18767466
Spectra of Regular Graphs and Hypergraphs and Orthogonal Polynomials
Abstract In this paper we study the distribution of eigenvalues of regular graphs, regular hypergraphs, and biregular bipartite graphs of given girth by considering the polynomials orthogonal with respect to the measures attached to the spectra of such graphs and to the continuous spectra of their ‘universal covers’. Our estimates are tight for Biggs graphs and generalized polygons. We also give an application to the distribution of eigenvalues of Hecke operators acting on weight 2 cusp forms for certain congruence subgroups.
206817675
Independence numbers of graphs and generators of ideals
This article investigates the generators of certain homogeneous ideals which are associated with graphs with bounded independence numbers. These ideals first appeared in the theory oft-designs. The main theorem suggests a new approach to the Clique Problem which isNP-complete. This theorem has a more general form in commutative algebra dealing with ideals associated with unions of linear varieties. This general theorem is stated in the article; a corollary to it generalizes Turán’s theorem on the maximum graphs with a prescribed clique number.
18531635
A generalized model for network survivability
The high expectation of network to be available and perform at all time has created growing concerns between network operators and engineers all over the globe. Network should be available to users whenever they want to use them. In the wake of an attack, network should be also able to recover as soon as possible. A survivable network is one that can provide services in the presence of an attack or failure and be able to recover fully in a timely manner. Designing a model for network survivability basically involves the understanding of three key issues, i.e, how the system will function in the wake of failures, what will be the impact of failures on the user, and how to overcome these failures. To achieve these goals, this paper proposes a quantitative approach to evaluate the network survivability in terms of using a generalized model; we consider a more complex system with several faults to study the survivability of a network using Markov chain. In presenting a better survivability performance, some numerical comparisons for the network availability, failure frequency and survivability is also developed.
7471984
QoS supporting and optimal energy allocation for a cluster based wireless sensor network
Wireless sensor networks (WSNs) have become a very active and important area of research due to their potential in civil and military applications. A lot of research works focus on energy efficient routing protocols due to the limited energy of battery-powered nodes. Currently, the increasing interest in multimedia applications has made the QoS (quality of service) supporting an unavoidable task. In this paper, we perform the analysis of QoS supporting and optimal energy allocation issues by presenting a cluster based WSN. A QoS supporting scheme is developed for dynamic traffic conditions by controlling data generating rates at individual clusters. In addition, an explicit solution on the energy distribution at different clusters in the WSN is investigated based on an optimal energy allocation criterion. The localized QoS controlling scheme is useful in WSNs due to flexibility and scalability, and the obtained network energy distribution formula is particularly convenient for node deployment design in WSNs and three specific situations are discussed as applications.
14663700
A scan BIST generation method using a markov source and partial bit-fixing
Recently, Markov sources were shown to be effective in designing pseudo-random test pattern generators with low area overhead for built-in self-test of scan designs. This paper presents a new test pattern generation scheme based on a Markov source and a partial bit-fixing technique. A new method is proposed for the computation of the state transition probabilities of the Markov source based on the statistics of a deterministic test set. This is enhanced by partial bit-fixing logic, which fixes a group of consecutive inputs to all-0 or all-1. Experimental results show that the proposed BIST scheme can achieve 100% fault coverage for large benchmark circuits with reduced hardware overhead and reduced pattern counts compared to the earlier method using Markov sources.
17270817
Grid Computing in China
Abstract
Grid computing presents a new trend to distributed computation and Internet applications, which can construct a virtual single image of heterogeneous resources, provide uniform application interface and integrate widespread computational resources into super, ubiquitous and transparent aggregation. In the adoption of Grid computing, China, who is facing more resource heterogeneity and other specific demands, has put much effort on both research and practical utilization. In this paper, we introduce the major China Grid research projects and their perspective applications. First we give the overview of the four government-sponsored programs in Grid, namely the China National Grid, ChinaGrid, NSFC Grid, and ShanghaiGrid. Then we present six representative ongoing Grid systems in details, which are categorized into Grid middleware and Grid application. This paper provides the general picture of Grid computing in China, and shows the great efforts, devotion and confidence in China to use Grid technology to boost the society, economics and scientific research.

31100803
Web Search Based on Ant Behavior: Approach and Implementation in Case of Interlegis
The World Wide Web today is considered the biggest information and knowledge source in every field. These Web pages are accessed daily by a great quantity of people with different interests. However, they are heterogeneously constructed both in available information and quality and majorities are presented in HTML language. This manner limits and makes it difficult to extract useful information and knowledge using simple search by Internet. The process of surfing the Web is similar to ant colonies foraging (Beckers, Deneubourg & AbstrAct