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A Global Spatial Model for Loop Pattern Fingerprints and Its Spectral Analysis
The use of fingerprints for personal identification has been around for thousands of years (first established in ancient China and India). Fingerprint identification is based on two basic premises that the fingerprint is unique to an individual and the basic characteristics such as ridge pattern do not change over time. Despite extensive research, there are still mathematical challenges in characterization of fingerprints, matching and compression. We develop a new mathematical model in the spatial domain for globally modeling loop pattern fingerprints. Although it is based on the well-known AM-FM (amplitude modulation and frequency modulation) image representation, the model is constructed by a global mathematical function for the continuous phase and it provides a flexible parametric model for loop pattern fingerprints. In sharp contrast to the existing methods, we estimate spatial parameters from the spectral domain by combining the exact values of frequencies with their orientations perpendicular to the fingerprint ridge flow. In addition, to compress fingerprint images and test background Gaussian white noise, we propose a new method based on periodogram spacings. We obtain the joint pdf of these m-dependent random variables at Fourier frequencies and derive the asymptotic distribution of the test statistic.
How the Conflict of Autonomous and Controlled Motivation Influences Sales Controls to Inside Sales Agents' Work Outcomes
Through the use of multiple methodologies and analytical approaches, this dissertation combines (1) sales control; (2) call center service; and (3) motivational theory to extend sales control literature beyond its current state, to consider the conflicting motivational perspectives an inside sales agent has to experience. To achieve this unification, this dissertation consists of three essays intended to: (1) identify the influence of autonomous and controlled motivation on operational sales outcome controls and performance; (2) explore the influence these motivators have on sales controls and sales performance; and, (3) understand the impact of autonomous and controlled motivation on sales agent tenure.
The Impact of Property Tax Exemptions on the Fiscal Behavior of Cities: A Longitudinal Analysis of 41 Texas Cities
As a form of tax and expenditure limitations, property tax exemptions result in an utility gap between two groups of population residing in the same community: free-riders who are paying less than they receive and contributors who are paying more than they receive. This utility gap is problematic to municipalities because contributors may exit the city as this gap becomes wider. How do municipalities respond to the increasing amount of property tax exemptions? Using 41 Texas cities data from 2000 to 2016, this dissertation examines how property tax exemptions affect municipalities' fiscal behavior. The analysis indicates that property tax exemptions lead to higher property tax burden, change municipalities' revenue structure, and lead to less capital spending.
Improving Actigraphy Specificity to Better Inform Insomnia Diagnosis and Treatment Decisions
Accurate assessment of sleep-wake patterns is important for sleep researchers and clinicians. Actigraphs are low-cost, non-intrusive, wrist-worn activity detectors used to estimate sleep-wake patterns in a natural environment for several nights. Although actigraphy shows good sensitivity (sleep detection), it has consistently demonstrated poor specificity (wakefulness detection while lying in bed relatively motionless). Because insomnia is characterized by wakefulness in bed, actigraphy may not be a valid objective measure of wakefulness for this group. It is possible that refinement of actigraphy software settings for sleep/wake algorithms might improve specificity. The current studies investigated this hypothesis by comparing wake parameters from 48 combinations of actigraphy settings to determine which sleep/wake algorithms best inform insomnia diagnosis and treatment. In the first study, none of the 48 actigraphy setting combinations consistently discriminated between adults with insomnia (n = 69) and non-insomnia (n = 80) on all three wake parameters, and no setting clearly discriminated between groups for the composite variable, total wake time. Similarly, in the second study, no setting combinations consistently discriminated between adults treated for insomnia (n = 18) and controls with untreated insomnia (n = 26) on all three wake parameters. Although two setting combinations discriminated between groups for the composite variable, total wake time, the values were extreme which raises validity concerns. Therefore, no actigraphy setting recommendations can be made based on the current findings. This research offers insights about the effects of actigraphy software settings on actigraphy specificity as it pertains to the diagnosis and treatment of insomnia.
John La Montaine's "Songs of the Rose of Sharon" and "Fragments from the Song of Songs": A Socio-Historical Analysis and Performer's Guide
The purpose of this research is to examine John La Montaine's only two song cycles for soprano and orchestra, Songs of the Rose of Sharon, opus 6 (1947) and Fragments from the Song of Songs, opus 29 (1959). In this investigation-the first ever specific to these works-I examine the works and cultural context in which they were created. I then evaluate the reasonable possibility that La Montaine used his public platform as a composer and performer to subtly celebrate taboo themes of feminism, sexuality, and blackness while shining a light on human injustice. Through close examination of social and historical context, I argue two points. Firstly, Rose of Sharon and Fragments are landmark American works. They are anomalies in classical music history in that a white male heralds texts about a black woman in an unlikely time in American history, thus arguably becoming an unlikely part of the evolution of African-American women in artistic endeavors. Secondly, in the performance guide, I advocate that these works would readily adapt to a staged performance. I discuss how La Montaine's musical settings illustrate the inherent drama of the text, provide a context for interpreting the protagonist in Rose of Sharon and Fragments, and present an interpretation of how these works could be staged. The ultimate goal of this research is to bring these intricately crafted masterpieces to the attention of singers and voice teachers so that they may assume their rightful place in the repertoire.
