Recently, orthogonal frequency-division multiplexing (OFDM) has been adopted for high-speed wireless communications due to its robustness against multipath fading. However, one of the main fundamental drawbacks of OFDM systems is the high peak-to-average-power ratio (PAPR). Several techniques have been proposed for PAPR reduction. Most of these techniques require transmitter-based (pre-compensated) processing. On the other hand, receiver-based alternatives would save the power and reduce the transmitter complexity. By keeping this in mind, a possible approach is to limit the amplitude of the OFDM signal to a predetermined threshold and equivalently a sparse clipping signal is added. Then, estimating this clipping signal at the receiver to recover the original signal. In this work, we propose a Bayesian receiver-based low-complexity clipping signal recovery method for PAPR reduction. The method is able to i) effectively reduce the PAPR via simple clipping scheme at the transmitter side, ii) use Bayesian recovery algorithm to reconstruct the clipping signal at the receiver side by measuring part of subcarriers, iii) perform well in the absence of statistical information about the signal (e.g. clipping level) and the noise (e.g. noise variance), and at the same time iv is energy efficient due to its low complexity. Specifically, the proposed recovery technique is implemented in data-aided based. The data-aided method collects clipping information by measuring reliable 
data subcarriers, thus makes full use of spectrum for data transmission without the need for tone reservation. The study is extended further to discuss how to improve the recovery of the clipping signal utilizing some features of practical OFDM systems i.e., the oversampling and the presence of multiple receivers. Simulation results demonstrate the superiority of the proposed technique over other recovery algorithms. The overall objective is to show that the receiver-based Bayesian technique is highly recommended to be an effective and practical alternative to state-of-art PAPR reduction techniques.

Main goal of this dissertation is read over principal and properties of the OFDM modulation. Onward we become acquainted with basic methods for PAPR dynamics reduction in OFDM such as Clipping or Interleaving. Simulation of reduction methods will be realized in Scilab environment, in which are made basic functions for OFDM modulator and demodulator. Furthermore there are created functions for PAPR reduction methods. All established functions are implemented in the GUI.

The influence of agronomic practices on forage production and chemical composition of grass-legume pasture mixture was studied at the Utah State University Dairy Farm, North Logan, Utah, during spring and summer, 1970. The soil is a well-drained Millville silt loam that has about a 1 percent slope . It is high in potash, phosphorus, and lime, having a pH of 7.9. Analysis of the clipping management showed that the early spring clipping decreased the yield of forage. The losses in total yield due to spring clipping were approximately four to five times the yields received in early spring clipping. The grasses were affected more than the legumes. The yields of dry forage increased with the increase in fertilizer rates from 0 through 300 pounds of nitrogen per acre. There was no advantage to splitting the nitrogen fertilizer of 300 pounds per acre into three applications. Most of the effects of spring clipp1ng and nitrogen fertilization were re fleeted in the first summer harvest. The plots fertilized with nitrogen produced a higher yield and nitrate content than the check plots. Legumes were higher in nitrate on the unfertilized plots than the grasses, but lower on the fertilized plots.

No description available.

