403 Matching Results

Results open in a new window/tab.

Ability Estimation Under Different Item Parameterization and Scoring Models (open access)

Ability Estimation Under Different Item Parameterization and Scoring Models

A Monte Carlo simulation study investigated the effect of scoring format, item parameterization, threshold configuration, and prior ability distribution on the accuracy of ability estimation given various IRT models. Item response data on 30 items from 1,000 examinees was simulated using known item parameters and ability estimates. The item response data sets were submitted to seven dichotomous or polytomous IRT models with different item parameterization to estimate examinee ability. The accuracy of the ability estimation for a given IRT model was assessed by the recovery rate and the root mean square errors. The results indicated that polytomous models produced more accurate ability estimates than the dichotomous models, under all combinations of research conditions, as indicated by higher recovery rates and lower root mean square errors. For the item parameterization models, the one-parameter model out-performed the two-parameter and three-parameter models under all research conditions. Among the polytomous models, the partial credit model had more accurate ability estimation than the other three polytomous models. The nominal categories model performed better than the general partial credit model and the multiple-choice model with the multiple-choice model the least accurate. The results further indicated that certain prior ability distributions had an effect on the accuracy …
Date: May 2002
Creator: Si, Ching-Fung B.
System: The UNT Digital Library
Abstract Moments of Art Found in the Ordinary (open access)

Abstract Moments of Art Found in the Ordinary

This paper is an experiment using digital video to locate and identify the abstract in everyday life and nature. The abstract moment occurs when the image that is captured by video loses its connection with the original context, allowing the images to be viewed in an entirely new way. The abstract moment is initiated by a transformative instant, that instant in which perception is altered and the viewer sees the intended content of composition of light and sound. The project contains four digital videos that record the artist's progress and interests.
Date: December 2002
Creator: Kraft, Stuart
System: The UNT Digital Library
Adolescent Psychopathy in an Adjudicated Male Population: The Role of Sensation Seeking, Impulsivity, and Externalizing Disorders (open access)

Adolescent Psychopathy in an Adjudicated Male Population: The Role of Sensation Seeking, Impulsivity, and Externalizing Disorders

Psychopathy, as conceptualized by Cleckley (1941), describes a constellation of psychological and behavioral correlates including superficial charm, untruthfulness, lack of remorse or shame, poor judgment, and failure to learn from experience. Based on Cleckley's initial work, Hare (1991) developed a two-factor model of psychopathy. The purpose of this study was to investigate the roles that sensation seeking, impulsivity, ADHD, conduct disorder, and oppositional defiant disorder have on adolescents classified as psychopaths. The participants consisted of 79 adjudicated male adolescents in a maximum-security facility. As hypothesized, adolescent male psychopaths had higher levels of sensation seeking, impulsivity, conduct disorder and oppositional defiant disorder. A discriminant function analysis found that sensation seeking, impulsivity, ADHD, Conduct Disorder, and Oppositional Defiant Disorder was moderately useful in classifying adolescent psychopathy. The results suggest that behavioral dysregulation is an important aspect of adolescent psychopathy. The relationship of these data to theories of adolescent psychopathy is discussed.
Date: August 2002
Creator: Vitacco, Michael J.
System: The UNT Digital Library
Advanced pulse-shape analysis and implementation of gamma-ray tracking in a position-sensitive coaxial HPGe detector (open access)

Advanced pulse-shape analysis and implementation of gamma-ray tracking in a position-sensitive coaxial HPGe detector

None
Date: November 12, 2002
Creator: Kuhn, Austin L.
System: The UNT Digital Library
Aerosol Property Comparison Within and Above the ABL at the ARM Program SGP Site (open access)

Aerosol Property Comparison Within and Above the ABL at the ARM Program SGP Site

This thesis determines what, if any, measurements of aerosol properties made at the Earth surface are representative of those within the entire air column. Data from the Atmospheric Radiation Measurement site at the Southern Great Plains, the only location in the world where ground-based and in situ airborne measurements are routinely made. Flight legs during the one-year period from March 2000 were categorized as either within or above the atmospheric boundary layer (ABL) by use of an objective mixing height determination technique. Correlations between aerosol properties measured at the surface and those within and above the ABL were computed. Aerosol extensive and intensive properties measured at the surface were found representative of values within the ABL, but not of within the free atmosphere.
Date: May 1, 2002
Creator: Delle Monache, L
System: The UNT Digital Library
Air Pollutant Penetration Through Airflow Leaks Into Buildings (open access)

