Presentations -

Optimization Framework for Terrorist-Attack-Resilient Building Design

Lucas VINCENT，Masayuki KOHIYAMA, and Taiki SAITO

Safety Engineering Symposium 2019 (日本学術会議（東京都港区）) , 

2019.07

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Oral presentation (general)

ガウス性白色雑音地動に伴う水平変位に直交する慣性力が誘発するねじれ応答の確率分布に関する基礎的検討

Hiroki YOKOYAMA and Masayuki KOHIYAMA

第89回日本建築学会関東支部研究発表会 (Chiyoda-ku, Tokyo) , 

2019.03

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Oral presentation (general), 日本建築学会関東支部

統計的グリーン関数法の要素地震波間の類似性をベータ関数で表した位相差モデル

Hajime IWAI, Haruka YOKOYAMA, and Masayuki KOHIYAMA

第89回日本建築学会関東支部研究発表会 (Chiyoda-ku, Tokyo) , 

2019.03

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Oral presentation (general), 日本建築学会関東支部

k近傍法とウェルチのt検定を用いた未学習損傷パターンデータの検知

Motoki FUTEMMA, Kazuya OKA, and Masayuki KOHIYAMA

第89回日本建築学会関東支部研究発表会 (Chiyoda-ku, Tokyo) , 

2019.03

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Oral presentation (general), 日本建築学会関東支部

Polynomial Control of Semi-Active Oil Damper for Functional Maintenance of Equipment

Yosuke KAWANISHI , Fumito NAKAMICHI, and Masayuki KOHIYAMA

15th Japanese Earthquake Engineering Symposium (Sendai, Japan) , 

2018.12

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Oral presentation (general), Japan Association for Earthquake Engineering

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In controlling a seismic isolation floor in a building during an earthquake, it is important to reduce not only the acceleration of the equipment on the isolation floor but also the relative displacement of the isolation floor to the placing building floor. In this research, to reduce the response of the equipment on the isolation floor, we investigate the effectiveness of a distributed polynomial control of a semi-active damper for an isolation floor. In a design of the control the total sum of kinetic energy and elastic potential energy is minimized, which are calculated using the relative velocity and relative displacement of an isolation floor as a cost function, and the state variables of the equipment are measured by the local sensor. We compared the performances of the proposed distributed polynomial control and a distributed linear-quadratic-Gaussian (LQG) control by conducting numerical simulation and shaking table experiment. As a result, we observed that the proposed control could reduce the absolute acceleration and relative displacement response of an isolated floor more than the distributed LQG control.

Models of Horizontal Components for Synthesized Wave Using the Stochastic Green's Function Method Considering Dominant Direction

Haruka YOKOYAMA and Masayuki KOHIYAMA

15th Japanese Earthquake Engineering Symposium (Sendai, Japan) , 

2018.12

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Poster presentation, Japan Association for Earthquake Engineering

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In order to synthesize simulated ground motion more properly, we propose models of horizontal components for synthesized wave using the stochastic Green’s function method considering dominant direction. By using aftershock records of the 2011 off the Pacific coast of Tohoku Earthquake, we calculate the mean square value of acceleration and search for the dominant directions. Then, we adopt directions with small angel difference, strike and orthogonal directions, as two directions for the model. In the same manner as Pao and Kawase (2007), optimum values of the duration time and the peak time are obtained by fitting an envelope to the section maximum values of acceleration, and we derive regression equations to estimate the duration time and the peak time, which are parameters of the Boore’s envelope function, using magnitude and hypocentral distance.

Fundamental Study on Torsional Response of High-Rise Buildings Induced by Inertial Force Perpendicular to Horizontal Displacement

Hiroki YOKOYAMA and Masayuki KOHIYAMA

Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan (東北大学川内北キャンパス（宮城県仙台市）) , 

2018.09

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Oral presentation (general), Architectural Institute of Japan

Detection Method of Unlearned Pattern Data of Deep Neural Network to Identify Damaged Brace Pattern of a Steel Frame

Kazuya OKA, Kenta WATANABE, Masayuki KOHIYAMA, and Takuzo YAMASHITA

Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan (東北大学川内北キャンパス（宮城県仙台市）) , 

2018.09

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Oral presentation (general), Architectural Institute of Japan

Design and Experiment of Inter-Story Tuned Mass Damper to Reduce Story Deformation

Masayuki KOHIYAMA and Masashi OMURA

Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan (東北大学川内北キャンパス（宮城県仙台市）) , 

2018.09

, 

Oral presentation (general), Architectural Institute of Japan

A Fundamental Study on Damage Detection Based on Deep Learning Using Data Obtained from Shake Table Tests of a Steel Frame

Kazuya Oka, Kenta Watanabe, Masayuki Kohiyama, Takuzo Yamashita, Kazutoshi Matsuzaki, and Yuji Mori

