UNT Libraries - 2,963 Matching Results

Search Results

Latent Transition Analysis of Pre-service Teachers' Efficacy in Mathematics and Science

Description: This study modeled changes in pre-service teacher efficacy in mathematics and science over the course of the final year of teacher preparation using latent transition analysis (LTA), a longitudinal form of analysis that builds on two modeling traditions (latent class analysis (LCA) and auto-regressive modeling). Data were collected using the STEBI-B, MTEBI-r, and the ABNTMS instruments. The findings suggest that LTA is a viable technique for use in teacher efficacy research. Teacher efficacy is modeled as a construct with two dimensions: personal teaching efficacy (PTE) and outcome expectancy (OE). Findings suggest that the mathematics and science teaching efficacy (PTE) of pre-service teachers is a multi-class phenomena. The analyses revealed a four-class model of PTE at the beginning and end of the final year of teacher training. Results indicate that when pre-service teachers transition between classes, they tend to move from a lower efficacy class into a higher efficacy class. In addition, the findings suggest that time-varying variables (attitudes and beliefs) and time-invariant variables (previous coursework, previous experiences, and teacher perceptions) are statistically significant predictors of efficacy class membership. Further, analyses suggest that the measures used to assess outcome expectancy are not suitable for LCA and LTA procedures.
Date: December 2009
Creator: Ward, Elizabeth Kennedy

Level Curves of the Angle Function of a Positive Definite Symmetric Matrix

Description: Given a real N by N matrix A, write p(A) for the maximum angle by which A rotates any unit vector. Suppose that A and B are positive definite symmetric (PDS) N by N matrices. Then their Jordan product {A, B} := AB + BA is also symmetric, but not necessarily positive definite. If p(A) + p(B) is obtuse, then there exists a special orthogonal matrix S such that {A, SBS^(-1)} is indefinite. Of course, if A and B commute, then {A, B} is positive definite. Our work grows from the following question: if A and B are commuting positive definite symmetric matrices such that p(A) + p(B) is obtuse, what is the minimal p(S) such that {A, SBS^(-1)} indefinite? In this dissertation we will describe the level curves of the angle function mapping a unit vector x to the angle between x and Ax for a 3 by 3 PDS matrix A, and discuss their interaction with those of a second such matrix.
Date: December 2009
Creator: Bajracharya, Neeraj

Learner-to-Learner: Refocusing the Lens of Educational Immediacy

Description: As the current body of instructional communication research focuses primarily on the relationship between teacher and learner, three studies investigating the relationship between learners were completed in order to better understand how student motivation and learning are influenced by learner-to-learner immediacy behaviors within the college classroom environment. Study I resulted in an extensive list of both positive and negative verbal and nonverbal immediacy behaviors commonly used by learners. Study II required the comparison of the behaviors identified in study one to existing measures of teacher to learner immediacy behaviors, producing a new measure focusing on learner-to-learner immediacy. Following a pilot survey, the reliability of this new measure was determined through face validity and factor analysis, producing the Learner-to-Learner Immediacy Behavior Scale. In Study III, the Learner-to-Learner Immediacy Behavior Scale was combined with Christophel's 1990 Immediacy Behavior Scale, Cognitive Learning Scale, Affective Learning Scale, and Trait and State Motivation Scales and administered to 273 undergraduate students to test the affects of common learner-to-learner immediacy behaviors on student state motivation, affective learning, and perceptions of cognitive learning loss. Multiple regression analyses indicated learner-to-learner immediacy as functioning similarly to teacher-to-student immediacy when mediated through state motivation in its influence on student affective learning and perceptions of cognitive learning loss.
Date: May 2009
Creator: Keller, Christine Ida

Racial Stereotypes and Racial Assimilation in a Multiracial Society

Description: Interest in a multiracial society has increased in recent years and including on racism and prejudice and in the propensity to stereotype out-groups. Theories on racism help explain the dominant group's prejudice toward subordinate groups. Yet they only explain why dominant group members stereotype subordinates or if the dominant group's propensity to stereotype is different from that of subordinate groups. Recent assimilation theories suggest that some minorities are assimilating with Whites but Blacks are not undergoing assimilation. Classic assimilation theory suggests that when a subordinate group assimilates with the dominant group then they will also take on the dominant group's values and beliefs, including their prejudices and propensities to stereotype. The use of racial stereotypes in support of the assimilation of a minority group has not been tested. Results from the LSAF national survey provide support for Asians to be assimilating with Whites. However, Hispanics do not appear to be taking on Whites' propensity to stereotype, contradicting the prediction that Hispanics are assimilating with Whites.
Date: December 2009
Creator: Youngblood, Thomas

