Download or read book Contribution la r solution des quations de Maxwell harmonique par une m thode num rique hybride written by Paul Soudais and published by . This book was released on 1996 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contribution la r solution des quations de Maxwell harmoniques par une m thode num rique hybride written by Paul Soudais and published by . This book was released on 1995 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'étude porte sur le développement d'une méthode numérique pour les calculs d'électromagnétisme sur des objets tridimensionnels (3D) places dans un milieu non borne. Les objets à étudier sont composés d'un ensemble quelconque de domaines parfaitement conducteurs et diélectriques anisotropes. Ce problème de diffraction est traite par une formulation hybride: équations intégrales pour le problème extérieur, équations locales pour le problème intérieur des domaines diélectriques. Deux formulations équivalentes du problème couple sont écrites. Ces deux formulations conduisent à une matrice du système linéaire discrétisé complexe symétrique. Une solution est donnée pour éviter le problème des fréquences irrégulières inhérent aux équations intégrales. Un traitement spécial par condition de transmission impédantielle est développé pour modéliser des domaines diélectriques minces internes. Le traitement des parties métalliques minces est aussi introduit. La formulation est discrétisée par éléments finis P1. Nous avons écrit un algorithme itératif efficace pour la résolution du système linéaire pour un grand nombre de seconds membres. Nous avons développé un code de calcul (code harmonique pour l'électromagnétisme 3D, HEM3D) qui est le résultat de cette étude et permet de la valider. Des validations sont données sur des objets conducteurs, diélectriques ou mixtes (conducteurs et diélectriques isotropes et anisotropes). La réalisation d'une version du code sur machine parallèle à mémoire distribuée a permis de vérifier l'intérêt de cette méthode sur ces ordinateurs

Download or read book R solution num rique des quations de Maxwell harmoniques par une m thode d l ments finis discontinus written by Philippe Helluy and published by . This book was released on 1994 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse porte sur la résolution théorique et numérique des équations de Maxwell dans le domaine temporel ou fréquentiel. Dans une première partie, on démontre l'existence et l'unicité mathématique de la solution du problème d'évolution. On s'intéresse également au comportement asymptotique en temps de cette solution lorsque le second membre des équations est sinusoïdal en temps. L'approche utilisée fait appel à la théorie des systèmes hyperboliques linéaires du premier ordre, au théorème de Hille-Yosida, aux principes d'amplitude limite et d'absorption limite, ainsi qu'à des théorèmes de traces (dans le cas du problème aux limites). Dans un second temps, on développe une approximation par éléments finis discontinus du problème fréquentiel, basée sur une décomposition de la matrice des flux en partie positive et négative (méthode de Flux-Splitting). Cette approche autorise l'utilisation de maillages totalement déstructurés. Une étude d'erreur lorsque le pas h du maillage tend vers zéro est proposée. Un algorithme itératif de résolution du problème discret, basé sur une décomposition de domaine sans recouvrement, est ensuite décrit. On démontre sa convergence vers l'unique solution discrète. L'implémentation sur un ordinateur à architecture massivement parallèle (ipsc 860) a été réalisée. Enfin, on construit une équation intégrale adaptée à la méthode, pour la résolution des problèmes en domaine non borné. Des expériences numériques sont décrites dans le cas d'éléments finis de type p#0 (approximation constante par élément).

