920 resultados para Formal spaces
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This paper relies on the study of fixed points and best proximity points of a class of so-called generalized point-dependent (K-Lambda)hybrid p-cyclic self-mappings relative to a Bregman distance Df, associated with a Gâteaux differentiable proper strictly convex function f in a smooth Banach space, where the real functions Lambda and K quantify the point-to-point hybrid and nonexpansive (or contractive) characteristics of the Bregman distance for points associated with the iterations through the cyclic self-mapping.Weak convergence results to weak cluster points are obtained for certain average sequences constructed with the iterates of the cyclic hybrid self-mappings.
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Increasing investment in estate and learning technologies, combined with the need for more cost-effective space utilisation, is making it increasingly important for senior managers to keep abreast of new thinking about the design of technology-rich learning spaces. Designing Spaces for Effective Learning, one of a series of guides, was launched at the JISC Conference 2006 which helped to meet this need. A visually-rich publication, it was designed to promote better understanding of what makes an effective design for the 21 century and to summarise the key points to consider when approaching a refurbishment or new-build project. The publication takes the reader on a ’walk through’ an educational institution, exploring the relationship between learning technologies and innovative examples of physical space design at each stage of the journey. Discussion of the key points is illustrated by ten case studies from further and higher education, and floor plans from AMA Alexi Marmot Associates, architects and space planners, which provide up-to-date guidelines on the integration of technologies into teaching and learning accommodation.
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This paper investigates a class of self-adjoint compact operators in Hilbert spaces related to their truncated versions with finite-dimensional ranges. The comparisons are established in terms of worst-case norm errors of the composite operators generated from iterated computations. Some boundedness properties of the worst-case norms of the errors in their respective fixed points in which they exist are also given. The iterated sequences are expanded in separable Hilbert spaces through the use of numerable orthonormal bases.
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479 p.
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Modern robots are increasingly expected to function in uncertain and dynamically challenging environments, often in proximity with humans. In addition, wide scale adoption of robots requires on-the-fly adaptability of software for diverse application. These requirements strongly suggest the need to adopt formal representations of high level goals and safety specifications, especially as temporal logic formulas. This approach allows for the use of formal verification techniques for controller synthesis that can give guarantees for safety and performance. Robots operating in unstructured environments also face limited sensing capability. Correctly inferring a robot's progress toward high level goal can be challenging.
This thesis develops new algorithms for synthesizing discrete controllers in partially known environments under specifications represented as linear temporal logic (LTL) formulas. It is inspired by recent developments in finite abstraction techniques for hybrid systems and motion planning problems. The robot and its environment is assumed to have a finite abstraction as a Partially Observable Markov Decision Process (POMDP), which is a powerful model class capable of representing a wide variety of problems. However, synthesizing controllers that satisfy LTL goals over POMDPs is a challenging problem which has received only limited attention.
This thesis proposes tractable, approximate algorithms for the control synthesis problem using Finite State Controllers (FSCs). The use of FSCs to control finite POMDPs allows for the closed system to be analyzed as finite global Markov chain. The thesis explicitly shows how transient and steady state behavior of the global Markov chains can be related to two different criteria with respect to satisfaction of LTL formulas. First, the maximization of the probability of LTL satisfaction is related to an optimization problem over a parametrization of the FSC. Analytic computation of gradients are derived which allows the use of first order optimization techniques.
The second criterion encourages rapid and frequent visits to a restricted set of states over infinite executions. It is formulated as a constrained optimization problem with a discounted long term reward objective by the novel utilization of a fundamental equation for Markov chains - the Poisson equation. A new constrained policy iteration technique is proposed to solve the resulting dynamic program, which also provides a way to escape local maxima.
The algorithms proposed in the thesis are applied to the task planning and execution challenges faced during the DARPA Autonomous Robotic Manipulation - Software challenge.
