Dissertations / Theses on the topic 'Fault location (Engineering) Computer programs'
To see the other types of publications on this topic, follow the link: Fault location (Engineering) Computer programs.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 34 dissertations / theses for your research on the topic 'Fault location (Engineering) Computer programs.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Ghimire, Sushma. "Analysis of Fault location methods on transmission lines." ScholarWorks@UNO, 2014. http://scholarworks.uno.edu/td/1800.
Full textAbstract:
Analysis of different types of fault is an important and complex task in a power system. Accurate fault analysis requires models that determine fault distances in a transmission line. The mathematical models accurately capture behavior of different types of faults and location in a timely manner, and prevents damaging power system from fault energy. The purpose of this thesis is to use two methods for determining fault locations and their distance to the reference end buses connected by the faulted transmission line. The two methods used in this investigation are referred to as impedance-based and traveling wave methods. To analyze both methods, various types of faults were modeled and simulated at various locations on a two-bus transmission system using EMTP program. Application and usefulness of each method is identified and presented in the thesis. It is found that Impedance-based methods are easier and more widely used than traveling-wave methods.
2
Caldwell, Gerald W. "Implementation of Configurable Fault Tolerant Processor (CFTP) experiments." Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion.exe/06Dec%5FCaldwell.pdf.
Full textAbstract:
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2006.Thesis Advisor(s): Herschel H. Loomis, Alan A. Ross. "December 2006." Includes bibliographical references (p. 107). Also available in print.
3
Mishra, Shivakant. "Consul: A communication substrate for fault-tolerant distributed programs." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185824.
Full textAbstract:
As human dependence on computing technology increases, so does the need for computer system dependability. This dissertation introduces Consul, a communication substrate designed to help improve system dependability by providing a platform for building fault-tolerant, distributed systems based on the replicated state machine approach. The key issues in this approach--ensuring replica consistency and reintegrating recovering replicas--are addressed in Consul by providing abstractions called fault-tolerant services. These include a broadcast service to deliver messages to a collection of processes reliably and in some consistent order, a membership service to maintain a consistent system-wide view of which processes are functioning and which have failed, and a recovery service to recover a failed process. Fault-tolerant services are implemented in Consul by a unified collection of protocols that provide support for managing communication, redundancy, failures, and recovery in a distributed system. At the heart of Consul is Psync, a protocol that provides for multicast communication based on a context graph that explicitly records the partial (or causal) order of messages. This graph also serves as the basis for novel algorithms used in the ordering, membership, and recovery protocols. The ordering protocol combines the semantics of the operations encoded in messages with the partial order provided by Psync to increase the concurrency of the application. Similarly, the membership protocol exploits the partial ordering to allow different processes to conclude that a failure has occurred at different times relative to the sequence of messages received, thereby reducing the amount of synchronization required. The recovery protocol combines checkpointing with the replay of messages stored in the context graph to recover the state of a failed process. Moreover, this collection of protocols is implemented in a highly-configurable manner, thus allowing a system builder to easily tailor an instance of Consul from this collection of building-block protocols. Consul is built in the x-Kernel and executes standalone on a collection of Sun 3 work-stations. Initial testing and performance studies have been done using two applications: a replicated directory and a distributed wordgame. These studies show that the semantic based order is more efficient than a total order in many situations, and that the overhead imposed by the checkpointing, membership, and recovery protocols is insignificant.
4
Singh, Shailendra. "Automated fault injection and analysis for wired/wireless networks." Diss., Online access via UMI:, 2009.
Find full text
5
Li, Yizhe. "A FAULT LOCATION ALGORITHM FOR UNBALANCED DISTRIBUTION SYSTEM WITHOUT FAULT TYPE INFORMATION." UKnowledge, 2018. https://uknowledge.uky.edu/ece_etds/112.
Full textAbstract:
Power system faults normally result in system damage, profit loss and consumer dissatisfaction. Consequently, there is a strong demand on precise and fast fault location estimation for power system to minimize the system restoration time.
This paper examines a method to locate short-circuit faults on a distribution system with unbalanced loads without fault type information. Bus impedance matrix technique was harnessed in the fault location estimation algorithm. The system data including line impedances, source impedance and distribution system layout was assumed to be known factors, hence pre-fault bus impedance can be calculated and implemented into the algorithm. Corresponding methods to derive system matrix information were discussed. Case studies were performed to evaluate the accuracy of the fault location algorithm and illustrate the robust performance under measurements errors influences, load variation impacts and load compensation implementations.
