Este trabalho apresenta a avaliação de diferentes algoritmos de roteamento utilizados na camada lógica ponto a ponto (P2P) adotada por um Metaescalonador que provê Qualidade de Serviços (QoS) na Computação em Nuvem. Experimentos mostram a superioridade de três algoritmos de roteamento P2P (BCR, Chord e Pastry) em relação à utilização de Round Robin, analisando-se o tempo de resposta e a variabilidade entre os resultados obtidos em diferentes testes. Os experimentos consideram, além dos algoritmos de roteamento, a influência do número de usuários e do tipo de serviço requisitado e como esses fatores interagem entre si. É apresentado ainda um estudo sobre a melhor métrica a ser adotada para representar as informações da rede. As métricas consideradas foram latência e número de saltos. Os resultados obtidos permitem determinar, com base nos objetivos especificados, qual o impacto dos sistemas P2P utilizados pelo metaescalonador na busca e descoberta de serviços em relação à forma como a qualidade de serviços é abordada / This work presents an evaluation of different routing algorithms that are employed in a logical layer peer-to-peer (P2P) that are adopted by a Metascheduler that provides quality of services (QoS) in Cloud Computing. The experiments show the superiority of three P2P routing algorithms (BCR, Chord, Pastry) in relation to Round Robin utilization, analysing the response times and the variation between the results obtained results in different tests. The experiments consider, besides the routing algorithms, the influence of the number of the users and the type of requested services and how these factors interact between themselves. Besides of this, it is presented a study about the better metric to be adopted to represent the network information. The considered metrics were the latency and number of hops. The obtained results allow to determine, based on specific objectives, the impact of the utilization of P2P systems by the metascheduler in the search and discovery of services in relation to the way that the QoS is performed

Made available in DSpace on 2016-04-29T14:23:28Z (GMT). No. of bitstreams: 1 Jose Roberto Madureira Junior.pdf: 2597024 bytes, checksum: f6b607352cabb213c3e453dae6b3b008 (MD5) Previous issue date: 2014-03-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The following research focuses on the widespread use of Cloud Computing as a result of a major market boost due to the latest trends and needs. It has progressed as a result of advanced technology providing businesses a high standard of service as well as being of great benefit to its users. This final work is aimed at demonstrating users and potencial ones the benefits as well as the possibilities and challenges involved in the use of Cloud Computing and therefore allow them to identify, understand and manage such a service. As a result users shall be able to hire services involving a low risk factor in addition to implementing an appropriate workload. Due to the lack of information regarding Cloud Computing services, we believe that this research can provide users a valuable contribution in clarifying and highlighting both the potentiality and benefits involved as well as analysing the reasons they have not been able to benefit from them so far. We would like to point out that when we searched for literature regarding specifically the service users no significant data was collected. As a result we strongly believe that if such material is published it will represent a significant contribution towards both the users and the academic community. At first we carried out a state of the art study regarding Cloud Computing, identifying the potential benefits involved in providing such a service as well as the impact such a model has had on the information technology scenario. Then we implemented the case study metodology in which three real cases with the model in use were closely followed. Reference is also made to prestigious companies with a solid background within their market segment and the respective services they provide. This will allow the users to obtain the necessary backup in order to be able to previously analyse the ideal sevice which will suit their needs. We concluded that companies seem to be cautious about implementing such a structure due to their concern about mainly operational and safety measures. Cloud Computing´s progress depends on such an acceptance. Therefore this text focuses on identifying and analysing the challenges and benefits involved in implementing such a model. Research has been done with the specific aim of offering a wide range of businesses an overview of Cloud Computing as well as enabling users to overcome any difficulties / Esta pesquisa trata da utilização de Cloud Computing, mostrando sua disseminação impulsionada pelas tendências e necessidades do mercado. Sua evolução é resultado dos avanços tecnológicos que possibilitam e garantem a disseminação e solidez dos serviços prestados, oferecendo grandes benefícios aos usuários. O objetivo desta dissertação é demonstrar as potencialidades, possibilidades e desafios da utilização de serviços de Cloud Computing para que usuários e potenciais usuários possam identificá-los, compreendê-los e prepararem-se para gerenciá-los, de modo tal a poder, nestes ambientes, contratar serviços com grau aceitável de risco e implementar a carga de trabalho correta. A falta de informações sobre os serviços de Cloud Computing. Nos leva a acreditar que esta pesquisa pode oferecer uma contribuição de alto valor para o esclarecimento dos potenciais e benefícios a serem alcançados com esta tecnologia, bem como analisar os desafios que impedem tais benefícios de serem alcançados pelos seus usuários. No que diz respeito especificamente aos usuários destes serviços, na revisão de literatura realizada nada de valor significativo foi encontrado. Desta forma acreditamos que produção e disponibilização de material esclarecedor e útil relacionado ao foco no usuário e demais assuntos relacionados ao tema proposto à comunidade acadêmica seja uma importante contribuição. Para tal, primeiramente, realizamos um estudo do estado da arte de Cloud Computing, identificando os potenciais benefícios obtidos na adoção deste serviço, bem como, a exposição de como o modelo tem transformado o cenário da tecnologia da informação. Em seguida, adotamos a metodologia de estudo de casos onde observamos três casos reais da utilização de serviços do modelo. São destacadas também empresas de renome e seus respectivos serviços oferecidos, que são relevantes em função de suas história e solidez no mercado, possibilitando ao usuário uma análise prévia para a aquisição do serviço ideal ao seu ramo de atividade. Concluímos que a adoção deste tipo de estrutura é tratada com cautela pelas empresas, por conta de preocupações quanto à interoperabilidade, à segurança e os acordos de nível de serviço, entre outros. Tais questões estão ditando o ritmo em que a Cloud Computing vem sendo adotada, bem como sua evolução. Desta forma, neste texto, identificamos e analisamos os desafios que impedem e dificultam a adoção dos benefícios deste modelo. Por fim, nossa intenção foi oferecer uma visão geral dos serviços de Cloud Computing que estão sendo utilizados e que ajudam aos usuários a vencer desafios em diferentes áreas

