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Title: AN EXPERIENCE SAMPLING STUDY OF COGNITIVE PREDICTORS OF SEASONAL DEPRESSIVE SYMPTOMS
Creator: Meyers, Katherine
Date: 2015, 2015-07
Description: According to the Dual Vulnerability Model of Seasonal Depression, the combination of a physiological vulnerability toward vegetative symptoms...
Show moreAccording to the Dual Vulnerability Model of Seasonal Depression, the combination of a physiological vulnerability toward vegetative symptoms in the winter and a psychological vulnerability toward responding negatively to the vegetative symptoms results in seasonal depressive episodes. In particular, coping and response mechanisms such as rumination, acceptance, and distraction in reaction to vegetative symptoms may act as risk or protective factors in the development of seasonal depressive symptoms. By increasing our understanding of the relationship between coping strategies and the development of mood symptoms we can enhance our understanding of the psychological mechanisms of Seasonal Affective Disorder and inform psychological interventions. Using experience sampling methodology, which has been shown to reduce reliance on memory and increase ecological validity, we prospectively examined the effect of different coping mechanisms (rumination, acceptance, and distraction) in response to vegetative symptoms (hunger and fatigue) on subsequent mood. This is the first study to use experiencing sampling method to investigate how psychological symptoms develop in Seasonal Affective Disorder. Results suggest that rumination in response to hunger is a risk factor for mood deterioration. In contrast, acceptance of both fatigue and hunger appeared to protect against lower mood. The relationship between hunger and mood depended on distraction focused on reducing negative experiences (“negative distraction”), with higher levels of distraction strengthening that relationship. However, distraction focused on increasing positive experiences (“positive distraction”) did not appear to affect subsequent mood. We also examined the relationships between acceptance and other coping responses, with rumination and both forms of distraction showing a negative relationship with acceptance. The implications of these findings for understanding the development of Seasonal Affective Disorder, as well as future directions for research, are discussed.
Ph.D. in Psychology, July 2015
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Title: MARKOV SWITCHING MODELS OF POPULAR FOREIGN EXCHANGE CARRY TRADE STRATEGIES
Creator: Miller, Larissa J.
Date: 2016, 2016-07
Description: The nature of the carry trade produces periods of steady profitability and periods of extreme terror. The 1980s proved to be a particularly...
Show moreThe nature of the carry trade produces periods of steady profitability and periods of extreme terror. The 1980s proved to be a particularly profitable time period. However, during market crashes in the either equity or bond market, the carry trade is marked with short periods of substantial losses (Menkhoff, Saro, Schmeling, Scrimpf 2012). The global financial crisis of 2007 – 2008 was associated with large losses to carry trades. History repeatedly suggests these two bull and bear states in the economic environment (Fabozzi, Francis 1977). An additional state of market neutrality or stability could also be considered. The purpose of this dissertation is to develop a model of the carry trade with multiple states using the Markov switching methodology. To accomplish this, we use two different popular carry trade strategies: (a) logistic regression and (b) mean-variance optimization. As a benchmark, we include an equally weighted portfolio of long positions in foreign currencies against the dollar. We develop a single state model as well as a normal mixture model for each of the two carry trade strategies. The mixture models assume a static probability of the economy being in either state. However, the financial markets are not static. Applying a Markov chain allows us to build a dynamic model, which allows for new information to determine the probability of the next state. We applied a Markov chain to determine the probability of the current state and the next state to improve trading results. We found the application of a Markov chain did not improve trading performance. The portfolio consists of 12 different currencies including both mature and emerging markets. The training period for determining the weights is 1998 through 2002. Using daily data from 2002 through 2015, we evaluate the performance of each strategy using cumulative returns. These results demonstrate the periods of profitability followed by short periods of terror. Next we evaluate the performance of each strategy with an applied mixture-model. The mixture-model improves the results of each strategy. Applying a Markov chain allows for better determination of both the bear and bull states. We use only the two state environment as the three state environment was unstable.
Ph.D. in Management Science, July 2016
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Title: SECURE DATA SERVICE OUTSOURCING IN CLOUD COMPUTING
Creator: Wang, Cong
Date: 2012-04-22, 2012-07
Description: Cloud computing economically enables a fundamental paradigm of data service outsourcing, which provides lower up-front capital costs and less...
