in some instances, it is inevitable that large amounts of potentially hazardous chemicals like chlorine gas are stored and used in facilities in densely populated areas. in such cases, all safety issues must be carefully considered. to reach this goal, it is important to have accurate information concerning chlorine gas behaviors and how it is dispersed in dense urban areas. furthermore, mainta...

Established in 1984, the Wharton Risk Management and Decision Processes Center develops and promotes effective corporate and public policies for low-probability events with potentially catastrophic consequences through the integration of risk assessment, and risk perception with risk management strategies. Natural disasters, technological hazards, and national and international security issues ...

Hazard avoidance is a key technology for landing large payloads safely on the surface of Mars. During hazard avoidance a lander uses onboard sensors to detect hazards in the landing zone, autonomously selects a safe landing site, and then maneuvers to the new site. Design of a system for hazard avoidance is facilitated by simulation where trades involving sensor and mission requirements can be ...

I n this paper, we propose a safety analysis method using coloured Petri nets (CPN). Our method employs a backward approach where a hazard is assumed to have occurred and backward simulation from the hazard is performed in order to determine i f and how the hazard might occur. Using CPN, we define a hazard as a set of markings and perform backward simulation by generating a reachability graph b...