Unsteady flows driven in cavities with aspect ratio of 1.0, 0.8 and 1.5 are studied by means of direct numerical simulation. A FDM code based on fourth-order compact schemes, low storage fourth-order Runge-Kutta method and the full multigrid V-cycle method is utilized. For the case of square cavity, bi-stable periodic solutions with different frequencies are found to exit when Re is increased beyond the quasi-periodic regime (Re &ge; Re_<cr3> = 10975). Results for cavities with aspect ratio of 0.8 and 1.5 will be presented.

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Symplectic integration algorithms (SIAs) have been proven to be robust and accurate for particle and beam dynamics. They are also successfully applied to the wave equations. In this paper, several SIAs are compared for problems in wave acoustics (one-dimensional acoustic wave equation) and geometrical acoustics (scatter of sound rays by a stationary viscous vortex). Methods are chosen for each problem which are considered to perform better than the other methods tested.

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This paper discourse about Nonlinear Finite Element Analysis of container stack failure on the carrier deck in manifold ocean condition. Now a days many container using for marine transportation, and container carrier became a large scale to tackle increasing traffic volume. Container stacks on deck is moving by wave, sometimes it clash each other and container brake, stack is disrupted. Using numerical analysis to this problem, research how to behaviour container stack and validate by experiment using stack on deck in transporting.

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本研究では,導入コストの低減に大きな期待のあるオープンCAEに注目し,建築系構造物への適用例の1つとして,鉄骨構造物におけるボルト接合部分の精密な接触解析を試みた.これにより,実用的な構造解析の課題に対応した,オープンCAEの数値解析の可能性を検証することを目的としている.数値解析では,フランス電力公社より開発され,オープンソースのソフトウエアとして公開されているSALOME-Mecaを活用し,接触解析機能を用いたボルト軸部と母材との接触面における応力や変形の状態を分析した.その結果より,基本的な接触挙動の分析が可能であることを確認し,具体的には,ボルト軸部の変形状態やボルト穴周辺における応力集中の状況を把握することができた.

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現在、我々の周辺には生活を便利にする高機能な機械が多くなっている.自動車の高機能化も進められているが、運転しながらの操作が困難な状況も起きている.そのため、自動的に情報を収集し運転者へ有益な情報を提供する機能の開発が重要となっている.本研究では人間の顔表情をインタフェースとして利用し、運転者の疲労度を測る、渋滞等によるストレスを解消するような情報を提供するシステムの開発を行う。本システムでは初めに人間の顔とそれ以外の領域に分類する。次に動画像中の特徴点の検出を行い、特徴点の位置変化から心理状態を推測し、改善に必要な情報を提供するシステムとする。しかし、順に影がある場合に特徴点の検出精度が大きく低下する。そのため影領域の明度補正を行い、特徴点の検出精度を改善させた。

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Fracture in the femur, particularly around the femoral head and neck region, is one of the complications of hip arthroplasty. In this study, femoral fractures in two types of hip arthroplasy, total hip (THA) and resurfacing (RHA), was compared. The two implants were fitted into a three-dimensional bone model created from CT scans of a 54-year old male. Finite element method was used to observe the stress and fracture distributions. The results indicated that tensile fracture dominates THA, while compressive fracture is more prominent in RHA. Furthermore, fractures in RHA appear earlier than in THA. Equivalent stress analysis indicates that the stress distribution of RHA is comparable to that of THA, the difference being it covering the proximal region of the femur.

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Novel tensor symbols are proposed, which represent concisely operation modes of the deformation gradient and physical meanings of the pull-back and push-forward operations and the convected derivatives. Then, relationships of several stress tensors are illustrated from the aspect of these operations, and various objective stress rate are derived from the convected derivative.

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Various cyclic plasticity models have been proposed to date. They are first classified from the aspect of mechanical structures and their mechanical features are analyzed. Then, their pertinences are compared for describing the cyclic loading behavior. Mechanical requirements for constitutive equations are shown and the pertinences are also discussed from these requirements.

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