This paper presents a development o f the extended Cellular Automata9CA),based on relational databases(RDB),to model dynamic interactions amon g spatial objects.The integration o f Geographical Information System(GIS)...This paper presents a development o f the extended Cellular Automata9CA),based on relational databases(RDB),to model dynamic interactions amon g spatial objects.The integration o f Geographical Information System(GIS)and CA has the great advantage of simu lationg geographical processes.But standard CA has some restrictions i n cellular shape and neighbourhood and neighbour rules,which restrict the CA’ s ability to simulate complex,real world environ-ments.This paper discusses a cell’ s spatialrelationbasedonthe spatialobject’ s geometricalandmon -geometricalc haracter-istics,and extends the cell’ s neighbour definition,and considers that the cell’ s neighbour lies in the forms of not on ly spa-tial adjacency but also attribute co rrelation.This paper then puts forw ard that spatial relations between t wo different cells can be divided into three types,including spatial adjacency,neighbour hood and complicated separation.Ba sed on tradition-al ideas,it is impossible to settle CA’ s restrictions completely.RDB -based CA is an academic experiment,in which some fields ard desighed to describe the essential information needed to define and select a cell’ s neighbour.The culture innovation diffusion system has mul tiple forms of space diffusion and in herited characteristics that the RD B -based CA is capable of simulating more effectiv ely.Finally this paper details a successful case study on the diffusion o f fashion wear trends.Compared to the original CA,the RDB -based CA is a more natural and efficient representation of human k nowl-edge over space,and is an effective t ol in simulation complex systems that have multiple forms of spatial diff usion.展开更多
The common properties of risk in long tunnel fires are high temperature, extreme difficulty of evacuation, rescue urgency and obstacle to rescue operation. Therefore, a complete ventilation design is an indispensable ...The common properties of risk in long tunnel fires are high temperature, extreme difficulty of evacuation, rescue urgency and obstacle to rescue operation. Therefore, a complete ventilation design is an indispensable safety measure. Hsueh-Shan Tunnel is the longest in Taiwan, the fifth longest in the world. On May 7, 2012, a serious tunnel fire caused two deaths and numerous victims suffered from smoke inhalation injury. Apart from this, there was smoking entering the cross-passages and shafts which were important for evacuation. In this research, the current ventilation system in Hsueh-Shan Tunnel was simulated with FDS （fire dynamics simulator） software, and the statistics of smoke, visibility and temperature profile were analyzed. The results of this research showed that, with the current ventilation system, the time was shorter and the distance was longer for the smoke spreading windward than in other models. Furthermore, the visibility of windward victims was more affected and the temperature above the fire source was higher than those in other systems. When the wind speed in tunnel is within 2.0-4.0 m/s, the condition for turning off the ventilation fan within 250 m upwind from the fire source can be prominently reduced to 50 m upwind from the fire source. This not only could avoid plume disturbance but also could be maintained. If victims＇ evacuation should be given the highest priority, it is recommended to straightly activate the maximum power of the fan.展开更多
文摘This paper presents a development o f the extended Cellular Automata9CA),based on relational databases(RDB),to model dynamic interactions amon g spatial objects.The integration o f Geographical Information System(GIS)and CA has the great advantage of simu lationg geographical processes.But standard CA has some restrictions i n cellular shape and neighbourhood and neighbour rules,which restrict the CA’ s ability to simulate complex,real world environ-ments.This paper discusses a cell’ s spatialrelationbasedonthe spatialobject’ s geometricalandmon -geometricalc haracter-istics,and extends the cell’ s neighbour definition,and considers that the cell’ s neighbour lies in the forms of not on ly spa-tial adjacency but also attribute co rrelation.This paper then puts forw ard that spatial relations between t wo different cells can be divided into three types,including spatial adjacency,neighbour hood and complicated separation.Ba sed on tradition-al ideas,it is impossible to settle CA’ s restrictions completely.RDB -based CA is an academic experiment,in which some fields ard desighed to describe the essential information needed to define and select a cell’ s neighbour.The culture innovation diffusion system has mul tiple forms of space diffusion and in herited characteristics that the RD B -based CA is capable of simulating more effectiv ely.Finally this paper details a successful case study on the diffusion o f fashion wear trends.Compared to the original CA,the RDB -based CA is a more natural and efficient representation of human k nowl-edge over space,and is an effective t ol in simulation complex systems that have multiple forms of spatial diff usion.
文摘The common properties of risk in long tunnel fires are high temperature, extreme difficulty of evacuation, rescue urgency and obstacle to rescue operation. Therefore, a complete ventilation design is an indispensable safety measure. Hsueh-Shan Tunnel is the longest in Taiwan, the fifth longest in the world. On May 7, 2012, a serious tunnel fire caused two deaths and numerous victims suffered from smoke inhalation injury. Apart from this, there was smoking entering the cross-passages and shafts which were important for evacuation. In this research, the current ventilation system in Hsueh-Shan Tunnel was simulated with FDS （fire dynamics simulator） software, and the statistics of smoke, visibility and temperature profile were analyzed. The results of this research showed that, with the current ventilation system, the time was shorter and the distance was longer for the smoke spreading windward than in other models. Furthermore, the visibility of windward victims was more affected and the temperature above the fire source was higher than those in other systems. When the wind speed in tunnel is within 2.0-4.0 m/s, the condition for turning off the ventilation fan within 250 m upwind from the fire source can be prominently reduced to 50 m upwind from the fire source. This not only could avoid plume disturbance but also could be maintained. If victims＇ evacuation should be given the highest priority, it is recommended to straightly activate the maximum power of the fan.