This work describes the development of an image processing algorithm, the implementation of that algorithm as both a strictly hardware design and as a multi-core software design, and the side-by-side comparison of the two implementations. In the course of creating the multi-core software design, several improvements are made to the OpenFire soft core micro-processor that is used to create the multi-core network. The hardware and multi-core software implementations of the image processing algorithm are compared side-by-side in an FPGA-based test platform. Results show that although the strictly hardware implementation leads in terms of lower power consumption and very low area consumption, modification of and programming for the multi-core software implementation is simpler to perform. / Master of Science

Made available in DSpace on 2016-08-03T12:31:00Z (GMT). No. of bitstreams: 1 Roni.pdf: 1747932 bytes, checksum: 43acd6a2ab25a724e73b6b088997f8c1 (MD5) Previous issue date: 2009-04-13 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Even though it has been implemented in Brazil in the 50's, the Television considered the most comprehensive and ideologically sweeping media among its public - faces its second major transformation: from an analog to a digital communication tool. That fact brings to light the new reception possibilities and the convergence of media. In this context, the objective of this study was to analyze the SBTVD-t s (Brazilian System of Digital Terrestrial Television) process of installation by using some online editions from the FNDC s (National Forum for Democratization of Communication) clipping. The analysis of that material concerned the investigation of tendentious characters in the FNDC s published material, which was geared to the technical aspects of the new technology rather than its social potential. Thus, a quantitative research technique basis was chosen to provide the information found in this thesis, leading to the finding that FNDC appears inefficiently when it comes to its critical posture facing the great media. It also showed that some of FNDC s goals weren t met since that forum only reproduces discourses and ideas from other communication vehicles. Similarly, it was found that the Brazilian Government didn t meet its SBTVD decrees either.(AU) / Implantada no Brasil na década de 50, a TV a mídia de maior abrangência e poder ideológico entre seus públicos encara sua segunda grande transformação: ela deixa de ser analógica e passa a ser digital. Com isso, traz à tona novas possibilidades de recepção e a possível convergência de meios. Nesse contexto, o objetivo deste estudo foi analisar o processo de instalação do Sistema Brasileiro de Televisão Digital Terrestre (SBTVD-t) a partir do clipping on-line do Fórum Nacional pela Democratização da Comunicação (FNDC). A análise desse material teve como foco averiguar se o FNDC foi tendencioso ou não na veiculação de matérias voltadas aos aspectos técnicos da nova tecnologia, em detrimento de seu potencial social. Para tanto, optou-se por uma pesquisa de base quantitativa em que as informações e os dados coletados levaram à constatação de que o FNDC se mostra pouco eficaz como aparato crítico-apreciativo da grande mídia, além de não cumprir alguns de seus objetivos ao reproduzir discursos e ideologias de outros veículos. Da mesma forma, verificou-se ainda que o Governo Federal também fugiu aos objetivos listados nos decretos presidenciais que instituem e dispõem sobre a implantação do SBTVD.(AU)

O presente trabalho teve o objetivo geral de estudar as respostas produtivas de capins do gênero Cynodon em resposta a estratégias de corte. O experimento foi conduzido no campus da ESALQ em Piracicaba, SP. Foram avaliados três cultivares, Tifton 85 e Jiggs (estabelecidos vegetativamente) e Vaquero (propagado por sementes) submetidos a três intervalos de corte, 14, 28 e 42 dias. O delineamento experimental foi completamente casualizado com arranjo fatorial completo. Foram medidas a produção de forragem, composição morfológica da forragem produzida, o índice de área foliar (IAF), a interceptação luminosa (IL) e altura do dossel. Foi feito também um estudo de análise de crescimento. Os cultivares Jiggs (22,6 Mg MS ha-1) e Tifton 85 (21,8 Mg MS ha-1) apresentaram os maiores acúmulos de forragem total na média das frequências de 28 e 42 dias de rebrotação. Na frequência de 14 dias de rebrotação, não houve diferença para o