Statistics and Probability Commons^™

Projections Of Alzheimer's Disease In The United States And The Public Health Impact Of Delaying Disease Onset., Ron Brookmeyer, Sarah Gray, Claudia Kawas

Ron Brookmeyer

OBJECTIVES: The goal of this study was to project the future prevalence and incidence of Alzheimer's disease in the United States and the potential impact of interventions to delay disease onset.

METHODS: The numbers of individuals in the United States with Alzheimer's disease and the numbers of newly diagnosed cases that can be expected over the next 50 years were estimated from a model that used age-specific incidence rates summarized from several epidemiological studies, US mortality rates, and US Bureau of the Census projections.

RESULTS: in 1997, the prevalence of Alzheimer's disease in the United States was 2.32 million (range: …

Measuring The Deterrent Effect Of Punitive Damages, Theodore Eisenberg

Cornell Law Faculty Publications

Professor Viscusi's article differs from the dominant mode of law and economics scholarship on punitive damages. The usual punitive damages article contains purely theoretical considerations about when punitive damages are appropriate and about their optimal level; no effort is made to ascertain whether the existing pattern of punitive awards corresponds with the theory. This is part of a larger problem: the dearth of empirical evidence in law and economics scholarship. Viscusi, on the other hand, provides empirical tests of whether punitive damages accomplish their goals, and he makes creative use of publicly available data sources. For the goal of his …

Student Fact Book, Fall 1998, Twenty Second Annual Edition, 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, 1998.

Assessing The Accuracy Of A New Diagnostic Test When A Gold Standard Does Not Exist, Todd A. Alonzo, Margaret S. Pepe

UW Biostatistics Working Paper Series

Often the accuracy of a new diagnostic test must be assessed when a perfect gold standard does not exist. Use of an imperfect test biases the accuracy estimates of the new test. This paper reviews existing approaches to this problem including discrepant resolution and latent class analysis. Deficiencies with these approaches are identified. A new approach is proposed that combines the results of several imperfect reference tests to define a better reference standard. We call this the composite reference standard (CRS). Using the CRS, accuracy can be assessed using multistage sampling designs. Maximum likelihood estimates of accuracy and expressions for …

Complexity Reduction In State-Based Modeling, Martin Zwick

Systems Science Faculty Publications and Presentations

For a system described by a relation among qualitative variables (or quantitative variables "binned" into symbolic states), expressed either set-theoretically or as a multivariate joint probability distribution, complexity reduction (compression of representation) is normally achieved by modeling the system with projections of the overall relation. To illustrate, if ABCD is a four variable relation, then models ABC:BCD or AB:BC:CD:DA, specified by two triadic or four dyadic relations, respectively, represent simplifications of the ABCD relation. Simplifications which are lossless are always preferred over the original full relation, while simplifications which lose constraint are still preferred if the reduction of complexity more …

A Messy, But Instructive, Case Study In Design Of Experiments, Leroy A. Franklin, Belva J. Cooley, Gary Elrod

Mathematical Sciences Technical Reports (MSTR)

A company manufacturing fans wished to conduct an experimental design to determine the best combination of three factors affecting the breaking torque of the fans. Analysis of the data ceased to be straightforward when the authors found that the data failed the test for homogeneity of variances. After unsuccessfully attempting to transform the data and thereby meet the assumptions necessary to carry on the analysis, the authors relied upon a graphical analysis and a careful study of the means for each design point. This paper describes a statistically sound but novel strategy used to complete the analysis.

But Was He Sorry? The Role Of Remorse In Capital Sentencing, Theodore Eisenberg, Stephen P. Garvey, Martin T. Wells

Cornell Law Faculty Publications

What role does remorse really play in capital sentencing? We divide this basic question in two. First, what makes jurors come to believe a defendant is remorseful? Second, does a belief in the defendant's remorse affect the jury's final judgment of life or death? Here we present a systematic, empirical analysis that tries to answer these questions.

What makes jurors think a defendant is remorseful? Among other things, we find that the more jurors think that the crime is coldblooded, calculated, and depraved and that the defendant is dangerous, the less likely they are to think the defendant is remorseful. …

Attractors For Non-Compact Semigroups Via Energy Equations, Ioana Moise, Ricardo Rosa, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

The energy-equation approach used to prove the existence of the global attractor by establishing the so-called asymptotic compactness property of the semigroup is considered, and a general formulation that can handle a number of weakly damped hyperbolic equations and parabolic equations on either bounded or unbounded spatial domains is presented. as examples, three specific and physically relevant problems are considered, namely the flows of a second-grade fluid, the flows of a Newtonian fluid in an infinite channel past an obstacle, and a weakly damped, forced Korteweg-de Vries equation on the whole line.

