UNT Theses and Dissertations - 420 Matching Results

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Jacques-Antoine-Hippolyte, Comte De Guibert: Father of the Grande Armée

Description: Jacques-Antoine-Hippolyte, comte de Guibert (1743-1790) dedicated his life and career to creating a new doctrine for the French army. Little about this doctrine was revolutionary. Indeed, Guibert openly decried the anarchy of popular participation in government and looked askance at the early days of the Revolution. Rather, Guibert’s doctrine marked the culmination of an evolutionary process that commenced decades before his time and reached fruition in the Réglement of 1791, which remained in force until the 1830s. Not content with military reform, Guibert demanded a political and social constitution to match. His reforms required these changes, demanding a disciplined, service-oriented society and a functional, rational government to assist his reformed military. He delved deeply, like no other contemporary writer, into the linkages between society, politics, and the military throughout his career and his writings. Guibert exerted an overwhelming influence on military thought across Europe for the next fifty years. His military theories provided the foundation for military reform during the twilight of the Old Regime. The Revolution, which adopted most of Guibert’s doctrine in 1791, continued his work. A new army and way of war based on Guibert’s reforms emerged to defeat France’s major enemies. In Napoleon’s hands, Guibert’s army all but conquered Europe by 1807. As other nations adopted French methods, Guibert’s influence spread across the Continent, reigning supreme until the 1830s. This dissertation adopts a biographical approach to examine Guibert’s life and influence on the creation of the French military system that led to Napoleon’s conquest of Europe. As no such biography exists in Anglophone literature, such a work will fill a crucial gap in understanding French military success to 1807. It examines the period of French military reform from 1760 to the creation and use of Napoleon’s Grande Armée from 1803 to 1807, illustrating the importance of ...
Date: August 2014
Creator: Abel, Jonathan, 1985-
Partner: UNT Libraries

Boosting for Learning From Imbalanced, Multiclass Data Sets

Description: In many real-world applications, it is common to have uneven number of examples among multiple classes. The data imbalance, however, usually complicates the learning process, especially for the minority classes, and results in deteriorated performance. Boosting methods were proposed to handle the imbalance problem. These methods need elongated training time and require diversity among the classifiers of the ensemble to achieve improved performance. Additionally, extending the boosting method to handle multi-class data sets is not straightforward. Examples of applications that suffer from imbalanced multi-class data can be found in face recognition, where tens of classes exist, and in capsule endoscopy, which suffers massive imbalance between the classes. This dissertation introduces RegBoost, a new boosting framework to address the imbalanced, multi-class problems. This method applies a weighted stratified sampling technique and incorporates a regularization term that accommodates multi-class data sets and automatically determines the error bound of each base classifier. The regularization parameter penalizes the classifier when it misclassifies instances that were correctly classified in the previous iteration. The parameter additionally reduces the bias towards majority classes. Experiments are conducted using 12 diverse data sets with moderate to high imbalance ratios. The results demonstrate superior performance of the proposed method compared to several state-of-the-art algorithms for imbalanced, multi-class classification problems. More importantly, the sensitivity improvement of the minority classes using RegBoost is accompanied with the improvement of the overall accuracy for all classes. With unpredictability regularization, a diverse group of classifiers are created and the maximum accuracy improvement reaches above 24%. Using stratified undersampling, RegBoost exhibits the best efficiency. The reduction in computational cost is significant reaching above 50%. As the volume of training data increase, the gain of efficiency with the proposed method becomes more significant.
Date: December 2013
Creator: Abouelenien, Mohamed
Partner: UNT Libraries

Cooperative Strategy and Sources of Knowledge Integration Capability and Innovation: A Relational View

Description: Faced with the challenges to addressing the novelties of the changing business environments (e.g., new customer requirement, changes in customers taste and preferences, the introduction of new products or services by competitors), organizations seek to build collaboration among their employees who possess complementary knowledge. Integrating complementary knowledge enhances employees' ability to address environmental challenges and foster innovation. Despite the importance of knowledge integration for innovation, integration of such knowledge becomes difficult when employees lack a shared understanding of knowledge, and when the knowledge is newly generated. Because new knowledge is tacit in nature and highly personal to a particular individual, it is difficult to articulate, making knowledge integration (KI) an arduous task. Lack of shared understanding, the presence of new knowledge, and lack of common interests in employees creates three types of knowledge boundaries – syntactic (information processing) boundaries, semantic (interpretive) boundaries, and pragmatic (political) boundaries. The presence of knowledge boundaries makes it difficult for employees to share and access their knowledge with each other. To overcome the challenges related to the knowledge boundaries, employees use boundary-spanning objects, which are common lexicons, common meaning, and common interests, to share and access their knowledge across the boundaries. Although prior studies have emphasized the importance of knowledge integration of various knowledge sources for innovations, examinations of what enhances KI capability of employees for organizational innovation remain limited. In addition, apart from Carlile, (2004) and Franco (2013), which are both case studies, other studies that examine the role of boundary spanning objects for knowledge integration are missing. The knowledge management literature also fails to measures (the success of common lexicons, common meaning, and common interests for achieving KI capability) boundary spanning objects. Therefore, in this study, new measurement items of boundary spanning objects and novelty are developed to test the hypotheses. A survey-based ...
Date: August 2016
Creator: Acharya, Chandan
Partner: UNT Libraries

