Statistics and Probability Commons^™

Regionalization Of Flood Data Using Probability Distributions And Their Parameters, Nageshwar Rao Bhaskar, Carol Alf O'Connor, Harold Andrew Myers, William Paul Puckett

KWRRI Research Reports

The U. S. Geological survey recently used the method of residuals to delineate seven flood regions for the State of Kentucky. As an alternative approach, the FASTCLUS clustering procedure of the Statistical Analysis system (SAS) is used in this study to delineate five to six cluster regions in conjunction with statistical properties of the AMF series, like the coefficient of variation as estimated using method of L-moments, LCV, the parameters of the EVl and GEV flood frequency distributions, and the specific mean annual flood, QSP. For both cluster and USGS flood regions, regionalized flood frequency growth curves are developed and …

Regression Models For Bivariate Binary Responses, Juni Palmgren

UW Biostatistics Working Paper Series

We discuss maximum likelihood inference for the bivariate logistic model, specified in terms of the marginal logits and the log odds ratio. Using the exponential family nonlinear model formulation the model fitting can be done in GLIM. The procedure is illustrated by modelling survival of unilateral and bilateral total hip arthroplasties as function of patient specific and hip specific covariates. We compare maximum likelihood inference with inference obtained from solving likelihood equations under the assumption of within block independence and using robust standard errors for the estimates. Simulations indicate that the latter procedure is effcient for block specific covariates but …

Treatment Modality And Quality Differences For Black And White Breast Cancer Patients Treated In Community Hospitals, Paula Diehr

Paula Diehr

This study assessed the relationship of race and patterns of care, defined by an expert NCI-appointed committee, for 7,781 patients with breast cancer treated in 107 hospitals in 45 communities between 1982 and 1985. After control for age and stage of disease, black patients had significantly different care from white patients for four of the ten patterns examined. They were less likely to have a progesterone receptor assay or to be referred for postmastectomy rehabilitation, two patterns deemed desirable for all patients. Black patients were also more likely to receive liver scans and radiation therapy in situations in which these …

Student Fact Book, Fall 1989, Wright State University 25 Years Vision Unlimited, 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, 1989.

Student Perceptions Of The Relative Importance Of Selected Attributes Of An Institution Of Higher Education: A Conjoint Approach, John Fraas, Ronald Paugh

John W. Fraas

A study investigated the relative importance of certain college attributes to the freshmen of Ashland University, a small, private university in Ohio. Five institutional characteristics were examined: availability and variety of financial aid, dorm life (living conditions and food quality), quality of education (quality of teaching, career relevance of the curriculum, and overall institutional reputation), student-faculty relationships and interaction (availability of faculty to students, faculty promotion of student development, and degree of faculty advice given to students on personal as well as academic matters), and campus social life.

Spatial Critical Points Of Solutions Of A One-Dimensional Nonlinear Parabolic Problem, Larry Turyn

Mathematics and Statistics Faculty Publications

The number of spatial critical points is nonincreasing in time, for positive, analytic solutions of a scalar, nonlinear, parabolic partial differential equation in one space dimension. While proving this, we answer the question: What happens to a critical point which loses simplicity?

Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure

Loma Linda University Electronic Theses, Dissertations & Projects

The best understood functional activity of the pineal gland is its diurnal production of melatonin in response to environmental lighting cues. Several enzymes of the melatonin pathway respond to daily photoperiod changes, for example hydroxyindole-O-methyltransferase (HIOMT) and serotonin N-acetyltransferase (SNAT). Increased levels of the glycolytic enzyme neuron-specific enolase (NSE) are thought to reflect increased physiological demands placed on neurons and neuroendocrine tissues. Homodimer non-neuronal enolase isoenzyme (NNE) is immunolocalized to cells, and the hybrid enolase (consisting of subunits from NSE and NNE) has been seen in cerebellar stellate and basket cells. Although not rate limiting, concentrations of both NSE and …

Software Reliability Models, Syed Afzal Hossain

Mathematics & Statistics Theses & Dissertations

The problem considered here is the building of Non-homogeneous Poisson Process (NHPP) model. Currently existing popular NHPP process models like Goel-Okumoto (G-O) and Yamada et al models suffer from the drawback that the probability density function of the inter-failure times is an improper density function. This is because the event no failure in (0, oo] is allowed in these models. In real life situations we cannot draw sample(s) from such a population and also none of the moments of inter-failure times exist. Therefore, these models are unsuitable for modelling real software error data. On the other hand if the density …

Mathematical Models Of Prevascular Tumor Growth By Diffusion, Sophia A. Maggelakis

Mathematics & Statistics Theses & Dissertations

A study of several complementary mathematical models that describe the early, prevascular stages of solid tumor growth by diffusion under various simplifying assumptions is presented. The advantage of these models is that their degree of complexity is relatively low, which ensures fairly straightforward comparisons with experimental or clinical data (as it becomes available), yet they are mathematically sophisticated enough to capture the main biological phenomena of interest.

