Nodes cooperation is a significant prerequisite for the realization of the relaying Ad Hoc.While with the development of multi-hop cellular networks, how to stimulate intermediate nodes to do the packet-forwarding des...Nodes cooperation is a significant prerequisite for the realization of the relaying Ad Hoc.While with the development of multi-hop cellular networks, how to stimulate intermediate nodes to do the packet-forwarding deserves more concerning.At present research,the incentive schemes in pure Ad Hoc and multi-hop cellular networks are analyzed and compared to classify the strengths and drawbacks of each scheme.We explain in particular what the key issues are to implement incentive schemes for cooperation. Finally,an incentive scheme based on integration of reputation and charging systems is proposed not only to block the existence of selfish nodes,but to satisfy the rational requirement of nodes.展开更多
A set of small-stencil new Pade schemes with the same denominator are presented to solve high-order nonlinear evolution equations. Using this scheme, the fourth-order precision can not only be kept, but also the final...A set of small-stencil new Pade schemes with the same denominator are presented to solve high-order nonlinear evolution equations. Using this scheme, the fourth-order precision can not only be kept, but also the final three-diagonal discrete systems are solved by simple Doolittle methods, or ODE systems by Runge-Kutta technique. Numerical samples show that the schemes are very satisfactory. And the advantage of the schemes is very clear compared to other finite difference schemes.展开更多
The wireless sensor network (WSN) is one of the budding exploring areas and fast rising fields in wireless communications. The sensor nodes in the network are generally small-size, low-cost, low-power and multi-functi...The wireless sensor network (WSN) is one of the budding exploring areas and fast rising fields in wireless communications. The sensor nodes in the network are generally small-size, low-cost, low-power and multi-function capabilities. Wireless sensor networks (WSNs) are used for various applications;since numerous sensor nodes are usually deployed on remote and inaccessible places, the employment and preservation should be easy and scalable. Sensor nodes in the field being run out of energy quickly has been an issue and many energy efficient routing protocols have been proposed to solve this problem and preserve the long life of the network. This paper work proposes a hierarchical based node activation routing technique which shows energy efficiency. This technique selects cluster head with highest residual energy in each communication round of transmission to the base station from the cluster heads. Hierarchical based node activation routing technique with different levels of hierarchy simulation results prolongs the lifetime of the network compared to other clustering schemes and communication rounds of simulation increase significantly.展开更多
缓存是命名数据网络(named data networking,NDN)有别于传统网络最突出的特性之一,NDN中默认所有节点都具有缓存所有经过数据的功能.这种"处处缓存"策略导致网内大量冗余数据的产生,使网内缓存被严重浪费.针对上述问题,首次...缓存是命名数据网络(named data networking,NDN)有别于传统网络最突出的特性之一,NDN中默认所有节点都具有缓存所有经过数据的功能.这种"处处缓存"策略导致网内大量冗余数据的产生,使网内缓存被严重浪费.针对上述问题,首次提出了一种基于节点分类(based on node classification,BNC)的数据存储策略.基于节点位置的不同,将数据返回客户端所经过的节点分为"边缘"类节点与"核心"类节点.当数据经过"核心"类节点时,通过权衡该类节点的位置与数据在不同节点的流行度分布,将数据存储在对其他节点最有利的节点中;当数据经过"边缘"类节点时,通过该数据流行度来选择最有利于客户端的位置.仿真结果表明,提出的策略将有效提高数据命中率,减少数据请求时延和距离.展开更多
基金supported by National "863" High Technology Research and Development Program Foundation(No.2006AA01Z208)Six Talented Eminence Foundation of Jiangsu Province+1 种基金Natural Science Foundation of Jiangsu Province(No. BK2004149)Green-Blue Academic Talented Project Foundation of Jiangsu Province
文摘Nodes cooperation is a significant prerequisite for the realization of the relaying Ad Hoc.While with the development of multi-hop cellular networks, how to stimulate intermediate nodes to do the packet-forwarding deserves more concerning.At present research,the incentive schemes in pure Ad Hoc and multi-hop cellular networks are analyzed and compared to classify the strengths and drawbacks of each scheme.We explain in particular what the key issues are to implement incentive schemes for cooperation. Finally,an incentive scheme based on integration of reputation and charging systems is proposed not only to block the existence of selfish nodes,but to satisfy the rational requirement of nodes.
文摘A set of small-stencil new Pade schemes with the same denominator are presented to solve high-order nonlinear evolution equations. Using this scheme, the fourth-order precision can not only be kept, but also the final three-diagonal discrete systems are solved by simple Doolittle methods, or ODE systems by Runge-Kutta technique. Numerical samples show that the schemes are very satisfactory. And the advantage of the schemes is very clear compared to other finite difference schemes.
文摘The wireless sensor network (WSN) is one of the budding exploring areas and fast rising fields in wireless communications. The sensor nodes in the network are generally small-size, low-cost, low-power and multi-function capabilities. Wireless sensor networks (WSNs) are used for various applications;since numerous sensor nodes are usually deployed on remote and inaccessible places, the employment and preservation should be easy and scalable. Sensor nodes in the field being run out of energy quickly has been an issue and many energy efficient routing protocols have been proposed to solve this problem and preserve the long life of the network. This paper work proposes a hierarchical based node activation routing technique which shows energy efficiency. This technique selects cluster head with highest residual energy in each communication round of transmission to the base station from the cluster heads. Hierarchical based node activation routing technique with different levels of hierarchy simulation results prolongs the lifetime of the network compared to other clustering schemes and communication rounds of simulation increase significantly.
文摘低占空比无线传感器网络(low-duty-cycle wireless sensor networks,简称LDC-WSN)可以有效地延长网络生命周期.但是,现有的LDC-WSN中端到端的延迟非常大,并且现在很多关于LDC-WSN的算法没有充分考虑传输链路质量的问题.为了解决这两个问题,提出了一种基于链路质量和能量感知的节点休眠调度算法(link-quality and energy-aware based scheduling scheme,简称LES).仿真实验结果表明,相比现在的典型算法,LES算法能够在满足同样延迟要求的情况下很明显地节省能量,从而延长网络的工作寿命.
文摘缓存是命名数据网络(named data networking,NDN)有别于传统网络最突出的特性之一,NDN中默认所有节点都具有缓存所有经过数据的功能.这种"处处缓存"策略导致网内大量冗余数据的产生,使网内缓存被严重浪费.针对上述问题,首次提出了一种基于节点分类(based on node classification,BNC)的数据存储策略.基于节点位置的不同,将数据返回客户端所经过的节点分为"边缘"类节点与"核心"类节点.当数据经过"核心"类节点时,通过权衡该类节点的位置与数据在不同节点的流行度分布,将数据存储在对其他节点最有利的节点中;当数据经过"边缘"类节点时,通过该数据流行度来选择最有利于客户端的位置.仿真结果表明,提出的策略将有效提高数据命中率,减少数据请求时延和距离.
