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Xiaolei LIU Xiaosong ZHANG Yiqi JIANG Qingxin ZHU
Optimizating the deployment of wireless sensor networks, which is one of the key issues in wireless sensor networks research, helps improve the coverage of the networks and the system reliability. In this paper, we propose an evolutionary algorithm based on modified t-distribution for the wireless sensor by introducing a deployment optimization operator and an intelligent allocation operator. A directed perturbation operator is applied to the algorithm to guide the evolution of the node deployment and to speed up the convergence. In addition, with a new geometric sensor detection model instead of the old probability model, the computing speed is increased by 20 times. The simulation results show that when this algorithm is utilized in the actual scene, it can get the minimum number of nodes and the optimal deployment quickly and effectively.Compared with the existing mainstream swarm intelligence algorithms, this method has satisfied the need for convergence speed and better coverage, which is closer to the theoretical coverage value.
Andrzej J. STROJWAS Xiaolei LI Kevin D. LUCAS
In this paper we present a rigorous vector 3D lithography simulator METROPOLE-3D which is designed to run moderately fast on conventional engineering workstations. METROPOLE-3D solves Maxwell's equations rigorously in three dimensions to model how the non-vertically incident light is scattered and transmitted in non-planar structures. METROPOLE-3D consists of several simulation modules: photomask simulator, exposure simulator, post-exposure baking module and 3D development module. This simulator has been applied to a wide range of pressing engineering problems encountered in state-of-the-art VLSI fabrication processes, such as layout printability/manufacturability analysis including reflective notching problems and optimization of an anti-reflective coating (ARC) layer. Finally, a 3D contamination to defect transformation study was successfully performed using our rigorous simulator.