Дисертації з теми "Winding machines Computer programs"

A stress model of the filament-winding fabrication process, previously implemented in a finite element program, was improved. Pre- and post-processing codes were developed to make the program easier and more efficient to use. A program which is used to design filament wound composite rocket motor cases was modified to write a model file for the fabrication stress code in the pre-processing stage. The same code was altered to provide post-processing output in the form of graphic displays. Also, a new code was written to provide additional post-processing capability for the fabrication stress model. Verification of the model of the filament-winding process was performed by comparing experimental pressure and strain data, for the fabrication of a filament wound bottle, with results of an analytical model. The final analytical results using consecutive models of the filament wound bottle show reasonable agreement with experimental pressure and hoop strain data. The maximum difference in the analytical and experimental values in the pressure data was about 25% for the final winding stage. The difference was smaller during the winding progression. These results also show that the accuracy of the model depends heavily on the assumptions made for input parameters during modelling. The stiffness of the segmented steel mandrel, simulated by an effective modulus (degraded by segmentation), and the instantaneous laydown tension loss parameters significantly affected the results of the model. Including the effective modulus for the segmented mandrel in the model reduced the difference in the experimental and analytical pressure results by about 150%. The inclusion of instantaneous laydown tension loss in the model reduced the analytical-experimental difference by roughly 225%. These two parameters reduced the largest difference in the predicted pressure values from about 400% for the first model to around 25% for the final model. The fabrication stress model was coupled with the thermo-kinetic cure model to provide more accurate fiber motion tension loss analysis capability. The stress model was modified to use the thermo-kinetic model as a subroutine to calculate fiber motion tension loss using a two-dimensional analysis. The results of the qualitative verification show that fiber motion tension loss is more important in the later stages of winding than in the beginning stages which indicates that it may provide the needed accuracy in the final winding stages.
Master of Science

The purpose of this thesis is to develop a software system simulating Turing machines using a Microsoft Windows' Interface.Developed in the 1930's by Alan Turing and Emil Post, Turing machines are defined as "abstract computers" . These machines seem able to solve all problems a modern computer can solve, however complex the problems may be. A Turing machine is a basic computational model for algorithms.The software provides a practical tool to students with a relative notion of Turing machines. The software contains introduction and general information on Turing machines that gives the beginner enough background to use the program. The user can create, modify or run Turing machines saved onto MS-DOS files. Some examples of Turing machines are preloaded. These examples give more help to the beginner.An on-line help facility is provided in order to direct and inform the learning student at each level of the software.The Microsoft Windows' Interface makes the software easy and friendly to use. The software has the modularity which will ease any future enhancement.
Department of Computer Science

Distributed-memory machines offer a very high level of performance, flexibility and scalability. But the memory organization of this kind of machine determines that processes on different processors must communicate explicitly by sending and receiving messages. As a result, the programmer faces the enormously difficult task of detailed planning of algorithm-irrelevant, low-level communication issues. This level of programming resembles writing assembly programs for a sequential machine. ACE is a message-passing language with abstract communication statements. It was defined by Dr. Jingke Li at Portland State University. The communication in ACE is still explicit, but it is abstracted to a higher level. The abstraction can help balance the needs of ease of programming and high performance. This thesis discusses how those high-level communication abstractions can be transformed into low-level communication routines. It presents the design and implementation of a compiler that transforms an ACE program into a C program with low-level communication routines. The compiler is implemented for the Intel iPSC/2 hypercube multiprocessor machine. Compared to their low-level counterparts, ACE programs are easier to write and are more understandable. Compared to their high level counterparts, more efficient code can be generated since the communication information is expressed explicitly in ACE and the compiler itself is much less complex. ACE also enables the users to fine tune some critical communication segments. Some well known parallel algorithms written in ACE are compiled by the compiler as examples, and experimental results of their performance are included.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1997.
"UMI number: 9724066"--T.p. verso. Vita. Includes bibliographical references (p. 182-189). Available electronically via Internet.

