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2011

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Articles 301 - 330 of 406

Full-Text Articles in Statistics and Probability

A Generalized Approach For Testing The Association Of A Set Of Predictors With An Outcome: A Gene Based Test, Benjamin A. Goldstein, Alan E. Hubbard, Lisa F. Barcellos Jan 2011

A Generalized Approach For Testing The Association Of A Set Of Predictors With An Outcome: A Gene Based Test, Benjamin A. Goldstein, Alan E. Hubbard, Lisa F. Barcellos

U.C. Berkeley Division of Biostatistics Working Paper Series

In many analyses, one has data on one level but desires to draw inference on another level. For example, in genetic association studies, one observes units of DNA referred to as SNPs, but wants to determine whether genes that are comprised of SNPs are associated with disease. While there are some available approaches for addressing this issue, they usually involve making parametric assumptions and are not easily generalizable. A statistical test is proposed for testing the association of a set of variables with an outcome of interest. No assumptions are made about the functional form relating the variables to the …


How Long Does A Santa Barbara Divorce Take?, Samuel J. Frame, Brian H. Burke Jan 2011

How Long Does A Santa Barbara Divorce Take?, Samuel J. Frame, Brian H. Burke

Statistics

There has been considerable research about the amount of time the psychological grief process requires when couples divorce. However, there has been little research on the time the actual process of divorce requires. To address this, we obtained free and publicly available information on divorce cases from Santa Barbara County. We are able to offer some insight about the relationship among the length of divorce, marriage length, and having minor children. Our results are consistent with those found in other literature that focuses on the length of the grief process, and our results are consistent with our experiences in family …


Book Review Of Graphics For Statistics And Data Analysis With R By Kevin J. Keen, Samuel J. Frame Jan 2011

Book Review Of Graphics For Statistics And Data Analysis With R By Kevin J. Keen, Samuel J. Frame

Statistics

No abstract provided.


Using Local Correlation To Explain Success In Baseball, Jeff Hamrick, John Rasp Jan 2011

Using Local Correlation To Explain Success In Baseball, Jeff Hamrick, John Rasp

Master of Science in Analytics (MSAN) Faculty Research

Statisticians have long employed linear regression models in a variety of circumstances, including the analysis of sports data, because of their flexibility, ease of interpretation, and computational tractability. However, advances in computing technology have made it possible to develop and employ more complicated, nonlinear, and nonparametric procedures. We propose a fully nonparametric nonlinear regression model that is associated to a local correlation function instead of the usual Pearson correlation coefficient. The proposed nonlinear regression model serves the same role as a traditional linear model, but generates deeper and more detailed information about the relationships between the variables being analyzed. We …


Balanced Pod For Model Reduction Of Linear Pde Systems: Convergence Theory, John R. Singler Jan 2011

Balanced Pod For Model Reduction Of Linear Pde Systems: Convergence Theory, John R. Singler

Mathematics and Statistics Faculty Research & Creative Works

We consider convergence analysis for a model reduction algorithm for a class of linear infinite dimensional systems. The algorithm computes an approximate balanced truncation of the system using solution snapshots of specific linear infinite dimensional differential equations. The algorithm is related to the proper orthogonal decomposition, and it was first proposed for systems of ordinary differential equations by Rowley (Int. J. Bifurc. Chaos Appl. Sci. Eng. 15(3), 997-1013, 2005). For the convergence analysis, we consider the algorithm in terms of the Hankel operator of the system, rather than the product of the system Gramians as originally proposed by Rowley. For …


Balanced Pod For Linear Pde Robust Control Computations, John R. Singler, Belinda A. Batten Jan 2011

Balanced Pod For Linear Pde Robust Control Computations, John R. Singler, Belinda A. Batten

Mathematics and Statistics Faculty Research & Creative Works

A mathematical model of a physical system is never perfect; therefore, robust control laws are necessary for guaranteed stabilization of the nominal model and also "nearby" systems, including hopefully the actual physical system. We consider the computation of a robust control law for large-scale nite dimensional linear systems and a class of linear distributed parameter systems. The controller is robust with respect to left coprime factor perturbations of the nominal system. We present an algorithm based on balanced proper orthogonal decomposition to compute the nonstandard features of this robust control law. Convergence theory is given, and numerical results are presented …


A Model Based Feedback Controller For Wing-Twist Via Piezoceramic Actuation, John R. Singler, Belinda A. Batten Jan 2011

A Model Based Feedback Controller For Wing-Twist Via Piezoceramic Actuation, John R. Singler, Belinda A. Batten

Mathematics and Statistics Faculty Research & Creative Works

In this paper we present a model for a rubber plate with piezoceramic actuators to represent a bioinspired flexible wing. Using a Galerkin based finite element approximation to the system, we compute a linear quadratic based tracking control for piezoelectric actuators placed along both leading and trailing edges. Using these piezoceramic devices, we demonstrate the effectiveness of model based feedback control in achieving a desired wing tip position; this modified shape is analogous to aircraft roll moment generation via wing twist.


