A finite element model,for the shallow water equations based on the quasi bubble-function approximation is discussed focusing on an alternative implementation of surface elevation boundary conditions. Numerical experiments demonstrate that the conventional imple-mentation of the boundary conditions originate spurious oscillations. In this work, the alternative implementation, which we refer to as Discontinuous Elevation Boundary Implementation (DEBI), is proposed with validation via numerical testing. The results indicate that the DBI improves accuracy of numerical solutions and eliminates the spurious modes.

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Simulated Annealing (SA) is an effective general heuristic method for solving many combinatorial optimization problems. But SA has two problems which are the long computational time of the numerical annealings and the determination of the appropriate temperature schedule. For the temperature schedule, Harry found that a specific constant temperature in SA yields good solutions for TSPs. The number of such specific constant or important temperature region has been thought to be one. But, Miki found that there are two important temperature regions in some TSPs. This paper discusses the multiple important temperature regions, and provides a guideline for determining proper temperature schedules in SA.

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This paper proposes a structural topology optimization method for obtaining mechanical resonators incorporating desired dynamic characteristics. First a new type of homogenization design method is introduced, in which the continuous material distributions are assumed using a continuous interpolation function at each node, in order to overcome numerical instabilities. Next, three design requirements to implement specific dynamic characteristics in the mechanical structures are clarified, namely eigen-frequency matching, eigen-mode control, and stiffness, and the corresponding objective functions are formulated. An optimization algorithm is developed using Sequential Linear Programming (SLP). Finally, several examples are provided in order to confirm the usefulness of the generated optimal designs for mechanical resonators.

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By the'explosion, high dense and high pressure detonation products gasses expand rapidly and extremely strong shock waves are driven. The three-dimensional simulation is executed for the propagation of the blast waves driven by TNT32kg explosion in the underground magazine. We present an effective visualization of the fireball, and the key idea for the fireball with complex surface illuminated by the black body radiation is the combination of volume rendering with iso surface rendering based on a pure ray tracing method.

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A huge amount of data has been produced from computations and experiments. Owing to the volume of data, it is quite difficult to extract useful information from these data even if using scientific/information visualization techniques. We have developed a new visualization environment using a concept of intelligent space to overcome these issues. In this paper, we remark displaying method in the intelligent space, and propose a new displaying system of the visualized results. The concept of tangible user interface (TUI) that can operate digital informatiori physicallyAnd intuitively is introduced into wall visualization (WV) that has achieved various effects such as the collaborations among researchers a presence and a full-scale, and provided an immersivel virtual environment bycdisplaying information to a large screen. And then, key techniques for constructing a system are examined.

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Diagonally Relaxed Quasi RICCG method is known to-be a powerful linear solver for FEM analysis. In this article, we evaluate its convergence through numerical experiments for linear systems which appear in the mesh superposition method as compared with a variety of preconditioned CG methods.

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The calculation of viscous flows inside deformable structures often encounters numerical instability, which is affected by compatibility condition enforced on the fluid structure interface. In this work, a numerical time integrator that can conserve total energy of the fluid structure system is discussed. To consider compatibility and conservation of energy, weak formulations for both fluid and structure are employed. To design the approximation of variables on the fluid structure interface, the domain decomposition approach is applied. Coupling algorithms including. Iterative weakly coupled scheme are also discussed.

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