西南交通大学学报

Overview of Fuzzy System Structure Identification

XIAO Jian, BAI Yifeng, YU Long

2006, 19(2): 135-142.

[Abstract](1495)

Abstract:
Fuzzy system identification is one of the main approaches of fuzzy system modeling.Optimized fuzzy system structure is the key of fuzzy system identification.The state of art of fuzzy system structure identification was briefly reviewed.Widely used methods of fuzzy system structure identification were discussed,including those based on fuzzy clustering,self-organizing neural-fuzzy network,support vector machine,kernel function,hierarchical fuzzy system,genetic algorithm and multi-resolution analysis.The characteristics of the methods were analyzed in detail.Future research directions of fuzzy system structure identification were outlined.

GeneralH ierarchicalFramework ofAgent in MAS EnvironmentBased on UML

TONGXiaoyang, WANGXiaoru, HANXudong, GAO Shibin

2006, 19(2): 143-149.

[Abstract](1233)

Abstract:
The agentmodel in amulti-agent system (MAS) environmentwith the restriction of time and resourceswas investigated, and a generalhierarchical framework of the hybrid agentwasproposed. This framework has a four-layer structure with feature declaration, mental status, computing and processing, and information interacting layers. The architecture, roles in the organization and components of the agentwere analyzed. UML (unified modeling language) technologieswere used to construct the conceptualclassdiagram of the agen.t The designmethodsof formalization expression and general agentprogram were given. The implementationmechanism of integrated scheduling engine and concurrentmessage processing was expatiated. The framework has been applied to the research of wide-area power line protection agentof theQinghai-Tibet railway, andmulti agentswere designed to implement the collaborative protection function to solve the problem of improper actions resulted from the traditional protection. The application shows that the proposed framework is effective for the complex problem.

Compound Approach of Predicting Fault Gases Dissolved in Transformer Oil

ZHOU Lijun, WU Guangning, SU Chong, WANG Hongliang

2006, 19(2): 150-153.

[Abstract](1473)

Abstract:
To improve the prediction result for transformer faults,a compound approach combining GM (1,1) model with self-learning BP-neural networks was proposed to predict fault gases dissolved in transformer oil.In this approach,the concentration and development trend of gases dissolved in transformer oil are predicted primarily using GM (1,1) model,and then the predicted results are calibrated by self-learning BP-neural networks with calibrated parameters obtained by analyzing the interaction of different types of gases and the relationship between the time sequences of gas concentrations.The proposed approach has been used in the practice of transformer fault prediction to show its validity.

Multipath Routing Protocol Based on Source Routing

ZHOU Xun, MA Hongge, LU Yu

2006, 19(2): 154-158.

[Abstract](1316)

Abstract:
To further effectively utilize network resources,the multipath mechanism was used to improve the network performance of OLSR (optimized link state routing),and a source routing-based SR-MPOLSR (source routing-multipath OLSR) protocol was proposed.In this protocol,MPRs (multipoint relays) are used to obtain the network topology effectively,and then the multiple Dijkstra algorithm is operated in nodes to calculate the routes and allocate the loads by the weighted round-robin.Finally,the source routing mechanism is adopted to retransmit data packets.The SR-MPOLSR can utilize the network resources ulteriorly,improve the throughput and average delay of chains,and increase the network robustness and dependability.The simulation result shows that compared with the OLSR,data deliver ratio for the SR-MPOLSR increases by 20% to 40%,and end-end delay reduces by 10% to 30%.

Recognition Approach of Signals Based on Short-Time Comparison Distribution

GAN Quan, LIAO Cheng, HU Laizhao

2006, 19(2): 159-162.

[Abstract](1159)

Abstract:
To recognize signals rapidly and effectively in the time-frequency domain,the concept and core function of short-time comparison distribution (SCD) were proposed for short-time signals through analyzing the short-time signal’s ambiguity function in the time-lag domain.As a result,a new approach of recognizing complex signals can be realized by selecting several short-time sections of a complex signal to be recognized and comparing their SCDs.Experimental results show that because the SCD of a short-time signal has a powerful ability in cross term suppression,the approach not only reduces the amount of calculation but also has a better anti-noise performance.

Answer Set Semantics for Ordered Logic Programs

ZHOU Yong, ZHU Wujia

2006, 19(2): 163-167.

[Abstract](996)

Abstract:
Based on the fixed-point theorem,a new method to treat the priori order was proposed in order to unify and extend the different answer set semantics resulted from different ways of dealing with the prior order in logic programs with a rule order.With this method,the rule order was taken into account in the iterative procedure of rules.As a result,nine kinds of answer set semantics were obtained,and the correlation between them was discussed in detail.It was proved that those nine semantics do not form a linear structure but a normal lattice structure.Furthermore,in ordered stratified logic programs,all of the nine answer set semantics become the normal answer set semantics.

