Advection and dispersion of swimming crab (Portunus trituberculatus MEIRS)larvae in the Hiuchi-Nada, a central part of the Seto Inland Sea, Japan is numerically simulated. A three-dimensional numerical model of tidal current and the residual flow in the Hiuchi-Nada is developed first. Calculated distribution of the larvae in the model well reproduces the observed one in the field. Diurnal vertical migration of swimming crab larvae plays an important role in their recruitment strategy from offshore region to the nearshore region.

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Analyses of inverse problems arising in the field of mechanics and strength of materials are reviewed. The inverse problems are defined as the problems dealing with the estimation of input from output. Based on this definition the inverse problems can be classified into boundary/domain inverse problems, governing equation inverse problems, boundary value/ initial value inverse problems, force/source inverse problems, and material properties inverse problems. It is noted that the inverse problems are usually ill-posed: they lack in existence, uniqueness or stability of the solution. Representative schemes for the solution of the inverse problems are introduced with special emphasis on regularization. Examples in these categories of inverse problems and their analyses are shown. Successful use of the regularization methods in the analyses are described. It is shown that subsidiary information, such as a priori knowledge and fundamental laws, can be successfully used for improving the mathematical structure of the ill-posed inverse problems and obtaining good estimates.

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Pattern formation of ice crystals during their growth in supercooled water shows a drastic change from a circular disk shape to a well-developed dendritic shape with hexagonal symmetry. Recent experiments for the pattern formation of ice crystal, which were carried out by modern experimental techniques, are summarized. As a result, it is to be emphasized that the anisotropy of inter facial free energy(inter facial tension) around the basal face is negligibly small, while the degree of anisotropy of inter facial kinetic effect increases with the increase of crystal growth velocity. This result means that the hexagonal symmetry of ice dendrite is governed by the inter facial kinetics, instead of the anisotropy of interface free energy.

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