty in Korean Patients

    PubMed Central

    2015-01-01

    We sought to document the clinical performance of the 1st American Academy of Orthopaedic Surgeons (AAOS) guideline on the prevention of symptomatic pulmonary embolism (PE) after total knee arthroplasty (TKA) in Korean patients, in terms of the proportions of the each risk-stratified group, efficacy and safety. Consecutive 328 patients underwent TKA were preoperatively assessed for the risks of PE and bleeding and categorized into 4 groups: 1) standard risk, 2) high risk for PE, 3) high risk for bleeding, and 4) high risks both for PE and bleeding. One of three options was administered according to the groups (aspirin in group 1 or 4; enoxaparin and following aspirin in group 2; antithrombotic stocking in group 3). Incidences of symptomatic deep vein thrombosis (DVT) and PE, and major or minor bleeding complications were evaluated. Majority of the patients (86%) were assessed to be with standard risks both for PE and bleeding. No patient experienced symptomatic DVT or PE and major bleeding. Eleven percent of the patients discontinued chemoprophylaxis because of bleeding-related wound complication. In conclusion, the 1st AAOS guideline functions successfully in Korean patients undergoing TKA in terms of prevention of symptomatic DVT and PE while avoiding major bleeding complications. PMID:26713064

  4. COERC 2002: Appreciating Scholarship. Proceedings of the Annual College of Education Research Conference (1st, Miami, Florida, April 27, 2002).

    ERIC Educational Resources Information Center

    Nielsen, Sarah M., Ed.; Rocco, Tonette S., Ed.

    This conference was designed to offer a view to novice scholars of what scholarship is and provide insights on how to share knowledge with others. The keynote speech by Lisa Delpit, "The Role of Scholarship," is not included in this volume. Other conference papers, presented in alphabetical order by first author, include: (1) "Social Studies in…

  5. Weather Education. Proceedings of the International Conference on School and Popular Meteorological Education (1st, Oxford, England, July 1984).

    ERIC Educational Resources Information Center

    Walker, J. M., Ed.

    The First International Conference on School and Popular Meteorological Education was designed to: (1) examine the need for the general public to be educated in science and mathematics in order to live in today's high technological society; (2) note special attributes that meteorology possesses as a vehicle to teach science and mathematics to all…

  6. Current practice of epidemiology in Africa: highlights of the 3rd conference of the African epidemiological association and 1st conference of the Cameroon society of epidemiology, Yaoundé, Cameroon, 2014

    PubMed Central

    Nkwescheu, Armand Seraphin; Fokam, Joseph; Tchendjou, Patrice; Nji, Akindeh; Ngouakam, Hermann; Andre, Bita Fouda; Joelle, Sobngwi; Uzochukwu, Benjamin; Akinroye, Kingsley; Mbacham, Wilfred; Colizzi, Vittorio; Leke, Rose; Victora, Cesar

    2015-01-01

    As the study of disease occurrence and health indicators in human populations, Epidemiology is a dynamic field that evolves with time and geographical context. In order to update African health workers on current epidemiological practices and to draw awareness of early career epidemiologists on concepts and opportunities in the field, the 3rd African Epidemiology Association and the 1st Cameroon Society of Epidemiology Conference was organized in June 2-6, 2014 at the Yaoundé Mont Febe Hotel, in Cameroon. Under the theme«Practice of Epidemiology in Africa: Stakes, Challenges and Perspectives», the conference attracted close to five hundred guest and participants from all continents. The two main programs were the pre-conference course for capacity building of African Early Career epidemiologists, and the conference itself, providing a forum for scientific exchanges on recent epidemiological concepts, encouraging the use of epidemiological methods in studying large disease burden and neglected tropical diseases; and highlighting existing opportunities. PMID:26523191

  7. Exogenous attention enhances 2nd-order contrast sensitivity.

    PubMed

    Barbot, Antoine; Landy, Michael S; Carrasco, Marisa

    2011-05-11

    Natural scenes contain a rich variety of contours that the visual system extracts to segregate the retinal image into perceptually coherent regions. Covert spatial attention helps extract contours by enhancing contrast sensitivity for 1st-order, luminance-defined patterns at attended locations, while reducing sensitivity at unattended locations, relative to neutral attention allocation. However, humans are also sensitive to 2nd-order patterns such as spatial variations of texture, which are predominant in natural scenes and cannot be detected by linear mechanisms. We assess whether and how exogenous attention--the involuntary and transient capture of spatial attention--affects the contrast sensitivity of channels sensitive to 2nd-order, texture-defined patterns. Using 2nd-order, texture-defined stimuli, we demonstrate that exogenous attention increases 2nd-order contrast sensitivity at the attended location, while decreasing it at unattended locations, relative to a neutral condition. By manipulating both 1st- and 2nd-order spatial frequency, we find that the effects of attention depend both on 2nd-order spatial frequency of the stimulus and the observer's 2nd-order spatial resolution at the target location. At parafoveal locations, attention enhances 2nd-order contrast sensitivity to high, but not to low 2nd-order spatial frequencies; at peripheral locations attention also enhances sensitivity to low 2nd-order spatial frequencies. Control experiments rule out the possibility that these effects might be due to an increase in contrast sensitivity at the 1st-order stage of visual processing. Thus, exogenous attention affects 2nd-order contrast sensitivity at both attended and unattended locations. PMID:21356228

  8. Exogenous attention enhances 2nd-order contrast sensitivity

    PubMed Central

    Barbot, Antoine; Landy, Michael S.; Carrasco, Marisa

    2011-01-01

    Natural scenes contain a rich variety of contours that the visual system extracts to segregrate the retinal image into perceptually coherent regions. Covert spatial attention helps extract contours by enhancing contrast sensitivity for 1st-order, luminance-defined patterns at attended locations, while reducing sensitivity at unattended locations, relative to neutral attention allocation. However, humans are also sensitive to 2nd-order patterns such as spatial variations of texture, which are predominant in natural scenes and cannot be detected by linear mechanisms. We assess whether and how exogenous attention—the involuntary and transient capture of spatial attention—affects the contrast sensitivity of channels sensitive to 2nd-order, texture-defined patterns. Using 2nd-order, texture-defined stimuli, we demonstrate that exogenous attention increases 2nd-order contrast sensitivity at the attended location, while decreasing it at unattended locations, relative to a neutral condition. By manipulating both 1st- and 2nd-order spatial frequency, we find that the effects of attention depend both on 2nd-order spatial frequency of the stimulus and the observer’s 2nd-order spatial resolution at the target location. At parafoveal locations, attention enhances 2nd-order contrast sensitivity to high, but not to low 2nd-order spatial frequencies; at peripheral locations attention also enhances sensitivity to low 2nd-order spatial frequencies. Control experiments rule out the possibility that these effects might be due to an increase in contrast sensitivity at the 1st-order stage of visual processing. Thus, exogenous attention affects 2nd-order contrast sensitivity at both attended and unattended locations. PMID:21356228

  9. The transient nature of 2nd-order stereopsis.

    PubMed

    Hess, Robert F; Wilcox, Laurie M

    2008-05-01

    There are currently two competing dichotomies used to describe how local stereoscopic information is processed by the human visual system. The first is in terms of the type of the spatial filtering operations used to extract relevant image features prior to stereoscopic analysis (i.e. 1st- vs 2nd-order stereo; [Hess, R. F., & Wilcox, L. M. (1994). Linear and non-linear filtering in stereopsis. Vision Research, 34, 2431-2438]). The second is in terms of the temporal properties of the mechanisms used to process stereoscopic information (i.e. sustained vs transient stereo; [Schor, C. M., Edwards, M., & Pope, D. R. (1998). Spatial-frequency and contrast tuning of the transient-stereopsis system. Vision Research, 38(20), 3057-3068]). Here we compare the dynamics of 1st- and 2nd-order stereopsis using several types of stimuli and find a clear dissociation in which 1st-order stimuli exhibit sustained properties while 2nd-order patterns show more transient properties. Our results and analyses unify and simplify two complimentary bodies of work. PMID:18407312

  10. Determination of modulation transfer function of a printer by measuring the autocorrelation of the transmission function of a printed Ronchi grating

    SciTech Connect

    Madanipour, Khosro; Tavassoly, Mohammad T

    2009-02-01

    We show theoretically and verify experimentally that the modulation transfer function (MTF) of a printing system can be determined by measuring the autocorrelation of a printed Ronchi grating. In practice, two similar Ronchi gratings are printed on two transparencies and the transparencies are superimposed with parallel grating lines. Then, the gratings are uniformly illuminated and the transmitted light from a large section is measured versus the displacement of one grating with respect to the other in a grating pitch interval. This measurement provides the required autocorrelation function for determination of the MTF.

  11. Effect of milk feed source, frequency of feeding and age at turnout on calf performance, live-weight at mating and 1st lactation milk production

    PubMed Central

    2012-01-01

    Female calves (n = 108) were assigned to 6 cold milk feeding treatments in two experiments for a 70-day period. Live-weight (LW) was measured weekly, with an additional LW taken at day 410 and post-calving for animals in experiment 1. In Experiment 1, the effect of feeding frequency and age of turnout to pasture on calf performance and 1st lactation milk yields were evaluated. The whole milk (WM) feeding treatments applied were (i) once daily feeding (OD), (ii) twice daily feeding (TD), (iii) OD feeding, outdoors at 38 days (ODO). In Experiment 2, the effects of feeding milk replacer (MR) as opposed to WM and age of turnout to pasture on calf performance were evaluated. The treatments applied were (i) OD feeding with WM (OD), (ii) OD feeding with milk replacer (MR) (ODMR), (iii) OD feeding with MR, outdoors at 38 days (ODMRO). Experiment 1: There were no differences (P > 0.05) in LW or average daily gain between TD and OD calves at day 80 or 410. ODO calves had lower LW at day 80 as compared to OD or TD (P < 0.001). Calf LW at day 80 was 86, 89 and 85 kg and at day 410 was 304, 309 and 316 kg for OD, TD and ODO, respectively. Milk feeding frequency or time of calf turnout had no effect on LW post calving, milk composition or 1st lactation milk yields. Experiment 2: Total LW at day 80 was higher (P < 0.05) for ODMR compared to OD or ODMRO calves. Calf LW was 87, 95, and 88 kg for OD, ODMR and ODMRO, respectively. However, LW at day 410 did not differ between treatments. This study showed that while some differences were observed in calf LW at day 80, these differences had no effect on LW at day 410 or 1st lactation milk yield. It can be concluded that calves can be successfully reared when fed OD with WM or MR, indoors and when turned out to pasture at 38 days of age. PMID:23078871

  12. Studies in astronomical time series analysis. III - Fourier transforms, autocorrelation functions, and cross-correlation functions of unevenly spaced data

    NASA Technical Reports Server (NTRS)

    Scargle, Jeffrey D.

    1989-01-01

    This paper develops techniques to evaluate the discrete Fourier transform (DFT), the autocorrelation function (ACF), and the cross-correlation function (CCF) of time series which are not evenly sampled. The series may consist of quantized point data (e.g., yes/no processes such as photon arrival). The DFT, which can be inverted to recover the original data and the sampling, is used to compute correlation functions by means of a procedure which is effectively, but not explicitly, an interpolation. The CCF can be computed for two time series not even sampled at the same set of times. Techniques for removing the distortion of the correlation functions caused by the sampling, determining the value of a constant component to the data, and treating unequally weighted data are also discussed. FORTRAN code for the Fourier transform algorithm and numerical examples of the techniques are given.

  13. Quantifying uncertainty in soot volume fraction estimates using Bayesian inference of auto-correlated laser-induced incandescence measurements

    NASA Astrophysics Data System (ADS)

    Hadwin, Paul J.; Sipkens, T. A.; Thomson, K. A.; Liu, F.; Daun, K. J.

    2016-01-01

    Auto-correlated laser-induced incandescence (AC-LII) infers the soot volume fraction (SVF) of soot particles by comparing the spectral incandescence from laser-energized particles to the pyrometrically inferred peak soot temperature. This calculation requires detailed knowledge of model parameters such as the absorption function of soot, which may vary with combustion chemistry, soot age, and the internal structure of the soot. This work presents a Bayesian methodology to quantify such uncertainties. This technique treats the additional "nuisance" model parameters, including the soot absorption function, as stochastic variables and incorporates the current state of knowledge of these parameters into the inference process through maximum entropy priors. While standard AC-LII analysis provides a point estimate of the SVF, Bayesian techniques infer the posterior probability density, which will allow scientists and engineers to better assess the reliability of AC-LII inferred SVFs in the context of environmental regulations and competing diagnostics.

  14. Temporal coherence effects in multiple ionization of N{sub 2} via XUV pump-probe autocorrelation

    SciTech Connect

    Jiang, Y. H.; Pfeifer, T.; Kurka, M.; Kuehnel, K. U.; Schroeter, C. D.; Moshammer, R.; Rudenko, A.; Foucar, L.; Herrwerth, O.; Lezius, M.; Kling, M. F.; Liu, X.; Ueda, K.; Duesterer, S.; Treusch, R.; Ullrich, J.

    2010-10-15

    Using a split-mirror stage combined with a reaction microscope, nonlinear autocorrelation traces of XUV pulses from the Free-electron LASer at Hamburg were recorded for N{sub 2} multiphoton-induced fragmentation into noncoincident N{sup 2+} and coincident N{sup 2+}+N{sup 2+} channels. We find a pulse duration of 40{+-}10 fs along with a sharp spike pointing to a coherence time of 4{+-}1 fs, almost twice as short as in previous observations. Both are well reproduced by a simulation based on the partial-coherence model that includes the molecular dynamics leading to an {approx}12-fs substructure in the trace.

  15. Analytical Tools To Distinguish the Effects of Localization Error, Confinement, and Medium Elasticity on the Velocity Autocorrelation Function

    PubMed Central

    Weber, Stephanie C.; Thompson, Michael A.; Moerner, W.E.; Spakowitz, Andrew J.; Theriot, Julie A.

    2012-01-01

    Single particle tracking is a powerful technique for investigating the dynamic behavior of biological molecules. However, many of the analytical tools are prone to generate results that can lead to mistaken interpretations of the underlying transport process. Here, we explore the effects of localization error and confinement on the velocity autocorrelation function, Cυ. We show that calculation of Cυ across a range of discretizations can distinguish the effects of localization error, confinement, and medium elasticity. Thus, under certain regimes, Cυ can be used as a diagnostic tool to identify the underlying mechanism of anomalous diffusion. Finally, we apply our analysis to experimental data sets of chromosomal loci and RNA-protein particles in Escherichia coli. PMID:22713559

  16. The ability of spectrum autocorrelation models to predict the lycopene concentration in foods through visible spectroscopic data.

    PubMed

    Torrecilla, José S; Fernández-Ruiz, Virginia; Cámara, Montaña; Mata, M Cortes Sánchez

    2011-10-15

    We developed a novel computerized approach based on lag-k autocorrelation coefficients (LCCs) and linear models (LMs) to estimate the concentration of lycopene in foods by the spectroscopy. The LCCs were calculated using the data obtained using whole visible scans from 400 to 600 nm (vide supra) of lycopene standards and food samples (ketchup, tomato juice and tomato sauce). The chaotic parameter (CP) was then transferred into a LM to estimate the concentration of lycopene compound. The integrated LCC/visible spectroscopy method developed can be considered as a satisfactory analytical technique able to estimate lycopene concentration in food samples in a fast accurate way, with a mean prediction error lower than 5.7% and a mean correlation coefficient higher than 0.957. PMID:21962671

  17. Quantum reaction rate from higher derivatives of the thermal flux-flux autocorrelation function at time zero.

    PubMed

    Ceotto, Michele; Yang, Sandy; Miller, William H

    2005-01-22

    A quantum theory of thermal reaction rates is presented which may be viewed as an extension of the recently developed "quantum instanton" (QI) model [W. H. Miller, Y. Zhao, M. Ceotto, and S. Yang, J. Chem. Phys. 119, 1329 (2003)]. It is based on using higher derivatives of the flux-flux autocorrelation function C(t) (as given by Miller, Schwartz, and Tromp) at t=0 to construct a short time approximation for C(t). Tests of this theory on 1d and collinear reactions, both symmetric and asymmetric, show it to be more accurate than the original QI model, giving rate constants to approximately 5% for a wide range of temperature. PMID:15740237

  18. Quantum reaction rate from higher derivatives of the thermal flux-flux autocorrelation function at time zero

    NASA Astrophysics Data System (ADS)

    Ceotto, Michele; Yang, Sandy; Miller, William H.

    2005-01-01

    A quantum theory of thermal reaction rates is presented which may be viewed as an extension of the recently developed "quantum instanton" (QI) model [W. H. Miller, Y. Zhao, M. Ceotto, and S. Yang, J. Chem. Phys. 119, 1329 (2003)]. It is based on using higher derivatives of the flux-flux autocorrelation function C(t) (as given by Miller, Schwartz, and Tromp) at t=0 to construct a short time approximation for C(t). Tests of this theory on 1d and collinear reactions, both symmetric and asymmetric, show it to be more accurate than the original QI model, giving rate constants to ˜5% for a wide range of temperature.

  19. Momentum autocorrelation function of an impurity in a classical oscillator chain with alternating masses III. Some limiting cases

    NASA Astrophysics Data System (ADS)

    Yu, Ming B.

    2016-04-01

    The momentum autocorrelation function of a mass impurity in a classic diatomic chain is studied using the recurrence relations method. General expressions for the contributions of branch cuts and resonant poles have been derived and illustrated in previous papers I and II, respectively. In the present paper a series of limiting cases that any one of the three masses m0 ,m1 ,m2 approaches to zero or infinity are analyzed. It is found that the cases m0 → 0 and →(2m2)+ are closely related to each other and that the general expressions for the amplitudes are valid also in the limits λ → 0 and ∞. The ergodicity in the case m2 → 0 is studied and the ratio of two specific infinite products is obtained.

  20. Order-parameter scaling in fluctuation-dominated phase ordering.

    PubMed

    Kapri, Rajeev; Bandyopadhyay, Malay; Barma, Mustansir

    2016-01-01

    In systems exhibiting fluctuation-dominated phase ordering, a single order parameter does not suffice to characterize the order, and it is necessary to monitor a larger set. For hard-core sliding particles on a fluctuating surface and the related coarse-grained depth (CD) models, this set comprises the long-wavelength Fourier components of the density profile, which capture the breakup and remerging of particle-rich regions. We study both static and dynamic scaling laws obeyed by the Fourier modes Q_{mL} and find that the mean value obeys the static scaling law 〈Q_{mL}〉∼L^{-ϕ}f(m/L) with ϕ≃2/3 and ϕ≃3/5 for Edwards-Wilkinson (EW) and Kardar-Parisi-Zhang (KPZ) surface evolution, respectively, and ϕ≃3/4 for the CD model. The full probability distribution P(Q_{mL}) exhibits scaling as well. Further, time-dependent correlation functions such as the steady-state autocorrelation and cross-correlations of order-parameter components are scaling functions of t/L^{z}, where L is the system size and z is the dynamic exponent, with z=2 for EW and z=3/2 for KPZ surface evolution. In addition we find that the CD model shows temporal intermittency, manifested in the dynamical structure functions of the density and the weak divergence of the flatness as the scaled time approaches 0. PMID:26871034

  1. Velocity autocorrelation by quantum simulations for direct parameter-free computations of the neutron cross sections. II. Liquid deuterium

    NASA Astrophysics Data System (ADS)

    Guarini, E.; Neumann, M.; Bafile, U.; Celli, M.; Colognesi, D.; Bellissima, S.; Farhi, E.; Calzavara, Y.