Predicting Chemical and Biochemical Properties Using the Abraham General Solvation Model

Description: Several studies were done to illustrate the versatillity of the Abraham model in mathematically describing the various solute-solvent interactions found in a wide range of different chemical and biological systems. The first study focused on using the solvation model to construct mathematical correlations describing the minimum inhibitory concentration of organic compounds for growth inhibition towards the three bacterial strains Porphyromonas gingivalis, Selenomonas artemidis, and Streptococcus sobrinus. The next several studies expand the practicallity of the Abraham model by predicting free energies of partition in chemical systems. The free energy studies expand the use of the Abraham model to other temperatures and properties by developing correlations for the enthalpies of solvation of gaseous solutes of various compounds dissolved in water, 1-octanol, hexane, heptane, hexadecane, cyclohexane, benzene, toluene, carbon tetrachloride, chloroform, methanol, ethanol, 1-butanol, propylene carbonate, dimethyl sulfoxide, 1,2-dichloroethane, N,N-dimethylformamide, tert-butanol, dibutyl ether, ethyl acetate, acetonitrile, and acetone. Also, a generic equation for linear alkanes is created for use when individual datasets are small. The prediction of enthalpies of solvation is furthered by modifying the Abraham model so that experimental data measured at different temperatures can be included into a single correlation expression. The temperature dependence is directly included in the model by separating each coefficient into an enthalpic and entropic component. Specifically, the final study describes the effects of temperature on the sorption coefficients of organic gases onto humic acid. The derived predicted values for each research study show a good correlation with experimental values.
Date: May 2009
Creator: Mintz, Christina

Investigating the effects on parallel play between siblings: Teaching children with autism to emit social phrases to their typically developing sibling.

Description: The focus of this study was three fold. First, modeling and feedback were investigated as a training package for social interactions between siblings. Second, the effects of social phrases taught to the sibling with autism were investigated. Third, the magnitude of these social phrases was measured by timing duration of parallel play. The experimental design is an A-B-A1-A2 design conducted in a clinic, with a probe for generalization in the home environment. This intervention was replicated across an additional sibling dyad to indicate its effectiveness. This study ascertained that the sibling with autism was a viable participant in learning new social skills that could function as a behavioral cusp and increase sibling interactions.
Date: December 2008
Creator: Hille, Katrina J.

A New Wireless Sensor Node Design for Program Isolation and Power Flexibility

Description: Over-the-air programming systems for wireless sensor networks have drawbacks that stem from fundamental limitations in the hardware used in current sensor nodes. Also, advances in technology make it feasible to use capacitors as the sole energy storage mechanism for sensor nodes using energy harvesting, but most current designs require additional electronics. These two considerations led to the design of a new sensor node. A microcontroller was chosen that meets the Popek and Goldberg virtualization requirements. The hardware design for this new sensor node is presented, as well as a preliminary operating system. The prototypes are tested, and demonstrated to be sustainable with a capacitor and solar panel. The issue of capacitor leakage is considered and measured.
Date: December 2009
Creator: Skelton, Adam W.

Grounds-Based and Grounds-Free Voluntarily Child Free Couples: Privacy Management and Reactions of Social Network Members

Description: Voluntarily child free (VCF) individuals face stigmatization in a pronatalist society that labels those who do not want children as deviant. Because of this stigmatization, VCF couples face privacy issues as they choose to reveal or conceal their family planning decision and face a variety of reactions from social network members. Therefore, communication privacy management and communication accommodation theory was use to examine this phenomenon. Prior research found two different types of VCF couples: grounds-based and grounds-free. Grounds-based individuals cite medical or biological reasons for not having children, while grounds-free individuals cite social reasons for not having children. The purpose of this study is to examine how grounds-based and grounds-free VCF couples manage their disclosure of private information and how social network members react to their family planning decision. Findings revealed that grounds-free individuals are more likely to engage in the self-defense hypothesis and grounds-based individuals are more likely to engage in the expressive need hypothesis. Grounds-based individuals were asked about their decision in dyadic situations, whereas grounds-free individuals were asked at group gatherings. Additionally, social network members used under-accommodation strategies the most frequently and grounds-free individuals experienced more name calling than grounds-based. Finally, while grounds-free individuals experienced non-accommodation and over-accommodation strategies, grounds-based did not. Findings suggest that grounds-free individuals are more stigmatized by social network members. Implications for merging CPM and CAT are discussed.
Date: May 2009
Creator: Regehr, Kelly A.

