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作者： Avery, Kelly M.

Evaluations of system operational effectiveness, suitability, and survivability increasingly rely on models to supplement live testing. In order for these supplements to be valuable, testers must understand how well the models represent the systems or processes they simulate. This means testers must quantify the uncertainty in there presentation and understand the impact of that uncertainty. Two broad categories of uncertainties statistical and knowledge are of central importance to test and evaluation T and E, particularly as testers try to extrapolate the model output and live test data into predictions of performance in combat. The validation process should include parametric analyses and a comparison of simulation output to live data to support quantification of statistical uncertainty. However, qualitative and non-statistical techniques may also be required to compare the future hypothetical combat environment with the non-quantitative portions of the validation referent.

关键词： test and evaluation computational science data science information science experimental design data analysis statistical analysis systems engineering data mining aircrafts knowledge management regression analysis statistical algorithms statistics acceptability factorial design normal distribution probability distributions simulations combinatorial analysis

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A Bayesian Approach to Multiple-Output Quantile Regression

A Bayesian Approach to Multiple-Output Quantile Regression

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作者： Guggisberg, Michael

This paper presents a Bayesian approach to multiple-output quantile regression. The unconditional model is proven to be consistent and asymptotically correct frequentist confidence intervals can be obtained. The prior for the unconditional model can be elicited as the ex-ante knowledge of the distance of the x1Ctau-Tukey depth contour to the Tukey median, the first prior of its kind. A proposal for conditional regression is also presented. The model is applied to the Tennessee Project Steps to Achieving Resilience STAR experiment and it finds a joint increase in x1C tau-quantile subpopulations for mathematics and reading scores given a decrease in the number of students per teacher. This result is consistent with, and much stronger than, the result one would find with multiple-output linear regression. Multiple-output linear regression finds the average mathematics and reading scores increase given a decrease in the number of students per teacher. However, there could still be subpopulations where the score declines. The multiple-output quantile regression approach confirms there are no quantile subpopulations of the inspected subpopulations where the score de-clines. This is truly a statement of no child left behind opposed to no average child left behind.

关键词： monte carlo method bayesian networks computational science random variables surveys information science operations research probability statistical algorithms data science databases probability distributions algorithms computations estimators statistics applied mathematics data analysis data mining mathematics

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Impact of Behavioral and Psychosocial Protective Factors on Health Outcomes in Heart Failure Patients: A Structural Equation Model Analysis

Impact of Behavioral and Psychosocial Protective Factors on ...

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作者： Garza, J. A UNIFORMED SERVICES UNIV OF THE HEALTH SCIENCES BETHESDA MD

Objective: Heart failure (HF) rates have continued to increase, despite decreases in the incidence of heart disease. In addition to health consequences of HF, it contributes a staggering financial cost to the individual, caregiver, and the broader health care. One significant component of the total cost and burden is frequent hospitalizations. HF research has suggested the importance of behavioral and psychological risk factors, but there has also been increased examination of protective factors that may reduce the progression of HF and improve overall prognosis. This study aims to determine if psychosocial or behavioral protective factors predict improved long-term health status and decreased hospitalizations in HF patients. The present study used a Structural Equation Model (SEM) approach to examine the impact of protective factors on outcomes in HF patients. Method and Results: This study is based on previously collected data from the Behavioral Triggers of Heart Failure (BETRHEART) study. One hundred and fifty participants were administered self-report measures on psychosocial (e.g., positive affect, optimism, self-efficacy, social support, coping styles), and behavioral variables (e.g., medication adherence, sleep quality, physical activity, adherence to a healthy diet), at the baseline assessment and up to a total of 39 months. The Kansas City Cardiomyopathy Questionnaire (KCCQ) was also administered at the baseline and subsequent follow-up assessments to evaluate HF symptoms and health status. Data on hospitalizations were collected over the entire 39-month study period. SEM was conducted to determine whether the two theoretical factors Psychosocial Protective Factor and Behavioral Protective Factor predict hospitalizations and KCCQ health status at a 9-month and up to a 39-month follow-up. Results of a confirmatory factor analysis indicated some of the items/measures had low factor loadings and were removed based on model fit statistics.

关键词： Health services Medical personnel Families (human) Data analysis Surveys Information science Heart diseases Regression analysis Cardiovascular diseases Data science Social psychology statistical algorithms Data mining Factor analysis Heart failure Cardiomyopathies Knowledge management

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Qualitative Assessments via Infrared Vision of Sub-surface Defects Present Beneath Decorative Surface Coatings

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INTERNATIONAL JOURNAL OF THERMOPHYSICS 2018年第1期39卷 13-13页

