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Communications in Computational Physics 2012年第2期11卷 674-690页

作者： Helene Barucq Julien Diaz Veronique Duprat INRIA Bordeaux-Sud Ouest Team-project MAGIQUE-3D lma CNRS UMR 5142University of PauFrance

We propose a new Absorbing Boundary Condition(ABC)for the acoustic wave equation which is derived from a micro-local diagonalization process formerly defined by *** and which does not depend on the geometry of the surface bearing the *** considering the principal symbol of the wave equation both in the hyperbolic and the elliptic regions,we show that a second-order ABC can be constructed as the combination of an existing first-order ABC and a Fourier-Robin *** compare the new ABC with other ABCs and we show that it performs well in simple configurations and that it improves the accuracy of the numerical solution without increasing the computational burden.

关键词： Wave equation micro-local diagonalization absorbing boundary condition finite element formulation

High-Order Schemes Combining the Modified Equation Approach and Discontinuous Galerkin Approximations for the Wave Equation

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Communications in Computational Physics 2012年第2期11卷 691-708页

作者： Cyril Agut Julien Diaz Abdelaaziz Ezziani lma CNRS UMR 5142Universite de PauFrance INRIA Bordeaux Research Center Project Team Magique3DFrance

We present a new high ordermethod in space and time for solving the wave equation,based on a newinterpretation of the“Modified Equation”***,contrary to most of the works,we consider the time discretization before the space *** the time discretization,an additional biharmonic operator appears,which can not be discretized by classical finite *** propose a new Discontinuous Galerkinmethod for the discretization of this operator,andwe provide numerical experiments proving that the new method is more accurate than the classicalModified Equation technique with a lower computational burden.

关键词： High order schemes discontinuous Galerkin method acoustic wave equation

Multi-axial unsplit frequency-shifted perfectly matched layer for displacement-based anisotropic wave simulation in infinite domain

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 407-421页

作者： Xie Zhinan Zheng Yonglu Paul Cristini Zhang Xubin Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China Aix Marseille University CNRSCentrale MarseilleLMAMarseille F-13353France

Multi-axial perfectly matched layer(M-PML),known to have lost the perfect-matching property owing to multi-axial coordinate stretching,has been numerically validated to be long-time stable and it is thus used extensively in linear anisotropic wave simulation and in isotropic cases where the PML becomes *** are concerned with the construction of the M-PML for anisotropic wave simulation based on a second order wave equation implemented with the displacement-based numerical *** address the benefit of the incorrect chain rule,which is implicitly adopted in the previous derivation of the *** show that using the frequency-shifted stretching function improves the absorbing efficiency of the M-PML for near-grazing incident ***,through multi-axial complex-coordinate stretching the second order anisotropic wave equation in a weak form,we derive a time-domain multi-axial unsplit frequency-shifted PML(M-UFSPML)using the frequency-shifted stretching function and the incorrect chain rule.A new approach is provided to reduce the number of memory variables needed for computing convolution terms in the *** obtained M-UFSPML is well suited for implementation with a finite element or the spectral element *** providing several typical examples,we numerically verify the accuracy and long-time stability of the implementation of our M-UFSPML by utilizing the Legendre spectral element method.

关键词： computational seismology seismic anisotropy wave propagation elastodynamics

Numerical modeling of zero-offset laboratory data in a strong topographic environment: results for a spectral-element method and a discretized Kirchhoff integral method

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Earthquake Science 2014年第4期27卷 391-399页

作者： Nathalie Favretto-Cristini Anastasiya Tantsereva Paul Cristini Bjφrn Ursin Dimitri Komatitsch Arkady M.Aizenberg Laboratory of Mechanics and Acoustics (lma) CNRS AixMarseille UniversityCentrale Marseille Department of Petroleum Engineering and Applied Geophysics Norwegian University of Science and Technology Institute of Petroleum Geology and Geophysics SB RAS

