57 research outputs found
Span Restoration in Optical Networks with Limited Wavelength Conversion
No full textNext generation optical networks provide functionalities to dynamically provision and recover connections, while emerging technologies allow for the conversion between wavelengths. These devices are however expensive and hence it is likely that only few are deployed throughout the network. Accordingly, the unavailability of wavelength converters decreases the chance for successful connection establishment, especially in the recovery phase, where several restoration requests try to access a limited pool of resources. The recently proposed suggested vector scheme has been designed to perform converter-saving wavelength assignment in GMPLS networks. The converter saving property of the Suggested Vector is particularly desirable in span restoration, where the pre-failure path stubs have to be merged to the restoration path at the failure-adjacent nodes. In order to avoid wavelength conversion at the merging nodes, the wavelength of the connection stubs can be considered. In this study, we evaluate the recovery performance of the suggested vector scheme and a scheme exploiting standard protocol extensions only. The behavior of both schemes with a stub-aware extension for span restoration is also assessed. Our simulations show that the Suggested Vector scheme achieves a higher recovery performance than the standard scheme. Both schemes benefit from the stub-aware modification. The performance increase is especially predominant if few wavelength converters are available and at medium load ranges. Furthermore, we describe different scenarios to extend the suggested vector wavelength assignment scheme to multi-domain networks with focus on span restoration
Wavelength converter placement in optical networks with dynamic traffic
No full textWe evaluate the connection provisioning performance of GMPLS-controlled wavelength routed networks under dynamic traffic load and using three different wavelength converter placement heuristics. Results show that a simple uniform placement heuristic matches the performance of complex heuristics under dynamic traffic assumptions
The reform of minority shareholder protection in Saudi Arabia and Dubai in private companies
No full textThis thesis explores the state of the law as it affects the protection of minority shareholders in private companies in Saudi Arabia and Dubai. This research was precipitated by the apparent insufficiency of the law in these two jurisdictions as far as minority shareholder protection is concerned. It has been found that the minority shareholder's rights and interests are not satisfactorily protected by the company law in these two countries. In fact, the law grants majority shareholders an unrestricted control over the company that is capable of causing abuses and injustice as far as minority shareholders are concerned. Thus, for these two countries to meet domestic demands to have effective protection and to match international trends in order to attract foreign investment, it is argued that they should develop and improve their company law in this respect.
This research has sought to address the following questions. How should Saudi Arabian and Dubai law be reformed in terms of minority shareholder protection? How can the UK company law with its long experience and knowledge proffer a way forward for the reform of both jurisdictions? What is workable in the context of SA and Dubai if UK law is adopted, and what adaptations may be required? In order to answer these questions the research has employed doctrinal, theoretical and empirical approaches.
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The products of this research are proposals for wide-ranging reforms to the system for minority shareholder protection that exist in SA and Dubai. The research has come up with codification of minority shareholder protection that follows in the footsteps of the UK statute, but not in every respect. The code has been carefully examined to comply with the needs, culture, tradition, conventions and Shari a that exist in both jurisdictions
Determinantes dos pedidos estrangeiros de patentes dos países do G7 nos BRICS
No full textTCC (graduação) - Universidade Federal de Santa Catarina. Centro Sócio-Econômico. Economia.Este estudo investiga os determinantes dos pedidos estrangeiros de patentes de origem no G7 (Alemanha, Canadá, Estados Unidos, França, Itália, Japão, Reino Unido) e destino nos BRICs (Brasil, Rússia, Índia, China). Com base na revisão da literatura e do cenário mundial de patentes, constrói-se um conjunto de hipóteses que destacam, entre outras variáveis, variáveis de caráter gravitacional, como: distância entre os países emissores e receptores; e o tamanho das economias, medido pelo seu PIB real. Os dados são agrupados em modelo painel, e compreendem 185 observações, referentes aos anos de 1995 a 2006. Os resultados corroboram a literatura empírica, que identifica como variáveis determinantes as variáveis gravitacionais mencionadas, além do investimento direto externo (IDE), exportações e pedidos estrangeiros de patentes dos BRICs no mundo. Com destaque para a última variável, que apresentou alta significância sobre a variável dependente, indicando que a sinalização de conhecimento tecnológico nos países de destino (BRICs) faz aumentar aos olhos dos países emissores (G7) a possibilidade de aqueles descobrirem os segredos das empresas estrangeiras as quais, portanto, têm incentivos a fazerem pedidos de patentes naqueles países de destino
Modeling GMPLS and Optical MPLS Networks
No full textA consequence of migrating the existing Internet architecture to an all-optical one is that the network will consist of a mixture of equipment, ranging from electrical routers to all-optical packet switches. Hence, future networks will consist of multiple domains employing different technologies. The MPLS concept is attractive because it can work as a unifying control structure. covering all technologies. This paper describes how a novel scheme for optical MPLS and circuit switched GMPLS based networks can incorporated in such multi-domain, MPLS-based scenarios and how it could be modeled. Network nodes supporting GMPLS the proposed novel scheme is implemented and routing and path setup is demonstrated
Magnesium transport through the basal plasma membrane of larval Malpighian tubules of Drosophila hydei studied by electron probe X ray-microanalysis
No full textMagnesium besides calcium is the most important excretion product. In the anterior Malpighian tubules of Drosophila, excretion of magnesium takes place via the hindgut by proteoglycan containing concretions. This study reports on magnesium transport through the basal plasma membrane of the principal cells of the proximal segment of the anterior Malpighian tubules. Measurements by electron probe X-ray microanalysis indicate the existence of two antiporters which transfer magnesium in still unknown stoichiometry from the hemolymph space into the cell: Mg/H and Mg/
Magnesium transport through the basal plasma membrane of larval Malpighian tubules of Drosophila hydei studied by electron probe X ray-microanalysis
No full textMagnesium besides calcium is the most important excretion product. In the anterior Malpighian tubules of Drosophila, excretion of magnesium takes place via the hindgut by proteoglycan containing concretions. This study reports on magnesium transport through the basal plasma membrane of the principal cells of the proximal segment of the anterior Malpighian tubules. Measurements by electron probe X-ray microanalysis indicate the existence of two antiporters which transfer magnesium in still unknown stoichiometry from the hemolymph space into the cell: Mg/H and Mg/
MUPBED: A Pan-European Prototype for Multi-Domain Research Networks
No full textIntegration and full interoperability are challenging areas of research in wide-area networks today. A European project, MUPBED, has recently concluded and achieved the main result of integrating and demonstrating technologies and network solutions that enable the operation of future European research infrastructures capable of supporting advanced applications. The achieved results are largely valid for any multi-domain network scenario. The test network set up by the project is a prototype of multi-domain optical network able to provide connectivity on-demand services across multiple domains directly driven by the applications. Rather than implementing ex-novo a unified control plane and replacing existing equipment, the project approach has been to enable seamless interworking of different control planes by means of ASON/GMPLS and standardized network interfaces. This was done in accomplishment of the project target, which was to test and trial a common migration path towards the future European research network that should be followed by national research and education network operators, together with commercial operators. This paper describes the main aspects of the MUPBED experience, which for its own peculiar nature provides a deep insight into the most recent evolution of control-plane enabled optical networking towards the multi-domain integration. Topics covered by the project and briefly related here, include: network architecture, applications, protocol and control-software development, standardization issues, design, analysis and simulation, testing, measurement and monitoring
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