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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

CausViz: Visual representations of complex causal semantics based on theories of perception

Kadaba, Nivedita 01 September 2011 (has links)
Michotte's theory of ampliation suggests that causal relationships are perceived by objects animated under appropriate spatiotemporal conditions. In this thesis I extend the theory of ampliation and propose that the immediate perception of complex causal relations is also dependent upon a set of structural and temporal rules. The thesis aims at achieving two main goals. The first goal is to define a taxonomy of semantics that describe different causal events in the environment. Ten semantics are defined in this thesis and divided into two main groups; simple causal semantics and complex causal semantics. Simple causal semantics describe basic semantics, which form the building blocks for more complex information and include causal amplification, causal dampening, causal strength, and causal multiplicity. Complex causal semantics are built by enhancing or combining one or more simple semantics and include additive causality, contradictive causality, fully-mediated causality, partially-mediated causality, threshold causality, and bidirectional causality. The second goal of this thesis is to design simple visual representations to describe the causal information. Three representation types were designed during the course of this research; static-graph, static-sequence, and animation. Nine experiments were also conducted to test the effectiveness of these representations. The first five experiments compared the static-graph and the animated representations through Memory Recall and Intuitiveness Evaluations tests. Results of these experiments suggest that animations were ~8% more accurate and performed ~9% faster than the static-graph representations. The last four experiments compared an enhanced static representation, called static-sequence, to the animations to test if sequential animation of causal relations had any influence on the superior performance of the animations in the previous experiments. Results of these experiments suggest that there was no significant difference in the performance of the static-sequence representations when compared to the static-graph representations. The results also suggest that the animations performed more accurately than their static counterparts mainly due to their intuitiveness. Overall our results show that animated diagrams that are designed based on perceptual rules such as those proposed by Michotte have the potential to facilitate comprehension of complex causal relations.
2

CausViz: Visual representations of complex causal semantics based on theories of perception

Kadaba, Nivedita 01 September 2011 (has links)
Michotte's theory of ampliation suggests that causal relationships are perceived by objects animated under appropriate spatiotemporal conditions. In this thesis I extend the theory of ampliation and propose that the immediate perception of complex causal relations is also dependent upon a set of structural and temporal rules. The thesis aims at achieving two main goals. The first goal is to define a taxonomy of semantics that describe different causal events in the environment. Ten semantics are defined in this thesis and divided into two main groups; simple causal semantics and complex causal semantics. Simple causal semantics describe basic semantics, which form the building blocks for more complex information and include causal amplification, causal dampening, causal strength, and causal multiplicity. Complex causal semantics are built by enhancing or combining one or more simple semantics and include additive causality, contradictive causality, fully-mediated causality, partially-mediated causality, threshold causality, and bidirectional causality. The second goal of this thesis is to design simple visual representations to describe the causal information. Three representation types were designed during the course of this research; static-graph, static-sequence, and animation. Nine experiments were also conducted to test the effectiveness of these representations. The first five experiments compared the static-graph and the animated representations through Memory Recall and Intuitiveness Evaluations tests. Results of these experiments suggest that animations were ~8% more accurate and performed ~9% faster than the static-graph representations. The last four experiments compared an enhanced static representation, called static-sequence, to the animations to test if sequential animation of causal relations had any influence on the superior performance of the animations in the previous experiments. Results of these experiments suggest that there was no significant difference in the performance of the static-sequence representations when compared to the static-graph representations. The results also suggest that the animations performed more accurately than their static counterparts mainly due to their intuitiveness. Overall our results show that animated diagrams that are designed based on perceptual rules such as those proposed by Michotte have the potential to facilitate comprehension of complex causal relations.
3

Model-Based Testing of Dosing System : An Introductory Review on Model-Based Automatic Test Case Generation with Matlab Simulink Proof-of-concept / Modellbaserad Testning av doseringssystem : En översiktlig genomgång av modellbaserad automatisk testfallgenerering med Matlab Simulink proof-of-concept

