Recently,the fundamental problem with Hybrid Mobile Ad-hoc Net-works(H-MANETs)is tofind a suitable and secure way of balancing the load through Internet gateways.Moreover,the selection of the gateway and overload of th...Recently,the fundamental problem with Hybrid Mobile Ad-hoc Net-works(H-MANETs)is tofind a suitable and secure way of balancing the load through Internet gateways.Moreover,the selection of the gateway and overload of the network results in packet loss and Delay(DL).For optimal performance,it is important to load balance between different gateways.As a result,a stable load balancing procedure is implemented,which selects gateways based on Fuzzy Logic(FL)and increases the efficiency of the network.In this case,since gate-ways are selected based on the number of nodes,the Energy Consumption(EC)was high.This paper presents a novel Node Quality-based Clustering Algo-rithm(NQCA)based on Fuzzy-Genetic for Cluster Head and Gateway Selection(FGCHGS).This algorithm combines NQCA with the Improved Weighted Clus-tering Algorithm(IWCA).The NQCA algorithm divides the network into clusters based upon node priority,transmission range,and neighbourfidelity.In addition,the simulation results tend to evaluate the performance effectiveness of the FFFCHGS algorithm in terms of EC,packet loss rate(PLR),etc.展开更多
Mobile Ad hoc Network (MANET) is a significant concept of wireless networks which comprises of thousands of nodes that are mobile as well as autonomous and they do not requires any existing network infrastructure. The...Mobile Ad hoc Network (MANET) is a significant concept of wireless networks which comprises of thousands of nodes that are mobile as well as autonomous and they do not requires any existing network infrastructure. The autonomous nodes can freely and randomly move within the network which can create temporary dynamic network and these networks can change their topology frequently. The security is the primary issue in MANET which degrades the network performance significantly. In this paper, cluster based malicious node detection methodology is proposed to detect and remove the malicious nodes. Each node within the cluster gets the cluster key from the cluster head and this key is used for the data transaction between cluster head and node. The cluster head checks this key for every data transaction from node and match with their cluster table. If match is valid, and then only it will recognize that this node is belongs to this cluster, otherwise it is decided as malicious node. This paper also discusses the detection of link failure due to the presence of malicious node by determining the gain of each link in the network. The performance of the proposed method is analyzed using packet delivery ratio, network life time, and throughput and energy consumption. The proposed malicious node detection system is compared with the conventional techniques as OEERP (Optimized energy efficient routing protocol), LEACH (Low energy adaptive clustering hierarchy), DRINA (Data routing for In-network aggregation) and BCDCP (Base station controlled dynamic clustering protocol).展开更多
