We present in this work a wide spectrum of results on analyzing the behavior of parallel heuristics (both pure and hybrid) for solving optimization problems. We focus on several evolutionary algorithms as well as on simulated annealing. Our goal is to offer a first study on the possible changes in the search mechanics that the algorithms suffer when shifting from a LAN network to a WAN environm...

This paper describes the use of a parallel discrete-event network emulator called the Internet Protocol Traffic and Network Emulator (IP-TNE) for Web server benchmarking. The experiments in this paper demonstrate the feasibility of highperformance WAN emulation using parallel discrete-event simulation techniques on a single shared-memory multiprocessor. Our experiments with an Apache Web server...

We present WPaxos, a multileader wide area network (WAN) Paxos protocol, that achieves low-latency high-throughput consensus across WAN deployments. WPaxos dynamically partitions the global object-space across multiple concurrent leaders that are deployed strategically using flexible quorums. This partitioning and emphasis on local operations allow our protocol to significantly outperform leade...

The performance of distributed shared memory (DSM) over a wide area network (WAN) may suffer due to high network latencies because of the low bandwidth available. To achieve acceptable performance, WAN-based DSM must minimize network traffic. DSM systems transmit consistency information over the network via diffs. Existing diff mechanisms for DSM systems that run on local area networks are not ...

Cheung Sha Wan Dermatological Clinic, 3/F, West Kowloon Health Centre, Cheung Sha Wan Government Offices, 303 Cheung Sha Wan Road, Kowloon, Hong Kong Porphyria cutanea tarda (PCT) is a rare metabolic disorder due to an inherited or acquired deficiency in uroporphyrinogen decarboxylase, the fifth enzyme in the haem synthesis pathway. We report a 57-year-old gentleman who presented with three mon...

422 Ching Wan, Division of Psychology, Nanyang Technological University; Carlos J. Torelli, Carlson School of Management, University of Minnesota; Chi-yue Chiu, Nanyang Business School, Nanyang Technological University. The present research was partly supported by a grant (BCS-0743119) the National Science Foundation awarded to the third author. Correspondence concerning this article should be ...

The widespread use of cloud computing services is expected to deteriorate a Quality of Service and toincrease the power consumption of ICT devices, since the distance to a server becomes longer than before. Migration of virtual machines over a wide area can solve many problems such as load balancing and power saving in cloud computing environments. This paper proposes to dynamically apply WAN a...

Due to the high bandwidth requirement and rate variability of compressed video, delivering video across wide area networks (WANs) is a challenging issue. Proxy servers have been used to reduce network congestion and improve client access time on the Internet by caching passing data. In this paper, we investigate ways to store or stage partial video in proxy servers to reduce the network bandwid...

International air travel has played a significant role in driving recent increases in the rates of biological invasion and spread of infectious diseases. By providing high speed, busy transport links between spatially distant, but climatically similar regions of the world, the worldwide airline network (WAN) increases the risks of deliberate or accidental movements and establishment of climatic...