Yifan Hu

A time synchronization method of Wireless Sensor Networks based on the simulated annealing algorithm

Time synchronization is very important for a Time Division Multiple Access (TDMA) Wireless Sensor Networks (WSNs). In this paper, we introduce a new method of time synchronization for WSNs based on the simulated annealing algorithm which is endowed with the search process of a time-varying and can effectively avoid falling into the local minimum and finally tends to the global optimum. Errors between the global time and prediction time are used as the evaluation function from which we can obtain more stable time synchronization. Our method is implemented on SCSC-RFA1 platform and the results show the validity of the method.

A particle swarm algorithm based routing recovery method for mobile sink wireless sensor networks

This paper presents the routing recovery problem of mobile sink wireless sensor networks (mWSNs), which is caused by the sink mobility. We propose an immune orthogonal learning particle swarm optimization algorithm (IOLPSOA) based routing recovery method to build and optimize the alternative path, in order to repair the broken path and maintain the available route from the source nodes to the mobile sink through a multi-hop network. The IOLPSOA can improve the method with faster global convergence and higher solution quality, which can provide more efficient routing recovery capability to mWSNs. We have evaluated the performance of routing recovery method through both mathematical analysis and simulation experiments. The results show that our method effectively supports sink mobility with low energy consumption, communication overhead, and the improvement of routing recovery problem.

Research on suboptimal energy balance of non-uniform distributed nodes in WSN

Wireless sensor networks (WSNs) are widely used in industrial production, environmental monitoring, and military applications. In the process of using, the node non-uniform distribution strategy can mitigate the energy hole and node suboptimal energy balance technology in wireless sensor networks. This paper discusses this strategy theoretically, proposes a node non-uniform distribution strategy, and it constructs a suboptimal energy balance algorithm, which based on the non-uniform distribution theory system. It has proved that in the circular network with non-uniform distribution of nodes, the uniform distributed method and the random non-uniform distributed method are tested and compared. The experimental results show that the non-uniform distributed method has high efficiency and good scalability, and it can be used to achieve the suboptimal energy balance. The simulation results also show that the nodes in the WSN are almost equal to the energy consumption.

A Real-Time Evaluation Method on Internet Data Centre's Equipment Corrosion by Wireless Sensor Networks

With the implementation of European Unions restriction of hazardous substances directive, there is a sharp decline on electronic equipment corrosion resistance. The reason is that gaseous contaminations cause creep corrosion on printed circuit boards. Based on wireless sensor networks, three-dimensional space model, environmental information and computational fluid dynamics theory, an evaluation method is proposed to calculate the wind speed, temperature, relative humidity and corrosive gas concentration around each equipment in internet data centre. To evaluate the performance of this method, a wireless sensors system is set up. Test results show that the real-time evaluation method can effectively guarantee equipment in safe environment.

Design and realization of a video monitoring system based on the intelligent behavior identify technique

A video monitoring system in construction site will produce a large number of video images, which influences safety production supervision personnel to find unsafe behaviors. This paper presents application of intelligent behavior identify technique. Based on this technique, the video monitoring system can capture video streaming data, exquisite frame image data, and identify of the image data by analyzing the video camera. The detection behaviors include: 1) Does there exist any moving object in designated areas? 2) Does every worker wear a safe helmet in construction site? If there is one or more of the above detection information in the current frame image, the video monitoring system will give tips in the human-machine interface, and adopt a variety of ways to deal with the corresponding information. From the implementation effect, this system meets the requirements on accuracy and efficiency.

Routing Fault-Tolerance for Heterogeneous WSNs Based on an Immune Cooperative Multi-Particle-Swarm Algorithm

In this paper, we address the fault-tolerant routing problem in a heterogeneous wireless sensor network consisting of several resource-rich supernodes, and large number of energy-constrained sensor nodes. We propose the immune cooperative multi-particle-swarm algorithm (ICMPSA) to provide fast routing recovery method, in order to maintain K disjoint paths from each source node to the nearest supernode, and the available path from supernode to the sink. The key concept of our method is to efficiently repair the broken links between intercluster supernodes or intracluster sensor nodes with less network resources. Performance and analysis results of our ICMPSA based routing fault-tolerant protocol approve that it can provide reliable communication with fast bio-heuristic routing recovery mechanism, thus extend the lifetime of WSNs.