Wing Ho Yuen

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— In wireless networks, it is often assumed that all nodes cooperate to relay packets for each other. Although this is a plausible model for military or mission based networks, it is unre-alistic for commercial networks and future pervasive computing environments. We address the issue of noncooperation between nodes in the context of content distribution in(More)
— We propose a novel cross layer design concept that could improve the network throughput significantly for mobile ad hoc networks. The channel reservation control packets employed at the MAC layer can be utilized at the physical layer in exchanging timely channel estimation information to enable an adaptive selection of a spectrally efficient transmission(More)
— In wireless networks, it is often assumed that all nodes cooperate to relay packets for each other. Although this is a plausible model for military or mission based networks, it is unrealistic for commercial networks and future pervasive computing environments. We address the issue of noncooperation between nodes in the context of content distribution in(More)
In a mobile infostation network, any two nodes communicate when they are in proximity. Under this transmission constraint, any pair of nodes is intermittently connected as mobility shuffles the node locations. In this paper, we evaluate the effect of node mobility on highway mobile infostation networks. Each node enters a highway segment at a Poisson rate(More)
— We characterize the resource usage of an upload application for partially connected ad hoc networks. Time-based (TB) and hop-based (HB) TTL schemes are proposed and evaluated via both analysis and simulation. A HB(b, 2) scheme is near optimal, where 2 and b denote depth and breadth of the data dissemination tree. b is chosen such that the probability of(More)
A mobile infostation network stipulates all transmissions to occur when nodes are in proximity. In this paper, the effect of transmit range on the capacity of four transmission strategies is studied. We show that a stipulated transmit range improves the capacity relative to the reference strategy with an unconstrained transmit range. This indicates an(More)
— In this paper, the network behavior of a routing algorithm for mobile ad hoc networks is investigated. Extensive simulations are performed using ns-2 in a variety of mobility scenarios and offered load regimes. In the literature, performance metrics (goodput, delay and path length) are often obtained through ensemble averaging of many flows. Here we(More)
There are two major pathways for methionine biosynthesis in micro-organisms. Little is known about these pathways in Bacillus subtilis. The authors assigned a function to the metI (formerly yjcI) and metC (formerly yjcJ) genes of B. subtilis by complementing Escherichia coli metB and metC mutants, analysing the phenotype of B. subtilis metI and metC(More)
— A mobile infostation network stipulates all transmissions to occur when nodes are in proximity. In this paper, we evaluate the effect of mobility on highway mobile infostation networks. Each node enters a highway section at a Poisson rate with a constant speed drawn from a known but arbitrary distribution. Both forward and backward traffic are considered.(More)
— In a partially connected ad hoc network, two nodes communicate and share data when they are in proximity. For the query based (QB) scheme, a node retrieves data from another node by querying. Search efficiency deteriorates when the query success probability is small. We propose a Bloom filter based (BF) scheme to improve search efficiency. A data holder(More)