    2016-06-01

    Very recently we showed that quantum centroid molecular dynamics (CMD) simulations of the velocity autocorrelation function provide, through the Gaussian approximation (GA), an appropriate representation of the single-molecule dynamic structure factor of liquid H2, as witnessed by a straightforward absolute-scale agreement between calculated and experimental values of the total neutron cross section (TCS) at thermal and epithermal incident energies. Also, a proper quantum evaluation of the self-dynamics was found to guarantee, via the simple Sköld model, a suitable account of the distinct (intermolecular) contributions that influence the neutron TCS of para-H2 for low-energy neutrons (below 10 meV). The very different role of coherent nuclear scattering in D2 makes the neutron response from this liquid much more extensively determined by the collective dynamics, even above the cold neutron range. Here we show that the Sköld approximation maintains its effectiveness in producing the correct cross section values also in the deuterium case. This confirms that the true key point for reliable computational estimates of the neutron TCS of the hydrogen liquids is, together with a good knowledge of the static structure factor, the modeling of the self part, which must take into due account quantum delocalization effects on the translational single-molecule dynamics. We demonstrate that both CMD and ring polymer molecular dynamics (RPMD) simulations provide similar results for the velocity autocorrelation function of liquid D2 and, consequently, for the neutron double differential cross section and its integrals. This second investigation completes and reinforces the validity of the proposed quantum method for the prediction of the scattering law of these cryogenic liquids, so important for cold neutron production and related condensed matter research.

  2. Joint U.S./Japan Conference on Adaptive Structures, 1st, Maui, HI, Nov. 13-15, 1990, Proceedings

    NASA Technical Reports Server (NTRS)

    Wada, Ben K. (Editor); Fanson, James L. (Editor); Miura, Koryo (Editor)

    1991-01-01

    The present volume of adaptive structures discusses the development of control laws for an orbiting tethered antenna/reflector system test scale model, the sizing of active piezoelectric struts for vibration suppression on a space-based interferometer, the control design of a space station mobile transporter with multiple constraints, and optimum configuration control of an intelligent truss structure. Attention is given to the formulation of full state feedback for infinite order structural systems, robustness issues in the design of smart structures, passive piezoelectric vibration damping, shape control experiments with a functional model for large optical reflectors, and a mathematical basis for the design optimization of adaptive trusses in precision control. Topics addressed include approaches to the optimal adaptive geometries of intelligent truss structures, the design of an automated manufacturing system for tubular smart structures, the Sandia structural control experiments, and the zero-gravity dynamics of space structures in parabolic aircraft flight.

  3. Experimental First Order Pairing Phase Transition in Atomic Nuclei

    NASA Astrophysics Data System (ADS)

    Moretto, L. G.; Larsen, A. C.; Giacoppo, F.; Guttormsen, M.; Siem, S.

    2015-02-01

    The natural log of experimental nuclear level densities at low energy is linear with energy. This can be interpreted in terms of a nearly 1st order phase transition from a superfluid to an ideal gas of quasi particles. The transition temperature coincides with the BCS critical temperature and yields gap parameters in good agreement with the values extracted from even- odd mass differences from rotational states. This converging evidence supports the relevance of the BCS theory to atomic nuclei.

  4. Spatial epidemiology in zoonotic parasitic diseases: insights gained at the 1st International Symposium on Geospatial Health in Lijiang, China, 2007

    PubMed Central

    Zhou, Xiao-Nong; Lv, Shan; Yang, Guo-Jing; Kristensen, Thomas K; Bergquist, N Robert; Utzinger, Jürg; Malone, John B

    2009-01-01

    The 1st International Symposium on Geospatial Health was convened in Lijiang, Yunnan province, People's Republic of China from 8 to 9 September, 2007. The objective was to review progress made with the application of spatial techniques on zoonotic parasitic diseases, particularly in Southeast Asia. The symposium featured 71 presentations covering soil-transmitted and water-borne helminth infections, as well as arthropod-borne diseases such as leishmaniasis, malaria and lymphatic filariasis. The work made public at this occasion is briefly summarized here to highlight the advances made and to put forth research priorities in this area. Approaches such as geographical information systems (GIS), global positioning systems (GPS) and remote sensing (RS), including spatial statistics, web-based GIS and map visualization of field investigations, figured prominently in the presentation. PMID:19193214

  5. JANNAF 25th Airbreathing Propulsion Subcommittee, 37th Combustion Subcommittee and 1st Modeling and Simulation Subcommittee Joint Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Fry, Ronald S.; Becker, Dorothy L.

    2000-01-01

    Volume I, the first of three volumes, is a compilation of 24 unclassified/unlimited-distribution technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 25th Airbreathing Propulsion Subcommittee, 37th Combustion Subcommittee and 1st Modeling and Simulation Subcommittee (MSS) meeting held jointly with the 19th Propulsion Systems Hazards Subcommittee. The meeting was held 13-17 November 2000 at the Naval Postgraduate School and Hyatt Regency Hotel, Monterey, California. Topics covered include: a Keynote Address on Future Combat Systems, a review of the new JANNAF Modeling and Simulation Subcommittee, and technical papers on Hyper-X propulsion development and verification; GTX airbreathing launch vehicles; Hypersonic technology development, including program overviews, fuels for advanced propulsion, ramjet and scramjet research, hypersonic test medium effects; and RBCC engine design and performance, and PDE and UCAV advanced and combined cycle engine technologies.

  6. Traumatic Floating 1st Metacarpal in a 14-Year-Old Boy Managed by Close Reduction and Thumb Spica Immobilization: A Rare Case Report

    PubMed Central

    Tyagi, Himanshu Ravindra; Kamat, Nandan; Wajekar, Sagar; Mandalia, Saumil H

    2014-01-01

    Introduction: Double dislocation of thumb metacarpal (MC) is a rare injury which may be secondarily complicated by growth plate injury in children. The management of floating 1st MC is also controversial since the treatment ranges from simple reduction to complex reconstruction surgeries. It is also important to understand the long-term results of different management strategies (close reduction, K-wire fixation, ligament reconstruction) as any residual stiffness or instability of thumb may result in severe disability of the hand. Case Report: A 14-year-old boy with an alleged history of injury to the thumb due to a fall. The postulated mechanism of injury was forced hyperextension of thumb and axial loading of hand in the prone position. On examination, there was prominent bony swelling over the dorsal aspect of carpometacarpal (CMC) and metacarpophalangeal (MCP) joints which was very tender with diffuse swelling over entire thumb. X-ray showed dorsal dislocation of both MCP and CMC joints, without any fracture (bony avulsion) or volar plate avulsion. Treatment was by way of closed reduction performed by axial traction followed by forced flexion at MCP joint with continuous pressure over the dorsal aspect of the joint. The reduction of CMC joint was done by direct pressure over the dorsal aspect and full abduction of thumb. Following reduction, the thumb was immobilized in a thumb spica. Conclusion: Thus, we conclude it is possible to manage a case of floating 1st MC by closed reduction and immobilization, using proper reduction technique. However, a careful clinical and radiological assessment should be done beforehand for signs of bony injury or ligamentous instability. PMID:27299001

  7. Superacid Catalyzed Coal Conversion Chemistry. 1st and 2nd Quarterly Technical Progress Reports, September 1, 1983-March 30, 1984.

    DOE R&D Accomplishments Database

    Olah, G. A.

    1984-01-01

    In our laboratories we have previously developed a mild coal conversion process. This involves the use of a superacid system consisting of HF and BF{sub 3} in presence of hydrogen and/or a hydrogen donor solvent. In order to understand the chemistry involved in the process of depolymerization of coal by the HF:BF{sub 3}:H{sub 2} system we are carrying out a systematic study of a number of coal model compounds. The model compounds selected for present study have two benzene rings connected with various bridging units such as alkylidene, ether, sulfide etc. From studies so far carried out it appears that high pyridine extractibilities achieved by treating coal at temperature below 100 degrees C results from the cleavage of bridges such as present in bibenzyl, diphenyl methane, dibenzyl ether, dibenzyl sulfide etc. On the other hand the increased cyclohexane extractibility and distillability observed at relatively higher temperatures and hydrogen pressures reflects the hydrogenation and cleavage of the aromatic backbone in coal structure similar to what is seen in the conversion of model compounds such as biphenyl, diphenyl ether, diphenyl sulfide, anthracene, etc.

  8. Preparing for introduction of a dengue vaccine: recommendations from the 1st Dengue v2V Asia-Pacific Meeting.

    PubMed

    Lam, Sai Kit; Burke, Donald; Capeding, Maria Rosario; Chong, Chee Keong; Coudeville, Laurent; Farrar, Jeremy; Gubler, Duane; Hadinegoro, Sri Rezeki; Hanna, Jeffrey; Lang, Jean; Lee, Han Lim; Leo, Yee Sin; Luong, Chan Quang; Mahoney, Richard; McBride, John; Mendez-Galvan, Jorge; Ng, Lee Ching; Nimmannitya, Suchitra; Ooi, Eng Eong; Shepard, Donald; Smit, Jaco; Teyssou, Rémy; Thomas, Laurent; Torresi, Joseph; Vasconcelos, Pedro; Wirawan, Dewa Nyoman; Yoksan, Sutee

    2011-11-28

    Infection with dengue virus is a major public health problem in the Asia-Pacific region and throughout tropical and sub-tropical regions of the world. Vaccination represents a major opportunity to control dengue and several candidate vaccines are in development. Experts in dengue and in vaccine introduction gathered for a two day meeting during which they examined the challenges inherent to the introduction of a dengue vaccine into the national immunisation programmes of countries of the Asia-Pacific. The aim was to develop a series of recommendations to reduce the delay between vaccine licensure and vaccine introduction. Major recommendations arising from the meeting included: ascertaining and publicising the full burden and cost of dengue; changing the perception of dengue in non-endemic countries to help generate global support for dengue vaccination; ensuring high quality active surveillance systems and diagnostics; and identifying sustainable sources of funding, both to support vaccine introduction and to maintain the vaccination programme. The attendees at the meeting were in agreement that with the introduction of an effective vaccine, dengue is a disease that could be controlled, and that in order to ensure a vaccine is introduced as rapidly as possible, there is a need to start preparing now. PMID:21864627

  9. Variation of the intensity of the Earth's magnetic field in Portugal in the 1st millennium BC

    NASA Astrophysics Data System (ADS)

    Nachasova, I. E.; Burakov, K. S.

    2009-07-01

    The study of magnetization of the ceramic material from 21 archeological monuments of Portugal (the Evora province), dated archeologically from the Bronze Age to the end of the Iron Age has been carried out. For the purpose of more detailed timing of the material from the monuments the method of ceramic age dating on the basis of its porosity has been used. In order to take into account the distorted factors in the determination of the parameters of the ancient geomagnetic field with the aim of the maximal approximation to the actual values the diagnostic features of magnetite weathering have been considered and the level of weathering of the magnetic fraction in the ceramics from archeological monuments has been determined. The data of geomagnetic field-strength variation in the time interval of the 12th century BC to the beginning of the Common Era have been obtained. The field-strength at this time interval varied in the range of 60-90 micro Tesla with the maximal values in the 9th, 8th, and the second half of the 5th to the beginning of the 4th century BC. In addition, the timing of the ceramic material from the urns of the megalithic complex Monte de Tera of the Evora province has been clarified.

  10. PREFACE: 1st METECH workshop - From deep-sea to coastal zones: Methods and Techniques for studying Palaeoenvironments

    NASA Astrophysics Data System (ADS)

    Veiga-Pires, C.; St-Onge, G.

    2008-10-01

    Reconstructing past climate and past ocean circulation demands the highest possible precision and accuracy which urges the scientific community to look at different sediment records such as the ones from coastal zones to deep-sea with a more complete set of technical and methodological tools. However, the information given by each tool varies in precision, accuracy and in significance according to their environmental settings. It is therefore essential to compare tools. With that in mind, and as part of the International year of Planet Earth, a workshop entitled `From deep-sea to coastal zones: Methods and Techniques for studying palaeoenvironments' took place in Faro (Portugal), from 25-29 February 2008 in order to: present several methods and techniques that can be used for studying sediments from deep-sea to coastal zones, namely for reconstructing palaeoenvironments in order to document past climatic changes and short to long-term environmental processes; allow cross experience between different fields and specialties, either from deep-sea to coastal zones or from micropaleontology to geochemistry; give the opportunity to students from different universities and countries to attend the workshop; publish a special volume on the presented methods and techniques during the workshop. The workshop was organized in four non-parallel sessions dealing with the use of micropaleontology, isotopes, biogeochemistry and sedimentology, as tools for palaeoenvironmental studies. The present IOP Conference Series: Earth and Environmental Science proceedings reflect this organization and papers are published in each theme. The papers are either short reviews or case studies and are highlighted below. The remains of microorganisms found in sediments are the main proxies used in micropaleontological studies. However, the link between fossilized remains and their living origin is not easy to reconstruct only based on the geologic/sedimentary record. Accordingly, Barbosa presents a

  11. 78 FR 60252 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Advance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-01

    ... Five-year (``Sunset'') Reviews of Antidumping and Countervailing Duty Orders; Policy Bulletin, 63 FR...) (3rd Review). Ferrovanadium from South Africa (A-791-815) David Goldberger, (202) 482-4136. (2nd Review... Innerspring Units from South Africa David Goldberger, (202) 482-4136. (A-791-821) (1st Review)....

  12. Spatio-temporal autocorrelation of Neogene-Quaternary volcanic and clastic sedimentary rocks in SW Montana and SE Idaho: Relationship to Cenozoic tectonic and thermally induced extensional events

    NASA Astrophysics Data System (ADS)

    Davarpanah, A.; Babaie, H. A.; Dai, D.

    2013-12-01

    Two systems of full and half grabens have been forming since the mid-Tertiary through tectonic and thermally induced extensional events in SW Montana and neighboring SE Idaho. The earlier mid-Tertiary Basin and Range (BR) tectonic event formed the NW- and NE-striking mountains around the Snake River Plain (SRP) in Idaho and SW Montana, respectively. Since the mid-Tertiary, partially synchronous with the BR event, diachronous bulging and subsidence due to the thermally induced stress field of the Yellowstone hotspot (YHS) has produced the second system of variably-oriented grabens through faulting across the older BR fault blocks. The track of the migration of the YHS is defined by the presence of six prominent volcanic calderas along the SRP which become younger toward the present location of the YHS. Graben basins bounded by both the BR faults and thermally induced cross-faults (CF) systems are now filled with Tertiary-Quaternary clastic sedimentary and volcanic-volcaniclastic rocks. Neogene mafic and felsic lava which erupted along the SRP and clastic sedimentary units (Sixmile Creek Fm., Ts) deposited in both types of graben basins were classified based on their lithology and age, and mapped in ArcGIS 10 as polygon using a combination of MBMG and USGS databases and geological maps at scales of 1:250.000, 1:100,000, and 1:48,000. The spatio-temporal distributions of the lava polygons were then analyzed applying the Global and Local Moran`s I methods to detect any possible spatial or temporal autocorrelation relative to the track of the YHS. The results reveal the spatial autocorrelation of the lithology and age of the Neogene lavas, and suggest a spatio-temporal sequence of eruption of extrusive rocks between Miocene and late Pleistocene along the SRP. The sequence of eruptions, which progressively becomes younger toward the Yellowstone National Park, may track the migration of the YSH. The sub-parallelism of the trend of the SRP with the long axis of the

  13. Construction and 1st Experiment of the 500-meter and 1000-meter DC Superconducting Power Cable in Ishikari

    NASA Astrophysics Data System (ADS)

    Yamaguchi, S.; Ivanov, Y.; Watanabe, H.; Chikumoto, N.; Koshiduka, H.; Hayashi, K.; Sawamura, T.

    Ishikari project constructs two lines. The length of the Line 1 is 500 m, and connects the photovoltaic cell to the internet-data center. The other line is 1 km length, and it is a test facility and called Line 2. The structures of the cable systems are not same to test their performance. The construction was started from 2014 in the field, the Line 1 was completed in May 2015, and it was cooled down and do the current experiment, and warmed up. The Line 2 is almost complete in October 2015. It will be tested in November and December, 2015. In order to reduce the stress of the cable induced by the thermal expansion and contraction, we adopted the way of the helical deformation of the cable. The force of the cable is reduced to 1/3 of an usual cable test. Because the cryogenic pipes are welded in the field and we cannot use the baking of the vacuum chamber of the cryogenic pipe, a new vacuum pumping method was proposed and tested for the cryogenic pipe. Since the straight pipes are used to compose the cryogenic pipe, the pressure drop of the circulation would be 1/100 of the corrugated pipe in the present condition, and it is suitable for longer cable system. The heat leak of the cryogenic pipe is ∼1.4W/m including the cable pipe's and the return pipe's. The heat leak of the current lead is ∼30W/kA in the test bench. Finally the current of 6kA/3 sec and the current of 5kA/15 min were achieved in Line 1. The reduction of heat leak will be a major subject of the longer cable system. The cost of the construction will be almost twice higher than that of the copper and aluminum over-head line with the iron tower in the present Japan. The cost construction of the over-head line is an average value, and depends on the newspaper.

  14. Climate, people, fire and vegetation: new insights into vegetation dynamics in the Eastern Mediterranean since the 1st century AD

    NASA Astrophysics Data System (ADS)

    Bakker, J.; Paulissen, E.; Kaniewski, D.; Poblome, J.; De Laet, V.; Verstraeten, G.; Waelkens, M.

    2012-08-01

    Ottoman times. The pollen data reveals that the old model of a fast rise in Pinus pollen after the end of the Beyşehir Occupation Phase is not necessarily accurate. The notion of high Pinus pollen percentages indicating an open landscape incapable of countering the influx of pine pollen is also deemed unrealistic. While multiple fires occurred in the region through time, they were never a major influence on vegetation dynamics and were mostly linked to increased abundance of pine forests, rather than the presence of human impact or of specifically wet or dry environmental conditions. While this study reveals much new information concerning the impact of climate change and human occupation on the environment, more studies from SW turkey are required in order to properly quantify the range of the observed phenomena and the magnitude of their impacts.

  15. Volume 1, 1st Edition, Multiscale Tailoring of Highly Active and Stable Nanocomposite Catalysts, Final Technical Report

    SciTech Connect

    Veser, Goetz

    2009-08-31

    Nanomaterials have gained much attention as catalysts since the discovery of exceptional CO oxidation activity of nanoscale gold by Haruta. However, many studies avoid testing nanomaterials at the high-temperatures relevant to reactions of interest for the production of clean energy (T > 700°C). The generally poor thermal stability of catalytically active noble metals has thus far prevented significant progress in this area. We have recently overcome the poor thermal stability of nanoparticles by synthesizing a platinum barium-hexaaluminate (Pt-BHA) nanocomposite which combines the high activity of noble metal nanoparticles with the thermal stability of hexaaluminates. This Pt-BHA nanocomposite demonstrates excellent activity, selectivity, and long-term stability in CPOM. Pt-BHA is anchored onto a variety of support structures in order to improve the accessibility, safety, and reactivity of the nanocatalyst. Silica felts prove to be particularly amenable to this supporting procedure, with the resulting supported nanocatalyst proving to be as active and stable for CPOM as its unsupported counterpart. Various pre-treatment conditions are evaluated to determine their effectiveness in removing residual surfactant from the active nanoscale platinum particles. The size of these particles is measured across a wide temperature range, and the resulting “plateau” of stability from 600-900°C can be linked to a particle caging effect due to the structure of the supporting ceramic framework. The nanocomposites are used to catalyze the combustion of a dilute methane stream, and the results indicate enhanced activity for both Pt-BHA as well as ceria-doped BHA, as well as an absence of internal mass transfer limitations at the conditions tested. In water-gas shift reaction, nanocomposite Pt-BHA shows stability during prolonged WGS reaction and no signs of deactivation during start-up/shut-down of the reactor. The chemical and thermal stability, low molecular weight, and

  16. Climate, people, fire and vegetation: new insights into vegetation dynamics in the Eastern Mediterranean since the 1st century AD

    NASA Astrophysics Data System (ADS)

    Bakker, J.; Paulissen, E.; Kaniewski, D.; Poblome, J.; De Laet, V.; Verstraeten, G.; Waelkens, M.