Show moreCloud computing economically enables a fundamental paradigm of data service outsourcing, which provides lower up-front capital costs and less hands-on management. However, outsourcing data services to the commercial public cloud deprives customers' control over the systems that manage their data, raising security and privacy as the primary obstacles to the adoption of the cloud. To address these challenges, in this dissertation we explore the problem of secure and privacy-assured data service outsourcing in cloud computing. We aim at deploying the most fundamental data services including data storage, search, and sharing on the commercial public cloud, with built-in security and privacy assurance as well as high level service performance, usability, and scalability. Our contributions are as follows: Firstly, we focus on privacy-preserving secure cloud storage auditing to maintain strong storage correctness guarantee, given the di culty that data les are no longer locally possessed by data owners. We rst develop a random-masking sampling approach to allow a third party auditor to perform on-demand privacy-preserving storage correctness auditing on behalf of data owners, without violating owners' data privacy. For storage correctness assurance with data dynamics, we further investigate a novel sequence-enforced Merkle Hash Tree and manipulate it with the random sampling approach to support fully dynamic data operations. Secondly, we focus on privacy-assured and e ective cloud data search services with strong privacy-assurance, while enjoying high service-level performance inherently demanded by the large number of data users and huge amount data les. We rst investigate a widely applicable fuzzy/similarity keyword search problem, and develop a brand new symbol-based trie-traverse searching approach, where transformed fuzzy keywords extracted from data les are stored using a multi-way tree structure, while protecting keyword privacy. To enable search result relevance ranking, we further investigate secure ranked search, which facilitates e cient server-side result ranking without leaking any keyword related information. Thirdly, we study how to enable scalable and owner-controlled cloud data sharing services, given the challenge that data no longer resides on owners' trusted domain. We rst associate data with a set of meaningful attributes, use logical composition of attributes to re ect ne-grained data access, and enforce owner's control via attribute-based encryption. For the inherent scalability requirement of cloud system, we further leverage the cloud as a mediated proxy, to which data owners can delegate most cumbersome data/user management workload, without a ecting the underlying data con dentiality.
Ph.D. in Electrical Engineering, July 2012
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Title: MINDFULNESS AND HEALTH BEHAVIORS: DOES AUTONOMOUS MOTIVATION MEDIATE ASSOCIATIONS BETWEEN MINDFULNESS AND HEALTH BEHAVIORS IN COLLEGE STUDENTS?
Creator: Coppersmith, Jody
Date: 2016, 2016-07
Description: College is a critical period for the development of life-long health behaviors, and college students are particularly vulnerable to engaging...
Show moreCollege is a critical period for the development of life-long health behaviors, and college students are particularly vulnerable to engaging in high risk health behaviors, including physical inactivity and poor nutritional habits, that are risk factors for the development of chronic diseases. Current interventions aimed at promoting positive health behaviors in this population have shown limited efficacy. However, prior research suggests that both mindfulness and autonomous motivation are important theoretical constructs in health promotion and disease prevention research and intervention. To date, limited research has been conducted to understand the relationship amongst mindfulness, autonomous motivation, and health behaviors. This study examined the relationship between mindfulness, autonomous motivation, and health behaviors in college students. Based on self-determination theory, it was hypothesized that autonomous motivation would mediate the relationship between mindfulness and health behaviors, specifically physical activity and fruit and vegetable intake. Participants were 187 college students who completed a series of online questionnaires including demographic information, mindfulness, autonomous motivation for physical activity and to eat fruits and vegetables, physical activity, and fruit and vegetable intake. Results indicated that autonomous motivation to eat fruits and vegetables mediated the association between mindfulness and fruit and vegetable intake. Similarly, autonomous motivation for physical activity mediated the association between mindfulness and physical activity. These findings support autonomous motivation as a mechanism through which mindfulness impacts health behaviors. Thus, mindfulness should be incorporated into the self-determination theory of health-behavior change and represents a promising avenue for health behavior intervention in college students.
Ph.D. in Psychology, July 2016
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Title: COGNITIVE IMPAIRMENT, DEPRESSION, AND INFLAMMATION IN OLDER HEMATOPOIETIC STEM CELL TRANSPLANT RECIPIENTS
Creator: Fong, Wing Man
Date: 2015, 2015-07
Description: Cancer is a common disease that increases in prevalence with age; it predominantly affects individuals over the age of 55. Cancer can be...
Show moreCancer is a common disease that increases in prevalence with age; it predominantly affects individuals over the age of 55. Cancer can be associated with a number of health complications due to the disease itself and/or its treatments such as higher risk of infection, anemia, fatigue, and cognitive dysfunction. Risks of developing these complications increase with age. Despite the increased vulnerability among older individuals, the existing literature and clinical trials show a disproportionately low enrollment rate for this population. This study aimed to provide to a mechanism-based understanding of cognitive impairment in older patients with hematologic malignancy who were scheduled to undergo hematopoietic stem cell transplantation (HSCT). Emerging evidence suggests that a significant portion of older persons with cancer demonstrate cognitive impairment prior to HSCT, and that cognitive deficits prior to HSCT are related to post-transplant complications. Hence, the goals of the study were to characterize cognitive impairment in older cancer patients prior to HSCT, and to examine the relations between cognitive impairment, depression, and inflammation. Sixty-one patients with hematologic malignancy participated in the current study and were administered a comprehensive neuropsychological assessment. Results showed that 50% of the sample was impaired on verbal memory. Correlation analyses revealed a significant association between depression and attention, with inflammation found to be a non-significant mediator. Possible alternative explanations with implications for future research and limitations of the study were discussed.
