Download or read book Analyse a posteriori et adaptation de maillage pour des probl mes d coulements souterrains et surface libre written by Tarek Ghoudi and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'objectif de cette thèse est d'analyser et de développer des outils numériques adaptatifs efficaces pour les problèmes d'écoulements souterrains et à surface libre, en proposant une nouvelle méthode d'adaptation basée sur les estimateurs d'erreur a posteriori.Dans la première partie, nous appréhendons le cadre mathématique en présentant une analyse détaillée sur l'existence et l'unicité ainsi que la convergence d'erreur dans les différentes normes pour les équations d'écoulement et de transport en milieux poreux.La deuxième partie est dédiée à une nouvelle stratégie d'adaptation de maillage qui consiste à coupler deux stratégies d'adaptation, à savoir la méthode Adapt et la stratégie Newest Vertex bisection (NVB). La première consiste à diviser un triangle en quatre-sous triangles, et la deuxième, consiste à le diviser en joignant le somment opposé à l'arête la plus longue par son milieu. La conformité de notre méthode émane de cette dernière méthode.La troisième partie est consacrée à la démarche empruntée pour valider notre nouvelle stratégie.Celle-ci s'appuie sur le schéma volumes finis "vertex centered", en considérant l'équation elliptique de second ordre à coefficients discontinus afin de prendre en compte les hétérogénéités du milieu. Des tests numériques viendront corroborer l'efficacité de notre méthode, ainsi que la convergence de l'erreur exacte et de l'estimateur, dont le rapport définit l'indice d'efficacité qui est proche de 1.Dans la quatrième partie, nous avons essayé d'optimiser cette stratégie d'adaptation, en concevant une stratégie multi-niveaux pour aboutir enfin à une nouvelle méthode numérique volumes finis-semi lagrangienne. Son principe est de résoudre le problème par une phase volume finis(phase correcteur) précédée d'une phase lagrangienne utilisant la méthode des caractéristiques(phase prédicteur). La phase volumes finis utilise comme flux numérique aux interfaces le vraiflux physique évalué en un état approché aux interfaces, obtenu dans la phase prédicteur par la méthode des caractéristiques. Elle fait également appel à des processus d'interpolation devant être judicieusement choisis.
Download or read book M thodes num riques pour les coulements en milieu poreux written by Vincent Baron and published by . This book was released on 2015 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: On cherche à améliorer l'efficacité de la résolution numérique de l'équation de Richards, qui est une équation parabolique non linéaire utilisée dans la modélisation d'écoulements souterrains. Dans une première partie, on propose une discrétisation DDFV, valable sur maillages généraux, couplée au schéma BDF2 pour la discrétisation du terme instationnaire. Des tests numériques confirment l'ordre élevé de la méthode, ainsi que sa stabilité dans différentes configurations. La deuxième partie s'articule autour des estimations a posteriori par la méthode des flux équilibrés. On obtient une borne supérieure garantie de l'erreur en norme duale, qui fait intervenir des estimateurs intégrés en espace et en temps. Cette borne repose sur une relation d'équilibrage de flux, qui nécessite en pratique de reconstruire des approximations pertinentes des flux continus à partir de la solution approchée. De telles reconstructions adaptées à la discrétisation DDFV-BDF2 sont présentées. Elles incluent un terme de correction spécifique au schéma DDFV, et une réécriture de la formule BDF2 à pas variable sous la forme d'un schéma à un pas. Enfin, on applique numériquement l'estimation précédente en proposant, à maillage fixé, un algorithme d'adaptation du critère d'arrêt des linéarisations et du pas de temps qui vise à équilibrer les différentes sources d'erreur. On analyse l'influence des paramètres de l'algorithme, et on observe le gain en termes de nombre d'itérations de linéarisation et de temps CPU par rapport à une simulation classique.