Air Pollutant Penetration Through Airflow Leaks Into Buildings

The penetration of ambient air pollutants into the indoor environment is of concern owing to several factors: (1) epidemiological studies have shown a strong association between ambient fine particulate pollution and elevated risk of human mortality; (2) people spend most of their time in indoor environments; and (3) most information about air pollutant concentration is only available from ambient routine monitoring networks. A good understanding of ambient air pollutant transport from source to receptor requires knowledge about pollutant penetration across building envelopes. Therefore, it is essential to gain insight into particle penetration in infiltrating air and the factors that affect it in order to assess human exposure more accurately, and to further prevent adverse human health effects from ambient particulate pollution. In this dissertation, the understanding of air pollutant infiltration across leaks in the building envelope was advanced by performing modeling predictions as well as experimental investigations. The modeling analyses quantified the extent of airborne particle and reactive gas (e.g., ozone) penetration through building cracks and wall cavities using engineering analysis that incorporates existing information on building leakage characteristics, knowledge of pollutant transport processes, as well as pollutant-surface interactions. Particle penetration is primarily governed by particle diameter and by the …
Date: September 1, 2002
Creator: Liu, De-Ling
System: The UNT Digital Library
Alcohol and Other Drugs: Attitudes and Use Among Graduate/Professional Students at a Health Science Center (open access)

Alcohol and Other Drugs: Attitudes and Use Among Graduate/Professional Students at a Health Science Center

Alcohol and other drug use continue to be a major issue on college and university campuses. Few studies have examined alcohol and other drug related issues for a graduate or professional student population. This study examines attitudes, incidents, and consequences of alcohol and other drug use among students enrolled at an academic heath science center. This study incorporated a descriptive research design and utilized the CORE Alcohol and Drug Survey for the collection of data. The data were then analyzed using descriptive statistics and represented in tables as frequencies and percentages. The survey was mailed to all students enrolled in didactic course work at the University of North Texas Health Science Center (UNTHSC) during the fall 2001 semester. This included master's students in physician assistant studies, master's and doctoral students in the biomedical sciences, master's and doctoral students in public health, as well as first and second year medical students. Of the 565 students enrolled in didactic course work, 321 responded to the survey for a return rate of 56.8 %. Statistically significant findings are reported for students at UNTHSC in relation to perceptions of use, actual use, reasons for use, and consequences for use. Similar findings are shown relative …
Date: August 2002
Creator: Moorman, Mark Thomas
System: The UNT Digital Library
Analysis of Gd5(Si2Ge2) Microstructure and Phase Transition (open access)

Analysis of Gd5(Si2Ge2) Microstructure and Phase Transition

With the recent discovery of the giant magnetocaloric effect and the beginning of extensive research on the properties of Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, a necessity has developed for a better understanding of the microstructure and crystal structure of this family of rare earth compounds with startling phenomenological properties. The aim of this research is to characterize the microstructure of the Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, with X {approx_equal} 2 and its phase change by using both transmission and electron microscopes. A brief history of past work on Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} is necessary to understand this research in its proper context.
Date: June 27, 2002
Creator: Meyers, John Scott
System: The UNT Digital Library
An Analysis of Periodic Rhythmic Structures in the Music of Steve Reich and György Ligeti (open access)

An Analysis of Periodic Rhythmic Structures in the Music of Steve Reich and György Ligeti

The compositions of Steve Reich and György Ligeti both contain periodic rhythmic structures. Although periods are not usually easily perceived, the listener may perceive their combinations in a hierarchy of rhythmic structures. This document is an attempt to develop an analytical method that can account for this hierarchy in periodic music. I begin with an overview of the features of Reich's and Ligeti's music that contribute to the property of periodicity. I follow with a discussion of the music and writings of Olivier Messiaen as a precedent for the periodic structures in the music of Reich and Ligeti. I continue by consulting the writings of the Israeli musicologist Simha Arom and describing the usefulness of his ideas and terminology in the development of my method. I explain the working process and terminology of the analytical method, and then I apply it to Reich's Six Pianos and Ligeti's Désordre.
Date: August 2002
Creator: Isgitt, David
System: The UNT Digital Library
Analysis Of Sequential Barycenter Random Probability Measures via Discrete Constructions (open access)

Analysis Of Sequential Barycenter Random Probability Measures via Discrete Constructions

