西南交通大学学报

Track Irregularity Analysis Based on Wavelet Transform

ZHANGJie, CHENChun-jun, LINJian-hui

2004, 17(5): 469-471.

[Abstract](2274)

Abstract:
To eliminate the disturbances from the speed-instability of the measurement vehicle on the collected track irregularity spectrum, Haar wavelet transform was used to analyze the instantaneous frequencies of the track irregularity signals. The relationship between the instantaneous frequencies of the ...

Bound Searching Algorithm for Shortest Path in a Network

LI Yin-zhen, GUO Yao-huang

2004, 17(5): 561-564.

[Abstract](1771)

Abstract:
Many irrelevant vertexes must be searched in order to find the shortest path between two vertexes in a large networkwith Dijkstra algorithm, resulting in low efficiency. To improve the searching efficiency, a new searching algorithm, named bidirectional bound searching algorithm, was proposed. With ...

Strong Kernel Graphic Algorithm for Searching All Essential Circuits of Simple Directed Graph

ZHAO Yu-hua, LIKe-bai, RENWei-min

2004, 17(5): 565-568.

[Abstract](1578)

Abstract:
The problem of searching all feedback loops of a system dynamics model is equal to calculating all essential circuits of a corresponding simple directed graph. The keyof the problem is time complexity. A newconcept named strong kernel was defined, and the algorithm based on strong kernel for searchi...

Tail-Number-Assignment Problem of Airliners Based on Fleet Balance Application

SUNHong, WENJun, XUJi

2004, 17(5): 569-572.

[Abstract](1455)

Abstract:
To solve airliner tail-number-assignment (TNA) problem with the requirement of balanced application of airplanes, a simulated annealing algorithmwas designed. According to the character of single hub and spoke network widely used in Chinese airliners, a new concept called flight pairing was defined....

Road Network Capacity Reliability Based on Link Travel Time Reliability

LIUHai-xu, PUYun

2004, 17(5): 573-576.

[Abstract](1475)

Abstract:
To decrease the amount of calculation, a bi-level programming model based on link travel time reliabilitywas set up for road network capacity reliability through analyzing the concept of road network capacity reliability. Based on the character of route choice shown in the model,i.e.user equilibrium...

Optimal Approval Model for Wagon Requisition in Railway Bureaus

WANG Wei, YAN Yu-son, WANG Yong, ZHAONan

2004, 17(5): 581-584.

[Abstract](1587)

Abstract:
An optimal approval model for wagon requisition in railway bureaus and the corresponding network were proposed. In this way, the problem of optimizing approval for wagon requisition was transformed into solving minimum cost and maximum flow in a network. A numerical algorithmwas derived to solve the...

Performance Evaluation of Public Administrative Departments by Means of Benchmarking and DEA

WANG Qian, ZHOUZhuo-r

2004, 17(5): 585-589.

[Abstract](1266)

Abstract:
A new method was proposed by combining benchmarking and data envelop analysis (DEA) to evaluate the performances of public administrative departments. With the newmethod, the effective decision making units for a public administrative department are primarily determined with DEA. The primarily deter...

Synthetical Evaluation of Risks of Venture Business during Start-up Period

LIAOLi-kun, ZHANG Wei

2004, 17(5): 590-594.

[Abstract](1631)

Abstract:
To roundly understand and scientifically evaluate the risks of a venture business, a risk evaluation systemwith multiple evaluation indexes was set up based on deeply analyzing its characteristics and risk factors during a start-up period, and the fuzzy synthetical evaluation method was used to eval...

Optimization of Lot-Size for Dynamic Order with Quantity Discount

TIANJun-feng, YANGMei

2004, 17(5): 595-599.

[Abstract](1439)

Abstract:
To optimize the lot-sizes for dynamic orders with quantity discounts offered by vendors, a non- linear mixed integer programming model was proposed. In the model, multi-products, multi-discounts and capacities constraints of the purchaser and vendors were taken into account. The model was resolved w...

Vortex-Induced Dynamic Response of Tension Legs for Submerged Floating Tunnel under Current Effect

MAIJi-ting, LUO Zhong-xian, GUANBao-shu

2004, 17(5): 600-604.

[Abstract](1609)

Abstract:
Based on the equations of vortex-induced oscillation of tension legs, the effect of parametric excitation frequency on the first-order dynamic response of a tension legwas investigated by considering the non-linear fluid damping and parametric excitation. In the investigation, the Galerkin method an...

Numerical Simulation of Reinforcing Effect of Horizontal Drilling Jet-Grouting Pegs on Shenzhen Metro Tunnel between Stations

WUBo, GAO Bo, LUOJian-jun

2004, 17(5): 605-608.

[Abstract](1716)

Abstract:
To explain the reinforcing effect and mechanism of horizontal drilling jet-grouting pegs on surrounding rock around a tunnel, as an example, the reinforcing result of horizontal drilling jet-grouting pegs for Shenzhen metro tunnel between Dajuyuan and Kexueguan stations was analyzed with the 3D elas...