Hydrophobicity of Magnetite Coating on Low Carbon Steel

Description: Superhydrophobic coatings (SHC) with excellent self-cleaning and corrosion resistance property is developed on magnetite coated AISI SAE 1020 steel by using a simple immersion method. Roughness measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), contact angle measurement (CAM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), and qualitative characterization of self-cleaning behavior, antifouling property and durability of the coatings are assessed. A water contact angle as high as 152o on the coated surface with excellent self-cleaning and resistivity to corrosion and good longevity in atmospheric air is obtained. Self-cleaning test results prove that these surfaces can find applications in large scale production of engineering materials. Potentiodynamic polarization tests and EIS tests confirm that the superhydrophobic low carbon steel surfaces have better resistance to corrosion compared to bare steel and magnetite coated steel in 3.5% NaCl solution. But the longevity of the coated steel surfaces in 3.5% salt solution is limited, which is revealed by the immersion durability test. However, hydrophobic coatings (HC) have better stability in normal tap water, and it can stay unharmed up to 15 days. Finally, hydrophobic coatings on low carbon steel surface retains hydrophobic in open atmosphere for more than two months. Results of this investigation show surface roughness is a critical factor in manufacturing hydrophobic steel surfaces. Higher contact angles are obtained for rougher and more uniform surfaces. A linear mathematical relationship (y =6x+104; R2 = 0.93) is obtained between contact angle (y) and surface roughness (x).
Date: August 2018
Creator: Akhtar, Mst Alpona
Partner: UNT Libraries

Effectiveness of Fillers for Corrosion Protection of AISI-SAE 1018 Steel in Sea Salt Solution

Description: Corrosion represents the single most frequent cause for product replacement or loss of product functionality with a 5% coat to the industrial revenue generation of any country in this dissertation the efficacy of using filled coatings as a protection coating are investigated. Fillers disrupt the polymer-substrate coating interfacial area and lead to poor adhesion. Conflicting benefits of increasing surface hardness and corrosion with long term durability through loss of adhesion to the substrate are investigated. The effects of filler type, filler concentration and exposure to harsh environments such as supercritical carbon dioxide on salt water corrosion are systematically investigated. The constants maintained in the design of experiments were the substrate, AISI-SAE 1018 steel substrate, and the corrosive fluid synthetic sea salt solution (4.2 wt%) and the polymer, Bismaleimide (BMI). Adhesion strength through pull-off, lap shear and shear peel tests were determined. Corrosion using Tafel plots and electrochemical impedance spectroscopy was conducted. Vickers hardness was used to determine mechanical strength of the coatings. SEM and optical microscopy were used to examine dispersion and coating integrity. A comparison of fillers such as alumina, silica, hexagonal boron nitride, and organophilic montmorillonite clay (OMMT) at different concentrations revealed OMMT to be most effective with the least decrease in adhesion from filler-substrate contact. Subsequently examining filler concentration, a 3 wt% OMMT was found to be most effective. A comparison of unmodified and modified BMI with 3 wt% OMMT exposed and not exposed to supercritical carbon dioxide showed that the BMI provided better corrosion protection; however, OMMT provided better wear, shear, and hardness performance.
Date: May 2017
Creator: Al-Shenawa, Amaal Abdallah Ali
Partner: UNT Libraries

University Faculty and Diverse Students' Self-Reported Attitudes toward Inclusive Teaching Strategies

