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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.
361

A customization framework for the SVG Graph Visualization Engine

Zou, Feng 30 December 2008 (has links)
The Rigi research group has built an SVG (Scalable Vector Graphics) Graph Visualization Engine to visualize, interactively explore and annotate software structures. The biggest difficulty we experienced during the customization of this engine for different domains is that we need to create idiosyncratic generators every time. Each generator is created by different developers using different approaches. If the subject information model does not contain layout information, developers of the generator are also responsible for writing algorithms to calculate layout. In this thesis, we present a customization framework for our SVG Graph Visualization Engine to provide flexible customization using third party libraries to construct specific SVG Graph Generators. The customization framework consists of documentation for the existing graph engine and a componentized abstract generator that can be extended for a variety of information domains. We also created two reference implementations for the abstract generator and included them in the template solution project to exemplify the usage of the customization framework. We also validated the template solution with an end user to build a generator for a new domain. Our customization framework greatly eases the process of building SVG Editor Generators for domain-specific visualization engine.
362

If and How Many 'Races'? The Application of Mixture Modeling to World-Wide Human Craniometric Variation

Algee-Hewitt, Bridget Frances Beatrice 01 December 2011 (has links)
Studies in human cranial variation are extensive and widely discussed. While skeletal biologists continue to focus on questions of biological distance and population history, group-specific knowledge is being increasingly used for human identification in medico-legal contexts. The importance of this research has been often overshadowed by both philosophic and methodological concerns. Many analyses have been constrained in their scope by the limited availability of representative samples and readily criticized for adopting statistical techniques that require user-guidance and a priori information. A multi-part project is presented here that implements model-based clustering as an alternative approach for population studies using craniometric traits. This project also introduces the use of forced-directed graphing and mixture-based supervised classification methods as statistically robust and practically useful techniques. This project considers three well-documented craniometric sources, whose samples collectively permit large-scale analyses and tests of population structure at a variety of partitions and for different goals. The craniofacial measurements drawn from the world-wide data sets collected by Howells and Hanihara permit rigorous tests for group differences and cryptic population structure. The inclusion of modern American samples from the Forensic Anthropology Data Bank allows for investigations into the importance of biosocial race and biogeographic ancestry in forensic anthropology. Demographic information from the United States Census Bureau is used to contextualize these samples within the range of the racial diversity represented in the American population-at-large. This project's findings support the presence of population structure, the utility of finite mixture methods to questions of biological classification, and the validity of supervised discrimination methods as reliable tools. They also attest to the importance of context for producing the most useful information on identity and affinity. These results suggest that a meaningful relationship between statistically inferred clusters and predefined groups does exist and that population-informative differences in cranial morphology can be detected with measured degrees of statistical certainty, even when true memberships are unknown. They imply, in turn, that the estimation of biogeographic ancestry and the identification of biosocial race in forensic anthropology can provide useful information for modern American casework that can be evidenced by scientific methods.
363

A model-based reasoning architecture for system-level fault diagnosis

Saha, Bhaskar 04 January 2008 (has links)
This dissertation presents a model-based reasoning architecture with a two fold purpose: to detect and classify component faults from observable system behavior, and to generate fault propagation models so as to make a more accurate estimation of current operational risks. It incorporates a novel approach to system level diagnostics by addressing the need to reason about low-level inaccessible components from observable high-level system behavior. In the field of complex system maintenance it can be invaluable as an aid to human operators. The first step is the compilation of the database of functional descriptions and associated fault-specific features for each of the system components. The system is then analyzed to extract structural information, which, in addition to the functional database, is used to create the structural and functional models. A fault-symptom matrix is constructed from the functional model and the features database. The fault threshold levels for these symptoms are founded on the nominal baseline data. Based on the fault-symptom matrix and these thresholds, a diagnostic decision tree is formulated in order to intelligently query about the system health. For each faulty candidate, a fault propagation tree is generated from the structural model. Finally, the overall system health status report includes both the faulty components and the associated at risk components, as predicted by the fault propagation model.
364

