Neste trabalho estudamos problemas de evolução da forma \'d \' úpsilond\' SUP. \' úpsilon\' t\'\' + A (t,\'úpsilon\' )\' úpsilon\' = f(t,\'úpsilon\' ) \'úpsilon\'(0) = \' \' úpsilon\' IND. 0\' \', em um espaço de Banach X onde A(t, \'úpsilon\' ) : D \'está contido em\' X \'SETA \' X é um operador linear fechado e setorial para cada (t, \' úpsilon\' ). Quando o operador A(t, \' úpsilon\' ) é independente de \' úpsilon\' , isto é, A(t, \' úpsilon\') = A(t), mostramos um resultado de exitência, unicidade, continuidade relativamente a dados iniciais e continuação para o caso em que a não linearidade f tem crescimento crítico. Se A(t, \'úpsilon\' ) depende do tempo e do estado, então mostramos um resultado de existência, unicidade com f tendo crescimento sub-crítico semelhante aos resultados encontrados em [7, 33] / In this work we study initial value problems of the form \' d \'úpsilon\' SUP. dt + A (t, \'úpsilon\')\'úpsilon\' = f (t, \'úpsilon\' ) \' úpsilon\' (0) = \' úpsilon IND.0\', in a Banach space X where A(t,\' úpsilon\' ) : D \' this contained \' X \' ARROW\' X is an unbounded closed linear operator which is sectorial for each (t,\' úpsilon\' ). When the operator family A(t, \' úpsilon\' ) is independent of \' úpsilon\' , that is, A(t, \' úpsilon\' ) = A(t), we show a result on local well posedness and continuation with the nonlinearity f growing critically. If A(t,\' úpsilon\' ) depends on the time t and on the state \' úpsilon\' we show a local well posedness and continuation result that is similar to the result found in [7, 33]

Orientadores: Maria Amelia Novais Schleicher, Joerg Dietrich Wilhelm Schleicher / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-15T16:25:22Z (GMT). No. of bitstreams: 1 Coimbra_TiagoAntonioAlves_M.pdf: 1644714 bytes, checksum: 5d506a3202c2283333d0f29819623fcc (MD5) Previous issue date: 2010 / Resumo: O deslocamento de um evento sísmico sob a chamada operação de continuação de afastamento (Offset Continuation Operation - OCO) pode ser descrita por uma equação diferencial parcial de segunda ordem que foi denominada de equação da onda imagem para OCO. Por substituição de uma solução tentativa da forma da teoria dos raios, pode se deduzir uma equação iconal OCO que descreve os aspectos cinemáticos da propagação da onda imagem OCO. Neste trabalho, resolvemos a equação da onda imagem OCO por meio do método das características. As características desta equação são as trajetórias OCO que descrevem o caminho do deslocamento de um evento sísmico sob variação do afastamento entre fonte e receptor. O conjunto de pontos finais de diversas trajetórias OCO, traçadas a partir do mesmo afastamento inicial até o mesmo afastamento final, define o raio de velocidade OCO ou, mais breve, raio OCO. Este raio OCO pode ser empregado para análise de velocidade. O algoritmo consiste do traçamento de raios OCO e então encontrar o ponto de interseção entre o raio OCO e o evento de reflexão sísmica dentro da seção final de afastamento comum. O procedimento tem a vantagem sobre a análise de velocidade convencional de que está baseado numa comparação de dados simulados com dados adquiridos ao invés de dois conjuntos de dados simulados. Exemplos numéricos demonstram que o traçamento de raios OCO pode ser executado de maneira precisa e de que a análise de velocidade resultante fornece velocidades confiáveis. Além disso, baseado nas expressões analíticas para os raios OCO que começam a partir do afastamento zero (migraton to common offset - MCO), deduzimos uma equação da onda imagem para continuação de velocidade MCO. Demonstramos que, em muitas situações práticas, esta equação pode ser empregada diretamente para OCO, assim evitando a necessidade de traçar trajetórias e raios OCO / Abstract: The dislocation of a seismic event under the so-called Offset Continuation Operation (OCO) can be described by a second-order partial differential equation, which has been called the OCO image-wave equation. By substitution of a ray-like trial solution, an OCO image-wave eikonal equation is obtained that describes the kinematic aspects of OCO imagewave propagation. In this work, we solve the OCO image-wave eikonal equation by means of the method of characteristics. The characteristics of this equation are the OCO trajectories that describe the path of dislocation of a seismic event under variation of the source-receiver offset. The set of endpoints of several OCO trajectories traced from the same initial to the same final offset under varying values for the medium velocity defines the OCO velocity ray or briefly OCO ray. This OCO ray can be employed for velocity analysis. The algorithm consists of OCO ray tracing an then finding the intersection point of the OCO ray with the seismic reflection event in the final common-offset section. The procedure has the advantage over conventional velocity analysis that it is based on a comparison of simulated and acquired data rather than two sets of simulated data. Numerical examples demonstrate that the OCO ray tracing can be accurately executed and that the resulting velocity analysis yields reliable velocities. Moreover, based on the analytic expressions for the OCO rays starting from zero-offset (migraton to common offset, MCO), we derived an image-wave equation for MCO velocity continuation. We demonstrate that in many practical situations this equation can be directly employed for OCO, thus avoiding the need to trace OCO trajectories and OCO rays / Mestrado / Geofisica Computacional / Mestre em Matemática Aplicada

