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Prophet Inequalities for Multivariate Random Variables with Cost for Observations
In prophet problems, two players with different levels of information make decisions to optimize their return from an underlying optimal stopping problem. The player with more information is called the "prophet" while the player with less information is known as the "gambler." In this thesis, as in the majority of the literature on such problems, we assume that the prophet is omniscient, and the gambler does not know future outcomes when making his decisions. Certainly, the prophet will get a better return than the gambler. But how much better? The goal of a prophet problem is to find the least upper bound on the difference (or ratio) between the prophet's return, M, and the gambler's return, V. In this thesis, we present new prophet problems where we seek the least upper bound on M-V when there is a fixed cost per observations. Most prophet problems in the literature compare M and V when prophet and gambler buy (or sell) one asset. The new prophet problems presented in Chapters 3 and 4 treat a scenario where prophet and gambler optimize their return from selling two assets, when there is a fixed cost per observation. Sharp bounds for the problems on small …
Date:
August 2019
Creator:
Brophy, Edmond M.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Safe Routes to School Youth Voices
Many communities are promoting physical activity and active transportation as ways to combat childhood obesity and change sedentary lifestyles of school-age children. Safe Routes to School Youth Voices is a mixed methods approach to understanding the experiences and perceptions of middle school students surrounding the use of active transportation. Student experiences are explored both independently and in comparison to parental perspectives of barriers to actives transportation. Data were collected in the form of parent surveys, observations, student interviews, and student focus groups. This study aims to answer the following primary research questions: (1) What are the conditions experienced along the route? (2) What are the students' perceptions of barriers to active transportation? (3) What are the compensation practices that students take to overcome barriers? and (4) How do the students' perceptions compare with their parents? Interviews and focus groups were transcribed and coded using in-vivo, descriptive, structural and pattern methods. Primary themes which emerged include how conditions of walking to school, personal safety, compensation practices, and systematic barriers all affect the perceptions of active transportation of the student. Findings highlight the difficulties many students face when considering active transportation, and discuss the inconsistencies between student experience, parental perceptions, and intervention …
Date:
August 2019
Creator:
Wright, Patricia Ann
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Ligand Effects in Gold(I) Acyclic Diaminocarbene Complexes and Their Influence on Regio- and Enantioselectivity of Homogeneous Gold(I) Catalysis
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This dissertation focuses on the computational investigation of gold(I) acyclic diaminocarbene (ADC) complexes and their application in homogeneous gold(I) catalysis. Chapter 2 is an in-depth computational investigation of the σ- and π-bonding interactions that make up the gold-carbene bond. Due to the inherent conformation flexibility of ADC ligands, distortions of the carbene plane can arise that disrupt orbital overlap between the lone pairs on the adjacent nitrogen atoms and the empty p-orbital of the carbene. This study investigated the affect these distortions have on the strength of the σ- and π-bonding interactions. This investigation demonstrated that while these distortions can affect the σ- and π-bonding interactions, the ADC ligand have to become highly distorted before any significant change in energy of either the σ- or π-bonding interactions occurs. Chapter 3 is a collaborative investigation between experimental and computational methods, DFT calculations were employed to support the experimental catalytic results and determine the role that steric effects have in controlling the regioselectivity of a long-standing electronically controlled gold(I)-catalyzed tandem 1,6-enyne cyclization/hydroarylation reaction with indole. This study demonstrated that by sterically hindering nucleophilic attack of indole at the favored position, nucleophilic attack would occur at a secondary position leading to the selective …
Date:
August 2019
Creator:
Ellison, Matthew Christopher
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Essential Competencies for Entry-Level Management Positions in the Food and Beverage Industry in Taiwan and Mainland China
The purpose of this study was to identify the essential competencies for entry-level management positions in the food and beverage (F&B) industry based on the perspectives of Taiwanese industry professionals across three groups: work experience in Taiwan and/or mainland China, two F&B sectors (Hotel F&Bs and restaurants), and three management levels (first-line, middle, and top). A total of 515 Taiwanese F&B industry professionals participated in this study with 104 participants currently employed in mainland China, some of whom worked previously in Taiwan, and 411 participants working in Taiwan, without work experience in mainland China. Factor analysis produced four dimensions of important competencies: leadership, F&B management, interpersonal skills, and communication skills. Results indicated that communication skills was the only dimension that showed significant difference between participants with and without work experience in mainland China. The findings of this study indicated that 14 of 41 competency items were ranked in the top 10 based on the responses of the three groups. Participants from all three groups ranked "high level of personal integrity" as the most important competence and "ability to communicate orally in proper English" was ranked as the second most important competence by all groups except the restaurant sector. The results …
Date:
August 2019
Creator:
Huang, Tai-Yi
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Choice Androgyny
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This work provides an alternative theory of gendered consumption that explains chronic and situational shifts in consumers' preferences for masculine, feminine, and androgynous choices, beyond the effects of gender identities.