    2013-01-01

    times. The pollen data reveal that a fast rise in Pinus pollen after the end of the Beyşehir Occupation Phase need not always occur. The notion of high Pinus pollen percentages indicating an open landscape incapable of countering the influx of pine pollen is also deemed unrealistic. While multiple fires occurred in the region through time, extended fire periods, as had occurred during the Bronze Age and Beyşehir Occupation Phase, did not occur, and no signs of local fire activity were observed. Fires were never a major influence on vegetation dynamics. While no complete overview of post-BO Phase fire events can be presented, the available data indicates that fires in the vicinity of Gravgaz may have been linked to anthropogenic activity in the wider surroundings of the marsh. Fires in the vicinity of Bereket appeared to be linked to increased abundance of pine forests. There was no link with specifically wet or dry environmental conditions at either site. While this study reveals much new information concerning the impact of climate change and human occupation on the environment, more studies from SW Turkey are required in order to properly quantify the range of the observed phenomena and the magnitude of their impacts.

  17. FOREWORD: 13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications/1st International Conference on Fusion Energy Materials Science 13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications/1st International Conference on Fusion Energy Materials Science

    NASA Astrophysics Data System (ADS)

    Jacob, Wolfgang; Linsmeier, Christian; Rubel, Marek

    2011-12-01

    The 13th International Workshop on Plasma-Facing Materials and Components (PFMC-13) jointly organized with the 1st International Conference on Fusion Energy Materials Science (FEMaS-1) was held in Rosenheim (Germany) on 9-13 May 2011. PFMC-13 is a successor of the International Workshop on Carbon Materials for Fusion Applications series. Between 1985 and 2003 ten 'Carbon Workshops' were organized in Jülich, Stockholm and Hohenkammer. Then it was time for a change and redefinition of the scope of the symposium to reflect the new requirements of ITER and the ongoing evolution in the field. Under the new name (PFMC-11), the workshop was first organized in 2006 in Greifswald, Germany and PFMC-12 took place in Jülich in 2009. Initially starting in 1985 with about 40 participants as a 1.5 day workshop, the event has continuously grown to about 220 participants at PFMC-12. Due to the joint organization with FEMaS-1, PFMC-13 set a new record with more than 280 participants. The European project Fusion Energy Materials Science, FEMaS, coordinated by the Max-Planck-Institut für Plasmaphysik (IPP), organizes and stimulates cooperative research activities which involve large-scale research facilities as well as other top-level materials characterization laboratories. Five different fields are addressed: benchmarking experiments for radiation damage modelling, the application of micro-mechanical characterization methods, synchrotron and neutron radiation-based techniques and advanced nanoscopic analysis based on transmission electron microscopy. All these fields need to be exploited further by the fusion materials community for timely materials solutions for a DEMO reactor. In order to integrate these materials research fields, FEMaS acted as a co-organizer for the 2011 workshop and successfully introduced a number of participants from research labs and universities into the PFMC community. Plasma-facing materials experience particularly hostile conditions as they are

  18. Exploring the spatial heterogeneity of terraced landscapes using LiDAR: the Slope Local Length of Auto-Correlation (SLLAC).

    NASA Astrophysics Data System (ADS)

    Sofia, Giulia; Marinello, Francesco; Tarolli, Paolo

    2014-05-01

    Terraces represent an outstanding example that displays centuries of a ubiquitous human-Earth interaction, in a very specific and productive way, and they are a significant part of numerous local economies. They, in fact, optimise the local resources for agricultural purposes, but also exploit marginal landscapes, expanding local populations. The ubiquity, variety, and importance of terraces have motivated studies designed to understand them better both as cultural and ecological features, but also as elements that can deeply influence runoff generation and propagation, contributing to local instabilities, and triggering or aggravating land degradation processes. Their vulnerability in the face of fast-growing urban settlements and the changes in agricultural practices is also well known, prompting protection measures strongly supported by local communities, but also by national and international projects. This work explores the spatial heterogeneity of terraced landscapes, identifying a proper indicator able to discriminate a terraced landscape respect to a more natural one. Recognizing and characterizing terraced areas can offer important multi-temporal insights into issues such as agricultural sustainability, indigenous knowledge systems, human-induced impact on soil degradation or erosive and landslide processes, geomorphological and pedologic processes that influence soil development, and climatic and biodiversity changes. More in detail, the present work introduces a new morphological indicator from LiDAR, effectively implementable for the automatic characterization of terraced landscapes. For the study, we tested the algorithm for environments that differ in term of natural morphology and terracing system. Starting from a LiDAR Digital Terrain Models (DTM), we considered the local auto-correlation (~local self-similarity) of the slope, calculating the correlation between a slope patch and its surrounding areas. We define the resulting map as the "Slope Local

  19. Prominent Higher-Order Contributions to Electronic Recombination

    SciTech Connect

    Beilmann, C.; Mokler, P. H.; Bernitt, S.; Keitel, C. H.; Ullrich, J.; Lopez-Urrutia, J. R. Crespo; Harman, Z.

    2011-09-30

    Intershell higher-order (HO) electronic recombination is reported for highly charged Ar, Fe, and Kr ions, where simultaneous excitation of one K-shell electron and one or two additional L-shell electrons occurs upon resonant capture of a free electron. For the mid-Z region, HO resonance strengths grow unexpectedly strong with decreasing atomic number Z ({proportional_to}Z{sup -4}), such that, for Ar ions the 2nd-order overwhelms the 1st-order resonant recombination considerably. The experimental findings are confirmed by multiconfiguration Dirac-Fock calculations including hitherto neglected excitation pathways.

  20. Putting the Students 1st

    ERIC Educational Resources Information Center

    Ziegler, Elizabeth

    2005-01-01

    This article profiles Randy Jensen, the 2005 MetLife/NASSP National Middle Level Principal of the Year. As the principal of William Thomas Middle School in American Falls, Idaho, Jensen is a committed advocate for his students as they grapple with the challenges that come with being an adolescent and has adopted an open-door policy with his school…

  1. GALEX 1st Light Compilation

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This compilation shows the constellation Hercules, as imaged on May 21 and 22 by NASA's Galaxy Evolution Explorer. The images were captured by the two channels of the spacecraft camera during the mission's 'first light' milestone.

    The Galaxy Evolution Explorer first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas.

    The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years.

  2. Order Up

    ERIC Educational Resources Information Center

    Gibeault, Michael

    2005-01-01

    Change orders. The words can turn the stomachs of administrators. Horror stories about change orders create fear and distrust among school officials, designers and builders. Can change orders be avoided? If car manufacturers can produce millions of intricately designed vehicles, why can't the same quality control be achieved on a construction…

  3. A hierarchical model of daily stream temperature using air-water temperature synchronization, autocorrelation, and time lags

    USGS Publications Warehouse

    Letcher, Benjamin; Hocking, Daniel; O'Neill, K.; Whiteley, Andrew R.; Nislow, Keith H.; O'Donnell, Matthew

    2016-01-01

    Water temperature is a primary driver of stream ecosystems and commonly forms the basis of stream classifications. Robust models of stream temperature are critical as the climate changes, but estimating daily stream temperature poses several important challenges. We developed a statistical model that accounts for many challenges that can make stream temperature estimation difficult. Our model identifies the yearly period when air and water temperature are synchronized, accommodates hysteresis, incorporates time lags, deals with missing data and autocorrelation and can include external drivers. In a small stream network, the model performed well (RMSE = 0.59 °C), identified a clear warming trend (0.63 °C · decade-1) and a widening of the synchronized period (29 d · decade-1). We also carefully evaluated how missing data influenced predictions. Missing data within a year had a small effect on performance (~ 0.05% average drop in RMSE with 10% fewer days with data). Missing all data for a year decreased performance (~ 0.6 °C jump in RMSE), but this decrease was moderated when data were available from other streams in the network.

  4. Depolarized light scattering from prolate anisotropic particles: The influence of the particle shape on the field autocorrelation function

    NASA Astrophysics Data System (ADS)

    Passow, Christopher; ten Hagen, Borge; Löwen, Hartmut; Wagner, Joachim

    2015-07-01

    We provide a theoretical analysis for the intermediate scattering function typically measured in depolarized dynamic light scattering experiments. We calculate the field autocorrelation function g1 V H ( Q , t ) in dependence on the wave vector Q and the time t explicitly in a vertical-horizontal scattering geometry for differently shaped solids of revolution. The shape of prolate cylinders, spherocylinders, spindles, and double cones with variable aspect ratio is expanded in rotational invariants flm(r). By Fourier transform of these expansion coefficients, a formal multipole expansion of the scattering function is obtained, which is used to calculate the weighting coefficients appearing in the depolarized scattering function. In addition to translational and rotational diffusion, especially the translational-rotational coupling of shape-anisotropic objects is considered. From the short-time behavior of the intermediate scattering function, the first cumulants Γ(Q) are calculated. In a depolarized scattering experiment, they deviate from the simple proportionality to Q2. The coefficients flm(Q) strongly depend on the geometry and aspect ratio of the particles. The time dependence, in addition, is governed by the translational and rotational diffusion tensors, which are calculated by means of bead models for differently shaped particles in dependence on their aspect ratio. Therefore, our analysis shows how details of the particle shape—beyond their aspect ratio—can be determined by a precise scattering experiment. This is of high relevance in understanding smart materials which involve suspensions of anisotropic colloidal particles.

  5. The Loudness of ``COMPLEX Noise'' in Relation to the Factors Extracted from the Auto-Correlation Function

    NASA Astrophysics Data System (ADS)

    Sato, S.; Kitamura, T.; Sakai, H.; Ando, Y.

    2001-03-01

    The loudness of complex signals, which include bandpass noises with different center frequencies (complex noise), is examined while changing the effective duration of the autocorrelation function (τe) based on a model of the human auditory-brain system for subjective response to a sound field. The center frequencies of each component of the complex noises were 2000 and 3000 Hz so that the perceived pitch was centered on 1000 Hz. The bandwidth of each component was changed by using a 2068 dB/octave sharp filter to control theτe of the source signal. The scale values for the loudness of the complex noises were obtained using a paired-comparison method. The results showed that the loudness increases with the τeof the source signal similar to that of the single-noise component centered on 1000 Hz. The loudness of complex noises having equal sound pressure levels is not constant within the critical band, 160 Hz.

  6. Depolarized light scattering from prolate anisotropic particles: The influence of the particle shape on the field autocorrelation function.

    PubMed

    Passow, Christopher; ten Hagen, Borge; Löwen, Hartmut; Wagner, Joachim

    2015-07-28

    We provide a theoretical analysis for the intermediate scattering function typically measured in depolarized dynamic light scattering experiments. We calculate the field autocorrelation function g1(VH)(Q,t) in dependence on the wave vector Q and the time t explicitly in a vertical-horizontal scattering geometry for differently shaped solids of revolution. The shape of prolate cylinders, spherocylinders, spindles, and double cones with variable aspect ratio is expanded in rotational invariants flm(r). By Fourier transform of these expansion coefficients, a formal multipole expansion of the scattering function is obtained, which is used to calculate the weighting coefficients appearing in the depolarized scattering function. In addition to translational and rotational diffusion, especially the translational-rotational coupling of shape-anisotropic objects is considered. From the short-time behavior of the intermediate scattering function, the first cumulants Γ(Q) are calculated. In a depolarized scattering experiment, they deviate from the simple proportionality to Q(2). The coefficients flm(Q) strongly depend on the geometry and aspect ratio of the particles. The time dependence, in addition, is governed by the translational and rotational diffusion tensors, which are calculated by means of bead models for differently shaped particles in dependence on their aspect ratio. Therefore, our analysis shows how details of the particle shape--beyond their aspect ratio--can be determined by a precise scattering experiment. This is of high relevance in understanding smart materials which involve suspensions of anisotropic colloidal particles. PMID:26233160

  7. Preliminary evidence for the influence of physiography and scale upon the autocorrelation function of remotely sensed data

    NASA Technical Reports Server (NTRS)

    Labovitz, M. L.; Toll, D. L.; Kennard, R. E.

    1980-01-01

    Previously established results demonstrate that LANDSAT data are autocorrelated and can be described by a univariate linear stochastic process known as auto-regressive-integrated-moving-average model of degree 1, 0, 1 or ARIMA (1, 0, 1). This model has two coefficients of interest for interpretation phi(1) and theta(1). In a comparison of LANDSAT thematic mapper simulator (TMS) data and LANDSAT MSS data several results were established: (1) The form of the relatedness as described by this model is not dependent upon system look angle or pixel size. (2) The phi(1) coefficient increases with decreasing pixel size and increasing topographic complexity. (3) Changes in topography have a greater influence upon phi(1) than changes in land cover class. (4) The theta(1) seems to vary with the amount of atmospheric haze. These patterns of variation in phi(1) and theta(1) are potentially exploitable by the remote sensing community to yield stochastically independent sets of observations, characterize topography, and reduce the number of bytes needed to store remotely sensed data.

  8. Autocorrelation Analysis Combined with a Wavelet Transform Method to Detect and Remove Cosmic Rays in a Single Raman Spectrum.

    PubMed

    Maury, Augusto; Revilla, Reynier I

    2015-08-01

    Cosmic rays (CRs) occasionally affect charge-coupled device (CCD) detectors, introducing large spikes with very narrow bandwidth in the spectrum. These CR features can distort the chemical information expressed by the spectra. Consequently, we propose here an algorithm to identify and remove significant spikes in a single Raman spectrum. An autocorrelation analysis is first carried out to accentuate the CRs feature as outliers. Subsequently, with an adequate selection of the threshold, a discrete wavelet transform filter is used to identify CR spikes. Identified data points are then replaced by interpolated values using the weighted-average interpolation technique. This approach only modifies the data in a close vicinity of the CRs. Additionally, robust wavelet transform parameters are proposed (a desirable property for automation) after optimizing them with the application of the method in a great number of spectra. However, this algorithm, as well as all the single-spectrum analysis procedures, is limited to the cases in which CRs have much narrower bandwidth than the Raman bands. This might not be the case when low-resolution Raman instruments are used. PMID:26163458

  9. A comparison of methods to compute the "effective duration" of the autocorrelation function and an alternative proposal.

    PubMed

    D'Orazio, Dario; De Cesaris, Simona; Garai, Massimo

    2011-10-01

    The "effective duration" of the autocorrelation function (ACF), τ(e), is an important factor in architectural and musical acoustics. For a general application, an accurate evaluation of τ(e) is relevant. This paper is focused to the methods for the extraction of τ(e) values from the ACF. Various methods have been proposed in literature for the extraction of the τ(e) from a given signal, but these methods are not unambiguously defined or may not work properly in case of particular signals. Therefore, the general use of these methods may sometimes give rise to questionable results. In the present work, the methods existing in literature for extracting τ(e) are analyzed, their advantages and drawbacks are summarized, and finally an alternative method is proposed. The proposed algorithm is compared to those found in previous literature, applying them on the same sound signals (classic literature references and other ones publicly available on the Internet). It is shown that the results obtained with the proposed method are consistent with the results of the previous literature; moreover the proposed method may overcome some of the limitations of the existing methods. PMID:21973350

  10. Sound quality characteristics of refrigerator noise in real living environments with relation to psychoacoustical and autocorrelation function parameters.

    PubMed

    Sato, Shin-ichi; You, Jin; Jeon, Jin Yong

    2007-07-01

    Psychoacoustical and autocorrelation function (ACF) parameters were employed to describe the temporal fluctuations of refrigerator noise during starting, transition into/from the stationary phase and termination of operation. The temporal fluctuations of refrigerator noise include a click at start-up, followed by a rapid increase in volume, a change of pitch, and termination of the operation. Subjective evaluations of the noise of 24 different refrigerators were conducted in a real living environment. The relationship between objective measures and perceived noisiness was examined by multiple regression analysis. Sound quality indices were developed based on psychoacoustical and ACF parameters. The psychoacoustical parameters found to be important for evaluating noisiness in the stationary phase were loudness and roughness. The relationship between noisiness and ACF parameters shows that sound energy and its fluctuations are important for evaluating noisiness. Also, refrigerator sounds that had a fluctuation of pitch were rated as more annoying. The tolerance level for the starting phase of refrigerator noise was found to be 33 dBA, which is the level where 65% of the participants in the subjective tests were satisfied. PMID:17614491

  11. A hierarchical model of daily stream temperature using air-water temperature synchronization, autocorrelation, and time lags.

    PubMed

    Letcher, Benjamin H; Hocking, Daniel J; O'Neil, Kyle; Whiteley, Andrew R; Nislow, Keith H; O'Donnell, Matthew J

    2016-01-01

    Water temperature is a primary driver of stream ecosystems and commonly forms the basis of stream classifications. Robust models of stream temperature are critical as the climate changes, but estimating daily stream temperature poses several important challenges. We developed a statistical model that accounts for many challenges that can make stream temperature estimation difficult. Our model identifies the yearly period when air and water temperature are synchronized, accommodates hysteresis, incorporates time lags, deals with missing data and autocorrelation and can include external drivers. In a small stream network, the model performed well (RMSE = 0.59°C), identified a clear warming trend (0.63 °C decade(-1)) and a widening of the synchronized period (29 d decade(-1)). We also carefully evaluated how missing data influenced predictions. Missing data within a year had a small effect on performance (∼0.05% average drop in RMSE with 10% fewer days with data). Missing all data for a year decreased performance (∼0.6 °C jump in RMSE), but this decrease was moderated when data were available from other streams in the network. PMID:26966662

  12. A hierarchical model of daily stream temperature using air-water temperature synchronization, autocorrelation, and time lags

    PubMed Central

    Hocking, Daniel J.; O’Neil, Kyle; Whiteley, Andrew R.; Nislow, Keith H.; O’Donnell, Matthew J.

    2016-01-01

    Water temperature is a primary driver of stream ecosystems and commonly forms the basis of stream classifications. Robust models of stream temperature are critical as the climate changes, but estimating daily stream temperature poses several important challenges. We developed a statistical model that accounts for many challenges that can make stream temperature estimation difficult. Our model identifies the yearly period when air and water temperature are synchronized, accommodates hysteresis, incorporates time lags, deals with missing data and autocorrelation and can include external drivers. In a small stream network, the model performed well (RMSE = 0.59°C), identified a clear warming trend (0.63 °C decade−1) and a widening of the synchronized period (29 d decade−1). We also carefully evaluated how missing data influenced predictions. Missing data within a year had a small effect on performance (∼0.05% average drop in RMSE with 10% fewer days with data). Missing all data for a year decreased performance (∼0.6 °C jump in RMSE), but this decrease was moderated when data were available from other streams in the network. PMID:26966662

  13. Anisotropy of the Earth's inner inner core from autocorrelations of earthquake coda in China Regional Seismic Networks

    NASA Astrophysics Data System (ADS)

    Xia, H.; Song, X.; Wang, T.

    2014-12-01

    The Earth's inner core possesses strong cylindrical anisotropy with the fast symmetry axis parallel to the rotation axis. However, recent study has suggested that the inner part of the inner core has a fast symmetry axis near the equator with a different form of anisotropy from the outer part (Wang et al., this session). To confirm the observation, we use data from dense seismic arrays of the China Regional Seismic Networks. We perform autocorrelation (ACC) of the coda after major earthquakes (Mw>=7.0) at each station and then stack the ACCs at each cluster of stations. The PKIKP2 and PKIIKP2 phases (round-trip phase from the Earth's surface reflections) can be clearly extracted from the stacked empirical Green's functions. We observe systematic variation of the differential times between PKIKP2 and PKIIKP2 phases, which are sensitive to the bulk anisotropy of the inner core. The differential times show large variations with both latitudes and longitudes, even though our ray paths are not polar (with our stations at mid-range latitudes of about 20 to 45 degrees). The observations cannot be explained by an averaged anisotropy model with the fast axis along the rotation axis. The pattern appears consistent with an inner inner core that has a fast axis near the equator.

