Tesis sobre el tema "Singular functions"
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Penso, Valentina <1988>. "Singular Sets of Generalized Convex Functions". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/7882/1/Penso_Valentina_Tesi.pdf.
Texto completoKytmanov, Aleksandr, Simona Myslivets y Nikolai Tarkhanov. "Removable singularities of CR functions on singular boundaries". Universität Potsdam, 2000. http://opus.kobv.de/ubp/volltexte/2008/2583/.
Texto completoNeuner, Christoph. "Generalized Titchmarsh-Weyl functions and super singular perturbations". Licentiate thesis, Stockholms universitet, Matematiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-113389.
Texto completoVutha, Amit C. "Normal Forms and Unfoldings of Singular Strategy Functions". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385461288.
Texto completoRaeisidehkordi, Hengameh. "Finsler Transnormal Functions and Singular Foliations of Codimension 1". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/45/45131/tde-05042018-210826/.
Texto completoAs funções transnormais são a generalização da função de distância e este tópico tem algumas aplicações em Física e no mundo real. Neste trabalho, alguns resultados do caso riemanniana para o Finsler são generalizados. Alem disso, alguns fenômenos novos que ocorrem apenas nos espaços de Finsler são discutidos. Para ter uma melhor compreensão, são fornecidos certos exemplos com base nos resultados mencionados nos espaços de Randers. Além disso, algumas aplicações sobre propagação de ondas de fogo e água são introduzidas.
Coiculescu, Ion. "Dynamics, Thermodynamic formalism and Perturbations of Transcendental Entire Functions of Finite Singular Type". Thesis, University of North Texas, 2005. https://digital.library.unt.edu/ark:/67531/metadc4783/.
Texto completoNguyen, Van Luong. "On regular and singular points of the minimum time function". Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3424058.
Texto completoLa presente tesi è dedicata allo studio della regolarità della funzione tempo minimo Τ per sistemi di controllo sia lineari che non lineari in dimensione finita. Si considerano dapprima problemi non lineari in cui la condizione di controllabilità detta di Petrov è soddisfatta. Come è ben noto, in questo caso Τ è localmente Lipschitziana e quindi è differenziabile quasi ovunque. In generale, Τ non è differenziabile nei punti dai quali escono diverse traiettorie ottimali e inoltre il fatto che Τ è differenziabile in un punto non garantisce che lo sia in un intorno (l'insieme dei punti di differenziabilità non è aperto). Imponendo alcune condizioni di regolarità sulla dinamica, si dimostra che se il sottodifferenziale prossimale di Τ è non vuoto in un punto x, allora Τ è differenziabile in tutto un intorno di x. La tecnica usata consiste nel derivare relazioni di sensitività per il sottodifferenziale prossimale di Τ e nell'escludere la presenza di punti coniugati dove tale sottodifferenziale è non vuoto. In secondo luogo si studia la regolarità di Τ sotto condizioni di controllabilità più generali, tali da non imporre la Lipschitzianità. In questo caso il bersaglio è l'origine e la dinamica è -- principalmente -- lineare a coefficienti costanti. Si identificano alcuni insiemi singolari (cioè dove Τ non è differenziabile), ad esempio l'insieme dove Τ non è Lipschitz e l'insieme dei punti dove l'insieme raggiungibile presenta più di un versore normale, e si dimostrano risultati di rettificabilità, in questo modo mostrando che sono ``molto piccoli''. Come conseguenza si ricavano ulteriori risultati di regolarità per Τ, fra i quali la regolarità SBV e la differenziabilità e l'analiticità in aperti il cui complementare ha dimensione inferiore a quella dello spazio degli stati. La tecnica usata è basata principalmente su un'analisi accurata degli zeri della cosiddetta funzione di switching.
Schürmann, Jörg. "Topology of singular spaces and constructible sheaves /". Basel [u.a.] : Birkhäuser, 2003. http://www.loc.gov/catdir/toc/fy0803/2003062963.html.
Texto completoPham, Hoang. "A perturbation solution for forced response of systems displaying eigenvalue veering and mode localization". Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/19120.
