Physical Sciences and Mathematics Commons^™

An Alternative For Mixed Model Analyses Of Large, Messy Data Sets (Mtdfreml), L. D. Van Vleck, R. K. Splan

Conference on Applied Statistics in Agriculture

Portable Fortran based programs (MTDFREML) were developed using a derivative-free algorithm to obtain REML estimates of (co)variance components. Computations are based on Henderson's mixed model equations for multiple-trait models with missing observations on some traits and incorporation of relationships among relatives. Many fixed and random factors are allowed with number of levels dependent on computer memory. Data sets with more than 40,000 genetic effects have been analyzed. Options allow solving MME at convergence. Constraints are automatically imposed. Expectations, standard errors of contrasts of solutions for fixed effects and prediction error variances of solutions for random effects can be obtained. Dimensions …

Statistical Threshold Values For Locating Quantitative Trait Loci, R. W. Doerge

Conference on Applied Statistics in Agriculture

The detection and location of quantitative trait loci (QTL) that control quantitative characters is a problem of great interest to the genetic mapping community. Interval mapping has proved to be a useful tool in locating QTL, but has recently been challenged by faster, more sophisticated regression methods (e.g. .. composite interval mapping). Regardless of the method used to locate QTL. the distribution of the test statistic (LOD score or likelihood ratio test) is unknown. Due to the quantitative trait values following a mixture distribution rather than a single distribution, the asymptotic distribution of the test statistic is not from a …

The Analysis Of Over-Dispersed Count Data From A Single Factor Study, George A. Capuano, Linda J. Young, Nancy L. Campbell

Conference on Applied Statistics in Agriculture

Methods for analyzing over-dispersed count data in a one-way layout were compared using a Monte Carlo study. Several variance stabilizing transformations were examined as alternatives to analyzing the raw data using a general linear model. Additionally, generalized linear models were fit using a log link. For the generalized linear model, three approaches to account for over-dispersion were investigated: (1) a negative binomial distribution with known k, (2) a Poisson distribution with Pearson's X² as an estimate of the scale parameter, and (3) a Poisson distribution with over-dispersion estimated using the deviance. The analysis of the raw data and log …

Risk Factors Associated With Culling Age In Dairy Cattle: Applications Of Frailty Models, Mohamed M. Shoukri, Jan M. Sargeant

Conference on Applied Statistics in Agriculture

Culling decisions for dairy cattle are an important component of dairy herd management. To investigate risk factors for culling, farms (clusters) constitute the sampling units. Therefore, we believe that ages-at-culling may be correlated within farms. The score test on the null hypothesis of no extra-variation in survival data was not supported by age-at-culling data collected from 72 dairy farms from the province of Ontario, Canada. To correct for the intraherd correlation, three modelling approaches were used to fit the data: Population-Averaged (PA) , cluster-specific (CS), and Random Effects Models (RAEM). The modelling approaches are described and compared using the dairy …

Assessing Variability Of Agreement Measures In Remote Sensing Using A Bayesian Approach, William J. Price, Bahman Shafii, Lawrence W. Lass, Donald C. Thill

Conference on Applied Statistics in Agriculture

Remote sensing imagery is a popular accessment tool in agriculture, forestry, and rangeland management. Spectral classification of imagery provides a means of estimating production and identifYing potential problems, such as weed, insect, and disease infestations. Accuracy of classification is traditionally based on ground truthing and summary statistics such as Cohen's Kappa. Variability assessment and comparison of these quantities have been limited to asymptotic procedures relying on large sample sizes and gaussian distributions. However, asymptotic methods fail to take into account the underlying distribution of the classified data and may produce invalid inferential results. Bayesian methodology is introduced to develop probability …

Hurst Phenomenon And Fractal Dimensions In Long-Term Yield Data, Susanne Aref

Conference on Applied Statistics in Agriculture

A fractal dimension may be thought of as a measure of randomness. Fractal dimensions based on semivariograms have been used to determine degree of randomness in yearly crop yields. Through rescaled range analysis Hurst exponents also define fractal dimensions. This method of obtaining fractal dimensions gives more reasonable and sensitive measures than the semivariogram method. To address the inherent randomness due to yearly variations, global trends in yield must be removed before either method is applied. After detrending, a fractal dimension obtained from semivariogram is usually that of a random process. The Hurst method yields an exponent H, which results …

Statistical Analysis Of Field Wheat Varietal Performance Trials, A. M. Feyerherm, R. G. Sears, J. J. Higgins

Conference on Applied Statistics in Agriculture

The purpose of this research was to formulate statistical models and assumptions to apply to the problem of comparing wheat varieties for yielding ability among locations within seasons and over seasons. The methodology could just as well be applied to field testing of other crops for yield or other characteristics of interest (test weight, protein level, etc.)

