生成曲线的有理稳定细分方法

本文推广稳定细分方法，得到生成曲线的有理稳定细分方法，并讨论了该方法所产生曲线的几何性质．有理稳定细分方法生成曲线的类型更为丰富，包括了计算机辅助几何设计中常用的有理B-样条曲线．     

分枝定界算法中的新区间剖分原则

在求解非凸规划的分枝定界法中,剖分区间的选取直接影响到整个算法的收敛速度.本文对现有的LDB区间剖分法进行了改进,给出了一种剖分区间的选取原则,理论分析和数值算例表明采用新的ILDB算法会具有更快的收敛速度.     

一种新的细分小波及其应用

在图形图像数据传输与数据处理过程中,数据鼍过大是造成不便的主要原因,因此用少量的数据更好地表现图形图像特征是人们追求的目标．图形简化的任务是在保留图形特征的同时删除过多的采样点．简化的中心问题是简化模板的选择,王国谨等人介绍了基于球面多边形逼近的曲面简化技术等方法．用小波技术进行图形简化也是目前图形图像处理过程中的常用方法,如孙延奎等人研究了B样条曲线的多分辨率表示,LounsberyM．等人研究了任意拓扑结构的曲面多分辨分析问题等等．     

一类融合逼近和插值的曲线细分

采用生成多项式为主的方法对一类融合逼近和插值三重细分格式的支撑区间、多项式生成、连续性、多项式再生及分形性质进行了分析,给出并证明了极限曲线C^k连续的充分条件.通过对融合型细分规则中参数变量的适当选择来实现对极限曲线的形状调整,从而衍生出具有良好性质的新格式,并将这类新格式与现有格式进行比较.数值实例表明这类新格式生成的极限曲线具有较好的保形性.     

一类连续函数模拟退火算法及其收敛性分析

高维连续函数的全局优化问题普遍存在于计算生物学、计算化学等领域．针对这类问题和现有连续函数模拟退火算法的某些不足,本文给出了一类改进的模拟退火算法．采用一种简单的方法证明了算法的全局收敛性．数值结果表明,对于高维连续函数,该算法能够快速有效地收敛到全局最优点,比较了两种新解产生方法的试验结果。     

一种改进的进化规划算法及其收敛性

1　引　言进化算法是一类借鉴生物界自然选择和自然遗传机制的随机搜索算法 ,主要包括遗传算法 ( genetic algorithms,GA)、进化规划 ( evolutionary programming,EP)和进化策略( evolution strategies,ES) [1 ] .遗传算法 ,进化策略和进化规划分别由 J.H.Holland,I.Rechenberg和 L.J.Fogel提出[2 ,3,4] .这些算法有许多相似性 ,且近年来都被应用于实值连续函数全局优化问题 ,并取得了较好的效果 .一些学者对进化算法的收敛性进行了分析[5,6,7,8] ,但总的说来 ,有关进化算法的理论研究成果目前还不是很多 ,尤其是进化规划和进化策略几…     

BEST LIPSCHITZ CONSTANTS FOR THE BEZIER NETS AND BERNSTEIN POLYNOMIALS OVER A SIMPLEX

1IntroductionBernsteinpolynothealspreservethepropertiesoftheircorrespondingfunctionsandB6ziernets,forexample,convekityandmononity,tolargeextends.Thisisknownasshapepreservingproperty.ShapepreservingpropertiesofBernsteinpolynomialsmakethemplayanimportantroleinComputerAidedGeometricDesignandApproximationThe6ry.Manyscholarshavemademucheffortsinstudyillgthoseproperties.In1987,Brown,etal[1]begantostudyLipschitzcontilluitypreservingpropertyofBernsteinpolynomials.Theyprovedthatifunivariatefuncti…     

二次半定规划问题及其投影收缩算法

In this paper,we discuss the relations among the quadratic semi-definite programming problem,the linear semi-definite porgramming and the linearquadratic semi-definite programming problem.The duality theories are presented.After proving the equivalence of its optimality conditions and monotonous linear variational inequalities,we use the projection and contraction algorithms to solve(QSDP),We present the algorithms and its convergence analysis.     

