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Title: THE ROLE OF ATTACHMENT IN THE RELATIONSHIP BETWEEN CHILD MALTREATMENT AND LATER EMOTIONAL AND BEHAVIORAL FUNCTIONING.
Creator: Lowell, Amanda, Renk, Kimberly, University of Central Florida
Abstract / Description: Childhood maltreatment is an experience that is likely to have lasting effects on individuals' emotional and behavioral functioning throughout their lifetimes. In particular, childhood maltreatment often is implicated in the etiology of numerous unfavorable psychological outcomes. Other research also suggested that there is a relationship between child maltreatment and the style of attachment that individuals exhibit post-abuse. Lastly, an association exists between individuals' attachment...
Show moreChildhood maltreatment is an experience that is likely to have lasting effects on individuals' emotional and behavioral functioning throughout their lifetimes. In particular, childhood maltreatment often is implicated in the etiology of numerous unfavorable psychological outcomes. Other research also suggested that there is a relationship between child maltreatment and the style of attachment that individuals exhibit post-abuse. Lastly, an association exists between individuals' attachment styles and their emotional and behavioral functioning. Despite substantial documentation of these relationships, few studies examine childhood maltreatment, attachment, and emotional and behavioral functioning collectively. As a result, this study examined the relationships among childhood maltreatment, attachment relationships, and later emotional and behavioral functioning, including eating behaviors. In addition, this study examined the role that attachment serves in the relationship between child maltreatment and later functioning. One hundred participants completed five questionnaires assessing experiences of childhood maltreatment, attachment relationships, emotional and behavioral functioning, and eating behaviors. Results of this study indicated that those individuals who report childhood maltreatment are more likely to report unfavorable emotional and behavioral functioning, whereas those who report childhood maltreatment but who exhibit a secure attachment style to either a parent or a peer are less likely to exhibit unfavorable emotional and behavioral functioning. Further, both the experience of childhood maltreatment and attachment were significant predictors of individuals' emotional and behavioral functioning. Finally, attachment contributed unique significant variance to the relationship between childhood maltreatment and emotional and behavioral functioning, particularly participants' internalizing and total problems. Such findings suggested that secure attachment may serve as a protective factor against problematic emotional and behavioral symptoms as children reach emerging adulthood, even when individuals have had childhood maltreatment experiences earlier in their lives. The importance of studying the relationships among these variables is discussed.
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Date Issued: 2011
Identifier: CFH0003788, ucf:44734
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0003788

Title: Theoretical and Computational Studies of the electronic, Structural, Vibrational, and Thermodynamic Properties of Transition Metal Nanoparticles.
Creator: Sadatshafaie, Ghazal, Rahman, Talat, Stolbov, Sergey, Ishigami, Masa, Masunov, Artem, University of Central Florida
Abstract / Description: The main objective of this dissertation is to provide better understanding of the atomic configurations, electronic structure, vibrational properties, and thermodynamics of transition metal nanoparticles and evaluate the intrinsic (i.e. size and shape) and extrinsic (i.e. ligands, adsorbates, and support) effects on the aforementioned properties through a simulational approach. The presented research provides insight into better understanding of the morphological changes of the nanoparticles...
Show moreThe main objective of this dissertation is to provide better understanding of the atomic configurations, electronic structure, vibrational properties, and thermodynamics of transition metal nanoparticles and evaluate the intrinsic (i.e. size and shape) and extrinsic (i.e. ligands, adsorbates, and support) effects on the aforementioned properties through a simulational approach. The presented research provides insight into better understanding of the morphological changes of the nanoparticles that are brought about by the intrinsic factors as well as the extrinsic ones. The preference of certain ligands to stabilize specific sizes of nanoparticles is investigated. The intrinsic and extrinsic effects on the electronic structure of the nanoparticles are presented. The physical and chemical properties of the nanoparticles are evaluated through better understanding of the above effects on the experimentally observed properties as well as the applied techniques. The unexpected experimental results are tested and interpreted by deconvolution of the affecting factors. The application of Debye model to nanoparticles is tested and its shortcomings at nanoscale are discussed. Predictions which can provide insight into intelligent choice of candidates to cater to certain properties are provided. The results of this thesis can be used in the future in design and engineering of functionalized materials. We use ab initio calculations based on Density Functional Theory (DFT) to obtain information about the energetics, atomic configuration, and electronic structure of the nanoparticles. Ab initio Molecular Dynamics (MD) is used to study the evolution of the structures of the nanoparticles. To calculate vibrational frequencies, the finite displacement method is employed.
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Date Issued: 2015
Identifier: CFE0006385, ucf:51536
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006385