Ligand Effects in Gold(I) Acyclic Diaminocarbene Complexes and Their Influence on Regio- and Enantioselectivity of Homogeneous Gold(I) Catalysis
This dissertation focuses on the computational investigation of gold(I) acyclic diaminocarbene (ADC) complexes and their application in homogeneous gold(I) catalysis. Chapter 2 is an in-depth computational investigation of the σ- and π-bonding interactions that make up the gold-carbene bond. Due to the inherent conformation flexibility of ADC ligands, distortions of the carbene plane can arise that disrupt orbital overlap between the lone pairs on the adjacent nitrogen atoms and the empty p-orbital of the carbene. This study investigated the affect these distortions have on the strength of the σ- and π-bonding interactions. This investigation demonstrated that while these distortions can affect the σ- and π-bonding interactions, the ADC ligand have to become highly distorted before any significant change in energy of either the σ- or π-bonding interactions occurs. Chapter 3 is a collaborative investigation between experimental and computational methods, DFT calculations were employed to support the experimental catalytic results and determine the role that steric effects have in controlling the regioselectivity of a long-standing electronically controlled gold(I)-catalyzed tandem 1,6-enyne cyclization/hydroarylation reaction with indole. This study demonstrated that by sterically hindering nucleophilic attack of indole at the favored position, nucleophilic attack would occur at a secondary position leading to the selective formation of the electronically unfavored product. Chapter 4 is a collaborative investigation between experimental and computational methods. DFT calculations were employed to investigate and rationalize the importance of secondary non-covalent interactions and their influence on the enantioselectivity of a gold(I)-catalyzed intramolecular hydroamination of allene reaction. Through computational investigation of the enantiodetermining step, and the non-covalent interactions present between 2′-aryl substituent and the rest of the catalyst, it was determined that the presence of CF3 group on the 3,5-position of the 2′-aryl ring is crucial to maintaining a more rigid chiral pocket leading to higher enantiomeric excesses in this dynamic system. …
Linking Enhanced Fatigue Life to Design by Modifying the Microstructure
Structural material fatigue is a leading cause of failure and has motivated fatigue-resistant design to eliminate risks to human lives. Intrinsic microstructural features alter fatigue deformation mechanisms so profoundly that, essentially, fatigue properties of structural materials become deviant. With this in mind, we initiated this project to investigate the microstructural effect on fatigue behavior of potential structural high entropy alloys. With a better understanding of the effect of microstructure features on fatigue properties, the ultimate goal was to engineer the microstructure to enhance the fatigue life of structural materials. The effects of two major deformation mechanisms presented here are twinning-induced fatigue crack retardation, and transformation-induced fatigue crack retardation. The fundamental principle of both mechanisms is to delay the fatigue crack propagation rate by altering the work hardening ability locally within the crack plastic zone. In ultrafine grained triplex Al0.3CoCrFeNi, nano-sized deformation twins were observed during cyclic loading in FCC matrix due to low stacking fault energy (SFE). The work-hardening ability of the material near the crack was sustained with the formation of twins according to Considere's criteria. Further, due to the ultrafine-grained (UFG) nature of the material, fatigue runout stress was enhanced. In a coarse-grained, dual-phase high entropy alloy, persistent slip bands formed in FCC matrix during cyclic loading due mainly to the slight composition change that affects the SFE in the FCC matrix and eventually alters the deformation mechanism. Another way known to alter an alloy's work hardening (WH) ability is transformation-induced plasticity (TRIP). In some alloys, phase transformation happens due to strain localization, which alters the work-hardening ability. iii In a fine-grained, dual-phase metastable high entropy alloy, gamma (f.c.c.) to epsilon (h.c.p.) transformation occurred in the plastic zone that was induced from cracks. Thus, we designed a Cu-containing FeMnCoCrSi high entropy alloy that exhibited a normalized fatigue ratio …
Lookouts
Lookouts follows Matt and Joann, two fire tower lookouts for the United States Forest Service, as they discuss their happiness living in seclusion as well as the decline of fire towers due to technological advances.
Luigi Boccherini's Cello Concerto in B-Flat Major, G.482: Creating a Performance Edition through a Critical Study of the 'Original' Version and Friedrich Grützmacher's Edition
The Cello Concerto in B-flat major, G.482, by Italian composer Luigi Boccherini (1743-1805), is the composer's most beloved work for the instrument, as well as one of the most performed pieces in the Classical concerto repertoire. Historically, cellists performing this work have used an edition prepared by German cellist Friedrich Grützmacher (1832-1903). However, an 'original' version that was discovered in 1949 is significantly different from that of Grützmacher. A comparison of both editions has revealed that Grützmacher in fact made considerable modifications to Boccherini's 'original.' Along with the issue of having two editions, cellists that have played the 'original' edition have noted that there are certain practical and interpretative matters that are not favorable to the cellist, particularly in terms of the way the music is notated and how it lacks many details. This dissertation provides clarity to these issues by undertaking a comprehensive analysis of both editions in order to make cellists become aware of the differences between both editions by comparing musical elements from a performance practice viewpoint. In addition, I discuss relevant issues that are present in the 'original' version, ultimately providing an alternative performance edition to this score that is based on historically informed performance (HIP) practices. Finally, I hope to draw attention on how a performance edition like this can be useful as a rare critical source to one of the major works from the eighteenth-century cello repertoire.
Measurement of Positive Continuance Intention Drivers within a Service Domain
The contribution of this dissertation is how model measurement allows examination of the balance between what is practical in terms of consumer concerns versus what is optimal in terms of cost control. Essay 1 examines a research framework that incorporates various service recovery strategies and simultaneously evaluates their comparative influences. Essay 2 evaluates the complex interrelationships among different factors related to the post-complaint behavioral process. Essay 3 fills a research gap by examining the role of brand equity by operationalizing a reflective model using PLS in operations management (OM) research. These three essays provide insight into the quality management domain and the value that is achieved via a data driven examination of theory. Moreover, this research will provide operations management practitioners a basis to carry out future research on quality management phenomena as well as insight into how to balance cost control and service recovery strategies with the goal of achieving a competitive advantage.
The Metabolic Physiology of Planarian Flatworms
Using a high throughput closed respirometry method to measure oxygen consumption, I determined metabolic rates in asexual and sexual Schmidtea mediterranea and Girardia dorotocephala, as a function of temperature, taxon, stressors, reproductive mode, age, regeneration, and specific dynamic action. This study has shown that oxygen consumption can reliably be measured in planaria using optode closed respirometry, and also provided a reliable method for measuring wet mass in planaria, which has been a challenge to researchers in the past. This research revealed that oxygen consumption in S. mediterranea is 1.5-2.1X greater in the sexual strain over the asexual strain at 13-18°C. Within the sexual strain, oxygen consumption is 1.5 -2.2X greater in sexually mature adults over the sexually immature groups (hatchlings, juveniles, and regenerating sexuals). Furthermore, I was able to quantify differences in sexual morphology between these groups exhibiting significant differences in oxygen consumption. The results of this research supports a theory of higher metabolic costs with sexual maturity in S. mediterranea. Therefore, this study has established sexual and asexual S. mediterranea as simple, yet attractive models for investigating energetic costs between sexual and asexual phenotypes. This research also provided quantitative values for specific dynamic action in planaria, with a maximum increase in oxygen consumption of 160% induced by feeding, as well as metabolic relationships in planaria involving temperature, age, and regeneration. These values establish planaria as one of the simplest animal models in which common metabolic patterns, such as SDA and poikilothermic temperature sensitivity, have been demonstrated. Therefore, this research has contributed to the overall knowledge of the basic physiology in this animal, providing the framework for future metabolic studies in planaria involving environmental factors, reproduction, regeneration, development, and aging. Information from this study may supplement interpretation and understanding of modern cellular, molecular, and genomic studies in planaria.
Method Development for Corrosion Testing of Carbon Steel and Ni-based Alloy Coatings Exposed to Gas Hydrate Formation Environments
Gas hydrate formation and corrosion can cause serious safety and flow assurance problems in subsea environments. One aspect that has been given less attention is the corrosion behavior of materials in gas hydrate formation environment (GHFE). This work introduces a new technique/method for corrosion testing of materials exposed to low temperatures GHFEs. This technique allows pH monitoring, and control of test conditions like temperature. In this work, GHFE is defined as an environment that includes water, methanol and its degraded products in the presence of corrosive agents like CO2 and chloride salt at gas hydrate formation temperatures (GHFT). After 20 hrs immersion in CO2-saturated salinity environment at GHFT, as-deposited Ni-Mo alloy coating has the highest corrosion resistance of 33.28 kΩ cm2. The corrosion resistance dropped to 14.36 kΩ cm2 and 11.11 kΩ cm2 in the sweet low-salinity and sweet high-salinity test solutions respectively. The combined results of SEM/EDX showed that the Ni-Mo coating oxide layer broke down quicker in sweet high-salinity environment than sweet low-salinity environment. When carbon steel was immersed in a CO2-saturated high salinity environment at GHFT, there was slight overall change in corrosion rate (CR) as salt concentration increase from 3 wt% to 25 wt%. In degraded methanol environment, methanol showed an inhibitive effect on the corrosion of carbon steel. Higher methanol content (up to 50 vol. %) increased the corrosion rate of carbon steel at gas hydrate formation temperature, however, the corrosion rates were lower with methanol contents between 10 to 20 vol%.