Convergent Snapshot Algorithms For Infinite-Dimensional Lyapunov Equations, John R. Singler Jan 2011

Convergent Snapshot Algorithms For Infinite-Dimensional Lyapunov Equations, John R. Singler

Mathematics and Statistics Faculty Research & Creative Works

We consider two algorithms to approximate the solution Z of a class of stable operator Lyapunov equations of the form AZ + ZA* + BB* = 0. The algorithms utilize time snapshots of solutions of certain linear infinite-dimensional differential equations to construct the approximations. Matrix approximations of the operators a and B are not required and the algorithms are applicable as long as the rank of B is relatively small. The first algorithm produces an optimal low-rank approximate solution using proper orthogonal decomposition. The second algorithm approximates the product of the solution with a few vectors and can be implemented …


Sub-Supersolution Method In Variational Inequalities With Multivalued Operators Given By Integrals, Vy Khoi Le Jan 2011

Sub-Supersolution Method In Variational Inequalities With Multivalued Operators Given By Integrals, Vy Khoi Le

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.


Research In Mathematics Educational Technology: Current Trends And Future Demands, Shannon O. Driskell, Robert N. Ronau, Christopher R. Rakes, Sarah B. Bush, Margaret L. Niess, David K. Pugalee Jan 2011

Research In Mathematics Educational Technology: Current Trends And Future Demands, Shannon O. Driskell, Robert N. Ronau, Christopher R. Rakes, Sarah B. Bush, Margaret L. Niess, David K. Pugalee

Mathematics Faculty Publications

This systematic review of mathematics educational technology literature identified 1356 manuscripts addressing the integration of educational technology into mathematics instruction. The manuscripts were analyzed using three frameworks (Research Design, Teacher Knowledge, and TPACK) and three supplementary lenses (Data Sources, Outcomes, and NCTM Principles) to produce a database to support future research syntheses and meta-analyses. Preliminary analyses of student and teacher outcomes (e.g., knowledge, cognition, affect, and performance) suggest that the effects of incorporating graphing calculator and dynamic geometry technologies have been abundantly studied; however, the usefulness of the results was often limited by missing information regarding measures of validity, reliability, …


Global Stability Of Complex-Valued Neural Networks On Time Scales, Martin Bohner, V. Sree Hari Rao, Suman Sanyal Jan 2011

Global Stability Of Complex-Valued Neural Networks On Time Scales, Martin Bohner, V. Sree Hari Rao, Suman Sanyal

Mathematics and Statistics Faculty Research & Creative Works

In this paper, activation dynamics of complex-valued neural networks are studied on general time scales. Besides presenting conditions guaranteeing the existence of a unique equilibrium pattern, its global exponential stability is discussed. Some numerical examples for different time scales are given in order to highlight the results. © 2011 Foundation for Scientific Research and Technological Innovation.


Variation In Sclerotinia Sclerotiorum Bean Isolates From Multisite Resistance Screening Locations, Lindsey Otto-Hanson, James R, Steadman, Rebecca Higgins, Kent M. Eskridge Jan 2011

Variation In Sclerotinia Sclerotiorum Bean Isolates From Multisite Resistance Screening Locations, Lindsey Otto-Hanson, James R, Steadman, Rebecca Higgins, Kent M. Eskridge

Department of Statistics: Faculty Publications

There is no complete resistance to Sclerotinia sclerotiorum, cause of white mold in dry bean (Phaseolus vulgaris). Variable resistance expression is one problem in screening for improved white mold resistance. With no previous information in the literature, pathogen variation in multisite screening nurseries was evaluated as one cause of diverse resistance expression. In all, 10 isolates of S. sclerotiorum used in greenhouse screening and 146 isolates collected from nine white mold field screening nurseries in major bean production areas in the United States were compared using mycelial compatibility groupings (MCGs) and an aggressiveness test. These 10 greenhouse …


