西南交通大学学报

M echanism and ExperimentalFormation ofW heel/RailCorrugation

ZHANG Li-min　ZHANG Wei-hua

2005, 18(4): 435-439.

[Abstract](1492)

Abstract:
The relationship betweenwheel/rail(W /R) corrugation and thewavelength of longitudinal self-vibration and the longitudinal axis of contactellipsewas analyzed based on the nonlinear vibration and Hertzian theories. The analysis shows that the mechanism of W /R corrugation is that the wavelength of longitudinal self-vibration is larger than the longitudinal axis ofcontactellipse; for a real W /R system, the criterion is that the lateral displacement of the wheelset is larger than a critical value. Numerical simulation and testwere conducted to verify the proposedmechanism and criterion. The simulation results show thatcorrugationswith lengthsbetween 16 to20mm appearwhen the lateral displacementof thewheelset is 8 mm. Corrugation testwas conducted on a rolling vibration test rig. Corrugations form when the lateraldisplacements of thewheelsetare 8 and 11mm, and the lengths are about20 mm and 18 to 27 mm, respectively, under the former and the latter conditions. There is no obvious corrugationwhen the lateral displacement is 6 mm.

Performance Test on H igh-PressureW ater AxialPiston Pump

DEN Bin, WANG Jin-nuo, WANG Guo-zhi, YULan-ying

2005, 18(4): 440-443.

[Abstract](1275)

Abstract:
A test rig forhigh-pressurewaterdriven systemswas developed tomeet the requirements of the performance test on water pumps, motors and valves, as well as synchronized tests on water cylinders. A high-pressurewateraxialpiston pumpwith an outputcapacity of25. 3mL/minwas tested on the test rig. The test result shows that the response time of the pump is 1. 1 ms, but its volumetric efficiency decreases obviously with an increase in pressure at speed less than 1 000 r/min. It is concluded that reducing leakage is one of the key issues to improve the performances ofhigh-pressure water pumps.

Direct Path Planning for Visual Servo Robot

ZHANGHai-bo, QIANQing-quan, XUGang, SUN Jian-guo

2005, 18(4): 444-448.

[Abstract](1681)

Abstract:
The Jacobin matrix for images of a GRB-400 visual servo robotwas derived. A control algorithm was designed to achieve a stable control strategy for dynamic double-loop feedback motion controlof the visualservo robo.t A directplanarpath planningmethod for the robotwasproposed based on the combination of steepest descentmethod and punishment function method to solve the least- energy costpath planning problem with time constrain.t Simulation and experiment results show that the robotcan determine an optimalpath by applying the proposedmethodwheneverobjects orobstacles arewithin the visual scope of the robot.

Influences ofLocomotive Dynam ic Brake on Brake Operation and Lim iting Grade

CHENQing, WANG Zi-li

2005, 18(4): 448-452.

[Abstract](1495)

Abstract:
Brake processes were analyzed under different locomotives, trains, brake operation procedures, and limiting grades. W ith application ofdynamic brake, release times increase from 110 s to 172 and 234 s for trains hauled by aDF8B or an SS7 locomotive, respectively, at a down slope of 12‰grade, and from 68 s to 138 and 225 s for trains hauled by double DF8B or double SS7 locomotives, respectively, at a down slope of 18‰grade. Combining air and dynamic brake also decreases the times ofairbrakes and the temperature raise on the thread surfaces, which increases the safety of trains and relaxes the constrainton limiting grades in railway design.

Dynam ic Stability of a ShapeM emory Alloy Beam

LIYing-hui, ZHANQing-quan

2005, 18(4): 453-456.

[Abstract](1423)

Abstract:
A nonlinear dynamicsmodelwas derived based on the constitutive equations of the thermo- mechanical and pseudoelastic behaviors of shape memory alloy (SMA) and the dynamic equilibrium equations of an SMA beam. The analytic results show that the transverse vibration stability of the beam corresponds to the equilibriums of the phase transformations. At lower temperaturewheremartensite is stable, there are three fixed points: one representing stable center and the other two describing unstable saddle points. At themiddle temperature where bothmartensite and austenite coexis,t there are five fixed points: three representing stable centers and the other two describing unstable saddle points. Athigh temperaturewhere austenite is the exclusive stable phase, there is only one fixed point representing a stable cent

Optim ization ofCutting Path Based on Genetic Algorithm

GAO Wei-zeng, ZHANG Bao-jian, CHEN Fu-gui, ZHU Jia-yi

2005, 18(4): 457-461.

