Physical Sciences and Mathematics Commons^™

Averaged Motion Of Charged Particles In A Curved Strip, Avner Friedman, Chaocheng Huang

Mathematics and Statistics Faculty Publications

This paper is concerned with the motion of electrically charged particles in a "curved" infinite strip.

Almost Everybody Disagrees Almost All The Time: The Genericity Of Weakly Merging Nowhere, Ronald I. Miller, Chris William Sanchirico

All Faculty Scholarship

Suppose we randomly pull two agents from a population and ask them to observe an unfolding, infinite sequence of zeros and ones. If each agent starts with a prior belief about the true sequence and updates this belief on revelation of successive observations, what is the chance that the two agents will come to agree on the likelihood that the next draw is a one? In this paper we show that there is no chance. More formally, we show that under a very unrestrictive definition of what it means to draw priors “randomly,” the probability that two priors have any …

Student Fact Book, Fall 1997, Wright State University, Office Of Student Information Systems, Wright State University

Wright State University Student Fact Books

The student fact book has general demographic information on all students enrolled at Wright State University for Fall Quarter, 1997.

Multiple Outcomes In Health Services Research: Hypothesis Tests And Power, Donald C. Martin, Paula Diehr, Thomas D. Koepsell, Stephan D. Fihn

UW Biostatistics Working Paper Series

Health services research often is directed towards making small improvements in a number of outcomes that reflect many aspects of the patient’s life rather than a large improvement in a single well defined outcome. A researcher might choose five scales to measure different aspects of treatment outcomes and not expect any large treatment differences on any single outcome measure. O’Brien (1984) has proposed a nonparametric statistical procedure which is particularly well suited to this type of problem and that can result in considerable increases in statistical power. This paper will briefly review O’Brien’s pooled rank method and develop power calculations. …

Evaluating The Impact Of The Focus Model On The Efficacy Levels Of Teachers: A Field Based Study, John Fraas, Gary Russell, Isadore Newman

John W. Fraas

No abstract provided.

The Convergence Of The Solutions Of The Navier-Stokes Equations To That Of The Euler Equations, R. Temam, X. Wang

Mathematics and Statistics Faculty Research & Creative Works

In this article, we establish partial results concerning the convergence of the solutions of the Navier-Stokes equations to that of the Euler equations. Convergence is proved in space dimension two under a physically reasonable assumption, namely that the gradient of the pressure remains bounded at the boundary as the Reynolds number converges to infinity.

Is Chapter 11 Too Favorable To Debtors? Evidence From Abroad, Theodore Eisenberg, Stefan Sundgren

Cornell Law Faculty Publications

Chapter 11 is widely believed to be among the industrialized world's most debtor-oriented reorganization laws. Critics assert that Chapter 11 is too easily available and that it allows debtors too much control by, inter alia, not requiring appointment of a trustee. One criticism of Chapter 11, low returns to unsecured creditors, resonates with an important theme of this Symposium, the Bebchuk-Fried proposal to reduce secured creditor priority in insolvency proceedings. The Chapter 11 criticisms and the Bebchuk-Fried proposal raise the question whether less easy access to Chapter 11, reduced debtor control, diminished secured creditor priority, or other changes could reduce …

Attractors For Nonautonomous Nonhomogeneous Navier-Stokes Equations, A. Miranville, X. Wang

Mathematics and Statistics Faculty Research & Creative Works

In this paper our aim is to derive an upper bound on the dimension of the attractor of the family of processes associated to the Navier-Stokes equations with nonhomogeneous boundary conditions depending on time. We consider two-dimensional flows with prescribed quasiperiodic (in time) tangential velocity at the boundary, and obtain an upper bound which is polynomial with respect to the viscosity.

On The Product Of Two Generalized Derivations, Mohamed Barraa, Steen Pedersen

Mathematics and Statistics Faculty Publications

Two elements A and B in a ring R determine a generalized derivation delta_A,B on R by setting δ_A,B(X) = AX - XA for any X in R. We characterize when the product δ_C,Dδ_A,B is a generalized derivation in the cases when the ring R is the algebra of all bounded operators on a Banach space epsilon, and when R is a C*-algebra U. We use the se characterizations to compute the commutant of the range of δ_A,B.

