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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

Dynamic discontinuity meshing

Worrall, Adam January 1998 (has links)
No description available.
2

Adaptive channel estimators suitable for implementation in coherent digital receivers operating in a mobile satellite environment

Lang, Andreas January 1999 (has links)
No description available.
3

Discontinuity meshing for complex environments

Hedley, David January 1998 (has links)
No description available.
4

Continuidade de atratores globais: o uso de corretores para a obtenção de melhores taxas de convergência / Continuity of global attractors: the use of correctors to obtain better convergence rates

Cardoso, Cesar Augusto Esteves das Neves 05 June 2017 (has links)
Neste trabalho estudamos a continuidade da dinâmica assintótica relativamente a perturbações e, em particular, exploramos a obtenção de melhorias para as taxas de convergência de atratores globais através da introdução de fatores de correção, inspirados pelos resultados da teoria de homogeneização e nos trabalhos de (BABIN; VISHIK, 1992) e (CARVALHO; CHOLEWA, 2011), e através da introdução de mecanismos que melhoram a transferência da taxa de convergência de semigrupos para a taxa de convergência de atratores, inspirados pelos trabalhos (SANTAMARÍA, 2013) e (BABIN; VISHIK, 1992; CARVALHO; CHOLEWA, 2011). A proposta inicial está centrada na obtenção de melhores taxas de convergência de atratores globais através da obtenção de equiatração e da melhoria da taxa de convergência dos semigrupos. Para isto, buscamos melhorar a taxa de convergência do resolvente dos operadores setoriais envolvidos, por meio de uma perturbação singular do resolvente limite que ainda gere uma família de operadores setoriais com resolventes que aproximam o resolvente do problema limite e aproximam melhor os resolventes das perturbações iniciais. Feito isto, obtemos uma melhora imediata de convergência dos semigrupos lineares, depois dos não lineares (através da fórmula da variação das constantes). Motivados pelos resultados de (SANTAMARÍA, 2013), que oferecem uma menor perda na transferência das taxas de convergência dos semigrupos para as taxas de convergência dos atratores, buscamos melhor compreender a propriedade Lipschitz Shadowing, que é responsável direta pela obtenção da taxa de convergência dos atratores diretamente da taxa de convergência dos semigrupos. Isto nos levou a descobrir que podemos obter as propriedade Lipschitz Shadowing e estabilidade estrutural para perturbações Lipschitz de semigrupos Morse-Smale. / Here we compare the continuity of the asymptotic dynamics with respect to perturbations and, in particular, we explored to obtain improvement of rates of convergence of the global attractor through the introduction of correction factors, inspired by the results of homogenization theory and work of (BABIN; VISHIK, 1992) and (CARVALHO; CHOLEWA, 2011), and the introduction of mechanisms that improve the transference of the convergence rate of semigroups to the convergence rate of attractors, inspired by the work of (SANTAMARÍA, 2013) and (BABIN; VISHIK, 1992; CARVALHO; CHOLEWA, 2011). The initial proposal is focused on achieving best rates of convergence of the global attractors by obtaining equi-atraction and improving the convergence rate of semigroups. For this, we seek to improve the rate of convergence of the resolvents of sectorial operators, through a singular perturbation of the resolvent associated with the limit problem and generate a new family of sectorial operators whose resolvents both approximate the resolvent of the limit problem as they were closer to the resolvents the initial perturbation. Having done this, we obtain an immediate improvement of convergence of linear semigroups, after the non-linear (using the variation of constants formula). Motivated by the results of (SANTAMARÍA, 2013), which offer an improvement in obtaining convergence rates, we seek to study property better Lipschitz Shadowing, which is basically responsible for obtaining the distance of the attractors directly from the convergence rate of the semigroups. This has led us to discover that we can both preserve the Lipschitz Shadowing property under Lipschitz perturbations of Morse-Smale semigroups, and The geometric stability of the attractors.
5