  14. First and second-order-motion perception after focal human brain lesions

    PubMed Central

    Rizzo, Matthew; Nawrot, Mark; Sparks, JonDavid; Dawson, Jeffrey

    2011-01-01

    Perception of visual motion includes a 1st-order mechanism sensitive to luminance changes and a 2nd-order motion mechanism sensitive to contrast changes. We studied neural substrates for these motion types in 142 subjects with visual cortex lesions, 68 normal controls and 28 brain lesion controls. On 1st-order motion, the visual cortex lesion group performed significantly worse than normal controls overall and in each hemifield, but 2nd-order motion did not differ. Only 1 individual showed a selective 2nd-order motion deficit. Motion deficits were seen with lesions outside the small occipitotemporal region thought to contain a human homolog of motion processing area MT (V5), suggesting that many areas of human brain process visual motion. PMID:18440580

  15. High-order fluorescence fluctuation analysis of model protein clusters.

    PubMed Central

    Palmer, A G; Thompson, N L

    1989-01-01

    The technique of high-order fluorescence fluctuation autocorrelation for detecting and characterizing protein oligomers was applied to solutions containing two fluorescent proteins in which the more fluorescent proteins were analogues for clusters of the less fluorescent ones. The results show that the model protein clusters can be detected for average numbers of observed subunits (free monomers plus monomers in oligomers) equal to 10-100 and for relative fluorescent yields that correspond to oligomers as small as trimers. High-order fluorescent fluctuation analysis may therefore be applicable to cell surface receptor clusters in natural or model membranes. PMID:2548201

  16. Stable isotopic evidence for diet at the Imperial Roman coastal site of Velia (1st and 2nd centuries AD) in Southern Italy.

    PubMed

    Craig, Oliver E; Biazzo, Marco; O'Connell, Tamsin C; Garnsey, Peter; Martinez-Labarga, Cristina; Lelli, Roberta; Salvadei, Loretana; Tartaglia, Gianna; Nava, Alessia; Renò, Lorena; Fiammenghi, Antonella; Rickards, Olga; Bondioli, Luca

    2009-08-01

    Here we report on a stable isotope palaeodietary study of a Imperial Roman population interred near the port of Velia in Southern Italy during the 1st and 2nd centuries AD. Carbon and nitrogen stable isotope analyses were performed on collagen extracted from 117 adult humans as well as a range of fauna to reconstruct individual dietary histories. For the majority of individuals, we found that stable isotope data were consistent with a diet high in cereals, with relatively modest contributions of meat and only minor contributions of marine fish. However, substantial isotopic variation was found within the population, indicating that diets were not uniform. We suggest that a number of individuals, mainly but not exclusively males, had greater access to marine resources, especially high trophic level fish. However, the observed dietary variation did not correlate with burial type, number of grave goods, nor age at death. Also, individuals buried at the necropolis at Velia ate much less fish overall compared with the contemporaneous population from the necropolis of Portus at Isola Sacra, located on the coast close to Rome. Marine and riverine transport and commerce dominated the economy of Portus, and its people were in a position to supplement their own stocks of fish with imported goods in transit to Rome, whereas at Velia marine exploitation existed side-by-side with land-based economic activities. PMID:19280672

  17. Report on: "The 1st Workshop on National Immunization Programs and Vaccine Coverage in ASEAN Countries, April 30, 2015, Pattaya, Thailand".

    PubMed

    Hattasingh, Weerawan; Pengsaa, Krisana; Thisyakorn, Usa

    2016-03-01

    The 1st Workshop on National Immunization Programs and Vaccine Coverage in Association of Southeast Asian Nations (ASEAN) Countries Group (WNIPVC-ASEAN) held a meeting on April 30, 2015, Pattaya, Thailand under the auspices of the Pediatric Infectious Diseases Society and the World Health Organization (WHO). Reports on the current status and initiatives of the national immunization program (NIP) in each ASEAN countries that attended were presented. These reports along with survey data collected from ministries of health in ASEAN countries NIPs demonstrate that good progress has been made toward the goal of the Global Vaccine Action Plan (GVAP). However, some ASEAN countries have fragile health care systems that still have insufficient vaccine coverage of some basic EPI antigens. Most ASEAN countries still do not have national coverage of some new and underused vaccines, and raising funds for the expansion of NIPs is challenging. Also, there is insufficient research into disease burden of vaccine preventable diseases and surveillance. Health care workers must advocate NIPs to government policy makers and other stakeholders as well as improve research and surveillance to achieve the goals of the GVAP. PMID:26805596

  18. Report from the 1st Cardiovascular Outcome Trial (CVOT) Summit of the Diabetes & Cardiovascular Disease (D&CVD) EASD Study Group.

    PubMed

    Schnell, Oliver; Standl, Eberhard; Catrinoiu, Doina; Genovese, Stefano; Lalic, Nebojsa; Skra, Jan; Valensi, Paul; Ceriello, Antonio

    2016-01-01

    The 1st Cardiovascular Outcome Trial (CVOT) Summit of the Diabetes & Cardiovascular Disease (D&CVD) EASD Study Group was held during the annual meeting on 30 October 2015 in Munich. This summit was organized in light of recently published and numerous ongoing CVOTs on diabetes, which have emerged in response to the FDA and the EMA Guidelines. The CVOT Summit stands as a novel conference setup, with the aim of serving as a reference meeting for all topics related to CVOTs in diabetes. Members of the steering committee of the D&CVD EASD Study Group constitute the backbone of the summit. It included presentations of key results on DPP-4 inhibitors, GLP-1-Analogues, SGLT-2 inhibitors, acarbose and insulins. Diabetologists' and cardiologists' perspective on the potential need of new study designs were also highlighted. Furthermore, panel discussions on the design of CVOTs on diabetes were included in the program. The D&CVD EASD Study Group will continue its activity. In-depth discussions and presentations of new CVOTs like LEADER, will be resumed at the 2nd CVOT on diabetes of the D&CVD EASD Study Group, which will be held from 20-22 October 2016 in Munich ( http://www.dcvd.org). PMID:26892706

  19. Structure of the North Anatolian Fault Zone from the Auto-Correlation of Ambient Seismic Noise Recorded at a Dense Seismometer Array

    NASA Astrophysics Data System (ADS)

    Taylor, D. G.; Rost, S.; Houseman, G.

    2015-12-01

    In recent years the technique of cross-correlating the ambient seismic noise wavefield at two seismometers to reconstruct empirical Green's Functions for the determination of Earth structure has been a powerful tool to study the Earth's interior without earthquake or man-made sources. However, far less attention has been paid to using auto-correlations of seismic noise to reveal body wave reflections from interfaces in the subsurface. In principle, the Green's functions thus derived should be comparable to the Earth's impulse response to a co-located source and receiver. We use data from a dense seismic array (Dense Array for Northern Anatolia - DANA) deployed across the northern branch of the North Anatolian Fault Zone (NAFZ) in the region of the 1999 magnitude 7.6 Izmit earthquake in western Turkey. The NAFZ is a major strike-slip system that extends ~1200 km across northern Turkey and continues to pose a high level of seismic hazard, in particular to the mega-city of Istanbul. We construct reflection images for the entire crust and upper mantle over the ~35 km by 70 km footprint of the 70-station DANA array. Using auto-correlations of vertical and horizontal components of ground motion, both P- and S-wave velocity information can be retrieved from the wavefield to constrain crustal structure further to established methods. We show that clear P-wave reflections from the crust-mantle boundary (Moho) can be retrieved using the autocorrelation technique, indicating topography on the Moho on horizontal scales of less than 10 km. Offsets in crustal structure can be identified that seem to be correlated with the surface expression of the fault zone in the region. The combined analysis of auto-correlations using vertical and horizontal components will lead to further insight into the fault zone structure throughout the crust and upper mantle.

  20. Order Nidovirales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter, entitled "Order Nidovirales", is for inclusion in the Ninth Report of the International Committee on Taxonomy of Viruses (ICTV), to be published as both a single volume text and online. The chapter details the taxonomy of members of the Nidovirus order, including family Arteriviridae o...

  1. Structural requirements of pyrido[2,3-d]pyrimidin-7-one as CDK4/D inhibitors: 2D autocorrelation, CoMFA and CoMSIA analyses.

    PubMed

    Caballero, Julio; Fernández, Michael; González-Nilo, Fernando D

    2008-06-01

    2D autocorrelation, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were undertaken for a series of pyrido[2,3-d]pyrimidin-7-ones to correlate cyclin-dependent kinase (CDK) cyclin D/CDK4 inhibition with 2D and 3D structural properties of 60 known compounds. QSAR models with considerable internal as well as external predictive ability were obtained. The relevant 2D autocorrelation descriptors for modeling CDK4/D inhibitory activity were selected by linear and nonlinear genetic algorithms (GAs) using multiple linear regression (MLR) and Bayesian-regularized genetic neural network (BRGNN) approaches, respectively. Both models showed good predictive statistics; but BRGNN model enables better external predictions. A weight-based input ranking scheme and Kohonen self-organized maps (SOMs) were carried out to interpret the final net weights. The 2D autocorrelation space brings different descriptors for CDK4/D inhibition, and suggests the atomic properties relevant for the inhibitors to interact with CDK4/D active site. CoMFA and CoMSIA analyses were developed with a focus on interpretative ability using coefficient contour maps. CoMSIA produced significantly better results. The results indicate a strong correlation between the inhibitory activity of the modeled compounds and the electrostatic and hydrophobic fields around them. PMID:18468903

  2. On the possible identification of defects using the autocorrelation function approach in double Doppler broadening of annihilation radiation spectroscopy

    NASA Astrophysics Data System (ADS)

    Beling, C. D.; Ming, W. Li; Shan, Y. Y.; Cheung, S. H.; Fung, S.; Panda, B. K.; Seitsonen, A. P.

    1998-11-01

    The recent revived interest in the use of double-Doppler broadening of annihilation radiation (D-DBAR) spectroscopy, which employs two Ge detectors in back-to-back geometry, has stemmed mainly from its potential in defect identification as a result of its elemental sensitivity through core annihilations in atoms at the defect site. Emphasis has thus largely concentrated on the high momentum spectral range. In contrast the present work emphasizes the need to also focus attention on the low momentum region of the D-DBAR spectra. It is argued that the 0953-8984/10/46/015/img9 improved resolving power of D-DBAR, in conjunction with spectral deconvolution, should give future 1D (one dimensional) momentum data approaching in quality those obtainable using 1D-ACAR (angular correlation of annihilation radiation), thus forming an alternative technique for observing the structure containing diffraction patterns that originate from annihilations with localized electron states at positron trapping defects. Rotation of the sample about a specified crystal axis, and the binning of events by angle, is suggested as a means of extending the technique to form a 2D- (two dimensional) DBAR counterpart to 2D-ACAR. The advantages of considering the real space positron electron wavefunction product AF (autocorrelation function), obtained by simple manipulation of the D-DBAR data in Fourier space, are outlined. In particular the possible visualization offered in real space of a defect's physical geometry, with the prospect of building up a library of contour patterns for future defect identification, is discussed, taking the silicon monovacancy in Si and the negative As vacancy in GaAs as examples.

  3. Spectral-domain optical coherence tomography with dual-balanced detection for auto-correlation artifacts reduction.

    PubMed

    Bo, En; Liu, Xinyu; Chen, Si; Yu, Xiaojun; Wang, Xianghong; Liu, Linbo

    2015-10-19

    We developed a spectral domain optical coherence tomography (SD-OCT) to reduce auto-correlation artifacts (AC) using dual-balanced detection (DBD). AC were composed of the interference signals between different sample tissue depths, and shown up as artifacts in OCT images. This system employed a free-space Michelson interferometer, at the refraction plane of whose beam splitter, the light reflected experienced a π/2 phase shift with respect to the light transmitted. Then two phase-opposed interferometric spectra sharing the same spectrometer optics were obtained simultaneously using two lines of a three-line CCD. This new design was of lower cost compared to the dual spectrometer design reported previously. DBD enabled this SD-OCT to achieve two-fold increase in the interested signal amplitude inherently, and obtain a SNR increase of ~2.9 dB experimentally. To demonstrate the feasibility and performance of this SD-OCT system with DBD, we conducted an imaging experiment using a glass plate to obtain the optimal spectral matching between dual-balanced spectrometer channels. As a result, this SD-OCT achieved AC reduction up to about 9 dB and direct current (DC) term suppression up to about 30 dB by cancelling the identical components between dual-balanced spectrometer channels. The efficacy of AC reduction and DC suppression was validated by imaging the polymer coating of a drug-eluting stent and fresh swine corneal tissue ex vivo. The quality of DBD optimized images was significantly improved with regard to the single-channel images. PMID:26480462

  4. PREFACE: 1st International Workshop on Theoretical and Computational Physics: Condensed Matter, Soft Matter and Materials Physics & 38th National Conference on Theoretical Physics

    NASA Astrophysics Data System (ADS)

    2014-09-01

    This volume contains selected papers presented at the 38th National Conference on Theoretical Physics (NCTP-38) and the 1st International Workshop on Theoretical and Computational Physics: Condensed Matter, Soft Matter and Materials Physics (IWTCP-1). Both the conference and the workshop were held from 29 July to 1 August 2013 in Pullman hotel, Da Nang, Vietnam. The IWTCP-1 was a new activity of the Vietnamese Theoretical Physics Society (VTPS) organized in association with the 38th National Conference on Theoretical Physics (NCTP-38), the most well-known annual scientific forum dedicated to the dissemination of the latest development in the field of theoretical physics within the country. The IWTCP-1 was also an External Activity of the Asia Pacific Center for Theoretical Physics (APCTP). The overriding goal of the IWTCP is to provide an international forum for scientists and engineers from academia to share ideas, problems and solution relating to the recent advances in theoretical physics as well as in computational physics. The main IWTCP motivation is to foster scientific exchanges between the Vietnamese theoretical and computational physics community and world-wide scientists as well as to promote high-standard level of research and education activities for young physicists in the country. About 110 participants coming from 10 countries participated in the conference and the workshop. 4 invited talks, 18 oral contributions and 46 posters were presented at the conference. In the workshop we had one keynote lecture and 9 invited talks presented by international experts in the fields of theoretical and computational physics, together with 14 oral and 33 poster contributions. The proceedings were edited by Nguyen Tri Lan, Trinh Xuan Hoang, and Nguyen Ai Viet. We would like to thank all invited speakers, participants and sponsors for making the conference and the workshop successful. Nguyen Ai Viet Chair of NCTP-38 and IWTCP-1

  5. Present status of the global change observation mission 1st - water 'SHIZUKU' (GCOM-W1) and the advanced microwave scanning radiometer 2 (AMSR2)

    NASA Astrophysics Data System (ADS)

    Tsutsui, Hiroyuki; Imaoka, Keiji; Kachi, Misako; Maeda, Takeshi; Kasahara, Marehito; Ito, Norimasa; Oki, Taikan; Shimoda, Haruhisa

    2014-11-01

    The Global Change Observation Mission 1st - Water (CGOM-W1) or "SHIZUKU" was launched on May 18, 2012 (JST) from the JAXA's Tanegashima Space Center. Subsequently, the GCOM-W1 satellite was joined to the NASA's A-train orbit since June 29, 2012 to succeed observation by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and to provide combined utilization with other A-train satellites. The Advanced Microwave Scanning Radiometer 2 (AMSR2), which is a successor of AMSR-E, onboard GCOM-W1 has started its scientific observation since July 3, 2012. AMSR-E was halted its scientific observation on October 4, 2011, but has restarted observation in slow antenna rotation rate since December 4, 2012 for cross-calibration with AMSR2. AMSR2 has multi-frequency, total-power microwave radiometer systems with dual polarization channels for all frequency bands, and continues AMSR-E observations: 1) Water vapor, 2) Cloud liquid water, 3) Precipitation, 4) SST, 5) Sea surface wind speed, 6) Sea ice concentration, 7) Snow depth, 8) Soil moisture. JAXA opened the AMSR2's brightness temperature products to the public since January 2013 after initial calibration/validation period by the GCOM-W1 Data Providing Service (https://gcomwl.jaxa.jp/). Thereafter, the retrieval algorithms of standard geophysical products for water vapor, cloud liquid water, precipitation, sea surface temperature, sea surface wind speed, sea ice concentration, snow depth and soil moisture were modified, and JAXA opened these standard geophysical products to the public since May 2013. In this paper, we present the present operation status of AMSR2.

  6. The truth about the 1st cycle Coulombic efficiency of LiNi1/3Co1/3Mn1/3O2 (NCM) cathodes.

    PubMed

    Kasnatscheew, J; Evertz, M; Streipert, B; Wagner, R; Klöpsch, R; Vortmann, B; Hahn, H; Nowak, S; Amereller, M; Gentschev, A-C; Lamp, P; Winter, M

    2016-02-01

    The 1st cycle Coulombic efficiency (CE) of LiNi1/3Co1/3Mn1/3O2 (NCM) at 4.6 V vs. Li/Li(+) has been extensively investigated in NCM/Li half cells. It could be proven that the major part of the observed overall specific capacity loss (in total 36.3 mA h g(-1)) is reversible and induced by kinetic limitations, namely an impeded lithiation reaction during discharge. A measure facilitating the lithiation reaction, i.e. a constant potential (CP) step at the discharge cut-off potential, results in an increase in specific discharge capacity of 22.1 mA h g(-1). This capacity increase during the CP step could be proven as a relithiation process by Li(+) content determination in NCM via an ICP-OES measurement. In addition, a specific capacity loss of approx. 4.2 mA h g(-1) could be determined as an intrinsic reaction to the NCM cathode material at room temperature (RT). In total, less than 10.0 mA h g(-1) (=28% of the overall capacity loss) can be attributed to irreversible reactions, mainly to irreversible structural changes of NCM. Thus, the impact of parasitic reactions, such as oxidative electrolyte decomposition, on the irreversible capacity is negligible and could also be proven by on-line MS. As a consequence, the determination of the amount of extracted Li(+) ("Li(+) extraction ratio") so far has been incorrect and must be calculated by the charge capacity (=delithiation amount) divided by the theoretical capacity. In a NCM/graphite full cell the relithiation amount during the constant voltage (CV) step is smaller than in the half cell, due to irreversible Li(+) loss at graphite. PMID:26771035

  7. Source Process of the Solomon Islands Earthquake of April 1st, 2007 (Mw8.1) Based on SAR Data and its Tectonic Implications

    NASA Astrophysics Data System (ADS)

    Mori, M.; Kato, T.; Furuya, M.; Ochi, T.; Miyazaki, S.; Aoki, Y.

    2008-12-01

    We analyzed SAR (Synthetic Aperture Radar) data to derive the crustal deformation due to the Solomon Islands earthquake (Mw8.1) that occurred on April 1st, 2007. Three tracks that cover the source areas were used and the image data taken before and after the earthquake were processed to make interferograms. Then, we examined the obtained interferograms if the previous two source models that were obtained by seismic wave form inversion analyses could reproduce them. However, none of the models were able to reproduce the crustal deformations derived from the SAR data analysis. Then, we tried to construct a source model that explains the observed crustal deformations well. We considered some geophysical data to constrain the source geometry; the multichannel reflection data and observed vertical deformations using coral reef survey. Considering these lines of evidence, we introduced two possible source geometries; one is single-segment model that assumes only shallow-dipping (10 deg.) main thrust ruptured, and the other is two-segment model that assumes both a high angle spray fault of 30 degree dip and the main thrust fault slipped. The comparison of models based on inversion analyses suggested that the two-segment model would be preferable. This result suggests that the Solomon Islands earthquake would be the first observed earthquake on a steeply dipping splay fault that ruptured off the main converging plate boundary. If this is the case, this earthquake might provide us with an important clue for understanding the mechanisms of land formation such as landward titling of the coastal terraces.

