Third-order elastic, piezoelectric, and dielectric constants

The definitions of the third-order elastic,piezoelectric,and dielectric constants and the properties of the associated tensors are discussed.Based on the energy conservation and coordinate transformation,the relations among the third-order constants are obtained.Furthermore,the relations among the third-order elastic,piezoelectric,and dielectric constants of the seven crystal systems and isotropic materials are listed in detail.These third-order constants relations play an important role in solving nonlinear problems of elastic and piezoelectric materials.It is further found that all third-order piezoelectric constants are 0 for 15 kinds of point groups,while all third-order dielectric constants are 0 for 16 kinds of point groups as well as isotropic material.The reason is that some of the point groups are centrally symmetric,and the other point groups are high symmetry.These results provide the foundation to measure these constants,to choose material,and to research nonlinear problems.Moreover,these results are helpful not only for the study of nonlinear elastic and piezoelectric problems,but also for the research on flexoelectric effects and size effects.

给定独立数谱半径最大的一致超树

一致超图H的谱半径就是其邻接张量A(H)特征值模的最大值.借助匹配多项式得到了使超树邻接谱半径增加的系列变换.作为这些变换的应用,确定了给定独立数且谱半径最大的k-一致超树.

关于局中人两个子集的部分对称博弈

研究了关于局中人两个子集的部分对称博弈。通过基于相邻对换的矩阵半张量积方法,首先得到了关于局中人两个子集的部分对称博弈的等价条件。利用该等价条件,计算出了该部分对称博弈子空间的维数并且构造出了它的一组基,进而导出了关于该部分对称博弈的方程数目最少的判别方程。

Least H-eigenvalue of adjacency tensor of hypergraphs with cut vertices

Let G be a connected hypergraph with even uniformity,which contains cut vertices.Then G is the coalescence of two nontrivial connected sub-hypergraphs(called branches)at a cut vertex.Let A(G)be the adjacency tensor of G.The least H-eigenvalue of A(G)refers to the least real eigenvalue of A(G)associated with a real eigenvector.In this paper,we obtain a perturbation result on the least H-eigenvalue of A(G)when a branch of G attached at one vertex is relocated to another vertex,and characterize the unique hypergraph whose least H-eigenvalue attains the minimum among all hypergraphs in a certain class of hypergraphs which contain a fixed connected hypergraph.

基于有向超图的图像匹配算法

为了提高复杂变换下图模型的匹配精度,提出了一种基于有向超图的图像匹配算法.该算法首先分别在两个待匹配的特征点集中构造3一致超图,计算每条超边所包含三元组的权值,然后利用这些权值来构造加权邻接张量,最后通过凸凹松弛算法实现图像匹配.模拟和真实图像的实验结果表明,文中算法能够获得更高的匹配精度,对于复杂变换的图像也有很好的匹配效果.

矩张量反演法在江苏及附近海域的应用

利用江苏区域数字地震台网宽频带地震计记录的Pnl波波形资料,采用TDMT-INV时间域地震矩张量反演方法,尝试反演2009—2011年江苏及附近海域7次中小地震(M_L3.5以上,最大震级M_L5.3)的地震矩张量解,并通过记录清晰的P波初动在震源球的下半球投影对反演结果进行评价。结果表明:反演结果与初动方向一致较好。由此说明在研究区域用矩张量反演法测定中小地震震源机制解具有一定的可行性。

k-一致线性超图的谱半径（英文）

设H=(V,E)是k-一致超图,A(H),Q(H)分别为k-一致超图H的邻接张量与无符号拉谱拉斯张量.本文研究了k-一致超图的顶点拆分运算下谱半径的变化与3-一致超树的极值谱半径,证明了固定顶点数与悬挂边数3-一致超树中Tn,k具有最大的谱半径的3-致超树,也证明了固定顶点数与直径的3-一致超树中Tnd具有最大的谱半径的3-一致超树.

基于结构张量特征邻域的机体损伤区域划分

为实现机体损伤区域准确高效的划分,实现对机体损伤模型重构的数据支持,引入结构张量理论,对机体损伤图像进行特征表示。构建结构张量特征空间,通过分析特征分布,可知损伤特征点分布相对独立,与特征取值无显著关联;以此为依据,提出基于特征邻域的损伤区域划分方法。通过机体损伤图像实例验证,与K均值聚类划分方法对比,对比结果表明,该方法划分的损伤区域准确,边界连续,细节完整,能够消除小范围邻接区域对划分结果的干扰。

张量空间中可合元素图的基本结构

应用诱导生成子图的方法,研究了可合张量的图论性质。通过讨论一个顶点和它的两个相邻顶点的诱导生成子图的结构,指出三角形和平形四边形结构是可合张量的图的基本结构,得到了由图论语言表达的可合张量的充分必要条件。