Title: ASYMPTOTIC FORMULAS FOR LARGE ARGUMENTS OF HYPERGEOMETRIC-TYPE FUNCTIONS USING THE BARNES INTEGRAL.
Creator: Heck, Adam, Andrews, Larry, University of Central Florida
Abstract / Description: Hypergeometric type functions have a long list of applications in the field of sciences. A brief history is given of Hypergeometric functions including some of their applications. A development of a new method for finding asymptotic formulas for large arguments is given. This new method is applied to Bessel functions. Results are compared with previously known methods.
Date Issued: 2004
Identifier: CFE0000235, ucf:46263
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000235

Title: On the Theory of Zeta-functions and L-functions.
Creator: Awan, Almuatazbellah, Mohapatra, Ram, Li, Xin, Brennan, Joseph, University of Central Florida
Abstract / Description: In this thesis we provide a body of knowledge that concerns Riemann zeta-function and its generalizations in a cohesive manner. In particular, we have studied and mentioned some recent results regarding Hurwitz and Lerch functions, as well as Dirichlet's L-function. We have also investigated some fundamental concepts related to these functions and their universality properties. In addition, we also discuss different formulations and approaches to the proof of the Prime Number Theorem and the...
Show moreIn this thesis we provide a body of knowledge that concerns Riemann zeta-function and its generalizations in a cohesive manner. In particular, we have studied and mentioned some recent results regarding Hurwitz and Lerch functions, as well as Dirichlet's L-function. We have also investigated some fundamental concepts related to these functions and their universality properties. In addition, we also discuss different formulations and approaches to the proof of the Prime Number Theorem and the Riemann Hypothesis. These two topics constitute the main theme of this thesis. For the Prime Number Theorem, we provide a thorough discussion that compares and contrasts Norbert Wiener's proof with that of Newman's short proof. We have also related them to Hadamard's and de la Vallee Poussin's original proofs written in 1896. As far as the Riemann Hypothesis is concerned, we discuss some recent results related to equivalent formulations of the Riemann Hypothesis as well as the Generalized Riemann Hypothesis.
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Date Issued: 2015
Identifier: CFE0005576, ucf:50268
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005576

Title: THE WAVE STRUCTURE FUNCTION AND TEMPORAL FREQUENCY SPREAD IN WEAK TO STRONG OPTICAL TURBULENCE.
Creator: Masino, Aaron Joseph, Young, Cynthia Y., University of Central Florida
Abstract / Description: This paper presents analytic expressions for the wave structure function, frequency spread of the temporal frequency spectrum, and the temporal frequency spectrum of optical signals propagating through a random medium, specifically the Earth's atmosphere. The results are believed to be valid for all optical turbulence conditions. These expressions are developed using the Rytov approximation method. Generally, the validity of statistical quantities obtained via this method is restricted to...
Show moreThis paper presents analytic expressions for the wave structure function, frequency spread of the temporal frequency spectrum, and the temporal frequency spectrum of optical signals propagating through a random medium, specifically the Earth's atmosphere. The results are believed to be valid for all optical turbulence conditions. These expressions are developed using the Rytov approximation method. Generally, the validity of statistical quantities obtained via this method is restricted to conditions of weak optical turbulence. However, in this work, by using a modification of the effective atmospheric spectral model presented by Andrews et al. for scintillation index, wave structure function expressions have been derived that are valid in all turbulence conditions as evidenced by comparison to experimental data. Analytic wave structure function results are developed for plane, spherical, and Gaussian-beam waves for one-way propagation. For the special case of a spherical wave, comparisons are made with experimental data. The double pass case is also considered. Analytic expressions for the wave structure function are given that incorporate reflection from a smooth target for an incident spherical wave. Additionally, analytic expressions for the frequency spread of the temporal frequency spectrum and the temporal frequency spectrum itself, after one-way propagation for horizontal and slant paths, are derived for plane and spherical waves. These results are also based on the Rytov perturbation method . Expressions that are believed to be valid in all turbulence conditions are also developed by use of the effective atmospheric spectral model used in the wave structure function development. Finally, double pass frequency spread expressions are also presented. As in the case of the wave structure function, reflection from a smooth target with an incident spherical wave is considered.
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Date Issued: 2004
Identifier: CFE0000073, ucf:46106
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000073