Date:
August 2019
Creator:
Jones, Niusha
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
A Grundgestalt Analysis of the Clarinet Trio and Clarinet Quintet by Johannes Brahms
The Grundgestalt (Ger: 'basic shape') is a term coined by Arnold Schoenberg to describe the basis for coherence within a musical composition. Although neither precisely defined, nor adequately supported by examples from his literature, the Grundgestalt remains an important facet of Schoenbergian theory. Composed of several gestalten that occur repeatedly, Schoenberg's Grundgestalt functions as a germinating factor within a piece that allows its motivic, thematic, and rhythmic information to become more accessible through their frequent repetition and diverse presentation. In addition to Schoenberg's definition, the first part of this dissertation discusses the individual findings of Schoenberg's pupils Josef Rufer and Rudolf Réti. Subsequently developed by the contributions of David Epstein, Walter Frisch, Patricia Carpenter, Michael Schiano, and Brent Auerbach, their combined efforts then attempt to illustrate the organicism of the Grundgestalt, to clarify its terminology, and to refine the framework of its analysis. Based upon the framework described in the previous chapter, the second half of this dissertation presents the criteria for the determination of the Grundgestalt. Beginning with a derivation of Brent Auerbach's proto-Grundgestalt analysis that catalogs the various voice-leading strands of a given composition into a summary chart that tracks the frequency of each motive's occurrence within its …
Date:
August 2019
Creator:
McConnell, Michael (Woodwind instrument player)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
EverWind: Original Composition and Analytical Essay on the Role of Inspiration and Nature in Music
This paper provides an overview of the inspiration, research, and creative process involved in the composition of EverWind for orchestra and electronics. EverWind is based on field recordings from the American Southwest. The composition uses pitch material derived from spectral analysis of the recordings, and it incorporates a fixed media element using the field recordings that are then electronically manipulated to various degrees; this fixed media element is played alongside the orchestra. The paper also analyzes John Luther Adams' Dark Waves for Orchestra and Electronics and R. Murray Schafer's Music for Wilderness Lake in order to place EverWind within the broader musical context.
Date:
August 2019
Creator:
Gerard, Garrison
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Telemedicine in Schools: Exploring Parent Perceptions and Desires
School-based health clinics are on the rise while telemedicine is increasingly used to provide communities access to health care. Incorporating the two together poses to create healthier school communities. Parker County Hospital District collaborated with Weatherford Independent School District (WISD) to implement the district's first telemedicine school-based health clinic. This project is in partnership with Parker County Hospital District to explore parent perceptions and desires of telemedicine and school-based health clinics to facilitate utilization among the WISD community.
Date:
August 2019
Creator:
Smith, Bethany Noel
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Shifting Identities: A Qualitative Inquiry of Black Transgender Men's Experiences
The purpose of this transcendental phenomenological study was to explore Black transgender men's experiences navigating systems of racism and transphobia. To this end, I utilized a critical race theory and intersectionality theory framework to answer the following question: What are Black transgender men's experiences with power, privilege, and oppression? The ten Black transgender men and transmasculine people who participated in this study provided detailed and moving accounts of their experiences with systems of oppression. Six major themes were prominent throughout participant narratives: (1) developing an empowered view of self, (2) navigating double consciousness, (3) having a target on your back, (4) strategies of resilience, (5) culture of silence, and (6) finding quality care. Overall, participants offered insight and keen awareness of their intersecting racial and gender identities, as well as speaking intimately about how the shift from societal perceptions and identification as a Black woman to a Black man impacted their sense of self and views of the world. Additionally, implications and conclusions drawn from the stories of participants offer recommendations for counselors, mental health professionals, practitioners, and programs to consider implementing to provide culturally responsive and competent care to Black transgender men.
