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Design Of Moving Target Indication Filters With Non-uniform Pulse Repetition IntervalsIspir, Mehmet 01 January 2013 (has links) (PDF)
Staggering the pulse repetititon intervals is a widely used solution to alleviate the blind speed problem in Moving Target Indication (MTI) radar systems. It is possible to increase the first blind speed on the order of ten folds with the use of non-uniform sampling. Improvement in blind speed results in passband fluctuations that may degregade the detection performance for particular Doppler frequencies. Therefore, it is important to design MTI filters with non-uniform interpulse periods that have minimum passband ripples with sufficient clutter attenuation along with good range and blind velocity performance.
In this thesis work, the design of MTI filters with non-uniform interpulse periods is studied through the least square, convex and min-max filter design methodologies. A trade-off between
the contradictory objectives of maximum clutter suppression and minimum desired signal attenuation is established by the introduction of a weight factor into the designs. The weight
factor enables the adaptation of MTI filter to different operational scenarios such as the operation under low, medium or high clutter power.
The performances of the studied designs are investigated by comparing the frequency response characteristics and the average signal-to-clutter suppression capabilities of the filters with respect to a number of defined performance measures.Two further approaches are considered to increase the signal-to-clutter suppression performance. First approach is based on a modified min-max filter design whereas the second one focuses on the multiple filter implementations. In addition, a detailed review and performance comparison with the non-uniform MTI filter designs from the literature are also given.
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A portable uniform random number generator well suited for the rejection methodHörmann, Wolfgang, Derflinger, Gerhard January 1992 (has links) (PDF)
Up to now all known efficient portable implementations of linear congruential random number generators with modulus 2^(31)-1 are working only with multipliers which are small compared with the modulus. We show that for non-uniform distributions, the rejection method may generate random numbers of bad quality if combined with a linear congruential generator with small multiplier. Therefore a method is described that works for any multiplier smaller than 2^(30). It uses the decomposition of multiplier and seed in high order and low order bits to compute the upper and the lower half of the product. The sum of the two halfs gives the product of multiplier and seed modulo 2^(31)-1. Coded in ANSI-C and FORTRAN77 the method results in a portable implementation of the linear congruential generator that is as fast or faster than other portable methods. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing
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Recursive subdivision algorithms for curve and surface designQu, Ruibin January 1990 (has links)
In this thesis, the author studies recursIve subdivision algorithms for curves and surfaces. Several subdivision algorithms are constructed and investigated. Some graphic examples are also presented. Inspired by the Chaikin's algorithm and the Catmull-Clark's algorithm, some non-uniform schemes, the non-uniform corner cutting scheme and the recursive subdivision algorithm for non-uniform B-spline curves, are constructed and analysed. The adapted parametrization is introduced to analyse these non-uniform algorithms. In order to solve the surface interpolation problem, the Dyn-Gregory-Levin's 4-point interpolatory scheme is generalized to surfaces and the 10-point interpolatory subdivision scheme for surfaces is formulated. The so-called Butterfly Scheme, which was firstly introduced by Dyn, Gregory Levin in 1988, is just a special case of the scheme. By studying the Cross-Differences of Directional Divided Differences, a matrix approach for analysing uniform subdivision algorithms for surfaces is established and the convergence of the 10-point scheme over both uniform and non-uniform triangular networks is studied. Another algorithm, the subdivision algorithm for uniform bi-quartic B-spline surfaces over arbitrary topology is introduced and investigated. This algorithm is a generalization of Doo-Sabin's and Catmull-Clark's algorithms. It produces uniform Bi-quartic B-spline patches over uniform data. By studying the local subdivision matrix, which is a circulant, the tangent plane and curvature properties of the limit surfaces at the so-called Extraordinary Points are studied in detail.
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Sesterská uniforma v minulosti a dnes / Nursing uniform in the past and the todayBRYNYCHOVÁ, Michaela January 2007 (has links)
This paper aims to describe the development of nurse uniforms in the Czech Lands since the beginnings of the nursing profession in the thirteenth century up to the present day. It is qualitative research,a historical data analysis. This paper outlines the development of nurse uniforms which is closely linked to the whole history of nursing care in our country. The paper is divided into two parts. The first one deals with regular uniforms of orders and congregations which have concerned themselves with nursing. The orders are arranged according to their beginnings of operation on our territory. Part two is dedicated to the actual garment of caregivers {--} nurses starting from the middle of the nineteenth century when the actual nursing profession originated and was closely linked with the name of Florence Nightingale.
