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Online Construction of Android Application Test Suites (open access)

Online Construction of Android Application Test Suites

Mobile applications play an important role in the dissemination of computing and information resources. They are often used in domains such as mobile banking, e-commerce, and health monitoring. Cost-effective testing techniques in these domains are critical. This dissertation contributes novel techniques for automatic construction of mobile application test suites. In particular, this work provides solutions that focus on the prohibitively large number of possible event sequences that must be sampled in GUI-based mobile applications. This work makes three major contributions: (1) an automated GUI testing tool, Autodroid, that implements a novel online approach to automatic construction of Android application test suites (2) probabilistic and combinatorial-based algorithms that systematically sample the input space of Android applications to generate test suites with GUI/context events and (3) empirical studies to evaluate the cost-effectiveness of our techniques on real-world Android applications. Our experiments show that our techniques achieve better code coverage and event coverage compared to random test generation. We demonstrate that our techniques are useful for automatic construction of Android application test suites in the absence of source code and preexisting abstract models of an Application Under Test (AUT). The insights derived from our empirical studies provide guidance to researchers and practitioners involved …
Date: December 2017
Creator: Adamo, David T., Jr.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Status and Challenges of Online Distance Education Programs in Post-Secondary Institutions in Ghana (open access)

The Status and Challenges of Online Distance Education Programs in Post-Secondary Institutions in Ghana

The purpose of this study was to identify the status and challenges of online distance education programs in post-secondary institutions in Ghana. This study was a replication of a similar study conducted in Kenya in 2009, at the University of Nairobi and Kenyatta University. This present study was conducted with an online survey using Google survey assessment. The survey requested responses from six post-secondary institutions in Ghana. Out of a total of 450 projected student responses, 309 responses were received with a 69% participation rate. A total of 14 responses were received for instructors out of a projected 30 resulting in 47% participation rate. And for administrators, 8 responses were received out of a projected 12 resulting in a 67% participation rate. Overall the study revealed that Ghana post-secondary institutions have established and incorporated online distance education into their programs, offering both online and blended courses. Some of these institutions established regional centers across the country and incorporated foreign instructors into their programs. The survey also revealed that students were satisfied with the overall online distance education program in their institutions which included the level of instruction, feedback and evaluation. However, there were still challenges revealed from the study that …
Date: May 2017
Creator: Adjabeng, Stanley
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Practical Evaluation of a Software Defined Cellular Network (open access)

Practical Evaluation of a Software Defined Cellular Network

This thesis proposes a design of a rapidly deployable cellular network prototype that provides voice and data communications and it is interoperable with legacy devices and the existing network infrastructure. The prototype is based on software defined radio and makes use of IEEE 802.11 unlicensed wireless radio frequency (RF) band for backhaul link and an open source GSM implementation software. The prototype is also evaluated in environments where there is limited control of the radio frequency landscape, and using Voice Over Internet Protocol (VoIP) performance metrics to measure the quality of service. It is observed that in environments where the IEEE 802.11 band is not heavily utilized, a large number of calls are supported with good quality of service. However, when this band is heavily utilized only a few calls can be supported as the quality of service rapidly degrades with increasing number of calls, which is due to interference. It is concluded that in order to achieve tolerable voice quality, unused licensed spectrum is needed for backhaul communication between base stations.
Date: May 2017
Creator: Agbogidi, Oghenetega
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Trajectories of Burden and Depression in Caregivers Following Traumatic Injury: The Role of Resilience (open access)

Trajectories of Burden and Depression in Caregivers Following Traumatic Injury: The Role of Resilience

