Journal of South China University of Technology(Natural Science Edition)

Design and Implementation of an Automatic Track and Recognition System of Human Faces

Xiao Nan- feng Zheng Yu

2004, 32(9): 1-5.

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An automatic track and recognition system of human faces with five freedom degrees was developed to rapidly and correctly recognize a person．In this systemthe skin-color model combined with the comparability degree and the face figure was adopted to detect and segment a human faceand the embedded hidden Markov model was ap-plied to the extraction and recognition of face characteristics．The experimental results indicate that the system can not only tracklocate and recognize a human face automaticallybut also confirm an identity on time by comparing the recognized images with those in the face database．The proposed system can be used to reconnoitre criminal cases and monitor the entrances of buildings．

Hopf Bifurcation and Design of PI Speed Controller in Induction Motors

Lu Yi- min Zhang Bo Mao Zong- yuan

2004, 32(9): 6-9.

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In the indirect -field oriented control （IFOC） system of induction motor with poor PI speed controller set -tingoscillation may occur due to the existence of Hopf bifurcation if the motor rotor resistance can not be exactly esti -mated．In this paperconditions of Hopf bifurcation happening were analyzed according to the Lyapunov stability theo-ryand principles for proper PI speed controller setting were deduced．Influence of d axis stator current reference on Hopf bifurcation was also discussed．The validity of the above analyses was finally proved by simulation results．The conditions of Hopf bifurcation happening can be used as the guidance for PI speed controller design for the purpose of improving the stability and reliability of IFOC system．

A Stability Criterion for Linear Neutral Delay Systems Based on Frequency Domain

Liu Xiu- xiang 　Xu Bu- gong

2004, 32(9): 10-12.

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Based on the frequency-domain techniques to analyze the stability of a systemthis paper deals with the sufficient conditions of the asymptotic stability of linear neutral delay systems．According to the characteristic equation of the systema new sufficient criterion expressed in terms of the modulus matrix and the spectral radius was then ob-tained by using the theory of matrix analysis．This criterions is more conservative than those expressed by the matrix measure and matrix norm．The corresponding numerical examples show that the obtained results are effective and more conservative than those in the literatures．

A Tree Role -based Access Control Strategy and Its Implementation

Zeng Ming Chen Li- ding

2004, 32(9): 13-16.

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For the enterprises characterized by high-coupling jobs and crossing businessesit is difficult to implement the administration of information system privilege by utilizing the traditional access control strategies based on user or role．In this paperaccording to the basic theory of the RBAC （Role-based Access Control）a mult- i layered TRBAC （Tree Role-based Access Control） model was presented and a role-based privilege administration scheme was imple-mented in the application layer．The practical example indicates that the TRBAC simplifies the configuration rules of userrole and permissionand makes the privilege management more convenient．

A Market Share Model Based on the Self-organized Fuzzy Neural Networks

Yin Gang Deng Fei- qi Ye Qi- ge

2004, 32(9): 17-22.

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Aiming at the unperfect forecast results obtained by the existing market share modelssuch as the tradition-al statistical methods and the fuzzy models or neural network models appeared in recent yearsa market share predict -ing model based on the self -organized fuzzy neural network was presented according to the fuzzy neural networks and the theory of self -organization．By using this modelpeople need not select any fuzzy logic in advanceand can adjust the network structure by the structure and parameter learning of the neural network．A simulation for the proposed model was finally carried out with an example．The results show that the proposed model is better than other existing modelsand is a powerful quantitative tool to analyze the market share for enterprises．

A New Fuzzy Clustering Algorithm of Categorical Data Set Based on the Kernel Method

Wu Zhong- dong Gao Xin- bo Xie Wei- xin

2004, 32(9): 23-28.

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Aiming at the clustering of the categorical data and by extending the kernel method to the fast efficient fuzzy c-means clustering algorithma fuzzy kernel c-means （FKCM） clustering algorithm based on the kernel func-tion was constructed．In this algorithmthe empirical kernel matrix is applied in order to fully utilize the dissimilarity information among the data．Unlike the fuzzy k-mode algorithmthe modes in the new algorithm need not be directly calculated in each iterationthus improving the precision and stability of the clustering algorithm and making the new algorithm insensitive to the selection of mode（centroid） initialization．A simulation was finally carried out on the actu-al linearly and nonlinearly separable categorical data setswhich demonstrates the effectiveness of the proposed algo-rithm．

Investigation and Implementation of a Web -based CAD/CAM System

Liu Wei- we Zhou Lai- shui Zhuang Hai- jun

2004, 32(9): 29-35.

