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open access

Comparisons of Improvement-Over-Chance Effect Sizes for Two Groups Under Variance Heterogeneity and Prior Probabilities

Description: The distributional properties of improvement-over-chance, I, effect sizes derived from linear and quadratic predictive discriminant analysis (PDA) and from logistic regression analysis (LRA) for the two-group univariate classification were examined. Data were generated under varying levels of four data conditions: population separation, variance pattern, sample size, and prior probabilities. None of the indices provided acceptable estimates of effect for all the conditions examined. There were … more
Date: May 2003
Creator: Alexander, Erika D.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Comparison of Heterogeneity and Heterogeneity Interval Estimators in Random-Effects Meta-Analysis

Description: Meta-analyses are conducted to synthesize the quantitative results of related studies. The random-effects meta-analysis model is based on the assumption that a distribution of true effects exists in the population. This distribution is often assumed to be normal with a mean and variance. The population variance, also called heterogeneity, can be estimated numerous ways. Accurate estimation of heterogeneity is necessary as a description of the distribution and for determining weights applied in … more
Date: May 2018
Creator: Boedeker, Peter
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Modeling and Simulation of the Vector-Borne Dengue Disease and the Effects of Regional Variation of Temperature in the Disease Prevalence in Homogenous and Heterogeneous Human Populations

Description: The history of mitigation programs to contain vector-borne diseases is a story of successes and failures. Due to the complex interplay among multiple factors that determine disease dynamics, the general principles for timely and specific intervention for incidence reduction or eradication of life-threatening diseases has yet to be determined. This research discusses computational methods developed to assist in the understanding of complex relationships affecting vector-borne disease dynamics. A… more
Date: August 2016
Creator: Bravo-Salgado, Angel D
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Social Network Simulation and Mining Social Media to Advance Epidemiology

Description: Traditional Public Health decision-support can benefit from the Web and social media revolution. This dissertation presents approaches to mining social media benefiting public health epidemiology. Through discovery and analysis of trends in Influenza related blogs, a correlation to Centers for Disease Control and Prevention (CDC) influenza-like-illness patient reporting at sentinel health-care providers is verified. A second approach considers personal beliefs of vaccination in social media. A … more
Date: August 2009
Creator: Corley, Courtney David
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Using a Slopes Difference Test to Probe Longitudinal Multilevel Interactions in an Aptitude-Treatment or Skill-by-Treatment Context: A Simulation

Description: In order to determine which interventions work best for which students, precision education researchers have examined aptitude-treatment interactions (ATI) or skill-by-treatment interactions (STI) by using multiple regression analysis. In recent years, technological innovation and greater accessibility to more advanced statistical techniques have allowed researchers to examine ATI or STI using longitudinal mixed modeling. Probing techniques for interaction effects like slopes difference tests f… more
Date: August 2021
Creator: DeJong, Trey L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Factor Retention Strategies with Ordinal Variables in Exploratory Factor Analysis: A Simulation

Description: Previous research has individually assessed parallel analysis and minimum average partial for factor retention in exploratory factor analysis using ordinal variables. The current study is a comprehensive simulation study including the manipulation of eight conditions (type of correlation matrix, sample size, number of variables per factor, number of factors, factor correlation, skewness, factor loadings, and number of response categories), and three types of retention methods (minimum average p… more
Date: August 2020
Creator: Fagan, Marcus A.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

FACET Simulation in the Imataca Forest Reserve, Venezuela: Permanent Plot Data and Spatial Analysis

Description: Tree diameter data from 29 years of observations in six permanent plots was used to calculate the growth rate parameter of the FACET gap model for 39 species in the Imataca forests in Venezuela. The compound topographic index was used as a measure of differential soil water conditions and was calculated using geographic information systems. Growth rate values and topographic conditions typical of hill and valley were input to FACET to simulate dynamics at the species level and by ecological and… more
Date: May 2006
Creator: Figuera, Dilcia
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Methodological Issues in Malingering Research: The Use of Simulation Designs

