Volume 32,Issue 7,2009 Table of Contents

1 Modeling and simulation based on open electrical impedance tomography

CHEN Minyou , ZHANG Xiaoju , LUO Ciyong , HE Wei

2009, 32(7):731-735. DOI: 10.11835/j.issn.1000-582X.2009.07.001

[Abstract](1909) [HTML](0) [PDF 6.14 M](429)

Abstract:
In order to improve the error in image reconstruction caused by changeable positions of the electrodes in closed electrical impedance tomography, we propose an open electrical impedance tomography (OEIT) model using fixed electrode array. The problem was approximately assumed to be a virtual field by defining certain local sensitive area instead of solving the boundary problem in the whole electromagnetic field strictly. Modeling and simulation of OEIT have been conducted to define reasonable boundary parameters and electrode array structure. The finite element method is used for forward computation while Newton onestep error reconstructor is used for image reconstruction. The target position, area and conductivity change can be reflected by the relative change of the boundary voltage and the reconstructed image is clear. Better resolution and positioning accuracy can be obtained in the shallower surface of the body by OEIT, so it is valuable in clinical applications.

2 Impacts of natural ventilation on indoor thermal environment for residential housing

LI Nan , LI Baizhan , SHENG Yan , YU Wei , DING Yong

2009, 32(7):736-742. DOI: 10.11835/j.issn.1000-582X.2009.07.002

[Abstract](2302) [HTML](0) [PDF 7.66 M](517)

Abstract:
A typical residential housing in Chongqing is taken as an example, which is with worse natural climate conditions and absent of wind resource. A feasibility study on improving the thermal environment by natural ventilation is analyzed based on the id chart. By the onsite tests，the indoor thermal comfort is evaluated based on the PMVPPD methodology. Better natural ventilation can not only save the building energy consumption, but also improve indoor thermal environment, especially in the rain and transition seasons, even in the urban area with poor wind resource.

3 Elastic deformable particle model in discrete element method

WEN Tong , LEI Jie , PEI Chunlei

2009, 32(7):743-746. DOI: 10.11835/j.issn.1000-582X.2009.07.003

[Abstract](2765) [HTML](0) [PDF 3.69 M](401)

Abstract:
A polygon particle model with discrete element method（DEM） is developed based on the Hooke’s law, in which the geometry change caused by the elastic deformation and features of material can be taken into account. A DEM programme is developed based on the proposed model and collision processes of elastic particles is studied with finite element method(FEM) and DEM. Comparing the result of DEM with that of FEM. When dealing with the problem of particles contact, the real deformation and the contact force variation of the particles can be presented more accurately with elastic deformable particle model, compared with that from traditional rigid particle model.

4 Sky luminance distribution model by ant colony systems

HE Ying , LIN Yong , WENG Ji

2009, 32(7):747-751. DOI: 10.11835/j.issn.1000-582X.2009.07.004

[Abstract](2425) [HTML](0) [PDF 4.89 M](400)

Abstract:
The sky luminance distribution model is developed by information analysis methods with ant colony system. A new arithmetic is given to solve complex optimization heuristic algorithm. The coefficient values of sky luminance distribution function are obtained by optimization analysis with ant colony system and on which a set of practical software is developed. It can provide an intuitive and easy calculation. The model has higher precision, which can provide valuable results on highprecision and standard daylighting design.

5 Multiclass obstacles recognition for intelligent vehicle in urban traffic scenes

YANG Xin , SHEN Zhixi , HUANG Xiyue , ZHAN Jianping

2009, 32(7):752-756. DOI: 10.11835/j.issn.1000-582X.2009.07.005

[Abstract](2551) [HTML](0) [PDF 11.35 M](494)

Abstract:
For multiclass obstacles recognition for intelligent vehicle in urban traffic scenes, an improved Binary Tree Support Vector Machine (BTSVM) based on ensemble learning is presented. Based on the distributing probability and pattern diversity of each obstacle in urban traffic scenes, a compatible tree structure of BTSVM is designed. An approach based on AdaBoost ensemble learning is applied to reduce the transfer error and improve the accuracy and generalization ability of pernode classifier. The proposed method can efficiently recognize 6 kinds of normal obstacle patterns in urban traffic scenes.