Hill and Monticino (1998) introduced a constructive method for generating random probability measures with a prescribed mean or distribution on the mean. The method involves sequentially generating an array of barycenters that uniquely defines a probability measure. This work analyzes statistical properties of the measures generated by sequential barycenter array constructions. Specifically, this work addresses how changing the base measures of the construction affects the statististics of measures generated by the SBA construction. A relationship between statistics associated with a finite level version of the SBA construction and the full construction is developed. Monte Carlo statistical experiments are used to simulate the effect changing base measures has on the statistics associated with the finite level construction.
Date: December 2002
Creator: Valdes, LeRoy I.
System: The UNT Digital Library
An Analysis of the Effectiveness of Computer Assisted Instruction in General Chemistry at an Urban University. (open access)

An Analysis of the Effectiveness of Computer Assisted Instruction in General Chemistry at an Urban University.

The science-major General Chemistry sequence offered at the University of Houston has been investigated with respect to the effectiveness of recent incorporation of various levels of computer technology. As part of this investigation, questionnaire responses, student evaluations and grade averages and distributions from up to the last ten years have been analyzed and compared. Increased use of web-based material is both popular and effective, particularly with respect to providing extra information and supplemental questions. Instructor contact via e-mail is also well-received. Both uses of technology should be encouraged. In contrast, electronic classroom presentation is less popular. While initial use may lead to improved grades and retention, these levels decrease quickly, possibly due to a reduction in instructor spontaneity.
Date: May 2002
Creator: McGuffey, Angela
System: The UNT Digital Library
And Drops of Rain Fall Like Tears: A Composition for Electroacoustic Music and Video (open access)

And Drops of Rain Fall Like Tears: A Composition for Electroacoustic Music and Video

And Drops of Rain Fall Like Tears is a composition for electroacoustic music with an optional ambient video component. The composition consists of a single movement electroacoustic work twenty-two minutes in duration. The piece creates an immersive sonic environment within the confines of a typical concert space, thereby recreating the powerful temper and subtle beauty of nature from different sonic perspectives. The paper is divided into four chapters, each discussing an element of the piece in detail. The introduction presents background information and compositional approach for the composition. Chapters 1 through 4 present detailed information related to the creation of both the electroacoustic music and video elements of the piece. Chapter 4 contains relevant information to the performance of the piece.
Date: May 2002
Creator: Thompson, Michael Allen
System: The UNT Digital Library
An Annotated Bibliography of Mobile Agents in Networks (open access)

An Annotated Bibliography of Mobile Agents in Networks

The purpose of this thesis is to present a comprehensive colligation of applications of mobile agents in networks, and provide a baseline association of these systems. This work has been motivated by the fact that mobile agent systems have been deemed proficuous alternatives in system applications. Several mobile agent systems have been developed to provide scalable and cogent solutions in network-centric applications. This thesis examines some existing mobile agent systems in core networking areas, in particular, those of network and resource management, routing, and the provision of fault tolerance and security. The inherent features of these systems are discussed with respect to their specific functionalities. The applicability and efficacy of mobile agents are further considered in the specific areas mentioned above. Although an initial foray into a collation of this nature, the goal of this annotated bibliography is to provide a generic referential view of mobile agent systems in network applications.
Date: December 2002
Creator: Sriraman, Sandhya
System: The UNT Digital Library
Anything Like Us (open access)

Anything Like Us

Anything Like Us is a collection of poems with a critical introduction. In this introduction, I explore modern alternatives to Romantic and Neo-Romantic lyric expression. I conclude that a contemporary lyric that desires to be, in some fashion, about itself, must exhibit an acceptance of the mediating influences of time and language, while cultivating an inter-subjective point-of-view that does not insist too much on the authority of a single, coherent voice. The poems in Anything Like Us reflect, in both form and content, many of the conclusions advanced in the introduction. Nearly all the poems concern the desire for, and failure to find, meaningful connections in an uncertain world .
Date: August 2002
Creator: Roth, Matthew
System: The UNT Digital Library
Application of the Finite Element Method to Some Simple Systems in One and Two Dimensions. (open access)

Application of the Finite Element Method to Some Simple Systems in One and Two Dimensions.