A Structural Result Of Irreducible Inclusions Of Type Iii Lambda Factors, Lambda Is An Element Of (0,1), Phan Loi

Mathematics and Statistics Faculty Publications

Given an irreducible inclusion of factors with finite index N ⊂ M, where M is of type III_λ1/m, N of type III_λ1/n, 0 < λ < 1, and m,n are relatively prime positive integers, we will prove that if N ⊂ M satisfies a commuting square condition, then its structure can be characterized by using fixed point algebras and crossed products of automorphisms acting on the middle inclusion of factors associated with N ⊂ M. Relations between N ⊂ M and a certain G-kernel on subfactors are also discussed.

Statistics Of Active Galactic Nuclei In Rich Clusters Revisited, M. Way, R. Flores, H. Quintana

Physics Faculty Works

Using the spectrophotometry of a large sample of galaxies in 19 Abell clusters, we have selected 42 candidate active galactic nuclei (AGNs) using the criteria used by Dressler and coworkers in their analysis of the statistics of 22 AGNs in 14 rich cluster fields, which are based on the equivalent width of [O II] 3727 Å, Hβ, and [O III] 5007 Å emission. We have then discriminated AGNs from H II region-like galaxies (hereafter H II galaxies) in the manner developed by Veilleux & Osterbrock using the additional information provided by Hα and [N II] 6583 Å or Hα and …

Evolution Of Mixed-State Regions In Type-Ii Superconductors, Chaocheng Huang, Tom Svobodny

Mathematics and Statistics Faculty Publications

A mean-field model for dynamics of superconducting vortices is studied. The model, consisting of an elliptic equation coupled with a hyperbolic equation with discontinuous initial data, is formulated as a system of nonlocal integrodifferential equations. We show that there exists a unique classical solution in C^1+α(Ω₀) for all t > Ω, where Ω₀ is the initial vortex region that is assumed to be in C^1+α. Consequently, for any time t, the vortex region Ω_t is of C^1+α, and the vorticity is in C^α(Ω_t).

Ranking And Explaining The Scholarly Impact Of Law Schools, Theodore Eisenberg, Martin T. Wells

Cornell Law Faculty Publications

This article measures 32 law schools' academic reputations by citations to their faculties' works. Yale, Chicago, Harvard, and Stanford rank alone at the top. Seven or eight schools compose the next group. We also explore the relation between scholarly impact and entry-level or lateral hire status, gender, minority status, subjects taught, and years in teaching. Lateral hires systematically outperform entry-level hires. We find no substantial evidence of male-female differences. We find some evidence of lower citations for minority females, but this difference is largely attributable to those in teaching fewer than 8 years. For faculty members in teaching more than …

Review Of: Charles R. Bennett, Risks In The Environment: How To Assess Them, Penny Dean

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

Review of: Charles R. Bennett, Risks in the Environment: How to Assess Them (Burloak Publications 1996). Appendices, references for the appendices, prologue. ISBN 0-9680438-0-1 [305 pp. Paper $23.95. 277 Belvenia Rd., Burlington, Ontario.]

Surface Models Of Finite Geometries, Ramon Manuel Figueroa-Centeno

Dissertations

The standard non-Euclidean geometries, hyperbolic geometry and elliptical geometry, both arise by negating the parallel postulate of Euclid. Both these geometries share with Euclidean geometries an infinitude of points and lines. But also possible are many finite geometries. Among these are the class of projective geometries PG(m,q) of projective dimension m (m > 2) and the k-configurations. These mathematical objects, although primarily geometric in nature, provide related structures of combinatorial interest: block designs. These have applications in scheduling problems and the design of experiments for statistical analysis. Recently, A. T. White has added a topological flavor to the study …

Perturbed Hamiltonian System Of Two Parameters With Several Turning Points, Myeong Joon Ann

Dissertations

No abstract provided.

A Pilot Study Testing A Proprietary Sealant For Plaque Reduction, Jennifer Rowland

Loma Linda University Electronic Theses, Dissertations & Projects

Enamel demineralization due to increased plaque accumulation is a well-recognized problem associated with fixed orthodontic appliances. The purpose of this study was to evaluate the efficacy of a proprietary product to be marketed by 3M Unitek for the reduction of plaque accumulation and thereby reduce enamel demineralization.