As part of an effort to understand psychological consequences among family members of patients sustaining a traumatic injury, medical research has turned to the role of resilience – or the ability to bounce back from and maintain psychological well-being in the wake of an adverse event— in mitigating the potential distress (i.e., depression and burden) of caregiving (Bonanno, 2004; Roberson et al., under review). This study sought to examine the ability for trait-resilience to predict trajectories of distress over the course of a year among 124 family members and loved ones of patients admitted to a Level I Trauma Center. A cross-lagged path model examining resilience, burden, and depression at baseline, 3, 6, and 12 months after injury showed that, while depression strongly predicted later burden, resilience was not a significant predictor of either outcome in the model. When depression and burden were subjected to a person-centered analysis (i.e., latent growth curve analysis), two major classes were identified: caregivers with high, chronic distress (33% of the sample) and low-moderate distress that declined over time. A three-class solution for caregiver burden further identified a moderate, increasing trajectory class. Predictive discriminant analyses revealed that trait-resilience was a major differentiating trait between class …
Date: August 2017
Creator: Agtarap, Stephanie D
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Sexual Identity and Social Anxiety in Emerging Adulthood (open access)

Sexual Identity and Social Anxiety in Emerging Adulthood

Elevated social anxiety (SA) is linked to issues with emotional distress, substance use, and social anxiety disorder (SAD). Notwithstanding concerns of how sexuality has been defined in the extant literature, emerging evidence suggests that the prevalence of SA and related challenges may be disproportionately present among sexual minorities, including lesbians, gay men, and bisexuals (LGBs). This trend may be especially relevant within the developmental context of emerging adulthood, an important period for development of sexual identity, and a time when individuals are already predisposed to heightened feelings of SA. The present study examined the relationship between sexual orientation (measured using sexual identity, sexual attraction, and past romantic and sexual behavior) and social anxiety (related to social interaction and social performance) among emerging adults. minority sexual identities [Welch's F(5,48.08) = 5.56, p = .002, ηp2 = .02.], same-sex attraction [Welch's F(4,108.06) = 11.27, p < .001, ηp2 = .04], and same-sex romantic [Welch's F(5,85.91) = 6.88, p < .001, ηp2 = .03] and sexual experiences[F(5,61.95) = 8.88, p < .001, ηp2 = .04], particularly among those who indicated attraction to multiple sexes. Findings support research that indicates that sexual minority adults experience higher levels of SA than majority (i.e., heterosexual, opposite-sex …
Date: May 2017
Creator: Akibar, Alvin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Effectiveness of Fillers for Corrosion Protection of AISI-SAE 1018 Steel in Sea Salt Solution (open access)

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

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 …
Date: May 2017
Creator: Al-Shenawa, Amaal
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Application of High Entropy Alloys in Stent Implants (open access)

Application of High Entropy Alloys in Stent Implants

High entropy alloys (HEAs) are alloys with five or more principal elements. Due to these distinct concept of alloying, the HEA exhibits unique and superior properties. The outstanding properties of HEA includes higher strength/hardness, superior wear resistance, high temperature stability, higher fatigue life, good corrosion and oxidation resistance. Such characteristics of HEA has been significant interest leading to researches on these emerging field. Even though many works are done to understand the characteristic of these HEAs, very few works are made on how the HEAs can be applied for commercial uses. This work discusses the application of High entropy alloys in biomedical applications. The coronary heart disease, the leading cause of death in the United States kills more than 350,000 persons/year and it costs $108.9 billion for the nation each year in spite of significant advancements in medical care and public awareness. A cardiovascular disease affects heart or blood vessels (arteries, veins and capillaries) or both by blocking the blood flow. As a surgical interventions, stent implants are deployed to cure or ameliorate the disease. However, the high failure rate of stents has lead researchers to give special attention towards analyzing stent structure, materials and characteristics. Many works related to …
Date: May 2017
Creator: Alagarsamy, Karthik
Object Type: Thesis or Dissertation
System: The UNT Digital Library
University Faculty and Diverse Students' Self-Reported Attitudes toward Inclusive Teaching Strategies (open access)

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

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 …
Date: May 2017
Creator: Alamri, Abdulrahman Saleh
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Motivating Academic Librarians: Implications of Maslow’s Hierarchy of Needs Theory