Military and Veteran Mental Health Stigma and Help-Seeking Behaviors: Role of Leadership and Attachment
Mental health stigma has been identified as a barrier to help-seeking in the United States. Research suggests that insecure attachment may contribute to higher mental health stigma and lower help-seeking behavior. This may be particularly salient in military personnel who tend to report higher mental health stigma than the general population. Evidence suggests that both supportive and destructive military leadership are related to service members' attitudes toward seeking help. In the current study, a sample of military service members and veterans (N = 232) completed an online survey regarding mental health stigma, military leadership experiences, attachment strategies, and mental health help-seeking behaviors. Findings indicated that destructive and supportive leadership experiences were significantly related to self and public stigma, and self-stigma mediated the relationship between destructive and supportive leadership experiences and likelihood to seek help. Attachment anxiety predicted higher self and public stigma, while attachment avoidance predicted high self-stigma but low public stigma, with high self-stigma partially mediating the relationship between attachment avoidance and help seeking.
Mining Biomedical Data for Hidden Relationship Discovery
With an ever-growing number of publications in the biomedical domain, it becomes likely that important implicit connections between individual concepts of biomedical knowledge are overlooked. Literature based discovery (LBD) is in practice for many years to identify plausible associations between previously unrelated concepts. In this paper, we present a new, completely automatic and interactive system that creates a graph-based knowledge base to capture multifaceted complex associations among biomedical concepts. For a given pair of input concepts, our system auto-generates a list of ranked subgraphs uncovering possible previously unnoticed associations based on context information. To rank these subgraphs, we implement a novel ranking method using the context information obtained by performing random walks on the graph. In addition, we enhance the system by training a Neural Network Classifier to output the likelihood of the two concepts being likely related, which provides better insights to the end user.
A Novel Two-Stage Adaptive Method for Estimating Large Covariance and Precision Matrices
Estimating large covariance and precision (inverse covariance) matrices has become increasingly important in high dimensional statistics because of its wide applications. The estimation problem is challenging not only theoretically due to the constraint of its positive definiteness, but also computationally because of the curse of dimensionality. Many types of estimators have been proposed such as thresholding under the sparsity assumption of the target matrix, banding and tapering the sample covariance matrix. However, these estimators are not always guaranteed to be positive-definite, especially, for finite samples, and the sparsity assumption is rather restrictive. We propose a novel two-stage adaptive method based on the Cholesky decomposition of a general covariance matrix. By banding the precision matrix in the first stage and adapting the estimates to the second stage estimation, we develop a computationally efficient and statistically accurate method for estimating high dimensional precision matrices. We demonstrate the finite-sample performance of the proposed method by simulations from autoregressive, moving average, and long-range dependent processes. We illustrate its wide applicability by analyzing financial data such S&P 500 index and IBM stock returns, and electric power consumption of individual households. The theoretical properties of the proposed method are also investigated within a large class of covariance matrices.
Optimizing Production System Maintenance Policies when Cyber Threats are Considered
In a production environment, physical and cyber-related failures become unavoidable because of the complexity of highly connected manufacturing systems and a finite equipment life cycle. The main purpose of this thesis is to investigate optimal maintenance outsourcing and replacement policies in the presence of cyber-threats, as well as policies to achieve channel coordination via cost subsidization. Although well-developed maintenance outsourcing literature has addressed many advanced and trending issues such as the costs and benefits of new technology adoptions, learning effects, forgetting effects, and systems with back-up machines, no study has looked at the effect of cyber threats on connected production systems. Besides filling this gap, this thesis addresses the most common replacement policies including preventive maintenance with minimal repairs and age replacement. The advent of the Internet of Things (IoT) has enabled the creation of "smart" manufacturing systems, However the resulting connected format makes these systems potential targets for cyber-attacks. Manufacturers have to face a difficult decision as to whether they should adopt costly security technologies or let the manufacturing systems be vulnerable to cyber-threats. This study develops a model addressing this dilemma by providing some insights into the effects of cost subsidization and installation of security systems on the system profit. Our findings suggest that a manufacturer can trade off cost subsidization to gain flexibility in the maintenance decision-making process. The study also provides evidence that, for a "smart" manufacturing system, the existence of a security system guarantees at least a marginal increase in system profit. With the help of an extensive numerical study, we provide guidelines for optimizing system profit and addressing the effect of various model parameters (such as a monetary parameter, failure rate and a cyber-attack related parameter) on the value of a security system.In the second part of this thesis, we build analytical models to …
Phase Transformation and Elastic Constants in Binary Titanium Alloys: An Atomistic Study
The current understanding of the mechanical properties and deformation behavior of some individual phases in titanium alloys is limited due to the fine scale at which these phases precipitate within the β-phase matrix. The α and ω phases represent the most widely observed phases in titanium alloys depending on the alloy composition and also the heat treatment procedure adopted during processing. The possibility of precipitating ω-phase depends on the content of the β-stabilizers within the system. Although a significant compositional partitioning occurs within ω-phase upon aging treatment, the knowledge of ω-phase mechanical properties as a function of composition is very limited. The initial part of the current work focuses on the effect of common β-stabilizers elements on the phase stability and mechanical properties of the ω-phase using first-principles calculations. A relation between the bonding nature, the phase stability, and elastic properties was proposed. Thereafter αʺ martensitic phase was investigated in Ti-Nb and Ti-Nb-O alloys. The phase stability and martensitic start temperature of αʺ-phase was studied as a function of Nb and oxygen content. Also, the effect of the lattice shear distortion induced by oxygen atom on stabilizing β-phase was investigated. Subsequently the effect of the β-stabilizers' elements on stacking faults energy and ductility in α-Ti alloys was studied. Both prismatic and basal slip system were investigated with different concentration of β-stabilizers at the slip plane. Lastly, while the Tadmor and Bernstein model was employed to predict the partial dislocation emission and twinning propensity, the Rice criterion was used to estimate the effect of different β-stabilizers on the ductility of α-Ti alloys.
