一类二元叠加码的卡氏积及其性质北大核心

二元叠加码d-析取矩阵是组合分组测试理论的一个极其重要的数学模型,定义了两个已知d-析取矩阵的卡氏积并证明了它的性质,最后,对这一定义进行了推广.     

一类二元叠加码的卡氏积及其性质

二元叠加码d-析取矩阵是组合分组测试理论的一个极其重要的数学模型,定义了两个已知d-析取矩阵的卡氏积并证明了它的性质,最后,对这一定义进行了推广.     

一类随机d-析取矩阵的构作及其性质

d-析取矩阵是组合群测的数学模型,也是检测试验中的识别工具.α-almost k-析取矩阵是一种随机d-析取矩阵,在α-almost k-析取矩阵的基础上定义了α-almost d~e-析取矩阵和α-almost(d,r,z]-析取矩阵,计算了它们的参数、研究了它们的性质.     

一类二元容错码的扩展和算法

d-析取矩阵是非适应性群测(NGT)算法和二元叠加码最有效的数学模型,研究了d-析取矩阵M_q(n,k,d)的扩展码M_q~*(n,k,d)的析取性和容错性.     

一类析取矩阵的构作和性质

利用BIB设计构作了一个d-析取矩阵A,研究了它的一些性质;然后,通过给矩阵A加行构作了一个新矩阵A+,研究了这个新矩阵的性质,并比较了两个矩阵的检纠错性.     

基于矩阵M_q(n,k,d)的可纠错非适应性群测

二元矩阵M_q(n,k,d)是一个非适应性分组测试(NGT)算法的数学模型,它是一个d-析取矩阵.在矩阵M_q(n,k,d)的基础上研究它的子矩阵M_q(n.k,d,z)的检纠错性质.     

二元叠加码M_q(n,k,d)的推广及其性质

利用有限域F_q上n维向量空间中子空间的相交关系定义了一个(0,1)-矩阵M_q(i:n,k,d),它是矩阵M_q(n,k,d)的推广.最后证明了这个矩阵M_q(i:n,k,d)是一个d-析取矩阵并且具有强容错能力.     

一个BSC码的扩展和它的性质

二元叠加码M_q(n,k,d)是一个非适应性分组测试(NGT)算法的数学模型,它是一个d-析取矩阵.将二元叠加码M_q(n,k,d)扩展到M_q(n,k,d,α)并研究了它的性质.     

基于两个常重码的(t,∈)-析取矩阵

(t,∈)-析取矩阵是组合群测理论中一个新型的随机数学模型,以两个二元常重叠加码为基础,根据它的性质和参数构作了一个(t,∈)-析取矩阵并给出了(t,∈)-析取矩阵的平均汉明距离.     

(d,r,k)-析取矩阵的卡氏积

(d,r,κ)-析取矩阵是分组测试理论中的一个Inhibitor模型.利用两个已知的(d,r,k)-析取矩阵定义了它们的卡氏积,并计算了这个新(d,r,κ)-析取矩阵的参数.     

具有常数行重的一类d-析取矩阵的界

首先介绍了辛空间上子空间的一些包含性质,利用这些性质构作了一类具有常数行重的dλ-析取矩阵,然后给出了这类矩阵相关参数的界.     

Calculating Thomson's Spectral Multitapers by Inverse Iteration

Abstract

Spectral estimation using a set of orthogonal tapers is becoming widely used and appreciated in scientific research. It produces direct spectral estimates with more than 2 df at each Fourier frequency, resulting in spectral estimators with reduced variance. Computation of the orthogonal tapers from the basic defining equation is difficult, however, due to the instability of the calculations—the eigenproblem is very poorly conditioned. In this article the severe numerical instability problems are illustrated and then a technique for stable calculation of the tapers—namely, inverse iteration—is described. Each iteration involves the solution of a matrix equation. Because the matrix has Toeplitz form, the Levinson recursions are used to rapidly solve the matrix equation. FORTRAN code for this method is available through the Statlib archive. An alternative stable method is also briefly reviewed.     