Ridge Orientation Modeling and Feature Analysis for Fingerprint Identification

Wang, Yi, alice.yi.wang@gmail.com January 2009 (has links)
This thesis systematically derives an innovative approach, called FOMFE, for fingerprint ridge orientation modeling based on 2D Fourier expansions, and explores possible applications of FOMFE to various aspects of a fingerprint identification system. Compared with existing proposals, FOMFE does not require prior knowledge of the landmark singular points (SP) at any stage of the modeling process. This salient feature makes it immune from false SP detections and robust in terms of modeling ridge topology patterns from different typological classes. The thesis provides the motivation of this work, thoroughly reviews the relevant literature, and carefully lays out the theoretical basis of the proposed modeling approach. This is followed by a detailed exposition of how FOMFE can benefit fingerprint feature analysis including ridge orientation estimation, singularity analysis, global feature characterization for a wide variety of fingerprint categories, and partial fin gerprint identification. The proposed methods are based on the insightful use of theory from areas such as Fourier analysis of nonlinear dynamic systems, analytical operators from differential calculus in vector fields, and fluid dynamics. The thesis has conducted extensive experimental evaluation of the proposed methods on benchmark data sets, and drawn conclusions about strengths and limitations of these new techniques in comparison with state-of-the-art approaches. FOMFE and the resulting model-based methods can significantly improve the computational efficiency and reliability of fingerprint identification systems, which is important for indexing and matching fingerprints at a large scale.
365

Highly redundant and fault tolerant actuator system : control, condition monitoring and experimental validation

Antong, Hasmawati P. January 2017 (has links)
This thesis is concerned with developing a control and condition monitoring system for a class of fault tolerant actuators with high levels of redundancy. The High Redundancy Actuator (HRA) is a concept inspired by biomimetics that aims to provide fault tolerance using relatively large numbers of actuation elements which are assembled in parallel and series configurations to form a single actuator. Each actuation element provides a small contribution to the overall force and displacement of the system. Since the capability of each actuation element is small, the effect of faults within the individual element of the overall system is also small. Hence, the HRA will gracefully degrade instead of going from fully functional to total failure in the presence of faults. Previous research on HRA using electromechanical technology has focused on a relatively low number of actuation elements (i.e. 4 elements), which were controlled with multiple loop control methods. The objective of this thesis is to expand upon this, by considering an HRA with a larger number of actuation elements (i.e. 12 elements). First, a mathematical model of a general n-by-m HRA is derived from first principles. This method can be used to represent any size of electromechanical HRA with actuation elements arranged in a matrix form. Then, a mathematical model of a 4-by-3 HRA is obtained from the general n-by-m model and verified experimentally using the HRA test rig. This actuator model is then used as a foundation for the controller design and condition monitoring development. For control design, two classical and control method-based controllers are compared with an H_infinity approach. The objective for the control design is to make the HRA track a position demand signal in both health and faulty conditions. For the classical PI controller design, the first approach uses twelve local controllers (1 per actuator) and the second uses only a single global controller. For the H_infinity control design, a mixed sensitivity functions is used to obtain good tracking performance and robustness to modelling uncertainties. Both of these methods demonstrate good tracking performance, with a slower response in the presence of faults. As expected, the H_infinity control method's robustness to modelling uncertainties, results in a smaller performance degradation in the presence of faults, compared with the classical designs. Unlike previous work, the thesis also makes a novel contribution to the condition monitoring of HRA. The proposed algorithm does not require the use of multiple sensors. The condition monitoring scheme is based on least-squares parameter estimation and fuzzy logic inference. The least-squares parameter estimation estimates the physical parameters of the electromechanical actuator based on input-output data collected from real-time experiments, while the fuzzy logic inference determines the health condition of the actuator based on the estimated physical parameters. Hence, overall, a new approach to both control and monitoring of an HRA is proposed and demonstrated on a twelve elements HRA test rig.
366

Abordagens para avaliação experimental de testes baseado em modelos de aplicações reativas. / Approaches for experimental evaluation of tests based on reactive application models

