707 resultados para Integrable hierarchies
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As migrações constituem um dos pilares da relação entre Brasil e Portugal. Com esta premissa este estudo tem por objetivo compreender a formação, a sustentação no tempo e a configuração atual do sistema migratório luso-brasileiro. Partindo da Geografia da População, dialoga-se tanto com os demais campos da própria ciência geográfica, especialmente a Geografia Política e a Geografia Econômica, como com as demais ciências humanas e sociais, dentre outras a Sociologia e a Antropologia. Adota- se uma periodização que busca articular as migrações e as imaginações geográficas produzidas e produtoras das ordens geopolíticas. Esta perspectiva diacrônica tem como ponto de partida a formação do estado territorial português e, posteriormente, do estado territorial brasileiro. Enfatiza-se, em especial, como homens e mulheres imigrantes brasileiros e portugueses participam das transformações recentes de Portugal e do Brasil, respectivamente. Desde o final da década de 2000 há uma situação em que fluxos e contrafluxos migratórios praticamente se equivalem. Dados quantitativos e qualitativos foram utilizados para demonstrar que portugueses no Brasil e brasileiros em Portugal imigrados a partir de 2000 possuem perfis diferentes quanto à idade, sexo, nível de instrução e inserção no mercado laboral. A análise das semelhanças e divergências entre estes grupos de imigrantes levou à consideração de que enfrentam barreiras e desafios distintos, mas têm em comum sua contribuição para ressignificação de uma relação pretérita e assimétrica, marcada pelo compartilhar de uma população luso-brasileira.
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Ao longo da segunda metade do século XIX, a região da África Centro-Ocidental foi palco do processo de intensificação de expedições europeias rumo ao interior do continente que conjugavam interesses econômicos, políticos e científicos. Esta pesquisa busca analisar o papel de relevo ocupado pela cultura material na agenda científica da expedição portuguesa à Lunda chefiada pelo militar português Henrique de Carvalho entre 1884 e 1888. Pretendemos também avaliar as potencialidades que o estudo sobre os objetos apresentam enquanto fontes para a compreensão mais ampla acerca das agências históricas africanas. Para tanto, selecionamos as obras Descripção da Viagem à Mussumba do Muatiânvua (1890-1894) e Ethnographia e História Tradicional dos Povos da Lunda (1890) e, de maneira complementar, o Album da Expedição ao Muatianvua (1887) e o catálogo Collecção Henrique de Carvalho (Expedição à Lunda), editado pela Sociedade de Geografia de Lisboa (1896). Assim, pela ótica da história social, pretendemos investigar como as exigências e predileções centro-africanas por determinados artigos moldaram as relações comerciais travadas nesse período, abordando os processos de incorporação e ressignificação de objetos particularmente, bens de prestígio e insígnias de poder - interpretados como expressões de identidades, códigos sociais e hierarquias políticas no âmbito dessas sociedades e de suas relações com os europeus.
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Research on the industrial transition in East Germany and its outcomes has long focused on the strategy of the Treuhand anstalt (IHA). According to institutionalists, David Stark and Lazlo Brust!: (1998), the powerful position of the German privatization agency was not only a result of German unification but also a function of a pathway rooted in the institutional peculiarities of the East German economy before 1989. This paper shows that neither a simple top-down perspective nor the pathway approach, as Stark and Brust!: suggested, are adequate for explaining the internal dynamic of enterprise transformation as well as the outcomes of this process. First of all, the dissolution of the former organizational structures and hierarchies was less coordinated by the 1HA than is often assumed. Often Kombinates fell apart more quickly from below than they could be dismantled from above since enterprises or their units chose the exit option and had good reasons to do so. Secondly, although the privatization by the 1HA resulted in the clear dominance of Western investors, the new ownership structure of East German industry as a whole could be characterized as a "capitalism without (East German) capitalists." In fact, what exists in East Germany is rather a kind of "small business capitalism" (KleinbetriebsknpitalifmllS) in which small-and medium-sized producers dominate the landscape. Finally, there was no single starting point in 1989. Two different industrial orders shaped the industrial history of the East German regions which were not destroyed between 1945-89, but rather transformed into the state socialist production system. It can be shown that these older historical patterns are relevant for transition and their outcomes as well.
