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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.
121

[en] GRADUATION METHODS UNDER PARAMETRIC AND NON-PARAMETRIC MODELS FOR SELECT AND ULTIMATE TABLES / [pt] METODOLOGIAS DE CONSTRUÇÃO DE TÁBUAS BIOMÉTRICAS SELETAS E FINAIS A PARTIR DE MODELOS PARAMÉTRICOS E NÃO-PARAMÉTRICOS

FABIO GARRIDO LEAL MARTINS 04 March 2008 (has links)
[pt] O estudo aborda as diversas metodologias de construção de tábuas biométricas: desde as técnicas de graduação tradicionalmente utilizadas para os casos em que há grande quantidade de dados, até um método específico de aplicação para o caso de poucos dados. Inclui uma discussão sobre as formas de construção de tábuas seletas, em particular de sobrevivência de inválidos. A população de servidores públicos estatutários da administração direta do município do Rio de Janeiro é utilizada para a graduação de tábuas de sobrevivência de válidos e de inválidos, enquanto que a dos aposentados urbanos por invalidez do INSS serve de base para a tábua seleta de sobrevivência de inválidos. / [en] This study represents an approach to the main methods of life tables construction. It shows traditional graduation techniques for cases including high exposure data, as well a methodology for few data. Further more, this study generates a discussion about select life tables construction, in particular disability mortality tables. Data set from Rio de Janeiro officials population were used for mortality and disability mortality tables construction. In addition, a select disability mortality table was constructed based on the INSS urban disability retired population.
122

Previsão de recalque e análise de confiabilidade de fundações em estacas hélice contínua / Prediction of settlements and reliability analysis of continuous flight auger piles

Barros, Nestor Benedito Fracasse de 02 July 2012 (has links)
Esta dissertação apresenta uma avaliação do comportamento de estacas hélice contínua quanto à capacidade de carga, ao recalque e à segurança e confiabilidade, a partir de um cenário de análise em que foi considerado um banco de dados de 58 provas de carga estáticas, realizadas em estacas hélice contínua de 13 obras distintas. Esta pesquisa está focada principalmente no comportamento carga-recalque e confiabilidade de fundações em estacas hélice contínua. Nesta análise foi também verificada a aplicabilidade do método proposto por Aoki (1989) para determinação da curva carga-recalque destas provas de carga. Os valores de capacidade de carga medidos foram comparados com os previstos pelos método Aoki & Velloso (1975), o método Decourt & Quaresma (1978), o método de Cabral (1996), e o método Alonso (1996). Estes métodos também foram utilizados para previsão de transferência de carga nas estacas, necessária para a previsão da curva carga-recalque pelos método de Aoki (1989). Adicionalmente, com os resultados das provas de carga foram estimadas para cada obra a probabilidade de ruína da fundação, e de ocorrência de recalques superiores a um valor limite. / This dissertation presents an evaluation of the behavior of continuous flight auger piles on ultimate capacity, settlments, safety and reliability, from a scenario analysis in which we considered a database of 58 static load tests, performed on piles of 13 distinct sites. However, this research is focused on the loaddisplacement behavior and reliability of this type of foundation. This analysis also verified the applicability of the method proposed by Aoki (1989) to determine the load-displacement curve of these pile load tests. The values of measured pile capacity were compared with those provided by the method Aoki & Velloso (1975), the method Decourt & Quaresma (1978), the method Cabral (1996), and the method Alonso (1996). These methods were also used to predict the load transfer along the piles, necessary to predict the load-displacement curve by the method of Aoki (1989). Additionally, the results of these load tests were used to estimate the probability of failure of the foundations tested, and the occurrence of settlements exceeding a threshold value.
123

Determinação da capacidade de carga última de estaca cravada em ensaio de carregamento dinâmico de energia crescente / The evaluation of the ultimate bearing capacity of driven piles by using increasing energy dynamic load tests