Setyawan, Albertus Adrian January 2021 (has links)
A modern truck contains a large number of functionalities implemented in its electronics system. Thus, testing all of these functions employs a considerable effort. The execution of tests against the system has been automated for a long time. Unfortunately, most of the test is still designed manually these days. This manual test design is sometimes not comprehensive enough to cover all possible scenarios within a complex system. At the moment, there is also a growing trend in the development process based on the model. Furthermore, model-based software can handle events and signal behaviour more robustly[1]. This thesis investigates the technique in model-based testing. The study evaluates the requirement modelling and automated abstract test generation of model-based testing over the existing testing method. A cause-effect graph is utilized for the modelling in Matlab Simulink tool with DesignVerifier feature. The case study is the truck dosing system in Scania. The results are the following. The temporal and static requirements modelling are capable of being modelled using the cause-effect graph in Matlab Simulink. Compared to the traditional method, the MBT method can achieve higher requirement coverage and more rigorous test with optimized test case generation. The MBT method also has a rapid test case generation time suitable for quick design iteration. However, the total test development time (including test case generation time) of using MBT is 12.5% higher than the manual method. Using a model-based platform like Matlab Simulink is recommended to assist the manual testing, not to replace the test flow entirely with the current research state. / En modern truck innehåller ett stort antal funktioner implementerade i dess elektroniksystem. Att testa alla dessa funktioner kräver därför en avsevärd ansträngning. Utförandet av tester mot systemet har varit automatiserat under lång tid. Tyvärr är det mesta av testet fortfarande utformat manuellt nu för tiden. Denna manuella testdesign är ibland inte tillräckligt omfattande för att täcka alla möjliga scenarier inom ett komplext system. För tillfället finns det också en växande trend i utvecklingsprocessen utifrån modellen. Dessutom kan modellbaserad programvara hantera händelser och signalbeteende mer robust[1]. Detta examensarbete undersöker tekniken i modellbaserad testning. Studien utvärderar kravmodellering och automatiserad abstrakt testgenerering av modellbaserad testning över den befintliga testmetoden. En cause-effect graph används för modelleringen i Matlab Simulink-verktyget med Design Verifier-funktionen. Fallstudien är lastbilens doseringssystem i Scania. Resultaten är följande. Den tidsmässiga och statiska kravmodelleringen kan modelleras med hjälp av cause-effect graph i Matlab Simulink. Jämfört med den traditionella metoden kan MBT-metoden uppnå högre kravtäckning och mer rigorösa test med optimerad testfallsgenerering. MBT-metoden har också en snabb genereringstid för testfall som är lämplig för snabb designiteration. Den totala testutvecklingstiden (inklusive genereringstid för testfall) för att använda MBT är 12,5% högre än den manuella metoden. Att använda en modellbaserad plattform som Matlab Simulink rekommenderas för att underlätta den manuella testningen, inte för att ersätta testflödet helt med det aktuella forskningsläget.
4

Management des processus collaboratifs dans les systèmes PLM / Collaborative processes management within PLM systems

