Degree Level

States

196 Matching Results

Results open in a new window/tab.

General Chemistry Topic Coverage (GCTC) comparison between community colleges and universities in the United States. (open access)

General Chemistry Topic Coverage (GCTC) comparison between community colleges and universities in the United States.

This study is based on survey responses of 224 general chemistry instructors at United States (U.S.) community colleges and universities representing 46 states. The mean values of General Chemistry Topic Coverage (GCTC) score, developed by this researcher specifically for this dissertation study as a measure of course content, were statistically analyzed. The aim of this study is to answer five research questions: (a) Is there a difference in mean GCTC scores between U.S. community colleges and four-year colleges and universities? (b) If there is a difference in mean GCTC score between the two study groups, what are the observed differences in subtopics covered between community colleges and four-year colleges and universities? (c) Considering both community colleges and universities, is there a difference in mean GCTC score between the different designated U.S. regions? (d) Considering both community college and university professors, is there a difference in GCTC score for professors with a master's degree compared to those with a doctorate?, and (e) Is there a correlation between GCTC score and the percentage of students that major in science? Results indicate that there is a statistically significant difference in course content between community colleges and universities, there is a statistically significant difference …
Date: December 2006
Creator: El-Ashmawy, Amina Khalifa
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Generic Algebras and Kazhdan-Lusztig Theory for Monomial Groups

Access: Use of this item is restricted to the UNT Community
The Iwahori-Hecke algebras of Coxeter groups play a central role in the study of representations of semisimple Lie-type groups. An important tool is the combinatorial approach to representations of Iwahori-Hecke algebras introduced by Kazhdan and Lusztig in 1979. In this dissertation, I discuss a generalization of the Iwahori-Hecke algebra of the symmetric group that is instead based on the complex reflection group G(r,1,n). Using the analogues of Kazhdan and Lusztig's R-polynomials, I show that this algebra determines a partial order on G(r,1,n) that generalizes the Chevalley-Bruhat order on the symmetric group. I also consider possible analogues of Kazhdan-Lusztig polynomials.
Date: May 2006
Creator: Alhaddad, Shemsi I.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Group-EDF: A New Approach and an Efficient Non-Preemptive Algorithm for Soft Real-Time Systems (open access)

Group-EDF: A New Approach and an Efficient Non-Preemptive Algorithm for Soft Real-Time Systems

Hard real-time systems in robotics, space and military missions, and control devices are specified with stringent and critical time constraints. On the other hand, soft real-time applications arising from multimedia, telecommunications, Internet web services, and games are specified with more lenient constraints. Real-time systems can also be distinguished in terms of their implementation into preemptive and non-preemptive systems. In preemptive systems, tasks are often preempted by higher priority tasks. Non-preemptive systems are gaining interest for implementing soft-real applications on multithreaded platforms. In this dissertation, I propose a new algorithm that uses a two-level scheduling strategy for scheduling non-preemptive soft real-time tasks. Our goal is to improve the success ratios of the well-known earliest deadline first (EDF) approach when the load on the system is very high and to improve the overall performance in both underloaded and overloaded conditions. Our approach, known as group-EDF (gEDF), is based on dynamic grouping of tasks with deadlines that are very close to each other, and using a shortest job first (SJF) technique to schedule tasks within the group. I believe that grouping tasks dynamically with similar deadlines and utilizing secondary criteria, such as minimizing the total execution time can lead to new and more …
Date: August 2006
Creator: Li, Wenming
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Health Care Among Low-income, White, Working-age Males in a Safety Net Health Care Network: Access and Utilization Patterns (open access)

Health Care Among Low-income, White, Working-age Males in a Safety Net Health Care Network: Access and Utilization Patterns

