On cascades of elliptic periodic points in two-dimensional symplectic maps with homoclinic tangencies

We study bifurcations of two-dimensional symplectic maps with quadratic homoclinic tangencies and prove results on the existence of cascade of elliptic periodic points for one and two parameter general unfoldings.      

Existence and generic stability of solutions for multiclass multicriteria traffic equilibrium problems with capacity constraints of arcs

ABSTRACT

In this paper, we introduce the multiclass multicriteria traffic equilibrium problem with capacity constraints of arcs and its equilibrium principle. Using Fan–Browder's fixed points theorem and Fort's lemma to prove the existence and generic stability results of multiclass multicriteria traffic equilibrium flows with capacity constraints of arcs.     

复射影空间中具有平行平均曲率向量的一般子流形

本文研究了复射影空间中具有平行平均曲率向量的一般子流形曲率性质与几何性质之间的关系. 利用活动标架法, 获得了关于截面曲率, Ricci 曲率和第二基本形式模长的刚性定理, 推广和完善了相关文献的若干结果.     

改进的遗传算法在连续体结构多目标拓扑优化中的应用

连续体结掏多目标拓扑优化是结构优化领域中的一个较难的研究课题.本文提出了一种改进的SPEA2多目标优化算法.该算法中采用数学形态学中的四方向链码的编码方式进行结构拓扑表达,使产生的拓扑结构清晰且无异议,完全消除了模糊的拓扑边界和棋盘格现象.提出了"质量向量"的概念,用以量化两个结构拓扑之间的相似性,从而使得不同结构拓扑之间的相似性比较成为可能.同时还将机器学习中的范例学习的思想融入到新算法中,利用前面的有限元分析结果对后来的结构分析进行指导,剔除了很多不必要的重复的计算,从而使算法的总计算量大幅度地减少.将新算法应用于悬臂和简支两类深梁的多目标拓扑优化,获得了高质量的Pareto最优解,且具有很好的分布.     

Wavefront solutions in diffusive Nicholson＇s blowflies equation with nonlocal delay

This paper is concerned with the diffusive Nicholson＇s blowflies equation with nonlocal delay incorporated as an integral convolution over the entire past time up to now and the whole one-dimensional spatial domain R. Assume that the delay kernel is a strong generic kernel. By the linear chain techniques and the geometric singular perturbation theory, the existence of travelling front solutions is shown for small delay.     

Maps of manifolds into the plane which lift to standard embeddings in codimension two

Let be a smooth map of a closed n-dimensional manifold (n2) into the plane and let be an orthogonal projection. We say that f has the standard lifting property, if every embedding with is standard in a certain sense. In this paper we give some sufficient conditions for a generic smooth map f to have the standard lifting property when M is a closed surface or an n-dimensional homotopy sphere.     

Oscillations of higher order differential equations of neutral type

In this paper, sufficient conditions have been obtained for oscillation of solutions of a class of nth order linear neutral delay-differential equations. Some of these results have been used to study oscillatory behaviour of solutions of a class of boundary value problems for neutral hyperbolic partial differential equations.     

Convergence and finite determination of formal CR mappings

It is shown that a formal mapping between two real-analytic hypersurfaces in complex space is convergent provided that neither hypersurface contains a nontrivial holomorphic variety. For higher codimensional generic submanifolds, convergence is proved e.g. under the assumption that the source is of finite type, the target does not contain a nontrivial holomorphic variety, and the mapping is finite. Finite determination (by jets of a predetermined order) of formal mappings between smooth generic submanifolds is also established.

     

Quantum Standard Teleportation Based on the Generic Measurement Bases

We study the quantum standard teleportation based on the generic measurement bases. It is shown that the quantum standard teleportation does not depend on the explicit expression of the measurement bases. We have given the correspondence relation between the measurement performed by Alice and the unitary transformation performed by Bob. We also prove that the single particle unknown states and the two-particle unknown cat-like states can be exactly transmitted by means of the generic measurement bases and the correspondence unitary transformations.     

同伦算法在并联机器人运动学中的应用

讨论同伦算法求解并联机器人运动学正问题.通过参系数同伦法大大减少了跟踪路径的数目,从而提高了同伦算法的效率使之对求解一般非线性代数方程组更为可行.采用这一算法,求出了中科院沈阳自动化研究所机器人开放研究实验室的新型并联机器人模型的全部正解.为新模型的机构分析和实时控制提供了理论依据.