西南交通大学学报

On Developing H igh-Speed Evacuated Tube Transportation in China

SHEN Zhi-yun

2005, 18(2): 133-137.

[Abstract](1422)

Abstract:
The necessity and feasibility of evacuated tube high-speed transportation were discussed. The fundamental problems of this technology, e. g. pressure in the tube, coefficient of coverage and other related techniques, were analyzed in detai.l More discussed were the strategy and technical choice ofdeveloping this kind of transportation in China. The system consisted of partial pressure in tube, high-temperature super conducting magnetic levitation and synchronic linearmotor traction is proposed to be the variantofdeveloping research, so that the 600-1 000 km/h high-speed evacuated tube trainmightbe able to run commercially by 2030.

Experimental Investigation on Reducing Gounding-Resistance in PerennialFrozen SedimentAreas

WUGuang-ning, ZHANG Jun, FULong-hai, WANGHao

2005, 18(2): 138-142.

[Abstract](1043)

Abstract:
To solve the problem ofgrounding for lighting along theQinghai-Tibetrailway, experiments were conducted in an perennial frozen sediment area, where there were similar environments as the sections of theQinghai-Tibetrailway. The factors affecting the resistivity of frozen soilswere discussed, and some solutions to grounding for lightning using groundingmoduleswere introduced. It is verified that the groundingmoduleshave good performance for reducing grounding resistance in perennial frozen sediment areas, and the design requirements can be fulfilled by parallelly connecting necessary number ofgroundingmodules.

Simple Adaptive Control for Constant Tension of Double Stand Revere Cold-RollingM ill

AN Shi-qi, SUN Yi-kang, WANG Jing

2005, 18(2): 142-146.

[Abstract](1342)

Abstract:
A simple adaptive control system was designed for constant tension of double stand revere cold rolling mil.l This system contains two inner loops for current and velocity control using PI regulators; its outer loop is for tension control using simple adaptive controller. Simulation results indicate that the simple adaptive controllerhas betterperformances than classicalPID controlmethod. The system has stronger robustness for constant force contro,l and improves the precision about the thickness and shapes of steel strap

M odel and Algorithm for Train Operation Adjustment on Single-Track Railways Based on Genetic Algorithm

ZHANG You-shi, JINWei-dong

2005, 18(2): 147-153.

[Abstract](1654)

Abstract:
The conceptof“adjacent train”was introduced to build a new model for train operation adjustmenton single-track railways based on their operational characteristics. Since the solution space of themodel is too large to be searchedwith conventionaloperational research (OR) technique, a new algorithm based on genetic algorithm (GA) was proposed. This algorithm divides themodel into sub- models according to the grades of a train followed by solving each sub-model with GA. Simulation results verify the effectiveness and real-time performances of the proposedmodel and algorithm.

Improvement ofTransientResponse Performances of M icroprocessor Voltage Regulator

WANG Feng-yan, XU Jian-ping, WU Song-rong, XU Jun-feng

2005, 18(2): 153-157.

[Abstract](1309)

Abstract:
The transient responses of voltage regulator (VR) to sudden load changes and the parameters of aVR affecting the transient response of output voltage were analyzed to achieve a VR with fast transient responses. The analyses show that using a low equivalent series resistance (ESR) capacitorwith a carefully determined value and raising switching frequency can decrease outputvoltage fal.l Simulation results verify thatdecreasing the inductance of the inductor reduces the outputvoltage fall and response time by about 20% and 60%, respectively; selecting a capacitorwith the critical capacitance reduces the outputvoltage fallby about40%, but increases response time; and compared with voltagemode contro,l currentmode control reduces the output voltage fall and response time by about20% and 70%, respectively.

OperationalEquation and Setting ofDifferentialProtection for Impedance-M atching Balance Transformer

LUTao

2005, 18(2): 158-162.