This study seeks to provide information relevant to public policy that will lead to increased access and utilization among this vulnerable population and to reinforce the validity of the behavioral model for vulnerable populations. This study is a secondary analysis of data collected in a study that examined adult, working-aged patients within the John Peter Smith Health Network, which is a large, urban, tax supported county health care system in Fort Worth, Texas. From a sampling frame of 10,000 patients, the study analyzed data for 243 low-income, white, working-age males, collected from computer assisted telephone interviews in 2000. Cross-tabulations and bivariate logistic regressions were used to analyze the effect of 8 independent variables (age, marital status, insurance, employment status, a usual source of care, competing needs, experiences with paperwork, and perceived health status upon 5 dependent variables pertaining to unmet health care, unmet prescription medicine needs, unmet dental needs, utilization of doctors in emergency departments, and overnight hospital stays. The results show the safety net system is failing to meet the needs of this vulnerable population. The findings indicate white men who found it necessary to forgo health care due to other needs were almost five (4.973) times as likely …
Date: August 2006
Creator: Whitworth, Keith Hugh
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The health status of people living with HIV/AIDS and in treatment in the United States. (open access)

The health status of people living with HIV/AIDS and in treatment in the United States.

Vulnerable populations comprise a growing number of people living with HIV/AIDS and are at increased risk for poorer health outcomes. The purpose of this research was to approximate the effect of the Ryan White CARE Act on the health status of people living with HIV/AIDS who were receiving medical care in the United States. The vulnerable populations model was utilized to identify appropriate variables for analysis as well as to provide a sequencing for the testing of models. Data analyzed in this study came from the 1996 Baseline Survey of the HIV Cost and Services Utilization Study (HCSUS), a cooperative study between RAND and the Agency for Health Care Policy and Research (now known as the Agency for Health Care Quality and Research). Three analyses sequences, using different dependent variables, to estimate health status were conducted. In the first analysis, health status was measured by CD-4 count and stage of illness. In the second analysis, only CD-4 counts were used for health status. In the final analysis, health status was estimated based on AIDS diagnosis. Each of the three analyses included the same independent variables: race, gender, education, sexual orientation, income, insurance status, region of the country, receipt of case …
Date: August 2006
Creator: Tilton, Abigail C.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Hiring preferences of employers of entry-level biomedical equipment technicians in Texas. (open access)

Hiring preferences of employers of entry-level biomedical equipment technicians in Texas.

This study examined the signaling strength, or marketing power, of the most common qualifications of entry-level biomedical equipment technicians (BMETs) in Texas, based on stated hiring preferences of BMET managers, using order ranking of fictitious resumes. This study also sought to determine whether certification status, education background, military training background as a BMET, or type of employer [hospital or ISO] of the hiring manager had an effect on hiring preference for applicant qualifications of associate degree, military training as a BMET, or certified biomedical equipment technician (CBET) certification candidacy. Participants were asked to rank 16 fictitious resumes representing the most common qualifications of entry-level BMETs and to fill out a background questionnaire regarding their education, military, certification, and employer. The number of times each resume ranked in first place was tabulated and inter-rater reliability was calculated. Resumes with qualifications of associate degree versus military training as a BMET were compared at three levels of work experience. A chi-square test for independence was conducted for the comparisons to determine whether work experience influenced preference. Chi-square tests were also conducted for comparisons of associate degree with candidacy for CBET certification versus associate degree and military training with CBET candidacy versus military training. …
Date: December 2006
Creator: Bowles, Roger A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Home-based family literacy practices of an Hispanic family: A case study of activities, functions, and the interface with school-based literacy expectations. (open access)

Home-based family literacy practices of an Hispanic family: A case study of activities, functions, and the interface with school-based literacy expectations.

This study examined the home-based family literacy practices of one Hispanic family, especially focusing on the parents' memories of home-based and school-based literacy activities, current home-based literacy activities and functions, and the interface of home-based family literacy practices and school-based literacy expectations. Ethnographic data offered insight into the understanding that literacy acquisition begins in the home and is dependent and reflective of literacy experiences that are sociocultural based. These home-based family literacy activities and functions are broad in scope and are valuable forms of literacy. However, these activities of marginalized families are often regarded as unimportant and/or unrelated to school-based literacy expectations, and therefore inferior. In response to this perceived mismatch between home-based family literacy activities and school-based literacy expectations, educators approached families from a deficit perspective. This deficit assumption created a sense of devalue on the part of the parents, who assisted their children by culturally and socially relevant means. To meet the school-based literacy expectations familial relationships were jeopardized as the pressure, frustration, and guilt from educators can result in emotional and physical abuse from mother to her children.
Date: August 2006
Creator: Page, Jim Larkin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
How Classroom Cultural Influences Second Language Acquisition for Two Four-Year-Olds in a Preschool Program for Children with Disabilities (open access)