Ph.D. in Psychology, July 2015
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Title: A PILOT STUDY TO ASSESS THE EFFICACY OF A MENTOR BASED ANTI- STIGMA MENTAL HEALTH CURRICULUM FOR BACCALAUREATE NURSING STUDENTS
Creator: Fokuo, Joyce Konadu Mansah
Date: 2017, 2017-07
Description: Stigma towards people with mental illness by healthcare providers results in disparities in help-seeking, treatment, and quality of care....
Show moreStigma towards people with mental illness by healthcare providers results in disparities in help-seeking, treatment, and quality of care. Within the health care system, professionals such as nurses and nursing students endorse negative stereotypes about people with mental illness. Using 23 nursing students this pilot study evaluated the efficacy and feasibility of a five-week manualized consumer-led mentorship program as a supplement to a mental health theory and clinical curriculum for baccalaureate nursing students. Participants completed measures on intended personal and professional behaviors, stigmatizing attitudes and affirming attitudes measures pre-intervention, post-intervention and at one-month follow-up. Feasibility measures were also completed by students, mentors and faculty members’ post-intervention. Results suggest a significant decrease in stigmatizing attitudes post intervention. The effect was maintained at one-month follow-up. There was also a significant decreased in affirming attitudes post intervention. This effect was unexpected and not maintained at one-month follow-up. Affirming attitudes significantly increased at one-month follow-up. There was no statistically significant change in intended personal and professional behaviors. Program feasibility was high for face-to-face meeting and participants were overall satisfied with the integration of the supplemental program. These findings suggest that a consumer-led mentoring program can effectively reduce mental health stigma within student nursing populations.
Ph.D. in Psychology, July 2017
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Title: A COMPARISON OF DIFFERENT METHODS OF DETECTING INATTENTIVE RESPONDING ON SELF-REPORT PERSONALITY MEASURES
Creator: Fleischer, Michael
Date: 2016, 2016-05
Description: The goal of this study was to identify the best indices for detecting inattentive respondents. This was accomplished by collecting data from...
Show moreThe goal of this study was to identify the best indices for detecting inattentive respondents. This was accomplished by collecting data from respondents who were attentive and inattentive. Five different methods for detecting inattention were com- pared to determine which of these methods were the most effective. The indices used for detecting inattention were: instructional items, nonsensical items, Fleischer type items, total time, and psychometric consistency. These were classified into two types item based indices and non-item based indices. It was hypothesized and found that Fleischer items were viewed as less awed or out of place when compared to nonsen- sical and instructional item types. Additional hypotheses tested the effectiveness of each the indices and supported the hypothesis, in finding the Fleischer type and total time to be the best identifiers of inattentive respondents. The final hypothesis did not find support that removing inattentive respondents would yield only better relia- bilities. The results were mixed and the interpretation of this and the other findings results are discussed in detail in the following paper.
Ph.D. in Psychology, May 2016
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Title: EFFECT OF ORGANIZATIONAL JUSTICE ON EMPLOYEE HEALTH
Creator: Cruz, Jaime L.
Date: 2013, 2013-05
Description: Although many studies in the justice literature have examined organizational justice and organizational outcomes, less research has been...
Show moreAlthough many studies in the justice literature have examined organizational justice and organizational outcomes, less research has been conducted on organizational justice and employee health. Specifically, this study examined the relationship between employees’ perceptions of organizational justice dimensions – distributive, interactional and procedural justice in relation to proximal health outcomes (i.e., general well-being, insomnia, emotional exhaustion, alcohol consumption and emotional eating). It was hypothesized that lower levels of perceived justice at work would be associated with worse health related outcomes. With the study’s sample size of 339, results partially supported the hypotheses. Explicitly, results indicated that lower perceptions of distributive and interactional justice were related to increased emotional exhaustion and poorer overall health assessments (general well-being) in employees. Additionally, procedural justice perceptions were found to interact with individuals’ use of heuristic devices in that those who were more inclined to use heuristic devices when making justice judgments displayed a significant relationship between procedural justice perceptions and certain health outcomes (i.e., emotional eating) while individuals less inclined to utilize heuristics did not display a significant relationship between the aforementioned justice and health measures. In sum, this study, provides a much needed starting point for organizational scholars to begin to address and understand the relationship between justice perceptions and health related outcomes at work.