El Kadiri, Soumaya 04 December 2009 (has links)
La tendance actuelle des organisations à développer des collaborations avec différentes parties prenantes a pour objectif de répondre à une complexité de plus en plus importante des produits et de favoriser l'innovation ; le tout sous de fortes pressions d'un environnement économique, liées aux exigences du développement durable, de l'accélération des cycles de vie, des normes qualité, etc. Les SIP tendent à garantir une transversalité entre l'ensemble des phases du cycle de vie produit ; répondant ainsi aux besoins d'amélioration de la qualité produit, de maîtrise des processus et de réduction des délais, tout en favorisant la collaboration. La complexité des processus collaboratifs liée à la gestion du cycle de vie du produit ne peut faire l’économie d’une réflexion sur les ressources engagées au regard des objectifs poursuivis, ni même d’une balance économique globale des coûts supportés. Ainsi les critères d’efficacité et d’efficience s’ajoutent aux critères les plus traditionnels du temps imparti et du degré de qualité visé. L'objectif de cette thèse consiste à définir une démarche méthodologique et applicative pour répondre à la question suivante : "Comment instrumenter le SIP pour analyser les activités menées au sein du système et déceler les freins au travail collaboratif ?". Ainsi, nous présentons dans cette thèse un cadre méthodologique et architectural permettant d'assurer un pilotage des processus collaboratifs dans les SIP. Il s'agit entre autre de mettre en place une expérience d'observation basée sur l’ingénierie des traces ; et de mener une réflexion sur la définition d'indicateurs permettant de mettre en place un contrôle de l'activité collaborative. La mise en œuvre effective de ces actions implique la définition d’une architecture complémentaire et générique adaptée à l'environnement du SIP. Finalement, le développement d'un prototype, intégré par la suite au SIP @udros, nous a permis de valider le cadre méthodologique et applicatif de cette thèse. / The current trend of organizations to develop partnerships with various stakeholders aims to respond to a rising complexity, of products and to foster innovation; all under great pressures of an economical environment, related to sustainability requirements, lifecycle acceleration, quality standards, etc. PLM systems tend to ensure the transversality within all the stages of product lifecycle; meeting the needs of product quality improvement, process control and delays reduction, while fostering collaboration. The complexity of collaborative processes related to the product lifecycle management cannot lean only on the engaged resources, or on the global balance between costs, budget, and receipts. Then efficacy and efficiency criterions come on top of the traditional ones (quality level, time, etc.). This thesis aims to propose a methodological and applicative approach responding to the following research question: “How can PLM System be « instrumented » in order to analyze the collaborative activities and to reveal the brakes causes?” We present in this thesis a methodological and architectural framework to ensure a collaborative process management in PLM System. The methodological framework leans on observation experiences based on tracks engineering (tracks generated by PLM system) and indicators definition supporting the control of the collaborative activity. The principal objective is to reduce risks by reacting in real time to the incidents or dysfunctions that may occur. The effective implementation of these actions involves the definition of a generic and complementary architecture suitable to the environment of the system. Finally, the development of a prototype, integrated then to the system @udros, allowed us to validate the methodological and architectural framework of this thesis.
5

End-to-end Timing Analysis of Task-Chains

Zhiqun, Jin, Shijie, Zhu January 2017 (has links)
Many automotive systems are real-time systems, which means that not only correct operationsbut also appropriate timings are their main requirements. Considering the in uence that end-to-end delay might have on the performance of the systems, the calculation of it is of necessity.Abundant techniques have actually been proposed, and some of them have already been applied intopractical systems. In spite of this, some further work still needs to be done. The target of thisthesis is to evaluate and compare two end-to-end timing analysis methods from dierent aspectssuch as data age, consumption time, and then decide which method is a prior choice for end-to-end timing analysis. The experiments can be divided into three blocks, system generation andend-to-end delay calculation by two methods respectively. The experiments focus on two kinds ofperformance parameters, data age and the consumption time that these two methods cost duringtheir execution. By changing the system generating parameters like task number and periods, thechanges of performances of the two methods are analyzed. The performances of the two dierentmethods are also compared when they are applied into the same automotive systems. According tothe results of the experiments, the second method can calculate more accurate data age and consumeless time than the rst method does.
6

Desenvolvimento e aplicação de ferramenta metodológica aplicável à identificação de rotas insumo - processo - produto para a produção de combustíveis e derivados sintéticos / Development and applications of a methodological tool to identify the most suitable routes: feedstock-process-products for the production of fuels and synthetic derivatives