Slaves and Slaveholders in the Choctaw Nation: 1830-1866

Description: Racial slavery was a critical element in the cultural development of the Choctaws and was a derivative of the peculiar institution in southern states. The idea of genial and hospitable slave owners can no more be conclusively demonstrated for the Choctaws than for the antebellum South. The participation of Choctaws in the Civil War and formal alliance with the Confederacy was dominantly influenced by the slaveholding and a connection with southern identity, but was also influenced by financial concerns and an inability to remain neutral than a protection of the peculiar institution. Had the Civil War not taken place, the rate of Choctaw slave ownership possibly would have reached the level of southern states and the Choctaws would be considered part of the South.
Date: May 2009
Creator: Fortney, Jeffrey L., Jr.

An Evaluation of the Effects of Two Different Role Play Formats on the Outcomes of a Parent Training Curriculum

Description: The current study was designed to replicate and extend previous research on the effectiveness of behavioral parent training. Specifically, the effectiveness of the Behavior Management and Parenting Services (BMAPS) curriculum in teaching parents to exhibit a set of parenting skills and respond accurately to a multiple choice examination about positive parenting techniques was evaluated. In addition, the curriculum was revised so that the relative effectiveness and acceptability of two role play formats could be assessed. The outcomes of the study showed an improvement in the participants' ability to identify correct answers on a multiple choice examination and apply the parenting skills taught in class within a role play format; results pertaining to the efficacy of each role play format were less conclusive.
Date: December 2009
Creator: Carlson Litscher, Barbara J.

Primary Stylistic Characteristics of Cindy McTee's Music as found in Timepiece, Ballet for Band and Finish Line

Description: Cindy McTee, Regents Professor of Composition in the College of Music at the University of North Texas, is one of America's leading composers. Her music is an eclectic blend of the "American" sound that is created by the use of a multiplicity of techniques. This document uses three of McTee's most recent (to date) works for wind band: Timepiece, Ballet for Band and Finish Line, to identify the primary stylistic characteristic's of the composer's music, which include: jazz influence; use of ostinati, pseudo-ostinati and machine-like rhythmic patterns and figures; creation of extended and angular melodic lines; progressive "walking" bass lines; and the use of octatonic and chromatic collections. Through the identification of stylistic characteristics, concise stylistic analysis of the works, interview transcript, list of composer's works to date, and selected discography, this document will add to the limited body of scholarly writing on the composer.
Date: May 2009
Creator: Williams, Nicholas E.

Thermochemical investigations of crystalline solutes in non-electrolyte solutions: Mathematical representation of solubility data and the development of predictive solubility equations in systems with specific and non-specific interactions.

Description: Understanding the thermodynamic properties of multicomponent mixtures is of critical importance in many chemical and industrial applications. Experimental measurements become progressively difficult as the number of solution components increases -- producing the need for predictive models. Problems in development of predictive models arise if the mixture has one or more components that interact through molecular complexation or association. Experimental solubilities of anthracene and pyrene dissolved in binary systems containing one or more alcohols were measured in order to address this problem. Alcohols examined in this study were: 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, and 1-octanol. In binary solvent mixtures containing only a single self-associating alcoholic solvent, the alkane cosolvents studied were: n-hexane, n-heptane, n-octane, 2,2,4-trimethylpentane, cyclohexane, methylcyclohexane, tert-butylcyclohexane. Predictive solubility equations were developed using mobile order theory. This approach differs from classical solution models by representing hydrogen bonding with a probability term rather than with expressions derived from stepwise equilibria or expressions to represent hypothetical solution aggregates. Results were compared with the predicted solubilities found from using expressions developed using the Kretschmer-Wiebe and Mecke-Kempter approaches for modeling associated solutions. It was found that the mobile order approach provided reasonably accurate predictions for the solute solubilities in the systems studied. The limitations and applications for mathematical methods of representing experimental isothermal solubility data were also studied for 72 systems. Two possible descriptive forms for this mathematical representation were suggested based on the various nearly ideal binary solvent (NIBS) and modified Wilson models.
Date: May 2008
Creator: Zvaigzne, Anita Ilze

