Due to France has suffered from many terrorist attacks and the number of visitors to the Louvre has gradually increased in recent years, a good evacuation plan for the Louvre is of vital significance. We use the minim...Due to France has suffered from many terrorist attacks and the number of visitors to the Louvre has gradually increased in recent years, a good evacuation plan for the Louvre is of vital significance. We use the minimization of the total evacuation time of all tourists as the optimization goal to find an optimal path. For conventional emergencies, a static model is built to evacuate visitors. And then we establish a nonlinear programming model. Using Lingo software, we get the distribution information of the visitors in different exhibition halls. For unconventional emergencies, we establish an adaptive dynamic model of tourist evacuation based on genetic algorithm. The sensitivity analysis of the model is considered by adding new paths. By solving the nonlinear programming problem with the double objective function of maximizing evacuation time and balancing the number of people in every path, we get the evacuation time last 1582.74 s. Finally, according to our result, we built mathematical models for the evacuation after an emergency and analyzed how to adapt and implement our models for other large and crowded structures.展开更多
文摘Due to France has suffered from many terrorist attacks and the number of visitors to the Louvre has gradually increased in recent years, a good evacuation plan for the Louvre is of vital significance. We use the minimization of the total evacuation time of all tourists as the optimization goal to find an optimal path. For conventional emergencies, a static model is built to evacuate visitors. And then we establish a nonlinear programming model. Using Lingo software, we get the distribution information of the visitors in different exhibition halls. For unconventional emergencies, we establish an adaptive dynamic model of tourist evacuation based on genetic algorithm. The sensitivity analysis of the model is considered by adding new paths. By solving the nonlinear programming problem with the double objective function of maximizing evacuation time and balancing the number of people in every path, we get the evacuation time last 1582.74 s. Finally, according to our result, we built mathematical models for the evacuation after an emergency and analyzed how to adapt and implement our models for other large and crowded structures.
文摘为减少电力线信道时变性对自动抄表系统(automaticmeter-reading system,AMRS)计量数据传输效率的不利影响,提出了中继路由与分组队列相结合的方法。中继路由将整条通信链路分割成若干子链路,可以有效提高传输效率,但传输效率仍受制于信噪比(signal to noise ratio,SNR)最低的子链路。为充分利用每条子链路的最大传输效率,在中继路由的基础上,引入了分组队列机制。该方法根据接收和发送子链路的信道状况,动态调整分组队列长度,实现了发送子链路和接收子链路独立传输。由基于SNR的3状态Markov信道模型得到分组的平均发送次数,以该次数表示中继路由的分组接收速率和分组发送速率,建立了基于OPNET的M/M/1/K的AMRS分组排队模型。通过分析不同排队强度时的分组队列长度与队列延时等参数,验证了该方法能够提高传输效率。