The finite element method (FEM) is reviewed and applied to the one-dimensional eigensystems of the isotropic harmonic oscillator, finite well, infinite well and radial hydrogen atom, and the two-dimensional eigensystems of the isotropic harmonic oscillator and the propagational modes of sound in a rectangular cavity. Computer codes that I developed were introduced and utilized to find accurate results for the FEM eigensolutions. One of the computer codes was modified and applied to the one-dimensional unbound quantum mechanical system of a square barrier potential and also provided accurate results.
Date: May 2002
Creator: Hunnell, Jason C.
System: The UNT Digital Library

Application of Thermomechanical Characterization Techniques to Bismuth Telluride Based Thermoelectric Materials

Access: Use of this item is restricted to the UNT Community
The thermoelectric properties of bismuth telluride based thermoelectric (TE) materials are well-characterized, but comparatively little has been published on the thermomechanical properties. In this paper, dynamic mechanical analysis (DMA) and differential scanning calorimetry data for bismuth telluride based TE materials is presented. The TE materials' tan delta values, indicative of viscoelastic energy dissipation modes, approached that of glassy or crystalline polymers, were greater than ten times the tan delta of structural metals, and reflected the anisotropic nature of TE materials. DMA thermal scans showed changes in mechanical properties versus temperature with clear hysteresis effects. These results showed that the application of DMA techniques are useful for evaluation of thermophysical and thermomechanical properties of these TE materials.
Date: August 2002
Creator: White, John B.
System: The UNT Digital Library

Approach to Quantum Information starting from Bell's Inequality (Part I) and Statistical Analysis of Time Series Corresponding to Complex Processes (Part II)

Access: Use of this item is restricted to the UNT Community
I: Quantum information obeys laws that subtly extend those governing classical information, making possible novel effect such as cryptography and quantum computation. Quantum computations are extremely sensitive to disruption by interaction of the computer with its environment, but this problem can be overcome by recently developed quantum versions of classical error-correcting codes and fault-tolerant circuits. Based on these ideas, the purpose of this paper is to provide an approach to quantum information by analyzing and demonstrating Bell's inequality and by discussing the problems related to decoherence and error-correcting. II: The growing need for a better understanding of complex processes has stimulated the development of new and more advanced data analysis techniques. The purpose of this research was to investigate some of the already existing techniques (Hurst's rescaled range and relative dispersion analysis), to develop a software able to process time series with these techniques, and to get familiar with the theory of diffusion processes.
Date: May 2002
Creator: Failla, Roberto
System: The UNT Digital Library
Approaches to Nature Aesthetics: East Meets West (open access)

Approaches to Nature Aesthetics: East Meets West

Nature aesthetics is examined as an approach to environmental ethics. The characteristics of proper nature appreciation show that every landscape can be appreciated impartially in light of the dynamic processes of nature. However, it is often claimed that natural beauty decreases if humans interfere into nature. This claim leads to the separation of human culture and nature, and limits the number of landscapes which can be protected in terms of aesthetic value. As a solution to this separation, a non-dualistic Japanese aesthetics is examined as a basis for the achievement of the coexistence of culture and nature. Ecological interrelationships between human culture and nature are possible by means of an aesthetic consciousness in terms of non-hierarchical attitudes.
Date: December 2002
Creator: Toyoda, Mitsuyo
System: The UNT Digital Library

Are the Needs of North Dakota's Aging Population with Developmental Disabilities Being Overlooked?

Access: Use of this item is restricted to the UNT Community
North Dakota is faced with the challenge of meeting the needs of its growing population of elderly persons aging with a developmental disability. The challenge of creating new service models presents itself to professionals in the fields of Aging and Developmental Disabilities. Traditionally, the aging person with a developmental disability has been sent to nursing homes or grouped into community programs with younger persons with developmental disability. North Dakota is looking toward the future of caring for this special population through integration with elderly without disabilities.
Date: May 2002
Creator: Clark, Amy Klein
System: The UNT Digital Library
Arrival Survival and Adaptation: The Quest for Gender Identity Among Female Mexican Immigrants (open access)

Arrival Survival and Adaptation: The Quest for Gender Identity Among Female Mexican Immigrants

Honors thesis written by a student in the UNT Honors College discussing anthropological issues for female anthropologists of color while researching the lives of several Latinas in Denton, Texas.
Date: Spring 2002
Creator: Vega, Sujey
System: The UNT Digital Library
Assessing the Effect of Inquiry-Based Professional Development on Science Achievement Tests Scores. (open access)

Assessing the Effect of Inquiry-Based Professional Development on Science Achievement Tests Scores.

