Using catastrophe theory to analyze subway fire accidents Catastrophe theory can describe a continuous process that is undergoing abrupt changes. A dynamic process can be considered to be a swallowtail catastrophe if it has the following six qualities: bimodality, divergence, sudden transitions, hysteresis, inaccessibility and irreversibility. In this paper, the swallowtail catastrophe model is applied to describe the changing dynamic process of subway fire accidents. This dynamic process is also proved to have the six qualities of a swallowtail catastrophe. By using the swallowtail catastrophe model, we construct a model for the subway fire accidents, and we present analyses of subway fire accidents. On the basis of the model and analyses, the dynamic changes in the subway fire accident evolution process can be described with a novel approach. The causes of fire accidents in subways are also discussed, from the perspective of the fire triangle and four elements of an accident. We hope that this studyxe2x80x99s theoretical descriptions and discussion of subway fire accidents will facilitate a profound analysis of subway safety.

Designing a Safety Confirmation System that Utilizes Human Behavior in Disaster Situations. This paper introduces a use case to discuss how to design services for disaster situations as well as to elucidate the development and evaluation of our safety confirmation system, which utilizes human behavior in disaster situation. The success of the safety confirmation system based on information sharing among evacuation centers depends on the intercenter movement of humans. In order to know whether the safety confirmation service would work effectively or not after a massive disaster, we conducted a survey that examined how many evacuation centers were visited after the East Japan Earthquake and the periods over which the evacuees visited the centers. As a result, we confirmed that many evacuees were still visiting centers 72 h after the earthquake, making our technology effective in responding to a disaster.