Phase Transformations in Refractory High Entropy Alloys
High entropy alloys (HEAs) based on refractory elements have shown a great potential for high temperature structural applications. In particular, the ones containing Al, exhibits a microstructure similar to the γ-γ' in Ni-based superalloys. While these alloys exhibit impressive strengths at room temperature (RT) and at elevated temperatures, the continuous B2 matrix in these alloys is likely to be responsible for their brittle behavior at RT. Phase stability of five such alloys are studied by thermo-mechanical treatments and characterization techniques using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Two of these alloys showed an inverted microstructure, where the disordered BCC phase becomes continuous, and therefore, they were characterized in detail using SEM, TEM, atom probe tomography (APT) and synchrotron x-ray diffraction experiments. The phenomenon of phase inversion lead to a better combination of strength and ductility as compared to the non-inverted microstructure.To enhance the stability of B2 intermetallic phase which provides the strength when present in a BCC matrix, multicomponent B2 phase compositions stable at 1000°C in some of the above studied alloys, were melted separately. The aim was to establish a single phase B2 at 1000°C and understand the mechanical behavior of these single-phase multicomponent B2 intermetallic alloys. These alloys exhibited a ductile behavior under compression and retained ~1 GPa yield strength at temperature up to 600°C. The ductile nature of these alloys is attributed to the change in bonding nature form directional to metallic bonding, possibly resulting from a significantly high configurational entropy compared to binary or ternary stoichiometric B2 compounds.
Prevalence and Proportionality of Dyslexia in Texas Public and Charter School Districts
Passed in 1985, the Texas Education Code (TEC) §38.003, Screening and Treatment of Dyslexia and Related Disorders, required public school districts and charters to identify and provide remediation services for students with dyslexia. While Texas was the first state to pass such a requirement, the question remains: What is the prevalence and proportionality of dyslexia in Texas public school districts and charters? In Phase 1 of this study, a secondary analysis using point prevalence and disproportionality calculations was conducted to analyze the impact of this more than 30-year-old law. In order to better help understand these findings, semi-structured interviews with district leaders were conducted in Phase 2 to gain insight on how students were identified with dyslexia across the state. The results of Phase 1 showed the estimated prevalence of dyslexia in Texas public school districts and charters to be low in comparison to the literature. Additionally, the findings suggested a discrepancy in identifications between gender and district type (public school versus charter) and across racial and ethnic groups. Meanwhile, the results of Phase 2 revealed that leadership, support, funding, and accountability impact dyslexia identifications. This study emphasizes the need to further explore and analyze how to best identify and service all students with dyslexia, regardless of gender, race and ethnicity, district type, and geographical location.
Processing-Structure-Property Relationships of Reactive Spark Plasma Sintered Boron Carbide-Titanium Diboride Composites
Sintering parameter effects on the microstructure of boron carbide and boron carbide/titanium diboride composites are investigated. The resulting microstructure and composition are characterized by scanning electron microscopy (SEM), x-ray microscopy (XRM) and x-ray diffraction (XRD). Starting powder size distribution effects on microstructure are present and effect the mechanical properties. Reactive spark plasma sintering introduces boron nitride (BN) intergranular films (IGF's) and their effects on fracture toughness, hardness and flexural strength are shown. Mechanical testing of Vickers hardness, 3-point bend and Chevron notch was done and the microstructural effects on the resulting mechanical properties are investigated.
Psychological Well-Being and Family Functioning in Middle Childhood: The Unique Role of Sibling Relational Dynamics
The current study examined associations between perceived family functioning, sibling relational dynamics, and individual's self-reported personal adjustment and internalizing problems among 8- to 11-year old children. Path analyses revealed significant direct effects between conflictual family functioning and children's psychological well-being (p < 0.05). Further, sibling conflict was found to indirectly affect these associations. Finally, significant interactions between family functioning and sibling dynamics were found suggesting that congruent relational dynamics at multiple levels of the family system had a cumulative impact on the child's well-being. Findings from the current study highlight the unique contributions of sibling relationships to the family and the child providing evidence for targeting the sibling relationship in clinical interventions and future family research.
Relationship Quality in Social Commerce Decision-Making
This research study involves three essays and examines CRQ-driven decision making from the points of view of the common firm, social-commerce platform provider, and social-commerce echo-system. It addresses CRQ's progression from traditional business-to-consumer (B2C) initiatives to social platform-specific antecedents and to environment-driven factors lying outside the direct control of the platform provider, yet influencing social commerce business decisions, such as user-generated content from peers (e.g. family, friends) and expert authority (e.g. specialists, experts, professional organizations). The research method used statistical, data mining and computer science techniques. The results suggest that social platform providers should take a proactive approach to CRQ, fully leverage their online platform to improve CRQ while paying special attention to security as a potential barrier, and consider the analysis of elements of the echo-system such as the electronic word of mouth (eWOM) to further drive CRQ and determine the level of alignment between customers and experts, suppliers and products featured, that may lead to value-added managerial insights such as the prioritization, promotion and optimization of such relationships.
The Role of Male Fashion in Protests against the Majority Culture: An Exploratory Study
Throughout history, the Black Diaspora has used fashion as a form of protest. The element of fashion is often overlooked when considering the history and struggle for Black equality, because it is less tangible or definable in terms of its influence and effect, but it is still important because Black males resist the dominant culture via dress by dressing in military uniforms, creating their own style, and using different colors in their dress. Studying the Black struggle in American history during specific periods is one way to better understand opposition to the majority culture through fashion. We should also consider the mood of a social system when examining the dress of a particular group during conflicts. Hence, the purpose of this study is to investigate the role of fashion as a protest tool against the majority culture, and the social mood that affects the fashion choices of Black males. The study focuses on Black fashion from 1910 to 2015. Text data were collected and analyzed from articles published in The Crisis magazine, and men's fashion was specially examined. Additionally, images were studied via visual ethnography and images were coded based on color choice, fit, and accessories. For conducting sentiment analysis, lexicons were used, and the text was examined for negative sentiment. The overall negative sentiment of the document was obtained. Graphical analyses are included to present the findings. The findings, conclusions, limitations, and future research are discussed.
A Smart Tale: An Examination of the Smart City Phenomena through the Lens of a Case Study
This dissertation addresses research questions related to defining a smart city and the associated activities. The general research question is explored in the dissertation via the conduct of three related studies. The finding from these three investigations are presented in the results section as 3 essays that collectively examine the smart city phenomena as it has emerged within the City. Essay 1 assesses building municipal open data capability. The study proposed an Opendata Roadmap Framework to enhance the organization's dynamic capability. The results provide a valuable practical framework to help cities develop open data capability. The results also provide a comparative study or benchmark for similar initiatives with other regional cities and within the nation. Essay 2 measures the residents' understanding and beliefs about smart cities. This portion of the research used a qualitative method that included interviewing residents and city officials to understand their definition of a smart city and what they believe makes a city smart. The interviews focused on understanding resident engagement because it is an important characteristic of a smart city. The gap between the city officials and residents understanding was examined. In addition, the interviews help identify essential factors associated with smart cities like trust in government, perceived security, perceived privacy, trust in technology, and perceived monetary value. Essay 3 examines the acceptance of smart city technologies and factors that affect the adoption of such technologies. This essay uses the insights from the other two essays to propose a smart city Unified Theory of Acceptance and Use of Technology (UTAUT) extension labelled Smart City UTAUT (SC-UTAUT). The new proposed model was tested using a survey method. The 1,786 valid responses were used to test the proposed structural equation model using Smart PLS. Results show a significant relationship between trust in technology, trust in government, perceived …
SurfKE: A Graph-Based Feature Learning Framework for Keyphrase Extraction
Current unsupervised approaches for keyphrase extraction compute a single importance score for each candidate word by considering the number and quality of its associated words in the graph and they are not flexible enough to incorporate multiple types of information. For instance, nodes in a network may exhibit diverse connectivity patterns which are not captured by the graph-based ranking methods. To address this, we present a new approach to keyphrase extraction that represents the document as a word graph and exploits its structure in order to reveal underlying explanatory factors hidden in the data that may distinguish keyphrases from non-keyphrases. Experimental results show that our model, which uses phrase graph representations in a supervised probabilistic framework, obtains remarkable improvements in performance over previous supervised and unsupervised keyphrase extraction systems.