Traditional fault location methods involve current and voltage measurements mandatorily locating at each ends of faulted section to locate the fault. The method examined finds fault location for distribution system utilizing impedance matrix accompanied with sparse measurements in the power network. This method fully considers the unbalance of distribution system.
6
Ayyagari, Suhaas Bhargava. "ARTIFICIAL NEURAL NETWORK BASED FAULT LOCATION FOR TRANSMISSION LINES." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_theses/657.
Full textAbstract:
This thesis focuses on detecting, classifying and locating faults on electric power transmission lines. Fault detection, fault classification and fault location have been achieved by using artificial neural networks. Feedforward networks have been employed along with backpropagation algorithm for each of the three phases in the Fault location process. Analysis on neural networks with varying number of hidden layers and neurons per hidden layer has been provided to validate the choice of the neural networks in each step. Simulation results have been provided to demonstrate that artificial neural network based methods are efficient in locating faults on transmission lines and achieve satisfactory performances.
7
Perez, Casanova Gaspar M. "Implementation of a fault tolerant control unit within an FPGA for space applications." Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion.exe/06Dec%5FPerez%5FCasanova.pdf.
Full textAbstract:
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2006.Thesis Advisor(s): Herschel H. Loomis, Alan A. Ross. "December 2006." Includes bibliographical references (p. 77-83). Also available in print.
8
Jiang, Bo, and 姜博. "Effective and efficient regression testing and fault localization through diversification, prioritization, and randomization." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46541214.
Full text
9
Qin, Mian. "Wireless sensor network fault localization /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CSED%202008%20QIN.
Full text
10
Chaiwan, Pramote. "NEW ACCURATE FAULT LOCATION ALGORITHM FOR PARALLEL TRANSMISSION LINES." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_diss/813.
Full textAbstract:
Electric power systems have been in existence for over a century. Electric power transmission line systems play an important role in carrying electrical power to customers everywhere. The number of transmission lines in power systems is increasing as global demand for power has increased. Parallel transmission lines are widely used in the modern transmission system for higher reliability. The parallel lines method has economic and environmental advantages over single circuit. A fault that occurs on a power transmission line will cause long outage time if the fault location is not located as quickly as possible. The faster the fault location is found, the sooner the system can be restored and outage time can be reduced.
The main focus of this research is to develop a new accurate fault location algorithm for parallel transmission lines to identify the fault location for long double-circuit transmission lines, taking into consideration mutual coupling impedance, mutual coupling admittance, and shunt capacitance of the line.
In this research, the equivalent PI circuit based on a distributed parameter line model for positive, negative, and zero sequence networks have been constructed for system analysis during the fault. The new method uses only the voltage and current from one end of parallel lines to calculate the fault distance. This research approaches the problem by derivation all equations from positive sequence, negative sequence, and zero sequence network by using KVL and KCL. Then, the fault location is obtained by solving these equations. EMTP has been utilized to generate fault cases under various fault conditions with different fault locations, fault types and fault resistances. Then the algorithm is evaluated using the simulated data. The results have shown that the developed algorithm can achieve highly accurate estimates and is promising for practical applications.
11
Hu, Peifeng. "Automated fault localization a statistical predicate analysis approach /." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38838035.
Full text
12
Hu, Peifeng, and 胡佩鋒. "Automated fault localization: a statistical predicate analysis approach." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38838035.
Full text
13
Chang, Jin. "SINGLE ENDED TRAVELING WAVE BASED FAULT LOCATION USING DISCRETE WAVELET TRANSFORM." UKnowledge, 2014. http://uknowledge.uky.edu/ece_etds/58.
Full textAbstract:
In power transmission systems, locating faults is an essential technology. When a fault occurs on a transmission line, it will affect the whole power system. To find the fault location accurately and promptly is required to ensure the power supply. In this paper, the study of traveling wave theory, fault location method, Karrenbauer transform, and Wavelet transform is presented. This thesis focuses on single ended fault location method. The signal processing technique and evaluation study are presented. The MATLAB SimPowerSystem is used to test and simulate fault scenarios for evaluation studies.
14
Wang, Ying, and 王鷹. "On-line fault diagnosis of nonlinear dynamical systems using recurrentneural networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31242388.
Full text
15
Nökel, Klaus. "Temporally distributed symptoms in technical diagnosis /." Berlin [u.a.] : Springer, 1991. http://www.loc.gov/catdir/enhancements/fy0815/91223341-d.html.
Full text
16
Mok, Hing-tung. "Online fault detection and isolation of nonlinear systems based on neurofuzzy networks." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B39794064.
Full text
17
Mok, Hing-tung, and 莫興東. "Online fault detection and isolation of nonlinear systems based on neurofuzzy networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B39794064.
