Thesis (MSc (Mathematics))--University of Stellenbosch, 2006. / The main topic of this thesis is the construction of the algebraic geometric codes (Goppa codes), and their decoding by the list-decoding, which allows one to correct beyond half of the minimum distance. We also consider the list-decoding of the Reed–Solomon codes as they are subclass of the Goppa codes, and the determination of the parameters of the non primitive BCH codes. AMS Subject Classification: 4B05, 94B15, 94B35, 94B27, 11T71, 94B65,B70. Keywords: Linear codes, cyclic codes, BCH codes, Reed–Solomon codes, list-decoding, Algebraic Geometric codes, decoding, bound on codes, error probability.

abstract: With tremendous increase in the popularity of networked multimedia applications, video data is expected to account for a large portion of the traffic on the Internet and more importantly next-generation wireless systems. To be able to satisfy a broad range of customers requirements, two major problems need to be solved. The first problem is the need for a scalable representation of the input video. The recently developed scalable extension of the state-of-the art H.264/MPEG-4 AVC video coding standard, also known as H.264/SVC (Scalable Video Coding) provides a solution to this problem. The second problem is that wireless transmission medium typically introduce errors in the bit stream due to noise, congestion and fading on the channel. Protection against these channel impairments can be realized by the use of forward error correcting (FEC) codes. In this research study, the performance of scalable video coding in the presence of bit errors is studied. The encoded video is channel coded using Reed Solomon codes to provide acceptable performance in the presence of channel impairments. In the scalable bit stream, some parts of the bit stream are more important than other parts. Parity bytes are assigned to the video packets based on their importance in unequal error protection scheme. In equal error protection scheme, parity bytes are assigned based on the length of the message. A quantitative comparison of the two schemes, along with the case where no channel coding is employed is performed. H.264 SVC single layer video streams for long video sequences of different genres is considered in this study which serves as a means of effective video characterization. JSVM reference software, in its current version, does not support decoding of erroneous bit streams. A framework to obtain H.264 SVC compatible bit stream is modeled in this study. It is concluded that assigning of parity bytes based on the distribution of data for different types of frames provides optimum performance. Application of error protection to the bit stream enhances the quality of the decoded video with minimal overhead added to the bit stream. / Dissertation/Thesis / M.S. Electrical Engineering 2011

abstract: My dissertation project, Mormons at the World's Fair: A Study of Religious and Cultural Agency and Transformation looks at a pivotal period of transition within the American religious and political national culture (1880-1907). Using Mormonism as an important focal point of national controversy and cultural change, this dissertation looks at the interconnections between Mormon transitions and the larger national transformations then under way in what historians call the "progressive" era. Prominent scholars have recognized the 1893 World's Fair as an important moment that helped initiate the "dawning" of religious pluralism in America. This national response to American religious diversity, however, is limited to a nineteenth-century historiographical framework, which made real religious pluralism in the next century more difficult. Bringing together into one narrative the story of the anti-polygamy crusades of the 1880s, the ambivalent presence (and non presence) of Mormonism at the World's Fair of 1893, and the drawn-out US Senate Hearings and ultimate victory of Mormon apostle and Senator Reed Smoot in 1907, this dissertation offers new insights into the meaning and limitations of American religious liberty, the dynamics of minority agency, as well as a deeper understanding of America's developing national identity. / Dissertation/Thesis / Ph.D. Religious Studies 2012

The aim of this thesis was to find out the extent of the predation of the Eurasian Reed Warbler (Acrocephalus scirpaceus) during the laying period in the South Bohemian Region. The survey was done by means of artificial nests containing fake eggs. Additional goal of the thesis was to evaluate the factors that can influence the predation according to measured nest parameters, such as the distance of the artificial nest from free water surface, the depth of water below the nest and the distance from the nearest tree.

Thesis deals with renewables resources, potential of biomass and plants phytomass. We focused on the cultivation of selected energy crops, as perennial grasses Elymus elongatus (subsp. ponticus, cv. Szarvasi-1), reed canary grass, miscanthus sinensis and annual crops of maize and sorghum. The practical part is aimed to the establishment of small plot trials with a variety Szarvasi-1, reed canary grass and miscanthus. We described the methods of field experiment establishing with crop Szarvasi-1 of their treatment and harvest. The results of our own experiments we compared with the literature data. The last part deals with the economy of growing selected crops.