作者： Sfarra, Stefano Fernandes, Henrique C. Lopez, Fernando Ibarra-Castanedo, Clemente Zhang, Hai Maldague, Xavier Univ Aquila Dept Ind & Informat Engn & Econ LasER Lab Piazzale E Pontieri 1 I-67100 Laquila AQ Italy Tomsk Polytech Univ Lenin Av 30 Tomsk 634050 Russia Univ Fed Uberlandia Dept Comp Sci 2121 Av Joao Naves de Avila BR-38400902 Uberlandia MG Brazil Laval Univ Dept Elect & Comp Engn Comp Vis & Syst Lab 1065 Av Med Quebec City PQ G1V 0A6 Canada Ist Nazl Fis Nucl CHNet Lab Nazl Gran Sasso Via G Acitelli 22 I-67100 Laquila AQ Italy

In this work, the potentialities of the infrared vision to explore sub-superficial defects in polychromatic statues were investigated. In particular, it was possible to understand how the reflector effect of the exterior golden layers could be minimized, applying advanced statistical algorithms to thermal images. Since this noble metal is present as external coating in both artworks, an in-depth discussion concerning its physicochemical properties is also added. In this context, the principal component thermography technique and, the more recent, partial least squares thermography technique were used on three different datasets recorded, providing long thermal stimuli. The main images were compared both to phasegrams and to the thermographic signal reconstruction results in order to have a clear outline of the situation to be debated. The effects of view factors on the radiation transfer linked to the specular reflections from the surface did not falsely highlight certain features inadvertently. Indeed, the raw thermograms were analyzed one by one. Reflectograms were used to pinpoint emissivity variations due to, e.g., possible repainting. The paper concludes that, as it is possible to understand from a physical point of view, the near-infrared reflectography technique is able to examine the state of conservation of the upper layers in cultural heritage objects, while the infrared thermography technique explores them more in-depth. The thesis statement is based on the thermal and nonthermal parts of the infrared region, therefore, indicating what can be detected by heating the surface and what can be visualized by illuminating the surface, bearing in mind the nature of the external coating.

关键词： Defect Gilded coatings Infrared thermography (IRT) Near-infrared reflectography (NIRR) Polychromatic statues statistical algorithms

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Tutorial: Parametric Reliability Models

Tutorial: Parametric Reliability Models

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作者： Pinelis, Y. K Whitledge, W. R INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA OFFICE OF THE SECRETARY OF DEFENSE WASHINGTON DC OPERATIONAL TEST AND EVALUATION OFFICE OF THE SECRETARY OF DEFENSE WASHINGTON DC

This tutorial demonstrates how to plot reliability functions parametrically in R using the output from any reliability modeling software. It provides code and sample plots of reliability and failure rate functions with confidence intervals for three different skewed probability distributions: the exponential, the two-parameter Weibull, and the lognormal. These three distributions are the most common parametric models for reliability or survival analysis. This paper also provides mathematical background for the models and recommendations for when to use them.

关键词： Test and evaluation Probability distributions Confidence limits Data analysis Probability United states Information science Normal distribution Random variables Reliability statistical inference Covariance Data science Data sets High resolution Maximum likelihood estimation statistical algorithms Boundaries Distribution functions Equations

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On the Complexity of Random Satisfiability Problems with Planted Solutions 15

On the Complexity of Random Satisfiability Problems with Pla...

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47th Annual ACM Symposium on Theory of Computing (STOC) held as part of the Federated Computing Research Conference

作者： Feldman, Vitaly Perkins, Will Vempala, Santosh IBM Res Almaden San Jose CA 95120 USA Univ Birmingham Birmingham B15 2TT W Midlands England Georgia Tech Atlanta GA 30332 USA

ISBN: (纸本)9781450335362

The problem of identifying a planted assignment given a random k-SAT formula consistent with the assignment exhibits a large algorithmic gap: while the planted solution can always be identified given a formula with O(n log n) clauses, there are distributions over clauses for which the best known efficient algorithms require n(k/2) clauses. We propose and study a unified model for planted k-SAT, which captures well-known special cases. An instance is described by a planted assignment sigma and a distribution on clauses with k literals. We define its distribution complexity as the largest r for which the distribution is not r-wise independent (1 <= r <= k for any distribution with a planted assignment). Our main result is an unconditional lower bound, tight up to logarithmic factors, of (Omega) over tilde (n(r/2)) clauses for statistical algorithms [42, 30], matching the known upper bound (which, as we show, can be implemented using a statistical algorithm) [31]. Since known approaches for problems over distributions have statistical analogues (spectral, MCMC, gradient based, convex optimization etc.), this lower bound provides a rigorous explanation of the observed algorithmic gap. The proof introduces a new general technique for the analysis of statistical algorithms. It also points to a geometric paring phenomenon in the space of all planted assignments. We describe consequences of our lower bounds to Feige's refutation hypothesis [26] and to lower bounds on general convex programs that solve planted k-SAT. Our bounds also extend to the planted k-CSP model, defined by Goldreich as a candidate for one-way function [37], and therefore provide concrete evidence for the security of Goldreich's one-way function and the associated pseudorandom generator when used with a sufficiently hard predicate.

