Esta dissertação apresenta o desenvolvimento de um software BGJ em LabVIEW para a geração de arquivos compatíveis com a formatação de sinais exportáveis ao OrCAD, as quais caracterizam os componentes de jitter determinístico e randômico, para a simulação e análise do comportamento dos circuitos detectores de fase digital em comunicações assíncronas. As simulação dos detectores de fase, são realizadas em OrCAD, programa que permite a simulação com alta precisão de circuitos eletrônicos, aproveitando o modela mento eletrônico dos componentes semicondutores. Assim, esta pesquisa traz a possibilidade de compartilhar os arquivos gerados no mundo científico e acadêmico, situando de tal modo o software numa ferramenta ímpar no desenvolvimento de circuitos eletrônicos CRC ou CRD, em nível de simulação numa plataforma gráfica. / This work presents the development of BGJ software in LabVIEW in order to generate files compatible with the format exportable to OrCAD signs, which characterize the components of deterministic and random jitter, to simulate and analyze the performance of digital phase detector circuits in asynchronous communications. The simulations of phase detectors are in OrCAD program, which allows the simulation with high precision electronic circuits, using the modeling of electronic semiconductor components. Thus, this research brings the possibility to share files generated in scientific and academic standing of such software in a unique tool in the development of electronic circuits or CRC CRD-level simulation on a graphics platform.

A new distributed object-oriented discrete event-driven simulation environment, DODESE, is developed to provide a common framework for simulation model design and implementation. The DODESE can be used to define a simulation including all the simulation objects participating in the simulation while the execution of the simulation can be interactively monitored on DODESE. The DODESE system has combined the strengths of both object-oriented paradigms and data base technology to make computer simulation more powerful and has achieved the goals of object-orientation, distribution, reusability, maintainability and extensibility. The system runs on two Sun workstations concurrently connected by an Ethernet. One of the workstations performs the simulation tasks while the other workstation displays the status of the simulation interactively. Both workstations communicate through the GemStone data base, thus a mechanism is designed for synchronization and concurrency control. The DODESE is implemented using OPAL, GemStone’s data definition and manipulation language, C and Xlib.

This research develops an algorithm for solving a class of multiple objective decision problems. These problems are characterized by continuous policy variables, nonlinear constraints, and nonlinear criterion functions. Our underlying philosophy is that of the Gestalt psychologists-- we cannot separate the problem and its solution from the environment in which the problem is placed. The decision maker is necessarily a part of this environment, thus implying that he, as an individual, must be part of the solution of the problem. Another central assumption in this research is that there is not an "optimal" answer to the problem, only "satisfactory" solutions. The reasons for this are based partly on the insensitivities of the body to minute changes and to the insensitivity of our preferences within certain ranges of acceptance. In addition, we assure that the individual is capable of solving decision situations involving a maximum of about 10 goals and that he operates upon them in some sort of serial manner as he searches for a satisfactory alternative. The serial manner is a reflection of his current ranking of the goals. Based on these assumptions we have developed a cyclical interactive algorithm in which the decision maker guides a search mechanism in attempting to find a satisfactory alternative. Each cycle in the search consists of an optimization phase and an evaluation phase, after which the decision maker can define a new direction of search or terminate the algorithm. The optimization phase is based on a linearization technique which has been quite effective in terms of the problems we have attempted to solve. It is capable of solving general nonlinear programming problems with a large number of nonlinear constraints. Although the constraint set must be convex in order to guarantee the location of a global optimum, we can use the method on concave sets recognizing that we may find only a local optimum. An extensive synthetic case study of a water pollution decision problem with 6 conflicting goals is provided to demonstrate the feasibility of the algorithm. Finally, the limitations of the research are discussed. We tentatively conclude that we have developed a method applicable to our research problem and that the method can be applied to "real world" decision situations.

