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Kalman Filtering Approach to Optimize OFDM Data Rate

Kalman Filtering Approach to Optimize OFDM Data Rate

Date: August 2011
Creator: Wunnava, Sashi Prabha
Description: This study is based on applying a non-linear mapping method, here the unscented Kalman filter; to estimate and optimize data rate resulting from the arrival rate having a Poisson distribution in an orthogonal frequency division multiplexing (OFDM) transmission system. OFDM is an emerging multi-carrier modulation scheme. With the growing need for quality of service in wireless communications, it is highly necessary to optimize resources in such a way that the overall performance of the system models should rise while keeping in mind the objective to achieve high data rate and efficient spectral methods in the near future. In this study, the results from the OFDM-TDMA transmission system have been used to apply cross-layer optimization between layers so as to treat different resources between layers simultaneously. The main controller manages the transmission of data between layers using the multicarrier modulation techniques. The unscented Kalman filter is used here to perform nonlinear mapping by estimating and optimizing the data rate, which result from the arrival rate having a Poisson distribution.
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Ruinous Pride: The Construction of the Scottish Military Identity, 1745-1918

Ruinous Pride: The Construction of the Scottish Military Identity, 1745-1918

Date: August 2011
Creator: Matheson, Calum Lister
Description: Following the failed Jacobite Rebellion of 1745-46 many Highlanders fought for the British Army in the Seven Years War and American Revolutionary War. Although these soldiers were primarily motivated by economic considerations, their experiences were romanticized after Waterloo and helped to create a new, unified Scottish martial identity. This militaristic narrative, reinforced throughout the nineteenth century, explains why Scots fought and died in disproportionately large numbers during the First World War.
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Molecular Basis of Plant Defense Against Aphids: Role of the Arabidopsis Thaliana PAD4 and MPL1 Genes

Molecular Basis of Plant Defense Against Aphids: Role of the Arabidopsis Thaliana PAD4 and MPL1 Genes

Date: August 2011
Creator: Louis, Joe
Description: Myzus persicae (Sülzer), commonly known as green peach aphid (GPA), utilizes its slender stylet to penetrate the plant tissues intercellularly and consume copious amounts of photoassimilates present in the phloem sap causing extensive damage to host plants. The compatible interaction between GPA and Arabidopsis thaliana enabled us to characterize plant response to aphid infestation. Upon GPA infestation, Arabidopsis PAD4 (PHYTOALEXIN DEFICIENT4) gene modulates premature leaf senescence, which is involved in the programmed degradation of cellular components and the export of nutrients out of the senescing leaf. Senescence mechanism is utilized by plants to limit aphid growth. In addition, PAD4 provides antixenosis (deters insect settling and feeding) and antibiosis (impair aphid fecundity) against GPA and adversely impact sieve element availability to GPA. Basal expression of PAD4 contributes to antibiosis, and the GPA-induced expression of PAD4 contributes to antixenosis. Mutation in the Arabidopsis stearoyl-ACP desaturase encoding SSI2 (suppressor of SALICYLIC ACID [SA] insensitivity2) gene that results in an accelerated cell death phenotype and dwarfing, also conferred heightened antibiosis to GPA. Results of this study indicate that PAD4 is required for the ssi2-mediated enhanced antibiosis to GPA. The PAD4 protein contains conserved Ser, Asp and His residues that form the catalytic triad of ...
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Genetic Analysis of Development and Behavior in Hypoxia and Cellular Characterization of Anoxia Induced Meiotic Prophase Arrest in Caenorhabditis Elegans

Genetic Analysis of Development and Behavior in Hypoxia and Cellular Characterization of Anoxia Induced Meiotic Prophase Arrest in Caenorhabditis Elegans

Date: August 2011
Creator: Little, Brent Ashley
Description: It was hypothesized that chronic hypoxia will affect various biological processes including developmental trajectory and behavior. To test this hypothesis, embryos were raised to adulthood in severe hypoxic environments (0.5% O2 or 1% O2, 22°C) and analyzed for survival rate, developmental progression, and altered behaviors. Wildtype hermaphrodites survive chronic hypoxia yet developmental trajectory is slowed. The hermaphrodites raised in chronic hypoxia had different phenotypes in comparison to the normoxic controls. First, hermaphrodites exposed to chronic hypoxia produced a significantly lower number of embryos and had a slight increase in male progeny. This suggests that chronic hypoxia exposure during development affects the germline. Second, animals raised in chronic hypoxia from embryos to young adults have a slight increase in lifespan when re-exposed to a normoxic environment, indicating that chronic hypoxia does not negatively decrease lifespan. Finally, hermaphrodites that were raised in hypoxia will lay the majority of their eggs on the area of the agar plate where the bacterial lawn is not present. This is in contrast to animals in normoxia, which lay the majority of their eggs on the bacterial lawn. One hypothesis for this hypoxia-induced egg-laying behavior is that the animal can sense microenvironments in hypoxia. To examine if ...
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Factors Influencing Post-adoptive Enterprise Resource Planning (ERP) Utilization