Download or read book Analyse de stabilit lin aire d coulements tournants en pr sence de surface libre written by Lyes Kahouadji and published by . This book was released on 2011 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce mémoire est une contribution numérique à l'étude des écoulements tournants en présence d'une surface libre. Trois configurations sont étudiées. La première est représentative d'un procédé de croissance cristalline particulier, connu sous le nom de "zone flottante chas d'aiguille", pour laquelle la rotation est utilisée comme un moyen pour minimiser des défauts d'axisymétrie du chauffage. La deuxième configuration étudiée consiste à étudier un écoulement induit par la rotation d'un disque dans une cavité cylindrique en présence d'une surface libre supposée comme plane. Dans la troisième partie, l'étude d'un écoulement induit par la rotation d'un disque dans une cavité cylindrique en présence d'une surface plane se voit enrichie par la prise en compte d'une surface libre déformée. Pour chacune des trois configurations, une analyse de stabilité linéaire est effectuée sur un champ de base supposé stationnaire et axisymétrique
Download or read book ANALYSE NUMERIQUE DES ECOULEMENTS D EAU ET DE LA CONSOLIDATION DES SOLS AUTOUR DE TUNNELS CREUSES DANS L ARGILE written by Mohamed Atwa and published by . This book was released on 1996 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: CETTE THESE ETUDIE LES ECOULEMENTS HYDRAULIQUES AUTOUR DES TUNNELS CREUSES EN TERRAINS AQUIFERES ET ANALYSE LES DEFORMATIONS INDUITES PAR LA CONSOLIDATION DU MASSIF EN PRESENCE DE SOLS COMPRESSIBLES. LE MEMOIRE COMPORTE PLUSIEURS SYNTHESES BIBLIOGRAPHIQUES PORTANT SUR LES PROBLEMES LIES AUX ECOULEMENTS HYDRAULIQUES VERS UN OUVRAGE SOUTERRAIN, SUR LES METHODES DE CALCULS EXISTANTES POUR L'ETUDE DE CES ECOULEMENTS, SUR LA REPONSE HYDROMECANIQUE DES MASSIFS DE SOLS AU CREUSEMENT DE TUNNEL (OBSERVATIONS DE CHANTIERS) ET SUR LES APPROCHES DE CALCULS DEVELOPPEES POUR LE TRAITEMENT DE LA CONSOLIDATION D'UN MASSIF EN PRESENCE D'UNE NAPPE A SURFACE LIBRE. PLUSIEURS ETUDES NUMERIQUES ONT ETE REALISEES A L'AIDE DU PROGICIEL CESAR-LCPC. LA METHODE DES ELEMENTS FINIS A ETE UTILISEE POUR ANALYSER LES ECOULEMENTS AUTOUR DE TUNNELS EN CONDITIONS BIDIMENSIONNELLES ET TRIDIMENSIONNELLES, EN REGIMES PERMANENT ET TRANSITOIRE. DIFFERENTES CONFIGURATIONS SONT ETUDIEES POUR ETUDIER LE ROLE DE L'ANISOTROPIE DE PERMEABILITE DES MASSIFS, LEUR STRATIFICATION, ET LE ROLE DU REVETEMENT DE LA PAROI DU TUNNEL ET DE DIFFERENTES DISPOSITIONS PROPOSEES POUR ATTENUER L'EFFET DES ECOULEMENTS AU FRONT EN CONSTRUCTION. LA REPONSE D'UN MASSIF DE SOLS COMPRESSIBLES AU CREUSEMENT D'UN TUNNEL A ETE ANALYSEE PAR DES CALCULS HYDROMECANIQUES COUPLES ET UN MODELE DE COMPORTEMENT ELASTOPLASTIQUE ADAPTE AUX SOLS ANISOTROPES MELANIE. LA THESE PRESENTE, DE PLUS, UNE CONTRIBUTION AU DEVELOPPEMENT DU CODE DE CALCUL CESAR-LCPC. LA PROGRAMMATION DU MODELE MELANIE DANS CESAR-LCPC A ETE ADAPTEE POUR TRAITER LA VARIATION DE LA CONTRAINTE DE PRECONSOLIDATION ET DES MODULES D'ELASTICITE AVEC LA PROFONDEUR, ET POUR ACTUALISER LE COEFFICIENT DE PERMEABILITE DU SOL EN FONCTION DE LA VARIATION DE L'INDICE DES VIDES. UNE APPROCHE EST, PAR AILLEURS, PROPOSEE POUR LE TRAITEMENT DE LA CONSOLIDATION EN PRESENCE D'UN NIVEAU PIEZOMETRIQUE VARIABLE. CETTE APPROCHE A ETE PROGRAMMEE DANS UN NOUVEAU MODULE S'INTEGRANT DANS LE CODE CESAR-LCPC ET A ETE APPLIQUEE A L'ETUDE DE LA CONSOLIDATION D'UN MASSIF SOUS LE CHARGEMENT D'UNE FONDATION ET SUITE A LA REALISATION D'UN TUNNEL. CE TRAVAIL S'ACHEVE PAR LA MODELISATION D'UN OUVRAGE INSTRUMENTE : LE TUNNEL DE GRIMSBY, CREUSE DANS UN MASSIF ARGILEUX COMPRESSIBLE. LES CALCULS ONT ETE REALISES AVEC DIFFERENTES LOIS DE COMPORTEMENT ET AVEC DIFFERENTES HYPOTHESES POUR LE TRAITEMENT DU COUPLAGE AU-DESSUS DU NIVEAU PIEZOMETRIQUE ; LES RESULTATS ONT ETE COMPARES AUX TASSEMENTS DE SURFACE MESURES SUR UNE PERIODE DE ONZE ANS APRES LA CONSTRUCTION.
