Em projetos de veículos, prever adequadamente a durabilidade de um componente estrutural é vital para a redução de custos assim como para se estipular prazos de garantia e de manutenção. Por outro lado, em diversas situações, tal previsão é difícil, pois inúmeros parâmetros não estão sob controle preciso do projetista, dentre eles os mais relevantes são: o carregamento ao qual o componente será submetido e as propriedades de vida em fadiga do material. Desta forma, pode-se aplicar, em conjunto com o MEF, tratamento probabilístico do cálculo da vida em fadiga,resultando em um valor de confiabilidade, a ser usado como esteio do critério de projeto, no intuito de conferir maior significado prático à análise e aos resultados obtidos. Assim sendo, o presente trabalho descreve e relaciona os principais aspectos de um tratamento probabilístico para cálculo de vida em fadiga, configurando-se um procedimento completo subdividido nas seguintes etapas: 1. Modelagem do carregamento sobre o veículo, visando análise espectral em MEF no domínio da freqüência; 2. Cálculo da densidade de probabilidade das amplitudes cíclicas de Rainflow para as tensões atuantes na estrutura, a partir dos resultados da análise espectral em MEF no domínio da freqüência; 3. Tratamento probabilístico das propriedades características de vida em fadiga do material; 4. Cálculo da confiabilidade estrutural de vida em fadiga, tomando os resultados prévios dos tratamentos probabilísticos de tensões e de vida em fadiga do material; 5. Demonstração da viabilidade e aplicação prática de tal procedimento, implementando-o para o caso de um semi-reboque tanque autoportante. As conclusões finais obtidas confirmam o fato de haver mais falhas estruturais em veículos no Brasil do que em países do primeiro mundo, pois se evidenciou que a pior qualidade das vias trafegáveis brasileiras exacerba a probabilidade de falha por fadiga. Por fim, a metodologia proposta na presente tese, quando implementada em um programa computacional pós-processador de MEF, que automaticamente transforme os desvios padrão das tensões, resultantes da análise espectral, em probabilidades de falha, pode, mais adequadamente, subsidiar critério de projeto fundamentado na avaliação probabilística de durabilidade de um veículo através de preceitos bem definidos de confiabilidade estrutural. / In structural design, forecast correctly the part’s lifetime is vital to reduce costs and to estimate the periods of warranty and of maintenance. On the other hand, in many situations, this forecast is difficult because many parameters are not under the engineers control, some examples of this kind of parameters are: the loads acting in the part and the fatigue properties of the material. Therefore, it is possible to apply finite element analysis with a probabilistic approach in fatigue lifetime calculation, what results in reliability values that can be used as design criterion in order to give a broader meaning to the analyses and its results. Hence, this text describes and establishes the relationship between the main aspects of the probabilistic approach in fatigue lifetime calculation, resulting in the definition of a complete procedure that is divided in the following steps: 1. Modeling of the vehicle’s load aiming spectral analysis in the frequency domain; 2. Calculation procedure of the probability density function of Rainflow stress amplitudes applied in the structure upon using the spectral analysis in frequency domain results; 3. Probabilistic approach of fatigue properties of the material; 4. Fatigue reliability calculation through the use of the previous results provided by the probabilistic approach of stresses and of fatigue properties of the material; 5. Implementation of the proposed methodology for fatigue lifetime prediction of a semi-trailer tank. The conclusion confirms the fact of having much more structural failures in Brazilian vehicles than in European ones. This can be said because the results show that the worsening of the roads quality increases the fatigue failure probability. Finally, when implemented in a post-processing software for finite element programs that automatically transforms the stresses standard deviation, obtained by spectral analysis, in the fatigue failure probability, the proposed methodology in the present thesis may, more adequately, work as design criterion based on the probabilistic evaluation of the vehicles durability, upon applying well established structural reliability theory.

