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Title: THE DEVELOPMENT OF AN INSTRUMENT TO EVALUATE TEACHERS’ CONCEPTS ABOUT NATURE OF MATHEMATICAL KNOWLEDGE
Creator: Kean, Lesa L.
Date: 2012-12-10, 2012-12
Description: While there does seem to be widespread consensus that teachers’ beliefs and concepts influence the way they teach, even the most recent...
Show moreWhile there does seem to be widespread consensus that teachers’ beliefs and concepts influence the way they teach, even the most recent international studies suggest that research-based evidence for this consensus is limited. In an effort to enlarge and enhance the pool of evidence that shows specific relationships between teacher beliefs and practice, the present author undertook to write an attitude survey and interview protocol that identifies and distinguishes teachers’ concepts on eight different aspects of NOMK. Such a survey seems to be a natural first step to providing evidence for the larger question of which beliefs correlate to what teacher behaviors. Eight NOMK aspects were identified and defined based on a review of over 68 resources including twelve that contained an existing assessment addressing NOMK concepts. While superficial inspection of the assessments referenced may suggest that the best solution may be to use an existing assessment or to compile a list of items from these various assessments and use that to assess NOMK, the researcher suggests four major issues that would suggest otherwise. The items of the assessment and the assessment as a whole were validated through several steps. First, the author started with over 40 survey items, distributed evenly over her eight aspects and including both Likert-type and open-ended items. Second, the items were randomized and distributed to practicing mathematics teachers for their feedback. Third, the items were revised and sent back out to teachers for additional feedback. Fourth, the resulting survey was piloted with over 20 community college teachers. Fifth, their responses were coded, and the open-ended items were coded by xii rubric and confirmed by a second coder. Sixth, the survey was revised once again and piloted to another sample of 20 with similar analysis. Finally, she conducted several forms of qualitative and quantitative analysis to cull down the items to those that produced the most valid and reliable survey items set possible. The resulting survey addresses six of the eight aspects proposed by the researcher and includes both Likert-type and open-ended items intended to be confirmed and clarified through interview. The researcher suggests further research be done in order to design items that validly and reliably identify teachers’ concepts of NOMK on the remaining two aspects.
PH.D in Mathematics Education, December 2012
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Title: SIMULATION AND DEVELOPMENT OF A CLINICAL ANALYZER-BASED IMAGING SYSTEM
Creator: Majidi, Keivan
Date: 2013, 2013-12
Description: The analyzer-based phase-sensitive X-ray imaging method (ABI) is emerging as a potential alternative to conventional radiography. ABI...
Show moreThe analyzer-based phase-sensitive X-ray imaging method (ABI) is emerging as a potential alternative to conventional radiography. ABI simultaneously generates a number of planar images containing information about scattering, refraction and absorption properties of the object. These parametric images are acquired by sampling the angular intensity profile (AIP) of an X-ray beam passing through the object at different positions of the analyzer crystal. Like many of the modern imaging techniques, ABI is a computed imaging method (meaning that the images are calculated from raw data). Therefore, the noise in ABI depends on the imaging conditions such as source flux, number of the analyzer positions, and the analyzer positions themselves as well as on the estimation method of the parameters. In the first part of this thesis, we use the Cramer-Rao lower bound to quantify the noise in ABI images and then investigate the effect of different analyzer-sampling strategies on this bound. The CRLB is the minimum bound for the variance of an unbiased estimator and defines the best noise performance that one can obtain regardless of which estimation method is used to estimate ABI parametric images. We will then use this bound to evaluate three ABI methods: Multiple-Image Radiography (MIR), Diffraction Enhanced Imaging (DEI) and Scatter Diffraction Enhanced Imaging (S-DEI). The proposed methodology can be used to evaluate any other ABI parametric image estimation technique. Synchrotron radiation has been the main source for experimental ABI and developing its methodologies, therefore the ABI application to clinical imaging has been very limited. It is inevitable to use conventional X-ray sources for ABI in order to utilize xii the technique in the clinical applications, however, due to the limited intensity of these sources and their finite source size, developing such systems is very challenging. In the second part of this thesis, we use computer simulations to understand the above challenges better. We measure the properties of this imaging system such as flux and point-spread function for various design parameters and discuss how to find an “optimal” setup based on these properties. The optimality of an imaging setup depends on the specific application that one wants to perform using the system; however, the results and discussions in this section layouts a design procedure for clinical ABI systems. In the last part of this thesis we review the steps we took in the Advanced X-ray Imaging Laboratory (AXIL) toward developing a clinical ABI system.