Description: This dissertation examines a university faculty (n = 41) and diverse students (n = 93) including students with disability (n = 44), students without disability (n = 21), and international students (n = 28) regarding their attitudes toward and actions associated with inclusive instruction based on the universal design for learning (UDL) principles and practices. Two online surveys, the Inclusive Teaching Strategies Inventory (ITSI) and the Inclusive Teaching Strategies Inventory-Student (ITSI-S), were administered at a large, public Southwest university (N = 134). The ITSI and ITSI-S contain seven subscales representing the following constructs: (a) accommodations, (b) accessible course materials, (c) course modifications, (d) inclusive lecture strategies, (e) inclusive classroom, (f) inclusive assessment, and (g) disability laws and concepts. A series of multivariate analyses of variances (MANOVAs) measured the overall of attitude subscales and overall action subscales, and an independent-samples test (t-test) compared mean scores on the seven Attitude subscales and seven Action subscales to identify predictors of these attitudes and actions among faculty and students. The main findings were (a) significant differences among diverse students, where students with disability responded negatively on the Action subscales and (b) significant differences between faculty and diverse students where international students had a positive attitude on the Attitude subscales, whereas students with disability had a negative attitude on the Action subscales toward the actual practices of their faculty. Results of the current study respond to the gap in the literature by examining the inclusive instruction environment based on UDL in a university environment. The implications of these findings and recommendations for future research are discussed.
Date: May 2017
Creator: Alamri, Abdulrahman Saleh
Partner: UNT Libraries

New Frameworks for Secure Image Communication in the Internet of Things (IoT)

Description: The continuous expansion of technology, broadband connectivity and the wide range of new devices in the IoT cause serious concerns regarding privacy and security. In addition, in the IoT a key challenge is the storage and management of massive data streams. For example, there is always the demand for acceptable size with the highest quality possible for images to meet the rapidly increasing number of multimedia applications. The effort in this dissertation contributes to the resolution of concerns related to the security and compression functions in image communications in the Internet of Thing (IoT), due to the fast of evolution of IoT. This dissertation proposes frameworks for a secure digital camera in the IoT. The objectives of this dissertation are twofold. On the one hand, the proposed framework architecture offers a double-layer of protection: encryption and watermarking that will address all issues related to security, privacy, and digital rights management (DRM) by applying a hardware architecture of the state-of-the-art image compression technique Better Portable Graphics (BPG), which achieves high compression ratio with small size. On the other hand, the proposed framework of SBPG is integrated with the Digital Camera. Thus, the proposed framework of SBPG integrated with SDC is suitable for high performance imaging in the IoT, such as Intelligent Traffic Surveillance (ITS) and Telemedicine. Due to power consumption, which has become a major concern in any portable application, a low-power design of SBPG is proposed to achieve an energy- efficient SBPG design. As the visual quality of the watermarked and compressed images improves with larger values of PSNR, the results show that the proposed SBPG substantially increases the quality of the watermarked compressed images. Higher value of PSNR also shows how robust the algorithm is to different types of attack. From the results obtained for the energy- efficient SBPG ...
Date: August 2016
Creator: Albalawi, Umar Abdalah S
Partner: UNT Libraries

Development of an Instrument to Measure the Level of Acceptability and Tolerability of Cyber Aggression: Mixed-Methods Research on Saudi Arabian Social Media Users

Description: Cyber aggression came about as a result of advances in information communication technology and the aggressive usage of the technology in real life. Cyber aggression can take on many forms and facets. However, the main focus of this study is cyberbullying and cyberstalking through information sharing practices that might constitute digital aggressive acts. Human aggression has been extensively investigated. Studies focusing on understanding the causes and effects that can lead to physical and digital aggression have shown the prevalence of cyber aggression in different settings. Moreover, these studies have shown strong relationship between cyber aggression and the physiological and physical trauma on both perpetrators and their victims. Nevertheless, the literature shows a lack of studies that could measure the level of acceptance and tolerance of these dangerous digital acts. This study is divided into two main stages; Stage one is a qualitative pilot study carried out to explore the concept of cyber aggression and its existence in Saudi Arabia. In-depth interviews were conducted with 14 Saudi social media users to collect understanding and meanings of cyber aggression. The researcher followed the Colaizzi’s methods to analyze the descriptive data. A proposed model was generated to describe cyber aggression in social media applications. The results showed that there is a level of acceptance to some cyber aggression acts due to a number of factors. The second stage of the study is focused on developing scales with reliable items that could determine acceptability and tolerability of cyber aggression. In this second stage, the researcher used the factors discovered during the first stage as source to create the scales’ items. The proposed methods and scales were analyzed and tested to increase reliability as indicated by the Cronbach’s Alpha value. The scales were designed to measure how acceptable and tolerable is cyber-bullying, cyber-stalking in Saudi ...
Date: May 2016
Creator: Albar, Ali A
Partner: UNT Libraries

Decision Makers’ Cognitive Biases in Operations Management: An Experimental Study