nÃo hà / A pesquisa aponta a necessidade de discutir a AnÃlise de DomÃnio na etapa de delimitaÃÃo do domÃnio, compreendendo os aspectos que influenciam na sua identificaÃÃo e na sua abordagem prÃtica. Investiga a contribuiÃÃo da AnÃlise de DomÃnio na etapa de delimitaÃÃo do domÃnio nocional das Linguagens DocumentÃrias. Tem como objetivo geral investigar a AnÃlise de DomÃnio e suas contribuiÃÃes para a construÃÃo de Linguagens DocumentÃrias. Os objetivos especÃficos sÃo: apresentar os conceitos e os aspectos que compÃem as tendÃncias metodolÃgicas e teÃricas da construÃÃo de Linguagens DocumentÃrias; apresentar o mÃtodo terminogrÃfico como instrumento metodolÃgico utilizados nas Linguagens DocumentÃrias; investigar a AnÃlise de DomÃnio no contexto da CiÃncia da InformaÃÃo; e as contribuiÃÃes da AnÃlise de DomÃnio no desenvolvimento da etapa de delimitaÃÃo de domÃnio na construÃÃo de Linguagens DocumentÃrias. A questÃo que justifica esta pesquisa à responder de que modo a AnÃlise de DomÃnio contribui na etapa de delimitaÃÃo do domÃnio para a construÃÃo de Linguagens DocumentÃrias. A pesquisa à exploratÃria e bibliogrÃfica, utilizando o aporte da abordagem qualitativa e o Funcionalismo como mÃtodo cientÃfico. Contempla uma revisÃo bibliogrÃfica que apresenta a evoluÃÃo das Linguagens DocumentÃrias a partir da LinguÃstica DocumentÃria e da Terminologia, alÃm de explicar a inserÃÃo da AnÃlise de DomÃnio enquanto paradigma da CiÃncia da InformaÃÃo. Recapitula a funÃÃo das metodologias terminolÃgicas utilizadas na construÃÃo de linguagens de representaÃÃo. Utiliza a AnÃlise de ConteÃdo de Bardin (2011) para viabilizar a anÃlise e o apontamento das categorias e, posteriormente, a discussÃo dos seus resultados. Por meio das inferÃncias do referencial teÃrico, os resultados demonstraram que a AnÃlise de DomÃnio à um paradigma jà estabelecido e utilizado em pesquisas, enquanto abordagem que resgata aspectos epistemolÃgicos, ontolÃgicos, socioculturais e terminolÃgicos. Aponta a existÃncia de dois tipos de aplicabilidades metodolÃgicas: a AnÃlise de DomÃnio Instrumental e a AnÃlise de DomÃnio Descritiva (TENNIS, 2012) e Ãs 11 possibilidades de abordagem analÃtica de domÃnio na CiÃncia da InformaÃÃo (HJÃRLAND 2002), dentre as quais aquelas que se referem à elaboraÃÃo de sistemas de classificaÃÃes e linguagens especializadas para fins de representaÃÃo. Demonstra a utilizaÃÃo dos elementos e dos eixos apresentados por Tennis (2003, 2012) que simulam o estudo inicial de definiÃÃo e delimitaÃÃo de um domÃnio. Descobriu que a Web of Science, e as ferramentas bibliomÃtricas sÃo utilizadas na AnÃlise de DomÃnio, possibilitando observar uma determinada comunidade discursiva e seu respectivo domÃnio. Conclui que a AnÃlise de DomÃnio trabalha com comunidades discursivas capaz de fornecer a garantia literÃria, presente nos documentos de uma determinada Ãrea de domÃnio, ou seja, configurando o sistema nocional de uma determinada linguagem. Nessa perspectiva a AnÃlise de DomÃnio, suas metodologias, instrumentos e tÃcnicas podem contribuir para a delimitaÃÃo do domÃnio na construÃÃo das Linguagens DocumentÃrias, sendo necessÃrias mais pesquisas que instrumentalizam esta etapa.

