著者

木村 和也 北山 哲士 山崎 光悦

出版者

一般社団法人日本機械学会

雑誌

設計工学・システム部門講演会講演論文集 (ISSN:13480286)

巻号頁・発行日

vol.2005, no.15, pp.435-438, 2005-08-02

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Particle Swarm Optimization (PSO) is one of the multipoint search methods to find global or quasi-optimum of non-convex function. The important characteristics of multipoint search methods are diversity and centralization of search points. In this paper we propose Improvement model to aim at the diversity and the centralization. Through numerical examples, it is examined that indicator of parameter decision, diversity, centralization, and the search ability of the Improved PSO.

著者

尾田 十八 山崎 光悦 坂本 二郎 北山 哲士 酒井 忍 金井 亮 李 鵬 李 鵬

出版者

金沢大学

雑誌

基盤研究(A)

巻号頁・発行日

2006

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本研究は,自然・生態系と調和した新しい材料,構造,機器,システム等の創生法を,生物に学ぶことによって確立することを目的としている.その方法は多様な生物の中で,特異性を有する生物にまず注目する.本研究では動物の例として繰返し衝撃負荷に耐える「キツツキ」を,植物の例としては,軽量であるが不燃性を示す「桐材」に注目した.そしてこれらの特性がどのようなメカニズムによって生じているのかを,主として力学的視点より明らかにした.これらの結果と,代表者らがすでに行って来ている竹や卵殻の構造・組織分析結果を含め,新しい構造設計および材料設計法の基本原理を提示した.

著者

北山 哲士 山川 宏

出版者

日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:03875024)

巻号頁・発行日

vol.67, no.653, pp.9-16, 2001-01-01

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金沢大学工学部

著者

山崎 祐亮 北山 哲士 高野 昌宏 合葉 修司

出版者

公益社団法人 日本設計工学会

雑誌

設計工学 (ISSN:09192948)

巻号頁・発行日

pp.2017.2784, (Released:2018-06-27)

参考文献数

15

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In plastic injection molding (PIM), warpage should be minimized for high product quality whereas cycle time should also be minimized for high productivity. Process parameters such as melt temperature, packing pressure, and cooling time strongly affect both the product quality and the productivity, and it is important to determine the optimal process parameters. This paper proposes a method to determine the optimal process parameters for the warpage and the cycle time minimization. Variable packing pressure profile that the packing pressure varies during the packing phase is adopted. Three dimensional cooling channel is also used for the warpage and cycle time minimization. Numerical simulation in the PIM is so intensive that a sequential approximate optimization is used to identify the pareto-frontier. Based on the numerical result, the experiment using the PIM machine is carried out. Through the numerical and experimental result, it is confirmed that the proposed approach is valid to the warpage and the cycle time minimization.

著者

横山 眞樹 北山 哲士 河本 基一郎 野田 拓也 宮坂 卓嗣 越後 雄斗

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.863, pp.18-00162, 2018 (Released:2018-07-25)

参考文献数

22

被引用文献数

2

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In sheet forming, the blank holder force (BHF) has a direct influence on product quality. A high BHF leads to tearing, whereas a low one results in wrinkling. For successful sheet forming, the BHF should be adjusted. Recently, the variable BHF (VBHF) that the BHF varies through stroke is recognized as one of the advanced sheet forming technologies. On the other hand, slide velocity (SV) that controls the die velocity is rarely discussed in the literature, and the SV should also be taken into account for the successful sheet forming. A high SV can achieve the high productivity, but wrinkling occurs. The VBHF trajectory and SV are unknown in advance, and the trial and error method is widely used. In this paper, design optimization approach using computational intelligence is adopted to determine them for achieving the high productivity. The processing time is taken as the objective function to be minimized for the high productivity. Numerical simulation in sheet forming is so intensive that a sequential approximate optimization using radial basis function network is adopted to determine the optimal solution. Based on the numerical result, the experiment using AC servo press (H1F200-2, Komatsu Industries Corp.) is carried out. Through the numerical and experimental result, the validity of proposed approach is examined.