PH.D in Electrical Engineering, December 2013
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Title: GOTTA EAT TO LIVE, GOTTA STEAL TO EAT: THE INVESTIGATION OF SERIOUS DISRUPTIVE BEHAVIOR, TEMPERAMENT, AND EXECUTIVE DYSFUNCTION AMONG HOMELESS YOUTH
Creator: Kaszynski, Katie
Date: 2014, 2014-07
Description: Background: Homeless youth are at risk for many adverse outcomes, including poor physical health, traumatic experiences, victimization, poor...
Show moreBackground: Homeless youth are at risk for many adverse outcomes, including poor physical health, traumatic experiences, victimization, poor academic achievement, cognitive deficits, psychopathology, and substance use. Research demonstrates that these individuals engage in substantial disruptive behavior (e.g., stealing, dealing drugs, breaking and entering, engaging in prostitution), which further increases their risk of negative outcomes. Individual factors, including innate temperament and executive functioning skills have been shown to relate to one another and be independently related to behavior problems, as evidenced by research investigating housed youth. Homeless youth are shown to exhibit poor effortful control, high distress, executive dysfunction, and substance abuse; factors of which have not been fully examined in relationship to persistent behavior problems as reflected in antisocial personality disorder (ASPD). Study Aim: The current study evaluated the association between temperament, executive functioning, and substance use disorders in their relation to the likelihood of meeting criteria for ASPD among homeless youth (ages 18-22). It was hypothesized that these variables would significantly relate to meeting criteria for ASPD in this population. Procedure: 87 homeless individuals (mean age = 19.27) who were residing at a homeless shelter at the time of the study (in Chicago or Los Angeles) participated over the course of two testing sessions. Each individual completed measures of ASPD and substance use disorders (MINI), temperament (ATQ), and executive functioning (D-KEFS), among other measures that are part of a larger studying conducted at University of Chicago Medical Center (UCMC). Results: Results suggested that temperament (specifically effortful control) executive dysfunction (specifically cognitive shifting), and substance use disorder (specifically substance abuse) were significantly related to the likelihood of a homeless individual meeting criteria for ASPD. Youth who showed poorer effortful control, better ability to shift attention between sets of information, and substance abuse were at a greater likelihood of meeting criteria for ASPD. Conclusions: These findings indicate that aspects of temperament, specific executive skills, and substance abuse are important variables in determining the likelihood of ASPD among a population of homeless individuals. Clinical implications, limitations, and suggestions for interventions are discussed.
Ph.D. in Psychology, July 2014
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Title: THE VAPORIZATION PHENOMENA OF FUEL DROPLETS EXPOSED TO ASYMMETRIC RADIANT HEATING USING PLANAR LASER-INDUCED FLUORESCENCE
Creator: Ammigan, Kavin
Date: 2012-04-17, 2012-05
Description: Droplet vaporization under asymmetric conditions is prevalent in many combustion related devices where fuel droplets may either experience...
