996 resultados para export operation methods


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AIM: To study prospectively patients after heart transplantation with respect to quality of life, mortality, morbidity, and clinical parameters before and up to 10 years after the operation. METHODS: Sixty patients (47.9 +/- 10.9 years, 57 men, 3 women) were transplanted at the University of Vienna Hospital, Department for Heart and Thorax Surgery and were included in this study. They were assessed when set on the waiting list, then exactly one, 5 and 10 years after the transplantation. The variables evaluated included physical and emotional complaints, well-being, mortality and morbidity. In the sample of patients who survived 10 years (n = 23), morbidity (infections, malignancies, graft arteriosclerosis, and rejection episodes) as well as quality of life were evaluated. RESULTS: Actuarial survival rates were 83.3, 66.7, 48.3% at 1, 5, and 10 years after transplantation, respectively. During the first year, infections were the most important reasons for premature death. As a cause of mortality, malignancies were found between years 1 and 5, and graft arteriosclerosis between years 5 and 10. Physical complaints diminished significantly after the operation, but grew significantly during the period from 5 to 10 years (p < 0.001). However, trembling (p < 0.05) and paraesthesies (p < 0.01) diminished continuously. Emotional complaints such as depression and dysphoria (both p < 0.05) increased until the tenth year after their nadir at year 1. In long-time survivors, 3 malignancies (lung, skin, thyroidea) were diagnosed 6 to 9 years postoperatively. Three patients (13%) had signs of graft arteriosclerosis at year 10; 9 (40%) patients suffered from rejection episodes during the course of 10 years. There were no serious rejection episodes deserving immediate therapy. Quality of life at 10 years is good in these patients. CONCLUSIONS: Heart transplantation is a successful therapy for patients with terminal heart disease. Long-term survivors feel well after 10 years and report a good quality of life.