Mobile cloud computing is a way of delegating complex algorithms from a mobile device to the cloud to complete the tasks quickly and save energy on the mobile device. However, the cloud may not be available or suitable for helping all the time. For example, in a battlefield scenario, the cloud may not be reachable. This work considers neighbouring devices as alternatives to the cloud for offloading computation and presents three key contributions, namely a comprehensive investigation of the trade-off between computation and communication, Multi-Objective Optimisation based approach to offloading, and Queuing Theory based algorithms that present the benefits of offloading to neighbours. Initially, the states of neighbouring devices are considered to be known and the decision of computation offloading is proposed as a multi-objective optimisation problem. Novel Pareto optimal solutions are proposed. The results on a simulated dataset show up to 30% increment in performance even when cloud computing is not available. However, information about the environment is seldom known completely. In Chapter 5, a realistic environment is considered such as delayed node state information and partially connected sensors. The network of sensors is modelled as a network of queues (Open Jackson network). The offloading problem is posed as minimum cost problem and solved using Linear solvers. In addition to the simulated dataset, the proposed solution is tested on a real computer vision dataset. The experiments on the random waypoint dataset showed up to 33% boost on performance whereas in the real dataset, exploiting the temporal and spatial distribution of the targets, a significantly higher increment in performance is achieved.