Gerosa, Tatiana Magalhães 16 April 2012 (has links)
Este trabalho tem como objetivo a identificação da melhor rota para a produção de combustíveis e derivados sintéticos através do desenvolvimento e aplicação de uma ferramenta metodológica desenvolvida tendo como base ferramentas da qualidade: diagrama de afinidade, diagrama de relações e matriz causa-efeito. Estes diagramas foram adaptados para a análise e discussão dos fatores positivos e negativos de cada item da tríade considerada: insumo-processo-produto. A partir desta análise foram criadas as matrizes de causa-efeito, também separadas em fatores positivos e negativos para os insumos: gás natural (GN), biomassa e carvão mineral; para os processos: produção de gás de síntese (syngas) a partir do GN, gaseificação do carvão e a gaseificação da biomassa; e para os produtos: óleo lubrificante, óleo diesel, nafta, metanol e amônia. A análise destas matrizes causa-efeito gerou a matriz final, denominada matriz saldo, que permitiu a seleção da rota mais adequada para a produção de combustíveis e derivados sintéticos. Dentre os insumos estudados, o gás natural apresentou evidentes vantagens e, consequentemente, o processo a ser utilizado deve ser a produção do syngas a partir do GN, e dentre os produtos o metanol apresentou maiores benefícios para ser produzido. / This paper aims to present to identify of the best route for the production of fuels and synthetic derivatives through the development and application of a methodological tool based on quality tools: affinity diagram, relations diagram and matrices cause-effect. The diagrams have been adapted for the analysis and discussion of positive and negative factors of each item of the triad considered: feedstock-process-product. From the analysis, matrices of cause and effect were created and also, separated into positive and negative factors for the inputs: natural gas (NG), biomass and coal; for the processes: production of synthesis gas (syngas) from GN, coal gasification and biomass gasification; and for the products: lubricating oil, diesel fuel, naphtha, methanol and ammonia. The analysis of cause-effect matrices generated the final matrix, named balance matrix, which allowed the selection of the most suitable route for the production of fuels and synthetic derivatives. Among the input studied, NG presented remarkable advantages among the others. Therefore, the process to be used should be the production of syngas from NG. Among the products considered, methanol showed the best benefits to be produced.
7

Diagnostic de pannes électriques dans les systèmes logiques / Diagnosis of Electrical Failures in Logic Systems

Ben Abboud, Youssef 30 April 2010 (has links)
Les dernières technologies comme la 65nm, 45nm et la nouvelle technologie 32nm qui sera disponible à la fin de 2010, permettent la production de circuits de plus en plus complexes avec des performances très élevées. Ces nouvelles technologies imposent donc de nouveaux challenges pour la conception de circuits, mais également pour les méthodologies de test de fabrication et de diagnostic. De ce point de vue, les défaillances observées dans ces technologies ne peuvent pas être modélisées par des fautes classiques de collage. Les fautes de délai, de court-circuit, de circuit ouvert, etc. doivent également être prises en compte. Dans ce contexte, l'objectif de cette thèse a été de développer une méthode de diagnostic logique capable à la fois de traiter un ensemble complet de modèles de fautes et de fournir une localisation fiable et précise des défaillances dans un système sur puce. Ce manuscrit est organisé comme suit. Dans la première partie, les modèles de faute existants sont analysés afin de montrer les conditions de sensibilisation de chacun d'eux. La deuxième partie présente une méthode de diagnostic logique basée sur une approche « Effet-à-Cause». La dernière partie propose une nouvelle technique de diagnostic basée sur une approche « Cause-à-Effet » et permettant de traiter les circuits séquentiels. Les deux approches de diagnostic proposées exploitent les conditions de sensibilisations afin de cibler un ensemble élargi de modèles de fautes durant le processus de diagnostic. Les deux techniques sont validées sur un ensemble important de circuits benchmark et sur des systèmes sur puce fournis par la société STMicroelectronics. / Latest technologies like 65nm, 45nm and the next 32nm technology available at the end of 2010, allow the production of more and more complex and vey high performance circuits. These technologies lead to face with new challenges related to design, test and diagnosis. From this perspective, failures observed in these recent technologies can no longer be modeled by the classical stuck-at fault model. Delay faults, short-circuits, opens, etc. have also to be considered. In this context, the purpose of this thesis has been to develop a logic diagnosis approach able to deal with many types of faults as well as providing an accurate and reliable localization of failures in a system on chip. This manuscript is organized as follows. In the first part, existing fault models are analyzed in order to show the sensitization conditions related to each of them. The second part presents a logic diagnosis method based on the 'Effect-Cause' paradigm. The last part proposes another diagnosis technique based on the 'Cause-Effect' paradigm to deal with sequential circuits. The two proposed diagnosis approaches exploit the sensitization conditions in order to be able to consider a large set of fault models during the diagnosis process. Both techniques have been validated on a large set of benchmark circuits and on System-On-Chips provided by STMicroelectronics.
8