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In order to set up a distributed support environment for design and manufacture processesa Web-based CAD／CAM system—WebSuperman was established by Browser／Server modein which the communication between the client and the server is implemented in Internet．The meaning and basic architecture of WebSuperman was then discussed．Some key technologies to implement the systemsuch as the graphic displaythe development strategy of geometry modeling and the data exchangewere also investigatedfollowed by some running instances．The system was finally tested in WAN and was proved wel- l running．

SMM Analysis of the Propagation Characteristics of One-dimension Inhomogeneous Anisotropic Media

Li Xue- chan Tian Li- bin

2004, 32(9): 36-40.

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A novel numerical technique for analyzing the propagation characteristics of one-dimension inhomogeneous anisotropic media was presented in this paper．In this techniquethe anisotropic medium is equivalent to the isotropic medium for circular polarized eigenwavesthus extending the scattering matrix method for one-dimension nonuniform isotropic media to the analysis of anisotropic media．The computer simulation results indicate that there is an excellent agreement between the results obtained by the new proposed method and by the approximate formulation．

Nonlinear Characteristics of the Multi -DOF Platform Driven by Pneumatic Artificial Muscle

Shi Guang- lin Zhou Ai- guo Zhong Ting- xiu

2004, 32(9): 41-45.

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An experimental system of the novel mult- i degree of freedom （Mult- i DOF） platform driven by pneumatic artificial muscle （PAM） was constructed in this paper．Based on the analysis of the kinematic property of the systema nonlinear dynamic model of the platform system was established in the form of a differential equation．Thenit was transformed into the state space with the style of an affine nonlinear model．Furthermoreby making a comparison between the numerical simulated and the experimental resultsthe correctness of the model was proved and the nonlinear characteristics of the system were obtained．It is concluded that the mult- i DOF platform driven by PAM is of excellent controllability and stability．

Formation Mechanism and Effecting Factors of the Gas Holes in the Al₂O₃ /Al Lanxide Composites

Zhou Xi- ya Gao Qin

2004, 32(9): 46-49.

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This paper puts forward the mechanism of the gas hole formation in the Al 2 O 3 /Al Lanxide composites formed by the direct oxidation of molten aluminum alloy based on the experiments.The effects of the processing tem-perature and the contents of doped elements Mg and Si in the parent alloy on the gas hole contents of Al 2 O 3 /Al Lanx-ide were also investigated .It is revealed that the gas hole contents in the Al 2 O 3 /Al Lanxide composites decrease with the increase in the processing temperaure and with the decrease in the Mg content in the parent alloy, and that the con-tent of Si in the parent alloy has little effect on the gas hole contents.

Microstructure and Properties of AZ31 Magnesium Alloy with ECAP

Liu Ying Chen Wei- ping Zhang Wei- wen Zhu Quan- li Zhao Hai- dong

2004, 32(9): 50-53.

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In order to further investigate the preparation and property of ultra-grained magnesium alloyAZ31magnesium alloy was prepared by means of equa- l channel angular pressing （ECAP） and B c route in the die with the intersecting angle φ＝120°．The microstructure and property of the processed material with different passes were then analyzed and tested．The results indicate thatwith the increase in the pressing passthe grains become finer and finer and the tensile behavior changes remarkablythat with 12 pressing passesthe total deformation strain of the alloy is about 8 and the grains are effectively refined to a mean size of 1～5μmand that the tensile strength of the alloy changes littlewhile the yield strength decreases to about100MPaand the ductility increases to more than45％．

Physicochemical Properties of MTGase -induced Biopolymers of Sodium Caseinate

Tang Chuan- he Yang Xiao- quan Cheng Zhong Peng Zhi- ying

2004, 32(9): 54-58.