NASCIMENTO, Laísa Helena Oliveira do. 27 August 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-27T18:21:34Z No. of bitstreams: 1 LAÍSA HELENA OLIVEIRA DO NASCIMENTO - DISS PPGCC 2008..pdf: 1446971 bytes, checksum: 3622ab4c366ab0a686c4f32d688c13b6 (MD5) / Made available in DSpace on 2018-08-27T18:21:34Z (GMT). No. of bitstreams: 1 LAÍSA HELENA OLIVEIRA DO NASCIMENTO - DISS PPGCC 2008..pdf: 1446971 bytes, checksum: 3622ab4c366ab0a686c4f32d688c13b6 (MD5) Previous issue date: 2008-02-28 / Processos de teste de software vêm ganhando cada vez mais espaço na indústria. Empresas têm investindo na definição e formalização dos seus processos e em meio a essa mudança de comportamento, Model-Based Testing (MBT) apresenta-se como uma técnica promissora de teste. No entanto, a utilização de MBT ainda é baixa e pesquisadores têm focado em maneiras de superar as barreiras para que se obtenha uma adoção maior por parte da indústria. O mundo empresarial é movido a processos e resultados. Dessa forma, o uso de MBT precisa se adaptar aos processos existentes, e estudos de caso que evidenciem as vantagens de sua utilização precisam ser conduzidos. Neste trabalho, o paradigma Goal Question Metric é utilizado na definição de modelos de medição que têm como foco principal a avaliação e o acompanhamento do desempenho de MBT sem causar impacto ao processo de teste já existente. Os modelos de medição consideram métricas como esforço, percentual de requisitos testáveis cobertos, percentual de casos de teste modificados, percentual de falhas,dentre outros. Os modelos não estão atrelados ao processo de MBT apresentado, podendo ser aplicados em qualquer processo que permita a coleta dos dados necessários para o cálculo das métricas. Para validar os modelos, estudos de caso foram conduzidos dentro do ambiente de testes da Motorola. / Software testing processes have become more common in industry. Companies are investing on the definition and the formalization of their test processes and, in this context, Model-Based Testing (MBT) appears as an interesting testing technique. However, industrial adoption of MBT remains low and researchers are also focusing on how to beat the barriers to wide adoption. Processes and results move the business world so, MBT processes must be adaptable to actual testing processes. For this, experiments to evaluate the results achieved with its use must be conduct. In this work, measurement models based on the Goal Question Metric methodology are proposed. The purpose is evaluating the use of MBT without increasing actual testing process costs. The models focus on aspects as effort, testable requirements coverage, modified test cases, failures, among others. The models are not associated with the MBT process presented. They can be applied with any process that allows metrics collection. In order to validate the measurement models, case studies were conducted into Motorola testing environment.
367

Methodologie pour l’analyse de la robustesse des plans de secours industriels / Methodology for the analysis of robustness of industrial emergency plans

