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  Partner: UNT Libraries
 Degree Level: Doctoral
 Collection: UNT Theses and Dissertations
Cooperation-induced Criticality in Neural Networks

Cooperation-induced Criticality in Neural Networks

Date: August 2013
Creator: Zare, Marzieh
Description: The human brain is considered to be the most complex and powerful information-processing device in the known universe. The fundamental concepts behind the physics of complex systems motivate scientists to investigate the human brain as a collective property emerging from the interaction of thousand agents. In this dissertation, I investigate the emergence of cooperation-induced properties in a system of interacting units. I demonstrate that the neural network of my research generates a series of properties such as avalanche distribution in size and duration coinciding with the experimental results on neural networks both in vivo and in vitro. Focusing attention on temporal complexity and fractal index of the system, I discuss how to define an order parameter and phase transition. Criticality is assumed to correspond to the emergence of temporal complexity, interpreted as a manifestation of non-Poisson renewal dynamics. In addition, I study the transmission of information between two networks to confirm the criticality and discuss how the network topology changes over time in the light of Hebbian learning.
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Correlates Between Adult Romantic Attachment Patterns and Dimensional Personality Pathology

Correlates Between Adult Romantic Attachment Patterns and Dimensional Personality Pathology

Date: August 2013
Creator: Ernest, Kimberly Dawn
Description: Previous research has suggested that adult attachment disturbance is related to maladaptic interaction patterns and personality disorder constructs. Specifically, research indicates that those with attachment disturbance are significantly more likely to meet criteria for a number of personality disorders, including borderline personality disorder, narcissistic personality disorder, and antisocial personality disorder. The purpose of this study was to investigate the associations between adult attachment and the new dimensional model of personality disorders scheduled to be released in the Diagnostic and Statistical Manual for Mental Health Diosrders (5th ed.) in spring 2013. Participants completed the Schedule for Adaptive and Nonadaptive Personality (SNAP) to measure dimensional personality functioning and the Experiences in Close Relationships (ECR-R) and the Attachment Prototypes to measure adult attachment patterns. Additionally, select scales from the Personality Assessment Inventory (PAI) and the Five Factor Model (FFM) will be utilized as secondary measures of personality patterns. The results suggest strong associations between adult attachment orientations and specific maladaptive personality characteristics.
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Detection of Temporal Events and Abnormal Images for Quality Analysis in Endoscopy Videos

Detection of Temporal Events and Abnormal Images for Quality Analysis in Endoscopy Videos

Date: August 2013
Creator: Nawarathna, Ruwan D.
Description: Recent reports suggest that measuring the objective quality is very essential towards the success of colonoscopy. Several quality indicators (i.e. metrics) proposed in recent studies are implemented in software systems that compute real-time quality scores for routine screening colonoscopy. Most quality metrics are derived based on various temporal events occurred during the colonoscopy procedure. The location of the phase boundary between the insertion and the withdrawal phases and the amount of circumferential inspection are two such important temporal events. These two temporal events can be determined by analyzing various camera motions of the colonoscope. This dissertation put forward a novel method to estimate X, Y and Z directional motions of the colonoscope using motion vector templates. Since abnormalities of a WCE or a colonoscopy video can be found in a small number of frames (around 5% out of total frames), it is very helpful if a computer system can decide whether a frame has any mucosal abnormalities. Also, the number of detected abnormal lesions during a procedure is used as a quality indicator. Majority of the existing abnormal detection methods focus on detecting only one type of abnormality or the overall accuracies are somewhat low if the method tries to ...
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Development of Novel Semi-conducting Ortho-carborane Based Polymer Films: Enhanced Electronic and Chemical Properties

Development of Novel Semi-conducting Ortho-carborane Based Polymer Films: Enhanced Electronic and Chemical Properties

