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1
Oinas, J. (Janne). "The degree theory and the index of a critical point for mappings of the type (S+)". Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514284878.
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Abstract
The dissertation considers a degree theory and the index of a critical point of demi-continuous, everywhere defined mappings of the monotone type.
A topological degree is derived for mappings from a Banach space to its dual space. The mappings satisfy the condition (S+), and it is shown that the derived degree has the classical properties of a degree function.
A formula for the calculation of the index of a critical point of a mapping A : X→X* satisfying the condition (S+) is derived without the separability of X and the boundedness of A. For the calculation of the index, we need an everywhere defined linear mapping A' : X→X* that approximates A in a certain set. As in the earlier results, A' is quasi-monotone, but our situation differs from the earlier results because A' does not have to be the Frechet or Gateaux derivative of A at the critical point. The theorem for the calculation of the index requires a construction of a compact operator T = (A' + Γ)-1Γ with the aid of linear mappings Γ : X→X and A'. In earlier results, Γ is compact, but here it need only be quasi-monotone. Two counter-examples show that certain assumptions are essential for the calculation of the index of a critical point.
2
Fedosov, Boris, Bert-Wolfgang Schulze e Nikolai Tarkhanov. "On the index formula for singular surfaces". Universität Potsdam, 1997. http://opus.kobv.de/ubp/volltexte/2008/2511/.
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In the preceding paper we proved an explicit index formula for elliptic pseudodifferential operators on a two-dimensional manifold with conical points. Apart from the Atiyah-Singer integral, it contains two additional terms, one of the two being the 'eta' invariant defined by the conormal symbol. In this paper we clarify the meaning of the additional terms for differential operators.
3
Fedosov, Boris, Bert-Wolfgang Schulze e Nikolai N. Tarkhanov. "The index of higher order operators on singular surfaces". Universität Potsdam, 1998. http://opus.kobv.de/ubp/volltexte/2008/2512/.
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The index formula for elliptic pseudodifferential operators on a two-dimensional manifold with conical points contains the Atiyah-Singer integral as well as two additional terms. One of the two is the 'eta' invariant defined by the conormal symbol, and the other term is explicitly expressed via the principal and subprincipal symbols of the operator at conical points. In the preceding paper we clarified the meaning of the additional terms for first-order differential operators. The aim of this paper is an explicit description of the contribution of a conical point for higher-order differential operators. We show that changing the origin in the complex plane reduces the entire
contribution of the conical point to the shifted 'eta' invariant. In turn this latter is expressed in terms of the monodromy matrix for an ordinary differential equation defined by the conormal symbol.
4
Segovia, Carlos. "Extrapolation and commutators of singular integrals". Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/97397.
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l. Introduction In these notes we shall present results concerning LP inequalities with different but related weights for commutators of singular and strongly singular integrals. These commutators turn out to be controlled by commutator of fractional order of the Hardy-Littlewood maximal operator. The boundedness properties are obtained by extrapolation from infinity. These notes are based mainly on [G-H-S-T].
5
Kunkel, Curtis J. Henderson Johnny. "Positive solutions of singular boundary value problems". Waco, Tex. : Baylor University, 2007. http://hdl.handle.net/2104/5022.
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Capri, Osvaldo N., e Carlos Segovia. "Convergence of singular integrals in weighted L 1 spaces". Pontificia Universidad Católica del Perú, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/97142.
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Morón, Urbina Juan Carlos. "El vicio de la derogación singular de las normas reglamentarias". IUS ET VERITAS, 2017. http://repositorio.pucp.edu.pe/index/handle/123456789/123590.
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Shively, William F. Khveshchenko D. V. "Novel behaviors in fermion systems with point-like Fermi surfaces and singular interactions". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,439.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics & Astronomy." Discipline: Physics and Astronomy; Department/School: Physics and Astronomy.
9
Dalbelo, Thaís Maria. "O índice de Poincaré-Hopf e generalizações no caso singular". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-15032011-163543/.
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Neste trabalho,estudamos o índice de Poincaré-Hopf, definido para singularidades isoladas de campos de vetores sobre variedades diferenciáveis. Além disso, investigamos algumas definições de índices de campos de vetores definido sem variedades singulares, como o índice de Schwartz e o índice GSV. Estudaremos estes invariantes no caso específico em que (V; 0) é um germe de uma interseção completa com singularidade isolada na origemIn this work, we study thePoincaré-Hopf index, defined for isolated singularities of vector fields on manifolds. Moreover, we investigate some definitions of indices of vector fields defined on singular varieties, as the Schwartz index and the GSV index. We study these invariants in the case where (V; 0) is a germ of a complete intersection with an isolated singularity at the origin
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Turkan, Erkan Murat. "On The Index Of Fixed Point Subgroup". Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613522/index.pdf.
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Let G be a finite group and A be a subgroup of Aut(G). In this work, we studied the influence of the index of fixed point subgroup of A in G on the structure of G.
When A is cyclic, we proved the following:
(1) [G,A] is solvable if this index is squarefree and the orders of G and A are coprime.
(2) G is solvable if the index of the centralizer of each x in H-G is squarefree where H denotes the semidirect product of G by A.
Moreover, for an arbitrary subgroup A of Aut(G) whose order is coprime to the order of G, we showed that when G is solvable, then the Fitting length f([G,A]) of [G,A] is bounded above by
the number of primes (counted with multiplicities) dividing the index of fixed point subgroup of A in G and this bound is best possible.
11
Barwani, Rahima. "Stoke's multipliers for a certain third order differential equation near an irregular singular point". Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/454815.
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This thesis is concerned with the asymptotic solutions of the differential equationz(2) d(3)y/dz(3) + (a0z) d(2)y/dz(2) + [b0+b1z+b2z(2)] dy/dz + (c0+ c1z) y=0Here, the variable z is complex as are the constants ai, ci(i=O,1) and bi(i=O,1,2) with b2 does not equal 0. It is also assumed that the roots of the indicial equation about z = 0 are such that the difference of no two of them is congruent to zero modular 1.Ball State UniversityMuncie, IN 47306
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Jakob, Ruben. "H-Flächen-Index Formel". Bonn : Mathematisches Institut der Universität, 2004. http://catalog.hathitrust.org/api/volumes/oclc/62767489.html.
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Benavides, Cristian Eduardo. "La crítica kierkegaardiana a la concepción hegeliana de libertad según la interpretación de Cornelio Fabro". Pontificia Universidad Católica del Perú - Departamento de Humanidades, 2016. http://repositorio.pucp.edu.pe/index/handle/123456789/113282.
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El presente trabajo tiene como finalidad exponer la discusión entre Kierkegaard y Hegel en torno a la noción de libertad, de acuerdo con la interpretación que ofrece concretamente sobre la misma el filósofo italiano Cornelio Fabro. De este modo, se mencionarán primeramente algunos de los puntos principales de estudio que aborda el filósofo italiano en su obra. Posteriormente se analizarán las posiciones especulativas que Hegel y Kierkegaard desarrollan, respectivamente, sobre el tema en cuestión. Por último, se realizarán algunas apreciaciones sobre la instancia existencial que presenta el pensador danés y que Fabro destaca.
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Ifrah, Philip. "Tree search and singular value decomposition : a comparison of two strategies for point-pattern matching". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27229.