Description: Behavioral operations management (BOM) has gained popularity in the last two decades. The main theme in this new stream of research is to include the human behavior in Operations Management (OM) models to increase the effectiveness of such models. BOM is classified into 4 areas: cognitive psychology, social psychology, group dynamics and system dynamics (Bendoly et al. 2010). This dissertation will focus on the first class, namely cognitive psychology. Cognitive psychology is further classified into heuristics and biases. Tversky and Kahneman (1974) discussed 3 heuristics and 13 cognitive biases that usually face decision makers. This dissertation is going to study 6 cognitive biases under the representativeness heuristic. The model in this dissertation states that cognitive reflection of the individual (Frederick 2005) and training about cognitive biases in the form of warning (Kaufmann and Michel 2009) will help decisions’ makers make less biased decisions. The 6 cognitive biases investigated in this dissertation are insensitivity to prior probability, insensitivity to sample size, misconception of chance, insensitivity to predictability, the illusion of validity and misconception of regression. 6 scenarios in OM contexts have been used in this study. Each scenario corresponds to one cognitive bias. Experimental design has been used as the research tool. To see the impact of training, one group of the participants received the scenarios without training and the other group received them with training. The training consists of a brief description of the cognitive bias as well as an example of the cognitive bias. Cognitive reflection is operationalized using cognitive reflection test (CRT). The survey was distributed to students at University of North Texas (UNT). Logistic regression has been employed to analyze data. The research shows that participants show the cognitive biases proposed by Tversky and Kahneman. Moreover, CRT is significant factor to predict the cognitive bias in two ...
Date: May 2016
Creator: Alkhars, Mohammed
Partner: UNT Libraries

Radio Resource Control Approaches for LTE-Advanced Femtocell Networks

Description: The architecture of mobile networks has dramatically evolved in order to fulfill the growing demands on wireless services and data. The radio resources, which are used by the current mobile networks, are limited while the users demands are substantially increasing. In the future, tremendous Internet applications are expected to be served by mobile networks. Therefore, increasing the capacity of mobile networks has become a vital issue. Heterogeneous networks (HetNets) have been considered as a promising paradigm for future mobile networks. Accordingly, the concept of small cell has been introduced in order to increase the capacity of the mobile networks. A femtocell network is a kind of small cell networks. Femtocells are deployed within macrocells coverage. Femtocells cover small areas and operate with low transmission power while providing high capacity. Also, UEs can be offloaded from macrocells to femtocells. Thus, the capacity can be increased. However, this will introduce different technical challenges. The interference has become one of the key challenges for deploying femtocells within a certain macrocells coverage. Undesirable impact of the interference can degrade the performance of the mobile networks. Therefore, radio resource management mechanisms are needed in order to address key challenges of deploying femtocells. The objective of this work is to introduce radio resource control approaches, which are used to increase mobile networks' capacity and alleviate undesirable impact of the interference. In addition, proposed radio resource control approaches ensure the coexistence between macrocell and femtocells based on LTE-Advanced environment. Firstly, a novel mechanism is proposed in order to address the interference challenge. The proposed approach mitigates the impact of interference based on controlling radio sub-channels' assignment and dynamically adjusting the transmission power. Secondly, a dynamic strategy is proposed for the FFR mechanism. In the FFR mechanism, the whole spectrum is divided into four fixed sub-channels and each ...
Date: August 2018
Creator: Alotaibi, Sultan Radhi
Partner: UNT Libraries

Customers' Attitudes toward Mobile Banking Applications in Saudi Arabia

Description: Mobile banking services have changed the design and delivery of financial services and the whole banking sector. Financial service companies employ mobile banking applications as new alternative channels to increase customers' convenience and to reduce costs and maintain profitability. The primary focus of this study was to explore the Saudi bank customers' perceptions about the adoption of mobile banking applications and to test the relationships between the factors that influence mobile banking adoption as independent variables and the action to adopt them as the dependent variable. Saudi customers' perceptions were tested based on the extended versions of IDT, TAM and other diffusion of innovation theories and frameworks to generate a model of constructs that can be used to study the use and the adoption of mobile technology by users. Koenig-Lewis, Palmer, & Moll's (2010) model was used to test its constructs of (1) perceived usefulness, (2) perceived ease of use, (3) perceived compatibility, (4) perceived credibility, (5) perceived trust, (6) perceived risk, and (7) perceived cost, and these were the independent variables in current study. This study revealed a high level of adoption that 82.7% of Saudis had adopted mobile banking applications. Also, the findings of this study identified a statistically significant relationship between all of demographic differences: gender, education level, monthly income, and profession and mobile banking services among adopters and non-adopters. Seven attributes relating to the adoption of mobile banking applications were evaluated in this study to assess which variables affected Saudi banks customers in their adoption of mobile banking services. The findings indicated that the attributes that significantly affected the adoption of mobile banking applications among Saudis were perceived trust, perceived cost, and perceived risk. These three predictors, as a result, explained more than 60% of variance in intention to adopt mobile banking technology in Saudi Arabia. ...
Date: August 2016
Creator: Alshara, Mohammed Ali
Partner: UNT Libraries