[Abstract](1211)

Abstract:
If impedance matching coefficientKZ≠3 + 1 for an impedance-matching balance transformer with differential protection based on phase current on primary side, there is inherent differential curren,t andmay result inmal-operation. Thisproblem was solved by taking the differences in phase currenton primary side as the parameters to form the operationalequations. Setting ruleswere discussed and formulaewere derived for impedance-matching balance transformersbased on the 3-slope operation characteristic, where the effects of normalmismatch curren,t current-transformer saturation and inrush currenton differential currentprotectionwere taken into consideration.

NeuralChebyshev OrthogonalPolynom ialEqualizer and ItsAdaptive Algorithm

DENGXiao-hong, ZHANG Jia-shu

2005, 18(2): 163-168.

[Abstract](1362)

Abstract:
A new structure of nonlinear equalizer-neural Chebyshev orthogonal polynomial adaptive equalizerwasproposed. It is composed ofa nonlinearneuraladaptive filterand aChebyshev orthogonal polynomial filter. The corresponding adaptive algorithm was derived based on the steepest descent method. Simulation results show that the proposed equalizer has less mean square error (MSE ) comparedwith the neural adaptive equalizer and the SVE ( second-order volterra equalizer ) in linear channe,l and that itcan achieve similargood performances as the 3-layered neuralnetwork trainedwith BP algorithm in the nonlinear channelwith a simpler structure.

Vision Subsystem and Identification Algorithm for M iroSotLarge Field Soccer-Robot System

PENG Qiang, JIANGHao

2005, 18(2): 168-172.

[Abstract](1353)

Abstract:
Tomeet the high controlaccuracy of the vision subsystem ofaMiroSot(Micro-RobotWorld SoccerTournament) large league system, a computer vision subsystem and a robot/ball identification algorithm were described. The vision subsystem was developed forMiroSotLarge League 11 vs. 11 for FIRA (Federation of International Robot-Soccer Association) RobotWorld Cup 2004. The vision subsystem structure, color jacketdesign for11 robots, algorithm for identifying home robots, and post- processing filterswere presented. A novel recognition algorithm of robot ID colors using theminimum hueMAD (mean absolute difference) was addressed especially. The subsystem has been tested, and the result shows a satisfactory performance in competitions.

Sparse Decomposition Based on StructuralProperties ofAtom Dictionary

YIN Zhong-ke, WANG Jian-ying, SHAO Jun

2005, 18(2): 173-178.

[Abstract](1427)

Abstract:
A new sparse decomposition algorithm was proposed bymodifyingmatching pursuit (MP) andmaking fulluse of the structural properties of the over-complete atom dictionary in signal sparse decomposition. The new algorithm deliberately balances the computing speed and required memory. The speed of the new algorithm is 15. 9 times faster than that of the conventionalMP algorithm. Experimental results verify the effectiveness of the proposed algorithm.

H igh-DimensionalAffine Codes

LIUXiu-feng, ZHANG Ai-li

2005, 18(2): 179-183.

[Abstract](1249)

Abstract:
High-dimensional affine codes were constructed using weak block designs, where thes- dimensional cosetofs-dimensional affine geometryG (m, p)over a finite fieldFpwas taken as an informationalbi,t and everys-dimensional coset family corresponding each elementwas regarded as a check line. The codes are the generalization of the affine manifold codes, and their lengths, dimensions, minimum distances and rateswere analyzed.

GDOP Performance Analysis ofCellular Location System

DENG Ping, YULi-jian

2005, 18(2): 184-188.

[Abstract](1096)

Abstract:
The relation betweenGDOP (geometry dilution ofposition) and BS (base station) number at the center of a polygon was derived with and without the correlativity between TDOA ( time difference of arrival) measurements considered. A GDOP method for computing TDOA and TDOA/ AOA (angle of arrival) under NLOS (non-line-of-sight) environment was presented. Theoretical analysis and simulation results show that the correlativity between TDOA measurements increases GDOP, and location performances are improved andGDOP is decreased byTDOA/AOAmethod if the standard error ofAOA measurement is less than 5°.

Multi-Intersected Copy Replication Based on ParallelLink

KOUWei-hua, JIAXing-min, XU Yang

2005, 18(2): 189-194.