acúmulo total de forragem entre os cultivares com média de 13,3 Mg MS ha-1. A proporção de folhas, em média, foi maior nas frequências de 14 (69,6%) e 28 (55,2%) dias de colheita no verão. No inverno a proporção de folhas foi de 57,6% e 59,8% para as frequências de 14 e 28 dias de corte, respectivamente. Tifton 85 e Vaquero apresentaram maior porcentagem de folhas no verão, com médias de 63,3% e 56,0%, respectivamente. No inverno o Tifton 85 apresentou maior porcentagem de folha, com média de 63%. As frequências de 14 e 28 dias resultaram em maiores porcentagens de folha. O Jiggs apresentou maior porcentagem de colmo (46,7%) no verão e no inverno (40,0%). A frequência de 42 dias de corte no verão resultou em maior porcentagem de colmo (51,2%) e maior IAF no pré-corte (4,8). No inverno, a porcentagem de colmo (43,9%) e o IAF pré-corte (3,9) também foram maiores sob a frequência de 42 dias de colheita. A altura pré-corte no verão foi maior na frequência de 42 dias com média de 32,7 cm e o cultivar Jiggs foi o que apresentou maior altura pré-corte com média de 26, 5 cm nessa estação. A frequência de 28 dias de colheita no verão resultou em IL de 93,4%. A frequência de 42 dias de colheita gerou maior taxa de crescimento de cultura, TCC (30,9 g MS m-2 dia-1) no verão. Maior taxa de crescimento relativo, TCR, ocorreu nas frequências de 28 (0,26 g g1dia1) e 42 dias (0,32 g g1dia1) também no verão. No inverno, maior TCR foi medida na frequência de 28 dias (0,21 g g-1 dia-1). Maiores razão de área foliar, RAF, e razão de peso foliar, RPF, ocorreram na frequência de 28 dias no verão. Jiggs e Tifton 85 são os cultivares mais recomendados para produção de forragem e a frequência de desfolhação a cada 28 dias é a que garante melhor produção quando o objetivo é produzir massa de forragem com uma proporção maior de folhas. / The objectives in this study were to investigate the productive responses of Cynodon grasses to a range of defoliation strategies. The field trial was conducted at ESALQ-USP in Piracicaba, SP, Brazil. Three commercial Cynodon cultivars (Tifton 85 and Jiggs, vegetatively propagated; and Vaquero, a seeded type) were mechanically harvested every 14, 28, and 42 days under a completely randomized design in a complete factorial arrangement with four replicates. Responses measured included forage accumulation (yield), plant-part composition in the accumulated forage, leaf area index (LAI), sward light interception (LI), and sward height. A classical growth analysis study was also carried in the same field plots. Jiggs (22.6 Mg DM ha-1) and Tifton 85 (21.8 Mg DM ha-1) were the highest yielding materials under the 28- and 42-d schedules. Under the 14-d frequency, total forage accumulation did not differ among cultivars, averaging 13.3 Mg DM ha-1. On average, leaf percentage in the accumulated forage was higher in plots clipped every 14 (69.6%) and 28 (55.2%) days. In the cool-dry season, with irrigation, leaf percentage in the harvested forage was 57.6 and 59.8% in plots harvested every 14 and 28 days, respectively. Tifton 85 and Vaquero forage had more percent leaves in the warm-rainy season (63.3 and 56 %, respectively). In the cool season, Tifton 85 forage was leafier, at 63%. The 14- and the 28-d harvest schedules resulted in leafier forage. Jiggs forage had more % stem both in the warm (46.7) and in the cool (40) seasons. The 42-d harvest schedule resulted in highest stem percentage (51.2%) but also higher LAI (4.8) at harvest during the warm season. In the cool season, stem percentage (43.9%) and LAI at harvest (3.9) were also highest in plots clipped every 42 days. Sward height at harvest during the warm season was greater in plots clipped every 42 days, averaging 32.7 cm, with Jiggs being the tallest grass in the warm season, on average (26.5 cm). The 28-d schedule resulted in mean sward LI of 93.4 % on average. Crop growth rate (CGR) was highest (30.9 g DM m-2 d-1) under the 42-d frequency in the warm season. Higher warm-season relative growth rates (RGR) were registered under the 28- and the 42-d schedule (0.26 and 0.32 g g-1d-1, respectively). In the cool season, the highest RGR (021 g g-1 d-1) was measured under the 28-d schedule. The highest leaf area ratio (LAR) and leaf weight ratio (LWR) were measured in the 28-d treatment during the warm-season. Jiggs and Tifton 85 are recommended for their high yield potential under a 28-d harvest schedule, which ensures the production of leafy forage.