关键词： planted satisfiability statistical algorithms k-SAT hypergraph partitioning refutation

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Ballistic Resistance Testing Techniques

Ballistic Resistance Testing Techniques

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作者： Johnson, T Freeman, L Hester, J Bell, J INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA Department of Defense Washington DC

The Department of Defense conducts ballistic resistance testing to estimate the probability that a projectile will perforate the armor of a system under test. Ballistic resistance testing routinely employs sensitivity experiment techniques in which sequential test designs are used to estimate armor performance. statistical procedures used to estimate the ballistic resistance of armor in the DoD have remained relatively unchanged for decades. New test design method scan lead to improved testing efficiency, which is critical for test and evaluation in the current fiscal climate.

关键词： Test and evaluation Test methods Department of defense Armor Probability Armor plate Body armor Monte carlo method Projectiles Resistance Sensitivity Materials Mathematics Perforation Standards Efficiency Estimators Reliability statistical algorithms Statistics

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Latest improvements in the performances of a Cryogenic Sapphire Oscillator 28

Latest improvements in the performances of a Cryogenic Sapph...

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28th European Frequency and Time Forum (EFTF)

作者： Grop, Serge Fluhr, Christophe Masson, Jean-Louis Kersale, Yann Rubiola, Enrico Giordano, Vincent Dubois, Benoit Haye, Gregory FEMTO ST Inst Besancon France Femto Engn Besancon France

ISBN: (纸本)9781479952526

In this paper, we report the characterization results of our cryogenic sapphire oscillators. The oscillator incorporates a sapphire resonator cooled down at the liquid helium temperature in a cryocooled ultra-low vibration cryostat. The phase noise of a single CSO is -104dBc/Hz at 1Hz offset of the 10GHz carrier. The frequency fluctuations were measured with three frequency counters using different statistical algorithms. The best result at 1 s integration time is sigma(y)(1 s) = 6.5 x 10(-16). For the integration time above 10 s, the Allan deviation of a single CSOs computed from each data sets reaches a floor around 3.2 x 10(-16) at 100 s integration time for a daily frequency stability of 3.5 x 10(-15).

关键词： cryogenic electronics cryostats microwave oscillators microwave resonators sapphire Allan deviation CSO cryocooled ultra-low vibration cryostat cryogenic sapphire oscillators frequency 10 GHz frequency counters frequency fluctuations liquid helium temperature phase noise sapphire resonator statistical algorithms time 1 s time 100 s Instruments Phase noise Radiation detectors Resonant frequency Time-frequency analysis

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Numerical Analysis of Stochastic Oscillators on Supercomputers

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NUMERICAL ANALYSIS AND APPLICATIONS 2012年第1期5卷 25-35页

作者： Artemiev, S. S. Ivanov, A. A. Korneev, V. D. Russian Acad Sci Inst Computat Math & Math Geophys Siberian Branch Pr Akad Lavrenteva 6 Novosibirsk 630090 Russia Novosibirsk State Univ Novosibirsk 630090 Russia

The problem of numerical analysis of stochastic differential equations (SDEs) with oscillating solutions is investigated. The expectation and variance of SDE numerical solutions are shown as functions of the mesh size of integrating the generalized Euler method. Results of some numerical experiments on the simulation of linear and nonlinear stochastic oscillators on the supercomputer of the Siberian Supercomputer Center are presented.

关键词： stochastic differential equations statistical algorithms parallelization super-computer cluster van der Pol equation phase trajectory stochastic oscillators

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Performance Assessment of Pre-processing Filters for Infrared Search and Track Applications

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DEFENCE SCIENCE JOURNAL 2011年第3期61卷 251-256页

作者： Srivastava, Hari Babu Kumar, Vinod Verma, H. K. Sundaram, S. S. Instruments Res & Dev Estab Dehra Dun 248008 India Indian Inst Technol Dept Elect Engn Roorkee 247667 Uttar Pradesh India Indian Inst Technol Continuing Educ Ctr Roorkee 247667 Uttar Pradesh India Indian Inst Technol Qual Improvement Ctr Roorkee 247667 Uttar Pradesh India

To enhance detection probability and to reduce false alarms, infrared imagery is pre-processed before subjecting it to detection algorithms in infrared search and track systems. Pre-processing algorithms are used to predict the complex background and then to subtract the predicted background from the original image. The difference image is passed to the detection algorithm to further distinguish between the target and the background and/or noise more accurately. A number of pre-processing algorithms have been reported in literature, with their relative advantages and disadvantages. This paper brings out the computational complexities and simulation results of various algorithms for assessing their relative performances. Based on these parameters, statistical algorithms in general and max-min algorithms in particular, are recommended to be used for infrared search and track systems.

关键词： Contrast sensitivity point targets pre-processing algorithms infrared search and track morphological filters statistical filters statistical algorithms max-min algorithms small target detection false alarms post-processing algorithms

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