Survey of Approximation Algorithms for Set Cover Problem

Description: In this thesis, I survey 11 approximation algorithms for unweighted set cover problem. I have also implemented the three algorithms and created a software library that stores the code I have written. The algorithms I survey are: 1. Johnson's standard greedy; 2. f-frequency greedy; 3. Goldsmidt, Hochbaum and Yu's modified greedy; 4. Halldorsson's local optimization; 5. Dur and Furer semi local optimization; 6. Asaf Levin's improvement to Dur and Furer; 7. Simple rounding; 8. Randomized rounding; 9. LP duality; 10. Primal-dual schema; and 11. Network flow technique. Most of the algorithms surveyed are refinements of standard greedy algorithm.
Date: December 2009
Creator: Dutta, Himanshu Shekhar

Dawn in the Empty House

Description: The preface to this collection of poems, "Memory and The Myth of Lost Truth," explores the physical and metaphysical roles memory plays within poetry. It examines the melancholy frequently birthed from a particular kind poetic self-inquiry, or, more specifically, the feelings associated with recognizing the self's inability to re-inhabit the emotional experience of past events, and how poetry can redeem, via engaging our symbolic intuition, the faultiness of remembered history. Dawn in the Empty House is a collection of poems about the implications of human relationships, self-deception, and memory as a tool for self-discovery.
Date: December 2008
Creator: Campbell, John

Tinder for the Bathhouses

Description: In the preface to this collection, "Poetry and History: Finding 'What Will Suffice,'" I show how Czeslaw Milosz's "Dedication" and Jorie Graham's "Guantánamo" embody the virtues of philosophical meditation and the moral imagination to create a unique poetry of witness. These poems also provide American poets with an example of how they can regain the trust of an apathetic general reading audience. Tinder for the Bathhouses is a collection of poems in which I use the moral imagination to indirectly bear witness to events as far ranging as the Holocaust and the Iraq War. Using the family as a foundation, I show how historical narratives can provide a poet with the tools to think about larger metaphysical questions that poetry can raise, such as the nature of beauty and the purpose of art.
Date: December 2008
Creator: Bredthauer, Bredt

Where My Own Grave Is

Description: The preface to this collection, "Against Expectation: The Lyric Narrative," highlights the ways James Wright, Stephen Dunn, and C.K. Williams use narrative to strengthen their poems. Where My Own Grave Is is a collection of poems that uses narrative to engage our historical fascination with death.
Date: December 2008
Creator: Collier, Jordan Taylor

Physical Gesture, Spatialization, Form and Transformation in Watershed I/IV, for Solo Percussion and Real-time Computer Spatialization, by Roger Reynolds

Description: Watershed I/IV, for Solo Percussion and Real-time Computer Spatialization was composed in 1995 by Pulitzer prize-winning composer Roger Reynolds. This work is a 25-minute choreographed music drama for one multiple-percussionist, in which Reynolds incorporates the musical transformation of percussion instrument families, the physical gestures of the performer, and the spatialization of processed sounds around the audience. This dissertation addresses several aspects of Watershed, which include: the expressive intent and extra-musical concepts; the formal organization, and several non-musical tools that Reynolds utilized in designing the piece (e.g. logarithmically derived sequences); the primary musical motives; the instrument setup and how the resulting physical gestures contribute to the musical intent; and the real-time computer spatialization. Throughout the document, specific musical passages are demonstrated with notated musical examples and embedded video/audio clips. In addition, transcripts of my interviews with composer Roger Reynolds, percussionist Steven Schick (premiere performer of Watershed) and engineer/technician Greg Dixon (engineer for my performances of Watershed IV) are also included.
Date: December 2009
Creator: Licata, Julie M.