6 Simulation analysis on braking system of hybrid vehicle with ISG

YANG Yang , LIU Song , QIN Datong , HUANG Xiaorong

2009, 32(7):757-761. DOI: 10.11835/j.issn.1000-582X.2009.07.006

[Abstract](2009) [HTML](0) [PDF 5.34 M](458)

Abstract:
A hydraulic braking system of the hybrid vehicle is designed based on braking force distribution and brake pressure coordination control strategy of integrated startor and generator(ISG) hybrid electric vehicle(HEV). Simulation model of hydraulic braking system has been established using AMESim software platform. Dynamic performance simulation and analysis to the key components and systems are performed. The results verify the correctness and feasibility of system program and provide evidence for designing and optimizing of HEV braking system.

7 Contact analysis of MW wind turbine hub and bearing bolt connection

HE Yulin , ZHANG Ligang , HAN Dehai , DU Jing

2009, 32(7):762-765. DOI: 10.11835/j.issn.1000-582X.2009.07.007

[Abstract](2063) [HTML](0) [PDF 12.49 M](409)

Abstract:
Using large finite element software MSC.Marc/Mentat, the contact analysis of bolted joints parts between the hub and the bearing of wind turbine is conducted for the contact stress suffering from the practical work load. The maximum stress acted on the bolt is obtained, and a detail contact analysis for this bolted joints parts is given. The accurate stress of bolts, bearing and hub is calculated. The FEA contact results are consistent with the theoretical calculation results, and the strength of materials meets the requirements, which means the structure is safe.

8 Simulation and verification experiment of thepneumatic brake LSPV based on AMESim

LI Yinong , WANG Yibao , LUO Zhiqian , WANG Jian , LI Hongjun

2009, 32(7):766-769. DOI: 10.11835/j.issn.1000-582X.2009.07.008

[Abstract](2905) [HTML](0) [PDF 10.13 M](506)

Abstract:
Based on the analysis of dynamics method of pneumatic transmission, the mathematic model of air brake Load Sensing Proportional Valve (LSPV) is established by fluid servo control theory. The air brake LSPV of one All Terrain Vehicle (ATV) is simulated with the platform of advanced modeling ervironment for performing simulations of engineering system(AMESim), then the input and output pressure characteristic curve of the valves are obtained. The characteristic curve shows, with the load increasing, the pressure adjustment point of Load Sensing Proportional Valve (LSPV) moves up. When the pressure reaches into the pressure adjustment point, the increase rate of output pressure is less than the increase rate of input pressure, so that it can effectively prevent the lockup of the rear wheel precede the front wheel. The result of the simulation is consistent with the experiment result. The validity of the model is verified, which provide foundation for the simulation of the air brake elements and brake system.

9 Gender recognition of speakers based on MFCC and SVM

XIAO Hanguang , HE Wei

2009, 32(7):770-774. DOI: 10.11835/j.issn.1000-582X.2009.07.009

[Abstract](2181) [HTML](0) [PDF 6.58 M](1794)

Abstract:
A Chinese speech (mandarin) database was established for speakers gender recognition. A combination method is proposed for gender recognition of speakers based on support vector machine and Melfrequency cepstrum coefficients (MFCC) for classification and feature extraction respectively. The comparative result shows that the accuracy of SVM is 98.7%, which is better than other methods.

10 Design of data acquisition and communication system for AMTcomprehensive performance testbench

LIU Zhenjun , HU Jianjun , WEN Shao , ZHANG Zhilong

2009, 32(7):775-781. DOI: 10.11835/j.issn.1000-582X.2009.07.010

[Abstract](1620) [HTML](0) [PDF 14.81 M](1187)

Abstract:
AMT (Automatic Manual Transmission) comprehensive performance test is one of the main means to develop and evaluate AMT. An overall scheme of the data acquisition and communication system for AMT comprehensive performance testbench is proposed according to the requirement of the testbench, and a communication network of data acquisition and communication system is built. The hardware and software of data acquisition system are designed. The experiments show that the system meets the requirement of data acquisition and communication system for AMT comprehensive performance testbench and it lays a foundation for AMT comprehensive test research.