Novel Role of Trypsin in Zebrafish

Description: It has been shown previously in our laboratory that zebrafish produce trypsin from their gills when they are under stress, and this trypsin is involved in thrombocyte activation via PAR2 during gill bleeding. In this study, I investigated another role of the trypsin that is secreted from zebrafish. This investigation has demonstrated a novel role of trypsin in zebrafish. Not only did this investigation demonstrate the role of trypsin in zebrafish behavior, but also it showed that PAR2 might be the receptor that is involved in trypsin-mediated behavioral response. In addition, we have shown that Gq and ERK inhibitors are able to block the trypsin pathway and prevent the escaping behavior. Finally, the results of this investigation suggest that the cells that respond to trypsin are surface cells, which have an appearance similar to that of neuromast cells.
Date: May 2013
Creator: Alsrhani, Abdullah Falleh
Partner: UNT Libraries

Studies in Trypsin as an Alarm Substance in Zebrafish

Description: Previous studies have shown that fish release alarming substances into the water to alert their kin to escape from danger. In our laboratory, we found that zebrafish produce trypsin and release it from their gills into the environment when they are under stress. By placing the zebrafish larvae in the middle of a small tank and then placing trypsin at one end of the tank, we observed that the larvae moved away from the trypsin zone and almost to the opposite end of the tank. This escape response was significant and did not occur in response to the control substances, bovine serum albumin (BSA), Russell's viper venom (RVV), and collagen. Also, previously, we had shown that the trypsin could act via a protease-activated receptor-2 (PAR2) on the surface of the cells. Therefore, we hypothesized that trypsin would induce a change in neuronal activity in the brain via PAR2-mediated signaling in cells on the surface of the fish body. To investigate whether the trypsin-responsive cells were surface cells, we generated a primary cell culture of zebrafish keratinocytes, confirmed these cells' identity by specific marker expression, and then incubated these cells with the calcium indicator Fluo-4 and exposed them to trypsin. By using calcium flux assay in a flow-cytometer, we found that trypsin-treated keratinocytes showed an increase in intracellular calcium release. To test whether PAR2 mediates the escape response to trypsin, we treated larvae with a PAR2 antagonist and showed that the trypsin-initiated escape response was abrogated. Furthermore, par2a mutants with knockdown of par2a by the piggyback knockdown method failed to respond to trypsin. Trypsin treatment of adult fish led to an approximately 2-fold increase in brain c-fos mRNA levels 45 mins after trypsin treatment, suggesting that trypsin signals may have reached the brain, probably via a spinothalamic pathway. Taken together, our ...
Date: August 2018
Creator: Alsrhani, Abdullah Falleh
Partner: UNT Libraries

The Use of Technology in the Early Childhood Schools and Homes and Its Impact on the Social and Language Development of Children: Perspectives of Parents and Teachers in Kuwait

Description: This study was aimed at understanding the use of technology in early childhood school and home settings as well as its impact on students' social and language development, specifically with children aged four to seven from two schools (Kindergarten and elementary) in Kuwait. The study followed a qualitative design in which the interpretative approach was applied. Non-participant observations were conducted to gather data concerning the actual use of technology in the classrooms, they were followed by interviews with teachers and a group of parents from each classroom. The study used Vygotsky's social development theory as a framework for the analysis of data. The analysis showed limitations in the use of technology in the classroom; teachers identified a need for training to increase their knowledge about how to integrate technology into instruction. Also, the limited availability of up-to-date technology was viewed as a challenge. Teachers and parents agreed that the use of technology may foster social and language development for most students, on the condition that their use is supervised and guided by an adult. However, they also perceived that technology could have a negative impact on the development of students' social development, an area that requires further investigation.
Date: August 2018
Creator: Alsuhail, Saffa Z A J Zaid
Partner: UNT Libraries

Improving the Gameplay Experience and Guiding Bottom Players in an Interactive Mapping Game

Description: In game based learning, motivating the players to learn by providing them a desirable gameplay experience is extremely important. However, it's not an easy task considering the quality of today's commercial non-educational games. Throughout the gameplay, the player should neither get overwhelmed nor under-challenged. The best way to do so is to monitor the player's actions in the game because these actions can tell the reason behind the player's performance. They can also tell about the player's lacking competencies or knowledge. Based on this information, in-game educational interventions in the form of hints can be provided to the player. The success of such games depends on their interactivity, motivational outlook and thus player retention. UNTANGLED is an online mapping game based on crowd-sourcing, developed by Reconfigurable Computing Lab, UNT for the mapping problem of CGRAs. It is also an educational game for teaching the concepts of reconfigurable computing. This thesis performs qualitative comparative analysis on gameplays of low performing players of UNTANGLED. And the implications of this analysis are used to provide recommendations for improving the gameplay experience for these players by guiding them. The recommendations include strategies to reach a high score and a compact solution, hints in the form of preset patterns and a clustering based approach.
Date: May 2017
Creator: Ambekar, Kiran
Partner: UNT Libraries

