Statistical Models Commons^™

Dysfunctional Attitudes, Life Stress And Coping Processes, Deborah Desalliers

Loma Linda University Electronic Theses, Dissertations & Projects

The findings of recent investigations earmarked chronic daily stressors as being highly related to stress levels. In addition, researchers are promoting a more integrative model of stress. The stress response is no longer thought of in strictly linear terms, i.e. an event causes stress. Rather, cognitive factors, existing within the human mind itself, strongly influence our coping processes and the chronic stress we experience.

Canonical correlation analysis was used to study how dysfunctional attitudes, a negative cognitive factor, were related to individuals' daily hassles and coping processes. An increase in dysfunctional attitudes was found to correspond to an increase in …

Modeling Mass Transport In Aquifers: The Distributed Source Problem, Sergio E. Serrano

KWRRI Research Reports

This report presents a new methodology to model the time and space evolution of groundwater variables in a system of aquifers when certain components of the model, such as the geohydrologic information, the boundary conditions, the magnitude and variability of the sources or physical parameters are uncertain and defined in stochastic terms. This facilitates a more realistic statistical representation of groundwater flow and groundwater pollution forecasting for either the saturated or the unsaturated zone. The method is based on applications of modern mathematics to the solution of the resulting stochastic transport equations. This procedure exhibits considerable advantages over the existing …

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 …

A Simulation Study Of Variable Selection Techniques In Linear Regression For Prediction, Deborah Lane Berrier

MUSC Theses and Dissertations

Linear regression analysis often involves considering a large number of potential variables of which only a subset are actually used in the regression equation. Many techniques for selecting subsets of variables for regression have been proposed and used. The efficiency of such techniques has been studied. However, no comprehensive comparison of the various regression procedures is available. The purpose of this study is to use simulated data to evaluate the predictive ability of the regression models generated by various variable selection techniques. The variable selection techniques considered are all possible regressions criteria (Akaike’s information criterion, Sawa's Bayesian information criterion, Mallows' …

Mathematical Programming Model Of Western Australian Dairy Farms, G R. Olney, D A. Falconer

Animal production and livestock research reports

A profit maximising mathematical programming dairy farm model has been developed which determines the most profitable management strategies for the full year. This model was initially an extension of the one used in the Western Australian Dairy Feed Management Service (DFMS) which determines the most profitable ration to feed for a specific period, the milk yield per cow and the number of cows to milk. The DFMS is useful for formulating a ration for a specific period, particularly during summer on non-irrigated farms in Western Australia when complete hand feeding is required, but it cannot be used to determine optimum …

Improved Methods And Guidelines For Modeling Stormwater Runoff From Surface Coal Mined Lands, Michael E. Meadows, George E. Blandford

KWRRI Research Reports

The investgations, developments and guidelines for several hydrologic modeling strategies are presented. Investigations were conducted to determine appropriate event curve numbers for surface mined disturbed watersheds; and performance of four synthetic unit hydrograph models (SCS curvilinear, SCS single triangle, Williams and TVA double triangle) on 38 USDA experimental watersheds in 14 physiographic provinces using in excess of 270 events. A second test using only the SCS curvilinear unit hydrograph on 11 small watersheds and 48 events was conducted to investigate the excess rainfall pattern simulated with the curve number model. A procedure for developing a unit hydrograph using the time …

Modeling Surface And Subsurface Stormflow On Steeply-Sloping Forested Watersheds, Patrick G. Sloan, Ian D. Moore, George B. Coltharp, Joseph D. Eigel

KWRRI Research Reports

A simple conceptual rainfall-runoff model, based on the variable source area concept, was developed for predicting runoff from small, steep-sloped, forested Appalachian watersheds. Tests of the model showed that the predicted and observed daily discharges were in good agreement. The results demonstrate the ability of the model to simulate the "flashy" hydrologic behavior of these watersheds.

Five subsurface flow models were evaluated by application to existing data measured at Coweeta on a reconstructed homogeneous forest soil. The five models were: Nieber 's 2-D and 1-D finite element models (based on Richards' equation), the kinematic wave equation, and two simple storage …

Multidimensional Graphical Representations By Chernoff-Type Faces In Color: Assigning Data Coordinates To Face Parameters Through Principal Component Analysis, Hendrik Johannes Beaujon

MUSC Theses and Dissertations

A new Chernoff-type face in color has been developed for purposes of representing and analyzing multidimensional data. This cartoon-like but fairly realistic face is defined by 20 parameters, including 4 color parameters. The programming was done in extended BASIC on the Hewlett-Packard 9845C color graphics computer. A method based on the mean pooled variances of parameter values within observed clusters was developed in order to establish an empirical rank order of importance among the face parameters. It was found experimentally that the smile, the outline of the face, and certain eye parameters were among the most important. Using a model …

The Effect Of Post-Hospital Nursing Intervention On Success In Breastfeeding, Melinda Hoskins

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the proportion of women in the experimental group who had a successful breastfeeding experience following post-discharge nursing intervention with the proportion of women in the control group who had a successful breastfeeding experience without nursing intervention. Criteria defining success in breastfeeding were established before the study. Chi-square analysis was used to test for significance with the preset level of significance being α = 0.05. The sample comprised 25 mother-infant dyads with 12 in the experimental group and 13 in the control group. Both groups were similar in type of delivery (spontaneous or …