PH.D in Psychology, May 2013
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Title: EMBEDDED SYSTEM DESIGN FOR TRAFFIC SIGN RECOGNITION USING MACHINE LEARNING ALGORITHMS
Creator: Han, Yan
Date: 2016, 2016-12
Description: Traffic sign recognition system, taken as an important component of an intelligent vehicle system, has been an active research area and it has...
Show moreTraffic sign recognition system, taken as an important component of an intelligent vehicle system, has been an active research area and it has been investigated vigorously in the last decade. It is an important step for introducing intelligent vehicles into the current road transportation systems. Based on image processing and machine learning technologies, TSR systems are being developed cautiously by many manufacturers and have been set up on vehicles as part of a driving assistant system in recent years. Traffic signs are designed and placed in locations to be easily identified from its surroundings by human eyes. Hence, an intelligent system that can identify these signs as good as a human, needs to address a lot of challenges. Here, ―good‖ can be interpreted as accurate and fast. Therefore, developing a reliable, real-time and robust TSR system is the main motivation for this dissertation. Multiple TSR system approaches based on computer vision and machine learning technologies are introduced and they are implemented on different hardware platforms. Proposed TSR algorithms are comprised of two parts: sign detection based on color and shape analysis and sign classification based on machine learning technologies including nearest neighbor search, support vector machine and deep neural networks. Target hardware platforms include Xilinx ZedBoard FPGA and NVIDIA Jetson TX1 that provides GPU acceleration. Overall, based on a well-known benchmark suite, 96% detection accuracy is achieved while executing at 1.6 frames per seconds on the GPU board.
Ph.D. in Computer Engineering, December 2016
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Title: INFLUENCE OF OWNER-ORGANIZATION IMPRESSION AND CONTRACT FRAMING ON CONSTRUCTION CONTRACTORS' RISK PERCEPTIONS
Creator: Hanioglu, Mehmet Nihat
Date: 2014, 2014-12
Description: In a construction project, it is generally accepted that the contractor's perceived risk is the main factor in determining what is to be...
Show moreIn a construction project, it is generally accepted that the contractor's perceived risk is the main factor in determining what is to be proposed as the project cost and duration. Both the owner-organization and the contractor are aware of the existing risks and the owner-organizations tend to mitigate the existing risks by using the construction contract. It is hypothesized that the contractor’s initial impression of the owner-organization is a factor in the contractor’s perception of risk. It is further hypothesized that the initial impression is influenced by the content and context of the construction bid documents, which further influences the perceived risk and the bid strategy. The goal is to investigate the factors that influence contractors' impression of the owner-organization and to study the effects of contract document language and content in the impression formation process and subsequent development of a bid strategy. By better understanding the factors and relationships that influence impression formation and risk perceptions, it is expected that substantial time, money and unnecessary contention between these parties can be eliminated.
Ph.D. in Civil Engineering, December 2014
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Title: CYCLIC THERMAL TREATMENT
Creator: Gu, Sijie
Date: 2015, 2015-12
Description: Cyclic thermal treatment has the potential to improve energy efficiency of thermal processing. It has been shown that in some cases, the...
Show moreCyclic thermal treatment has the potential to improve energy efficiency of thermal processing. It has been shown that in some cases, the productivity was enhanced by the cyclic thermal treatment operation. In order to investigate the cyclic thermal treatment effect, Copper-Nickel interdiffusion couples were investigated. When the Cu-Ni interdiffusion couple showed positive results, the cyclic thermal treatment was applied to pack carburization and gas carburization of steel. The Cu-Ni interdiffusion couples were annealed with different time-temperature profiles for 5 days. There are three types of time-temperature profile; isothermal, symmetric, and asymmetric cyclic thermal treatment. After thermal treatment, concentration-distance profiles were. Based on the concentration-distance profile, the interdiffusion coefficients of different time-temperature profiles were calculated. The interdiffusion coefficient of the diffusion couple with a ramp rate of 1°C/min had a higher diffusion coefficient than that of the diffusion couple annealed isothermally at the equivalent temperature, 863°C, which means that cyclic thermal treatment has the effect of accelerating diffusion. When the ramp rate was 5ºC/min interdiffusion coefficients were higher than that of the diffusion couple annealed isothermally at the maximum temperature. However, when the ramp rate was increased to 10°C/min, the diffusion coefficient decreased to almost the same as the interdiffusion coefficient of the diffusion couple at the equivalent temperature. After achieving a promising result for the Cu-Ni diffusion couples, we expanded the cyclic thermal treatment to carburizing. The temperature range for cyclic pack carburization was 850° to 950°C. Increasing the cyclic ramp rate resulted in an increase in the case depth. Due to the setup of the pack carburization, the maximum cooling rate achievable is 5°C/min. In order to reach a higher ramp rate, an induction heating gas carburization system was setup. The temperature range for the cyclic induction heat gas carburization was 850°C to 950°C. For the cyclic induction heat gas carburization with increase in ramp rate, the case depth increased. The sample induction gas carburized at a ramp rate of 20°C/min had a deeper case depth than the sample induction gas carburized isothermally at 904.4°C, the equivalent temperature. The first test showed the sample induction gas carburized with a ramp rate of 20°C/min had a deeper case depth than the sample induction gas carburized isothermally at 950° C. With this we draw the conclusion that the cyclic induction gas carburization can achieve a deeper case depth than the isothermal at equivalent temperature induction gas carburization.