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O atendimento às demandas de determinada parcela da população que vive nas chamadas Regiões Metropolitanas no Brasil tem apresentado acentuada dificuldade em obter resultados satisfatórios, na medida em que estes espaços territoriais estejam situados em diferentes jurisdições político-territoriais. Tais dificuldades têm origem, sobretudo, na necessidade da composição de arranjos governamentais que possam atuar de forma conjunta e coordenada, abrangendo Estados e Municípios envolvidos nesta dinâmica metropolitana, e que abrange aspectos fiscais, sociais, ambientais e jurídicos. O presente trabalho analisa este último aspecto, sobretudo, em relação à questão das competências constitucionais dos entes envolvidos e o papel a ser desempenhado por cada um na regulação do solo urbano, um dos aspectos mais relevantes em relação ao tema metropolitano. Se a dependência de um eventual acordo entre os entes federativos tem se mostrado raro na história federativa brasileira, tal fato não pode constituir-se em um fator impeditivo do alcance dos direitos fundamentais estabelecidos pela Constituição Federal, principalmente levando-se em consideração que uma regulação adequada do solo urbano em uma perspectiva regional (metropolitana) é uma meio fundamental para o alcance de vários direitos, como moradia, meio ambiente equilibrado. Identificando o Estado-Membro como figura principal deste mister, por meio de uma interpretação sistemática e teleológica da Constituição, e reconhecendo o cenário de constitucionalização do direito administrativo atual bem como da chamada crise da lei, verifica-se que este ente federativo pode e deve assumir plenamente suas competências, elaborando um estudo técnico de planejamento regional, não necessariamente aprovado por lei formal, e vinculante para os Municípios.
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A educação ambiental vem sendo disseminada por grande parte das escolas do país, conforme atestam pesquisas oficiais, mas uma lenta transformação a acompanha no que diz respeito à mudança dos princípios do modelo de desenvolvimento industrial, que enfatiza o consumismo como estratégia de reprodução. Ao mesmo tempo em que as pesquisas sugerem uma ampliação da consciência ambiental da sociedade como um todo, percebe-se um acirramento dos problemas socioambientais e soluções sendo alcançadas em escala inferior ao patamar considerado desejado. Onde estaria, então, o problema? Qual a razão desta possível defasagem educação ambiental x resultados? Foi com o intuito de responder a estas perguntas que essa tese foi realizada. Parte-se de uma percepção de que a Educação Ambiental praticada na escola reflete e acentua o paradigma moderno hegemônico, que se baseia em uma concepção dualista homem / natureza, em que uma está a serviço do outro, sem promover o questionamento sobre os desdobramentos da adoção dos valores da sociedade de consumo no desequilíbrio da vida no planeta. Essa dicotomia entre cultura e natureza, sociedade e ciência, sujeito e objeto se reflete na busca de soluções parciais, incompletas, visando-se apenas a uma parte do problema socioambiental, que não é visto como um sistema complexo. A educação ambiental realizada nessas bases dificulta a reunião das condições necessárias à mudança das estruturas da atual sociedade brasileira e à busca das soluções dos seus problemas socioambientais. Nessa perspectiva, esse trabalho objetiva criar subsídios para um caminho para a educação ambiental que possa contribuir para uma visão complexa da realidade e dos problemas socioambientais, na busca de soluções mais abrangentes. Para isto procura entender: a) como a teoria da complexidade poderia colaborar para esta mudança; b) em quais modelos práticos e teóricos a Educação Ambiental se dá no Brasil, ou seja, quais as diversas tendências da educação ambiental brasileira; e c) como esses modelos se expressam nas práticas dos professores analisando-se artigos publicados em anais de seminários, congressos e/ou encontros sobre o tema.
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We consider canonical systems with singular left endpoints, and discuss the concept of a scalar spectral measure and the corresponding generalized Fourier transform associated with a canonical system with a singular left endpoint. We use the framework of de Branges’ theory of Hilbert spaces of entire functions to study the correspondence between chains of non-regular de Branges spaces, canonical systems with singular left endpoints, and spectral measures.
We find sufficient integrability conditions on a Hamiltonian H which ensure the existence of a chain of de Branges functions in the first generalized Pólya class with Hamiltonian H. This result generalizes de Branges’ Theorem 41, which showed the sufficiency of stronger integrability conditions on H for the existence of a chain in the Pólya class. We show the conditions that de Branges came up with are also necessary. In the case of Krein’s strings, namely when the Hamiltonian is diagonal, we show our proposed conditions are also necessary.
We also investigate the asymptotic conditions on chains of de Branges functions as t approaches its left endpoint. We show there is a one-to-one correspondence between chains of de Branges functions satisfying certain asymptotic conditions and chains in the Pólya class. In the case of Krein’s strings, we also establish the one-to-one correspondence between chains satisfying certain asymptotic conditions and chains in the generalized Pólya class.
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The intent of this study is to provide formal apparatus which facilitates the investigation of problems in the methodology of science. The introduction contains several examples of such problems and motivates the subsequent formalism.
A general definition of a formal language is presented, and this definition is used to characterize an individual’s view of the world around him. A notion of empirical observation is developed which is independent of language. The interplay of formal language and observation is taken as the central theme. The process of science is conceived as the finding of that formal language that best expresses the available experimental evidence.
