Akira Takeyama
Fujitsu
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Publication
Featured researches published by Akira Takeyama.
international performance computing and communications conference | 2006
Shinji Kikuchi; Ken Yokoyama; Akira Takeyama
It is a common task for many system managers to analyze performance problems to keep the system response time small, but it is difficult to identify the characteristics of the situations in which performance problems occur. To solve this problem, we developed an analysis method that uses a decision tree approach for Web system performance problems. In order to output simpler and more understandable results, we developed an original evaluation function for tree construction rather than using an existing one. In addition, to construct an appropriate decision tree from a huge number of parameters, we developed an algorithm which repeats decision tree construction and evaluation with a changing set of construction parameters and chooses the best tree. We implemented and evaluated our algorithm in an actual Web system and we found that our approach is much better than extant decision tree algorithms in terms of accuracy, simplicity, and computational time
international conference on networking | 2005
Shinji Kikuchi; Ken Yokoyama; Akira Takeyama
These days, the majority of large systems serving large numbers of users prefer N-tier architecture because of its scalability and flexibility. To maintain the quality of service in these systems, we need to understand how much delay is generated in each tier. However, the structure and the behavior of this architecture is so complicated that it is difficult to analyze these delays without installing special software or hardware – improvements that might change the servers behavior or result in significant additional costs. To solve these problems, we developed a practical method for estimating the delays generated in each tier of N-tier architecture that uses only easily obtainable parameters. In this paper, we first discuss what these easily obtainable parameters are. We then construct a performance model of the N-tier architecture using these parameters and analyze the delays in the model. Finally, we describe the experiments we conducted to evaluate our approach.
Archive | 2001
Naoki Matsuhira; Akira Takeyama
Archive | 2004
Tetsuya Okano; Akira Takeyama; Toshihiko Naritomi
Archive | 1983
Akira Takeyama; Kenshi Tazaki; Satoshi Nojima; Norihiro Aritaka; Teruyoshi Mita
Archive | 1991
Mitsuru Tsuboi; Susumu Tominaga; Akira Takeyama; Satoshi Nojima
Archive | 2004
Shinji Kikuchi; Ken Yokoyama; Akira Takeyama; Kenichi Shimazaki; Takamitsu Maeda; Koji Ishibashi; Seiya Shindo; Koutarou Tsuro
Archive | 2004
Shinji Kikuchi; Ken Yokoyama; Akira Takeyama; Kenichi Shimazaki; Takamitsu Maeda; Koji Ishibashi; Seiya Shindo; Koutarou Tsuro
Archive | 1983
Akira Takeyama; Kenshi Tazaki; Satoshi Nojima; Norihiro Aritaka; Teruyoshi Mita
Archive | 2008
Shinji Kikuchi; Ken Yokoyama; Akira Takeyama; Koji Ishibashi; Kenichi Shimazaki; Lilian Harada; Nobuhiro Yugami; Yukiko Seki