Book Review Of Deborah G. Mayo, Error And The Growth Of Experimental Knowledge (University Of Chicago Press 1996), Kristin S. Shrader-Frechette

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

Review of the book: Deborah G. Mayo, Error and the Growth of Experimental Knowledge (University of Chicago Press 1996). Figures, index, preface, references. ISBN 0-226-51197-9 [493 pp. $74.00 Cloth; $29.95 Paper. 5801 S. Ellis Ave., Chicago, IL 60637.]

Infinite-Dimensional Hamilton-Jacobi-Bellman Equations In Gauss-Sobolev Spaces, Pao-Liu Chow, Jose-Luis Menaldi

Mathematics Faculty Research Publications

We consider the strong solution of a semi linear HJB equation associated with a stochastic optimal control in a Hilbert space H: By strong solution we mean a solution in a L²(μ,H)-Sobolev space setting. Within this framework, the present problem can be treated in a similar fashion to that of a finite-dimensional case. Of independent interest, a related linear problem with unbounded coefficient is studied and an application to the stochastic control of a reaction-diffusion equation will be given.

Hypersurfaces In R-D And The Variance Of Exit Times For Brownian Motion, Kimberly Kinateder, Patrick Mcdonald

Mathematics and Statistics Faculty Publications

Using the first exit time for Brownian motion from a smoothly bounded domain in Euclidean space, we define two natural functionals on the space of embedded, compact, oriented, unparametrized hypersurfaces in Euclidean space. We develop explicit formulas for the first variation of each of the functionals and characterize the critical points.

Seasonal Adjustment Of Naira Exchange Rate Statistics 1970-1995, O M. Akinuli

CBN Occasional Papers

This paper uses a current statistical approach to examine and adjust the seasonalities in the Naira exchange rate statistics, vis-a-vis the U.S. Dollar and the pound sterling for a period of twenty-five (25) years. Such study is necessary as it helps to understand the behavioural pattern of a trend in an attempt to predict the future. An investigation like this also helps to expose both the short and long run tendencies of a series which may require urgent or new policy measures to be taken sooner than expected. This paper reviews the regimes of exchange rate under the period, the …

A Cephalometric Study Of The Class Ii Correction Effects Of The Eureka Spring, Ernest L. Stromeyer

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of the Eureka Spring appliance, was investigated on 37 consecutively treated, non compliant, bilateral Class II malocclusions, requiring at least 3 mm or more of additional molar correction. The mean pretreatment age of this sample was 13.9 years. All patients were treated by a single clinician utilizing the Eureka Spring. Lateral cephalographs were taken at start of orthodontic treatment (T1), at insertion of Eureka Springs (T2), and at removal of the Eureka Springs (T3). The average treatment interval between T2 and T3 was 4 months. Class II correction occurred almost entirely by dentoalveolar movement, 33% in the maxilla …

Mark-Recapture Creel Survey And Survival Models, Shampa Saha

Mathematics & Statistics Theses & Dissertations

In this dissertation, we consider a model based approach to the estimation of exploitation rate of a fish population by combining mark-recapture procedures with a creel survey. We also consider the analysis of a proportional hazards survival model for randomly censored observations, known as the Koziol-Green model. The model assumes that the lifetime survivor function is a power of the censored time survivor function.

In Chapter 2, we introduce the model based approach to the estimation of the exploitation rate of a fish population by combining mark-recapture procedures with a creel survey. We assume that in the beginning of a …

The Predictability Of Punitive Damages, Theodore Eisenberg, John Goerdt, Brian Ostrom, David Rottman, Martin T. Wells

Cornell Law Faculty Publications

Using one year of jury trial outcomes from 45 of the nation's most populous counties, this article shows a strong and statistically significant correlation between compensatory and punitive damages. These findings are replicated in 25 years of punitive damages awards from Cook County, Illinois, and California. In addition, we find no evidence that punitive damages awards are more likely when individuals sue businesses than when individuals sue individuals. With respect to award frequency, juries rarely award punitive damages and appear to be especially reluctant to do so in the areas of law that have captured the most attention, products liability …

Effect Size And Power For Clinical Trials Using Years Of Healthy Life As The Primary Endpoint, Paula Diehr