Submitted by André Luís Severino Abrego (andre-luis-severino@hotmail.com) on 2018-04-16T18:14:30Z No. of bitstreams: 1 Dissertation_Andre.pdf: 17535518 bytes, checksum: cb53444410befce5cbc54c52ebcb1a5d (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-04-16T19:13:50Z (GMT) No. of bitstreams: 1 abrego_als_me_ilha.pdf: 17535518 bytes, checksum: cb53444410befce5cbc54c52ebcb1a5d (MD5) / Made available in DSpace on 2018-04-16T19:13:50Z (GMT). No. of bitstreams: 1 abrego_als_me_ilha.pdf: 17535518 bytes, checksum: cb53444410befce5cbc54c52ebcb1a5d (MD5) Previous issue date: 2018-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A maioria dos sistemas de refrigeração por compressão de vapor de uso doméstico utilizam compressores alternativos com válvulas automáticas do tipo palheta para controlar os processos de sucção e descarga do fluido refrigerante. O ciclo de operação dessas válvulas é descrito por uma série de fenômenos complexos que ocorrem em um curto período de tempo. Grande parte das perdas responsáveis pela redução da eficiência do compressor é devido aos fenômenos físicos que ocorrem nessas válvulas, predominantemente devido a interação fluido-estrutura. Assim, o estudo dessa dinâmica é essencial quando o objetivo é aumentar a eficiência do compressor. Estudar o problema usando técnicas da Mecânica dos Fluidos Computacional permite encontrar solução de forma relativamente rápida. Porém, desenvolver uma metodologia confiável exige o estudo detalhado de vários aspectos que podem influenciar os resultados e, principalmente, exige a validação experimental. Neste trabalho, propomos avaliar alguns desses aspectos para verificar suas influências na validação da metodologia por meio de dados experimentais. Para isso, uma modelo de válvula tipo palheta em escala ampliada, muito usado como válvula de sucção, é testado experimentalmente e os resultados são usados para validar a metodologia numérica aplicada. A solução numérica do problema é realizada usando o código Ansys® CFX para a solução do escoamento do fluido e o código Ansys® Mechanical para a solução do problema estrutural da válvula. A solução do problema de interação fluido-estrutura é obtida usando uma metodologia particionada, na qual a discretização e a solução do problema nos domínios do sólido e do fluido são realizadas separadamente. Dados do deslocamento instantâneo da válvula são usados para estudar a influência de vários parâmetros adotados na solução numérica do problema. Os resultados mostram que o fator normal de rigidez, a força de pré-carga, a força de gravidade e a condição de contorno usada na solução do problema da estrutura, influenciam na solução do problema. / Most domestic vapor compressor refrigeration systems use reciprocating compressors with automatic reed type valves to control the suction and discharge processes of the refrigerant fluid. The operating cycle of these valves is described by a series of complex phenomena that occur in a short period of time. Most of the losses responsible for reducing the efficiency of the compressor are due to physical phenomena occurring in these valves, mainly due to the fluid-structure interaction. To study this problem is essential to improve the efficiency of the compressor. Performing this study by using Computational Fluid Dynamic methodologies allows relative fast solution of the problem. However, developing a reliable methodology requires detail study of several aspects that can influence the results and, mainly, requires the experimental validation. In this work, we propose to evaluate some of these aspects to verify their influence in the validation process of the numerical methodology through experimental data. Here, we experimentally test a large scale model of a reed type valve usually used as suction valve and the results are used to validate the numerical methodology. The numerical solution is obtained by using the Ansys® CFX code to solve the fluid flow and the Ansys® Mechanical code to solve the structural problem of the valve. In this methodology, we solve the fluid-structure interaction by using a segregated method in which the discretization and the solution of the problem in the solid and fluid domains are performed separately. Data for the instantaneous displacement of the valve are used to analyze the influence of several parameters applied to solve the problem. The results show that the stiffness normal factor, the preload force, the gravity force, and the boundary condition used to solve the structure of the valve, influence the numerical solution of the problem. / CNPq: 131150/2015-4.