Ph.D. in Materials Science and Engineering, December 2015
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Title: POWER GRID VERIFICATION ON CLOUD
Creator: Gupte, Naval
Date: 2016, 2016-05
Description: Reliability and performance of modern ICs is becoming increasingly susceptible to supply voltage variations. Increased demand for low voltage...
Show moreReliability and performance of modern ICs is becoming increasingly susceptible to supply voltage variations. Increased demand for low voltage integrated circuits has made power grid analysis extremely critical and indispensable in modern design flows. Efficient validation of on-chip power distribution network is computationally demanding because of increasing grid sizes. Power grid simulation is critical for analysis and verification of power supply noises for robust and reliable IC designs. Computational demands to simulate power grids for ICs with increasing complexity is never-ending. Cloud computing platforms can be leveraged to mitigate costs associated with making these resources available. However, since simulation data usually contains sensitive design information, simulating on third-party platforms lead to major security concerns. In this study, we propose a framework for secure power grid simulation on Cloud. A transformation algorithm to hide current excitations is presented, while still allowing a majority of computations to be completed on Cloud. We employ multiple compression strategies to significantly reduce communication and storage overheads. Experiments show that our framework can achieve similar turn-around time as an insecure simulator on Cloud, while securing current excitations and output voltage vectors with reasonable communication and computational overheads. Vectorless technique to grid verification estimates worst-case voltage noises without detailed enumeration of load current excitations. We study voltage noise assessment in RLC models of VDD and GND networks in integrated power grids. Abstract grid model is utilized to abbreviate runtime, while transient constraints capture transitory circuit behaviour. Heuristics are employed to extract constraints that restrict power consumption profiles to realistic scenarios. Multiple linear programming problems are formulated to evaluate bounds on voltage overshoots and undershoots. We propose ways to mitigate storage and computational requirements on processing resources, enabling users to deploy computations on economical Cloud Computing platforms. Recommended solution is parallelizable, thereby reducing the overall verification time. Data compression is applied to fully exploit the compute capabilities of contemporary processors for higher throughputs. Experimental results suggest that the proposed technique is practical and scalable for industrial grids.
Ph.D. in Electrical Engineering, May 2016
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Title: PERFECTIONISM AS A MODERATOR OF ASSOCIATIONS BETWEEN BODY DISSATISFACATION AND DISORDERED EATING: AN ECOLOGICAL MOMENTARY ASSESSMENT STUDY
Creator: Hansen, Meghan A.
Date: 2017, 2017-07
Description: Disordered eating attitudes and behavioral urges are prevalent in community samples and contribute to numerous negative physical and...
Show moreDisordered eating attitudes and behavioral urges are prevalent in community samples and contribute to numerous negative physical and psychological outcomes. Using an ecological momentary assessment, this study examines how body dissatisfaction, perfectionism, and disordered eating relate to one another. Over the course of one week, women (n=49) with disordered eating completed multiple daily ratings of body dissatisfaction and disordered eating attitudes, urges and behaviors. Multilevel model analyses were used to test study hypotheses that; (1) body dissatisfaction prospectively predicts disordered eating attitudes and urges; and (2) perfectionism moderates the associations between body dissatisfaction and subsequent disordered eating attitudes and behaviors, such that individuals higher in perfectionism will report stronger associations between these variables. Results indicate that, in this sample, greater body dissatisfaction does not predict disordered eating attitudes, urges or behaviors. However, the interaction between increased body dissatisfaction and perfectionism predicted subsequent disordered eating attitudes and behavioral urges, but did not predict engagement in eating disorder behaviors. Results have important clinical and treatment implications for including perfectionism in the treatment of eating disorders.
Ph.D. in Psychology, July 2017
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Title: DEPRESSION AND ATTRIBUTIONS FOR DISTRESS
Creator: Hanson, Bjorn J.
Date: 2013, 2013-07
Description: Distress caused by depressive symptoms includes both direct and mediated pathways. Attributions for distress in individuals suffering from...