Download or read book ETUDE MISE EN OEUVRE ET OPTIMISATION D UNE METHODE ELEMENTS FINIS POUR LA RESOLUTION DES EQUATIONS DE MAXWELL EN HYPOTHESE HARMONIQUE written by Hélène Fourment-Gaible and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: CE MEMOIRE EST CONSACRE A L'ETUDE NUMERIQUE D'UNE FORMULATION MATHEMATIQUE, PERMETTANT LE CALCUL DU CHAMP ELECTROMAGNETIQUE DIFFRACTE PAR UNE STRUCTURE DIELECTRIQUE COMPLEXE, SOUMISE A UNE ONDE INCIDENTE PLANE. LE PROBLEME CONSISTE A CONSTRUIRE LA SOLUTION DES EQUATIONS DE MAXWELL EN REGIME HARMONIQUE DANS UN DOMAINE BORNE QUI SOIT LA RESTRICTION DE LA SOLUTION DANS TOUT L'ESPACE. LA METHODE UNIMOMENT CLASSIQUE CONSTITUE UNE APPROCHE POSSIBLE, MAIS TIENT EFFECTIVEMENT COMPTE DU CARACTERE BIDIMENSIONNEL D'UN PROBLEME. POUR REMEDIER A CELA, TOUT EN GARDANT L'ASPECT MIXTE DE CETTE METHODE, ON INTRODUIT D'UNE PART DES ELEMENTS FINIS MIXTES, QUI PERMETTENT LA PRISE EN COMPTE NATURELLE DES CONDITIONS D'INTERFACE, ET D'AUTRE PART UNE METHODE DE RACCORDEMENT SUR LA FRONTIERE REGULIERE BORNANT LE DOMAINE. L'APPROXIMATION ELEMENTS FINIS CONSIDEREE CONDUIT A LA RESOLUTION DE SYSTEMES LINEAIRES COMPLEXES SYMETRIQUES, D'ORDRE ELEVE. DEUX ALGORITHMES ITERATIFS, LE BI-GRADIENT CONJUGUE ET LE GRADIENT CONJUGUE CARRE SONT COMPARES. AFIN D'ACCELERER LA CONVERGENCE DE CES METHODES, DIVERS TYPES DE PRECONDITIONNEMENT SONT ENVISAGES. PAR AILLEURS, DANS L'OPTIQUE D'UN STOCKAGE PAR ELEMENT, L'ALGORITHME DE POWELL ET WELSH EST ADAPTE: IL PERMET D'AUGMENTER LE DEGRE DE VECTORISATION. POUR MINIMISER LE COUT INFORMATIQUE, LA VALIDATION DE LA METHODE A ETE REALISEE SUR DES CAS TESTS BIDIMENSIONNELS, DE SOLUTION ANALYTIQUE CONNUE. ENFIN, LES RESULTATS DES EXPERIENCES NUMERIQUES MENEES SUR DEUX CIBLES DEFINIES AU WORKSHOP JINA'90 SONT EN ACCORD AVEC CEUX OBTENUS PAR D'AUTRES APPROCHES.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book African Doctorates in Mathematics written by and published by Lulu.com. This book was released on 2007 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a catalogue of over 2000 doctoral theses by Africans in all fields of mathematics, including applied mathematics, mathematics education and history of mathematics. The introduction contains information about distribution by country, institutions, period, and by gender, about mathematical density, and mobility of mathematicians. Several appendices are included (female doctorate holders, doctorates in mathematics education, doctorates awarded by African universities to non-Africans, doctoral theses by non-Africans about mathematics in Africa, activities of African mathematicians at the service of their communities). Paulus Gerdes compiled the information in his capacity of Chairman of the African Mathematical Union Commission for the History of Mathematics in Africa (AMUCHMA). The book contains a preface by Mohamed Hassan, President of the African Academy of Sciences (AAS) and Executive Director of the Academy of Sciences for the Developing World (TWAS). (383 pp.)

Download or read book Multiscale Problems Theory Numerical Approximation And Applications written by Alain Damlamian and published by World Scientific. This book was released on 2011-10-13 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this is on the latest developments related to the analysis of problems in which several scales are presented. After a theoretical presentation of the theory of homogenization in the periodic case, the other contributions address a wide range of applications in the fields of elasticity (asymptotic behavior of nonlinear elastic thin structures, modeling of junction of a periodic family of rods with a plate) and fluid mechanics (stationary Navier-Stokes equations in porous media). Other applications concern the modeling of new composites (electromagnetic and piezoelectric materials) and imperfect transmission problems. A detailed approach of numerical finite element methods is also investigated.

Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.