CONVERGENCE PROPERTIES OF A MODIFIED BFGS ALGORITHM FOR MINIMIZATION WITHARMIJO-GOLDSTEIN STEPLENGTHS

1.IntroductionAssumethatwearefindingtheminimizerofthefollowingunconstrainedoptimizationproblemminf(x),(1.1)acReandassumethecurrentpointisxk'TOcalculatexk 1fromxkbyalinesearchmethod,thefollowingiterationXk 1~Xk Akpk,k~1,2,'(1.2)isapplied.IntheBFGSal...     

并行Halley迭代法的修正及其效率分析

In this paper a modification of the parallel Halley iteration method for simultaneously finding polynomial zeros is discussed. The convergence and the convergence rate with high order are obtained and the efficiency analysis is given.     

MODIFIABLE QUARTIC AND QUINTIC CURVES WITH SHAPE-PARAMETERS

1　IntroductionBecause of their good properties,the cubic Bézier,B-spline and NURBScurves play animportantrole in CAD,CAGD and modeling systems.When interpolation by the abovecurvesto all ora partofthe control pointsisrequired,itis necessary eitherto find new control pointsby solving a system of linear equations or to insert additional control points. Moreover,thewhole interpolating curve may be affected by moving an individual control point[1～ 6] .By uisng the matrix form ofthe Bernst…     

非奇异M矩阵的判定及并行算法的注记

In this paper a new necessary and sufficient condition for judging Mmatrix is given. It improved the latest result.     

LEVERRIER-LAGUERRE ALGORITHM FOR THE MATRIX POLYNOMIAL OF DEGREE TWO

1　ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔＡｂｅａｎ×ｎｍａｔｒｉｘ ,Ｉｎｄｅｎｏｔｅｓｔｈｅｕｎｉｔｍａｔｒｉｘｏｆｏｒｄｅｒｎ .Ａｎｄｌｅｔ ａ(λ) =ｄｅｔ(λＩｎ-Ａ) =λｎ+ ａ1λｎ- 1+… + ａｎ- 1λ+ ａｎ (1 .1 )ｂｅｔｈｅｃｈａｒａｃｔｅｒｉｓｔｉｃｐｏｌｙｎｏｍｉａｌｏｆＡ ,ｔｈｅａｄｊｏｉｎｔｍａｔｒｉｘｏｆλＩｎ-Ａｂｅ Ｂ(λ) =ａｄｊ(λＩｎ-Ａ) =λｎ- 1Ｉｎ+λｎ- 2 Ｂ1+… +λ Ｂｎ- 2 + Ｂｎ- 1. (1 .2 )Ｔｈｅｎ(λΙｎ-Ａ) - 1= Ｂ(λ) / ａ(λ) . (1 .3)　　Ａｗｅｌｌ ｋｎｏｗＬｅｖｅｒｒｉ…     

THE PRIMAL—DUAL POTENTIAL REDUCTION ALGORITHM FOR POSITIVE SEMI—DEFINITE PROGRAMMING

In this paper we introduce a primal-dual potential reduction algorithm for positive semi-definite programming. Using the symetric preserving scalings for both primal and dual interior matrices, we can construct an algorithm which is very similar to the primal-dual potential reduction algorithm of Huang and Kortanek [6] for linear programming. The complexity of the algorithm is either O(nlog(X0 · S0/ε) or O(nlog(X0· S0/ε) depends on the value of ρ in the primal-dual potential function, where X0 and S0 is the initial interior matrices of the positive semi-definite programming.     