O presente trabalho teve o objetivo geral de estudar as respostas produtivas de capins do gênero Cynodon em resposta a estratégias de corte. O experimento foi conduzido no campus da ESALQ em Piracicaba, SP. Foram avaliados três cultivares, Tifton 85 e Jiggs (estabelecidos vegetativamente) e Vaquero (propagado por sementes) submetidos a três intervalos de corte, 14, 28 e 42 dias. O delineamento experimental foi completamente casualizado com arranjo fatorial completo. Foram medidas a produção de forragem, composição morfológica da forragem produzida, o índice de área foliar (IAF), a interceptação luminosa (IL) e altura do dossel. Foi feito também um estudo de análise de crescimento. Os cultivares Jiggs (22,6 Mg MS ha-1) e Tifton 85 (21,8 Mg MS ha-1) apresentaram os maiores acúmulos de forragem total na média das frequências de 28 e 42 dias de rebrotação. Na frequência de 14 dias de rebrotação, não houve diferença para o acúmulo total de forragem entre os cultivares com média de 13,3 Mg MS ha-1. A proporção de folhas, em média, foi maior nas frequências de 14 (69,6%) e 28 (55,2%) dias de colheita no verão. No inverno a proporção de folhas foi de 57,6% e 59,8% para as frequências de 14 e 28 dias de corte, respectivamente. Tifton 85 e Vaquero apresentaram maior porcentagem de folhas no verão, com médias de 63,3% e 56,0%, respectivamente. No inverno o Tifton 85 apresentou maior porcentagem de folha, com média de 63%. As frequências de 14 e 28 dias resultaram em maiores porcentagens de folha. O Jiggs apresentou maior porcentagem de colmo (46,7%) no verão e no inverno (40,0%). A frequência de 42 dias de corte no verão resultou em maior porcentagem de colmo (51,2%) e maior IAF no pré-corte (4,8). No inverno, a porcentagem de colmo (43,9%) e o IAF pré-corte (3,9) também foram maiores sob a frequência de 42 dias de colheita. A altura pré-corte no verão foi maior na frequência de 42 dias com média de 32,7 cm e o cultivar Jiggs foi o que apresentou maior altura pré-corte com média de 26, 5 cm nessa estação. A frequência de 28 dias de colheita no verão resultou em IL de 93,4%. A frequência de 42 dias de colheita gerou maior taxa de crescimento de cultura, TCC (30,9 g MS m-2 dia-1) no verão. Maior taxa de crescimento relativo, TCR, ocorreu nas frequências de 28 (0,26 g g1dia1) e 42 dias (0,32 g g1dia1) também no verão. No inverno, maior TCR foi medida na frequência de 28 dias (0,21 g g-1 dia-1). Maiores razão de área foliar, RAF, e razão de peso foliar, RPF, ocorreram na frequência de 28 dias no verão. Jiggs e Tifton 85 são os cultivares mais recomendados para produção de forragem e a frequência de desfolhação a cada 28 dias é a que garante melhor produção quando o objetivo é produzir massa de forragem com uma proporção maior de folhas. / The objectives in this study were to investigate the productive responses of Cynodon grasses to a range of defoliation strategies. The field trial was conducted at ESALQ-USP in Piracicaba, SP, Brazil. Three commercial Cynodon cultivars (Tifton 85 and Jiggs, vegetatively propagated; and Vaquero, a seeded type) were mechanically harvested every 14, 28, and 42 days under a completely randomized design in a complete factorial arrangement with four replicates. Responses measured included forage accumulation (yield), plant-part composition in the accumulated forage, leaf area index (LAI), sward light interception (LI), and sward height. A classical growth analysis study was also carried in the same field plots. Jiggs (22.6 Mg DM ha-1) and Tifton 85 (21.8 Mg DM ha-1) were the highest yielding materials under the 28- and 42-d schedules. Under the 14-d frequency, total forage accumulation did not differ among cultivars, averaging 13.3 Mg DM ha-1. On average, leaf percentage in the accumulated forage was higher in plots clipped every 14 (69.6%) and 28 (55.2%) days. In the cool-dry season, with irrigation, leaf percentage in the harvested forage was 57.6 and 59.8% in plots harvested every 14 and 28 days, respectively. Tifton 85 and Vaquero forage had more percent leaves in the warm-rainy season (63.3 and 56 %, respectively). In the cool season, Tifton 85 forage was leafier, at 63%. The 14- and the 28-d harvest schedules resulted in leafier forage. Jiggs forage had more % stem both in the warm (46.7) and in the cool (40) seasons. The 42-d harvest schedule resulted in highest stem percentage (51.2%) but also higher LAI (4.8) at harvest during the warm season. In the cool season, stem percentage (43.9%) and LAI at harvest (3.9) were also highest in plots clipped every 42 days. Sward height at harvest during the warm season was greater in plots clipped every 42 days, averaging 32.7 cm, with Jiggs being the tallest grass in the warm season, on average (26.5 cm). The 28-d schedule resulted in mean sward LI of 93.4 % on average. Crop growth rate (CGR) was highest (30.9 g DM m-2 d-1) under the 42-d frequency in the warm season. Higher warm-season relative growth rates (RGR) were registered under the 28- and the 42-d schedule (0.26 and 0.32 g g-1d-1, respectively). In the cool season, the highest RGR (021 g g-1 d-1) was measured under the 28-d schedule. The highest leaf area ratio (LAR) and leaf weight ratio (LWR) were measured in the 28-d treatment during the warm-season. Jiggs and Tifton 85 are recommended for their high yield potential under a 28-d harvest schedule, which ensures the production of leafy forage.