Aoki, Nelson 07 November 1997 (has links)
Esta tese aplica o conceito de energia complementar para a determinação da capacidade de carga última de estaca cravada no ensaio de carregamento dinâmico de energia crescente. O ensaio de carregamento dinâmico com impactos de energia constante só permite obter a resistência estática mobilizada do modelo de CASE ou de SMITH com base na teoria da equação da onda e no Pile Driving Analyzer. A aplicação de impactos de energia crescente mostra que a curva de resistência estática - deslocamento dinâmico apresenta: a) trecho linear crescente seguido de trecho que se curva até que a tangente se torna vertical ou b) trecho crescente quase linear até um pico de resistência, seguido de uma curva de descarga até um determinado valor que corresponde à tangente vertical ou, c) trecho linear crescente seguido de trecho curvo cuja tangente não se verticaliza e onde a resistência volta a crescer. A ruptura do sistema estaca - maciço de solos é caracterizada pela energia complementar que passa em um máximo sempre que a resistência mobilizada atinge um pico. No pós-ruptura o excesso de energia aplicada e o excesso de trabalho das forças de amortecimento do impacto, em relação ao pico máximo, crescem linearmente com o nível de energia cinética aplicada. / This thesis suggests how to evaluate the ultimate bearing capacity of driven piles by using dynamic load tests with increasing energy. The dynamic load test with constant energy blows only allows the determination of the mobilized static resistance (CASE and SMITH\'s model), by using the wave equation theory and the Pile Driving Analyzer. The application of increasing energy blows shows that this static resistance: a) increases with increasing energy and then becomes constant or; b) increases with increasing energy up to a peak resistance and thereafter first decreases and then becomes constant or, c) starts to increase with increasing energy, then remains constant and after some blows starts to increase again. lt is shown that the rupture of the pile-soil system is characterized by the kinetic complementary energy reaching an upper limit when the impact mobilizes the maximum static pile capacity. All the energy or work done by damping forces, in excess of this maximum or peak situation, increases linearly with increasing energy.
124

Comparison of Emperical Decline Curve Analysis for Shale Wells

Kanfar, Mohammed Sami 16 December 2013 (has links)
This study compares four recently developed decline curve methods and the traditional Arps or Fetkovich approach. The four methods which are empirically formulated for shale and tight gas wells are: 1. Power Law Exponential Decline (PLE). 2. Stretched Exponential Decline (SEPD). 3. Duong Method. 4. Logistic Growth Model (LGM). Each method has different tuning parameters and equation forms. The main objective of this work is to determine the best method(s) in terms of Estimated Ultimate Recovery (EUR) accuracy, goodness of fit, and ease of matching. In addition, these methods are compared against each other at different production times in order to understand the effect of production time on forecasts. As a part of validation process, all methods are benchmarked against simulation. This study compares the decline methods to four simulation cases which represent the common shale declines observed in the field. Shale wells, which are completed with horizontal wells and multiple traverse highly-conductive hydraulic fractures, exhibit long transient linear flow. Based on certain models, linear flow is preceded by bilinear flow if natural fractures are present. In addition to this, linear flow is succeeded by Boundary Dominated Flow (BDF) decline when pressure wave reaches boundary. This means four declines are possible, hence four simulation cases are required for comparison. To facilitate automatic data fitting, a non-linear regression program was developed using excel VBA. The program optimizes the Least-Square (LS) objective function to find the best fit. The used optimization algorithm is the Levenberg-Marquardt Algorithm (LMA) and it is used because of its robustness and ease of use. This work shows that all methods forecast different EURs and some fit certain simulation cases better than others. In addition, no method can forecast EUR accurately without reaching BDF. Using this work, engineers can choose the best method to forecast EUR after identifying the simulation case that is most analogous to their field wells. The VBA program and the matching procedure presented here can help engineers automate these methods into their forecasting sheets.
125

Undersökande arbetssätt i NO-undervisningen i grundskolans tidigare årskurser / Inquiry practises in primary science education