[Abstract](1235)

Abstract:
To eliminate overlapping data spreading repeatedly and nonupdated data spreading, and to replicatemulti-intersected copy in parallel links, based on the state of copy replication on every node in parallel links, the following three strategies were proposed: twice-spread once-replication, twice- spread once-thruput twice-replication, and parallel-spread twice-thruput three-time-replication. The mechanism of the strategies is thatmulti-intersected copy is disassembled and spread followed by reassembly and replication.

Analysis for Dynam ic Properties ofM odelArch Structure ofConcrete-Filled SteelTube

XIONG Feng, LIUHao-wu

2005, 18(2): 195-199.

[Abstract](1440)

Abstract:
The natural frequencies of amodel arch structure of concrete-filled steel tube were got by shaking table tests. In addition, a structural analysis software SAP2000 and the finite elementmethod were used to obtain the natural frequencies and vibration modes of the structure. In the numerical analysis three dimensional beam elementswere adopted and concrete-filled steel tube was taken as a combinatorialmateria.l The computed results get a good agreementwith the experimental ones. To extend the research, the dynamic properties of themodel arch structurewere analyzed under different cases. Through changing the structural stiffness, the numberof lateralbraces and fixed conditions, the changes of the natural frequencies and vibration modes were researched and factors influencing the dynamic properties of concrete-filled steel tubular arch structureswere analyzed. The resultshows that increasing lateralbraces can increase the lateral frequencies of an arch structure, the stiffness of arch rib is not an important influencing factor to its natural frequencies.

Stationary Stochastic Response ofCFST Arch Bridge to Multi-component Seism ic Excitation

ZHAO Can-hui, ZHOUZhi-xiang

2005, 18(2): 200-204.

[Abstract](1650)

Abstract:
The response of concrete-filled steel tube (CFST) arch bridges tomulti-componentseismic excitation and its calculation were investigated using the theory of random vibration. A pseudo- excitation method for multi-component seismic excitation was proposed, the stationary stochastic response ofCFST arch bridges tomulti-component seismic excitation was analyzed with thismethod, and the effectof traverse brace stiffness on the stochastic responsewasdiscussed. The resultshows that thismethod has the same accuracy as the classic stochastic vibration method and an advantage in calculation velocity. Transverse and vertical seismic excitationshave a large effecton the internal force of arch rib, and the internal force increaseswith the increasing of traverse brace stiffness.

Stress Increment ofExternally Pre-stressed Tendons of Three-Span Continuous Concrete Beam swith Varying Section

YANG Li, ZHAO Ren-da, ZHANGXiao-yong

2005, 18(2): 205-209.

[Abstract](1463)

Abstract:
Based on the experimental resultof4 three-span externally pre-stressed concrete continuous beamswith different pre-stress degrees, reinforcement ratios and sections, the stress increment of externally pre-stressed tendonswas investigated. The result shows that the stress increment is directly proportional to the deflection atmid-section in the middle span, and the relation among the stress incremen,t the deflection and the load may be described using a model of tri-broken line. In this mode,l crackings of themid-section and themid-support section are taken as its turning points. As a resul,t a simplified method of calculating the stress increment based on the elastic theory was proposed, the calculated resultbeing accordedwith thatof a non-linear analysis.

Reliability Calibration ofComposite Beam Section Based on European Standard

XUHai-qing

2005, 18(2): 210-215.

[Abstract](1341)

Abstract:
The necessary safety factor ofcomposite beam section in an ultimate limitstate (ULS) was investigated for the goal reliability indexβ= 4. 7. A composite beam section designed according to European standard EC 4 (Euro code 4) was calibrated and its actual safety factor in the ultimate limit statewas obtained. Comparison between the necessary safety factor and the actual safety factor shows that an additional safety factor is necessary for a composite beam section to ensure the reliability level demanded byEuropean standard EC 1 (Euro code 1).

