Shortest or locally quickest?A prediction-based approach for evacuation choice simulation between multiple staircases

Staircase choice is one of the most critical factors leading to the difference in pedestrian flow and evacuation routes in buildings with multiple staircases.Neither the shortest path to the building exit nor the locally quickest path to the nearest staircase can represent the natural mode of evacuation path choices for an authentic evac-uation simulation.Thus,a prediction-based approach is established to predict and simulate evacuation choices,which helps to address three key issues:(1)extracting evacuation data through a controlled experiment;(2)establishing a Logit model for staircase choice prediction based on experimental data;(3)developing a prediction-based cellular automaton model.The proposed approach has achieved the coupling between choice prediction and evacuation simulation.A comparison with Pathfinder software is conducted to reveal the supe-riority of the prediction-based CA model for simulating staircase choice.

Multi-UAV surveillance implementation under hierarchical dynamic task scheduling architecture

In this paper,we consider a multi-UAV surveillance scenario where a team of unmanned aerial vehicles(UAVs)synchronously covers an area for monitoring the ground conditions.In this scenario,we adopt the leader-follower control mode and propose a modified Lyapunov guidance vector field(LGVF)approach for improving the precision of surveillance trajectory tracking.Then,in order to adopt to poor communication conditions,we propose a prediction-based synchronization method for keeping the formation consistently.Moreover,in order to adapt the multi-UAV system to dynamic and uncertain environment,this paper proposes a hierarchical dynamic task scheduling architecture.In this architecture,we firstly classify all the algorithms that perform tasks according to their functions,and then modularize the algorithms based on plugin technology.Afterwards,integrating the behavior model and plugin technique,this paper designs a three-layer control flow,which can efficiently achieve dynamic task scheduling.In order to verify the effectiveness of our architecture,we consider a multi-UAV traffic monitoring scenario and design several cases to demonstrate the online adjustment from three levels,respectively.

Dynamic admission control in hybrid QoS networks with WiFi access

Providing quality of service （QoS） guarantees for multimedia applications over Hybrid networks by wired and wireless LANs is rapidly becoming an important issue. In order to protect the high priority traffic flows and improve network performance in a heavy-loaded network, a new dynamic admission control algorithm is proposed in this paper. We firstly propose a method to fit the fractional autoregressive integrated moving average （FARIMA） models to four actual wireless traffic traces and a traffic prediction based on the upper probability limit. Our experiments show that the one-step forecasts based on the FARIMA models are better than those based on autoregressive integrated moving average （ARIMA） models. We also propose a prediction-based admission control algorithm in hybrid QoS networks with WiFi access using the FARIMA models. The comprehensive simulation experiments are performed to verify the effectiveness of the proposed admission control algorithm.