Patterns and Mechanisms of High Slope Deformation and Failure of Hydropower Station in Southwest China

SHI Yu-chuan, FENG Wen-kai, LIUHan-chao, ZHOUChun-hong, SHANZhi-gang

2004, 17(5): 609-613.

[Abstract](1335)

Abstract:
Based on systematic field survey and comprehensive analyses, the types, characteristics, influencing factors and mechanism of the deformation and failure of high slopes, located in two sides in the lock site region of a hydropowerstation in southwestChina, were investigated. The research shows thatt...

FEM-Based Parametrization Design of Cone Angle of Anchors

ZHAOTong, ZUO De-yuan, TONGJian-gang

2004, 17(5): 614-617.

[Abstract](1465)

Abstract:
A parametrical non-linear finite element model for mono-strand anchors was established. The influence of cone angle on the mechanical characteristics including deformation and stress distribution was analyzed, and a newwayto determine the optimum cone angle, parametrization design by usingFEM(finite...

Random Optimal Vibration Control of Combined Isolation Structures

ZOULi-hua, ZHAO Ren-da

2004, 17(5): 618-622.

[Abstract](1458)

Abstract:
A new pattern of structures, combined isolation structure, was presented, and its vibration and control equations were derived. Based on the hypothesis that the input for earthquakes is white noise and using the principle of random optimal control, the features of vibration control and the effects o...

Experimental Research of Shear Lag Effect of Cable-Stayed Bridge withΠCross-Section Main Girder

WANZhen, LIQiao, MAOXue-ming

2004, 17(5): 623-627.

[Abstract](1662)

Abstract:
Amodel for a prestressed concrete cable-stayed bridge with aΠcross-section main girder was established in a scale of one to five for a concrete cable-stayed bridge over the Jinsha River in Yibin City. The shear lag effect of this bridgewas analyzed experimentally andwas comparedwith the one obtained...

Analysis of Loaded Frequency of Simply-Supported Beam Bridge

TANGHe-qiang, SHENRui-li

2004, 17(5): 628-832.

[Abstract](1629)

Abstract:
Based on the definition of natural bridge frequency, the analytical expression of loaded frequency of a simply-supported beam bridge under train loads was given through solving the vibration differential equation for bridges . The research shows that the loaded frequency of a bridge is in relation t...

Visual Load Paths in Elastic Structures Based on Equilibrium Principle

WANPeng, ZHENGKai-feng

2004, 17(5): 633-637.

[Abstract](1568)

Abstract:
Based on the definition of load paths, an approach was proposed to determine visual load paths in elastic structures. This approach is based on the equilibrium principle and combines the finite element method and the stream tracing algorithm. In order to get continuous visual load paths, commercial ...

Bifurcations of 2-Multiple Semistable Limit Cycles of Airfoils with Cubic Nonlinearity

LIUFei, YANG Yi-ren

2004, 17(5): 638-641.

[Abstract](1385)

Abstract:
Bifurcations of 2-multiple semi-stable limit cycles, as well as supercritical and subcritical Hopf bifurcations of an airfoil flutter system with cubic nonlinearity in incompressible flows were studied. Air speed and the linear stiffness coefficient of pitching were taken to form a 2-dimensional par...

Bifurcation of Nonlinear Plate-Type Beams in Inviscid Fluids

LULi, YANG Yi-ren

2004, 17(5): 641-644.

[Abstract](1309)

Abstract:
The bifurcation of parallel plate-type beams with cubic nonlinear stiffness in inviscid fluids was investigated. A nonlinear model for a simply supported plate-type beam in inviscid fluids, a solid-liquid coupling system, was established on the basis of the hypothesis that all the plates have the sa...

Synchronization between Two Chaotic Systems Using Lyapunov Method

TANXiao-hui, ZHANGJi-ye, YANG Yi-ren

2004, 17(5): 645-647.

[Abstract](1368)

Abstract:
Based on Lyapunov stabilitytheory and exemplified by aLorenz system, synchronization between two chaotic systems was achieved by directly transmitting the output of the drive system to the response systemto control the outputof the response system. Thismethod helps to avoid using complicated control...

Influence of Damping Characteristics of Dampers on Dynamic Performances of Four-Axle Power Cars

LUO Yun, CHENKang, JINDing-chang

2004, 17(5): 648-652.

[Abstract](1544)

Abstract:
A dynamic model for a four-axle power car was established and analyzed by using software SIMPACK and the nonlinear response analysis in time domain with random track irregularity to improve its dynamic performances. The numerical results show that the optimum damping coefficients of the secondary la...

Establishment and Application of Prediction Model for Total Phosphorus in Channel Reservoirs

LIUYang, YANGLi-zhon

2004, 17(5): 653-655.

[Abstract](1468)

Abstract:
Based on the different hydrological and hydraulical conditions of channel reservoirs during a hydrological year, the prediction model of their total phosphorus (TP) was established by combining the 2- D straight river model and the polar coordinate diffusion model proposed by A B Karaueshev (A B Kap...

SONG Wen； YILiang-zhong； MUXing-jun

SONG Wen, YILiang-zhong, MUXing-jun

2004, 17(5): 656-659.

