11 research outputs found

    Reduced complexity turbo equalization using a dynamic Bayesian network

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    It is proposed that a dynamic Bayesian network (DBN) is used to perform turbo equalization in a system transmitting information over a Rayleigh fading multipath channel. The DBN turbo equalizer (DBN-TE) is modeled on a single directed acyclic graph by relaxing the Markov assumption and allowing weak connections to past and future states. Its complexity is exponential in encoder constraint length and approximately linear in the channel memory length. Results show that the performance of the DBN-TE closely matches that of a traditional turbo equalizer that uses a maximum a posteriori equalizer and decoder pair. The DBN-TE achieves full convergence and near-optimal performance after small number of iterations.Additional file 1: DBN-TE Pseudocode algorithm. (a) DBN-TE function pseudocode. (b) FORWARD MESSAGE function pseudocode. (c) BACKWARD MESSAGE function pseudocode. (d) FORWARD BACKWARD MESSAGE function pseudocode. (e) LLR ESTIMATES function pseudocode.http://www.hindawi.com/journals/asp/am2013ai201

    History of clinical transplantation

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    How transplantation came to be a clinical discipline can be pieced together by perusing two volumes of reminiscences collected by Paul I. Terasaki in 1991-1992 from many of the persons who were directly involved. One volume was devoted to the discovery of the major histocompatibility complex (MHC), with particular reference to the human leukocyte antigens (HLAs) that are widely used today for tissue matching.1 The other focused on milestones in the development of clinical transplantation.2 All the contributions described in both volumes can be traced back in one way or other to the demonstration in the mid-1940s by Peter Brian Medawar that the rejection of allografts is an immunological phenomenon.3,4 © 2008 Springer New York

    A new evaluation function for face image enhancement in unconstrained environments using metaheuristic algorithms

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    Image enhancement is an integral component of face recognition systems and other image processing tasks such as in medical and satellite imaging. Among a number of existing image enhancement methods, metaheuristic-based approaches have gained popularity owing to their highly effective performance rates. However, the need for improved evaluation functions is a major research concern in the study of metaheuristic-based image enhancement methods. Thus, in this paper, we present a new evaluation function for improving the performance of metaheuristic-based image enhancement methods. Essentially, we applied our new evaluation function in conjunction with metaheuristic-based optimization algorithms in order to select automatically the best enhanced face image based on a linear combination of different key quantitative measures. Furthermore, different from other existing evaluation functions, our evaluation function is finitely bounded to determine easily whether an image is either too dark or too bright. This makes it better suited to find optimal solutions (best enhanced images) during the search process. Our method was compared with existing metaheuristic-based methods and other state-of-the-art image enhancement techniques. Based on the qualitative and quantitative measures obtained, our approach is shown to enhance facial images in unconstrained environments significantly.The Council for Scientific and Industrial Research (CSIR), South Africahttps://jivp-eurasipjournals.springeropen.comam2020Electrical, Electronic and Computer Engineerin

    Post-apartheid transition in a small South African town: interracial property transfer in Margate, KwaZulu-Natal

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    Post-apartheid transition in South Africa's small towns has received little attention. Using the South African Property Transfer Guide, 2500 residential transfers were analysed in Margate. Spatial and temporal patterns in Black house purchase were interpreted through discussions with key actors. The findings indicate the importance of micro-dynamics in determining specific post-apartheid transitions and confirm the relationship between racial employment profiles and housing markets. Black in-movement to previously White areas has focused on Extension 3, where private building of low-cost housing has occurred, but the area is now becoming resegregated. Whilst peripheral housing need not imply exclusion from services in small towns, unpaid mortgage bills and municipal rates have led to repossessions and affected the credit status of new Black buyers. <br/

    The relationship between blood lactate and survival following the use of adrenaline in the treatment of septic shock

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    This prospective observational study evaluates the relationship between adrenaline, lactate and intensive care unit survival in septic shock. Forty patients requiring adrenaline therapy for a first episode of septic shock acquired >24 hours after admission to the intensive care unit had blood lactate levels measured two-hourly over a 24-hour period. Adrenaline therapy was escalated until target mean arterial pressure was reached. The lactate index was calculated as the ratio of maximum lactate increase to the adrenaline increase. Lactate increased from 2.3 to 2.9 mmol.l (P=0.024) and the mean adrenaline increase was 0.14 μg.kg.minute. Peak lactate correlated with peak adrenaline (rho=0.34, P=0.032). Lactate index was the only independent predictor of survival after controlling for age and Acute Physiological and Chronic Health Evaluation II score (odds ratio 1.14, 95% confidence interval 1.03 to 1.26, P=0.009). A high lactate following adrenaline administration may be a beneficial and appropriate response

    Produção e qualidade da videira 'Superior Seedless' sob restrição hídrica na fase de maturação Production and quality of 'Superior Seedless' grapes under irrigation restrictions during berry maturation

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    O objetivo deste trabalho foi avaliar o efeito das condições de deficit hídrico, na fase de maturação da uva, sobre a produção e qualidade da uva 'Superior Seedless' entre julho e novembro de 2007. O experimento foi realizado em delineamento de blocos ao acaso, com quatro repetições, em arranjo fatorial (3x3) + 1: três épocas de alteração da aplicação das lâminas de irrigação (21, 13 e 5 dias antes da colheita); três lâminas de irrigação (100, 50 e 0% da evapotranspiração da cultura); e um tratamento controle (manejo de irrigação adotado pelo produtor). As épocas de irrigação e as lâminas de irrigação utilizadas influenciaram a firmeza das bagas e a acidez titulável. A interrupção da irrigação, aos 13 ou 21 dias antes da colheita, resultou em produtividade, qualidade de frutos e eficiência do uso da água semelhante às obtidas pelo produtor, assim, pode ser adotada para economia da água de irrigação na Região do Submédio do Vale do São Francisco.<br>The objective this work was to evaluate the effect of water deficit conditions, during the maturation phase of grapes, on the production and quality of the 'Superior Seedless', between July and November of 2007. The experiment was carried out in a randomized block design, with four replicates, in a (3x 3) + 1 factorial arrangement: three times of alteration of the irrigation depths (21, 13 e 5 days before harvest); three irrigation depths (100, 50 e 0% of crop evapotranspiration); and a control treatment, which was the producer's irrigation management scheme. Irrigation timing and depth influenced berry firmness and titrable acidity. The management with cut-off irrigation depths at 13 or 21 days before harvesting and the control had the same yield, grape quality and water use efficiency, and may be adopted to save water for irrigation in the São Francisco Valley region

    Advances in soil physics and soil water management research in South Africa, 1979–2003

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    Behavior of Flies in the Genus Ceratitis (Dacinae

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    Cerebral Vasospasm in Critically III Patients with Aneurysmal Subarachnoid Hemorrhage: Does the Evidence Support the Ever-Growing List of Potential Pharmacotherapy Interventions?

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