The tumor growth and cell proliferation rate are assumed to depend on the local concentrations of nutrients and inhibitory factors. The effects of geometry and spatially non-uniform inhibitor production and non-uniform nutrient consumption …

Detection Of Outliers And Influential Observations In Regression Models, Anwar M. Hossain

Mathematics & Statistics Theses & Dissertations

Observations arising from a linear regression model, lead one to believe that a particular observation or a set of observations are aberrant from the rest of the data. These may arise in several ways: for example, from incorrect or faulty measurements or by gross errors in either response or explanatory variables. Sometimes the model may inadequately describe the systematic structure of the data, or the data may be better analyzed in another scale. When diagnostics indicate the presence of anomalous data, then either these data are indeed unusual and hence helpful, or contaminated and, therefore, in need of modifications or …

Responses To Corporate Versus Individual Wrongdoing, Valerie P. Hans, M. David Ermann

Cornell Law Faculty Publications

For many years, researchers assumed that the public was indifferent to corporate wrongdoing, but recent surveys have discovered evidence to the contrary. Taking insights from these data a step further, this study employed an experimental design to examine whether people responded differently to corporate versus individual wrongdoers. We varied the identity of the central actor in a scenario involving harm to workers. Half the respondents were informed that a corporation caused the harm; the remainder were told that an individual did so. Respondents applied a higher standard of responsibility to the corporate actor. For identical actions, the corporation was judged …

Feasibility Of An Extraoral Method For Predicting Manibular Incisor Relapse, Mark J. Saylor

Loma Linda University Electronic Theses, Dissertations & Projects

The author undertook to develop an extraoral model for predicting mandibular incisor relapse similar to the model described by Harvey and Sheldon Peck. Whereas the Peck and Peck method involves intraoral measurements, the method described in this paper relied on the taking of measurements from the patient's pre-treatment plaster models. Two hundred and sixty teeth were measured both orally and on plaster casts, and several statistical tests were performed to isolate any differences between the intraoral and extraoral methods. The principal difference was identified as the faciolingual measurement of the incisor, due to the height of contour often being subgingival …

Misfit Between Motivational Style And Type Of Job Demand As A Factor In Developing Occupational Stress, Arlene Gray Blix

Loma Linda University Electronic Theses, Dissertations & Projects

Occupational stress is costly in terms of human suffering and impaired organizational effectiveness. Occupational stress involves the interface between the individual worker and the work environment. The purpose of the study was to analyze the fit between motivational style and the type of job demands as a contributing factor in developing occupational stress symptoms. A literature review of occupational stress models was conducted. The six models compared and contrasted included the Person-Environment fit model (French, Rodgers, & Cobb, 1974), Integrative Transactional Model (Schuler, 1982), Organizational Stress Models (Ivancevich & Matteson, 1987; Parker & DeCotiis, 1983), Facet Analysis Model (Beehr & …

Facial Typing Methods : A Comparative Study, James A. Grabow

Loma Linda University Electronic Theses, Dissertations & Projects

Facial typing methods are used to determine to which of three basic facial pattern categories an individual patient belongs. These three categories are mesofacial, brachyfacial, and dolichofacial. It is important to establish the correct facial type because the reaction to treatment mechanics and the stability of the denture is dependent upon the analysis of the facial patterns. The purpose of this paper was to show a comparative study of facial typing classification methods used on 100 patients (47 boys and 53 girls). The eight different methods used were as follows: Bioprogressive, Ricketts LLU1, LLU2, QuickCeph™, Jarabak, Facial-Mandibular Index, and Steiner. …

Some Estimates For Finite Difference Approximations, José-Luis Menaldi

Mathematics Faculty Research Publications

Some estimates for the approximation of optimal stochastic control problems by discrete time problems are obtained. In particular an estimate for the solutions of the continuous time versus the discrete time Hamilton-Jacobi-Bellman equations is given. The technique used is more analytic than probabilistic.

Probability Of Discrete Failures, Weibull Distribution, Mary Jo Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The intent of this research and these is to describe the development of a series of charts and tables that provide the individual and cumulative probabilities of failure applying to the Weibull statistical distribution. The mathematical relationships are developed and the computer programs are described for deterministic and Monte Carlo models that compute and verify the results. Charts and tables reflecting the probabilities of failure for a selected set of parameters of the Weibull distribution functions are provided.