  8. [The clinical significance of reverse redistribution of Tl-201 SPECT at rest in the 1st month after the onset of acute myocardial infarction].

    PubMed

    Umamoto, I; Sugihara, H; Harada, Y; Sawada, T; Matsumuro, A; Matsubara, K; Shiga, K; Nakagawa, T; Oonishi, K; Nakamura, T

    1991-07-01

    The pattern of Thallium-201 reverse redistribution (r-RD) at rest has been reported in some patients with acute myocardial infarction (AMI) in the acute phase. But there is no report of this pattern in the later phase. To investigate the significance of Thallium-201 reverse redistribution in the subacute phase, 37 patients with AMI underwent Thallium-201 SPECT at rest a month after the onset. The patients were classified into three groups visually and 19 of 37 patients (51%) showed the persistent defect pattern (Group PD), and the remaining 18 patients (49%) had the reverse redistribution pattern (Group r-RD). None of them had the redistribution pattern. Coronary reflow was earlier and the incidence of the scintigraphic overlap on Dual SPECT image of 99mTc-PYP/201TlCl in the acute phase was more frequent in Group r-RD than in Group PD. A decrease in thallium defect size of patients with r-RD from the acute phase to one month after the onset represented improvement more significantly than that with PD. Initial %Tl uptake of the infarcted region of Group r-RD was greater than that of Group PD. The degree of stenosis of the infarct-related coronary artery in Group r-RD was less severe than that in Group PD. And corresponding regional wall motion of Group r-RD was less impaired. The Thallium-201 washout in the infarcted region with r-RD was significantly faster than that in the normal region. It is concluded that the r-RD pattern at rest in the 1st month after the onset of AMI may be a sign of viable myocardium. PMID:1833574

  9. A complete theoretical description of the first-order delta-sigma modulation for analog-to-NRZ binary conversion

    NASA Astrophysics Data System (ADS)

    Siahmakoun, A.; Reeves, E.; Costanzo-Caso, P.

    2015-03-01

    A novel photonic analog-to-digital converter (ADC) based on asynchronous delta-sigma modulation (ADSM) has been investigated. The architecture utilizes an optical leaky integrator, optoelectronic bistable quantizer, and positive corrective feedback for a non-interferometric optical implementation of ADSM. The principles of the proposed 1st -order ADSM are mathematically modeled and simulated.

  10. Orthogonal Higher Order Structure and Confirmatory Factor Analysis of the French Wechsler Adult Intelligence Scale (WAIS-III)

    ERIC Educational Resources Information Center

    Golay, Philippe; Lecerf, Thierry

    2011-01-01

    According to the most widely accepted Cattell-Horn-Carroll (CHC) model of intelligence measurement, each subtest score of the Wechsler Intelligence Scale for Adults (3rd ed.; WAIS-III) should reflect both 1st- and 2nd-order factors (i.e., 4 or 5 broad abilities and 1 general factor). To disentangle the contribution of each factor, we applied a…

  11. Poincaré plot analysis of autocorrelation function of RR intervals in patients with acute myocardial infarction.

    PubMed

    Chuang, Shin-Shin; Wu, Kung-Tai; Lin, Chen-Yang; Lee, Steven; Chen, Gau-Yang; Kuo, Cheng-Deng

    2014-08-01

    The Poincaré plot of RR intervals (RRI) is obtained by plotting RRIn+1 against RRIn. The Pearson correlation coefficient (ρRRI), slope (SRRI), Y-intercept (YRRI), standard deviation of instantaneous beat-to-beat RRI variability (SD1RR), and standard deviation of continuous long-term RRI variability (SD2RR) can be defined to characterize the plot. Similarly, the Poincaré plot of autocorrelation function (ACF) of RRI can be obtained by plotting ACFk+1 against ACFk. The corresponding Pearson correlation coefficient (ρACF), slope (SACF), Y-intercept (YACF), SD1ACF, and SD2ACF can be defined similarly to characterize the plot. By comparing the indices of Poincaré plots of RRI and ACF between patients with acute myocardial infarction (AMI) and patients with patent coronary artery (PCA), we found that the ρACF and SACF were significantly larger, whereas the RMSSDACF/SDACF and SD1ACF/SD2ACF were significantly smaller in AMI patients. The ρACF and SACF correlated significantly and negatively with normalized high-frequency power (nHFP), and significantly and positively with normalized very low-frequency power (nVLFP) of heart rate variability in both groups of patients. On the contrary, the RMSSDACF/SDACF and SD1ACF/SD2ACF correlated significantly and positively with nHFP, and significantly and negatively with nVLFP and low-/high-frequency power ratio (LHR) in both groups of patients. We concluded that the ρACF, SACF, RMSSDACF/SDACF, and SD1ACF/SD2ACF, among many other indices of ACF Poincaré plot, can be used to differentiate between patients with AMI and patients with PCA, and that the increase in ρACF and SACF and the decrease in RMSSDACF/SDACF and SD1ACF/SD2ACF suggest an increased sympathetic and decreased vagal modulations in both groups of patients. PMID:24356909

  12. Development of China Hydrogeology Exploring Techniques in 30 Years --Comparison of Handbook of Hydrogeology of 1st and 2nd Edition

    NASA Astrophysics Data System (ADS)

    Tong, Y.

    2013-12-01

    Handbook of Hydrogeology (2nd edition) is supported by one program from China Geological Survey (CGS): Research of Technical Methods of Hydrogeological Survey and Revision of Handbook of Hydrogeology. It is a reference book for those who are engaged in hydrogeological survey and research in China and covers fundamental principles, theories, survey and exploring techniques, and traditional experiences and achievements in hydrogeology. By comparing the 1st (1978) and 2nd (2012) edition of Handbook of Hydrogeology (in Chinese), this paper analyses the development of China hydrogeological survey and exploring techniques in last 30 years, especially the great change and progress in survey techniques of hydro-remote sensing and hydro-geophysical prospecting. In the first edition of Handbook of Hydrogeology, hydro-remote sensing was only mentioned as an interpretation of aerial pictures in a hydrogeological way, but had not yet formed an independent system and discipline. In the second edition, hydro-remote sensing is an important and independent chapter as one of the hydrogeological techniques. In it, various survey techniques of hydro-remote sensing and types and features of remote sensing data are classified. General systems of interpretation marks of remote sensing images are established, including marks of landform and Quaternary sediment, bedrock, structure types, water yield property, environmental elements of hydrogeology, aquifer group and so on. Systematic workflow is constructed, esp. in remote sensing images mapping and interpreting techniques. GPS and GIS are integrated into remote sensing. Remote sensing exploring instruments and interpreting softwares are also introduced and classified. Although hydro-geophysical prospecting, in the first edition of Handbook of Hydrogeology, was one independent chapter, there were only 10 exploring techniques. Equipments and instruments were simple and lagged in comparison to those in the second edition. The precision and

  13. Spatial and Temporal Characterization of Femtosecond Pulses at High-Numerical Aperture Using Collinear, Background-Free, Third-Harmonic Autocorrelation

    SciTech Connect

    Fittinghoff, D N; der Au, J A; Squier, J A

    2004-08-09

    We show that a simple plane wave analysis can be used even under tight focusing conditions to predict the dependence of third-harmonic generation on the polarization state of the incident beam. Exploiting this fact, we then show that circularly polarized beams may be used to spatially characterize the beam focus and temporally characterize ultrashort pulses in high numerical aperture systems by experimentally demonstrating, for the first time, novel collinear, background-free, third-harmonic intensity autocorrelations in time and space in a high numerical aperture microscope. We also discuss the possibility of using third harmonic generation with circularly polarized beams for background-free collinear frequency resolved optical gating.

  14. Stick boundary conditions and rotational velocity auto-correlation functions for colloidal particles in a coarse-grained representation of the solvent

    NASA Astrophysics Data System (ADS)

    Padding, J. T.; Wysocki, A.; Löwen, H.; Louis, A. A.

    2005-11-01

    We show how to implement stick boundary conditions for a spherical colloid in a solvent that is coarse-grained by the method of stochastic rotation dynamics. This allows us to measure colloidal rotational velocity auto-correlation functions by direct computer simulation. We find quantitative agreement with Enskog theory for short times and with hydrodynamic mode-coupling theory for longer times. For aqueous colloidal suspensions, the Enskog contribution to the rotational friction is larger than the hydrodynamic one when the colloidal radius drops below 35 nm.

  15. Direct autocorrelation of soft-x-ray free-electron-laser pulses by time-resolved two-photon double ionization of He

    NASA Astrophysics Data System (ADS)

    Mitzner, R.; Sorokin, A. A.; Siemer, B.; Roling, S.; Rutkowski, M.; Zacharias, H.; Neeb, M.; Noll, T.; Siewert, F.; Eberhardt, W.; Richter, M.; Juranic, P.; Tiedtke, K.; Feldhaus, J.

    2009-08-01

    The pulse duration of soft x-ray free-electron laser (FEL) radiation is directly measured by time-resolved observation of doubly charged helium ions at 51.8 eV. A wave front splitting autocorrelator produces two correlated FEL pulses with a resolution of better than a femtosecond. In the interesting intensity range from 1013 to 1016W/cm2 direct and sequential double ionization contribute to the ion yield which has significant influence on the correlation width, being a general feature at high photon energies. Here, a duration of τL=(29±5)fs is derived for the soft x-ray pulses at FLASH.

  16. The adaptive nature of liquidity taking in limit order books

    NASA Astrophysics Data System (ADS)

    Taranto, D. E.; Bormetti, G.; Lillo, F.

    2014-06-01

    In financial markets, the order flow, defined as the process assuming value one for buy market orders and minus one for sell market orders, displays a very slowly decaying autocorrelation function. Since orders impact prices, reconciling the persistence of the order flow with market efficiency is a subtle issue. A possible solution is provided by asymmetric liquidity, which states that the impact of a buy or sell order is inversely related to the probability of its occurrence. We empirically find that when the order flow predictability increases in one direction, the liquidity in the opposite side decreases, but the probability that a trade moves the price decreases significantly. While the last mechanism is able to counterbalance the persistence of order flow and restore efficiency and diffusivity, the first acts in the opposite direction. We introduce a statistical order book model where the persistence of the order flow is mitigated by adjusting the market order volume to the predictability of the order flow. The model reproduces the diffusive behaviour of prices at all time scales without fine-tuning the values of parameters, as well as the behaviour of most order book quantities as a function of the local predictability of the order flow.

  17. Power spectral density function and spatial autocorrelation of the ambient vibration full-wavefield generated by a distribution of spatially correlated surface sources

    NASA Astrophysics Data System (ADS)

    Lunedei, Enrico; Albarello, Dario

    2016-03-01

    Synthetic dispersion curves are here computed in the frame of an ambient-vibration full-wavefield model, which relies on the description of both ambient-vibration ground displacement and its sources as stochastic fields defined on the Earth's surface, stationary in time and homogeneous in space. In this model, previously developed for computing synthetic Horizontal-to-Vertical Spectral Ratio curves, the power spectral density function and the spatial autocorrelation of the displacement are naturally described as functions of the power spectral density function of the generating forces and of the subsoil properties (via the relevant Green's function), by also accounting for spatial correlation of these forces. Dispersion curves are computed from the displacement power spectral density function and from the spatial autocorrelation according with the well-known f-k and SPAC techniques, respectively. Two examples illustrate the way this new ambient-vibration model works, showing its possible use in better understanding the role of the surface waves in forming the dispersion curves, as well as its capability to capture some remarkable experimental findings.

  18. Autocorrelation standard deviation and root mean square frequency analysis of polymer electrolyte membrane fuel cell to monitor for hydrogen and air undersupply

    NASA Astrophysics Data System (ADS)

    Kim, Joo Gon; Mukherjee, Santanu; Bates, Alex; Zickel, Benjamin; Park, Sam; Son, Byung Rak; Choi, Jae Sung; Kwon, Osung; Lee, Dong Ha; Chung, Hyun-Youl

    2015-12-01

    Proton exchange membrane fuel cells are a promising energy conversion device which can help to solve urgent environmental and economic problems. Among the various types of fuel cells, the air breathing proton exchange membrane fuel cell, which minimizes the balance of plant, has drawn a lot of attention due to its superior energy density. In this study a compact, air breathing, proton exchange membrane fuel cell based on Nafion and a Pt/C membrane electrode assembly was designed. The fuel cell was tested using a Scribner Associates 850e fuel cell test station. Specifically, the hydrogen fuel and oxygen starvation of the fuel cell were accurately and systematically tested and analyzed using a frequency analysis method which can analyze the input and output frequency. The analysis of the frequency variation under a fuel starvation condition was done using RMSF (root mean square frequency) and ACSD (autocorrelation standard deviation). The study reveals two significant results: first, the fuel starvations show entirely different phenomenon in both RMSF and ACSD and second, the results of the Autocorrelation show clearer results for fuel starvation detection than the results with RMSF.

  19. FOREWORD: 13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications/1st International Conference on Fusion Energy Materials Science 13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications/1st International Conference on Fusion Energy Materials Science

    NASA Astrophysics Data System (ADS)

    Jacob, Wolfgang; Linsmeier, Christian; Rubel, Marek

    2011-12-01

    The 13th International Workshop on Plasma-Facing Materials and Components (PFMC-13) jointly organized with the 1st International Conference on Fusion Energy Materials Science (FEMaS-1) was held in Rosenheim (Germany) on 9-13 May 2011. PFMC-13 is a successor of the International Workshop on Carbon Materials for Fusion Applications series. Between 1985 and 2003 ten 'Carbon Workshops' were organized in Jülich, Stockholm and Hohenkammer. Then it was time for a change and redefinition of the scope of the symposium to reflect the new requirements of ITER and the ongoing evolution in the field. Under the new name (PFMC-11), the workshop was first organized in 2006 in Greifswald, Germany and PFMC-12 took place in Jülich in 2009. Initially starting in 1985 with about 40 participants as a 1.5 day workshop, the event has continuously grown to about 220 participants at PFMC-12. Due to the joint organization with FEMaS-1, PFMC-13 set a new record with more than 280 participants. The European project Fusion Energy Materials Science, FEMaS, coordinated by the Max-Planck-Institut für Plasmaphysik (IPP), organizes and stimulates cooperative research activities which involve large-scale research facilities as well as other top-level materials characterization laboratories. Five different fields are addressed: benchmarking experiments for radiation damage modelling, the application of micro-mechanical characterization methods, synchrotron and neutron radiation-based techniques and advanced nanoscopic analysis based on transmission electron microscopy. All these fields need to be exploited further by the fusion materials community for timely materials solutions for a DEMO reactor. In order to integrate these materials research fields, FEMaS acted as a co-organizer for the 2011 workshop and successfully introduced a number of participants from research labs and universities into the PFMC community. Plasma-facing materials experience particularly hostile conditions as they are

  20. X-ray diffraction study on ordered, disordered and reconstituted intercellular lipid lamellar structure in stratum corneum.

    PubMed

    Hatta, I; Ohta, N; Ban, S; Tanaka, H; Nakata, S

    2001-02-15

    From small angle X-ray diffraction for the stratum corneum of hairless mouse, it was obtained that in the normal stratum corneum, the 1st, 2nd and 3rd order diffraction peaks for the intercellular lipid lamellar structure appear at 13.8, 6.87 and 4.59 nm, respectively and also a broad hump for the 4th order reflection appears as observed by the previous researchers. In the damaged stratum corneum prepared by the treatment of sodium dodecyl sulfate, these small-angle diffraction peaks disappear and only the broad maxima remain around the 1st, 2nd and 3rd order diffraction peaks. These facts indicate that in the normal stratum the lamellar structure is ordered and in the damaged stratum corneum the lamellar structure is disordered. Furthermore, in the reconstituted lamellar structure obtained by immersing into the dilute suspension of the mixture of ceramide 3, cholesterol and stearic acid, the 1st, 2nd and 3rd order diffraction peaks reappear at 13.3, 6.67 and 4.44 nm, respectively. This fact indicates that the reorganization of the ordered lamellar structure takes place by adding the mixture to the damaged stratum corneum. PMID:11254216

  1. [The flagship of the national naval medical science (on the 80th anniversary of establishment of the 1st Central Research Institute of the Defense Ministry of Russian Federation)].

    PubMed

    Chumakov, Vl V; Arkhipov, A V; Borodavko, V K; Vasil'kov, A M; Groshilin, S M; Ivanov, A O; Smurov, A V

    2013-02-01

    The article is devoted to the 80th anniversary of the formation of the naval medical science subunit, which is the part of the 1st Central Research Institute of the Defense Ministry of Russian Federation. In the 30th years of XX century, a group of naval doctors formulated the main directions of preventive naval medicine. For eight decades, several generations of medical scientists have developed and ensured implementation of regulatory requirements for habitability and ergonomics of Navy ships. At the present stage, this work focuses on promising directions of the development of the domestic military shipbuilding and the use of advanced and innovative biomedical technologies. PMID:23808207

  2. The Hospital Microbiome Project: Meeting Report for the 1st Hospital Microbiome Project Workshop on sampling design and building science measurements, Chicago, USA, June 7th-8th 2012

    PubMed Central

    Smith, Daniel; Alverdy, John; An, Gary; Coleman, Maureen; Garcia-Houchins, Sylvia; Green, Jessica; Keegan, Kevin; Kelley, Scott T.; Kirkup, Benjamin C.; Kociolek, Larry; Levin, Hal; Landon, Emily; Olsiewski, Paula; Knight, Rob; Siegel, Jeffrey; Weber, Stephen; Gilbert, Jack

    2013-01-01

    This report details the outcome of the 1st Hospital Microbiome Project workshop held on June 7th-8th, 2012 at the University of Chicago, USA. The workshop was arranged to determine the most appropriate sampling strategy and approach to building science measurement to characterize the development of a microbial community within a new hospital pavilion being built at the University of Chicago Medical Center. The workshop made several recommendations and led to the development of a full proposal to the Alfred P. Sloan Foundation as well as to the creation of the Hospital Microbiome Consortium. PMID:23961316

  3. Orthogonal higher order structure and confirmatory factor analysis of the French Wechsler Adult Intelligence Scale (WAIS-III).

    PubMed

    Golay, Philippe; Lecerf, Thierry

    2011-03-01

    According to the most widely accepted Cattell-Horn-Carroll (CHC) model of intelligence measurement, each subtest score of the Wechsler Intelligence Scale for Adults (3rd ed.; WAIS-III) should reflect both 1st- and 2nd-order factors (i.e., 4 or 5 broad abilities and 1 general factor). To disentangle the contribution of each factor, we applied a Schmid-Leiman orthogonalization transformation (SLT) to the standardization data published in the French technical manual for the WAIS-III. Results showed that the general factor accounted for 63% of the common variance and that the specific contributions of the 1st-order factors were weak (4.7%-15.9%). We also addressed this issue by using confirmatory factor analysis. Results indicated that the bifactor model (with 1st-order group and general factors) better fit the data than did the traditional higher order structure. Models based on the CHC framework were also tested. Results indicated that a higher order CHC model showed a better fit than did the classical 4-factor model; however, the WAIS bifactor structure was the most adequate. We recommend that users do not discount the Full Scale IQ when interpreting the index scores of the WAIS-III because the general factor accounts for the bulk of the common variance in the French WAIS-III. The 4 index scores cannot be considered to reflect only broad ability because they include a strong contribution of the general factor. PMID:21171782

  4. 1st, 2nd and 3rd Generation Implementations of an eLearning Design: Re-Use from Postgraduate Law to Block/Online Engineering Course

    ERIC Educational Resources Information Center

    Lambert, Sarah; Brewer, Chris

    2007-01-01

    In order to meet the demands of postgraduate students who were time poor and unable to regularly attend face-to-face classes, one lecturer in the Faculty Law at the University of Wollongong (UOW) sought the assistance of a Learning Designer to redesign the Postgraduate Practical Legal Training (PLT) program into a flexible blended learning format,…

  5. Interacting gaps model, dynamics of order book, and stock-market fluctuations

    NASA Astrophysics Data System (ADS)

    Svorenčík, A.; Slanina, F.