Full text
18
Kung, Chi-yau, and 龔子游. "Fuzzy genetic modelling of air-conditioning systems for fault detection and diagnosis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B43895682.
Full text
19
Tiew, Chin-Yaw. "On improving the performance of parallel fault simulation for synchronous sequential circuits." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-03042009-040323/.
Full text
20
Chang, Hsuan-Kai. "An integrated SPC/EPC system for fault diagnosis." Diss., Online access via UMI:, 2009.
Find full textAbstract:
Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Systems Science and Industrial Engineering, 2009.Includes bibliographical references.
21
Patrick-Aldaco, Romano. "A Model Based Framework for Fault Diagnosis and Prognosis of Dynamical Systems with an Application to Helicopter Transmissions." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16266.
Full textAbstract:
The thesis presents a framework for integrating models, simulation, and experimental data to diagnose incipient failure modes and prognosticate the remaining useful life of critical components, with an application to the main transmission of a helicopter. Although the helicopter example is used to illustrate the methodology presented, by appropriately adapting modules, the architecture can be applied to a variety of similar engineering systems. Models of the kind referenced are commonly referred to in the literature as physical or physics-based models. Such models utilize a mathematical description of some of the natural laws that govern system behaviors.
The methodology presented considers separately the aspects of diagnosis and prognosis of engineering systems, but a similar generic framework is proposed for both. The methodology is tested and validated through comparison of results to data from experiments carried out on helicopters in operation and a test cell employing a prototypical helicopter gearbox. Two kinds of experiments have been used. The first one retrieved vibration data from several healthy and faulted aircraft transmissions in operation. The second is a seeded-fault damage-progression test providing gearbox vibration data and ground truth data of increasing crack lengths. For both kinds of experiments, vibration data were collected through a number of accelerometers mounted on the frame of the transmission gearbox. The applied architecture consists of modules with such key elements as the modeling of vibration signatures, extraction of descriptive vibratory features, finite element analysis of a gearbox component, and characterization of fracture progression.
Contributions of the thesis include: (1) generic model-based fault diagnosis and failure prognosis methodologies, readily applicable to a dynamic large-scale mechanical system; (2) the characterization of the vibration signals of a class of complex rotary systems through model-based techniques; (3) a reverse engineering approach for fault identification using simulated vibration data; (4) the utilization of models of a faulted planetary gear transmission to classify descriptive system parameters either as fault-sensitive or fault-insensitive; and (5) guidelines for the integration of the model-based diagnosis and prognosis architectures into prognostic algorithms aimed at determining the remaining useful life of failing components.
22
Schneider, C. "Using unsupervised machine learning for fault identification in virtual machines." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7327.
Full textAbstract:
Self-healing systems promise operating cost reductions in large-scale computing environments through the automated detection of, and recovery from, faults. However, at present there appears to be little known empirical evidence comparing the different approaches, or demonstrations that such implementations reduce costs. This thesis compares previous and current self-healing approaches before demonstrating a new, unsupervised approach that combines artificial neural networks with performance tests to perform fault identification in an automated fashion, i.e. the correct and accurate determination of which computer features are associated with a given performance test failure. Several key contributions are made in the course of this research including an analysis of the different types of self-healing approaches based on their contextual use, a baseline for future comparisons between self-healing frameworks that use artificial neural networks, and a successful, automated fault identification in cloud infrastructure, and more specifically virtual machines. This approach uses three established machine learning techniques: Naïve Bayes, Baum-Welch, and Contrastive Divergence Learning. The latter demonstrates minimisation of human-interaction beyond previous implementations by producing a list in decreasing order of likelihood of potential root causes (i.e. fault hypotheses) which brings the state of the art one step closer toward fully self-healing systems. This thesis also examines the impact of that different types of faults have on their respective identification. This helps to understand the validity of the data being presented, and how the field is progressing, whilst examining the differences in impact to identification between emulated thread crashes and errant user changes – a contribution believed to be unique to this research. Lastly, future research avenues and conclusions in automated fault identification are described along with lessons learned throughout this endeavor. This includes the progression of artificial neural networks, how learning algorithms are being developed and understood, and possibilities for automatically generating feature locality data.
23
Johnson, Darrel E. "Estimating the Dynamic Sensitive Cross Section of an FPGA Design through Fault injection." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd803.pdf.
Full text
24
Fonda, James William. "Energy efficient wireless sensor network protocols for monitoring and prognostics of large scale systems." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2008. http://scholarsmine.mst.edu/thesis/pdf/fonda_09007dcc805070d4.pdf.