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Two approaches for solving point-pattern matching problems are compared; namely, a graph-matching algorithm (1) and an SVD-based procedure (2). In both cases, the features that are used in the matching process are point coordinates in Euclidean n-space, ${ rm I !E} sp{n}.$ The patterns being matched are assumed to be related by a combination of two transformations: (1) a permutation of the feature points which establishes the correspondence between the feature points of the different patterns and (2) a global geometric transformation based on rigid motions which aligns the patterns once the point correspondences are known. The problem of finding the first transformation, known as the point correspondence problem, is the most demanding part of the matching process in terms of computational requirements; accordingly, the focus is placed on the algorithms' ability to establish point correspondences. Computer simulations are used to evaluate the performance of the algorithms' respective search strategies in terms of both the accuracy of the final solution and the speed with which the solution is obtained. In all of the experiments, the performance of the graph matching algorithm is clearly superior to that of the SVD-based method in terms of both speed and accuracy; however, it is shown that the computational requirements of the tree search procedure used by the graph matching algorithm are strongly dependent on factors such as the magnitude of the noises that are contained in the patterns and on the mutual distances between the feature points. The major weakness of the SVD-based algorithm is its inconsistency in converging to the expected solution, especially when extra or occluded points are present in one or more of the patterns to be matched.
15
Ifrah, Philip Isaac. "Tree search and singular value decomposition, a comparison of two strategies for point-pattern matching". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq29602.pdf.
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Celestin, Kamta, e Sampid Marius Galabe. "Constructing an Index Fund Using Interior Point Primal- Dual Method". Thesis, Mälardalens högskola, Akademin för utbildning, kultur och kommunikation, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-13041.
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Optimization methods nowadays play a very important role in financial decisions such as portfolio managements, construction of index funds and pension funds. This Master Thesis is devoted to the problem of an index fund construction. The problem is represented as a linear optimization problem of re-balancing the portfolio at minimum cost and solved using the Primal-Dual interior point method. The index fund is constructed using ten companies from the Dow Jones Industrial Average Index (DJIA). The Primal-Dual interior point method was first implemented in Matlab and later on in Java.
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Workalemahu, Tsegaselassie. "Singular Value Decomposition in Image Noise Filtering and Reconstruction". Digital Archive @ GSU, 2008. http://digitalarchive.gsu.edu/math_theses/52.
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The Singular Value Decomposition (SVD) has many applications in image processing. The SVD can be used to restore a corrupted image by separating significant information from the noise in the image data set. This thesis outlines broad applications that address current problems in digital image processing. In conjunction with SVD filtering, image compression using the SVD is discussed, including the process of reconstructing or estimating a rank reduced matrix representing the compressed image. Numerical plots and error measurement calculations are used to compare results of the two SVD image restoration techniques, as well as SVD image compression. The filtering methods assume that the images have been degraded by the application of a blurring function and the addition of noise. Finally, we present numerical experiments for the SVD restoration and compression to evaluate our computation.
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Torres, Guardia Luis Ernesto, e Lima Gilson Alvez. "Interior point methods for multicommodity network flows". Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/95524.
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This article studies the linear multicommodity network flow problem. This kind of problem arises in a wide variety of contexts. A numerical implementation of the primal-dual interior-point method is designed to solve the problem. In the interior-point method, at each iteration, the corresponding linear system, expressed as a normal equations system, is solved by using the AINV algorithm combined with a preconditioned conjugate gradient algorithm or by the AINV algorithm for the whole normal equations. Numerical experiments are conducted for networks of different dimensions and numbers of products for the distribution problem. The computational results show the effectiveness of the interior-point method for this class of network problems.
19
Munyakazi, Justin Bazimaziki. "Higher Order Numerical Methods for Singular Perturbation Problems". Thesis, Online Access, 2009. http://etd.uwc.ac.za/usrfiles/modules/etd/docs/etd_gen8Srv25Nme4_6335_1277251056.pdf.
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Vieira, Cleide. "Formulação de um elemento finito singular para problemas elásticos bidimensionais". Universidade do Estado de Santa Catarina, 2007. http://tede.udesc.br/handle/handle/1711.
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O objetivo principal deste trabalho foi desenvolver um elemento finito singular O para determinar o fator de intensidade de tensão K1 com precisão. Este elemento singular e o elemento Quarter-pojnt são utilizados para duas aplicações bastante comuns: uma placa com trinca central com carregamento de tração e uma viga com trinca lateral e ao carregamento de flexão. Neste trabalho são mostrados em detalhes as malhas as nas analises e os métodos da Extrapolação e da Tangente para o deslocamento e tensão empregados para o cálculo do Fator de Intensidade de Tensão K1. Os resultados de métodos foram comparados com os resultados analíticos para o fator de intensidade de tensão K1. Os melhores resultados encontrados para K1 foram obtidos com o a Extrapolação de deslocamento e com o elemento finito singular apresentado neste trabalho.
21
Koo, Bhon Kyoung. "Agricultural non-point source nitrate pollution control by land use optimisation". Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268366.
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Giachetti, B. Silvana, e de Abram Ana Pastor. "Estudio fitoquímico de la Hyptis pectinata (L.) Point". Revista de Química, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/99477.
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Nyamayaro, Takura T. A. "On the design and implementation of a hybrid numerical method for singularly perturbed two-point boundary value problems". University of the Western Cape, 2014. http://hdl.handle.net/11394/4326.
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>Magister Scientiae - MScWith the development of technology seen in the last few decades, numerous solvers have been developed to provide adequate solutions to the problems that model different aspects of science and engineering. Quite often, these solvers are tailor-made for specific classes of problems. Therefore, more of such must be developed to accompany the growing need for mathematical models that help in the understanding of the contemporary world. This thesis treats two point boundary value singularly perturbed problems. The solution to this type of problem undergoes steep changes in narrow regions (called boundary or internal layer regions) thus rendering the classical numerical procedures inappropriate. To this end, robust numerical methods such as finite difference methods, in particular fitted mesh and fitted operator methods have extensively been used. While the former consists of transforming the continuous problem into a discrete one on a non-uniform mesh, the latter involves a special discretisation of the problem on a uniform mesh and are known to be more accurate. Both classes of methods are suitably designed to accommodate the rapid change(s) in the solution. Quite often, finite difference methods on piece-wise uniform meshes (of Shishkin-type) are adopted. However, methods based on such non-uniform meshes, though layer-resolving, are not easily extendable to higher dimensions. This work aims at investigating the possibility of capitalising on the advantages of both fitted mesh and fitted operator methods. Theoretical results are confirmed by extensive numerical simulations.
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Bulunga, Meshack Linda. "Change-point detection in dynamical systems using auto-associative neural networks". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20267.