Texto completoDu, Zhe. "A description of discrete spectrum of (spin(10,2) x SL(2, R)) and singular theta correspondence /". View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?MATH%202009%20DU.
Texto completoLuther, Uwe. "Approximation Spaces in the Numerical Analysis of Cauchy Singular Integral Equations". Doctoral thesis, Universitätsbibliothek Chemnitz, 2005. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200500895.
Texto completoGrudsky, Serguey y Nikolai Tarkhanov. "Conformal reduction of boundary problems for harmonic functions in a plane domain with strong singularities on the boundary". Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2012/5774/.
Texto completoHirose, Toru. "The reduction of quantum many-body systems with symmetry and the boundary behavior of wave functions at singular configurations". 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/148782.
Texto completoHanine, Abdelouahab. "Cyclic vectors in some spaces of analytic functions". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4725.
Texto completoIn this thesis, we study the cyclicity problem in some spaces of analytic functions on the open unit disc. We focus our attention on Korenblum type spaces and on weighted Bergman type spaces. First, we use the technique of premeasures, introduced and developed by Korenblum in the 1970-s and the 1980-s, to give a characterization of cyclic functions in the Korenblum type spaces. In particular, we give a positive answer to a conjecture by Deninger. Second, we use the so called resolvent transform method to study the cyclicity of the one point mass singular inner function in weighted Bergman type spaces, especially with weights depending on the distance to a subset of the unit circle
Sendov, Hristo. "Variational Spectral Analysis". Thesis, University of Waterloo, 2000. http://hdl.handle.net/10012/1089.
Texto completoGokay, Kemal. "Contact Mechanics Of Graded Materials With Two Dimensional Material Property Variations". Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606527/index.pdf.
Texto completokay, Kemal M.S., Department of Mechanical Engineering Supervisor: Asst. Prof. Dr. Serkan Dag September 2005, 62 pages Ceramic layers used as protective coatings in tribological applications are known to be prone to cracking and debonding due to their brittle nature. Recent experiments with functionally graded ceramics however show that these material systems are particularly useful in enhancing the resistance of a surface to tribological damage. This improved behavior is attributed to the influence of the material property gradation on the stress distribution that develops at the contacting surfaces. The main interest in the present study is in the contact mechanics of a functionally graded surface with a two &ndash
dimensional spatial variation in the modulus of elasticity. Poisson&rsquo
s ratio is assumed to be constant due to its insignificant effect on the contact stress distribution [30]. In the formulation of the problem it is assumed that the functionally graded surface is in frictional sliding contact with a rigid flat stamp. Using elasticity theory and semi-infinite plane approximation for the graded medium, the problem is reduced to a singular integral equation of the second kind. Integral equation is solved numerically by expanding the unknown contact stress distribution into a series of Jacobi polynomials and using suitable collocation points. The developed method is validated by providing comparisons to a closed form solution derived for homogeneous materials. Main numerical results consist of the effects of the material nonhomogeneity parameters, coefficient of friction and stamp size and location on the contact stress distribution.
Quellmalz, Michael. "Reconstructing Functions on the Sphere from Circular Means". Universitätsverlag Chemnitz, 2019. https://monarch.qucosa.de/id/qucosa%3A38406.