The methodology approaches the problem of comparing varieties by comparing how well each "measures up" when matched against some common checks. For each variety, the basic data are differences in yield between the variety and the average yield of the checks at different …

Linear And Nonlinear Mixed-Effects Models, Douglas M. Bates, Jose C. Pinheiro

Conference on Applied Statistics in Agriculture

Recent developments in computational methods for maximum likelihood (ML) or restricted maximum likelihood (REML) estimation of parameters in general linear mixed-effects models have made the analysis of data in typical agricultural settings much easier. With software such as SAS PROC MIXED we are able to handle data from random-effects one-way classifications, from blocked designs including incomplete blocked designs, from hierarchical designs such as splitplot designs, and other types of data that may be described as repeated measures or longitudinal data or growth-curve data. It is especially helpful that the new computational methods do not depend on balance in the data …

Editor's Preface, Table Of Contents, And List Of Attendees, George A. Milliken

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented in the tenth annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 26-28, 1998..

Predicting Future Years Of Healthy Life For Older Adults, Paula Diehr

Paula Diehr

Cost-effectiveness studies often need to compare the cost of a program to the lifetime benefits of the program, but estimates of lifetime benefits are not routinely available, especially for older adults. We used data from two large longitudinal studies of older adults (ages 65-100) to estimate transition probabilities from one health state to another, and used those probabilities to estimate the mean additional years of healthy life that an older adult of specified age, sex, and health status would experience. We found, for example, that 65-year-old women in excellent health can expect 16.8 years of healthy life in the future, …

Larger Board Size And Decreasing Firm Value In Small Firms, Theodore Eisenberg, Stefan Sundgren, Martin T. Wells

Cornell Law Faculty Publications

Several studies hypothesize a relation between board size and financial performance. Empirical tests of the relation exist in only a few studies of large U.S. firms. We find a significant negative correlation between board size and profitability in a sample of small and midsize Finnish firms. Finding a board-size effect for a new and different class of firms affects the range of explanations for the board-size effect.

A Longitudinal Study Of Hospitalization Rates For Patients With Chronic Disease: Results From The Medical Outcomes Study., Eugene C. Nelson, Colleen A. Mchorney, Willard G. Manning, W H. Rogers

Dartmouth Scholarship

To prospectively compare inpatient and outpatient utilization rates between prepaid (PPD) and fee-for-service (FFS) insurance coverage for patients with chronic disease. Data from the Medical Outcomes Study, a longitudinal observational study of chronic disease patients conducted in Boston, Chicago, and Los Angeles.A four-year prospective study of resource utilization among 1,681 patients under treatment for hypertension, diabetes, myocardial infarction, or congestive heart failure in the practices of 367 clinicians.

Semi-Permanent Vacuum Closure With Multiple Retubulation Capability, Arthur A. Eneim, Tom K. Evans, Timothy S. Romano, Gary B. Hughes

Statistics

A vacuum system (20) includes an enclosure (22) having a vacuum-tight wall (26) and an internally threaded aperture (66) through the wall (26). A tip-off fitting (24) has a base (50) with a bore (52) therethrough, a hollow tube (62) fixed to the base (50) with a vacuum-tight seal, such that an interior (64) of the tube (62) is in communication with the bore (52) in the base (50), and an external thread (58) on the exterior of the base (50). The external thread (58) on the exterior of the base (50) is dimensioned to threadably engage the internal thread …