11 Channel estimation for MBOFDM UWB system based on tap detecting

LIU Yulin , ZHANG Xianyu , LUO Yingguang

2009, 32(7):782-786. DOI: 10.11835/j.issn.1000-582X.2009.07.011

[Abstract](1848) [HTML](0) [PDF 8.75 M](1237)

Abstract:
A novel channel estimation algorithm is proposed for MBOFDM Ultra WideBand systems based on tap detecting by exploiting the sparse property of channel impulse response. The channel parameters are estimated using the DFT algorithm based on cyclic convolution property of the receive signals. The nonzero taps are detected by exploiting the matching pursuit(MP) algorithm. The new estimated channel parameters are obtained by forcing the zero taps to zeros. Simulation results demonstrate that it has better MSE (mean square error) performance for the four channels proposed by IEEE. Especially for CM1 and CM2 channels, the performance of the algorithm has been greatly improved.

12 Numerical method for galloping of icing twin bundle conductors

YAN Bo , LI Wenyun , ZHANG Hongyan , ZHOU Song

2009, 32(7):787-792. DOI: 10.11835/j.issn.1000-582X.2009.07.012

[Abstract](1981) [HTML](0) [PDF 6.57 M](1472)

Abstract:
The dynamic balance equation of the system is set up by means of the Hamilton variational principles with the constraint conditions of the clamp points of spacers in the subconductors by the penalty function. The numerical simulation for galloping of twin bundle conductors is achieved with the time integral by Newmark method and the NewtonRaphson iteration solution for nonlinear equation. The validity is approved with simulation for the galloping of horizontal and vertical icing twin bundle conductor. The difference of aerodynamic loads, which is due to the impacts of wake flow of windward subconductor on lee subconductor, on the individual subconductors can be considered with the proposed approach. It is appropriate for further study in the field of bundle conductor galloping.

13 Application of GCFTIR technology in the analysis of SF6 decomposition products

YAO Qiang , CHANG Tao , LIU Yong , QIU Ni , ZHANG Xiaoxing

2009, 32(7):793-797. DOI: 10.11835/j.issn.1000-582X.2009.07.013

[Abstract](1751) [HTML](0) [PDF 6.58 M](1344)

Abstract:
The composition of SF6 decomposition products is directly associated with the safe operation of equipment. Through GCFTIR coupling technique,the SF6 decomposition products are divided, the qualitative analysis is made with FTIR to the outlier,and spectrogram was processed with subtract and searched the analogous one. Above data is used to generate the tridimensional atlas of infrared spectrumabsorbanceGC holding time. Single gas analysis is compared with local measurement, the foregoing method can make the qualitative analysis and quantitative analysis for the decomposition products, the fault features detected by gas composition and chroma is anastomotic with the actual fault, the result indicates that this method can be used in GIS fault diagnosis.

14 Curve fitting of main section for subsidence basin by observing data

CAO Shugang , LIU Yucheng , LIU Yanbao , LI Yong , WANG Jun

2009, 32(7):798-803. DOI: 10.11835/j.issn.1000-582X.2009.07.014

[Abstract](1945) [HTML](0) [PDF 4.30 M](1029)

Abstract:
The existing section function for mining subsidence prediction has several shortcomings, such as complex expression, uncertainty of coordinates origin and parameters in application. The features of observing data in the ground subsidence of rectangular goaf are studied and a new fit function of main section is proposed for mining subsidence prediction.This new function has some merit that the mathematical formula is simple and the parameter is also easy to identify in practices. It is proved that the results of this new function is fit well with onsite survey .

15 Natural convection heat transfer in the airlayer of insulating glass

WANG Houhua , HUANG Chunyong

2009, 32(7):804-808. DOI: 10.11835/j.issn.1000-582X.2009.07.015

[Abstract](2672) [HTML](0) [PDF 5.37 M](2025)

Abstract:
The numerical simulation with FLUENT software is addressed for the natural convection heat transfer under the conditions of different airlayer thickness with 6 mm,9 mm,12 mm,14 mm and 16 mm. The heat transfer rate is compared with that by heat conduction. Gas types, Rayleigh number (Ra),the relative thickness of airlayer,δ/H,and the surface (ΔT) are main factors for natural convection heat transfer. The natural convection heat transfer could be approximately regarded as the pure heat conduction in the conditions of above airlayer thickness. The heat transfer coefficient of the insulating glass with simulation is approximate to that with empirical calculation.