Computer-aided applications in process plant safety

An, Hong January 2010 (has links)
Process plants that produce chemical products through pre-designed processes are fundamental in the Chemical Engineering industry. The safety of hazardous processing plants is of paramount importance as an accident could cause major damage to property and/or injury to people. HAZID is a computer system that helps designers and operators of process plants to identify potential design and operation problems given a process plant design. However, there are issues that need to be addressed before such a system will be accepted for common use. This research project considers how to improve the usability and acceptability of such a system by developing tools to test the developed models in order for the users to gain confidence in HAZID s output as HAZID is a model based system with a library of equipment models. The research also investigates the development of computer-aided safety applications and how they can be integrated together to extend HAZID to support different kinds of safety-related reasoning tasks. Three computer-aided tools and one reasoning system have been developed from this project. The first is called Model Test Bed, which is to test the correctness of models that have been built. The second is called Safe Isolation Tool, which is to define isolation boundary and identify potential hazards for isolation work. The third is an Instrument Checker, which lists all the instruments and their connections with process items in a process plant for the engineers to consider whether the instrument and its loop provide safeguards to the equipment during the hazard identification procedure. The fourth is a cause-effect analysis system that can automatically generate cause-effect tables for the control engineers to consider the safety design of the control of a plant as the table shows process events and corresponding process responses designed by the control engineer. The thesis provides a full description of the above four tools and how they are integrated into the HAZID system to perform control safety analysis and hazard identification in process plants.
9

Desenvolvimento e aplicação de ferramenta metodológica aplicável à identificação de rotas insumo - processo - produto para a produção de combustíveis e derivados sintéticos / Development and applications of a methodological tool to identify the most suitable routes: feedstock-process-products for the production of fuels and synthetic derivatives

Tatiana Magalhães Gerosa 16 April 2012 (has links)
Este trabalho tem como objetivo a identificação da melhor rota para a produção de combustíveis e derivados sintéticos através do desenvolvimento e aplicação de uma ferramenta metodológica desenvolvida tendo como base ferramentas da qualidade: diagrama de afinidade, diagrama de relações e matriz causa-efeito. Estes diagramas foram adaptados para a análise e discussão dos fatores positivos e negativos de cada item da tríade considerada: insumo-processo-produto. A partir desta análise foram criadas as matrizes de causa-efeito, também separadas em fatores positivos e negativos para os insumos: gás natural (GN), biomassa e carvão mineral; para os processos: produção de gás de síntese (syngas) a partir do GN, gaseificação do carvão e a gaseificação da biomassa; e para os produtos: óleo lubrificante, óleo diesel, nafta, metanol e amônia. A análise destas matrizes causa-efeito gerou a matriz final, denominada matriz saldo, que permitiu a seleção da rota mais adequada para a produção de combustíveis e derivados sintéticos. Dentre os insumos estudados, o gás natural apresentou evidentes vantagens e, consequentemente, o processo a ser utilizado deve ser a produção do syngas a partir do GN, e dentre os produtos o metanol apresentou maiores benefícios para ser produzido. / This paper aims to present to identify of the best route for the production of fuels and synthetic derivatives through the development and application of a methodological tool based on quality tools: affinity diagram, relations diagram and matrices cause-effect. The diagrams have been adapted for the analysis and discussion of positive and negative factors of each item of the triad considered: feedstock-process-product. From the analysis, matrices of cause and effect were created and also, separated into positive and negative factors for the inputs: natural gas (NG), biomass and coal; for the processes: production of synthesis gas (syngas) from GN, coal gasification and biomass gasification; and for the products: lubricating oil, diesel fuel, naphtha, methanol and ammonia. The analysis of cause-effect matrices generated the final matrix, named balance matrix, which allowed the selection of the most suitable route for the production of fuels and synthetic derivatives. Among the input studied, NG presented remarkable advantages among the others. Therefore, the process to be used should be the production of syngas from NG. Among the products considered, methanol showed the best benefits to be produced.
10

