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Sobolev型方程Wilson元解的高精度分析 总被引:1,自引:0,他引:1
本文利用积分恒等式和插值后处理等技术对 Sobolev型方程 Wilson非协调有限元解进行了高精度算法分析 ,获得了解的超逼近性质和插值有限元解的整体超收敛 .在此基础上 ,运用外推与校正方法进一步获得了具有更高精度的近似解及后验误差估计 . 相似文献
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孙旭 《数学的实践与认识》2011,41(19)
技术差距带来的技术扩散效应决定了区域间可能存在着技术收敛.在限制指数模型中,所有国家和地区将获得相同的技术进步率,在逻辑斯蒂模型中,人力资本水平成为制约技术收敛的条件.将Benhabib和Speigel(2005)的跨国技术收敛的实证研究工作推广到国内地区研究之中,分析了中国30个省区1990-2008年技术进步率的影响因素及收敛情况.实证研究结果表明,中国30个省区的技术进步率趋异.人力资本是促进地区自主创新和技术扩散的积极因素. 相似文献
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In order to evaluate the material composition of Ultra High Performance Concrete (UHPC), material properties such as dynamic tensile strength or fracture strength and also the fracture energy under impact loading are of significant importance. The use of a modified Hopkinson Bar enables the determination of the required data. On the basis of experimental investigations our contribution deals with the numerical finite element simulation of the Hopkinson Bar test. The propagation of stress waves is reproduced by means of a special time-integration scheme. We simulate the propagation of cracks by using adaptive cohesive elements including a corresponding separation law. The critical energy release rate (Griffith-energy) is calculated and compared to the values determined by experimental results. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Ultra High Performance Concrete (UHPC) is defined as a new generation of concrete which shows improved performance and higher strength than traditional concrete. This allows to realize slender and much more durable structures and in this way significantly reduces the required resources. Despite its huge potential in construction, technical information about this new type of material is still limited. This contribution presents investigations on the dynamic mechanical behavior and properties of UHPC specimens by spalling experiments. Two different recipes were used to compare the properties. Due to the special specimen geometry (slender cylindrical) a flowable consistency was required to enable a sufficient degassing of the mixtures. For the test, a Split Hopkinson Pressure Bar (SHPB) has been modified and used. A high speed photograph system was focused on the fragmentation process during the test. On the basis of these experiments the dynamic E-moduli as well as the dynamic tensile strength of the UHPC specimens were determined. By observation of the specific crack patterns on each tested specimen and corresponding times, the dynamic fracture energy is calculated. Numerical simulations also were performed and compared to the experimental result. It is concluded that the dynamic tensile strength of the UHPC increases at higher strain rates. The results of the current study provide technical information about fracture and dynamic behavior of UHPC and the obtained values could be used for future computational models. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Qingzhi Yang 《Journal of Mathematical Analysis and Applications》2005,302(1):166-179
Projection algorithms are practically useful for solving variational inequalities (VI). However some among them require the knowledge related to VI in advance, such as Lipschitz constant. Usually it is impossible in practice. This paper studies the variable-step basic projection algorithm and its relaxed version under weakly co-coercive condition. The algorithms discussed need not know constant/function associated with the co-coercivity or weak co-coercivity and the step-size is varied from one iteration to the next. Under certain conditions the convergence of the variable-step basic projection algorithm is established. For the practical consideration, we also give the relaxed version of this algorithm, in which the projection onto a closed convex set is replaced by another projection at each iteration and latter is easy to calculate. The convergence of relaxed scheme is also obtained under certain assumptions. Finally we apply these two algorithms to the Split Feasibility Problem (SFP). 相似文献
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Split cuts are prominent general-purpose cutting planes in integer programming. The split closure of a rational polyhedron is what is obtained after intersecting the half-spaces defined by all the split cuts for the polyhedron. In this paper, we prove that deciding whether the split closure of a rational polytope is empty is NP-hard, even when the polytope is contained in the unit hypercube. As a direct corollary, we prove that optimization and separation over the split closure of a rational polytope in the unit hypercube are NP-hard, extending an earlier result of Caprara and Letchford. 相似文献
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本文推广Bar Lev M.等人在1975年提出的求解突然起动单圆柱初期流场的方法,研究了双圆柱的相应问题,对流函数φ采用匹配渐近展开法求出直到二级近似的分析解。 相似文献
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We propose a prototypical Split Inverse Problem (SIP) and a new variational problem, called the Split Variational Inequality
Problem (SVIP), which is a SIP. It entails finding a solution of one inverse problem (e.g., a Variational Inequality Problem
(VIP)), the image of which under a given bounded linear transformation is a solution of another inverse problem such as a
VIP. We construct iterative algorithms that solve such problems, under reasonable conditions, in Hilbert space and then discuss
special cases, some of which are new even in Euclidean space. 相似文献
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In this paper, we propose a methodology for branch-and-cut-and-price when cuts and columns are generated simultaneously. The methodology is illustrated with two application cases: the Split Delivery Vehicle Routing Problem (SDVRP) and the Bus Rapid Transit Route Design Problem (BRTRDP). 相似文献
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This article gives a sufficient condition which guarantees the existence of a reference frame in which a multi-output nonlinear system is linearizable with a linear part depending on its outputs. Our method is based on the design of a reference frame associated with nonlinear observable systems. Moreover, we give a generalization of the result obtained in [D. Boutat, G. Zheng, J.P. Barbot, Observer error linearization multi-output depending, in: Proc. of IEEE CDC 06, 2006] and [G. Zheng, D. Boutat, J.P. Barbot, Single output-dependent observability normal form, SIAM Journal on Control and Optimization 46 (6) (2007)]. And some examples are given in order to illuminate our thinking. 相似文献
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Chih-Sheng Chuang 《Optimization》2016,65(4):859-876
Split variational inclusion problem is an important problem, and it is a generalization of the split feasibility problem. In this paper, we present feasible algorithms for the split variational inclusion problems in Hilbert spaces, and provide convergence theorems for these algorithms. As application, we study the split feasibility problem in real Hilbert spaces. Final, numerical results are given for our main results. 相似文献