How Classroom Cultural Influences Second Language Acquisition for Two Four-Year-Olds in a Preschool Program for Children with Disabilities

As states begin to highlight the system supports used to include English language learners with disabilities in standards-based assessments and accountability programs, implementation of those supports will be closely examined by school districts. This case study investigates the classroom culture in an early childhood preschool program for four-year-old children with disabilities. Classroom observations were used to determine how two young children with disabilities were acquiring English as a second language. Specific focus was given to activities that allowed for second language acquisition, native language development, the attainment of developmental skills, and alternative communication skills such as sign language and a communication board. An investigation took place into current theories to create a knowledge base for understanding how young children acquire linguistic skills in English and how classroom culture was created.
Date: December 2006
Creator: Casey, Susan Denise
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Hyperbolic Monge-Ampère Equation

Access: Use of this item is restricted to the UNT Community
In this paper we use the Sobolev steepest descent method introduced by John W. Neuberger to solve the hyperbolic Monge-Ampère equation. First, we use the discrete Sobolev steepest descent method to find numerical solutions; we use several initial guesses, and explore the effect of some imposed boundary conditions on the solutions. Next, we prove convergence of the continuous Sobolev steepest descent to show local existence of solutions to the hyperbolic Monge-Ampère equation. Finally, we prove some results on the Sobolev gradients that mainly arise from general nonlinear differential equations.
Date: August 2006
Creator: Howard, Tamani M.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Identification and characterization of an incomplete root hair elongation (IRE)-like gene in Medicago truncatula (L.) root nodules.

Access: Use of this item is restricted to the UNT Community
Cloning and molecular characterization of new genes constitutes a useful approach in studying the symbiotic interactions between the model plant Medicago truncatula and Synorhizobium meliloti. Large numbers of expressed sequence tags (ESTs) available for Medicago truncatula, along with numerous cDNA, oligonucleotides, and Affimetrix DNA microarray chips, represent useful tools for gene discovery. In an attempt to identify a new gene that might be involved in the process of nodulation in Medicago truncatula, preliminary data reported by Fedorova et al. (2002), who identified 340 putative gene products or tentative consensus sequences (TCs) expressed only in nodules, was used. This research was focused on TC33166 (TC103185), which has 3 ESTs in the TC, and whose strongest BLASTX hit of TC103185 is the incomplete root hair elongation (IRE) protein kinase-like protein (NP_192429) from Arabidopsis thaliana. The Arabidopsis IRE gene is required for normal root hair growth, and a role in apical growth was suggested (Oyama et al., 2002). Infection thread growth can be looked at as an inward growth of the root hair. Thus, TC103185 was a good candidate for identifying a gene that may be involved in early events of nodulation. MtIRE (GenBank accession AC122727) is organized in 17 exons and 16 …
Date: May 2006
Creator: Pislariu, Catalina Iulia
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Impact of Child-Centered Play Therapy on Children of Different Developmental Stages (open access)

Impact of Child-Centered Play Therapy on Children of Different Developmental Stages

The purpose of this study was to determine the impact of child-centered play therapy on children of Piaget's preoperational and concrete operations developmental stages. Piaget's assertions about the contributions of play to cognitive, affective, and social development have provided a basis for the theoretical rationale for the use of play as a therapeutic intervention. The impact of child-centered play therapy was measured by a decrease in parent-child relationship stress as measured by scores on the Child Domain, Parent Domain, and Total Stress Score of the Parenting Stress Index. This study utilized a three wave repeated measures ANOVA design to analyze the impact of child-centered play therapy on children between the ages of 3-8 who received 19-23 individual child-centered play therapy sessions. A pretest, approximate midpoint, and posttest administration was collected for use in the analysis. The population study comprised 24 children referred to the Child and Family Resource Clinic on the University of North Texas campus. Participating children were divided into two treatment groups based on their age at the time of treatment. The preoperational development treatment group consisted of 12 children aged of 3-6 years and the concrete operations development treatment group consisted of children aged 7-8 years. Nine …
Date: May 2006
Creator: Dougherty, Jennifer L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The impact of child teacher relationship training on teachers' and aides' use of relationship-building skills and the effect on student classroom behavior. (open access)

The impact of child teacher relationship training on teachers' and aides' use of relationship-building skills and the effect on student classroom behavior.

