Applied Mechanics and Materials Vols. 397-400

Abstract: Circular features are one of the most widely used shapes for camera calibration, due to several advantages: easy to make and recognize, not sensitive to image noise, symmetry, analytic formulation is simple. However, perspective projection is generally not a shape preserving transformation. A circle often mapped as an ellipse on the image plane when the feature and the image plane are not parallel to each other, as a result, the center of the circle shift from the center of the ellipse. In this paper we present a simple and robust algorithm to compensate this bias before camera calibration. Experimental results show the algorithm is important and convenient.

Abstract: This paper proposes a new approximation method called Enhanced Two-Point Exponential Approximation (ETPEA), which is derived based on Two-Point Exponential Approximation (TPEA). In TPEA, when the exponents of intervening variables cannot be calculated by fitting the sensitivities of the previous design point, the accuracy of TPEA is decreased. In such cases, ETPEA uses a substitution function to construct the approximate function, and the optimum result can be improved. Some typical structural optimization problems are tested, and the results indicate that the optimum design can be found accurately and quickly with the new approximation method. It is verified that the new approximation method is also efficient for large structural optimization problems.

Abstract: The monitor terminal (Single Chip Microcomputer 89c51) can be used as the portable device, also can be fixed at the farm to form the monitor terminal internet. It can be connected with the control center (the upper computer) by wired and wireless transmission. It can be functioned as the monitor by PCB design, the perceptual layer module design and the electric equipment controller design.

Abstract: Species evolution model in natural is introduced into the genetic algorithm to reflect the true laws of evolution. A multi-population genetic algorithm based on species evolution is developed. In the algorithm, the parameters of species evolution model are considered as design variables, and the equation is regarded as modified arithmetic crossover operator to participate in genetic operation. Immigration operator is used to promote convergence and enhance the ability of search optimal solution. The improved genetic algorithm is applied to mold optimization design to search the optimal gate location. The examples indicate that this algorithm can effectively solve the mold optimization problem.

Abstract: The paper makes an analysis on the working device of loader, which plays an important role in the performance and economic benefit of the overall unit. The paper tries to develop the mathematical model of a loader working device, apply complex method taking the maximum breakout force of cylinder of rotating bucket as well as maximum lifting force of boom cylinder as the objective function and finally realize the optimization design of its design based on MATLAB software, probing into finding a efficient solution for the technical problems existing in the working device design and manufacturing.

Abstract: At present, the real-time data of the section passenger flow can’t be acquired in the process of urban rail transit operation, which brings some difficulties to the passenger monitoring and controlling. After analyzing the spatio-temporal complexity characters, this paper adopted BP neural network to predict the section passenger flow, which was based on the first three consecutive periods of the in and out station traffic and the next period of the section passenger flow data. Finally, Fuxingmen and Xidan in Beijing urban rail transit were selected, their first three consecutive periods of the in and out traffic are put as the input data, and the next period of the section traffic as the output data, then BP neural network was used to train and predict under MATLAB. The anticipant and the actual output results are well fitted, which proves that the data processing method is effective and the parameters of the BP neural network are reasonable, and it can provide theoretical reference for the transport operators to some extent.

Abstract: Two factors must be given considered in low friction cylinder , which are sealing and wear. A lower contact pressure can lead to seal failure. However, a heavier contact press can increase friction force and wear. In the present paper a method have been proposed to obtain the optimal contact pressure between PTFE wear-resistant ring and the steel bushing at first, with analysis of the relationship among the surface roughness, the sealing contact pressure and the leakage. Secondly,the piston groove Diameter has been designed by using the finite element analysis software of ABAQUS to simulate the Mooney-Rivlin model, which is corresponding to this optimal contact pressure. On the premise of meeting the requirement of the specific leakage standard between the cylinder and the wear-resistant ring, the optimal contact pressure and the corresponding piston groove size have been obtained, with different surface roughnesses of the friction pairs.

Abstract: The paper introduces that the mechanical machining system can be divided into various objects such as parts, machining processes and manufacture resources and classified by using the objected-oriented technology in the CAD/CAPP/CAM integrated systems produced from some kind parts. Using the method of shape and surface description, the parts features can also be classified in various levels. The paper also introduces the principle and method of establishing system model on the basis of summarizing and inducing interrelation among features. We have applied the method to practice and achieved better results.

Abstract: In knowledge economy and web economy times, cooperations for knowledge among firms are becoming more and more important. But, since some characteristics of cooperating organization and knowledge itself, there exist many risks during the choice of its partners. Firstly, the article analyses 7 risks during the choice of partners; Secondly, expounds thesteps that chooses partners based on Method of MatterElement Analysis; At last, creates an example to explain the use of the method. At the same time, bring the Multi Response Variable Analysis and Borda Method to perfect the use of Matter-element analysis during the choice of partners for knowledge chain.

Abstract: The fracture surface of con-rod is difficult to be quantitatively described due to its indented macro morphology. Thus, the range of fracture surface defect dimension has no uniform standard. In order to solve this question, 3D software about the digital fracture surface reconstruction was developed by combining the fracture splitting technology of con-rod with reverse engineering, which realized the reproduction of its morphology and completed the real area calculation of the surface. The results show that the fracture surface area processed by fracture splitting is 13.1% larger than that of the plane processed by machining. It represents that the defect dimension range of fracture surface is improved compared to empirical value without reducing the bearing capacity and usability.