Orientadores: Sergio Nascimento Bordalo, Denis Jose Schiozer / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-24T03:21:33Z (GMT). No. of bitstreams: 1 Paiva_RonaldoOliveirade_M.pdf: 5372317 bytes, checksum: 87a623d365c62b997b5436706619b759 (MD5) Previous issue date: 1997 / Resumo: Os custos envolvidos em intervenções de sonda e a perda de receita nos poços aguardando intervenções são elevados. Este trabalho propõe métodos para analisar profundamente a priorização dos poços em que a sonda deverá intervir. Para determinar a seqüência de intervenção nos poços, é necessário comparar o gasto de sonda com as perdas dos poços. Para calcular as perdas dos poços, é necessário analisar a influência monetária do fechamento dos poços nas curvas de produção dos reservatórios. Neste trabalho, esta análise é feita utilizando-se um simulador numérico de reservatórios. São apresentadas, também, simplificações possíveis para um cálculo expedito. A priorização dos poços é baseada na redução do custo total do caminho, que se constitui da soma das perdas devidas à espera da intervenção, somadas aos custos das sondas. Para determinar o itinerário ideal das sondas, existem muitos algoritmos. Neste trabalho, são implementados e comparados alguns algoritmos considerados intuitivos e de simples implementação. Recomenda-se o algoritmo da Têmpera Simulada para priorizar os poços. Este algoritmo foi implementado para rotear sondas terrestres em uma região petrolífera brasileira. Otimizando as seqüências de intervenção realizadas no ano de 1996, nesta região, identificou-se uma economia potencial de 15%nas perdas de produção, equivalente a 4.000 metros cúbicos/anode petróleo (25.000 bbl/ano) / Abstract: The costs of workover and the loss of revenue in wells waiting workover rigs are very high. This work proposes methods to prioritize these wells in order to minimize the total cost. To determine the workover sequence it is necessary to compare the rig expense with the wells'losses. To ca1culatethe wells' losses, it is necessary to analyze the monetary influence of the well shutdown in the production curves. In this work, this analysis is made by using a numerical reservo ir simulator. Simplified ca1culation procedures are also presented. The priority of the wells is based on the reduction of the total cost, which consists of the rig costs plus the revenue losses due to workover waiting. There are many algorithms able to determine the ideal rig path. In this work, simple and intuitive algorithms, are implemented and ,)mpared. The Simulated Annealing algorithm is recommended. This algorithm was implemented to optimize workover rig routes in a brazilian production region. Otimization of the workover sequence carried out in that region in 1996 identified a potential economy of 15% in the production losses, equivalent to 4.000 'm POT. 3¿/year ofoil (25.000 bbl/year) / Mestrado / Mestre em Engenharia de Petróleo

Orientadores: Rodolfo Jardim de Azevedo, Sandro Rigo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-27T12:16:48Z (GMT). No. of bitstreams: 1 Cardoso_RogerioAlves_M.pdf: 7699903 bytes, checksum: be514fda4ed9849ea41a1899010841c7 (MD5) Previous issue date: 2015 / Resumo: Com o aumento da complexidade dos sistemas eletrônicos, novos desafios foram surgindo na fase de projeto desses sistemas; assim, os requisitos de projeto estão cada vez mais complexos, implicando diretamente no time-to-market que torna-se cada vez mais difícil de ser cumprido. As abordagens tradicionais como o projeto RTL tornaram-se impraticáveis visto que é cada vez mais evidente a necessidade da criação de software paralelamente ao projeto de hardware. Nesse contexto, metodologias modernas como ESL têm sido utilizadas com sucesso, para que os projetistas possam solucionar esses problemas. Com o crescente numero de funcionalidades que os novos dispositivos implementam e o aumento da complexidade das aplica coes, muitas vezes exigem que esses dispositivos rodem um sistema operacional embarcado. Isso dificulta ainda mais o desenvolvimento homogêneo hardware/software, pois demanda a criação de plataformas virtuais completas capazes de executarem um sistema operacional e suas aplicações, e o desenvolvimento dessas plataformas não é uma tarefa trivial. Este trabalho apresenta a implementação de uma plataforma, em nível de sistema, completa da arquitetura LEON, utilizando a ferramenta ArchC. A plataforma apresentada permite executar um sistema operacional Linux e suas aplica coes, com suporte a gerenciamento de memoria virtual. Além de demonstrar as dificuldades e as limitações da ferramenta ArchC na geração desse tipo plataformas / Abstract: Design challenges in electronic systems increase with their size and the design require- ments, leading to even more pressure in time-to-market issues. Traditional approaches like RTL become unaffordable, due to the need for parallel development of hardware and software necessity. In this context, modern methodologies like ESL have been success- fully used to tackle this kind of problem. With the increasing number of features and the complexity of the applications to that new devices, these devices, in major, may need an embedded operating system. This poses a challenge in the homogeneous development of hardware and software, demanding a complex virtual platform development, capable of running an operating system and its applications. But, developing this kind of platform is not a simple task. This work presents an ArchC System Level Platform implementation, based on LEON architecture. This platform can execute a Linux operating system and user applications with virtual memory support. It besides demonstrates the challenges and limitations of the ArchC tools on development of this type of platform / Mestrado / Ciência da Computação / Mestre em Ciência da Computação

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The purpose of this research paper was to translate a Computer Model (SIGART), capable of simulating a progressive traffic signal lights system, from Burroughs B5500 FORTRAN II to the IBM 360 FORTRAN IV computer language, to outline the program algorithm, to set up detailed program documentation and to validate this model by applying practical system data. Expansion of the SIGART program by addition of an option to produce a time space plot of the output data utilizing a Calcomp plotter was also to be considered.

