To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model （CTM）. Based ...To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model （CTM）. Based on the traffic management measures used under special events, a semi-dynamic assignment algorithm is proposed, which is combined with an algorithm for logit multi-path traffic assignment and the CTM. In a simple calculation network, the spacial and temporal characteristics of traffic flows which vary with different traffic management schemes are studied, and a method to obtain the influence range of emergency is proposed by computing the jam time of the intersections. By contrasting the average delay of each vehicle, the dissipation effect is studied under two different traffic management schemes. The example shows that the spatial and temporal variety of the traffic flow can be easily simulated and the influence range of emergency can be confirmed by the method based on the CTM. The proposed method provides a new idea for decision-making on traffic management under emergency under special events.展开更多
In this research, five plots are Selected based on stand storage and productivity of planted forest of Larix kaempferi （Japanese larch） as well as their relationship with factors suCh as forest age, site condition a...In this research, five plots are Selected based on stand storage and productivity of planted forest of Larix kaempferi （Japanese larch） as well as their relationship with factors suCh as forest age, site condition and stand density. Through standard plot investigation and method of trunk analysis, systematic research is conducted on storage and productivity of the planted forest and their relationship with site condition. As shown in the research, productivity of planted forest of Larix kaempferi in low latitude area is higher than that in high latitude area while stand productivity is higher in slight acid soil. Contents of potassium element in the soil have Considerable influence on productivity of the Larix kaempferi forest.展开更多
基金The National High Technology Research and Development Program of China(863 Program)(No.2007AA11Z210)
文摘To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model （CTM）. Based on the traffic management measures used under special events, a semi-dynamic assignment algorithm is proposed, which is combined with an algorithm for logit multi-path traffic assignment and the CTM. In a simple calculation network, the spacial and temporal characteristics of traffic flows which vary with different traffic management schemes are studied, and a method to obtain the influence range of emergency is proposed by computing the jam time of the intersections. By contrasting the average delay of each vehicle, the dissipation effect is studied under two different traffic management schemes. The example shows that the spatial and temporal variety of the traffic flow can be easily simulated and the influence range of emergency can be confirmed by the method based on the CTM. The proposed method provides a new idea for decision-making on traffic management under emergency under special events.
文摘In this research, five plots are Selected based on stand storage and productivity of planted forest of Larix kaempferi （Japanese larch） as well as their relationship with factors suCh as forest age, site condition and stand density. Through standard plot investigation and method of trunk analysis, systematic research is conducted on storage and productivity of the planted forest and their relationship with site condition. As shown in the research, productivity of planted forest of Larix kaempferi in low latitude area is higher than that in high latitude area while stand productivity is higher in slight acid soil. Contents of potassium element in the soil have Considerable influence on productivity of the Larix kaempferi forest.
