Applied Mechanics and Materials Vols. 321-324

Abstract: This paper addresses the cooperative random access problem for distributed wireless sensor networks through network utility maximization framework based on persistence probabilistic model. To exploit spatial diversity, we also present a virtual link scheduling policy by employing multi-relay cooperative transmission and interference avoidance. Numerical results illustrate that our proposed cooperative medium access control (MAC) significantly improves the system throughput compared with the one based on deterministic model and the one without cooperative diversity.

Abstract: Wireless sensor networks integrated four technologies including sensor, embedded computing, network technology and wireless communication. It is a new type of non-infrastructure wireless network. In this paper, a data fusion method has been brought forward based on wireless sensor networks, and through an algorithm simulation test, It is proved that the algorithm is effective to reduce the energy consumption of the network, and extend the lifetime of the network.

Abstract: Node positioning technology in the Wireless sensor network is a very important issue. This article introduces the ant colony algorithm and its characteristics. It is a good solution to the static and dynamic portfolio optimization problem. The node positioning method in the wireless sensor network can be divided into two categories based ranging and no ranging. In order to get a higher positioning accuracy, and a further improvement the positioning accuracy, this paper introduces the ant colony optimization algorithm based on the first positioning method of the feasibility. The experimental results demonstrate the decrease of the number of transmitting beacon and the optimal mobile path after being optimized.

Abstract: This article has minutely designed the hardware structure of the tropical crop monitoring system in which Zigbee wireless sensor network is used to collect and monitor the information of tropical trop environments temperature and humidity. A system hardware circuit is also given in this article to meet the requirements of the tropical crop rubber monitoring.

Abstract: Aiming at monitoring the temperature, humidity and illumination intensity in the growing environment of a tropical crop---rubber tree, this article builds ZigBee wireless sensor network, and designs the software structure of this system based on fulfilling the hardware designing requirements. Combining Cluster tree algorithm in ZigBee network with AODVjr algorithm, this article enhances the use value of ZigBee wireless sensor network efficiently, and realizes that making use of ZigBee wireless sensor network technique in the tropical crops monitoring system.

Abstract: In order to accurately simulate the transient aerodynamic heating conditions experienced by aircraft when flying at high speeds, rapid and highly precise non-linear dynamic control of the heating process in aerodynamic simulation experiments must be conducted using a transient heat flux control system. This process involves carrying out ‘thermoelectric potential - temperature (E-T)’ conversion of sensors. Here a fast and high-precision ‘E-T’ sensor conversion method for the transient aerodynamic heating control systems of high-speed aircraft is proposed. The developed method has the advantages of easy calculation, rapid conversion speed and high calibration precision, and can thus be employed for fast non-linear dynamic control of rapidly-changing temperature fields in the aerodynamic heating process of high-speed aircraft.

Abstract: In recent years, researchers have increasingly paid more attention to the Wireless Body Area Sensor Network (WBASN) for its potential applications in medical care and health care field. In these applications, the reliable data transmission is the key point. This paper presents a simple protocol for WBASN, and the reliability of data transport is concerned. The protocol design is described in detailed, and then the protocol evaluation is given. The evaluation result shows that the protocol is suitable for the application of WBASN.

Abstract: Time synchronization is important for wireless sensor networks. In this paper RBS time synchronization algorithm principle and EECH routing protocol are introduced, and the simulation of RBS on the basis of EECH routing protocol is realized using the Synsinc software. The average synchronization error of the simulation is 25.86 us.This value is basically same with other types of simulation, which confirmed the simulation is credible.

Abstract: Aiming the problems caused by the narrow path recognition range of auto-tracking smart cars, this paper proposes a follow-up control based on the Freescale K10 microcontroller. A laser detection sensor was used to percept the path information. And a follow-up steering servo was used to drive the laser detection sensor to track the road path and controlled by the PID algorithm. Moreover, the system combined Ziegler-Nichols method and trial-and-error method to tune the PID parameters. Experiments show that, the smart car with the follow-up control has a wider path recognition range, an improved driving path and a higher speed.

Abstract: The water-entry point was the first information collecting point on detecting an object which was dropped into water from air. Single vector sensor could estimate the direction of the water-entry point with its sound field pressure and particle velocity signals. The complex sound intensity method was applied in vector signal processing. The simulating experiment and the practical experiment on the lake were all based on the estimation deviation of the theory on different SNR. By processing the devided signal in time domain with this theory, the water-entry object could be tracing timely.