Description: The accurate determination of malingering relies on the use of validated and clinically relevant assessment measures. Simulation design is the most often-used research design to accomplish this. However, its external validity is sometimes questioned. The goal of the thesis was to systematically evaluate these major elements: situation, incentives, and coaching. The situation in simulation studies can vary from relevant (academic failure in a college population) to irrelevant (capital murder) fo… more
Date: December 2010
Creator: Gillard, Nathan D.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Supply Chain Network Evolution: Demand-based Drivers of Interfirm Governance Evolution

Description: Which form of exchange governance performs better in a dynamic environment? This remains an unanswered question in the transaction cost analysis (TCA) and relational exchange literatures. Some researchers purport that transactional governance provides superior performance by providing firms the flexibility to change suppliers. Others suggest that relational governance leads to superior performance because of the willingness of both parties to adapt. Reviews of TCA have turned up ambivalent empi… more
Date: August 2007
Creator: Gravier, Michael J.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

An Empirical Evaluation of Communication and Coordination Effectiveness in Autonomous Reactive Multiagent Systems

Description: This thesis describes experiments designed to measure the effect of collaborative communication on task performance of a multiagent system. A discrete event simulation was developed to model a multi-agent system completing a task to find and collect food resources, with the ability to substitute various communication and coordination methods. Experiments were conducted to find the effects of the various communication methods on completion of the task to find and harvest the food resources. R… more
Date: May 2005
Creator: Hurt, David
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

A Global Stochastic Modeling Framework to Simulate and Visualize Epidemics

Description: Epidemics have caused major human and monetary losses through the course of human civilization. It is very important that epidemiologists and public health personnel are prepared to handle an impending infectious disease outbreak. the ever-changing demographics, evolving infrastructural resources of geographic regions, emerging and re-emerging diseases, compel the use of simulation to predict disease dynamics. By the means of simulation, public health personnel and epidemiologists can predict t… more
Date: May 2012
Creator: Indrakanti, Saratchandra
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
captions transcript

[News Clip: Video trivia]

Description: Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: November 15, 1984, 6:00 p.m.
Duration: 1 minute 37 seconds
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Item Type: Refine your search to only Video
Partner: UNT Libraries Special Collections
open access

Reporting the Performance of Confidence Intervals in Statistical Simulation Studies: A Systematic Literature Review

Description: Researchers and publishing guidelines recommend reporting confidence intervals (CIs) not just along with null hypothesis significance testing (NHST), but for many other statistics such as effect sizes and reliability coefficients. Although CI and standard errors (SEs) are closely related, examining standard errors alone in simulation studies is not adequate because we do not always know if a standard error is small enough. Overly small SEs may lead to increased probability of Type-I error and C… more
Date: August 2019
Creator: Kabakci, Maside
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Bias and Precision of the Squared Canonical Correlation Coefficient under Nonnormal Data Conditions

Description: This dissertation: (a) investigated the degree to which the squared canonical correlation coefficient is biased in multivariate nonnormal distributions and (b) identified formulae that adjust the squared canonical correlation coefficient (Rc2) such that it most closely approximates the true population effect under normal and nonnormal data conditions. Five conditions were manipulated in a fully-crossed design to determine the degree of bias associated with Rc2: distribution shape, variable sets… more
Date: August 2006
Creator: Leach, Lesley Ann Freeny
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

First Principle Calculations of the Structure and Electronic Properties of Pentacene Based Organic and ZnO Based Inorganic Semiconducting Materials

Description: In this thesis, I utilize first principles density functional theory (DFT) based calculations to investigate the structure and electronic properties including charge transfer behaviors and work function of two types of materials: pentacene based organic semiconductors and ZnO transparent conducting oxides, with an aim to search for high mobility n-type organic semiconductors and fine tuning work functions of ZnO through surface modifications. Based on DFT calculations of numerous structure comb… more
Date: May 2012
Creator: Li, Yun
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Comparing Raw Score Difference, Multilevel Modeling, and Structural Equation Modeling Methods for Estimating Discrepancy in Dyads