Continuidade de atratores globais: o uso de corretores para a obtenção de melhores taxas de convergência / Continuity of global attractors: the use of correctors to obtain better convergence rates

Cesar Augusto Esteves das Neves Cardoso 05 June 2017 (has links)
Neste trabalho estudamos a continuidade da dinâmica assintótica relativamente a perturbações e, em particular, exploramos a obtenção de melhorias para as taxas de convergência de atratores globais através da introdução de fatores de correção, inspirados pelos resultados da teoria de homogeneização e nos trabalhos de (BABIN; VISHIK, 1992) e (CARVALHO; CHOLEWA, 2011), e através da introdução de mecanismos que melhoram a transferência da taxa de convergência de semigrupos para a taxa de convergência de atratores, inspirados pelos trabalhos (SANTAMARÍA, 2013) e (BABIN; VISHIK, 1992; CARVALHO; CHOLEWA, 2011). A proposta inicial está centrada na obtenção de melhores taxas de convergência de atratores globais através da obtenção de equiatração e da melhoria da taxa de convergência dos semigrupos. Para isto, buscamos melhorar a taxa de convergência do resolvente dos operadores setoriais envolvidos, por meio de uma perturbação singular do resolvente limite que ainda gere uma família de operadores setoriais com resolventes que aproximam o resolvente do problema limite e aproximam melhor os resolventes das perturbações iniciais. Feito isto, obtemos uma melhora imediata de convergência dos semigrupos lineares, depois dos não lineares (através da fórmula da variação das constantes). Motivados pelos resultados de (SANTAMARÍA, 2013), que oferecem uma menor perda na transferência das taxas de convergência dos semigrupos para as taxas de convergência dos atratores, buscamos melhor compreender a propriedade Lipschitz Shadowing, que é responsável direta pela obtenção da taxa de convergência dos atratores diretamente da taxa de convergência dos semigrupos. Isto nos levou a descobrir que podemos obter as propriedade Lipschitz Shadowing e estabilidade estrutural para perturbações Lipschitz de semigrupos Morse-Smale. / Here we compare the continuity of the asymptotic dynamics with respect to perturbations and, in particular, we explored to obtain improvement of rates of convergence of the global attractor through the introduction of correction factors, inspired by the results of homogenization theory and work of (BABIN; VISHIK, 1992) and (CARVALHO; CHOLEWA, 2011), and the introduction of mechanisms that improve the transference of the convergence rate of semigroups to the convergence rate of attractors, inspired by the work of (SANTAMARÍA, 2013) and (BABIN; VISHIK, 1992; CARVALHO; CHOLEWA, 2011). The initial proposal is focused on achieving best rates of convergence of the global attractors by obtaining equi-atraction and improving the convergence rate of semigroups. For this, we seek to improve the rate of convergence of the resolvents of sectorial operators, through a singular perturbation of the resolvent associated with the limit problem and generate a new family of sectorial operators whose resolvents both approximate the resolvent of the limit problem as they were closer to the resolvents the initial perturbation. Having done this, we obtain an immediate improvement of convergence of linear semigroups, after the non-linear (using the variation of constants formula). Motivated by the results of (SANTAMARÍA, 2013), which offer an improvement in obtaining convergence rates, we seek to study property better Lipschitz Shadowing, which is basically responsible for obtaining the distance of the attractors directly from the convergence rate of the semigroups. This has led us to discover that we can both preserve the Lipschitz Shadowing property under Lipschitz perturbations of Morse-Smale semigroups, and The geometric stability of the attractors.
6

Instilling an entrepreneurial culture in a small growth-oriented firm : An explorative study using a shadowing approach