Development Of An Internet Based System For Modeling Biotin Metabolism Using Bayesian Networks, Jinglei Zhou, Dong Wang, Vicki L. Schlegel, Janos Zempleni Jan 2011

Development Of An Internet Based System For Modeling Biotin Metabolism Using Bayesian Networks, Jinglei Zhou, Dong Wang, Vicki L. Schlegel, Janos Zempleni

Department of Statistics: Faculty Publications

Biotin is an essential water-soluble vitamin crucial for maintaining normal body functions. The importance of biotin for human health has been under-appreciated but there is plenty of opportunity for future research with great importance for human health. Currently, carrying out predictions of biotin metabolism involves tedious manual manipulations. In this paper, we report the development of BiotinNet, an internet based program that uses Bayesian networks to integrate published data on various aspects of biotin metabolism. Users can provide a combination of values on the levels of biotin related metabolites to obtain the predictions on other metabolites that are not specified. …


If The Shoe Fits They Might Acquit: The Value Of Forensic Science Testimony, Jonathan Koehler Jan 2011

If The Shoe Fits They Might Acquit: The Value Of Forensic Science Testimony, Jonathan Koehler

Faculty Working Papers

The probative value of forensic science evidence (such as a shoeprint) varies widely depending on how the evidence and hypothesis of interest is characterized. This paper uses a likelihood ratio (LR) approach to identify the probative value of forensic science evidence. It argues that the "evidence" component should be characterized as a "reported match," and that the hypothesis component should be characterized as "the matching person or object is the source of the crime scene sample." This characterization of the LR forces examiners to incorporate risks from sample mix-ups and examiner error into their match statistics. But how will legal …


Monitoring Radiation Use In Cardiac Fluoroscopy Imaging Procedures, Nathaniel Stevens, S H. Steiner, I R. Smith, R J. Mackay Jan 2011

Monitoring Radiation Use In Cardiac Fluoroscopy Imaging Procedures, Nathaniel Stevens, S H. Steiner, I R. Smith, R J. Mackay

Mathematics

Objective: Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry out this task. To address this issue we propose the implementation of an ongoing monitoring process that utilizes procedural data to identify unexpected large or small radiation exposures for individual patients, as well as to detect persistent changes in the radiation output of imaging platforms.

Methods: Data used in this study were obtained from …


Approximating Confidence Intervals About Discrete Time Survival/Cumulative Incidence Estimates Using The Delta Method, Alexis Dinno, Jong-Sung Kim Jan 2011

Approximating Confidence Intervals About Discrete Time Survival/Cumulative Incidence Estimates Using The Delta Method, Alexis Dinno, Jong-Sung Kim

Community Health Faculty Publications and Presentations

Poster focuses on answering the questions whether and when and event will happen in a population at risk.


Ua56/1 Fact Book, Wku Institutional Research Jan 2011

Ua56/1 Fact Book, Wku Institutional Research

WKU Administration Documents

Statistical and demographic profile of WKU.


Flipping The Winner Of A Poset Game, Adam O. Kalinich '12 Jan 2011

Flipping The Winner Of A Poset Game, Adam O. Kalinich '12

Student Publications & Research

Partially-ordered set games, also called poset games, are a class of two-player combinatorial games. The playing field consists of a set of elements, some of which are greater than other elements. Two players take turns removing an element and all elements greater than it, and whoever takes the last element wins. Examples of poset games include Nim and Chomp. We investigate the complexity of computing which player of a poset game has a winning strategy. We give an inductive procedure that modifies poset games to change the nim-value which informally captures the winning strategies in the game. For a generic …


Assessing The Necessity Of Chimpanzee Experimentation, Andrew Knight Jan 2011

Assessing The Necessity Of Chimpanzee Experimentation, Andrew Knight

Experimentation Collection

No abstract provided.


A Guide To Defining And Implementing Protocols For The Welfare Assessment Of Laboratory Animals: Eleventh Report Of The Bvaawf/Frame/Rspca/Ufaw Joint Working Group On Refinement, P. Hawkins, D. B. Morton, O. Burman, N. Dennison, P. Honess, M. Jennings, S. Lane, V. Middleton, J. V. Roughan, S. Wells, K. Westwood Jan 2011

A Guide To Defining And Implementing Protocols For The Welfare Assessment Of Laboratory Animals: Eleventh Report Of The Bvaawf/Frame/Rspca/Ufaw Joint Working Group On Refinement, P. Hawkins, D. B. Morton, O. Burman, N. Dennison, P. Honess, M. Jennings, S. Lane, V. Middleton, J. V. Roughan, S. Wells, K. Westwood

