西南交通大学学报

Relationship of Distance Between Stations and Passenger Train Speed-Rising in Double Track Automatic Block Segment

PENG Qi-yuan, YANHai-feng

2003, 16(6): 615-618.

[Abstract](1310)

Abstract:
By a theoretic analysis and computer simulation, the relationship of number and speed of speed-rising trains and distance between stations in a double track automatic block segment was investigated under the given speed and deduction coefficients. The regularity of variation in these factors was obtained through the theoretic analysis, and the result was verified by computer simulation. At last, the relationship of number and speed of express passenger trains and distance between stations was obtained.

Principal Component Analysis of Dependency of Urban Intersections

DONG Jing, ZHANG Yi, ZHANG Zuo, KUANG Xiao-xuan

2003, 16(6): 619-622.

[Abstract](1489)

Abstract:
From the characteristics of urban traffic flow, the principal component analysis(PCA) was applied to analyzing the dependency of urban intersections, and the corresponding model and algorithm were proposed. Through the analysis of historic data of traffic flow in twenty intersections in Beijing City, as an example, the dependency of these intersections was obtained. As a result, the research offers a reference for the intelligent control of traffic signals and the guidance of vehicles .

Scheduling of Single-Item Freight Transportation and Inventory

LI Bing, DU Wen

2003, 16(6): 623-628.

[Abstract](1351)

Abstract:
The single-item freight transportation and inventory scheduling problem with a time- varying demand and a convex cost function was investigated. To minimize farthest the total cost of transportation and inventory, the optimal transportation and inventory scheduling scheme must be arranged. For this reason, a graph algorithm to optimize transportation and inventory scheduling schemes was proposed. At last, the proposed algorithm was illustrated using an example. The result shows that the algorithm is feasible.

Risk Prediction of Water Inflow into Extra-long Qinling Tunnel with Environmental Isotopes

LIU Dan, YANG Li-zhong

2003, 16(6): 629-632.

[Abstract](1484)

Abstract:
A comparison of environmental isotopes D and3H in surface water and deep underground water shows that F4, a regional fault in the northern slope of extra-long Qinling tunnel, has a poor hydraulic conductivity and there is no direct hydraulic connection between Shibianyu river flowing across fault F4and deep underground water. The calculated result with environmental isotope tritium shows that the possible amount of water inflow into the tunnel from the river will be less than 6% of total possible water amount. For this reason, there is no the possibility that water in the river flows into the tunnel through fault F4.

Analyses of No.108 Landslide in Beijing-Zhuhai Highway and Its Treatment Measures

ZHANG Yu-fang

2003, 16(6): 633-637.

[Abstract](1545)

Abstract:
Based on analyzing the conditions of landform, strata lithology, geologic structure and underground water, external and internal causes of No.108 landslide occurring were discussed, and the effects of two anti-sliding measures were analyzed. The result shows that eluvial-declivous soils in Quaternary system with a large thickness and low strength is the basic cause of the landslide, the enrichment of underground water, leading to the decrease in the shear strength of slide surfaces, is an important condition of its formation, and slope excavation and rail falling are the direct cause of the landslide. The analysis also indicates that the underground drain tunnel and bored grouting can control the development of a landslide effectively.

In-Situ Observation of Embankment Experiments on Soft Soil Roadbed of Second Xiaoshan-Ningbo Railway

YAN Qi-xiang, SHAO Chang-jiang, LIUHao-wu

2003, 16(6): 638-640.

[Abstract](1472)

Abstract:
The settlement, lateral displacement and pore water pressure for four schemes to consolidate the soft soil roadbed of the second Xiaoshan-Ningbo railway and the effect on the existing railway were observed on site and analyzed. These consolidation schemes are plastic plank, sand well and fibred fabric and cement-mixed pile.The observational result shows that consolidation of cement- mixed piles has more advantages over the three other schemes in reducing the settlement, lateral displacement and the influence on the existing railway and improving pore water pressure and is the best scheme.

2D and 3D Finite Element Analyses of Overlapping Tunnels

CHENXian-guo, WANG Xian-jun

2003, 16(6): 643-647.

[Abstract](1483)

Abstract:
ANSYS, a finite element program, was used to analyze three typical cross-sections for the first stage of Shenzhen metro project, and the effects of different driving sequences and lining methods were investigated. The calculated result shows that the construction of the second tunnel has an effect on the constructed tunnel, the displacement and the plastic zone are different for different driving sequences, and it is better to drive the upper tunnel when the lower one has been driven. In addition, simultaneous lining is helpful for the control of surface subsidence

Experimental Research on Seismic Fortification Properties of Unbonded Prestressed Concrete Frames

LIU Yan-hui, ZHAO Shi-chun

2003, 16(6): 647-650.

