A localization method is developed using time differences of eigenray arrivals in a two-dimensional range-dependent underwater multiple reflection environment. This fast and robust method applies a perturbation theory to a horizontal range and a travel time which are the ray solutions given as a functional of both horizontal slowness and the sound speed profile. The linearized equations for estimating the horizontal range and depth of an unknown sound source are derived in a Cartesian coordinate system. The method’s only constraint is the applicability of the ray theory. That implies that a low-frequency sound in a shallow water environment is no more applicable than a high-frequency sound to the method because it violates the ray approximation. Identification of three eigenrays provides the passive range and depth estimation of underwater sources without a priori information on sub-bottom properties. Experiments with an impulsive source were conducted at coastal areas in Suruga Bay, Japan, to validate the patented method. The bathymetry gradually deepens toward the location of the receiver around1 km from the source. Four arrivals were detected by the use of the Wigner distribution and identified as the corresponding eigenrays. The estimated range and depth of the source are in an excellent agreement with the measurements.

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The dynamic processes of chaotic neural networks are investigated in the reinforcement adaptation scheme as a simple model of brain-like function. There appears spontaneous transition from a learning phase with slow adjustment to a retrieving phase with fast adjustment under switching inputs. Learning and retrieving can be considered as two aspects of the same dynamical process. In a reinforcement scenario, it is important that there should be some source of fluctuation in the network, so that the space of possible outputs can be explored until a correct output is found. This is well done by using chaotic neurons, not stochastic units.

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Based on the observation, we examined an indoor airflow and detailed distribution of age of air at main building of the National Museum of Western Art. Also from the view of the recovery of the authenticity which is important world heritage registration, we predicted the event that glass board partitions which didn't exist the original design were to be removed by using CFD. We confirmed actual measurements of air age distribution and the reproducibility of CFD analysis results in the current condition. And if the partition were to be reverted, it is fear that outdoor air come in the 19th century hall.

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Thermal sensation in a heated room can be much influenced by the building thermal insulation and a heating system equipped. Thermal sensation can be correlated with the sensible heat release from human body within a range of thermally neutral state. In this study thermal insulation of an experimental house installed in an artificial climate chamber is varied in three ways and the indoor thermal environment and the heat release from a thermal manikin are measured for a floor heating system and a wall-mounted air-conditioner. The equivalent temperature calculated from the heat release of the thermal manikin considerably differs from the operative temperature.

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In desiging of bolted joints with gaskets, contact stresses and the compressive spring constant K_cg for clamped parts with a gasket have been estimated using a model in which laminated hollow cylinders are fastened by a single set of a bolt and a nut. But, most practical bolted joints with gaskets are fastened by multiple bolts. Therefore, it is of practical importance to examine the effects of multiple fastenings on the contact stresses and the compressive spring constant K_cg. In the present paper, a model in which clamped parts with a gasket are fastened by multiple bolts is proposed and an analysis is done. By comparing the analytical results with the results obtained from a single fastening model, the effects of multiple fastenings on the contact stresses and the value of K_cg are made clear by numerical computations. In addition, an engineering calculation method of K_cg is proposed.

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本論文は,プログラミングをはじめとする情報系専門科目を実施可能なアクティブラーニング環境の構築について述べる.情報系専門科目をアクティブラーニング可能な空間で実施する意義は大きいと考えられる.しかし授業で利用する機材等の都合上,PCの利用のために整備された実験室等で実施されることが多かった.機能の十分なコンピュータを利用しながら,ペアやグループでの活動を行うことは容易ではなかった.本研究では情報系専門科目を実施可能なアクティブラーニング空間の要件を整理し,「空間利用の柔軟性を損なわないICT」「速度と反応性と構成管理のバランス」「授業と密接に連携できる運用と保守性」の3点にまとめた.それらを実現するためのテクノロジーについて検討し,情報系専門科目を実施できる教室MILAiSを設計・構築した.3年間の授業事例から,情報系専門科目が実施可能であり,多様な授業も実践可能であることを示した.

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