Health-related Quality of Life and Social Engagement in Assisted Living Facilities

Description: This research project aims to clarify the factors that impact successful aging in Assisted Living facilities (ALFs) in Denton County, Texas. We hypothesize that social disengagement decreases physical and mental components of quality of life. This exploratory research project employed standardized questionnaires to assess residents in the following domains; HRQOL, social engagement status, level of cognition, depression, and the level of functioning. This study collected data from 75 participants living in five ALFs. The average of Physical Component Scale (PCS) and Mental Component Scale (MCS) was 35.33, and 53.62 respectively. None of the participants had five or more social contacts out of facilities, and two-third of them had two or less social contacts. On average, those participants who were more socially engaged had higher score of MCS compared with disengaged counterparts. The level of physical function significantly affects social engagement, when people with more disabilities are more likely to be socially disengaged. Social engagement and depression significantly impact MCS, when depression is a mediating factor between social engagement and mental component of quality of life. Considering the expansion in aging population in the United States within the next three decades, the demand for high quality long-term care will skyrocket consequently. This study reveals that external social engagement can sustain HRQOL of residents in assisted living facilities.
Date: August 2015
Creator: Amini, Reza
Partner: UNT Libraries

A Guide to Arranging Late Eighteenth and Early Nineteenth Century Harmoniemusik in an Historical Style

Description: The wind octet was a popular ensemble of the classical period. In 1782, the Viennese Emperor formed a wind octet which specialized in playing opera arrangements. This music was used primarily as a form of background entertainment for dinners. This guide analyzes and compares the works of several well-known arrangers from the classical period in order to demonstrate arranging styles of the time. The arrangers of the period were often the performers of these various wind octets who were writing specifically for the players in their own ensembles. The style of Mozart’s original wind music is also discussed, in contrast to the arrangements of his works made by others. This guide is intended for serve performers of today as a tool to learn the art of arranging in an historical style. Idiosyncrasies of the classical-period wind instruments are discussed, as they relate to the style of wind arranging. The role of the contemporary arranger is compared with that of the classical period, and the case is made for the need for more contemporary arrangements of classical works using period arrangers as models.
Date: August 2015
Creator: April Marie Ross
Partner: UNT Libraries

Space and Spectrum Engineered High Frequency Components and Circuits

Description: With the increasing demand on wireless and portable devices, the radio frequency front end blocks are required to feature properties such as wideband, high frequency, multiple operating frequencies, low cost and compact size. However, the current radio frequency system blocks are designed by combining several individual frequency band blocks into one functional block, which increase the cost and size of devices. To address these issues, it is important to develop novel approaches to further advance the current design methodologies in both space and spectrum domains. In recent years, the concept of artificial materials has been proposed and studied intensively in RF/Microwave, Terahertz, and optical frequency range. It is a combination of conventional materials such as air, wood, metal and plastic. It can achieve the material properties that have not been found in nature. Therefore, the artificial material (i.e. meta-materials) provides design freedoms to control both the spectrum performance and geometrical structures of radio frequency front end blocks and other high frequency systems. In this dissertation, several artificial materials are proposed and designed by different methods, and their applications to different high frequency components and circuits are studied. First, quasi-conformal mapping (QCM) method is applied to design plasmonic wave-adapters and couplers working at the optical frequency range. Second, inverse QCM method is proposed to implement flattened Luneburg lens antennas and parabolic antennas in the microwave range. Third, a dual-band compact directional coupler is realized by applying artificial transmission lines. In addition, a fully symmetrical coupler with artificial lumped element structure is also implemented. Finally, a tunable on-chip inductor, compact CMOS transmission lines, and metamaterial-based interconnects are proposed using artificial metal structures. All the proposed designs are simulated in full-wave 3D electromagnetic solvers, and the measurement results agree well with the simulation results. These artificial material-based novel design methodologies pave the way ...
Date: May 2015
Creator: Arigong, Bayaner
Partner: UNT Libraries

The Design and Development of Lightweight Composite Wall, Roof, and Floor Panels for Rigid Wall Shelter