Download or read book Quantum Mechanics Volume 3 written by Claude Cohen-Tannoudji and published by John Wiley & Sons. This book was released on 2019-12-16 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new, third volume of Cohen-Tannoudji's groundbreaking textbook covers advanced topics of quantum mechanics such as uncorrelated and correlated identical particles, the quantum theory of the electromagnetic field, absorption, emission and scattering of photons by atoms, and quantum entanglement. Written in a didactically unrivalled manner, the textbook explains the fundamental concepts in seven chapters which are elaborated in accompanying complements that provide more detailed discussions, examples and applications. * Completing the success story: the third and final volume of the quantum mechanics textbook written by 1997 Nobel laureate Claude Cohen-Tannoudji and his colleagues Bernard Diu and Franck Laloë * As easily comprehensible as possible: all steps of the physical background and its mathematical representation are spelled out explicitly * Comprehensive: in addition to the fundamentals themselves, the books comes with a wealth of elaborately explained examples and applications Claude Cohen-Tannoudji was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris where he also studied and received his PhD in 1962. In 1973 he became Professor of atomic and molecular physics at the Collège des France. His main research interests were optical pumping, quantum optics and atom-photon interactions. In 1997, Claude Cohen-Tannoudji, together with Steven Chu and William D. Phillips, was awarded the Nobel Prize in Physics for his research on laser cooling and trapping of neutral atoms. Bernard Diu was Professor at the Denis Diderot University (Paris VII). He was engaged in research at the Laboratory of Theoretical Physics and High Energy where his focus was on strong interactions physics and statistical mechanics. Franck Laloë was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris. His first assignment was with the University of Paris VI before he was appointed to the CNRS, the French National Research Center. His research was focused on optical pumping, statistical mechanics of quantum gases, musical acoustics and the foundations of quantum mechanics.

Download or read book History of Nonlinear Oscillations Theory in France 1880 1940 written by Jean-Marc Ginoux and published by Springer. This book was released on 2017-04-18 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reveals the French scientific contribution to the mathematical theory of nonlinear oscillations and its development. The work offers a critical examination of sources with a focus on the twentieth century, especially the period between the wars. Readers will see that, contrary to what is often written, France's role has been significant. Important contributions were made through both the work of French scholars from within diverse disciplines (mathematicians, physicists, engineers), and through the geographical crossroads that France provided to scientific communication at the time. This study includes an examination of the period before the First World War which is vital to understanding the work of the later period. By examining literature sources such as periodicals on the topic of electricity from that era, the author has unearthed a very important text by Henri Poincaré, dating from 1908. In this work Poincaré applied the concept of limit cycle (which he had introduced in 1882 through his own works) to study the stability of the oscillations of a device for radio engineering. The “discovery” of this text means that the classical perspective of the historiography of this mathematical theory must be modified. Credit was hitherto attributed to the Russian mathematician Andronov, from correspondence dating to 1929. In the newly discovered Poincaré text there appears to be a strong interaction between science and technology or, more precisely, between mathematical analysis and radio engineering. This feature is one of the main components of the process of developing the theory of nonlinear oscillations. Indeed it is a feature of many of the texts referred to in these chapters, as they trace the significant developments to which France contributed. Scholars in the fields of the history of mathematics and the history of science, and anyone with an interest in the philosophical underpinnings of science will find this a particularly engaging account of scientific discovery and scholarly communication from an era full of exciting developments.

Download or read book Linear and Quasilinear Elliptic Equations written by Olʹga Aleksandrovna Ladyzhenskai︠a︡ and published by . This book was released on 1968 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Topics in Kinetic Theory written by Thierry Passot and published by American Mathematical Soc.. This book was released on 2005 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a variety of topics related to kinetic theory in neutral gases and magnetized plasmas, with extensions to other systems such as quantum plasmas and granular flows. A comprehensive presentation is given for the Boltzmann equations and other kinetic equations for a neutral gas, together with the derivations of compressible and incompressible fluid dynamical systems, and their rigorous justification. Several contributions are devoted to collisionless magnetized plasmas. Rigorous results concerning the well-posedness of the Vlasov-Maxwell system are presented. Special interest is devoted to asymptotic regimes where the scales of variation of the electromagnetic field are clearly separated from those associated with the gyromotion of the particles. This volume collects lectures given at the Short Course and Workshop on Kinetic Theory organized at the Fields Institute of Mathematical Sciences in Toronto during the Spring of 2004.