Three Essays on Artificial Intelligence Adoption and Use
Artificial intelligence (AI) is quickly transforming business operations and society, as AI capabilities are incorporated into applications ranging from mobile personal assistants to self-driving cars. The potentially disruptive nature of AI calls for an extensive investigation into all aspects of AI-human interactions at individual, group, organizational and market levels. However, there is paucity of academic information systems (IS) research in this area that goes beyond the development and testing of specific narrow AI capabilities. AI represents an important opportunity for organizational and behavioral IS researchers, but also presents challenges associated with the underlying complexity of AI technologies and the diversity of AI applications. Understanding how existing AI research and business practice relate to traditional areas of IS research is an important step towards creating a comprehensive behavioral and organizational AI research agenda. This dissertation seeks to achieve a dual purpose in a series of three essays. Essay 1 seeks to understand the current state of business AI research and practice in business through a quantitative literature review, relate the findings to traditional IS research areas, and identify potentially fruitful research areas for AI-focused IS research. Essays 2 and 3 seek to address specific research questions related to one of such research areas, namely, human interactions with AI enabled applications. Essay 2 focus on user experience with a chatbot, a popular AI application, and Essay 3 explores how user experiences with AI assistant apps differ from their interactions with more traditional IT artifacts.
Turkish Gazis' (Injured Veterans) Transition into Civilian Life
The aim of this study was to describe the dimensions of Turkish Gazis' transition to civilian life, to explore the main factors that make this process easier or more difficult, and their psychological integration, that is, specifically, satisfaction with their life. To that end, this study examined the impact of combat-related traumatic stressor (e.g., functional limitations), personal resources (social support, sense of mastery), perceived mental health on Turkish veterans' adjustment into civilian life and their psychological integration. The data was collected in Turkey in 2015 by the researcher with the help of Türkiye Harp Malulü Gaziler Şehit Dul ve Yetimler Derneği, a non-profit veteran organization. The final sample included 240 Turkish Gazis. The level of perceived transition into civilian life and veterans' life satisfaction were the dependent variables in this study. A series of ordinary least squares (OLS) regression was conducted. Hayes' PROCESS macro 3.0 was utilized to measure the direct, indirect and moderation effects of variables on transition and life satisfaction among Gazis. The results demonstrated that perceived available social support, perceived sense of mastery and mental health partially mediated the association between Gazis' functional limitations and transition into civilian life and they fully mediated the association between functional limitations and life satisfaction. Among control variables, only household income predicted transition into civilian life, and place of residence was the only significant predictor of life satisfaction. However, neither social support nor mastery had moderation effect on the relationship between functional limitations and dependent variables. Policy implications and suggestions for further studies are also provided at the end of the dissertation.
Uncle Sam Does Not Want You: Military Rejection and Discharge during the World Wars
In the United States, rapid military mobilization for the world wars marked a turning point in the national need to manage and evaluate manpower. To orchestrate manpower needs for the military, industry, and those relating to familial obligations, Woodrow Wilson's administration created the Selective Service System during the First World War. In categorizing men, local Selective Service boards utilized rapid physical and psychological diagnostic techniques and applied their assessments to current military branch induction standards to pronounce candidates as militarily fit or unfit. From World War I to World War II, the Selective Service System expanded as a bureaucracy but did not adequately address induction issues surrounding rapidly changing standards, racism, and inconsistent testing procedures. These persistent problems with Selective Service prevented the system from becoming truly consistent, fair, or effective. As a result of Selective Service System, War Department, and military branch standards, military rejection and prematurely military discharge rates increased in World War II. Additionally, though Selective Service did not accurately predict who would or would not serve effectively, rejected and prematurely discharged men faced harsh discrimination on the American home front during World War II.
Understanding the Micromechanism of Cyclic Loading Behavior of Ultrafine Grained Alloys
In the current study, we have investigated the cyclic loading behavior of conventional as well as novel alloy system exhibiting fine and ultrafine-grained structure. While in case of conventional alloy systems (here aluminum alloy AA5024), the effect of three different grain sizes was investigated. Improvement in fatigue properties was observed with decreasing grain size. The unique microstructure produced via Friction stir processing was responsible for the improved fatigue response. Additionally, microstructures consisting of a high fraction of special boundaries within the fine and ultrafine-grained regime were also subjected to cyclic loading. The hierarchical features introduced in the eutectic high entropy alloy deflected the persistent slip bands, responsible for fatigue cracking, thus resulted in delayed crack initiation and improved fatigue life. The selective nature of fatigue was learnt in the fine grain Al0.5CoCrFeNi, where the introduction of hierarchical features did not result in improved fatigue properties. The weak links in the microstructure, while not affecting the tensile properties, got exposed during cyclic loading. Further study on the medium entropy alloy revealed the inherent reason for the improved fatigue properties. The medium entropy alloys utilized the benefit of UFG single-phase FCC matrix. The UFG matrix showed signs of transformation of FCC phase into the HCP phase during fatigue deformation and hence exhibited improved work-hardening. Alongside atomic scale transformation, stacking faults and nano-twins can also be attributed for obtained cyclic properties.
Universal Suicide Risk Screening in the Parkland Health and Hospital System: Evaluation of the Parkland Algorithm for Suicide Screening
Suicide is a significant public health issue in the US. Despite national and international prioritization since 1996, little definitive progress has been made in terms of identification and intervention in cases of elevated suicide risk. Forty percent of those who died by suicide attended an emergency department within a year of death. Therefore, universal suicide risk screening in emergency departments could prove a vital component to a national suicide prevention strategy. The present study empirically evaluated the universal suicide risk screening program recently implemented at Parkland Health and Hospital System. The sample consisted of patients over 18 years of age (N=333,855; Mage=42.7, 32% male) screened as part of routine clinical care from May 4th, 2015, through November 3rd, 2015. The Parkland Algorithm for Suicide Screening (PASS) is part of a clinical decision support system for responses to Columbia - Suicide Severity Rating Scale Clinical Practice Screener (C-SSRS) items, leading to an automated clinical response via three suicide risk stratification levels: no action for no risk identified, psychiatric social worker assessment for moderate risk identified, and psychiatrist/psychologist interview for high risk identified. The present study used receiver operating characteristic (ROC) curve analysis, which found the PASS predicted disposition (z=30.46, p<.001, AUC=.78, CI95=.77, .81). This study also evaluated the cutpoints separating suicide risk stratification and levels of clinical response. The results supported the first cutpoint and highlighted a need for additional data to address the second cutpoint. The results of the present study suggest that the universal suicide risk screening program at Parkland Health and Hospital System is an important step toward addressing suicide prevalence in the US.
