摘要：
A multirate nonuniform subband method with general parameter filter banks for wideband beamforming of harmonic nested array is proposed. The harmonic nested array is composed of several uniformly-spaced linear subarrays, each of which processes an octave subband signal. The nonuniform subband signal is generated by general parameter filter banks. Each subarray beamforming is carried out with space-frequency signal processing approach, and four subarrays share the same weights among themselves. Based on this kind of processing architecture, the proposed beamformer splits the wideband signal into several nonuniform narrow subband ones which are processed in parallel, and only one subarray weights are needed. In this way, the proposed beamformer greatly alleviate burden of demanding too many weights for the arrays and hence contributes to significantly decreasing the computational load and improving the speed as well. Simulations show that the proposed beamformer is competent for wideband beamforming with much lower computation complexity.
作者机构：
Department of Computer Science,Hunan City University, Yiyang Hunan 413000, P.R. China;School of Computer Science, China University of Geosciences, Wuhan 430074, P.R. China
会议名称：
The 4th International Symposium on Intelligence Computation and Applications(第四届智能计算及其应用国际会议 ISICA2009)
会议时间：
2009-10-23
会议地点：
湖北黄石
会议论文集名称：
The 4th International Symposium on Intelligence Computation and Applications(第四届智能计算及其应用国际会议 ISICA2009)论文集
摘要：
Differential evolution (DE), a fast and robust evolutionary algorithm for global optimization, has been widely used in many areas. However, the success of DE for solving different problems mainly depends on properly choosing the control parameter values. On the other hand, DE is good at exploring the search space and locating the region of global minimum, but it is slow at exploiting the solution. In order to alleviate these drawbacks of DE, this paper proposes an improved self-adaptive control parameter of DE, referred to as ISADE, for global numerical optimization. The proposed approach employs the individual fitness information to adapt the parameter settings. Hence, it can exploit the information of the individual and generate the promising offspring efficiently. To verify the viability of the proposed ISADE, 10 high-dimensional benchmark problems are chosen from literature. Experiment results indicate that this approach is efficient and effective. It is proved that this approach performs better than the original DE in terms of the convergence rate and the quality of the final solutions.Moreover, ISADE obtains faster convergence than the original self-adaptive control parameter of DE (SADE).
作者机构：
School of Civil Engineering, HuNan City University, YiYang 413000, China School of Resource and safe;School of Resource and safety Engineering, Central South University, ChangSha 410083, China;School of Civil Engineering, HuNan City University, YiYang 413000, China
会议名称：
The 3rd International Symposium on Modern Mining & Safety Technology Proceedings(第三届现代采矿与安全技术国际学术会议)
会议时间：
2008-08-04
会议地点：
辽宁阜新
会议论文集名称：
The 3rd International Symposium on Modern Mining & Safety Technology Proceedings(第三届现代采矿与安全技术国际学术会议)论文集
关键词：
stratified rock slope;simulation of stage ezcavation;elasto-plastic finite element method of lowing material's strength;slope integrity stability analysis
摘要：
The slope stage excavation process is: (i) excavating the first part of the slope rock and exerting rock bolting and concrete shotcrete layer (ii) excavating the second part and exerting the second layer rock bolting and concrete shot-crete layer. The next construction process is the same as the upper step. In this article, the bolting is simulated with onedimension axial bar, the joint is simulation by no thickness Goodman element, the effect of blasting is calculated using dynamic stress method, the slope stability safety factor derives from using elastoplastic finite element method of lowing material's strength. The simulation of stage excavation of the stratified rock slope is carried out, considering unloading effect of excavation. These functions are realized by my own finite element program. This program is applied to the K135 slope of ChangZhang highway. The stresses and displacements of K135 slope for every excavation step are analyzed and the safety factors are gotten. The slope's stability is evaluated and some suggestions are proposed for improving and strengthening the slope. The analysis result shows the K135 slope is stability in the process of construction.
摘要：
The mutual authentication mechanism in the IEEE802.16e can avoid the man-in-middle attack, and can protect the multi-hop WiMax security in efficiency. An improved X.509 certificate based on ECC algorithm is designed, then an enhanced mutual authentication flow was proposed in this paper, which enhances the security and working efficiency of the mutual authentication in multi-hop WiMax system. The proposed scheme heightens the security and practicability of WiMax system, which has better referenced value to the improvement of IEEE 802.16e standards.
摘要：
Since the operations of sensors in wireless sensor networks (WSNs) mainly rely on battery energy, energy consumption becomes an important issue. In this paper, we use a global simulated annealing genetic algorithm (GSAGA) to create energy efficient clusters for routing in WSNs. The simulation results show that the proposed GSAGA algorithm has higher efficiency and can achieve better network lifetime and data delivery at the base station than a few existing cluster-based routing protocols.