Using Interaction In Two-Way Data Tables, Hugh G. Gauch Jr., Richard W. Zobel

Conference on Applied Statistics in Agriculture

Agronomists and breeders frequently collect yield data for a number of genotypes in a number of environments (site-years), resulting in a two-way data table. The Additive Main effects and Multiplicative Interaction (AMMI) model combines regular analysis of variance (ANOVA) for additive main effects with principal components analysis (PCA) for multiplicative structure within the interaction (that is, within the residual from ANOVA). AMMI is effective for (1) understanding genotype-environment interaction, (2) improving the accuracy of yield estimates, (3) increasing the probability of successfully selecting genotypes with the highest yields, (4) imputing missing data, and (5) increasing the flexibility and efficiency of …

The Analysis Of The Additive Mixed Model For Classes Of Non Orthogonal Designs, Christine A. Stidley

Conference on Applied Statistics in Agriculture

Tests for fixed and random effects can be difficult to derive for nonorthogonal designs with mixed models. However, extensions of the intrablock and inter-block analyses of Balanced Incomplete Block Designs can often be obtained. Here we derive the extensions for the broad class of Group Divisible Designs. Decompositions of the design space are used to develop exact tests for fixed and random effects in the additive mixed model with random block effects. Conditions on the design which permit the standard use of the intra-block and inter-block test statistics are given. Important subclasses of Group Divisible Designs include Equireplicate Variance Balanced …

A Combined Analysis Of Experiments When Treatments Differ Among Experiments, Paul N. Hinz, Mario R. Pareja

Conference on Applied Statistics in Agriculture

The advantages of repeating experiments in several locations and years are discussed and standard methods of analysis are reviewed. The methods assume that the same treatments are used in each experiment. This paper discusses a method used for a combined analysis when the treatments represent levels of a quantitative factor but differ among experiments. The method makes use of multiple regression analysis in which a continuous variable represents treatment levels, classification variables represent experiments, and products of the continuous and classification variables represent differences among experiments. The method is illustrated on data from a series of experiments designed to study …

Evaluating The Effect Of Commodity Donation Programs Using The Truncated Normal Distribution, J. William Levedahl

Conference on Applied Statistics in Agriculture

The magnitude of both the displacement of commercial sales and the increase in consumption associated with a commodity distribution program are characterized using the truncated normal distribution. This method is easier to implement and requires less data than previous methods. It is applied to data from the 1986 Survey of TEFAP Recipients and is quite accurate.

Forecasting Corn Ear Weight Using Surface Area And Volume Measurements: A Preliminary Report, Fatu Bigsby

Conference on Applied Statistics in Agriculture

Data from the Corn Ear Weight Study were used to analyze the forecast performance of models estimated using surface area and volune measurements to predict corn ear weight. Two models based on research measurements were compared to models estimated using the operational procedures from the Corn Objective Yield Survey. Research and operational models were estimated both within and across years using data from the 1986 and 1987 Michigan Corn Ear Weight Study. Results show that research models based on surface area and volune measurements have mean square errors that are 32 to 52 percent lower than models estimated using the …

Forecasting Corn Ear Weights From Daily Weather Data, Fred B. Warren

Conference on Applied Statistics in Agriculture

Statistical models were developed to predict the State average grain weight per ear using daily temperature and precipitation data, recorded from May 1 through late July. The required daily weather data was successfully obtained in an operational test of these models for ten major corn producing States in 1988. Relative forecast errors of ear weight averaged almost one-third smaller than those from a regular survey. Additional refinements of the models to make them more responsive to abnormally early adverse weather, as in 1988, are underway.

Kansas Wheat Objective Yield Survey, Eldon J. Thiessen

Conference on Applied Statistics in Agriculture

In response to farmers, millers, and government needs, the USDA began research on objective measurements of wheat yields in 1938. USDA's current objective yield program providing monthly pre-harvest forecasts of wheat production beginning on May 1 now includes 18 states and accounted for 87 percent of the U.S. wheat production in 1988 .