Factors of the Geriatric Depression Scale that may Distinguish between Four Cognitive Diagnostic Groups: Normal, Mild Cognitive Impairment, Dementia of the Alzheimer's Type, and Vascular Dementia

Description: The purpose of the current study was to explore the relationship between cognitive status and depression in a sample of geriatric patients. Participants included 282 geriatric patients ranging in age from 65 to 96 years who were classified according to diagnosis as: DAT, VaD, MCI, and Norm. All were referred for neurocognitive testing from the Geriatric Assessment Program (GAP) at the University of North Texas Health Science Center (UNTHSC) in Fort Worth, Texas. This study sought to identify factor structures for two versions of the GDS using a geriatric sample of cognitively impaired and intact patients. It then compared these factors to each other to determine whether the GDS-15 is truly a shorter version of the GDS-30. These were then compared to a previously determined factor structure. This study explored whether the four-factors of the GDS-30 are able to differentiate cognitive diagnostic groups. Further, this study sought to identify whether the severity of cognitive decline impacted GDS factor score for each of the cognitively impaired groups. Results revealed a two-factor model of the GDS - 15 and a four-factor model with the GDS - 30. The GDS-15 factors did not differ from the first two factors of the GDS-30. Comparison between the GDS-30 factor structure and that reported by Hall and Davis (in press) revealed no significant differences despite the inclusion of a normal, non-demented group in the current study. Comparisons of subscale scores revealed that DAT patients tended to score lower than the other groups on all but the cognitive impairment subscale. Severity level analyses indicated that as severity of deficits increases, awareness of deficits decreases. This study found that although the GDS-30 is a good screening tool for depression in geriatric patients, it is not particularly useful in differentiating cognitive status group. Also, the GDS-15 was not found ...
Date: December 2009
Creator: Cornett, Patricia F.

Design and Validation of an Automated Multiunit Composting System.

Description: This thesis covers the design of an automated multiunit composting system (AMUCS) that was constructed to meet the experimental apparatus requirements of the ASTM D5338 standard. The design of the AMUCS is discussed in full detail and validated with two experiments. The first experiment was used to validate the operation of the AMUCS with a 15 day experiment. During this experiment visual observations were made to visually observe degradation. Thermal properties and stability tests were performed to quantify the effects of degradation on the polymer samples, and the carbon metabolized from the degradation of samples was measured. The second experiment used the AMUCS to determine the effect of synthetic clay nanofiller on the aerobic biodegradability behavior of poly (3-hydroxybutyrate-co-3-hydroxyvalerate).
Date: December 2009
Creator: Pickens, Mark Everett

Does the Knowledge of Unaudited Account Balances Adversely Affect the Performance of Substantive Analytical Procedures?

Description: Auditors use substantive analytical procedures to make assertions about the adequacy and appropriateness of client balances. The analytical procedure process consists of auditors creating independent account expectations and corroborating unusual fluctuations through obtaining and evaluating additional audit evidence. Prior analytical procedure research has found that knowledge of clients' unaudited account balances biases auditors' expectations towards the current year figures. However, this research has failed to examine the impact of biased expectations on the subsequent stages of analytical procedures. This dissertation assesses the full impact of biased account expectations on auditors' use of analytical procedures. I experimentally test the hypotheses of my dissertation through administering an experiment to senior level auditors. After inducing an account expectation bias that favors the client account balance in half the participants, I examine the auditors' cognitive investigation into an unusual account fluctuation. The results indicate that a biased account expectation negatively affects auditors' judgment quality. In particular, a biased expectation leads auditors to favor hypotheses and additional information that supports the proposition that the client's balance is reasonably stated. Alternatively, auditors with unbiased account expectations are more willing to consider all hypotheses and are able to identify the most pertinent additional information to the decision task. As a result of the different decision strategies employed, auditors who form unbiased account expectations are significantly more likely than auditors with biased account expectations to identify the correct relationship among the underlying data and the proposed hypotheses during a substantive analytical procedure.
Date: December 2009
Creator: Pike, Byron J.

Does Stimulus Complexity Affect Acquisition of Conditional Discriminations and the Emergence of Derived Relations?