[Abstract](1709)

Abstract:
Genetic algorithm was applied to optimize cutting path. Aimed at the optimization objective,i. e., a processing path should include every outline in each part and has the shortest distance, a nondeterministic polynomial cost function was designed and simplified to the optimization among points. In addition, a genetic encodingwas given, and nesting parts including 75 partswere simulated numerically. The simulation results show thatthe optimal length 37 129mm ofcutting path is 85% of the original length 43 622 mm so as to prove the validity of the proposed algorithm.

Load-Deformation Relation ofPrestressed Anchor Cable Based onM indlin Solution

WANGHai-bin, GAO Bo, CHENKai

2005, 18(4): 462-467.

[Abstract](1346)

Abstract:
Based on the compatibility conditions of axial and radial deformations of anchor-rock interface, an equivalentmedium modelwas established by analyzing the dynamic load character and boundary conditions of a prestressed anchor cablewith a free partwithout injecting cementpaste. The axial force distribution and themathematicalexpression to describe the relation between the deformation and pretension of a prestressed anchor cable were derived by using theMindlin integral solution in column space and the Mindlin solution for axisymmetric radial dilation load. In addition, the characteristic curve of load-deformation and the distributionmodality ofaxial stresswere comparedwith field testing results.

Stability Analysis ofPrelim inary Schemes of Nanjing No. 3 Bridge in Construction Stage

ZHAO Lei, WUFang-wen

2005, 18(4): 467-472.

[Abstract](1657)

Abstract:
Three preliminary schemes of theNanjingNo. 3 bridgewere investigate by considering the nonlinearity of structures and the ultimate load-carrying capacity of components. They are the schemes of steel cable-stayed bridgewith one tower and two poles, orwith two towers and one pole, orwith two towers and two poles. And in the investigation, the superposition effects of deformations and stresses during the construction were also included. The research was focused on the stability of structures during the construction. The research resultshows thatelastic stability factors for the three schemes are 4. 9 to10. 2, and theirnonlinear stability factors are 2. 1 to7. 9, so theirelastic stability and nonlinear stability are adequate in construction stage. At las,t their stability safety factors in a state of ultimate load-carrying capacity during constructionwere appraised.

Cross Section Aerodynam ic Optim ization of SteelBox G irder in X ihoumen Suspension Bridge Prelim inary Design

LUGui-chen, ZHANGHong-fen, YANG Yong-xi, GE Yao-jun

2005, 18(4): 473-477.

[Abstract](1713)

Abstract:
To optimize the cross section of steel box girder of the Xihoumen bridge, a suspension bridgewith amain span of 1 650 m, the aerodynamic performance of twin-box cross sections slotted respectivelywith awidth of5. 5, 6. 0 and 6. 5 m were simulated numericallywith the computational fluid dynamics (CFD) method. The numerical simulation indicates that the aerodynamic performance of the twin-box cross section slotted 6. 0m wide isbes.t The critical flutterspeedsof the twin-box cross section slotted 6. 0m wide, a traditional single box cross section and a twin-box grid cross sectionwere measured by 1∶80 section model tests, and their aerodynamic performances were discussed. The experimental result shows that the three kinds of cross section can meet the requirement for flutter speed of78. 2 m/s, but it is necessary to adopt aerodynamic controlmeasures to a traditional single box cross section

M odelTest ofConstructing Shield Tunnel under Large Underground Structure

LIWei, HE Chuan, ZHANG Zhi-qiang

2005, 18(4): 478-483.

[Abstract](1712)

Abstract:
A 3D model testwas carried out to investigate the interference when a metro tunnel is excavatedwith the shield method under an existing underground structure, the Xuanwuhu tunnel in NanjingCity. The experimental results show thatthe construction of the shield tunnelhas a slighteffect on theXuanwuhu tunnel is and large deformation to lead to the“excursion”of the Xuanwuhu tunnel does not occur. Under the conditions of setting uplife piles and reinforcing the ground below the Xuanwuhu tunne,l the additional deformations and internal forces are obviously reduced. In addition, the settlementof ground is smal,l so pavement structures can not be destroyed. Finally, to compare with the experimental resultFEM (finite elementmethod) was used. The numerical simulation result shows that both the Xuanwuhu tunnel and the shield tunnel are safe during the construction of the shield tunne,l and specialmeasures are needed.

Design ofM icro-computerized Dual-Computer Redundant Automatic Block System between Railway Stations

GUO Jin, CHENHong-xia, YANG Yang

2005, 18(4): 484-488.

[Abstract](1429)

Abstract:
A dual-computer parallel redundant structure of a micro-computerized automatic block system between railway stationswas designed tomeet the need forhigh reliability of railway signalling. The principle and behavior of safety control lock were discussed to avoid the state of dual-host- computer. The theory of Petri net was used to model and analyze the system to investigate its transforming performance. The analytical results show that the proposed structure and the transforming method are reasonable, the states in the system can be transformed safely and perfectly, and there isno a dead lock state.