Em nosso mundo altamente conectado, novas tecnologias provêm contínuas mudanças na velocidade e eficiência das redes de telecomunicações e de transporte. Muitas dessas tecnologias são originárias de pesquisas em problemas de otimização em redes aplicadas a diferentes áreas. Nesta tese, investigamos três problemas de otimização combinatória que podem ser abordados como estruturas de redes. Primeiramente, são abordados problemas de engenharia de tráfego em redes de transporte. O objetivo principal é investigar os efeitos de alterar o custo de um subconjunto de arcos da rede, considerando que os clientes desta rede agem com um comportamento bem definido. O objetivo é controlar o fluxo na rede de modo a obter uma melhor distribuição do fluxo, minimizando o congestionamento ou maximizando o fluxo em um subconjunto de arestas. No primeiro problema considerase instalar um número fixo de postos de pedágios e definir os valores das tarifas para minimizar o tempo médio de viagem dos usuários. No segundo problema abordado, o objetivo é definir os valores das tarifas para maximizar a receita arrecadada nos arcos com pedágios. Em ambos os problemas, os usuários escolhem as rotas com base nos caminhos de menor custo da origem para o destino. Em redes de telecomunicações, um problema de alocação sujeito às condições da rede é considerado. O objetivo é alocar um conjunto de recursos, minimizando o custo de comunicação. Uma aplicação de computação em nuvem é considerada, onde os recursos são máquinas virtuais que devem ser alocadas em um conjunto de centros de dados. Condições da rede como largura de banda e latência são consideradas de modo a garantir a qualidade dos serviços. Para todos estes problemas, os modelos matemáticos são apresentados e avaliados usando um solver comercial de propósito geral como um método exato. Além disso, abordagens heurísticas são propostas, incluindo uma classe de algoritmo genético de chaves aleatórias viciadas (BRKGA). Resultados experimentais demonstram o bom desempenho das abordagens heurísticas propostas, mostrando que o BRKGA é uma ferramenta eficiente para resolver diferentes tipos de problemas de otimização combinatória, especialmente sobre estruturas de rede. / In our highly connected world, new technologies provide continuous changes in the speed and efficiency of telecommunication and transportation networks. Many of these technologies come from research on network optimization problems with applications in different areas. In this thesis, we investigate three combinatorial optimization problems that arise from optimization on networks. First, traffic engineering problems in transportation networks are addressed. The main objective is to investigate the effects of changing the cost of some links in the network regarding some well-defined user behavior. The goal is to control the flow in the network and seek a better flow distribution over the network and then minimize the traffic congestion or maximize the flow on a subset of links over network conditions. The first problem considered is to install a fixed number of tollbooths and define the values of tariffs to minimize the average user travel time. The second problem considered is to define the values of tariffs to maximize the revenue collected in the tolled arcs. In both problems, users choose the routes based on the least cost paths from source to destination. From telecommunication networks, a placement problem subjected to network conditions is considered. The main objective is to place a set of resources minimizing the communication cost. An application from cloud computing is considered, where the resources are virtual machines that should be placed in a set of data centers. Network conditions, such as bandwidth and latency, are considered in order to ensure the service quality. For all these problems, mathematical models are presented and evaluated using a general-purpose commercial solver as an exact method. Furthermore, new heuristics approaches are proposed, including some based on biased random-key genetic algorithm (BRKGA). Experimental results demonstrate the good performance of the proposed heuristic approaches, showing that BRKGA is an efficient tool for solving different kinds of combinatorial optimization problems, especially over network structures.

A computação em nuvem é um modelo que catalisa mudanças marcantes na forma com que a Tecnologia da Informação é distribuída. Como benefícios, sobressai-se a viabilidade de acesso rápido, de qualquer lugar, a recursos disponibilizados como serviços e utilizados sob demanda, subsidiando a criação de novos modelos de negócios. Entretanto, com os ativos da TI externos à organização, aumenta-se o interesse por estudos sobre adoção. A literatura retrata a utilização de vários modelos de adoção, entre eles o TAM (Technology Acceptance Model) e o TOE (Technology-Organizational-enviroment framework). Uma pesquisa que utilizou a combinação TAM-TOE revelou bom grau de previsão da adoção pelo modelo, porém indicou a necessidade de estudos de casos para aprofundar o tema em outros contextos, ensejando a questão: como ocorre o processo de adoção da computação em nuvem em relação às questões organizacionais e ambientais? Foi realizada uma revisão sistemática da literatura para confirmar lacunas de pesquisa e estender o modelo TAM-TOE, destacando-se elementos da teoria institucional no processo de adoção. Trata-se de uma pesquisa qualitativa, descritiva e estruturada por meio de estudos de casos múltiplos, com unidade de análise definida pelo estudo do processo de adoção de um serviço de nuvem em empresa de grande porte caracterizada como suporte no modelo de grade estratégica da TI. Sete unidades foram analisadas abordando-se influência das pressões institucionais sobre a alta gestão, as avaliações dos serviços e os termos de licenciamento dos contratos. O estudo contribui para a elucidação de comportamentos diferenciados das pressões institucionais sobre a alta gestão na decisão de adoção, destacando-se os mecanismos coercitivos. Expõe situações onde a gestão dos serviços requer a participação da TI sob o modo tradicional e discute aspectos contratuais sobre o licenciamento de serviços. Por fim, apresenta-se uma reflexão sobre a utilização do modelo, do método e limitações da pesquisa, com a indicação de estudos futuros para aprofundar as contribuições indicadas em outros contextos. / Cloud Computing is a model that has brought revolutionary changes in the way Information Technology (IT) is distributed. As benefits, it stands out the feasibility of fast access possible from anywhere to resources made available as on-demand services that help to create new business models. However, with IT assets outside the organization, interest in adoption studies have increased. The literature describes the use of several adoption models, among which are the Technology-Acceptance-Model (TAM) and the Technology-Organizational-environment (TOE). One research used the TAM-TOE combination and revealed a good degree of prediction to justify adoptions, but indicated the need for case studies to better understanding of adoptions in other contexts, raising the question: how should the process of adopting cloud computing occur regarding organizational and environmental questions? A systematic literature review was conducted to confirm research gaps and to broaden the TAM-TOE model, highlighting elements of institutional theory and its influence in the adoption process. This is a qualitative, descriptive and structured research using multiple case studies, with unit of analysis defined by the study of the process of adopting a cloud service in a large company characterized as support in the IT strategic grid model. Seven units were analyzed by addressing institutional pressures on top management, service evaluations and contract licensing terms. The study contributes to the elucidation of different behaviors of the institutional pressures on the top management in the decision making for its adoption, emphasizing the coercive mechanisms. It exposes situations in which the service management might require the participation of IT in the traditional way and the discussion of contractual aspects about the licensing of services. Finally, a reflection on the use of the model, method and limitations of the research is presented, indicating future studies.

