Applied Mechanics and Materials Vols. 644-650

Abstract: Most seismological instruments recording ground motion use three sensors oriented north, east, and upward. In this cardinal configuration horizontal and vertical sensors differ in their construction because of the gravitational acceleration affecting the vertical sensor. In order to solve this inconsistence, we have developed a new posthole broadband seismometer with Galperin’s configuration. In this arrangement three identical sensors are also positioned orthogonally to each other but are tilted at the same angle to the vertical axis. We have presented the nominal coordinate transformations used to derive the differential output signals X, Y, Z from the cube-corner-oriented sensor output signals U, V, W, including four types of corrections: orthogonal correction, sensitivity correction, tilt correction and orientation correction. In addition, the hardware circuit for the coordinate transformation matrix is also described in details.

Abstract: In this article, a design method of asynchronous FIFO memory based on FPGA is put forward. With FPGA as the core controller, We adopt Verilog HDL and top-down design method to build a top-level module design and also analyze the mark logic of asynchronous FIFO and the elimination of semi-stable state under Quartus II development platform. Besides, with the application of Gray code conversion technology, not only the reliable transmission of data is guaranteed but also design efficiency is improved. Through contrast experiment analysis and simulation test, the validity and reliability of asynchronous FIFO memory are verified, meeting the basic requirement that FIFO can hold more enough data without spillovers despite the fullness of data.

Abstract: Wind power prediction techniques can be used in wind power scheduling control. Aim at the scheduling control deviation caused by the error between predicted power and actual power output, a Wind power scheduling optimization allocation algorithm based on predictive power correction is proposed, which adopts Auxiliary Particle Filter Algorithm to adjust the values of predicted wind power .Then the adjusted values are used in the proportional allocation according to the maximum power strategy ,and the superiority of this method will be verified by MATLAB simulation with the real wind farm operating data .

Abstract: This paper analyzed the important of lighting in museum from three main aspects, environmental lighting. LED lighting can not only meet requirements of museum lighting, and also has advantage of protecting historical relics and intelligent energy saving. The dimming control of accent lighting is achieved by infrared detection, distance detection of visitor and exhibits. Intelligent lighting and bionic controlling improve the intelligent level of exhibition, protect historical relics effectively, reflect the topic of energy saving and environmental protection.

Abstract: This paper relates to a high reliable communication method for the terminal of a networked and distributed power supply system. Terminal refers to the realization of two-way communication between high voltage source of distributed power supply and laden multiple electrical appliances. Due to the characteristics of long distance, complex electromagnetic environment and small amount of communication information between the voltage source and the electrical appliance, this paper designs a new kind of high reliable communication method along with high-voltage transmission, narrow-banded and single-ended synchronous [1,2,8]. Under the condition of satisfying the communication capacity and reliability, this method has been successfully applied to the city network and LED street lamp management system with the advantage of simple circuit design and inexpensive manufacturing cost.

Abstract: Processing and interpretation of magnetic data usually require information of total magnetization direction. However, under the effects of remanent magnetization, total magnetization direction is different from induced magnetization direction, which makes data processing and interpretation complexity. In this paper, we present a new method by cross-correlation of magnetic dipole source for determination of magnetization direction from relatively isolated and approximate equiaxial-shape magnetic total field anomaly. This method calculates cross-correlation coefficient between observed magnetic total field anomaly and theoretical magnetic total field anomaly caused by a magnetic dipole source, by using a set of varying parameters of positions and total magnetization direction of dipole source for trial and error. The corresponding magnetization direction of maximum correlation coefficient is regarded as estimated total magnetization direction. Test on synthetic data indicates that this method reliably and effectively estimates the magnetization direction from relatively isolated and approximate equiaxial-shape magnetic total field anomaly.

Abstract: It is very vital for the distribution transformer in the distribution system, crucially ensuring its reliable operation is, therefore, timely and accurately grasping the state of the transformer is very meaningful for guiding the condition maintenance of transformer and improving the operation reliability of distribution system. It is very difficult for AHP to inspect and adjust the consistency of judgment matrix, and its inspection standard lacks of scientific basis, so we put forward a fuzzy comprehensive evaluation method which uses five-demarcation method to establish the fuzzy complementary matrix on the condition assessment of distribution transformer. Through an example analysis, which proposed method is proved to be rationality and validity.

Abstract: The sampling resistor method is commonly used in the laboratory to measure the insulator leakage current. To study the effects of different resistance on the leakage current acquisition results, a series of experiments are systematically conducted in laboratory. Leakage current waveforms of a clean porcelain insulator under 9 kV and 27 kV power frequency voltages are acquired respectively through the oscilloscope with sampling resistance of 5 Ω, 10 Ω, 100 Ω, 1 kΩ and 17 kΩ. The results reveal that: rated voltage been applied, weak discharge exits on the surface of the porcelain insulator which leads to the appearance of the pulse in the leakage current waveforms and a larger sampling resistance weakens the pulse signal. When the voltage is 9 kV, the measurement result under 5 Ω sampling resistance is 49.4 times amplitude of the result under 17 kΩ sampling resistance and when the voltage turns to 27 kV, the ratio increased to 131.5.

Abstract: According to the requirement of real-time detection system towards acquisition, storage and display of video data, a design method of video acquisition system based on FPGA is put forward. With FPGA as its core controller, the design presents a simplified video acquisition system to achieve standard video images. The design elaborately illustrates key points of video acquisition system, thus the acquisition, storage and display function of real-time video can be technically realized. In the end, the validity and reliability of this system is verified through simulation under Modelsim circumstance combined with online logical analyzer.

Abstract: Designed a high rate data transmission system based on OFDM for well logging. The system used time domain equalization and frequency domain equalization. The transmission data rate of the system can reach 1.2Mbps over 7440 meters CAMESA cable, and its BER is less than .