Title: NON-ACUTE COGNITIVE SEQUELAE ASSOCIATED WITH RECREATIONAL ECSTASY USE: A META-ANALYSIS.
Creator: Linkovich Kyle, Tiffany, Dunn, Michael, University of Central Florida
Abstract / Description: Studies using animal models have found considerable evidence of neurological damage resulting from exposure to 3,4- methylenedioxymethamphetamine (MDMA, ecstasy). Yet, studies comparing the cognitive performance of human recreational ecstasy users to ecstasy naïve controls have produced inconsistent results. The present study is a meta-analysis of the published empirical literature on the cognitive sequelae of human recreational ecstasy use. The pooled effect size estimate for combined...
Show moreStudies using animal models have found considerable evidence of neurological damage resulting from exposure to 3,4- methylenedioxymethamphetamine (MDMA, ecstasy). Yet, studies comparing the cognitive performance of human recreational ecstasy users to ecstasy naïve controls have produced inconsistent results. The present study is a meta-analysis of the published empirical literature on the cognitive sequelae of human recreational ecstasy use. The pooled effect size estimate for combined cognitive domains was statistically significant and moderate in size. Small to large, statistically significant aggregate effect sizes resulted for eight of the nine cognitive ability domains included in the analysis. Moderator analyses suggested that frequent ecstasy use is associated with greater cognitive impairment, cognitive impairment can occur after relatively low amounts of total lifetime cumulative use, and recovery of functioning does not occur within one year post cessation.
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Date Issued: 2005
Identifier: CFE0000701, ucf:46614
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000701

Title: SYNTHESIS OF ALKYLTHIOL-CONTAINING FLUORENE DERIVATIVES FOR GOLD NANOPARTICLE FUNCTIONALIZATION.
Creator: Mukundarajan, Sriram, Belfield, Kevin, University of Central Florida
Abstract / Description: A novel synthetic methodology has been developed for attaching fluorene derivatives, containing different types of electron donating and accepting groups at the 2 and 7 positions, to gold nanoparticles of different sizes by exploiting the affinity of the thiol functional group for gold. The distance between the dye and nanoparticles was varied by introducing two alkyl chains containing different number of carbon atoms at the 9 position on the fluorene ring system. The methodology that was...
Show moreA novel synthetic methodology has been developed for attaching fluorene derivatives, containing different types of electron donating and accepting groups at the 2 and 7 positions, to gold nanoparticles of different sizes by exploiting the affinity of the thiol functional group for gold. The distance between the dye and nanoparticles was varied by introducing two alkyl chains containing different number of carbon atoms at the 9 position on the fluorene ring system. The methodology that was developed gave enough scope for performing Radiative Decay Engineering (RDE) studies, in order to investigate the impact of gold nanoparticles on the singlet oxygen quantum yields of fluorene dyes that already exhibit high singlet oxygen quantum yields as well as high two photon absorption (2PA) cross-sections. The dialkylation of the fluorene derivatives was accomplished by reacting the dye with ƒÑ, ƒç-dibromoalkanes containing different number of carbon atoms in a biphasic reaction mixture containing toluene and aqueous sodium hydroxide solution in the presence of tetrabutylammonium bromide (TBAB) as a phase transfer catalyst. The bromine atom on the alkyl chains was converted to thioester by reaction with potassium thioacetate. This was followed by the hydrolysis of the thioester to form the thiol moiety. The compounds synthesized were characterized using 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. Functionalization of gold nanoparticles was attempted by bringing into contact a solution of the thiol compound in toluene and an aqueous gold nanoparticles solution. UV-vis absorbance spectroscopy was used to monitor the progress of the attachment. Surface Enhanced Raman Scattering (SERS) spectroscopy was used to probe the enhancement of Raman signal by the metallic nanoparticles.
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Date Issued: 2005
Identifier: CFE0000769, ucf:46589
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000769

Title: THE STUDY OF THE ADVERSE EFFECTS OF CHILDHOOD MALTREATMENT.
Creator: Kennie, Katie A, Saunders, Steven, University of Central Florida
Abstract / Description: This study explores the link between the presence of childhood trauma and adult criminal behavior. In this study, four distinct categories of childhood trauma (physical abuse, sexual abuse, psychological abuse, and neglect) were examined. In addition, this study conducts a comparative analysis of the United States crime rate with that of Switzerland and Japan. This study examines and compares the policies utilized in ensuring the protection of child welfare. The ultimate goal is to provide...
Show moreThis study explores the link between the presence of childhood trauma and adult criminal behavior. In this study, four distinct categories of childhood trauma (physical abuse, sexual abuse, psychological abuse, and neglect) were examined. In addition, this study conducts a comparative analysis of the United States crime rate with that of Switzerland and Japan. This study examines and compares the policies utilized in ensuring the protection of child welfare. The ultimate goal is to provide research which may build a foundation that will assist in creating and improving policies which will ensure a child's psychological health.
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Date Issued: 2016
Identifier: CFH2000081, ucf:45543
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000081