Melhorias no sistema de planejamento, programação e controle da produção : um estudo de caso em empresa eletroeletrônica

Marcos Rogério Ribeiro Campos 09 March 2009 (has links)
A flexibilidade dos sistemas de produção tornou-se indispensável para a sobrevivência das empresas de manufatura no mercado global, que impulsionada pelo crescente avanço das tecnologias utilizadas nos processos, nem sempre encontra ressonância nos sistemas de PPCP (planejamento, programação e controle da produção) existentes. Neste sentido, esta dissertação apresenta o estudo de caso realizado em uma empresa eletroeletrônica que mesmo dispondo de alta tecnologia em seu processo de fabricação, se deparava com a necessidade de implementação de técnicas que pudessem proporcionar melhorias na captação e atendimento de pedidos com curto prazo de entregas ou de alterações de pedidos já colocados. Seria necessário melhorar a flexibilização do processo de produção através de novas ações do PPCP que adotando uma posição mais analítica com o emprego de novas ferramentas de trabalho teria meios de agir decisivamente para a obtenção de melhores resultados. Não dispondo de muitos recursos, a empresa pesquisada deveria adotar soluções de baixo custo e complexidade que pudessem viabilizar sua rápida implantação. A modalidade de pesquisa realizada foi o estudo de caso, favorecido pela participação do autor ao longo do processo em estudo. Para gerar subsídios para essa dissertação foram feitas pesquisas em livros, dissertações, monografias, teses, artigos, sites da internet, e vários relatórios e documentos da empresa pesquisada. A metodologia aplicada para a análise e solução do problema foi elaborada através do ciclo PDCA e diagrama de causa-efeito. O detalhamento do trabalho, o emprego das técnicas, seu processo de implantação e os resultados obtidos serão descritos nesta dissertação. / The flexibility of the production systems became indispensable for the survival of the companies of manufacture in the global market, who stimulated for the increasing advance of the technologies used in the processes, nor always find resonance in the systems of PPCP (planning, programming and control of the production) existing. In this direction, this dissertation display the study of case in a eletroeletrônic company who even though disposing of high technology in your process of manufacture, if came across with the necessity of implementation of techniques that could provide to improvements in the captation and attendance of order with short term of deliveries or placed alterations of placed order. Looking for the flexibilization of production process through new-positioning of the PPCP taking on a more analytical position with the use of new tools of work with had half to act decisively for the attainment of better resulted. No disposing of much time to act, the searched company would have to adopt tools of work of low cost and complexity that could make possible its fast implantation. The kind of fulfilled inquiry was the case study, favored by the participation of the author along the process of study. To produce subsidies for this dissertation inquiry were done in books, dissertations, monographs, theories, articles, sites of the Internet, and several reports and documents of the investigated enterprise. The methodology applied for the analysis and solution of the problem was prepared through the cycle PDCA and diagram of cause-effect. The detailing of the case study, the use of the techniques, your process of implantation and results will be described in this dissertation.

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