This thesis presents a series of neural network classifiers for object detection in both optical and infrared images. The focus of this work is on efficient and accurate solutions. The thesis discusses the evolution of the highly efficient and tiny network Binary Classification Vision Transformer (BC-ViT) and how through thoughtful modifications and improvements, the BC-ViT can be utilized for tasks of increasing complexity. Chapter 2 discusses the creation of BC-ViT and its initial use case for underwater image classification of optical images. The BC-ViT is able to complete its task with an accuracy of 99.29\% while being comprised of a mere 15,981 total trainable parameters. Chapter 3, Waste Multi-Class Vision Transformer (WMC-ViT), introduces the usefulness of mindful algorithm design for the realm of multi-class classification on a mutually exclusive dataset. WMC-ViT shows that the task oriented design strategy allowed for a network to achieve an accuracy score of 94.27\% on a five class problem while still maintaining a tiny parameter count of 35,492. The final chapter demonstrates that by utilizing functional blocks of BC-ViT, a simple and effective target detection algorithm for infrared images can be created. The Edge Infrared Vision Transformer (EIR-ViT) showed admirable results with a high IoU …

Using queer and Afrofuturist frameworks, this Black feminist qualitative study explored queer Black pre-and in-service teachers' cultural and intersectional practices as they navigated traditional heteronormative educational spaces. This research study relied on counternarratives and storytelling and drew from Afrofuturism to understand the use of their lived experiences to counter monolithic queer narratives. The queer Black teachers in this study examined and negotiated how their Blackness and queerness showed up in teacher preparation programs (TPP) and K-12 classrooms. Moreover, they eventually refused to hide or censure their authentic selves. An analysis of the narratives and counternarratives showed that queer Black teachers drew from ancestral traditions to create queer Afrofuturist spaces in TPPs and educational places. Furthermore, due to their queer Black intersectional approaches, their classrooms, assignments, curriculum, and pedagogy disrupted normative teaching practices. Implications, recommendations, and future research are discussed.

Transition metal oxynitrides are of growing interest for their use as electrocatalyst for nitrogen reduction reaction. The metals in the oxynitride used for catalytic process are stabilized in intermediate state for effective activation of nitrogen. Therefore, studying the interaction of metal oxynitrides films to ambient exposure is necessary. Here, sputter deposited vanadium oxynitride is compared to cobalt oxynitride using insitu Auger electron spectroscopy (AES), ex situ X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). After deposition in Ar/N2 environment, in situ AES spectra indicate that film is vanadium oxynitride despite oxygen is not the reactive gas. In contrast, in situ AES indicate film is pure cobalt nitride at the same base pressure and deposition condition (as vanadium). For ambient exposure, in situ AES indicate the incorporation of oxygen in the cobalt nitride film to form cobalt oxynitride. Ex situ XPS indicate both films get more oxidized but uniformly distributed as there is only slight difference in grazing and normal emission XPS. XRD and SEM also indicate how homogeneously distributed both films are. These finding confirms how important it is that transition metal centers are kept in intermediate oxidation state for the activation of nitrogen bond.

In this dissertation, we introduce novel exponential jump-diffusion models for pricing options. Firstly, the normal convolution gamma mixture jump-diffusion model is presented. This model generalizes Merton's jump-diffusion and Kou's double exponential jump-diffusion. We show that the normal convolution gamma mixture jump-diffusion model captures some economically important features of the asset price, and that it exhibits heavier tails than both Merton jump-diffusion and double exponential jump-diffusion models. Secondly, the normal convolution double gamma jump-diffusion model for pricing options is presented. We show that under certain configurations of both the normal convolution gamma mixture and the normal convolution double gamma jump-diffusion models, the latter exhibits a heavier left or right tail than the former. For both models, the maximum likelihood procedure for estimating the model parameters under the physical measure is fairly straightforward; moreover, the likelihood function is given in closed form thereby eliminating the need to embed a probability density function recovery procedure such as the fast Fourier transform or the Fourier-cosine expansion methods in the parameter estimation procedure. In addition, both models can reproduce the implied volatility surface observed in the options data and provide a good fit to the market-quoted European option prices.