The Hypertext concept was introduced about 50 years ago. This thesis presents the development of a reference system using the Hypertext concept. HYATS (HYpertext Automata and Turing Theory Learning 5ys,em) is a system which helps users learn many topics in the area of theory of computation. The system is implemented by Guide which is a general purpose Hypertext system running on PC-Windows environment. HYATS also includes a Turing machine simulating program which was written by Dominique Atger as her Master's Thesis in 1993, so that users can actually experiment with Turing machines learned through HYATS. HYATS will be not only the reference system, but also the complete package of actual learning system. The motivation behind this project is to study basic concepts of a Hypertext system so that it will also contribute to G-Net research. HYATS can be used as a prototype for future development of versions of by using other Hypertext systems such as NoteCards.
Department of Computer Science

Orientadores: Guido Costa Souza de Araújo, Edson Borin
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação
Made available in DSpace on 2018-08-23T12:28:12Z (GMT). No. of bitstreams: 1 Lucas_DivinoCesarSoares_M.pdf: 1053361 bytes, checksum: e29ab79838532619ba298ddde8ba0f39 (MD5) Previous issue date: 2013
Resumo: Máquinas virtuais (MVs) são sistemas que se propõem a eliminar a incompatibilidade entre duas, em geral diferentes, interfaces e dessa forma habilitar a comunicação entre diferentes sistemas. Nesse sentido, atuando como mediadores, uma MV está em um ponto que a permite fomentar o desenvolvimento de soluções inovadoras para vários problemas. Tais sistemas geralmente utilizam técnicas de emulação, por exemplo, interpretação ou tradução dinâmica de binários, para executar o código da aplicação cliente. Para determinar qual técnica de emulação é a ideal para um trecho de código geralmente é necessário que a MV empregue algum tipo de predição para determinar se o benefício de compilar o código supera os custos. Este problema, na maioria dos casos, resume-se a predizer se o dado trecho de código será frequentemente executado ou não, problema conhecido pelo nome de Predição de Código Quente. Em geral, se o preditor sinalizar um trecho de código como quente, a MV imediatamente toma a decisão de compilá-lo. Contudo, um problema surge nesta estratégia, à resposta do preditor é apenas a decisão de uma heurística e é, portanto, suscetível a erros. Quando o preditor sinaliza como quente um trecho de código que não será frequentemente executado, ou seja, um código que de fato é "frio", ele está fazendo uma predição errônea de código quente. Quando uma predição incorreta é feita, ocorre que a técnica de emulação que a MV utilizará para emular o trecho de código não compensará o seu custo e, portanto a MV gastará mais tempo executando o seu próprio código do que o código da aplicação cliente. Neste trabalho, foi avaliado o impacto de predições incorretas de código quente no desempenho de MVs emulando vários tipos de aplicações. Na análise realizada foi avaliado o preditor de código quente baseado em limiar, uma técnica frequentemente utilizada para identificar regiões de código que serão frequentemente executadas. Para fazer esta análise foi criado um modelo matemático para simular o comportamento de tal preditor e a partir deste modelo uma série de resultados puderam ser explorados. Inicialmente é mostrado que este preditor frequentemente erra a predição e, como conseqüência, o tempo gasto fazendo compilações torna-se o maior componente do tempo de execução da MV. Também é mostrado como diferentes limiares de predição afetam o número de predições incorretas e qual o impacto disto no desempenho da MV. Também são apresentados resultados indicando qual o impacto do custo de compilação, tradução e velocidade do código traduzido no desempenho da MV. Por fim é mostrado que utilizando apenas o conjunto de aplicações do SPEC CPU 2006 para avaliar o desempenho de MVs que utilizam o preditor de código quente baseado em limiar pode levar a resultados imprecisos
Abstract: Virtual machines are systems that aim to eliminate the compatibility gap between two, possible distinct, interfaces, thus enabling them to communicate. This way, acting like a mediator, the VM lies at an important position that enables it to foster innovative solutions for many problems. Such systems usually rely on emulation techniques, such as interpretation and dynamic binary translation, to execute guest application code. In order to select the best emulation technique for each code segment, the VM typically needs to predict whether the cost of compiling the code overcome its future execution time. This problem, in the common case, reduce to predicting if the given code region will be frequently executed or not, a problem called Hot Code Prediction. Generally, if the predictor flags a given code region as hot the VM instantly takes the decision to compile it. However, a problem came out from this strategy, the predictor response is only a decision made by means of a heuristic and thus it can be incorrect. Whenever the predictor flags a code region that will be infrequently executed (cold code) as hot code, we say that it is doing a hotness misprediction. Whenever a misprediction happens it means that the technique the VM will use to emulate the code will not have its cost amortized by executing the optimized code and thus the VM will, in fact, spend more time executing its own code rather than the guest application code. In this work we measure the impact of hotness mispredictions in a VM emulating several kinds of applications. In our analysis we evaluate the threshold-based hot code predictor, a technique commonly used to predict hot code fragments. To do so we developed a mathematical model to simulate the behavior of such predictor and we use it to estimate the impact of mispredictions in several benchmarks. We show that this predictor frequently mispredicts the code hotness and as a result the VM emulation performance becomes dominated by miscompilations. Moreover, we show how the threshold choice can affect the number of mispredictions and how this impacts the VM performance. We also show how the compilation, interpretation and steady state execution cost of translated instructions affect the VM performance. At the end we show that using SPEC CPU 2006 benchmarks to measure the performance of a VM using the threshold-based predictor can lead to misleading results
Mestrado
Ciência da Computação
Mestre em Ciência da Computação