[Abstract](1481)

Abstract:
Through the experiment of two types of two double-span, single-story unbonded prestressed concrete frames under horizontal low cyclic loading, their destructive formation, ductility feature, strength, stiffness and energy-dissipating capacity were investigated. In the first type, beams and columns were collocated with unbonded prestressed bars, and in the second type, only beams with unbonded prestressed bars. The experimental result shows that non-prestressed frame members dissipate a amount of energy and columns have greater energy-dissipating capacity than beams, and that when the beams and columns of a frame are collocated with unbonded prestressed bars most of energy will be concentrated in its central column.

Application of Distributed Optical Fiber Sensing Technique to Detection of Cracks in Concrete

DING Rui, LIUHao-wu

2003, 16(6): 651-654.

[Abstract](1571)

Abstract:
To overcome the difficulty in the detection of cracks in concrete, distributed optical fiber sensors can be pre-embedded in structures. Based on the principle of crack detection using distributed optical fiber sensing technique, the layout of optical fiber was discussed, the relationship between light attenuation and crack width was investigated through tests in laboratory, and a semi- empirical formula for light attenuation and crack width was obtained. In addition, the measures of optical fiber sensor protecting in construction and their long-term stability and reliability in structures were discussed.

Stability Analysis of Long-Span Arch Bridge of Concrete-Filled Steel Tubes

SHEN Yao-xing, ZHAO Zhi-jun, HUA Xu-gang

2003, 16(6): 655-659.

[Abstract](1610)

Abstract:
The two methods, the linear and nonlinear bucking analyses, to determine the critical load of a long-span arch bridge of concrete-filled steel tubes were presented. A 3D FE model of Maocaojie arch bridge in Hunan, as an example, was set up, and its stability was analyzed using finite element program ANSYS. The effects of geometry nonlinearity, material nonlinearity and initial defects of the structure on the stability of this arch bridge were investigated. The results show that large displacement occurs at arch top when loading reaches to the load of stability loss, so the effect of large displacement should be considered in the analysis of stability; and the material nonlinearity and initial defects of the structure make its stability decrease.

Numerical Method for Vehicle-Bridge Coupled Vibrations

SHENHuo-ming, XIAO Xin-biao

2003, 16(6): 658-662.

[Abstract](1716)

Abstract:
The coupled vibration functions for a half railway vehicle model running on a simply sported beam bridge were derived. Based on Ruge-Kutta method, the coupled vibration functions were solved with the ODE serial functions of MATLAB. Compared with Nemark-βmethod, the proposed method has higher computing efficiency with the same accuracy.

Research on Control Strategy of Application of Magnetorheological Dampers to Structural Vibration Reduction

LENG Qian, YUJian-hua

2003, 16(6): 663-667.

[Abstract](1373)

Abstract:
Based on the Bingham resilience model, the control strategy of using magnetorheological dampers for structural vibration reduction was investigated. An improved control strategy and its mathematical model were proposed by considering the character of the dampers, and its simplified solution method was given. To verify the efficiency of the proposed strategy, a computer program was written and used for the simulation of an actual project. The simulative result shows that compared with the existing control strategy, the proposed control strategy has a better result and stability.

Structural and Dynamical Analyses of New Gauge-Changeable Bogies of Railway Passenger Car

HUANG Yun-hua, LI Fu, FU Mao-hai

2003, 16(6): 668-672.

[Abstract](1669)

Abstract:
Application and development of gauge-changeable bogies abroad are briefly introduced. According to the situation in China, a new scheme for gauge-changeable bogies was proposed, its structure was presented, and its dynamic performances were analyzed with numerical simulation. The results show that the proposed scheme is basically feasible, with good hunting stability and riding quality, except that the curving performance needs to be improved.

Subharmonic Resonance of Nonlinear Forced Vibration Systems

YEJian-jun

2003, 16(6): 673-676.

[Abstract](1459)

Abstract:
The forced vibrations of nonlinear systems were studied with the theory of nonlinear dynamics equations. The conditions for subharmonic resonance to exist were obtained, and the subharmonic periodic orbits of the system and their Melnikov functions were derived. The results presented can be used in prediction of chaotic motion of a nonlinear system.

Method of Noninferior Matrix of Multi-objective Dynamic Programming with Indefinite Phases

ZHAO Dong-mei, TAO Zhang-hua

2003, 16(6): 677-681.

