Statistics and Probability Commons^™

Critical Values For The Two Independent Samples Winsorized T Test, Piper Alycee Farrell-Singleton

Wayne State University Dissertations

ABSTRACT

CRITICAL VALUES FOR THE TWO INDEPENDENT SAMPLES WINSORIZED T TEST

by

PIPER A. FARRELL-SINGLETON

AUGUST 2010

Advisor: Dr. Shlomo Sawilowsky

Major: (Education, Evaluation and Research)

Degree: Doctor of Philosophy

Through Monte Carlo Simulation, this study explores the approximate behavior of the two sample winsorized t test. Samples are drawn from the normal population and symetrically winsorized up to 20%. The two independent samples winsorized t test is then calculated on each sample using Monte Carlo methods using 1,000,000 iterations. The t values are then sorted from low to high and the critical values for both one and two tailed …

Bayesian Nonparametric Regression With A Flexible Error Term Distribution, Courtney Marie Barnes

Open Access Theses & Dissertations

Datasets often exhibit heavy tailed behavior and standard analyses are often heavily influenced by outliers. We propose a nonparametric regression model whose error term distribution is a mixture of a normal and a Student t distribution. This results in a model that is more resistant to outliers compared to a model with a normal error term.

Symmetry Of Nonparametric Statistical Tests On Three Samples, Anna E. Bargagliotti, Donald G. Saari

Mathematics, Statistics and Data Science Faculty Works

Problem statement: Many different nonparametric statistical procedures can be used to analyze ranked data. Inconsistencies among the outcomes of such procedures can occur when analyzing the same ranked data set. Understanding why these peculiarities can occur is imperative to providing an accurate analysis of the ranking data. In this context, this study addressed why inconsistent outcomes can occur and which types of data structures cause the different procedures to yield different outcomes. Approach: Appropriate properties were identified and developed to explain why different methods can define different rankings of three samples with the same data. The approach identifies certain symmetry …

Anomalous Diffusion In Trading Models., Sidiq Mohamad Khidzir

Student Works (2010-2019)

Econophysics is an interdisciplinary research field applying the mathematical methods of statistical physics to economics and finance. It emphasizes quantitative analysis of large amounts of economic and financial data as oppose to the more philosophical approach of political economics. A popular topic studied in econophysics is the distribution of wealth.Many models have been proposed to explain the trading dynamics [12,13] leading to the distribution of wealth universally observed in many countries. A more recent topic in econophysics is the movement of money studied by Brockmann in [19,20]. In this work, we are interested in studying the relation between the distribution …

Investigating An Optimal Decision Point For Probability Bounds Analysis Models When Used To Estimate Remedial Soil Volumes Under Uncertainty At Hazardous Waste Sites, Charles O. Dankwah

Walden Dissertations and Doctoral Studies

Hazardous waste site remediation cost estimation requires a good estimate of the contaminated soil volume. The United States Environmental Protection Agency (U.S. EPA) currently uses deterministic point values to estimate soil volumes but the literature suggests that probability bounds analysis (PBA) is the more accurate method to make estimates under uncertainty. The underlying statistical theory is that they are more accurate than deterministic estimates because probabilistic estimates account for data uncertainties. However, the literature does not address the problem of selecting an optimal decision point from the interval-valued PBA estimates. The purpose of this study was to identify the optimal …

Troubleshooting With Surveys, Sandra Pereira

ECU Research Week

This presentation discusses ways to identify and avoid the problems commonly encountered in draft surveys.

A Markov Transition Model To Dementia With Death As A Competing Event, Liou Xu

University of Kentucky Doctoral Dissertations

The research on multi-state Markov transition model is motivated by the nature of the longitudinal data from the Nun Study (Snowdon, 1997), and similar information on the BRAiNS cohort (Salazar, 2004). Our goal is to develop a flexible methodology for handling the categorical longitudinal responses and competing risks time-to-event that characterizes the features of the data for research on dementia. To do so, we treat the survival from death as a continuous variable rather than defining death as a competing absorbing state to dementia. We assume that within each subject the survival component and the Markov process are linked by …

Canonical Correlation Analysis For Longitudinal Data, Raymond Mccollum

Mathematics & Statistics Theses & Dissertations

Data (multivariate data) on two sets of vectors commonly occur in applications. Statistical analysis of these data is usually done using a canonical correlation analysis (CCA). Occurrence of these data at multiple occasions or conditions leads to longitudinal multivariate data for a CCA. We address the problem of canonical correlation analysis on longitudinal data when the data have a Kronecker product covariance structure. Using structured correlation matrices we model the dependency of repeatedly observed data. Recent work of Srivastava, Nahtman, and von Rosen (2008) developed an iterative algorithm to determine the maximum likelihood estimate of the Kronecker product covariance structure …

Comparison Of Two Samples By A Nonparametric Likelihood-Ratio Test, William H. Barton

University of Kentucky Doctoral Dissertations

In this dissertation we present a novel computational method, as well as its software implementation, to compare two samples by a nonparametric likelihood-ratio test. The basis of the comparison is a mean-type hypothesis. The software is written in the R-language [4]. The two samples are assumed to be independent. Their distributions, which are assumed to be unknown, may be discrete or continuous. The samples may be uncensored, right-censored, left-censored, or doubly-censored. Two software programs are offered. The first program covers the case of a single mean-type hypothesis. The second program covers the case of multiple mean-type hypotheses. For the first …

Inadequate Health Numeracy Affects Cancer Screening Practices In Vulnerable Populations, Sherrine Eid Mph, Dorothy Faulkner Phd

Administration & Leadership

No abstract provided.