ILSM:Incorporated Lightweight Security Model for Improving QOS in WSN

In the network field,Wireless Sensor Networks(WSN)contain prolonged attention due to afresh augmentations.Industries like health care,traffic,defense,and many more systems espoused the WSN.These networks contain tiny sensor nodes containing embedded processors,TinyOS,memory,and power source.Sensor nodes are responsible for forwarding the data packets.To manage all these components,there is a need to select appropriate parameters which control the quality of service of WSN.Multiple sensor nodes are involved in transmitting vital information,and there is a need for secure and efficient routing to reach the quality of service.But due to the high cost of the network,WSN components have limited resources to manage the network.There is a need to design a lightweight solution that ensures the quality of service in WSN.In this given manner,this study provides the quality of services in a wireless sensor network with a security mechanism.An incorporated hybrid lightweight security model is designed in which random waypoint mobility(RWM)model and grey wolf optimization(GWO)is used to enhance service quality and maintain security with efficient routing.MATLAB version 16 andNetwork Stimulator 2.35(NS2.35)are used in this research to evaluate the results.The overall cost factor is reduced at 60%without the optimization technique and 90.90%reduced by using the optimization technique,which is assessed by calculating the signal-to-noise ratio,overall energy nodes,and communication overhead.

自组网Random Waypoint移动模型节点空间概率分布的研究

Random Waypoint模型是自组网经常使用的移动模型,对这种移动模型下运动节点的空间概率分布进行了研究,得到了一维与二维区域的运动节点空间概率分布的精确公式,解决了自组网仿真模型的一个遗留问题·研究结果为基于Random Waypoint移动模型的自组网理论的推导、证明、仿真与应用提供了理论依据,对基于该模型的自组网仿真具有实践指导意义·

基于Waypoint8的GPS精密单点定位研究

介绍了精密单点定位的基本原理,对IGS精密星历进行了研究,利用Waypoint8软件对精密单点定位精度进行了测试与分析。结果表明:GPS精密单点定位在NEU三维分量上的精度约为20cm。

NS-2运动场景对路由协议仿真的影响

用NS-2仿真各种路由协议性能时用到的传统运动场景发生器存在两个缺陷:运动状态不能迅速过渡到稳态,节点速度的均匀分布区间起始值只能为0。为了弥补上述缺陷,Tracy Camp研制了稳态运动场景发生器。通过仿真验证了采用该发生器可大大缩短仿真时间,在此基础上仿真AODV和DSDV两种路由协议,首次从吞吐量、协议包开销、平均延迟三个方面对稳态运动场景下的两种路由协议性能进行分析,得出结论表明采用稳态运动场景进行路由协议仿真是非常必要的。

移动自组网应用建模及无线收发器选用策略

移动自组网作为一种特殊的无线网络被越来越广泛的应用,随之也变得越来越复杂.所以不同的应用场景需要采用不同的配置来组建自组网,才能达到网络性能相对最优.其中网络连通性和能源问题成为重点需要考虑的因素.为了更加合理高效地组建自组网,本文定义了一种移动自组网应用模型,并采用此模型对自组网应用场景进行了分类,提出了一种组建自组网的方法,重点对无线收发器的选择进行了研究.

基于反弹成簇策略的自组织网络组网模型

提出一种基于反弹成簇和簇合并策略的自组织网络组网模型。借鉴物理学中光的反射原理,确定网络节点的移动方向,实现分布式组网的目标。采用基于细胞自动机的模拟方法分析该模型的组网性能。实验结果表明,与Random Waypoint模型相比,该模型在组网速度方面有明显优势。

Reentry trajectory rapid optimization for hypersonic vehicle satisfying waypoint and no-fly zone constraints

To rapidly generate a reentry trajectory for hypersonic vehicle satisfying waypoint and no-fly zone constraints, a novel optimization method, which combines the improved particle swarm optimization （PSO） algorithm with the improved Gauss pseudospectral method （GPM）, is proposed. The improved PSO algorithm is used to generate a good initial value in a short time, and the mission of the improved GPM is to find the final solution with a high precision. In the improved PSO algorithm, by controlling the entropy of the swarm in each dimension, the typical PSO algorithm＇s weakness of being easy to fall into a local optimum can be overcome. In the improved GPM, two kinds of breaks are introduced to divide the trajectory into multiple segments, and the distribution of the Legendre-Gauss （LG） nodes can be altered, so that all the constraints can be satisfied strictly. Thereby the advan- tages of both the intelligent optimization algorithm and the direct method are combined. Simulation results demonstrate that the proposed method is insensitive to initial values, and it has more rapid convergence and higher precision than traditional ones.

Performance Analysis of Outage Probability and Error Rate of Square M-QAM in Mobile Wireless Communication Systems over Generalized α-μ Fading Channels with Non-Gaussian Noise

This paper derives new and exact closed-form expressions for the average symbol error rate(SER) of square M-ary quadrature amplitude modulation(M-QAM) in wireless communication systems over theα-μfading channels subject to an additive non-Gaussian noise. The obtained expressions take into account static and mobile wireless receivers. In addition, a closed-form expression for the outage probability in mobile networks is obtained. Please note that all derived expressions in this paper a valid for integer and non-integer values of the fading parameters. Analytical results are presented to study the impact of noise shaping parameter, severity of fading, and mobility on the average SER. Monte-Carlo simulations results are also provided to validate the accuracy of the analytical results.