In this study, high-fidelity conjugate heat transfer simulations are used to model a micro-channel heat exchanger (MCHE) in a crossflow to study its thermal-hydraulic performance. This study considers three different microchannels (internal flow) geometries (circular, triangular, and square) with louver-shaped fins. The local flow field showed a strong coupling between the microchannel flow, solid domain, and crossflow. The flow separation and wake regions formed near MCHE resulted in a large variation in the velocity field and temperature in the crossflow. The wake region had a significant spanwise variation due to its interaction with fins, which also causes variations in the thermal boundary layer. The heat conduction in the solid structure provided a non-uniform temperature field with a higher temperature near the microchannel and a slightly lower temperature near the surface exposed to the crossflow. The microchannel flow analysis showed that the internal geometry affects the pressure drop, which is highest for the triangular MCHE and lowest for the circular MCHE. However, the microchannel flow temperature change was relatively similar for all microchannels. Results showed that for the same volume of the microchannel, the circular shape microchannel has a higher performance index value than the triangular and square shapes. This study …

The thermophysical properties and deformation behavior of a systematic series of model metallic glasses was investigated. For Zr-based metallic glasses with all metallic constituents, the activation energy of glass transition was determined to be in the range of 74-173 kJ/mol while the activation energy of crystallization was in the range of 155-170 kJ/mol. The reduced glass transition temperature was roughly the same for all the alloys (~ 0.6) while the supercooled liquid region was in the range of 100-150 K, indicating varying degree of thermal stability. In contrast, the metal-metalloid systems (such as Ni-Pd-P-B) showed relatively higher activation energy of crystallization from short range ordering in the form of triagonal prism clusters with strongly bonded metal-metalloid atomic pairs. Deformation mechanisms of all the alloys were investigated by uniaxial compression tests, strain rate sensitivity (SRS) measurements, and detailed characterization of the fracture surface morphology. For the metal-metal systems, plasticity was found to be directly correlated with shear transformation zone (STZ) size, with systems of larger STZ size showing better plasticity. In metal-metalloid amorphous alloys, plasticity was limited by the distribution of STZ units, with lower activation energy leading to more STZ units and better plasticity. The alloys with relatively higher plasticity …

Previous studies have shown that human platelets and megakaryocytes carry microRNAs suggesting their role in platelet function and megakaryocyte development, respectively. However, there is limited information on microRNAs' role in zebrafish thrombopoiesis. Zebrafish thrombocytes could be used as a model to study their role in megakaryocyte maturation and platelet function because thrombocytes have both megakaryocyte features and platelet properties. In our laboratory, I identified 15 microRNAs in thrombocytes using single-cell RNA sequencing. Knockdown of three microRNAs, mir-7148, let-7b, and mir-223, by the piggyback method in zebrafish led to an increase in the percentage of thrombocytes. Functional thrombocyte analysis using plate tilt assay showed no modulatory effect of the three microRNAs on thrombocyte aggregation/agglutination. I then verified these findings in zebrafish larvae after the knockdown of the above microRNAs followed by an arterial laser thrombosis assay. I concluded mir-7148, let-7b, and mir-223 are repressors for thrombocyte production. Furthermore, I explored let-7b downstream genes in thrombocytes detected by RNA-seq analysis and chose 14 targets based on their role in cell differentiation (rorca, tgif1, rfx1a, deaf1, zbtb18, mafba, cebpa, spi1a, spi1b, fhl3b, ikzf1, irf5, irf8, and lbx1b) that are transcriptional regulators. The qRT-PCR analysis of expression levels the above genes following let-7b knockdown …

In this study, we investigate the fundamental mechanisms defining the approach for addressing tribological challenges in mechanical systems via the use of the tribocatalytically active coating. The coating is designed using an electrodeposition process and consists of a hard amorphous cobalt-phosphorous matrix with the incorporation of tribocatalytically-active nickel and copper. Our focus is on understanding the effect of the tribocatalytic elements, Cu vs Ni, on the coating's performance in high-contact stress conditions, generating local heating, shear, and compression. By optimizing the relative composition and mechanical characteristics of the coating, we aim to enhance its tribological performance in the presence of a hydrocarbon environment. Through extensive characterization of the wear tracks using SEM/EDS and Raman analyses, we identify the formation of a protective carbon-based tribofilm on the coating's surface during sliding as the key factor behind its excellent performance. Our findings not only contribute to the understanding of material transformations in the contact but also offer a robust and versatile approach to addressing tribological challenges in mechanical systems. The development of this innovative coating opens up new possibilities for promoting the formation of protective tribofilms and improving the performance of mechanical components operating in low-viscosity fuels and synthetic oils.

This dissertation investigates videoconference technology adoption by aging-in-place organizations to facilitate the social engagement of older adults. It comprises three studies that examine the initiation and coordination of technology adoption by aging-in-place organizations and addresses the factors associated with successful adoption of relational videoconference technology by older adults. The first study is a systematic literature review exploring the role of aging-in-place organizations in social engagement of older adults through videoconference technology. The second study is a survey of adult relatives and friends of older adults regarding videoconference technology adoption by older adults during the COVID-19 pandemic and their experience with facilitating resources. It applies technology adoption theory and a structural equation model to characterize the role of aging-in-place organizations. The third study is a pilot test of a new online platform called Circular that is designed to support social engagement of older adults. Through these studies, this research extends the existing body of knowledge regarding modes to facilitate adoption of relational technology by older adults and to empower senior centers and other aging-in-place organizations as they seek to socially engage the aging members of their communities.