Title: NEUROPSYCHOLOGICAL FUNCTIONING IN SOCIAL PHOBIA.
Creator: Sutterby, Scott, Bedwell, Jeffrey, University of Central Florida
Abstract / Description: The purpose of the current study was to clarify the neurocognitive mechanisms underlying social phobia. Previous research has identified some specific group differences in neurocognitive functioning between individuals diagnosed with social phobia and nonpsychiatric controls, but has failed to administer a comprehensive neuropsychological battery to a social phobia patient group, resulting in a piecemeal understanding of the neurocognitive functioning of this population and an incomplete...
Show moreThe purpose of the current study was to clarify the neurocognitive mechanisms underlying social phobia. Previous research has identified some specific group differences in neurocognitive functioning between individuals diagnosed with social phobia and nonpsychiatric controls, but has failed to administer a comprehensive neuropsychological battery to a social phobia patient group, resulting in a piecemeal understanding of the neurocognitive functioning of this population and an incomplete picture of the neuropsychological profile inherent to this group. The present research utilized a broader collection of neuropsychological tests to assess nine cognitive domains: Verbal Learning, Verbal Delayed Memory, Visual Immediate Memory, Visual Delayed Memory, Visual-Spatial Processing, Verbal Working Memory, Visual Working Memory, Executive Functioning, and Attention. A mixed analysis of variance (ANOVA) did not reveal a significant group by cognitive domain interaction, nor a significant main effect of group. As this was the first study to examine multiple cognitive domains in a single sample of individuals with generalized social phobia, exploratory univariate analyses were performed to examine group differences for the specific cognitive domains. This revealed significant group differences specific to the Visual Working Memory domain, with the social phobia group scoring significantly lower than the nonpsychiatric control group. Implications of these findings and directions for future research are discussed.
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Date Issued: 2009
Identifier: CFE0002859, ucf:48049
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002859

Title: DYNAMIC TASK ALLOCATION IN MOBILE ROBOT SYSTEMS USING UTILITY FUNTIONS.
Creator: Vander Weide, Scott, Bölöni, Ladislau, University of Central Florida
Abstract / Description: We define a novel algorithm based on utility functions for dynamically allocating tasks to mobile robots in a multi-robot system. The algorithm attempts to maximize the performance of the mobile robot while minimizing inter-robot communications. The algorithm takes into consideration the proximity of the mobile robot to the task, the priority of the task, the capability required by the task, the capabilities of the mobile robot, and the rarity of the capability within the population of mobile...
Show moreWe define a novel algorithm based on utility functions for dynamically allocating tasks to mobile robots in a multi-robot system. The algorithm attempts to maximize the performance of the mobile robot while minimizing inter-robot communications. The algorithm takes into consideration the proximity of the mobile robot to the task, the priority of the task, the capability required by the task, the capabilities of the mobile robot, and the rarity of the capability within the population of mobile robots. We evaluate the proposed algorithm in a simulation study and compare it to alternative approaches, including the contract net protocol, an approach based on the knapsack problem, and random task selection. We find that our algorithm outperforms the alternatives in most metrics measured including percent of tasks complete, distance traveled per completed task, fairness of execution, number of communications, and utility achieved.
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Date Issued: 2008
Identifier: CFE0002274, ucf:47871
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002274

