Visual simulation of natural scenery using computer graphics is an interesting research field with wide applications such as flight simulation and special effects in movies. There have been many studies of fractal techniques that use 1/f noise generated by FFT or the midpoint displacement method as modelling methods for imaginary mountain scenery. These methods are suitable for creating impressive mountain scenes, but they cannot create clear ridge and valley lines, which are notable features of mountains produced by erosion processes. Although a few reports have presented modelling methods that take erosion processes into account, the results have not been satisfactory. In this paper we present a simple ‘quasi‐physically based’ method for simulating the topography of eroded mountains based on velocity fields of water flow. © 1998 John Wiley & Sons, Ltd.

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In this paper, we introduce Community Organizer, a system designed to support network communities by providing spatial representations of community members and communication exchanged among these members. This spatial representation reflects the closeness of interests and concerns among them. We conducted an experiment with two different versions of the software. One version offered meaningful spatial representation while the other version did not. Experiment results indicate the eflectiveness of the proposed spatial representation. The subjects who used the software providing the spatial representations felt a greater sense of "community, " enjoyed using the software more, and actively used it longer than subjects in the control condition.

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Integrated large-scale multivariable control and closedloop real-time optimization was implemented on the power plant in Mitsubishi Chemical (Mizushima plant). The multivariable control system controls 3 boilers and 5 turbines simultaneously. Also, the control system controls the site-wide steam header pressure. The realtime optimization system is composed of power plant model and ethylene plant steam turbine model and a number of model's equation is about 10.000. The realtime optimization system optimizes turbine load in the power plant and the site-wide steam balance with about 10 minutes frequency. Most efficient operation of the power plant is realized by the integrated system.