Description: Despite the central importance of conditional discriminations to the derivation of equivalence relations, there is little research relating the dynamics of conditional discrimination learning to the derivation of equivalence relations. Prior research has shown that conditional discriminations with simple sample and comparison stimuli are acquired faster than conditional discriminations with complex sample and comparison stimuli. This study attempted to replicate these earlier results and extend them by attempting to relate conditional discrimination learning to equivalence relations. Each of four adult humans learned four, four-choice conditional discriminations (simple-simple, simple-complex, complex-simple, and complex-complex) and were tested to see if equivalence relations had developed. The results confirm earlier findings showing acquisition to be facilitated with simple stimuli and retarded with complex stimuli. There was no difference in outcomes on equivalence tests, however. The results are in implicit agreement with Sidman's theory of stimulus equivalence.
Date: December 2009
Creator: Martin, Tiffani L.

Do Different Political Regime Types Use Foreign Aid Differently to Improve Human Development?

Description: Existing literature on foreign aid does not indicate what type of political regime is best to achieve human development outcomes or use aid funds more efficiently. I contend that political leaders of different regime types have personal incentives that motivate them to utilize foreign aid to reflect their interests in providing more or less basic social services for their citizens. Using a data set of 126 aid-recipient countries between the years of 1990 and 2007, I employ fixed effects estimation to test the model. The overall results of this research indicate that foreign aid and democratic institutionalization have a positive effect on total enrollment in primary education, while political regime types show little difference from one another in providing public health and education for their citizens.
Date: December 2009
Creator: Phan, Thu Anh

The Effects of Attendance at a Senior Center on the Quality of Life and Well Being of Grandparents Rearing Grandchildren.

Description: The purpose of this study was to determine the effects of attendance at a senior center on the well being and quality of life of grandparents that were rearing grandchildren. Using convenience sampling, grandparents (N=130) who were rearing grandchildren were given a self administered demographic data survey along with an attendance at a senior center questionnaire, the Quality of Life Scale, the Well Being Scale by Liang, the UCLA Loneliness Scale, the Caregiver Burden Scale, and the Role Satisfaction Scale. An initial MANOVA (F 7, 69 = 2.72, p < .01) suggesting that senior center attendance affect the measures as a set was conducted and then a series of one way ANOVAs were carried out to test the hypothesis that attending a senior center has an effect on the dependent variables: well being, quality of life, role satisfaction, caregiver burden, loneliness, current health, and heath one year ago. Subsequently, a hierarchical regression analysis was conducted to find out whether frequency and quality of attendance of a senior center predicted quality of life, caregiver burden, well being, loneliness, and role satisfaction, controlling for the demographic data. The results of the MANOVA showed that the dependent variables: quality of life, caregiver burden, well being and role satisfaction were impacted positively by the attendance of a senior center. The results of the regression analyses showed that for each of the major dependent variables, after controlling for the demographic data, the quality and frequency of involvement at the senior center did not have a uniquely significant role in predicting the dependent variables. The results of this study shows that further research need to be conducted to answer other questions regarding grandparents who are rearing minor grandchildren and the affects that senior centers may have in assisting in the management of this new task that ...
Date: December 2009
Creator: Rhynes, LaTrica Q.

Effects of Background Music on Preschoolers' Attention.

Description: Background music is often used in preschool classrooms with the belief that music makes children smarter and increases attention. The purpose of this study was to determine if background music increased children's focused attention during play activities. Focused attention occurs when children maintain attention to a task regardless of distractions. This quasiexperimental study investigated background music and play in a laboratory setting. I videotaped individual children during play with math manipulatives in a pretest-posttest research design with background music used as the treatment. Forty-three 3-, 4-, and 5-year-olds played for 15 minutes. The first 5 minutes of play had no music (pretest), the second 5-minute play episode had background music (treatment), and the final 5-minute play episode had no background music (posttest). Data were analyzed using one-way repeated measures analysis of variance. Findings revealed that the subjects paid less attention to the play task with background music than they did during the pretest, with no music. Another key finding was that children with more musical experiences at home, as reported by the Child's Home Musical Experience Survey (CHIMES), exhibited longer periods of focused attention with background music. This study confirmed previous research that 3-year-old children have shorter focused attention than 4- and 5-year-old children with and without background music. These findings have implications for teachers and parents that background music, instead of increasing attention in children, might indeed decrease children's focused attention during play activities.
Date: December 2009
Creator: Dartt, Kevin Maurine