Description: The current study focused on dyadic discrepancy, the difference between two individuals. A Monte Carlo simulation was used to compare three dyadic discrepancy estimation methods across a variety of potential research conditions, including variations on intraclass correlation, cluster number, reliability, effect size, and effect size variance. The methods compared were: raw score difference (RSD); empirical Bayes estimate of slope in multilevel modeling (EBD); and structural equation modeling es… more
Date: May 2020
Creator: McEnturff, Amber L
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Fossil-Energy Program. Quarterly Progress Report for June 30, 1983

Description: This quarterly report covers the progress made during the period March 31 through June 30 for the Oak Ridge National Laboratory research and development projects that are carried out in support of the increased utilization of coal and other fossil fuels as sources of clean energy. These projects are supported by various parts of DOE including Fossil Energy, Basic Energy Sciences, Office of Health and Environmental Research, Office of Environmental Compliance and Overview, the Electric Power Res… more
Date: August 1, 1983
Creator: McNeese, L. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Anchor Nodes Placement for Effective Passive Localization

Description: Wireless sensor networks are composed of sensor nodes, which can monitor an environment and observe events of interest. These networks are applied in various fields including but not limited to environmental, industrial and habitat monitoring. In many applications, the exact location of the sensor nodes is unknown after deployment. Localization is a process used to find sensor node's positional coordinates, which is vital information. The localization is generally assisted by anchor nodes that … more
Date: August 2010
Creator: Pasupathy, Karthikeyan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Regional Economic Impact of Texas Motor Speedway: A Simulation

Description: This study proposes a method for measuring the regional economic impact of a relatively new sport: stock car racing. Although research on the economic impact of most major league sports is abundant, little has been written on stock car racing. The purpose of this paper is to estimate, through a simulation, the regional economic impact of Texas Motor Speedway. The study finds that the Texas Motor Speedway boosted economic activity by $87,179,367 in 1998 from racetrack operations, and supported … more
Date: August 2000
Creator: Rattner, Laura E.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Molecular Dynamics Simulations of the Structures and Properties of Aluminosilicate and Borosilicate Glasses

Description: Silicate glasses are the most common glass types and have impact on almost every aspect in our lives: from window, containers, to glass fibers for telecommunications. Unlike their crystalline counterparts, glass materials lack long-range order in their atomic arrangement but their structures do possess short and medium range characteristics that play critical roles in their physical and chemical properties. Despite active development of characterization techniques that have contributed to the u… more
Date: December 2018
Creator: Ren, Mengguo
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Reactions and Interfacial Behaviors of the Water–Amorphous Silica System from Classical and Ab Initio Molecular Dynamics Simulations

Description: Due to the wide application of silica based systems ranging from microelectronics to nuclear waste disposal, detailed knowledge of water-silica interactions plays an important role in understanding fundamental processes, such as glass corrosion and the long term reliability of devices. In this dissertation, atomistic computer simulation methods have been used to explore and identify the mechanisms of water-silica reactions and the detailed processes that control the properties of the water-sili… more
Date: May 2016
Creator: Rimsza, Jessica M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Ability of Offenders with Psychopathic Traits to Simulate Cognitive and Affective Empathy

Description: The accurate assessment of psychopathy constitutes a critical component of forensic assessments addressing offender populations. Among the core characteristics of psychopathy, the interpersonal component of deception and empathic deficits are prominently observed in offenders with psychopathic traits. Given the negative consequences of being classified as a psychopath, offenders may be likely to minimize their psychopathic traits. In particular, no research has investigated whether offenders… more
Date: August 2013
Creator: Robinson, Emily V.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Simulation of local watershed nutrient and sediment delivery to Lake Texoma.

Description: A hydrologic model and watershed export model was used to estimate the loading of nutrients and total suspended solids from un-gaged local watersheds associated with Lake Texoma. Discharge to the reservoir from local watersheds was predicted using a modification of the curve number method in HEC Hydrologic Modeling System (HEC-HMS). Event mean concentrations were applied to land use to estimate loadings of nutrients and TSS. Total discharge from the local watersheds was estimated to be 3.02 x 1… more
Date: May 2004
Creator: Upton, Alexandra C.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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