In this research, we designed and developed a "playground" using fog as a media of expression. The "playground" is a space where children express themselves and connect with others using bodily expressions while playing. To realize this concept, we developed the fog display system to satisfy the following requirements. (1) Everyone has access to the media space created by the fog. (2) Fog displays are scattered all over the space. (3) Images projected on fog displays are visible from various directions inside and outside the space. (4) The expelling, rectification, and diffusion of the fog are controlled. And, we tested the effectiveness of the system through its on-site use. As a result, it was found that this system, which can project an image on the fog that has a naturalness (disappearance, spatiality, and extraordinariness), versatility, and plasticity, has the potential to function as the playground.

No abstract

Recently the deregulation of electric power industly has progressed in the world. In Japan the electric power industry law was revised in 1995, and competition in the power generation market has started. Moreover, the retail wheeling to l q e customers has begun from March 2000. In the circumstances it is more important to know how to secure supply reliability from the viewpoint of system operation.In this paper, we a s m e that there exist Power Producers and Suppliers (PPSs) and Indepmdmt System Operators (ISOs) of different companies in the future. Firstly, we deal with a PPS which aims at stable supply, on behalf ofcustomers whom he has bilateral contracts with and provides baekup supplies between PPSs or behveen PPSs and transmission owners for PPS generator tmubles. Secondly we deal with an IS0 that has responsibility for stable supply, and provides a backup supply between PPSs and uansmission owners for transmission line troubles. And we investigate how the control outputs are influenced by the way of backup contracts with other PPSs and transmission owners for anticipated troubles.