[Abstract](1394)

Abstract:
From the fact that multi-objective programming with indefinite phases has usually only noninferior solutions, the concepts of the noninferior compound matrix of phase return and the recurrence matrix for multi-objective programming with indefinite phases were put forward. Based on these concepts, method of noninferior matrix to solve multi-objective dynamic programming problems with indefinite phases was given. In this method, it is not necessary to give the relative weights of objectives beforehand, and all the noninferior solutions can be gotten easily. The validity of the method was verified by an example.

Multi-attribute Group Decision-Making Algorithm Based on Group s Ideal Solution

PENG Yi, HU Yang, GUO Yao-huang

2003, 16(6): 682-685.

[Abstract](1452)

Abstract:
To solve multi-attribute group decision-making problems, individual judgements for each single attribute were aggregated into group judgement by using the ideal point method, and so a group s multi-attribute decision-making matrix was obtained. As a result, a complicated multi- attribute group decision-making problem was transformed into a general multi-attribute decision- making problem easy to solve and was solved using the ideal point method. Finally, a calculational example for the selection of a group investment project was given.

Profit Distributing Mechanism of Dynamic Alliance Based on Prior Consultation

HANJian-jun, GUO Yao-huang

2003, 16(6): 686-690.

[Abstract](1544)

Abstract:
Through considering the uncertainty of alliance profit and the expectation of each member in alliances to profit, a game model based on prior consultation for profit distributing of a dynamic alliance was set up. By analyzing the function of a prior contract of profit distributing in the cooperation behaviour and result of members, the effects of different distributing mechanisms on the total profit of a dynamic alliance were discussed, and the basic principle of determining the profit distributing mechanism of a dynamic alliance based on prior consultation was proposed. The research result shows that all the members in a dynamic alliance will select their behaviours in light of the prior contract of profit distributing to maximize their profit and so have an effect on the result of cooperation.

Analysis of Corrupt Competition in Bids

DENG Pei-lin, ZHANG Rui-ming

2003, 16(6): 691-694.

[Abstract](1387)

Abstract:
Based on the game theory, a game model was proposed to describe the behaviors of a benefit-shared alliance. Mutually dependent relationship between members in the competition procedure was analyzed. In addition, the basic features of profit-dividing groups was discussed, and a conclusion was drawn that lowering expected profit and increasing initial cost are efficient measures to prevent illegal profits in the competition.

Product Life Cycle Assessment Based on Enterprise Resources Planning System

DAI Ying

2003, 16(6): 695-698.

[Abstract](1380)

Abstract:
To perfect the data available for product life cycle assessment (LCA) in the current enterprise resources planning (ERP) systems, such as materials, products, technical process, transportation and solid waste, the framework of an ERP system supporting LCA was proposed. In this system, by adding an environmental function module, it can track, analyze and control environmental data for product production continuously and automatically gather the data for LCA. As a result, a new approach of implementing LCA and environment management was provided.

Necessary and Sufficient Condition for Identifying Independent Random Processes

LI Yu-qi

2003, 16(6): 699-702.

[Abstract](1343)

Abstract:
A necessary and sufficient condition for an identifying independent random process is that the finite-dimensional probability density function of the process can be expressed with a product of some one-dimensional functions. The only difference between the one-dimensional functions and the corresponding marginal density function is a constant, and the boundary constants are irrelevant with variables and parameters. Those are two important characters of density functions of independent random processes. Using those characters to avoid solving the marginal density function makes the identification of an independence of random process simple.

Discussion of Category Model of Relational Algebra in Relational Database

DU Ya-jun, XU Yang

2003, 16(6): 703-707.

[Abstract](1488)

Abstract:
To optimize multi-condition selection and projection operations in a relational database, a category model for relational databases was established based on the category theory and its characters were discussed. On the basis of this model, the connecting laws of selection and projection operations in the equivalent transformation of relational algebra in a relational database were investigated and the functions of the laws were extended.

Power Topological Molecular Lattice Category and Its Product Operation

JIANG Bao-qing, WANG Wei, QIN Ke-yun

2003, 16(6): 708-711.

[Abstract](1111)

Abstract:
Four categories, power molecular lattice category,L-base power molecular lattice category, power topological molecular lattice category andL-base power topological molecular lattice category, were defined. The relations between power molecular lattice and molecular lattice categories,L-base power molecular lattice and power molecular lattice categories, power topological molecular lattice and topological molecular lattice categories, andL-base power topological molecular lattice and power topological molecular lattice categories were discussed. It was proved that a - product of power molecular lattices is the product in power molecular lattice category, a product of L-base power molecular lattices is the product inL-base power molecular lattice category, a - product of power topological molecular lattices is the product in power topological molecular lattice category, and a product ofL-base power topological molecular lattices is the product inL-base power topological molecular lattice category

Generalized Satisfactory Theory and Its Characterization

YAO Xin-sheng, HUANG Hong-zhong, ZHOUZhong-rong

2003, 16(6): 712-716.