Weapons of Mass Deception: Opacity and the Israeli Nuclear Program
Access to nuclear technology and growing concern over the spread of nuclear weapons triggered an international debate in the 1960s that led to the creation of the Nonproliferation Treaty. Ratified in 1970, NPT was designed to prevent the horizontal spread of nuclear weapons and limit destructive uses of nuclear energy. At the same time, it also normalized the arsenals of existing nuclear states and encouraged exchanges of nuclear information, technology, and materials for peaceful purposes. Nonproliferation policy relies on a theory of the development process that identifies a nuclear frontier to locate evidence of nuclear capabilities. Absent from the proliferation model, however, are cases of covert nuclear weapons programs. For almost 50 years, it has been generally accepted that Israel is a nuclear weapon state, yet Israeli officials have never confirmed nor denied the possession of nuclear weapons. Israel has not signed NPT and has not appeared to conduct a nuclear test, in effect absolving the nuclear program's main reactor from international inspections. Uncertainty surrounding the Israeli program stems from a tradition of deliberate secrecy and deception that constitutes a national policy of opacity. This study argues that opacity has armed Israel with the privilege of nuclear immunity, exempting its secret nuclear activity from the standards and regulations imposed on all other nuclear weapon states. To circumvent the barriers built by opacity, a mixture of declassified material, nuclear history and security literature, and postcolonial studies refines the history of Israel's nuclear program. By examining the American-Israeli nuclear relationship, the sources of opacity, and the framework of nonproliferation that sustains an international nuclear regime, Israel's role in the nuclear world becomes visible.
Who Does Online Dating Benefit? Association of Adult Attachment with Relationship and Sexual Satisfaction for Online Daters
Research on associations between online dating and later relationship and sexual satisfaction is limited. The purpose of this study is to examine the association between meeting a romantic partner online or in person and later relationship and sexual satisfaction for heterosexual males and females. Main analysis results suggest that men report higher relationship satisfaction when they met their partner online and women with a preoccupied and dismissing attachment style reported higher sexual satisfaction when they met their partner online. Overall, there were few differences in relationship and sexual satisfaction for heterosexual men and women who met their partner online or in person.
Allusions and Borrowings in Selected Works by Christopher Rouse: Interpreting Manner, Meaning, and Motive through a Narratological Lens
Christopher Rouse (b. 1949), winner of the Pulitzer Prize for his Trombone Concerto (1993) and a Grammy award for his Concerto de Gaudi (1999), has come to the forefront as one of America's most prominent orchestral composers. Several of Rouse's works feature quotations of and strong allusions to other composers' works that are used both rhetorically and structurally. These borrowings range from a variety of different genres and styles of works, from Claudio Monteverdi's L'incoronazione di Poppea to Jay Ferguson's "Thunder Island." Due to the more accessible filtering and funneling methods of musical borrowings (proliferation of mass media), the weighty discourses attached to them, and their variety of functions (critiquing canons, engaging in an allusive tradition, etc.), quotation has become elevated to the most prominent of musical actors that trigger narrative listening strategies, which in turn have a stronger role in the formation of narratives about music as well as narratives of music. The primary aim of this study is to adapt and apply more recent methodological narrativity frameworks to selected instrumental compositions by Rouse containing quotations, suggesting that their manner of insertion, their method of disclosure, and their referential potential can benefit from being examined through various narrative lenses as well as reveal their participation in certain roles of narrative functions. For this study, I have chosen six instrumental works by Rouse for examination - the Violoncello Concerto, Symphony No. 1, Iscariot, String Quartet No. 2, Seeing, and Thunderstuck. On a more specific level, the aim of this study is to investigate the manner, meaning, and motive of the quoted material in a select group of Rouse's compositions through various narratological lenses. To accomplish this, I intend 1) to establish a context for understanding the musical borrowing procedures of Rouse; 2) to explore how works containing quotations can be …
Animals Alive and Dead
Collection of poems.
Bio-Inspired Material Surfaces with Self-cleaning, Micromanipulation and Water Collection
Geckos are famous for the skill of switchable adhesion that they use to stick on various surface while keep their fingers super clean. In the dissertation, a unique mechanism was discovered to explain gecko self-cleaning phenomena. Using atomic force microscopy (AFM), we managed to compare the microparticle-substrate adhesion and the microparticle-seta adhesion with a single seta bonded to the AFM cantilever. A dynamic effect was approved that high pulling-off speed could increase the microparticle-substrate adhesion and thus the self-cleaning appears at high moving speed. Based on the self-cleaning theory, a gecko-inspired N-doped graphene surface with switchable adhesion was achieved, which was designed into a bio-inspired micromanipulator with a success rate over 90%. When electrical bias was applied on this biomimetic surface, the charge concentration induced an electrical double layer (ELD) on the convex surfaces, which attracts polar water molecules to form a water bridge on it, significantly enhancing the adhesion on the wrinkled graphene surface, mimicking the capillary force on beetle feet. Therefore, the bio-inspired adhesive surface can be controlled with speed, electrical bias, humidity and different material surfaces. The water attraction phenomenon on the polarized surface was further tested for the potential application of water collection and evaporation in microsystems.
Brazos
Brazos is a collection of poetry that comments on and critiques life in a small town in Texas. These poems situate the speaker both in this town and in spaces removed from the town, but the work always grapples with questions of how the speaker identifies himself via the relationship to that space. The creative portion is accompanied by a critical introduction that looks at the intersections of poetry and the lyric essay.
Cold-Formed Steel Member Connections Using BAC Screw Fasteners
In this project, the main research objective is intend to seek criteria for evaluating the capacity of BAC screw fasteners with mixed configuration of waterproof seal washer, sealer tape and different pre-drill holes to determine shear and tension strength values for the screws used in cold-formed steel connections. The thesis presents the design methods and test program conducted to investigate the behavior and strength of the screw connections in shear and tension test. Test results were compared with AISI design provisions to determine if new design equations will be developed for those screws used in BAC cooling tower applications. LRFD resistance factors and ASD safety factors were investigated to the proposed design equations.
Complex-Restricted Repetitive Patterns of Vocal Behavior of Individuals with High Functioning Autism: An Innovative Intervention
Repetitive verbal patterns of speech are a trait associated with high-functioning autism (HFA). For some, this higher-order restricted, repetitive behavior impedes learning, social opportunities, and access to work environments. Despite emerging motivation for establishing social relationships, some individuals with HFA lack the behavioral prerequisites to establish meaningful relationships. The purpose of this study is to demonstrate the effectiveness of teaching interaction to decrease higher-order verbal restricted and repetitive behaviors (RRBs) for four adults with HFA. Through a multiple baseline design across participants, individuals were exposed to a function-based intervention (i.e., teaching interaction) that systematically taught and reinforced alternative communicative behaviors while interrupting repetitive speech with specific feedback. Teaching interaction effectively reduced RRBs and increased alternative conversation for all four participants. Three of the four participants elected to participate in post-intervention maintenance sessions that occurred in individualized naturalistic settings. Their conversation behaviors maintained with one participant receiving one booster session.