Description: This thesis presents a research effort aimed at developing a stronger, lighter, and more economic shelter using rigid wall panels. Reported herein is insulation research, wall and roof panel design and testing, floor section modeling and strength calculations, and cost and weight calculations. Beginning stages focus on developing solid wall and roof panels using cold-formed steel corrugated sheathing and members, as well as polyurethane spray foam for insulation. This research includes calculating uniform load density, to determine the overall strength of the panel. The next stage focuses on the flexural strength of the wall and roof panels, as well as finalizing the floor design for the shelter. This includes determining maximum flexural strength required to meet the standards set by the project goal. Direct strength method determined the correct thickness of members to use based on the dimension selected for the design. All Phases incorporated different connection methods, with varied stud spacing, to determine the safest design for the new shelters. Previous research has shown that cold-formed steel corrugated sheathing performs better than thicker flat sheathing of various construction materials, with screw and spot weld connections. Full scale shear wall tests on this type of shear wall system have been conducted, and it was found that the corrugated sheathing had rigid board behavior before it failed in shear buckling in sheathing and sometimes simultaneously in screw connection failures. Another aspect of the research is on the insulation of the wall panels. Research was conducted on many different insulation options for the mobile facilities. Specifically, insulation made of lightweight material, is non-combustible, added rigidity to the structure, and has high thermal properties. Closed cell polyurethane spray foam was selected for full-scale testing in this research. Closed cell polyurethane adds extra rigidity, is lighter than common honeycomb insulation, and has a higher ...
Date: May 2018
Creator: Artman, Jeremy J
Partner: UNT Libraries

Determinants of Corporate Governance Choices: Evidence from Listed Foreign Firms on U.S. Stock Exchanges

Description: This study analyzes corporate governance practices of foreign (non-U.S.) issuers listed on the New York Stock Exchange (NYSE) and Nasdaq. Specifically, I examine the extent to which these foreign issuers voluntarily comply with U.S. stock exchange corporate governance requirements applicable to domestic issuers. My sample consists of 201 foreign companies primarily domiciled in Brazil, China, Israel, and the United Kingdom. I find that 151 (75 per cent) of the sample firms do not elect to comply with any of the U.S. corporate governance requirements. Logistic regression analysis generally supports the hypotheses that conformance with U.S. GAAP and percentage of managerial ownership are positively associated, and that percentage ownership by major shareholders is negatively associated with foreign firms electing to comply with U.S. corporate governance rules. This evidence is relevant for regulators and investors.
Date: May 2017
Creator: Attachot, Weerapat
Partner: UNT Libraries

Witchcraft: a Targeted Societal Discrimination Against Women in Northern Ghana

Description: A combination of aging and poverty is becoming dominant in African society today, at a time when African countries are expected to be recovering from poverty, and are projected to house the economic growth of the next century. The emergence of aging in African context and the aging of the world population will expose the weakness of the current mechanisms used for older people around the world. As economies grow around the world, the distribution gap between the affluent and the poor widens, and the constant struggles for wealth, power, and social status, amidst scarce resources, continue to be sustained. To remain in charge of economic resources, the powerful few devise means to disenfranchise the weak, and witchcraft accusation is one of such tools used in Northern Ghana today. A new wave of witchcraft accusation has caught the attention of many in Northern Ghana. These victims with certain socioeconomic characteristics appear helpless and without defense against such accusations. As a result, they suffer untold hardships and are often compelled to leave their homes and to reside in camps reserved for witches. This study was undertaken to identify those sociodemographic characteristics, which are commonly shared by witchcraft accusation victims. These sociodemographic characteristics can be used to predict those who are most likely to be discriminated against using accusations of witchcraft in Northern Ghana. As age places more strain on existing systems and as more people survive into old age with inadequate healthcare, more accusations may be predicted to occur against the elderly, unless enough government intervention is used to address the present redistribution of income in third world countries.
Date: December 2013
Creator: Atumah, Oscar Nwagbo
Partner: UNT Libraries