Show moreDroplet vaporization under asymmetric conditions is prevalent in many combustion related devices where fuel droplets may either experience asymmetric thermal radiant heating or travel in velocity and temperature gradients. Asymmetric radiant heating is particularly common in spray flames, counter-flow diffusion flames, regions close to the walls of conventional combustion chambers and more importantly in liquid-fueled microcombustors. In this study, experiments are carried out to observe how droplets vaporize when exposed to asymmetric radiant heating. The experimental set-up consists of applying radiant heating, through a radiant panel heater, to one face of a monodisperse droplet stream while using the planar-laser induced fluorescence (PLIF) diagnostic tool to reveal the spatial vapor distribution around vaporizing droplets. Since most fuels are made up of multiple components, bicomponent droplets are also investigated. Pure acetone droplets as well as mixtures of acetone/alkanes (octane and hexane) and acetone/alcohols (ethanol and 2-propanol) droplets are investigated. Results in the form of PLIF images, reveal asymmetric vapor distributions around the droplets with the apparent induction of Stefan flow from the irradiated droplet surface. Such phenomena have not previously been reported in the literature and have relevance to the overall fuel vaporization process as well as subsequent ignition and pollutant formation processes. To further investigate the experimental results, a convective and radiative heat transfer model is employed to simulate the droplets under corresponding experimental conditions. Results from the model show convective cooling and a strong thermal radiation absorption near the droplets’ surface. The induced asymmetric Stefan flow observed experimentally is therefore a consequence of the high thermal radiation absorption at the droplets’ surface. This study gives both experimental and theoretical results of the vaporization phenomena of asymmetrically irradiated fuel droplets with varying compositions, diameters and irradiation temperatures.
Ph.D. in Mechanical and Aerospace Engineering, May 2012
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Title: ANALYSIS AND CONTROL OF COMPRESSION-IGNITION AND SPARK-IGNITED ENGINES OPERATING WITH DUAL-FUEL COMBUSTION STRATEGY
Creator: Kassa, Mateos
Date: 2017, 2017-07
Description: In recent years, the implementation of a dual-fuel combustion strategy has been explored as a means to improve the thermal efficiencies of...
Show moreIn recent years, the implementation of a dual-fuel combustion strategy has been explored as a means to improve the thermal efficiencies of internal combustion engines while simultaneously reducing their emissions. The dual-fuel combustion strategy was introduced in compression ignition engines to control the combustion phasing by varying the proportion of two simultaneously injected fuels, and altering the combustion timing. The dual-fuel injection strategy also allowed to extend the load limitation of advanced combustion engines, since the two injected fuel ignite in succession reducing the high peak pressures that generally act as a limiting factor. In spark-ignited (SI) engine, the implementation of a dual-fuel combustion strategy serves as an alternative approach to avoid knock (the inadvertent auto-ignition of the fuel mixture). Although conventional engines rely on delaying spark timing to avoid knocking cycles (which significantly reduces the thermal efficiency), the dual-fuel SI engine rely on the simultaneous injection of a low knock resistance and high knock resistance fuel to dynamically adjust the fuel resistance to knock as required. The dual-fuel SI engine thereby successfully suppresses knock without compromising the engine efficiency. Despite the benefits of the dual-fuel combustion strategy, several challenges arise in its implementation, especially when it is implemented along with other advanced combustion strategy leveraging variable valve timing, exhaust gas recirculation, turbocharging, and so forth. This study explores some of these challenges and addresses them from a control standpoint. Cylinder-to-cylinder variations is identified as one of the main challenges. An in-cylinder oxygen estimation strategy and modification to the conventional fueling strategy are proposed as approaches to reduce the combustion variations. In SI engines, the valve dynamics in transient operations are shown to negatively impact the dual-fuel control strategy. The effect of the valve timing on knock propensity and the resulting effect on the fueling strategy is investigated. Finally, the dual-fuel SI engine relies on measurements of the combustion intensity to adjust the fuel split between the low RON and high RON fuel. The implementation of a conventional knock control is shown to be counterintuitive for dual-fuel SI engines due to the highly reactive nature of the controller and the deterministic approach that assumes cycle-to-cycle correlation of the combustion intensity. Statistical investigation of the combustion intensity metric is conducted to identify key properties that can be leveraged for more effective control strategy.
Ph.D. in Mechanical, Material and Aerospace Engineering
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Title: SLIP-LINK MODELING OF ENTANGLED POLYMERS: RHEOLOGICAL APPLICATIONS AND EXTRACTING FRICTION FROM ATOMISTIC SIMULATION
Creator: Katzarova, Maria
Date: 2016, 2016-05
Description: The Discrete Slip-link Model (DSM) is a robust mesoscopic theory that has great success predicting the rheology of flexible entangled polymer...