Texto completoDie vorliegende Arbeit beschäftigt sich mit dem Problem der Rekonstruktion einer Funktion f, die auf der d-dimensionalen Einheitssphäre definiert ist, anhand ihrer Mittelwerte entlang von Schnitten mit Hyperebenen. Im Fall d=2 sind diese Schnitte genau die Kreise auf der Sphäre. In vielen tomografischen Anwendungen sind aber nur eingeschränkte Daten verfügbar. Deshalb besteht das Interesse an der Rekonstruktion der Funktion f nur anhand der Mittelwerte bestimmter Familien von Hyperebenen-Schnitten der Sphäre. Verglichen mit dem Fall vollständiger Daten birgt dieses Problem mehrere Herausforderungen und Fragen. Die erste ist die Injektivität, also können alle Funktionen anhand der gegebenen Daten eindeutig rekonstruiert werden? Weitere Punkte sind die die Frage nach der Stabilität der Rekonstruktion, welche eng mit einer Beschreibung der Bildmenge verbunden ist, sowie der praktische Bedarf an Rekonstruktionsmethoden und -algorithmen. Diese Arbeit gibt einen detaillierten Überblick und Antworten auf diese Fragen für verschiedene Familien von Hyperebenen-Schnitten, angefangen von vertikalen Schnitten über Schnitte mit Hyperebenen durch einen festen Punkt sowie Kreisbögen. Solche Rekonstruktionsprobleme treten in diversen Anwendungen auf wie der Bildgebung mittels Compton-Kamera, Magnetresonanztomografie, fotoakustischen Tomografie, Radar-Bildgebung sowie der Tomografie seismischer Wellen. Weiterhin nutzen wir unsere Ergebnisse über sphärische Mittelwerte, um eine Singulärwertzerlegung für die Kegelstrahltomografie zu zeigen.
Filip, Tomić. "A new type of regularity with applications to the wave front sets". Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2016. https://www.cris.uns.ac.rs/record.jsf?recordId=101444&source=NDLTD&language=en.
Texto completoU ovoj tezi definišemo novu klasu glatkih funkcija i izučavamo njihove osnovne osobine. Pokazujemo da naše klase imaju svojsto algebre kao i da su zatvorene u odnosu na delovanje operatora izvoda konačnog reda.Sta više, konstruišemo diferencijalne operatore beskonačnog reda i to nas dovodi do definicije ultradiferencijabilnih klasa funkcija. Takode dokazujemo osobinu zatvorenosti u odnosu na inverze, i taj rezultat je najvažniji deo u dokazu glavne teoreme koja je formulisana u poslednjoj glavi. Koristeći tehnike mikrolokalne analize, uvodimo i izučavamo odgovarajuće talasne frontove, i pokazujemo odgovarajuća tvrdjenja vezana za singularni nosač distribucije. Naš glavni rezultat pokazuje kako se prostiru singulariteti rešenja linearnih parcijalnih diferencijalnih jednačina u okviru naše regularnosti.
Pukhtaievych, Roman. "Periodic and hypercomplex potentials. Properties and applications". Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3425759.
Texto completoQuesta Tesi si occupa dello studio di problemi al contorno e analizza due linee di ricerca. La prima riguarda lo studio di perturbazioni di problemi al contorno in domini perforati e la sua applicazione all'analisi delle proprieta efficaci dei materiali compositi. Studiamo la dipendenza delle soluzioni di problemi di trasmissione da alcuni parametri e il loro comportamento quando il parametro corrispondente alla dimensione delle inclusioni tende a zero e gli altri parametri tendono ad alcuni valori fissati. In seguito, applichiamo i nostri risultati allo studio della conduttivita efficace di composti periodici. Analizziamo anche il comportamento della soluzione del problema di Dirichlet per l'equazione di Poisson nell'insieme di R3 che consiste in una serie periodica di cilindri in caso di perturbazione della forma della sezione trasversale dei cilindri e la struttura periodica. Inoltre, applichiamo i nostri risultati per studiare il comportamento della permeabilita longitudinale di una serie periodica di cilindri rispetto a tale perturbazione. La seconda parte della Tesi riguarda lo sviluppo di strumenti per risolvere problemi al contorno per funzioni che assumono valore in algebre di Banach commutative. In particolare, studiamo le proprieta dei residui logaritmici delle funzioni monogeniche (continue e differenziabili nel senso di Gateaux) e il comportamento di certi integrali di tipo Cauchy sulla frontiera dell'insieme di definizione. La Tesi si suddivide in due parti ed è organizzata come segue. La parte I è composta da tre capitoli. Nel capitolo 1 studiamo il comportamento asintotico delle soluzioni di problemi di trasmissione (ideale e nonideale) singolarmente perturbati in un dominio periodicamente perforato. Nel capitolo 2 applichiamo i risultati del capitolo 1 per studiare il comportamento asintotico della conduttivita termica efficace di un composto periodico a due fasi diluito. Il capitolo 3 è dedicato allo studio del comportamento della permeabilita longitudinale di una serie periodica di cilindri quando perturbiamo la forma della sezione trasversale dei cilindri e la struttura periodica. La parte II è composta da due capitoli. Nel capitolo 4 introduciamo un'algebra commutativa tridimensionale su C con un radicale unidimensionale e studiamo i residui logaritmici delle funzioni monogeniche in questa algebra. Il capitolo 5 è dedicato allo studio di un analogo dell'integrale di Cauchy che assume valore nell'algebra menzionata e dei suoi valori limite sulla frontiera del dominio di definizione. Alla fine della Tesi, abbiamo inserito tre appendici con alcuni risultati che abbiamo utilizzato nella Tesi.