Download or read book Abnormal Pressures While Drilling written by Awdesh Tiwari and published by . This book was released on 2015-03 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies the mechanisms and causes of abnormal pressure distribution while drilling.
Download or read book The Use of Analog and Digital Computers in Hydrology Proceedings of the Tucson Symposium written by tucson Symposium on the use of analog and digital computers in hydrology and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Draft International Covenant on Environment and Development written by International Union for Conservation of Nature and Natural Resources. Commission on Environmental Law and published by IUCN. This book was released on 2000 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an updated edition of the 1995 version. In the mid-1980's, the IUCN CEL, in consultation with leading experts from around the world, began to respond to a need later identified by Agenda 21: the preparation of an integrated framework for international environmental law.
Download or read book Geosimulation written by Itzhak Benenson and published by John Wiley & Sons. This book was released on 2004-08-20 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geosimulation is hailed as ‘the next big thing’ in geographic modelling for urban studies. This book presents readers with an overview of this new and innovative field by introducing the spatial modelling environment and describing the latest research and development using cellular automata and multi-agent systems. Extensive case studies and working code is available from an associated website which demonstrate the technicalities of geosimulation, and provide readers with the tools to carry out their own modelling and testing. The first book to treat urban geosimulation explicitly, integrating socio-economic and environmental modelling approaches Provides the reader with a sound theoretical base in the science of geosimulation as well as applied material on the construction of geosimulation models Cross-references to an author-maintained associated website with downloadable working code for readers to apply the models presented in the book Visit the Author's Website for further information on Geosimulation, Geographic Automata Systems and Geographic Automata Software http://www.geosimulationbook.com
Download or read book Indicators of Environmental Quality written by William A. Thomas and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: Researchers and agencies collect reams of objective data and authors publish volumes of subjective prose in attempts to explain what is meant by environmental quality. Still, we have no universally recognized methods for combining our quantitative measures with our qualitative concepts of environ ment. Not all of our environmental goals should be reduced to mere numbers, but many of them can be; and without these quantitative terms, we have no way of defining our present position nor of selecting positions we wish to attain on any logically established scale of environmen tal values. Stated simply, in our zeal to measure our environment we often forget that masses of numbers describing a system are insufficient to understand it or to be used in selecting goals and priorities for expending our economic and human resources. Attempts at quantitatively describing environmental quality, rather than merely measuring different environmental variables, are relatively recent. This condensing of data into the optimum number of terms with maximum information content is a truly interdisciplinary challenge. When Oak Ridge National Laboratory initiated its Environmental Program in early 1970 under a grant from the National Science Foundation, the usefulness of environmental indicators in assessing the effects of technology was included as one of the initial areas for investigation. James L. Liverman, through his encouragement and firm belief that these indicators are indispensable if we are to resolve our complex environmental problems, deserves much of the credit for the publication of this book.
Download or read book Virtual Geographic Environments written by Hui Lin and published by ESRI Press. This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Virtual Geographic Environments, edited by Hui Lin and Michael Batty, collects key papers that define the current momentum in GIS and "virtual geographies." Contributions by leading members of the geospatial community to Virtual Geographic Environments illustrate the cutting edge of GIScience, as well as new applications of GIS with the processing and delivery of geographic information through the Web and handheld devices, forming two major directions to these developments. The four-part organization leads from a primer on VGEs to virtual cities and landscapes, interface design and public participation, and finally mobile and networked VGEs. Current topics, such as crowd sourcing and related services, point to the development of new business models that merge proprietary and nonproprietary systems.
Download or read book Payments for Ecosystem Services written by Thomas Greiber and published by IUCN. This book was released on 2009 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Governance written by Asanga Gunawansa and published by Edward Elgar Publishing. This book was released on 2013-01-01 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: ÔEnsuring that everybody has access to drinking water, sanitation and enough nutritious food, which depends on water to grow it, are prerequisites for a healthy life. Water management is not just about the technical aspects of water supply and sanitation. It is equally about our water governance systems, including policies, regulation and societal perception of water rights. This book presents many helpful examples of how different societies are dealing with these issues and of the performance of public and private sector players in this important arena.Õ Ð Colin Chartres, International Water Management Institute (IWMI), Colombo, Sri Lanka ÔI congratulate the Institute of Water Policy, the two editors and the contributors for a very thoughtful book on urban water governance. Our objective is to deliver sustainable water and sanitation services to our people. This book contains useful lessons on how to achieve that objective.Õ Ð Tommy Koh, Chairman, Governing Council, Asia-Pacific Water Forum This insightful book explores urban water governance challenges in different parts of the world and highlights the advantages and disadvantages of publicly run, privatized, and publicÐprivate partnership managed water facilities. The contributors expertly discuss various types of public and private water governance architectures as well as identifying the trends, challenges, opportunities and the shifts in perceptions with regard to the provision of water supply services. Many chapters are dedicated to analyzing the urban water supply scenarios in selected countries, with specific focus on legal, policy and institutional frameworks. The study reveals that while private sector participation has been largely promoted by multilateral institutions as part of institutional and financial reforms, ultimately governments bear the major responsibility for provision of water supply services either as Ôservice providerÕ or as Ôregulator and policy-makerÕ. Containing a detailed overview and analysis of the global urban water supply sector, this timely compendium will strongly appeal to academics, researchers and university students following water-related courses. Water sector professionals, water regulators and public officers as well as managers and researchers employed by private sector water operators will also find plenty of invaluable information in this important book.