[Abstract](2320)

Abstract:
The concepts of satisfactory degree, satisfactory rank, satisfactory criterion, and satisfactory solution were defined based on system analysis, and the generalized satisfactory theory was introduced. By building an axiom system, the obtaining, identification and transformation of satisfactory solutions in application of the generalized satisfactory theory were analysed, and the correlation between satisfactory degree and satisfactory level was dervied .

Improvement of Quantum Genetic Algorithm and Its Application

ZHANG Ge-xiang, JIN Wei-dong

2003, 16(6): 717-722.

[Abstract](1823)

Abstract:
An improved quantum genetic algorithm (IQGA) was proposed to overcome the shortcoming of the quantum genetic algorithm(QGA),i.e.local optimization, when it is used for the optimization of continuous functions with many extreme values. In IQGA, the strategies of updating quantum gate using the best solution obtained and population catastrophe were adopted. The test results for two typical functions show that the convergence speed of IQGA is faster than that of QGA, and IQGA can converge in a global solution space, overcoming the shortcoming of QGA. The application results indicate that IQGA is better than QGA and other genetic algorithms.

Method of Fuzzy Analysis on Game with Uncertain Payoff

GUJian-zhuang, TAN De-qing, WAN Yu

2003, 16(6): 723-726.

[Abstract](1579)

Abstract:
The risk and expected payoff of players were analyzed with fuzzy comprehensive evaluation. The Nash equilibrium of the game was obtained with the classical game theory based on the fuzzy comprehensive evaluation results. An example was presented, in which the method was employed to compute the equilibrium. The result shows high income with high risk and low income with low risk, which is consistent with the reality, and verifies the feasibility of the proposed method.

Spectrum of OperatorTwhenT*=T2

CUIHong-wei, HAN Liu-bing

2003, 16(6): 727-727.

[Abstract](1232)

Abstract:
The concept of a self-conjugate operator in Hilbert space was extended by introducing the definition of a conjugate square-operator. The properties of the operator and the necessary and sufficient conditions for the regular value to exist were studied using the concept and properties of normal operators in Hilbert space, the spectrum mapping principle and analogy. The results obtained show that, whenT*=T2,the spectrum of conjugate square-operatorTis a finite spectrum.

Routing Protocol Based on Multimedia Traffic in Mobile Ad Hoc Networks—Adaptive Selection and Performance Analysis

ZHUXi-ping, FANG Xu-ming

2003, 16(6): 730-733.

[Abstract](1304)

Abstract:
In order to apply multimedia traffic in mobile ad hoc networks, the performances of AODV(ad hoc on-demand distance vector routing) and DSR(dynamical source routing) protocols at the transmission rate of 144 kb/s were investigated. Through analyzing and comparing their performances, the result indicates that a great packet delivery fraction can be obtained in AODV and its variation with mobility is small. In addition, average end-to-end delay forAODV is shorter under the high mobility, while the delay for DSR is shorter under the low mobility.

Efficient Remote Password Authentication Scheme Using Smart Cards

YUAN Ding, FANPing-zhi

2003, 16(6): 734-737.

[Abstract](1102)

Abstract:
To overcome the shortcoming of the present schemes, a remote password authentication scheme based on discrete logarithms and ElGamal public key scheme and using smart cards was proposed. In this scheme, any legitimate user can freely choose his own password at the registration phase, and at the verification phase, the scheme can verify the remote password without the need of his verification table. Forgery and replay attacks can be resisted using the scheme.

Research on Oil Sorption Behavior of Exfoliated Graphite

CHEN Yue-jun, SHOJI Muro, J RGEN Walter, DAI Guang-ze

2003, 16(6): 738-740.

[Abstract](1125)

Abstract:
The influence of specific surface and packed density on the specific sorption of exfoliated graphite (EG) with different particles and packed densities was investigated by a wicking method, and both diesel oil and A-grade heavy oil were employed as standard sorbates. The experimental result shows that the specific sorption of refined EG particles on diesel oil is not sensitive to the change of specific surface even from 0. 624 to 34. 200 m2/g, compared with the refined EG particles, worm-like EG ones have significantly high specific sorption on diesel oil, and the packed density of EG influences the specific sorption on A-grade heavy oil greatly.

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2003 Vol. 16, No. 6