Johansson, Annie-Maj January 2012 (has links)
This thesis deals with the use of inquiry-based approaches in primary school science. The aim is to investigate the goals and purposes that are constituted by the curriculum and by the teachers in interviews and through their teaching in the classroom. The results are used to develop conceptual tools that can be used by teachers’ in their work to support students’ learning of science when using an inquiry-based approach. The thesis is comprised of four papers. In paper one a comparative analysis is made of five Swedish national curricula for compulsory school regarding what students should learn about scientific inquiry. In paper two 20 teachers were interviewed about their own teaching using inquiry. Classroom interactions were filmed and analyzed in papers three and four, which examine how primary teachers use the various activities and purposes of the inquiry classroom to support learning progressions in science. The results of paper one show how the emphasis within and between the two goals of learning to carry out investigations and learning about the nature of science shifted and changed over time in the different curricula. Paper two describes the selective traditions and qualities that were emphasized in the teachers’ accounts of their own teaching. The results of papers three and four show how students need to be involved in the proximate and ultimate purposes of the teaching activities for progression to happen. The ultimate purposes are the scientific purposes for the lesson (as given by the teacher or by the curriculum), whereas the proximate purposes are the more student-centered purposes that through different activities should allow the students to relate their own experiences and language to the ultimate purpose. The results show the importance of proximate purposes working as ends-in-view in the sense of John Dewey, meaning that the students see the goal of the activity and that they are able to relate to their experiences and familiar language. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: In press. Paper 2: Manuscript. Paper 4: Manuscript.</p>
126

Undersökande arbetssätt i NO-undervisningen i grundskolans tidigare årskurser

Johansson, Annie-Maj January 2012 (has links)
This thesis deals with the use of inquiry-based approaches in primary school science. The aim is to investigate the goals and purposes that are constituted by the curriculum and by the teachers in interviews and through their teaching in the classroom. The results are used to develop conceptual tools that can be used by teachers’ in their work to support students’ learning of science when using an inquiry-based approach. The thesis is comprised of four papers. In paper one a comparative analysis is made of five Swedish national curricula for compulsory school regarding what students should learn about scientific inquiry. In paper two 20 teachers were interviewed about their own teaching using inquiry. Classroom interactions were filmed and analyzed in papers three and four, which examine how primary teachers use the various activities and purposes of the inquiry classroom to support learning progressions in science. The results of paper one show how the emphasis within and between the two goals of learning to carry out investigations and learning about the nature of science shifted and changed over time in the different curricula. Paper two describes the selective traditions and qualities that were emphasized in the teachers’ accounts of their own teaching. The results of papers three and four show how students need to be involved in the proximate and ultimate purposes of the teaching activities for progression to happen. The ultimate purposes are the scientific purposes for the lesson (as given by the teacher or by the curriculum), whereas the proximate purposes are the more student-centered purposes that through different activities should allow the students to relate their own experiences and language to the ultimate purpose. The results show the importance of proximate purposes working as ends-in-viewin the sense of John Dewey, meaning that the students see the goal of the activity and that they are able to relate to their experiences and familiar language. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: In press. Paper 2: Manuscript. Paper 4: Manuscript.</p>
127

Beitrag zur numerischen Untersuchung der Bewegungs- und Beanspruchungsprofilen in einer Kugelmühle unter Verwendung von physikalisch begründeten Stoßparametern

Tichý, Richard 22 June 2011 (has links) (PDF)
Die am häufigsten für die Zerkleinerung des Zementklinkers eingesetzte Kugelmühle stellt eine relativ einfache Maschine dar, in der sehr komplizierte dynamische Wechselwirkungen herrschen. Die direkte Messung der Beanspruchungsintensitäten ist heutzutage immer noch eine schwierige Aufgabe. In der vorliegenden Arbeit sind die Spektren der Beanspruchungsgrößen sowie einige spezifische integrale Größen mit der Methode der diskreten Elemente (DEM) untersucht worden. Eine besondere Aufgabe bestand in der Ermittlung der Parameter des viskoelastischen Kontaktmodells und der den Zementklinker charakterisierenden mechanischen Größen. Die reale Abbildung der Stoßvorgänge wurde anhand vereinfachter Modelle der Messprüfstände validiert. Mit den ermittelten Parametern sind numerische Untersuchungen durchgeführt worden, mit denen ihre Auswirkung auf die Zielgrößen bestimmt wurde. In Hinsicht auf eine mögliche konstruktive Weiterentwicklung sind Simulationen mit festgelegten betrieblichen und zu variierenden konstruktiven Parametern durchgeführt worden.
128