The Wheat Objective Yield Survey is a systematic subsample of the March Agricultural Survey conducted by Kansas Agricultural Statistics as part of the Quarterly Agricultural Survey program of the National Agricultural Statistics Service (NASS). The fields and sample plots within the fields are selected following very carefully …

Model Building To Measure Impact Of Weather On Crop Yields, Arlin M. Feyerherm, Gary M. Paulsen

Conference on Applied Statistics in Agriculture

The object of this research was to identify and evaluate alternatives when building mathematical models to measure the impact of weather on crop yields. Alternatives exist relative to selection of: (1) observational units with attention to size and coverage (areal and temporal), (2) observational periods for defining weather variables, and (3) mathematical forms and types of weather variables to measure impacts of moisture and temperature. The study involved an analysis of four weather-yield functions for winter wheat. The functions represented combinations of levels of two factors: (1) size and coverage of the observational units (plot yields from a multi-state area …

Teaching Statistical Methods To Graduate Students In Colleges Of Agriculture, D. F. Cox

Conference on Applied Statistics in Agriculture

One method of judging the effectiveness of the teaching of statistical methods is to rate the quality of their use in the research journals of the agricultural sciences. A conclusion that improvement is possible is easily supported by such a review. Basic concepts such as the meaning of replication, the definition of an experimental unit and the nature of experimental error are misunderstood, and this leads to faulty analyses and incorrect conclusions. Changes in teaching that would improve the product are not specified easily because research on the topic is difficult. Perhaps more emphasis on the basic concepts of experimental …

Evaluation Of Presentation Graphics For The Agricultural Sciences, Kathy Shelley

Conference on Applied Statistics in Agriculture

Professional-looking text and graphic slides enable an audience to comprehend the main ideas of a presentation more quickly. With the advent of easy-to-use graphic software packages and the affordability of personal computer hardware to run this software, researchers may now prepare their own slides or transparencies. This paper describes basic graphic software design and offers criteria for selection of an appropriate software package for scientific research presentations. Comparisons between two prototype graphics packages, Harvard Graphics and SAS/Graph, are made on the basis of the following selection criteria: (1) basic software design, (2) available hardware, (3) output device drivers, (4) available …

The 2-Sprt As An Alternative To Wald's Sprt When Testing Hypotheses Concerning Insect Populations, Linda J. Young, Jerry H. Young

Conference on Applied Statistics in Agriculture

Exact and Wald's approximations for the operating characteristic and average sample number functions are compared for a sequential probability ratio (SPRT) test commonly used in cotton integrated pest management (IPM) programs in southwestern Oklahoma. The 95th percentile of the sample size is also given. For the same set of hypotheses and stated error probabilities, the exact operating characteristic and average sample number functions and the 95th percentile of sample size are compared for the SPRT and 2-SPRT.

Multiple Regression Analysis Of Soil Properties On Eroded And Native Deep Loess Missouri Soils, S. J. Indorante, J. M. Maatta, R. D. Hammer, J. R. Brown

Conference on Applied Statistics in Agriculture

Researchers have described the difficulty of studying the effects of cultivation on soil properties unless native (uncultivated) areas can be used as a baseline for comparison. Even when suitable areas are located the problems of quantifying and comparing the horizontal and vertical distributions of soil properties remain. Areal distributions of soil surface, subsurface, and upper subsoil properties were compared in cultivated and forested deep loess soils on similar geomorphic surfaces and hillslope positions in two counties adjacent to the Missouri River. A 3-dimensional grid was used to sample selected soils from the summit to the lower backs lope on 3 …

Evaluation Of The Three Plantain (Musa Aab) Cultivars For Agronomic Characteristics, Ahmad R. Rafie, Carlos Medina

Conference on Applied Statistics in Agriculture

Plantains (Musa AAB) are widely used as a source of carbohydrate in Latin America and Africa. The most commonly grown plantain cultivar, "Horn plantain" is tall which makes it susceptible to losses by wind. Recently, two dwarf mutants of "Horn plantain" were selected. A randomized complete block design experiment with four replications was conducted to compare the agronomic characteristics of the dwarf mutants with those of the traditional cultivar. The data was analyzed as if the experiment was strip-plot design with cultivar as the horizontal factor and harvest as the vertical factor. "Analysis of variance" and "Least significant difference" test …

Comparison Of Hop Downy Mildew Epidemics Using Spatial Analysis, J. Richard Alldredge, Dennis A. Johnson, Rochelle Allwine

Conference on Applied Statistics in Agriculture

Methods of spatial analysis including distribution fitting, variance-to-mean ratios, Morisita's index, doublet and runs analyses, Greig-Smith analysis and variography were used to investigate the spatial pattern of hop downy mildew. Use of these methods allowed examination of the spatial structure of hop downy mildew at three spatial scales: within hop hills, between nearby hop hills, and for hop hills more separated in space. The results obtained were in general agreement for methods of analysis which assessed spatial structure at the same spatial scale with the exception of Morisita's index of clumping which did not identify clumps of diseased hills of …