Full textAbstract:
Thesis (Ph. D.)--Missouri University of Science and Technology, 2008.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 27, 2008) Includes bibliographical references.
25
Iftakhar, Mohammad M. "Thevenin Equivalent Circuit Estimation and Application for Power System Monitoring and Protection." UKnowledge, 2008. http://uknowledge.uky.edu/gradschool_theses/583.
Full textAbstract:
The Estimation of Thevenin Equivalent Parameters is useful for System Monitoring and Protection. We studied a method for estimating the Thevenin equivalent circuits. We then studied two applications including voltage stability and fault location. A study of the concepts of Voltage Stability is done in the initial part of this thesis. A Six Bus Power System Model was simulated using MATLAB SIMULINK®. Subsequently, the Thevenin Parameters were calculated. The results were then used for two purposes, to calculate the Maximum Power that can be delivered and for Fault Location.
26
Maree, Charl. "Diagnostic monitoring of dynamic systems using artificial immune systems." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/1780.
Full textAbstract:
Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2006.The natural immune system is an exceptional pattern recognition system based on memory and learning that is capable of detecting both known and unknown pathogens. Artificial immune systems (AIS) employ some of the functionalities of the natural immune system in detecting change in dynamic process systems. The emerging field of artificial immune systems has enormous potential in the application of fault detection systems in process engineering. This thesis aims to firstly familiarise the reader with the various current methods in the field of fault detection and identification. Secondly, the notion of artificial immune systems is to be introduced and explained. Finally, this thesis aims to investigate the performance of AIS on data gathered from simulated case studies both with and without noise. Three different methods of generating detectors are used to monitor various different processes for anomalous events. These are: (1) Random Generation of detectors, (2) Convex Hulls, (3) The Hypercube Vertex Approach. It is found that random generation provides a reasonable rate of detection, while convex hulls fail to achieve the required objectives. The hypercube vertex method achieved the highest detection rate and lowest false alarm rate in all case studies. The hypercube vertex method originates from this project and is the recommended method for use with all real valued systems, with a small number of variables at least. It is found that, in some cases AIS are capable of perfect classification, where 100% of anomalous events are identified and no false alarms are generated. Noise has, expectedly so, some effect on the detection capability on all case studies. The computational cost of the various methods is compared, which concluded that the hypercube vertex method had a higher cost than other methods researched. This increased computational cost is however not exceeding reasonable confines therefore the hypercube vertex method nonetheless remains the chosen method. The thesis concludes with considering AIS’s performance in the comparative criteria for diagnostic methods. It is found that AIS compare well to current methods and that some of their limitations are indeed solved and their abilities surpassed in certain cases. Recommendations are made to future study in the field of AIS. Further the use of the Hypercube Vertex method is highly recommended in real valued scenarios such as Process Engineering.
27
Gongora, Wylliam Salviano. "Uma abordagem neural no diagnóstico de falhas em rolamentos de motores de indução trifásicos." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/782.
Full textAbstract:
Fundação Araucária, CNPqO motor de indução trifásico ocupa uma posição de destaque na produção de força eletromotriz e isso o torna vastamente utilizado em aplicações industriais. Consequentemente, também fica submetido às condições de funcionamento e manutenção das máquinas como um todo, bem como das falhas que os mesmos estão sujeitos. Assim, este trabalho propõe um método alternativo aos tradicionais para detecção de falhas em rolamentos de motores de indução trifásicos ligados diretamente a rede elétrica. Os objetivos consistem na utilização de uma abordagem neural capaz de classificar a existência de falha de rolamento com um alto percentual de acerto. Analisando para isto, no domínio do tempo, um semiciclo das tensões de alimentação e das correntes de estator dos motor em estudo. A proposta é validada através de ensaios experimentais num computador e de forma on-line embarcada num DSP. Como conseqüência do trabalho tem-se a criação de um banco de dados de falhas, com mais de mil ensaios envolvendo as principais falhas encontradas em motores de indução trifásicos. Estes ensaios são realizados contemplando as condições de desbalanço de tensão de alimentação e com várias situações de carga mecânica no eixo da máquina.
The three phase induction motor occupies a prominent position in the production of electromotive force and this makes it widely used in industrial applications. Consequently, it is also subjected to the conditions of operation and maintenance of the machines as a whole, as well as faults which they are subject. Thus, this paper proposes an alternative method to traditional in fault detection in bearing of induction motors connected directly to the power grid. The objectives consist in using a neural approach able to classify the existence of bearing fault with a high percentage of correct. Analyzing for this, in the time domain, one half cycle of the voltages and currents of stator the motor in study. The proposal is validated through experimental tests on a computer and monitoring on-line embedded in a DSP. As a result, the work has the creation of a database of failure, with more than a thousand trials involving the main flaws found in three phase induction motors. These tests are performed considering the conditions of voltage supply unbalanced and with several situations of mechanical load on the machine shaft.