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Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: In this research work, auto-associative neural networks have been used for changepoint detection. This is a nonlinear technique that employs the use of artificial neural networks as inspired among other by Frank Rosenblatt’s linear perceptron algorithm for classification. An auto-associative neural network was used successfully to detect change-points for various types of time series data. Its performance was compared to that of singular spectrum analysis developed by Moskvina and Zhigljavsky. Fraction of Explained Variance (FEV) was also used to compare the performance of the two methods. FEV indicators are similar to the eigenvalues of the covariance matrix in principal component analysis. Two types of time series data were used for change-point detection: Gaussian data series and nonlinear reaction data series. The Gaussian data had four series with different types of change-points, namely a change in the mean value of the time series (T1), a change in the variance of the time series (T2), a change in the autocorrelation of the time series (T3), and a change in the crosscorrelation of two time series (T4). Both linear and nonlinear methods were able to detect the changes for T1, T2 and T4. None of them could detect the changes in T3. With the Gaussian data series, linear singular spectrum analysis (LSSA) performed as well as the NLSSA for the change point detection. This is because the time series was linear and the nonlinearity of the NLSSA was therefore not important. LSSA did even better than NLSSA when comparing FEV values, since it is not subject to suboptimal solutions as could sometimes be the case with autoassociative neural networks. The nonlinear data consisted of the Belousov-Zhabotinsky (BZ) reactions, autocatalytic reaction time series data and data representing a predator-prey system. With the NLSSA methods, change points could be detected accurately in all three systems, while LSSA only managed to detect the change-point on the BZ reactions and the predator-prey system. The NLSSA method also fared better than the LSSA method when comparing FEV values for the BZ reactions. The LSSA method was able to model the autocatalytic reactions fairly accurately, being able to explain 99% of the variance in the data with one component only. NLSSA with two nodes on the bottleneck attained an FEV of 87%. The performance of both NLSSA and LSSA were comparable for the predator-prey system, both systems, where both could attain FEV values of 92% with a single component. An auto-associative neural network is a good technique for change point detection in nonlinear time series data. However, it offers no advantage over linear techniques when the time series data are linear.
AFRIKAANSE OPSOMMING: In hierdie navorsing is outoassosiatiewe neurale netwerk gebruik vir veranderingspuntwaarneming. Dis is ‘n nielineêre tegniek wat neurale netwerke gebruik soos onder andere geïnspireer deur Frank Rosnblatt se lineêre perseptronalgoritme vir klassifikasie. ‘n Outoassosiatiewe neurale netwerk is suksesvol gebruik om veranderingspunte op te spoor in verskeie tipes tydreeksdata. Die prestasie van die outoassosiatiewe neurale netwerk is vergelyk met singuliere spektrale oontleding soos ontwikkel deur Moskvina en Zhigljavsky. Die fraksie van die verklaarde variansie (FEV) is ook gebruik om die prestasie van die twee metodes te vergelyk. FEV indikatore is soortgelyk aan die eiewaardes van die kovariansiematriks in hoofkomponentontleding. Twee tipes tydreeksdata is gebruik vir veranderingspuntopsporing: Gaussiaanse tydreekse en nielineêre reaksiedatareekse. Die Gaussiaanse data het vier reekse gehad met verskillende veranderingspunte, naamlik ‘n verandering in die gemiddelde van die tydreeksdata (T1), ‘n verandering in die variansie van die tydreeksdata (T2), ‘n verandering in die outokorrelasie van die tydreeksdata (T3), en ‘n verandering in die kruiskorrelasie van twee tydreekse (T4). Beide lineêre en nielineêre metodes kon die veranderinge in T1, T2 en T4 opspoor. Nie een het egter daarin geslaag om die verandering in T3 op te spoor nie. Met die Gaussiaanse tydreeks het lineêre singuliere spektrumanalise (LSSA) net so goed gevaar soos die outoassosiatiewe neurale netwerk of nielineêre singuliere spektrumanalise (NLSSA), aangesien die tydreekse lineêr was en die vermoë van die NLSSA metode om nielineêre gedrag te identifiseer dus nie belangrik was nie. Inteendeel, die LSSA metode het ‘n groter FEV waarde getoon as die NLSSA metode, omdat LSSA ook nie blootgestel is aan suboptimale oplossings, soos wat soms die geval kan wees met die afrigting van die outoassosiatiewe neural netwerk nie. Die nielineêre data het bestaan uit die Belousov-Zhabotinsky (BZ) reaksiedata, ‘n outokatalitiese reaksietydreeksdata en data wat ‘n roofdier-prooistelsel verteenwoordig het. Met die NLSSA metode kon veranderingspunte betroubaar opgespoor word in al drie tydreekse, terwyl die LSSA metode net die veranderingspuntin die BZ reaksie en die roofdier-prooistelsel kon opspoor. Die NLSSA metode het ook beter gevaaar as die LSSA metode wanneer die FEV waardes vir die BZ reaksies vergelyk word. Die LSSA metode kon die outokatalitiese reaksies redelik akkuraat modelleer, en kon met slegs een komponent 99% van die variansie in die data verklaar. Die NLSSA metode, met twee nodes in sy bottelneklaag, kon ‘n FEV waarde van slegs 87% behaal. Die prestasie van beide metodes was vergelykbaar vir die roofdier-prooidata, met beide wat FEV waardes van 92% kon behaal met hulle een komponent. ‘n Outoassosiatiewe neural netwerk is ‘n goeie metode vir die opspoor van veranderingspunte in nielineêre tydreeksdata. Dit hou egter geen voordeel in wanneer die data lineêr is nie.
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Saldaña, Cuba José. "La historia también la escriben los perdedores: el valor del voto singular en el caso “El Frontón” (STC 3173-2008-PHC)". Foro Jurídico, 2015. http://repositorio.pucp.edu.pe/index/handle/123456789/120107.
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En este artículo, el autor describe y señala la importancia del voto singular o dissenting opinion en el marco del Estado Constitucional de Derecho. Asimismo presenta de manera detallada la postura minoritaria dentro de un órgano como el Tribunal Constitucional, lo que garantiza la calidad de los argumentos presentados, pero que a su vez representa la opinión de una minoría fuera del colegiado, que encuentra en el voto singular la garantía de protección de sus derechos. Luego de introducir al lector en el tema, el autor hace referencia a la rele- vancia del voto singular en el caso “El Frontón” en el cual se logró un equilibrio entre una opinión mayoritaria y formalista, de acuerdo al autor, y una opinión minoritaria de carácter activista. Así pues, el autor finaliza su análisis realizando una reflexión de la importancia del disentimiento para poder “escuchar la voz de pocos”.
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Cai, Yulin. "Integral Points on Modular Curves, Singular Moduli and Conductor-Discriminant Inequality". Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0098.
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Cette thèse traite de trois sujets en trois parties. Dans la première partie, nous étudions les points S-entiers de la courbe modulaire X0(p). Yuri Bilu a montré qu’en utilisant la méthode de Baker, on peut donner une borne effective de la hauteur de ces points en fonction de p, du corps de base et de l’ensemble de places S. Min Sha a rendu ce résultat explicite. avec une borne doublement exponentielle en dans p. Nous améliorons considérablement dans cette thèse le résultat de Sha, en obtenant une borne simplement exponentielle. Cela se fait en utilisant une version très explicite du principe de Chevalley-Weil basée sur des travaux de Qing Liu et Dino Lorenzini. Notre borne est non seulement plus nette que celle de Sha, mais également explicite en tous les paramètres. Dans la deuxième partie, nous considérons des modules singuliers de courbes elliptiques. Pour un module singulier fixe a, nous donnons une borne supérieure effective de la norme de x - a pour un autre module singulier x avec un grand discriminant. Dans la troisième partie, nous donnons une relation entre les conducteurs d’Artin d’un modèle Werestrass Y et ceux de deux modèles de Weierstrass donnés Y1,Y2. Avec cette relation, nous déduisons que l’inégalité conducteur-discriminant est valable pour Y si elle est valable pour Y1 et Y2This thesis discusses three topics, so it includes three parts. In the first part, we study S-integral points on the modular curve X0(p). Bilushowed that, using Baker’s method, they can be effectively bounded in terms of p, the base field and the set of places S. Sha made this result explicit, but the bound he obtained is double exponential in p. We drastically improve upon the result of Sha, obtaining a simple exponential bound. This is done using a very explicit version of the Chevalley-Weil principle based on the work of Liu and Lorenzini. Our bound is not only sharper than that of Sha, but is also explicit in all parameters. In the second part, we consider singular moduli. For a fixed singular modulus a, we give an effective upper bound of norm of x - a for another singular modulus x with large discriminant. In the third part, we give a relation between Artin conductors of a Weierstrass model Y and the ones of two given Weierstrass models Y1,Y2. With this relation, we know that the conductor-discriminant inequality holds for Y if it holds for Y1 and Y2
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Tidefelt, Henrik. "Structural algorithms and perturbations in differential-algebraic equations". Licentiate thesis, Linköping : Department of Electrical Engineering, Linköpings universitet, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9011.
