一类新的二阶切导数及其在集值优化中的应用

提出了一种新的二阶切锥,讨论了它与二阶广义相依切集的关系.利用此锥定义了一种新的二阶切导数,讨论了它与二阶广义相依上图切导数的关系.利用Henig扩张锥的性质,给出了集值优化在Henig有效元意义下的二阶最优性必要条件.在近似锥-次类凸假设下给出了Benson真有效元意义下的二阶最优性必要条件.举例说明了本文的主要结论.     

二阶变系数线性微分方程的几个可积类型

利用变量代换把二阶变系数线性微分方程降阶为一阶线性微分方程,讨论了二阶变系数线性微分方程可积4个充分条件及通解公式.     

二维分数阶发展型方程的正式的二阶BDF交替方向隐式紧致差分格式

该文将研究二维分数阶发展型方程的正式的二阶向后微分公式(BDF)的交替方向隐式(ADI)紧致差分格式.在时间方向上用二阶向后微分公式离散一阶时间导数,积分项用二阶卷积求积公式近似,在空间方向上用四阶精度的紧致差分离散二阶空间导数得到全离散紧致差分格式.基于与卷积求积相对应的实二次型的非负性,利用能量方法研究了差分格式的稳定性和收敛性,理论结果表明紧致差分格式的收敛阶为O(k~(a+1)+h_1~4+h_2~4),其中k为时间步长,h_1和h_2分别是空间x和y方向的步长.最后,数值算例验证了理论分析的正确性.     

直立圆柱二阶波浪力解析解

大直径直立圆柱体上的二阶波浪力目前已有一些研究结果,但仍存在一些值得进一步探讨之处.这一方面在于二阶辐射条件还不甚清楚:另一方面在于已有的二阶力公式或是所含积分的收敛精度不易保证,或是表达式繁杂,不利于实际计算.本文在求解这一问题时,不是对二阶势提出辐射条件,而是对二阶势的周向富里叶分量提出辐射条件──Sommerfeld辐射条件.求解中,利用本文推导出的数学公式,简化了二阶自由面条件非齐次项的表达式,得到了形式简单,易于计算的二阶波浪力精确公式.二阶力计算结果与实验结果吻合良好.     

二阶矩阵快速乘法的一个新的算法集合

文献[1]—[4]从不同角度研究了二阶矩阵快速乘的各种问题,所有算法分属于以S算法与W算法为基础的两个算法集合.本文作者深入研究了算法的结构和性质,通过计算机检索,得到一个不属于上述两集合的算法和相应的包含有1048576个算法的封闭的算法集合.     

特殊双列代数的Hochschild上同调

本文基于四项正合序列,利用组合的方法给出了具有正规基的特殊双列代数的一阶和二阶Hochschild上同调群的维数公式.     

求二阶和三阶常系数非齐次线性微分方程特解的一个公式

基于微分算子分裂的思想,受到一阶线性方程求解公式的启发,运用多重积分交换积分顺序的技巧,得到求二阶和三阶常系数非齐次线性微分方程特解的一般性公式.     

Gauss-Bonnet-Chern曲率的变分公式（英文）

p阶Gauss-Bonnet-Chern曲率L_p是数量曲率的一种推广.本文考虑了由此曲率定义的黎曼泛函F~p.计算了F~p的二阶变分公式.应用该公式证明了球面上的标准度量和复射影空间上的Fubini-Study度量是F~p的鞍点.     

非线性Hénon方程解的Liouville定理

该文研究了二阶和四阶非线性Henon-Lane-Emden方程有限Morse指标解的Liouville定理.利用一种新方法,即使用单调公式、Pohozaev恒等式和doubling引理等相结合证明了其结果.     

一类二阶微分方程的特征值估计及其反问题

借助Rouché定理及渐近分析的方法,给出了边界条件含有特征参数的一类二阶微分方程的特征值渐近公式.运用特征值渐近公式给出了特征值反问题的一个惟一性结果及重构公式.     

集值向量优化的二阶最优性必要条件

在赋范空间中给出了集值映射的二阶切集的概念,利用二阶切集,定义了集值映射的二阶切导数。然后,获得了集值向量优化问题弱极小元的两个二阶最优性必要条件。     

一类新的二阶组合切导数及其应用

引进了一种新的切锥,讨论它与相依切锥的关系.借助这种新的切锥引进了一类新的二阶组合切导数,并讨论了它与其他二阶切导数的关系.利用这类新的二阶组合切导数,建立了集值优化分别取得Henig有效元和全局有效元的最优性必要条件.     