Factors Influencing Post-adoptive Enterprise Resource Planning (ERP) Utilization

Date: August 2011
Creator: McGinnis, Thomas C.
Description: Organizations expend a great deal of time, effort and money on the implementation of enterprise resource planning (ERP) systems. They are considered the price of entry for large organizations to do business. Yet the success rate of ERP systems is poor. IS literature suggests that one possible reason for this is the underutilization of these systems. Existing ERP literature is replete with research to improve ERP project implementation success; however, notably absent from these streams is the research that identifies how ERP systems are utilized by individuals or organizations. This dissertation posits that increased ERP utilization can result from increased software and business process understanding gained from both formal training and experiential interventions. New dimensions of system utilization (required vs. optional) are proposed. The purpose of this dissertation is to examine how these interventions impact ERP utilization. The results of this dissertation show that while software-training interventions are important to understanding, it is the business process training interventions that seem to provide the greater effect on understanding. This increased understanding positively affects utilization scenarios where a mixture (required vs. optional) of software features and business process tasks can be leveraged by end-users. The improved understanding of post-adoptive ERP utilization gained ...
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Tribological Improvements of Carbon-Carbon Composites by Infiltration of Atomic Layer Deposited Lubricious Nanostructured Ceramic Oxides

Tribological Improvements of Carbon-Carbon Composites by Infiltration of Atomic Layer Deposited Lubricious Nanostructured Ceramic Oxides

Date: August 2011
Creator: Mohseni, Hamidreza
Description: A number of investigators have reported enhancement in oxidation and wear resistant of carbon-carbon composites (CCC) in the presence of protective coating layers. However, application of a surface and subsurface coating system that can preserve its oxidation and wear resistance along with maintaining lubricity at high temperature remains unsolved. To this end, thermodynamically stable protective oxides (ZnO/Al2O3/ZrO2) have been deposited by atomic layer deposition (ALD) to infiltrate porous CCC and graphite foams in order to improve the thermal stability and wear resistance in low and high speed sliding contacts. Characterization of microstructural evolution was achieved by using energy dispersive x-ray spectroscopy (EDS) mapping in scanning electron microscope (SEM) coupled with focused ion beam (FIB), x-ray tomography, high resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM) and X-ray diffraction (XRD). Evaluation of the tribological properties of CCC coated with abovementioned ALD thin films were performed by employing low speed pure sliding tribometer and a high speed/frequency reciprocating rig to simulate the fretting wear behavior at ambient temperature and elevated temperatures of 400°C.It was determined with x-ray tomography imaging and EDS mapping that ALD ZnO/Al2O3/ZrO2 nanolaminates and baseline ZrO2 coatings exhibited excellent conformality and pore-filling capabilities down to ~100 μm ...
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Correlates of Post-Traumatic Stress Disorder and Disorder of Extreme Stress Not Otherwise Specified among Palestinian Child Ex-Detainees

Correlates of Post-Traumatic Stress Disorder and Disorder of Extreme Stress Not Otherwise Specified among Palestinian Child Ex-Detainees

Date: August 2011
Creator: Nabhan, Inshirah Nimer
Description: The objective of this study is to investigate the variations in the type of trauma (post-traumatic stress disorder (PTSD) and disorder of extreme stress not otherwise specified (DESNOS) resulting first from group membership, and second from variations in socioeconomic status, and last, from exposure to physical and psychological methods of interrogation due to imprisonment. I use a diverse sample of 202 child ex-detainees who served sentences in Israeli prisons and were 17 years of age or less at the time of arrest. Various regression techniques were utilized to determine the most parsimonious way to distinguish between the three groups in their trauma responses. The key finding in this study is that child refugee ex-detainees living in refugee camps, in general, did not report PTSD or DESNOS reactions compared to their counterparts. Continuing PTSD and DESNOS symptoms were more prevalent among the group of refugees living outside the camps. However, there is at least one finding that supported what I hypothesized: refugees living in camps were more likely to experience elevated levels of alterations in attention or consciousness (DESNOS2). For refugees in camps, the DESNOS absence tells us that the volatile childhood these children experienced was not associated with severe pathological ...
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A Pedagogical and Analytical Study of Dušan Bogdanović’s Polyrhythmic and Polymetric Studies for Guitar