Orientador: José Luiz Gasche / Resumo: A maioria dos sistemas de refrigeração por compressão de vapor de uso doméstico utilizam compressores alternativos com válvulas automáticas do tipo palheta para controlar os processos de sucção e descarga do fluido refrigerante. O ciclo de operação dessas válvulas é descrito por uma série de fenômenos complexos que ocorrem em um curto período de tempo. Grande parte das perdas responsáveis pela redução da eficiência do compressor é devido aos fenômenos físicos que ocorrem nessas válvulas, predominantemente devido a interação fluido-estrutura. Assim, o estudo dessa dinâmica é essencial quando o objetivo é aumentar a eficiência do compressor. Estudar o problema usando técnicas da Mecânica dos Fluidos Computacional permite encontrar solução de forma relativamente rápida. Porém, desenvolver uma metodologia confiável exige o estudo detalhado de vários aspectos que podem influenciar os resultados e, principalmente, exige a validação experimental. Neste trabalho, propomos avaliar alguns desses aspectos para verificar suas influências na validação da metodologia por meio de dados experimentais. Para isso, uma modelo de válvula tipo palheta em escala ampliada, muito usado como válvula de sucção, é testado experimentalmente e os resultados são usados para validar a metodologia numérica aplicada. A solução numérica do problema é realizada usando o código Ansys® CFX para a solução do escoamento do fluido e o código Ansys® Mechanical para a solução do problema estrutural da válvula. A solu... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Most domestic vapor compressor refrigeration systems use reciprocating compressors with automatic reed type valves to control the suction and discharge processes of the refrigerant fluid. The operating cycle of these valves is described by a series of complex phenomena that occur in a short period of time. Most of the losses responsible for reducing the efficiency of the compressor are due to physical phenomena occurring in these valves, mainly due to the fluid-structure interaction. To study this problem is essential to improve the efficiency of the compressor. Performing this study by using Computational Fluid Dynamic methodologies allows relative fast solution of the problem. However, developing a reliable methodology requires detail study of several aspects that can influence the results and, mainly, requires the experimental validation. In this work, we propose to evaluate some of these aspects to verify their influence in the validation process of the numerical methodology through experimental data. Here, we experimentally test a large scale model of a reed type valve usually used as suction valve and the results are used to validate the numerical methodology. The numerical solution is obtained by using the Ansys® CFX code to solve the fluid flow and the Ansys® Mechanical code to solve the structural problem of the valve. In this methodology, we solve the fluid-structure interaction by using a segregated method in which the discretization and the solution of the problem... (Complete abstract click electronic access below) / Mestre

Nach offiziellen Schätzungen sind weltweit derzeit rund drei Milliarden Geräte im Bereich der Kälte- und Klimatechnik im Einsatz. In diesen kommen vornehmlich Hubkolbenverdichter zum Einsatz. Entsprechend bergen die Auswirkungen selbst kleinster, energetischer Verbesserungen in der Summe ein enormes Einsparungspotential. Als essentieller und eng mit dem Gütegrad verknüpfter Bestandteil eines Verdichters nehmen die Ventile eine zentrale Rolle ein. Zu diesen kann dem Stand der Technik bereits eine Vielzahl numerischer und experimenteller Untersuchungen entnommen werden. Eine Literaturrecherche zeigte, dass im Laufe der analysierten 68 Jahre, zwar ein breites Spektrum an Messmethoden angewandt wurde, diese aber fast ausschließlich einen punktuellen Charakter besaßen. Hinsichtlich der im Bereich der Kälte- und Klimatechnik hauptsächlich eingesetzten Lamellenventile, deren Öffnungs- bzw. Schließvorgang keiner linearen Bewegungsfunktion entspricht, können daraus nur eingeschränkte Erkenntnisse gewonnen werden. Der Bedarf an einer experimentellen Validierung existierender Berechnungsmethoden bestand. Aus diesem Grund wird im Rahmen dieser Arbeit erstmals, unter Anwendung des Messverfahrens der Laserlinientriangulation, die Erfassung einer Reihe aufeinanderfolgender Abstandsinformationen durchgeführt. Die eingesetzte, optische Methode beeinflusst den Bewegungsvorgang der Lamelle demnach nicht. Hierzu ist an der Technische Universität Dresden ein Versuchsstand eingerichtet worden, der die Analyse der Bewegungsprofile einer Sauglamelle sowohl entlang als auch senkrecht zur neutralen Faser erlaubt. Dabei stellte sich heraus, dass die parallel mit einem marktseitig verfügbaren Simulationsprogramm durchgeführten Berechnungen, das Biegeverhalten bereits sehr gut abbilden. Bedingung hierfür ist jedoch die rechenintensive, zweiseitige Kopplung der Strukturmechanik von z. B. ANSYS Mechanical mit der Fluiddynamik von z. B. ANSYS CFX sowie der zielgerichteten Beeinflussung der Netzverformung. Doch weitere, gewinnbringende Erkenntnisse sind ableitbar. Insbesondere die Torsionsbewegung der Lamelle, deren messtechnische Untersuchung aufgrund ihrer Größenordnung herausfordernd ist, und deren Entstehung konnte somit untersucht werden. Weiterhin sind Versuche an einem Verdichterleistungsprüfstand mit dem Kältemittel R449A durchgeführt worden. Die hierfür notwendige Bewertung der Einflussgrößen zeigte eine Verwendbarkeit der Messmethode für sämtliche, in einer Kälteanlage auftretenden Zustände. Ferner konnte, als Parameter mit dem größten Einfluss auf die Messwerterfassung, das Öl identifiziert und quantifiziert werden. Solange das Laserlicht eine Schichtdicke von weniger als 1 mm durchdringen muss, ist das Verfahren verwendbar. Werte, die darüber liegen, erfordern eine zusätzliche Korrektur. Die abschließenden Vergleiche mit der numerischen Simulation zeigen eine gute Übereinstimmung und ermöglichen Einblicke auf die Belastung der Lamelle vom Hineindrücken in die Bohrung bis zum Anschlag an den Hubfänger.

