Basic ideas of Fast Multipole Method (FMM) and FMM accelerated Boundary Element Method (BEM) are
explained briefly. Some developments of FMM in computational mechanics related to elasticity, periodicity
and Maxwell’s equations are discussed.
Tornadoes and dust devils are violent small-scale vortices in the atmosphere. Although they have affected human lives significantly, their smallness and short lifetime have prevented detailed investigations until re-cently. In the present talk, our current understandings of these vortices are reviewed and future subjects to be studied are proposed.
Who discovered CHAOS for the first time? This question is about the interest of many people. From the theoretical point of view, the question dates back to centuries ago. However, as a physical phenomenon, people say that the observation of chaos was first done by the author using analog computer on the 27th of November, 1961.
In this talk, the phenomenon itself and its whereabouts are explained briefly. And the purpose and motive of the author’s experimental research are described. Then the seemingly mysterious phenomenon which he accidentally came upon during his experiments is demonstrated. Finally, subsequent chaos researches and its impact on science and society are overviewed and application and theoretical studies of the phenomena will be stated as his personal opinion.
Ice going ships need to estimate their performance in ice conditions. An ice model basin, maybe called as “ice
tank,” is a facility that contains a towing tank in a cold chamber in order to make ice on the water surface. The
Ice Model Basin at National Maritime Research Institute (NMRI) has been used for various model tests and
for the development of testing schemes in ice. The author briefly introduces the ice model basin at NMRI
including the how to form model ice. The formulation of resistance in ice and corrections of towing test
results are also overviewed, with reference to ITTC guidelines.
The sea ice begins to melt in the Arctic Ocean because of global warming. The possibility of the Commercial Navigation in the Arctic Ocean also has risen. The author considers the current state and the problem in this text.
International Maritime Organization (IMO) had discussed for developing the harmonized requirements for ships navigating in ice covered waters from middle of 90’s and issued the “Guidance for Ships Operating in Arctic Ice Covered Waters” as MSC (Maritime Safety Committee) / Circ. 1056 and MEPC (Marine Environment Protection Committee) / Circ. 399, in 2002. After that, the International Association of Classification Society (IACS) issued the Unified Requirements (URs) for Polar Class Ships in 2006 in order to supplement the provisions regarding a hull structure and a machinery mentioned in the IMO Guidance. This paper describes the summaries of the IACS URs.
The paper presents two-dimensional and three-dimensional viscoelastic simulation of multi-layer flow for
polymer melts and discuss about the effects of channel geometries, rheological properties of each layer,
number of layers, flow rate of each layer, etc. on the flow phenomena and interface geometry. We also
discuss the instability phenomena of interface often encountered in multi-layer coextrusion based on the
Solving large systems of linear equations represents the most time consuming part of Finite Element Analyses.
For the case of very large matrices, Krylov solvers like Conjugate Gradients or GMRES are usually preferred.
In this research we investigate the acceleration of Krylov methods on commodity graphic hardware. To assess
the real-world performance, we test the performance and the cost/performance of the solvers on a large
collection of test matrices. For large matrices, up to 15x speedup is obtained when using three GPUs.
An efficient environment for design process, which combines advanced scientific simulators and information
technology, was proposed for skilled manufacturing field. The proposed system is based on a volume data as
shape modeling, which can fully eliminate time-consuming preprocess for CFD. Simulator codes are
constructed on modern object-oriented middleware V-Sphere. This framework provides functions such as
unified user interface, maintenance performance, and development efficiency.
This paper describes the progress of visualization based on virtual reality (VR) technology and its application
to pre- and post-processing for large scale 3-D computations. The binocular parallax is employed for the
visualization by stereo view. The visualization based on VR is employed to evaluate the quality of shape
model, mesh, and the three dimensional computational results. The mesh correction system in VR space is
also developed for the application to pre-processing.
This presentation briefly explains information technologies that are used for the observation and sensing of
earthquake related issues. The examples are satellite observation for crust deformation, remote sensing of
urban area, and MEMS sensing of structures. While quality and quantity of the data that are obtained by
means of these technologies are being improved, it is not sufficient to generate information from them so that
more rational mitigation plans are made against earthquake disasters. Integration of these data with numerical
simulation of computational mechanic is needed for the information generation. The examples of such
integration are mentioned.
従来のXFEMは節点単位で解の特性を有したエンリッチ関数を付加するが，これにより生じるBlending Elements (BE)の内部において近似精度の低下が指摘されている．これに対し本研究では，領域全体の近似精度を包括的に保証するPUFEM近似に基づいて，XFEMに関する再定式化を行った．さらに，この再定式化したXFEMを2次元の線形破壊力学問題に適用し，エンリッチ関数として付加したき裂先端近傍の漸近解の再現性に関する評価を行った．その結果，従来のXFEMを用いた場合，漸近解の再現性に重大な問題があることが示された．一方，本研究で再定式化したXFEMを用いた場合，き裂先端近傍の漸近解を正確に再現可能であることが示された．