Title: ON THE USE OF GAUSSIAN FILTER FUNCTIONS FOR ADAPTIVE OPTICS.
Creator: Assad, Merfit, Andrews, Larry, University of Central Florida
Abstract / Description: For adaptive optic systems, the use of aperture filter functions calculated using various Zernike modes can be useful in removing lower-order aberrations caused by atmospheric turbulence. Traditionally, these filter functions are calculated using the step function depicting a hard aperture that introduces integrals that are sometimes difficult to integrate and must be done numerically. The Gaussian method can be used in place of the conventional method for calculating the aperture filter...
Show moreFor adaptive optic systems, the use of aperture filter functions calculated using various Zernike modes can be useful in removing lower-order aberrations caused by atmospheric turbulence. Traditionally, these filter functions are calculated using the step function depicting a hard aperture that introduces integrals that are sometimes difficult to integrate and must be done numerically. The Gaussian method can be used in place of the conventional method for calculating the aperture filter functions. Evaluation of the Gaussian approximation for modeling a finite receiver aperture can be made by comparison of reduction in phase variance with results achieved using the conventional method. The validity of Gaussian approximation in this application is demonstrated by the consistency of results between the two methodologies. Comparison of reduction in scintillation by the two methodologies reveals several benefits derived from utilization of Gaussian approximation. The Gaussian approximation produces data that can be interpreted analytically. It further produces greater scintillation reduction. This paper will first examine the use of statistical models for predicting atmospheric turbulence and then the use of Zernike polynomials in adaptive optics. Next, this paper compares the reduction of phase variance and scintillation using the conventional method with the Gaussian approximation to evaluate the effectiveness of the new filter functions. The results of these comparisons are presented both as mathematical expressions and graphically.
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Date Issued: 2006
Identifier: CFE0001436, ucf:52885
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001436

Title: DETERMINING SEX AND ANCESTRY OF THE HYOID FROM THE ROBERT J. TERRY ANATOMICAL COLLECTION.
Creator: Kindschuh, Sarah, Dupras, Tosha, University of Central Florida
Abstract / Description: One of the basic goals of the physical anthropologist is to create a biological profile, consisting of sex, ancestry, age, and stature, from the skeletal material that they are presented with. This thesis seeks to explore size and shape differences related to sex and ancestry from the hyoid bones of the Robert J. Terry Anatomical Collection in order to gauge its usefulness in the process of developing a biological profile. A series of measurements were taken from 398 hyoids and analysis was...
Show moreOne of the basic goals of the physical anthropologist is to create a biological profile, consisting of sex, ancestry, age, and stature, from the skeletal material that they are presented with. This thesis seeks to explore size and shape differences related to sex and ancestry from the hyoid bones of the Robert J. Terry Anatomical Collection in order to gauge its usefulness in the process of developing a biological profile. A series of measurements were taken from 398 hyoids and analysis was conducted using a number of statistical methods. Independent samples t-tests were used to examine size differences between sexes and ancestries, while linear regression analysis and principle component analysis were used to examine shape differences. Discriminant function analysis was employed to test the ability of the hyoids to be classified by sex or ancestry. The ultimate goal of the thesis is to provide physical anthropologists with a series of discriminant function equations that can be used to estimate the sex and ancestry of a hyoid. Five equations ranging in accuracy from 83-88% were developed to determine sex of a hyoid, while four equations ranging in accuracy from 70-89% can be used to determine ancestry. In addition, the t-tests, regression analyses, and principle component analysis have identified several variations in size and shape between sexes and ancestries. These analyses have provided further knowledge as to the morphological form of the hyoid, as well as a method that can be easily used by physical anthropologists to assess sex and ancestry.
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Date Issued: 2009
Identifier: CFE0002599, ucf:48282
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002599

Title: DOES CHRONIC STRESS ACCELERATE LATE-AGING COGNITIVE DECLINE IN MEMORY AND EXECUTIVE FUNCTIONING?.
Creator: Robinson, Diane, Bedwell, Jeffrey, University of Central Florida
Abstract / Description: Few studies exist examining the relationship between self-reported stress and cognitive function in healthy nonpsychiatric older adults, and even less studies have examined whether high levels of self-reported stress accelerate the cognitive decline found in normal late-aging populations. A group of older nonpsychiatric adults, ages 54 years and above, were asked to complete three measures assessing their self-perceived stress over the past month, past year, and their lifetime. Sixty-one...
Show moreFew studies exist examining the relationship between self-reported stress and cognitive function in healthy nonpsychiatric older adults, and even less studies have examined whether high levels of self-reported stress accelerate the cognitive decline found in normal late-aging populations. A group of older nonpsychiatric adults, ages 54 years and above, were asked to complete three measures assessing their self-perceived stress over the past month, past year, and their lifetime. Sixty-one adults between the ages of 54 and 88 (52% female) participated in a second phase in which neuropsychological tasks were administered to assess three cognitive domains; memory, learning, and executive functioning. A hierarchical regression examined each of the three domain scores to explore whether self-perceived acute and chronic stress, after covaring for state anxiety, was related to neuropsychological performance. No statistically significant regressions were found, which was predicted for the learning domain, but contrary to the hypotheses for the memory and executive functioning domain. The potential influence of age in this study was explored in a series of ANOVAs examining the interactions between the three stress measures with state anxiety and age on the three cognitive domains. A statistically significant interaction was found between age and perceived lifetime stress when examining the memory domain score. In the young-old participants an increase in stress showed a non-significant relationship with a decrease in memory performance, while in the older-old participants the opposite non-significant tendency was found. The current study also partially replicated an earlier report of a relationship between an increase in recent self-reported stress and a decrease in performance on a specific divided attention task, and extended this finding to include older adults. While the majority of the studyÃ‚Â's hypotheses were not supported, these preliminary findings provide the field with interesting areas to explore in future studies.
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Date Issued: 2010
Identifier: CFE0003256, ucf:48515
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003256