Orientadores: Sandro Rigo, Edson Borin
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação
Made available in DSpace on 2018-08-23T22:21:33Z (GMT). No. of bitstreams: 1 Zinsly_RaphaelMoreira_M.pdf: 2659662 bytes, checksum: 961bbb4fb596ee0d81d07c51279c44ed (MD5) Previous issue date: 2013
Resumo: O resumo poderá ser visualizado no texto completo da tese digital
Abstract: The complete abstract is available with the full electronic document
Mestrado
Ciência da Computação
Mestre em Ciência da Computação

Particle swarms can easily be used to optimize a function with a set of linear equality constraints, by restricting the swarm’s movement to the constrained search space. A “Linear Particle Swarm Optimiser” and “Converging Linear Particle Swarm Optimiser” is developed to optimize linear equality-constrained functions. It is shown that if the entire swarm of particles is initialized to consist of only feasible solutions, then the swarm can optimize the constrained objective function without ever again considering the set of constraints. The Converging Linear Particle Swarm Optimiser overcomes the Linear Particle Swarm Optimiser’s possibility of premature convergence. Training a Support Vector Machine requires solving a constrained quadratic programming problem, and the Converging Linear Particle Swarm Optimiser ideally fits the needs of an optimization method for Support Vector Machine training. Particle swarms are intuitive and easy to implement, and is presented as an alternative to current numeric Support Vector Machine training methods.
Dissertation (MSc)--University of Pretoria, 2007.
Computer Science
Unrestricted