16 Experimental study on eccentric compression behaviour of autoclaved flyashlime brick masonry

QIN Shihong , CAO Huanming , NI Xiaojun , LUO Wankang

2009, 32(7):809-814. DOI: 10.11835/j.issn.1000-582X.2009.07.016

[Abstract](2413) [HTML](0) [PDF 7.78 M](1170)

Abstract:
To study the eccentric compression performance of autoclaved flyashlime brick masonry, and validate the applicability of current code’s calculation method, static tests on 36 eccentrically loaded puncheons of standard autoclaved flyashlime solid brick and KP1 type perforated brick with circular holes masonry are carried out by applying eccentric load on the top of the specimens. The bearing capacity of eccentric compression is analyzed using planesection assumption and ideal stress/strain curve. The features and shapes during the process of failure are obtained and the eccentric compression impact factor formula is also obtained by regression analysis of experimental data. With eccentricity increasing, cracking load and failure load are gradually decreased, and the failure features gradually change into large eccentric compression from axial compression. Most test values of bearing capacity under eccentric compression are higher than code calculating values. The average strain distribution in the section is in accordance with the planesection assumption. The theoretical analysis method used is feasible, current code’s formula can be used to calculate the bearing capacity of flyashlime brick masonry under eccentric compression.

17 Stratification transfer model for predicting complex mining subsidence

REN Song , JIANG Deyi , YANG Chunhe

2009, 32(7):815-822. DOI: 10.11835/j.issn.1000-582X.2009.07.017

[Abstract](1744) [HTML](0) [PDF 6.06 M](1338)

Abstract:
Based on the new probability integral 3D model for forecasting the solution mining subsidence, the transfer rule of superincumbent strata in mining subsidence is studied and a prediction model of stratification transfer for mining subsidence is developed. The model can take into account of the impacts of features of different rock strata on mining subsidence and improve prediction precision of irregular goaf. Based on the situation that it’s hard to get the analytical solution of the model with triple integral, the numerical algorithm of the model is supplied. With the superposition principle theory, a prediction model of multicavern mining subsidence is developed. With the application in ground subsidence prediction of oilgas storage in Jintan, it proves that the transfer prediction model holds higher precision than those of traditional models

18 Energy delivery model for implanted devices

TANG Zhide , XIE Di , FENG Lixiao , WU Mingpeng

2009, 32(7):823-828. DOI: 10.11835/j.issn.1000-582X.2009.07.018

[Abstract](1528) [HTML](0) [PDF 5.99 M](1501)

Abstract:
FEMlab3.3(Finite Element Model Lab) is used to develop an energy delivery model for implanted devices. We designed three different shape electrodes made of Ag to enhance current transmitting efficiency. Several voltages were used for pursuing perfect goal. With the body safety current, we can get the results with a current transmitting efficiency of 20% and the energy delivery efficiency of 4%~9%. It is clear that the high energy delivery efficiency can be obtained and the results provide references for further study of energy delivery through body conduction.

19 Effects of cover displacement functions for the stiffness matrixof the numerical manifold method

DENG Anfu , ZHENG Bing , ZHOU Xiaoyi

2009, 32(7):829-833. DOI: 10.11835/j.issn.1000-582X.2009.07.019

[Abstract](1739) [HTML](0) [PDF 3.86 M](343)

Abstract:
Based on basic theory of numerical manifold method, effects of cover displacement functions for the stiffness matrix is analyzed with the relationship between the cover displacement function and the formation of the stiffness matrix. The increasing speed of matrix element value has relation to the values of absolute coordinates in cover displacement function. An improved function is adopted for better solution to solve partial oversize problem of stiffness values in the stiffness matrix with the highorder cover displacement function. The validity of the proposed approach is approved with case study.

20 Measurement methodology of color reflectionperformance of building facing materials

YANG Chunyu , CHEN Yonggan , ZHANG Qingwen

2009, 32(7):834-838. DOI: 10.11835/j.issn.1000-582X.2009.07.020

[Abstract](1903) [HTML](0) [PDF 4.37 M](370)

Abstract:
With the measurement of reflection spectrum and the experimental measurement of illumination observing angle, color temperature of light source, effects of field viewing angles, it is found that the color of facing materials have relation to light incidence and observing angle. The chroma number varies with the changing of light incidence and observing angle based on the features of facing materials. The chroma number has more fluctuation with the angle close to mirror reflection direction while it is more steady with other angles. Besides, the mirror reflection phenomenon is not obvious for subbrightness facing tile. The color temperature of light source affects material color and the chroma number varies with the incidence changing, etc. All of these have provided fundamental for quantitative study of architecture color design.