A diversificação de pastagens em conjunto com menor dependência de insumos de alta energia, como a adubação mineral em sistemas de produção de forragem é uma alternativa promissora para o desenvolvimento dessa indústria. No entanto, a falta de informações sobre as características morfológicas e fisiológicas de muitas forrageiras promissoras, tais como as leguminosas, limita a utilização racional e gestão adequada deste recurso. Estudos morfológicos, fisiológicos e características agronômicas de leguminosas forrageiras são importantes para caracterizar seus padrões de crescimento, bem como para descrever o seu desenvolvimento e produção. A fim de estabelecer uma base para o uso de cultivares de amendoim forrageiro e verificar a adaptação e o potencial destes materiais para as condições Sudeste do Brasil, este estudo foi elaborado para descrever e explicar a morfologia, fisiologia e respostas agronômicas, bem como características estruturais do pasto e valor nutritivo da forragem de quatro genótipos de amendoim forrageiro (Arachis pintoi (Krapov. & WC Gregory) submetidos a duas frequências de corte. O estudo foi realizado em Piracicaba, São Paulo, Brasil. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 4x2 (cultivares Mandobi, Amarillo, Belmonte, e Alqueire-1, colhidas a cada 28 ou 42 dias a 10 cm), com três repetições, totalizando 24 unidades experimentais. As variáveis medidas incluíram a produção de forragem, atributos estruturais do dossel, incluindo altura, índice de área foliar, interceptação luminosa, composição morfológica e valor nutritivo. O acúmulo total de forragem na estação (5,8 Mg MS ha-1) e taxa de acúmulo (52 kg MS ha-1 dia-1) foram maiores sob o cronograma de colheita de 28 dias. A cultivar Belmonte apresentou a maior produtividade (8,1 Mg MS ha-1) e taxa de acúmulo (69 kg MS ha-1 d-1) de todos os genótipos. O IAF médio na pré-colheita (4,5) e interceptação luminosa (97%) não variou em resposta à frequência de colheita. A concentração de proteína bruta da forragem foi maior aos 28 dias (253 g kg-1) e a cultivar Belmonte apresentou maiores concentrações (265 g kg-1) do que Mandobi e Amarillo. As concentrações de fibra em detergente neutro (FDN) não variaram com a frequência de colheita nem cultivar Belmonte apresentou maior concentração de FDN (369 g kg-1) do que Alqueire-1 (337 g kg-1). A produção de folhas e pecíolos não variou em função da frequência de colheita e Belmonte teve a maior produção de folhas (6,0 Mg MS ha-1) e pecíolos (2,6 Mg MS ha-1). Belmonte teve melhor desempenho agronômico com maior interceptação de luz e IAF, resultando em maior acúmulo total de forragem. A produção total de forragem foi maior em frequências de corte menores e a cultivar Belmonte obteve maior produção e taxa de acúmulo de forragem. A maturidade do amendoim forrageiro afetou valor nutritivo da forragem aos 28 dias de frequência de corte, resultando em melhor forragem. / The diversification of pastures together with lower dependence on high energy inputs such as mineral fertilization in forage-livestock systems is a promising alternative in the development of this industry. However, the lack of information on morphological and physiological characteristics of many promising forages such as legumes limits the rational utilization and adequate management of this resource. Studies morphological, physiological, and agronomic characteristics of forage legumes are important to characterize their growth patterns as well as to describe their growth, development and production. In order to establish a basis for the use of forage peanut genotypes and to ascertain the adaptation and the potential of these materials to the southeastern conditions of Brazil, this study was devised to describe and explain the morphological, physiological, and agronomic responses as well as the sward structural characteristics, and