Title: Work Function Extraction of Indium Tin Oxide Used As Transparent Gate Electrode For MOSFET.
Creator: Nehate, Shraddha, Sundaram, Kalpathy, Kapoor, Vikram, Yuan, Jiann-Shiun, University of Central Florida
Abstract / Description: Recent commercialization has peaked interest in transparent conducting oxides being implemented in display technology. Indium Tin Oxide (ITO) is a popular transparent conducting oxide which has been utilized as high work function electrode in liquid crystal displays, solar cells, gas sensors and heat reflecting films. Indium Tin Oxide films exhibit excellent transmission characteristics in the visible and infrared spectrum while maintaining high electrical conductivity. High work function...
Show moreRecent commercialization has peaked interest in transparent conducting oxides being implemented in display technology. Indium Tin Oxide (ITO) is a popular transparent conducting oxide which has been utilized as high work function electrode in liquid crystal displays, solar cells, gas sensors and heat reflecting films. Indium Tin Oxide films exhibit excellent transmission characteristics in the visible and infrared spectrum while maintaining high electrical conductivity. High work function electrodes are used to inject holes into organic materials. In majority applications the ITO work function has an impact on the device performance as it affects the energy barrier height at the hetero-junction interface. Hence, the work function of ITO is of critical importance.In this thesis, the work function of ITO is extracted successfully from a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) device for the first time. Two MOSFET devices are fabricated using a four level mask under exact same conditions. Aluminum metal is used as a drain and source contact for both MOSFETs. One of the MOSFET has aluminum gate contact and transparent conducting ITO is used as gate contact for the second MOSFET. From the threshold voltage equation of both the fabricated MOSFETs, work function of ITO is extracted. Further optical transmission studies of ITO performed in the visible spectra are also reported in this study.
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Date Issued: 2016
Identifier: CFE0006364, ucf:51534
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006364

Title: Psychometric Issues Related to the Tinker Toy Test.
Creator: Guzman, Daniel, Fouty, Ed, Berman, Steven, Damato-Kubiet, Leslee, University of Central Florida
Abstract / Description: An evaluation of executive functioning is a critical component of a comprehensive assessment of higher cerebral functioning. The Tinker Toy Test (TTT) was introduced in 1982. This test allows an individual to demonstrate the extent of their executive capacities by permitting them to initiate, plan, and structure a potentially complex activity and carry it out independently in an unstructured fashion and administration is simple. This is a departure from more complex and structured tests of...
Show moreAn evaluation of executive functioning is a critical component of a comprehensive assessment of higher cerebral functioning. The Tinker Toy Test (TTT) was introduced in 1982. This test allows an individual to demonstrate the extent of their executive capacities by permitting them to initiate, plan, and structure a potentially complex activity and carry it out independently in an unstructured fashion and administration is simple. This is a departure from more complex and structured tests of executive function. There is a dearth of research on the TTT and this study seeks to examine some of the psychometric properties of this instrument; i.e., working time minimum, gender effects, convergent and divergent validity, and potential intellectual correlates. Participants included 10 male and 30 female student volunteers from a large university in Central Florida. Participants had no history of neurologic disease/trauma or conditions that would affect motor functioning of the upper extremities. Participants completed a demographic questionnaire, the WASI-II, and the TTT. A two-way mixed-design ANOVA examining TTT scores as a function of work time and gender revealed a non-significant gender main effect, F(1, 21) = .09, p = .767. The work time main effect was not significant, , F(1, 21) = .324, p = .575. A significant work time x gender interaction was observed, F(1, 21) = 4.983, p = .037. Convergent validity was assessed by comparing the TTT scores with the Matrix Reasoning subtest, r(38) = .32, p = .044, and the Similarities, r(38) = .34, p = .03, subtest on the WASI-II. Divergent validity was assessed by comparing TTT scores to the Block Design subtest of the WASI-II, r(38) = .245, p = .127. No significant correlation was found between intelligence and TTT (VCI, r(38) = -.16, p = .335; PRI, r(38) = .15, p = .344; and FSIQ, r(38) = -.02, p = .928). The data supports the continued use of the 5-minute working time minimum presented by Lezak, as this temporal index was a more accurate representation of executive functioning. This study demonstrated no association between TTT scores and intellectual functioning. The findings of this study support the validity of this underutilized test of executive functioning and its inclusion in neuropsychological test batteries.
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Date Issued: 2015
Identifier: CFE0005802, ucf:50044
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005802

