为了降低基于接收信号强度(Received signal strength Index,RSS)测距误差对节点定位的影响,解决基于RSS测距定位误差较大的问题,提出了基于优化RSS测距的平方最小平方定位算法(Square-least Square localization algorithm based on im...为了降低基于接收信号强度(Received signal strength Index,RSS)测距误差对节点定位的影响,解决基于RSS测距定位误差较大的问题,提出了基于优化RSS测距的平方最小平方定位算法(Square-least Square localization algorithm based on improved RSS,SLS-I-RSS)。SLS-I-RSS算法先通过多组锚节点间的距离和接收功率作为参考,降低基于RSS测距误差,然后再建立定位优化问题,并将定位优化问题转成规则化信任区域子问题,最后,再利用拉格朗日优化算法求解优化问题。实验结果表明,提出的SLS-I-RSS算法能够有效地降低定位误差,比传统的基于RSS定位算法减少了约12%~20%,但算法复杂度略有增加。展开更多
扇区划分是平衡管制员工作负荷、提升空域通行能力的有效技术措施。采用Voronoi图自顶向下切割空域的方法具有自动保证扇区凸性、连通性和压缩性的特性,但计算时间过长。根据航迹状态计算工作负荷,构建了Voronoi图自顶向下切割空域模型...扇区划分是平衡管制员工作负荷、提升空域通行能力的有效技术措施。采用Voronoi图自顶向下切割空域的方法具有自动保证扇区凸性、连通性和压缩性的特性,但计算时间过长。根据航迹状态计算工作负荷,构建了Voronoi图自顶向下切割空域模型,设计了动态步长蚁群搜索算法。测试结果表明,在太原高空划分成4个扇区的情况下,与MC-CLFV(Monte Carlo method by changing location of flexible vertices)算法相比较,采用动态步长蚁群搜索算法求解,扇区的不平衡性显著减少,总工作负荷也减少了11.2%。大规模重复实验表明,随扇区数量增加,解的质量差异减少,但解的效率差异却不断增大,划分8个扇区时,动态步长蚁群搜索算法的计算时间统计中位数值仅为MC-CLFV算法的1/10。这说明该算法在一次划分数量少的时候,质量高而且计算时间短,在采用多层规划扇区的时候,应该采用组合数字和较小的划分方案。研究结果为采用Voronoi图直接切割空域形成管制扇区奠定了基础。展开更多
The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos ...The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos characteristics is proposed. First, the chaos sequence is gotten by iterating cellular neural network with Runge Kutta algorithm, and then the chaos sequence is iterated with the message. The hash code is obtained through the corre- sponding transform of the latter chaos sequence. Simulation and analysis demonstrate that the new method has the merit of convenience, high sensitivity to initial values, good hash performance, especially the strong stability.展开更多
文摘为了降低基于接收信号强度(Received signal strength Index,RSS)测距误差对节点定位的影响,解决基于RSS测距定位误差较大的问题,提出了基于优化RSS测距的平方最小平方定位算法(Square-least Square localization algorithm based on improved RSS,SLS-I-RSS)。SLS-I-RSS算法先通过多组锚节点间的距离和接收功率作为参考,降低基于RSS测距误差,然后再建立定位优化问题,并将定位优化问题转成规则化信任区域子问题,最后,再利用拉格朗日优化算法求解优化问题。实验结果表明,提出的SLS-I-RSS算法能够有效地降低定位误差,比传统的基于RSS定位算法减少了约12%~20%,但算法复杂度略有增加。
文摘扇区划分是平衡管制员工作负荷、提升空域通行能力的有效技术措施。采用Voronoi图自顶向下切割空域的方法具有自动保证扇区凸性、连通性和压缩性的特性,但计算时间过长。根据航迹状态计算工作负荷,构建了Voronoi图自顶向下切割空域模型,设计了动态步长蚁群搜索算法。测试结果表明,在太原高空划分成4个扇区的情况下,与MC-CLFV(Monte Carlo method by changing location of flexible vertices)算法相比较,采用动态步长蚁群搜索算法求解,扇区的不平衡性显著减少,总工作负荷也减少了11.2%。大规模重复实验表明,随扇区数量增加,解的质量差异减少,但解的效率差异却不断增大,划分8个扇区时,动态步长蚁群搜索算法的计算时间统计中位数值仅为MC-CLFV算法的1/10。这说明该算法在一次划分数量少的时候,质量高而且计算时间短,在采用多层规划扇区的时候,应该采用组合数字和较小的划分方案。研究结果为采用Voronoi图直接切割空域形成管制扇区奠定了基础。
基金supported by Key Program of Natural Science Fund of Tianjin of China (Grant No 07JCZDJC06600)
文摘The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos characteristics is proposed. First, the chaos sequence is gotten by iterating cellular neural network with Runge Kutta algorithm, and then the chaos sequence is iterated with the message. The hash code is obtained through the corre- sponding transform of the latter chaos sequence. Simulation and analysis demonstrate that the new method has the merit of convenience, high sensitivity to initial values, good hash performance, especially the strong stability.