Contour Tiling ofObject Surface Reconstruction Based on aM odified Genetic Algorithm

HE Feng-dao, CHEN Yong

2005, 18(4): 488-491.

[Abstract](1504)

Abstract:
The contour tiling problem in object surface reconstructionwas transformed to a problem of searching for an optimal path in a directed graph. An improved generic algorithm (GA) was proposed to solve the objective functions related to the contour tiling problem. The improvements on initial population, crossover and mutation were made to the conventional GA to ensure any individual to present a valid resolution. The result of an example shows that the proposed algorithm is simple and feasible, with better performances in optimization, convergence speed and robustness compared with simulated annealing for contour tiling.

Listless SPIHT Image Coding Hardware Algorithm Based on LiftingW avelet

LIANG Chun-yong

2005, 18(4): 492-496.

[Abstract](1327)

Abstract:
To overcome the shortcoming ofwavelet zero-tree coding algorithms,i. e., the hardware implementation ofSPIHT (setpartitioning in hierarchical trees) algorithm needs toomanymemories, a listless SPIHT algorithm wasproposed. In this algorithm, waveletcoefficients are input into an encoder in the SPIHT order, and then they are coded by using the NLS (no list SPIHT) algorithm. In addition, the 9/7 lifting schemes and uniform quantization are employed, and the adding zeromethod is applied forborder extension of images. The experimental results show that the compression ratio of the proposed algorithm is almostthe same as thatof theEBCOT(embedded block codingwith optimized truncation) algorithm of JPEG2000, but its running speed is two times that of the EBCOT algorithm. Furthermore, the proposed algorithm needs fewermemories, such as only an additional 17. 875 KB memory for a 512×512 image.

Geometric Prim itive Extraction Using ChaosGenetic Algorithm

JIADong-li, ZHANG Jia-shu, ZHANG Chao

2005, 18(4): 496-500.

[Abstract](1846)

Abstract:
A chaosgenetic algorithm wasproposed to extractgeometric primitivesdirectly from original images. Comparedwith the traditionalgeometric primitive extraction, this algorithm needs notdo edge detection before geometric primitive extraction. Instead, it directly searches for geometric primitives from an original grey image based on the gradient information. Additionally, this algorithm reduces time and space consumption compared with Hough transform. Simulations show that this method is simple, efficient and reasonably robust.

Network Scheduling ofDistributed Real-Time Control System

HE Jian-qiang, ZHANGHuan-chun, JING Ya-zhi

2005, 18(4): 501-504.

[Abstract](1618)

Abstract:
Based on the fact that the performance of distributed real-time control systems closed through control network depends on not only control algorithms but also network scheduling, time divisionmultiple access (TDMA) with determinate timing and reliabilitywasused as controlnetwork to describe the controlmessages through network. A scheduling model for distributed real-time control systems based on TDMA control network was established. Based on thismode,l a genetic algorithm- based scheduling algorithm was proposed to improve the control performance and network utilization ratio. A scheduling example shows that compared with the normal condition, the period of optimized control tasks isminimized and the control performance and the network utilization ratio are improved.

Security Scheme forM obile Agent inM aliciousHosts

WANG Da-yong, MEIZhi-hong, JINWei-dong

2005, 18(4): 505-509.

[Abstract](1273)

Abstract:
A scheme for solving the security threat to mobile agent (MA) in malicious hosts was proposed based on asymmetricalencryption. In the scheme, only can the hosts thatgetpermissions run the codes ofMA, and data for exchanging are also encrypted. After returning to the source hos,t MA checks the data ithas collected to ascertain if ithas been attacked. The security threats thatMA may encounter inmalicioushostswere analyzed one by one, and each of them was solvedwith the proposed scheme.

Approach SchedulingM odelBased on EarliestEstimated ArrivalTime and ItsAlgorithm

JIANG Bo, ZHANG Fei-qiao

2005, 18(4): 509-512.

[Abstract](1452)

Abstract:
To avoid approach congestion due to rapid increase of air traffic flows, reduce delays and make fulluse of the runway capacity, schedulingmodels available in literature were simplified. The minimum radar intervals defined by theGeneralAdministration ofCivilAviation ofChinawas taken as the safe intervals between two aircrafts. The effect of aircraft speed on the safe interva,l estimated arrival time and priority of an aircraftwere analyzed. A new approach scheduling model based on earliest estimated arrival time and its algorithm was proposed. A calculation example shows that the newmodel and its algorithm give better approach schedulingwith obvious less computation.