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Negron, Luis G. "Initial-value technique for singularly perturbed two point boundary value problems via cubic spline". Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4597.
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A recent method for solving singular perturbation problems is examined. It is designed for the applied mathematician or engineer who needs a convenient, useful tool that requires little preparation and can be readily implemented using little more than an industry-standard software package for spreadsheets. In this paper, we shall examine singularly perturbed two point boundary value problems with the boundary layer at one end point. An initial-value technique is used for its solution by replacing the problem with an asymptotically equivalent first order problem, which is, in turn, solved as an initial value problem by using cubic splines. Numerical examples are provided to show that the method presented provides a fine approximation of the exact solution. The first chapter provides some background material to the cubic spline and boundary value problems. The works of several authors and a comparison of different solution methods are also discussed. Finally, some background into the specific singularly perturbed boundary value problems is introduced. The second chapter contains calculations and derivations necessary for the cubic spline and the initial value technique which are used in the solutions to the boundary value problems. The third chapter contains some worked numerical examples and the numerical data obtained along with most of the tables and figures that describe the solutions. The thesis concludes with some reflections on the results obtained and some discussion of the error bounds on the calculated approximations to the exact solutions for the numeric examples discussed.ID: 029051011; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2010.; Includes bibliographical references (p. 48-50).
M.S.
Masters
Department of Mathematics
Sciences
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Sensoy, Aynur. "Physically Based Point Snowmelt Modeling And Its Distribution In Euphrates Basin". Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605945/index.pdf.
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Since snowmelt runoff is important in the mountainous parts of the world, substantial efforts have been made to develop snowmelt models with many different levels of complexity to simulate the processes at the ground, within the snow, and at the interface with the atmosphere. The land-atmosphere interactions and processing influencing heat transfer to and from a snowpack are largely variable and the conceptual representation of this temporal and spatial variability is difficult.
A physically based, two layer point model, is applied to calculate the energy and mass balance of snowmelt in the Upper Karasu Basin, eastern part of Turkey during 2002-2004 snow seasons. The climate data are provided from automated weather stations installed and upgraded to collect quantitative and qualitative data with automated transfer. Each form of energy transfer is evaluated to understand the key processes that have major impact on the snow simulation during accumulation and ablation in two-hourly timesteps. The model performance is evaluated as accurate according to the results, compared with observed snow water equivalents, snow depth and lysimeter runoff yield. In the second part, calculated snowmelt values based on energy and mass balance at the automated stations are related to radiation index model through regression. Then, the spatial patterns of snow water equivalent, solar illumination, albedo and air temperature are used to predict the melt at each grid cell over the whole watershed. The results of distributed model application are evaluated in terms of snow covered area of satellite products, observed snow water equivalent at points through snow pillows and discharge values at the outlet runoff station.
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Bernet, Rudolf. "Affectuum imitatio y point de vue: en torno a la intersubjetividad en Spinoza y Leibniz". Pontificia Universidad Católica del Perú - Departamento de Humanidades, 2016. http://repositorio.pucp.edu.pe/index/handle/123456789/112938.
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Salcedo, Luis E. "The Proto-Lauricocha Phase Of The Central Andes And The Origin Of Andean Foliated Point Tradition". Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/113582.
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This paper discusses early evidence for the Andean Foliated Point Tradition (TAPF in Spanish), with special emphasis on theCentral Andes region and the Lauricocha complex, which are included into the so-called ‘Proto-Lauricocha’ phase (Salcedo 2006).This phase is characterized by the indiscriminate consumption of animal species prior to food production, and the presence of foliated projectile points featuring centripetal retouch and minute ailerons located at one-third of the maximum longitude of thepiece, defi ning in that way a pseudo-peduncle. The cultural phase has been dated by the radiocarbon method in the 10,500-7400 years cal BC interval, employing the dendrochronological calibration with the support of the OxCal v3.10r program (Bronk-Ramsey 2005) and the current calibration curves (Reimer et al. 2004; Reimer et al. 2009). Comparative evidence found in North America and Japan is used to discuss the probable origin of TAPF.El presente artículo discute las evidencias más tempranas correspondientes a la Tradición Andina de Puntas Foliáceas (TAPF), con especial énfasis en los hallazgos realizados en los Andes Centrales, adscritos al complejo Lauricocha, los que son incluidos dentro de la denominada fase Proto-Lauricocha (Salcedo 2006), la que se caracteriza por un consumo indiscriminado de especies animales, previo a la producción de alimentos y la presencia de puntas de proyectil foliáceas de retoque centrípeto, con diminutos alerones ubicadosa un tercio del largo máximo de la pieza, con lo que se definió un pseudopedúnculo. Esta fase cultural ha sido fechada por el método de radiocarbono en el intervalo 10.500-7400 cal AC por medio del empleo de la calibración dendrocronológica con ayuda delprograma OxCal v3.10r (Bronk-Ramsey 2005) y las curvas de calibración vigentes (Reimer et al. 2004; Reimer et al. 2009). Asimismo, se rastrea el probable origen de la TAPF en virtud a las evidencias similares halladas en Norteamérica y Japón.
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Iezzi, Annamaria. "Nombre de points rationnels des courbes singulières sur les corps finis". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4027/document.
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On s'intéresse, dans cette thèse, à des questions concernant le nombre maximum de points rationnels d'une courbe singulière définie sur un corps fini, sujet qui, depuis Weil, a été amplement abordé dans le cas lisse. Cette étude se déroule en deux temps. Tout d'abord on présente une construction de courbes singulières de genres et corps de base donnés, possédant un grand nombre de points rationnels : cette construction, qui repose sur des notions et outils de géométrie algébrique et d'algèbre commutative, permet de construire, en partant d'une courbe lisse X, une courbe à singularités X', de telle sorte que X soit la normalisée de X', et que les singularités ajoutées soient rationnelles sur le corps de base et de degré de singularité prescrit. Ensuite, en utilisant une approche euclidienne, on prouve une nouvelle borne sur le nombre de points fermés de degré deux d'une courbe lisse définie sur un corps fini.La combinaison de ces résultats, à priori indépendants, permet notamment d'étudier le problème de savoir quand la borne d'Aubry-Perret, analogue de la borne de Weil dans le cas singulier, est atteinte. Cela nous amène de façon naturelle à l'étude des propriétés des courbes maximales et, lorsque la cardinalité du corps de base est un carré, à l'analyse du spectre des genres de ces dernièresIn this PhD thesis, we focus on some issues about the maximum number of rational points on a singular curve defined over a finite field. This topic has been extensively discussed in the smooth case since Weil's works. We have split our study into two stages. First, we provide a construction of singular curves of prescribed genera and base field and with many rational points: such a construction, based on some notions and tools from algebraic geometry and commutative algebra, yields a method for constructing, given a smooth curve X, another curve X' with singularities, such that X is the normalization of X', and the added singularities are rational on the base field and with the prescribed singularity degree. Then, using a Euclidian approach, we prove a new bound for the number of closed points of degree two on a smooth curve defined over a finite field.Combining these two a priori independent results, we can study the following question: when is the Aubry-Perret bound (the analogue of the Weil bound in the singular case) reached? This leads naturally to the study of the properties of maximal curves and, when the cardinality of the base field is a square, to the analysis of the spectrum of their genera
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Lapp, Frank. "An index theorem for operators with horn singularities". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2013. http://dx.doi.org/10.18452/16838.
