Applied Mechanics and Materials Vol. 734

Abstract: A new visualized fiber fence alarm system was put forward in this paper, which was used Sagnac interferometric sensor of optical fiber fence on the surrounding invasion of signal detection and positioning, and sent alarm information and video monitoring system linkage, in order that the monitoring equipment switch to intrusion scene view timely. Finally the video record the intrusion events. This visualized alarm system makes full use of advantages of optical fiber detection and video surveillance, which improved the level of intelligence of security system and the security performance of the system.

Abstract: The present study about forensics technology intelligent of electronic terminal is mainly in utility demand, and there are many shortcomings in the point of view of forensics mode, evidence standard, forensics technology comprehensive etc.. This article conducts the research from the legal standard, technical standard, technical model, key technology and other aspects of the intelligent terminal of electronic forensics. Firstly , the characteristics and requirements of the intelligent terminal in electronic evidence are analyzed, the status of the domestic and foreign research about intelligent forensic is also analyzed. Then the electronic forensics model of intelligent terminal is proposed in terms of legal standards, technical standards, technical model, key technologies, and in the model as a guide, the related technologies of electronic evidence extraction, evidence analysis, evidence preservation, and other in the intelligent terminal are studied. Forensic Model and related techniques are proposed in this paper have important theoretical and application value for the Judiciary to electronic forensics in intelligent terminal.

Abstract: In tracking object by a camera, the jolting of the vehicle will increase the deviation of the skewing value of the air object in the image. a method of image stability based on digital inclinometer is presented in this paper. The incline angles caused by the jolting of the vehicle are measured by the angle sensor, and the incline angles are used to eliminate the object image deviation caused by jolting and to stabilize the object image. The method for acquiring the height of object by a single camera is also discussed in the paper during the process of extracting the image deviation. The extraction errors of the deviation are analyzed and simulated; the simulation results show the efficiency of the method.

Abstract: The system included a sound module and four audio receivers. The frequency of sound module was 500 Hz, and the duration was 1 second. The four audio receivers took different time to pick up the sound from sound module. Subtractors converted the time lags between every two receivers into phase difference. The hyperbolas were established by calculating the digital signal which was transformed from phase difference.

Abstract: In order to raise the efficiency of on-site live detection, we proposed a new study of live detection data management system which based piconet and Electric Power System Secure Access Platform(EPSSAP). Piconet of comprehensive multi professional testing equipments with Bluetooth technology is established to wireless acquisite field testing data. Using mobile APN secure access technology, secure communication between the intranet information system and PC power system is realized. Application of the platform will provide basis for a unified multiple data acquisition system, extend functions of intranet information system, such as data storage, information processing regulate the process of on-site live detection work and improve the efficiency of the use of live detection data.

Abstract: This paper presents an indoor location system. The system is comprised of a RFID reader and several low-power active RFID tags.This designed active RFID tag consists of an ultra low power micro-controller, a low power RF transceiver, micro-strip antenna and an on-board battery. The indoor location system uses a RSSI-based ranging technology location algorithm. The experimental results show that the system is a good location system of high precision. And thanks to the advantage of these low-power active RFID tags, this system can be implemented simply for different applications.

Abstract: The increasing demand for high precision indoor positioning in many public services has urged research to implement cost-effective systems for a rising number of applications. However, current systems with either short-range positioning technology based on wireless local area networks (WLAN) and ZigBee achieving meter-level accuracy, or ultra-wide band (UWB) and 60 GHz communication technology achieving high precision but with high cost required, could not meet the need of indoor wireless positioning. This paper presents a new method of high precision indoor positioning by autocorrelation phase measurement of spread spectrum signal utilizing carrier frequency lower than 1 GHz, thereby decreasing power emission and hardware cost. The phase measurement is more sensitive to the distance of microwave transmission than timing, thus achieving higher positioning accuracy. Simulation results demonstrate that the proposed positioning method can achieve high precision of less than 1 centimeter decreasing when various noise and interference added.

Abstract: Traveling wave in transit, wave head is easy to produce distortion and affected by environmental interference, so accurately measuring the head of traveling wave singularity occurrence time become extremely difficult. The key to improve the precision of traveling wave detection is to accurately capture the happening time of wave head of singular points. Recently, traveling wave singularity detection usually use wavelet, EMD-HHT transform technique, but both have mixing phenomenon, affecting the accuracy of detection. In this paper, we propose a new method that use Duffing chaotic oscillator to suppress traveling wave interference signal. By Matlab simulation and it is proved that this method can effectively suppress noise singular point. Meanwhile, we propose an anti-mixing EEMD-HHT wave head detection technology. Through simulation experiment and field test, it is proved that, compared with EMD, EEMD can more accurately identify the traveling wave arrival time, detection accuracy increasing by 1.52%.

Abstract: The MOA is the main lightning protection equipment in power system, The status is generally monitored by online monitoring and offline test in routine maintenance. Traditional MOA live detection requires a lot of wiring, and has operation problems and safety risks. A new distributed MOA online monitoring wireless measurement is presented in this paper, that is, 433M wireless transmission and GPS clock synchronization technology fulfill distributed wireless synchronization measurement in MOA online monitoring device. Focusing on the design principles, implementation methods and the device composition, it is indicated that the wireless synchronization testing result is same with wired synchronization testing result, which can meet the requirements of MOA online monitoring.