Aiming at the problem that node load is rarely considered in existing clustering routing algorithm for Wireless Sensor Networks (WSNs), a dynamic clustering routing algorithm for WSN is presented in this paper called ...Aiming at the problem that node load is rarely considered in existing clustering routing algorithm for Wireless Sensor Networks (WSNs), a dynamic clustering routing algorithm for WSN is presented in this paper called DCRCL (Dynamic Clustering Routing Considering Load). This algorithm is comprised of three phases including cluster head (CH) selection, cluster setup and inter-cluster routing. First, the CHs are selected based on residual energy and node load. Then the non-CH nodes choose a cluster by comparing the cost function of its neighbor CHs. At last, each CH communicates with base station by using multi-hop communication. The simulation results show that comparing with the existing one, the techniques life cycle and date volume of the network are increased by 30.7 percent and 29.8 percent respectively by using the proposed algorithm DCRCL.展开更多
Mobile Ad hoc Networks (MANET) are infrastructure less networks which provide multi-hop wireless links between nodes. The main applications of MANET in real time environment are military and emergency areas where the ...Mobile Ad hoc Networks (MANET) are infrastructure less networks which provide multi-hop wireless links between nodes. The main applications of MANET in real time environment are military and emergency areas where the fixed infrastructure is not required. It is a temporary communication infrastructure network for quick communication with minimal configuration settings among the group of nodes. The security is one of the primary concerns in MANET. The malicious nodes in MANET environment degrade the performance of the network. In this paper, the nodes in MANET are grouped using back-off duration technique and further the malicious nodes are detected using this algorithm. The proposed clustering based malicious nodes detection in MANET achieves higher performance in terms of packet delivery ratio, latency and energy consumption. The proposed method achieves 89.35% of packet delivery ratio, 36.2 ms latency and 26.91 mJ of energy consumption.展开更多
With the growing popularity of wireless sensor networks, network stability has become a key area of current research. Different applications of wireless sensor networks demand stable sensing, coverage, and connectivit...With the growing popularity of wireless sensor networks, network stability has become a key area of current research. Different applications of wireless sensor networks demand stable sensing, coverage, and connectivity throughout their operational periods. In some cases, the death of just a single sensor node might disrupt the stability of the entire network. Therefore, a number of techniques have been proposed to improve the network stability. Clustering is one of the most commonly used techniques in this regard. Most clustering techniques assume the presence of high power sensor nodes called relay nodes and implicitly assume that these relay nodes serve as cluster heads in the network. This assumption may lead to faulty network behavior when any of the relay nodes becomes unavailable to its followers. Moreover, relay node based clustering techniques do not address the heterogeneity of sensor nodes in terms of their residual energies, which frequently occur during the operation of a network. To address these two issues, we present a novel clustering technique, Dynamic Clustering with Relay Nodes (DCRN), by considering the heterogeneity in residual battery capacity and by removing the assumption that relay nodes always serve as cluster-heads. We use an essence of the underlying mechanism of LEACH (Low-Energy Adaptive Clustering Hierarchy), which is one of the most popular clustering solutions for wireless sensor networks. In our work, we present four heuristics to increase network stability periods in terms of the time elapsed before the death of the first node in the network. Based on the proposed heuristics, we devise an algorithm for DCRN and formulate a mathematical model for its long-term rate of energy consumption. Further, we calculate the optimal percentage of relay nodes from our mathematical model. Finally, we verify the efficiency of DCRN and correctness of the mathematical model by exhaustive simulation results. Our simulation results reveal that DCRN enhances the network stability period by a significant margin in comparison to LEACH and its best-known variant.展开更多