Transforming an error-tolerant separable matrix to an error-tolerant disjunct matrix

Recently, Chen and Hwang [H.B. Chen, F.K. Hwang, Exploring the missing link among d-separable, -separable and d-disjunct matrices, Discrete Applied Mathematics 133 (2007) 662-664] provided a method for transforming a separable matrix to a disjunct matrix. In [D.Z. Du, F.K. Hwang, Pooling Designs and Nonadaptive Group Testing — Important Tools for DNA Sequencing, World Scientific, 2006], Du and Hwang attempted to extend this result to its error-tolerant version; unfortunately, they gave an incorrect extension. This note gives a solution to this problem.     

次Hermite矩阵的对角化及次Hermite矩阵的应用

循环矩阵在理论及实际问题上都得到了广泛的应用,而循环矩阵是一类典型的次对称矩阵,此外Hadamare 矩阵中也涉及到了次对称矩阵,本文将对次对称矩阵进一步的推广,定义了次Hermite 矩阵及次正定的次Hermite 矩阵.并且讨论它们的对角化方法,得出了类以于Hermite 矩阵的一些结论,最后作为应用,讨论了次Hermite 矩阵的算子范数及F—范数的理论值。关键词次Hermite 矩阵次特征值及次特征向量次正定的次Hermite 矩阵.     

Stabilization criteria of a class of switched systems

In this paper, stabilizability property for a switched system under arbitrary switching is considered from an algebraic point of view by means of the existence of a set of block‐diagonal Lyapunov solutions with common Schur complement of certain order—or, equivalently, with common block (1,1)—for the matrix bank. It is shown that the existence of that set is equivalent to the existence of solutions for some Riccati inequalities done in terms of the blocks of matrices of the bank. In addition, we conclude that a particular class of systems with matrix bank constituted by Metzler matrices—Positive Switched Systems—are stabilizable by partial state reset.     

A spectral algorithm for envelope reduction of sparse matrices

The problem of reordering a sparse symmetric matrix to reduce its envelope size is considered. A new spectral algorithm for computing an envelope-reducing reordering is obtained by associating a Laplacian matrix with the given matrix and then sorting the components of a specified eigenvector of the Laplacian. This Laplacian eigenvector solves a continuous relaxation of a discrete problem related to envelope minimization called the minimum 2-sum problem. The permutation vector computed by the spectral algorithm is a closest permutation vector to the specified Laplacian eigenvector. Numerical results show that the new reording algorithm usually computes smaller envelope sizes than those obtained from the current standards such as the Gibbs—Poole—Stockmeyer (GPS) algorithm or the reverse Cuthill—McKee (RCM) algorithm in SPARSPAK, in some cases reducing the envelope by more than a factor of two.     

关于实方阵的正定性与规范性的进一步拓广

对亚正定矩阵类与实规范矩阵类作进一步拓广 ,得到一个新的矩阵类——亚规范矩阵 .研究了它的等价条件 ,合同下的标准形及有关行列式的性质 ,所得结果推广并改进了亚正定矩阵与实规范矩阵的一些结论 .     

Massive vector gauge theory and comparison with Higgs—Connes—Lott

A massive vector gauge theory constructed from the matrix derivative approach of non-commutative geometry is compared with the Higgs—Connes—Lott theory. In the massive vector gauge theory, a new extra shift-like symmetry which is due to the one form constant matrix derivative allows the theory to have a mass term while keeping the gauge symmetry intact. In the Higgs—Connes—Lott theory, the transformation of scalar field makes up the deficiency of symmetry due to the mass term. Thus, when the scalar field is absent there remains no gauge symmetry just like the Proca model. In the massive vector gauge theory, the shift-like symmetry makes up the deficiency of symmetry due to the mass term even in the absence of the scalar field.     

基于结构元方法的模糊数互补判断矩阵排序法

利用模糊结构元方法,研究了决策信息以模糊数互补判断矩阵形式给出的有限方案决策问题。给出了模糊数互补判断矩阵的定义,介绍了模糊数排序的一种简捷方法——组合序。在该序的基础上,对模糊有序加权平均(FOWA)算子的若干性质进行证明。利用该算子能够将模糊数互补判断矩阵转换为实数矩阵,进而,对模糊数互补矩阵的排序问题转换成实数矩阵的排序问题。只要矩阵中的元为有界闭模糊数,就可以利用FOWA算子进行排序。最后通过算例对比分析,算例表明利用本文的方法进行排序更为简捷。