Made available in DSpace on 2015-10-19T11:50:12Z (GMT). No. of bitstreams: 1 RibeiroCJS.pdf: 3597289 bytes, checksum: 466e93e1d9f91a6982f2922abe3f8a70 (MD5) Previous issue date: 2001-12-17 / In order to develop knowledge organization process within a given context, to understand the information environment, application systems and there data as well as its information stocks and information flow. The present work studies the use of Domain Analysis approach as an artifact to support the knowledge organization process at the Brazilian Social Security. In this context it is presented the essence of the relation between data and information on the basis of the concept of relevance and on the use of Domain Analysis. Taking into consideration the information questions in the Social Security and on its efforts towards knowledge organization in the last few years. The JAD technique was used as a tool to conduct the investigation. The results obtained may contribute to the generation of better products to make available a wider set of social security and social assistance information increasing the relationships between the State and Citizens / Para desenvolver processos de organização do conhecimento é necessário compreender o ambiente informacional, os sistemas aplicativos e seus dados, além dos estoques e fluxo de informações. O presente trabalho estuda o uso da abordagem da Análise de Domínio, como artefato para apoio ao processo de organização do conhecimento na Previdência Social Brasileira. Dentro deste contexto é apresentada a essência da relação entre dados e informação, bem como, o uso destes, como insumo para o entendimento dos conceitos de relevância e possíveis abordagens para o uso da Análise de Domínio. São apresentadas considerações que endereçam para a questão da Informação na Previdência Social e para os esforços de organização do conhecimento que ocorreram ao longo dos últimos anos. A técnica de JAD foi utilizada para conduzir a dinâmica de investigação. Os resultados obtidos contribuirão para gerar melhores produtos, tornando disponível para a sociedade em geral um conjunto mais abrangente de informações previdenciárias e assistenciais, trazendo melhorias no relacionamento entre Estado e Cidadão

Orientadores: Aldario Chrestani Bordonalli, Hugo Enrique Hernandez Figueroa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-09T17:10:22Z (GMT). No. of bitstreams: 1 Goncalves_MarcosSergio_D.pdf: 5511725 bytes, checksum: 912286218aecf274afdc63d4eb68d0b5 (MD5) Previous issue date: 2007 / Resumo: Este trabalho apresenta uma nova formulação para a simulação da propagação de campos eletromagnéticos no domínio do tempo em duas e três dimensões. Os algoritmos desenvolvidos incorporam a discretização por elementos finitos e usam as funções de base de arestas ortogonais em duas e, pela primeira vez, em três dimensões para descrever o comportamento de propagação dos campos elétrico e magnético em diferentes estruturas. Tais funções são baseadas nos elementos de arestas de Whitney e preservam as mesmas características que as funções de bases de arestas convencionais. Com o uso destas funções de bases, obtêm-se, naturalmente, matrizes massas diagonais, eliminando-se, por completo, a resolução, a cada passo temporal, do sistema matricial resultante dos métodos convencionais, resultando em um alto desempenho no processamento de dados. Os campos são analisados no domínio do tempo através do método da envoltória, modelado pela equação de onda vetorial, sendo a principal aplicação o estudo de componentes fotônicos / Abstract: This work presents a new approach for the simulation of the time-domain electromagnetic fields in two and three dimensions. The developed algorithms incorporate finite-element discretization and make use of two- and three-dimension orthogonal edge basis functions to describe the electric and magnetic fields. Such functions are based on the Whitney¿s edge elements and preserve the same characteristics as those of the conventional edge basis functions. With the use of these basis functions, solution of diagonal mass matrices appear naturally, eliminating, at each time step, the matrix equations that result from conventional methods and producing a high performance data processing. The fields are analyzed in time-domain using the slow-wave method, modeled by the vector wave equation. The study of photonic components is the main application of this method / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Orientador: Alberto Luiz Serpa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-22T21:32:28Z (GMT). No. of bitstreams: 1 Ferreira_LuanJoseFranchini_M.pdf: 31334961 bytes, checksum: 0c668b476e8b23fc3d0c578acdda9020 (MD5) Previous issue date: 2013 / Resumo: O vibro-impacto de vigas ocorre devido ao contato intermitente das estruturas na presença de folgas, gerando desgaste excessivo, vibração com grandes amplitudes, falhas prematuras de componentes e altos níveis de ruído. A determinação da resposta no domínio do tempo do sistema, ou seja, deslocamentos, velocidades e acelerações, juntamente com os esforços de contato são de fundamental importância para o projeto desses sistemas, na prevenção de falhas e no controle de vibrações e ruído. Foi desenvolvido um