Title: SMOOTHING PARAMETER SELECTION IN NONPARAMETRIC FUNCTIONAL ESTIMATION.
Creator: Amezziane, Mohamed, Ahmad, Ibrahim, University of Central Florida
Abstract / Description: This study intends to build up new techniques for how to obtain completely data-driven choices of the smoothing parameter in functional estimation, within the confines of minimal assumptions. The focus of the study will be within the framework of the estimation of the distribution function, the density function and their multivariable extensions along with some of their functionals such as the location and the integrated squared derivatives.
Date Issued: 2004
Identifier: CFE0000307, ucf:46314
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000307

Title: METHOD TO DISCRETIZE CONTINUOUS GRADIENT STRUCTURES AND CALCULATE THERMAL RESIDUAL STRESSES WITHIN LAYERED FUNCTIONALLY GRADED CERAMICS.
Creator: Neale, Ryan E, Orlovskaya, Nina, University of Central Florida
Abstract / Description: Functionally graded materials (FGMs) are an advanced class of material which seeks to leverage the strengths of one material to mitigate the weaknesses of another. This allows for operation in extreme environments or conditions where materials properties must change at various locations within a structure. Fabrication of this advanced class of material is limited due to geometric, economic, and material constraints inherent in the various methods. For this reason, a model was developed to...
Show moreFunctionally graded materials (FGMs) are an advanced class of material which seeks to leverage the strengths of one material to mitigate the weaknesses of another. This allows for operation in extreme environments or conditions where materials properties must change at various locations within a structure. Fabrication of this advanced class of material is limited due to geometric, economic, and material constraints inherent in the various methods. For this reason, a model was developed to discretize continuous gradient curves to allow for the use of a step-wise approximations to such gradients. These alternative step-wise gradients would allow for the use of numerous manufacturing techniques which have improved composition control, cost of processing, cost of equipment, and equipment availability. One such technique, tape casting, was explored due to its robustness and ability to create layered ceramics. Since ceramics are inherently brittle materials, they serve to be strengthened by the thermal residual stresses that form in the creation of these step-wise graded composites. With models to calculate these residual stresses and determine step-wise approximations of various compositional gradients, the process of designing these layered ceramics can be significantly improved.
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Date Issued: 2019
Identifier: CFH2000530, ucf:45633
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000530

Title: Image degradation due to surface scattering in the presence of aberrations.
Creator: Choi, Narak, Harvey, James, Zeldovich, Boris, Moharam, M., Eastes, Richard, University of Central Florida
Abstract / Description: This dissertation focuses on the scattering phenomena by well-polished optical mirror surfaces. Specifically, predicting image degradation by surface scatter from rough mirror surfaces for a two-mirror telescope operating at extremely short wavelengths (9nm~30nm) is performed. To evaluate image quality, surface scatter is predicted from the surface metrology data and the point spread function in the presence of both surface scatter and aberrations is calculated.For predicting the scattering...
Show moreThis dissertation focuses on the scattering phenomena by well-polished optical mirror surfaces. Specifically, predicting image degradation by surface scatter from rough mirror surfaces for a two-mirror telescope operating at extremely short wavelengths (9nm~30nm) is performed. To evaluate image quality, surface scatter is predicted from the surface metrology data and the point spread function in the presence of both surface scatter and aberrations is calculated.For predicting the scattering intensity distribution, both numerical and analytic methods are considered. Among the numerous analytic methods, the small perturbation method (classical Rayleigh-Rice surface scatter theory), the Kirchhoff approximation method (classical Beckman-Kirchhoff surface scatter theory), and the generalized Harvey-Shack surface scatter theory are adopted. As a numerical method, the integral equation method (method of moments) known as a rigorous solution is discussed. Since the numerical method is computationally too intensive to obtain the scattering prediction directly for the two mirror telescope, it is used for validating the three analytic approximate methods in special cases. In our numerical comparison work, among the three approximate methods, the generalized Harvey-Shack model shows excellent agreement to the rigorous solution and it is used to predict surface scattering from the mirror surfaces.Regarding image degradation due to surface scatter in the presence of aberrations, it is shown that the composite point spread function is obtained in explicit form in terms of convolutions of the geometrical point spread function and scaled bidirectional scattering distribution functions of the individual surfaces of the imaging system. The approximations and assumptions in this formulation are discussed. The result is compared to the irradiance distribution obtained using commercial non-sequential ray tracing software for the case of a two-mirror telescope operating at the extreme ultra-violet wavelengths and the two results are virtually identical. Finally, the image degradation due to the surface scatter from the mirror surfaces and the aberration of the telescope is evaluated in terms of the fractional ensquared energy (for different wavelengths and field angles) which is commonly used as an image quality requirement on many NASA astronomy programs.
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Date Issued: 2012
Identifier: CFE0004289, ucf:49492
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004289