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When analysing software metrics, users find that visualisation tools lack support for (1) the detection of patterns within metrics; and (2) enabling analysis of software corpora. In this paper we present Explora, a visualisation tool designed for the simultaneous analysis of multiple metrics of systems in software corpora. Explora incorporates a novel lightweight visualisation technique called PolyGrid that promotes the detection of graphical patterns. We present an example where we analyse the relation of subtype polymorphism with inheritance and invocation in corpora of Smalltalk and Java systems and find that (1) subtype polymorphism is more likely to be found in large hierarchies; (2) as class hierarchies grow horizontally, they also do so vertically; and (3) in polymorphic hierarchies the length of the name of the classes is orthogonal to the cardinality of the call sites.
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Thesis (Ph.D.)--University of Washington, 2016-06
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Thesis (Ph.D.)--University of Washington, 2016-06
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Thesis (Ph.D.)--University of Washington, 2016-06
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We show that an Anderson Hamiltonian describing a quantum dot connected to multiple leads is integrable. A general expression for the nonlinear conductance is obtained by combining the Bethe ansatz exact solution with Landauer-Buttiker theory. In the Kondo regime, a closed form expression is given for the matrix conductance at zero temperature and when all the leads are close to the symmetric point. A bias-induced splitting of the Kondo resonance is possible for three or more leads. Specifically, for N leads, with each at a different chemical potential, there can be N-1 Kondo peaks in the conductance.
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We show that deterministic quantum computing with a single bit can determine whether the classical limit of a quantum system is chaotic or integrable using O(N) physical resources, where N is the dimension of the Hilbert space of the system under study. This is a square-root improvement over all known classical procedures. Our study relies strictly on the random matrix conjecture. We also present numerical results for the nonlinear kicked top.
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The XXZ Gaudin model with generic integrable boundaries specified by generic non-diagonal K-matrices is studied. The commuting families of Gaudin operators are diagonalized by the algebraic Bethe ansatz method. The eigenvalues and the corresponding Bethe ansatz equations are obtained. (C) 2004 Elsevier B.V. All rights reserved.
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Delayering and the flattening of organizational hierarchies was a widespread trend through the 1990s. Peters (1992) in the USA promoted flattening as an organizational strategy and Keuning and Opheij (1994) promoted the prescriptions in Europe. Despite these strategies and apparent structural changes, the number and ratio of managers appears to have grown. This paradox of managerial downsizing has not been adequately probed in the literature. The predominant explanation, that there has been a 'myth of managerial downsizing', is associated with Gordon (1996). However, this debate has been shaped by the US experience and data. There is a need to reassess the dynamics of the 1990s in relation to other economies. This article focuses on a semi-peripheral economy, that of Australia. A study of the population of firms over time is necessary in order to resolve the issues. The article utilizes a comprehensive range of data, including several national surveys and a longitudinal database of all larger private-sector firms in Australia during the 1990s. The results indicate that the 'myth of managerial downsizing' must be rejected. There were dramatic effects on managers through the course of the 1990s in larger Australian firms. The dynamics of the process are analysed, tracking 4,153 firms across the decade and the paradox explained. The theoretical implications are discussed.
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We obtain a diagonal solution of the dual reflection equation for the elliptic A(n-1)((1)) solid-on-solid model. The isomorphism between the solutions of the reflection equation and its dual is studied. (C) 2004 American Institute of Physics.
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We study the distribution of energy level spacings in two models describing coupled single-mode Bose-Einstein condensates. Both models have a fixed number of degrees of freedom, which is small compared to the number of interaction parameters, and is independent of the dimensionality of the Hilbert space. We find that the distribution follows a universal Poisson form independent of the choice of coupling parameters, which is indicative of the integrability of both models. These results complement those for integrable lattice models where the number of degrees of freedom increases with increasing dimensionality of the Hilbert space. Finally, we also show that for one model the inclusion of an additional interaction which breaks the integrability leads to a non-Poisson distribution.
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We apply a three-dimensional approach to describe a new parametrization of the L-operators for the two-dimensional Bazhanov-Stroganov (BS) integrable spin model related to the chiral Potts model. This parametrization is based on the solution of the associated classical discrete integrable system. Using a three-dimensional vertex satisfying a modified tetrahedron equation, we construct an operator which generalizes the BS quantum intertwining matrix S. This operator describes the isospectral deformations of the integrable BS model.
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The central elements of the algebra of monodromy matrices associated with the Z(n) R-matrix are studied. When the crossing parameter w takes a special rational value w = n/N, where N and n are positive coprime integers, the center is substantially larger than that in the generic case for which the quantum determinant provides the center. In the trigonometric limit, the situation corresponds to the quantum group at roots of unity. This is a higher rank generalization of the recent results by Belavin and Jimbo. (c) 2004 Elsevier B.V. All rights reserved.