Biphysical cloaks that can manipulate both electromagnetic and acoustic waves are optimally designed by a topology optimization based on covariance matrix adaptation evolution strategy. The presented method explores optimum sets of level set functions which express the structures of biphysical cloaks for minimizing three objective functions on the scattering of E and H polarized electromagnetic and acoustic waves. We solve two Helmholtz equations derived from Maxwell’s equations evaluating the performances of electromagnetic cloaks and solve an acoustic-elastic coupled problem for evaluating the performance of acoustic cloak.

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Acoustic cloaks that can cloak an object from both air- and water-borne sounds are designed by a topology optimization based on covariance matrix adaptation evolution strategy (CMA-ES). Two objective functions for cancelling the scattering of both air- and water-borne sounds are minimized and the optimum sets of level set functions which express the structures of acoustic cloaks are explored for the scattering cancellations. Acoustic-elastic coupled problems are solved by finite element method for evaluating the performance of acoustic cloaks.

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This paper presents a topology optimization for carpet cloaks by means of an evolutionary strategy. Carpet cloaks are the cloaking devices which can render an bump on a flat plane invisible by imitating the reflection from the flat plane. The objective function is defined as the integrated intensity of the difference between the reflected wave from flat plane and that from carpet cloaks covering the bumps. The structures of carpet cloaks made of dielectrics are expressed by level set functions and the structural boundaries between air and dielectrics are expressed by the iso-surfaces of the level set functions. Level set functions are optimized by CMA-ES which is the most powerful evolutionary algorithm for multimodal problem. Obtained optimal configurations realize good performance under the explicit perimeter constraint.

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This paper presents a topology optimization based on a covariance matrix adaptation evolution strategy (CMA-ES) for bifunctional cloaks controlling both thermal flow and direct current governed by Laplace equations. The structures of bifunctional cloaks are expressed by an immersed boundary-level set method and optimal sets of the level set function — design variables in the presented optimization — are explored by the CMA-ES with a box constraint handling with an adaptive penalty function.

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In this study, two-dimensional thermal cloak for circular domain is discussed numerically by using transformed steady heat conduction equation and finite-element analysis. It was found that both of ideal cloak and Han's cloak work well for cloaking a circular domain within a rectangular conductive domain having two thermal boundary conditions.

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In this study, three-dimensional thermal cloak for spherical domain is examined numerically based on transformed steady heat conduction equation and finite element analysis. It was found that both of ideal cloak and Han's cloak work well for cloaking a spherical domain within a rectangular conductive domain.

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This paper presents a topology optimization based on a covariance matrix adaptation evolution strategy (CMA-ES) for acoustic cloaks rendering a scattering object acoustically invisible. The cloaks are designed by minimizing the scattering of acoustic waves around the object and the objective function is defined as the integrated intensity of the scattered wave. CMA-ES is employed to search the optimal set of level set functions as design variables during a topology optimization for minimizing the objective function regularized by a perimeter constraint. Level set functions express structures with its structural boundaries clearly without grayscales during the optimization process. In the best case in our simulation, we succeed to obtain an optimal configuration which can reduce the amount of acoustic scattering to 0.81% of that in the absence of cloaking.

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In this paper, we aim to make a reference for planning of the lobby and foyer in multi-purpose hall, theatre and concert hall. To study our theme, we investigate the use of the lobby and foyer during not running time. We send questionnaires to house keepers in 477 halls. In this questionnaire, we ask them how to use their lobby and foyer during not running time. In the result, the lobby and foyer is used for programs which are planned by their own, and rented for various purpose. They answered various problems on such a use and the idea in the future.

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近年，人工材料の概念に基づくメタマテリアルの研究が進んでおりマイクロ波デバイスやアンテナへの応用に広がっている．本稿では最近のメタマテリアル研究のトピックの中から，変換電磁気学に基づく任意の物体と同じ散乱波を持たせたイリュージョン，Γ点において群速度が非零となる分散特性を人工的に実現したディラックコーンメタ表面，フォスターのリアクタンス定理に従わない負のキャパシタンスや負のインダクタンスを実現するノンフォスター素子，及びフェライトを利用して位相の非相反性を実現した非相反メタマテリアルを紹介する．

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本研究では，自立性を満たす構造設計案を創出するためのトポロジー最適化法を提案する．まず，自立性を満たさない構造を検出するために，仮想的な物理モデルを導入する．次に，レベルセット法に基づくトポロジー最適化法を導入し，自立性を実現するための制約条件を仮想的な物理場によって表現する．自立性が求められる代表例として，音響クローキング設計問題を対象に最適化問題の定式化を行う．トポロジー導関数の考え方に基づく設計感度の表式を述べ，複数の数値解析例を示すことによって提案手法の妥当性及び有用性を示す．具体的には，提案する仮想的な物理場の特徴を説明し，自立性を満たさない構造が排除された音響クローキング構造の最適設計案を示す．

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