This study aims to find out the impact of the credibility and content quality of social media influencers on the various stages of the customer's journey and the intention to choose a destination for the Saudi tourist. The target segment was Saudis in general, who are 18 years or above. To conduct this study, 618 usable questionnaires were collected. This study tested twenty-two hypotheses. The result of this study showed that the relationship between content quality, expertise, and similarity was significantly positive with the tourist's desire and information searching. As well, the relationship between the tourist's desire and information searching was significantly positive with the intention of choosing a destination. Conservatism, engagement, and gender were tested as moderators. Conservatism was not significant while the engagement was significant. Gender was only significant in the relationship between content quality and the tourist's desire. This study contributes to information and knowledge in the fields of tourism, hospitality, travel, marketing, tourist behavior, information science, and social media. Researchers and those interested in tourist and customer behavior can benefit from the results of this study. In the industrial field, this study will be very useful to the Saudi government, which has recently begun to rely …

Previous work was successful at delineating reaction pathways for the photoactivated synthesis of an amine, [CztBu(PyriPr)(NH2−PyriPr)], by double intramolecular C−H activation and functionalization via irradiating a metal(II) azido complex, [CztBu(PyriPr)2NiN3. The present work seeks to expand upon earlier research, and to substitute the metal with iron or cobalt, and to expand the study to photocatalyzed intermolecular C−H activation and functionalization of organic substrates. Density functional theory (DFT) – B3LYP/6-31+G(d') and APFD/Def2TZVP – and time-dependent density functional theory (TDDFT) were used to propose a detailed pathway comprised of intermediates of low, intermediate, or high spin multiplicity and photo-generated excited states for the reaction of the azido complex, [CztBu(PyriPr)2MN3] to form the amine complex [CztBu(PyriPr)M(NH2−PyriPr)], M = Co, Ni or Fe, and the intermediates along the reaction pathway. For applications on quantum computing, the photophysical properties of photoactive d8 nickel(II) complexes are modeled. Such systems take advantage of a two-level system pathway between ground to excited state electronic transitions and could be useful for the discovery of successful candidates for a room temperature qubit, the analogue of a classical computational bit. A modified organometallic model, inspired by a nitrogen vacancy selective intersystem crossing model in diamond, was developed to take advantage of …

This research investigates existing and new HR practices that have impacted public health employee retention in Saudi Arabia during the COVID-19 pandemic. It builds on social support theory and social exchange theory to better understand the relationships between HR practices and retention, and uses quantitative methods to examine the hypotheses based on a conceptual framework. While OLS regression is employed to analyze the relationships between HR practices and retention, path analysis (bootstrapping) is used to examine the mediator variable. Based on 417 valid questionnaires distributed to public health employees in Saudi Arabia's central, western, and eastern regions, the analysis illustrates that while training and emphasis on work-life-balance as existing HR practices had a positive effect on retention, social support (supervisory support) and promotion of mental well-being as new HR practices also had a positive effect on retention during the COVID-19 pandemic. However, the hypothesis that compensation and occupational health and safety would improve retention was not supported. These results indicate that financial benefits and providing safety materials did not lead to employee retention. Meanwhile, safety training programs, psychosocial support, and promotion of well-being have been essential HR practices during the pandemic. Regarding the mediation hypotheses, interestingly, the results show that …

Hateful content and offensive language are commonplace on social media platforms. Many surveys prove that high percentages of social media users experience online harassment. Previous efforts have been made to detect and remove online hate content automatically. However, removing users' content restricts free speech. A complementary strategy to address hateful content that does not interfere with free speech is to counter the hate with new content to divert the discourse away from the hate. In this dissertation, we complement the lack of previous work on counterhate arguments by analyzing and detecting them. Firstly, we study the relationships between hateful tweets and replies. Specifically, we analyze their fine-grained relationships by indicating whether the reply counters the hate, provides a justification, attacks the author of the tweet, or adds additional hate. The most obvious finding is that most replies generally agree with the hateful tweets; only 20% of them counter the hate. Secondly, we focus on the hate directed toward individuals and detect authentic counterhate arguments from online articles. We propose a methodology that assures the authenticity of the argument and its specificity to the individual of interest. We show that finding arguments in online articles is an efficient alternative compared to …

The research examines the relationship between cyber addiction (excessive use of the Internet, CA), information overload (IO), and assesses their impact on workplace productivity. A multi-methods approach is used employing the Internet Addiction Test (IAT) and a quantitative survey design to assess and test the stated hypothesis. The study used random sampling methods targeting 150 respondents from different information technology departments of various organizations. The study hypothesizes that CA and IO have a reciprocal association, which adversely affects workplace productivity and employee performance. From the findings, IAT scores increase with an associated possibility of reporting burnout, fatigue, and other components associated with CA and IO. Also, CA and IO were significantly correlated, as evaluated by the chi-square test, although the same approach did not yield significant associations between CA and perceived internet dependence. Other findings CA components, such as social media use, significantly associated with task postponement and burnout. As well, CA affected IO with substantial impacts on workplace productivity. The paper highlights managerial aspects that organizations should consider in optimizing the output of their staff. Recommendations include wellness programs, altering the leadership and management styles, and sensitizing the employees on the adverse effects caused by the two variables.