Date:
August 2019
Creator:
White, Mickey E.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
SurfKE: A Graph-Based Feature Learning Framework for Keyphrase Extraction
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Current unsupervised approaches for keyphrase extraction compute a single importance score for each candidate word by considering the number and quality of its associated words in the graph and they are not flexible enough to incorporate multiple types of information. For instance, nodes in a network may exhibit diverse connectivity patterns which are not captured by the graph-based ranking methods. To address this, we present a new approach to keyphrase extraction that represents the document as a word graph and exploits its structure in order to reveal underlying explanatory factors hidden in the data that may distinguish keyphrases from non-keyphrases. Experimental results show that our model, which uses phrase graph representations in a supervised probabilistic framework, obtains remarkable improvements in performance over previous supervised and unsupervised keyphrase extraction systems.
Date:
August 2019
Creator:
Florescu, Corina Andreea
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Impact of Property Tax Exemptions on the Fiscal Behavior of Cities: A Longitudinal Analysis of 41 Texas Cities
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As a form of tax and expenditure limitations, property tax exemptions result in an utility gap between two groups of population residing in the same community: free-riders who are paying less than they receive and contributors who are paying more than they receive. This utility gap is problematic to municipalities because contributors may exit the city as this gap becomes wider. How do municipalities respond to the increasing amount of property tax exemptions? Using 41 Texas cities data from 2000 to 2016, this dissertation examines how property tax exemptions affect municipalities' fiscal behavior. The analysis indicates that property tax exemptions lead to higher property tax burden, change municipalities' revenue structure, and lead to less capital spending.
Date:
August 2019
Creator:
Sun, Jingran
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Three Essays on Artificial Intelligence Adoption and Use
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Use of this item is restricted to the UNT Community
Artificial intelligence (AI) is quickly transforming business operations and society, as AI capabilities are incorporated into applications ranging from mobile personal assistants to self-driving cars. The potentially disruptive nature of AI calls for an extensive investigation into all aspects of AI-human interactions at individual, group, organizational and market levels. However, there is paucity of academic information systems (IS) research in this area that goes beyond the development and testing of specific narrow AI capabilities. AI represents an important opportunity for organizational and behavioral IS researchers, but also presents challenges associated with the underlying complexity of AI technologies and the diversity of AI applications. Understanding how existing AI research and business practice relate to traditional areas of IS research is an important step towards creating a comprehensive behavioral and organizational AI research agenda. This dissertation seeks to achieve a dual purpose in a series of three essays. Essay 1 seeks to understand the current state of business AI research and practice in business through a quantitative literature review, relate the findings to traditional IS research areas, and identify potentially fruitful research areas for AI-focused IS research. Essays 2 and 3 seek to address specific research questions related to one of such …
Date:
August 2019
Creator:
Nguyen, Quynh
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Transcription and Critical Edition of Carl Nielsen's Songs, Op. 4 and 10 for Flute and Piano
Widely regarded as one of the most significant composers of the late nineteenth and early twentieth centuries, Carl Nielsen and his music have come to define the early twentieth-century musical traditions of Denmark. His original songs for voice and piano are often revered as popular folk tunes and contributed to his status as a national icon. My dissertation explores Nielsen's vocal repertoire through a multipart project that includes transcribing and editing eleven of Nielsen's early songs from Op. 4 (1891) and Op. 10 (1894), originally for voice and piano, for flute and piano. I discuss the reception history and context of Nielsen's Songs, the important role of transcription in flute literature, and provide full score transcription of the original works for flute and piano. Many vocal works have been transcribed for flute from the original vocal score, providing variety in programming and attracting diverse audiences to performances. Transcription offers scholars a new view into a work, by determining what elements of the piece are integral to maintain the composer's intentions.
Date:
August 2019
Creator:
Pillman, Laura, 1990-
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Processing-Structure-Property Relationships of Reactive Spark Plasma Sintered Boron Carbide-Titanium Diboride Composites
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Sintering parameter effects on the microstructure of boron carbide and boron carbide/titanium diboride composites are investigated. The resulting microstructure and composition are characterized by scanning electron microscopy (SEM), x-ray microscopy (XRM) and x-ray diffraction (XRD). Starting powder size distribution effects on microstructure are present and effect the mechanical properties. Reactive spark plasma sintering introduces boron nitride (BN) intergranular films (IGF's) and their effects on fracture toughness, hardness and flexural strength are shown. Mechanical testing of Vickers hardness, 3-point bend and Chevron notch was done and the microstructural effects on the resulting mechanical properties are investigated.