Karagiannis, Georgio Marios 10 December 2010 (has links)
Ce travail de recherche vise à développer une méthode pour l'analyse de la robustesse des plans de secours industriels. Des défaillances peuvent survenir lors de la mise en œuvre de ces plans, qui peuvent entrainer à un fonctionnement en mode dégradé des dispositifs. Les approches existantes d’analyse de ces plans ne permettent pas une analyse structurée du dispositif de gestion de crise. La méthodologie proposée dans le cadre de ce travail repose sur une formalisation structuro-fonctionnelle et générique des plans de secours industriels, décrivant à la fois les fonctions et les ressources permettant la réalisation de ces fonctions. De plus, ce travail s’est accompagné de retours d’expérience à partir de 159 rapports d’accidents et de 61 exercices POI/PPI, qui ont permis d’identifier des défaillances pouvant survenir lors de la mise en œuvre des POI/PPI. Le modèle développé et les informations obtenues par le retour d’expérience permettent de structurer l’analyse des dysfonctionnements pouvant se manifester lors de la mise en œuvre des plans. Cette analyse de la robustesse est basée sur une évaluation du risque de défaillance des fonctions du plan. La probabilité de défaillance est estimée à partir des questions d’évaluation et des arbres de défaillances des ressources et des fonctions. La gravité de la défaillance de chaque fonction est déterminée en utilisant les études de dangers de l’installation, en suivant la règle des dommages maximum qu’elle peut provoquer. La criticité de défaillance de chaque fonction est ainsi obtenue, et la criticité du plan résulte de l'agrégation des criticités de ses fonctions. Cette méthodologie constitue ainsi une boite à outils qui peut être utilisée à la fois pour l’évaluation des plans existants, mais aussi pour l’élaboration du dispositif défini dans un plan de secours industriel. / The objective of this research thesis is to develop a methodology for the analysis of robustness of industrial emergency plans. Failures can occur when these plans are put into action; they can result to deteriorated operating conditions for these systems. Existing emergency plan analysis approaches do not allow for a structured analysis of the emergency response mechanism. The methodology developed in this research project is based on a structuro-functional and generic formalization of industrial emergency plans, which describes both the functions of the plans and the resources necessary for accomplishing them. Furthermore, lessons learned through the analysis of 159 industrial accidents and 61 internal and external industrial emergency plan exercises have led to the identification of failures that may occur during the use of industrial emergency plans for emergency response. The model that was developed and the information obtained through experience feedback result in a structured analysis of failures of these plans. This robustness analysis is based on the failure risk assessment of the plan’s functions. The failure probability is estimated through assessment questions and the plan’s functions and resources fault trees. The failure severity of each function is determined by using the facility’s hazard study and by applying the maximum damage rule. The failure criticality of each function is hence obtained, and the plan’s criticality results from the aggregation of the criticalities of the plan’s functions. The approach followed is hence based on a failure risk analysis, which in turn is built upon lessons learned and the critical analysis of the plan’s model. This methodology therefore constitutes a toolbox that can be used both for the analysis of existing plans and the development of emergency response mechanism.
368

La evaluación actitudinal en las clases de matemática en el modelo educativo basado en competencias / The attitudinal evaluation in mathematics classes in the competence-based educational model

Medina Martínez, Antonio Marcos, Alva Cabrera, Rubén 02 July 2018 (has links)
32 Reunión Latinoamericana de Matemática Educativa (Relme), evento desarrollado en la Universidad de Medellín, Colombia, del 2 al 6 de Junio de 2018. / El trabajo de investigación tiene como objetivo determinar la incidencia de la evaluación actitudinal en la formación de los alumnos de Matemática Discreta de la Universidad Peruana de Ciencias Aplicadas, en el modelo educativo basado en competencias. Se trabajó con todas las secciones de Matemática Discreta del ciclo 2018-1 para la aplicación del modelo. Para la comparación se han considerado los resultados de cinco ciclos anteriores, antes de que se aplicara el modelo, a los cuales se les denomina resultados históricos del curso. Con los resultados obtenidos en este primer ciclo podremos ajustar el modelo, y obtener luego resultados satisfactorios. / The aim of the research work is to determine the incidence of attitudinal evaluation in the training of Discrete Mathematics students of the Peruvian University of Applied Sciences, in the competency-based educational model. We worked with all the Discrete Mathematics sections of cycle 2018-1 for the application of the model. For the comparison, the results of five previous cycles have been considered, before the model was applied, which are called historical course results. With the results obtained in this first cycle we can adjust the model, and then obtain satisfactory results.
369

Geração automática e assistida de interfaces de usuário / Automatic and aided generation of user interfaces

