作者机构：
[上官文斌; 贺良勇; 黄志] School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, China;[上官文斌; 段小成] Ningbo Tuopu Vibro-Acoustics Co. Ltd., Ningbo 315806, China
通讯机构：
School of Mechanical and Automotive Engineering, South China University of Technology, China
会议名称：
The Second International Joint Conference on Computational Science and Optimization(CSO 2009)(2009 国际计算科学与优化会议)
会议时间：
2009-04-24
会议地点：
三亚
会议论文集名称：
The Second International Joint Conference on Computational Science and Optimization(CSO 2009)(2009 国际计算科学与优化会议)论文集
摘要：
The numerical simulation model of mechanical oil expression from vegetable oil was developed. It was solved by using of combining finite difference with finite element. The displacement experiment for extracted sesame was used to validate the model. As an applied example, the predictions of pore-fluid pressure dissipation and distribution were carried out. The predicted values of displacement conformed to the measured values well. The pore-fluid pressure decreased with increasing pressing time. The pore-fluid pressure dissipation for the case of double surface seepage was faster than for the case of single surface under the same pressing pressure. The pore-fluid pressure distribution would become uniform with pressing time, and become nonuniform with pressing pressure. And the pore-fluid pressure distributions for the case of double surface seepage were generally more uniform than for the case of single surface.
关键词：
nonlinear systems;fault diagnosis;differential elimination;algebraic observability and diagnosability
摘要：
The differential elimination algorithm is used to eliminate the non-observed variables of the nonlinear systems. By incorporating the algebraic observability and diagnosability concepts and using numerical differentiation algorithms, another approach to the certain classes of nonlinear systems fault diagnosis problem is presented.
关键词：
uncertain structural system;semidefinite programming;linear fractional representation;finite element method
摘要：
A semidefinite programming (SDP) approach is presented to estimate bounds on static responses of structural systems with uncertain material and geometric parameters that are described as interval numbers. Under the constraint of static governing equations of the structural system, an ellipsoid of minimal size in the sense that minimizes the sum of squares of semi-axis lengths is sought to contain the exact solution set of the displacement responses. The computation is formulated as a (convex) SDP problem based on the results from semidefinite relaxation techniques, which can be solved very efficiently using interior-point algorithms. The approach presented here considers the modeling of the structural stiffness matrix containing uncertain structural parameters using linear fractional representation (LFR). We present a procedure to formulate the LFR of the structural stiffness matrix, combining with the finite-element method. It is shown by numerical examples that the approach can give reasonable estimates on the solution intervals, and tends to overestimate the bounds of some response quantities with the increasing number of the uncertain parameters. Using an interval-truncation procedure, more accurate results can be obtained. Keywords: uncertain structural system, semidefinite programming, linear fractional representation, finite element method.
关键词：
signals separation;adaptive line enhancer;colored noise;fault diagnosis
摘要：
The rub failures between rotating and stationary parts in rotating machinery may contribute to vibration signals measured on the machine as the colored noise component. But, for the colored noise mixed in vibration signals, ordinary FFT or autoregressive (AR) spectrum analysis methods can't provide sufficient and reasonable spectra estimates. In this paper, we exploited Adaptive Line Enhancer (ALE) technique to separate the colored noise from vibration signals in the time domain. The capability of the technique was evaluated using Simulink for some simulated vibration signals composed of three sinusoids and an additive colored noise. The results show that the technique is capable of separating accurately colored noise even at a lower level of colored noise, and tracking the level variation of colored noise in simulated signals. Further experimental tests for actual complex vibration signals will be conducted to validate the technique.
会议名称：
The Second International Joint Conference on Computational Science and Optimization(CSO 2009)(2009 国际计算科学与优化会议)
会议时间：
2009-04-24
会议地点：
三亚
会议论文集名称：
The Second International Joint Conference on Computational Science and Optimization(CSO 2009)(2009 国际计算科学与优化会议)论文集
摘要：
The microstructures of peanut cake under five applied pressures were measured using stereo light microscope and Image-pro software. Fractal dimensions of pore section border and pore size distribution were measured and calculated by the slit island process. Regression method was used to analyse the correlation between the fractal dimension and applied pressure. Results showed that the fractal characteristic of pore structure in peanut cake was obvious, and its fractal dimension values decreased significantly with increasing applied pressure.
作者机构：
[宋少云] Machine Engineering Department, Wuhan Polytechnic University, Wuhan 430023, China;[李世其] College of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
通讯机构：
Machine Engineering Department, Wuhan Polytechnic University, China
作者机构：
[王继焕] School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, China;[刘启觉] School of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China
通讯机构：
School of Mechanical Engineering, Wuhan Polytechnic University, China