Neste trabalho consideramos o problema de Navier-Stokes em RN <div style=\"width: 50%; margin: auto;\">ut = &Delta;u &mdash; &nabla;&pi; + f (t) &mdash; (u .&nabla;)u,&nbsp; &nbsp;x&isin; &Omega; <br />div(u) = 0,&nbsp; &nbsp; x &isin; &Omega; <br />u = 0,&nbsp; &nbsp;&nbsp;x &isin; &part; &Omega; <br />u(0, x) = u0 (x), onde u0 &isin; LN (&Omega;)N e &Omega; &eacute; um subconjunto aberto, limitado e suave de RN. Provamos que o problema acima &eacute; localmente bem colocado e fornecemos condi&ccedil;&otilde;es para obter que estas solu&ccedil;&otilde;es existem para todo t &ge; 0. Utilizamos t&eacute;cnicas de equa&ccedil;&otilde;es parab&oacute;licas semilineares considerando n&atilde;o linearidades com crescimento cr&iacute;tico desenvolvidas em (ARRIETA; CARVALHO, 1999). / In this work we we consider the Navier-Stokes problem on RN <div style=\"width: 50%; margin: auto;\">ut = &Delta;u &mdash; &nabla;&pi; + f (t) &mdash; (u .&nabla;)u,&nbsp; &nbsp;x&isin; &Omega; <br />div(u) = 0,&nbsp; &nbsp; x &isin; &Omega; <br />u = 0,&nbsp; &nbsp;&nbsp;x &isin; &part; &Omega; <br />u(0, x) = u0 (x), where u0 &isin; LN (&Omega;)N and &Omega; is an open, bounded and smooth subset of RN. We prove that the above problem is locally well posed and give conditions to obtain that these solutions exist for all t &ge; 0. We used techniques of semilinear parabolic equations considering nonlinearities with critical grouth developed in (ARRIETA; CARVALHO, 1999).

At the beginning of the Continuation War in 1941, Finnish and German troops commenced a gradual escalation which resulted in swift successive victories against the Soviets. Yet, Finland´s Field Marshal Mannerheim unexpectedly turned his back on military rationality at Leningrad and Murmansk despite his knowledge of how vitally strategic the locations were to the Soviet war effort. Leningrad was encircled by German and Finnish forces and a successful siege was achievable, yet Mannerheim abruptly discontinued the offensive and chose to assume a stale war lasting until 1944. Likewise, Mannerheim withheld his troops from cutting off Murmansk Railway. These events beckon important inquiries regarding Mannerheim´s decision to de-escalate during successful offensives in a total war and presents a conundrum that few have to date examined holistically. As such, this thesis offers an alternative perspective to the current rational explanations of Finnish warfare in the Continuation War. This thesis discusses specific social processes of Finnish society that rationalist explanations overlook and applies the theory of constructivism to identify that normative factors can complement the prevailing rationalist explanations. This thesis further identifies how the social concepts of identity, shared culture and knowledge, and the norms of the Finnish people, and its leadership, contributed to Mannerheim’s decision to disregard military rationality and de-escalate. Lastly, this thesis determines that norms and ideas matter in war studies and future research should incorporate an interpretivist approach which contemplates social constructions and norms as alternative explanations in complex, multi-casual social phenomena like war.