[Abstract](1024)

Abstract:
Based on the structural theory of Petri nets, the boundedness and liveness monotonicity of a subcategory of asymmetric choice (AC) nets, new extended strong asymmetric choice (NESAC) nets, were studied. The sufficient and necessary condition for determining structural liveness and boundedness of an ...

Simulation Investigation of Channel Access Mechanism for 802.11e EDCF

ZHANGLian-bo, FANGXu-ming

2004, 17(5): 660-664.

[Abstract](1033)

Abstract:
To deeply discuss the mathematics model for EDCF (enhanced distributed coordination function), the performances of two access mechanisms, 802.11 DCF (distributed coordination function) and 802.11e EDCF, were analyzed and compared through simulation. The differences between 802.11 DCF and 802.11e EDC...

A Family of Irregular LDPC Codes Based on Optical Orthogonal Codes

WENHong, HUFei, JINFan, DUANHui-yong

2004, 17(5): 665-669.

[Abstract](1115)

Abstract:
Based on the optical orthogonal codes, a method for constructing irregular LDPC (low-density parity check) codes was presented. These LDPC codes are quasi-cyclic codes and can be encoded with low complexity with a linear relationship to code length. These codes haveTanner graphs free of 4-cycles. Th...

Automatic Abstraction Algorithm for Timed Automata

ZHIXiao-li, TONG Wei-qin, RONGLu

2004, 17(5): 670-674.

[Abstract](1300)

Abstract:
To deal with the state-explosion problem in the specification analysis and verification of timed automata, an automatic abstraction algorithm for timed automata was proposed. By directly abstracting the specifications of a timed automaton instead of its semantic model ofmuch bigger size, this algori...

New Comprehensive Learning Method Based on LM-QuasiNewton Algorithm Applying for Feed-Forward Neural Network

XUJin

2004, 17(5): 675-679.

[Abstract](1503)

Abstract:
To solve the large residual problems which may occur during weight training, QuasiNewton algorithm was combined with Levernberg-Marquardt algorithm to form a new comprehensive learning algorithm, named LM-QuasiNewton, for feed-forward neural networks. Simulation shows that LM- QuasiNewton algorithm ...

Asynchronous Parallel Iterative Algorithm Solving Equation of Higher Degree

YANG Ben-li, LIAn-zhi, ZENGXian-wen, HANWei-hua

2004, 17(5): 679-683.

[Abstract](1332)

Abstract:
By using the method for positive term resolution of equations of higher degree, all non-zero real roots of a real coefficient equation of higher degreewere obtained by determiningthe abscissas of intersection points of two monotonically increasing concave functions in the first quadrant of a planar ...

Properties and Computation of Linear System Transfer MatrixH∞-norm

XUYue-liang, LI Zhi

2004, 17(5): 684-687.

[Abstract](1584)

Abstract:
An equivalence theorem was derived to determine if the transfer matrixH∞-norm between two linear systems [A,B,C,D] and [A+BR-1DTC,BR-1/2,(I+DR-1DT)1/2C,0] is smaller than 1. This theoremwas then used to derive another theorem about the stability of system [A,B,C,D]. This equivalence theorem simplifi...

Interval Estimation of Chance-Constrained Programming Based on Genetic Algorithm

CHENGao-bo, LIUHai-yan

2004, 17(5): 687-690.

[Abstract](1875)

Abstract:
The interval of the optimal value of the non-linear objective function of chance-constrained programmingwas estimated from the viewpoint of mathematical statistics, and the ways of improving the precision of the estimated interval were discussed. The genetic algorithm and the spline regression were ...

Semantics of Lattice-Valued Tense Propositional Logic System

LI Wen-jiang, XUYang

2004, 17(5): 691-695.

[Abstract](1307)

Abstract:
Tense operatorsE(ever)andF(will)as well as their dual operatorsH(ever always be) andG (will always be) were introduced into lattice-valued propositional logic system LP(X), forming a lattice- valued tense propositional logic system LTP(X).It takes time axis as language circumstances. The properties ...

Comparison of Dissolving Processes for Preparation of Nano-CeO2Powers

ZHANGXi-yan, GAOJie-ming, ZHOUShi-jie, ZHANGJin

2004, 17(5): 696-698.

[Abstract](1124)

Abstract:
The dissolving processes with HCl and HNO3were compared experimentally. The proportion of dissolved CeO2with HCl was less than 25% accompanied with large consumption in raw materials and serious pollution by Cl2, unsuitable for production. On the other hand, the proportion of CeO2dissolved withHNO3w...

Research of Reflection Characteristics of Magnetic Boundary

GUANZheng-tao, ZHANG Shuang-wen, LIUYun-lin, YANG Ru-gui

2004, 17(5): 699-702.

[Abstract](1219)

Abstract:
To provide a basis for the deep research of the transmission characteristic of magnetic radome, the reflection characteristics of an air-magnetic boundaryon a planarwavewith different incident angleswere investigated. By changing the parameters of magnetic media, the relationships between the reflec...

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2004 Vol. 17, No. 5