在复杂网络中高质量的社团划分会更好地揭示网络的结构特性与功能。基于节点相似性的算法是一类具有代表性的社团划分算法,但现有的基于节点相似性算法没有充分考虑到共邻节点之间的联系导致准确率下降。针对上述问题,首先定义共邻节点...在复杂网络中高质量的社团划分会更好地揭示网络的结构特性与功能。基于节点相似性的算法是一类具有代表性的社团划分算法,但现有的基于节点相似性算法没有充分考虑到共邻节点之间的联系导致准确率下降。针对上述问题,首先定义共邻节点贡献度概念,提出一种基于共邻节点贡献度的社团划分算法(Contribution of Common Neighbor Nodes Based Community Division Algorithm, CCNNA),将共邻节点之间的连边数参与到RA相似度指标的计算当中,提高了度量的准确性;然后运用改进的层次聚类与最优模块度值的思想实现网络的社团划分。在人工合成网络与真实网络上的实验结果表明,所提算法能够很好地挖掘社团结构,与模块度优化CNM(Clauset-Newman-Moore)算法以及最新的基于节点相似性算法相比,所提算法有更高的社团模块度和划分准确率。展开更多
航路网络作为民航运输网络的运行载体,承担着保障航空器安全高效运行的重要任务。当重要航路点因雷暴扰动失效时,易连锁反应至相邻节点最终导致网络性能的显著下降。针对现有复杂网络节点重要度评估模型未有效考虑雷暴扰动的问题,面向...航路网络作为民航运输网络的运行载体,承担着保障航空器安全高效运行的重要任务。当重要航路点因雷暴扰动失效时,易连锁反应至相邻节点最终导致网络性能的显著下降。针对现有复杂网络节点重要度评估模型未有效考虑雷暴扰动的问题,面向雷暴天气场景,将雷暴扰动特性纳入航路点重要度评估体系,利用博弈论方法对评估指标进行组合赋权,基于引力模型理论改进了TOPSIS(technique for order preference by similarity to an ideal solution)综合评价方法,建立基于博弈论-改进TOPSIS法的节点重要度评估模型,进而采用K中心点算法实现航路点聚类分级。以京津冀地区航班运行为例,对雷暴天气场景下的航路网络节点重要度进行评估,结果表明:在京津冀航路网络内,南部地区的航路点更易受雷暴天气影响且分布较为密集,该航路网络包含9个重要航路点,当航路网络中的重要航路点因雷暴影响而失效时,会对航路网络性能产生显著的负面影响。提出的基于博弈论-改进TOPSIS法的节点重要度评估模型可以有效识别出雷雨季节或雷暴高发地区航路网络中的重要航路点,从而为雷暴场景下航路网络结构优化与资源配置提供有效依据。展开更多
传统的数据挖掘方法一般从组方中所有的药物出发,挖掘药物的用药规律,计算量大,且仅仅基于药物频次对组方进行研究,忽略了药物剂量因素,难以发现频次低但剂量占比高的具有良好疗效的药物。针对以上问题,提出一种改进的基于效用度(Effect...传统的数据挖掘方法一般从组方中所有的药物出发,挖掘药物的用药规律,计算量大,且仅仅基于药物频次对组方进行研究,忽略了药物剂量因素,难以发现频次低但剂量占比高的具有良好疗效的药物。针对以上问题,提出一种改进的基于效用度(Effect Degree,ED)核心药物发现算法,并将基于效用度的点式互信息(Pointwise Mutual Information with Herb Pair ED,PMIED)与节点度结合,定义一种新的加权相关系数作为药物权重,在所发现的核心药物中运用层次聚类算法研究用药规律。实验结果表明,该算法可有效挖掘出组方中的核心药物,经过分析,所发现的核心药物和药物组合均对痰瘀互阻证具有良好疗效。展开更多
随着现代通信和信息技术的飞速发展,智能交通系统(Intelligent Transportation System,ITS)逐渐成为热门研究领域,车载自组网(Vehicular Ad Hoc Network,VANET)作为其关键技术,在实时道路信息共享和车辆间通信中起重要作用.然而,现有VA...随着现代通信和信息技术的飞速发展,智能交通系统(Intelligent Transportation System,ITS)逐渐成为热门研究领域,车载自组网(Vehicular Ad Hoc Network,VANET)作为其关键技术,在实时道路信息共享和车辆间通信中起重要作用.然而,现有VANET分簇算法仍存在簇稳定性低、分簇开销大等问题.为解决这些问题,本文提出了一种端云协同的VANET分簇算法,在端云协同阶段,车辆通过路边单元(Road Side Unit,RSU)将自身特征数据上传至云,云侧根据特征变化,对车辆进行动态稳定性分类.稳定的端节点具有更高的可靠性和更长的连接持续时间.在端端协同阶段,考虑了稳定节点的相对移动性和覆盖节点数量等因素,进行簇头选举,简化簇头选举过程,提高了簇的稳定性.此外,针对控制开销大的问题,本文提出了一种邻居发现和更新机制,限制HELLO消息的转发操作,降低开销并优化资源使用.实验结果表明:本文提出的算法在簇稳定性、簇数量及分簇开销等关键性能指标上均优于基线算法,展示了其在实际交通场景中的应用潜力.展开更多
文摘Recently,the fundamental problem with Hybrid Mobile Ad-hoc Net-works(H-MANETs)is tofind a suitable and secure way of balancing the load through Internet gateways.Moreover,the selection of the gateway and overload of the network results in packet loss and Delay(DL).For optimal performance,it is important to load balance between different gateways.As a result,a stable load balancing procedure is implemented,which selects gateways based on Fuzzy Logic(FL)and increases the efficiency of the network.In this case,since gate-ways are selected based on the number of nodes,the Energy Consumption(EC)was high.This paper presents a novel Node Quality-based Clustering Algo-rithm(NQCA)based on Fuzzy-Genetic for Cluster Head and Gateway Selection(FGCHGS).This algorithm combines NQCA with the Improved Weighted Clus-tering Algorithm(IWCA).The NQCA algorithm divides the network into clusters based upon node priority,transmission range,and neighbourfidelity.In addition,the simulation results tend to evaluate the performance effectiveness of the FFFCHGS algorithm in terms of EC,packet loss rate(PLR),etc.