Download or read book Distributed Optical Fiber Sensing written by Luc Thevenaz and published by Wiley. This book was released on 2012-03 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Serving as a unique, efficient solution to modern demands for security and safety sensing, distributed optical fiber sensing are critical components in areas such as natural disaster prevention and civil engineering. The unique book provides detailed explanations on how to install early warning systems for the prevention of natural disasters, flaws in civil engineering structures (dams, bridges, tunnels), and issues in the oil industry (pipeline leakage detection, off-shore platform anchoring.) Addressing the principles and specificities of distributed fiber sensing, this resource shows different possible implementations, their potential, and their limitations.

Download or read book The Theory of Ionization of Gases by Collision written by Sir John Townsend and published by . This book was released on 1910 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ray Tracing and Beyond written by E. R. Tracy and published by Cambridge University Press. This book was released on 2014-02-27 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This complete introduction to the use of modern ray tracing techniques in plasma physics describes the powerful mathematical methods generally applicable to vector wave equations in non-uniform media, and clearly demonstrates the application of these methods to simplify and solve important problems in plasma wave theory. Key analytical concepts are carefully introduced as needed, encouraging the development of a visual intuition for the underlying methodology, with more advanced mathematical concepts succinctly explained in the appendices, and supporting Matlab and Raycon code available online. Covering variational principles, covariant formulations, caustics, tunnelling, mode conversion, weak dissipation, wave emission from coherent sources, incoherent wave fields, and collective wave absorption and emission, all within an accessible framework using standard plasma physics notation, this is an invaluable resource for graduate students and researchers in plasma physics.

Download or read book Whistlers and Related Ionospheric Phenomena written by Robert A. Helliwell and published by Courier Corporation. This book was released on 2014-06-10 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The investigation of whistlers and related phenomena is a key element in studies of very-low-frequency propagation, satellite communication, the outer ionosphere, and solar-terrestrial relationships. This comprehensive text presents a history of the study of the phenomena and includes all the elements necessary for the calculation of the characteristics of whistlers and whistler-mode signals. An introduction and brief history are followed by a summary of the theory of whistlers and a detailed explanation of the calculation of their characteristics. Succeeding chapters offer a complete atlas of a variety of whistlers, including those observed in satellites and those generated by nuclear explosions; the results of satellite observation of whistler-mode propagation; the method of reducing whistler data and obtaining electron density information; a full atlas of the various kinds of emissions; and an outline and comparison of the theories of generation of emissions.

Download or read book The Finite Element Method for Electromagnetic Modeling written by Gérard Meunier and published by John Wiley & Sons. This book was released on 2010-01-05 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by specialists of modeling in electromagnetism, this book provides a comprehensive review of the finite element method for low frequency applications. Fundamentals of the method as well as new advances in the field are described in detail. Chapters 1 to 4 present general 2D and 3D static and dynamic formulations by the use of scalar and vector unknowns and adapted interpolations for the fields (nodal, edge, face or volume). Chapter 5 is dedicated to the presentation of different macroscopic behavior laws of materials and their implementation in a finite element context: anisotropy and hysteretic properties for magnetic sheets, iron losses, non-linear permanent magnets and superconductors. More specific formulations are then proposed: the modeling of thin regions when finite elements become misfit (Chapter 6), infinite domains by using geometrical transformations (Chapter 7), the coupling of 2D and 3D formulations with circuit equations (Chapter 8), taking into account the movement, particularly in the presence of Eddy currents (Chapter 9) and an original approach for the treatment of geometrical symmetries when the sources are not symmetric (Chapter 10). Chapters 11 to 13 are devoted to coupled problems: magneto-thermal coupling for induction heating, magneto-mechanical coupling by introducing the notion of strong and weak coupling and magneto-hydrodynamical coupling focusing on electromagnetic instabilities in fluid conductors. Chapter 14 presents different meshing methods in the context of electromagnetism (presence of air) and introduces self-adaptive mesh refinement procedures. Optimization techniques are then covered in Chapter 15, with the adaptation of deterministic and probabilistic methods to the numerical finite element environment. Chapter 16 presents a variational approach of electromagnetism, showing how Maxwell equations are derived from thermodynamic principles.