    2007-06-01

    Inspired by order-book models of financial fluctuations, we investigate the Interacting gaps model, which is the schematic one-dimensional system mimicking the order-book dynamics. We find by simulations the power-law tail in return distribution, power-law decay of volatility autocorrelation with exponent 0.5 and Hurst exponent close to 1/2. Surprisingly, when we make a mean-field approximation, i.e. replace the one-dimensional system by effectively infinite-dimensional one, we obtain analytically the return exponent 5/2, in perfect accord with one-dimensional simulations.

  6. FY-2015 FES (Fusion and Energy Sciences) Joint Research Target: Final Report for the Period October 1st, 2014, through September 30th, 2015

    SciTech Connect

    Podesta, M.; Holcomb, C.; Wallace, G.; Gerhardt, S. P.; Scott, S. D.; Solomon, W.

    2015-09-30

    Annual JRT-15 Target: Conduct experiments and analysis to quantify the impact of broadened current and pressure profiles on tokamak plasma confinement and stability. Broadened pressure profiles generally improve global stability but can also affect transport and confinement, while broadened current profiles can have both beneficial and adverse impacts on confinement and stability. This research will examine a variety of heating and current drive techniques in order to validate theoretical models of both the actuator performance and the transport and global stability response to varied heating and current drive deposition.

  7. Post waterflood CO2 miscible flood in light oil fluvial - dominated deltaic reservoirs. Technical progress report, October 1, 1994--December 30, 1994. 1st Quarter, fiscal year 1995

    SciTech Connect

    1994-01-15

    Production is averaging about 450 BOPD for the quarter. The fluctuation was primarily due to a temporary shutdown of CO{sub 2} delivery and maturing of the first WAG cycle. CO{sub 2} and water injection were reversed again in order to optimize changing yields and water cuts in the producing wells. Measured BHP was close to the anticipated value. A limited CO{sub 2} volume of 120 MMCF was injected to stimulate well Kuhn No. 6 to test the Huff-Puff process, since the well did not respond to CO{sub 2} injection from the main reservoir. The well will be placed on February 1, 1995. Total CO{sub 2} injection averaged this quarter about 8.8 MMCFD, including 3.6 MMCFD purchased CO{sub 2} from Cardox. The stratigraphy of the sand deposits is also discussed.

  8. Uncertainty calculation in the RIO air quality interpolation model and aggregation to yearly average and exceedance probability taking into account the temporal auto-correlation.

    NASA Astrophysics Data System (ADS)

    Maiheu, Bino; Nele, Veldeman; Janssen, Stijn; Fierens, Frans; Trimpeneers, Elke

    2010-05-01

    RIO is an operational air quality interpolation model developed by VITO and IRCEL-CELINE and produces hourly maps for different pollutant concentrations such as O3, PM10 and NO2 measured in Belgium [1]. The RIO methodology consists of residual interpolation by Ordinary Kriging of the residuals of the measured concentrations and pre-determined trend functions which express the relation between land cover information derived from the CORINE dataset and measured time-averaged concentrations [2]. RIO is an important tool for the Flemish administration and is among others used to report, as is required by each member state, on the air quality status in Flanders to the European Union. We feel that a good estimate of the uncertainty of the yearly average concentration maps and the probability of norm-exceedance are both as important as the values themselves. In this contribution we will discuss the uncertainties specific to the RIO methodology, where we have both contributions from the Ordinary Kriging technique as well as the trend functions. Especially the parameterisation of the uncertainty w.r.t. the trend functions will be the key indicator for the degree of confidence the model puts into using land cover information for spatial interpolation of pollutant concentrations. Next, we will propose a method which enables us to calculate the uncertainty on the yearly average concentrations as well as the number of exceedance days, taking into account the temporal auto-correlation of the concentration fields. It is clear that the autocorrelation will have a strong impact on the uncertainty estimation [3] of yearly averages. The method we propose is based on a Monte Carlo technique that generates an ensemble of interpolation maps with the correct temporal auto-correlation structure. From a generated ensemble, the calculation of norm-exceedance probability at each interpolation location becomes quite straightforward. A comparison with the ad-hoc method proposed in [3], where

  9. High order sideband generation in terahertz quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Cavalié, P.; Freeman, J.; Maussang, K.; Strupiechonski, E.; Xu, G.; Colombelli, R.; Li, L.; Davies, A. G.; Linfield, E. H.; Tignon, J.; Dhillon, S. S.

    2013-06-01

    We demonstrate the generation of high order terahertz (THz) frequency sidebands (up to 3rd order) on a near infrared (NIR) optical carrier within a THz quantum cascade laser (QCL). The NIR carrier is resonant with the interband transition of the quantum wells composing the QCL, allowing the nonlinearity to be enhanced and leading to frequency mixing. A phonon depopulation based QCL with a double metal cavity was used to enhance the intracavity power density and to demonstrate the higher order sidebands. The 1st order sideband intensity shows a linear dependence with THz power corresponding to a single THz photon, while the second order sideband has a quadratic dependence implying a two THz photon interaction and hence a third order susceptibility. These measurements are compared to the photoluminescence and the QCL bandstructure to identify the states involved, with the lowest conduction band states contributing the most to the sideband intensity. We also show that the interaction for the second order sideband corresponds to an enhanced direct third order susceptibility χ(3) of ˜7 × 10-16(m/V)2, two orders of magnitude greater than the bulk value.

  10. Developing, enabling and facilitating practice-based research in primary dental care. Report of a one-day seminar, held at the Royal College of Surgeons of England on Friday, 1st February 2008.

    PubMed

    Eaton, Kenneth A; Narain, Amrita; Batchelor, Paul

    2008-07-01

    As part of the Faculty of General Dental Practice (UK)'s strategy to develop a research base for primary dental care, a one-day seminar was held at The Royal College of Surgeons of England on Friday, 1st February 2008. The aims for the day were to bring together the Divisional Research Contacts (DRCs), Faculty members with an interest in research, and regional and national leaders in primary care research; to update DRCs and Faculty members on developments and opportunities in primary care research; and to raise awareness of the Faculty's work among the leaders of primary care research. Of the 33 who attended the seminar, 12 were DRCs. PMID:18755058

  11. All Roads Lead to Rome: Exploring Human Migration to the Eternal City through Biochemistry of Skeletons from Two Imperial-Era Cemeteries (1st-3rd c AD).

    PubMed

    Killgrove, Kristina; Montgomery, Janet

    2016-01-01

    Migration within the Roman Empire occurred at multiple scales and was engaged in both voluntarily and involuntarily. Because of the lengthy tradition of classical studies, bioarchaeological analyses must be fully contextualized within the bounds of history, material culture, and epigraphy. In order to assess migration to Rome within an updated contextual framework, strontium isotope analysis was performed on 105 individuals from two cemeteries associated with Imperial Rome-Casal Bertone and Castellaccio Europarco-and oxygen and carbon isotope analyses were performed on a subset of 55 individuals. Statistical analysis and comparisons with expected local ranges found several outliers who likely immigrated to Rome from elsewhere. Demographics of the immigrants show men and children migrated, and a comparison of carbon isotopes from teeth and bone samples suggests the immigrants may have significantly changed their diet. These data represent the first physical evidence of individual migrants to Imperial Rome. This case study demonstrates the importance of employing bioarchaeology to generate a deeper understanding of a complex ancient urban center. PMID:26863610

  12. All Roads Lead to Rome: Exploring Human Migration to the Eternal City through Biochemistry of Skeletons from Two Imperial-Era Cemeteries (1st-3rd c AD)

    PubMed Central

    Killgrove, Kristina; Montgomery, Janet

    2016-01-01

    Migration within the Roman Empire occurred at multiple scales and was engaged in both voluntarily and involuntarily. Because of the lengthy tradition of classical studies, bioarchaeological analyses must be fully contextualized within the bounds of history, material culture, and epigraphy. In order to assess migration to Rome within an updated contextual framework, strontium isotope analysis was performed on 105 individuals from two cemeteries associated with Imperial Rome—Casal Bertone and Castellaccio Europarco—and oxygen and carbon isotope analyses were performed on a subset of 55 individuals. Statistical analysis and comparisons with expected local ranges found several outliers who likely immigrated to Rome from elsewhere. Demographics of the immigrants show men and children migrated, and a comparison of carbon isotopes from teeth and bone samples suggests the immigrants may have significantly changed their diet. These data represent the first physical evidence of individual migrants to Imperial Rome. This case study demonstrates the importance of employing bioarchaeology to generate a deeper understanding of a complex ancient urban center. PMID:26863610

  13. Variability of Polychaete Secondary Production in Intertidal Creek Networks along a Stream-Order Gradient

    PubMed Central

    Chu, Tianjiang; Sheng, Qiang; Wang, Sikai; Wu, Jihua

    2014-01-01

    Dendritic tidal creek networks are important habitats for sustaining biodiversity and ecosystem functioning in salt marsh wetlands. To evaluate the importance of creek heterogeneity in supporting benthic secondary production, we assess the spatial distribution and secondary production of a representative polychaete species (Dentinephtys glabra) in creek networks along a stream-order gradient in a Yangtze River estuarine marsh. Density, biomass, and secondary production of polychaetes were found to be highest in intermediate order creeks. In high order (3rd and 4th) creeks, the density and biomass of D. glabra were higher in creek edge sites than in creek bottom sites, whereas the reverse was true for low order (1st and 2nd) creeks. Secondary production was highest in 2nd order creeks (559.7 mg AFDM m−2 year−1) and was ca. 2 folds higher than in 1st and 4th order creeks. Top fitting AIC models indicated that the secondary production of D. glabra was mainly associated with geomorphological characters including cross-sectional area and bank slope. This suggests that hydrodynamic forces are essential factors influencing secondary production of macrobenthos in salt marshes. This study emphasizes the importance of microhabitat variability when evaluating secondary production and ecosystem functions. PMID:24817092

  14. Determination of the normalized-surface-height autocorrelation function of a two-dimensional randomly rough dielectric surface by the inversion of light-scattering data

    NASA Astrophysics Data System (ADS)

    Simonsen, I.; Hetland, Ø. S.; Kryvi, J. B.; Maradudin, A. A.

    2016-04-01

    An expression is obtained on the basis of phase perturbation theory for the contribution to the mean differential reflection coefficient from the in-plane co-polarized component of the light scattered diffusely from a two-dimensional randomly rough dielectric surface when the latter is illuminated by s -polarized light. This result forms the basis for an approach to inverting experimental light-scattering data to obtain the normalized-surface-height autocorrelation function of the surface. Several parametrized forms of this correlation function, and the minimization of a cost function with respect to the parameters defining these representations, are used in the inversion scheme. This approach also yields the rms height of the surface roughness, and the dielectric constant of the dielectric substrate if it is not known in advance. The input data used in validating this inversion consist of computer simulation results for surfaces defined by exponential and Gaussian surface-height correlation functions, without and with the addition of multiplicative noise, for a single or multiple angles of incidence. The reconstructions obtained by this approach are quite accurate for weakly rough surfaces, and the proposed inversion scheme is computationally efficient.

  15. Streamflow trend analysis by considering autocorrelation structure, long-term persistence, and Hurst coefficient in a semi-arid region of Iran

    NASA Astrophysics Data System (ADS)

    Zamani, Reza; Mirabbasi, Rasoul; Abdollahi, Sajjad; Jhajharia, Deepak

    2016-03-01

    Due to the substantial decrease of water resources as well as the increase in demand and climate change phenomenon, analyzing the trend of hydrological parameters is of paramount importance. In the present study, investigations were carried out to identify the trends in streamflow at 20 hydrometric stations and 11 rainfall gauging stations located in Karkheh River Basin (KRB), Iran, in monthly, seasonal, and annual time scales during the last 38 years from 1974 to 2011. This study has been conducted using two versions of Mann-Kendall tests, including (i) Mann-Kendall test by considering all the significant autocorrelation structure (MK3) and (ii) Mann-Kendall test by considering LTP and Hurst coefficient (MK4). The results indicate that the KRB streamflow trend (using both test versions) has decreased in all three time scales. There is a significant decreasing trend in 78 and 73 % of the monthly cases using the MK3 and MK4 tests, respectively, while these percentages changed to 80 and 70 % on seasonal and annual time scales, respectively. Investigation of the trend line slope using Theil-Sen's estimator showed a negative trend in all three time scales. The use of MK4 test instead of the MK3 test has caused a decrease in the significance level of Mann-Kendall Z-statistic values. The results of the precipitation trends indicate both increasing and decreasing trends. Also, the correlation between the area average streamflow and precipitation shows a strong correlation in annual time scale in the KRB.

  16. Computation of ESR spectra from the time evolution of the magnetization: Comparison of autocorrelation and Wiener-Khinchin-relation-based methods

    NASA Astrophysics Data System (ADS)

    Ikeuchi, Hiroki; De Raedt, Hans; Bertaina, Sylvain; Miyashita, Seiji

    2015-12-01

    The calculation of finite temperature electron spin resonance (ESR) spectra for concrete specified crystal configurations is a very important issue in the study of quantum spin systems. Although direct evaluation of the Kubo formula by means of numerical diagonalization yields exact results, memory and CPU time restrictions limit the applicability of this approach to small system sizes. Methods based on the time evolution of a single pure quantum state can be used to study larger systems. One such method exploits the property that the expectation value of the autocorrelation function obtained for a few samples of so-called thermal typical states yields a good estimate of the thermal equilibrium value. In this paper, we propose a new method based on a Wiener-Khinchin-like theorem for quantum system. By comparison with exact diagonalization results, it is shown that both methods yield correct results. As the Wiener-Khinchin-based method involves sampling over thermal typical states, we study the statistical properties of the sampling distribution. Effects due to finite observation time are investigated and found to differ for the two methods but it is also found that, for both methods, the effects vanish as the system size increases. We present ESR spectra of the one-dimensional XXZ Heisenberg chain of up to 28 spins and discuss the dependence of separation of double peaks on the chain length.

  17. Dynamic critical behavior of the Landau-Peierls fluctuations: Scaling form of the dynamic density autocorrelation function for smectic-A films

    NASA Astrophysics Data System (ADS)

    Poniewierski, A.; Hołyst, Robert; Price, A. C.; Sorensen, L. B.

    1999-03-01

    In this paper, we study the dynamic density autocorrelation function G(r,t) for smectic-A films in the layer sliding geometry. We first postulate a scaling form for G, and then we show that our postulated scaling form holds by comparing the scaling predictions with detailed numerical calculations. We find some deviations from the scaling form only for very thin films. For thick films, we find a region of a bulklike behavior, where the dynamics is characterized by the same static critical exponent η, which was originally introduced by Caillé [C. R. Acad. Sci. Ser. B 274, 891 (1972)]. In the limit of very large distance perpendicular to the layer normal, or in the limit of very long time, we find that the decay of G is governed by the surface exponent χ=kBTq2z/(4πγ), where γ is the surface tension and the wave-vector component qz satisfies the Bragg condition. We also find an intermediate perpendicular distance regime in which the decay of G is governed by the time-dependent exponent χexp(-t/τ0), where the relaxation time is given by τ0=η3(Ld)/(2γ), where η3 is the layer sliding viscosity, and Ld is the film thickness.

  18. EDITORIAL: Special section: Selected papers from OMS'05, the 1st Topical Meeting of the European Optical Society on Optical Microsystems (OMS)

    NASA Astrophysics Data System (ADS)

    Rendina, Ivo; Fazio, Eugenio; Ferraro, Pietro

    2006-07-01

    OMS'05 is the first international conference wholly dedicated to optical microsystems. It was organized by the European Optical Society (EOS) in the frame of its international topical meeting activity and was held in Italy, September 2005, amidst the wonderful scenery of the Island of Capri. A possible definition of an optical microsystem is a complex system, able to perform one or more sensing and actuation functions, where optical devices are integrated in a smart way with electronic, mechanical and sensing components by taking advantage of the progress in micro- and nano-technologies. The increasing interest in this field arises from the expected applications that would significantly improve the quality of life. The list of possibilities offered by the optical microsystem enabling technologies is very long and seems to increase day by day. We are not only thinking about the next generation of optical telecommunication networks and computers, but also about low-cost, compact microsystems for environmental monitoring, in order to improve safety in the avionic and automotive fields, medical diagnostics and proteomic/genomic studies, or just finding general applications in several industrial fields. The goal of the conference was to involve scientists and young researchers from the main public and private laboratories, giving them the opportunity to present new scientific results and compare their know-how in the exciting and emerging field of optical microsystems. We believe that we succeeded in this. More than 200 scientists from all over the world attended the conference. We had more than 100 oral presentations and approximately 20 from the keynote lectures and invited speeches. It was an opportunity to define the most recent progress carried out in the field and to outline the possible road-map leading to the expected results in the industrial and social fields. We strongly believe that research and technology are closely interconnected at present and cannot

  19. First- and second-order PMD mitigation using 3R regeneration

    NASA Astrophysics Data System (ADS)

    Pan, Shilong; Huo, Li; Yang, Yanfu; Lou, Caiyun; Gao, Yizhi

    2005-11-01

    We experimentally studied the PMD mitigation schemes using two different optical 3R regenerators. One is based on synchronous modulation and the other using an optical decision gate based on an electroabsorption modulator. The experimental results show that both schemes are useful to mitigate the signal quality degeneration induced by both first and second order PMD. System performance without and with 3R regeneration was separately studied by eye analysis and BER measurements. The signal quality was significantly improved by 3R regeneration under serious 1st-order PMD (up to 40% of the bit interval) combined with 2nd-order PMD (up to ~520ps2). We compared the performance between the two different 3R regenerators. The results show that 3R regenerator using an optical decision gate has a superior performance in synchronously mitigating 1st-order and 2nd-order PMD. Moreover, 3R based on EAM performs wavelength conversion simultaneously, which can be used to avoid wavelength blocking at nodes of the optical networks. Further studies indicate that 3R regenerators have the potential to combat with the effects of PMD combined with PDL and PHB. The limitation of the two schemes is also discussed.

  20. Variable Order and Distributed Order Fractional Operators

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.; Hartley, Tom T.

    2002-01-01

    Many physical processes appear to exhibit fractional order behavior that may vary with time or space. The continuum of order in the fractional calculus allows the order of the fractional operator to be considered as a variable. This paper develops the concept of variable and distributed order fractional operators. Definitions based on the Riemann-Liouville definitions are introduced and behavior of the operators is studied. Several time domain definitions that assign different arguments to the order q in the Riemann-Liouville definition are introduced. For each of these definitions various characteristics are determined. These include: time invariance of the operator, operator initialization, physical realization, linearity, operational transforms. and memory characteristics of the defining kernels. A measure (m2) for memory retentiveness of the order history is introduced. A generalized linear argument for the order q allows the concept of "tailored" variable order fractional operators whose a, memory may be chosen for a particular application. Memory retentiveness (m2) and order dynamic behavior are investigated and applications are shown. The concept of distributed order operators where the order of the time based operator depends on an additional independent (spatial) variable is also forwarded. Several definitions and their Laplace transforms are developed, analysis methods with these operators are demonstrated, and examples shown. Finally operators of multivariable and distributed order are defined in their various applications are outlined.

  1. Simulation study of the impact of AGIPD design choices on X-ray Photon Correlation Spectroscopy utilizing the intensity autocorrelation technique

    NASA Astrophysics Data System (ADS)

    Becker, J.; Gutt, C.; Graafsma, H.