Computational Studies of C-H Bond Activation and Ethylene Polymerization Using Transition Metal Complexes
This work discusses the C-H bond activation by transition metal complexes using various computational methods. First, we performed a DFT study of oxidative addition of methane to Ta(OC2H4)3A (where A may act as an ancillary ligand) to understand how A may affect the propensity of the complex to undergo oxidative addition. Among the A groups studied, they can be a Lewis acid (B or Al), a saturated, electron-precise moiety (CH or SiH), a σ-donor (N), or a σ-donor/π-acid (P). By varying A, we seek to understand how changing the electronic properties of A can affect the kinetics and thermodynamics of methane C–H activation by these complexes. For all A, the TS with H trans to A is favored kinetically over TS with CH3 trans to A. Upon moving from electron-deficient to electron-rich moieties (P and N), the computed C–H activation barrier for the kinetic product decreases significantly. Thus, changing A greatly influences the barrier for methane C–H oxidative addition by these complexes. Secondly, a computational study of oxidative addition (OA) of methane to M(OC2H4)3A (M = Ta, Re and A = ancillary ligand) was carried out using various computational methods. The purpose of this study was to understand how variation in A and M affects the kinetics and thermodynamics of OA. Results obtained from MP2 calculations revealed that for OA of CH4 to Re(OC2H4)3A, the order of ΔG‡ for a choice of ancillary ligand is B > Al > SiH > CH > N > P. Single point calculations for ΔG‡ obtained with CCSD(T) showed excellent agreement with those computed with MP2 methods. MCSCF calculations indicated that oxidative addition transition states are well described by a single electronic configuration, giving further confidence in the MP2 approach used for geometry optimization and ΔG‡ determination, and that the transition states are more …
Computational Studies of Catalysis Mediated by Transition Metal Complexes
Computational methods were employed to investigate catalytic processes. First, DFT calculations predicted the important geometry metrics of a copper–nitrene complex. MCSCF calculations supported the open-shell singlet state as the ground state of a monomeric copper nitrene, which was consistent with the diamagnetic character deduced from experimental observations. The calculations predicted an elusive terminal copper nitrene intermediate. Second, DFT methods were carried out to investigate the mechanism of C–F bond activation by a low-coordinate cobalt(I) complex. The computational models suggested that oxidative addition, which is very rare for 3d metals, was preferred. A π–adduct of PhF was predicted to be a plausible intermediate via calculations. Third, DFT calculations were performed to study ancillary ligand effects on C(sp3)–N bond forming reductive elimination from alkylpalladium(II) amido complexes with different phosphine supporting ligands. The dimerization study of alkylpalladium(II) amido complexes indicated an unique arrangement of dative and covalent Pd-N bonds within the core four-membered ring of bimetallic complexes. In conclusion, computational methods enrich the arsenal of methods available to study catalytic processes in conjunction with experiments.
Decision Making in Alternative Modes of Transportation: Two Essays on Ridesharing and Self-Driving Vehicles
This manuscript includes an investigation of decision making in alternative modes of transportation in order to understand consumers' decision in different contexts. In essay 1 of this study, the motives for participation in situated ridesharing is investigated. The study proposes a theoretical model that includes economic benefits, time benefits, transportation anxiety, trust, and reciprocity either as direct antecedents of ridesharing participation intention, or mediated through attitude towards ridesharing. Essay 2 of this study, focuses on self-driving vehicles as one of the recent innovations in transportation industry. Using a survey approach, the study develops a conceptual model of consumers' anticipated motives. Both essays use partial least square- structural equation modeling for assessing the proposed theoretical models.
Defining Components Linked to Bacterial Nutritional Utilization of Cyanide as a Sole Nitrogen Source
One of the challenges in biology is placing a function on the myriad of gene sequences having become available from rapid advances in genome sequencing. One such example is a gene cluster (Nit1C) found in bacteria that is tied to the unusual ability of certain bacteria to grow when supplied cyanide as the sole nitrogen source. The term cyanotrophs has been applied to such bacteria, for which a genetic linkage between cyanotrophy and Nit1C was demonstrated for 10 separate bacteria. In addition to growth, cyanide induced the expression of Nit1C genes in all organisms tested, and in one case, deletion of one of the Nit1C genes (nitC) caused a loss of growth. Of the ten bacteria able to grow cyanotrophically, all gave evidence of harboring Nit1C on their genome except for two (Pseudomonas fluorescens Pf11764 and P. monteilii BCN3), which were sequenced and the presence of Nit1C was also confirmed. A broader search of bacteria identified 270 separate strains with the cluster, all limited to bacteria spanning the phyla Firmicutes, Actinobacteria, Proteobacteria and Cyanobacteria. Remarkably, many examples of a single representative of a given taxon contained Nit1C, most poignantly displayed by Pf11764 and PmBCN3; the interpretation being the cluster was likely acquired by horizontal gene transfer in response to cyanide as an environmental cue. Consistent with its absence in Archaea is the time line for the emergence of cyanide producing organisms (cyanogens) on earth dating back only 400-500 million years.
Design, Synthesis and Characterization of Polymer and Protein Coated Hybrid Nanomaterials: Investigation of Prototypes for Antimicrobial and Anticancer Applications
This work involves synthesis and characterization of isotropic and anisotropic noble metal nanoparticles for applications ranging from antimicrobial uses to anticancer applications. These nanomaterials are stabilized in genuinely benign biomaterials ranging from polymers to cross linked proteins for targeted cancer treatments. The nanoparticles are found to have tunable optical properties.
Development and Testing of Gold(I) and Europium(III) Based Sensors for Environmental Applications
This dissertation focuses on the development, characterization, and analysis of luminescent materials and coatings for sensing applications, including CO2, heavy metals, and silver. Chapter 2 involves the use of a gold(I) pyrazolate trimer that is able to detect silver ions with an AgNP medium. Detection of silver is vital, because there is an influx of silver into our environment caused by the increased use of AgNP. Therefore, having a sensor that is able to differentiate between and detect only Ag ions is an important first step to solving the toxicity mystery of AgNPs. Chapter 3 focuses on the development of sensor coatings containing a Eu(III) based luminescent system for sensing dissolved CO2 without the aid of an absorption-based dye. It is well-known that monitoring CO2 levels in our environment is important since even at low concentrations it can cause adverse health effects to the human body. This work demonstrates a pH-sensitive Eu complex being used directly as a CO2 sensor without the aid of any other absorption-based dye. Chapter 4 explores the idea of developing a heavy metal sensor for lead and its ability to detect lead in wide concentration range upon changing the pH of the medium and the polymer matrix. Different heavy metals have toxicity at different concentrations, therefore, being able to change the dynamic range of the sensor is advantageous. This research is the first step towards developing a luminescent Pb sensor with a tunable dynamic range.
