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Application of modified NSGA-II algorithm to multi-objective reactive power planning 总被引:1,自引:0,他引:1
This paper discusses the application of Modified Non-Dominated Sorting Genetic Algorithm-II (MNSGA-II) to multi-objective Reactive Power Planning (RPP) problem. The three objectives considered are minimization of combined operating and VAR allocation cost, bus voltage profile improvement and voltage stability enhancement. For maintaining good diversity in nondominated solutions, Dynamic Crowding Distance (DCD) procedure is implemented in NSGA-II and it is called as MNSGA-II. The standard IEEE 30-bus test system, practical 69-bus Indian system and IEEE 118-bus system are considered to analyze the performance of MNSGA-II. The results obtained using MNSGA-II are compared with NSGA-II and validated with reference pareto-front generated by conventional weighted sum method using Covariance Matrix Adapted Evolution Strategy (CMA-ES). The performance of NSGA-II and MNSGA-II are compared with respect to best, mean, worst and standard deviation of multi-objective performance measures namely gamma, spread, minimum spacing and Inverted Generational Distance (IGD) in 15 independent runs. The results show the effectiveness of MNSGA-II and confirm its potential to solve the multi-objective RPP problem. A decision-making procedure based on Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method is used for finding best compromise solution from the set of pareto-solutions obtained through MNSGA-II. 相似文献
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基于QoS路由及保障路由实施是支持MANET应用的关键.为解决MANET中QoS问题,在移动预测机制下提出了一种基于QoS保障的组播协议.该协议通过簇头选举,移动预测和QoS控制策略在组播源与含目的节点的组播簇头间确定最稳传输路径,并采用基于动态资源管理的QoS路由模型来保障路由实施.仿真结果显示该方案可获得较高传输成功率和较低控制开销,能有效支持MANET中具有QoS需求的组播传输. 相似文献
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The mobile ad-hoc network is well studied on the routing issues, and the security constraints around achieving higher quality of service (QoS) values are well analyzed. The main task is to establish the path to the target with reliable intermediate nodes based on quality parameters because of the lack of node mobility and central management. In a multi-constrained QoS issuance, more than the QoS requirements must be satisfied at the end of the application. There are several secure routing protocols available to improve the QoS of Manet by routing packets securely. However, they do not meet the performance requirements. To solve this problem, and efficient Multi-Constrained Network Feature Approximation (MCNFA) technique is proposed based on safe routing. The method first determines the list of paths between source and destination. According to that, the method approximates the congestion, latency, and hop count values for each route. According to the value obtained in approximation of various parameters, the legitimate weight is computed for all the routes towards the destination. According to the value of the legitimate weight, a single route is selected to perform data transmission. The MCNFA approach improves the routing performance and increases the throughput ratio and other QoS factors. The performance of the proposed method will be assessed using NS2 simulation. The results show that the proposed scheme can maintain a longer network lifecycle in tight scenarios suitable for delay-tolerant networking. The performance is compared with energy recognition and MCNFA technique-based energy-saving routing protocols in various QoS scenarios. 相似文献
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As the use of mobile devices continues to rise, trust administration will significantly improve security in routing the guaranteed quality of service (QoS) supply in Mobile Ad Hoc Networks (MANET) due to the mobility of the nodes. There is no continuance of network communication between nodes in a delay-tolerant network (DTN). DTN is designed to complete recurring connections between nodes. This approach proposes a dynamic source routing protocol (DSR) based on a feed-forward neural network (FFNN) and energy-based random repetition trust calculation in DTN. If another node is looking for a node that swerved off of its path in this situation, routing will fail since it won’t recognize it. However, in the suggested strategy, nodes do not stray from their pathways for routing. It is only likely that the message will reach the destination node if the nodes encounter their destination or an appropriate transitional node on their default mobility route, based on their pattern of mobility. The EBRRTC-DTN algorithm (Energy based random repeat trust computation) is based on the time that has passed since nodes last encountered the destination node. Compared to other existing techniques, simulation results show that this process makes the best decision and expertly determines the best and most appropriate route to send messages to the destination node, which improves routing performance, increases the number of delivered messages, and decreases delivery delay. Therefore, the suggested method is better at providing better QoS (Quality of Service) and increasing network lifetime, tolerating network system latency. 相似文献