Optimum Preventive Maintenance Policies For The Amraam Missile, Scott J. Ruflin

Theses and Dissertations

The overall objective of this research effort was to formulate a preventive maintenance strategy for AMRAAM missiles subject to extended captive carry flight time. A preventive maintenance policy is only applicable if the item in question is aging, or deteriorating with time. Therefore, a supporting objective of this research is to characterize the aging process of the missile system through a non-parametric analysis of its Mean Residual Life (MRL) function. Three non-parametric, censored-data MRL function estimation techniques discussed in the literature are examined via a numerical example. All three estimation techniques provide MRL functions that exhibit greatly exaggerated decreasing trends …

Spatial Estimates For Stochastic Flows In Euclidean Space, Salah-Eldin A. Mohammed, Michael K. R. Scheutzow

Articles and Preprints

We study the behavior for large |x| of Kunita-type stochastic flows φ(t, ω, x) on R^d, driven by continuous spatial semimartingales. For this class of flows we prove new spatial estimates for large |x|, under very mild regularity conditions on the driving semimartingale random field. It is expected that the results would be of interest for the theory of stochastic flows on noncompact manifolds as well as in the study of nonlinear filtering, stochastic functional and partial differential equations. Some examples and counterexamples are given.

Further Properties Of An Extremal Set Of Uniqueness, David E. Grow, Matt Insall

Mathematics and Statistics Faculty Research & Creative Works

Consider the circle group T = R mod 2_ as the interval [0, 1). Then each x 2 T has a binary expansion: x =P1 k=1 xk2−k where each xk is 0 or 1. Let S be the set of x with a binary expansionsuch that the number of 1's does not exceed the number of the leading zeros by more than one. The authors prove that the countable compact set S cannot be expressed as the union of a finite number of Dirichlet sets.

Attractor Dimension Estimates For Two-Dimensional Shear Flows, Charles R. Doering, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

We study the large time behavior of boundary and pressure-gradient driven incompressible fluid flows in elongated two-dimensional channels with emphasis on estimates for their degrees of freedom, i.e., the dimension of the attractor for the solutions of the Navier-Stokes equations. for boundary driven shear flows and flux driven channel flows we present upper bounds for the degrees of freedom of the form ca Re^3/2 where c is a universal constant, a denotes the aspect ratio of the channel (length/width), and Re is the Reynolds number based on the channel width and the imposed "outer" velocity scale. for fixed pressure …

Atomoicity Of Mappings, J. J. Charatonik, W. J. Charatonik

Mathematics and Statistics Faculty Research & Creative Works

A mapping f:X→Y between continua X and Y is said to be atomic at a subcontinuumK of the domain X provided that f(K) is nondegenerate and K=f^-1(f(K)). The set of subcontinua at which a given mapping is atomic, considered as a subspace of the hyperspace of all subcontinua of X, is studied. The introduced concept is applied to get new characterizations of atomic and monotone mappings. Some related questions are asked.

Arc Approximation Property And Confluence Of Induced Mappings, W. J. Charatonik

Mathematics and Statistics Faculty Research & Creative Works

We say that a continuum X has the arc approximation property if every subcontinuum K of X is the limit of a sequence of arcwise connected subcontinua of X all containing a fixed point of K. This property is applied to exhibit a class of continua Y such that confluence of a mapping f : X - Y implies confluence of the induced mappings 2^f : 2^x - @^y and C(f) : C(x) - C(y). The converse implications are studied and similar interrelations are considered for some other classes of mappings, related to confluent ones.

Intracellular Coexpression Of Epidermal Growth Factor Receptor, Her-2/Neu, And P21ras In Human Breast Cancers: Evidence For The Existence Of Distinctive Patterns Of Genetic Evolution That Are Common To Tumors From Different Patients, Stanley E. Shackney, Agnese A. Pollice, Charles A. Smith, Laura E. Janocko, Lillian Sweeney, Kathryn A. Brown, Sarita G. Singh, Lingping Gu, Robert Yakulis, Joseph F. Lucke

Joseph Lucke

Multiparameter flow cytometry studies were performed on cells from the primary tumors of 94 patients with breast cancer. Correlated cellular measurements of cell DNA content, Her-2/neu, epidermal growth factor receptor (EGFR), and p21ras levels were performed on each of 5,000 to 100,000 cells from each tumor. When criteria for positivity were matched with those in common use for immunohistochemical studies, 28 of 94 (30\%) breast cancers were classified as positive for Her-2/neu overexpression. When similar criteria were applied to the EGFR measurements, 23 of 94 (24\%) cases were classified as positive for EGFR overexpression. Similarly, 23 of 94 (24\%) cases …

Orthogonal Harmonic Analysis Of Fractal Measures, Palle Jorgensen, Steen Pedersen

Mathematics and Statistics Faculty Publications

We show that certain iteration systems lead to fractal measures admitting an exact orthogonal harmonic analysis.

