卒業生の石川君，M2の入江君，碓井君，木原君，西田君の論文が国際会議APCC2008に採択されました。
論文については以下のとおりです。
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タイトル: “Fast Replica Allocation Method by Parallel Calculation on DAPDNA-2”
著者: Hiroyuki Ishikawa, Sho Shimizu, Yutaka Arakawa, Naoaki Yamanaka, and Kosuke Shiba
要旨: This paper proposes a fast calculation method of the replica placement problem, which is implemented on reconfigurable processor DAPDNA-2 of IPFlex Inc. Our proposed method divides the combination optimally and performs pipeline operation. Beeler’s algorithm can calculate all combinations in ascending order but it has data dependence. It’s difficult to calculate any pattern because each data increases irregularly. In order to solve this problem, we propose the new algorithm that generates any order pattern. In addition, the optimal number of partitions depends on the number of combinations and calculation clocks of Beeler’s algorithm. In order to solve this problem, we think about the optimal division number in theory. While the time complexity of conventional method is proportional to the number of combinations, that of proposed method is proportional to the square root of the number of combinations. Experimental results show that the proposed algorithm reduces the execution time by 40 times compared to Intel Pentium 4 (2.8GHz).
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タイトル: “Efficient Contents Delivery Method with Scheduled Unicast and Multicast”
著者: Kazuki IRIE, Yutaka ARAKAWA, Satoru OKAMOTO, and Naoaki YAMANAKA
要旨: We propose the efficient contents delivery method with scheduled unicast and multicast to reduce the load of contents server and network congestion. In our proposed method, the timing of transmitting contents is arranged when many users access the contents in short period of time.Furthermore, the method of transmitting contents is switched from unicast to multicast. The simulation results show that average download time can be reduced in our proposed method.
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タイトル: “A Novel Distributed Data Access Scheme Considering with Link Resources and Metric in Lambda Grid Networks”
著者: Ryota Usui, Hiroyuki Miyagi, Yutaka Arakawa, Satoru Okamoto, Naoaki Yamanaka
要旨: A link load balancing technique that uses a normalized link metric based on a new wavelength utilization and link metric is proposed. The new normalized link metric is a combination of a previous link metric and wavelength utilization. In this paper, we propose a novel server selection method for parallel downloading in WDM networks. The server selection method creates link load balancing and suppresses bottleneck links. Computer simulations show that the proposed scheme can reduce bottleneck link number and the blocking probability by up to 90%.
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タイトル: “Fast Link-Disjoint Path Algorithm on Parallel Reconfigurable Processor DAPDNA-2”
著者: Taku KIHARA, Sho SHIMIZU, Yutaka ARAKAWA, Naoaki YAMANAKA, Kosuke SHIBA
要旨: This paper proposes fast parallel link-disjoint path algorithm using dynamically reconfigurable processor and implements it on DAPDNA-2 (IPFlex Inc) which is newly structured. The conventional k-shortest path algorithm finds multiple link-disjoint paths between the source node and the destination node. When the network scale is large, the calculation time of k-shortest path algorithm increases rapidly. Moreover, in the worst case, k-shortest path algorithm can not find optimum link-disjoint path pair because this algorithm always finds the shortest path at first and removes those links from network. Our proposed algorithm collects all path information in the network and calculates optimum link-disjoint path pair (i.e. minimum cost link-disjoint path pair) at high speed by using parallel operation. Additionally, our proposed algorithm finds optimum link-disjoint path pair at a high rate in a limited of calculation time. The evaluation shows our proposed algorithm can decrease the calculation clock about 90%.
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タイトル: “Adaptive Resource Reservation Protocol for High-speed Resource Information Advertisement”
著者: Masahiro Nishida, Hiroyuki Ishikawa, Sho Shimizu, Yutaka Arakawa, Satoru Okamoto, and Naoaki Yamanaka
要旨: This paper proposes an adaptive resource reservation protocol for high-speed resource information advertisement. The adaptive resource reservation protocol (ARRP) is a protocol that adaptively decides whether to uses a 1-way reservation scheme or 2-way reservation scheme on the basis of resource information in the route calculation. It is indicated that the number of the control packets in proposed method is one digit less than that in the conventional OSPF-TE. Compared to the OSPF-TE, the proposed method keeps low blocking probability even when traffic occurs more frequently.