    2011-11-01

    The European XFEL, currently under construction, will produce a coherent X-ray pulse every 222 ns in pulse trains of up to 2700 pulses. In conjunction with the fast 2D area detectors currently under development, it will be possible to perform X-ray Photon Correlation Spectroscopy (XPCS) experiments on sub-microsecond timescales with non-ergodic systems. A case study for the Adaptive Gain Integrating Pixel Detector (AGIPD) at the European XFEL employing the intensity autocorrelation technique was performed using the detector simulation tool HORUS. As optimum results from XPCS experiments are obtained when the pixel size approximates the (small) speckle size, the presented study compares the AGIPD (pixel size of (200 μm)2) to a possible apertured version of the detector and to a hypothetical system with (100 μm)2 pixel size and investigates the influence of intensity fluctuations and incoherent noise on the quality of the acquired data. The intuitive conclusion that aperturing is not beneficial as data is 'thrown away' was proven to be correct for low intensities. For intensities larger than approximately 1 photon per (100 μm)2 aperturing was found to be beneficial, as charge sharing effects were excluded by it. It was shown that for the investigated case (100 μm)2 pixels produced significantly better results than (200 μm)2 pixels when the average intensity exceeded approximately 0.05 photons per (100 μm)2. Although the systems were quite different in design they varied in the signal to noise ratio only by a factor of 2-3, and even less in the relative error of the extracted correlation constants. However the dependence on intensity showed distinctively different features for the different systems.

  2. Mono-static GPR without transmitting anything for pavement damage inspection: interferometry by auto-correlation applied to mobile phone signals

    NASA Astrophysics Data System (ADS)

    Feld, R.; Slob, E. C.; Thorbecke, J.

    2015-12-01

    Creating virtual sources at locations where physical receivers have measured a response is known as seismic interferometry. A much appreciated benefit of interferometry is its independence of the actual source locations. The use of ambient noise as actual source is therefore not uncommon in this field. Ambient noise can be commercial noise, like for example mobile phone signals. For GPR this can be useful in cases where it is not possible to place a source, for instance when it is prohibited by laws and regulations. A mono-static GPR antenna can measure ambient noise. Interferometry by auto-correlation (AC) places a virtual source on this antenna's position, without actually transmitting anything. This can be used for pavement damage inspection. Earlier work showed very promising results with 2D numerical models of damaged pavement. 1D and 2D heterogeneities were compared, both modelled in a 2D pavement world. In a 1D heterogeneous model energy leaks away to the sides, whereas in a 2D heterogeneous model rays can reflect and therefore still add to the signal reconstruction (see illustration). In the first case the amount of stationary points is strictly limited, while in the other case the amount of stationary points is very large. We extend these models to a 3D world and optimise an experimental configuration. The illustration originates from the journal article under submission 'Non-destructive pavement damage inspection by mono-static GPR without transmitting anything' by R. Feld, E.C. Slob, and J.W. Thorbecke. (a) 2D heterogeneous pavement model with three irregular-shaped misalignments between the base and subbase layer (marked by arrows). Mono-antenna B-scan positions are shown schematically. (b) Ideal output: a real source at the receiver's position. The difference w.r.t. the trace found in the middle is shown. (c) AC output: a virtual source at the receiver's position. There is a clear overlap with the ideal output.

  3. The 1st Grade Plant Museum.

    ERIC Educational Resources Information Center

    Wallach, Christine; Callahan, Susan

    1994-01-01

    A Saint Louis school experimenting with applying multiple intelligences theory to curricula and instruction defines "genuine understanding" as using information in novel ways. By surveying area museums and designing user-friendly botanical exhibits for a community-based project, first graders developed a better understanding of their own varied…

  4. GALEX 1st Light Near Ultraviolet -50

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This image was taken May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered by the two channels of the spacecraft camera during the mission's 'first light' milestone. It shows about 50 celestial objects in the constellation Hercules. The reddish objects represent those detected by the camera's near ultraviolet channel over a 5-minute period, while bluish objects were detected over a 3-minute period by the camera's far ultraviolet channel. Deeper imaging may confirm the apparent existence in this field of galaxy pairs and triplets or individual star formation regions in single galaxies.

    The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas.

    The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years.

  5. GALEX 1st Light Near Ultraviolet

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This image was taken on May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered during the missions 'first light' milestone, and shows celestial objects in the constellation Hercules. The objects shown represent those detected by the camera's near ultraviolet channel over a 5-minute period. The radial streaks at the edge of the image are due to stars reflecting from the near ultraviolet detector window.

    The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas.

    The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years.

  6. GALEX 1st Light Far Ultraviolet

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This image was taken May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered by the far ultraviolet channel of the spacecraft camera during the mission's 'first light' milestone. It shows about 400 celestial objects, appearing in blue, detected over a 3-minute, 20-second period in the constellation Hercules.

    The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas.

    The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years.

  7. Dewarless Logging Tool - 1st Generation

    SciTech Connect

    HENFLING,JOSEPH A.; NORMANN,RANDY A.

    2000-08-01

    This report focuses on Sandia National Laboratories' effort to create high-temperature logging tools for geothermal applications without the need for heat shielding. One of the mechanisms for failure in conventional downhole tools is temperature. They can only survive a limited number of hours in high temperature environments. For the first time since the evolution of integrated circuits, components are now commercially available that are qualified to 225 C with many continuing to work up to 300 C. These components are primarily based on Silicon-On-Insulator (SOI) technology. Sandia has developed and tested a simple data logger based on this technology that operates up to 300 C with a few limiting components operating to only 250 C without thermal protection. An actual well log to 240 C without shielding is discussed. The first prototype high-temperature tool measures pressure and temperature using a wire-line for power and communication. The tool is based around the HT83C51 microcontroller. A brief discussion of the background and status of the High Temperature Instrumentation program at Sandia, objectives, data logger development, and future project plans are given.

  8. Phase-ordering kinetics on curved surfaces

    NASA Astrophysics Data System (ADS)

    Schoenborn, Oliver Lars

    I investigate phase-ordering kinetics on static curved surfaces, starting from a well-known time-dependent Ginzburg-Landau equation, known as model A and valid in flat two-dimensional systems, and generalizing this to apply on curved surfaces. I develop and implement an interface formalism for model A, valid in both curved and flat surfaces. This is based on an interface velocity equation explicitly showing how interface motion couples to local surface geometry. I discuss extensively both theoretical and numerical aspects of this formalism. I derive a coupled set of curvature equations and use them to obtain an approximate expression for the curvature autocorrelation function (CAF) in the flat case. This is compared for the first time to numerical simulation results and shows that the CAF provides dynamical information not readily available from the traditional order-parameter structure-factor, yet is far easier to compute than the latter. A dominant length-scale is observed for the first time, in the domain interface undulations, even in Euclidean model A dynamics. I discuss how this affects the interpretation of what is needed for a system to exhibit dynamical scaling. I look at the effect of surface Gauss curvature on the growth rate of domains and show that when the phase-ordering occurs on a corrugated surface, metastable long-range disorder may result. I show how these effects cause a break-down of dynamical scaling and power-law growth, how they bring about the elimination of the zero-temperature fixed point of Euclidean model A, and how phase-ordering in curved lipid-bilayer membranes should be affected. A new very-late stage regime appears for simulations of model A on sinusoid (i.e. egg-carton-like) surfaces. These features indicate that thermal noise should be included in future studies of phase ordering kinetics on curved surfaces. They also indicate that even before the order-parameter is explicitly coupled to surface quantities such as the local mean

  9. 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad: 1st International Conference held in San Francisco, California, May 2012 and 2nd International Conference held in Indianapolis, Indiana, May 2013.

    PubMed

    De Souza, Mary Jane; Nattiv, Aurelia; Joy, Elizabeth; Misra, Madhusmita; Williams, Nancy I; Mallinson, Rebecca J; Gibbs, Jenna C; Olmsted, Marion; Goolsby, Marci; Matheson, Gordon

    2014-02-01

    The Female Athlete Triad is a medical condition often observed in physically active girls and women, and involves three components: (1) low energy availability with or without disordered eating, (2) menstrual dysfunction and (3) low bone mineral density. Female athletes often present with one or more of the three Triad components, and an early intervention is essential to prevent its progression to serious endpoints that include clinical eating disorders, amenorrhoea and osteoporosis. This consensus statement represents a set of recommendations developed following the 1st (San Francisco, California, USA) and 2nd (Indianapolis, Indiana, USA) International Symposia on the Female Athlete Triad. It is intended to provide clinical guidelines for physicians, athletic trainers and other healthcare providers for the screening, diagnosis and treatment of the Female Athlete Triad and to provide clear recommendations for return to play. The 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad expert panel has proposed a risk stratification point system that takes into account magnitude of risk to assist the physician in decision-making regarding sport participation, clearance and return to play. Guidelines are offered for clearance categories, management by a multidisciplinary team and implementation of treatment contracts. This consensus paper has been endorsed by the Female Athlete Triad Coalition, an International Consortium of leading Triad researchers, physicians and other healthcare professionals, the American College of Sports Medicine and the American Medical Society for Sports Medicine. PMID:24463911

  10. Ecosystem functional assessment based on the "optical type" concept and self-similarity patterns: An application using MODIS-NDVI time series autocorrelation

    NASA Astrophysics Data System (ADS)

    Huesca, Margarita; Merino-de-Miguel, Silvia; Eklundh, Lars; Litago, Javier; Cicuéndez, Victor; Rodríguez-Rastrero, Manuel; Ustin, Susan L.; Palacios-Orueta, Alicia

    2015-12-01

    Remote sensing (RS) time series are an excellent operative source for information about the land surface across several scales and different levels of landscape heterogeneity. Ustin and Gamon (2010) proposed the new concept of "optical types" (OT), meaning "optically distinguishable functional types", as a way to better understand remote sensing signals related to the actual functional behavior of species that share common physiognomic forms but differ in functionality. Whereas the OT approach seems to be promising and consistent with ecological theory as a way to monitor vegetation derived from RS, it received little implementation. This work presents a method for implementing the OT concept for efficient monitoring of ecosystems based on RS time series. We propose relying on an ecosystem's repetitive pattern in the temporal domain (self-similarity) to assess its dynamics. Based on this approach, our main hypothesis is that distinct dynamics are intrinsic to a specific OT. Self-similarity level in the temporal domain within a broadleaf forest class was quantitatively assessed using the auto-correlation function (ACF), from statistical time series analysis. A vector comparison classification method, spectral angle mapper, and principal component analysis were used to identify general patterns related to forest dynamics. Phenological metrics derived from MODIS NDVI time series using the TIMESAT software, together with information from the National Forest Map were used to explain the different dynamics found. Results showed significant and highly stable self-similarity patterns in OTs that corresponded to forests under non-moisture-limited environments with an adaptation strategy based on a strong phenological synchrony with climate seasonality. These forests are characterized by dense closed canopy deciduous forests associated with high productivity and low biodiversity in terms of dominant species. Forests in transitional areas were associated with patterns of less

  11. Surface Roughness and Critical Exponent Analyses of Boron-Doped Diamond Films Using Atomic Force Microscopy Imaging: Application of Autocorrelation and Power Spectral Density Functions

    NASA Astrophysics Data System (ADS)

    Gupta, S.; Vierkant, G. P.

    2014-09-01

    The evolution of the surface roughness of growing metal or semiconductor thin films provides much needed information about their growth kinetics and corresponding mechanism. While some systems show stages of nucleation, coalescence, and growth, others exhibit varying microstructures for different process conditions. In view of these classifications, we report herein detailed analyses based on atomic force microscopy (AFM) characterization to extract the surface roughness and growth kinetics exponents of relatively low boron-doped diamond (BDD) films by utilizing the analytical power spectral density (PSD) and autocorrelation function (ACF) as mathematical tools. The machining industry has applied PSD for a number of years for tool design and analysis of wear and machined surface quality. Herein, we present similar analyses at the mesoscale to study the surface morphology as well as quality of BDD films grown using the microwave plasma-assisted chemical vapor deposition technique. PSD spectra as a function of boron concentration (in gaseous phase) are compared with those for samples grown without boron. We find that relatively higher boron concentration yields higher amplitudes of the longer-wavelength power spectral lines, with amplitudes decreasing in an exponential or power-law fashion towards shorter wavelengths, determining the roughness exponent ( α ≈ 0.16 ± 0.03) and growth exponent ( β ≈ 0.54), albeit indirectly. A unique application of the ACF, which is widely used in signal processing, was also applied to one-dimensional or line analyses (i.e., along the x- and y-axes) of AFM images, revealing surface topology datasets with varying boron concentration. Here, the ACF was used to cancel random surface "noise" and identify any spatial periodicity via repetitive ACF peaks or spatially correlated noise. Periodicity at shorter spatial wavelengths was observed for no doping and low doping levels, while smaller correlations were observed for relatively

  12. Critical comparison of several order-book models for stock-market fluctuations

    NASA Astrophysics Data System (ADS)

    Slanina, F.

    2008-01-01

    Far-from-equilibrium models of interacting particles in one dimension are used as a basis for modelling the stock-market fluctuations. Particle types and their positions are interpreted as buy and sel orders placed on a price axis in the order book. We revisit some modifications of well-known models, starting with the Bak-Paczuski-Shubik model. We look at the four decades old Stigler model and investigate its variants. One of them is the simplified version of the Genoa artificial market. The list of studied models is completed by the models of Maslov and Daniels et al. Generically, in all cases we compare the return distribution, absolute return autocorrelation and the value of the Hurst exponent. It turns out that none of the models reproduces satisfactorily all the empirical data, but the most promising candidates for further development are the Genoa artificial market and the Maslov model with moderate order evaporation.

  13. Density functional theory calculations on the active site of biotin synthase: mechanism of S transfer from the Fe(2)S(2) cluster and the role of 1st and 2nd sphere residues.

    PubMed

    Rana, Atanu; Dey, Subal; Agrawal, Amita; Dey, Abhishek

    2015-10-01

    Density functional theory (DFT) calculations are performed on the active site of biotin synthase (BS) to investigate the sulfur transfer from the Fe(2)S(2) cluster to dethiobiotin (DTB). The active site is modeled to include both the 1st and 2nd sphere residues. Molecular orbital theory considerations and calculation on smaller models indicate that only an S atom (not S²⁻) transfer from an oxidized Fe(2)S(2) cluster leads to the formation of biotin from the DTB using two adenosyl radicals generated from S-adenosyl-L-methionine. The calculations on larger protein active site model indicate that a 9-monothiobiotin bound reduced cluster should be an intermediate during the S atom insertion from the Fe(2)S(2) cluster consistent with experimental data. The Arg260 bound to Fe1, being a weaker donor than cysteine bound to Fe(2), determines the geometry and the electronic structure of this intermediate. The formation of this intermediate containing the C9-S bond is estimated to have a ΔG(≠) of 17.1 kcal/mol while its decay by the formation of the 2nd C6-S bond is calculated to have a ΔG(≠) of 29.8 kcal/mol, i.e. the 2nd C-S bond formation is calculated to be the rate determining step in the cycle and it leads to the decay of the Fe(2)S(2) cluster. Significant configuration interaction (CI), present in these transition states, helps lower the barrier of these reactions by ~30-25 kcal/mol relative to a hypothetical outer-sphere reaction. The conserved Phe285 residue near the Fe(2)S(2) active site determines the stereo selectivity at the C6 center of this radical coupling reaction. Reaction mechanism of BS investigated using DFT calculations. Strong CI and the Phe285 residue control the kinetic rate and stereochemistry of the product. PMID:26369537

  14. Results of Primary Total Hip Arthroplasty Using 36 mm Femoral Heads on 1st Generation Highly Cross Linked Polyethylene in Patients 50 Years and Less with Minimum Five Year Follow-up

    PubMed Central

    Choi, Won-Kee; Kim, Hee-soo; Nam, Jun-Ho; Chae, Seung-Bum

    2016-01-01

    Purpose We evaluated the clinical and radiographic midterm results of primary total hip arthroplasty (THA) using a 36 mm diameter femoral head on 1st generation highly cross-linked polyethylene (HXLPE) in patients 50 years and less with minimum five year follow-up. Materials and Methods We retrospectively reviewed 31 patients (41 hips) aged 50 years and less underwent primary THA with a 36 mm diameter femoral head on HXLPE between 2004 and 2010. Clinical follow-ups included specific measurements like modified Harris hip scores (HHS) and Merle d'Aubigne and Postel score. For radiologic evaluations, together with position of acetabular cup at six weeks later of postoperation, we separately calculated the penentrations of femoral head into polyethylene liners during postoperation and one year later check-ups, and during one year later check-ups and final check-ups. Results There were no major complications except for one case of dislocation. Average modified HHS at final follow-up was 88 (81-98), and Merle d'Aubigne and Postel scores were more than 15. Mean acetabular cup inclination and anteversion were 45.81°(36.33°-54.91°) and 13.26°(6.72°-27.71°), respectively. Average femoral head penetration of steady-state wear rate determined using radiographs taken at one-year postoperatively and at latest follow-up was 0.042±0.001 mm/year. Conclusion Based on minimum 5 years clinical results, we think 36 mm metal head coupling with HXLPE as the good alternate articulation surface when planning THA for patients aged 50 years and less. PMID:27536648

  15. Order Theoretical Semantic Recommendation

    SciTech Connect

    Joslyn, Cliff A.; Hogan, Emilie A.; Paulson, Patrick R.; Peterson, Elena S.; Stephan, Eric G.; Thomas, Dennis G.

    2013-07-23

    Mathematical concepts of order and ordering relations play multiple roles in semantic technologies. Discrete totally ordered data characterize both input streams and top-k rank-ordered recommendations and query output, while temporal attributes establish numerical total orders, either over time points or in the more complex case of startend temporal intervals. But also of note are the fully partially ordered data, including both lattices and non-lattices, which actually dominate the semantic strcuture of ontological systems. Scalar semantic similarities over partially-ordered semantic data are traditionally used to return rank-ordered recommendations, but these require complementation with true metrics available over partially ordered sets. In this paper we report on our work in the foundations of partial order measurement in ontologies, with application to top-k semantic recommendation in workflows.

  16. Minimal Orderings Revisited

    SciTech Connect

    Peyton, B.W.

    1999-07-01

    When minimum orderings proved too difficult to deal with, Rose, Tarjan, and Leuker instead studied minimal orderings and how to compute them (Algorithmic aspects of vertex elimination on graphs, SIAM J. Comput., 5:266-283, 1976). This paper introduces an algorithm that is capable of computing much better minimal orderings much more efficiently than the algorithm in Rose et al. The new insight is a way to use certain structures and concepts from modern sparse Cholesky solvers to re-express one of the basic results in Rose et al. The new algorithm begins with any initial ordering and then refines it until a minimal ordering is obtained. it is simple to obtain high-quality low-cost minimal orderings by using fill-reducing heuristic orderings as initial orderings for the algorithm. We examine several such initial orderings in some detail.