文摘Mobile Ad hoc Network (MANET) is a significant concept of wireless networks which comprises of thousands of nodes that are mobile as well as autonomous and they do not requires any existing network infrastructure. The autonomous nodes can freely and randomly move within the network which can create temporary dynamic network and these networks can change their topology frequently. The security is the primary issue in MANET which degrades the network performance significantly. In this paper, cluster based malicious node detection methodology is proposed to detect and remove the malicious nodes. Each node within the cluster gets the cluster key from the cluster head and this key is used for the data transaction between cluster head and node. The cluster head checks this key for every data transaction from node and match with their cluster table. If match is valid, and then only it will recognize that this node is belongs to this cluster, otherwise it is decided as malicious node. This paper also discusses the detection of link failure due to the presence of malicious node by determining the gain of each link in the network. The performance of the proposed method is analyzed using packet delivery ratio, network life time, and throughput and energy consumption. The proposed malicious node detection system is compared with the conventional techniques as OEERP (Optimized energy efficient routing protocol), LEACH (Low energy adaptive clustering hierarchy), DRINA (Data routing for In-network aggregation) and BCDCP (Base station controlled dynamic clustering protocol).
文摘Aiming at the problem that node load is rarely considered in existing clustering routing algorithm for Wireless Sensor Networks (WSNs), a dynamic clustering routing algorithm for WSN is presented in this paper called DCRCL (Dynamic Clustering Routing Considering Load). This algorithm is comprised of three phases including cluster head (CH) selection, cluster setup and inter-cluster routing. First, the CHs are selected based on residual energy and node load. Then the non-CH nodes choose a cluster by comparing the cost function of its neighbor CHs. At last, each CH communicates with base station by using multi-hop communication. The simulation results show that comparing with the existing one, the techniques life cycle and date volume of the network are increased by 30.7 percent and 29.8 percent respectively by using the proposed algorithm DCRCL.
文摘Mobile Ad hoc Networks (MANET) are infrastructure less networks which provide multi-hop wireless links between nodes. The main applications of MANET in real time environment are military and emergency areas where the fixed infrastructure is not required. It is a temporary communication infrastructure network for quick communication with minimal configuration settings among the group of nodes. The security is one of the primary concerns in MANET. The malicious nodes in MANET environment degrade the performance of the network. In this paper, the nodes in MANET are grouped using back-off duration technique and further the malicious nodes are detected using this algorithm. The proposed clustering based malicious nodes detection in MANET achieves higher performance in terms of packet delivery ratio, latency and energy consumption. The proposed method achieves 89.35% of packet delivery ratio, 36.2 ms latency and 26.91 mJ of energy consumption.
文摘With the growing popularity of wireless sensor networks, network stability has become a key area of current research. Different applications of wireless sensor networks demand stable sensing, coverage, and connectivity throughout their operational periods. In some cases, the death of just a single sensor node might disrupt the stability of the entire network. Therefore, a number of techniques have been proposed to improve the network stability. Clustering is one of the most commonly used techniques in this regard. Most clustering techniques assume the presence of high power sensor nodes called relay nodes and implicitly assume that these relay nodes serve as cluster heads in the network. This assumption may lead to faulty network behavior when any of the relay nodes becomes unavailable to its followers. Moreover, relay node based clustering techniques do not address the heterogeneity of sensor nodes in terms of their residual energies, which frequently occur during the operation of a network. To address these two issues, we present a novel clustering technique, Dynamic Clustering with Relay Nodes (DCRN), by considering the heterogeneity in residual battery capacity and by removing the assumption that relay nodes always serve as cluster-heads. We use an essence of the underlying mechanism of LEACH (Low-Energy Adaptive Clustering Hierarchy), which is one of the most popular clustering solutions for wireless sensor networks. In our work, we present four heuristics to increase network stability periods in terms of the time elapsed before the death of the first node in the network. Based on the proposed heuristics, we devise an algorithm for DCRN and formulate a mathematical model for its long-term rate of energy consumption. Further, we calculate the optimal percentage of relay nodes from our mathematical model. Finally, we verify the efficiency of DCRN and correctness of the mathematical model by exhaustive simulation results. Our simulation results reveal that DCRN enhances the network stability period by a significant margin in comparison to LEACH and its best-known variant.
