Applied Mechanics and Materials Vols. 433-435

Abstract: According to the matrix relationship between the induced source and an incident wave in the electromagnetic scattering theory, the formula connecting the scattering center parameters and the matrix element are deducted, and matrix diagonalization and aggregation approximation of the induced source and the incident wave is pointed as the main establish condition of scattering center. Based on the conclusion, the scattering center distribution of a metal plate is given; the RCS error of the scattering center approximate model is analyzed. It is demonstrated that the approximate establish condition of the scattering center is valid.

Abstract: For instrument multifunction, this article introduces a new multi-parameter environmental monitoring instrument. This article chooses the electrochemistry gas sensor as signal acquisition element which has the characteristics of small volume, high sensitivity. Using a single crystal designed as PM2.5 detection module. It can measure SO₂NO₂COH₂S and PM2.5 meanwhile. It simply and exactly achieved the measurement of every parameter by designing related circuits. The communication between computer and Labview was realized by serial port. This instrument has high accuracy, small volume, and higher performance price ratio and so on.

Abstract: In this paper, we present different code rates of LDPC decoding on Chinese Mobile Multimedia Broadcasting standard (CMMB). There are two different code rates (0.5 and 0.75) of LDPC in CMMB standard.In this paper, we use LLR-SPA algorithm to decode and make a simulation. Simulation results show that the higher code rate (0.75) of LDPC code in CMMB standard provides a better performance.

Abstract: Estimates for multilinear Hilbert operators on central Morrey spaces and Morrey spaces are obtained.The best constants for the Hilbert operators on Morrey Spaces is obtained, under some condition.

Abstract: This paper focuses on the perception step of robotic grasping unknown objects in order to get a stable grasping hypothesis. At first, hierarchical shape context feature is proposed to depict the local and global shape character of a sample point along the edges of the object. Moreover a kind of random forests classifier is adopted to recognize the grasping candidates in the image from vision system so that a 2D grasping rectangle can be generated through kernel density estimation. Finally, by means of stereo matching, the grasping rectangle can be mapped into the 3D space. Thus, the center of the grasping rectangle can be applied as the center of the gripper. The approaching vector and the grasping rectangle direction can be employed to determine the pose of the gripper. Simulated experiments showed that a reasonable and stable grasping rectangle can be generated for various unknown objects.

Abstract: Demand forecasting for port critical spare parts (CSP) is notoriously difficult as it is expensive, lumpy and intermittent with high variability. In this paper, some influential factors which have an effect on CSP consumption were proposed according to port CSP characteristics and historical data. Combined with the influential factors, a least squares support vector machines (LS-SVM) model optimized by particle swarm optimization (PSO) was developed to forecast the demand. And the effectiveness of the model is demonstrated through a real case study, which shows that the proposed model can forecast the demand of port CSP more accurately, and effectively reduce inventory backlog.

Abstract: Grounding grid is an important device which ensures the safe operation of substation. Its corrosion is influenced by various factors and the influence of these factors is varied. It is difficult to infer the relationship between the corrosion rate and its influencing factors, so this paper apply the grey clustering method of grey system theory in the grounding grid corrosion and gives an application instance and realizes it by MATLAB. The results demonstrate the practicality and effectiveness of the method mentioned in this paper. This method can provide reference for high reliability for related departments in the implementation of emergency situation due to grounding grid corrosion.

Abstract: Quality abnormal pattern recognition for dynamic process is the key problem to achieve the online quality control and diagnose of automatic production. Firstly, this paper analyzed the quality patterns of dynamic process. Secondly, we established recognition model of quality recognition in dynamic process using MSVM and compared the SVM recognition accuracy of different kernel functions for different quality patterns. Simulation experiment indicates that different SVM classifiers should choose specified kernel functions to recognition quality patterns. At last, we established MSVM recognition model of quality pattern in dynamic process using multi-kernel function according to the experiment results.

Abstract: The algorithm has been improved to the adaptive genetic operators and flow based on the basic theory of simple genetic algorithm and adopted elitism strategy to select the best individual for iterative operation. Program the operation process in the MATLAB software. The improved genetic algorithm not only ensured better global search performance, but also improved the convergent speed. The optimal solution was obtained by the improved genetic algorithms under the kinematical constraints.

Abstract: The Multidimensional 0-1 knapsack problem is a NP hard problem, though there are many algorithm is used to solve the problem, but there is still not a good solution to solving the problem. This paper improved niche genetic algorithm, established a master-slave mode niche genetic algorithm, and carried on adaptive setting the individual Euclidean distance criterion, making it can changed with the evolving algebra incremental. At last, used master-slave niche genetic algorithm to solve the Multidimensional 0-1 knapsack problem, test results showed, the algorithm has good applicability and superiority in solving the Multidimensional 0-1 knapsack problem.