28
Almeida, Diony José de. "Proposta de um sistema de simulação e diagnóstico de falhas aplicado a um sistema de produção." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/1397.
Full textAbstract:
Este trabalho apresenta uma proposta de um software de simulação e diagnóstico de falhas aplicado a um sistema de automação. para realizar esta tarefa foi desenvolvido um estudo de caso que contem um problema de automação industrial. Deste estudo foi retirado um modelo, usado como base para criar do software de simulação que segue as especificações dos modelos, no qual é possível observar a evolução dos eventos através de sua linguagem e diagnosticar falhas, quando estas ocorrem em uma das máquinas da planta. O processo de diagnóstico de falhas tem como base as regras de diagnosticabilidade apresentadas na literatura. As máquinas, assim como suas restrições, são modeladas dentro do próprio software, onde são definidas as estruturas de cada automato assim como características como observabilidade, controlabilidade e a possibilidade de falhar. Os testes realizados no sistema apresentado mostraram que a linguagem de controle consegue, mesmo permitindo um nivel de liberdade ao sistema, identificar as falhas verificando somente para os eventos que ocorrem após a ocorrência da mesma.This work we presents a proposal a software of simulation and fault diagnosis applied to an automation system. In that task was developed , a case study that contains a problem of industrial automation. The study was used as the source for creating the simulation that follows the specifications of software models, where you can observe the evolution of events through its language and diagnose faults when they occur in one of the machines of the plant. The process of fault diagnosis is based on the rules of diagnosticabilidades presented in the literature. The machines, as well as its restrictions are modeled within the software itself, where the structures of each automaton are defined the caracteristics as observability an the possibility of failure. The tests in the system showed that of the language used can allowing identify fails, checking only for events that occorem after the occurence the fails.
29
Mori, Fernando Maruyama. "Uma metodologia de desenvolvimento de diagnóstico guiado para veículos automotivos." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/981.
Full textAbstract:
A utilização de ferramentas externas de diagnóstico guiado tem se tornado cada vez mais importante nas atividades de pós-venda da indústria automotiva. Isso se dá principalmente devido ao uso extensivo de sistemas embarcados nos veículos, tornando-os mais complexos e difíceis de diagnosticar. Atualmente, as técnicas empregadas para o desenvolvimento da ferramenta de diagnóstico guiado são fortemente dependentes da experiência do projetista e centralizadas nas peças e subsistemas do veículo, possibilitando baixo grau de flexibilidade e reaproveitamento da informação. Este trabalho propõe uma nova metodologia para o desenvolvimento da ferramenta de diagnóstico guiado, aplicado a um estudo de caso da indústria automotiva, numa arquitetura de software em três camadas: peças e componentes do veículo, informações e estratégia para o diagnóstico e uma camada de apresentação. Isso permite grande flexibilidade no projeto da ferramenta de diagnóstico guiado para diferentes modelos de veículos, fabricantes de peças e sistemas automotivos. A metodologia proposta é aplicada em um estudo de caso de diagnóstico da Volvo caminhões, mostrando o processo de adaptação da arquitetura de software de três camadas à metodologia proposta e seu impacto no custo do desenvolvimento da ferramenta de diagnóstico.External guided diagnostic tools are increasingly important to the aftermarket business of automotive industry. It occurs mainly due to the extensive using of embedded systems in vehicles, making them more complex and difficult to diagnose. Currently, the techniques used to develop a guided diagnostic tool are strongly dependent on designer’s experience and are usually focused on parts and vehicle’s subsystems, allowing low flexibility and reduced information reusage. This paper proposes a new methodology for development of a guided diagnostic tool applied to the automotive industry. This methodology is based on a three-tier software architecture composed of vehicle’s parts and components, diagnostic information and strategy, and presentation layer. It allows great flexibility for designing a guided diagnostic tool for different vehicle models, parts OEMs and automotive systems. The proposed methodology has been applied to a case study at Volvo Trucks. The corresponding adaptation process to the three-tier software architecture is presented as well as its impact on development costs.
5000
30
Silva, Lyvia Regina Biagi. "Classificação de falhas em maquinas eletricas usando redes neurais, modelos wavelet e medidas de informação." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/1201.