Presentation describes Daniel Alemneh's experiences as a Fulbright Scholar.

Presentation discusses the process to publishing an open access book, and they discuss the critical role of OA in facilitating equitable global education. Authors of the presentation also introduce current and future work in the area of open access.

This presentation asserts that in Ethiopia, the BDA concept and its implementation are either not know or left insignificant. The aim of this study was to investigate the current trends, challenges and opportunities of applying BDA in precision medicine globally and take lessons for Ethiopia.

Article describes how data-driven decision-making (DDDM) technologies are increasingly being utilized, aiming to enhance education quality. Authors assert that this paper examines articles that explore the implementation of DDDM technologies and their effects on education quality.

This presentation details how the authors' study investigates the practice of data-driven decision-making in higher education institutions in Ethiopia. The study also involved interviews with two directors from the university's education program relevance and enhancement office and four senior officers from library departments.

Article describes how the study investigates the practice of data-driven decision-making in higher education institutions in Ethiopia. It then presents the results of a mixed-methods investigation that was conducted at two public universities in Ethiopia.

Presentation describes how teaching is one of the activities as a Fulbright Scholar. Alemneh describes a plethora of open-source tools and technologies used to prepare, organize and deliver the courses I taught.

In this dissertation, I examine the political shift or reorientation of Arabs and Muslims from the supranational Ummah to the Western form of nation-state by attending to modern Arabic novel in the period between World War I and World War II. I explore the emergence of secularism in Arab national formation. One of my central arguments is that Arab nationalism is indeed a misleading phrase as it gives the impression of unity and coherence to a complex phenomenon that materialize in a number of trends as a form of struggle. In the first chapter, I defined the scope of my argument and the underlying structure and function of nationalism as a form of representation masked by nationalist ideologies. To investigate the reorientation of Arabs and Muslims from Ummah to adopting nation-state, I utilize Spivak's criticism of the system of representation along with Foucault's theorization of discourse. I argued along Edward Said that although the Western national discourse might have influenced the Arab nationalists, I do not believe they prevented them from consciously appropriating nationalism in a free creative way. I also explained that the Arab adoption of a secularist separatist nationalism was more an outcome than an effect in the …

This study aims to investigate college students' security awareness of using social media in sharing information. The two theories that have guided this study are the theory of planned behavior (TPB) and the technology acceptance model (TAM). Data was collected from both undergraduate and graduate students from the University of North Texas (UNT) in Denton. The total responses included 380 students from different majors with 291 valid responses for data analysis; The structural equation model (SEM) Lavaan package was used to find out the best fit of the model. A diagonally weighted least squares (DWLS) was used to model the variables as ordinal in this study's analysis as ordinal data made the model fit substantially. The study found that 6 factors: attitude (AB), subjective norm (SN), perceived behavior control (PBC), perceived usefulness (PU), perceived risks (PR), and security awareness (SA) influenced behavior intention (BI). Also, I found that AB was influenced by PR and SA, as well as SN influenced by SA. Self-efficacy (SE) influenced PBC. On the other hand, the study found that controllability (C) did not influence PBC; perhaps, an individual's skills do not interact with social media security settings. Perceived ease of use (PEOU) did not influence …

Recognizing the dual ability of the nitride ligand to react as a nucleophile or an electrophile – depending on the metal and other supporting ligands – is a key to their broad-range reactivity; thus, three DFT studies were initiated to investigate these two factors effects (the metal and supporting ligands) for tuning nitride ligand reactivity for C-H and N-H bond activation/functionalization. We focused on studying these factors effects from both a kinetic and thermodynamic perspective in order to delineate new principles that explain the outcomes of TMN reactions. Chapter 2 reports a kinetic study of C–H amination of toluene to produce a new Csp3–N (benzylamine) or Csp2–N (para-toluidine) bond activated by diruthenium nitride intermediate. Studying three different mechanisms highlighted the excellent ability of diruthenium nitride to transform a C-H bond to a new C-N bond. These results also revealed that nitride basicity played an important role in determining C–H bond activating ability. Chapter 3 thus reports a thermodynamic study to map basicity trends of more than a one hundred TMN complexes of the 3d and 4d metals. TMN pKb(N) values were calculated in acetonitrile. Basicity trends decreased from left to right across the 3d and 4d rows and increases from …