The cloud computing paradigm introduces an efficient utilisation of huge computing resources by multiple users with minimal expense and deployment effort compared to traditional computing facilities. Although cloud computing has incredible benefits, some governments and enterprises remain hesitant to transfer their computing technology to the cloud as a consequence of the associated security challenges. Security is, therefore, a significant factor in cloud computing adoption. Cloud services consist of three layers: Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). Cloud computing services are accessed through network connections and utilised by multi-users who can share the resources through virtualisation technology. Accordingly, an efficient access control system is crucial to prevent unauthorised access. This thesis mainly investigates the IaaS security enhancement from an access control point of view.

Information Technology is advancing at a frightening pace. Cloud computing and its subset, Software as a Service (SaaS), are rapidly challenging traditional thinking for enterprise-level application and infrastructure provision. The project-centric nature of the construction industry provides an environment where the utilisation of SaaS is commercially appropriate, given its ability to provide rapid set-up and predictable costs at the outset. Using project extranets, the construction industry has been - unusually for it as an industry sector - early-adopters of this cloud computing model. However, findings from the research highlight that there is a gap in the information and documents that pass from the construction phase into the operational phase of a building. This research considers examples of the SaaS IT model and how it has been used within a construction and facilities management industry context. A prototype system was developed to address the requirements of facilities management work order logging and tracking process. These requirements were gathered during detailed case studies of organisations within both the construction and facilities management sectors with a view to continue the use of building-specific information through its full life-cycle. The thesis includes a summary of the lessons learnt through system implementation within the construction-contracting organisation Taylor Woodrow, and it concludes with an IT strategy proposal that was developed based on a cloud computing model.

abstract: Machine learning tutorials often employ an application and runtime specific solution for a given problem in which users are expected to have a broad understanding of data analysis and software programming. This thesis focuses on designing and implementing a new, hands-on approach to teaching machine learning by streamlining the process of generating Inertial Movement Unit (IMU) data from multirotor flight sessions, training a linear classifier, and applying said classifier to solve Multi-rotor Activity Recognition (MAR) problems in an online lab setting. MAR labs leverage cloud computing and data storage technologies to host a versatile environment capable of logging, orchestrating, and visualizing the solution for an MAR problem through a user interface. MAR labs extends Arizona State University’s Visual IoT/Robotics Programming Language Environment (VIPLE) as a control platform for multi-rotors used in data collection. VIPLE is a platform developed for teaching computational thinking, visual programming, Internet of Things (IoT) and robotics application development. As a part of this education platform, this work also develops a 3D simulator capable of simulating the programmable behaviors of a robot within a maze environment and builds a physical quadrotor for use in MAR lab experiments. / Dissertation/Thesis / Masters Thesis Computer Science 2018