21 Lighting quality indicators with space sense for urban lighting environment

CHEN Zhonglin , MA Yulin , HU Yingkui

2009, 32(7):839-843. DOI: 10.11835/j.issn.1000-582X.2009.07.021

[Abstract](2214) [HTML](0) [PDF 4.33 M](312)

Abstract:
In order to find out a space sense indicator that can present the real appearance of human and natural in urban lighting environment, three common used indicators are studied, which are ratio of vertical illuminance to semicylindrical illuminance, ratio of vertical illuminance to horizontal illuminance and ratio of average cylindrical illuminance to horizontal illuminance.An onsite test is taken at Three Gorges Square Pedestrian Street of Chongqing. The variation law of ratio of vertical illuminance to horizontal illuminance is approximate to ratio of average cylindrical illuminance to horizontal illuminance, which varies with the changing of measure point location and reach maximum at the axial central section of pedestrian street between two streetlamps. The change of ratio of vertical illuminance to semicylindrical illuminance is small correspondingly and it is more appropriate to be as a lighting quality indicator with space sense for urban illuminance environment.

22 Application of soft sensor in the online measurement of theiron ore’s surface temperature

LI Shaoming , ZHANG Jiayan , XIE Fuchun , JI Ping

2009, 32(7):844-847. DOI: 10.11835/j.issn.1000-582X.2009.07.022

[Abstract](1946) [HTML](0) [PDF 3.11 M](325)

Abstract:
It is difficult to measure the surface temperature of iron ore directly. A method is put forward to handle this problem by using softsensing technique. This online measurement method is used to replace the Lagrange interpolation offline method to estimate surface temperature. The method used LM optimum algorithm to build up ANN soft sensor model combined with offline learning neural network to establish the correlation between input variables and target variables, to achieve the surface temperature on line detection. The results of simulation and experimentation indicate that the method is reasonable and feasible.

23 Information systems planning model and its applicationin automobile manufacturing enterprises

SONG Yuchuan , MA Zhihua , WANG Yongjing , JIANG Linghui

2009, 32(7):848-853. DOI: 10.11835/j.issn.1000-582X.2009.07.023

[Abstract](2500) [HTML](0) [PDF 4.71 M](472)

Abstract:
Effective information strategy and information systems are important for the development of automobile manufacturing enterprises. In complicated and dynamic business environment, information systems planning (ISP) faces the problem of lacking integrated optimization of enterprise strategy, business strategy, and IT strategy. A hierarchical information system planning model is developed for automobile manufacturing enterprises. A planning approach is proposed to make the information system continuously mating the enterprises' strategy. The proposed studies were applied to agile ISP of an automobile manufacturing enterprise with satisfied result.

24 Synthesis and characterization of a new pHsensitive hydrogel

LUO Yanfeng , QU Sheng , SUN Jiaoxia , WANG Yuanliang

2009, 32(7):854-858. DOI: 10.11835/j.issn.1000-582X.2009.07.024

[Abstract](1804) [HTML](0) [PDF 3.83 M](390)

Abstract:
A novel pHsensitive degradable hydrogel based on ethylenediaminetetraacetic dianhydride (EDTAD) was synthesized.EDTAD reacted with butanediamine through Nacylation ringopening polymerization of anhydride groups to give a linear copolymer (pEDTADBDA) with carboxyl groups on its side chains and amide groups on its backbone. pEDTABDA was dehydrated between those carboxyl groups on its side chains and amide groups on its backbone at 160℃ with phosphoric acid as a catalyst. A copolymer was produced containing imide groups (pEDTADBDAImide). pEDTADBDAImide was crosslinked by BDA via Nacylation of the imide groups, yielding the desired network polymer with pendant amino groups (BDAcrosslinkedEDTADBDA). BDAcrosslinkedEDTADBDA is a promising hydrogel for drug controlled release integrating such advantages as degradability, good biocompatibility and pHsensitivity. FTIR and ninhydrin reaction are employed to qualitatively and quantitatively characterize pEDTADBDA and BDAcrosslinkedEDTADBDA.

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