Advanced Analysis of Steel Frame Structures Subjected to Lateral Torsional Buckling Effects

Yuan, Zeng January 2004 (has links)
The current design procedure for steel frame structures is a two-step process including an elastic analysis to determine design actions and a separate member capacity check. This design procedure is unable to trace the full range of load-deflection response and hence the failure modes of the frame structures can not be accurately predicted. In recent years, the development of advanced analysis methods has aimed at solving this problem by combining the analysis and design tasks into one step. Application of the new advanced analysis methods permits a comprehensive assessment of the actual failure modes and ultimate strengths of structural steel systems in practical design situations. One of the advanced analysis methods, the refined plastic hinge method, has shown great potential to become a practical design tool. However, at present, it is only suitable for a special class of steel frame structures that is not subject to lateral torsional buckling effects. The refined plastic hinge analysis can directly account for three types of frame failures, gradual formation of plastic hinges, column buckling and local buckling. However, this precludes most of the steel frame structures whose behaviour is governed by lateral torsional buckling. Therefore, the aim of this research is to develop a practical advanced analysis method suitable for general steel frame structures including the effects of lateral-torsional buckling. Lateral torsional buckling is a complex three dimensional instability phenomenon. Unlike the in-plane buckling of beam-columns, a closed form analytical solution is not available for lateral torsional buckling. The member capacity equations used in design specifications are derived mainly from testing of simply supported beams. Further, there has been very limited research into the behaviour and design of steel frame structures subject to lateral torsional buckling failures. Therefore in order to incorporate lateral torsional buckling effects into an advanced analysis method, a detailed study must be carried out including inelastic beam buckling failures. This thesis contains a detailed description of research on extending the scope of advanced analysis by developing methods that include the effects of lateral torsional buckling in a nonlinear analysis formulation. It has two components. Firstly, distributed plasticity models were developed using the state-of-the-art finite element analysis programs for a range of simply supported beams and rigid frame structures to investigate and fully understand their lateral torsional buckling behavioural characteristics. Nonlinear analyses were conducted to study the load-deflection response of these structures under lateral torsional buckling influences. It was found that the behaviour of simply supported beams and members in rigid frame structures is significantly different. In real frame structures, the connection details are a decisive factor in terms of ultimate frame capacities. Accounting for the connection rigidities in a simplified advanced analysis method is very difficult, but is most critical. Generally, the finite element analysis results of simply supported beams agree very well with the predictions of the current Australian steel structures design code AS4100, but the capacities of rigid frame structures can be significantly higher compared with Australian code predictions. The second part of the thesis concerns the development of a two dimensional refined plastic hinge analysis which is capable of considering lateral torsional buckling effects. The formulation of the new method is based on the observations from the distributed plasticity analyses of both simply supported beams and rigid frame structures. The lateral torsional buckling effects are taken into account implicitly using a flexural stiffness reduction factor in the stiffness matrix formulation based on the member capacities specified by AS4100. Due to the lack of suitable alternatives, concepts of moment modification and effective length factors are still used for determining the member capacities. The effects of connection rigidities and restraints from adjacent members are handled by using appropriate effective length factors in the analysis. Compared with the benchmark solutions for simply supported beams, the new refined plastic hinge analysis is very accurate. For rigid frame structures, the new method is generally more conservative than the finite element models. The accuracy of the new method relies on the user's judgement of beam segment restraints. Overall, the design capacities in the new method are superior to those in the current design procedure, especially for frame structures with less slender members. The new refined plastic hinge analysis is now able to capture four types of failure modes, plastic hinge formation, column buckling, local buckling and lateral torsional buckling. With the inclusion of lateral torsional buckling mode as proposed in this thesis, advanced analysis is one step closer to being used for general design practice.
129