This study examined the impact of child teacher relationship training (CTRT) on teachers' and aides' use of relationship- building skills in the classroom and the correlation between teachers' and aides' demonstration of relationship- building skills and the effect on student behavior. CTRT was modeled after Landreth and Bratton's (2006) 10-session filial therapy model titled child parent relationship therapy (CPRT) which is based on the principles and procedures of child -centered play therapy. The CPRT manual was adapted slightly for use with teachers and aides for this project. In this quasi-experimental design, 12 teacher aide dyads (n = 24) were assigned to the experimental (n = 12) or active control groups (n = 12). Children who scored in the Borderline/Clinical range on at least one scale of the Child Behavior Checklist-Caregiver/Teacher Report Form (C-TRF) at pretest qualified for the study (N = 32). During the first phase of treatment, teachers and aides participated in the equivalent of 10 training/supervision sessions consistent with the principles and procedures of CPRT. During CTRT Phase II, teachers and aides participated in 10 weeks of coaching/modeling to facilitate the use of CTRT skills in the classroom environment and continued to participate in weekly 1-hour group training/supervision …
Date: December 2006
Creator: Helker, Wendy Pretz
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The impact of selected school factors on the test performance of African-American economically disadvantaged elementary students. (open access)

The impact of selected school factors on the test performance of African-American economically disadvantaged elementary students.

In order for America to retain its superior position in a global economy it is imperative that all students receive educational opportunities that will prepare them for the future. Currently, African-American economically disadvantaged students in the United States perform lower on standardized tests than their grade and age-level peers. Educators must find ways to improve the performance of students in this group in order to maximize future opportunities. Through a mixed-methodology approach, the current study finds three school factors that may positively impact the performance of African-American economically disadvantaged students: high expectations, student-teacher relationships and teacher effectiveness. Quantitative and qualitative analysis provides perspectives from principals primarily from a large urban school district on the impact of these factors on student performance.
Date: May 2006
Creator: Griffin, Wynette O.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Impact of Teachers' Common Planning Time on the Academic Performance of Students in a Middle School Setting (open access)

Impact of Teachers' Common Planning Time on the Academic Performance of Students in a Middle School Setting

The purpose of this study was to assess the impact of the common planning time for a team of middle school teachers by comparing the standardized test scores of middle school students selected from two school districts located in North Texas. An analysis of variance (ANOVA) 2 * 4 design was utilized to measure the Texas Assessment of Knowledge and Skills (TAKS) math and reading scale score for 7th grade students from the test administered in spring 2005. The data for this study were compared by the variables of school, gender, and ethnicity. The measuring tool utilized in this study determined the ratio of the amount of variance of the scores for individuals of between-groups as opposed to the amount of variance of within-groups, indicating if there were a statistically significant difference on the scores in any one particular variable compared to the variances of scores for the other variables in this study. The statistical results indicated that there were no statistical significant differences in the scores of students attending a middle school where the teachers received a common planning time. However, there was a noted difference in the percentage ratings on the Academic Excellence Indicator System (AEIS) report published …
Date: December 2006
Creator: Smitt, Shauna M.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

The impact of the Home Instruction for Parents of Preschool Youngsters (HIPPY) program on reading, mathematics, and language achievement of Hispanic English language learners.