Sixty four bovine teeth were divided equally into an untreated control group and a group treated with the proprietary sealant product. Both groups were subsequently immersed in a Streptococcus mutans culture. Plaque deposits from each group were removed, suspended in trypticase soy broth, serially diluted, and plated on trypticase soy agar at 1, …

Does The Oswestry Or Sf-36 Help A Therapist To Predict Treatment Classification, Amy Crawford, Denese D. Kaufeldt-Soliz

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the relationship of two disability questionnaires, the Oswestry Low Back Pain Disability Questionnaire (Oswestry) and the Medical Outcome Study Short Form-36 (SF-36), and a standardized physical examination and diagnostic classification system. The physical examination was performed by the evaluating therapists from the clinic and classification was determined by the evaluating therapists and the investigators to ensure correct subject placement into treatment Stages la, lb, or II. Data collection occurred at an outpatient physical therapy clinic in a metropolitan area health maintenance organization, where a sample of 221 subjects with low back pain …

Preparation Of Gold-Coated Molybdenum Articles And Articles Prepared Thereby, Timothy S. Romano, Tom K. Evans, Gary B. Hughes, Karl H. Neumann

Statistics

A gold-coated molybdenum article (30) is made by furnishing a substrate (32) made of pure molybdenum or an alloy of molybdenum, and preparing a slurry of gold powder, acrylic binder, and acetone liquid carrier. The slurry is applied to a portion of a surface of the substrate. The substrate with applied slurry is heated in vacuum or inert atmosphere to an elevated temperature, preferably about 2040.degree. F., and thereafter cooled to ambient temperature. The result is an article (30) having at least a portion of the substrate (32) covered with an adherent gold coating (34).

On The Model Selection In A Frailty Setting, Jill F. Lundell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When analyzing data in a survival setting, whether of people or objects, one of the assumptions made is that the population is homogeneous. This is not true in reality and certain adjustments can be made in the model to account for heterogeneity. Frailty is one method of dealing with some of this heterogeneity. It is not possible to measure frailty directly and hence it can be very difficult to determine which frailty model is appropriate for the data in interest. This thesis investigates three model selection methods in their effectiveness at determining which frailty distribution best describes a given set …

Some Statistical Considerations To On-Farm Trials In Kenya, Peter M. Njuho

Conference on Applied Statistics in Agriculture

The issue of design and analysis of on-farm trials is not clearly understood by agricultural researcher in Kenya. Since on-farm trials require participation and co-operation of the farmers who often differ in education level, chances of collecting unreliable and quite variable data are high. This paper highlights the importance of collecting quality data from on-farm trials, and in particular from the researcher designed and farmer managed trial type. Some complexities associated with the implementation, application of basic statistical principles, and analysis of on-farm trials are discussed. Questions that need to be considered priori to the implementation of any trial implementation …

Optimum Design On Step-Stress Life Testing, C. Xiong

Conference on Applied Statistics in Agriculture

This paper presents exact optimum test plans for simple time-step stress models in accelerated life testing. An exponential life distribution with a mean that is a log-linear function of stress, and a cumulative exposure model are assumed. Maximum likelihood methods are used to estimate the parameters of such models. Optimum test plans are obtained by minimizing the mean square error between the maximum likelihood estimate of a certain moment of the lifetime at a design stress and the real moment. The advantage of our optimum test plans is that it does not require large number of items to be tested. …

Modelling The Coefficient Of Variation In Factorial Experiments, Craig A. Wilson, Mark E. Payton

Conference on Applied Statistics in Agriculture

The coefficient of variation (CV) has long been used as a measure of the relative consistency of sample data. However, little attention has been paid to using the CV to make conclusions about the relative consistency of the population(s) from which the data are drawn, particularly when the data are observed in the context of a designed factorial experiment. This research focused on using three approximations to the exact distribution of the sample CV of normally distributed data (McKay's, David's, and Iglewicz and Myers') in the context of the generalized linear model to develop a method for detecting main effects …

A Repeated Measures Analysis Of The Effect Of Vegetative Buffers On Contaminant Runoff From Bermudagrass Turf, Craig A. Wilson, Mark E. Payton, Ellen W. Stevens, Raymond L. Huhnke, Daniel E. Storm, Nick T. Basta, James H. Baird

Conference on Applied Statistics in Agriculture

A repeated measures analysis was conducted on a set of data from a multi-year study to assess the effect of vegetative buffers on the surface runoff of selected herbicides and nutrients. Multiplicative models describing the observed behavior of runoff concentration over time for buffered and non-buffered plots were fitted on a log-transformed scale using linear mixed models with PROC MIXED in PC SAS version 6.11. A spatial power covariance structure was used. Additional models for contaminant mass flow rates were fitted to evaluate the effect of buffers on total runoff mass.