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Las redes de sensores inalámbricas son uno de los sectores con más crecimiento dentro de las redes inalámbricas. La rápida adopción de estas redes como solución para muchas nuevas aplicaciones ha llevado a un creciente tráfico en el espectro radioeléctrico. Debido a que las redes inalámbricas de sensores operan en las bandas libres Industrial, Scientific and Medical (ISM) se ha producido una saturación del espectro que en pocos años no permitirá un buen funcionamiento. Con el objetivo de solucionar este tipo de problemas ha aparecido el paradigma de Radio Cognitiva (CR). La introducción de las capacidades cognitivas en las redes inalámbricas de sensores permite utilizar estas redes para aplicaciones con unos requisitos más estrictos respecto a fiabilidad, cobertura o calidad de servicio. Estas redes que aúnan todas estas características son llamadas redes de sensores inalámbricas cognitivas (CWSNs). La mejora en prestaciones de las CWSNs permite su utilización en aplicaciones críticas donde antes no podían ser utilizadas como monitorización de estructuras, de servicios médicos, en entornos militares o de vigilancia. Sin embargo, estas aplicaciones también requieren de otras características que la radio cognitiva no nos ofrece directamente como, por ejemplo, la seguridad. La seguridad en CWSNs es un aspecto poco desarrollado al ser una característica no esencial para su funcionamiento, como pueden serlo el sensado del espectro o la colaboración. Sin embargo, su estudio y mejora es esencial de cara al crecimiento de las CWSNs. Por tanto, esta tesis tiene como objetivo implementar contramedidas usando las nuevas capacidades cognitivas, especialmente en la capa física, teniendo en cuenta las limitaciones con las que cuentan las WSNs. En el ciclo de trabajo de esta tesis se han desarrollado dos estrategias de seguridad contra ataques de especial importancia en redes cognitivas: el ataque de simulación de usuario primario (PUE) y el ataque contra la privacidad eavesdropping. Para mitigar el ataque PUE se ha desarrollado una contramedida basada en la detección de anomalías. Se han implementado dos algoritmos diferentes para detectar este ataque: el algoritmo de Cumulative Sum y el algoritmo de Data Clustering. Una vez comprobado su validez se han comparado entre sí y se han investigado los efectos que pueden afectar al funcionamiento de los mismos. Para combatir el ataque de eavesdropping se ha desarrollado una contramedida basada en la inyección de ruido artificial de manera que el atacante no distinga las señales con información del ruido sin verse afectada la comunicación que nos interesa. También se ha estudiado el impacto que tiene esta contramedida en los recursos de la red. Como resultado paralelo se ha desarrollado un marco de pruebas para CWSNs que consta de un simulador y de una red de nodos cognitivos reales. Estas herramientas han sido esenciales para la implementación y extracción de resultados de la tesis. ABSTRACT Wireless Sensor Networks (WSNs) are one of the fastest growing sectors in wireless networks. The fast introduction of these networks as a solution in many new applications has increased the traffic in the radio spectrum. Due to the operation of WSNs in the free industrial, scientific, and medical (ISM) bands, saturation has ocurred in these frequencies that will make the same operation methods impossible in the future. Cognitive radio (CR) has appeared as a solution for this problem. The networks that join all the mentioned features together are called cognitive wireless sensor networks (CWSNs). The adoption of cognitive features in WSNs allows the use of these networks in applications with higher reliability, coverage, or quality of service requirements. The improvement of the performance of CWSNs allows their use in critical applications where they could not be used before such as structural monitoring, medical care, military scenarios, or security monitoring systems. Nevertheless, these applications also need other features that cognitive radio does not add directly, such as security. The security in CWSNs has not yet been explored fully because it is not necessary field for the main performance of these networks. Instead, other fields like spectrum sensing or collaboration have been explored deeply. However, the study of security in CWSNs is essential for their growth. Therefore, the main objective of this thesis is to study the impact of some cognitive radio attacks in CWSNs and to implement countermeasures using new cognitive capabilities, especially in the physical layer and considering the limitations of WSNs. Inside the work cycle of this thesis, security strategies against two important kinds of attacks in cognitive networks have been developed. These attacks are the primary user emulator (PUE) attack and the eavesdropping attack. A countermeasure against the PUE attack based on anomaly detection has been developed. Two different algorithms have been implemented: the cumulative sum algorithm and the data clustering algorithm. After the verification of these solutions, they have been compared and the side effects that can disturb their performance have been analyzed. The developed approach against the eavesdropping attack is based on the generation of artificial noise to conceal information messages. The impact of this countermeasure on network resources has also been studied. As a parallel result, a new framework for CWSNs has been developed. This includes a simulator and a real network with cognitive nodes. This framework has been crucial for the implementation and extraction of the results presented in this thesis.

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In this paper a new technique for partial product reduction based on the use of look-up tables for efficient processing is presented. We describe how to construct counter devices with pre-calculated data and their subsequent integration into the whole operation. The development of reduction trees organizations for this kind of devices uses the inherent integration benefits of computer memories and offers an alternative implementation to classic operation methods. Therefore, in our experiments we compare our implementation model with CMOS technology model in homogeneous terms.