Show moreDistress caused by depressive symptoms includes both direct and mediated pathways. Attributions for distress in individuals suffering from depressive symptoms represent indirect pathways that have a high potential to be modified by psychotherapeutic interventions; however, little research has focused on the content of these attributions. This study provides the first quantitative measurement of this reasons-for-distress paradigm. Specifically, we aim to describe the frequencies, intensities, and co-occurrence patterns of attributions for distress, as well as distinguish the attributions for distress paradigm from previous attributions for depression research. Furthermore, we seek to demonstrate the accuracy of an illness behavior model for conceptualizing distress caused by depressive symptoms by differentiating symptom severity from symptom distress. In addition to quantifying attributions for distress, this study also extends previous research regarding rumination, the severity of distress caused by cognitive and vegetative symptoms of depression, and the co-occurrence of specific symptoms and specific reasons for distress. Individuals currently suffering from depressive symptoms were recruited from web-based advertisements to participate in this cross-sectional, online self-report study. A total of 204 individuals qualified for the study and completed some portion of the Reasons for Distress Questionnaire-Depression (RDQ-D). Results demonstrated that all reasons provided as part of the RDQ-D represented common attributions for distress in depressed individuals. Reasons related to personalized reasons for distress (Other), long-term outcomes (Long-term Consequences), productivity impairment (Work and Productivity Impairment), and x existential distress (Lack of Purpose or Meaning) were rated as significantly more distressing when compared with all reasons for distress. Cluster analysis suggested that certain reasons tended to co-occur and that some attributions for distress are nearly universal amongst individuals suffering from significant depressive symptoms. The reason-for-distress paradigm was demonstrated to be related to, yet distinct from, the reason-for-depression paradigm (Addis, Truax, & Jacobson, 1995). Distress ratings were also found to be moderately positively correlated with some depressive symptoms, but not others, providing support for an illness behavior conceptualization of distress severity in depression. Expanding on prior research, results showed that rumination was equally distressing and frequent across gender. Also, cognitive/affective symptoms of depression were rated as more distressing than vegetative symptoms of depression. Additionally, participants demonstrated the capacity to endorse specific reasons for distress in association with specific symptoms. As predicted, the existential reason for distress Lack of Purpose or Meaning was endorsed more frequently in relation to cognitive/affective symptoms of depression as compared to vegetative symptoms of depression. By focusing on specific symptoms of depression, the RDQ-D provides a clinical assessment that has the ability to identify specific unhelpful responses to symptoms that may be causing distress in addition to that inherent in the experience of the symptom. These unhelpful responses can then be included in case conceptualization, treatment planning, and intervention selection.
PH.D in Psychology, July 2013
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Title: COMPUTER AIDED DIAGNOSIS IN MAMMOGRAPHY WITH CONTENT-BASED IMAGE RETRIEVAL
Creator: Jing, Hao
Date: 2011-11, 2011-12
Description: Computer-aided diagnosis (CAD) for breast cancer, a common form of cancer in women, has been an active research area. This work aims to...
Show moreComputer-aided diagnosis (CAD) for breast cancer, a common form of cancer in women, has been an active research area. This work aims to investigate and develop CAD techniques for clustered microcalcifications (MCCs), which can be an important early sign of breast cancer. The contributions of this work include development of a database of cancer cases and algorithms for detection and classification of MCCs. First, a database consisting of a large number of cases is built from different sources. To support the merging of cases from different data sources, a feature comparison study is conducted between mammograms from screen film and full field digital mammography (FFDM) systems. It is demonstrated that the features extracted from film and FFDM are highly correlated and there is no adverse effect on a CAD task of classification when used together. Second, a spatial point process (SPP) approach is proposed to exploit the spatial distribution among different MCs in a mammogram directly during the detection process. This is different from the conventional approach in which detection algorithms are employed to first identify individual MCs in a mammogram, which are subsequently grouped into clusters by a clustering algorithm. The performance of the proposed approach is demonstrated to be superior to an existing method based on the support vector machine (SVM). Third, in observation of the emerging of large databases from the picture archiving and communication (PAC) systems in the clinics, a retrieval driven approach is proposed for classification of MCCs. In this approach, for a case to be diagnosed (i.e., query), a set of similar cases is retrieved from a database and subsequently is used to train xii an adaptive classifier specifically for the query case using the technique of logistic regression. The proposed approach is demonstrated to lead to significant improvement in classification accuracy. Moreover, the proposed adaptive classification approach is further developed using regularization techniques, where a prior is first derived from a baseline classifier and then used to regularize the adaptive classifier trained with the retrieved cases. The regularized adaptive classifier can be more computationally efficient, and is demonstrated to achieve further improvement in performance.