No description available.

In practice, graphs often occur as perturbed product structures, so-called approximate graph products. The practical application of the well-known prime factorization algorithms is therefore limited, since most graphs are prime, although they can have a product-like structure. This work is concerned with the strong graph product. Since strong product graphs G contain subgraphs that are itself products of subgraphs of the underlying factors of G, we follow the idea to develop local approaches that cover a graph by factorizable patches and then use this information to derive the global factors. First, we investigate the local structure of strong product graphs and introduce the backbone B(G) of a graph G and the so-called S1-condition. Both concepts play a central role for determining the prime factors of a strong product graph in a unique way. Then, we discuss several graph classes, in detail, NICE, CHIC and locally unrefined graphs. For each class we construct local, quasi-linear time prime factorization algorithms. Combining these results, we then derive a new local prime factorization algorithm for all graphs. Finally, we discuss approximate graph products. We use the new local factorization algorithm to derive a method for the recognition of approximate graph products. Furthermore, we evaluate the performance of this algorithm on a sample of approximate graph products.

The Cayley-Hamilton Theorem is an important result in the study of linear transformations over finite dimensional vector spaces. In this thesis, we show that the Cayley-Hamilton Theorem can be extended to self-adjoint trace-class operators and to closed self-adjoint operators with trace-class resolvent over a separable Hilbert space. Applications of these results include calculating operators resolvents and finding the inverse of a frame operator.

This concept of calculating, optimizing, and utilizing a trajectory known as a ``Free Return Trajectory" to facilitate spacecraft rendezvous with Near-Earth Asteroids is presented in this dissertation. A Free Return Trajectory may be defined as a trajectory that begins and ends near the same point, relative to some central body, without performing any deterministic velocity maneuvers (i.e., no maneuvers are planned in a theoretical sense for the nominal mission to proceed). Free Return Trajectories have been utilized previously for other purposes in astrodynamics, but they have not been previously applied to the problem of Near-Earth Asteroid rendezvous. Presented here is a series of descriptions, algorithms, and results related to trajectory initial guess calculation and optimal trajectory convergence. First, Earth-centered Free Return Trajectories are described in a general manner, and these trajectories are classified into several families based on common characteristics. Next, these trajectories are used to automatically generate initial conditions in the three-body problem for the purpose of Near-Earth Asteroid rendezvous. For several bodies of interest, example initial conditions are automatically generated, and are subsequently converged, resulting in feasible, locally-optimal, round-trip trajectories to Near-Earth Asteroids utilizing Free Return Trajectories. Subsequently, a study is performed on using an unpowered flyby of the Moon to lower the overall DV cost for a nominal round-trip voyage to a Near-Earth Asteroid. Using the Moon is shown to appreciably decrease the overall mission cost. In creating the formulation and algorithms for the Lunar flyby problem, an initial guess routine for generic planetary and lunar flyby tours was developed. This continuation algorithm is presented next, and details a novel process by which ballistic trajectories in a simplistic two-body force model may be iteratively converged in progressively more realistic dynamical models until a final converged ballistic trajectory is found in a full-ephemeris, full-dynamics model. This procedure is useful for constructing interplanetary transfers and moon tours in a realistic dynamical framework; an interplanetary and an inter-moon example are both shown. To summarize, the material in this dissertation consists of: novel algorithms to compute Free Return Trajectories, and application of the concept to Near-Earth Asteroid rendezvous; demonstration of cost-savings by using a Lunar flyby; and a novel routine to transfer trajectories from a simplistic model to a more realistic dynamical representation. / text

