基于节点标号的Koch网络结构性质研究

针对正多边形Koch分形岛所映射成的Koch网络,根据节点接入网络的时间和位置信息给节点标号。在节点标号的基础上,研究网络的最短路由及计算最短路径长度;并分析网络的主要结构性质,如节点的度、度分布和累积度分布函数,以及网络的聚类系数、平均最短路径长度、度关联函数和介数中心性,得出结构性质的解析解。结果表明,所构建的Koch网络是无标度和小世界的;其聚类系数趋向于比较大的常数值;平均路径长度与网络节点数的对数呈正比关系,度相关函数、点介数和边介数都随节点度的变化而指数变化。     

Objectivity in confirmation: Post hoc monsters and novel predictions

The aim of this paper is to put in place some cornerstones in the foundations for an objective theory of confirmation by considering lessons from the failures of predictivism. Discussion begins with a widely accepted challenge, to find out what is needed in addition to the right kind of inferential–semantical relations between hypothesis and evidence to have a complete account of confirmation, one that gives a definitive answer to the question whether hypotheses branded as “post hoc monsters” can be confirmed. The predictivist view is then presented as a way to meet this challenge. Particular attention is paid to Worrall’s version of predictivism, as it appears to be the most sophisticated of the lot. It is argued that, despite its faults, his view turns our heads in the right direction by attempting to remove contingent considerations from confirmational matters. The demand to remove such considerations becomes the first of four cornerstones. Each cornerstone is put in place with the aim to steer clear of the sort of failures that plague various kinds of predictivism. In the process, it becomes obvious that the original challenge is wrongheaded and in need of revision. The paper ends with just such a revision.     

基于上市公司交叉持股网络的区域发展政策成效

选择沪深两市2000～2009年的上市公司的数据,将上市公司按其所在省份进行划分.以某一省的所有上市公司对另一省的所有上市公司的投资来反映这两省之间的相互投资关系.实际数据证实了省间的相互投资网络属于典型的稀疏型无标度网络,网络中存在相对较多的hub节点.通过聚类分析、绘制网络图的方式研究了网络的变化趋势,证明了西部大...     

Connecting informal networks to management of tacit knowledge

The relationship between tacit knowledge and informal networks has not been fully explored.Tacit knowledge cannot be well managed directly,because it is deeply embedded in individual actions and experiences.This study proposes an approach to managing informal networks as a new middle way to facilitate the sharing and transferring of tacit knowledge,owing to the fact that tacit knowledge is mostly shared and transferred through informal networks.To support the idea of the approach,an empirical case study of applying the approach to management of a large scientific project is also included.Our findings suggest that informal networks play essential roles for management of tacit knowledge,and thus good management of informal networks can lead to efficient sharing and transferring of tacit knowledge.     

Cohen-Grossberg神经网络稳定性分析

为了研究具有逆Lipschitz激励函数的Cohen-Grossberg神经网络的稳定性,应用Brouwer拓扑度性质和线性矩阵不等式技术,探讨了Cohen-Grossberg神经网络的平衡点的存在性及唯一性。通过构造合适的Lyapunov函数和利用Lyapunov对角稳定性矩阵,给出了唯一平衡点全局指数稳定的充分条件。     

无线传感器网络改进质心算法的节点自定位

节点自定位是无线传感器网络的关键技术之一。在对距离无关的定位机制质心算法研究的基础上,采用极大似然估计法,估算信标节点与未知节点间的距离,以距离作约束降低误差值,从而提高定位的精度。通过MATLAB仿真,结果表明算法能够有效提高定位精度。     

WSN中一种基于叠加编码的协同传输方案

针对分簇无线传感器网络WSN(wireless sensor networks)中现有的协同传输方案以牺牲频谱利用率来换取能效增益的不足,提出了一种基于叠加编码的簇间协同传输方案.该方案在保证系统的频谱利用率条件下,通过相邻簇的簇头节点相互协作来完成数据的传输.在频谱利用率相同的条件下,对现有的簇内协同传输方案和提出的...     

基于被分块的无线传感器网络故障恢复方法

针对网络间不能正常通信的问题,提出了一种解决该类故障的恢复方法。此方法将整个网络监测区域划分成若干个同心圆,被孤立的区域将自己区域的转置节点代表移动到最近的同心圆上,从而实现了重建连通性的目的。     

基于LMI的随机时滞神经网络的全局渐近稳定性分析

研究了一类时变时滞与分布时滞的随机神经网络模型的全局渐近稳定性,该模型考虑了神经网络的随机扰动性.通过构造适当的Lyapunov泛函,以线性矩阵不等式的形式给出了系统全局渐近稳定的充分条件.最后,数值算例说明了结果的正确性.     

基于改进粒子群算法的集成网络节点部署优化

针对集成RFID与WSNs网络中智能节点最佳位置的选择问题,采用改进粒子群算法优化策略,在复杂的传播环境、交叉覆盖及智能节点间不可避免的干扰等影响因素下,寻找智能节点的最佳位置。该最佳位置不仅要保证给定智能节点对标签的最大覆盖率,而且要使得智能节点间的干扰最小。仿真结果表明,基于惯性权重线性递减策略的粒子群算法,加快了寻找最优节点部署的速度,并能快速有效地收敛于最优解,从而在保证覆盖率的前提下使干扰最小。