Applied Mechanics and Materials Vols. 457-458

Abstract: For the issue of the industrial pipe wall lining the thickness of dynamic changes difficult to be measured, based on the principle of ultrasonic thickness measurement and ultrasonic propagation in solids and based on existing research and theory of ultrasonic, this topic has designed a ultrasonic technology solution for measuring the thickness of the pipe wall lining. This technology achieves online measurement and non-destructive thickness measurement. Through processing and analysis of the experimental results, it demonstrates the feasibility and reliability of the technology. This technology has great significance for improving the security and stability of the pipeline.

Abstract: Integrated project delivery as a new mode of project management, its ideas of integration guides the future development direction for the construction, but its theory and practice of development is not mature either. There is still a lot of uncertainty in the process of practical application, need to identify and analyze various of risk factors, which provide theoretical basis for that the IPD model are fully used to project management practices.

Abstract: By theoretical analysis and computer simulation,this paper has successfully solved the compatibility problembetween the Leakage protection with additional DCand zero-sequence power direction Leakage protection, and realized the goal of the two different ways of leakage protection sharingone set of electrical leakage protection system.This paper focuses on the basic components of "EDS-336/660 centralized-distributed selective leakage protection system"and its practical usage in Lvjiatuo Coal Mine.

Abstract: A novel online verification instrument for diaphragm gas meter based on positive displacement principle is proposed. Through an in-depth research on online verification technology, a dedicated wave absorber is designed to eliminate the effect of pressure pulsation. The whole series of the online diaphragm gas meter verification in normal operation condition is realized by adopting fixed-point calibration and nonlinear correction technology. The experimental data shows that the uncertainty is within 0.5% and the ratio of the measurement range is reach to 100:1.

Abstract: This paper aims to improve the control performance of series HEV, and mainly conducts the study of the basic components of the control systems bidirectional DC/DC converter and motor drive circuit--the buck chopper and boost chopper. Also, this paper constructs a hardware platform and designs the fuzzy self-tuning PI controller. Through the comparative experiments of PI control and fuzzy PI control, it has been verified that the fuzzy PI controller has better control effect.

Abstract: In the speech recognition technology, feature extraction is essential for the system recognition rate, taking amount of strategies to find the better feature vectors are most researchers target. This paper presents a method of extracting feature of audio signal based on the discrete wavelet transform, then decomposed the coefficient matrix by the matrix analysis way, through this method to find a new thinking on the way of extracting feature vector. The method can be achieved in the procedure. The main purpose is to reduce the dimension of feature vector, make the vector briefer, and then reduce the computing complexity in the embedded system. This method can reduce the feature vectors dimension, accelerated the computing velocity.

Abstract: Synthetic aperture radar (SAR) Image containing the coherent speckle noise, traditional methods can't very well to SAR image segmentation, based on SAR image grayscale distribution model, this paper proposes a combination of pixel gray level and area information of the image segmentation method. First of all, based on SAR image in all kinds of feature of gray histogram presents the facts of the Rayleigh distribution, fitting of image gray level of probability density distribution; Then use fuzzy biggest office methods select the optimal threshold, and the resulting statistics as the related parameters of image, the image blur ; Then to 3 x3 neighborhood pixels within the membership degree of fuzzy characteristics of Kohonen self-organizing map neural network is adopted to improve the coarse segmentation, the segmentation of noise and boundary classes pixels using a region growing technique relaxation iteration to fine segmentation.

Abstract: Due to the continuous increasing of operating frequency in the power system and the transmission speed, under the high frequencies of the transmission line calculation and simulation process, it is necessary to consider the frequency-dependent properties. At present, the frequency-dependent transmission line modeling has a variety of methods, but in the modeling and calculation of frequency variable term, processing is relatively complicated. This article will introduce transmission line equation of fractional calculus, intuitive representation of frequency varying parameters, and by a time-domain fractional solution, simplify the operation, improve the computational efficiency. Application of this algorithm for fractional differential equations can be obtained the voltage and current responses at any point in the transmission line. Thesis also by comparison with actual example, confirmed the validity and feasibility of the algorithm. At the same time, proposed algorithm can be extended to the multiple conductor transmission lines of fractional order model, also has certain applicability.

Abstract: For meeting the needs of vehicle control system to some real-time parameters, a kind of soft-sensing technique was studied by using the extended Kalman filter theory in this paper. The specific flow for the application of extended Kalman filtering theory about the estimation of vehicle state parameters was presented detailedly, a state observer was established based on the vehicle dynamic model of a 2 degree of freedom. Simulation results indicate that these types of soft-sensing technique can measure some key state information of vehicle easily and accurately, such as longitudinal and lateral acceleration, and get real-time state estimates required by vehicle control system. Hence, it has very important meaning in reducing the cost of control system of vehicle.

Abstract: It was hard to obtain sensitivity distribution of Inlet electrostatic sensor by mathematical model and analytic method. To this problem, the sensing model and sensitivity function of circular electrostatic sensor were established by Point-charge principle. In addition, the main factors to electrostatic sensor sensitivity were analyzed and discussed by ANSYS with an optimized probe size. Accordingly, this simulation analysis had provided a theoretical basis and guidance for latter designs of inlet electrostatic sensor as well as guidance for structures of experimental environment of aero-engine gas path.