forage nutritive value of four forage peanut (Arachis pintoi (Krapov. & W.C. Gregory) genotypes submitted to two harvest frequencies. The study was conducted in Piracicaba, São Paulo, Brazil. The experimental design was completely randomized in a 4x2 factorial design (genotypes Mandobi, Amarillo, Belmonte, and Alqueire-1, harvested every 28 or 42 days at 10 cm), with three replications, totalling 24 experimental units. Responses measured included forage yield, canopy structural attributes, including height, leaf area index, light interception and plant-part composition and nutritive value. Total warm-season forage accumulation production (5,8 Mg MS ha-1) and accumulation rate (52 kg DM ha-1 d-1) were higher under the 28-d harvest schedule. The Belmonte cultivar showed the highest yield (8,1 Mg MS ha-1) and accumulation rate (69 kg DM ha-1 d-1) of all genotypes. The mean pre-harvest LAI (4,5) and light interception (97%) did not vary in response to harvest frequency. The forage crude protein concentration was higher at 28 days (253 g kg-1) and cultivar Belmonte forage had higher concentrations (265 g kg-1) than Mandobi and Amarillo. The concentrations of neutral detergent fiber did not vary with harvest frequency and Belmonte forage had higher NDF (369 g kg-1) than Alqueire-1 (337 g kg-1). Production of leaves and petioles did not vary as a function of harvest frequency, and Belmonte had the highest yield of leaves (6,0 Mg MS ha-1) and petioles (2,6 Mg MS ha-1). Belmonte had better agronomic performance with higher light interception andLAI, resulting in higher total forage accumulation. Harvest frequency impact yield characteristics and can modify sward architecture. Plant maturity affected forage nutritive value, with the 28-d schedule resulting in better forage.,

Subarachnoid hemorrhage (SAH) is a disease with high risk of mortality and morbidity. Elderly patients have an even higher risk of poor outcome. The incidence of SAH increases with age and the elderly constitute a substantial and increasing proportion of the population. Thus, the management of elderly SAH patients is an imminent clinical challenge. Time trends in clinical management and outcome were investigated in 281 SAH patients aged ≥65 years admitted over an 18-year period. The volume of elderly patients, especially patients ≥70 years and patients in worse clinical condition increased over time. The proportion of patients with favorable outcome increased over time, without an increase in severely disabled patients. Technical results and clinical outcome of endovascular aneurysm treatment (EVT) was investigated in 62 elderly SAH patients. EVT can be performed in elderly SAH patients with high technical success, acceptable aneurysm occlusion degree, acceptable procedural complication rate, and fair outcome results. EVT was compared to neurosurgical clipping (NST) in 278 elderly SAH patients in the International Subarachnoid Aneurysm Trial. In good grade elderly SAH patients, EVT should probably be the favored treatment for internal carotid and posterior communicating artery aneurysms, while elderly patients with middle cerebral artery aneurysms appear to benefit from NST. Occurrence of secondary insults and their impact on clinical deterioration were studied in 99 patients with severe SAH. High intracranial pressure increased and high cerebral perfusion pressure decreased the risk of clinical deterioration. Elderly patients had less intracranial hypertension insults and more hypertensive, hypotensive and hypoxemic insults. Good outcome was achieved in 24% of elderly patients with severe SAH, and the proportion of severe disability was similar to that of younger patients. Patient age was not a significant predictor for vasospasm in 413 SAH patients when admission and treatment variables were adjusted for with multiple logistic regression.