Date: August 2013
Creator: Pasquale, Frank L.
Description: A novel class of semi-conducting ortho-carborane (B10C2H12) based polymer films with enhanced electronic and chemical properties has been developed. The novel films are formed from electron-beam cross-linking of condensed B10C2H12 and B10C2H12 co-condensed with aromatic linking units (Y) (Y=1,4-diaminobenzene (DAB), benzene (BNZ) and pyridine (PY)) at 110 K. The bonding and electronic properties of the novel films were investigated using X-ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS) and Mulliken charge analysis using density functional theory (DFT). These films exhibit site-specific cross-linking with bonding, in the pure B10C2HX films, occurring at B sites non-adjacent to C in the B10C2H12 icosahedra. The B10C2H12:Y films exhibit the same phenomena, with cross-linking that creates bonds primarily between B sites non-adjacent to C in the B10C2H12 icosahedra to C sites in the Y linking units. These novel B10C2HX: Y linked films exhibit significantly different electron structure when compared to pure B10C2HX films as seen in the UPS spectra. The valence band maxima (VBM) shift from - 4.3 eV below the Fermi level for pure B10C2HX to -2.6, -2.2, and -1.7 for B10C2HX:BNZ, B10C2HX:PY, and B10C2HX:DAB, respectively. The top of the valence band is composed of states derived primarily from the Y linking units, suggesting ...
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The Effects of the Texas Reading First Response to Intervention Program on Student Achievement and Campus Special Education Rates

The Effects of the Texas Reading First Response to Intervention Program on Student Achievement and Campus Special Education Rates

Date: August 2013
Creator: Batts, Troy D.
Description: The purpose of this study was to examine special education populations, special education reading achievement, and regular education reading achievement in relation to the implementation of the Reading First three-tiered model as a response to Intervention platform. The population for this study focused on rural schools with Grades K-3 in attendance. Schools participated in the reading first grant period of the 2003-2009 school years. Forty-seven Texas Reading First schools were compared to 47 campuses having similar populations, socioeconomic makeups, and grade structures. This study utilized quantitative research measures to evaluate the level of special education populations on Reading First campuses using a response to intervention model. Quantitative measures were also used to evaluate those same campuses achievement rates of both special education and regular education students on the Texas Assessment of Knowledge and Skills reading tests. The study's outcome data showed little to no statistic significance for the three research questions. However, the inferential statistics showed a decrease in the special education population of the Reading First schools. Inferential statistics also indicated both the special education and the regular education students showed growth on the Texas Assessment of Knowledge and Skills reading tests. The use of a response to intervention ...
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Endocrine Disruption of Levonorgestrel in Early-life Stages of Fathead Minnows, Pimephales Promelas

Endocrine Disruption of Levonorgestrel in Early-life Stages of Fathead Minnows, Pimephales Promelas

Date: August 2013
Creator: Overturf, Matthew D.
Description: Pharmaceuticals have routinely been detected in the environment resulting in a growing concern about whether these drugs could elicit effects on aquatic organisms. The concerns are centered on the highly conserved nature of mammalian therapeutic targets in fish. These pharmaceuticals are found at very low levels in the environment, which can result in sub-lethal effects in aquatic organisms. Therefore, 28 d early-life stage studies were conducted on six pharmaceuticals to assess their impacts on survival and growth fathead minnow larvae. Two pharmaceuticals tested, carbamazepine and fenofibrate, resulted in no alterations to survival and growth. However, amiodarone, clozapine, dexamethasone, and levonorgestrel (LNG) reduced survival at concentrations tested with LNG being the most potent at 462 ng/L. Survival was increased with amiodarone and clozapine; however LNG significantly decreased growth at 86 ng/L. Therefore, the most potent pharmaceutical tested was the synthetic progestin LNG with survival and growth impacts at concentrations less than 1 μg/L. Further analysis was conducted by measuring specific endocrine related mRNA transcript profiles in FHM larvae following the 28 d ELS exposure to LNG. Transcripts of 3β-HSD, 20β-HSD, and FSH were significantly down-regulated following 28 d exposure to both 16.3 and 86.9 ng/L LNG. Also, CYP19a expression was significantly ...
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Enterprise Social Software: an Empirical Assessment of Knowledge Sharing in the Workplace

Enterprise Social Software: an Empirical Assessment of Knowledge Sharing in the Workplace

Date: August 2013
Creator: Harden, Gina
Description: Social software has become pervasive including technologies such as blogs, wikis, and social networking sites. Interactive Web 2.0 technology is distinguished from earlier Internet channels, with content provided not only from the website host, but also and most importantly, user-generated content. These social technologies are increasingly entering the enterprise, involving complex social and psychological aspects as well as an understanding of traditional technology acceptance factors. Organizations trying to reap potential benefits of enterprise social software (ESS) must successfully implement and maintain ESS tools. This research develops a framework for assessing knowledge sharing based on reciprocal determinism theory and augmented with technology acceptance, sociological, and psychological factors. Semi-structured interviews with IT professionals, followed by a written survey of employees using ESS are used to collect data. The hermeneutic circle methodology is used to analyze the interview transcripts and structural equation modeling is used to analyze the survey data. Results show technological advantage has no significant effect on the intention to share knowledge, but community cohesiveness and individual willingness significantly affect knowledge sharing intention and behavior. The study offers a synthesized model of variables affecting knowledge sharing as well as a better understanding of best practices for organizations to consider when implementing ...
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An Examination of Resnick's Model of Malingering: a Pai Study of Feigned Ptsd