The purpose of this research report is to compare two simulation languages; GASP and GPSS. An economical comparison was performed by simulating the same system in each language and examine parameters such as run time, core size, program time, and debug time. A statistical comparison of the results of the system simulation was also performed using a 90% confidence level testing procedure. The system simulated was the proposed Orlando Police Department Automatic Vehicle Locator (AVL) Operational System.

Simulation is one of the most important tools for system performance evaluation in communication networks as well as many other areas. However, simulation is computationally intensive. A traditional sequential simulation of a complex model or a rare-event system may require days or even weeks of computer execution time. Therefore, simulation often becomes a bottleneck of a performance study. With the growing availability of multiprocessor computing systems (e.g., tightly-coupled parallel computers or distributed networks of workstations), parallel simulation, which parallelizes a simulation program for execution on multiple processors, becomes an attractive means to reduce simulation execution time. With few exceptions, existing parallel simulation algorithms can be broadly classified into four methods: multiple replication, time-parallel, parallel regenerative, and space-parallel. Each method is associated with some advantages and limitations. We study these methods and propose a number of parallel simulation algorithms for a class of communication network systems modeled by queueing systems. In multiple replication simulation, each processor simulates a replication of the target simulation model independently. Due to the lack of a prior: knowledge about the steady state conditions, an arbitrarily selected initial state is often used for each simulation run. This can result in significant bias in the simulation outcome. To reduce this initial transient bias, we propose a polling initialization technique, in which a pilot simulation is used to find 'good' initial states that are representative of the steady-state conditions. Time-parallel simulation obtains parallelism by partitioning the time domain of the simulation model into a number of batches. Each batch is computed by a processor independently. Time-parallel simulation has not been fully explored by the research community partly because finding the exact initial states for the batches is often challenging and problem dependent. We develop two approximation time-parallel simulation algorithms for acyclic networks of loss G/G/1/K and G/D/1/K queues. These algorithms exploit unbounded parallelism and can achieve near-linear speedup when the number of arrivals is large. Two other time-parallel approaches are also proposed for Markov chains. For more general simulation models, an approximation approach that uses a substate matching technique is presented. Parallel regenerative simulation exploits parallels in by partitioning the simulation trajectory into a number of regeneration cycles. The amount of parallelism relies on the regeneration frequency of the model. In practice a regeneration state that has a short expected regeneration cycle length often does not exist in the target simulation model. As a result, a sufficient number of observations can not be obtained in a finite simulation interval. To overcome this constraint, we propose a partial regeneration algorithm that uses a substate matching technique to increase the number of observations. When the memory requirement of the target simulation models exceeds the storage capacity of a single processor, space-parallel simulation is an appropriate method. In space-parallel simulation, the target simulation model is decomposed into a number of components such that each component contains a disjoint subset of the model state variables. Each component is mapped into a logical process which is responsible for computing the trajectory corresponding to the component over the simulation time interval. An important class of space-parallel simulation is the conservative simulation, in which each logical process can proceed processing an event only if the process ensures that no event. will arrive later with a smaller timestamp. A number of previous experimental studies have suggested that lookahead, a capability that allows a simulation to look into the simulation time future, plays an important role in the performance of the conservative simulation. Although the performance of conservative simulation has been the interest in many previous studies, there has been a lack of formal arguments to quantify the impact of lookahead to conservative simulation performance. To address this question, we develop stochastic models to study the relationship between the amount of lookahead and the simulation performance with respect to different model topologies. We show that for closed simulation models, the simulation execution time is proportional to the amount of lookahead. For open models, on the other hand, lookahead is effectively useless when the simulation length is long. / Ph. D.

The mining of coal within 110 feet below a previously mined seam creates interaction effects which can be detrimental to work in the lower seam. These interaction effects are characterized by zones of very high stress and result in floor and roof instability and pillar crushing. Recent developments in the field of ground control make it possible to determine with a certain degree of confidence the location of these zones and estimate the degree to which the interaction will affect the lower seam. This information has been incorporated into a software package for microcomputers which will predict lower seam problems and suggest design criteria for minimizing the difficulties which will be encountered. / M.S.