Paula Diehr

Some clinical trials perform repeated measurements on patients over time, plot those measures against time, and summarize the results in terms of the area under the curve. If the measured variable is health status, the summary outcome is sometimes referred to as years of healthy life (YHL), or quality-adjusted life years (QALY). This paper investigates some theoretical and practical aspects of randomized trials designed to assess measures such as YHL. We first derived algebraic expressions for the effect size of YHL measures under several theoretical models of the treatment's effect on health. We used these expressions to examine how the …

An Administrative View Of Model Uncertainty In Public Health, Clark D. Carrington

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

Dr. Carrington reviews several ways to deal with model uncertainty, including those failing to acknowledge any use of models. He then evaluates six such methods with regard to, e.g., transparency and cost of execution.

Pooling Community Data For Community Interventions When The Number Of Pairs Is Small, Paula Diehr, Ted Lystig, Holly Andrilla, Ziding Feng

UW Biostatistics Working Paper Series

There is considerable interest in community interventions for health promotion, where the community is the experimental unit. Because such interventions are expensive, the number of experimental units (communities) is usually very small, yielding a study with low power. We examined the ability of a process known as “pooling” or “preliminary significance testing” to improve the power of community variations. In this process, one first tests whether there is significant community variation, using type 1 error of perhaps 0.25. If there is significant variation, the usual community-level test is performed. If not, a person-level test is performed. We found through Monte …

Single Row Routing: Theoretical And Experimental Performance Evaluation, And New Heuristic Development, David A. Hysom

Computer Science Theses & Dissertations

The Single Row Routing Problem (SRRP) is an abstraction arising from real-world multilayer routing concerns. While NP-Complete, development of efficient SRRP routing heuristics are of vital concern to VLSI design. Previously, researchers have introduced various heuristics for SRRP; however, a comprehensive examination of SRRP behavior has been lacking.

We are particularly concerned with the street-congestion minimization constraint, which is agreed to be the constraint of greatest interest to industry. Several theorems stating lower bounds on street congestion are known. We show that these bounds are not tight in general, and argue they may be in error by at least 50% …

Using Ranks To Perform Exact And Estimated Exact Tests In Designed Experiments, Scott J. Richter, Mark E. Payton

Conference on Applied Statistics in Agriculture

A procedure is studied that uses rank transformed data to perform exact and estimated exact tests which is an alternative to the commonly used F-ratio test procedure. First, a common parametric test statistic is computed using rank transformed data, where two methods of ranking - ranks taken of the original observations, and ranks taken after aligning the observations - are studied. Significance is then determined using either the exact permutation distribution of the statistic or an estimate of this distribution based on a random sample of all possible permutations. Simulation studies compare the performance of this method to both the …

Testing Variance Components Using The Glm And Mixed Procedures Of Sas®, Ron Mcnew, Andy Mauromoustakos

Conference on Applied Statistics in Agriculture

The test of a variance component in random and mixed normal linear models can be done using the F statistic from the analysis of variance or the Wald statistic which is the ratio of the variance component estimate to its estimated standard error. These are the methods used in the GLM and MIXED procedures of SAS®. We show that these two tests can give different results on the same data. For the one-way random model, the one-sided Wald test on the among group variance component can never be significant at the 0.05 probability level when the number of levels of …

The Statistical Analysis Of Active Control Equivalence Studies, Armando Garsd, Susana F. Delfino

Conference on Applied Statistics in Agriculture

In experimental work, the notion of equivalence falls short of the idea of equality. Thus, the effects of two treatments, while not identical, may still be regarded as equivalent if their difference is negligible in a certain sense. This simple distinction raises not only technical difficulties, since of necessity it results in special statistical procedures, but also deeper conceptual issues, since one has to ask why two treatments should be equivalent but not equal, more specifically, whether their being merely equivalent has any bearing on the practical questions posed by the data. In this paper we present examples, drawn from …

The Analysis Of The Two-Period Repeated Measurements Crossover Design With Application To A Forestry Problem, Armando Garsd, Maria C. Fabrizio, Maria V. López

Conference on Applied Statistics in Agriculture

The two-period repeated measurements crossover design is not often used in agricultural studies. It is, however, an attractive model, involving the confluence of two powerful statistical ideas, treatment crossover and repeated measurements on the same experimental unit. This paper presents one approach for the statistical analysis of such design based on the work of Wallenstein and Fisher (1977). It is shown how the data may be transformed so that it can be analyzed under the framework of a completely randomized repeated measurements design. We formalize the analysis in the context of a forestry experiment conducted on poplar trees (Populus SP.), …