Date:
August 2019
Creator:
Lide, Hunter
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Doing Our Work Better, Together: An Application of Relational Coordination Theory to Explore and Shape Excellence in Trauma Care
I conducted a mixed-methods collaborative ethnography using the lens of relational coordination theory. This included a qualitative survey using an established tool to analyze the relational dimensions of multidisciplinary teamwork, participant observation, interviews, and narrative surveys. Findings were presented to clinicians in working groups for further interpretation and to facilitate co-creation of targeted interventions designed to improve team relationships and performance. I engaged a complex multidisciplinary network of ~500 care providers dispersed across seven core interdependent clinical disciplines. Initial findings highlighted the importance of each dimension of relational coordination in trauma care. Narrative survey and ethnographic findings further highlighted the centrality of team briefings and a translational simulation program in contributing positively to team culture and relational ties. A range of 16 interventions – focusing on structural, process and relational dimensions – were co-created with participants after reflecting on findings and are now being implemented and evaluated by various trauma care providers. Relational coordination theory is a valuable way to conceptualize the coordination of trauma care. Collaborative reflection on quantitative and narrative data through this lens can be used as a community-based quality improvement tool.
Date:
August 2019
Creator:
Purdy, Eve Isabelle
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Differences in Coping Strategies and Multifaceted Psychological Outcomes among Trauma Survivors
The World Health Organization has proposed for the ICD-11 a differentiation of symptoms to distinguish separate disorders of PTSD and complex PTSD (CPTSD), rather than one disorder of PTSD as in the current DSM-5. In addition, the accuracy and usefulness of the borderline personality disorder (BPD) diagnosis has been debated for years due to this history of trauma often associated with the diagnosis. New instruments have been developed to assess CPTSD, allowing needed research to expand our understanding of CPTSD and how it may differ from PTSD. The present study explored the relationships between the three different patterns of symptom expression associated with these disorders and various coping strategies in a sample of trauma survivors. A canonical correlation analysis (CCA) showed a significant relationship between trauma symptoms and coping strategies and suggested that individuals with higher borderline personality disorder symptoms, and subsequently complex PTSD and PTSD symptoms, were more likely to cope using avoidant coping strategies- behavioral disengagement, denial, and substance use. This finding was similar to previous research findings that suggested high rates of negative psychological outcomes for adults cognitive and behavioral avoidant coping strategies. Contributions from other coping techniques, such as restraint and venting, also showed significant, but …
Date:
August 2019
Creator:
Flachs, Amanda Shaunessy
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Oration, Concerto Elegiaco by Frank Bridge: A Practical Guide for Performance
English composer Frank Bridge (1879-1941) is well known as Benjamin Britten's teacher and to a lesser degree for his chamber music. Because his mature creative period occurred between the First and Second World War, his works were not well studied or performed until the 1970s, well after his death. This dissertation discusses Bridge's life and his music, how World War I affected in this work, and specifically the work Oration Concerto Elagiaco. Oration is considered historically in terms of its meaning and delayed premiere. Additionally, the work's fantasy arch form, Bridge's signature compositional style, and the character of each section is discussed. Finally, this dissertation provides a practical guide to the work, providing practice and performance suggestions for the numerous complex and technically challenging portions of the concerto.
