26 resultados para 29000


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A database containing the global and diffuse components of the surface solar hourly irradiation measured from 1 January 2004 to 31 December 2010 at eight stations of the Egyptian Meteorological Authority is presented. For three of these sites (Cairo, Aswan, and El-Farafra), the direct component is also available. In addition, a series of meteorological variables including surface pressure, relative humidity, temperature, wind speed and direction is provided at the same hourly resolution at all stations. The details of the experimental sites and instruments used for the acquisition are given. Special attention is paid to the quality of the data and the procedure applied to flag suspicious or erroneous measurements is described in details. Between 88 and 99% of the daytime measurements are validated by this quality control. Except at Barrani where the number is lower (13500), between 20000 and 29000 measurements of global and diffuse hourly irradiation are available at all sites for the 7-year period. Similarly, from 9000 to 13000 measurements of direct hourly irradiation values are provided for the three sites where this component is measured. With its high temporal resolution this consistent irradiation and meteorological database constitutes a reliable source to estimate the potential of solar energy in Egypt. It is also adapted to the study of high-frequency atmospheric processes such as the impact of aerosols on atmospheric radiative transfer. In the next future, it is planned to complete regularly the present 2004-2010 database.

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Esta tesis presenta un novedoso marco de referencia para el análisis y optimización del retardo de codificación y descodificación para vídeo multivista. El objetivo de este marco de referencia es proporcionar una metodología sistemática para el análisis del retardo en codificadores y descodificadores multivista y herramientas útiles en el diseño de codificadores/descodificadores para aplicaciones con requisitos de bajo retardo. El marco de referencia propuesto caracteriza primero los elementos que tienen influencia en el comportamiento del retardo: i) la estructura de predicción multivista, ii) el modelo hardware del codificador/descodificador y iii) los tiempos de proceso de cuadro. En segundo lugar, proporciona algoritmos para el cálculo del retardo de codificación/ descodificación de cualquier estructura arbitraria de predicción multivista. El núcleo de este marco de referencia consiste en una metodología para el análisis del retardo de codificación/descodificación multivista que es independiente de la arquitectura hardware del codificador/descodificador, completada con un conjunto de modelos que particularizan este análisis del retardo con las características de la arquitectura hardware del codificador/descodificador. Entre estos modelos, aquellos basados en teoría de grafos adquieren especial relevancia debido a su capacidad de desacoplar la influencia de los diferentes elementos en el comportamiento del retardo en el codificador/ descodificador, mediante una abstracción de su capacidad de proceso. Para revelar las posibles aplicaciones de este marco de referencia, esta tesis presenta algunos ejemplos de su utilización en problemas de diseño que afectan a codificadores y descodificadores multivista. Este escenario de aplicación cubre los siguientes casos: estrategias para el diseño de estructuras de predicción que tengan en consideración requisitos de retardo además del comportamiento tasa-distorsión; diseño del número de procesadores y análisis de los requisitos de velocidad de proceso en codificadores/ descodificadores multivista dado un retardo objetivo; y el análisis comparativo del comportamiento del retardo en codificadores multivista con diferentes capacidades de proceso e implementaciones hardware. ABSTRACT This thesis presents a novel framework for the analysis and optimization of the encoding and decoding delay for multiview video. The objective of this framework is to provide a systematic methodology for the analysis of the delay in multiview encoders and decoders and useful tools in the design of multiview encoders/decoders for applications with low delay requirements. The proposed framework characterizes firstly the elements that have an influence in the delay performance: i) the multiview prediction structure ii) the hardware model of the encoder/decoder and iii) frame processing times. Secondly, it provides algorithms for the computation of the encoding/decoding delay of any arbitrary multiview prediction structure. The core of this framework consists in a methodology for the analysis of the multiview encoding/decoding delay that is independent of the hardware architecture of the encoder/decoder, which is completed with a set of models that particularize this delay analysis with the characteristics of the hardware architecture of the encoder/decoder. Among these models, the ones based in graph theory acquire special relevance due to their capacity to detach the influence of the different elements in the delay performance of the encoder/decoder, by means of an abstraction of its processing capacity. To reveal possible applications of this framework, this thesis presents some examples of its utilization in design problems that affect multiview encoders and decoders. This application scenario covers the following cases: strategies for the design of prediction structures that take into consideration delay requirements in addition to the rate-distortion performance; design of number of processors and analysis of processor speed requirements in multiview encoders/decoders given a target delay; and comparative analysis of the encoding delay performance of multiview encoders with different processing capabilities and hardware implementations.

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Resumen de la historia de las teorías antropológicas.

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INTRODUCTION: Vascular endothelial growth factor (VEGF)-induced angiogenesis requires endothelial nitric oxide synthase (eNOS) activation, however, the mechanism is largely unknown. As nitric oxide(NO) inhibits endothelial proliferation to promote capillary formation (Am J Path,159:993-1008,2001) and p21WAF1 is an important cell cycle inhibitor, we hypothesised that eNOS-induced angiogenesis requires up regulation of p21WAF1. METHODS: Human and porcine endothelial cells were cultured on growth factor reduced Materigel for in vitro tube formation and in vivo angiogenesis was assessed by hind limb ligation ischemia model.Conversely, we propose that the cytoprotective enzyme, heme oxygenase-1(HO-1), may suppress p21WAF1 to limit angiogenesis. RESULTS: The expression of p21WAF1 was up regulated in porcine aorticenothelial cells stablely transfected with a constitutively activated form of eNOS (eNOSS1177D) as well as in HUVEC infected by adenovirus encoding eNOSS1177D. When these cells were plated on growth-factor reduced Matrigel (compaired to empty vector), they enhanced in vitro angiogenesis, which was inhibited following knockdown of p21WAF1. Furthermore, over expression of p21WAF1 led to increased tube formation while p21WAF1 knockdown abrogated vascular endothelial growth factor(VEGF) and fibroblast growth factor (FGF-2) mediated angiogenesis.Conversely, the cytoprotective enzyme, heme oxygenase-1 (HO-1) when over expressed decreased p21WAF1 expression and reduced VEGF, FGF-2 and eNOSS1177D-induced angiogenesis. CONCLUSIONS: These results demonstrate that eNOS-induced angiogenesis requires up regulation of p21WAF1/CIP1 wherease, induction of HO-1 will decrease the expression of p21WAF1/CIP1 to limit angiogenesisindicating that eNOS and HO-1 regulate angiogenesis via p21WAF1/CIP1 in adiametrically opposed manner and that p21WAF1/CIP1 appears to be a central regulator of angiogenesis that offers a new therapeutic target.

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App collusion refers to two or more apps working together to achieve a malicious goal that they otherwise would not be able to achieve individually. The permissions based security model (PBSM) for Android does not address this threat, as it is rather limited to mitigating risks due to individual apps. This paper presents a technique for assessing the threat of collusion for apps, which is a first step towards quantifying collusion risk, and allows us to narrow down to candidate apps for collusion, which is critical given the high volume of Android apps available. We present our empirical analysis using a classified corpus of over 29000 Android apps provided by Intel Security.