The Use Of Inverse Theory On An Ill-Posed Environmental Composite Sampling Problem, V. A. Lancaster, S. Keller-Mcnulty

Conference on Applied Statistics in Agriculture

As an alternative to retesting, the use of inverse theory techniques is proposed to resolve the lack of information inherent in composite sampling methods. This paper evaluates the feasibility of combining composite sampling with the inverse theory technique of linear regularization on an environmental site characterization investigation. Federal legislation has mandated the cleanup of hazardous waste sites, creating the need to characterize these sites for various chemical constituents. An abundance of samples, high measurement costs, and limited budgets create the appeal of compositing samples. We propose that the number of costly laboratory analyses can be reduced by combining composite sampling …

Bootstrap Confidence Intervals From Adaptive Sampling Of An Insect Population, Jeffrey S. Pontius, Mary C. Christman

Conference on Applied Statistics in Agriculture

We construct 90% normal, percentile, and bias-corrected and accelerated confidence intervals using a finite population bootstrapping algorithm based on adaptive sampling in an agroecosystem. We evaluate the interval estimates based on sampling simulations of a spatially arranged population of plots that contain counts of beet webworms and based on an adaptive condition that generates small networks. The sampling distributions of the original sample estimates and of the bootstrap estimates were generally similar and symmetric. The simulation coverages were from 84% to 90% and similar under any of the sample sizes and any of the three confidence interval types. This study …

Some Experiences With Neural Networks, Lynda L. Ballou, Dallas E. Johnson

Conference on Applied Statistics in Agriculture

This paper gives a brief overview of artificial neural networks which may be used to model data similar to the kind where one usually considers regression models. Many practitioners believe that neural networks perform better than regression models for prediction purposes. Some simulations were performed using three different neural net programs, namely Braincel, Ripley's S+ program, and Nychka's S+ program. These simulations reveal some interesting aspects of neural net programs which should be of interest to anyone considering the use of neural net programs to model continuous data.

Some Factors Limiting The Use Of Generalized Linear Models In Agricultural Research, Walter W. Stroup

Conference on Applied Statistics in Agriculture

The generalized linear model (GLM) is a "hot" topic in statistics. Numerous research articles on GLM's appear in each edition of all major journals in statistics. GLM's are the subject of substantial numbers of presentations at most statistics conferences. Despite the high level of interest and research activity within the statistics community, GLM's are not widely used, with some exceptions, by biological scientists in the statistical analysis of their research data. Why? Reasons include 1) many statisticians are not comfortable with GLM's, 2) the biological research community is not familiar with GLM's, and 3) there is little in introductory statistics …

How Good Are Spatial Glm's? A Simulation Study, Roger G. Collins, Walter W. Stroup, Stephen D. Kachman

Conference on Applied Statistics in Agriculture

An area of increasing interest to agricultural and ecological researchers is the analysis of spatially correlated non-normal data. A generalized linear model(GLM) accounting for spatial covariance was presented by Gotway and Stroup (1997). Their method included approximate inference based on asymptotic distributions. A simulation study was conducted to assess the small sample behavior of their proposed estimates and test statistics. This study suggests that the spatial GLM yields unbiased estimates of treatment means and differences for binomial data, that the spatial GLM improves precision, as measured by MSE, and that the approximate F-statistic is acceptable for hypothesis testing.

Alternative Analyses Of Crossover Designs With More Than Two Periods, Carla L. Goad, Dallas E. Johnson

Conference on Applied Statistics in Agriculture

A crossover experiment is a special form of a repeated measures experiment. An appropriate analysis of a repeated measures experiment depends on the form of the varian-cecovariance matrix of the repeated measures. Certain forms of this matrix yield valid analysis of variance F -tests while other forms invalidate these tests. In a crossover experiment where analysis of variance tests are invalid, two alternative tests of a linear contrast of the parameters are proposed. In addition to these approximate t-tests, three alternative methods for testing for equal treatment effects and equal carryover effects are proposed. A simulation study is conducted to …