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Die abgeschlossenen Erweiterungen der sogenannten geometrischen Operatoren (Spin-Dirac, Gauß-Bonnet und Signatur-Operator) auf Mannigfaltigkeiten mit metrischen Hörnern sind Fredholm-Operatoren und ihr Index wurde von Matthias Lesch, Norbert Peyerimhoff und Jochen Brüning berechnet. Es wurde gezeigt, dass die Einschränkungen dieser drei Operatoren auf eine punktierte Umgebung des singulären Punkts unitär äquivalent zu irregulär singulären Operator-wertigen Differentialoperatoren erster Ordnung sind. Die Lösungsoperatoren der dazugehörigen Differentialgleichungen definierten eine Parametrix, mit deren Hilfe die Fredholmeigenschaft bewiesen wurde. In der vorliegenden Doktorarbeit wird eine Klasse von irregulären singulären Differentialoperatoren erster Ordnung, genannt Horn-Operatoren, eingeführt, die die obigen Beispiele verallgemeinern. Es wird bewiesen, dass ein elliptischer Differentialoperator erster Ordnung, dessen Einschränkung auf eine punktierte Umgebung des singulären Punkts unitär äquivalent zu einem Horn-Operator ist, Fredholm ist, und sein Index wird berechnet. Schließlich wird dieser abstrakte Index-Satz auf geometrische Operatoren auf Mannigfaltigkeiten mit "multiply warped product"-Singularitäten angewendet, welche eine wesentliche Verallgemeinerung der metrischen Hörner darstellen.The closed extensions of geometric operators (Spin-Dirac, Gauss-Bonnet and Signature operator) on a manifold with metric horns are Fredholm operators, and their indices were computed by Matthias Lesch, Norbert Peyerimhoff and Jochen Brüning. It was shown that the restrictions of all three operators to a punctured neighbourhood of the singular point are unitary equivalent to a class of irregular singular operator-valued differential operators of first order. The solution operators of the corresponding differential equations defined a parametrix which was applied to prove the Fredholm property. In this thesis a class of irregular singular differential operators of first order - called horn operators - is introduced that extends the examples mentioned above. It is proved that an elliptic differential operator of first order whose restriction to the neighbourhood of the singular point is unitary equivalent to a horn operator is Fredholm and its index is computed. Finally, this abstract index theorem is applied to compute the indices of geometric operators on manifolds with multiply warped product singularities that extend the notion of metric horns considerably.
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Filla, David. "Biometrie otisku prstu". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219256.
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This project deals with fingerprint biometrics. Describes the origin and significance of ridges. Project denote the significance and detection of singular points. The way of classication fingerprint to the vlase usány by the singular points. It contains a list of types of minutiae and their detection. There is basic methods for matching fingerprints. The minutae-based matching method is realize in program Matlab.
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Caldas, Miguel, e Saeid Jafari. "Remarks on strongly precloseds functions in topological space". Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/96055.
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Ruttkay, Michal. "Biometrická identifikace otisku prstu". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221371.
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This thesis describes the anatomical characteristics of fingerprints and their applications in identifying the person. The theoretical part describes the importance of papillary lines on fingerprints, statistical analysis and pre-processing of images in particular. The practical section provides the necessary operations to compare fingerprints. The implementation was done in Matlab.
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Torres, Guardia Luis Ernesto, e Nelson N. Lacerda. "Multiple objetive network flow problems". Pontificia Universidad Católica del Perú, 2012. http://repositorio.pucp.edu.pe/index/handle/123456789/97276.
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In this work, it is presented the multiple objective networkflow problems. This kind of problem is converted into singleo bjective problem and solved by using the primal dual interior point method. The linear system associated to the interior point method is solved by using the Cholesky decomposition, implemented in MATLAB code. Networks of different dimensions are constructed and the computational results show the efficiency of the mentioned interior point method for solving multiple objective network flow problems.
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Pavis, d'Escurac Philippe. "Etude des singularités de la fonction "valeur à canard" de certaines équations différentielles complexes singulièrement perturbées". Thesis, Mulhouse, 2018. http://www.theses.fr/2018MULH0578.
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Les canards ont été découverts au début des années 1980 par É. Benoît, F. et M. Diener et J.-L. Callot lors de l’étude de la fameuse équation de van der Pol. Étant donnée une équation différentielle réelle singulièrement perturbée par un petit paramètre ɛ, une solution canard – si elle existe – a la particularité de longer partiellement ou en totalité la partie répulsive d’une courbe lente pour une certaine valeur du paramètre de contrôle a, appelée valeur à canard. Une généralisation aux EDO complexes a ensuite donné lieu aux solutions surstables, bornées dans tout un voisinage d'un point tournant où la courbe lente présente une inversion de stabilité. Il est connu que dans le plan complexe, les valeurs à canard admettent un même développement asymptotique Gevrey d’ordre 1 noté â(ɛ), si bien que la transformée de Borel A(t) de cette série â(ɛ) est analytique au voisinage de l’origine. En utilisant la récente théorie des développements asymptotiques combinés due à A. Fruchard et R. Schäfke, nous étudions la première singularité de A(t) dans le cas de deux EDO : une équation de Riccati et l’équation de van der Pol. Pour ces deux équations, la série â(ɛ) est Borel-sommable dans toutes les directions du plan complexe excepté l’axe des réels positifs qui constitue une ligne de Stokes. Nous obtenons d’abord une estimation de la différence des valeurs à canard de part et d’autre de cette ligne que nous traduisons ensuite dans le plan de Borel. Pour l’équation de Riccati, cette estimation contient un terme exponentiellement petit et un développement asymptotique Gevrey. Ainsi, la transformée de Borel A(t) admet en 1/3 une singularité ramifiée, isolée sur le premier feuilletCanards were discovered in the early 80s by É. Benoît, F. and M. Diener and J.-L. Callot while studying the famous van der Pol equation. Given a real differential equation, singularly perturbed by epsilon small, a canard solution – if it exists – has the particularity to follow partially or totally a slow curve from its attractive part to its repulsive part for a certain value of the control parameter a, named a canard value. A generalization to complex ODEs leads to overstable solutions, bounded in a neighborhood of a turning point, i.e. a point where the slow curve presents an inversion of stability. It is known that canard values admit a unique asymptotic expansion of Gevrey order one denoted by â, so that the Borel transform A(t) of â(epsilon) is analytic near the origin. Using the recent theory of composite asymptotic expansions due to A. Fruchard and R. Schäfke, we study the first singularity of this Borel transform A(t). We focus on two differential equations: a Riccati equation and the van der Pol equation. For these two equations, the formal series â(epsilon) is Borel summable in every direction except the real positive axis which constitutes a Stokes line. We first obtain an estimate of the difference of the canard values on each side of this line and then translate the result in the Borel plane. For the Riccati equation, this estimate contains an exponentially small term and a Gevrey asymptotic expansion. Thus the Borel transform A(t) has in 1/3 a ramified singularity, isolated on the first sheet
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ROCHA, Valdomiro. "Centros Persistentes". Universidade Federal de Goiás, 2010. http://repositorio.bc.ufg.br/tede/handle/tde/1966.
