Applied Mechanics and Materials Vols. 220-223

Abstract: Monitoring system for mine emergency system was discussed. Mine emergency system helps the people to survive when mine disaster occurs. The monitoring system is essential part of the system and is designed in VC++.The demand analysis and the system architecture was discussed. The user-defined communication protocol was described and the system handled the communication data using buffer method.

Abstract: For the purpose of meeting the desert soil moisture easurements and control requirements accurately, a soli moisture control model is set in this paper. As the system is of delay and nonlinear characteristics, we used a frequency domain reflectometry (FDR) principle moisture sensor to measure the desert soil in tratification and a threshold switch fuzzy adaptive PID control method is taken in order to get a highly dynamic performance. Additionally, We made an experiment and a simulation analysis, The results show that the measure and control method we used not only has a strong robustness, but also can quickly and accurately detect and control the sand pit soil moisture.

Abstract: Previous works had proved that a directed complex network could be pinned to its equilibrium by a single controller if it had a spanning tree. But in fact, most of the real networks do not have spanning tree. In this paper, we study the pinning control of a general directed network without spanning tree. We prove that a general network could be divided into some sub-networks with spanning trees, and then the aggregation network is stabilized by stabilizing every sub-network with a single controller. As an illustrative example, a network without spanning tree is simulated to verify the effectiveness and convenience with the selective pinning control strategy.

Abstract: Landslide is a main type of natural disasters, and makes huge human life losses and property losses. Landslides are often triggered by rainfall, especially long time rainfall or high intensity rainfall. Model test is an effective method to study the mechanism of landslide. An artificial rainfall simulator for model test of landslide is designed, which including water reservoir, water pressure control and rainfall drop making needles. To maintain the rainfall intensity, the water lever of reservoir is kept constant by a servo-control system. And a cross leaf can rotate in the raining process is set in the front of rainfall drop making needle to make the local rainfall drop distribution uniform. Then particle flow method is used to simulate the rainfall drops making process, and the result shows that he reasonable rotation velocity of needle leaf should be confirmed in the rainfall calibration to maintain a uniform distribution before test.

Abstract: Due to layering distribution, double network and dual-disposition characteristics of 750kV substation, Petri net diagnosis model which based on redundant protection for substation is proposed. In this model, a redundant knowledge representation method is adopted from components to the local and the whole, then components redundant diagnosis-model is constructed on basis of it. The model can be decomposed into main and redundant subnet-model based on Petri net by using two sets of protective device information, and considered remote backup protection, which realize fault tolerance of dual-machine. Through information fusion of redundant diagnosis model of components, the local and the overall model is established. The results show that the model achieves high efficiency and reliability.

Abstract: To realize accurate acoustic source localization with variable power in noisy environments, a novel acoustic source localization method with variable power based on LSSVR regression learning (ALVP-LRL) was proposed. The ratio values of any two adjacent nodes’ theoretical measurements of acoustic energy comprise feature vector, which has stable mapping relationship to source’s coordinates. LSSVR was applied to build regression models approximately reflecting that mapping relationship. By inputting feature vector constructed by real measurements into the regression models, the models’ outputs were then regarded as the estimated coordinates. Experiments were performed in 121 test locations. As SNR level reduced, amount of test locations where location errors were less than 2 meters by ALVP-LRL method changed from 77 to 54, while that amount by MLE method rapidly decreased from 121 to 11. It shows ALVP-LRL method preliminarily achieves certain effects and has more significant advantages on lower SNR occasions.

Abstract: Recently, China is developing smart grid with great strength, more and more digital substations will be built, therefore, it is time for thinking of the accuracy of the new electric energy metering devices. But the new electric energy metering devices are different from the traditional meters by using Digi-Data interface instead of voltage and current interface, requiring a new method of testing error. By equivalently transforming electric power from analog to digital, we design a special electric power standard with digital-data-interface according to IEC61850. Based on the special electric power standard, this article introduces a new method for calibrating digi-data input power meter.

Abstract: Electrical overheating and fire are multiple faults in power system, optical fiber temperature measurement technology is better than the traditional temperature measurement device. It can test electrical system changes in temperature more effective and reliable, thus effectively contain similar accidents. This paper expounds the optical fiber temperature monitoring system warning the working principle, system constitution and its characteristics, discusses the practical application of optical fiber temperature warning monitoring system in power system.

Abstract: The type of land cover is principally determined by spectral reflectance of land. Different surface features have distinct absorption and reflection properties on different bands. The characteristic is used to identify land cover type from multi-spectral images. Reflectance coefficients and spectral differences are extracted as feature vector to represent each pixel. Self-Organizing Feature Map neural network is adopted for feature classification. A semi-supervised correction strategy is proposed to amend the classification errors. The images of Qingdao Agricultural University campus acquired by SPOT5 were selected as experimental data. The results show that the overall classification accuracy of samples is up to 83%, moreover, the proposed method is helpful in solving the phenomena of same object with different spectrums or different objects with same spectrum.

Abstract: In order to recognize and extract feature dimensions automatically from point clouds of human body, a method based on National Institute of Standards is proposed. Using the data provided by the National Institute of Standards GB10000-1988 to divide the search region of each feature point firstly. Then, extracting the feature points in the search region by comparing the coordinate values and the distance from point to straight line with other points . The method has nothing to do with the body shape and improves the robustness of feature point extracting. In the aspect of body dimension's measurement, the critical feature dimensions are calculated by intersection-contour perimeter method and distance between two points methods.