基于张量建模和进化K均值聚类的社区检测方法

很多传统社区检测方法大多局限于单关系网络,适用性和准确性均较弱。针对此问题,提出了一种针对多关系网络的社区检测方法。首先,为进行多关系网络建模,使用了三阶邻接张量,其中张量的每个切片表示与参与者之间一种类型的关系相对应的邻接矩阵。从数据表示的角度,将多关系网络解读为三阶张量利于将因子分解方法作为学习方法使用。然后,应用RESCAL分解作为关系学习的工具,从而揭示参与者的唯一隐性表征。最后,在上一步得到的结果上应用进化K均值聚类算法,以确定多维度上的社区结构。在一个合成数据集和两个公开数据集上进行实验。实验结果表明,与基于上下文信息的社区检测(CICD)方法、Memetic方法和局部谱聚类(LSC)方法相比,所提方法的纯度最少提高了5个百分点,重叠归一化互信息(ONMI)最少提高了2个百分点,F得分最少提高了3个百分点,并且验证了该方法具有较快的收敛速度。

The Adjacency and Signless Laplacian Spectra of Cored Hypergraphs and Power Hypergraphs

In this paper,we study the adjacency and signless Laplacian tensors of cored hypergraphs and power hypergraphs.We investigate the properties of their adjacency and signless Laplacian H-eigenvalues.Especially,we find out the largest H-eigenvalues of adjacency and signless Laplacian tensors for uniform squids.We also compute the H-spectra of sunflowers and some numerical results are reported for the H-spectra.

m, argest adjacency, signless Laplacian, and Laplacian H-eigenvalues of loose paths

We investigate k-uniform loose paths. We show that the largest H- eigenvalues of their adjacency tensors, Laplacian tensors, and signless Laplacian tensors are computable. For a k-uniform loose path with length l≥ 3, we show that the largest H-eigenvalue of its adjacency tensor is （（1 ＋ √-5）/2）2/k when = 3 and ）λ（A） = 31/k when g = 4, respectively. For the case of l ≥ 5, we tighten the existing upper bound 2. We also show that the largest H-eigenvalue of its signless Laplacian tensor lies in the interval （2, 3） when l≥ 5. Finally, we investigate the largest H-eigenvalue of its Laplacian tensor when k is even and we tighten the upper bound 4.

一致超树的邻接张量的Z-谱半径

设T是任意给定的r一致超树,ρZ(T)是T的邻接张量的Z-谱半径.证明了当r≥3时,ρZ(T)=r^(1-r/2).

一类Petri网系统建模与可达性分析的STP方法

基于矩阵半张量积(STP)方法研究了一类Petri网系统(PNSs)的建模和可达性问题.首先,利用STP将这类PNSs的动态演化表示为离散时间双线性方程;然后,给出了这类PNSs的变迁-状态邻接矩阵的定义,利用所建立的双线性方程和变迁-状态邻接矩阵给出了这类PNSs状态可达性判别的几个充要条件,同时设计了计算这类PNSs任意两可达状态的所有路径的有效算法;最后,用实例说明了所得结果的可行性与有效性.

张量乘积图的同构因子分解

本文讨论了两个可分图的张量乘积图的同构因子分解问题.给出了张量乘积图可同构因子分解的判定条件.

有序势博弈及其在智能体无线网络中的应用

有序势博弈具有广泛的应用,势有向图中不含单向圈是判定有序势博弈的一个充分必要条件.利用矩阵半张量积和置换矩阵,通过博弈的支付矩阵求取势有向图的邻接矩阵.通过收缩势有向图中的双向圈,将单向圈的存在性问题转化为判断收缩后的图中圈的存在性问题.此外,分析有序势函数的一些基本性质,并给出有序势函数的具体计算方法.最后结合线性规划讨论了有序势博弈在延长智能体无线网络系统寿命的应用.

Ordering uniform supertrees by their spectral radii

A supertree is a connected and acyclic hypergraph. For a hypergraph H, the maximal modulus of the eigenvalues of its adjacency tensor is called the spectral radius of H. By applying the operation of moving edges on hypergraphs and the weighted incidence matrix method, we determine the ninth and the tenth k-uniform supertrees with the largest spectral radii among all k-uniform supertrees on n vertices, which extends the known result.

Largest H-eigenvalue of uniform s-hypertrees

The k-uniform s-hypertree G = （V, E） is an s-hypergraph, where 1 ≤ s ≤ k - 1, and there exists a host tree T with vertex set V such that each edge of G induces a connected subtree of T. In this paper, some properties of uniform s-hypertrees are establised, as well as the upper and lower bounds on the largest H-eigenvalue of the adjacency tensor of k-uniform s-hypertrees in terms of the maximal degree A. Moreover, we also show that the gap between the maximum and the minimum values of the largest H-eigenvalue of k-uniform s-hypertrees is just （△S/k）.

Upper bounds for signless Laplacian Z-spectral radius of uniform hypergraphs

Let ■ be a k-uniform hypergraph on n vertices with degree sequence △= d1≥…≥ dn =δ. In this paper, in terms of degree di , we give some upper bounds for the Z-spectral radius of the signless Laplacian tensor (Q(■)) of ■. Some examples are given to show the efficiency of these bounds.

The Linear Unicyclic Hypergraph with the Second or Third Largest Spectral Radius

The spectral radius of a uniform hypergraph is defined to be that of the adjacency tensor of the hypergraph.It is known that the unique unicyclic hypergraph with the largest spectral radius is a nonlinear hypergraph,and the unique linear unicyclic hypergraph with the largest spectral radius is a power hypergraph.In this paper we determine the unique linear unicyclic hypergraph with the second or third largest spectral radius,where the former hypergraph is a power hypergraph and the latter hypergraph is a non-power hypergraph.