Modified fully discretized projection method for the incompressible Navier–Stokes equations

The stability and convergence of a second-order fully discretized projection method for the incompressible Navier–Stokes equations is studied. In order to update the pressure field faster, modified fully discretized projection methods are proposed. It results in a nearly second-order method. This method sacrifices a little of accuracy, but it requires much less computations at each time step. It is very appropriate for actual computations. The comparison with other methods for the driven-cavity problem is presented.     

子空间约束下矩阵方程ATXB+BTXTA=D的解及最佳逼近

约束矩阵方程求解是指在满足一定约束条件下求矩阵方程（组）的解.在子空间约束条件下,利用共轭梯度法,结合线性投影算子,得到矩阵方程A^TXB+B^TX^TA=D的解,进一步得到其最佳逼近.最后用数值例子证实了算法的有效性.     

基于毕达哥拉斯犹豫模糊距离测度的灰关联双向投影决策法

为解决多属性决策单方向偏差难题所提出的灰关联投影法尚存在适用性差的技术不足。为此,在借鉴双向投影技术要点的基础上联合新型灰关联系数,并引入毕达哥拉斯犹豫模糊集的表达优势,提出基于毕达哥拉斯犹豫模糊距离测度的灰关联双向投影决策方法。新方法能够有效解决毕达哥拉斯犹豫模糊多属性决策问题,具有较高的分辨度。通过算例应用分析,直接验证了毕达哥拉斯犹豫模糊灰关联双向投影方法的实用性,间接验证了毕达哥拉斯犹豫模糊距离测度和灰关联双向投影法的有效性。     

Decomposition through formalization in a product space

When an optimization problem is posed in a product space it is classical to decompose this problem. The goal of this paper is to show how such an approach can be used when the problem to be solved is not naturally posed in a product space. By associating systematically to this problem an equivalent one posed in ann-fold cartesian product space, we obtain by decomposition of the latter both a splitting of operators and a desintegration of constraints for the former. Applications to three rather classical mathematical programming problems are given.     

中国红豆杉细胞紫杉醇合成期特异表达新基因TS1-FL的部分cDNA克隆

采用mRNA差异显示技术(DDRT—PCR)比较了悬浮培养的中国红豆杉细胞合成紫杉醇前后的基因表达差异,并从紫杉醇合成期细胞中分离出一个特异表达的cDNA克隆TS1．TS1长度为638bp,序列相似性分析结果表明它代表一新基因序列(Genbank登录号：AF426429),将此新基因命名为TS1-FL．开放读框分析结果表明Tsl拥有一个不完整的开放读框,蛋白质同源性检索没有发现与TS1翻译序列有较大同源性的蛋白质．对此基因的进一步研究可揭示它在紫杉醇生物合成中所扮演的角色．     

Shape and topology optimization for elliptic boundary value problems using a piecewise constant level set method

The aim of this paper is to propose a variational piecewise constant level set method for solving elliptic shape and topology optimization problems. The original model is approximated by a two-phase optimal shape design problem by the ersatz material approach. Under the piecewise constant level set framework, we first reformulate the two-phase design problem to be a new constrained optimization problem with respect to the piecewise constant level set function. Then we solve it by the projection Lagrangian method. A gradient-type iterative algorithm is presented. Comparisons between our numerical results and those obtained by level set approaches show the effectiveness, accuracy and efficiency of our algorithm.     

集值混合变分不等式的一类自适应惯性投影次梯度算法

本文在实Hilbert空间上引入了一类求解集值混合变分不等式新的自适应惯性投影次梯度算法.在集值映射T为f-强伪单调或单调的条件下,我们证明了由该自适应惯性投影次梯度算法所产生的序列强收敛于集值混合变分不等式问题的的唯一解.     

一点到一仿射集合投影的加权扰动分析

1引言设AEC“”,M和N分别为m和,;阶Hermite正定阵,则存在唯一的矩阵X6C”””满足AXA一A,XAX一X,（MAX）”一MAX,（NXA）”一NXA,（．1）其中B”为B的共轭转置阵．称满足（互．l）的X为A的加权M－P逆,记作X二A和．特别,当M—I。,N—I。时,A;一A”为矩阵的M－P逆．文献［3—5,11,13］讨论了一点到一仿射集合投影的挑动和加权扰动理论．文献［7,9,18」研究了极小N一范数、M一最小二乘解的扰动分析．本文推广了以上文献的主要结果．考虑如下问题「1,2〕：给定AE〔叩“”,bEC一和广EO,找一个向量X”E…