Dubins Waypoint Navigation of Small-Class Unmanned Aerial Vehicles

This paper considers a variation on the Dubins path problem and proposes an improved waypoint navigation (WN) algorithm called Dubins waypoint navigation (DWN). Based on the Dubins path problem, an algorithm is developed that is updated in real-time with a horizon of three waypoints. The purpose of DWN is to overcome a problem that we find in existing WN for small-class fixed-wing unmanned aerial vehicles (UAV) of not accurately reaching waypoints. This problem results at times in high overshoot and, in the presence of wind disturbances, it can cause a vehicle to miss the waypoint and swirl around it. To prevent this, the DWN creates “new waypoints” that are in the background, called turning points. Examples illustrate the improvement of the performance of WN achieved using the DWN algorithm in terms of the targeting of waypoints while reducing fuel and time.

Hybrid IWD-DE:A Novel Approach to Model Cooperative Navigation Planning for Multi-robot in Unknown Dynamic Environment

The current study emphasizes inadequacies of earlier research findings on multi-robot navigation and offers a robust approach to guide the robots in an unknown dynamic workspace.To attain the objective,the Intelligent Water Drop(IWD)algorithm is combined with Differential Evolution(DE)in a new conceptual fashion to optimize the navigation path of multiple mobile robots.The hybrid IWD-DE,basic IWD and DE algorithms are then explored for multi-robot navigation in a dynamic workspace through simulation.The simulation outcomes demonstrate the competency of the proposed method to guide the robot in predicting the nature of the obstacle and to generate an optimal and safe trajectory in a dynamic workspace.The potency of the proposed algorithm is further validated through experimentation with fire bird robot in a real platform.The outcomes of the simulation and experimentation,by employing IWD-DE algorithm are compared with those of basic IWD and DE algorithm.The error estimated for Average Navigation Path Travelled(ANPT),Aggregate Navigation Path Deviation(ANPD)and number of turns between simulation and experimental results by employing IWD-DE is 8.96,9.09,and 11.13,respectively while reaching 16.43,28.61,29.15 for IWD,and 6.66,10.20,14.28 for DE.The efficiency of the proposed approach is further verified with the state-of-the-art in a dynamic workspace.The outcomes reveal the efficiency and flexibility of the proposed approach in resolving the multi-robot navigation problem as compared to the state-of-the-art in a dynamic workspace.

Multiple Robots Formation Manoeuvring and Collision Avoidance Strategy

This paper presents a multiple robots formation manoeuvring and its collision avoidance strategy. The direction priority sequential selection algorithm is employed to achieve the raw path, and a new algorithm is then proposed to calculate the turning-compliant waypoints supporting the multi-robot formation manoeuvre. The collision avoidance strategy based on the formation control is presented to translate the collision avoidance problem into the stability problem of the formation. The extension-decomposition-aggregation scheme is next applied to solve the formation control problem and subsequently achieve the collision avoidance during the formation manoeuvre. Simulation study finally shows that the collision avoidance problem can be conveniently solved if the stability of the constructed formation including unidentified objects can be satisfied.

Parasitic Robot System for Waypoint Navigation of Turtle

In research on small mobile robots and biomimetic robots, locomotion ability remains a major issue despite many advances in technology. However, evolution has led to there being many real animals capable of exceUent locomotion. This paper presents a ＂parasitic robot system＂ whereby locomotion abilities of an animal are applied to a robot task. We chose a turtle as our first host animal and designed a parasitic robot that can perform ＂operant conditioning＂. The parasitic robot, which is attached to the turtle, can induce object-tracking behavior of the turtle toward a Light Emitting Diode （LED） and positively reinforce the behavior through repeated stimulus-response interaction. After training sessions over five weeks, the robot could successfully control the direction of movement of the trained turtles in the waypoint navigation task. This hybrid animal-robot interaction system could provide an alternative solution to some of the limitations of conventional mobile robot systems in various fields, and could also act as a useful interaction system for the behavioral sciences.

Reentry trajectory optimization for hypersonic vehicle satisfying complex constraints

The reentry trajectory optimization for hypersonic vehicle（HV）is a current problem of great interest.Some complex constraints,such as waypoints for reconnaissance and no-fly zones for threat avoidance,are inevitably involved in a global strike mission.Of the many direct methods,Gauss pseudospectral method（GPM）has been demonstrated as an effective tool to solve the trajectory optimization problem with typical constraints.However,a series of diffculties arises for complex constraints,such as the uncertainty of passage time for waypoints and the inaccuracy of approximate trajectory near no-fly zones.The research herein proposes a multi-phase technique based on the GPM to generate an optimal reentry trajectory for HV satisfying waypoint and nofly zone constraints.Three kinds of specifc breaks are introduced to divide the full trajectory into multiple phases.The continuity conditions are presented to ensure a smooth connection between each pair of phases.Numerical examples for reentry trajectory optimization in free-space flight and with complex constraints are used to demonstrate the proposed technique.Simulation results show the feasible application of multi-phase technique in reentry trajectory optimization with waypoint and no-fly zone constraints.

A New Protocol for the Detection of Node Replication Attacks in Mobile Wireless Sensor Networks

Wireless sensor networks （WSNs） are often deployed in harsh environments. Thus adversaries can capture some nodes, replicate them and deploy those replicas back into the strategic positions in the network to launch a variety of attacks. These are referred to as node replication attacks. Some methods of defending against node replication attacks have been proposed, yet they are not very suitable for the mobile wireless sensor networks. In this paper, we propose a new protocol to detect the replicas in mobile WSNs. In this protocol, polynomial-based pair-wise key pre-distribution scheme and Counting Bloom Filters are used to guarantee that the replicas can never lie about their real identifiers and collect the number of pair-wise keys established by each sensor node. Replicas are detected by looking at whether the number of pair-wise keys established by them exceeds the threshold. We also derive accurate closed form expression for the expected number of pair-wise keys established by each node, under commonly used random waypoint model. Analyses and simulations verify that the protocol accurately detects the replicas in the mobile WSNs and supports their removal.