Show moreThe Discrete Slip-link Model (DSM) is a robust mesoscopic theory that has great success predicting the rheology of flexible entangled polymer liquids and gels. In the most coarse-grained version of the DSM, we exploit the university observed in the shape of the relaxation modulus of linear monodisperse melts. For this type of polymer we present analytic expressions for the relaxation modulus. The high-frequency dynamics which are typically coarse-grained out from the DSM are added back into these expressions by using a Rouse chain with fixed ends. We find consistency in the friction used for both fast and slow modes. Using these analytic expressions, the polymer density, the molecular weight of a Kuhn step, Mk, and the low-frequency cross-over between the storage and loss moduli, G' and G", it is now straightforward to estimate model parameter values and obtain predictions over the experimentally accessible frequency range. Moreover it has previously been shown that the two static parameters can be obtained from primitive path analysis of molecular dynamics simulations. In this work, two ways are shown for obtaining the friction parameter (i) from atomistic simulations of short chains using the free-volume theory, and (ii) from atomistic simulations of entangled chains by scaling the chain center-of-mass mean-square displacement from the slip-link model to that of the atomistic simulation. Futhermore three standing challenges for molecular theories of polymers (i) predictions for uniaxial extension of star-branched polymer melts (ii) predictions for blends of star-branched and linear chains and (iii) predictions for normal stress differences in start-up of shear and followoing cessation are addressed here using the DSM. Additionally the DSM is used to predict the mechanical properties of a cross-linked polydimethylsiloxane (PDMS) network swollen with non-reactive entangled PDMS solvent. These successful predictions strongly suggest that the observed rheological modification in the swollen blend arises from the constraint dynamics between the network chains and the dangling ends.
Ph.D. in Chemical Engineering, May 2016
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Title: ENACTMENT OF COMMON CORE STATE STANDARDS FOR MATHEMATICS: RELATIONSHIP BETWEEN TEACHERS’ CHOICES OF CURRICULUM, TEACHING, AND PROFESSIONAL DEVELOPMENT
Creator: Kartal, Ozgul
Date: 2015, 2015-07
Description: In response to perceived problems of the United States mathematics curriculum, the Common Core State Standards (CCSS) were developed under the...
Show moreIn response to perceived problems of the United States mathematics curriculum, the Common Core State Standards (CCSS) were developed under the leadership of the National Governor Association (NGA) and the Council of Chief State School Officers (CCSSO), and were released in 2010. As of the time of this study, forty-four states, the District of Columbia, four territories, and the Department of Defense Education Activity have adopted the CCSS. The CCSS for Mathematics (CCSSM) initiative has raised many research questions for the field concerning the quality, enactment, and effectiveness and impact of the standards. There is a great deal of concern, in particular, about the enactment of the standards, because􀁿as pointed out by Heck, Weiss, and Pasley (2011)􀁿if standards have not been well implemented in a particular setting, then failure or ineffectiveness shouldn’t be blamed on the standards. Various researchers identified the key components of a successful enactment of a set of standards as curriculum, assessment, professional development, and teachers and teaching practice (e.g., Confrey & Krupa, 2010; Goertz, 2010; Weiss et al., 2002; Wu, 2011b). Therefore, this research study focused on the enactment of the CCSSM, and analyzed the curriculum, teaching, assessment, and teacher professional development as the key components of the enactment process. This study focused on the state of Illinois which is one of the states that started fully implementing the new academic standards in the 2013-14 school year, and hence had ample preparation and trial time between the adoption and full implementation years. This study investigated the alignment between teachers’ choices of curriculum and CCSSM, and relation between the curriculum resources, professional development, and enactment of CCSSM. The focus of the study was on the content of basic algebra and concepts of solving equations and slope