An Examination of Resnick's Model of Malingering: a Pai Study of Feigned Ptsd

Date: August 2013
Creator: Wooley, Chelsea N.
Description: Malingered posttraumatic stress disorder (PTSD) poses a formidable clinical challenge in personal injury and disability cases because of the apparent ease in feigning PTSD and the supposed link (proximate cause) to the claimed damages. The effective assessment of feigned PTSD is particularly challenging because this diagnosis is both easier to fake than other Axis I disorders and more difficult to detect. As an additional confound, some patients with genuine PTSD produce highly variable, elevated profiles on multiscale inventories that are difficult to distinguish from feigned PTSD. The current study examined whether the Personality Assessment Inventory (PAI) can effectively differentiate between genuine and feigned PTSD in 109 inpatients from a trauma unit. The two most effective scales were the MAL and the NDS scales. As a primary focus, the current study was the first empirical investigation of Resnick's model of malingered PTSD that is comprised of three subtypes: pure malingering (pure-M), partial malingering (partial-M), and false imputation (false-I). The primary goal was to evaluate whether each feigning group was able to (a) effectively simulate PTSD symptoms and diagnoses and (b) avoid being classified as feigning. The partial-M group proved to be the best feigning group in achieving these two goals. Furthermore, ...
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An Examination of the Similarities and Differences Between Transformational and Authentic Leadership and Their Relationship to Followers' Outcomes

An Examination of the Similarities and Differences Between Transformational and Authentic Leadership and Their Relationship to Followers' Outcomes

Date: August 2013
Creator: McKee, Victoria
Description: To date there is no comprehensive understanding of what leadership is, nor is there an agreement among different theorists on what a good or effective leader should be. The purpose of this dissertation is to examine the theoretical and empirical similarities and differences of two styles of leadership – transformational and authentic leadership. Follower outcomes, as well as, the effects of trust and psychological capital within these paradigms are of particular interest. Although theoretical differences are proposed for the leadership style, the extent of overlap suggests the need to more closely examine each theory. Pilot studies were created to validate original scenarios created for the study as well as to examine the validity and reliability of new measurement instruments. The dissertation is designed to determine whether the relationships between authentic leadership and a variety of follower outcomes including performance, affective commitment, satisfaction, trust, and organizational citizenship behavior are similar to those between transformational leadership and these outcomes. In addition, variables more unique to authentic leadership research including psychological capital and follower well-being were examined within both paradigms to determine whether their relationships are similar to each type of leadership style. An experimental study using Qualtrics was used to collect the ...
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An Exploration of Teachers' Adoption of the Bring Your Own Technology Program

An Exploration of Teachers' Adoption of the Bring Your Own Technology Program

Date: August 2013
Creator: Cardoza, Yanet
Description: The purpose of this study was to explore teachers' concerns, use, and actual practices in their adoption of the bring your own technology (BYOT) initiative. Twelve secondary teachers in a private school setting participated in this study. The participants represented all content areas including reading, math, science, and electives. The private school was in its third year of implementing BYOT. This case study incorporated multiple methods to collect data to gain a better understanding of teachers' adoption of an innovation, BYOT. The concerns-based adoption model (CBAM) was used as a theoretical framework. All three CBAM tools provided data: the Stages of Concern Questionnaire (SoCQ), levels of use interview protocol (LoUIP), and the innovation configuration (IC) map. Twelve of the participants completed the SoCQ across three different points in time. Six of the twelve teachers participated in three one-on-one interviews, including the LoUIP. Additionally, six teachers were observed in their classrooms during instruction. After triangulating all pieces of data, the majority of teachers had highest concerns related to self. Teachers were concerned about their ability to implement the innovation and managing BYOT in their classroom. Four of the six teachers had a level of use (LoU) at mechanical, and two teachers ...
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