Nonlinear KBarrier Coverage in Mobile Sensor Network. Intrusion detection is an important application of wireless sensor network. A belt region is said to be kbarrier covered if any intruder crossing the width of this region can be detected by at least k sensors. After initial random sensor deployment, kbarrier coverage can be achieved by relocating mobile sensors to construct k barriers appropriately. Due to energy limit of mobile sensors, it is important to reduce the amount of movements of mobile sensors. Existing algorithms focused on forming k linear barriers energyefficiently. However, large redundant sensor movement are needed by mobile sensors to move to linear barriers. In this paper, we will study how to form k nonlinear barriers energyefficiently, which can result smaller sensor movement than linear barriers. We define a notion of horizontal virtual force by considering the euclidean distance and also horizontal angle and then propose an energyefficient algorithm to form k nonlinear barriers based on the initial deployment of mobile sensors. The algorithm first divides the region into several subregions and then constructs k subbarriers from the left boundary of each subregion to the right boundary respectively by always choosing the mobile sensor chain with the largest horizontal virtual force and also flattening it and finally connects the subbarriers in neighbor subregions for forming k barriers in the whole region. Simulation results show that this algorithm efficiently decreases the movements of mobile sensors compared to a linear kbarrier coverage algorithm and it can be applicable to large scale sensor networks.

CostEfficient Node Deployment for Intrusion Detection in Underwater Sensor Networks Underwater sensor network has broad application prospects for performing underwater warning, target detection, and marine environment monitoring. However, traditional cubefilled fullcoverage node deployment schemes are costly and infeasible to detect target objects due to the considerably redundant nodes. In this paper, we propose a new scheme with a low cost to detect the target in dynamic waters to reduce the cost of the deployment. Our scheme controls the distributed sensors to move and construct an angular sensor barrier through which the target may pass. The profilebased barrier deployment scheme only needs to adjust node depth to reduce movement costs. During depth adjustment, the proposed method takes the node density, the residual energy of the node and the node movement effect into account so that the randomly distributed nodes are sunk at different depths, and the redundant nodes are removed by the 2Voronoi diagram lemma. We use the simulation experiment to evaluate the coverage and energy consumption during the movement of the nodes. The analysis of the experimental results shows that the method has good coverage performance. Also, it can reduce and balance energy consumption during the anchor node deployment to extend network uptime.