Title: FAITH IN A GALAXY FAR, FAR AWAY: STAR WARS AS RELIGION.
Creator: Hunter, Darryl B, DiBernardo, Sabatino, University of Central Florida
Abstract / Description: Within the past three decades, Star Wars has become nothing short of a household name. The millions of dollars gained from the films and various products, as well as the enjoyment and enthusiasm generated among fans, shows that Star Wars' value and significance in the realm of entertainment is substantial. In addition to this value, there are also many religious and mythological elements that are embedded within each of the movies. However, these elements do not carry the same prominence or...
Show moreWithin the past three decades, Star Wars has become nothing short of a household name. The millions of dollars gained from the films and various products, as well as the enjoyment and enthusiasm generated among fans, shows that Star Wars' value and significance in the realm of entertainment is substantial. In addition to this value, there are also many religious and mythological elements that are embedded within each of the movies. However, these elements do not carry the same prominence or interest that the plotline has with the audience. In an interview, Lucas stated that it was not his intent to use Star Wars to create a new religion or ideology. Nevertheless, the movie series has raised questions regarding its ability to attain such a devoted following. Consequently, the thesis will look into the dynamic between authorial intent and reader response. In addition, this thesis will investigate the religious themes and mythological elements of the Star Wars series and use this analysis to corroborate the position that Star Wars both resembles traditional religion and functions as religion for the fans. This thesis will analyze the religious elements and myths that are embedded in the general story, as well as those that are unique to the individual movies, by highlighting a family resemblance/functionalist approach to religion that focuses on not only the resemblances to traditional religion but also the religious effects that Star Wars has on its fans and society; namely, moral issues and the sense of meaning and belonging it inculcates among the fan base.
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Date Issued: 2017
Identifier: CFH2000168, ucf:46009
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000168

Title: AUTOMATED ADAPTIVE DATA CENTER GENERATION FOR MESHLESS METHODS.
Creator: Mitteff, Eric, Divo, Eduardo, University of Central Florida
Abstract / Description: Meshless methods have recently received much attention but are yet to reach their full potential as the required problem setup (i.e. collocation point distribution) is still significant and far from automated. The distribution of points still closely resembles the nodes of finite volume-type meshes and the free parameter, c, of the radial-basis expansion functions (RBF) still must be tailored specifically to a problem. The localized meshless collocation method investigated requires a local...
Show moreMeshless methods have recently received much attention but are yet to reach their full potential as the required problem setup (i.e. collocation point distribution) is still significant and far from automated. The distribution of points still closely resembles the nodes of finite volume-type meshes and the free parameter, c, of the radial-basis expansion functions (RBF) still must be tailored specifically to a problem. The localized meshless collocation method investigated requires a local influence region, or topology, used as the expansion medium to produce the required field derivatives. Tests have shown a regular cartesian point distribution produces optimal results, however, in order to maintain a locally cartesian point distribution a recursive quadtree scheme is herein proposed. The quadtree method allows modeling of irregular geometries and refinement of regions of interest and it lends itself for full automation, thus, reducing problem setup efforts. Furthermore, the construction of the localized expansion regions is closely tied up to the point distribution process and, hence, incorporated into the automated sequence. This also allows for the optimization of the RBF free parameter on a local basis to achieve a desired level of accuracy in the expansion. In addition, an optimized auto-segmentation process is adopted to distribute and balance the problem loads throughout a parallel computational environment while minimizing communication requirements.
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Date Issued: 2006
Identifier: CFE0001321, ucf:47032
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001321

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