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Made available in DSpace on 2014-07-29T16:02:22Z (GMT). No. of bitstreams: 1
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Previous issue date: 2010-03-05The problem of destingnishing whether a monodromic critical point with imaginary eigenvalues of a family of a planar analitical vector field is a center or a focus was already solved by Lyapunov. This is the famous center-focus problem which was solved by calculating the so-called Lyapunov constants and see whether or not they are zero. We present a few ways to calculate them acording the approaches that they use: camputation of a Lyapunov function; use of normal forms; computation of the power of expansion of a solution in polar coordinates; use of the algebraic structure of Lyapunov constants; method of Lyapunov-Schmit and Melnikov functions. Despite all of the above the centerfocus problem for a simple family as the cube is resisting all attempts at solution. For this reason the centers, we propose to grade the in three levels in order to make the problem more feasible.
O problema de decidir se um ponto singular monodrômico com autovalores imaginários para uma família analítica de um campo de vetores planares é um centro ou um foco foi resolvido por Lyapunov. Este é o famoso problema centro- foco, que foi resolvido calculando as chamadas constantes de Lyapunov e verificar se elas são ou não nulas. Existem métodos diferentes de calculá-las dependendo da aproximação a ser utilizada: cálculo da função de Lyapunov; uso de formas normais; cálculo da potência na expansão da solução em coordenadas polares; uso da estrutura algébrica das constantes de Lyapunov; método de Lyapunov-Schmit e funções de Melnikov. Apesar de todos os métodos acima o problema centro-foco para uma família simples, como a cúbica, tem resisitido a todas as tentativas de solução, por isto classificamos os centros em três níveis para tornar o problema mais viável.
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Jakaitytė, Eglė. "Paprastųjų diferencialinių lygčių su ypatuma modifikuotieji kraštiniai uždaviniai". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080924_175412-35930.
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Magistro baigiamajame darbe nagrinėjama antrosios eilės tiesinė nehomogeninė diferencialinė lygtis intervale, kurio kairysis kraštas yra nagrinėjamosios lygties koeficientų ireguliarusis ypatingasis taškas. Ištirta sprendinių asimptotika ypatingojo taško aplinkoje ir išnagrinėti trys šios lygties kraštiniai uždaviniai, kurių formulavimas iš esmės priklauso nuo lygties parametro ženklo.The present Master thesis analyses the second order linear differential equation in interval which left side coincides with irregular singular point of this equation. The asymptotics of the solutions in the neighbourhood of singular point is investigated and three boundary value problems, statement of which principally depends on equation parameter sign, have been analyzed.
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Kronborg, Pelle. "Identifying Quaternary Climate Change with XRF Analysis on Loess From South-Western England". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-412179.
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Huge changes in climate occurred at the end of the last Quaternary glaciation. The end of this glaciation corresponds with the end of Pleistocene with its repeated glacial cycles and the start of the current geological epoch, the Holocene interglacial. The climate at this time was characterized by increasing temperatures and an increase in rainfall. This project focuses on understanding and examining these changes in climate using loess deposits from south-western England. Loess is an aeolian sediment and covers around 10 % of the Earth’s land surface and these deposits are excellent archives of past climate. Investigating loess can give understanding of past regional and local wind circulation patterns, atmospheric dustiness as well as weathering conditions. Studying paleoclimate is important since studying and understanding trends in past climate can increase our understanding of how the climate will change in the future. This study examined loess from two sites in south-western England, Porth Cressa and Lowland Point. These are relatively thin deposits; Lowland Point has a thickness of 180 cm and Porth Cressa has a thickness of 97 cm. England lacks the thick loess deposits that can be found in other parts of the world and thus the study of English loess has mostly been neglected. These deposits thus could contain unutilized information about paleoclimate. The elemental composition of the samples was examined using X-Ray Fluorescence (XRF). With the measured elemental composition, it’s possible to use weathering indices to see trends in postdepositional weathering. Low weathering intensities indicate a colder and drier climate, while higher weathering intensities indicate a warmer and more humid climate. The results from the weathering indices were plotted against depth at the two sites to identify changes in weathering and hence climate over time. Compared with the results from previous studies the results from some weathering indices seemed credible. Previous studies have indicated that the Chemical Proxy of Alteration (CPA) is the most appropriate weathering index for loess and the results from this study supports that theory. The results from the CPA show a trend with decreasing weathering intensities followed by a trend with increasing weathering intensities This implies that there was a period with decreasing temperatures/humidity followed by a period with increasing temperature humidity sometime at the end of the last glaciation. The geochemical data also showed support for a previous archaeological theory that there has been human reworking in the upper horizons at Lowland Point.Slutet av den sista kvartära glaciationen var en tid med stora klimatförändringar. Denna tid sammanfaller med slutet av Pleistocene och dess glaciära cyklar samt starten på den nuvarande geologiska epoken, Holocen. Klimatet vid den här tiden karaktäriserades av ökande temperaturer och ökande nederbörd. Det här projektet fokuserar på att granska och förstå dessa klimatförändringar med hjälp av lössjordar från sydvästra England. Löss bildas av vindburet sediment och täcker ungefär 10 % av jordens landyta, dessa avlagringar är utmärkta arkiv för historiskt klimat. Att undersöka lössjordar kan ge information om historiska regionala och lokala vindcirkulations-mönster, vittringsförhållanden samt mängden damm i atmosfären. Att undersöka paleoklimat är viktigt då förståelse för trender i tidigare klimat kan ge oss förståelse för hur klimatet kommer förändras i framtiden. Den här studien undersökte löss från två platser i sydvästra England, Lowland Point och Porth Cressa. Dessa avlagringar är relativt tunna; Lowland Point har en tjocklek på 180 cm och Porth Cressa har en tjocklek på 97 cm. England har inte de tjocka lössavlagringarna som går att hitta i andra delar av världen och därför har lite forskning utförts på brittiskt löss. Dessa avlagringar kan alltså innehålla oanvänd information om paleoklimat. Provernas grundämnessammansättning undersöktes med X-Ray Fluorescence (XRF). Med den uppmäta grundämnessammansättningen är det möjligt att använda vittringsindex för att se trender i vittring efter deposition. En låg vittringsintensitet indikerar ett kallare och torrare klimat medan en högre vittringsintensitet indikerar ett varmare och fuktigare klimat. Resultaten plottades mot djup för att visuellt identifiera förändringar i klimatet över tid. Vid jämförelse med tidigare studier verkade resultaten från vittringsindexen trovärdiga. Tidigare studier har föreslagit att CPA (Chemical Proxy of Alteration) är det mest lämpliga vittringsindexet för lössjordar och resultaten från denna studie stödjer den teorin. Resultaten från CPA visade på en trend med minskade vittringsintensitet följt av en trend med ökande vittrings intensitet. Detta antyder att det var en period med minskande temperatur/fuktighet följt av en period med ökande temperatur/fuktighet runt slutet av den senaste istiden. De geokemiska resultaten stödde också den tidigare arkeologiska teorin att mänsklig aktivitet har påverkat de övre horisonterna vid Lowland Point.
