检索结果-南通市图书馆

Micro-macro models for viscoelastic fluids： modelling, mathematics and numerics Dedicated to the NSFC-CNRS Chinese-French summer institute on fluid mechanics in 2010

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2012年第2期55卷 353-384页

作者： LE BRIS Claude LELIVRE Tony CERMICS Ecole des Ponts ParisTech inria rocquencourt MICMAC team

This paper is an introduction to the modelling of viscoelastic fluids, with an emphasis on micromacro （or multiscale） models. Some elements of mathematical and numerical analysis are provided. These notes closely follow the lectures delivered by the second author at the Chinese Academy of Science during the Workshop ＂Stress Tensor Effects on Fluid Mechanics＂ in January 2010.

关键词： viscoelastic fluids micro-macro models entropy methods Monte Carlo methods

Composite Waves for a Cell Population System Modeling Tumor Growth and Invasion

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2013年第2期34卷 295-318页

作者： Min TANG Nicolas VAUCHELET Ibrahim CHEDDAD Irene VIGNON-CLEMENTEL Dirk DRASDO Benoit PERTHAME Department of mathematics Institute of Natural Sciences and MOE-LSCShanghai Jiao Tong University inria paris rocquencourt ParisFrance Laboratoire Jacques-Louis Lions UPMC Univ Paris 06 and CNRS UMR 7598F-75005ParisFrance

In the recent biomechanical theory of cancer growth,solid tumors are considered as liquid-like materials comprising elastic *** this fluid mechanical view,the expansion ability of a solid tumor into a host tissue is mainly driven by either the cell diffusion constant or the cell division rate,with the latter depending on the local cell density(contact inhibition) or/and on the mechanical stress in the *** the two by two degenerate parabolic/elliptic reaction-diffusion system that results from this modeling,the authors prove that there are always traveling waves above a minimal speed,and analyse their *** appear to be complex with composite shapes and *** small parameters allow for analytical solutions,and in particular,the incompressible cells limit is very singular and related to the Hele-Shaw *** singular traveling waves are recovered numerically.

关键词： Traveling waves Reaction-diffusion Tumor growth Elastic material

Operator Factorization forMultiple-Scattering Problems and an Application to Periodic Media

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2012年第2期11卷 303-318页

作者： J.Coatleven P.Joly POems Project Team UMR ENSTA/CNRS/INRIAInria Rocquencourt78153 Le Chesnay CedexFrance

This work concerns multiple-scattering problems for time-harmonic equations in a reference *** consider scatterers that can be sources,obstacles or compact perturbations of the reference *** aim is to restrict the computational domain to small compact domains containing the *** use Robin-to-Robin(RtR)operators(in the most general case)to express boundary conditions for the interior *** show that one can always factorize the RtR map using only operators defined using single-scatterer *** factorization is based on a decomposition of the diffracted field,on thewhole domainwhere it is *** that there exists a good method for solving single-scatterer problems,it then gives a convenient way to compute RtR maps for a random number of scatterers.

关键词： Multiple-scattering harmonic wave equation exact boundary conditions periodic media

ALowFrequencyModel for Acoustic Propagation in a 2D Flow Duct:Numerical Computation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2012年第2期11卷 508-524页

作者： Lauris Joubert Patrick Joly POEMS CNRS-INRIA-ENSTA UMR 270632 Boulevard Victor75015 ParisFrance POEMS CNRS-INRIA-ENSTAUMR 2706INRIA RocquencourtBP 10578153 Le Chesnay CedexFrance

In this paper we study a low frequency model for acoustic propagation in a 2D flow *** some Mach profile flow,we are able to give a well-posedness *** proof relies on a quasi-explicit expression of the solution which provides us an efficient numerical *** give and comment numerical results for particular linear,tangent and quadratic ***,we give a numerical validation of our asymptotic model.

关键词： Acoustics in flow Galbrun’s equations asymptotic analysis Laplace transform

Exploring system architectures in AADL via Polychrony and SynDEx

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2013年第5期7卷 627-649页

作者： Huafeng YU Yue MA Thierry GAUTIER Loc BESNARD Jean-Pierre TALPIN Paul Le GUERNIC Yves SOREL inria Rennes-Bretagne Atlantique 263 av. du Général LeclercRennes 35042 France IRISA/CNRS 263 av. du Général LeclercRennes 35042 France inria paris-rocquencourt Domaine de VoluceauBP 105Le Chesnay Cedex 78153 France

Architecture analysis&design language(AADL)has been increasingly adopted in the design of embedded systems,and corresponding scheduling and formal verification have been well ***,little work takes code distribution and architecture exploration into account,particularly considering clock constraints,for distributed multi-processor *** this paper,we present an overview of our approach to handle these concerns,together with the associated toolchain,***,in order to avoid semantic ambiguities of AADL,the polychronous/multiclock semantics of AADL,based on a polychronous model of computation,is *** synthesis is then carried out in Polychrony,which bridges the gap between the polychronous semantics and the synchronous semantics of *** same timing semantics is always preserved in order to ensure the correctness of the transformations between diferent *** distribution and corresponding scheduling is carried out on the obtained SynDEx model in the last step,which enables the exploration of architectures originally specified in *** contribution provides a fast yet efcient architecture exploration approach for the design of distributed real-time and embedded *** avionic case study is used here to illustrate our approach.