Presented at the 2017 International Conference on Knowledge Management. This presentation examines the motivators of academic librarians that helped them efficiently achieve their tasks.
Date: October 26, 2017
Creator: Alasousi, Hessah & Alajmi, Bibi
Object Type: Presentation
System: The UNT Digital Library

Big Data and Government Information

Panel for the 2017 International Conference on Knowledge Management. This panel presentation examines various issues of big data applications for governmental information.
Date: October 25, 2017
Creator: Alemneh, Daniel Gelaw
Object Type: Presentation
System: The UNT Digital Library

Every Day is Digital Preservation Day @ the UNT Libraries

Presented at the 2017 International Digital Preservation Day. This presentation introduces the University of North Texas Libraries' legacy with digital preservation.
Date: November 30, 2017
Creator: Alemneh, Daniel Gelaw
Object Type: Presentation
System: The UNT Digital Library
ICKM 2017 Program (open access)

ICKM 2017 Program

This is the final program for the 2017 International Conference on Knowledge Management.
Date: October 25, 2017
Creator: Alemneh, Daniel Gelaw; Allen, Jeff M. & Hawamdeh, Suliman M.
Object Type: Text
System: The UNT Digital Library
Preface (open access)

Preface

Preface to Knowledge Discovery and Data Design Innovation: Proceedings of the International Conference on Knowledge Management (ICKM 2017), Dallas, Texas, USA, 25-26 October 2017.
Date: October 19, 2017
Creator: Alemneh, Daniel Gelaw; Allen, Jeff M. & Hawamdeh, Suliman M.
Object Type: Book Chapter
System: The UNT Digital Library
Big Data and Government Information (open access)

Big Data and Government Information

Panel paper for the 2017 International Conference on Knowledge Management. This panel explores the current landscape of big data applications for government information.
Date: October 25, 2017
Creator: Alemneh, Daniel Gelaw; Phillips, Mark Edward; Smith, Lisa & Shimabuku, Hope
Object Type: Paper
System: The UNT Digital Library
The Effectiveness of Hybrid Problem-Based Learning versus Manual-Based Learning in the Microbiology Laboratory (open access)

The Effectiveness of Hybrid Problem-Based Learning versus Manual-Based Learning in the Microbiology Laboratory

Promising results from the use of problem-based learning (PBL) as a teaching method in medical programs have encouraged many institutions to incorporate PBL into their curricula. This study investigates how applying hybrid-PBL (H-PBL) in a microbiology laboratory impacts students' higher-order thinking as compared to applying a lecture-based pedagogy. The experimental design compared the learning outcomes of two groups of students: the control group and the H-PBL group, for whom PBL cases comprised 30% of the curriculum. Both groups were taught basic skills for the microbiology lab by the same instructor. Using the traditional teaching style for the control group, the instructor offered each student what they needed for their experiments. The H-PBL group practiced experimental design, data analysis, theory proposal, and created research questions by using six study cases that were closely linked to the area of study. The outcome was measured using a pre- and post- assessment consisting of 24 questions that was designed by following Bloom's taxonomy of learning levels. A one-way ANOVA was used to analyze the data. The results showed that for the first three levels of Bloom's taxonomy— knowledge, comprehension, and application—there were no statistically significant differences between the H-PBL and control group gain scores …
Date: May 2017
Creator: Alharbi, Najwa
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Study of Mobility Models based on Spatial Node Distribution and Area Coverage (open access)