著者

坂本 二郎 小林 佳介 北山 哲士 清水 信孝

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00212-17-00212, 2017 (Released:2017-10-25)

参考文献数

27

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An optimum design method for determining the cross-sectional sizes of thin steel plate columns used for steel framed house was developed to maximize their buckling strength under a constraint of constant volume using evolutionary computing and cold forming. Buckling analysis was performed by finite strip method (FSM) that can analyze the buckling loads of local, torsional, and total buckling within less computational time. Differential evolution (DE) was used for the optimization algorithm because it is a fast and reliable method for non-linear, non-convex, and multimodal optimization problems. In this research, an optimum design method is proposed, which combines DE and FSM to achieve an efficient global optimum design considering comprehensive buckling modes. This method was applied to overcome the optimum design problems of the thin steel plate columns with a lip channel cross-section. Normal axial compression capacity (Nc) of the column under a constant volume was maximized by considering design variables such as web height, flange width, and lip length of the cross-section. The search performance of the optimization method was evaluated by obtaining an objective function (1/Nc), which was calculated at the lattice points of the design variables. The optimum design point obtained by the optimization method included a global minimum point of the objective function surface, hence ensuring the validity of the proposed method. Furthermore, the optimum design problem was solved under the deformation constraint by considering connection to the wall panels for the column length of 1000 mm, 2000 mm, and 3000 mm. Optimum designs with the open profile cross-section was obtained for all the abovementioned column length. The optimum designs obtained by the proposed method can be used for practical purposes because of their open profiled cross-section and can be produced by cold forming.

著者

玉田 可南子 北山 哲士 高野 昌宏 合葉 修司

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.17-00209-17-00209, 2017 (Released:2017-08-25)

参考文献数

17

被引用文献数

1

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In plastic injection molding (PIM), the process parameters such as melt temperature, mold temperature, injection time, and so on strongly affect the energy consumption as well as the product quality. It is preferable to produce plastic products with a small clamping force for the energy consumption. Weldlines, which are formed when two or more melt fronts meet, influence not only the strength of products but also the appearance, so it is preferable to reduce the weldlines as much as possible. In order to reduce the weldlines with the small clamping force, a simultaneous optimization of the process parameters in PIM is performed and the pareto-frontier is identified. The weldline temperature is maximized for the weldlines reduction, whereas the clamping force is minimized. The numerical simulation in PIM is so intensive that a sequential approximate optimization using radial basis function network is adopted. The difference between conformal and conventional cooling channel is also discussed. The numerical result shows that the trade-off between the weldline temperature and the clamping force is clarified and the effectiveness of conformal cooling channel is clarified.

著者

横山 眞樹 北山 哲士 高野 昌宏 合葉 修司

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.850, pp.17-00067-17-00067, 2017 (Released:2017-06-25)

参考文献数

18

被引用文献数

1

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Process parameters in plastic injection molding (PIM) such as packing pressure, melt temperature and cooling time have a direct influence on the product quality and it is important to determine the optimal process parameters for the high product quality as well as the high productivity. This paper proposes a method to determine the optimal process parameters in the PIM for high product quality and high productivity. In particular, the variable packing pressure profile that the packing pressure varies through the packing phase is adopted as the advanced PIM. Warpage and cycle time are taken as the product quality and the productivity, respectively. Therefore, a multi-objective optimization of the process parameters using the variable packing pressure profile is performed. Numerical simulation in the PIM is so intensive that a sequential approximate optimization using radial basis function is adopted. It is found through the numerical result that the proposed packing pressure profile can improve both the warpage and the cycle time. Based on the numerical result, the experiment is also carried out. It is confirmed through the numerical and experimental result that the variable packing pressure profile is an effective approach for the warpage reduction and the short cycle time.

著者

北山 哲士 安田 恵一郎

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.125, no.5, pp.813-820, 2005 (Released:2005-08-01)

参考文献数

24

被引用文献数

4 8

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Particle Swarm Optimization (PSO) for mixed integer programming problems is proposed. PSO is mainly a method to find a global or quasi-minimum for a nonlinear and non-convex optimization problem, and few researches about optimization problems with discrete decision variables have been studied. In this paper, we present the treatment of discrete decision variables. To treat discrete decision variables as a penalty function, it is possible to treat all decision variables as a continuous decision variable. As a result, the penalty parameter for the penalty function is needed. In this paper, we also present how to determine the penalty parameter for the penalty function. Through mathematical and structural optimization problems, we examine the validity of PSO for the mixed decision variables.