关键词： Polychrony Signal AADL SynDEx architecture exploration modeling timing analysis scheduling distribution

PerfectlyMatched Layer withMixed Spectral Elements for the Propagation of LinearizedWaterWaves

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2012年第2期11卷 285-302页

作者： Gary Cohen Sebastien Imperiale inria Domaine de VoluceauRocquencourt-BP 10578153 Le Chesnay CedexFrance

After setting a mixed formulation for the propagation of linearized water waves problem,we define its spectral element ***,in order to take into account unbounded domains,we construct absorbing perfectly matched layer for the *** approximate these perfectly matched layer by mixed spectral elements and show their stability using the“frozen coefficient”***,numerical results will prove the efficiency of the perfectly matched layer compared to classical absorbing boundary conditions.

关键词： Linearized water waves perfectly matched layer mixed finite elements

HIGH-ORDER EXPLICIT TIME-INTEGRATORS FOR DISCONTINUOUS GALERKIN DISCRETIZATIONS OF THE MAXWELL EQUATIONS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2013年第1期4卷 132-153页

作者： H.FAHS M.SAFA LAMA Laboratory University Paris-Est Marne-la-Vallee UMR CNRS 80505 boulevard Descartes 77454 Marne-la-Vall´ee Cedex 2France inria paris-rocquencourt Domaine de Voluceau BP.10578153 Le Chesnay CedexFrance

We investigate the practical implementation of a high-order explicit time-stepping method based on polynomial approximations,for possible application to large-scale problems in *** the spatial discretization by a high-order discontinuous Galerkin method,we obtain a linear system of differential equations of the form,∂tY(t)=HY(t)+S(t),where H is a matrix containing the spatial derivatives and t is the time *** formal solution can be written in terms of the matrix exponential,exp(tH),acting on some *** introduce a general family of time-integrators based on the approximation of exp(tH)by Jacobi polynomial *** discuss the efficient implementation of this technique,and based on some test problems,we compare the virtues and shortcomings of the *** also demonstrate how these schemes provide an efficient alternative to standard explicit integrators for computing solutions over long time intervals.

关键词： Maxwell’s equations discontinuous Galerkin method time-stepping schemes

Error Estimates for 1D Asymptotic Models in Coaxial Cables with Non-Homogeneous Cross-Section

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2012年第6期4卷 647-664页

作者： Sébastien Imperiale Patrick Joly Department of Applied Physics and Applied Mathematics Columbia UniversityNY 10027USA inria rocquencourt POemsdomaine de Voluceau78153 Le ChesnayFrance

This paper is the first contribution towards the rigorous justification of asymptotic 1D models for the time-domain simulation of the propagation of electromagnetic waves in coaxial *** general objective is to derive error estimates between the"exact"solution of the full 3D model and the"approximate"solution of the 1D model known as the Telegraphist’s equation.

关键词： Coaxial cables Telegraphist’s equation error estimates non-homogeneous crosssection

Transversal Instability for the Thermodiffusive Reaction-Diffusion System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2015年第5期36卷 871-882页

作者： Michal KOWALCZYK Benoit PERTHAME Nicolas VAUCHELET Departamento de Ingenieria Matematica and Centro de Modelamiento Matem'atico(UMI CNRS 2807) Universidad de Chile Sorbonne Universités UPMC Univ Paris 06UMR 7598Laboratoire Jacques-Louis LionsF-75005ParisFrance CNRS UMR 7598Laboratoire Jacques-Louis LionsF-75005ParisFrance inria-paris-rocquencourt EPC MAMBADomaine de VoluceauBP10578153 Le Chesnay CedexFrance

The propagation of unstable interfaces is at the origin of remarkable patterns that are observed in various areas of science as chemical reactions, phase transitions, and growth of bacterial colonies. Since a scalar equation generates usually stable waves, the simplest mathematical description relies on two-by-two reaction-diffusion systems. The authors' interest is the extension of the Fisher/KPP equation to a two-species reaction which represents reactant concentration and temperature when used for flame propagation,and bacterial population and nutrient concentration when used in *** authors study circumstances in which instabilities can occur and in particular the effect of dimension. It is observed numerically that spherical waves can be unstable depending on the coefficients. A simpler mathematical framework is to study transversal instability, which means a one-dimensional wave propagating in two space ***, explicit analytical formulas give explicitely the range of paramaters for instability.

关键词： Traveling waves Stability analysis Reaction-diffusion equation Thermodiffusive system