16657537
Differentiated Domain Protection Algorithm Based on Virtual Topology Graph in Multi-Domain Optical Networks
This paper proposes a novel Differentiated Domain Protection (DDP) algorithm to address survivability in multi-domain optical networks. In order to ensure the principle of transparent management in multi-optical domains, DDP abstracts the multi-domain optical networks to Virtual Topology Graph (VTG) to solve the inter-domain routing. In order to satisfy the survivable requirements of different domains, DDP considers the differentiated protection in different domains. Compared with traditional algorithms, DDP not only has the performance trade-off ability but also has the better resource utilization ratio. Simulation results are shown to be promising.
9609952
A survivable routing algorithm with differentiated domain protection based on a virtual topology graph in multi-domain optical networks
In this paper, we propose a novel differentiated domain protection (DDP) scheme to address survivability in multi-domain optical networks. Survivable routing in multi-domain networks is a challenging algorithmic problem because it requires choosing links that provide adequate protection both between domains and within domains that may offer different protection services. To satisfy the survivability requirements of different domains, DDP considers differentiated protection schemes, i.e., dedicated protection, shared protection, or no protection in different domains. In order to respect the principle of transparent management in multiple domains, DDP abstracts a multi-domain optical network to a virtual topology graph (VTG) for solving routing between domains. Simulation results show that DDP, unlike traditional schemes, can provide trade-off between protection methods and also allows better resource utilization.
7343144
A New Recovery Escalation Algorithm with Load Balancing and Backup Resources Sharing in Path Protected WDM Optical Networks
This paper proposes a new survivable algorithm, enhanced shared-path protection (ESPP), to tolerate multi-link failures in WDM optical networks. In ESPP, we consider the load balancing to reduce the blocking probability, use resources sharing to save backup resources, and perform recovery escalation to carry the affected traffic. Compared with the conventional algorithm, ESPP has better resource utilization ratio, lower blocking probability and higher protection ability. Simulation results are shown to be promising.
18135167
Localized and Integrated Topology Maintenance for Wireless Sensor Networks
The energy consumed by topology maintenance could be higher than that in the initialization stage and the cost will increase steadily with the turns of maintenance process. Therefore, when design a self-organization protocol for WSN, not only initialization cost should be considered but also the maintenance cost in the whole lifetime. Moreover, to reduce the footprint on system resource, the maintenance process should be integrated with the initialization process but not separated. We propose a localized and integrated topology maintenance algorithm in this paper. This algorithm could maintain the topology in a localized manner and the maintenance process is integrated with the initialization process by nature. Simulation results show it has less energy cost in the network lifetime than two other typical protocols.
17509795
Collaborative attacks in WiMAX networks
Summary In this paper, we discuss security problems, with a focus on collaborative attacks, in the Worldwide Interoperability for Microwave Access (WiMAX) scenario. The WiMAX protocol suite, which includes but is not limited to DOCSIS, DES, and AES, consists of a large number of protocols. We present briefly the WiMAX standard and its vulnerabilities. We pinpoint the problems with individual protocols in the WiMAX protocol suite, and discuss collaborative attacks on WiMAX systems. We present several typical WiMAX attack scenarios, including: bringing a large number of attackers to increase their computation power and break WiMAX protocols; assembling a sufficient number of attackers to influence the decision-making of core machines, which includes routing attacks and Sybil attacks; and exploiting implementations that do not conform to the WiMAX specification completely, causing interoperability problems among various protocols, including the ones in typical WiMAX/WiFi/LAN deployment scenarios. We present theoretical models and practical solutions to profile, model, and analyze collaborative attacks in WiMAX. We employ attack graphs to do vulnerability analysis. Experimental results verify our models and validate our analysis. Copyright © 2009 John Wiley & Sons, Ltd.
5397904
Modeling and Throughput Analysis for Wireless Ad Hoc Networks
This paper presents a novel analytical model for wireless ad hoc networks. Based on the strong points in the literature, an accurate performance model for IEEE 802.11 MAC protocol is proposed. Moreover, by introducing the properties of spatial reuse, we extend the proposed model to support the throughput analysis of wireless ad hoc networks with directional antenna. An extensive set of simulations and numerical calculations validate our model by showing high accurate results.
172003
Reconstructing the Evolutionary History of Complex Human Gene Clusters
Clusters of genes that evolved from single progenitors via repeated segmental duplications present significant challenges to the generation of a truly complete human genome sequence. Such clusters can confound both accurate sequence assembly and downstream computational analysis, yet they represent a hotbed of functional innovation, making them of extreme interest. We have developed an algorithm for reconstructing the evolutionary history of gene clusters using only human genomic sequence data. This method allows the tempo of large-scale evolutionary events in human gene clusters to be estimated, which in turn will facilitate primate comparative sequencing studies that will aim to reconstruct their evolutionary history more fully.
656139
HIT: Web based Scoring Method for English Lexical Substitution
This paper describes the HIT system and its participation in SemEval-2007 English Lexical Substitution Task. Two main steps are included in our method: candidate substitute extraction and candidate scoring. In the first step, candidate substitutes for each target word in a given sentence are extracted from WordNet. In the second step, the extracted candidates are scored and ranked using a web-based scoring method. The substitute ranked first is selected as the best substitute. For the multiword subtask, a simple WordNet-based approach is employed.