Abstract Accurate simulation of seismic wave propaga- tion in complex geological structures is of particular interest nowadays. However conventional methods may fail to simulate realistic wavefields in environments with great and rapid structural changes, due for instance to the presence of shadow zones, diffractions and/or edge effects. Different methods, developed to improve seismic model- ing, are typically tested on synthetic configurations against analytical solutions for simple canonical problems or ref- erence methods, or via direct comparison with real data acquired in situ. Such approaches have limitations,especially if the propagation occurs in a complex envi- ronment with strong-contrast reflectors and surface irreg- ularities, as it can be difficult to determine the method which gives the best approximation of the ＂real＂ solution, or to interpret the results obtained without an a priori knowledge of the geologic environment. An alternative approach for seismics consists in comparing the synthetic data with high-quality data collected in laboratory experi- ments under controlled conditions for a known configuration. In contrast with numerical experiments, laboratory data possess many of the characteristics of field data, as real waves propagate through models with no numerical approximations. We thus present a comparison of laboratory-scaled measurements of 3D zero-offset wave reflection of broadband pulses from a strong topographic environment immersed in a water tank with numerical data simulated by means of a spectral-element method and a discretized Kirchhoff integral method. The results indicate a good quantitative fit in terms of time arrivals and acceptable fit in amplitudes for all datasets.

关键词： Numerical modeling . Zero-offset reflection Laboratory experiments Strong topography

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北大附中办公楼改造

城市环境设计 2012年第3期 239-240页

作者：兰闽吴晓峰 lma

这原是一栋陈旧的普通二层小楼,使用者为明教育机构希望通过改造体现出开放的现代教育观。新的设计将入口处的二层楼板打通,使门厅宽阔和充满光线,可以类比传统书院建筑的"明间"。同时这一空间的存在,使得原来狭小的沿水平方向分布的办... 详细信息

这原是一栋陈旧的普通二层小楼,使用者为明教育机构希望通过改造体现出开放的现代教育观。新的设计将入口处的二层楼板打通,使门厅宽阔和充满光线,可以类比传统书院建筑的"明间"。同时这一空间的存在,使得原来狭小的沿水平方向分布的办公室,连接为一个整体的二层空间。业主:为明教育机构地点:北京设计时间:2008竣工时间:2009方案设计:lma室内设计:lma施工图:lmalma设计师:兰闽、吴晓峰

关键词：办公楼北大附中书院建筑层空间明间竣工时间施工图设计师

LIMIT CYCLES OF THE GENERALIZED POLYNOMIAL LINARD DIFFERENTIAL SYSTEMS

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Annals of Applied Mathematics 2016年第3期32卷 221-233页

作者： Amel Boulfoul Amar Makhlouf Dept. of Math. 20 August 1955 University Dept. of Math. LMA Laboratory Badji Mokhtar University

Using the averaging theory of first and second order we study the maximum number of limit cycles of generalized Linard differential systems{x = y ＋ εhl1（x）＋ ε2hl2（x）,y=-x- ε（fn1（x）y（2p＋1）＋ gm1（x））＋ ∈2（fn2（x）y（2p＋1）＋ gm2（x））,which bifurcate from the periodic orbits of the linear center x = y,y=-x,where ε is a small *** polynomials hl1 and hl2 have degree l;fn1and fn2 have degree n;and gm1,gm2 have degree m.p ∈ N and[·]denotes the integer part function.

关键词： limit cycle periodic orbit Li′enard differential system averaging theory

Minimum Penalized Hellinger Distance for Model Selection in Small Samples

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Open Journal of Statistics 2012年第4期2卷 369-382页

作者： Papa Ngom Bertrand Ntep Department of Mathematics and Computer Science Cheikh Anta DIOP University Dakar Sénégal Laboratory of Applied Mathematics (LMA) FST

In statistical modeling area, the Akaike information criterion AIC, is a widely known and extensively used tool for model choice. The φ-divergence test statistic is a recently developed tool for statistical model selection. The popularity of the divergence criterion is however tempered by their known lack of robustness in small sample. In this paper the penalized minimum Hellinger distance type statistics are considered and some properties are established. The limit laws of the estimates and test statistics are given under both the null and the alternative hypotheses, and approximations of the power functions are deduced. A model selection criterion relative to these divergence measures are developed for parametric inference. Our interest is in the problem to testing for choosing between two models using some informational type statistics, when independent sample are drawn from a discrete population. Here, we discuss the asymptotic properties and the performance of new procedure tests and investigate their small sample behavior.