LongitudinalCurve Design ofCable Saddles in Suspension Bridge

WEIJian-dong, XUWei-guo, LIUZhong-yu

2005, 18(2): 215-219.

[Abstract](1424)

Abstract:
To reasonably design the longitudinal curves of cable saddles and improve the control precision in construction, the design of longitudinal curves composed of compound arcswas developed based on the analytical solutions for elastic catenary. Under the condition of given distances or horizontal distances between the turning point and the two tangential points on main saddle, or given arc radii of anchorage cable saddles, a nonlinear equation corresponding to a main saddle and two nonlinear equations corresponding to anchorage saddle were respectively derived from equilibrium conditions and geometrical relations. The corresponding drawingmethod was proposed to each case. The result shows that it is easier to design amain saddle if the horizontal distances are given.

Dynam ic StressM easurement and Analysis of Subgrade-Culvert Transition Section on Q inhuangdao-Shenyang Passenger SpecialLine

HUANG Wan-qing, LU Yang, LUO Shu-xue, CHEN Cheng-die

2005, 18(2): 220-223.

[Abstract](1584)

Abstract:
Dynamic soil stress of a subgrade-culvert transition section from DK49+689. 0 toDK49+ 700. 7 on theQinhuangdao-Shenyang passenger special linewasmeasured and its influencing factors, including train speed, structural changes and soil depth, were analyzed. The results indicate that dynamic earth pressure trends to rise with the increase of train speed. When train speed exceeds 220 km/h, dynamic earth pressure trends to be unchanged, but it is always bigger than the earth pressure ofquasi-static state. In addition, dynamic earth pressure attenuates rapidlywith the increase of soil depth, approaching to the quasi-static earth pressure. Furthermore, it is also related to the structure of subgrade andmuch greater over the culvert than in normal subgrade.

Effects ofCrosswinds on Curve Negotiation ofH igh-Speed Power Cars

WANG Yong-guan, CHENKang

2005, 18(2): 224-227.

[Abstract](1657)

Abstract:
The aerodynamic lift forces, lateral forces and rolling moment on high-speed power cars were investigated experimentally to study the effects of crosswinds on the aerodynamics of EMU (electricmultiple unit). The dynamics of curve negotiation ofhigh-speed power carunder crosswinds was analyzed using software SIMPACK. The results indicate thatwheel load reduction induced by crosswind is an importantsafety factor. Underdiscussed conditions, the safe speed ofpower car is less than 220 km/h under a mild wind (15 m/s); and there is no safe speed under a gust crosswind (25 m/s) when power cars run at speed of100 ~ 180 km/h.

Experimental Investigation on Spalling ofRailway CarW heels

WANG Wen-jian　LIUQi-yue

2005, 18(2): 228-231.

[Abstract](1269)

Abstract:
Spalling and wear behaviors of four kinds of wheel steels with different carbon concentrationswere investigated on JD-1 wheel-rail simulating testmachine underHertzian contact condition. The results show tha,t with an increase in carbon concentration, thewear volume ofwheel decreases; but the degree of spalling increases with larger fragments; and decreasing carbon concentration alleviate spalling, but increaseswear volume of the specimens.

Starting Control ofAMT with Adaptive Temperature Compensation

YINXiao-feng, TAN Jing-xing

2005, 18(2): 232-236.

[Abstract](1410)

Abstract:
The engagement-speed of clutch was determined with a weighted method based on the starting performance indices of AMT (automated mechanical transmission) and torque-transferring characteristics of clutch. In the method, the driver s intention and the requirements of starting performances are taken into consideration. A clutch engagement-speed control algorithm was proposed based on peak error sampling and adaptive temperature compensation. Experimental results show that the algorithm satisfies the requirements for three typical startingmodes, namely, creeping, normal and abrupt startmode and improves the adaptability to temperature variation.

Positioning ofM oving Table for Checking Screw Holes of Nuclear Reactor Pressure Vessel

TANG Lan, CHEN Chong, LISheng

2005, 18(2): 237-240.

