定义在范畴_RM_n~l上的张量函数

文[1]引进了左R-n模范畴_RM_n~1,将Hom函子推扩到_RM_n~l上,且讨论了它的拟正合性。在模范畴中,张量函子与Hom函子一样是一个重要的函子。文[2]企图在_RM_n~l上建立相应的张量积,并证明张量函子M_n~:AG_(rn)→_RM_n~l与Hom函子Hom(M_):AG_(rn)′→_RM_n~l为伴随对。但其构造的交换自由n-群仅对满足(E)条件的交换n-群具有泛性,故其张量积亦只是     

同调函子的一个应用

本文利用同调函子给出了交换的 Noether环上单模的投射性与内射性是等价的一个简单证明 ,同时推广了文 [1]的一些结论     

自映射的过滤子、Ω-稳定性及R-稳定性

在文献[1]中我们得到了关于自映射的一系列结果,这些结果或多或少都与微分同胚情形的结论相似。本文以过滤子为过渡,得到Q-稳定性及R-稳定性。我们遵循微分同胚情形的线索,本文与文献[1]中的论述密切相关。为了节省篇幅,除非特殊申明,我们不再重复文献[1]中的结论。     

模糊拟一致空间完备性之间的关系

本文基于1-滤子定义了概率拟一致空间的一种柯西1-完备性,研究概率拟一致结构与Hutton[0,1]-拟一致结构两者完备性之间的关系。在模糊拟度量空间里,我们建立了诱导的概率拟一致空间和诱导的Hutton[0,1]-拟一致空间两者完备性之间的关系。     

一类KdV非线性Schrdinger组合微分方程组周期初值问题和柯西问题整体解的存在性唯一性

<正> 在[1]、[2]、[3]中研究了组合微分方程组——低频电场扰动密度满足具有质动力项的KdV方程和电场满足的Schrodinger类方程——的偶合孤立子问题.在[1]中用数值解方法研究了Langmuir波和离子声波偶合的C孤立子结构,分析了它和非线性Schrodinger孤立子、Langmuir孤立子以及离子声波孤立子的相互作用问题.为了更好地研究这类方程组及其孤立子的性质,有必要对它的整体解的存在性、唯一性加以论证. 本文考虑如下一类KdV非线性Schrodinger组合微分方程组     

一维广义Ginzburg－Landau方程的指数吸引子

本文在[1]的基础上,得到了一维广义Ginzburg-Landau方程的指数吸引子的存在性。     

Lozi映射奇怪吸引子的探讨

本文利用横截环理论,详细分析了Lozi映射的奇怪吸引子的存在性和结果,所得结果与数值结果相吻合,并解释了若干数值现象,从而进一步论证[1]所提出奇怪吸引子结论是合理的。     

耦合非线性波方程的指数吸引子

在文[1]的基础上，得到了耦合非线性波方程的指数吸引子的存在性．     

二维广义Ginzburg-Landau方程的指数吸引子

在文[1]的基础上，得到了二维广义的Ginzburg－Landau方程的指数吸引子的存在性．     

也谈子不等式从何而来

文[1]介绍了用“子不等式法”证明与自然数n有关的不等式的方法.针对文[1]的遗留问题,文[2]介绍了“子不等式从何而来?”文[2]认为:“一旦证明了子不等式,就……改为非数学归纳法的证明.”但从所举例题来看,“子不等式”均系由数学归纳法的第二步并通过分析法得出,其实质仍为数学归纳法.若要“改为非数学归纳法的证明”,即用“子不等式法”,直接得出“子不等式”并予以证明方可.但子不等式是否存在?能否直接得出?成为解决问题的关键.笔者研究发现,子不等式完全可直接由欲证之不等式直接得出.下面介绍给读者.     

Local Tensor Valuations

The local Minkowski tensors are valuations on the space of convex bodies in Euclidean space with values in a space of tensor measures. They generalize at the same time the intrinsic volumes, the curvature measures and the isometry covariant Minkowski tensors that were introduced by McMullen and characterized by Alesker. In analogy to the characterization theorems of Hadwiger and Alesker, we give here a complete classification of all locally defined tensor measures on convex bodies that share with the local Minkowski tensors the basic geometric properties of isometry covariance and weak continuity.     

Contact Tensor Calculus

Summary It is shown that a Tensor Calculus in which the group of transformations is the group of contact transformations can be developed by making a systematic use of existing theories of non-holonomic spaces. The generalizations of Riemannian Geometry are then considered in relation to the new Calculus.     

Tensor spline approximation

The cyclic-shift tensor-factorization interpolation method recently described by de Boor can be used in particular for least-squares fitting of multivariate data on a rectangular grid and for evaluation of the resulting tensor-product splines, taking advantage of existing linear algebra and univariate spline software. We discuss the computational details of this method, pointing out variants and suggesting techniques for dealing with ill-conditioned least-squares problems.     

L—fuzzy模范畴的张量积与张量函子

本文在Ｌ—ｆｕｚｚｙ模范畴中，建立了相应的张量积，给出了它的结构性、存在性与唯一性定理，并讨论了张量函子与Ｈｏｍ函子的伴随性。所得结果为通常张量积的“良好推广”（ｇｏｏｄｅｘｔｅｎｓｉｏｎ）。     

半模的张量积

本文引入了半模的张量积的泛性定义，给出了半模范畴中的有向正向系的上极限以及任意一个半模同态的上核，讨论了半模张量积的若干性质，主要结果是：证明了张量函子保持半模的右正合性和上积，并且上积保持半模的平坦性，半模范畴中的张量函子保持上极限和上核．     

Tensor eigenvalue complementarity problems

This paper studies tensor eigenvalue complementarity problems. Basic properties of standard and complementarity tensor eigenvalues are discussed. We formulate tensor eigenvalue complementarity problems as constrained polynomial optimization. When one tensor is strictly copositive, the complementarity eigenvalues can be computed by solving polynomial optimization with normalization by strict copositivity. When no tensor is strictly copositive, we formulate the tensor eigenvalue complementarity problem equivalently as polynomial optimization by a randomization process. The complementarity eigenvalues can be computed sequentially. The formulated polynomial optimization can be solved by Lasserre’s hierarchy of semidefinite relaxations. We show that it has finite convergence for generic tensors. Numerical experiments are presented to show the efficiency of proposed methods.     

Tensor products of orthoalgebras

We define a tensor product via a universal mapping property on the class oforthoalgebras, which are both partial algebras and orthocomplemented posets. We show how to construct such a tensor product forunital orthoalgebras, and use the Fano plane to show that tensor products do not always exist.     

Tensor rank is NP-complete

We prove that computing the rank of a three-dimensional tensor over any finite field is NP-complete. Over the rational numbers the problem is NP-hard.