Access: Use of this item is restricted to the UNT Community
This study sought to answer if the Home Instruction for Parents of Preschool Youngsters (HIPPY) program had a positive academic impact on Hispanic English language learners (ELL). HIPPY is a free, 2-year, home-based early intervention program for 4-and 5-year-old children. The program is intended to provide educational enrichment to at-risk children from poor and immigrant families, increase school readiness, and foster parent involvement in their children's education. A quasi-experimental design and quantitative measures were used to measure the academic success of Hispanic ELL students in reading, mathematics, and language arts. The sample included an experimental group and a purposeful control group. Hispanic students who attended an early childhood school as 4 year olds and participated in the HIPPY 4 and 5 programs were compared to Hispanic students who attended an early childhood school as 4 year olds and did not participate in HIPPY. Results from the Texas-mandated criterion referenced Texas Assessment Knowledge and Skills (TAKS™) Test and the TerraNova® and TerraNova SUPERA® norm referenced tests were used in this study. Results from the TAKS Reading and TAKS Mathematics Grade 3 and the TerraNova reading, language, mathematics, and total composite scores were analyzed using a one-way analysis of variance. The treatment …
Date: May 2006
Creator: García, Maria G.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Improving Recall of Browsing Sets in Image Retrieval from a Semiotics Perspective (open access)

Improving Recall of Browsing Sets in Image Retrieval from a Semiotics Perspective

The purpose of dissertation is to utilize connotative messages for enhancing image retrieval and browsing. By adopting semiotics as a theoretical tool, this study explores problems of image retrieval and proposes an image retrieval model. The semiotics approach conceptually demonstrates that: 1) a fundamental reason for the dissonance between retrieved images and user needs is representation of connotative messages, and 2) the image retrieval model which makes use of denotative index terms is able to facilitate users to browse connotatively related images effectively even when the users' needs are potentially expressed in the form of denotative query. Two experiments are performed for verifying the semiotic-based image retrieval model and evaluating the effectiveness of the model. As data sources, 5,199 records are collected from Artefacts Canada: Humanities by Canadian Heritage Information Network, and the candidate terms of connotation and denotation are extracted from Art & Architecture Thesaurus. The first experiment, by applying term association measures, verifies that the connotative messages of an image can be derived from denotative messages of the image. The second experiment reveals that the association thesaurus which is constructed based on the associations between connotation and denotation facilitates assigning connotative terms to image documents. In addition, the …
Date: May 2006
Creator: Yoon, JungWon
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Improving self-efficacy in college students: A modified adventure therapy program. (open access)

Improving self-efficacy in college students: A modified adventure therapy program.

Adventure therapy employs a technique in which therapists use controlled amounts of stress to bring about change in the behavior of clients. One of the domains in which adventure therapy reports improvement is that of self-efficacy. Perceived self-efficacy is the belief that individuals have in their ability to overcome and change their situation in life. This study examines the effect of a modified adventure therapy program on the perceived self-efficacy of college students who were enrolled in an Outdoor Pursuits course at a major metropolitan university. Students received 16 weeks of outdoor adventure therapy programming that culminated in a voluntary weekend camping trip. The students were administered the General Self-Efficacy (GSE) scale on the second day of class to determine a baseline level of self-efficacy to be compared to the posttest completed on the last day of class. The study examined 3 consecutive semesters of archival data collected by the researcher while instructing the course. Fifty-six participants across the 3 semesters were usable for data analysis. The results show there is a significant difference between students' level of perceived self-efficacy from pre- to posttest, and no difference in the effect on gender, classification of students, or the participation of the …
Date: December 2006
Creator: Peebles, Larry Mason
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Influence of executive function on medication adherence in neurologically impaired and non-impaired elderly.

Access: Use of this item is restricted to the UNT Community
Medication non-compliance has become one of the most prevalent reasons for hospitalization and doctor's visits by the elderly. As the elderly population is more likely to have decreased cognitive abilities, it is suggested that neuropsychological factors, especially executive function, are more influential in medication non-compliance than once thought. This study looked at executive function performance on a traditional battery of neuropsychological tests, self-report of perceived ability to perform executive function tasks, and the newly developed Pillbox Test, a performance based IADL measure. The Pillbox Test is designed to replicate a type of medication-management specific IADL as a means to asses executive function. Standard executive function measures only tap a portion of executive function, but it is believed that the Pillbox Test incorporates all four theoretical domains of executive function. The multiple measures of executive function performance were compared in three prevalent subgroups of the elderly population (mixed neurological group, cardiac medical-control group, and healthy community-control group). Results found significant differences, where the community-control and cardiac groups outperformed the mixed neurological group on the large majority of executive function tasks. Smaller differences were also noted between the community-control and cardiac groups and between the cardiac and mixed neurological groups. Together, these …
Date: August 2006
Creator: Zartman, Andrea Leigh
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Influence of Sediment Exposure and Water Depth on Torpedograss Invasion of Lake Okeechobee, Florida