Stackelberg DifferentialGameM odel for Cooperative Advertising Strategies in Supply Chain

ZHANG Shu-ping, ZHANG Shi-ying

2005, 18(4): 513-518.

[Abstract](1302)

Abstract:
Dynamic cooperative advertising strategies in a supply chainwith a singlemanufacture and an exclusive retailerwere studied. Themanufacture acts as the channel leader to design and implement a dynamic advertising program to support advertising effort of the retailer to optimize his own and the retailer s profi.t Theymaymake advertising expenditures on both shortand long term advertising. The manufacture pays a certain costs of the retailer for advertising. Stackelberg differentialgamemodelwas used to describe the strategiesof themanufacturerand the retailer. The stationary feedback Stackelberg equilibrium was characterized using dynamic programming principle. The results show that the types of advertising of the retailer supported by the manufacture are determined by the marginal profits of the bothmembers. In the equilibrium advertising strategies, themanufacturerpaysmuch of its attention to long term advertising to build brand goodwil,l while the retailer lays stress on short term advertising to stimulate sales under the support of the manufacture. Cooperative advertising scheme is a coordinate mechanism in a supply chain that induces the retailer to follow themanufacturer.

Multi-vendor SelectionM odel forMulti-product and ItsDecomposing Algorithm s

YAO Jian-ming, PU Yun, ZHOUGuo-hua, ZHAO Zheng-jia

2005, 18(4): 519-524.

[Abstract](1459)

Abstract:
To solve the multi-vendor selection problem in a multi-product supply chain, an optimizationmodewas constructed with the lowest composite cost taken as the objective function and with necessary constraints. A decomposing algorithm was used to overcome the difficulty in solving the mode.l The originalmodelwas transformed into an integer programming mode.l Based on different iteration procedure, two algorithms were presented. The model and algorithms were applied in a numeral example, and an optimized assignment of the products was obtained. The proposed method overcomes the limitation in the conventional vendor evaluation models where only single product or single vendor is considered.

M odel ofPartner Information Exchange Protocol for C ivilEngineering Industry

CHENNing, ZHANGXue-yan, Wu Zhen-ye

2005, 18(4): 525-529.

[Abstract](1173)

Abstract:
To overcome the difficulties in electronic data exchanges in civilengineering industry due to complicated relationships and frequent communications among enterprise partners, a partner information exchange protocol (PIEP) model was established. Efforts were made to combine the advantages of aceXML and RosettaNet protocols and to meet the requirements of civil engineering industry. PIEP uses Internet for efficientand accurate information exchanges among partner enterprises and realizes.

Facility LocationM odel for Multi-levelReturned Logistics and ItsAlgorithm

ZHAO Yi, YING Chuan-zhong, PU Yun

2005, 18(4): 530-534.

[Abstract](1714)

Abstract:
A facility locationmodel formulti-level returned logisticswas proposed to study the issues of collection, preprocessing and remanufacture of end-of-life products. Thismodel is amixed integer linear program (MILP), and is solved with a branch and bound (B&B) algorithm. To make B&B faster in convergence and less in calculation, a genetic algorithm is used to obtain a reasonably good resolution at the beginning ofB&B. The objective value corresponding to the resolution is taken as the upperbound ofB&B to prune a large number of branches from the searching tree. An example was presented to verify the effectiveness and feasibility of the proposedmethod.

RationalExpectationM odel for Securities Frauds

XULiu-ying, CHENQi-huan

2005, 18(4): 535-538.

[Abstract](1117)

Abstract:
The fraud behaviors ofdishonestcompanieswere studiedwith a rational expectationsmodel to analyze the dynamic relations between the possibility of frauds to happen and the efficiencies of the regulatory authorities. It is found that frauds are a common phenomenon independentof the developing degree of securitiesmarkets, and the expectation by the dishonest companies ofbeing found is one of the key factors affecting the happening of frauds. The data from Chinese securitiesmarketwere taken to verify the arguments, and the result is the same as the theoretic analysis. Frauds in Chinese securities markethappenedmostly in 1996, accounting for40. 5% of the tota.l Investigations started in 2000, 4 years later than the happening peak of the frauds, suggesting that the investigations were too late, which is themain cause for the high rate of frauds to happenwithin a period.

Existence andMultiplicity of Solutions and Positive Solutions for Sem ipositive Neumann Boundary Value Problem s

YAO Qing-liu, LIYong-xiang

2005, 18(4): 539-543.