Full textAbstract:
CAPES; CNPqEste trabalho apresenta uma proposta de metodologia para detecção e classificação de falhas em motores de indução trifásicos ligados diretamente à rede elétrica. O método proposto é baseado na análise dos sinais de corrente do estator, com e sem a presença de falhas nos rolamentos, estator e rotor. Um dos efeitos desses tipos de falhas é o aparecimento de componentes de frequência específicas, relacionados à velocidade de rotação da máquina. Os sinais foram analisados usando a decomposição wavelet-packet, que permite a avaliação dos sinais em bandas de frequência de tamanhos variáveis. A partir dessa decomposição, aplicaram-se medidas de previsibilidade, como entropia relativa, potência de previsão e variância de erro normalizada, obtida com a análise de componentes previsíveis. Com essas medidas, foi possível verificar quais componentes da decomposição são mais previsíveis. Neste trabalho, a variância de erro normalizada e a potência de previsão foram utilizadas como entradas para três topologias de redes neurais artificiais classificadoras: perceptron multicamadas, redes de funções de base radial e mapas auto-organizáveis de Kohonen. Foram testados seis diferentes vetores de entrada para as redes neurais, utilizando medidas de previsibilidade e número de elementos dos vetores variados. Os ensaios foram realizados considerando amostras de sinal de diferentes motores, com vários tipos de falha, operando sob diversos regimes de torque e condições de desequilíbrio de tensão. Primeiramente, os sinais foram classificados em dois padrões: com e sem a presença de falhas. Posteriormente, detectou-se o tipo de falha presente nos sinais: rolamento, estator ou rotor. Por último, as amostras foram classificadas dentro do subgrupo de falha em que estavam presentes.
This work presents a methodology for diagnosis and classification of faults in three-phase induction motors connected directly to the power grid. The proposed method is based on the analysis of the stator current signals, with and without the presence of faults in the bearings, stator and rotor. These faults cause the presence of specific frequency components that are related to the machine rotational speed. The signals were analyzed using wavelet-packet decomposition, which allows a multiresolution evaluation of the signals. Using this decomposition, we estimated some predictability measures, such as relative entropy, predictive power and normalized error variance, obtained with the predictability component analysis. With this measures, we verified which were the most predictable components. In this work, normalized error variance and the predictive power were used as inputs to three topologies of artificial neural networks used as classifiers: multilayer perceptron, radial basis function and Kohonen self-organizing maps. We tested six different input vectors to the artificial neural networks, in which we vary the predictability measures and the number of elements of the vectors. The studies were performed considering samples of signals from different motors, with various kinds of faults, working under several load conditions and with voltage unbalance. The signals were firstly classified in two patterns: with and without the presence of faults. After, we detected the kind of fault was present in the signal: bearing, stator or rotor fault. Last, the samples were classified inside the subgroup in which they were.
31
Felix, Kleber Gonçalves. "Classificação automática de falhas em arquitetura orientada a serviços." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2822.
Full textAbstract:
Uma arquitetura distribuída é composta de diversos sistemas que trocam mensagens entre si. Falhas na integração destes sistemas podem ocorrer, exigindo uma investigação detalhada dos profissionais de suporte para encontrar a causa raiz do problema. O processo manual de identificação de falhas é difícil e demorado. Ganhos significativos podem ser obtidos através da automação do processo de classificação de falhas. Este trabalho tem por objetivo apresentar um método para auxílio no processo de diagnóstico de falhas, classificando automaticamente as falhas geradas em uma arquitetura orientada a serviços. Este método, denominado SOAFaultControl, se beneficia de arquiteturas distribuídas que adotam SOA e um Enterprise Service Bus (ESB). Utilizando-se de técnicas de aprendizado de máquina, foi possível estabelecer um modelo para classificação de falhas em categorias preestabelecidas. Para alcançar o objetivo deste trabalho foi necessário testar e avaliar os seguintes algoritmos de aprendizagem de máquina: Support Vector Machine, Naive Bayes e AdaBoost. Como resultado, o algoritmo Support Vector Machine obteve melhor desempenho nas métricas: acurácia, precisão, revocação e F1.A distributed architecture is composed of many systems that exchange messages between each other. Faults in the integration of these systems may occur and they required a detailed investigation of support professionals to identifying the root cause of the problem. The manual process to identify causes of failure is difficult and time-consuming. Significant efficiency gains can be achieved by automating the faults classification process. This work presents a method to support the automated fault diagnostic process, automatically classifying faults generated in a Service Oriented Architecture (SOA). This method denominated SOAFaultControl, may be executed in a distributed architecture that adote SOA and an Enterprise Service Bus (ESB). Using machine learning techniques, was possible build a model to classify fault messages captured in a SOA environment, in pre-established classes. To achieve the objectives of this work it was necessary to test the following machine learning algorithms: Support Vector Machine, Naive Bayes, and AdaBoost. Results show that Support Vector Machine algorithm achieved better performance in the following metrics: precision, accuracy, recall, and F1.