集值优化Benson真有效元的二阶刻画

引进了一种新的二阶组合切锥, 利用它引进了一种新的二阶组合切导数, 称为二阶组合径向切导数, 并讨论了它的性质及它与二阶组合切导数的关系, 借助二阶径向组合切导数, 分别建立了集值优化取得Benson真有效元的最优性充分和必要条件.     

No Gap Second-Order Optimality Conditions for Circular Conic Programs

In this article, we study the second-order optimality conditions for a class of circular conic optimization problem. First, the explicit expressions of the tangent cone and the second-order tangent set for a given circular cone are derived. Then, we establish the closed-form formulation of critical cone and calculate the “sigma” term of the aforementioned optimization problem. At last, in light of tools of variational analysis, we present the associated no gap second-order optimality conditions. Compared to analogous results in the literature, our approach is intuitive and straightforward, which can be manipulated and verified. An example is illustrated to this end.     

Second-order conditions for extremum problems with nonregular equality constraints

Combining results of Avakov about tangent directions to equality constraints given by smooth operators with results of Ben-Tal and Zowe, we formulate a second-order theory for optimality in the sense of Dubovitskii-Milyutin which gives nontrivial conditions also in the case of equality constraints given by nonregular operators. Secondorder feasible and tangent directions are defined to construct conical approximations to inequality and equality constraints which within a single construction lead to first- and second-order conditions of optimality for the problem also in the nonregular case. The definitions of secondorder feasible and tangent directions given in this paper allow for reparametrizations of the approximating curves and give approximating sets which form cones. The main results of the paper are a theorem which states second-order necessary condition of optimality and several corollaries which treat special cases. In particular, the paper generalizes the Avakov result in the smooth case.This research was supported by NSF Grant DMS-91-009324, NSF Grant DMS-91-00043, SIUE Research Scholar Award and Fourth Quarter Fellowship, Summer 1992.     

Second-Order Optimality Conditions in Multiobjective Optimization Problems

In this paper, we develop second-order necessary and sufficient optimality conditions for multiobjective optimization problems with both equality and inequality constraints. First, we generalize the Lin fundamental theorem (Ref. 1) to second-order tangent sets; then, based on the above generalized theorem, we derive second-order necessary and sufficient conditions for efficiency.     

Second-order optimality conditions in set-valued optimization via asymptotic derivatives

In this article we give new second-order optimality conditions in set-valued optimization. We use the second-order asymptotic tangent cones to define second-order asymptotic derivatives and employ them to give the optimality conditions. We extend the well-known Dubovitskii–Milutin approach to set-valued optimization to express the optimality conditions given as an empty intersection of certain cones in the objective space. We also use some duality arguments to give new multiplier rules. By following the more commonly adopted direct approach, we also give optimality conditions in terms of a disjunction of certain cones in the image space. Several particular cases are discussed.     

Optimality Conditions in Differentiable Vector Optimization via Second-Order Tangent Sets

We provide second-order necessary and sufficient conditions for a point to be an efficient element of a set with respect to a cone in a normed space, so that there is only a small gap between necessary and sufficient conditions. To this aim, we use the common second-order tangent set and the asymptotic second-order cone utilized by Penot. As an application we establish second-order necessary conditions for a point to be a solution of a vector optimization problem with an arbitrary feasible set and a twice Fréchet differentiable objective function between two normed spaces. We also establish second-order sufficient conditions when the initial space is finite-dimensional so that there is no gap with necessary conditions. Lagrange multiplier rules are also given. This research was partially supported by Ministerio de Ciencia y Tecnología (Spain), Project BFM2003-02194. Online publication 29 January 2004.     

New Results on Second-Order Optimality Conditions in Vector Optimization Problems

In this paper, we study second-order optimality conditions for multiobjective optimization problems. By means of different second-order tangent sets, various new second-order necessary optimality conditions are obtained in both scalar and vector optimization. As special cases, we obtain several results found in the literature (see reference list). We present also second-order sufficient optimality conditions so that there is only a very small gap with the necessary optimality conditions. The authors thank Professor P.L. Yu and the referees for valuable comments and helpful suggestions.     

变序结构局部弱非控点的二阶刻画

引进了一种二阶切导数,借助该切导数给出了变序结构集值优化问题取得局部弱非控点的二阶最优性必要条件.在某种特殊情况下,给出了一阶最优性条件.通过修正的Dubovitskij-Miljutin切锥导出的约束规格,给出了两个集值映射之和的二阶相依切导数的关系式,进一步得到目标函数与变锥函数的二阶相依切导数分开形式的最优性必要条件.