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931.
Ismael Herrera‐Revilla 《Numerical Methods for Partial Differential Equations》2008,24(3):845-878
This article is devoted to introduce a new approach to iterative substructuring methods that, without recourse to Lagrange multipliers, yields positive definite preconditioned formulations of the Neumann–Neumann and FETI types. To my knowledge, this is the first time that such formulations have been made without resource to Lagrange multipliers. A numerical advantage that is concomitant to such multipliers‐free formulations is the reduction of the degrees of freedom associated with the Lagrange multipliers. Other attractive features are their generality, directness, and simplicity. The general framework of the new approach is rather simple and stems directly from the discretization procedures that are applied; in it, the differential operators act on discontinuous piecewise‐defined functions. Then, the Lagrange multipliers are not required because in such an environment the functions‐discontinuities are not an anomaly that need to be corrected. The resulting algorithms and equations‐systems are also derived with considerable detail. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008 相似文献
932.
Jiří Maryška Otto SeverýnMiloslav Tauchman David Tondr 《Journal of Computational and Applied Mathematics》2008
The paper deals with a new approach to the numerical modelling of groundwater flow in compact rock massifs. 相似文献
933.
J. Sakalauskaitė 《Lithuanian Mathematical Journal》2006,46(3):347-355
We consider logic of knowledge and past time. This logic involves the discrete-time linear temporal operators next, until, weak yesterday, and since. In addition, it contains an indexed set of unary modal operators agent i knows.We consider the semantic constraint of the unique initial states for this logic. For the logic, we present a sequent calculus
with a restricted cut rule. We prove the soundness and completeness of the sequent calculus presented. We prove the decidability
of provability in the considered calculus as well. So, this calculus can be used as a basis for automated theorem proving.
The proof method for the completeness can be used to construct complete sequent calculi with a restricted cut rule for this
logic with other semantical constraints as well.
Published in Lietuvos Matematikos Rinkinys, Vol. 46, No. 3, pp. 427–437, July–September, 2006. 相似文献
934.
对一类具有散度形式的拟线性椭圆型微分方程建立了若干新的振动准则,所得结果仅依赖于方程在外区域Ω(?)R~n的一个区域序列的信息而有别于已知的大多数结论. 相似文献
935.
Fluid flow in naturally fractured porous media can always be regarded as an unbounded domain problem and be better solved by finite/infinite elements. In this paper, a three-dimensional two-direction mapped infinite element is generated and combined with conventional finite elements and one direction infinite element to simulate poroelasticity. Therefore, the entire semi-infinite domain can be included in the numerical analysis. Both single- and dual-porosity porous media are considered. For the purpose of validation, we compare the results of finite/infinite elements with those of finite elements under two extreme boundary conditions. The comparison indicated that mapped infinite element is an appropriate approach to model fluid flow in porous media and provides an intermediate solution. 相似文献
936.
It is proved that every proper holomorphic self-map of a smooth bounded Reinhardt domain in ℂ2 is an automorphism.
The first author’s work was supported in part by the National Natural Science Foundation of China (Grant No. 10571135) and
the Doctoral Program Foundation of the Ministry of Education of China (Grant No. 20050240711) 相似文献
937.
Giacomo Quaranta Clara Argerich Martin Ruben Ibañez Jean Louis Duval Elias Cueto Francisco Chinesta 《Comptes Rendus Mecanique》2019,347(5):445-454
The present paper analyzes different integration schemes of solid dynamics in the frequency domain involving the so-called Proper Generalized Decomposition – PGD. The last framework assumes for the solution a parametric dependency with respect to frequency. This procedure allowed introducing other parametric dependences related to loading, geometry, and material properties. However, in these cases, affine decompositions are required for an efficient computation of separated representations. A possibility for circumventing such difficulty consists in combining modal and harmonic analysis for defining an hybrid integration scheme. Moreover, such a procedure, as proved in the present work, can be easily generalized to address nonlinear parametric dynamics, as well as to solve problems with non-symmetric stiffness matrices, always operating in the domain of low frequencies. 相似文献
938.
Vibe B. Jakobsen Elzbieta Trzop Laurence C. Gavin Emiel Dobbelaar Shalinee Chikara Xiaxin Ding Kane Esien Helge Müller‐Bunz Solveig Felton Vivien S. Zapf Eric Collet Michael A. Carpenter Grace G. Morgan 《Angewandte Chemie (International ed. in English)》2020,59(32):13305-13312
Domain wall motion is detected for the first time during the transition to a ferroelastic and spin state ordered phase of a spin crossover complex. Single‐crystal X‐ray diffraction and resonant ultrasound spectroscopy (RUS) revealed two distinct symmetry‐breaking phase transitions in the mononuclear Mn3+ compound [Mn(3,5‐diBr‐sal2(323))]BPh4, 1. The first at 250 K, involves the space group change Cc→Pc and is thermodynamically continuous, while the second, Pc→P1 at 85 K, is discontinuous and related to spin crossover and spin state ordering. Stress‐induced domain wall mobility was interpreted on the basis of a steep increase in acoustic loss immediately below the the Pc‐P1 transition 相似文献
939.
940.
This work extends the application of finite volume method (FVM) to structural–acoustic problems. A three-dimensional time domain FVM (TDFVM) is proposed to predict the transient response and natural characteristics of structural–acoustic coupling systems. Acoustic wave equation in heterogeneous medium and structural dynamic equation are solved in fluid and solid sub-domains respectively. The structural–acoustic coupling is implemented according to normal components of particle acceleration continuity condition and normal traction equilibrium condition at the interface. The computational domain is discretized with four-node tetrahedral grid which is generated easily and has strong adaptability to complicated geometries. Numerical experiments are carried out to examine the accuracy of the method in both time domain and frequency domain. The results show good agreement with analytical solutions and numerical results. For structural–acoustic problem, TDFVM has the capability to consider the heterogeneity of both fluid and solid. 相似文献