13th World Congress on Computational Mechanics (WCCM XIII) and 2nd Pan American Congress on Computational Mechanics (PANACM II) (New York, NY, USA) , 

2018.07

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Oral presentation (general), The International Association for Computational Mechanics (IACM)

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To employ neural networks in structural health monitoring, a large volume of training data is required. The data can be obtained by a generative learning method based on high-precision simulation of seismic responses. We investigate appropriate machine learning parameters such as the numbers of layer nodes in a deep neural network and the number of epochs for training. Response records measured in shaking table tests of a steel frame structure are used as training, validation, and test data. Our results show that response data of only the translational component can achieve high accuracy of damage pattern classification. Regarding the length of response data, clear difference is not observed in two durations of 1 s and 2 s. We propose a method to detect unlearned damage pattern data using the Mahalanobis distance.

Seismic Response Control for Equipment with Casters Using Switching Wheel Lock Conditions

Yosuke Kawanishi, Masayuki Kohiyama

13th World Congress on Computational Mechanics (WCCM XIII) and 2nd Pan American Congress on Computational Mechanics (PANACM II) (New York, NY, USA) , 

2018.07

, 

Oral presentation (general), The International Association for Computational Mechanics (IACM)

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When an earthquake occurs, the people in and/or contents of buildings may suffer damage due to the sliding or overturning of furniture and equipment or the falling of objects even if the structure of the building experiences no damage. In this study, using numerical analyses, we investigate a model of effective equipment caster wheel control to reduce damage caused by the moving and overturning of equipment during earthquakes and propose a control method to switch the lock and free conditions of the caster wheel. In the numerical analyses, a simulator library of three-dimensional rigid body dynamics is used and two-direction earthquake ground motion is input into a model of a 10-story steel frame building. The horizontal displacement and the falling down of the equipment model are expressed depending on the caster lock condition.

深層学習を用いた鋼構造骨組の損傷ブレース部材の推定

Takuzo Yamashita, Masayuki Kohiyama, Kenta Watanabe, Kazutoshi Matsuzaki, and Yuji Mori

第23回計算工学講演会 (ウインクあいち（愛知県名古屋市）) , 

2018.06

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Oral presentation (general), 日本計算工学会

建築構造シミュレーションの利活用研究－ＡＩを用いた構造ヘルスモニタリング－

Masayuki KOHIYAMA

最先端の構造シミュレーション技術が拓く地震防災研究のこれから－数値震動台プロジェクト成果発表会－ (日本建築学会 建築会館ホール（東京都港区）) , 

2018.03

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Oral presentation (invited, special), 国立研究開発法人防災科学技術研究所

数値解析を用いた２階建て木造建物の一構面の耐力における上下階壁配置の影響分析

Natsuo KAWAMURA, Kazuya OKA, and Masayuki KOHIYAMA

第88回日本建築学会関東支部研究発表会 (Chiyoda-ku, Tokyo) , 

2018.03

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Oral presentation (general), 日本建築学会関東支部

セミアクティブ免震システムの構造パラメータの同定と地震リスク解析に基づいたLQG制御ゲインの更新

大村 真史，小檜山 雅之，髙橋正樹，吉田治，中塚光一

日本地震工学会大会－2017 (東京大学生産技術研究所（東京都目黒区）) , 

2017.11

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Poster presentation, 日本地震工学会

統計的グリーン関数法における隣接する要素断層地震の位相類似性に関する2016年熊本地震の余記録を用いた分析

青海 美沙希，小檜山 雅之

日本地震工学会大会－2017 (東京大学生産技術研究所（東京都目黒区）) , 

2017.11

, 

Poster presentation, 日本地震工学会

A Survey on the Consideration of Community Formation in and around Disaster Public Housing in Tohoku Earthquake Disaster Areas

Aoi SUNOUCHI, Masayuki KOHIYAMA

Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan (広島工業大学（広島県広島市）) , 

2017.09

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Oral presentation (general), Architectural Institute of Japan

Effects of Torsional Vibration Caused by Eccentrically-Located Mass in Wooden Housing under Strong Ground Motion

Kazuya OKA and Masayuki KOHIYAMA

Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan (広島工業大学（広島県広島市）) , 

2017.09

, 

Oral presentation (general), Architectural Institute of Japan

Fundamental study on damage detection based on neural network using the data of shaking table experiment of a scaled steel structure

Kenta WATANABE, Masayuki KOHIYAMA, Yakuzo YAMASHITA, and Tomohiro SASAKI

Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan (広島工業大学（広島県広島市）) , 

2017.09

, 

Oral presentation (general), Architectural Institute of Japan

Proposal of Indices of Earthquake-induced Fire Damage for Risk Communication to Solve a Vacant House Problem

Yosuke KAWANISHI and Masayuki KOHIYAMA

Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan (広島工業大学（広島県広島市）) , 

2017.09

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Oral presentation (general), Architectural Institute of Japan