The Effect of Processing Conditions on the Surface Morphology of Few-Layered WS2 Thin Films
Recent progress in layered transition metal dichalcogenides (TMDs) has led to various promising electronic and optoelectronic applications. However, the structure of materials plays a critical role in electronic and optoelectronic devices, and determines performance. Electronic and optoelectronic devices typically consist of multiple layers that form electrical homojunctions or heterojunctions. Therefore, in a device it can be expected that a WS2 layer may serve as the substrate for a subsequent layer in a multilayer device stack and determine how the layer grows. In transistor structures, roughness at the channel/gate dielectric interface introduces field variations and charge scattering. Therefore, understanding the relations between processing, surface morphology and properties is important. In this project, the effects of pulsed laser deposition (PLD) processing conditions on the surface morphology of few layered WS2 films were studied. WS2 films were synthesized under processing conditions that represent the extremes of surface supersaturation and kinetic energy transfer from the flux to the growing films, and evolution of the surface morphology was studied. The specific conditions were 1Hz/50mJ, 10Hz/50mJ, 1Hz/300mJ, and 10Hz/300mJ respectively. Combining AFM, XRD and Raman analyses, it was determined that deposition at 10Hz/300mJ, provided the best structural properties and surface morphology. Growth appeared to be 3D-cluster, and was governed by supersaturation rather than by surface diffusion processes. No clear correlation between mobility and surface roughness was found. Hall measurements and XPS data show the highest mobility was obtained with the highest S/W ratio, indicating that point defect scattering rather than scattering from surface roughness was dominant.
The Effect of Trauma Experiences and PTSD Severity on Positive Memory Recall and Memory Phenomenology
Positive memories play an important role in the etiology and maintenance of posttraumatic stress disorder (PTSD). Additionally, there are potential clinical benefits of recalling positive memories on affect, cognitions, and behaviors. However, most research/clinical work has focused on the role of traumatic memories in PTSD's symptomatology and treatment. The current study examined positive memory recall difficulties and positive memory phenomenology among 185 trauma-exposed individuals with varying PTSD severity. Participants completed the Life Events Checklist for DSM-5, PTSD Checklist for DSM-5, Autobiographical Memory Test, Memory Experiences Questionnaire – Short Form, Ruminative Thought Style Questionnaire, Difficulties in Emotional Regulation Scale – Brief 16-Item Version, Difficulties in Emotional Regulation Scale – Positive Emotions, the Positive Affect subscale of the Affective Control Scale, and two items from the Pittsburg Sleep Quality Index. Results showed that (1) greater PTSD severity was a marginally significant predictor of fewer recalled positive memories; (2) greater positive emotional dysregulation predicted fewer recalled positive memories controlling for PTSD severity; and (3) increasing PTSD severity predicted more negative valence, less vividness, less coherence, less accessibility, less clear time perspective, fewer sensory details, and greater distancing ratings of the recalled positive memory, controlling for sleep quantity/quality. Such findings add to the PTSD-positive memory literature by informing PTSD theoretical perspectives; enhancing an understanding of if/how positive memories may be incorporated into PTSD treatments; and highlighting potential clinical targets, such as positive emotional regulation skills, when integrating a focus on positive memories into PTSD intervention.
Effects of Telepractice for Training Autism Teachers to Contrive Motivating Operations
The rising rate of the autism spectrum disorders (ASD) has resulted in challenges for teachers in public schools, concerning the delivery of evidence-based practices for superior outcomes. Thus, school districts are in need of professional learning options that can be efficiently and effectively delivered to improve the procedural fidelity of interventions. The purpose of this study is to demonstrate the effectiveness of using telepractice to teach autism teachers how to contrive motivating operations to teach manding to students with ASD. By utilizing multiple baselines across participants design, four autism teachers in public schools received intervention support through an online module along with video models as well as direct performance feedback from autism specialists via video-conferencing. The primary dependent variable was the percentage of correct responses from the instructional procedures of task analysis, and the secondary measure was the subsequent rate of student mands. Data were analyzed both visually (i.e., through the study of behavioral patterns) and statistically (i.e., analysis of effect size). Results indicate that telepractice increased accuracy of both teacher and student target responses.
Enhancing Storage Dependability and Computing Energy Efficiency for Large-Scale High Performance Computing Systems
With the advent of information explosion age, larger capacity disk drives are used to store data and powerful devices are used to process big data. As the scale and complexity of computer systems increase, we expect these systems to provide dependable and energy-efficient services and computation. Although hard drives are reliable in general, they are the most commonly replaced hardware components. Disk failures cause data corruption and even data loss, which can significantly affect system performance and financial losses. In this dissertation research, I analyze different manifestations of disk failures in production data centers and explore data mining techniques combined with statistical analysis methods to discover categories of disk failures and their distinctive properties. I use similarity measures to quantify the degradation process of each failure type and derive the degradation signature. The derived degradation signatures are further leveraged to forecast when future disk failures may happen. Meanwhile, this dissertation also studies energy efficiency of high performance computers. Specifically, I characterize the power and energy consumption of Haswell processors which are used in multiple supercomputers, and analyze the power and energy consumption of Legion, a data-centric programming model and runtime system, and Legion applications. We find that power and energy efficiency can be improved significantly by optimizing the settings and runtime scheduling of processors, and Legion runtime performs well for larger-scale computation in terms of power and energy consumption.
Flotsam: Men in Isolation
An interrogation of male behavior in isolated masculine spaces through short stories, an essay, and chapters from a novel-in-progress.
The Food-Drug Relationship in Health and Medicine
In this dissertation, I apply Gadamerian philosophical hermeneutics to examine interpretations of the food-drug relationship within the contexts of health and medicine. Assumptions regarding the relationship between these categories undergird a substantial academic discourse and function as key components in worldviews beyond the academy. Despite this, little work has been done in foregrounding them to allow for critique and consideration of alternative perspectives. Unearthing philosophical assumptions within various fields, epistemic systems, and regulatory bodies, I classify food-drug interpretations into two main categories: dichotomous interpretations of the categories of "food" and "drugs" as ontologically distinct, and continuum-based interpretations where these categories overlap. Rather than arguing for a single appropriate way of understanding the food-drug relationship, my project aims to disclose the complexities of both sets of interpretations, illustrating their virtues and vices, and underscoring the need for people to call their own interpretations into question while taking seriously those of others. The dialogical structure of philosophical hermeneutics provides a useful foundation for dialogue within and between dichotomous and continuum-based interpretations. We do not have unmediated access to a mind-independent reality, the terms "food" and "drugs" do not necessarily refer to natural kinds, and all interpretations likely have different degrees of strengths and blind spots. Food-drug interpretations are bound up with larger worldviews, holistic systems that generate meaning for their adherents. Granting this, conversation partners can seek to gain a clearer picture of differing interpretations, what they can learn from these interpretations, and how they can interrogate their own interpretive modes.
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