A criatividade do amor criante de Deus : uma vivência de cura na criação artística

Maria Glória Dittrich 29 August 2008 (has links)
Esta tese trata sobre a criatividade do amor criante de Deus, como fundamento para a criatividade do ser humano e seu processo de cura na vivência da criação artística. Dentro de uma metodologia interdisciplinar, apoiada numa hermenêutica fenomenológica, se construiu um arcabouço teórico para a compreensão de uma vivência prática na criação da obra de arte, intitulada Caso R., que ocorreu no Atelier de Arte Maria Glória Dittrich, na cidade de Brusque, Estado de Santa Catarina, Brasil. A primeira parte, chamada Vivência, apresenta nos seus três quadros uma abordagem sobre a história de vida da pesquisadora e sua descoberta do tema de pesquisa. Descreve o Caso R. como uma vivência de criação na arte, marcada pelo amor e pelo desejo de ajudar o ser humano e nela ocorre um processo de cura. Por último, apresenta a metodologia da pesquisa do tipo teórico-prático, dentro de uma hermenêutica fenomenológica. A segunda parte, chamada A Compreensão, se organiza em três quadros. O primeiro, mostra os fundamentos da criatividade do corpo-criante. Explica que a criatividade nasce na auto-organização do corpo-criante e sua base é o amor vital. No segundo, apresenta a concepção de corpo-criante como um todo multidimensional sustentado, na sua criatividade, por um fundamento último Deus - amor criante, espiritual, que dá coragem para o ser humano enfrentar a finitude e a infinitude da vida. O segundo, discute sobre a obra de arte como revelação da criatividade do amor criante de Deus e sua relação com a criatividade humana sob o movimento da vida. Aponta a razão profunda como instância capaz de desenvolver a obra de arte e dar sentido a ela. Mostra a obra de arte desde o conceito de revelação como mistério, como êxtase e milagre. Por último, a obra de arte é apresentada como revelação da criatividade do amor criante de Deus para a descoberta de sentido para o viver. O terceiro, mostra uma concepção de cura espiritual como vivência da criatividade do amor criante de Deus no ser humano diante das ambigüidades da vida. Conceitualiza a fé como um sentir-se possuído por uma força espiritual, criadora. Essa força causa impactos na estrutura e organização do corpo-criante, implicando um processo criativo para a cura. A cura espiritual é a manifestação do amor criante do Espírito de Deus, no espírito humano. Essa manifestação é processo de fé no movimento das três dimensões da vida. A terceira parte, intitulada O Testemunho, é a hermenêutica sobre o Caso R. Esta parte está organizada em três quadros. O primeiro, apresenta a descoberta da Maria Glória sobre o fundamento último da criatividade humana nas relações de criação na criação artística. Confirma que essa descoberta levou à tomada de consciência sobre a força do poder da criatividade do amor criante de Deus, para o ser humano descobrir um novo sentido de vida através da criação na arte. No segundo, a revelação da criatividade do amor criante de Deus acontece para Maria Glória e R., dentro de uma experiência inusitada de fé que se tornou palavra encarnada, sinalizando um processo de cura. Por último, apresenta a confirmação da cura espiritual do R., como uma vivência criativa em processo, sustentada pela criatividade do amor criante de Deus no corpo-criante humano e sua auto-afirmação no mundo pela sua criatividade. / This thesis is about the creativity of Gods creating love as basis for the creativity of human being and its cure process at the living experience of artistic creation. In an interdisciplinary methodology, supported by a phenomenological hermeneutic, it has been built a theoretical skeleton for the comprehension of a practical living experience in the creation of the work of art entitled Caso R., which occurred in the art atelier Maria Glória Dittrich, in the city of Brusque, state of Santa Catarina, Brazil. The first part, called Living Experience, shows in its three boards an approach on the researchers life story and her discovery on the subject of research. It describes Caso R. as a creation living experience in art, marked by the love and by the desire of helping human being and in it there occurs a cure process. At last, it shows the methodology of research of the theoretical-practical type, in a phenomenological hermeneutic. The second part, named The Comprehension, is organized in three boards. The first shows the basis of creativity of the creating body. It explains that the creativity grows from self-organization of the creating body and its basis is vital love. On the second, it shows the conception of creating body as a multidimensional whole, maintained, in its creativity, by an ultimate basis God creating, spiritual love, which gives courage to human being to face finiteness and infiniteness of life. The second discusses about the work of art as a revelation of the creativity of Gods creating love and its relation to human creativity under lifes motion. It points out the profound reason as an instance capable of developing the work of art and give it a meaning. It shows the work of art from the concept of revelation as mystery, as ecstasy and miracle.At last, the work of art is shown as revelation of creativity of Gods creating love for the discovery of meaning for living. The third shows a conception if spiritual cure as living experience of creativity of Gods creating love in human being in the presence of life ambiguities. It reputes faith as feeling possessed by a spiritual, creative force. This force causes impacts on the structure and organization of the creating body, implying a creative process for the cure. Spiritual cure is creating love manifestation of God Spirit in human spirit. This manifestation is a faith process in the motion of the three dimensions in life. The third part, entitled The Testimony, is the hermeneutic about Caso R. This part is organized in three boards. The first shows the discovery of Maria Glória about the ultimate basis of human creativity in relations of artistic creation. It confirms that this discovery led to the conscience take about the force of creativity power of Gods creating love, for the human being to discover a new meaning of life through creation in art. In the second, revelation of creativity of Gods creating love happens to Maria Glória and R., in an unsusual faith experience that has become embodied word, signalizing a cure process. At last, it shows confirmation of spiritual cure of R., as a creative living experience in process, maintained by creativity of Gods creating love in the human creating body and its self-affirmation in the world by its creativity.
130