32
"Design and implementation of a fault-tolerant multimedia network and a local map based (LMB) self-healing scheme for arbitrary topology networks." 1997. http://library.cuhk.edu.hk/record=b5889296.
Full textAbstract:
by Arion Ko Kin Wa.Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.
Includes bibliographical references (leaves 101-[106]).
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Overview --- p.1
Chapter 1.2 --- Service Survivability Planning --- p.2
Chapter 1.3 --- Categories of Outages --- p.3
Chapter 1.4 --- Goals of Restoration --- p.4
Chapter 1.5 --- Technology Impacts on Network Survivability --- p.5
Chapter 1.6 --- Performance Models and Measures in Quantifying Network Sur- vivability --- p.6
Chapter 1.7 --- Organization of Thesis --- p.6
Chapter 2 --- Design and Implementation of A Survivable High-Speed Mul- timedia Network --- p.8
Chapter 2.1 --- An Overview of CUM LAUDE NET --- p.8
Chapter 2.2 --- The Network Architecture --- p.9
Chapter 2.2.1 --- Architectural Overview --- p.9
Chapter 2.2.2 --- Router-Node Design --- p.11
Chapter 2.2.3 --- Buffer Allocation --- p.12
Chapter 2.2.4 --- Buffer Transmission Priority --- p.14
Chapter 2.2.5 --- Congestion Control --- p.15
Chapter 2.3 --- Protocols --- p.16
Chapter 2.3.1 --- Design Overview --- p.16
Chapter 2.3.2 --- ACTA - The MAC Protocol --- p.17
Chapter 2.3.3 --- Protocol Layering --- p.18
Chapter 2.3.4 --- "Segment, Datagram and Packet Format" --- p.20
Chapter 2.3.5 --- Fast Packet Routing --- p.22
Chapter 2.3.6 --- Local Host NIU --- p.24
Chapter 2.4 --- The Network Restoration Strategy --- p.25
Chapter 2.4.1 --- The Dual-Ring Model and Assumptions --- p.26
Chapter 2.4.2 --- Scenarios of Network Failure and Remedies --- p.26
Chapter 2.4.3 --- Distributed Fault-Tolerant Algorithm --- p.26
Chapter 2.4.4 --- Distributed Auto-Healing Algorithm --- p.28
Chapter 2.4.5 --- The Network Management Signals --- p.31
Chapter 2.5 --- Performance Evaluation --- p.32
Chapter 2.5.1 --- Restoration Time --- p.32
Chapter 2.5.2 --- Reliability Measures --- p.34
Chapter 2.5.3 --- Network Availability During Restoration --- p.41
Chapter 2.6 --- The Prototype --- p.42
Chapter 2.7 --- Technical Problems Encountered --- p.45
Chapter 2.8 --- Chapter Summary and Future Development --- p.46
Chapter 3 --- A Simple Experimental Network Management Software - NET- MAN --- p.48
Chapter 3.1 --- Introduction to NETMAN --- p.48
Chapter 3.2 --- Network Management Basics --- p.49
Chapter 3.2.1 --- The Level of Management Protocols --- p.49
Chapter 3.2.2 --- Architecture Model --- p.51
Chapter 3.2.3 --- TCP/IP Network Management Protocol Architecture --- p.53
Chapter 3.2.4 --- A Standard Network Management Protocol On Internet - SNMP --- p.54
Chapter 3.2.5 --- A Standard For Managed Information --- p.55
Chapter 3.3 --- The CUM LAUDE Network Management Protocol Suite (CNMPS) --- p.56
Chapter 3.3.1 --- The Architecture --- p.53
Chapter 3.3.2 --- Goals of the CNMPS --- p.59
Chapter 3.4 --- Highlights of NETMAN --- p.61
Chapter 3.5 --- Functional Descriptions of NETMAN --- p.63
Chapter 3.5.1 --- Topology Menu --- p.64
Chapter 3.5.2 --- Fault Manager Menu --- p.65
Chapter 3.5.3 --- Performance Meter Menu --- p.65
Chapter 3.5.4 --- Gateway Utility Menu --- p.67
Chapter 3.5.5 --- Tools Menu --- p.67
Chapter 3.5.6 --- Help Menu --- p.68
Chapter 3.6 --- Chapter Summary --- p.68
Chapter 4 --- A Local Map Based (LMB) Self-Healing Scheme for Arbitrary Topology Networks --- p.70
Chapter 4.1 --- Introduction --- p.79
Chapter 4.2 --- An Overview of Existing DCS-Based Restoration Algorithms --- p.72
Chapter 4.3 --- The Network Model and Assumptions --- p.74
Chapter 4.4 --- Basics of the LMB Scheme --- p.75
Chapter 4.4.1 --- Restoration Concepts --- p.75
Chapter 4.4.2 --- Terminology --- p.76
Chapter 4.4.3 --- Algorithm Parameters --- p.77
Chapter 4.5 --- Performance Assessments --- p.78