while investigating the alignment of enactment of the CCSSM. The sample was comprised of twelve 9th grade algebra teachers from six different schools in the state of Illinois. The criteria in selecting the schools were the geographic location of the schools, the types of the schools, the curricula used at the schools, and the professional development on CCSSM offered at the schools. Results of this study found that the curricula have limited alignment with CCSSM, and that teachers’ enactment of mathematical practices was affected by the availability of variety of standards for mathematical practices in their curriculum as well as professional development opportunities. The curricula provided opportunities for various mathematical practice standards throughout the content of basic algebra, but some practice standards were left out. Teachers provided opportunities for a subset of the standards that were present in the instructional segments of their curriculum. If not, they provided opportunities for practice standards as a result of acquisition from professional developments. The impact of professional development was most evident when teachers using the same curriculum differed in their enactment of the practices. This study portrayed the relations between (low/high) enactments of CCSSM, curriculum resources (aligned or not aligned), and professional developments. Many states and districts are just beginning to incorporate CCSSM into their math curriculum at the time of this study. Therefore, the findings of this study will guide them as they make their textbook, curriculum, and professional development choices and decisions. In addition, this research generated valuable knowledge that would be useful not only in improving the enactment of the CCSSM, but also improving the enactment of future sets of standards. There are implications for curriculum designers, administrators/school and district leaders, professional development designers, and teacher educators.
Ph.D. in Mathematics Education, July 2015
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Title: IRRITABILITY IN CHILDREN: SAME AS FRUSTRATION AND ANGER?
Creator: Kozy, Karyn Brasky
Date: 2013, 2013-12
Description: The primary aims of this study were four-fold. The first aim was to examine which of the three alternative models of irritability provided a...
Show moreThe primary aims of this study were four-fold. The first aim was to examine which of the three alternative models of irritability provided a better fit to the data. The second aim was to further refine the model of irritability by examining the gender and age invariance of the best-fitting models. After establishing which model showed the best fit, the third aim was to empirically examine the reliability and validity of the irritability scale that included items from both temperament and psychopathology scales. Finally, the fourth aim was to examine the rank-order stability and mean-levels of irritability between the ages of 4 and 6. Participants included a diverse, community sample of 796 children and their parents. Irritability, frustration, and anger were measured by selected items from temperament and psychopathology scales, including the Children’s Behavior Questionnaire (CBQ; Rothbart et al., 2001), Child Symptom Inventory (CSI; Gadow & Sprafkin, 1994, 1997), and Eyberg Behavior Inventory (ECBI; Eyberg & Pincus, 1999). Results indicate that the three-factor and two-factor measurement models were viable, alternative models at age 4. Contrary to expectation, neither the three-factor nor the twofactor models were invariant for both genders combined, or between the ages of 4 and 6. Based on the definition of irritability in the three-factor model, the irritability scale demonstrated adequate internal consistency, convergent validity, and divergent validity. Finally, the rank-order stability of irritability was in the moderate range during the period from preschool through kindergarten and formal school entry, but mean-levels of irritability did not differ across time. Implications of the findings and suggestions for future research are discussed.
PH.D in Psychology, December 2013
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Title: RHEOLOGY OF ENTANGLED POLYMER LIQUIDS IN EQUIBIAXIAL ELONGATIONAL FLOWS
Creator: Mick, Rebecca M.
Date: 2015, 2015-05
Description: Equibiaxial deformation is an important flow in industrial processes such as film blowing and blow molding. Unfortunately, it is very...
