Applied Mechanics and Materials Vols. 416-417

Abstract: The measurement of meteorological elements is of great significance in marine environment monitoring. Air pressure and air temperature/humidity are important parts of marine meteorological observation. An application example of the integrated meteorological measurement system composed by new pressure sensor and temperature/humidity sensor in remote island meteorological measurement is introduced, and also the basic characteristics of the two sensors and also the hardware interface design and software control method of microcontroller C8051F120 are described, and finally RS-485 bus interface circuit design and software design as well as its integration method are provided. Practical application proves that this system features high accuracy, low power consumption, convenient maintenance, and high reliability.

Abstract: To demonstrate the importance of abrasion and clearance to machinery, this paper studied abrasion of Cam mechanism contact surface, illustrated how abrasion and clearance relate to each other and investigated how they influence kinematic accuracy of the mechanism. In the case of Cam mechanism with flat-bottomed translation follower, it elaborated abrasion styles and bad points and depicted heart-shaped abrasion rate curve. It proposed a mathematical model and optimized design for cam profile, taking abrasion design as an objective function. Aided by Matlab and its optimization toolbox, it also proposed a optimized solution to the objective function mathematical model. And powered by computing capabilities of Matlab, it determined the coefficients in a high-order five-term function and found the optimal value of the objective function quickly in need. By optimization, mechanism abrasion improves and its kinematic accuracy and reliability increase, prolong its life.

Abstract: In this paper, the thermal behavior of a 12kW, 12000rpm, wet-type Permanent Magnet Brushless DC motor (BLDC) with skydrol oil inside designed for electro-hydraulic actuation system (EHA) was analyzed. A 3-D computational fluid dynamics (CFD) model has been built. The influence of skydrol hydraulic oil in thermal behavior at both low-speed and high-speed conditions was discussed. The results confirm that the skydrol oil passing through the motor has different impact on the thermal performance in different conditions.

Abstract: The later-period structure of Fuyang oil layer is very complex, and its reservoir mainly consists of riverway sand bodies; the oil and gas reservoir is significantly concealed, so it is greatly difficult to identify. In order to accurately predict sand bodies by using seismic data, a well constrained inversion is made to the layer flattening seismic data using Jason software under the high-resolution sequence framework. Through a comprehensive analysis on seismic and geological data, the absolute error is within ±500, the relative error is within 10%; the predicted sand body plane distribution is reasonable, and the absolute error of 82% sand bodies is less than 10%. This proves that well constrained inversion for the Jason-based layer flattening seismic data under the high-resolution isochronous framework has an obvious effect on the areas of complex later-period structure, and thin and complex changed sand bodies. Therefore, it can meet the needs of the oil field exploration and development to a certain extent.

Abstract: Take a typical region in the Loess Plateau of North Shaanxi Province zone as the study area.Based on relief map with a scale of 1:1000 to generate accurate 3D terrain DEM using Anudem algorithm. Compared with the production of Anudem method TIN method and Kriging method between DEM. DEM accuracy evaluation including value target, profile and slope and terrain attribute visualization, contour line playbacking and different differential value algorithm result variance analysis. The DEM difference that the result demonstrates that the different algorithm obtains is big, and DEM precision of Anudem method production is best, can very good response precise three-dimensional terrain.

Abstract: The signal preprocessing methods in a directional audio system are almost based on Berkatay far-field solution. In this paper, the basic principle and performance of square root method are analyzed, and also a directional audio system based on floating-point DSP is designed with the 4-order approximate square root method. Through theory simulation and practical test, the effect is proven to be satisfactory.

Abstract: Based on the video data, the paper analyzed the rotation factor sensitivity and diffusion of fractional Fourier transform. During the fractional Fourier transform process, we adopted three ways to process the video data. Through comparison of them, the second way, which is 4byte cast to 1float, is the most suitable for the sensitivity and diffusion analysis. Sensitivity analysis showed that the fractional Fourier transform rotation factor sensitivity and diffusion analysis showed that when any one of elements plus or minus greater than 0.2 times the transform, it would lead to completely fail to recover the original video data of inverse transform.

Abstract: Speech recognition technology is one of the hottest and the most promising new information technologies in the world. This paper studied the voice pretreatment and extractions of MFCC characteristic parameters, constructed speech keywords recognition algorithm with the core of the VQ model and the HMM model, using MATLAB to complete the training and simulation of algorithm, FPGA-based voice recognition technology, and the simulation and implementation of its hardware and software. It laid the foundation for the realization of speech recognition and control based FPGA.

Abstract: In this paper, we design and develop Vehicle License Plate Recognition (VLPR) System, which is one part of comprehensive video management platform for parking lot. Combined with intelligent video analysis module, the proposed VLPR system can not only capture the license plates of those vehicles through ENTRANCE and EXIT of parking lot, but also recognize the contents of the captured license plates. In addition, the driver and passenger in the front row of the vehicle can be captured too. The capture subsystem operates well on embedded Linux environment running on Hi3516 SoC chip, and test results of the VLPR system meet the requirements of accuracy and real-time field applications. The VLPR system is easy to expand and modified for other Management Information System to realize functions like personnel management, vehicle tracking, and more automatic and intelligent functions of parking lot management.

Abstract: According to the important position of DCT in image coding, the research of image retrieval performance based on DCT is advanced. In the paper, we take color descriptors of MPEG-7 as the color image feature, and acquire new image features through giving different weights to the different elected DCT coefficients, Using Euclidean distance as the similar distance measurement to retrieve color images in DCT. Then the relationship between the choice of weight and retrieval performance is studied by experiments, and moreover the retrieval conclusion is analyzed in detail. The result shows it can acquire relatively satisfactory outcome when selecting right weights of the elected DCT coefficients based on a concrete condition.