Date:
August 2019
Creator:
Yoo, Kyungjin
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Charpy Impact Testing of Twinning Induced Plasticity and Transformation Induced Plasticity High Entropy Alloys
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Use of this item is restricted to the UNT Community
High entropy alloys (HEAs) are a new class of solid solution alloys that contain multiple principal elements and possess excellent mechanical properties, from corrosion resistance to fatigue and wear resistance. Even more recently, twinning induced plasticity (TWIP) and transformation induced plasticity (TRIP) non-equiatomic high entropy alloys have been engineered, promising increased strength and ductility as compared to their equiatomic counterparts. However, impact and fracture resistance of these HEAs has not been studied as much as their other mechanical properties. In this thesis, the hardness, tensile properties, and Charpy impact energy of Al0.3CoCrFeNi, a TWIP HEA, and 50Fe-30Mn-10Co-10Cr (at.%), a TRIP HEA, was explored. First, three processing conditions, (1) as-received, (2) recrystallized, and (3) peak hardness, were chosen for each alloy and verified with Vickers microhardness measurements. Next, the tensile properties of each alloy and condition were investigated. Charpy impact specimen size was then selected based on the final plate thickness, and the machined samples were tested. Plastic zone size and change in sample thickness in the deformed region of each condition after testing was measured. Post-impact test inspection of the samples in all conditions showed that the samples were in tension near the V-notch root and in compression at the …
Date:
August 2019
Creator:
Zellner, Samantha R
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Enhanced Approach for the Classification of Ulcerative Colitis Severity in Colonoscopy Videos Using CNN
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Ulcerative colitis (UC) is a chronic inflammatory disease characterized by periods of relapses and remissions affecting more than 500,000 people in the United States. To achieve the therapeutic goals of UC, which are to first induce and then maintain disease remission, doctors need to evaluate the severity of UC of a patient. However, it is very difficult to evaluate the severity of UC objectively because of non-uniform nature of symptoms and large variations in their patterns. To address this, in our previous works, we developed two different approaches in which one is using the image textures, and the other is using CNN (convolutional neural network) to measure and classify objectively the severity of UC presented in optical colonoscopy video frames. But, we found that the image texture based approach could not handle larger number of variations in their patterns, and the CNN based approach could not achieve very high accuracy. In this paper, we improve our CNN based approach in two ways to provide better accuracy for the classification. We add more thorough and essential preprocessing, and generate more classes to accommodate large variations in their patterns. The experimental results show that the proposed preprocessing can improve the overall accuracy …
Date:
August 2019
Creator:
Sure, Venkata Leela
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Use of Data Analytics in Internal Audit to Improve Decision-Making: An Investigation of Data Visualizations and Data Source
The purpose of this dissertation was to examine how managers' judgments from an internal auditor's recommendation are influenced by some aspects of newer data sources and the related visualizations. This study specifically examined how managers' judgments from an internal auditor's recommendation are influenced by the (1) supportiveness of non-financial data with the internal auditor's recommendation and (2) evaluability of visual representations for non-financial data used to communicate the recommendation. This was investigated in a setting where financial data does not support the internal auditor's recommendation. To test my hypotheses, I conducted an experiment that uses an inventory write-down task to examine the likelihood that a manager agrees with an internal auditor's inventory write-down recommendation. This task was selected as it requires making a prediction and both financial and newer non-financial data sources are relevant to inform this judgment. The study was conducted with MBA students who proxy for managers in organizations. Evaluability of visual representations was operationalized as the (1) proximity of financial and non-financial graphs, and (2) type of non-financial graph as requiring a length judgment or not. This dissertation contributes to accounting literature and the internal auditing profession. First, I contribute to recent experimental literature on data analytics …
Date:
August 2019
Creator:
Seymore, Megan
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Modeling and Design of Antennas for Loosely Coupled Links in Wireless Power Transfer Applications
Wireless power transfer (WPT) systems are important in many areas, such as medical, communication, transportation, and consumer electronics. The underlying WPT system is comprised of a transmitter (TX) and receiver (RX). For biomedical applications, such systems can be implemented on rigid or flexible substrates and can be implanted or wearable. The efficiency of a WPT system is based on power transfer efficiency (PTE). Many WPT system optimization techniques have been explored to achieve the highest PTE possible. These are based on either a figure-of-merit (FOM) approach, quality factor (Q-factor) maximization, or by sweeping values for coil geometries. Four WPT systems for biomedical applications are implemented with inductive coupling. The thesis later presents an optimization technique for finding the maximum PTE of a range of frequencies and coil shapes through frequency, geometry and shape sweeping. Five optimized TX coil designs for different operating frequencies are fabricated for three shapes: square, hexagonal, and octagonal planar-spirals. The corresponding RX is implemented on polyimide tape with ink-jet-print (IJP) silver. At 80 MHz, the maximum measured PTE achieved is 2.781% at a 10 mm distance in the air for square planar-spiral coils.