Chapter 4.6 --- The LMB Network Restoration Scheme --- p.80
Chapter 4.6.1 --- Initialization - Local Map Building --- p.80
Chapter 4.6.2 --- The LMB Restoration Messages Set --- p.81
Chapter 4.6.3 --- Phase I - Local Map Update Phase --- p.81
Chapter 4.6.4 --- Phase II - Update Acknowledgment Phase --- p.82
Chapter 4.6.5 --- Phase III - Restoration and Confirmation Phase --- p.83
Chapter 4.6.6 --- Phase IV - Cancellation Phase --- p.83
Chapter 4.6.7 --- Re-Initialization --- p.84
Chapter 4.6.8 --- Path Route Monitoring --- p.84
Chapter 4.7 --- Performance Evaluation --- p.84
Chapter 4.7.1 --- The Testbeds --- p.84
Chapter 4.7.2 --- Simulation Results --- p.86
Chapter 4.7.3 --- Storage Requirements --- p.89
Chapter 4.8 --- The LMB Scheme on ATM and SONET environment --- p.92
Chapter 4.9 --- Future Work --- p.94
Chapter 4.10 --- Chapter Summary --- p.94
Chapter 5 --- Conclusion and Future Work --- p.96
Chapter 5.1 --- Conclusion --- p.95
Chapter 5.2 --- Future Work --- p.99
Bibliography --- p.101
Chapter A --- Derivation of Communicative Probability --- p.107
Chapter B --- List of Publications --- p.110
33
Tangkoonsombati, Choowong. "Assembly tolerance analysis in geometric dimensioning and tolerancing." Thesis, 1994. http://hdl.handle.net/1957/35573.
Full textAbstract:
Tolerance analysis is a major link between design and
manufacturing. An assembly or a part should be designed
based on its functions, manufacturing processes, desired
product quality, and manufacturing cost. Assembly tolerance
analysis performed at the design stage can reduce potential
manufacturing and assembly problems. Several commonly used
assembly tolerance analysis models and their limitations are
reviewed in this research. Also, a new assembly tolerance
analysis model is developed to improve the limitations of the
existing assembly tolerance analysis models. The new model
elucidates the impact of the flatness symbol (one of the
Geometric Dimensioning and Tolerancing (GD&T) specification
symbols) and reduces design variables into simple
mathematical equations. The new model is based on beta
distribution of part dimensions. In addition, a group of
manufacturing variables, including quality factor, process
tolerance, and mean shift, is integrated in the new assembly
tolerance analysis model.
A computer integrated system has been developed to
handle four support systems for the performance of tolerance
analysis in a single computer application. These support
systems are: 1) the CAD drawing system, 2) the Geometric
Dimensioning and Tolerancing (GD&T) specification system, 3)
the assembly tolerance analysis model, and 4) the tolerance
database operating under the Windows environment. Dynamic
Data Exchange (DDE) is applied to exchange the data between
two different window applications, resulting in improvement
of information transfer between the support systems. In this
way, the user is able to use this integrated system to select
a GD&T specification, determine a critical assembly dimension
and tolerance, and access the tolerance database during the
design stage simultaneously. Examples are presented to
illustrate the application of the integrated tolerance
analysis system.Graduation date: 1995
34
"AI-assisted local area network diagnostic system." Chinese University of Hong Kong, 1993. http://library.cuhk.edu.hk/record=b5887709.
Full textAbstract:
by Chi-kwong Fong.Thesis (M.Sc.)--Chinese University of Hong Kong, 1993.
Includes bibliographical references (leaves 30-[31]).
Chapter 1 --- Introduction --- p.1
Chapter 2 --- Data Capture Subsystem --- p.7
Chapter 3 --- Anomaly Detection Subsystem --- p.10
Chapter 4 --- Descriptive Language Translation System --- p.14
Chapter 5 --- Rule-based Analysis Subsystem --- p.20
Chapter 6 --- Testing Results --- p.22
Chapter 7 --- Summary --- p.27
Bibliography --- p.30