Tang, Hongzhen. "Efficient analysis for nonlinear effects and power handling capability in high power HTSC thin film microwave circuits". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0015/NQ56679.pdf.
Texto completoSalles, Nicolas. "Calcul des singularités dans les méthodes d’équations intégrales variationnelles". Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112164/document.
Texto completoThe implementation of the boundary element method requires the evaluation of integrals with a singular integrand. A reliable and accurate calculation of these integrals can in some cases be crucial and difficult. The proposed method is a recursive reduction of the dimension of the integration domain and leads to a representation of the integral as a linear combination of one-dimensional integrals whose integrand is regular and that can be evaluated numerically and even explicitly. The 3-D Helmholtz equation is used as a model equation, but these results can be used for the Laplace and the Maxwell equations in 3-D. The integrand is decomposed into a homogeneous part and a regular part, the latter can be treated by conventional numerical integration methods. For the discretization of the domain we use planar triangles, so we evaluate integrals over the product of two triangles. The technique we have developped requires to distinguish between several geometric configurations, that's why we treat separately the case of triangles in the same plane, in secant planes and in parallel planes
Tu, Xuemin. "Enhanced Singular Function Mortar Finite Element Methods". Digital WPI, 2002. https://digitalcommons.wpi.edu/etd-theses/947.
Texto completoZhang, Lingsong Marron James Stephen Zhu Zhengyuan Shen Haipeng. "Functional singular value decomposition and multi-resolution anomaly detection". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,1166.
Texto completoTitle from electronic title page (viewed Mar. 27, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Statistics and Operations Research." Discipline: Statistics and Operations Research; Department/School: Statistics and Operations Research.
Cerezo, Graciela M. "Solution Representation and Indentification for Singular neutral Functional Differential Equations". Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/30365.
Texto completoPh. D.
AGOSTI, ABRAMO. "MODELS OF TURBULENCE. APPLICATIONS TO PARTICULATE MIXING INDUCED BY TRAFFIC FLOW IN URBAN AREAS". Doctoral thesis, Università degli Studi di Milano, 2013. http://hdl.handle.net/2434/217169.
Texto completoCerezo, Graciela M. "Numerical approximation and identification problems for singular neutral equations". Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-09052009-040632/.
Texto completoSensi, Mattia. "A Geometric Singular Perturbation approach to epidemic compartmental models". Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/286191.
Texto completoSensi, Mattia. "A Geometric Singular Perturbation approach to epidemic compartmental models". Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/286191.
Texto completoAvila, Leonardo. "Sobre singularidades analíticas de soluções de uma classe de campos vetoriais no Toro". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-30032010-104911/.
Texto completoThe main goal of this work is to study global analytic regularity properties of certain differential operators acting in the torus. A main tool that will be used to achieve our goals are the partial Fourier series, which allow us to characterize objects such as periodic distributions or periodic real analytic functions in terms of the growth of their partial Fourier coefficients
Workalemahu, Tsegaselassie. "Singular Value Decomposition in Image Noise Filtering and Reconstruction". Digital Archive @ GSU, 2008. http://digitalarchive.gsu.edu/math_theses/52.