Determinação da capacidade de carga última de estaca cravada em ensaio de carregamento dinâmico de energia crescente / The evaluation of the ultimate bearing capacity of driven piles by using increasing energy dynamic load tests

Nelson Aoki 07 November 1997 (has links)
Esta tese aplica o conceito de energia complementar para a determinação da capacidade de carga última de estaca cravada no ensaio de carregamento dinâmico de energia crescente. O ensaio de carregamento dinâmico com impactos de energia constante só permite obter a resistência estática mobilizada do modelo de CASE ou de SMITH com base na teoria da equação da onda e no Pile Driving Analyzer. A aplicação de impactos de energia crescente mostra que a curva de resistência estática - deslocamento dinâmico apresenta: a) trecho linear crescente seguido de trecho que se curva até que a tangente se torna vertical ou b) trecho crescente quase linear até um pico de resistência, seguido de uma curva de descarga até um determinado valor que corresponde à tangente vertical ou, c) trecho linear crescente seguido de trecho curvo cuja tangente não se verticaliza e onde a resistência volta a crescer. A ruptura do sistema estaca - maciço de solos é caracterizada pela energia complementar que passa em um máximo sempre que a resistência mobilizada atinge um pico. No pós-ruptura o excesso de energia aplicada e o excesso de trabalho das forças de amortecimento do impacto, em relação ao pico máximo, crescem linearmente com o nível de energia cinética aplicada. / This thesis suggests how to evaluate the ultimate bearing capacity of driven piles by using dynamic load tests with increasing energy. The dynamic load test with constant energy blows only allows the determination of the mobilized static resistance (CASE and SMITH\'s model), by using the wave equation theory and the Pile Driving Analyzer. The application of increasing energy blows shows that this static resistance: a) increases with increasing energy and then becomes constant or; b) increases with increasing energy up to a peak resistance and thereafter first decreases and then becomes constant or, c) starts to increase with increasing energy, then remains constant and after some blows starts to increase again. lt is shown that the rupture of the pile-soil system is characterized by the kinetic complementary energy reaching an upper limit when the impact mobilizes the maximum static pile capacity. All the energy or work done by damping forces, in excess of this maximum or peak situation, increases linearly with increasing energy.

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