Applied Mechanics and Materials Vols. 556-562

Abstract: A visible difference exists between the measured Bidirectional Reflectance Distribution Function (BRDF) and the modeled BRDF. The Cook-Torrance model is chosen to simulate the BRDF for its popularity and flexibility. Taking aluminum for example, this paper analyzes the difference between the experiment data and the simulation data. There is a great and remarkable difference in the situation of specular reflection by comparison in this paper. Consequently, trigonometric factor, numerator and denominator addition factors and scaling factor are brought in the Cook-Torrance model. Finally, a modified Cook-Torrance model is presented. The simulation data of the modified Cook-Torrance model show that it’s more suitable for the analysis of the aluminum BRDF than the classic Cook-Torrance model.

Abstract: Quantization methods are very significant mining task for presenting some operations, i.e., learning and classification in machine learning and data mining since many mining and learning methods in such fields require that the testing data set must include the partitioned features. In this paper, we propose a spheriform quantization method based on sub-region inherent dimension, which induces the quantified interval number and size in data-driven way. The method assumes that a quantified cluster of points can be contained in a lower intrinsic m-dimensional spheriform space of expected radius. These sample points in the spheriform can be obtained by adaptively selecting the neighborhood at initial observation based on sub-region inherent dimension. Experimental results and analysis on UCI real data sets demonstrate that our method significantly enhances the accuracy of classification than traditional quantization methods by implementing C4.5 decision tree.

Abstract: Rotor machining is a traditional discrete manufacturing process, among which large amount of non-essential energy is being wasted. The machining process belongs to pipeline production, so a flow-shop scheduling model is built to optimize it. But when there are over three machines, this will be an NP-hard problem. We introduce an improved ant-colony algorithm to find the best solution and then use the real machining data to test it. The total energy consumption is reduced by over 10% and this shows the model and intelligent algorithm work well.

Abstract: Fixture Tolerance is one of the most important factors influencing the machined part accuracy. However caused by the manufacturing error and the assembly error of locator, the workpiece location error should not be neglected, which has led to fixture accuracy decay. A location error verification method is presented to improve the workpiece location accuracy. First, the origin of location error and the transfer process of error between locators and the workpiece are given. Second, random numbers and statistical analysis method are used to simulate locators’ errors. Finally, the location layout optimization model and the process are given. This method can be used to verify the location error and fixture design process.

Abstract: Target tracking algorithm mean-shift and kalman filter does well in tracking target. However, mean-shift algorithm may not do well in tracking the target which the size of target is changing gradually. Although some scholars put forward by 10% of the positive and negative incremental to scale adaptive,the algorithm can not be applied to track the target which gradually becomes bigger. In this paper, we propose registration corners of the target of the two adjacent frames, then calculate the distance ratio of registration corners.Use the distance ratio to determine the target becomes larger or smaller. The experimental results demonstrate that the proposed method performs better compared with the recent algorithms.

Abstract: In melt spinning process, evenness of polypropylene melt spun yarns affects the appearance, hairiness, strength and productivity of yarns, as well as product production and profits, causing rejection due to nonconformity. The research is to find optimal manufacturing parameters of melt spun yarns. Firstly, to proceed the parameter design by Taguchi method, then to select a manufacturing parameter which will affect the quality of melt spun yarns as controllable factors. Also to choose a suitable orthogonal arrays. Meanwhile, according to variation of analysis, to decide optimal manufacturing parameters of melt spun yarns and its remarkable factor. Finally, using 95% confidence interval to proof the experiment’s reliability and repeatability.

Abstract: MIMO-OFDM is one of the core technologies of 4G in the future, but the problem of high Peak—to—Average Power Ratio (PAPR) of LTE systems remains as one of the main obstacles that limit the application of OFDM. A method of space-frequency rotation and inversion has been proposed. According to the results of the Simulation, suppresses the smaller loss of PAPR performance, to improve the performance of LTE system.

Abstract: The finite element method was used to analyze the bubble in the ship wake. The single bubble model in the ship wake was created and studied after the material property parameters of the bubble were got by the finite element computation. The finite element model was then analyzed by SYSNOISE. From the analyzing, the displacement of the point on the surface of the bubble was gained when the sound press changing as the frequency varies; the distribution of the pressure was displayed when the frequency of the sound is equal to the resonant frequency of the bubble.

Abstract: Fully developed turbulence single phase convection heat transfer of water in pipes filled with sintered porous metal inner rings or solid inner rings was investigated numerically respectively. Numerical calculations were conducted with the Fluent 6.3 code, using the SST k-ω turbulence model. Comparing to solid-ring turbulator pipes, porous-ring turbulator pipes have better comprehensive heat transfer effect. The maximum PEC for porous-ring turbulator pipes is 4.4 and the PEC of solid-ring turbulator pipes is less than 1. It was also analyzed effect of geometric structures on porous-ring turbulator pipe performance. f/f₀ for porous-ring turbulator pipes increases with the increasing of Re while Nu/Nu₀ decreases with the increasing of Re ,and PEC decreases with the increasing of Re. With the same Re, if the width of the porous ring is equal to the width of groove, f/f₀, Nu/Nu₀ increases and PEC decreases with the increasing height of porous ring. When the height of porous ring is constant, the f/f₀, Nu/Nu₀ and PEC decreases with the increasing height of porous ring under the same Re.

Abstract: The machining parameter is very important for quality control in electrical discharge machining (EDM). This paper analysis the pit size in different electric parameter based on ANSYS, and then revises the simulation results according to the experiment test data. Taking advantage of numerical fitting methods to determine the relationship between electric parameters and machining quality. The experiments show the ratio of prediction to test for V_m , R_a , θ is 120.58%,108.18%,78.47% separately. The precision is higher and it can meet the need of the actual processing.