Surface Degradation Behavior of Bulk Metallic Glasses and High Entropy Alloys

Description: In this study, the surface degradation behavior was studied for typical examples from bulk metallic glasses (BMGs), metallic glass composites (MGCs) and high entropy alloys (HEAs) alloy systems that are of scientific and commercial interest. The corrosion and wear behavior of two Zr-based bulk metallic glasses, Zr41.2Cu12.5Ni10Ti13.8Be22.5 and Zr57Cu15.4Ni12.6Al10Nb5, were evaluated in as-cast and thermally relaxed states. Significant improvement in corrosion rate, wear behavior, and friction coefficient was seen for both the alloys after thermal relaxation. Fully amorphous structure was retained with thermal relaxation below the glass transition temperature. This improvement in surface properties was explained by annihilation of free volume, the atomic scale defects in amorphous metals resulting from kinetic freezing. Recently developed MGCs, with in situ crystalline ductile phase, demonstrate a combination of mechanical properties and fracture behavior unseen in known structural metals. The composites showed higher wear rates but lower coefficient of friction compared to monolithic amorphous glasses. No tribolayer formation was seen for the composites in sharp contrast to that of the monolithic metallic glasses. Corrosion was evaluated by open circuit potential (OCP) analysis and potentiodynamic polarization. Site-specific corrosion behavior was studied by scanning vibration electrode technique (SVET) to identify formation of galvanic couples. Scanning kelvin probe microscope was used to map elecropositivity difference between the phases and linked to wear/corrosion behavior. Phases with higher elecropositivity were more susceptible to surface degradation. Wear and corrosion synergy in marine environment was evaluated for two high entropy alloys (HEAs), CoCrFeMnNi and Al0.1CoCrFeNi. Between the two alloys, Al0.1CoCrFeNi showed better wear resistance compared to CoCrFeMnNi in dry and marine conditions due to quicker passivation, a higher magnitude of polarization resistance and significantly larger pitting resistance.
Date: December 2017
Creator: Ayyagari, Venkata A
Partner: UNT Libraries

The Acceptance and Use of Cloud Computing Services by Small and Medium Enterprises in Lagos, Nigeria

Description: This study explored the acceptance of cloud computing (CC) services by small and medium enterprises (SMEs) in Lagos, Nigeria, which has been missing from CC services literature. It aimed to understand the motivations for adoption, the uses of the services, and the benefits they derive from it. The uses and gratification theory was applied as the theoretic framework for this endeavor. An online survey with close-ended and open-ended questions was distributed to 1200 randomly selected participants through email. In total, 392 valid responses were collected and analyzed using descriptive statistics and categories. The results found that SMEs in Lagos, Nigeria had a low level of awareness and appreciation of CC services. The adoption rate was also low. Unlike their counterparts in other regions, SMEs primary concerns were service downtime, stable power supply, and better internet access. The study found that SMEs were not taking full advantage of the capabilities of CC services. Some sections, however, were doing better than others, such as the information and communications sub-sector. This study suggested that targeted interventions should be conducted to raise the awareness of CC services in SMEs, and to improve their efficient and effective use of CC services. The uses and gratification theory was appropriate for guiding this study to understand the acceptance and use of CC services by SMEs in Lagos, Nigeria.
Date: May 2017
Creator: Azogu, Olajumoke O
Partner: UNT Libraries

Functional Characterization of Mtnip/latd’s Biochemical and Biological Function

Description: Symbiotic nitrogen fixation occurs in plants harboring nitrogen-fixing bacteria within the plant tissue. The most widely studied association is between the legumes and rhizobia. In this relationship the plant (legumes) provides the bacteria (rhizobia) with reduced carbon derived from photosynthesis in exchange for reduced atmospheric nitrogen. This allows the plant to survive in soil, which is low in available of nitrogen. Rhizobia infect and enter plant root and reside in organs known as nodules. In the nodules the bacteria fix atmospheric nitrogen. The association between the legume, Medicago truncatula and the bacteria Sinorhizobium meliloti, has been studied in detail. Medicago mutants that have defects in nodulation help us understand the process of nitrogen fixation better. One such mutant is the Mtnip-1. Mtnip-1 plants respond to S. meliloti by producing abnormal nodules in which numerous aberrant infection threads are produced, with very rare rhizobial release into host plant cells. The mutant plant Mtnip-1 has an abnormal defense-like response in root nodules as well as defects in lateral root development. Three alleles of the Mtnip/latd mutants, Mtnip-1, Mtlatd and Mtnip-3 show different degrees of severity in their phenotype. Phylogenetic analysis showed that MtNIP/LATD encodes a protein belonging to the NRT1(PTR) family of nitrate, peptide, dicarboxylate and phytohprmone transporters. Experiments with Mtnip/latd mutants demonstrats a defective nitrate response associated with low (250 μM) external nitrate concentration rather than high (5 mM) nitrate concentration. This suggests that the mutants have defective nitrate transport. To test if MtNIP/LATD was a nitrate transporter, Xenopus laevis oocytes and Arabidopsis thaliana mutant plants Atchl1-5, defective in a major nitrate transporter AtNRT1.1(CHL1), were used as surrogate expression systems. Heterologous expression of MtNIP/LATD in X. laevis oocytes and Atchl1-5 mutant plants conferred on them the ability to take up nitrate from external media with high affinity, thus demonstrating that MtNIP/LATD ...
Date: December 2013
Creator: Bagchi, Rammyani
Partner: UNT Libraries