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Introdução e objetivo: Atualmente as Instituições Particulares de Solidariedade Social deparam-se com mudanças de caracter social, económico e legislativo, que têm afetado o seu funcionamento e financiamento. Pelo que, impõe-se às suas direções responder às necessidades sociais com maior responsabilidade e eficiência num contexto de maior escassez de recursos. Neste sentido, o presente estudo tem como objetivo compreender o modo como as Instituições Particulares de Solidariedade Social tomam decisões, ao nível do financiamento, para um funcionamento eficiente das mesmas. Metodologia: Optou-se por realizar estudos de caso com uma amostra constituída por quatro Instituições Particulares de Solidariedade Social. A recolha de dados foi feita através de entrevistas semiestruturadas e análise documental. O tratamento de dados foi feito através de análise de conteúdo e com recurso ao software QRS Nvivo versão 10. Resultados: Os principais resultados indicam que: a) as necessidades sociais influenciam decisões de aumento e diminuição da capacidade de respostas das instituições; b) o sistema legal influencia a perpetuação de intervenções de caracter institucional; c) a conjuntura económica influencia a pressão sobre o preço da comparticipação familiar e o aumento da concorrência entre instituições; d) a escassez de recursos constitui-se como denominador comum entre instituições, influenciando decisões de investimento que assumem o financiamento público como um facto consumado; e) as práticas de liderança e gestão desenvolvidas por direções com elementos que têm conhecimentos na área financeira são mais propensas a assumir o risco e a aumentar a complexidade operativa das instituições f) as práticas de envolvimento de stakeholders internos e externos contribuem para a aquisição de apoio na prossecução dos seus objetivos. Conclusão: As tomadas de decisão das instituições com acordos com a segurança social assemelham-se por prevalecer o desenvolvimento de respostas tipificadas, com acordo com a segurança social. Apesar disso, os resultados evidenciam a importância de práticas de liderança e gestão desenvolvidas com a presença de elementos com conhecimentos na área financeira, para o desenvolvimento de respostas tipificadas com rentabilidade económica. Salienta-se ainda que o desenvolvimento de práticas de envolvimento de stakeholders internos e externos, baseados na responsabilização e transparência, promovem o alcance de apoios para assegurar o desenvolvimento das atividades institucionais, com maior incidência na instituição sem acordos com a segurança social, mas que os mesmos não asseguram a sua eficiência económica.

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Introduction. The energy sector, especially with regard to the gas trade, is one of the key areas of co-operation between the EU and Russia. However, the form this co-operation has taken has been giving rise to some concern, both in Brussels and in the EU member states. Questions arise as to whether the EU has not become excessively dependent on Russia for energy, and whether the presence of the Russian gas monopoly in the EU does not enable Russian interference with the development of EU energy policy. The objective of this series of OSW reports (for the previous edition,see Gazprom’s expansion in the EU: co-operation or domination? April 2008 – pdf 1.2 MB) is to provide facts which will permit an accurat answer to these questions to be formulated. Over the course of last year, two new factors strongly affected Gazprom’s capability to operate on the EU market. One was the ongoing global economic crisis, which has depressed demand for gas both in Russia and in Europe. Gazprom has cut both its own production and the quantities of gas it purchases from the Central Asian states, and the decrease in export revenues has forced the company to modify some of its current investment plans. Less demand for gas and the need to reduce production are also having a positive impact – the Russian company is likely to avoid the difficulties in meeting all of its export commitments which, only a year or so ago, it was expected to experience. The other factor affecting Gazprom’s expansion in Europe is the observed radicalisation of the rhetoric and actions of both the company itself and of the Russian authorities with regard to the gas sector as broadly understood. The gas crisis between Russia and Ukraine in January 2009, which resulted in a two-week interruption of gas supplies from Russia to Europe via Ukraine, was the most prominent example of this radicalisation. The hardening of rhetoric in the ongoing energy talks with the EU and other actors, and increased political and business activities designed to promote Russian gas interests in Europe, in particular the lobbying for the Nord Stream and South Stream projects, are further signs of this shift in tone. These issues raise the question of whether, and to what extent, the current condition of Gazprom’s finance will permit the company to implement the infrastructural projects it has been endorsing and its other investment plans in Europe. Another important question is whether the currently observed changes in how Gazprom operates will take on a more permanent character, and what consequences this will have for the European Union. The first part of this report discusses Gazprom’s production and export potential. The second comprehensively presents the scope and nature of Gazprom’s economic presence in the EU member states. Finally, the third part presents the Russian company’s methods of operation on foreign markets. The data presented in the report come mainly from the statistics of the International Energy Agency, the European Commission and Gazprom, as well as the Central Bank of Russia and the Russian Statistical Office. The figures presented here also include proprietary calculations by the OSW based on figures disclosed by energy companies and reports by professional press and news agencies.

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"Bibliographical note" at end of chapters.

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"Supported by the McDonnell Aircraft Corporation under Contract no. 6140-20 P. O. 7S4899-R. Purdue Research Foundation. Research project no. 1717. Project Ae-33.

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Mode of access: Internet.