  17. Infant temperament: stability by age, gender, birth order, term status, and socioeconomic status.

    PubMed

    Bornstein, Marc H; Putnick, Diane L; Gartstein, Maria A; Hahn, Chun-Shin; Auestad, Nancy; O'Connor, Deborah L

    2015-01-01

    Two complementary studies focused on stability of infant temperament across the 1st year and considered infant age, gender, birth order, term status, and socioeconomic status (SES) as moderators. Study 1 consisted of 73 mothers of firstborn term girls and boys queried at 2, 5, and 13 months of age. Study 2 consisted of 335 mothers of infants of different gender, birth order, term status, and SES queried at 6 and 12 months. Consistent positive and negative affectivity factors emerged at all time points across both studies. Infant temperament proved stable and robust across gender, birth order, term status, and SES. Stability coefficients for temperament factors and scales were medium to large for shorter (< 9 months) interassessment intervals and small to medium for longer (> 10 months) intervals. PMID:25865034

  18. Infants Communicate in Order to Be Understood

    ERIC Educational Resources Information Center

    Grosse, Gerlind; Behne, Tanya; Carpenter, Malinda; Tomasello, Michael

    2010-01-01

    Infants intentionally communicate with others from before their 1st birthday. But there is some question about how they understand the communicative process. Do they understand that for their request to work the recipient must both understand the request and be cooperatively disposed to fulfill it? On the basis of the study by Shwe and Markman…

  19. 0.1 Trend analysis of δ18O composition of precipitation in Germany: Combining Mann-Kendall trend test and ARIMA models to correct for higher order serial correlation

    NASA Astrophysics Data System (ADS)

    Klaus, Julian; Pan Chun, Kwok; Stumpp, Christine

    2015-04-01

    Spatio-temporal dynamics of stable oxygen (18O) and hydrogen (2H) isotopes in precipitation can be used as proxies for changing hydro-meteorological and regional and global climate patterns. While spatial patterns and distributions gained much attention in recent years the temporal trends in stable isotope time series are rarely investigated and our understanding of them is still limited. These might be a result of a lack of proper trend detection tools and effort for exploring trend processes. Here we make use of an extensive data set of stable isotope in German precipitation. In this study we investigate temporal trends of δ18O in precipitation at 17 observation station in Germany between 1978 and 2009. For that we test different approaches for proper trend detection, accounting for first and higher order serial correlation. We test if significant trends in the isotope time series based on different models can be observed. We apply the Mann-Kendall trend tests on the isotope series, using general multiplicative seasonal autoregressive integrate moving average (ARIMA) models which account for first and higher order serial correlations. With the approach we can also account for the effects of temperature, precipitation amount on the trend. Further we investigate the role of geographic parameters on isotope trends. To benchmark our proposed approach, the ARIMA results are compared to a trend-free prewhiting (TFPW) procedure, the state of the art method for removing the first order autocorrelation in environmental trend studies. Moreover, we explore whether higher order serial correlations in isotope series affects our trend results. The results show that three out of the 17 stations have significant changes when higher order autocorrelation are adjusted, and four stations show a significant trend when temperature and precipitation effects are considered. Significant trends in the isotope time series are generally observed at low elevation stations (≤315 m a

  20. First-order inflation

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.

    1991-01-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result if inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models.

  1. First-order inflation

    SciTech Connect

    Kolb, E.W. Chicago Univ., IL . Enrico Fermi Inst.)

    1990-09-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result in inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. 58 refs., 3 figs.

  2. Nonlinear Fourier-transform spectroscopy of D{sub 2} using high-order harmonic radiation

    SciTech Connect

    Furukawa, Yusuke; Nabekawa, Yasuo; Saugout, Sebastien; Midorikawa, Katsumi; Okino, Tomoya; Yamanouchi, Kaoru

    2010-07-15

    We have determined the multiphoton ionization and dissociation pathways of D{sub 2} with the simultaneous irradiation of the high-order harmonic fields and the low-order harmonic fields of Ti:sapphire laser pulses in the visible-vacuum ultraviolet region with the aid of a nonlinear Fourier-transform spectroscopy. By analyzing the interferometric autocorrelation signal of the measured velocity map images of D{sup +}, we were able to decompose the measured momentum distribution into three momentum distribution images representing the three distinct dissociation pathways, which are sequentially two-photon absorption processes of D{sub 2} via the electronic ground state (X {sup 2{Sigma}}{sub g}{sup +}) of D{sub 2}{sup +} to the first excited state (A {sup 2{Sigma}}{sub u}{sup +}), leading to the dissociation into D{sup +} + D.

  3. Complete Sequence of pEC012, a Multidrug-Resistant IncI1 ST71 Plasmid Carrying blaCTX-M-65, rmtB, fosA3, floR, and oqxAB in an Avian Escherichia coli ST117 Strain

    PubMed Central

    Pan, Yu-Shan; Zong, Zhi-Yong; Yuan, Li; Du, Xiang-Dang; Huang, Hui; Zhong, Xing-Hao; Hu, Gong-Zheng

    2016-01-01

    A 139,622-bp IncI1 ST71 conjugative plasmid pEC012 from an avian Escherichia coli D-ST117 strain was sequenced, which carried five IS26-bracketed resistance modules: IS26-fosA3-orf1-orf2-Δorf3-IS26, IS26-fip-ΔISEcp1-blaCTX-M-65-IS903D-iroN-IS26, IS26-ΔtnpR-blaTEM-1-rmtB-IS26, IS26-oqxAB-IS26, and IS26-floR-aac(3)-IV-IS26. The backbone of pEC012 was similar to that of several other IncI1 ST71 plasmids: pV408, pM105, and pC271, but these plasmids had different arrangements of multidrug resistance region. In addition, the novel ISEc57 element was identified, which is in the IS21 family. The stepwise emergence of multi-resistance regions demonstrated the accumulation of different resistance determinants through homologous recombination. To the best of our knowledge, this is the first study to identify a multidrug-resistant IncI1 ST71 plasmid carrying blaCTX-M-65, rmtB, fosA3, floR, and oqxAB in an avian E. coli ST117 strain. PMID:27486449

  4. Extended-spectrum beta-lactamase-producing Shiga toxin gene (stx1)-positive Escherichia coli O91:H14 carrying blaCTX-M-15 on an IncI1-ST31 plasmid isolated from a human patient in Germany.

    PubMed

    Arvand, Mardjan; Bettge-Weller, Gudrun; Fruth, Angelika; Uphoff, Helmut; Pfeifer, Yvonne

    2015-05-01

    In 2011, the Shiga toxin- and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli O104:H4 caused a serious outbreak of gastroenteritis in Germany. This strain carried bla(CTX-M-15) and bla(TEM-1) on an IncI1-ST31 plasmid. During screening of individuals at risk for acquisition of the epidemic E. coli O104:H4, we isolated another ESBL-producing and Shiga toxin-positive E. coli belonging to serotype O91:H14 from feces of a human patient. Interestingly, the patient also carried a further ESBL-producing but Shiga toxin-negative E. coli. Both strains harbored bla(CTX-M-15) and bla(TEM-1) on an IncI1-ST31 plasmid, which was indistinguishable regarding size and plasmid restriction pattern from the plasmid of the epidemic E. coli O104:H4 strain. The patient had traveled to India 6 months prior to the isolation of the E. coli strains. This is the first report of an ESBL-producing, Shiga toxin-positive E. coli of serogroup O91. Our data suggest a high propensity of the IncI1-ST31 plasmid to spread in the human and/or animal population. PMID:25801683

  5. Complete Sequence of pEC012, a Multidrug-Resistant IncI1 ST71 Plasmid Carrying bla CTX-M-65, rmtB, fosA3, floR, and oqxAB in an Avian Escherichia coli ST117 Strain.

    PubMed

    Pan, Yu-Shan; Zong, Zhi-Yong; Yuan, Li; Du, Xiang-Dang; Huang, Hui; Zhong, Xing-Hao; Hu, Gong-Zheng

    2016-01-01

    A 139,622-bp IncI1 ST71 conjugative plasmid pEC012 from an avian Escherichia coli D-ST117 strain was sequenced, which carried five IS26-bracketed resistance modules: IS26-fosA3-orf1-orf2-Δorf3-IS26, IS26-fip-ΔISEcp1-bla CTX-M-65-IS903D-iroN-IS26, IS26-ΔtnpR-bla TEM-1-rmtB-IS26, IS26-oqxAB-IS26, and IS26-floR-aac(3)-IV-IS26. The backbone of pEC012 was similar to that of several other IncI1 ST71 plasmids: pV408, pM105, and pC271, but these plasmids had different arrangements of multidrug resistance region. In addition, the novel ISEc57 element was identified, which is in the IS21 family. The stepwise emergence of multi-resistance regions demonstrated the accumulation of different resistance determinants through homologous recombination. To the best of our knowledge, this is the first study to identify a multidrug-resistant IncI1 ST71 plasmid carrying bla CTX-M-65, rmtB, fosA3, floR, and oqxAB in an avian E. coli ST117 strain. PMID:27486449

  6. Multiple ordering in magnetite.

    NASA Technical Reports Server (NTRS)

    Cullen, J. R.; Callen, E. R.

    1973-01-01

    Results of a self-consistent band calculation of the ground-state energy and charge orderings based on a tight-binding scheme in magnetite are presented. They show that below a critical (about 2.2) value of the ratio of interatomic Coulomb energy to bandwidth the lowest energy state has no order. Between this critical value and 2.5, the preferred state is multiply ordered.

  7. After order 636

    SciTech Connect

    Katz, M.G.

    1995-02-01

    Through its Order 636, the Federal Energy Regulatory Commission (FERC) completed a restructuring of the natural gas industry. The order severed the last links in the chain linking gas producers to pipeline companies to local gas distribution companies (LDCs) to customers. Before Order 636 took effect, many predicted electric power generation, particularly by cogenerators and independent power producers (IPPs), would be a major growth area for natural gas. In fact, what Order 636 has shown is, that timing is everything, and that it`s difficult to sort out the effect of one agent of change when many others are at work.

  8. Order, Disorder and Confinement

    SciTech Connect

    D'Elia, M.; Di Giacomo, A.; Pica, C.

    2006-01-12

    Studying the order of the chiral transition for Nf = 2 is of fundamental importance to understand the mechanism of color confinement. We present results of a numerical investigation on the order of the transition by use of a novel strategy in finite size scaling analysis. The specific heat and a number of susceptibilities are compared with the possible critical behaviours. A second order transition in the O(4) and O(2) universality classes are excluded. Substantial evidence emerges for a first order transition. Results are in agreement with those found by studying the scaling properties of a disorder parameter related to the dual superconductivity mechanism of color confinement.

  9. Bioregions and World Order.

    ERIC Educational Resources Information Center

    Breakthrough, 1985

    1985-01-01

    What bioregions can do to contribute to world order and security is discussed in this newsletter. A bioregion is defined as an identifiable geographical area of interacting life-systems that is relatively self-sustaining in the ever-renewing processes of nature. Articles included are: "Bioregionalism and World Order" (Gerald Mische); "Bioregions:…

  10. ASDC Order Tools

    Atmospheric Science Data Center

    2012-04-17

    ... users to search our data holdings without logging in to the system. The user, however, must log in before ordering the data. ... Reverb, developed by Earth Science Data and Information System (ESDIS), gives the user community an improved search and order ...

  11. On mechanisms triggering the levees failure along the Foenna stream on 1st January 2006 and which caused the flooding in the urban area of Sinalunga, Tuscany Region (Italy). A case study

    NASA Astrophysics Data System (ADS)

    Camici, Stefania; Moramarco, Tommaso; Brocca, Luca; Melone, Florisa; Lapenna, Vincenzo; Perrone, Angela; Loperte, Antonio

    2010-05-01

    On 1st January 2006, during an ordinary flood event, a levee failure along the Foenna stream caused the flooding in the urban area of Sinalunga, a small town located in Tuscany region (Italy). The event was monitored by a public agency with the responsibility for the control and maintenance of the natural channel networks. Long time before of flooding, people living in the surrounding area of the stream blamed the presence of wild animals and of numerous burrows along the levees. Although the numerous actions of maintenance along the levees mainly for removing the burrows, a levee seepage occurred during that flood. The presence of an outflow located on the downstream face, almost 2 m below the levee top, caused the spurt of brown water denoting the presence of sediment erosion. On the upstream face of levee, a little hole of about 30 cm at the same height of the outflow was discovered. Although the agency workers tried to close the hole by using appropriate blankets, in short time the top of the levee subsided and the overtopping flow caused a trapezoidal breach typical for an earth-fill embankment. The formation of breach was so fast that in a little more of one hour the urban area near to the Foenna stream was flooded causing high economic damages. Mechanisms triggered the levees failure are the object of this work. The analysis of the event has been first addressed to assess the state of-fact of levees conditions along the Foenna stream, thus to understand how much the activity of wild animals, in particular that of porcupine, may have affected the hydraulic safety of the embankment. At the purpose, after the event, topographical surveys of cross sections have been done along with tomographic surveys by geoelectric technique for investigating the possible presence, besides of burrows, also of tunnels dug into the levees by animals. Then, the analysis of hydrometeorological conditions of the event has allowed to better understand the evolution of the flood and

  12. Influences of experimental parameters and inverse algorithms on nanometer particle size measured by self-designed system based on dynamic light scattering

    NASA Astrophysics Data System (ADS)

    Deng, Shaoyong; Zhang, Qi; Xia, Junying

    2014-12-01

    A totally self-designed experimental system based on dynamic light scattering is developed. The method of photon correlation spectroscopy is used to simulate the autocorrelation of measured scattering photons and scattering field. The dynamic autocorrelation software is self-compiled to replace the popular hardware digital correlator for much more correlation channels and much lower costs. Several inverse algorithms such as 1st-order Cumulants, 2nd-order Cumulants, NNLS, CONTIN and Double Exponents are used to compute the particle sizes and decay linewidths of both monodisperse systems and polydisperse systems. The programs based on these inverse algorithms are all self-compiled except the CONTIN. Influences of systematical parameters such as sample time, the last delay time, elapsed time, suspension's concentration and the baseline of scattering photons autocorrelation on the scattering photon counts, the autocorrelations of scattering photons and scattering field and the distribution of particle sizes are all investigated detailedly and are explained theoretically. The appropriate choices of systematical parameters are pointed out to make the experimental system more perfect. The limitations of the inverse algorithms are described and explained for the self-designed system. The methods of corrected 1st-order Cumulants and corrected Double Exponents are developed to compute particle sizes correctly at wide time scale. The particle sizes measured by the optimized experimental system are very accurate.

  13. Second order Standard Model

    NASA Astrophysics Data System (ADS)

    Espin, Johnny; Krasnov, Kirill

    2015-06-01

    It is known, though not commonly, that one can describe fermions using a second order in derivatives Lagrangian instead of the first order Dirac one. In this description the propagator is scalar, and the complexity is shifted to the vertex, which contains a derivative operator. In this paper we rewrite the Lagrangian of the fermionic sector of the Standard Model in such second order form. The new Lagrangian is extremely compact, and is obtained from the usual first order Lagrangian by integrating out all primed (or dotted) 2-component spinors. It thus contains just half of the 2-component spinors that appear in the usual Lagrangian, which suggests a new perspective on unification. We sketch a natural in this framework SU (2) × SU (4) ⊂ SO (9) unified theory.

  14. Court Ordered Desegregation

    ERIC Educational Resources Information Center

    Reber, Sarah J.

    2005-01-01

    The effect of the court ordered desegregation plans, on trends in segregation and white flight, are estimated. The effect of availability of school districts and other factors on the white flight across districts is also mentioned.

  15. 'Good palliative care' orders.

    PubMed

    Maddocks, I

    1993-01-01

    A Select Committee of the Parliament of South Australia, considering revisions to legislation governing care of the dying, did not support allowing doctors to assist suicide. They recommended that no liability attach to the provision of reasonable palliative care which happens to shorten life. The Committee affirmed the suggestion that positive open orders to provide 'good palliative care' should replace 'do not resuscitate' orders. PMID:7506978

  16. Arguments from Developmental Order.

    PubMed

    Stöckle-Schobel, Richard

    2016-01-01

    In this article, I investigate a special type of argument regarding the role of development in theorizing about psychological processes and cognitive capacities. Among the issues that developmental psychologists study, discovering the ontogenetic trajectory of mechanisms or capacities underpinning our cognitive functions ranks highly. The order in which functions are developed or capacities are acquired is a matter of debate between competing psychological theories, and also philosophical conceptions of the mind - getting the role and the significance of the different steps in this order right could be seen as an important virtue of such theories. Thus, a special kind of strategy in arguments between competing philosophical or psychological theories is using developmental order in arguing for or against a given psychological claim. In this article, I will introduce an analysis of arguments from developmental order, which come in two general types: arguments emphasizing the importance of the early cognitive processes and arguments emphasizing the late cognitive processes. I will discuss their role in one of the central tools for evaluating scientific theories, namely in making inferences to the best explanation. I will argue that appeal to developmental order is, by itself, an insufficient criterion for theory choice and has to be part of an argument based on other core explanatory or empirical virtues. I will end by proposing a more concerted study of philosophical issues concerning (cognitive) development, and I will present some topics that also pertain to a full-fledged 'philosophy of development.' PMID:27242648

  17. Birth Order and Psychopathology

    PubMed Central

    Risal, Ajay; Tharoor, Hema

    2012-01-01

    Context: Ordinal position the child holds within the sibling ranking of a family is related to intellectual functioning, personality, behavior, and development of psychopathology. Aim: To study the association between birth order and development of psychopathology in patients attending psychiatry services in a teaching hospital. Settings and Design: Hospital-based cross-sectional study. Materials and Methods: Retrospective file review of three groups of patients was carried out. Patient-related variables like age of onset, birth order, family type, and family history of mental illness were compared with psychiatry diagnosis (ICD-10) generated. Statistical Analysis: SPSS 13; descriptive statistics and one-way analysis of variance (ANOVA) were used. Results: Mean age of onset of mental illness among the adult general psychiatry patients (group I, n = 527) was found to be 33.01 ± 15.073, while it was 11.68 ± 4.764 among the child cases (group II, n = 47) and 26.74 ± 7.529 among substance abuse cases (group III, n = 110). Among group I patients, commonest diagnosis was depression followed by anxiety and somatoform disorders irrespective of birth order. Dissociative disorders were most prevalent in the first born child (36.7%) among group II patients. Among group III patients, alcohol dependence was maximum diagnosis in all birth orders. Conclusions: Depression and alcohol dependence was the commonest diagnosis in adult group irrespective of birth order. PMID:24479023

  18. Arguments from Developmental Order

    PubMed Central

    Stöckle-Schobel, Richard

    2016-01-01

    In this article1, I investigate a special type of argument regarding the role of development in theorizing about psychological processes and cognitive capacities. Among the issues that developmental psychologists study, discovering the ontogenetic trajectory of mechanisms or capacities underpinning our cognitive functions ranks highly. The order in which functions are developed or capacities are acquired is a matter of debate between competing psychological theories, and also philosophical conceptions of the mind – getting the role and the significance of the different steps in this order right could be seen as an important virtue of such theories. Thus, a special kind of strategy in arguments between competing philosophical or psychological theories is using developmental order in arguing for or against a given psychological claim. In this article, I will introduce an analysis of arguments from developmental order, which come in two general types: arguments emphasizing the importance of the early cognitive processes and arguments emphasizing the late cognitive processes. I will discuss their role in one of the central tools for evaluating scientific theories, namely in making inferences to the best explanation. I will argue that appeal to developmental order is, by itself, an insufficient criterion for theory choice and has to be part of an argument based on other core explanatory or empirical virtues. I will end by proposing a more concerted study of philosophical issues concerning (cognitive) development, and I will present some topics that also pertain to a full-fledged ‘philosophy of development.’ PMID:27242648

  19. Concomitant Ordering and Symmetry Lowering

    ERIC Educational Resources Information Center

    Boo, William O. J.; Mattern, Daniell L.

    2008-01-01

    Examples of concomitant ordering include magnetic ordering, Jahn-Teller cooperative ordering, electronic ordering, ionic ordering, and ordering of partially-filled sites. Concomitant ordering sets in when a crystal is cooled and always lowers the degree of symmetry of the crystal. Concomitant ordering concepts can also be productively applied to…

  20. Land and World Order.

    ERIC Educational Resources Information Center

    Mische, Patricia, Ed.; And Others

    1982-01-01

    The papers in this publication discuss the land and how what happens to the land affects us. The publication is one in a series of monographs that examine the linkages between local and global concerns and explore alternative world futures. Examples of topics discussed in the papers follow. The paper "Land and World Order" examines implications of…