Texto completoBank, Peter. "Singular control of optional random measures". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2000. http://dx.doi.org/10.18452/14556.
Texto completoIn this thesis, we study the problem of maximizing certain concave functionals on the space of optional random measures. Such functionals arise in microeconomic theory where their maximization corresponds to finding the optimal consumption plan of some economic agent. As an alternative to the well-known methods of Dynamic Programming, we develop a new approach which allows us to clarify the structure of maximizing measures in a general stochastic setting extending beyond the usually required Markovian framework. Our approach is based on an infinite-dimensional version of the Kuhn-Tucker Theorem. The implied first-order conditions allow us to reduce the maximization problem to a new type of representation problem for optional processes which serves as a non-Markovian substitute for the Hamilton-Jacobi-Bellman equation of Dynamic Programming. In order to solve this representation problem in the deterministic case, we introduce a time-inhomogeneous generalization of convexity. The stochastic case is solved by using an intimate relation to the theory of Gittins-indices in optimal dynamic scheduling. Closed-form solutions are derived under appropriate conditions. Depending on the underlying stochastics, maximizing random measures can be absolutely continuous, discrete, and also singular. In the microeconomic context, it is natural to embed the above maximization problem in an equilibrium framework. In the last part of this thesis, we give a general existence result for such an equilibrium.
Hassanpour, Hamid. "Time-frequency based detection of newborn EEG seizure". Thesis, Queensland University of Technology, 2004. https://eprints.qut.edu.au/15853/1/Hamid_Hassanpour_Thesis.pdf.
Texto completoHassanpour, Hamid. "Time-Frequency Based Detection of Newborn EEG Seizure". Queensland University of Technology, 2004. http://eprints.qut.edu.au/15853/.
Texto completoPrescott, Thomas Paul. "Large-scale layered systems and synthetic biology : model reduction and decomposition". Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:205a18fb-b21f-4148-ba7d-3238f4b1f25b.
Texto completoMusolino, Paolo. "Singular perturbation and homogenization problems in a periodically perforated domain. A functional analytic approach". Doctoral thesis, Università degli studi di Padova, 2012. http://hdl.handle.net/11577/3422452.
Texto completoQuesta Tesi è dedicata all'analisi di problemi di perturbazione singolare e omogeneizzazione nello spazio Euclideo periodicamente perforato. Studiamo il comportamento delle soluzioni di problemi al contorno per le equazioni di Laplace, di Poisson e di Helmholtz al tendere a 0 di parametri legati al diametro dei buchi o alla dimensione delle celle di periodicità. La Tesi è organizzata come segue. Nel Capitolo 1, presentiamo due costruzioni note di un analogo periodico della soluzione fondamentale dell'equazione di Laplace, e introduciamo potenziali di strato e di volume periodici per l'equazione di Laplace e alcuni risultati basilari di teoria del potenziale periodica. Il Capitolo 2 è dedicato a problemi di perturbazione singolare e omogeneizzazione per le equazioni di Laplace e Poisson con condizioni al bordo di Dirichlet e Neumann. Nel Capitolo 3 consideriamo il caso di problemi al contorno di Robin (lineari e nonlineari) per l'equazione di Laplace, mentre nel Capitolo 4 analizziamo problemi di trasmissione (lineari e nonlineari). Nel Capitolo 5 applichiamo i risultati del Capitolo 4 al fine di provare l'analiticità della conduttività effettiva di un composto periodico. Il Capitolo 6 è dedicato alla costruzione di un analogo periodico della soluzione fondamentale dell'equazione di Helmholtz e dei corrispondenti potenziali di strato. Nel Capitolo 7 raccogliamo alcuni risultati di teoria spettrale per l'operatore di Laplace in domini periodicamente perforati. Nel Capitolo 8 studiamo problemi di perturbazione singolare e di omogeneizzazione per l'equazione di Helmholtz con condizioni al contorno di Neumann. Nel Capitolo 9 consideriamo problemi di perturbazione singolare e di omogeneizzazione con condizioni al contorno di Dirichlet per l'equazione di Helmholtz, mentre nel Capitolo 10 studiamo problemi al contorno di Robin (lineari e nonlineari). Il Capitolo 11 è dedicato allo studio di potenziali di strato periodici per operatori differenziali generali del secondo ordine a coefficienti costanti. Alla fine della Tesi abbiamo incluso delle Appendici con alcuni risultati utilizzati.