一种求解非线性互补问题的方法及其收敛性

本文将Newton方法和外梯度方法相结合,提出了一种求解非线性互补问题的方法,证明了此方法的全局收敛性和超线性收敛性,在适当的条件下给出了一个有限终止结果。数值实验表明,此方法是有效的。     

非奇异M矩阵的判定及并行算法

1　引　　言M矩阵是一类具有非正非对角元和非负对角元的实方阵 .M矩阵在生物学、经济学、智能科学、计算方法等许多学科中都有重要应用 .许多实际问题的应用都归到 M矩阵的判定上 .例如判定一个矩阵是否为 M矩阵在网络计算中可以判定一个离散动力系统是否稳定 .在数值计算中 ,可以判定一个迭代系统是否收敛 .因此研究 M矩阵的判定方法成为矩阵理论研究中极为活跃的一个领域 .目前国内外许多数学工作者都在研究 M矩阵的判定方法 ,已有的研究成果都是对 M矩阵的整体进行讨论 ,这对高阶矩阵来说 ,不仅计算困难 ,而且需要对判定定理进行消化…     

改进的自组织映射(SOM)蛋白质折叠算法和计算实现

蛋白质结构预测是生物信息学中的重要研究方向．为了研究蛋白质折叠的机理,人们引入了只考虑蛋白质疏水核心和亲水外围位置导致能量差别的简化HP模型．即使是求解二维HP模型已被证明是一个NP完全问题,因此需要设计有效的近似算法来求解较大规模的HP模型．从旅行商问题(TSP)的求解看,自组织映射是构造近似算法的有效工具．本文将归一化的F-W自组织模型应用到蛋白质二维HP问题的求解中,结合为克服多重映射构造的局部线搜索算法．数值试验表明,该算法改进了现有的HP模型的SOM求解算法, 只需很少的迭代步数就能找到最低能量构象．这一改进算法可以成为进一步研究的基础．     

MERIT FUNCTION AND GLOBAL ALGORITHM FOR BOX CONSTRAINED VARIATIONAL INEQUALITIES

1 IntroductionWe consider tlie variational inequality problelll, deuoted by VIP(X, F), wliicli is to find avector x* E X such thatF(X*)"(X -- X-) 2 0, VX E X, (1)where F: R" - R" is any vector-valued f11uction and X is a uonelllpty subset of R'.This problem has important applicatiolls. in equilibriun1 modeIs arising in fields such asecououtics, transportatioll scieuce alld operations research. See [1]. There exist mauy lllethodsfor solviug tlie variational li1equality problem VIP(X. …     

THE CONVERGENCE OF A DOMAIN DECOMPOSITION ALGORITHM FOR PARABOLIC PROBLEMS

At recent, Hourgat et gave a domain decomposition algorithm for elliptic problems which can be implemented in parallel. Many numerical experiments have illustrated its efficiency. In the present paper, we apply this algorithm to solve the discrete parabolic problems, analyse its convergence and show that its convergence rale is about (1 - 2p + σp2 ) which is nearly optimal and independent of the parameter τ, where σ τ O((1 +H )(1 + ln(H / h))2 ). 0 < p < 1 / σ,τ,h,H are the time step size, finite element parameter and subdomain diameter, respectively.     

THE CALCULUS OF GENERATING FUNCTIONS AND THE FORMAL ENERGY FOR HAMILTONIAN ALGORITHMS

1.DarbouxTransformationConsidercotangentbundleT*R"acRZnwithnaturalsymplecticstructureandtheproductofcotangentbundles(T*R")x(T*R")=R4nwithnaturalproductsymplecticstructureCorrespondingly,weconsidertheproductspaceR"xR"rsRZn.ItscotangentbunT*(R"xR")=T*Rzn=R'nhasnaturalsymplecticstructure')PreparedbyQinMengzhaoChoosesymplecticcoordinatesz~(p,q)onthesymplecticmanifold,thenforsymplectictransformationg:T*R"~T*R",wehaveitisaLagrangiansubmanifoldofT*R"xT*RninR4n~(R'",J4.).NotethatonR4nth…