Liapunov spectra for infinite chains of nonlinear oscillators

We argue that the spectrum of Liapunov exponents for long chains of nonlinear oscillators, at large energy per mode, may be well approximated by the Liapunov exponents of products of independent random matrices. If, in addition, statistical mechanics applies to the system, the elements of these random matrices have a distribution which may be calculated from the potential and the energy alone. Under a certain isotropy hypothesis (which is not always satisfied), we argue that the Liapunov exponents of these random matrix products can be obtained from the density of states of a typical random matrix. This construction uses an integral equation first derived by Newman. We then derive and discuss a method to compute the spectrum of a typical random matrix. Putting the pieces together, we see that the Liapunov spectrum can be computed from the potential between the oscillators.     

On -Hadamard matrices

In this paper, we use the Sylvester's approach to construct another Hadamard matrix, namely a J_m-Hadamard matrix, from a given one. Consequently, we can generate other 2^m-1 Hadamard matrices from the constructed J_m-Hadamard matrix. Finally, we also discuss the Kronecker product of an Hadamard matrix and a J_m-Hadamard matrix.     

Unimodularity of the Clar number problem

We study the generalization to bipartite and 2-connected plane graphs of the Clar number, an optimization model proposed by Clar [E. Clar, The Aromatic Sextet, John Wiley & Sons, London, 1972] to compute indices of benzenoid hydrocarbons. Hansen and Zheng [P. Hansen, M. Zheng, The Clar number of a benzenoid hydrocarbon and linear programming, J. Math. Chem. 15 (1994) 93–107] formulated the Clar problem as an integer program and conjectured that solving the linear programming relaxation always yields integral solutions. We establish their conjecture by proving that the constraint matrix of the Clar integer program is always unimodular. Interestingly, in general these matrices are not totally unimodular. Similar results hold for the Fries number, an alternative index for benzenoids proposed earlier by Fries [K. Fries, Uber Byclische Verbindungen und ihren Vergleich mit dem Naphtalin, Ann. Chem. 454 (1927) 121–324].     

Ranking fuzzy numbers by distance minimization

In this paper, we proposed a defuzzification using minimizer of the distance between the two fuzzy numbers. Then, we obtain the nearest point with respect to a fuzzy numbers and by considering the nearest point, we can present a ranking method for the fuzzy numbers. Also we give two new properties for ordering. Theorems and remarks are proposed for existence and uniqueness of the nearest point. The method is illustrated by numerical examples and compared with other methods.     

约束矩阵方程的解的表示及行列式公式

本文利用Ｂｏｔｔ－Ｄｕｆｆｉｎ逆导出约束矩阵方程的唯一解或通解的表示及其较为简洁的行列式公式，并由之给出了某些特殊矩阵方程与约束性方程组的解以及几个重要广义逆矩阵的表示及其较是洁的行列式公式，我们的结果改进与推广了文（２－１１，１４，１５）中的有关结果。     

A fixed point theorem for a family of mappings in a fuzzy metric space

In this paper we give a common fixed point theorem for a family of mappings of a G-complete fuzzy metric space (X, M, *) into itself. From this result we deduce a common fixed point theorem for a family of mappings of a complete metric space (X, d) into itself. Supported by University of Palermo.     

Fuzzy判断矩阵的一致性修正

本文给出了一种由分析者求解和决策者修正判断交替进行寻求一致性Fuzzy判断矩 阵的方法,证明了按照此方法。在对Fuzzy判断矩阵进行有限次修正之后,可以得到一个满足 给定精度要求的一致性Fuzzy判断矩阵.     

夸克质量矩阵与CP对称性破坏

本文给出一类夸克质量矩阵与CP破坏参量的精确解析关系. 有关结果适用于唯象研究不同质量矩阵模型及其CP破坏效应的细微差别.     

SEMIGROUPS CHARACTERIZED BY THEIR FUZZY IDEALS

ＳＥＭＩＧＲＯＵＰＳＣＨＡＲＡＣＴＥＲＩＺＥＤＢＹＴＨＥＩＲＦＵＺＺＹＩＤＥＡＬＳＪ．ＡｈｓａｎａｎｄＫ．Ｓａｉｆｕｌｌａｈ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃａｌＳｃｉｅｎｃｅｓＫｉｎｇＦａｈｄＵｎｉｖｅｒｓｉｔｙｏｆＰｅｔｒｏｌｅｕｍａ...     

Matrix summability and uniform convergence of series

Some classical results about uniform convergence of unconditionally convergent series are generalized to weakly unconditionally Cauchy series by means of the matrix summability method for regular matrices.