Olsson, Henric, Eriksson, Anders January 2015 (has links)
Good working conditions have become one of the most important factors in today’s Swedish workplaces. The impact that culture has on companies and their atmosphere is of great importance for overall productivity. Existing research has mainly focused on large established businesses. As a consequence, the work that has been conducted on small entrepreneurial companies is limited. There are studies highlighting the difficulty of transitioning from a small firm to a large entrepreneurial firm. Still, there is a lack of studies investigating this process in depth. Gaining insight into this process is highly relevant for practitioners, policy makers and researchers alike. Therefore, we have chosen to study this field closer. In order to explore this field and to dive deeper within the concept of organizational culture, a shadowing method has been used on a newly started growth oriented company. The company is founded by two opportunity driven leaders who strongly believe in a happy workplace where the focus lies on the individual and where problems are met with a “how hard can it be” attitude. We followed the firm for 8 weeks. During that time we were present full time in their facilities, conducted formal interviews, informal interviews, interacted with employees and the entrepreneurs during lunches and small gatherings. In order to develop an entrepreneurial culture they follow an ideology that is based on a few cornerstones; they strive to have short decision paths, a familial atmosphere, individual focus, strong commitment mixed with a fun factor. When investigating how the culture expresses itself we have found four different forums of particular interest; the office where the decision process takes place, the group meetings where beliefs and values are shared, the individual meetings where feedback is provided and the recruitment process where the cultural marketing takes place. Our conclusion is that these forums work together in a circular motion that expresses – shapes - shares - aligns the organizational culture of this small and young company.
7

Pay tracing tools for high frequency electromagnetics simulations

Sefi, Sandy January 2003 (has links)
<p>Over the past 20 years, the development in ComputationalElectromagnetics has produced a vast choice of methods based onthe large number of existing mathematical formulations of theMaxwell equations. None of them dominate over the others,instead they complement each other and the choice of methoddepends on the frequency range of the electromagnetic waves.This work is focused on the most popular method in the highfrequency scenario, namely the Geometrical Theory ofDiffraction (GTD). The main advantage of GTD is the ability topredict the electromagnetic field asymptotically in the limitof vanishing wavelength, when other methods, such as the Methodof Moments, become computationally too expensive.</p><p>The low cost of GTD is due to both the fact that there is noruntime penalty in increasing the frequency and that the raytracing, which GTD is based on, is a geometrical technique. Thecomplexity is then no longer dependent on electrical size ofthe problem but instead on geometrical sub problems which aremanageable. For industrial applications the geometricalstructures, with which the rays interact, are modelled bytrimmed Non-Uniform Rational B-Spline (NURBS) surfaces, themost recent standard used to represent complex free-formgeometries.</p><p>Due to the introduction of NURBS, the geometrical subproblems tend to be mathematically and numerically cumbersome,but they can be highly simplified by proper Object Orientedprogramming techniques. This allowed us to create a flexiblesoftware package, MIRA: Modular Implementation of Ray Tracingfor Antenna Applications, with an architecture that separatesmathematical algorithms from their implementation details andmodelling. In addition, its design supports hybridisationtechniques in combination with other methods such as Method ofMoment (MoM) and Physical Optics (PO).</p><p>In a first hybrid application, a triangle-based PO solveruses the shadowing information calculated with the ray tracerpart of MIRA. The occlusion is performed between triangles andtheir facing NURBS surfaces rather than between their facingtriangles, thus reducing the complexity. Then the shadowinginformation is used in an iterative MoM-PO process in order tocover higher frequencies, where the contribution of theshadowing effects, in the hybrid formulation, is believed to bemore significant.</p><p>Thesis presented at the Royal Institute of Technology ofStockholm in 2003, for the degree of Licentiate in ScientificComputing.</p>
8