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Haouas, Nabiha. "Wind energy analysis and change point analysis". Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22554.
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L’énergie éolienne, l’une des énergies renouvelables les plus compétitives, est considérée comme une solution qui remédie aux inconvénients de l’énergie fossile. Pour une meilleure gestion et exploitation de cette énergie, des prévisions de sa production s’avèrent nécessaires. Les méthodes de prévisions utilisées dans la littérature permettent uniquement une prévision de la moyenne annuelle de cette production. Certains travaux récents proposent l’utilisation du Théorème Central Limite (TCL), sous des hypothèses non classiques, pour l’estimation de la production annuelle moyenne de l’énergie éolienne ainsi que sa variance pour une seule turbine. Nous proposons dans cette thèse une extension de ces travaux à un parc éolien par relaxation de l’hypothèse de stationnarité la vitesse du vent et la production d’énergie, en supposant que ces dernières sont saisonnières. Sous cette hypothèse la qualité de la prévision annuelle s’améliore considérablement. Nous proposons aussi de prévoir la production d’énergie éolienne au cours des quatre saisons de l’année. L’utilisation du modèle fractal, nous permet de trouver une division ”naturelle” de la série de la vitesse du vent afin d’affiner l’estimation de la production éolienne en détectant les points de ruptures. Dans les deux derniers chapitres, nous donnons des outils statistiques de la détection des points de ruptures et d’estimation des modèles fractalsThe wind energy, one of the most competitive renewable energies, is considered as a solution which remedies the inconveniences of the fossil energy. For a better management and an exploitation of this energy, forecasts of its production turn out to be necessary. The methods of forecasts used in the literature allow only a forecast of the annual mean of this production. Certain recent works propose the use of the Central Limit Theorem (CLT), under not classic hypotheses, for the estimation of the mean annual production of the wind energy as well as its variance for a single turbine. We propose in this thesis, an extension of these works in a wind farm by relaxation of the hypothesis of stationarity the wind speed and the power production, supposing that the latter are seasonal. Under this hypothesis the quality of the annual forecast improves considerably. We also suggest planning the wind power production during four seasons of the year. The use of the fractal model, allows us to find a "natural" division of the series of the wind speed to refine the estimation of the wind production by detecting abrupt change points. Statistical tools of the change points detection and the estimation of fractal models are presented in the last two chapters
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Stantic, Bela, e n/a. "Access Methods for Temporal Databases". Griffith University. School of Information and Communication Technology, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20060906.144815.
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A Temporal database is one that supports some aspect of time distinct from user defined time. Over the last two decades interest in the field of temporal databases has increased significantly, with contributions from many researchers. However, the lack of efficient access methods is perhaps one of the reasons why commercial RDBMS vendors have been reluctant to adopt the advances in temporal database research. Therefore, an obvious research question is: can we develop more robust and more efficient access methods for temporal databases than the existing ones? This thesis attempts to address this question, and the main contributions of this study are summarised as follows: We investigated different representations of 'now' and how the modelling of current time influences the efficiency of accessing 'now relative' temporal data. A new method, called the 'Point' approach, is proposed. Our approach not only elegantly models the current time but also significantly outperforms the existing methods. We proposed a new index structure, called a Virtual Binary tree (VB-tree), based on spatial representation of interval data and a regular triangular decomposition of this space. Further, we described a sound and complete query algorithm. The performance of the algorithm is then evaluated both asymptotically and experimentally with respect to the state-of-the-art in the field. We claim that the VB-tree requires less space and uses fewer disk accesses than the currently best known structure - the RI-tree.
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Mahmoud, Hamdy Fayez Farahat. "Some Advanced Semiparametric Single-index Modeling for Spatially-Temporally Correlated Data". Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/76744.
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Semiparametric modeling is a hybrid of the parametric and nonparametric modelings where some function forms are known and others are unknown. In this dissertation, we have made several contributions to semiparametric modeling based on the single index model related to the following three topics: the first is to propose a model for detecting change points simultaneously with estimating the unknown function; the second is to develop two models for spatially correlated data; and the third is to further develop two models for spatially-temporally correlated data.
To address the first topic, we propose a unified approach in its ability to simultaneously estimate the nonlinear relationship and change points. We propose a single index change point model as our unified approach by adjusting for several other covariates. We nonparametrically estimate the unknown function using kernel smoothing and also provide a permutation based testing procedure to detect multiple change points. We show the asymptotic properties of the permutation testing based procedure. The advantage of our approach is demonstrated using the mortality data of Seoul, Korea from January, 2000 to December, 2007.
On the second topic, we propose two semiparametric single index models for spatially correlated data. One additively separates the nonparametric function and spatially correlated random effects, while the other does not separate the nonparametric function and spatially correlated random effects. We estimate these two models using two algorithms based on Markov Chain Expectation Maximization algorithm. Our approaches are compared using simulations, suggesting that the semiparametric single index nonadditive model provides more accurate estimates of spatial correlation. The advantage of our approach is demonstrated using the mortality data of six cities, Korea from January, 2000 to December, 2007.
The third topic involves proposing two semiparametric single index models for spatially and temporally correlated data. Our first model has the nonparametric function which can separate from spatially and temporally correlated random effects. We refer it to "semiparametric spatio-temporal separable single index model (SSTS-SIM)", while the second model does not separate the nonparametric function from spatially correlated random effects but separates the time random effects. We refer our second model to "semiparametric nonseparable single index model (SSTN-SIM)". Two algorithms based on Markov Chain Expectation Maximization algorithm are introduced to simultaneously estimate parameters, spatial effects, and times effects. The proposed models are then applied to the mortality data of six major cities in Korea. Our results suggest that SSTN-SIM is more flexible than SSTS-SIM because it can estimate various nonparametric functions while SSTS-SIM enforces the similar nonparametric curves. SSTN-SIM also provides better estimation and prediction.Ph. D.
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Tian, Feng. "On commutativity of unbounded operators in Hilbert space". Diss., University of Iowa, 2011. https://ir.uiowa.edu/etd/1095.
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We study several unbounded operators with view to extending von Neumann's theory of deficiency indices for single Hermitian operators with dense domain in Hilbert space. If the operators are non-commuting, the problems are difficult, but special cases may be understood with the use representation theory. We will further study the partial derivative operators in the coordinate directions on the L2 space on various covering surfaces of the punctured plane. The operators are defined on the common dense domain of C∞ functions with compact support, and they separately are essentially selfadjoint, but the unique selfadjoint extensions will be non-commuting. This problem is of a geometric flavor, and we study an index formulation for its solution.
The applications include the study of vector fields, the theory of Dirichlet problems for second order partial differential operators (PDOs), Sturm-Liouville problems, H.Weyl's limit-point/limit-circle theory, Schrödinger equations, and more.
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Letalleur, Séverine Martinet Marie-Madeleine Cotte Pierre. "Réflexion croisée sur la notion de focalisation en langue et dans les théories des représentations". Paris : Université Paris Sorbonne - Paris IV, 2008. http://www.theses.paris4.sorbonne.fr/letalleur/paris4/2006/letalleur/html/index-frames.html.
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Letalleur, Séverine. "Réflexion croisée sur la notion de focalisation en langue et dans les théories des représentations". Paris 4, 2006. http://www.theses.paris-sorbonne.fr/letalleur/paris4/2006/letalleur/html/index-frames.html.