Date:
August 2019
Creator:
Sinclair, Melissa Ann
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
BSM Message and Video Streaming Quality Comparative Analysis Using Wave Short Message Protocol (WSMP)
Vehicular ad-hoc networks (VANETs) are used for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. The IEEE 802.11p/WAVE (Wireless Access in Vehicular Environment) and with WAVE Short Messaging Protocol (WSMP) has been proposed as the standard protocol for designing applications for VANETs. This communication protocol must be thoroughly tested before reliable and efficient applications can be built using its protocols. In this paper, we perform on-road experiments in a variety of scenarios to evaluate the performance of the standard. We use commercial VANET devices with 802.11p/WAVE compliant chipsets for both BSM (basic safety messages) as well as video streaming applications using WSMP as a communication protocol. We show that while the standard performs well for BSM application in lightly loaded conditions, the performance becomes inferior when traffic and other performance metric increases. Furthermore, we also show that the standard is not suitable for video streaming due to the bursty nature of traffic and the bandwidth throttling, which is a major shortcoming for V2X applications.
Date:
August 2019
Creator:
Win, Htoo Aung
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Synthesis, Characterization, and Reactivity of Prochiral Ruthenium Clusters and Bimetallic Rhenium Complexes with an Unsymmetrical Diphosphine and Hard-Soft Donor Ligands
The reaction of [BrRe(CO)₄]₂ with 2-(diphenylphosphino)pyridine (PN) and 6-(diphenylphosphino)-2-formylpyridine (PON) was investigated. The reactions were regiospecific and exclusively produced the phosphorus-coordinated products, BrRe(CO)₄(κᵖ-PN) and BrRe(CO)₄(κᴾ-PON). The kinetics for the chelate ring closure (κᴾ→ κᴾᴺ) in BrRe(CO)₄(κᴾ-PN) were confirmed to occur by dissociative CO loss. The reaction of [BrRe(CO)₄]₂ with 2-(diphenylphosphino)pyridine (PN) was modeled computationally by DFT calculations. The preferred reaction pathway for the substitution reaction was determined to occur by direct attack of the pnictogen donor on the dimer and formation of the κᴺ isomer as the kinetic substitution product occurs. The κᴺ kinetic product then rapidly isomerizes to the κᴾ thermodynamic product by way of a reversible ligand dissociation. Treatment of the tetrahedral cluster H₂Ru₃(CO)₃(μ₃-S) (1) with 2-(diphenylphosphino)thioanisole (PS) furnishes the cluster H₂Ru₃(CO)₇(κ²-PS)(μ₃-S) (2). Cluster 2, which exhibits a chelated thiophosphine ligand (κ²-PS), exists as a pair of diastereomers with Keq = 1.55 at 298 K that differ in their disposition of ligands at the Ru(CO)(κ²-PS) center. The PS ligand occupies the equatorial sites (Peq, Seq) in the kinetic isomer and axial and equatorial sites (Pax, Seq) in the thermodynamically favored species. The reversible first-order kinetics to equilibrium have been measured experimentally by NMR spectroscopy and HPLC over the …
Date:
August 2019
Creator:
Mayberry, Darrell D.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Higher Education Students' Perspectives on the Influence of Computer-Based Instructional Systems on Self-Efficacy and Motivation
This dissertation aims to identify undergraduate students' perspectives concerning the effectiveness of CBI environments as an instructional tool, and the influence it has on their self-efficacy and motivation. Data was collected from 221 participants from two midwestern universities. A convergent mixed-method research was conducted using a Likert-style survey and semistructured interviews. Stepwise regression, Pearson correlation coefficient, effect sizes and thematic analysis were used to identify significant relationships between variables, and find recurring themes. It was found that over 70% of the student population had positive attitudes towards the use of CBI environments with a mean of 3.5 on a 5-point scale. Students who had a high mean attitude towards CBI systems also had a high mean self-efficacy score. Secondly, four models emerged which suggests that; the value student assign to tasks, the control over the CBI environment, control over their learning, and motivation are significant factors (p>.50) that affect their self-efficacy. Finally, it was found that students' motivation is affected by instructional components, challenges, lack of instructor presence, and feedback. It can be concluded that varying factors that can affect how students' perceive the courses and their abilities, and the implementation of adaptive CBI systems maybe an option to meet …
Date:
August 2019
Creator:
Popkin, Kashieka N.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library