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Historische Uniformen digitalHermann, Kostantin, Jordan, Alexander 11 December 2013 (has links) (PDF)
Spätestens seit der Tagung „Staat Macht Uniform“ in Münster 2010 gilt die „Uniformenkunde“ nicht mehr als Liebhaberei von Militärgeschichtsfreunden, die Paspelierungen, Knöpfe und Schulterstücke akribisch dokumentieren. Auch die Militärgeschichte, die in Deutschland durch die Rolle der Wehrmacht im Zweiten Weltkrieg bis in die 1990er Jahre eher ein Schattendasein führte, was den breiten geschichtswissenschaftlichen Fachdiskurs betraf, wird inzwischen mit der Sozial-, Kultur-, Kommunikations- und Geistesgeschichte verbunden und gilt als innovativer Zweig der Geschichtswissenschaft: Neue Fragen werden gestellt, neue Antworten gegeben.
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Consistency of Spectral Algorithms for Hypergraphs under Planted Partition ModelGhoshdastidar, Debarghya January 2016 (has links) (PDF)
Hypergraph partitioning lies at the heart of a number of problems in machine learning as well as other engineering disciplines. While partitioning uniform hypergraphs is often required in computer vision problems that involve multi-way similarities, non-uniform hypergraph partitioning has applications in database systems, circuit design etc. As in the case of graphs, it is known that for given objective and balance constraints, the problem of optimally partitioning a hypergraph is NP-hard. Yet, over the last two decades, several efficient heuristics have been studied in the literature and their empirical success is widely appreciated. In contrast to the extensive studies related to graph partitioning, the theoretical guarantees of hypergraph partitioning approaches have not received much attention in the literature. The purpose of this thesis is to establish the statistical error bounds for certain spectral algorithms for partitioning uniform as well as non-uniform hypergraphs.
The mathematical framework considered in this thesis is the following. Let V be a set of n vertices, and ψ : V ->{1,…,k} be a (hidden) partition of V into k classes. A random hypergraph (V,E) is generated according to a planted partition model, i.e., subsets of V are independently added to the edge set E with probabilities depending on the class memberships of the participating vertices. Let ψ' be the partition of V obtained from a certain algorithm acting on a random realization of the hypergraph. We provide an upper bound on the number of disagreements between ψ and ψ'. To be precise, we show that under certain conditions, the asymptotic error is o(n) with probability (1-o(1)). In the existing literature, such error rates are only known in the case of graphs (Rohe et al., Ann. Statist., 2011; Lei \& Rinaldo, Ann. Statist., 2015), where the planted model coincides with the popular stochastic block model. Our results are based on matrix concentration inequalities and perturbation bounds, and the derived bounds can be used to comment on the consistency of spectral hypergraph partitioning algorithms.
It is quite common in the literature to resort to a spectral approach when the quantity of interest is a matrix, for instance, the adjacency or Laplacian matrix for graph partitioning. This is certainly not true for hypergraph partitioning as the adjacency relations cannot be encoded into a symmetric matrix as in the case of graphs. However, if one restricts the problem to m-uniform hypergraphs for some m ≥ 2, then a symmetric tensor of order m can be used to express the multi-way interactions or adjacencies. Thus, the use of tensor spectral algorithms, based on the spectral theory of symmetric tensors, is a natural choice in this scenario. We observe that a wide variety of uniform hypergraph partitioning methods studied in the literature can be related to any one of two principle approaches: (1) solving a tensor trace maximization problem, or (2) use of the higher order singular value decomposition of tensors. We derive statistical error bounds to show that both these approaches lead to consistent partitioning algorithms.
Our results also hold when the hypergraph under consideration allows weighted edges, a situation that is commonly encountered in computer vision applications such as motion segmentation, image registration etc. In spite of the theoretical guarantees, a tensor spectral approach is not preferable in this setting due to the time and space complexity of computing the weighted adjacency tensor. Keeping this practical scenario in mind, we prove that consistency can still be achieved by incorporating certain tensor sampling strategies. In particular, we show that if the edges are sampled according to certain distribution, then consistent partitioning can be achieved with only few sampled edges. Experiments on benchmark problems demonstrate that such sampled tensor spectral algorithms are indeed useful in practice.
While vision tasks mostly involve uniform hypergraphs, in database and electronics applications, one often finds non-uniform hypergraphs with edges of varying sizes. These hypergraphs cannot be expressed in terms of adjacency matrices or tensors, and hence, use of a spectral approach is tricky in this context. The partitioning problem gets more challenging due to the fact that, in practice, these hypergraphs are quite sparse, and hence, provide less information about the partition. We consider spectral algorithms for partitioning clique and star expansions of hypergraphs, and study their consistency under a sparse planted partition model.