The Effect Of A Values Clarification Strategy On The Smoking Behavior Of Pregnant Women, Jean Eiber

Loma Linda University Electronic Theses, Dissertations & Projects

The null hypothesis of this study stated that there would be no significant difference (α=.05) in the change in smoking behavior following a teaching intervention to discourage smoking in pregnant women between those who completed a values clarifying strategy prior to the intervention and those who did not. Forty subjects were randomly assigned 20 to an experimental group and 20 to a control group. Both groups completed a pretest questionnaire concerning demographic data and smoking behavior. Information regarding the adverse effects on the fetus and on the developing child of smoking was presented to each subject by the researcher. The …

The Maine Coast, A Statistical Source, Maine Coastal Program

Maine Collection

The Maine Coast, A Statistical Source

Maine Coastal Program, Natural Resource Planning Division, Maine State Planning Office , Augusta, Maine

First Printing June 1978 - Second Printing September 1978

Contents: Preface / Introduction / Chapter 1 - Demography / Chapter 2 - Land Use and Taxation / Chapter 3 - Economy / Chapter 4 - Housing / Chapter 5 - Transportation / Chapter 6 - Education / Chapter 7 - Recreation / Chapter 8 - Social Services / Chapter 9 - Natural Resources / References / Index

Improving On The Contingent Fee, Kevin M. Clermont, John D. Currivan

Cornell Law Faculty Publications

Two basic fees--contingent and hourly--dominate the variety of fees that lawyers charge clients for pursuing damage claims. Each of these two types has its advantages; each is plagued with substantial disadvantages. This Article proposes a new type of fee, one that preserves the respective advantages of the two present fees while minimizing their distinct disadvantages.

In essence, the proposed fee calls for the payment, on a contingent basis, of an amount computed by adding one component tied to hours worked and another component linked to amount recovered. The preferability and feasibility of this proposed fee argue for the abolishment, or …

A Statistical Approach To The Study Of The Ecosystems Of Seven Ponds In East-Central Illinois, Gregory Lee Orr

Masters Theses

Gross primary productivity, heterotrophic bacterial numbers, and net phytoplankton densities of seven ponds in Coles County, Illinois, were studied in relation to physical, chemical, and biological habitat variables (light intensity and duration, turbidity, water temperature, pH, dissolved oxygen, sulfur, nitrogen, phosphorus, production, bacteria, and phytoplankton). Ten observations were made for each pond (except where otherwise noted) from 17 June through 25 August 1974. Stepwise multiple linear regression analyses of the data were used in order to determine those environmental factors which were important in predicting (i.e., significantly correlated with) bacterial and phytoplankton densities, and production. A multiple linear regression equation …

Multiregional Interactions Between Energy And Transportation, Karen R. Polenske

Applications

Because of the number and complexity of the issues that will determine the use of coal by the electric-generating plants, an important asset of policy makers will be the availability of a method of analysis that allows for quick studies of many different combinations of assumptions and policies. The present prototype study is designed to show how the multiregional input-output model can be used to investigate each different assumption and policy alternative. For this paper, the analysis has necessarily been restricted to two issues. First, the results of using regional rather than national technologies in the model are assessed. This …

Some Aspects Of Ties In Wilcoxon Signed Ranks, Kathleen M. Keenan

Journal of the Minnesota Academy of Science

Assuming basic principles of statistical inference, the signed rank and rank sum hypothesis testing procedures of Wilcoxon ore reviewed briefly and illustrated. Some recent literature of interest is cited. The problem of ranking tied data is considered, and the effect of ties on the distribution of the signed rank statistic is examined.

Opset Program For Computerized Selection Of Watershed Parameter Values For The Stanford Watershed Model, Earnest Yuan-Shang Liou, L. Douglas James

KWRRI Research Reports

The advent of high-speed electronic computer made it possible to model complex hydrologic processes by mathematical expressions and thereby simulate streamflows from climatological data. The most widely used program is the Stanford Watershed Model, a digital parametric model of the land phase of the hydrologic cycle based on moisture accounting processes. It can be used to simulate annual or longer flow sequences at hourly time intervals. Due to its capability of simulating historical streamflows from recorded climatological data, it has a great potential in the planning and design of water resources systems. However, widespread use of the Stanford Watershed Model …

A Cephalometric Study Of The Face And Dentition Of Several Contemporary Western United States And Alaskan Eskimo Groups, Robert C. Parkard

Loma Linda University Electronic Theses, Dissertations & Projects

A total of 223 cephalometric radiographs selected from six contemporary western United States and Alaskans native groups were analyzed by use of the Bjork cephalometric analysis. Those native groups selected were the Eskimos, Apaches, Navajos, Papagos, Pimas and Mayos. Approximately thirty to forty natives from each group were used in the study with ages ranging from thirteen to thirty-five years. The majority were in the fifteen to twenty year age range.

All data was submitted to various statistical analyses to establish a mean, standard deviation, and other relevant values for each of the native groups and to compare these values …

Simulation Of Mathematical Models In Genetic Analysis, Dinesh Govindal Patel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years a new field of statistics has become of importance in many branches of experimental science. This is the Monte Carlo Method, so called because it is based on simulation of stochastic processes. By stochastic process, it is meant some possible physical process in the real world that has some random or stochastic element in its structure. This is the subject which may appropriately be called the dynamic part of statistics or the statistics of "change," in contrast with the static statistical problems which have so far been the more systematically studied. Many obvious examples of such processes …