[Abstract](1312)

Abstract:
To inspect the defects on the screw hole surfaces of nuclear reactor pressure vessel in nuclear power station, an automatic moving table was designed to carry sophisticated inspecting devices. Its precise positioningwas successfully realized by determining the positionsof the screw holes in the flange of the pressure vesselwith two optical sensors. Its positioning precision is 0. 15 mm, in accordancewith the design requiremen,t and themoving table has been put into operationwith precise and stable performances.

Optim ization ofM ilitary Transportation Routes Based on Genetic Algorithm

SHIYu-feng, SU Shi, PENG Qi-yuan

2005, 18(2): 241-243.

[Abstract](1568)

Abstract:
On the basis of establishing the optimalmodel ofmilitary transportation routes, a genetic algorithm was designed to obtain the routewith aminimum generalized weigh.t To solve the problems of“necessity-nodes”,i. e., the nodes amilitary transportation routemustpass, and order preserving ofnodes, the rules of coding and the methods of crossover and mutation were constructed. Initial chromosomeswere predisposed to improve the efficiency of this algorithm. In the end, comparative experimentswere performed and the experimental resultwas analyzed so as to show the feasibility and effectiveness of the algorithm.

ForecastM odel ofRoad Section Traffic Flow Based onM aximum Likelihood Estimation

LIU Shi-chao

2005, 18(2): 245-248.

[Abstract](1475)

Abstract:
Based on analyzing the shortcoming of present traffic flow forecasting, the maximum likelihood estimationwasused to forecastthe traffic flow ofroad sections. The essence of thismethod is thatupstream observationalvariables in a successional time region are looked as explanatory variables, and the maximum likelihood estimation is applied to seek the relationship between the observational variables and the variables to be predicted to forecast the traffic flow of a road section. An example shows that themaximum error rate between the forecasted and actual values of traffic flow is 5. 76%.

User-Based Structure Configuration of Comprehensive Transportation Corridor

LIDe-gang, LUO Xia

2005, 18(2): 249-253.

[Abstract](1212)

Abstract:
The limitations of the traditionalmethods of corridor structure configuration were analyzed based on the characters ofdemand and supply ofusers in a comprehensive transportation corridor. The corridor structure was defined from point of view of users, a multidimensional Logit function of transportationmethod selectingwas given, and amethod of the reasonable structure configuration of a comprehensive transportation corridorwas proposed. In addition, the maximum likelihood estimation was applied to determine the related parameters. At las,t the feasibility of the proposed method was proved by a practical example, Chengdu to Chongqing section on the corridor to the sea for the SouthwestChina.

JointOptimalDecision-M akingM odel Based on Supply ChainM anagement

TIAN Jun

2005, 18(2): 254-258.

[Abstract](1588)

Abstract:
To encourage the firmswithmerits and prevent the enterprises from gaining colossalprofits, the problem of jointoptimal decision-making of supply chain constructed by cooperative suppliers and submitters in the situation ofhaving no discountwas discussed. A jointoptimaldecision-makingmodel of the supply chainwith restraint factorswas setup using the linearweighted sum approach. Onlywhen some firms in the supply chain have the tendency ofmaking colossal profits or only when they exert great influences on the supply chain, can thismodel and the relevantstrategies be taken so as to avoid the supply chain’s risk. The feasibility of thismodelwas verified through an example.

Strategic Information System s Planning Method Based on Core Competence

XUZuo-ning, LITao, WUZhen-ye

2005, 18(2): 259-263.

[Abstract](1278)

Abstract:
A new strategic information systems planningmethodwas put forward to raise the efficiency and effectiveness of planning. Based on the core competence theory of competitive advantage, this method insists thatbusiness strategies planning should be integrated with strategic information systems planning, and inner and exterior information demand of a business should be concerned. It includes information technology planning, information resource planning, information structure planning and business process reengineering.

W eight Syncretizing forMultiattribute Decision- M aking withoutDecision Attribute

JIANMing, HUANG Ding-xuan, WUZhen-ye

2005, 18(2): 264-268.

