Thesis (M.S.)--Mississippi State University. Department of Computer Science. / Title from title screen. Includes bibliographical references.

Thesis (M.S.)--Mississippi State University. Department of Computer Science. / Title from title screen. Includes bibliographical references.

This research explores the complexities of database security, encompassing both the computer hardware and software. Also important is its nature as a people oriented issue. A risk analysis of a database system's security can be examined by creating a simulation model. Though, in order for it to be truly meaningful and accurate, all aspects of design, performance and procedure must be thoroughly and carefully scrutinized.Computer or data security is a major problem in today's world of data processing. This thesis outlines the security problem' and presents trends and issues. It also addresses current trends in computer security environments, database risk analysis, and simulations.Risk analysis is a technique used to quantitatively assess the relative value of protective measures. It is useful when appropriately applied and is in some cases required by regulatory agencies.The goal of security environments is to outline the framework which is valuable in assessing security issues and in establishing partitions in the overall environment within which this and other approaches to security can be examined.A simulation prototype is given which demonstrates the concepts of risk analysis for a database system. / Department of Computer Science

Thesis (M.S. in computer science)--Washington State University, December 2007. / Includes bibliographical references (p. 61-69).

Thesis (M. Sc.)--Carleton University, 2003. / Includes bibliographical references (p. 106-111). Also available in electronic format on the Internet.

Thesis (Ph. D.)--Open University. BLDSC no. DX196536.

Thesis (M.S. in Modeling, Virtual Environments and Simulations (MOVES))--Naval Postgraduate School, Sept. 2004. / Thesis Advisor(s): Rudy Darken, Joe Sullivan. Includes bibliographical references (p. 53). Also available online.

Thesis (M.Sc. (Computer Science)) - Rhodes University, 2009.

Orientador: João Mauricio Rosario / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-05T04:11:52Z (GMT). No. of bitstreams: 1 CarvajalRojas_JaimeHumberto_D.pdf: 18722503 bytes, checksum: cf7052f5959f02f6c052c5b501ca7f6b (MD5) Previous issue date: 2004 / Resumo: O principal objetivo de esta pesquisa consiste no desenvolvimento de uma metodologia geral para a integração, simulação e programação of-line de robôs e mecanismos mecatrônicos em células de manufatura flexíveis FMC. O desenvolvimento da metodologia implica a modelagem da FMC usando Redes de Petri PN, a modelagem geométrica com sistemas CAD do ambiente de atuação do robô incluindo equipamento e mecanismos associados, modelagem da cinemática direta e inversa do robô baseada na metodologia de Denavit -Hartenberg, modelagem do Jacobiano direto e inverso do robô, modelagem da cinemática com Quaterniones, simulação gráfica das trajetórias do robô, simulação gráfica da movimentação dos mecanismos, e coordenação e integração da movimentação dos robôs e dos mecanismos. A programação off-line do robô é o principio de integração dos componentes dentro da FMC. Estudos de casos encaminhados à implementação, validação e probas da metodologia desenvolvida, são apresentados, incluindo programação off-line independente, programação off-line simultânea, programação off-line seqüencial e programação of line integrada / Abstract: The main objective of this research consists on the development of a general methodology for the integration, simulation and ofl-line programming of robots and mechatronic mechanisms into Flexible Manufacturing Cells FMC. The development ofthe methodology embraces the modeling of FMC using Petri Nets PN, the geometric modeling with system CAD of the environrnent of the robot's performance inc1udingequipment and associate mechanisms, mathematica1modeling of the direct kinematics and inverse kinematics of the robot based on Denavit - Hartenberg metodology, mathematical modeling of kinematics with Quaternions, mathematical modeling of the direct Jacobian and inverse Jacobian of the robot, the graphic simulation ofthe robot's trajectories, graphic simulation of the movement of the mechanisms and the coordination and integration of the robot's movements and of mechanisms. The off line programming of the robots is the principIe for the integration of the components. Studies of cases allows the implementation, validation and it proves of the developed methodology, are presented, including off line programming independent, of-line programming simultaneous, off-line programming sequential, and off-line programming integrated. / Doutorado / Mecatronica, Robotica e Sistemas Mecanicos Atuados / Doutor em Engenharia Mecânica

Orientador: Jose Vicente Hallak d'Angelo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T03:30:00Z (GMT). No. of bitstreams: 1 Lobosco_RaquelJahara_M.pdf: 1406343 bytes, checksum: 34dc2d91be7e56471efaccf2dae92582 (MD5) Previous issue date: 2009 / Resumo: Este trabalho apresenta a proposta de uma função para avaliação do desempenho de ciclos de refrigeração, do ponto de vista termodinâmico e ambiental, através da análise estatística dos resultados da simulação computacional de um ciclo de refrigeração por compressão a vapor. A função proposta representa um índice global de avaliação da eficiência termodinâmica e dos critérios ambientais e foi desenvolvida com o intuito de facilitar a combinação de critérios utilizados na avaliação de ciclos termodinâmicos e envolve a análise exergética do ciclo, valores do COP (coefficient of performance), do ODP (ozone depletion potencial) e do GWP (Global Warming Potential). Para a simulação computacional foi utilizado o software Hysys versão 3.2 da Aspen Technology. As simulações permitiram testar diferentes combinações de misturas de refrigerantes. As equações de estado de Peng-Robinson e Peng-Robison Stryjek-Vera (PRSV) foram comparados entretanto a equação de estado Peng-Robinson foi utilizada neste trabalho para estimar as propriedades termodinâmicas. Foram consideradas neste trabalho duas eficiências do compressor, 55% e 75%. Nas simulações foram avaliados diversos refrigerantes puros (R134a, R290, R152a e R600a) e misturas binárias dos mesmos em três proporções mássicas: 75%, 50% e 25%. O desempenho do ciclo termodinâmico foi avaliado com uma variação de 10% e 20% das pressões da região de alta pressão e de baixa pressão e através dessa avaliação foi possível sugerir nova faixa de atuação das pressões visando uma otimização do ciclo. Através do índice da função de desempenho foi possível determinar que o R600a e suas misturas são os refrigerantes mais adequados para o ciclo proposto / Abstract: This work presents a proposal function to vapor compression refrigerator cycle performance from environmental and thermodynamic point of view. The function was developed through the statistic analysis of a refrigerator cycle computational results. The proposal function represents an evaluation indice of efficiency and environment criterions and was developed to make the analysis of combining criterions evaluations easier in thermodynamics cycles. It includes an exergetic analysis, COP (Coefficient of Performance), ODP (Ozone Depletion Potencial) and GWP (Global Warming Potential). Software Hysys version 3.2 from Aspen Technology was used for computational simulation development. The simulations allowed testing several combinations of refrigerants. The thermodynamic packages Peng-Robison and Peng-Robison Stryjek and Vera was compared however Peng-Robinson equation of state, was used to estimate thermodynamic properties of proposed cycle in this work. Two different efficiencies for the compressor were considered, 55% and 75%. The mixtures of refrigerants tested were pair's combinations of: R134a, R290, R152a and R600a. The variation of these mixtures was in the following proportions: 75, 50 e 25% and it was compared with the own refrigerant. In order to evaluate the performance of refrigerant mixtures, the pressure of high pressure region and low pressure region suffered a change of 10%. With this analysis was possible to suggest a new pressure range for cycle optimization. Considering the values of performance function, it was possible to conclude that R600a and its mixtures are the most indicated ones to be used in the proposed cycle / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química