Research Methodology and Laboratory Animals Collection

The refinement of husbandry and procedures to reduce animal suffering and improve welfare is an essential component of humane science. Successful refinement depends upon the ability to assess animal welfare effectively, and detect any signs of pain or distress as rapidly as possible, so that any suffering can be alleviated. This document provides practical guidance on setting up and operating effective protocols for the welfare assessment of animals used in research and testing. It sets out general principles for more objective observation of animals, recognizing and assessing indicators of pain or distress and tailoring these to individual projects. Systems for …


Testing The Mean For Business Data: Should One Use The Z-Test, T-Test, F-Test, The Chi-Square Test, Or The P-Value Method?, Jiajuan (John) Liang, William S. Pan Jan 2011

Testing The Mean For Business Data: Should One Use The Z-Test, T-Test, F-Test, The Chi-Square Test, Or The P-Value Method?, Jiajuan (John) Liang, William S. Pan

Marketing and Quantitative Analysis Faculty Publications

Purpose – The overall purpose of this research is to discuss the relationship among the tests for population mean that are taught in the Business Statistics course for business majors. Design/methodology/approach – The approach to this study is to describe the types of business data according to one-sample, two-sample, and multi-sample cases first and then combine tests for categorical data with tests for continuous data into a unified format on testing the mean of a population. Under this unified format, we summarize the methodology on the topic of testing the mean in business statistics course. Findings – One of the …


Self Learning Strategies For Experimental Design And Response Surface Optimization, Adel Alaeddini Jan 2011

Self Learning Strategies For Experimental Design And Response Surface Optimization, Adel Alaeddini

Wayne State University Dissertations

Most preset RSM designs offer ease of implementation and good performance over a wide range of process and design optimization applications. These designs often lack the ability to adapt the design based on the characteristics of application and experimental space so as to reduce the number of experiments necessary. Hence, they are not cost effective for applications where the cost of experimentation is high or when the experimentation resources are limited. In this dissertation, we present a number of self-learning strategies for optimization of different types of response surfaces for industrial experiments with noise, high experimentation cost, and requiring high …


Angiogenic Biomarkers For Risk Stratification In Women With Suspected Preeclampsia, Andreea Balan, Heather Young, Linda Ojo, Jennifer Keller, Sharon Maynard Jan 2011

Angiogenic Biomarkers For Risk Stratification In Women With Suspected Preeclampsia, Andreea Balan, Heather Young, Linda Ojo, Jennifer Keller, Sharon Maynard

Epidemiology Faculty Posters and Presentations

This poster presents the results of a single-center prospective cohort study of 315 pregnant women who presented to George Washington University Hospital Labor and Delivery service with a clinical suspicion of preeclampsia between February 2007 and November 2011. Informed consent was obtained. Baseline demographic information and medical history was collected on each patient including maternal age, ethnicity, body mass index, tobacco and other substance use, gestational age, medical problems and obstetric history. Serum samples were obtained from each enrolled subject within 24 hours of admission, and sFlt1, PlGF and sEng ELISA assays were performed in duplicate by a blinded laboratory …


Statistical Properties Of A Convoluted Beta-Weibull Distribution, Jianan Sun Jan 2011

Statistical Properties Of A Convoluted Beta-Weibull Distribution, Jianan Sun

Theses, Dissertations and Capstones

A new class of distributions recently developed involves the logit of the beta distribution. Among this class of distributions are the beta-normal (Eugene et.al. (2002)); beta-Gumbel (Nadarajah and Kotz (2004)); beta-exponential (Nadarajah and Kotz (2006)); beta-Weibull (Famoye et al. (2005)); beta-Rayleigh (Akinsete and Lowe (2008)); beta-Laplace (Kozubowski and Nadarajah (2008)); and beta-Pareto (Akinsete et al. (2008)), among a few others. Many useful statistical properties arising from these distributions and their applications to real life data have been discussed in the literature. One approach by which a new statistical distribution is generated is by the transformation of random variables having known …


Robustness Analysis Of Slow Learning In Iterative Learning Control Systems, John R. Singler, Douglas A. Bristow Jan 2011

Robustness Analysis Of Slow Learning In Iterative Learning Control Systems, John R. Singler, Douglas A. Bristow