[Abstract](1004)

Abstract:
By using cone expansion-compression fixed point theorem, the solutions and positive solutionswere studied for the nonlinearNeumann boundary value problem, where the nonlinear term was allowed to have a nonpositive lowerbound. It is shown that the problem hasnsolutions orpositive solutions provided themaximum andminimum heights of the nonlinear terms are appropriate on some bounded sets, wherenis a naturalnumber

α-Resolution Fields ofGeneralized Literals ofLogic LP(X)

WANG Wei, JIANG Bao-qing, XU Yang

2005, 18(4): 544-547.

[Abstract](953)

Abstract:
The research onα-resolution fields of generalized literals of lattice-valued propositional logic LP (X) is the subsequence of the work onα-resolution principle based on lattice-valued propositional logic LP(X), where the algebra of true-values is a lattice implication algebra. The characteristics of constants, prepositional variables and some generalized literals of LP (X) were discussed, and theirα-resolution fieldswere obtained.

Universal Immune Evolutionary Algorithm for Interval-Constrained Optim ization Problem s

NIChang-jian, CUIPeng, XIANG Rui

2005, 18(4): 548-552.

[Abstract](1612)

Abstract:
Based on the current immune evolutionary algorithm ( IEA) and aimed at interval- constrained problems, a universal immune evolutionary algorithm was proposed. W ith this universal algorithm, any individualofevery generation canmeet the requirementof interval constraintsbymeans of interval transition, and the subjectivity ofparameters setting can be further eliminated. As a resul,t the computation efficiency is greatly raised, the unitarity of the universal algorithm is improved, and the disadvantages of the IEA adopting penalty for similar problems are also avoided. In addition, the universal algorithm was applied to the optimization ofmulti-model functions and the test of a GA (genetic algorithm) deceptive problem. The results show that compared with the IEA adopting penalty, programming is easy for the universal algorithm, and the global optimal solution can be obtained at a fast and stable speed.

Special9-BitLattice BoltzmannM odel

WANG Qin, YAO Ling-kan, TANG Jia-fa

2005, 18(4): 553-557.

[Abstract](1183)

Abstract:
Based on the Stokes hypothesis, the characteristics of the Navier-Stokes equation for compressible liquids were analyzed. Through the above analysis, a special 9-bit lattice Boltzmann modelwas setup. The proposed model not only satisfies the Stokes hypothesis but also can simulate compressible liquids. In addition, the parameters in this model were determined through using the relative theory of the lattice Boltzmann method. At las,t the feasibility of the proposed model was proved through simulating the tail flow problem.

Nernst Theorem and Entropy ofTwo DimensionalBlack Holes

LIUWen-li

2005, 18(4): 558-561.

[Abstract](1171)

Abstract:
The brickwallmodelwas used to directly calculate the Boson entropy of scalar field in the background of1+1 dimensional(space-time) black holes. The results show that the entropy is related to both the outer and innerhorizons. If the contribution of the innerhorizon is considered, the entropy approaches zero as the radiation temperature approaches zero. The entropy satisfies the Nernst theorem, so itcan be regarded asPlank absolute entropy. If the contribution of the innerhorizon isnot considered, the entropy has a logarithmically divergent term, which is the same with the known conclusion.

Screening and Characteristic ofReactive Red PBL Decolorizing Strains

FU Yong-sheng, WEIJian-bin, LIXiang-mei

2005, 18(4): 561-564.

[Abstract](1206)

Abstract:
Some strains having decoloration and degradation effects on reactive red PBLwere isolated from sludge from bioreactors of a dye factory. Through re-screening, one strain, named asTS4, was found to have a better decoloration performance and identified preliminarily asBacillus Sp. Experimental results show that the effect of decoloration is influenced by temperature, pH value and oxygen supply conditions. The optimum growth condition for the strain is 37℃, pH=7. 8 and sealed culture. In addition, this strain can endure the reactive red PBL to a concentration of200 mg/L, and the decoloration performance of a single strain isweaker thanmixed strains.

Synthesis ofo-Chloro-Cyclohexanone Oxime and ItsAnalog

LU Shu-he, TONG Zhi-ping, LIMin

2005, 18(4): 565-568.

[Abstract](1078)

Abstract:
o-Chloro-cyclohexanone oxime and its analog were synthesized with cyclohexanone, cyclohexene and 2-methyl-2-butene. The results show that almost theoretical yield foro-Chloro- cyclohexanone oxime is obtainable with chloro-oximation reaction from hexanone, chlorine and hydroxylamine hydrochloride at0~5℃, and thathigh yield forα-chloro-α-methylbutanone oxime is also securablewith the addition reaction from alkene and nitrous acid ester followed by rearranging the resultant in ethanol solven

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2005 Vol. 18, No. 4