System Reliability of Continuous Composite Beam Based on European Standard

XU Haiqing

2006, 19(2): 168-173.

[Abstract](1449)

Abstract:
The reliability calibration of continuous composite beams shows that to a continuous composite beam designed as composite section classes Ⅰ and Ⅱ and with 2 to 4 spans,its reliability,as a system,does not meet the requirement of EC1 (Eurocode 1) even though all sections are designed according to EC 4 (Eurocode 4) and have a reliability index greater than or equal to 4.7 according to EC1.Therefore,an extra safety factor was introduced.As a result,a continuous composite beam designed according to EC1,as a system,has the necessitated reliability.

Redistribution of Longitudinal Shear Force on Interface of Steel-Concrete Composite Beams

MAO Xueming, ZHAO Renda, WAN Zhen

2006, 19(2): 174-178.

[Abstract](1434)

Abstract:
By taking a simply supported composite beam under uniformly distributed load as an example,the redistribution of longitudinal shear force,induced by the plastic deformation of flexible connectors such as studs,was investigated.Based on the actual working condition of the connectors,the mechanical full-range of the interface of a steel-concrete composite beam was divided into elastic,elasto-plastic and failure stages.Simplified analytical models were established for every stage and corresponding formulae for calculating longitudinal shear force and axial force were derived.The research shows that axial force increases linearly with the increase of load when the redistribution is taken into account and load is less;then with the growth of load,the increasing is non-linear;lastly,it trends to be unchanged.

Analyses of Stresses and Force Transmission Route in Box-Shaped Anchorage Zone for Cable-Stayed Bridges

ZHANG Yuzhi, LI Qiao, MAN Honggao

2006, 19(2): 179-183.

[Abstract](1457)

Abstract:
The finite element method was used to investigate stresses in the box-shaped anchorage zone for a cable-stayed bridge in order to give the quantitative description of cable force distribution along principal welding lines,the mechanical characteristics of the main plates and the cause of stress concentration.The research shows that the pad plate of the anchorage box bears about 20% of the total cable force,and its main function is not to bear the cable force but to transmit it to the two webs of the anchorage box.The two welding lines between the two webs and the girder web bear about 80% of the total cable force,and they bear almost equal force.The distribution shape of shear stress on the two welding lines looks like a saddle,and the concentration of stresses on the main plates is caused by in-plane and out-of-plane concentrated forces and bending moments.

Centrifugal Model Test for Ground Surface Subsidence Caused by Metro Tunneling in Saturated Soft Clay Strata

QI Taiyue, GAO Bo, MA Liang

2006, 19(2): 184-189.

[Abstract](1653)

Abstract:
To choose the optimum construction method for metro tunneling in saturated soft clay strata,the control effects of pumping,dynamic pumping and un-pumping construction methods on ground surface subsidence caused by metro tunneling in saturated soft clay strata were compared through centrifugal model tests by taking the integrated effects of fluid-solid coupling,time and tunneling process into account.The research result shows that the un-pumping construction method is the most effective method for metro tunneling in saturated soft clay strata in the three methods.The research results have been successfully applied in the construction of the Shenzhen metro.

Shaking Table Test of Composite Foundation Reinforcement of Saturated Silty Soil Ground for High Speed Railway

JIANG Guanlu, LIU Xianfeng, ZHANG Jianwen, ZHAO Ruyi

2006, 19(2): 190-196.

[Abstract](1621)

Abstract:
Three shaking table model tests were conducted with a geometrical scale of 1:10 using a large-scale laminar shear box to investigate the reinforcement effects of compacted gravel column-net composite foundation and cement fly-ash gravel (CFG)column-net composite foundation on the saturated silty soil ground along the Beijing-Shanghai high speed railway.The research results indicate that the increase of excess pore water pressure can be restrained effectively by the compacted gravel column-net composite foundation to improve the anti-liquefaction ability of ground,and that shear displacement of ground can be reduced greatly by the compacted gravel column-net and CFG column-net composite foundations to improve the anti-shear displacement ability of ground.Furthermore,the amplifying of response acceleration,induced by foundation liquefaction,and the settlement of foundation and subgrade can be reduced greatly by the compacted gravel column-net and CFG column-net composite foundations to improve the aseismatic property of foundation and subgrade.