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper examines robust stability and robust transient growth in Iterative Learning Control (ILC). It is well known that small perturbations in system dynamics can result in very large transient growth of some ILC systems. Even larger perturbations can result in instability. One ad hoc technique commonly employed to improve robustness is to slow the learning rate by reducing the learning filter gain or lowpass filtering the error signal. Here, pseudospectra analysis is used to analyze the robustness of ILC algorithms with slow learning. It is found that robustness bounds can be increased and transient growth decreased with decreasing learning …


Towards Transient Growth Analysis And Design In Iterative Learning Control, Douglas A. Bristow, John R. Singler Jan 2011

Towards Transient Growth Analysis And Design In Iterative Learning Control, Douglas A. Bristow, John R. Singler

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this article the problem of bounding transient growth in iterative learning control (ILC) is examined. While transient growth is not a desirable property, the alternative, robust monotonic convergence, leads to fundamental performance limitations. to circumvent these limitations, this article considers the possibility that some transient growth, if properly limited, is a viable and practical option. Towards this end, this article proposes tools for analysing worst-case transient growth in ILC. the proposed tools are based on pseudospectra analysis, which is extended to apply to ILC of uncertain systems. Two practical problems in norm-optimal ILC weighting parameter design are considered. Using …


Inflated Type I Error Rates When Using Aggregation Methods To Analyze Rare Variants In The 1000 Genomes Project Exon Sequencing Data In Unrelated Individuals: Summary Results From Group 7 At Genetic Analysis Workshop 17, Nathan L. Tintle, Hugues Aschard, Inchi Hu, Nora Nock, Haitian Wang, Elizabeth Pugh Jan 2011

Inflated Type I Error Rates When Using Aggregation Methods To Analyze Rare Variants In The 1000 Genomes Project Exon Sequencing Data In Unrelated Individuals: Summary Results From Group 7 At Genetic Analysis Workshop 17, Nathan L. Tintle, Hugues Aschard, Inchi Hu, Nora Nock, Haitian Wang, Elizabeth Pugh

Faculty Work Comprehensive List

As part of Genetic Analysis Workshop 17 (GAW17), our group considered the application of novel and standard approaches to the analysis of genotype-phenotype association in next-generation sequencing data. Our group identified a major issue in the analysis of the GAW17 next-generation sequencing data: type I error and false-positive report probability rates higher than those expected based on empirical type I error levels (as high as 90%). Two main causes emerged: population stratification and long-range correlation (gametic phase disequilibrium) between rare variants. Population stratification was expected because of the diverse sample. Correlation between rare variants was attributable to both random causes …


Identification Of Genetic Association Of Multiple Rare Variants Using Collapsing Methods, Yan V. Sun, Yun Ju Sung, Nathan L. Tintle, Andreas Ziegler Jan 2011

Identification Of Genetic Association Of Multiple Rare Variants Using Collapsing Methods, Yan V. Sun, Yun Ju Sung, Nathan L. Tintle, Andreas Ziegler

Faculty Work Comprehensive List

Next-generation sequencing technology allows investigation of both common and rare variants in humans. Exomes are sequenced on the population level or in families to further study the genetics of human diseases. Genetic Analysis Workshop 17 (GAW17) provided exomic data from the 1000 Genomes Project and simulated phenotypes. These data enabled evaluations of existing and newly developed statistical methods for rare variant sequence analysis for which standard statistical methods fail because of the rareness of the alleles. Various alternative approaches have been proposed that overcome the rareness problem by combining multiple rare variants within a gene. These approaches are termed collapsing …


Gis Will Affect The Political Landscape For The Next Decade And Beyond, Mark Salling Jan 2011

Gis Will Affect The Political Landscape For The Next Decade And Beyond, Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.


Epidemic Spread Of Influenza Viruses: The Impact Of Transient Populations On Disease Dynamics, Karen R. Ríos-Soto, Baojun Song, Carlos Castillo-Chavez Jan 2011

Epidemic Spread Of Influenza Viruses: The Impact Of Transient Populations On Disease Dynamics, Karen R. Ríos-Soto, Baojun Song, Carlos Castillo-Chavez

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

The recent H1N1 ("swine u") pandemic and recent H5N1 ("avian u") outbreaks have brought increased attention to the study of the role of animal populations as reservoirs for pathogens that could invade human populations. It is believed that pigs acquired u strains from birds and humans, acting as a mixing vessel in generating new influenza viruses. Assessing the role of animal reservoirs, particularly reservoirs involving highly mobile populations (like migratory birds), on disease dispersal and persistence is of interests to a wide range of researchers including public health experts and evolutionary biologists. This paper studies the interactions between transient and …