Showing papers by "Yan Gu published in 2012"
04 Jul 2012
TL;DR: In this paper, the problem of moving n sensors on a line to form a barrier coverage of a specified segment of the line such that the maximum moving distance of the sensors is minimized was solved in O(n2lognloglogn) time.
Abstract: In this paper, we study the problem of moving n sensors on a line to form a barrier coverage of a specified segment of the line such that the maximum moving distance of the sensors is minimized. Previously, it was an open question whether this problem on sensors with arbitrary sensing ranges is solvable in polynomial time. We settle this open question positively by giving an O(n2lognloglogn) time algorithm. Further, if all sensors have the same-size sensing range, we give an O(nlogn) time algorithm, which improves the previous best O(n2) time solution.
45 citations
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TL;DR: This paper studies the problem of moving n sensors on a line to form a barrier coverage of a specified segment of the line such that the maximum moving distance of the sensors is minimized, and gives an O(n2lognloglogn) time algorithm, if all sensors have the same-size sensing range.
Abstract: In this paper, we study the problem of moving $n$ sensors on a line to form a barrier coverage of a specified segment of the line such that the maximum moving distance of the sensors is minimized. Previously, it was an open question whether this problem on sensors with arbitrary sensing ranges is solvable in polynomial time. We settle this open question positively by giving an $O(n^2 \log n)$ time algorithm. For the special case when all sensors have the same-size sensing range, the previously best solution takes $O(n^2)$ time. We present an $O(n \log n)$ time algorithm for this case; further, if all sensors are initially located on the coverage segment, our algorithm takes $O(n)$ time. Also, we extend our techniques to the cycle version of the problem where the barrier coverage is for a simple cycle and the sensors are allowed to move only along the cycle. For sensors with the same-size sensing range, we solve the cycle version in $O(n)$ time, improving the previously best $O(n^2)$ time solution.
17 citations
21 May 2012
TL;DR: The multicore specific optimization modules of two common MPI implementations â" MPICH2 and Open MPI are introduced and their performance, including bandwidth and latency, under different circumstances are provided.
Abstract: We first introduced the multicore specific optimization modules of two common MPI implementations â" MPICH2 and Open MPI, and then tested their performance on one multicore computer. By enabling and disabling these modules, we provided their performance, including bandwidth and latency, under different circumstances. Finally, we analyzed the two MPI implementations and discussed the choice of MPI implementations and possible improvements.
1 citations