The results of hypergraph partitioning can be further extended to address the well-known hypergraph vertex coloring problem, where the objective is to color the vertices such that no edge is monochromatic. The hardness of this problem is well established. In fact, even when a hypergraph is bipartite or 2-colorable, it is NP-hard to find a proper 2-coloring for it. We propose a spectral coloring algorithm, and show that if the non-monochromatic subsets of vertices are independently added to the edge set with certain probabilities, then with probability (1-o(1)), our algorithm succeeds in coloring bipartite hypergraphs with only two colors.
To the best our knowledge, these are the first known results related to consistency of partitioning general hypergraphs.
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O princípio da interpretação uniforme na Convenção de Viena sobre compra e venda internacional de mercadorias (1980): realidade, utopia e necessidade / The principle of uniform interpretation in the United Nations Convention on Contracts for the Sale of Goods (1980): reality, utopia and urgeVieira, Fabio Alonso 07 March 2017 (has links)
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Previous issue date: 2017-03-07 / This paper aims to demonstrate why the uniform application principle provided
in CISG is, at the same time, real, utopic and necessary. Since the invasion of
Rome by the barbarians there has not been a universal or uniform law, such as
jus gentium. Thenceforth, in a legal pluralism environment, the world has been
through moments of seeking for nationalism or the uniformization of the law.
With the emergence of lex mercatoria and, more recently, with the advent of
globalization, the world has become extremely dynamic and without barriers
between the States. In this context, various schools of thought have risen
advocating for a “global uniform Law” and, afterwards, given its impossibility, a
uniform law for specific matters of substantive law. Then, the most successful
uniform law of all times: CISG was drafted. Intending to be a uniform legal
diploma, it is necessary for its provisions to be understood in a uniform manner.
As the provided in article 7 of CISG. However, the interpretation of the
provisions of the convention drawn up in a vague concept and in several official
languages, ratified by States in different social, economic, political and religious
backgrounds is a utopia. Although, this utopia is necessary to maintain limits
and borders when the application of the legal provisions by the CISG
interpreters. Without the established frame work by the utopic uniform
interpretation, CISG would never reach its objectives and, most likely, would be
dead / O presente trabalho tem por objetivo demonstrar que o princípio da
interpretação uniforme inserido na CISG é, ao mesmo tempo, real, utópico e
necessário. Desde a invasão de Roma pelos bárbaros não se tem mais um
direito universal ou uniforme como o jus gentium. A partir daí, num ambiente de
pluralismo jurídico, o mundo passou por momentos de busca pelo nacionalismo
ou pela uniformização do direito. Com o surgimento da lex mercatoria e, mais
recentemente, com o advento da globalização, o mundo tornou-se
extremamente dinâmico e sem barreiras entre os Estados. Nesse contexto,
surgem diversas correntes doutrinárias defendendo a tese de um “direito
uniforme mundial” e, posteriormente, dada a sua impossibilidade, um direito
uniforme para determinadas matérias do direito substantivo. É elaborada,
então, a mais bem-sucedida lei uniforme de todos os tempos: a CISG. Para
tentar ser um diploma uniforme, torna-se necessário que os seus dispositivos
sejam interpretados de maneira uniforme. É o que dispõe o artigo 7 da CISG.
Contudo, interpretar artigos da convenção redigida com conceitos vagos e em
diversos idiomas oficiais, ratificada por Estados em diferentes momentos
sociais, econômicos, políticos e religiosos é uma utopia. No entanto, essa
utopia é necessária para manter limites e fronteiras quando da aplicação dos
dispositivos legais pelos intérpretes da CISG. Sem essa moldura estabelecida
pela utópica interpretação uniforme, a CISG jamais chegaria perto dos fins para
os quais ela foi criada e, muito provavelmente, já estaria morta
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Analysis of algorithms for filter bank design optimizationElGarewi, Ahmed 06 September 2019 (has links)
This thesis deals with design algorithms for filter banks based on optimization. The design specifications consist of the perfect reconstruction and frequency response specifications for finite impulse response (FIR) analysis and synthesis filters. The perfect reconstruction conditions are formulated as a set of linear equations with respect to the analysis filters’ coefficients and the synthesis filters’ coefficients. Five design algorithms are presented. The first three are based on an unconstrained optimization of performance indices, which include the perfect reconstruction error and the error in the frequency specifications. The last two algorithms are formulated as constrained optimization problems with the perfect reconstruction error as the performance index and the frequency specifications as constraints. The performance of the five algorithms is evaluated and compared using six examples; these examples include uniform filter bank, compatible non-uniform filter bank and incompatible non-uniform filter bank designs. The evaluation criteria are based on distortion and aliasing errors, the magnitude response characteristics of analysis and synthesis filters, the computation time required for the optimization, and the convergence of the performance index with respect to the number of iterations. The results show that the five algorithms can achieve almost perfect reconstruction and can meet the frequency response specifications at an acceptable level. In the case of incompatible non-uniform filter banks, the algorithms have challenges to achieve almost perfect reconstruction. / Graduate