Thesis (MTech (Information Technology))--Cape Peninsula University of Technology, 2018. / Organizations and the private individual, look to technology advancements to increase their ability to make informed decisions. The motivation for technology adoption by entities sprouting from an innate need for value generation. The technology currently heralded as the future platform to facilitate value addition, is popularly termed cloud computing. The move to cloud computing however, may conceivably increase the obsolescence cycle for currently retained Information Technology (IT) assets. The term obsolescence, applied as the inability to repurpose or scale an information system resource for needed functionality. The incapacity to reconfigure, grow or shrink an IT asset, be it hardware or software is a well-known narrative of technical debt. The notion of emergent technical debt realities is professed to be all but inevitable when informed by Moore’s Law, as technology must inexorably advance. Of more imminent concern however are that major accelerating factors of technical debt are deemed as non-holistic conceptualization and design conventions. Should management of IT assets fail to address technical debt continually, the technology platform would predictably require replacement. The unrealized value, functional and fiscal loss, together with the resultant e-waste generated by technical debt is meaningfully unattractive. Historically, the cloud milieu had evolved from the grid and clustering paradigms which allowed for information sourcing across multiple and often dispersed computing platforms. The parallel operations in distributed computing environments are inherently value adding, as enhanced effective use of resources and efficiency in data handling may be achieved. The predominant information processing solutions that implement parallel operations in distributed environments are abstracted constructs, styled as High Performance Computing (HPC) or High Throughput Computing (HTC). Regardless of the underlying distributed environment, the archetypes of HPC and HTC differ radically in standard implementation. The foremost contrasting factors of parallelism granularity, failover and locality in data handling have recently been the subject of greater academic discourse towards possible fusion of the two technologies. In this research paper, we uncover probable platforms of future technical debt and subsequently recommend redeployment alternatives. The suggested alternatives take the form of scalable grids, which should provide alignment with the contemporary nature of individual information processing needs. The potential of grids, as efficient and effective information sourcing solutions across geographically dispersed heterogeneous systems are envisioned to reduce or delay aspects of technical debt. As part of an experimental investigation to test plausibility of concepts, artefacts are designed to generically implement HPC and HTC. The design features exposed by the experimental artefacts, could provide insights towards amalgamation of HPC and HTC.

As one of the major energy consumers in the world, the Information and Communication Technology (ICT) sector searches for efficient ways to cope with the energy expenditure of the infrastructure. One of the areas that tend to grow in the coming years, the Cloud Computing services providers look for approaches to change the energy expenditure pattern, concurrently reducing the operational costs. The most common strategy to cope with the energy consumption is related to its efficiency. However, there is the opportunity to encourage a new demand standard, based on the energy supply and price variation. A management approach that takes into account the uctuation of the energy to negotiate the contracts allocation is proposed. Contractible service terms regarding powering the services are established to enable the proposed management approach. Also, a new service layer able to deal with energy requirements is defined as an element of the Cloud Computing environment. Existing literature does not cope with the different terms of the energy supply and does not apply a management of the contracts simultaneously. The proposed method includes a service terms description, the energy-related service layer definition, and a framework for its implementation. A model designed to validate the approach applies a Use Case that simulates Data Centers (DCs) spread through the metropolitan area of S~ao Paulo. The obtained results show the ability of the model to manage the contracts allocation in accordance to the best exploitation of the self-generated energy. Taking into account the assignment costs range, to both user and services provider, the method negotiates the most affordable contracts assignment regarding the energy supply variation. / Como um dos maiores consumidores de energia do mundo, o setor de Tecnologia da Informação e Comunicação (TIC) busca por maneiras eficientes para lidar com o consumo de energia da infraestrutura. Uma das áreas que tende a crescer nos próximos anos, os provedores de serviço de Computação em Nuvem procuram por abordagens para mudar o padrão de consumo de energia, ao mesmo tempo reduzindo custos operacionais. A estratégia mais comum para lidar com o consumo de energia é relacionada à sua eficiência. No entanto, há a oportunidade para incentivar um novo padrão de demanda por serviços de Computação em Nuvem, baseado na variação do fornecimento e preços da energia. Uma solução que considera a flutuação da energia para negociar a alocação é proposta. Termos de serviços contratáveis referentes a energizar os serviços são estabelecidos para permitir a solução de gerenciamento proposta. Também, uma nova camada de serviço capaz de lidar com requisitos da energia é definida como um elemento do ambiente de Computação em Nuvem. A literatura existente não lida com os diferentes termos do fornecimento da energia e com o gerenciamento de contratos simultaneamente. O método proposto inclui descrição dos termos de serviço, a definição da camada de serviço relacionada à energia e uma metodologia de implementação. Um modelo foi construído para validar a proposta através de um Caso de Uso que simula uma quantidade de Data Centers (DCs) espalhados pela região metropolitana de São Paulo. Os resultados obtidos mostram a capacidade de gerenciar a alocação dos serviços buscando o melhor aproveitamento da energia auto-gerada pelo ambiente. Utilizando do critério de variação dos custos de alocação, tanto para o usuário quanto para o provedor de serviços, o método negocia a alocação mais favorável para os contratos em razão da variação do fornecimento de energia.