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The polymerization process of sodium caseinates （SC） induced by microbial transglutaminse （MTGase）and some physicochemical properties of the new-forming biopolymers such as the relative molecular massthe viscosity and the heat stability were investigated．SDS-PAGE and GPC analyses showed that biopolymers with higher molecular mass can be produced after the polymerization of SC induced by MTGase．The relative molecular masses and their distributions of the biopolymers change with the incubation time with MTGase．Brabender analysis shows that the apparent viscosity of SC-biopolymer solution is2～4times that of SC solution with the same protein mass fraction．Heat -treat -ment experiment shows that the heat stability of SC-biopolymer solution is markedly higher than that of SC solution．DSC analysis indicates that the heat resistance of SC-biopolymers polymerized at different temperatures is variableand better heat resistance will be obtained at a highter temperature （50℃） rather than at37℃．

Isolation, Purification and Structure Analysis of Sweet Potato Glycoprotein

Li Ya- na Lin Yong- cheng She Zhi- gang

2004, 32(9): 59-62.

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By using DEAE-52 cellulose and Sephadex G100 column chromatographysweet potato glycoprotein （SPG） was isolated and purified from sweet potatoand its structure was analyzed including the determination of the purity and molecular mass of SPG by SDS-PAGEthe identification of the linkage mode of glycopeptide bond by β-erase reactionthe analysis of monose composition by GLCand the deduction of the linkage type of glycosidic bond by IR spectra．The results indicate that SPG is a kind of conjugated protein with covalent bondtakes on white solid powder and is easily dissolved in waterwith a molecular mass of62ku and an O-linkage．It is also indicated that there areβ-glycosidic bonds and typical amido-carbonyl groups in SPG containing12．01％ protein （mass fraction）and that SPG saccharide chain is composed of fucosearabinosemannoseglucose and galactose．

Emergy Analysis in Waste Disposal

Lou Bo

2004, 32(9): 63-66,71.

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Several common methods for waste disposal were analyzed by the emergy theory and the corresponding EIR （Emergy Investment Ratio） and EYR （Emergy Yield Ratio） were calculated．The results indicate that the EYR of the electric power generation from waste landfill gas and from the combustion of waste is slightly greater than1while the EYR from composting is less than1．Although the former is a little promisingthe EYR is still low．This is why the application of these methods needs the support from government and the application of new technologies in our country at present．The latterdespite relatively low EYRwas used for waste disposal in the pastand is still used at the pre-sent time due to the low EIR．

Numerical Simulation of the Thermodynamic Process of Air Flow on Fin Surfaces in Heat Exchangers

Jian Qi- fei Gan Qing- jun Xu Shi- song

2004, 32(9): 67-71.

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In order to reduce the blindness and complexity of designing heat exchanger finsthe air flow and heat transfer process on the surface of double／cross-row corrugated fin were simulated by the software of FLUENT．On the basis of the reasonable predigestion of the physical model of heat transfer and by using the standard k-εmodel and the SIMPLE arithmetic of velocity-pressure couplingsome typical contour charts describing the surface temperature distribution and heat exchange coefficient of the fin were obtainedand so were the vector charts of the air velocity on the fin surface and the relevant calculated data．The influence of the air velocity in the inlet on the surface temperaturethe air flowthe heat exchange coefficientthe heat exchange quantity and the airflow resistance of the fin was also analyzed．It is concluded that the increasing of the air velocity in the inlet will improve the heat exchange ability of the finand increase the energy consumption of the systemwhich proves the necessity of the optimization of the system performance for setting the air velocity in the inlet．

An Artificial Neural Network Method to Evaluate Bridge Damage Conditions

Han Da- jian Yang Bing- yao Yan Quan- sheng

2004, 32(9): 72-75,96.

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In view of the weakness of existing bridge evaluation methodsa neural network method was first intro-duced to evaluate the damage conditions of a bridge．The evaluation effects of several common artificial neural network （ANN） models were then compared．The ANN models were finally trained and tested based on the maintenance data of1018bridges on the nationa- l grade roads in Guangdong．It is found that the neural network method is effective in e-valuating the bridge conditionsmore than60％ of the bridge grade being correctly evaluated and the average evaluation error of each bridge being0．25grades．

Analyses of the Dynamic Characteristics of Large-scale Aqueduct-water Coupling Systems

Wu Yi Mo Hai- hong Yang Chun

2004, 32(9): 76-81.