关键词： Generalized Information Estimation Hypothesis Test Monte Carlo Simulation

Analytical Solution for Waves Propagation in Heterogeneous Acoustic/Porous Media. Part I: The 2D Case

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Communications in Computational Physics 2010年第3期7卷 171-194页

作者： Julien Diaz Abdelaaziz Ezziani Project-team Magique-3D INRIA Bordeaux Sud-Ouest lma Pau CNRS UMR 5142I.P.R.A-Universit´e de Pau et des Pays de l’Adouravenue de l’Universit´e BP 1155-64013 PAU CEDEXFrance

Thanks to the Cagniard-de Hoop’s method we derive the solution to theproblem of wave propagation in an infinite bilayered acoustic/poroelastic media, wherethe poroelastic layer is modelled by the biphasic Biot’s model. This first part is dedi-cated to solution to the two-dimensional problem. We illustrate the properties of thesolution, which will be used to validate a numerical code.

关键词： Biot’s model poroelastic waves acoustic waves acoustic/poroelastic coupling ana-lytical solution Cagniard-de Hoop’s technique 2D

Performance Analysis of a High-Order Discontinuous Galerkin Method Application to the Reverse Time Migration

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Communications in Computational Physics 2012年第2期11卷 660-673页

作者： Caroline Baldassari Helene Barucq Henri Calandra Bertrand Denel Julien Diaz INRIA Bordeaux Research Center Project Team Magique3DAvenue de l’universite64013 Pau CedexFrance. lma CNRS UMR 5142Universite de PauAvenue de l’universite64013 Pau CedexFrance TOTAL Avenue Larribau64000 PauFrance

This work pertains to numerical aspects of a finite element method based discontinuous *** study focuses on the Interior Penalty Discontinuous Galerkin method(IPDGM)because of its high-level of flexibility for solving the full wave equation in *** assess the performance of IPDGMthrough a comparison study with a spectral element method(SEM).We show that IPDGM is as accurate as *** addition,we illustrate the efficiency of IPDGM when employed in a seismic imaging process by considering two-dimensional problems involving the Reverse Time Migration.

关键词： Interior penalty discontinuous Galerkin method spectral element method reverse time migration seismic imaging process

WNT/β-catenin pathway and circadian rhythms in obsessive-compulsive disorder

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Neural Regeneration Research 2022年第10期17卷 2126-2130页

作者： Alexandre Vallée Yves Lecarpentier Jean-Noël Vallée Department of Clinical Research and Innovation(DRCI) Foch HospitalSuresnesFrance Centre de Recherche Clinique Grand Hôpital de l’Est Francilien(GHEF)MeauxFrance Laboratoire de Mathématiques et Applications(lma) Universitéde PoitiersPoitiersFrance Centre Hospitalier Universitaire(CHU)Amiens Picardie UniversitéPicardie Jules Verne(UPJV)AmiensFrance

The neuropsychiatric disease named obsessive-compulsive disorder is composed by obsessions and/or ***-compulsive disorder etiologies are ***,numerous mechanisms in several localizations are *** studies showed that both glutamate,inflammatory factors and oxidative stress could have main functions in obsessive-compulsive *** synthase kinase-3β,the major negative controller of the WNT/β-catenin pathway is upregulated in obsessive-compulsive *** obsessive-compulsive disorder,some studies presented the actions of the different circadian clock ***/β-catenin pathway and circadian clock genes appear to be ***,this review focuses on the interaction between circadian clock genes and the WNT/β-catenin pathway in obsessive-compulsive disorder.

关键词： circadian rhythms glutamatergic pathway inflammation obsessive-compulsive disorder oxidative stress WNT/β-catenin pathway