Risk Regulation And The Faces Of Uncertainty, Vern R. Walker

RISK: Health, Safety & Environment (1990-2002)

Dr. Walker addresses the difficulty of regulators' working with potentially inaccurate information and clarifies related aspects of decision making by presenting a taxonomy for the kinds of uncertainty inherent in necessarily incomplete data.

Monte Carlo Simulation In Environmental Risk Assessment--Science, Policy And Legal Issues, Susan R. Poulter

RISK: Health, Safety & Environment (1990-2002)

Dr. Poulter notes that agencies should anticipate judicial requirements for justification of Monte Carlo simulations and, meanwhile, should consider, e.g., whether their use will make risk assessment policy choices more opaque or apparent.

A Method Of Identifying Hazardous Highway Locations Using The Principle Of Individual Lifetime Risk, Paul J. Ossenbruggen

RISK: Health, Safety & Environment (1990-2002)

Dr. Ossenbruggen presents a scientific framework for identifying hazardous highway locations that may be more easily understood by non-scientists and has potential for comparing highway with other risks to health.

A Probability Programming Language: Development And Applications, Andrew Gordon Glen

Dissertations, Theses, and Masters Projects

A probability programming language is developed and presented; applications illustrate its use. Algorithms and generalized theorems used in probability are encapsulated into a programming environment with the computer algebra system Maple to provide the applied community with automated probability capabilities. Algorithms of procedures are presented and explained, including detailed presentations on three of the most significant procedures. Applications that encompass a wide range of applied topics including goodness-of-fit testing, probabilistic modeling, central limit theorem augmentation, generation of mathematical resources, and estimation are presented.

Unrelieved Pain And Distress In Animals: An Analysis Of Usda Data On Experimental Procedures, Martin Stephens, Philip Mendoza, Adrianna Weaver, Tamara Hamilton

Experimentation Collection

Pain and distress are core issues in the field of animal experimentation and in the controversy that surrounds it. We sought to add to the empirical base of the literature on pain and distress by examining government data on experimental procedures that caused unrelieved pain and distress (UPAD) in animals. Of the species regulated by the U.S. Department of Agriculture (USDA), most of the approximately 100,000 animals subjected to UP AD during the year analyzed (1992) were guinea pigs and hamsters. Most of these animals were used in industry laboratories for various testing procedures, primarily vaccine potency testing. We discuss …

Convergence Of Random Walks On The Circle Generated By An Irrational Rotation, Francis E. Su

All HMC Faculty Publications and Research

Fix . Consider the random walk on the circle which proceeds by repeatedly rotating points forward or backward, with probability , by an angle . This paper analyzes the rate of convergence of this walk to the uniform distribution under ``discrepancy'' distance. The rate depends on the continued fraction properties of the number . We obtain bounds for rates when is any irrational, and a sharp rate when is a quadratic irrational. In that case the discrepancy falls as (up to constant factors), where is the number of steps in the walk. This is the first example of a sharp …

Analysis Of Experimental Designs Used In Bioassays, Vidyadhar Kshirsagar

Master's Theses and Doctoral Dissertations

No abstract provided.

Ua56/1 Fact Book, Wku Institutional Research

WKU Archives Records

Statistical and demographic profile of WKU.

Exponential Dichotomy And Mild Solutions Of Nonautonomous Equations In Banach Spaces, Y. Latushkin, Timothy W. Randolph, R. Schnaubelt

Mathematics and Statistics Faculty Research & Creative Works

We prove that the exponential dichotomy of a strongly continuous evolution family on a Banach space is equivalent to the existence and uniqueness of continuous bounded mild solutions of the corresponding inhomogeneous equation. This result addresses nonautonomous abstract Cauchy problems with unbounded coefficients. The technique used involves evolution semigroups. Some applications are given to evolution families on scales of Banach spaces arising in center manifolds theory. © 1998 Plenum Publishing Corporation.