A project funded by the Southern California Edison (SCE) Company, Research Center of Irwindale, California, has supported the development of a performance and parameter prediction software program for use during the refurbishment of large synchronous machines, turbine generators, and synchronous condensers. The computer program was developed for SCE to allow user friendly input of a machine's physical parameters such as pole/field/winding/stator dimensions, type of steel, and other related information in order to calculate the machine's reactances, time constants, and performance curves. The program also allows some degree of design calculation to be performed in order to meet certain design criteria where appropriate. The theory behind the calculations upon which the electrical calculations are built is obtained primarily from literature published in the early 1950's. Since that time, however, machine design has progressed into ever larger generators, most often in the hundreds of Megawatt range with some units exceeding one thousand Megawatts. This size increase has established the practice of winding the stator coils into parallel circuits to maintain acceptable flux and generated voltage levels. These design practices justify a re-examination of the traditional methods used to calculate a machine's reactances and time constants. Accordingly, the use of parallel circuits in the stator winding and their effect on machine parameters has not, to this author's knowledge, been addressed in public literature. These issues are exam fled and modifications to the traditional formulas have been derived for the reactances along with the process of carrying out the calculations on a per pole basis. In addition, the calculation of the parameter and performance equations of a machine are suitable for implementation on a computer due to the length and often iterative calculation procedures. The procedures used to calculate the capability and saturation curves directly from the machine's physical dimensions are developed. During development of the program a forty megawatt generator was measured in order to test and debug the program. Results of this test case are presented and compared to test values obtained at the time of the generator's installation.
Graduation date: 1994

Thesis (M.A.)--York University, 2005. Graduate Programme in Translation.
Typescript. Includes bibliographical references (leaves 88-94). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11831

This thesis advances the state of the art in modeling electric machines in electro-magnetic transient simulation programs, particularly in real-time digital simulators. A new tool, developed in this thesis, expands the application of real-time digital simulators to closed-loop testing of protection relays designed to protect synchronous machines during internal faults. To evaluate the inductances of synchronous machines, a winding function approach was developed in this thesis which is capable of taking into account both the actual distribution of windings and the shape of the pole-arc. Factors such as MMF drop in the iron and effects of slots are compensated by evaluating the effective permeance function of the machine using experimentally measured values of d-, q- and 0- axis inductances. In this winding function approach, the effects of magnetic saturation are also included by considering the actual distribution of magneto-motive force in each loading condition of the machine. The inductances of an experimental machine are evaluated using this approach and validated using the finite-element method and laboratory measurements. This thesis also proposes an embedded phase-domain approach for time-domain simulation of the machine model in electromagnetic transients programs. The approach significantly improves the numerical stability of the simulations. Special numerical techniques are introduced, which speed up the execution of the algorithm as needed for real-time simulation. The machine model is validated in healthy and faulted conditions using simulations and laboratory experiments. Effects of damper grid representation on simulating turn-to-turn faults are investigated. The capability of this new real-time synchronous machine model in closed-loop testing of synchronous machines ground- faults protection relays is clearly demonstrated.

Indiana University-Purdue University Indianapolis (IUPUI)
The objective of this thesis is to compare automated methods for performing analysis of flow cytometry data. Flow cytometry is an important and efficient tool for analyzing the characteristics of cells. It is used in several fields, including immunology, pathology, marine biology, and molecular biology. Flow cytometry measures light scatter from cells and fluorescent emission from dyes which are attached to cells. There are two main tasks that must be performed. The first is the adjustment of measured fluorescence from the cells to correct for the overlap of the spectra of the fluorescent markers used to characterize a cell’s chemical characteristics. The second is to use the amount of markers present in each cell to identify its phenotype. Several methods are compared to perform these tasks. The Unconstrained Least Squares, Orthogonal Subspace Projection, Fully Constrained Least Squares and Fully Constrained One Norm methods are used to perform compensation and compared. The fully constrained least squares method of compensation gives the overall best results in terms of accuracy and running time. Spectral Clustering, Gaussian Mixture Modeling, Naive Bayes classification, Support Vector Machine and Expectation Maximization using a gaussian mixture model are used to classify cells based on the amounts of dyes present in each cell. The generative models created by the Naive Bayes and Gaussian mixture modeling methods performed classification of cells most accurately. These supervised methods may be the most useful when online classification is necessary, such as in cell sorting applications of flow cytometers. Unsupervised methods may be used to completely replace manual analysis when no training data is given. Expectation Maximization combined with a cluster merging post-processing step gives the best results of the unsupervised methods considered.