Download or read book Redefining Normal written by Alexis Black and published by . This book was released on 2019-11-09 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growing up, they didn't believe they had a future. Together, they are building forever. Alexis Black persevered through her mother's death and her father's imprisonment. And after escaping a long and abusive relationship, the college junior promised her foster parents not to date for at least a year. But when she meets an incoming freshman on the first day of their scholarship program, she feels the world melt away, as though it were only the two of them in the room. Justin Black lived in the poorest section of Detroit before his parents surrendered him to the foster care system at the age of nine. But when he grabs the chance for better opportunities by pursuing higher education, he can't help but be drawn to a beautiful third-year student. At first, their past traumas--and their age difference--conspired to complicate their attraction. But the joy each took in the other and eventually conquered those obstacles, and these two survivors journeyed together toward healing. In a stark and wholehearted true story that shares how two individuals on separate paths found each other, Alexis and Justin merge their course into one full of hope and purpose. And hand-in-hand, with a desire to help others, they learned to reject the abusive patterns of their past, thereby intentionally breaking the cycle of generational violence and unhealthy behaviors. Written in an engaging novelistic style, the authors put forward a thoughtful exchange of ideas and personal experiences illustrating how anybody, no matter their backgrounds, can have a life of self-empowerment and joy. Broken down into four sections that cover crucial topics such as "Worthiness" and "Mental Health," this compelling narrative will help any who are learning to love themselves and want to end the line of toxic relationships. Redefining Normal: How Two Foster Kids Beat The Odds and Discovered Healing, Happiness, and Love is a page-turning memoir that will open your eyes to possibilities and dreams. If you like honest tales of triumph, refreshing transparency, and resilient faith in God, then you'll adore Justin and Alexis' inspirational story. This story contains mentions of domestic violence, trauma, sexual assault, and other difficult issues faced on the road to healing. Buy Redefining Normal to claim victory over harmful pasts today!
Download or read book Urban Remote Sensing written by Xiaojun Yang and published by John Wiley & Sons. This book was released on 2011-04-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Urban Remote Sensing is designed for upper level undergraduates, graduates, researchers and practitioners, and has a clear focus on the development of remote sensing technology for monitoring, synthesis and modeling in the urban environment. It covers four major areas: the use of high-resolution satellite imagery or alternative sources of image date (such as high-resolution SAR and LIDAR) for urban feature extraction; the development of improved image processing algorithms and techniques for deriving accurate and consistent information on urban attributes from remote sensor data; the development of analytical techniques and methods for deriving indicators of socioeconomic and environmental conditions that prevail within urban landscape; and the development of remote sensing and spatial analytical techniques for urban growth simulation and predictive modeling.
Download or read book Urban Remote Sensing written by Xiaojun X. Yang and published by John Wiley & Sons. This book was released on 2021-10-11 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Urban Remote Sensing The second edition of Urban Remote Sensing is a state-of-the-art review of the latest progress in the subject. The text examines how evolving innovations in remote sensing allow to deliver the critical information on cities in a timely and cost-effective way to support various urban management activities and the scientific research on urban morphology, socio-environmental dynamics, and sustainability. Chapters are written by leading scholars from a variety of disciplines including remote sensing, GIS, geography, urban planning, environmental science, and sustainability science, with case studies predominately drawn from North America and Europe. A review of the essential and emerging research areas in urban remote sensing including sensors, techniques, and applications, especially some critical issues that are shifting the directions in urban remote sensing research. Illustrated in full color throughout, including numerous relevant case studies and extensive discussions of important concepts and cutting-edge technologies to enable clearer understanding for non-technical audiences. Urban Remote Sensing, Second Edition will be of particular interest to upper-division undergraduate and graduate students, researchers and professionals working in the fields of remote sensing, geospatial information, and urban & environmental planning.
