Applied Mechanics and Materials Vols. 556-562

Abstract: Tunnel roof separation monitoring is an important research content of tunnel supporting technology, it is of great significance to guarantee the safety of mine production. The traditional detection methods of roof separation have disadvantages of low precision, poor reliability, high cost, and the comprehensive analysis of measurement results is difficult. In the paper, a roof separation monitoring device based on STC12C5A is proposed. It has the core of STC12C5A single-chip microcomputer, and realizes the accurate measurement of displacement by using the fine drag-rope displacement sensor, and realizes the data communication and sharing by using bus interface. The device can achieve real-time, reliable monitoring of roof separation condition and also can make pre-caution to the possible production accident.

Abstract: BP neural network model for state monitoring data tendency prediction is constructed based upon neural network theory, and simulation programming is achieved with MATLAB. In the experiment, multiple data sets are selected for training and testing of the network to prove the validity of algorithm and model.

Abstract: One method for diagnosis of faults with generator rotor is contrived by combining local wave method and blind source separation. Time-frequency image varies with local wave of different fault signals, and this feature is applied to identify different faults. In order to realize automatic classification of faults, blind source separation is employed for separation of independent components in time-frequency image of local wave of different fault signals, so as to derive projection coefficients for a set of source images. On the basis of this, automatic classification of faults is realized with probability nerve network. Taking fault signal of rotor as an example, this method is investigated, and the validity is proved by experimental results.

Abstract: We proposed a motion edge detection method in our previous work. However, the edge of the moving object detected from the image sequence is always unclosed. In this paper, we propose a method of a hybrid field snake to close the edge of the object. The initial curve of the snake is rectangle, so that the curve can be used in the tracking and recognition applications, but its corners always locate out of the GVF field. The hybrid field snake method is proposed to solve this problem. Some experiments are performed at the last part of this paper to test our method, and the results are satisfactory.

Abstract: Aimed at the disadvantage of traditional magnetic detection such as susceptible to magnetic interference and positioning not accurate, the paper presents an algorithm of passive route detection and localization of armored optical fiber cable based on the pulse induction. By injecting changing current to the detection coil, the algorithm used induction technology to incentive out the induction voltage in metallic materials of the detected armored optical fiber cable and established the model about the distance between them. Then derived that the impact of the armored optical fiber cable on the coil voltage was in reverse proportion to the distance six powers of exponent. In addition , the algorithm used coil array to detect and localize the cable to determine the position of the armored optical fiber cable. The results of the simulation indicates the effectiveness of the presented algorithm and passive route detection system and provides feasible ideas to make the technology of passive route detection of armored optical fiber cable practical on the next step.

Abstract: To solve problems met in an offshore High-Pressure High-Temperature (HPHT) well testing, a new technology is put forward—placing seal bore extension above permanent packer, and the upper landing tools being connected with seal bore extension through shear pins. This method gives a reverse position of seal bore extension compared with conventional way in which seal bore extension is below permanent packer. So, the feasibility must be considered. Two technological procedures, testing before cutting pins and testing after cutting pins, are discussed, and the highlight is on axial force and deformation of testing string at crucial moments. Results indicate that this new technology is feasible. Of the two technological procedures, axial force is the key factor when testing before cutting pins and axial deformation is the key factor when testing after cutting pins. Conclusions have been used in an offshore HPHT well testing design.

Abstract: Based on the basic principle of wireless sensor networks, the communication platform of a new ZigBee wireless ad hoc network is applied to the on-line monitoring system of transmission lines. In this article, the hardware and software platform architecture of the system is introduced, the scheme and algorithm for cluster network of monitoring nodes based on ZigBee technology are described; moreover a reliable, energy-saving and efficient data transmission method is designed. Application results show that ZigBee technology has the features such as self-organization, dynamic topology, large network capacity and data-centeredness, and possess a distinct advantage in on-line monitoring of electrical equipments.

Abstract: In this paper, a distributed testing execution system is designed, which provides a mechanism of node communication, test script deployment, test scheduling, executor-driving and test result collection in distributed environment. A workload model is established, by which testers can describe the performance testing requirement. A performance testing framework is given, which simulates user behaviors in real environment based on virtual users so as to generate workload from the system under test (SUT). It can control the execution of virtual users by TTCN-3 standard interface. After executing the performance testing, test report is generated by extracting log. A method of generating performance test-case is studied by reusing functional test scripts. By executing performance testing on an online bookstore, this paper demonstrates the availability of the method of reusing TTCN-3 functional test scripts and the capability of distributed performance testing system that had been established.

Abstract: In recent years, fluorescent ink, with a unique color performance and the advantages of green non-toxic, fast drying, thin ink, etc., is widely used in packaging printing, security printing, and other fields. What^’s more, the luminescent properties and the interaction with paper of fluorescent ink are pained more and more attention. In this experiment, an ultraviolet light source is used to motivate the samples to emit, the fiber spectrophotometer is used to receive the reflected light of the samples in the vertical direction of the samples. The tone rendering curve and dot gain curve are obtained according to the radiation energy data of the sample, the printing indicators of fluorescent ink are obtained by analyzing the reproducing image tone scale and dot expansion characteristics of ink on the paper.

Abstract: For GPS measurement signal in aircraft experiment is often affected by transmission environment, and interfered with impulsive noise, hereby a SVD combined with wavelet neural network to detect and eliminate the impulsive noise method was proposed. The received GPS data is decomposed by SVD, and the decomposed component is acted as the input of wavelet neural network. Letts criterion is adopted to detect the impulsive noise according to the output residue error of the wavelet neural network. For the detection of the interference points of impulse noise, it can use wavelet network output to replace the measured value, so as to eliminate impulsive noise.