Orientadores: Christian Rodolfo Esteve Rothenberg, Maurício Ferreira Magalhães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-23T02:35:23Z (GMT). No. of bitstreams: 1 Cabral_CarlosManuelSilvestre_M.pdf: 7624416 bytes, checksum: f758b7fa3db350c16219153bff10654b (MD5) Previous issue date: 2013 / Resumo: A pesquisa experimental em Redes Orientadas a Conteúdo (ROCs) é crucial para a validação de novas propostas arquiteturais que trazem o conteúdo como o elemento central das redes. Essa dissertação apresenta uma nova ferramenta de prototipagem rápida para o modelo CCN (Content-Centric Networking), o Mini-CCNx, que visa preencher uma lacuna existente entre as plataformas experimentais atualmente disponíveis. Usando emulação baseada em contêineres e técnicas de isolamento de recursos, o Mini-CCNx aparece como uma ferramenta flexível, escalável, com baixo custo e alta fidelidade de desempenho possibilitando experimentos em redes emuladas com centenas de nós CCN em um simples laptop. Assim, esse trabalho de Mestrado traz como principal contribuição a disponibilização do Mini-CCNx, o primeiro emulador genérico especificamente focado para o desenvolvimento e testes de propostas para o modelo CCN. O Mini-CCNx é publicado com seu código aberto e documentação online e, portanto, pode ser melhorado e estendido por qualquer pesquisador da área. Essa dissertação apresenta 18 experimentos utilizando o Mini- CCNx, abrangendo desde análises de escalabilidade e coerência até a distribuição de vídeo e protocolos de roteamento. A reprodução de comportamentos observados em redes reais utilizando o emulador também é uma contribuição importante, pois mostra que se pode utilizar o Mini-CCNx para detectar eventuais falhas em aplicações e algoritmos antes dos testes em testbeds reais, que certamente são mais complexos e custosos quando comparados ao ambiente emulado. Porém, as características de baixo custo e flexibilidade indicam que o Mini-CCNx também pode ser utilizado em atividades de ensino como uma ferramenta prática de aprendizado e introdução ás ROCs e ao modelo CCN / Abstract: Experimental research in Information-Centric Networking (ICN) is crucial to the evaluation of new architectural proposals that bring named pieces of content as the main element of networks. This thesis presents a new fast prototyping tool for the CCN (Content-Centric Networking) model, Mini-CCNx that aims at filling an existing gap in generally available experimental platforms. Using container-based emulation and resource isolation techniques, Mini-CCNx appears as a flexible, scalable, high-fidelity, and low-cost tool that enables experiments on emulated networks with hundreds of CCN nodes in a commodity laptop. Therefore, this Master's project's main contribution is making Mini-CCNx, the first generic emulator focused on the development and evaluation of new proposals for the CCN model, available. Mini-CCNx is opensource and its documentation is publicly available online so it can be extended by any researcher in the area. This thesis presents 18 experiments using Mini-CCNx, ranging from scalability and coherence analysis to video distribution and routing protocols. The reproduction of real networks behavior using the emulator is also an important contribution because it shows one can use Mini-CCNx to detect flaws in applications or algorithms prior to real testbeds tests, which are certainly more complex and costly when compared to the emulated environment. Finally, Mini-CCNx's low-cost and flexibility indicate it can also be used in teaching activities as a practical ICN and CCN learning tool / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

M.Com. (Computer Auditing) / Intranets and related technology, can be used to solve many problems in the local computing environment. But the use of the Intranet and the related technology also raises several control concerns. Because of the increased use of Intranets within the business environment, the internal control related to the Intranet has become an issue that needs to be addressed by management and the auditor. Computerization in the accounting environment has made it virtually impossible to audit around the computer. It is therefore essential that the auditor, and more specifically the computer auditor, should assess the influence of the Intranet on the audit objectives. The objective of this short dissertation is to evaluate the influence of Intranet technology on the audit objectives (within the Intranet's different spheres of application) in terms of the risks posed for the auditor and management. It was also aimed at identifying the security risks in relationship with the audit objectives...

With network enabled consumer devices becoming increasingly popular, the number of connected devices and available services is growing considerably - with the number of connected devices es- timated to surpass 15 billion devices by 2015. In this increasingly large and dynamic environment it is important that users have a comprehensive, yet efficient, mechanism to discover services. Many existing wide-area service discovery mechanisms are centralised and do not scale to large numbers of users. Additionally, centralised services suffer from issues such as a single point of failure, high maintenance costs, and difficulty of management. As such, this Thesis seeks a Peer to Peer (P2P) approach. Distributed Hash Tables (DHTs) are well known for their high scalability, financially low barrier of entry, and ability to self manage. They can be used to provide not just a platform on which peers can offer and consume services, but also as a means for users to discover such services. Traditionally DHTs provide a distributed key-value store, with no search functionality. In recent years many P2P systems have been proposed providing support for a sub-set of complex query types, such as keyword search, range queries, and semantic search. This Thesis presents a novel algorithm for performing any type of complex query, from keyword search, to complex regular expressions, to full-text search, over any structured P2P overlay. This is achieved by efficiently broadcasting the search query, allowing each peer to process the query locally, and then efficiently routing responses back to the originating peer. Through experimentation, this technique is shown to be successful when the network is stable, however performance degrades under high levels of network churn. To address the issue of network churn, this Thesis proposes a number of enhancements which can be made to existing P2P overlays in order to improve the performance of both the existing DHT and the proposed algorithm. Through two case studies these enhancements are shown to improve not only the performance of the proposed algorithm under churn, but also the performance of traditional lookup operations in these networks.

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

published_or_final_version / Computer Science and Information Systems / Master / Master of Philosophy

published_or_final_version / Computer Science and Information Systems / Master / Master of Philosophy

published_or_final_version / Computer Science / Master / Master of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Master / Master of Philosophy

This thesis describes a new simulation technique, Synchronous Faults Simulation by Surrogate with Exception, first proposed by Dr. F. J. Hill and has been initiated under the direction of Xiolin Wang. This paper reports early results of that project. The Sequential Circuit Test Sequence System, SCIRTSS, is an automatic test generation system which is developed in University of Arizona which will be used as a target to compare against the results of the new simulator. The major objective of this research is to analyze the results obtained by using the new simulator SFSSE against the results obtained by using the parallel simulator SCIRTSS. The results are listed in this paper to verify superiority of the new simulation technique.

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