A new methodology for optimum design of elasto-plastic structure is presented on the basis of theory of game. The two-person zero-sum game is constituted by two players of design strategy and loading strategy. Pure strategy of design player is a selection of members for weight reduction, and that of loading player a selection of discretized loads for the structure. The objective function of the optimum design is set as sum of squares of all the nodal displacements. The outcome of players concerning the objective function is evaluated through the elasto-plastic finite element analysis of the structure subject to a discretized load after reduction of small amount of weight of a member. The optimum strategy of the design player is decided in line with the minimax strategy by means of the linear programming. The final optimum design is determined after iterative reductions of weight and revisions of outcome until total weight of the structure decreases to its prescribed value. The proposed methodology is demonstrated in problem of a planar twenty-bar truss structure.

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This paper describes an efficient route search method for traffic simulator. In general, probabilistic methods such as rogit model are used to determine one route out of multiple possible ones. However these methods require a large amount of memory, and are not efficient because the calculation of all the possible routes is necessary to determine only one route. In this study, we propose a new route search method based on A* algorithm with a new heuristic function.The algorithm is implemented into the multi-agent-based traffic simulator we are developing. The method is applied to a road-network in Kashiwa-city, and its fundamental performance is discussed.

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A parallel computing with a hierarchical domain decomposition method is performed for three-dimensional eddy current problems. The magnetic vector potential, which is considered as the unknown complex function, is descretized by the Nedelec elements of simplex type. Numerical results show that the method is applicable for a problem, in which the number of complex degrees of freedom is about 500,000.

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The high performance TV game machine "PlayStation2" that has 6.2GFlops at the peak performance has been brought out. By using PlayStation2, a high-speed computation for Poisson equation is carried out by solving such problems as the single precision floating-point calculation and vectorizing optimization at the same time. We also use parallel computing for further speed-up.

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This paper reports an application of High-Throughput Computing to numerical simulations. The Condor environment is employed here. Its fundamental performances are examined for the multiagent traffic simulator we are developing.

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SPH(Smoothed Particle Hydrodynamics) method, which is one of the meshless analysis, has been proved as a powerful tool for structural analysis especially in hyper-velocity impact problems. Recently the method has been shown to have much potentials for general dynamic structural problems, however, the applications have not been sufficient because the fracture analysis by SPH has not fully developed. In this study crack analysis of SPH in 2 -dim has investigated to clarify the accuracy and characteristics of this method.

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