Oikonomopoulos, Dimitrios [Verfasser]. "Functional Inequalities and Heat Kernel Asymptotics on Some Classes of Singular Riemannian Manifolds / Dimitrios Oikonomopoulos". Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/1200019814/34.
Texto completoTanja, Krunić. "Numeričke procedure u definisanju pravilnih rešenja zakona održanja". Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2016. https://www.cris.uns.ac.rs/record.jsf?recordId=101094&source=NDLTD&language=en.
Texto completoWe consider conservation laws with a flux discontinuity at x = 0, where the flux parts from both left and right hand side of x = 0 have at most one extreme on the observed domain. The first chapter provides elementary definitions and theorems..The second chapter refers to hyperbolic systems of conservation laws, their solutions, and numerical procedures. The third chapter is devoted to discrete shock profiles. The fourth chapter describes conservation laws with discontinuous flux functions and provides basic information upon known results in this field. In the fifth chapter, we first analyse the two-flux equation when both flux parts have a minimum and cross at most at one point in the interior of the domain. Using a flux regularization on the interval [−ε, ε], for ε > 0 small enough, we show the existence of discrete shock profiles for Godunov’s scheme for conservation laws with discontinuous flux functions. We also define a discrete entropy condition accordingly, and use the existence of an entropy discrete shock profile as an entropy criterion for shocks. Then we analyse the same problem in the case when the flux part on the left of x = 0 has a maximum and the part on the right of x = 0 has a minimum, whereas the fluxes cross at the edges of the interval. We derive a more general discrete entropy condition in this case. We provide several numerical examples in both of the above mentioned flux cases. All the presented numerical results are obtained using a program written in Mathematica. Finally, in chapter six, we prove the existence of singular shock waves in the case when the graph of one of the flux parts is above the graph of the other one on the entire domain. For that purpose, we use the shadow wave technique. At the end of this chapter, we provide a numerical verification of the obtained singular solution.
Ouoba, Mahamadi. "Asymptotic expansion of the expected discounted penalty function in a two-scalestochastic volatility risk model". Thesis, Mälardalens högskola, Akademin för utbildning, kultur och kommunikation, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-26100.
Texto completoKerker, Mohamed Amine. "Sur le problème de Cauchy singulier". Thesis, Reims, 2013. http://www.theses.fr/2013REIMS005.
Texto completoThis thesis deals with the singular Cauchy problem in the complex domain. We study the singularities of the solution of the problem for three classes of partial differential equations. This thesis is a continuation of the work initiated by Jean Leray and his school. To describe the singularities of the solution, we seek the solution in the form of asymptotic an expansion of Gauss hypergeometric functions. As the singularities are carried by the hypergeometric functions, the study of the ramification of the solution reduces to that of these functions
Pugliese, Alessandro. "Theoretical and numerical aspects of coalescing of eigenvalues and singular values of parameter dependent matrices". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24730.
Texto completoCommittee Chair: Dieci, Luca; Committee Member: Chow, Shui-Nee; Committee Member: Liu, Yingjie; Committee Member: Loss, Michael; Committee Member: Verriest, Erik.
Hamedani, Ladan. "The Function of Number in Persian". Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20167.
Texto completoJunior, Raimundo Alves LeitÃo. "Regularidade e estimativas geomÃtricas para mÃnimos de funcionais descontÃnuos e singulares". Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11135.