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Based on beam-type aqueduct structuresthe arbitrary Lagrangian-Eulerian （ALE） method was used to study the dynamic characteristics of large-scale rectangular and U-shaped aqueduct -water coupling systems．The vibra-tion reactions of the aqueduct structures with different water levels to the harmonic excitation and earthquake action were then investigatedas well as the action of water to the aqueduct．The results indicate that the sloshing of water in the aqueduct is remarkably nonlinearand that the sloshing action is very remarkable under certain external excitation．Meanwhilethe hydraulic pressure aroused by water sloshing will change the stress distribution in the aqueduct struc-turewithout losing the transverse stability of the aqueduct structure if the ratio of depth to width of the aqueduct cross section is reasonable．By making a comparison of dynamic characteristicsit is found that the sloshing action of waterin the U-shaped aqueduct is commonly more significant than that in the rectangular aqueductwhich greatly affects the behaviors of high frame-supported aqueduct structures to which great attention should be paid in the aseismic design of aqueduct structures．

Inspection of Pavement Structural Defects Based on the Ground Penetrating Radar

Ye Jia- wei Wu Peng Zheng Guo- liang

2004, 32(9): 82-85.

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In order to improve the adaptability of the Ground Penetrating Radar （GPR） to actual inspected objects and the efficiency of inspecting the pavement structural defectsa software system of the data transformation and image recognition of GPR was developed by using Borland C＋＋ Builder6．0．The comparison between the proposed system and the original GPR software kit—the IRIS-L proves that the methods of data transformation and signal processing／identification applied to the developed system are correctand that the proposed system is of an additional function of pavement defect identification and can improve the veracity of pavement quality inspection as well as the efficiency of structural defect identification．

Connection index ^mZ of the Valence Electron Orbit Energy and Its Application

Xu Shi- you

2004, 32(9): 86-89.

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In order to investigate the intrinsic relationship between the physicochemical property and the structure ofinorganic materialsa new topological indexmZ of the valence electron orbit energy was proposed．This index was con-structed by the formation of point valence value which consisted of the valence electron orbit energy E i of the atom and the outermost effective main quantum number of atom n ∗i ．The corresponding0-and1-rank indexes of m Z were then respectively fitted with the pKa 1 values of inorganic hydridesthe lattice energy Uformation enthalpyΔ f Hθm and hy-drated energyΔ f Gθm of20kinds of alkali halidesand the internuclear distance R 0 of the gaseous alkali halidesThe re-lated coefficients（re-related coefficients） of the corresponding regression equations are respectively0．9962（0．9966）0．9966（0．9981）0．9769（0．9830）0．9768（0．9798） and0．9963（0．9963）the obtained results being better than those reported in the former literatures.

Optimum Control Relations of the Entrustment-agent System

Luo Wen- biao Yang Lun- biao

2004, 32(9): 90-92.

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In this paperthe optimum fuzzy implicative algorithm was firstly adopted to investigate the entrustment -a-gent relations among all administrative levels within a corporationwith a conclusion that these entrustment -agent rela-tions are all the fuzzy control relations．The properties of the optimum control action and reactionas well as the trans-fer relations among all administrative levels were then deduced by means of the optimum implicative algorithm．The logical operations of the optimum implication relations for the union and the intersection were finally proved．It is con-cluded that the fuzzy mathematical method is a good method to quantitatively analyze the entrustment -agent relations a-mong all administrative levels in a corporation．

Prediction of the Viscosity of Mixed Rubber in Mixer Based on SVM

Hu Rong Wang Guo- qiang Liao Qin

2004, 32(9): 93-96.

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In order to improve the usability and precision of the model for predicting the viscosity of mixed rubber in mixera new predicting model using the nonlinear regression algorithm of Support Vector Machine （SVM） was pro-posed based on a single-mixer model and the prediction of the measured data was then carried out by the proposed model．The results show that the new model not only simplifies the establishing process of the predicting model but al -so improves the precision and speed of prediction．It is also shown thatcompared with the results obtained by mult- iregressionthe new model is more accurate and effective when applied to predict the on-line quality indexes of the mixed rubber．

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