The availability of feedback from the receiver to the transmitter in a communication system can play a significant role. In this dissertation, our focus is specifically on binary or one-bit feedback. First, we study the problem of successive beam alignment for millimeter-wave channels where the receiver sends back only one-bit of information per beam sounding. The sparse nature of the channel allows us to interpret channel sounding as a form of questioning. By posing the alignment problem as a questioning strategy, we describe adaptive (closed-loop) and non-adaptive (open-loop) channel sounding techniques which are robust to erroneous feedback signals caused by noisy quantization. In the second part, we tightly characterize the capacity for two binary stochastic-adversarial mixed noise channels. Specifically, the transmitter (Alice) intends to convey a message to the receiver (Bob) over a binary symmetric channel (BSC) or a binary erasure channel (BEC) in the presence of an adversary (Calvin) who injects additional noise at the channel's input subject to a budget constraint. Calvin is online or causal in that at any point during the transmission, he can infer the bits being sent by Alice and those being received by Bob via a feedback link. Finally in the third part, we study the applicability of binary feedback for encoding and propose the framework of linearly adapting block feedback codes. We also prove a new result for Reed-Muller (RM) codes to demonstrate how an uncoded system can mimic a RM code under this framework, against remarkably large feedback delays.

Arundo donax (Giant Reed) is quickly being developed as a rapidly-growing, robust, and highly productive bioenergy crop, with large scale cultivation of this species planned for the Columbia River basin of the Pacific Northwest (USA). Despite its potential as a next generation biomass crop, relatively few studies have examined the physiological performance of A. donax under agricultural conditions. Unlike traditional crops, A. donax is known to be a high-emitter of the volatile compound isoprene, which may significantly impact regional air quality, but it has not been widely cultivated in North America and little is known about how this species will perform in the Pacific Northwest. Over two field seasons, we measured isoprene fluxes from A. donax plants in both greenhouse conditions and in an agricultural field setting under a variety of conditions and fertilizer treatments. We also measured several other attributes of A. donax productivity and leaf physiology including chlorophyll content, photosynthesis rate, stomatal conductance, specific leaf mass, water use efficiency and gas exchange. We found that A. donax physiologically performs well under cultivation in the Columbia River basin, but that it also emits isoprene at significantly higher rates than previous reports indicate. We also found that both isoprene emission and leaf physiology were highly affected by agricultural management decisions, including nitrogen and irrigation management. Our findings indicate that crop management strategies can be developed that simultaneously seek to minimize isoprene emission while maximizing biomass production in this newly emerging bioenergy crop.