scholarly journals Some new optimal and suboptimal infinite families of undirected double-loop networks

2006 ◽  
Vol Vol. 8 ◽  
Author(s):  
Bao-Xing Chen ◽  
Ji-Xiang Meng ◽  
Wen-Jun Xiao

International audience Let n, s be positive integers such that 2 ≤ s < n and s = n/2 . An undirected double-loop network G(n; 1, s) is an undirected graph (V,E), where V =Zn={0, 1, 2, . . . , n−1} and E={(i, i+1 (mod n)), (i, i+s (mod n)) | i ∈ Z}. It is a circulant graph with n nodes and degree 4. In this paper, the sufficient and necessary conditions for a class of undirected double-loop networks to be optimal are presented. By these conditions, 6 new optimal and 5 new suboptimal infinite families of undirected double-loop networks are given.

2005 ◽  
Vol 06 (01) ◽  
pp. 1-15 ◽  
Author(s):  
BAOXING CHEN ◽  
WENJUN XIAO ◽  
BEHROOZ PARHAMI

An n-node network, with nodes numbered 0 to n-1, is an undirected double-loop network with chord lengths 1 and s(2≤s<n/2) when each node i(0≤i<n) is connected to each of the four nodes i±1 and i±s via an undirected link; all node-index expressions are evaluated modulo n. Let n=qs+r, where r(0≤r<s) is the remainder of dividing n by s. Furthermore, let s=ar+b, where b(0≤b<r) is the remainder of dividing s by r. In this paper, we provide closed-form formulas for the diameter of a double-loop network for the case q>r and for a subcase of the case q≤r when b≤aq+1. In the complementary subcase of q≤r, when b>aq+1, network diameter can be derived by applying the O(log n)-time algorithm of Zerovnik and Pisanski (J. Algorithms, Vol. 14, pp. 226-243, 1993). Obtaining a closed-form formula for diameter of the double-loop network in the latter subcase remains an open problem.


1991 ◽  
Vol 5 (3) ◽  
pp. 255-272 ◽  
Author(s):  
F.K. Hwang ◽  
Wen-Ching Winnie Li

A double-loop network G(h1, h2) has n nodes represented by the n residues modulo n and 2n links given by i ↦i + h1, i ↦ i + h2, i = 0,1,…,n – 1.We consider the reliability model where each link fails independently with probability p, the nodes always work, and the network fails if it is not strongly connected. There exists no known polynomial time algorithm to compute the reliabilities of general double-loop networks. When p is small, the reliability is dominated by the link connectivity. As all strongly connected double.loop networks have link connectivity exactly 2, a finer measure of reliability is needed. In this paper we give such a measure and show how to use it to obtain the most reliable double-loop networks.


2006 ◽  
Vol 359 (1-3) ◽  
pp. 69-76 ◽  
Author(s):  
Chiuyuan Chen ◽  
James K. Lan ◽  
Wen-Shiang Tang

2003 ◽  
Vol 04 (01) ◽  
pp. 3-16 ◽  
Author(s):  
S. K. CHEN ◽  
F. K. HWANG ◽  
Y. C. LIU

We propose a new network called the mixed chordal ring where the amount of hardware and its structure are very comparable to the (directed) double-loop network, and yet can achieve a better diameter. We also investigated other combinatorial properties such as connectivity and hamiltonian circuits in the mixed chordal ring.


2009 ◽  
Vol 31 (3) ◽  
pp. 536-542
Author(s):  
Mu-Yun FANG ◽  
Yu-Gui QU ◽  
Bao-Hua ZHAO

1998 ◽  
Vol 1 (4) ◽  
pp. 265-268 ◽  
Author(s):  
B. G. Zhang ◽  
S. T. Liu

This paper is concerned with the linear delay partial difference equationAm,n=∑i=1upiAm−ki,n−li+∑j=1vqjAm+τj,n+σj, wherepiandqjarer×rmatrices,Am,n=(am,n1,am,n2, …,am,nr)T, ki, li , τjandσjare nonnegative integers,uandvare positive integers. Sufficient and necessary conditions for all solutions of this equation to be oscillatory componentwise are obtained.


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