To characterize the manner in which a formal language imposes structure on its universe of discourse, the fundamental concepts of elements and states of a formal language are introduced. Using these, the notion of a basis for a formal language is developed as a collection of minimal states distinguishable within the language. The relation of these concepts to those of model theory is discussed.
An a priori probability defined on sets of observations is postulated as a reflection of an individual’s ontology. This probability, in conjunction with a formal language and a basis for that language, induces a subjective probability describing an individual’s conceptual view of admissible configurations of the universe. As a function of this subjective probability, and consequently of language, a measure of the informativeness of empirical observations is introduced and is shown to be intuitively plausible – particularly in the case of scientific experimentation.
The developed formalism is then systematically applied to the general problems presented in the introduction. The relationship of scientific theories to empirical observations is discussed and the need for certain tacit, unstatable knowledge is shown to be necessary to fully comprehend the meaning of realistic theories. The idea that many common concepts can be specified only by drawing on knowledge obtained from an infinite number of observations is presented, and the problems of reductionism are examined in this context.
A definition of when one formal language can be considered to be more expressive than another is presented, and the change in the informativeness of an observation as language changes is investigated. In this regard it is shown that the information inherent in an observation may decrease for a more expressive language.
The general problem of induction and its relation to the scientific method are discussed. Two hypotheses concerning an individual’s selection of an optimal language for a particular domain of discourse are presented and specific examples from the introduction are examined.
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A Riesz space with a Hausdorff, locally convex topology determined by Riesz seminorms is called a locally convex Riesz space. A sequence {xn} in a locally convex Riesz space L is said to converge locally to x ϵ L if for some topologically bounded set B and every real r ˃ 0 there exists N (r) and n ≥ N (r) implies x – xn ϵ rb. Local Cauchy sequences are defined analogously, and L is said to be locally complete if every local Cauchy sequence converges locally. Then L is locally complete if and only if every monotone local Cauchy sequence has a least upper bound. This is a somewhat more general form of the completeness criterion for Riesz – normed Riesz spaces given by Luxemburg and Zaanen. Locally complete, bound, locally convex Riesz spaces are barrelled. If the space is metrizable, local completeness and topological completeness are equivalent.
Two measures of the non-archimedean character of a non-archimedean Riesz space L are the smallest ideal Ao (L) such that quotient space is Archimedean and the ideal I (L) = { x ϵ L: for some 0 ≤ v ϵ L, n |x| ≤ v for n = 1, 2, …}. In general Ao (L) ᴝ I (L). If L is itself a quotient space, a necessary and sufficient condition that Ao (L) = I (L) is given. There is an example where Ao (L) ≠ I (L).
A necessary and sufficient condition that a Riesz space L have every quotient space Archimedean is that for every 0 ≤ u, v ϵ L there exist u1 = sup (inf (n v, u): n = 1, 2, …), and real numbers m1 and m2 such that m1 u1 ≥ v1 and m2 v1 ≥ u1. If, in addition, L is Dedekind σ – complete, then L may be represented as the space of all functions which vanish off finite subsets of some non-empty set.
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A.G. Vulih has shown how an essentially unique intrinsic multiplication can be defined in certain types of Riesz spaces (vector lattices) L. In general, the multiplication is not universally defined in L, but L can always be imbedded in a large space L# in which multiplication is universally defined.
If ф is a normal integral in L, then ф can be extended to a normal integral on a large space L1(ф) in L#, and L1(ф) may be regarded as an abstract integral space. A very general form of the Radon-Nikodym theorem can be proved in L1(ф), and this can be used to give a relatively simple proof of a theorem of Segal giving a necessary and sufficient condition that the Radon-Nikodym theorem hold in a measure space.
In another application, the multiplication is used to give a representation of certain Riesz spaces as rings of operators on a Hilbert space.
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No ensino de língua nacional, concordância é um dos tópicos em cujo aprendizado observa dificuldade por parte dos discentes, principalmente pelo grande número de regras facultativas das gramáticas, que muitas vezes não levam em conta o uso formal real da língua. Este trabalho visa a descrever esse uso, a partir da observação de um corpus do caderno opinião de jornais de grande circulação, confrontando os resultados com as prescrições da norma gramatical escolar, a fim de separar, em tais prescrições, a parte aproveitável da não coincidente com a realidade do corpus, se for o caso. Pretende-se, dessa forma, contribuir para a boa qualidade do ensino da língua portuguesa nos níveis fundamental e médio, especificamente no que se refere à concordância