Ph.D. in Electrical Engineering, December 2011
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Title: MEASUREMENT OF INTRARETINAL NITRIC OXIDE IN EARLY DIABETIC RETINOPATHY
Creator: Guthrie, Micah
Date: 2014, 2014-12
Description: Diabetic retinopathy (DR) is the most frequent cause of new cases of blindness among adults aged 20-74 years. Nearly all patients with Type 1...
Show moreDiabetic retinopathy (DR) is the most frequent cause of new cases of blindness among adults aged 20-74 years. Nearly all patients with Type 1 diabetes and greater than 60% of patients with Type 2 diabetes will develop retinopathy within the rst two decades of the disease. Nitric oxide (NO) has been shown to play a role in the progression of DR, contributing to neuronal dysfunction and the breakdown of the blood-retina barrier early stages of the disease. The objective of the current study was to investigate the changes in intraretinal NO levels in early DR. To accomplish this, a dual NO/electroretinogram (ERG) electrode was developed to make the rst direct measurements of NO concentration throughout the in vivo retina. These electrodes were validated in an in vivo animal model by comparing control recordings to those taken after injection of the broad spectrum nitric oxide synthase (NOS) inhibitor L-NG-Nitroarginine methyl ester (L-NAME). Control NO pro les showed high levels of NO in the photoreceptor layer with localized areas of increased NO in the amacrine/ganglion cell layer. L-NAME NO pro les showed substantially reduced NO in the retina, indicating that the electrodes were measuring actual NO. The electrodes were then used to record NO pro les from the retinas of rats made diabetic with streptozotocin (STZ). The recordings were obtained three weeks after injection of STZ. Blood glucose levels were also monitored in order to correlate the blood glucose level with intraretinal NO concentration. It was found that mild diabetic rats (blood glucose 250-400 mg/dL) had higherthan- control levels of NO throughout their retinas. Severe diabetics (500-600 mg/dL) had lower-than-control levels, while moderate diabetics (400-500 mg/dL) did not have signi cantly di erent NO levels than controls. The NO pro les from the severe diabetics were very similar to L-NAME pro les, indicating that NOS production may be abnormal in severe diabetics. It was also found that intraretinal NO concentration was inversely correlated with the blood glucose of diabetic rats. To determine if the changes in NO seen in diabetic rats were due to direct tissue exposure to high glucose, NO pro les were also recorded from rats acutely injected with glucose solution to achieve similar levels of hyperglycemia. No changes in NO levels were seen in the retinas of these acute hyperglycemic rats, indicating that there are other factors besides high glucose contributing to the NO changes in DR. The results show that there is not a simple increase in NO as severity of diabetes increases and highlight the importance of being able to make measurements of bioavailable NO in retinal tissue. The electrodes were able to detect clear di erences in experimental DR, indicating their utility in investigating NO changes in the early stages of the disease. Future work with the electrodes needs to be performed to investigate the mechanisms of NO changes in DR in order to develop potential treatments which could mitigate the damage at an early stage before vision loss occurs.
M.S. in Biomedical Engineering, December 2014
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Title: TOWARD A NATURAL GENETIC/EVOLUTIONARY ALGORITHM FOR MULTIOBJECTIVE OPTIMIZATION
Creator: Ramasamy, Hariharane
Date: 2013, 2013-05
Description: Practical optimization problems often have multiple objectives, which are likely to conflict with each other, and have more than one optimal...
Show morePractical optimization problems often have multiple objectives, which are likely to conflict with each other, and have more than one optimal solution representing the best trade-offs among the competing objectives. Genetic algorithms, which optimize by repeatedly applying genetic operators to a population of possible solutions, have been used recently in multiobjective optimization, but often converge to a single solution that is not necessarily optimal due to lack of diversity in the population. Current multiobjective genetic and other evolutionary methods prevent this premature convergence by promoting new members that are dissimilar in parameter or objective space. A distance measure, which calculates similarities among the members in either objective or parameter space, is used to degrade the fitness of solutions when they are crowded in a small region. This process forces the algorithm to find new but distinct trade-off points in the objective or parameter space, but is computationally expensive. As the number of objectives or parameters increases, the methods fail to scale up and they deviate from the motivating concept of the genetic algorithm—natural evolution. We extend the standard genetic algorithm through two simple, yet powerful, changes motivated by natural evolution. In the first method, the algorithm, at each step, randomly or sequentially chooses one of the objectives for optimization; hence the method is called sequential extended genetic algorithm (SEGA). In the second method, a population is maintained for each objective, and crossover is performed selecting parents from across populations. This method is called parallel extended genetic algorithm (PEGA). We applied these methods to test problems from the literature, and to two well known problems, protein folding and multiple knapsack. We discovered our methods found better trade-off solutions than current multiobjective methods, without increasing computational complexity of genetic algorithms.