Show moreEquibiaxial deformation is an important flow in industrial processes such as film blowing and blow molding. Unfortunately, it is very difficult to implement experimentally which has led to empirical design of these processes. A technique called continuous lubricated squeezing flow (CLSF) has been developed to perform equibiaxial deformation on systems such as polymer melts. This technique is used in this study to measure the behavior of entangled polymer melts in equibiaxial elongation to further the understanding of these materials in industrially relevant flows. The results of CLSF experiments on three linear chain polymer systems show strain softening for strain rates resulting in Weissenberg numbers, Wi = ε˙Bτd > 1. Higher rates lead to greater softening. The deviation from the linear viscoelastic (LVE) prediction occurs at about a strain of one for all the materials. Equibiaxial and shear behavior were compared for two monodisperse linear systems. When normalized by LVE behavior, the two flows yield similar behavior such that the equibiaxial rheology could be inferred from shear rheology. Unfortunately, polydisperse linear and branched systems did not show the same behavior. The two monodispere systems were compared to the GLaMM and Discrete Slip-Link molecular theories. Neither model could successfully predict the equibiaxial behavior; both predicted excessive strain softening and a premature deviation from LVE. Recent literature has suggested that based on uniaxial measurements, dilution changes the behavior of an entangled polymer system. This is contrary to theories of polymer dynamics. A pure melt and diluted melt with the same entanglement density were compared in shear and equibiaxial flows after adjusting for changes in friction. The results were consistent with universality principles of entangled polymers; the uniaxial results require further investigation.
Ph.D. in Chemical Engineering, May 2015
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Title: THE IMPACT OF TRUST ON LEADER EMPOWERING BEHAVIOR
Creator: Sternburgh, Angela M.
Date: 2011-04-22, 2011-05
Description: This study examined the relationship between trust and leader empowering behaviors across 250 matched pairs of leaders and employees in a...
Show moreThis study examined the relationship between trust and leader empowering behaviors across 250 matched pairs of leaders and employees in a Fortune 500 Midwestern U.S. company. The relationships between propensity to trust, trustworthiness, trust, a meta-perception of trust, and leader empowering behavior were examined. The goal of this study was to test the mediating role of trust and/or the metaperception of trust on the relationship between trustworthiness and leader empowering behavior. This study obtained both leader and employee ratings, which permitted the examination of both single source and multi source data. Results supported a partial mediation effect indicating that trust and the meta-perception of trust partially mediated the relationship between trustworthiness and leader empowering behavior. This study is important because previous research has predominantly focused on examining employee perceptions of trust, this was the first study to explore the meta-perception of trust, and this study transferred measures of leader empowering behaviors to more behaviorally based statements. Implications of this study are explored.
Ph.D. in Psychology, May 2011
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Title: THE IMPACT OF EXPLICIT AND IMPLICIT ATTITUDES COMPRISING MENTAL ILLNESS STIGMA ON TAKING PSYCHOTROPIC MEDICATIONS AS PRESCRIBED
Creator: Michaels, Patrick
Date: 2015, 2015-07
Description: Research suggests mental illness stigma adversely impacts psychotropic medication use. Few studies have examined stigma and psychotropic...
Show moreResearch suggests mental illness stigma adversely impacts psychotropic medication use. Few studies have examined stigma and psychotropic medication use with a naturalistic design. This study assessed the independent impact of attitudes toward psychiatric medication, cognitive insight, explicit and implicit attitudes of public stigma and self-stigma on psychotropic medication use for people with serious mental illnesses. Medication use was examined in this one-month longitudinal study via self-reported medication use, desire to take medication as directed, pill count use rates over a onemonth period, and pharmacy records including maximum continuous gap, number of gaps, and medication possession ratios. The primary expectation that explicit and implicit attitudes would independently explain lower psychotropic medication use was mostly not supported. On average participants took 82% of psychotropic medication as prescribed, indicating medication was taken at a therapeutic level despite stigma. The most consistent association across time was a positive relationship among desire to take medication and self-application of negative stereotypes. The second finding was that attitudes toward psychotropic medication may be associated with self-reported use, maximum continuous gap, and medication possession. Implications for clinical practice recommend providers are aware, discuss, and intervene in consumer’s experiences with stigma, which can improve medication use and psychological stability. Future research should specifically enroll participants who concurrently take suboptimal doses of medication (<80% of medication) to study stigma and non-adherence. Research should seek to understand how internalized stigma and psychotropic medication stigma are related to suboptimal medication use behaviors among people with mental illness in longitudinal non-intervention studies.
Ph.D. in Psychology, July 2015
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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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