This study analyzed student test scores to determine if teacher participation in an inquiry-based professional development was able to make a statistically significant difference in student achievement levels. Test scores for objectives that assessed the critical thinking skills and problem-solving strategies modeled in a science inquiry institute were studied. Inquiry-based experiences are the cornerstones for meeting the science standards for scientific literacy. State mandated assessment tests measure the levels of student achievement and are reported as meeting minimum expectations or showing mastery for specific learning objectives. Students test scores from the Texas Assessment of Academic Skills Test (TAAS) for 8th grade science and the Biology End Of Course (EOC) exams were analyzed using ANCOVA, Chi Square, and Logistic Regression, with the Iowa Test of Basic Skills (ITBS) 7th Grade Science Subtest as covariate. It was hypothesized that the students of Inquiry Institute teachers would have higher scale scores and better rates of mastery on the critical thinking objectives than the students of non-Institute teachers. It was also hypothesized that it would be possible to predict student mastery on the objectives that assessed critical thinking and problem solving based on Institute participation. This quasi-experimental study did not show a statistically significant …
Date: December 2002
Creator: Dickson, Teresa K.
System: The UNT Digital Library
Assessing the Efficacy of Learning Communities at Four North Texas Community Colleges. (open access)

Assessing the Efficacy of Learning Communities at Four North Texas Community Colleges.

This observational study involving intact groups and convenient sampling examined learning communities at four North Texas Community Colleges. The purpose of this study was to determine if there was a significant difference in cathectic learning climate, inimical ambiance, academic rigor, affiliation and structure among students in learning communities and freestanding classes. Learning communities are gaining nationwide popularity as instruments of reform in Higher Education. Recent studies have discussed the benefits of learning communities to student, faculty and institutions. As learning communities are gaining popularity, especially at the community college level, there is a need to determine if the learning communities are significantly different than freestanding classes. The College Classroom Environment Scales, developed by Winston, Vahala, Nichols, Gillis, Wintrow, and Rome (1989), was used as the survey instrument for this study. Using SPSS 10.1, a multivariate analysis of variance, (Hotelling's T2) was performed on five dependent variables: cathectic learning climate (CLC), inimical ambiance (IA), academic rigor (AR), affiliation (AF), and structure (ST), which yielded a significant difference. The independent variable was learning community compared to freestanding classes (group). Follow-up independent t tests were also conducted to evaluate the differences in the means between the two groups and to explore which dependent …
Date: August 2002
Creator: Dodd, Patricia M.
System: The UNT Digital Library
An Assessment of the Parent Orientation Program at the University of North Texas (open access)

An Assessment of the Parent Orientation Program at the University of North Texas

Although most institutions offer a parent program option to the orientation program, there has been little formalized research into the quality, planning or programming of parent orientation. There has been very little research into the impact parent orientation has on parents and whether or not they feel that such programs have met their needs, particularly by gender, minority status, educational background, or by geographic distance from the institution. This study seeks to determine the effectiveness of the parent orientation program at the University of North Texas to the parents who participate in this program. The study attempts to measure whether parents feel that they have adequate information about the institution to adequately support their student through the college transition; if parents feel welcomed by the UNT campus community; and if they feel that they have developed resources and institutional contacts that may be useful in the future in assisting their child to have a successful college experience at UNT. The study, conducted in the summer of 2002, had 736 respondents. An instrument developed to determine parent's perceptions of the effectiveness of the parent orientation program consisted of 31 questions using a Likert scale. A t-Test was utilized to analyze the …
Date: December 2002
Creator: With, Elizabeth
System: The UNT Digital Library

Attrition Rates of Teachers Trained in Alternative Teacher Certification Programs, Those Trained in the Centers for the Professional Development of Teachers, and Those Trained in Traditional University Programs.

Access: Use of this item is restricted to the UNT Community
This study uses teacher employment data provided by the State Board for Educator Certification to examine the similarities and differences between initial employment and attrition rates of teachers trained in three prevalent types of Texas teacher preparation programs; alternative certification programs (ACP), the centers for professional development of teachers (CPDT), and traditional certification programs (TCP). The population for the study includes all Texas teachers who completed training in these programs in 1995, 1996, and 1997. The study found that ACP participants gain employment as Texas public school teachers at a significantly higher rate than their CPDT and TCP trained peers in year-one after completion of their training. However, ACP completers experience higher attrition rates in each of the subsequent years investigated. The study concludes that the overall cumulative attrition rate of new teachers trained in these programs is not as pronounced as originally presumed, but that low production levels cannot keep up with the growing demand for new teachers. Teacher preparation program leaders must seek ways to recruit and train more teachers.
Date: May 2002
Creator: Harris, Steven A.
System: The UNT Digital Library