本研究旨在探討我國高職進修學校學生學習動機及學習滿意度的相關影響因素，並以研究結果提供作為高職進修學校與各教育主管機關提升教育品質之參考。 本研究以臺北縣高職進修學校學生為研究對象，並以「高職進修學校學習情況調查問卷」為施測工具進行問卷調查。有效樣本984 人。所得資料以平均數、標準差、t 考驗、單因子變異數分析、皮爾遜積差相關等統計方法加以處理及分析。綜合本研究之結果如下： 壹、台北縣私立高職進修學校學生，就讀台北縣九大行政區中所設立之私立高職進修學校學生，以女性學生佔多數(佔58.9%)，男性學生較少(佔41.1%)。 貳、私立高職進修學校學生之學習動機層面中，較佳為「自我學習信念」、「自我認同」及「自我要求」等因素，但仍應加強自我專業與技能實踐能力。 參、私立高職進修學校學生之學習滿意度層面中，較佳為「課程教材」、「學習教材」、「人際互動」、「生涯規劃」等因素，但仍應加強學習環境之改善。 肆、不同背景變項學生學習動機上有所不同。 伍、私立高職進修學校學生在學習動機與學習滿意度呈現正相關。 陸、私立高職進修學校學生在學生學習動機各因素與學習滿意度各層面之相關呈現正相關。 最後，研究者依據研究所得結果提出幾點建議，作為學校教育、 家長及未來研究之參考。 關鍵字：高職進修學校、學習動機、學習滿意度 / The research aims to explore the relationship and relevant factors between learning motivation and satisfaction of continuation vocational high school students. It would provide references for the authority of educational units and administration of continuation vocation high school to enhance teaching and learning quality. The research takes continuation vocational high school students in Taipei County for studying objects. The questionnaire “Continuation vocational high school student learning situation” was used as a tool and the valid data was collected from 984 students. The data was analyzed and processed through statistical methods such as Average, Standard Deviation, T tests, Single factor variance analysis, and Pearson’s product-moment correlation analysis. Finally, according to the results and investigations, findings and conclusions were come up along with recommendations as follows: 1. The female students who study in private continuation vocational high school in nine main districts of Taipei County is more (58.9%) than that of male ones (41.1%). 2. In the coverage of learning motivation, the continuation vocational high school students pay more concern on the factors such as “Self- monitoring learning belief”, “Self- Identity”, and “Self- development”. However, the schools should teach students how to enhance their professional and practical skills. 3. In the coverage of learning satisfaction, the continuation vocational high school students are pleased with the factors such as “Curriculum materials”, “Learning materials”, “Relationship”, and “Career Planning”. However, the school should improve the quality of learning environment. 4. The students from different backgrounds and family conditions have different learning motivation. 5. There is positive correlation between learning motivation and learning satisfaction of private continuation vocational high school students. 6. There is positive correlation between different factors of learning motivation and learning satisfaction of private continuation vocational high school students. In sum, based on the conclusion of the study, the author suggests some recommendations for school education, parents, and future researchers. Key word: continuation vocational high school, learning motivation, learning satisfaction

Soit une famille de couples (ft,Xt)t∈J , où J est un intervalle, ft est une fonction lisse à valeurs réelles définie sur une variété lisse et compacte V , et Xt est un pseudo-gradient associé à la fonction ft. L’objet de ce mémoire est l’étude des bifurcations subies par les complexes de Morse associés à ces couples. Deux approches sont utilisées : l’étude directe des bifurcations et l’approche par homotopie. On montre que finalement ces deux approches permettent d’obtenir les mêmes résultats d’un point de vue fonctoriel. / Let (ft,Xt)t∈J be a family of pairs, where J is an interval, ft is a smooth real-valued Morse function defined on a smooth compact manifold V , and Xt is a pseudo-gradient field associated to ft. The purpose of this master thesis is to study the bifurcations undergone by the associated Morse complexes. Two ways are used to reach this result : the direct study of the bifurcations and the continuation method. We prove that the two methods produce the same results from a functorial point of view.