Mrack, Marcelo January 2009 (has links)
A geração automatizada de Interfaces de Usuário (IU) é objeto de estudo há muitos anos. Desde a década de 80, dezenas de projetos foram desenvolvidos e várias soluções apresentadas ao mercado. Entretanto, mesmo com os avanços obtidos neste cenário, inúmeras dificuldades ainda continuam presentes no dia-a-dia dos desenvolvedores de sistemas. A necessidade de processos, sintaxes e linguagens proprietárias associado ao elevado esforço de configuração e à baixa reutilização de tecnologias são os principais problemas nessa área. Objetivando sanar essas dificuldades, este trabalho propõe uma solução diferenciada para o problema, a qual reutiliza e integra-se à maioria das tecnologias comumente presentes nos ambientes de desenvolvimento e que conta com um exclusivo sistema de configuração, capaz de minimizar o trabalho de geração das IU. Sendo um típico gerador baseado em modelos, o software proposto é chamado MERLIN, e objetiva automatizar completamente a geracão de interfaces CRUD, as quais estão presentes em até 30% dos sistemas que operam sobre banco de dados. Para alcançar este objetivo, o software aposta no uso intensivo de heurísticas e na formação de uma estrutura auto-contida e realimentada de configurações, a qual reside unicamente nas classes compiladas da aplicação. Completando a sua arquitetura, um processo de geração em tempo de execução inibe a produção de qualquer linha de código-fonte, o que evita a necessidade de refatoração ao longo da evolução dos sistemas. Com esses elementos em evidência e focando inicialmente a plataforma Java, sinaliza-se uma solução diferenciada, apta para ser utilizada em ambientes profissionais de desenvolvimento. / The automated generation of User Interfaces (UI) has been the object of study for many years. Since the 1980s, dozens of projects have been developed and various solutions presented to the market. However, even with the advances obtained under this scenario, innumerable difficulties still continue to present themselves in the daily routine of system developers. The demands of proprietary methodologies, syntaxes and languages, the high level of effort needed for configuration and low reuse of technologies are the main problems in the area. With the object of rectifying these difficulties, this work proposes a solution specific to the problem, which reuses and combines the majority of the technologies already existing in development environments and relies on an exclusive configuration system, capable to minimize the work of generating the UI. Being a typical model based generator, the software under consideration is called MERLIN, and has as its objective to completely automate the generation of CRUD interfaces, which are present in up to 30% of the systems that interact with data bases. To achieve this objective, the software relies on the intensive use of heuristics and the creation of a self contained configuration feedback structure, which exists solely in the compiled classes of the application. Completing this architecture, a process of execution time generation eliminates the need for any source code, which significantly reduces the costs of refactoring the code throughout the evolution of the systems. With these elements in evidence and focusing initially on the Java platform, indicates that this distinguished solution is ready for use in professional development environments.
370

Handling domain knowledge in system design models. An ontology based approach. / Explicitation de la sémantique du domaine dans les modèles de systèmes : une approche à base d'ontologies

Hacid, Kahina 06 March 2018 (has links)
Les modèles de systèmes complexes sont conçus dans différents contextes. Cependant, l'hétérogénéité induite par ces contextes n’est pas prise en compte lors de la description et de la validation de ces systèmes. De plus, ces systèmes impliquent généralement l’intervention deplusieurs experts du domaine et la réalisation de plusieurs modèles correspondant à différentes analyses (vues) de ce même système. Aucune information concernant les caractéristiques du domaine ni des analyses réalisées n'est explicitée. Nous proposons un cadre méthodologiquepermettant d’une part, de formaliser les connaissances de domaine à l’aide d’ontologies, et d’autre part d'enrichir les modèles à l’aide des connaissances de domaine en définissant des références explicites aux informations formalisées dans ces ontologies. Ce cadre permet également de rendre explicites les caractéristiques d'une analyse en les formalisant dans des modèles qualifiés de «points de vue». Nous avons réalisé deux déploiements de ce cadre méthodologique : un premier déploiement utilisant les techniques de l’Ingénierie Dirigée par les Modèles (IDM) et un second fondé sur les méthodes formelles basées sur des techniques de preuve et de raffinement. Ce cadre a été validé sur plusieurs cas d'études non triviaux issus de l'ingénierie système. / Complex systems models are designed in heterogeneous domains and this heterogeneity is rarely considered explicitly when describing and validating processes. Moreover, these systems usually involve several domain experts and several design models corresponding to different analyses (views) of the same system. However, no explicit information regarding the characteristics neither of the domain nor of the performed system analyses is given. In our thesis, we propose a general framework offering first, the formalization of domain knowledge using ontologies and second, the capability to strengthen design models by making explicit references to the domain knowledgeformalized in these ontology. This framework also provides resources for making explicit the features of an analysis by formalizing them within models qualified as ‘’points of view ‘’. We have set up two deployments of our approach: a Model Driven Engineering (MDE) based deployment and a formal methods one based on proof and refinement. This general framework has been validated on several no trivial case studies issued from system engineering.

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