A Study of Mobility Models based on Spatial Node Distribution and Area Coverage

Mobile wireless sensor networks are not widely implemented in the real world, even after years of research carried out in this field. One reason is the lack of understanding of the impact that mobility has on network performance. The simulation and emulation of mobile wireless sensor networks is necessary before they are deployed for the real-world applications. This thesis presents a simulation-based study of different mobility models. The total area coverage that depends on the pattern of node movements is observed through simulations. The spatial distribution of node locations is also studied. Various synthetic mobility models available are explored based on their theoretical descriptions. ‘BonnMotion' is used as the network simulator for investigating different mobility scenarios. The results obtained after simulations are imported to MATLAB and the analysis of node movements is done through various plots and inferences from the data. The comparison of mobility models is also discussed based on their spatial node distribution in the simulated scenarios.
Date: May 2017
Creator: Alla, Sindhu
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Classification of the Homogeneity of Countable Products of Subsets of Real Numbers (open access)

A Classification of the Homogeneity of Countable Products of Subsets of Real Numbers

Spaces such as the closed interval [0, 1] do not have the property of being homogeneous, strongly locally homogeneous (SLH) or countable dense homogeneous (CDH), but the Hilbert cube has all three properties. We investigate subsets X of real numbers to determine when their countable product is homogeneous, SLH, or CDH. We give necessary and sufficient conditions for the product to be homogeneous. We also prove that the product is SLH if and only if X is zero-dimensional or an interval. And finally we show that for a Borel subset X of real numbers the product is CDH iff X is a G-delta zero-dimensional set or an interval.
Date: August 2017
Creator: Allen, Cristian Gerardo
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Transformative Learning Theory as a Basis for Identifying Barriers to Faculty Confidence in Online Instruction (open access)

Transformative Learning Theory as a Basis for Identifying Barriers to Faculty Confidence in Online Instruction

This study applied the stages of transformative learning to faculty perceptions and application of best practices to online learning. Research questions included: Can transformative learning theory constructs be used to identify potential barriers in faculty development and delivery of online instruction?; How does the stage of transformative learning of online faculty relate to their perceptions about online learning and their application of best practices?; Is there a correlation between stage of transformative learning and the amount of experience with online instruction a faculty member has? Principal component analysis and cluster analysis support a four-component solution. The four constructs equate to Mezirow's four stages of learning: transforming frames of reference through critical reflection of assumptions, validating contested beliefs through discourse, taking action on one's reflective insight, and critically assessing it. Multiple regression analyses were run to predict faculty perceptions on the identified components. Three of these were statistically significant based on years of experience teaching online, the number of professional development workshops taken on online teaching, or both. While the instrument appears to be a valid measurement of transformation of frame of reference, examination of previously contested beliefs, and critical assessment of action, further efforts will be needed before this is …
Date: August 2017
Creator: Allen, Julia Elizabeth
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Generation of Recombinant Zea mays Spastin and Katanin Proteins for In Vitro Analysis (open access)

The Generation of Recombinant Zea mays Spastin and Katanin Proteins for In Vitro Analysis

Plant microtubules play essential roles in cell processes such as cell division, cell elongation, and organelle organization. Microtubules are arranged in highly dynamic and ordered arrays, but unlike animal cells, plant cells lack centrosomes. Therefore, microtubule nucleation and organization are governed by microtubule-associated proteins, including a microtubule-severing protein, katanin. Mutant analysis and in vitro characterization has shown that the highly conserved katanin is needed for the organization of the microtubule arrays in Arabidopsis and rice as well as in a variety of animal models. Katanin is a protein complex that is part of the AAA+ family of ATPases. Katanin is composed of two subunits, katanin-p60, a catalytic subunit and katanin-p80, a regulatory subunit. Spastin is another MT-severing protein that was identified on the basis of its homology to katanin. In animal cells, spastin is also needed for microtubule organization, but its functionality has not yet been investigated in plants. To initiate an exploration of the function of katanin-p60 and spastin in Zea mays, my research goal was to generate tools for the expression and purification of maize katanin-p60 and spastin proteins in vitro. Plasmids that express katanin-p60 and spastin with N-terminal GST tags were designed and constructed via In-Fusion® cloning …
Date: December 2017
Creator: Alodailah, Sattam Sonitan
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Examining the Influence of Visual Culture on a Saudi Arabian Child's Drawings (open access)