Access: Use of this item is restricted to the UNT Community
Torpedograss (Panicum repens) was first observed in Lake Okeechobee in the 1970s and appears to have displaced an estimated 6,400 ha of native plants, such as spikerush (Eleocharis cellulosa), where inundation depths are often less than 50 cm. Two series of studies evaluated substrate exposure and water depth influences on torpedograss establishment and competitiveness. Results revealed that fragments remain buoyant for extended periods and so facilitate dispersal. Once anchored to exposed substrate fragments can readily root and establish. Subsequently, torpedograss thrives when subjected to inundations to 75 cm and survives prolonged exposure to depths greater than 1 m. These findings suggest that fluctuating water levels contribute to torpedograss dispersal and colonization patterns and that low water levels increase marsh area susceptible to invasion. The competition study found that spikerush grown in monoculture produces significantly more biomass when continually inundated to shallow depths (10 to 20 cm) than when subjected to drier conditions (-25 cm) or greater inundations (80 cm). In contrast, torpedograss establishes more readily on exposed substrate (-25 to 0 cm) compared to inundate substrates. During the first growing season biomass production increases as substrate exposure interval increases. However, during the second year, established torpedograss produces more biomass when …
Date: December 2006
Creator: Smith, Dian H.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Instructional Effectiveness of an Integrated Holistic Teaching Method of German Language at the Community College Level

Access: Use of this item is restricted to the UNT Community
The propose of this study was to determine the effectiveness and appropriateness of the integrated holistic method for teaching grammatical structure, cultural norms and behavior, writing and listening skills to beginning German language students. The study examined a sample of undergraduate students who were enrolled in the introductory college level German offered at the Collin County Community College, Spring Creek Campus in Plano, Texas. A total of 24 students participated in this study. This study utilized a pre- and posttest group to measure the instructional effectiveness of the integrated holistic teaching method. Structural grammar, cultural norms and behavior, writing, and listening skills were used as dependent variables. The holistic integrated teaching method were measured at the end of the course as independent variables. Individual pre- and posttests were used for each of the dependent variables. The higher posttest mean scores indicated significant improvement in student learning level in four major language skills such as structural grammar, cultural norms and behavior, writing, and listening through the holistic integrated teaching method.
Date: August 2006
Creator: Moosavi, Amir
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Intangible Qualities of Rare Books: Toward a Decision-Making Framework for Preservation Management in Rare Book Collections, Based Upon the Concept of the Book as Object (open access)

Intangible Qualities of Rare Books: Toward a Decision-Making Framework for Preservation Management in Rare Book Collections, Based Upon the Concept of the Book as Object

For rare book collections, a considerable challenge is involved in evaluating collection materials in terms of their inherent value, which includes the textual and intangible information the materials provide for the collection's users. Preservation management in rare book collections is a complex and costly process. As digitization and other technological advances in surrogate technology have provided new forms representation, new dilemmas in weighing the rare book's inherently valuable characteristics against the possibly lesser financial costs of surrogates have arisen. No model has been in wide use to guide preservation management decisions. An initial iteration of such a model is developed, based on a Delphi-like iterative questioning of a group of experts in the field of rare books. The results are used to synthesize a preservation management framework for rare book collections, and a small-scale test of the framework has been completed through two independent analyses of five rare books in a functioning collection. Utilizing a standardized template for making preservation decisions offers a variety of benefits. Preservation decisions may include prioritizing action upon the authentic objects, or developing and maintaining surrogates in lieu of retaining costly original collection materials. The framework constructed in this study provides a method for reducing …
Date: May 2006
Creator: Sheehan, Jennifer Karr
Object Type: Thesis or Dissertation
System: The UNT Digital Library
An Integrated Architecture for Ad Hoc Grids (open access)