文摘在复杂网络中高质量的社团划分会更好地揭示网络的结构特性与功能。基于节点相似性的算法是一类具有代表性的社团划分算法,但现有的基于节点相似性算法没有充分考虑到共邻节点之间的联系导致准确率下降。针对上述问题,首先定义共邻节点贡献度概念,提出一种基于共邻节点贡献度的社团划分算法(Contribution of Common Neighbor Nodes Based Community Division Algorithm, CCNNA),将共邻节点之间的连边数参与到RA相似度指标的计算当中,提高了度量的准确性;然后运用改进的层次聚类与最优模块度值的思想实现网络的社团划分。在人工合成网络与真实网络上的实验结果表明,所提算法能够很好地挖掘社团结构,与模块度优化CNM(Clauset-Newman-Moore)算法以及最新的基于节点相似性算法相比,所提算法有更高的社团模块度和划分准确率。
文摘航路网络作为民航运输网络的运行载体,承担着保障航空器安全高效运行的重要任务。当重要航路点因雷暴扰动失效时,易连锁反应至相邻节点最终导致网络性能的显著下降。针对现有复杂网络节点重要度评估模型未有效考虑雷暴扰动的问题,面向雷暴天气场景,将雷暴扰动特性纳入航路点重要度评估体系,利用博弈论方法对评估指标进行组合赋权,基于引力模型理论改进了TOPSIS(technique for order preference by similarity to an ideal solution)综合评价方法,建立基于博弈论-改进TOPSIS法的节点重要度评估模型,进而采用K中心点算法实现航路点聚类分级。以京津冀地区航班运行为例,对雷暴天气场景下的航路网络节点重要度进行评估,结果表明:在京津冀航路网络内,南部地区的航路点更易受雷暴天气影响且分布较为密集,该航路网络包含9个重要航路点,当航路网络中的重要航路点因雷暴影响而失效时,会对航路网络性能产生显著的负面影响。提出的基于博弈论-改进TOPSIS法的节点重要度评估模型可以有效识别出雷雨季节或雷暴高发地区航路网络中的重要航路点,从而为雷暴场景下航路网络结构优化与资源配置提供有效依据。
文摘传统的数据挖掘方法一般从组方中所有的药物出发,挖掘药物的用药规律,计算量大,且仅仅基于药物频次对组方进行研究,忽略了药物剂量因素,难以发现频次低但剂量占比高的具有良好疗效的药物。针对以上问题,提出一种改进的基于效用度(Effect Degree,ED)核心药物发现算法,并将基于效用度的点式互信息(Pointwise Mutual Information with Herb Pair ED,PMIED)与节点度结合,定义一种新的加权相关系数作为药物权重,在所发现的核心药物中运用层次聚类算法研究用药规律。实验结果表明,该算法可有效挖掘出组方中的核心药物,经过分析,所发现的核心药物和药物组合均对痰瘀互阻证具有良好疗效。
文摘随着现代通信和信息技术的飞速发展,智能交通系统(Intelligent Transportation System,ITS)逐渐成为热门研究领域,车载自组网(Vehicular Ad Hoc Network,VANET)作为其关键技术,在实时道路信息共享和车辆间通信中起重要作用.然而,现有VANET分簇算法仍存在簇稳定性低、分簇开销大等问题.为解决这些问题,本文提出了一种端云协同的VANET分簇算法,在端云协同阶段,车辆通过路边单元(Road Side Unit,RSU)将自身特征数据上传至云,云侧根据特征变化,对车辆进行动态稳定性分类.稳定的端节点具有更高的可靠性和更长的连接持续时间.在端端协同阶段,考虑了稳定节点的相对移动性和覆盖节点数量等因素,进行簇头选举,简化簇头选举过程,提高了簇的稳定性.此外,针对控制开销大的问题,本文提出了一种邻居发现和更新机制,限制HELLO消息的转发操作,降低开销并优化资源使用.实验结果表明:本文提出的算法在簇稳定性、簇数量及分簇开销等关键性能指标上均优于基线算法,展示了其在实际交通场景中的应用潜力.