[Abstract](1608)

Abstract:
A syncretized weight allocation method was proposed to overcome the limitations of two weight allocation methods of multiattribute decision-making without decision attribute,i. e., the impersonal method and the subjective method. To obtain the optimal weight integration between subjectiveweights and objective oneswith thismethod, amathematicalplanningmodelwas setup and the genetic algorithm was used to gain the global optimal solution. As a resul,t subjective factors in weigh syncretizing can be avoidedwith thismethod. At las,t an instancewas given out.

Lattice Ordering of Incomplete Lattice

GUO Chun-xiang, GUO Yao-huang

2005, 18(2): 269-272.

[Abstract](1190)

Abstract:
A problem in the lattice orderdecision-making theory,i. e., the structure of lattice order is incomplete, was investigated. By defining the regulation ofdetermining key elements and theminimal decision se,t a method was given to directly work out join-and meet-irreducible elements of the smallest complete lattice from a partial order se.t The inverse order embeddingmappingmethod was used to determine the greatest lowerbound or the leastupperbound of two elementswithoutthe greatest lowerbound or the least upper bound to obtain the lattice order of incomplete lattice. Finally, an examplewas given to illustrate the feasibility of thismethod.

Solving Herm ite Interpolation Functionswith theM ethod ofDivided Difference at the Same Node

FENG Tian-xiang

2005, 18(2): 273-277.

[Abstract](1218)

Abstract:
To solve cubic-Hermite interpolation functions, the method of divided difference at same nodewas used, and the result similar toNewton s interpolation function was obtained. The proposed method ismuch simpler comparedwith Lagrange interpolationwith base function. An error formula for cubic-Hermite s interpolation functionwas derived and proven for general cases.

Research onM onitoringM ethod for Nitrite and Nitrate in EnvironmentalW ater

GONG Zheng-jun, ZHANG Zhu-jun

2005, 18(2): 277-280.

[Abstract](1337)

Abstract:
An experiment shows that nitrate can be reduced to nitrite by spongiform zinc-cadmium reducer. Based on the experimental resul,t the chemiluminescence of hydrogen dioxide and luminol solutionwas used to the on-line analysis ofnitrite and nitrate. As a resul,t a new chemiluminescence method for the simultaneous determination of nitrite and nitrate was proposed. The system responds linearly in the range of3×10-3~3 mg/L for nitrite and 1~100 mg/L for nitrate, and the detection limits fornitrite and nitrate are 1. 5×10-3and 0. 33mg/L respectively. Thismethod hasbeen used to determine nitrite and nitrate in environmental water samples. The result shows that the maximum relative standard deviation is less than 4%.

Callus Induction and PlantRegeneration from Bulbs of Fritillaria thunbergiiM iq.

YUAN Yi, LINHong-hui, WANG Wan-jun, LIPing

2005, 18(2): 281-284.

[Abstract](988)

Abstract:
The effects ofmediums, phytohormones and phytohormone combinations on induction of calluses and protocorm-like bodies (PLBs) from the explants of bulbs ofFritillaria thunbergiiMiq.. The induction ofcalluses and PLBs is closely related tomedium, hormone combination and the type of the explants. The best callus induction is achieved inMurashige-Skoog (MS) medium supplemented with 1. 0 mg/L 2, 4-D (2, 4-dichlorophenoxyacetic acid)+1. 5 mg/L NAA (1-naphthalene acetic acid)+300 mg/L casein hydrolysate+0. 55% (mass proportion) agar by taking the bulbs of Fritillaria thunbergiiMiq. as explants. Plantlets are bestregenerated from snuff-colored calluses of the bulbs ofFritillaria thunbergiiMiq. inMSmedium supplementedwith 1. 0 mg/LNAA+2. 0 mg/L ZT (zeatin)+0. 55% casein hydrolysate. The bestmedium forPLBs induction isMS supplemented with 1. 0 mg/L 2, 4-D+2. 0 mg/LKT (6-furfurylaminopurine)+0. 55% casein hydrolysate.

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2005 Vol. 18, No. 2