Tópicos de Dinâmica Hiperbólica / Topics of Hyperbolic Dynamics

DINIZ, Diego Araújo 02 May 2017 (has links)
Submitted by Daniella Santos (daniella.santos@ufma.br) on 2017-06-22T12:57:55Z No. of bitstreams: 1 Diego Araújo.pdf: 749439 bytes, checksum: e6b630a6b28df216e5e6fc70dbeead61 (MD5) / Made available in DSpace on 2017-06-22T12:57:55Z (GMT). No. of bitstreams: 1 Diego Araújo.pdf: 749439 bytes, checksum: e6b630a6b28df216e5e6fc70dbeead61 (MD5) Previous issue date: 2017-05-02 / The main goal of this work is to discuss some topics about hyperbolic dynamical systems. We collect results and definitions that are dispersed, or even in works of generalized context. Thus, we propose a tour that begins with the definition of orbit, passes through classical results like Hartman-Grobman Theorem and shadowing lemma, and ends with the Omega stability theorem. / O objetivo deste trabalho é dissertar sobre alguns tópicos dos sistemas dinâmicos hiberbólicos. Nós coletamos resultados e definicões que em sua maioria encontram-se dispersos, ou ainda, em obras de contexto generalizado. Assim, nos propomos a fazer uma caminhada que começa com a definicão de órbita, passa por resultados clássicos como o Teorema de Hartman-Grobman e o Lema de Sombreamento, e termina com o teorema da Omega estabilidade.
9

英語 シャドーイングからセルフトーク・ミラーリングへの段階的指導方法の開発(IX. 教科研究)

鈴木, 克彦, SUZUKI, K. 25 January 2010 (has links)
No description available.
10

Shadowing practices: Ethnographic accounts of private eyes as entrepreneurs

Engstrom, Craig L. 01 May 2010 (has links)
In recent years, entrepreneurship studies scholars have begun studying entrepreneurship from a process-oriented philosophy and with an interest in the prosaic, everyday practices of entrepreneurs. In keeping with these "new movement" approaches, I have tried to "catch" entrepreneurship as it is happening within the field of private investigations. An in-depth, two-year field study of private investigators engaged in the entwined practices of investigating and entrepreneuring was conducted. Methodologically, I shadowed five private investigators and interviewed an additional 25. Because shadowing is an emergent methodology, an in-depth discussion of conducting and writing shadowing research is provided. As noted in this discussion, it is important that writing remain primarily descriptive yet linked to dominant contemporary discourses. Consequently, an overview of dominant narrative themes in popular and academic discourses about private investigating and entrepreneurship are included. Based on the framework of this methodology, dominant narrative themes, and field notes, various culturally-situated accounts of private investigator practices are offered. The findings of this research project suggest that private investigators use various rhetorical and practical strategies to successfully and simultaneously complete investigative and business-related tasks, such as "planting suspicions," using gender and race to strategically position themselves in relation to others in opportunistic ways, and incorporating contemporary technology into their work routines. Drawing on actor-network-theory, I argue that opportunities are enacted through a series of taken-for-granted and everyday interactions among subjects and objects. This research privileges descriptive accounts over theory-building. However, the descriptive accounts of the practices of subjects and objects suggest pragmatic solutions for private investigators to create and manage entrepreneurial opportunities. For example, I propose that private investigators should collectively engage in practices that further professionalize their field. Such professionalizing activities would include, among other things, engaging in knowledge accumulation through academic and professional research activities and professional association public relations campaigns. Insights are also provided regarding the role of rhetoric and technology in opportunity creation and destruction. Readers interested in organization communication and theory will find many of the descriptions to be empirically rich examples of ethno-methods used by actors in highly institutionalized contexts. Similarly, these scholars may also find the descriptions to validate recent arguments regarding organizing as "hybridized actions" (or action nets) occurring in multiple spaces, places, and times. The examples herein demonstrate the usefulness of shadowing as an approach to understanding organizing practices, especially in fields where actors are always "on the move." Readers interested in private investigating will find many of the examples rich in techniques that will enhance profitability. Finally, readers interested in entrepreneurship studies will undoubtedly find many novel potential research projects that are embedded in the various thick descriptions throughout the document.

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