PH.D in Computer Science, May 2013
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Title: POLARIZATION COUPLING IN SEMICONDUCTOR NANO-DIMERS IN THE TERAHERTZ RANGE
Creator: Hu, Zhijing
Date: 2017, 2017-05
Description: Surface plasmon resonance (SPR) occurs at the interface of a semiconductor and a dielectric when certain conditions are satisfied. SPR is...
Show moreSurface plasmon resonance (SPR) occurs at the interface of a semiconductor and a dielectric when certain conditions are satisfied. SPR is impetus to new sensor and device development in the optical range, with nanoparticles of noble metals taking up major roles. Typical conduction band electron concentrations in semiconductors lead to resonance frequencies in the terahertz and infrared bands. While the response strength is weaker than those exhibited by metals, it can be made up for by the formation of aggregates. The added degree of freedom by doping or carrier injection further enhances the versatility of semiconductor nanoclusters. To obtain a first principle solution to the coupled set of equations for charge carrier transport and electrodynamics in a conductive cluster is a formidable task with a high computational cost. Employing a finite-element based tool, the COMSOL Multiphysics Simulation Software, the interaction inside and outside some elementary semiconductor structures such as slab and sphere have been solved, which revealed the screening of the internal field while displaying dispersion and absorptions effects. The study of semiconductor dimer also showed a significant field enhancement and frequency shift. Under strong applied field, asymmetric polarization within the particles is revealed. The accompanying nonlinear polarization response can be employed to develop new devices. These model structures can serve to provide insight to the analysis and synthesis more complex structures.
Ph.D. in Electrical Engineering, May 2017
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Title: A NANO-STRUCTURED CERAMIC/POLYMER COMPOSITE FILM FOR ELECTRONIC INTERCONNECTIONS
Creator: Harwath, Frank
Date: 2016, 2016-05
Description: Separable electrical interconnections are a ubiquitous part of modern life and for technical reasons are currently based on the use of gold....
Show moreSeparable electrical interconnections are a ubiquitous part of modern life and for technical reasons are currently based on the use of gold. Since gold is a commodity and subject to significant price fluctuations there is a need for separable interconnects not based on gold. Polymer/ceramic films were produced from various polymer precursors with loadings of multi-wall nanotubes (MWNT) and inert fillers. A variety of applications means were employed with the best success being achieved by means of a modified doctor blade. Pyrolysis was conducted in an inert atmosphere at 1 bar at a range of temperatures in a tube furnace. Pyrolysis was also conducted using a fiber laser. The modulus of the film is estimated to be 71.8 MPa with an ultimate tensile strength of 179 MPa based on hardness tests and anisotropic crack dimensions which developed as a result of uniaxial stress induced during application of the precursor. Uniaxial stress improved film adhesion regardless of filler type or level. Modification of film characteristics after pyrolysis was attempted using spark plasma sintering (SPS). Electrical testing displayed a percolation threshold above loadings of 1% (wt) of MWNTs where there is a significant drop in electrical resistivity. Further reductions in contact resistance were demonstrated up to 2% loading of MWNTs. The level of contact resistance achieved (<10) for a separable contact, in conjunction with a gold plated contact representative of most electronic connectors, indicates that an acceptable level of contact resistance may be achieved using these materials. Characterization of the film using attenuated total reflectance (ATR), xray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy point to a morphology which is dominated by crystallites joined by regions of aliphatic carbon chains. Work function measurements were consistent with highly ordered pyrolytic graphite. (HOPG)
Ph.D. in Materials Science and Engineering, May 2016
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Title: CRITICISM, HEALTH FUNCTIONING, AND MARITAL ADJUSTMENT IN COUPLES WITH CARDIOVASCULAR DISEASE
Creator: Hicks, R. Elliott Iii
Date: 2017, 2017-07
Description: Destructive communication and hostile interactions between spouses are associated with poor behavior maintenance and can elicit substantial...
Show moreDestructive communication and hostile interactions between spouses are associated with poor behavior maintenance and can elicit substantial increases in systolic blood pressure, heart rate, and cardiac output in patients (Broadwell, & Light, 2005; Nealey-Moore et al., 2007; Ryan & Deci, 2000). This negatively impacts the cardiovascular health of the targeted partner (Nealey-Moore et al., 2007; Ryan & Deci, 2000; Smith et al., 2009). Constructive, non-hostile criticism between partners may bolster behavior change and maintenance (Zinbarg, 2007). The present study assesses the relationship between forms of criticism and reports of marital adjustment, autonomous support, health functioning, and health behavior change in a sample of couples participating in a cardiac risk reduction intervention. Results indicate that Hostile Criticism predicted Physical Health Functioning. Further, there were no significant moderating relationships. Interpretation of results and future directions are discussed.
Ph.D. in Psychology, July 2017
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