código utilizando a linguagem MATLAB que a partir dos dados de uma malha de elementos finitos de viga, determina a resposta dinâmica da viga sobre a condição de vibro-impacto. A resposta dinâmica foi obtida utilizando a integração numérica da equação do movimento discretizada. Os métodos de integração numérica da diferença centrada, Newmark e alpha-HHT foram implementados para o caso de contato intermitente e utilizados na determinação da resposta dinâmica da estrutura. A condição de contato intermitente originada pelo processo de vibro-impacto foi tratada avaliando a condição de não penetração dos corpos nos instantes de tempo específicos definidos pelo intervalo de tempo utilizado na integração numérica. Os modelos de contato mecânico utilizados foram os modelos de força de contato proporcional e o cúbico / Abstract: The vibro-impact of beams occurs due to intermittent contact of the structures in the presence of clearances, generating excessive wear, vibration with large amplitudes, premature failure of components and high noise level. A MATLAB code was developed using the finite element model of the beam, obtaining the dynamic response of the beam with the vibro-impact condition. The dynamic response was obtained using numerical integration of the discretized equation of motion. The numerical integration method of the central difference, Newmark and alpha-HHT were implemented for the case of contact and used for the determination of the structure time response. The contact condition caused by vibro-impact process was treated evaluating the condition of nonpenetration bodies in specific instants of time defined by the numerical integration method. The mechanical contact models proportional force and cubic force were used / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

This master thesis examines the cataloguing practices of two art libraries in Sweden in relation to contemporary art. The aim of this study is to show how classification systems and other forms of controlled vocabulary correspond to contemporary art and reveal the factors that influence the everyday practice of cataloguing. The qualitative methods of semi-structured interviews and an analysis of bibliographic records have been used for the purposes of this study. The study is based on domain analysis as conceived by Hjørland and Albrechtsen and some concepts and principles of Knowledge Organisation in the field of Library and Information Science. A total of three interviews of cataloguers has proved that perceptions concerning classification and subject indexing differ among cataloguers and cataloguing practices depend on local policies concerning acquisition, shelving and user perspectives, but also each library’s resources and the institutional context (academic vs museum). Through the analysis of eleven bibliographic records, no consistent pattern has been detected, in relation to indexing and classification. The libraries do not use special systems for subject analysis. The classifications provided by universal systems have been considered insufficient to express all the concepts found in documents. The use of subject headings is, therefore, important and complements the process of subject analysis. The classification systems and subject headings lists analysed include the Dewey Decimal Classification (DDC), the Swedish Sveriges Allmänna Biblioteksförenings Klassifikationssystem (SAB) and the Svenska ämnesord (SAO). This is a two-year master’s thesis in Archive, Library and Museum studies. / Denna masteruppsats handlar om katalogiseringspraktiker på två konstbibliotek, nämligen Umeå universitetsbibliotek och Konstbiblioteket, i relation till samtida konst. Syftet med denna studie är att visa hur samtida konst återspeglas i klassifikationssystem och andra former av kontrollerad vokabulär och ta reda på vilka faktorer påverkar katalogiseringsarbete. Metoden som har använts i studien består av halvstrukturerade intervjuer med katalogisatörer och en analys av bibliografiska poster. Studien baseras på domänanalys som har utarbetats av Hjørland och Albrechtsen samt vissa begrepp och principer från Kunskapsorganisation inom ramen för Biblioteks- och Informationsvetenskap. Analysen av tre intervjuer visade på att uppfattningar om klassifikation och ämnesordsindexering skiljer sig åt bland katalogisatörer och att katalogiseringspraktiker beror på varje biblioteks riktlinjer med avseende på förvärv, hylluppställning, användarperspektiv, bibliotekets resurser samt institutionell kontext (akademisk vs museal). Elva bibliografiska poster har analyserats och genom analysen har inga mönster i relation till ämnesordsindexering och klassificering identifierats. De undersökta bibliotek använder inte något specialsystem för klassifikation eller ämnesordsindexering. Klassifikationskoder från universella system ansågs otillräckliga för att uttrycka alla begrepp i dokumenten. Ämnesordsindexering är därför viktig och anses vara mer effektiv för ämnesanalys. Klassifikationsssystem och ämnesordlistor som har analyserats är Dewey Decimal Klassifikation (DDK), Sveriges Allmänna Biblioteksförenings Klassifikationssystem (SAB) och Svenska ämnesord (SAO). Detta är en tvåårig masteruppsats i Arkiv-, Bibliotek- och Museumstudier.