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Cet examen de la notion de focalisation en langue et en peinture porte en priorité sur des questions de sémiotique. L’hybridation du champ exploratoire a nécessité que l’on étende la réflexion aux notions plus vastes de temps et d’espace dont il apparaît qu’elles sont intrinsèquement liées ; ce ne sont des entités distinctes que du fait de contraintes épistémologiques dues à une perception erronée de notre environnement immédiat. Temps et espace se présentent toujours à nous confondus dans le quadridimensionnel mouvant dont nous sommes partie intégrante. La poésie, prise dans son acception la plus large, une visée unidimensionnelle, est l’ex-pression cinétique du flux invisible de la conscience. La peinture en retour est la fixation bidimensionnelle d’une réorganisation objectale de soi. Si la focalisation, en tant que concentration et fixation de l’attention, se joue à tous les niveaux représentationnels, elle a également lieu au moment du passage d’un mode à un autre, la concentration accédant à son degré ultime dans le passage au linéaire linguistique. En tant qu’outils de mise en forme du sens, énoncé et peinture agissent tels des instruments de mesure intersubjective, ils fixent et ciblent ponctuellement l’espace-temps commun mais instable dans lequel les interlocuteurs s’inscrivent. Ces repérages autorisent la pleine restitution par le sujet-récepteur des dimensions dont les représentations sont une épure. Ainsi, les phénomènes de focalisation sont des haltes éphémères sur le chemin qui mène à l’abstraction - un mouvement de concentration partant du quadridimensionnel diffus à un bidimensionnel figé mais suggestif, puis filtré à nouveau pour se muer en une ligne abstraite jusqu’au foyer quantique de l’invisible du sens : l’outopos, lieu de l’impossible mise au point, une fissure signifiante dans la représentation, qu’il échoit au récepteur de comblerThis research on word and image - more specifically on the focusing phenomena at stake in language and painting - mainly has an impact in the field of semiotics. The systematic cross-examination of both linguistic and pictorial signs leads to an in-depth reflection on the vaster notions of time and space. The two entities are distinct only in the artificial theoretical fields of science, due to epistemological constraints which alternatively make us blind to movement or space. Concretely, we never experience time without space or space without time, there is only movement and it is four-dimensional. Poetry taken in its widest acceptation - i. E. A one-dimensional linguistic representation - is the kinetic ex-pression of an internal invisible flow of consciousness. Conversely, painting is the two-dimensional fixation and external reordering of the self. Focusing phenomena occur at all representational levels but also when moving from the more concrete to the more abstract: the linguistic line. In a way, representations act as inter-subjectivity’s measuring tools. They act as landmarks towards which interlocutors’ shifting environment is targeted and from which it derives. Each time the subject compensates for the missing dimension(s) in the representation, whether linguistic or pictorial. I therefore define focusing phenomena as the momentous but ephemeral halts in an ever-shifting flow towards the more abstract and back. Fixing those miscellaneous ideas and impressions requires such illusory breaks, while meaning on the whole never occurs in one specific identifiable spot; it is an u-topos, the only genuine abstraction. Representations thus always deictically point to an intrinsic lacuna: what they signify is neither visual nor linguistic; literally, the focus is a hole in the fabric left for the interpreter to fill
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Perron, Pierre, e Gabriel Rodríguez. "GLS detrending, efficient unit root tests and structural change". Economía, 2012. http://repositorio.pucp.edu.pe/index/handle/123456789/117533.
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We extend the class of M-tests for a unit root analyzed by Perron and Ng (1996) and Ng and Perron (1997) to the case where a change in the trend function is allowed to occur at an unknown time. These tests M(GLS) adopt the GLS detrending approach of Dufour and King (1991) and Elliott, Rothenberg and Stock (1996) (ERS). Following Perron (1989), we consider two models: one allowing for a change in slope and the other for both a change in intercept and slope. We derive the asymptotic distribution of the tests as well as that of the feasible point optimal tests PT(GLS) suggested by ERS. The asymptotic critical values of the tests aretabulated. Also, we compute the non-centrality parameter used for the local GLS detrending that permits the tests to have 50% asymptotic power at that value. We show that the M(GLS) and PT(GLS) tests have an asymptotic power function close to the power envelope. An extensive simulation study analyzes the size and power in finite samples under various methods to select the truncation lag for the autoregressive spectral density estimator. An empirical application is also provided.Extendemos los estadísticos tipo M para una raíz unitaria analizados por Perron y Ng (1996) y Ng y Perron (2001) al caso donde se permite que el cambio en la función de tendencia ocurra en un punto desconocido. Estos estadísticos (MGLS) adoptan el enfoque GLS para eliminar la tendencia desarrollado por Elliott et al. (1996) (ERS) siguiendo los resultados de Dufour y King (1991). Siguiendo a Perron (1989), consideramos dos modelos: uno que permite un cambio en la pendiente y otro que permite tanto un cambio en el intercepto como en la pendiente. Derivamos las distribuciones asintóticas así como el estadístico óptimo factible en un punto de la hipótesis alternativa (PT GLS) sugerido por ERS. También computamos el parámetro de no centralidad utilizado por el enfoque GLS local a la unidad con el fin de eliminar la tendencia que permite que el estadístico PT GLS tenga 50% de potencia asintótica en ese valor. Asimismo, se han tabulado los valores críticos asintóticos de los estadísticos. Mostramos que los estadísticos MGLS y PT GLS tienen una función de potencia asintótica cercana a la envolvente de potencia. Un estudio de simulación analiza el tamaño y potencia en muestras finitas bajo varios métodos para seleccionar la truncación para estimar la densidad espectral autorregresiva. Finalmente, también se presenta una aplicación empírica.
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Berthomieu, Alain. "Métriques de Quillen et suite spectrale de Leray". Paris 11, 1993. http://www.theses.fr/1993PA112199.
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Soient x et y deux variétés kahleriennes compactes telles qu'il existe une submersion holomorphe pi de x sur y. Soit xi une fibre vectorielle holomorphe hermitien sur x et r. Le faisceau image directe de xi par pi. D'après Knudsen et Mumford, les inverses l(xi) et l(r. ) Des déterminants des cohomologies de xi et r. Sont canoniquement isomorphes. Une construction explicite de cet isomorphisme peut être déduite de la suite spectrale de Leray. Dans la première partie de la thèse, sous l'hypothèse que r. Est localement libre, On établit une formule de comparaison des métriques de Quillen sur l(xi) et l(r. ) En termes d'intégrales de formes de transgression de Bott-chern et de formes de torsion analytique de Bismut-Kohler. Dans la seconde partie de la thèse, on étudie le cas du fibre de Poincaré p sur le produit d'un tore complexe t et de son dual t, la submersion étant ici la projection sur t. Les faisceaux image directe de p ne sont pas localement libres. Le modèle a suivre est alors donne par un travail de Bismut-Lebeau sur les immersions de variétés complexes: On montre dans notre cas une certaine compatibilite entre les formules de Bismut-Lebeau et de la 1ere partie. Un calcul explicite montre que tous les termes s'annulent
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Robin-Clerc, Michèle Carmona Michel. "Une analyse architecturale et urbaine de l'agglomeration de Pointe-à-Pitre et des abymes en Guadeloupe du point de vue des risques majeurs et du developpement durable". Paris : Université Paris Sorbonne - Paris IV, 2008. http://www.theses.paris4.sorbonne.fr/these_robin_clerc/paris4/2006/these_robin_clerc/html/index-frames.html.
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