Advanced Materials Research Vols. 945-949

Abstract: ZigBee is the new standard that has been developed for low cost, low data rate and low power consumption wireless network,The routing algorithm is the key of the research and development work. This paper introduces the ZigBee protocol model of specification, And focuses on the ZigBee protocol network layer routing algorithm, Analyzes the advantages and disadvantages of tree routing and AODVjr routing algorithm.

Abstract: SAW (Surface acoustic wave) is an elastic wave, which spreads in the presence of solid half-space and the energy concentrates on the vicinity of the solid surface. SAW-RFID technology is purely passive and low cost, long reading distance and resistant to harsh environments. It has a wide use in the intelligent transportation, logistics management, access control systems, district personnel and vehicle management and other fields. This paper focuses on the principles of the SAW-RFID system, introduces some multi-recognition ways of the SAW-RFID system in detail and discusses the applications of SAW-RFID technology.

Abstract: To improve the management of production site, a RFID middleware was designed to process production information. This middleware is based on Savant architecture. It contains three modules: reader adapters, data processing and API. Compatible with various readers, the middleware can send demanded data to upper application, connect RFID device to collect data, and is easy to develop and extend. Besides, a filter algorithm and a grouping algorithm were designed for processing data.

Abstract: The MAC layer protocol for wireless sensor networks has reached a goal of the low-power and low-latency. Existing protocols using periodic sleep mechanism achieve energy efficiency, but the low duty cycle will bring considerable transmission delay, and the delay will accumulate at each hop. This paper presents a wake protocol one by one (Weak up One by One MAC, WOO-MAC), the introduction of an arbitration has been an active device (Mediation Device, MD) as the basis of managers, the agreement for the use of sleep mechanisms exists data forward interrupt and control overhead or other issues, using the method of MD waking each node and reducing the energy, accumulating delay will be decreased based on saving energy.

Abstract: Since the nodes of WSNs are always deployed on the outside, nodes are easy to be captured. The traditional detection approaches of capture attack can be categorized as approaches based on time of absence and approaches based on target tracking. The former only suitable in static WSNs and the latter usually requires a large communication cost. In this paper, a novel node capture attack detection approach is proposed in dynamic WSNs. Through this approach, every node record its neighbors and detect new nodes in real-time, if new nodes join in the network, a new node tracking algorithm is performed in WSNs and find out which of them are captured by adversaries. Simulation results show that, this method can greatly improve the detection accuracy in dynamic WSNs, and the communication cost is low.

Abstract: This paper studies on the algorithm to improve the location of Wireless Sensor Network (WSN) in Intelligent Transportation System (ITS). Considering multi-path effect in the localization, an improved RSSI algorithm is introduced in the localization algorithm. The localization results are analyzed under different density of beacon nodes, and Kalman filtering algorithm is introduced to reduce the influence of signal noise. Finally, to test the algorithm based on Kalman filtering algorithm, a simulation model of ITS is developed, which is used to simulate the localization of real vehicles. The simulation shows the algorithm has effect to improve location accuracy and to application.

Abstract: For the optimization of WSN coverage, this paper proposes a coverage optimization approach: Adaptive Disturbance Chaotic Particle Swarm Optimization, referred as ADCPSO. Based on the effective coverage of the network as the optimization goal, the method first conducts adaptive operation on the particles. Introducing perturbations factor and making particles trapped into local optimum quickly jump out, this method then use the randomness and the ergodicity of chaotic motion, to make local fine search. This effectively avoids particles’ “being premature” and improves the accuracy of the algorithm. The simulation results show that the ADCPSO algorithm can get better coverage.

Abstract: Due to the special demand of energy control and balancing the energy of nodes in wireless sensor networks，multipath routing based on ant colony system(MACS)was proposed. The algorithm utilizes the self-organization，self-adaptability and dynamic optimization capabilities of the ant colony to find the optimal routing and suboptimal routing from sources to Sink．Simulation results show the algorithm balances energy consumption of nodes and extends network lifetime effectively．

Abstract: This paper presents an improved algorithm-iDAT, which is based on Double-Array Trie Tree for Chinese Word Segmentation Dictionary. Chinese word segmentation dictionary based on the Double-Array Trie Tree has higher efficiency of search, but the dynamic insertion will consume a lot of time. After initialization the original dictionary. We implement a Hash process to the empty sequence index values for base array. The final Hash table stores the sum of the empty sequence before the current empty sequence. This algorithm adopt Sunday jumps algorithm of Single Pattern Matching. With slightly and reasonable space cost increasing, iDAT reduces the average time complexity of the dynamic insertion process in Trie Tree. Practical results shows it has a good operation performance.

Abstract: Nowadays, safety and reliability in a system are becoming more and more important. The prediction on the system's failure sequence has been the focus of research. In this paper GSP algorithm is improved in two aspects, then used for the specific application of high-speed EMU CRH2A systematic fault sequence and received good result that has certain reference value for high-speed train system failure and preventive maintenance.