Most drill wear monitoring research found in the literature is based on conventional vibration technologies. However, these conventional approaches still have not attracted real interest from manufacturers for multiples of reasons: some of these techniques are not practical and use complicated Tool Condition Monitoring (TCM) systems with less value in industry. In addition, they are also prone to give spurious drill deterioration warnings in industrial environments. Therefore, drills are normally replaced at estimated preset intervals, sometimes long before they are worn or by expertise judgment. Two of the great problems in the implementation of these systems in drilling are: the poor signal-to-noise ratio and the lack of system-made sensors for drilling, as is prevalent in machining operations with straight edge cutters. In order to overcome the noise problems, many researchers recommend advanced and sophisticated signal processing while the work of Rehorn et al. (2005) advises the following possibilities to deal with the lack of commercial system-made sensors:  Some research should be directed towards developing some form of instrumented tool for drill operations.  Since the use of custom-made sensors is being ignored in drilling operations, effort should be focused on intelligent or innovative use of available sensor technology. It is expected that the latter could minimize implementation problems and allows an optimal drill utilization rate by means of modern and smart sensors. In addition to the accelerometer sensor commonly used in conventional methods, this work has considered two other sensor-based methods to monitor the drill wear indirectly. These methods entail the use of an instrumented drill with strain gauges to measure the torque and the use of an encoder to measure the Instantaneous Angular Speed (IAS). The signals from these sensors were analyzed using signal processing techniques such as, statistical parameters, Fast Fourier Transform (FFT), and a ii preliminary Time-Frequency (TF) analysis. A preliminary investigation has revealed that the use of a Regression Analysis (RA) based on a higher order polynomial function can very well follow and give prognosis of the development of the monitored parameters. The experimental investigation has revealed that all the above monitoring systems are sensitive to the deterioration of the drill condition. This work is however particularly concerned with the use of IAS on the spindle of the drill, compared to conventional monitoring systems for drill condition monitoring. This comparison reveals that the IAS approach can generate diagnostic information similar to vibration and torque measurements, without some of the instrumentation complications. This similitude seems to be logical, as it is well known that the increase of friction between the drill and workpiece due to wear increase the torque and consequently it should reduce or at least affect the spindle rotational speed. However, the use of a drill instrumented with a strain gauge is not practical, because of the inconvenience it causes on production machines. By contrast, the IAS could be measured quite easily by means of an encoder, a tachometer or some other smart rotational speed sensors. Thus, one could take advantage of advanced techniques in digital time interval analysis applied to a carrier signal from a multiple pulse per revolution encoder on the rotating shaft, to improve the analysis of chain pulses. As it will be shown in this dissertation, the encoder resolution does not sensibly affect the analysis. Therefore, one can easily replace encoders by any smart transducers that have become more popular in rotating machinery. Consequently, a non-contact transducer for example could effectively be used in on-line drill condition monitoring such as the use of lasers or time passage encoder-based systems. This work has gained from previous research performed in Tool Condition Monitoring TCM, and presents a sensor that is already available in the arsenal of sensors and could be an open door for a practical and reliable sensor in automated drilling. iii In conclusion, this dissertation strives to answer the following question: Which one of these methods could challenge the need from manufacturers by monitoring and diagnosing drill condition in a practical and reliable manner? Past research has sufficiently proved the weakness of conventional technologies in industry despite good results in the laboratory. In addition, delayed diagnosis due to time-consuming data processing is not beneficial for automated drilling, especially when the drill wears rapidly at the end of its life. No advanced signal processing is required for the proposed technique, as satisfactory results are obtained using common time domain signal processing methods. The recommended monitoring choice will definitely depend on the sensor that is practical and reliable in industry. / Dissertation (MEng)--University of Pretoria, 2012. / gm2013 / Mechanical and Aeronautical Engineering / MEng / Unrestricted

This thesis deals with a theoretical analysis and experimental verification of a new method for the refractive index of air measurement. This method uses a combination of laser and low-coherence interferometry. The experimental setup is based on the Michelson interferometer equipped with a double-spaced glass cell. The optical path difference between the inner and outer part of the cell that is proportional to air refractivity is estimated using two low-coherence interference signals. These signals are analysed in the frequency domain which results in the dependence of the phase change caused the by air on vacuum wavelength. This dependency is fitted by a theoretical function based on Edlén's equations in order to calculate the phase difference for laser wavelength. This value is then made more accurate utilising two laser interference signals and used for the air refractive index calculation. The new method was experimentally verified and compared to two different techniques. Moreover, the measurement uncertainty was evaluated.

The aim of the research documented in the thesis was to design an ontology for the knowledge organization domain. Three requirements specifying areas of ontology use have been identified: making of statements for a knowledge base for knowledge organization, indexing of resources in the domain and interlinking with content-relevant ontologies. The design was elaborated by the method of reengineering the first version of ontology, created in the framework of the NAKI research project Knowledge base for subject area of knowledge organization in 2013-2015. The second version of ontology is based on the DOLCE foundational ontology, specifically on the reusing of its selected classes and predicates, including the axioms associated with them. The reengineering of the content of the first version of ontology was done by the domain and facet analysis methodology. The outcome is divided in two interlinked modules - axiomatized heavy- weight core ontology and light-weight terminological ontology. The ontology offers a solution to the compatibility of Czech and world terminology, it applies an extended concept of domain beyond the scope of memory institutions, and it presents a partial contribution to the development of the theory of knowledge organization. The content of the thesis is divided into five...

Thesis (S.M.)--Joint Program in Oceanographic Engineering (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and the Woods Hole Oceanographic Institution), 1999. / Bibliography: p. 111-112. / by Kevin Xu. / S.M.