Sampling Plans For Monitoring Rust In Coffee Trees, Raw E. Macchiavelli, Roclo Rodriguez

Conference on Applied Statistics in Agriculture

Rust is an important fungal disease of coffee that causes defoliation of plants, thus affecting production and yield of coffee beans. Management of coffee rust with fungicides should be based on disease incidence at the onset of the epidemic. Previously, sampling has been done in a two-step systematic plan: trees are sampled in a systematic pattern (in the shape of a W covering the field), and then leaves are randomly sampled within each selected tree. Since coffee in Puerto Rico is typically grown in areas with pronounced slopes, these plans require walking diagonally along slopes, which is not feasible for …

Blocking In Partial Diallel Crosses, D. R. Aneja, L . S. Kaushik

Conference on Applied Statistics in Agriculture

Generally the parents are included in the experimental material for combining ability analysis for comparing the performance of crosses with parents and also for calculating heterosis. But unfortunately the parents are ignored for combining ability analysis because of non-availability of analysis procedure. Method of analysis of partial diallel crosses in incomplete blocks for the method -2 of Griffing (1956) has been given.

Construction Of Asymmetrical Response Surface Designs, V. P . Manocha, L. S. Kaushik

Conference on Applied Statistics in Agriculture

The paper proposes several methods for constructing both rotatable and non-rotatable asymmetrical response surface designs. The idea of modified rotatable design is introduced. In most of the experiments conducted by the experimenter it is not necessary that all the factors under study may have equal number of levels The methods proposed will have wider use under these circumstances.

On-Farm Research In A Decentralized Information Model Or Grassroots Statistics, Derrick N. Exner, Jennifer Kendall, Dick Thompson

Conference on Applied Statistics in Agriculture

Practical Farmers of Iowa (PFI) is an organization that seeks to provide interactive methods of relaying information through farmer-to-farmer sharing (farm field days, workshop discussions, networking) and the generation of new information. On-farm research (OFR) is an important information-generating activity of this group. PFI has shown that key to doing research on farms lies in combining practical protocols with the statistician's old familiar friends - replication and randomization.

We provide background on PFI and how PFI cooperators carne to using strip plots and paired comparisons to answer fundamental questions about what to do on their individual farms. We discuss the …

Blocking Factorial Designs In Greenhouse Experiments, Steve Ferris, Steven G. Gilmour

Conference on Applied Statistics in Agriculture

Experiments in greenhouses usually have to be conducted with very limited resources. This makes it particularly important to control the between plot variation by appropriate use of blocking. Many greenhouse experiments are naturally laid out in a pattern that makes a class of designs known as semi-Latin squares useful. Their properties have been studied recently by a number of authors and this work is reviewed. Often, the experimental treatments will have a factorial structure. An example of a 23 structure is used to show how factorial treatments can be assigned to treatment labels to ensure that the appropriate information is …

Daily Solar Radiation Estimated From Tkmpera Ture Records, D. W. Meek

Conference on Applied Statistics in Agriculture

Crop growth models and other environmental analyses require the input of daily global solar radiation values. Unfortunately many locations lack long-term solar radiation data. Most agricultural experiment stations, however, have daily temperature records. Also they are often the locations for which crop growth simulations are conducted. In an unpublished manuscript in the field of agricultural meteorology, researchers wanted to address this need. Specifically they wanted to estimate historical daily global solar radiation using daily air temperature data records by adapting a single published empirical intrinsically nonlinear model, a form of the Weibull curve. In order to help future research in …

Using Confidence Intervals To Obtain A Family Of Estimators Of The Intraclass Correlation Coefficient (Or Heritability), Brent D. Burch, Ian R. Harris

Conference on Applied Statistics in Agriculture

A family of point estimators is presented for the intraclass correlation coefficient (or heritability) in the balanced one-way random effects model. The family is obtained by equating a pivotal quantity to different values of the pivoting distribution, and includes the familiar ML and REML estimators. In terms of mean-squared error, most members of the family of estimators are admissible within the family. A sire model is used to illustrate the estimation of heritability. The authors provide guidance concerning the choice of an individual member of the family for estimation purposes and indicate how the method can be extended to unbalanced …