Examining the Influence of Visual Culture on a Saudi Arabian Child's Drawings

This study examines the ways visual culture influences a child's drawings. The child is my 9-year-old daughter Nada, who was born in Saudi Arabia and is a fourth-grade student temporarily living in the United States. The study uses qualitative methods of data collection and exploratory case study research design as a methodology. The data were analyzed in light of Althusser's theory of ideology, specifically the notion of interpellation, along with visual culture theories. In addition, gender performativity theory, specifically the work of Judith Butler, was used to consider gender issues when these concerns emerged from the study. Nada has been exposed to two diverse cultures, those of Saudi Arabia and the United States. Both cultures may impact Nada's interpretations of her visual surroundings in various ways. Therefore, recognizing and examining how she interacts with US visual culture might help to uncover how such interactions constitute the basis of her perceptions, identities, and critical thinking. Drawing is not only a means of self-expression but also an important function of communication, identity formation, and represents possible ways of being in the world that are related to culture, community, and society as a whole. The study begins with the premise that there is …
Date: December 2017
Creator: Alshaie, Fouzi Salem
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics using Practical Enhanced Surfaces (open access)

Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics using Practical Enhanced Surfaces

The objective of this research was to investigate the performance of two-phase spray cooling with HFC-134a and HFO-1234yf refrigerants using practical enhanced heat transfer surfaces. Results of the study were expected to provide a quantitative spray cooling performance comparison with working fluids representing the current and next-generation mobile air conditioning refrigerants, and demonstrate the feasibility of this approach as an alternative active cooling technology for the thermal management of high heat flux power electronics (i.e., IGBTs) in electric-drive vehicles. Potential benefits of two-phase spray cooling include achieving more efficient and reliable operation, as well as compact and lightweight system design that would lead to cost reduction. The experimental work involved testing of four different enhanced boiling surfaces in comparison to a plain reference surface, using a commercial pressure-atomizing spray nozzle at a range of liquid flow rates for each refrigerant to determine the spray cooling performance with respect to heat transfer coefficient (HTC) and critical heat flux (CHF). The heater surfaces were prepared using dual-stage electroplating, brush coating, sanding, and particle blasting, all featuring "practical" room temperature processes that do not require specialized equipment. Based on the obtained results, HFC-134a provided a better heat transfer performance through higher HTC and …
Date: August 2017
Creator: Altalidi, Sulaiman Saleh
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Nuestra Voz (Fort Worth, Tex.), Vol. 3, No. 38, Ed. 1, January 2017 (open access)

Nuestra Voz (Fort Worth, Tex.), Vol. 3, No. 38, Ed. 1, January 2017

Monthly newspaper providing news and information to the Tarrant, Dallas, and Denton County Latino communities along with advertising.
Date: January 2017
Creator: Alvarado, Felix
Object Type: Newspaper
System: The Portal to Texas History
Nuestra Voz (Fort Worth, Tex.), Vol. 3, No. 39, Ed. 1, February 2017 (open access)

Nuestra Voz (Fort Worth, Tex.), Vol. 3, No. 39, Ed. 1, February 2017

Monthly newspaper providing news and information to the Tarrant, Dallas, and Denton County Latino communities along with advertising.
Date: February 2017
Creator: Alvarado, Felix
Object Type: Newspaper
System: The Portal to Texas History
Nuestra Voz (Fort Worth, Tex.), Vol. 3, No. 40, Ed. 1, March 2017 (open access)

Nuestra Voz (Fort Worth, Tex.), Vol. 3, No. 40, Ed. 1, March 2017

Monthly newspaper providing news and information to the Tarrant, Dallas, and Denton County Latino communities along with advertising.
Date: March 2017
Creator: Alvarado, Felix
Object Type: Newspaper
System: The Portal to Texas History