Texto completoConselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
Este trabalho à constituÃdo de duas partes. Na primeira parte estudamos mÃnimos nÃo negativos de funcionais elÃpticos degenerados, ∫ F (X, u, ∇u)dX → min, para nÃcleos variacionais F que sÃo descontÃnuos em u com descontinuidade de ordem ~ X{u>0}. A equaÃÃo de Euler-Lagrange à governada por uma equaÃÃo elÃptica degenerada e nÃo-homogÃnea, com fronteira livre entre as fases positiva e zero do mÃnimo. Mostraremos estimativa gradiente Ãtima e nÃo-degenerescÃncia do mÃnimo. TambÃm trataremos de propriedades de regularidade fracas e fortes de fronteira livre. Provaremos que o conjunto {u>0} tem localmente perÃmetro finito e que a fronteira livre reduzida ∂ red {u>0} tem medida Hn-1-total. Para problemas mais especÃficos que aparecem em Jet flows, provaremos que a fronteira livre reduzida à localmente o grÃfico de uma funÃÃo C1,y. Na segunda parte do trabalho forneceremos uma descriÃÃo bastante completa da teoria de regularidade Ãtima para uma famÃlia de problemas de fronteira livre de duas fases, heterogÃneos, y→ min, governados por operadores elÃpticos degenerados e nÃo-lineares. IncluÃdos em tal famÃlia estÃo os problemas de Jet flows heterogÃneos e os problemas de cavidades do tipo Prandtl-Batchelor, y = 0; equaÃÃes elÃpticas degeneradas singulares e sistemas do tipo obstÃculo y =1.VersÃes lineares destes problemas tÃm sido objeto de intensa pesquisa nas Ãltimas quatro dÃcadas ou mais. As contrapartidas nÃo-lineares tratadas neste trabalho introduzem novas e considerÃveis dificuldades, pois a maioria das teorias desenvolvidas anteriormente, tais como fÃrmulas de monotonicidade e de quase monotonicidade nÃo estÃo disponÃveis. Contudo, as soluÃÃes inovadoras desenvolvidas neste trabalho fornecem novas respostas mesmo no contexto clÃssico de equaÃÃes lineares e nÃo-degeneradas.
This work consists of two parts. In the first part we study nonnegative minimizers of general degenerate elliptic functionals, ∫ F (X, u, ∇u)dX → min, for variational kernels F that are discontinuous in ụ with discontinuity of order ~ X{u>0}. The Euler-Lagrange equation is therefore governed by a non-homogeneous, degenerate elliptic equation with free boundary between the positive and the zero phases of the minimizer. We show optimal gradient estimate and nondegeneracy of minima. We also address weak and strong regularity properties of free boundary, ∂ red {u>0}, has H n-1- total measure. For more specific problems that arise in jet flows, we show the reduced free boundary is locally the graph of a C1,y function. In the second part of work we provide a rather complete description of the sharp regularity theory for a family of heterogeneous, two-phase variational free boundary problems, y→ min, ruled by nonlinear, degenerate elliptic operators. Included in such family are heterogeneous jets and cavities problems of Prandtl-Batchelor type, y = 0; singular degenerate elliptic equations and obstacle type systems, y = 1. Linear versions of these problems have been subjects of intense research for the past four decades or so. The nonlinear counterparts treated in this present work introduce substantial new difficulties since the most of the classical theories developed earlier, such that as monotonicity and almost monotonicity formulae, are no longer available. Nonetheless, the innovative solutions designed in this work provide new answers even in the classical context of linear, nondegenerate equations.
Patiño, Diego. "Pilotage des cycles limites dans les systèmes dynamiques hybrides : application aux alimentations électriques statiques". Electronic Thesis or Diss., Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL013N.