A Pedagogical and Analytical Study of Dušan Bogdanović’s Polyrhythmic and Polymetric Studies for Guitar

Date: May 2011
Creator: Morey II, Michael J.
Description: Polymeter has been a relatively unexplored compositional technique of music of the Common Practice Period. Dušan Bogdanović’s Polyrhythmic and Polymetric Studies for Guitar is recognized in the guitar world as not only an important theoretical treatise, but also a benchmark for more advanced levels of improvisation. Currently, his treatise remains the best source for learning polymetric improvisation on the guitar. My personal contribution stems from the idea that multiple interpretations of thought processes and technical approaches are possible when learning to play polymeters on the guitar. The first section focuses on providing an alternative technical approach towards learning to play polymeters on the guitar by simplifying selected exercises in Bogdanović’s treatise from their original presentation, and demonstrating further possibilities as to how the exercises can be applied in a practical manner to improvisation. The second part reveals through analysis of the Concert Studies 1, 2, and 5 both his innovative improvisatory use of polymeter as a stylistic device, and his ties to traditional ideas of structure.
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The Roles Elementary School Counselors Perform in the Education of Students with Autism Spectrum Disorders

The Roles Elementary School Counselors Perform in the Education of Students with Autism Spectrum Disorders

Date: August 2011
Creator: Miller, Trube Cassandra
Description: This nation-wide study investigated elementary school counselors (ESC) self-reported: (a) professional background and training; (b) general knowledge of autism spectrum disorders (ASD); (c) attitudes towards ASD; and (d) roles performed with students identified with ASD. Also investigated was the predictive relationships between professional background, training, knowledge, and attitudes on roles (counseling, consultation, curriculum, and coordination) performed with students identified with ASD. Descriptive statistics were utilized to address professional background, training, knowledge, attitude and characteristics of ESC participants. These variables were also examined in relationship to the four role types. Multivariate analyses of variance (MANOVA) and Pearson’s correlation coefficients were used to test for significant relationships. A series of four multiple regression analyses predicting each of the total roles scores for counseling, consultation, curriculum, and coordination were also conducted. Results of the study suggest (a) ESC have limited training experiences of ASD, leading to self-education about this population of students, (b) ESC possess general knowledge about ASD, (c) overall, ESC have positive attitudes towards ASD, and (d) ESC perform all conceptualized roles in the education of students with ASD. Regression models revealed eight predictors found to influence roles: total knowledge, attitudes, geographic setting, U.S. region, years practiced, conference training, self-education, and ...
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Soil and Forest Variation by Topography and Succession Stages in the Greenbelt Corridor, Floodplain of the Elm Fork of the Trinity River, North Texas.

Soil and Forest Variation by Topography and Succession Stages in the Greenbelt Corridor, Floodplain of the Elm Fork of the Trinity River, North Texas.

Date: August 2011
Creator: Rijal, Rajan
Description: The Greenbelt Corridor (GBC), located in a floodplain of the Elm Fork of the Trinity River, contains patches of bottomland forest and serves as part of Lake Lewisville’s flood control backwaters. This study examines forest structure and composition in relation to topographic position and forest stage in the GBC. Thirty two plots were surveyed within various stage classes, topographic positions, and USDA soil types. Trees were identified and measured for height and DBH. Density, basal area, and importance value for each of species was calculated. Soil and vegetation were analyzed using ANOVA, Principal Component Analysis, Canonical Correlation, Canonical Correspondence Analysis and Cluster Analysis. Tests confirmed that calcium carbonate and pH show significant differences with topographic positions but not with forest stage. Potassium shows no significant difference with soil texture class. Sand shows a strong negative correlation with moisture, organic matter, organic carbon and negative correlation with calcium carbonate and potassium. Silt shows positive correlation with moisture, organic matter, organic carbon, and calcium carbonate. Clay shows strong positive correlation with moisture, organic matter and organic carbon but negative correlations with pH. Swamp privet is dominant tree types in wetland forest. Sugarberry cedar elm, green ash and American elm are widely distributed ...
Contributing Partner: UNT Libraries