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Luo Z.,Huazhong University of Science and Technology | He X.,Public Security Marine Police Academy | Chen X.,Huazhong University of Science and Technology | Luo X.,Huazhong University of Science and Technology | Li X.,Huazhong University of Science and Technology
International Journal of Antennas and Propagation | Year: 2015

Teaching-learning-based optimization (TLBO) algorithm is a new kind of stochastic metaheuristic algorithm which has been proven effective and powerful in many engineering optimization problems. This paper describes the application of a modified version of TLBO algorithm, MTLBO, for synthesis of thinned concentric circular antenna arrays (CCAAs). The MTLBO is adjusted for CCAA design according to the geometry arrangement of antenna elements. CCAAs with uniform interelement spacing fixed at half wavelength have been considered for thinning using MTLBO algorithm. For practical purpose, this paper demonstrated SLL reduction of thinned CCAAs in the whole regular and extended space other than the phi = 0° plane alone. The uniformly and nonuniformly excited CCAAs have been discussed, respectively, during the simulation process. The proposed MTLBO is very easy to be implemented and requires fewer algorithm specified parameters, which is suitable for concentric circular antenna array synthesis. Numerical results clearly show the superiority of MTLBO algorithm in finding optimum solutions compared to particle swarm optimization algorithm and firefly algorithm. © 2015 Zailei Luo et al. Source

Xiao F.,Dalian Maritime University | Jin Y.,Dalian Maritime University | Yin Y.,Dalian Maritime University | Li Y.,Dalian Maritime University | Li Y.,Public Security Marine Police Academy
Proceedings - 2nd International Conference on Information Technology and Computer Science, ITCS 2010 | Year: 2010

Search and Rescue (SAR) at sea is one of the most important humanitarian activities and also an extremely complex operation based on the coordination of each unit within search and rescue event. Taking real equipments to do SAR rehearsal has many disadvantages such as high cost and great danger. In order to overcome these shortcomings and enhance the flexibility and the collaborative ability of each unit within search and rescue event, developing and using the Marine Search and Rescue Simulation System (MSRSS) is a good solution. This paper analyzes the marine SAR system first and then present a marine SAR system model for MSRSS based on Activity Cycle Diagram (ACD), furthermore brings forward a research scheme of MSRSS including system architecture, the configuration and function of all units in MSRSS such as distress ship, rescue ship and rescue helicopter. Distress ship, rescue ships, rescue helicopter are shared one highly realistic marine SAR virtual environment through visual and auditory system. MSRSS is an integrated simulation system with searching and rescuing function, which can provide different kinds of marine SAR environments and is effective for marine disaster rescue, harbor project evaluation, navigation teaching and research, and marine SAR missions training. Till now, MSRSS has been put into trial operation, and the results of trial operation indicate that the research scheme is rational and feasible. © 2010 IEEE. Source

Ding J.,Public Security Marine Police Academy
2010 International Conference on Computational Intelligence and Software Engineering, CiSE 2010 | Year: 2010

In this paper, the performances of FSR wireless routing protocol under different parameters are simulated based on ns2 network simulation platform. The reference point group mobility model is selected as the mobile ad hoc network mobility model. Through the detailed analysis of the results, the three features of the FSR routing protocol in terms of end-to-end delay, packet delivery ratio and routing overhead are concluded under reference point group mobility model. This work is useful for further study about variety applications based on FSR wireless routing protocol in mobile ad hoc network. ©2010 IEEE. Source

Li Y.,Dalian Maritime University | Li Y.,Public Security Marine Police Academy | Jin Y.,Dalian Maritime University | Yin Y.,Dalian Maritime University | And 2 more authors.
Proceedings of the 5th International Conference on Image and Graphics, ICIG 2009 | Year: 2010

A novel method for simulating large-scale, near-shore sea surface is presented. The whole simulating process can be divided into two phases: pre-computing phase and real-time computing phase. In pre-computing phase, wave parameter distribution of a simulation area is worked out using the SWAN (Simulating WAves Nearshore) model on a coarse grid. In real-time computing phase, a small height field surrounding the viewpoint is generated using the Fast Fourier Transformation (FFT) based method every frame. The wave parameters used in the FFT-based method are dynamically changed according to viewpoint's projective position on the coarse grid. Then, the height field is saved as a vertex texture, which can be tiled in horizontal directions seamlessly. At last, the vertex texture is sampled by a sector sea surface, which is viewpoint-dependent and has Level Of Detail (LOD) effect. Several shading trips are used to generate optical effects of sea surface, such as reflection, refraction etc. Experimental results show this method can be applied to simulating large-scale sea surface in real-time with realistic effect. It is especially suitable for the application in maritime simulators. © 2009 IEEE. Source

Chen X.,Huazhong University of Science and Technology | Luo Z.,Huazhong University of Science and Technology | He X.,Public Security Marine Police Academy | Zhu L.,Public Security Marine Police Academy
Journal of Electromagnetic Waves and Applications | Year: 2014

Synthesizing antenna arrays with a minimum number of active elements is a problem of high importance in ultrasonic applications. This paper proposes a modified teaching-learning-based optimization (MTLBO) algorithm for thinning and weighting planar arrays to synthesize the desired antenna array factor. Not only the number of active elements and their corresponding excitation weights are optimized, but the peaks of side lobe level, main-lobe width, and current taper ratio are also minimized as objective functions in the multi-objective formulation. The optimization method for designing thinned planar arrays proposed in this work is easy to be implemented and requires few controlling parameters. The simulation cases demonstrate effectiveness of the proposed method, and it is proved that the MTLBO outperforms simulated annealing method and hybrid genetic algorithm through comparisons. © 2014 Taylor and Francis. Source

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