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Renormamiento en espacios de BanachGuirao Sánchez, Antonio José 18 October 2007 (has links)
La Tesis está compuesta por un capítulo introductorio y cuatro capítulosque pasamos a describir.El Capítulo 2 contiene un análisis de las funciones que son posiblementemódulo de convexidad (m.c.) para un espacio de Banach uniformementeconvexo (UC). Se muestra que las funciones m.c. están caracterizadas,salvo equivalencia, por ciertas propiedades clásicas de éstas.En el Capítulo 3, se estudia la noción de m.c. de una función convexadefinida en un espacio de Banach. Éste es el primer trabajo con resultadosgenerales y completos en espacios de Banach. Se muestra que un espacio essuperreflexivo sii admite una función (UC) definida en todo el espacio.En el Capítulo 4 se resuelve un problema establecido por Godefroy yZizler; un espacio de Banach superreflexivo con base de Schauder admiteuna norma (UC) que hace monótona a la base. Se obtienen mejoras deestimaciones de James y Gurari.En el Capítulo 5 el autor estudia la noción del módulo de cuadratura. Éstepermite reconocer la (UC) y la suavidad uniforme. El autor define laversión local, y prueba varias caracterizaciones del comportamientopuntual de la norma. / The thesis consists of one introductory chapter and four chapterscontaining original mathematical results. Let us pass to a briefdescription of the main results.Chapter 2 contains an analysis of the possible modulus of rotundityfunctions (m.r.f) for a given uniformly rotund (UC) Banach space. It isshown that m.r.f. are characterized, up to equivalence, by certainclassical properties of them.In Chapter 3, the notion of m.r. for a convex function defined on a Banachspace is studied. This seems to be the first instance of rather completegeneral results on Banach spaces. It is shown that a Banach space issuperreflexive iff it admits a (UC) function defined on the whole space.In Chapter 4 a problem asked by Godefroy and Zizler is solved; asuperreflexive Banach space with Schauder basis can be renormed by (UC)norm which makes the given basis monotone. An improvement of a result ofGurarii is an immediate corollary.In Chapter 5 the author studies the notion of modulus of squareness. Itallows to recognize (UC) and uniform smoothness. The author succeeds todefine the local version, and proves various characterizations ofpointwise behaviour of the norm.
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Analyse asymptotique de systèmes hyperboliques quasi-linéaires du premier ordre / Asymptotic analysis of first-order quasilinear hyperbolic systemsWasiolek, Victor 29 May 2015 (has links)
Les systèmes hyperboliques interviennent dans de nombreuses branches des sciences : théorie cinétique, mécanique des fluides non visqueux, magnéto hydrodynamique, dynamique des gaz non visqueux, trafic routier, flux d’une rivière ou d’un glacier, processus de sédimentation, processus d’échanges chimiques, etc. Et souvent, les systèmes qui régissent ces évènements font intervenir des petits paramètres, dont l’étude asymptotique permet d’envisager des simplifications mathématiques et/ou informatiques notoires. L’existence locale et l’existence globale de solutions, uniformément par rapport à ces paramètres, sont des questions fondamentales. Cette thèse regroupe à la fois des résultats généraux sur l’existence locale uniforme de solutions pour des systèmes hyperboliques quasi-linéaires du premier ordre ; et sur l’existence globale uniforme de solutions autour d’un équilibre constant pour ces mêmes systèmes. Le cas du système d’Euler-Maxwell ne satisfaisant pas les conditions requises pour l’existence uniforme globale, nous le traitons à part. / Hyperbolic systems arise in a large field of sciences : kinetic theory, inviscid reactive flow, magnetohydrodynamics, inviscid gas dynamics, traffic flow, river or glacier flow, sedimentation processes, chemical exchange processes, etc. In these kind of systems, small paramaters often appear, and an asymptotic study may lead to mathematical or computational simplifications. One fundamental problem that we may work on is local and global existence of solutions for these systems, uniformly with respect to these parameters. This Ph.D. thesis includes, on one hand, general results on uniform local existence of solutions for first order quasi-linear hyperbolic systems ; and on the other hand, results on uniform global existence of solutions near constant equilibriums for these same systems. In the case of Euler-Maxwell systems, required conditions are not fulfilled for uniform global existence, then we treat it separately.
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