Texto completoThis work deals with limit cycle control for one particular class of hybrid dynamical systems (HDS): The cyclic switched systems. The HDS were born because the traditional dynamical models were not able to describe complex behaviors and most of all, behaviors with discontinuities. From an application point of view, one important class of HDS depicts a cyclic behavior in steady state. The main characteristic of these systems is that the operation point cannot be maintained: It does not exist a control that maintains the system on a desired operation point. However, this point can be obtained in average by turning into its neighborhood. Thus, a cycle is produced by switching among the system modes. A switched control law must satisfy stability and dynamic performance. Moreover, criteria related to the waveform must be verified. Nowadays, few methods take into account the cyclic behavior of the system. In this research, some generic methods are studied. They show good performance for controlling the cyclic switched systems. The proposed algorithms can be implemented in real-time. The approaches are based on an affine non-linear model of the system whose control explicitly appears. Two control methods are considered: i) A predictive control, ii) An optimal control. Since the predictive control is a good choice for tracking, it will be able to maintain the system in a cycle. The optimal control yields solutions that can be applied to the transients. Some experiments with both control methods applied to the power converters are shown. These tests were carried out not only in our laboratory (CRAN), but also in other laboratories as part of the HYCON excellence network
Franz, Sebastian. "Uniform Error Estimation for Convection-Diffusion Problems". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-133017.
Texto completoDavis, Paige N. "Localised structures in some non-standard, singularly perturbed partial differential equations". Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/201835/1/Paige_Davis_Thesis.pdf.
Texto completoTang, Ying. "Stability analysis and Tikhonov approximation for linear singularly perturbed hyperbolic systems". Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT054/document.
Texto completoSystems modeled by partial differential equations (PDEs) with infinite dimensional dynamics are relevant for a wide range of physical networks. The control and stability analysis of such systems become a challenge area. Singularly perturbed systems, containing multiple time scales, often occur naturally in physical systems due to the presence of small parasitic parameters, typically small time constants, masses, inductances, moments of inertia. Singular perturbation was introduced in control engineering in late $1960$s, its assimilation in control theory has rapidly developed and has become a tool for analysis and design of control systems. Singular perturbation is a way of neglecting the fast transition and considering them in a separate fast time scale. The present thesis is concerned with a class of linear hyperbolic systems with multiple time scales modeled by a small perturbation parameter. Firstly we study a class of singularly perturbed linear hyperbolic systems of conservation laws. Since the system contains two time scales, by setting the perturbation parameter to zero, the two subsystems, namely the reduced subsystem and the boundary-layer subsystem, are formally computed. The stability of the full system implies the stability of both subsystems. However a counterexample is used to illustrate that the stability of the two subsystems is not enough to guarantee the full system's stability. This shows a major difference with what is well known for linear finite dimensional systems. Moreover, under certain conditions, the Tikhonov approximation for such system is achieved by Lyapunov method. Precisely, the solution of the slow dynamics of the full system is approximated by the solution of the reduced subsystem for sufficiently small perturbation parameter. Secondly the Tikhonov theorem is established for singularly perturbed linear hyperbolic systems of balance laws where the transport velocities and source terms are both dependent on the perturbation parameter as well as the boundary conditions. Under the assumptions on the continuity for such terms and under the stability condition, the estimate of the error between the slow dynamics of the full system and the reduced subsystem is the order of the perturbation parameter. Thirdly, we consider singularly perturbed coupled ordinary differential equation ODE-PDE systems. The stability of both subsystems implies that of the full system where the perturbation parameter is introduced into the dynamics of the PDE system. On the other hand, this is not true for system where the perturbation parameter is presented to the ODE. The Tikhonov theorem for such coupled ODE-PDE systems is proved by Lyapunov technique. Finally, the boundary control synthesis is achieved based on singular perturbation method. The reduced subsystem is convergent in finite time. Boundary control design to different applications are used to illustrate the main results of this work
Hofmann, Bernd y Wolfersdorf Lothar von. "New results on the degree of ill-posedness for integration operators with weights". Universitätsbibliothek Chemnitz, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200800545.
Texto completoJakaitytė, 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.
Texto completoThe 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.
Ramos, Anthony Kojo. "Forecasting Mortality Rates using the Weighted Hyndman-Ullah Method". Thesis, Mälardalens högskola, Akademin för utbildning, kultur och kommunikation, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-54711.
Texto completoITAKURA, Fumitada, Kazuya TAKEDA y Hani C. YEHIA. "An Acoustically Oriented Vocal-Tract Model". Institute of Electronics, Information and Communication Engineers, 1996. http://hdl.handle.net/2237/15049.
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