An Integrated Architecture for Ad Hoc Grids

Extensive research has been conducted by the grid community to enable large-scale collaborations in pre-configured environments. grid collaborations can vary in scale and motivation resulting in a coarse classification of grids: national grid, project grid, enterprise grid, and volunteer grid. Despite the differences in scope and scale, all the traditional grids in practice share some common assumptions. They support mutually collaborative communities, adopt a centralized control for membership, and assume a well-defined non-changing collaboration. To support grid applications that do not confirm to these assumptions, we propose the concept of ad hoc grids. In the context of this research, we propose a novel architecture for ad hoc grids that integrates a suite of component frameworks. Specifically, our architecture combines the community management framework, security framework, abstraction framework, quality of service framework, and reputation framework. The overarching objective of our integrated architecture is to support a variety of grid applications in a self-controlled fashion with the help of a self-organizing ad hoc community. We introduce mechanisms in our architecture that successfully isolates malicious elements from the community, inherently improving the quality of grid services and extracting deterministic quality assurances from the underlying infrastructure. We also emphasize on the technology-independence of our …
Date: May 2006
Creator: Amin, Kaizar Abdul Husain
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Interfacial Studies of Bimetallic Corrosion in Copper/Ruthenium Systems and Silicon Surface Modification with Organic and Organometallic Chemistry

Access: Use of this item is restricted to the UNT Community
To form Cu interconnects, dual-damascene techniques like chemical mechanical planarization (CMP) and post-CMP became inevitable for removing the "overburden" Cu and for planarizing the wafer surface. During the CMP processing, Cu interconnects and barrier metal layers experience different electrochemical interactions depending on the slurry composition, pH, and ohmic contact with adjacent metal layers that would set corrosion process. Ruthenium as a replacement of existing diffusion barrier layer will require extensive investigation to eliminate or control the corrosion process during CMP and post CMP. Bimetallic corrosion process was investigated in the ammonium citrate (a complexing agent of Cu in CMP solutions) using micro test patterns and potentiodynamic measurements. The enhanced bimetallic corrosion of copper observed is due to noble behavior of the ruthenium metal. Cu formed Cu(II)-amine and Cu(II)-citrate complexes in alkaline and acidic solutions and a corrosion mechanism has been proposed. The currently used metallization process (PVD, CVD and ALD) require ultra-high vacuum and are expensive. A novel method of Si surface metallization process is discussed that can be achieved at room temperature and does not require ultra-high vacuum. Ruthenation of Si surface through strong Si-Ru covalent bond formation is demonstrated using different ruthenium carbonyl compounds. RBS analysis accounted for …
Date: August 2006
Creator: Nalla, Praveen Reddy
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Interorganizational Relationships: The Effects of Organizational Efficacy on Member Firm Performance

Access: Use of this item is restricted to the UNT Community
Relationships between the collective actors within interorganizational relationships are a growing area of research in management. Interorganizational networks continue to be a popular mechanism used by organizations to achieve greater performance. Organizations develop competencies to work with other organizations, but the confidence of these organizations to use these strengths for a competitive advantage has yet to be empirically examined. The purpose of this study is to examine organizational efficacy, how competencies may related to that efficacy, and the relationship of efficacy with performance. The goal of this study is to observe the relationship among trust, dependence, information quality, continuous quality improvement, and supplier flexibility with organizational efficacy. In addition, the relationship between organizational efficacy and performance is also observed. There are two primary research questions driving this study. First, what is the relationship between trust, dependence, information quality, continuous quality improvement, supplier flexibility and organizational efficacy? Second, what is the relationship between organizational efficacy and performance? The theories supporting the hypotheses generated from these questions include theories such as social cognitive theory, quality improvement, and path-goal theory. Data collected from the suppliers of a large university support the hypotheses. Regression analysis and structure coefficients were used to analyze the data. …
Date: August 2006
Creator: McDowell, William C.
Object Type: Thesis or Dissertation
System: The UNT Digital Library