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Most of the group communication technologies support real-time multimedia applications such as video conferencing and distributed gaming. These applications require quality-of-service (QoS) aware multicast routing protocol to deliver the same data stream to a predefined group of receivers. Since nodes in wireless networks are severely energy constrained due to finite battery source, hence it is of paramount importance that QoS aware multicast routing protocol be energy efficient. Transmission power control is one of the methods used to save energy. In this method, the nodes dynamically adjust the transmission power so that energy consumption in the tree is minimized. However, reduction in the transmission power increases the number of forwarding nodes in the multicast tree. This negatively impacts the QoS in terms of propagation delay, delay jitter, and packet loss etc. In wireless networks, there is a trade-off between the energy consumption and the QoS guarantees provided by the network. We unify these requirements into a multiobjective framework referred to as Energy Efficient QoS Multicast Routing (E2QoSMR). The goal is to simultaneously optimize the total power consumption and the QoS parameters in the multicast tree. We extend two algorithms based on metaphor of swarm intelligence for finding an energy efficient multicast tree satisfying the QoS guarantees. Extensive simulations have been conducted to validate the correctness and efficiency of the algorithms. The simulation result of the algorithms is compared with the nondominated sorting genetic algorithm, NSGA-III. The experimental results are consolidated by statistical analyses that demonstrate the ability of the algorithms to generate the Pareto optimal solution set. 相似文献
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赵丽萍 《计算机与数字工程》2012,40(6):13-15,103
针对Ad Hoc网络中传统AODV协议不支持QoS的缺陷,提出了一种多约束QoS AODV跨层优化方法MQ-AODV(Multi-Constrained QoS AODV)。该方法采用跨层设计的思想,除以传统AODV协议的转发跳数作为路由选择判据之外,而且加入应用层的QoS需求信息和MAC层的多种QoS指标作为路由选择判据,并通过改进AODV路由表结构和路由查找算法,提高AODV路由协议性能。仿真测试结果表明MQ-AODV协议缩短了传输时延,增强了路由协议的适应性和鲁棒性。 相似文献
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无线视频传感器网络(WVSNs)集成了视频传感器、计算机、通信三大技术,是当前国际上的一个研究热点。介绍了WVSNs的结构,并针对网络的QoS问题进行了分析,随后针对网络的QoS需求,综合考虑传感器节点能量、输出码率、传输时延、信道差错率和数据失真等因素,设计了一个提供QoS保证的传输模型,并对常见的QoS路由协议进行了比较。 相似文献
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对Ad hoc网络各种路由协议进行仿真评估,分析它们在不同约束条件下不同度量的相对性能,是了解与学习路由协议性能的重要手段.目前的度量标准主要集中在吞吐量、延时、抖动、丢包率等QoS因子或路由负载、寻路时间等外部特性上,还没有以Ad hoc网络系统本身的连通度作为度量标准进行仿真,评价各种路由协议在不同试验条件下对于同一网络系统连通度的影响的相关研究.基于能量模型、节点密度、停留时间及移动速率四种约束条件对MANET提出的四种路由协议进行了关于网络连通度的仿真与评估,给出了这方面的初步结论. 相似文献
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在AdHoc网络中,QoS路由是提供QoS保证的一种重要手段。大多数QoS路由都是建立在单径的基础上,没有充分利用AdHoc网络资源。此外,网络中节点的能量也是影响网络性能的关键因素。然而,现有的QoS路由协议却很少考虑网络中节点.能量有限这一问题。对此,文中在DSR路由协议的基础上提出一种基于能量约束的多径QoS路由协议(MPQE)。该协议主要考虑带宽和剩余能量来选择多条QoS路由。仿真结果表明,MPQE协议提高了吞吐率,降低了时延并延长了网络的生命周期。 相似文献
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在分析无线Mesh网络结构特点的基础上,针对无线Mesh网中客户端网络节点的移动性、拓扑结构变化较大等特点,提出了一种基于泛洪协议改进的路由算法.该算法设计了以序列号形式存在的路由表,同时通过调节最大、最小序列号的大小,泛洪消息的生命周期TTL等形式提高算法的性能.仿真结果显示,提出的算法在网络吞吐量和平均传输速率等方面要好于AODV算法,算法在拓扑变换频繁的无线Mesh网络中是可行的. 相似文献
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结合机会路由和网络编码两项新技术各自的优势,提出了一种新的基于部分网络编码的机会路由算法(Opportunistic Routing Algorithm for Wireless Network Based on Partial Network Coding,ORAPNC)。为了避免数据包分叉传输,同时利于执行转发节点间协调机制,ORAPNC首先以期望传输次数作为路由度量建立一条固定路由,并将候选转发节点集中在这条固定路径附近;为了充分减小网络中的冗余数据包,ORAPNC采用一种新的转发节点间协调机制(Forwarding Nodes Coordination Mechanism,FNCM)来实现每跳的数据包传输。仿真结果表明,与其他相关路由协议相比较,ORAPNC可以有效提高网络吞吐量,减小目的节点解出原始数据包的平均时延。 相似文献
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目前,在无线网络研究领域,为无线网状网络(WMN)设计一个完善的路由协议是现在的研究热点之一。无线网状网络(WMN)与Adhoe网络有许多共同属性,尤其是在它结点的静态特性方面,无线网状网络(WMN)有自己一些独特的特征,其相邻结点间的跳数保持不变。无线网状网络(WMN)的静态特性结构所需的网络协议更注重链接质量而不是跳数,因此论文以动态源路由协议(DSR)为基础来检测链路链接的质量,同也考虑了单个链接延迟的影响因素,将协议的量度方式由跳数改为链接质量。 相似文献
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基于稳定路径的MAODV协议改进 总被引:1,自引:0,他引:1
移动Ad Hoc网络组播路由协议MAODV中,组播树在节点移动速度较快的情况下会频繁重构,使得路由开销、传输时延显著增大。针对基于邻居节点变化率的稳定路径选择方法,提出一种新的节点邻居变化率的检测机制,不需要周期性地发送Hello消息,并在此基础上设计和仿真实现了基于稳定路径的MAODV协议SP-MAODV,新协议选择的路径稳定性好且跳数小。最后从数据分组传输成功率、路由开销、平均端到端时延和时延抖动四个方面对两个协议进行了仿真比较,结果表明SP-MAODV协议减少了路径中断概率,提高了协议性能。 相似文献
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一种能量捕获无线传感网络机会路由算法 总被引:1,自引:1,他引:0
在无线传感网络中,采用能量捕获技术理论上可以无限延长节点的使用寿命。基于该技术,提出了一种新的机会路由算法——能量潜能机会路由(Energy Potential Opportunistic Routing,EPOR)算法。该算法首先用到目的节点的期望传输次数衡量各节点到目的节点的距离,然后用节点的剩余能量与节点所捕获的能量之和表示节点的能量潜能,最后用期望传输次数和节点能量潜能决定节点的退避时间,退避时间最短的节点即为转发节点。理论分析和仿真实验表明,该算法不但可以延长网络生命期,而且可以明显改善网络中节点能量的均衡性。 相似文献
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