In-situ Test of Anti-washing-out of Red-Bed Soft Rock Slope Protected by Plants

ZHOU Lirong, XIANG Bo, ZHOU Depei

2006, 19(2): 197-201.

[Abstract](1155)

Abstract:
An in-situ washing-out test was carried out by the artificial simulation of rainfall to quantitatively investigate the anti-washing-out of a red-bed soft rock slope protected by plants.Some parameters,such as runoff amount,rainfall interception and erosion volume,were measured in the conditions of different rainfall intensities.The results show that a red-bed soft rock slope protected by plants is not washed out nearly when the rain intensity is 20 and 50 mm/h and the duration is 190 and 120 min respectively,and that ecological protections can prevent a red-bed soft rock slope from weathering and disintegrating in a water environment to decrease its washing-out.

Adjusting Model and Algorithm for Application of Arrival and Departure Lines in Technical Stations

WANG Zhengbin, DU Wen

2006, 19(2): 202-205.

[Abstract](1707)

Abstract:
To meet the requirement of application of arrival and departure lines and reduce the mutual interference of operations and routes,an adjusting model for the application of arrival and departure lines was set up to railway technical stations.From the characteristic of nonlinear programming of this model,an equivalent model was designed based on analyzing the causes of the interference.Furthermore,a genetic algorithm was presented in accordance with the characteristics of the equivalent model and was verified by an actual example,the running time of program being less than 100 s.

System Dynamics Model for Pricing of High-Speed Railways

SHUAI Bin, SUN Chaoyuan

2006, 19(2): 206-209.

[Abstract](1911)

Abstract:
An SD (system dynamics) flow chart for rational pricing of high-speed railways was drawn.Based on the flow chart,a simulation model and the corresponding equations were presented.The SD model can be used for simulation during the pricing process.The ideas of price policy makers can be reflected in the SD model,and the parameters in the model can be controlled as necessary,so that it has excellent controllability and flexibility.The pricing of Jing-Hu (Beijing-Shanghai) high-speed railway was taken as example of simulation.The simulation result shows that the variation of prices and its influences on gross transport earnings and profits are accordant with the system dynamic consequences,which indicates that the proposed model is feasible.

Optimization of Flash Butt Welding Parameters for Welding of U75V Rails

DAI Hong, LUO Deyang, TAN Keli

2006, 19(2): 210-213.

[Abstract](1594)

Abstract:
Welding procedure tests were arranged with orthogonal design on 13 important parameters to optimize the welding parameters for welding of U75V rails.The factors affecting the welding quality were analyzed according to the results of the welding procedure tests.Among the 13 parameters,feeding speed is the most important.The optimized welding procedure was obtained and has been successfully applied in production.

Fatigue Reliability of Contact Wire

WAN Yi, DENG Bin, LI Huijie, TIAN Zhijun, KE Jian

2006, 19(2): 214-217.

[Abstract](1884)

Abstract:
Vibration equations of contact wires were used to derive the formulae for calculation of mean and standard deviations of stresses.Statistical characteristic of fatigue strength of contact wires was obtained by comprehensively considering such coefficients as stress concentration,size and surface quality.A mathematic model for fatigue reliability of contact wires was presented based on statistical principle.Analyses results show that the materials,tension and rigidity of wires,speed of trains,wave speed,and lift forces are primary factors that affect fatigue life of contact wires.

Damping Characteristics of Microfluid on Perforated Disks with a Centre Hole

WANG Weidong, JIA Jianyuan

2006, 19(2): 218-222.

[Abstract](1235)

Abstract:
Based on the equations of gap flow and squeezed flow,the viscous-modified solution under the slip boundary condition was obtained to calculate the damping characteristic of microfluid acting on a perforated disk with a centre hole.The correlation between the kinetic damping and dimensions of the perforated disk,such as the gap and the radius of the centre hole and the thickness of the disk,was obtained.An analytical expression of damping composed of slide film damping and squeeze film damping was presented.It was found that the damping of microfluid acting on the disk is correlative with surface characteristics of the disk.Suitable equivalent viscosity can be obtained by introducing a momentum accommodation coefficient to calculate the damping forces of microfluid acting on moving objects.A calculation example shows that the analytical solutions accord well with the numerical results obtained with finite element method.

Linear Detection Method for Multiple Damages in Structures

ZHANG Jiping, CHEN Qiu, CAO Jixing

2006, 19(2): 223-226.

[Abstract](1366)

Abstract:
The definition of variation rate of the first modal was presented.It was proved that the variation rates are superpositionable,so that the variation rate of the first modal caused by multiple damages is obtained by superposition of all variation rates of the first modal caused by all the damages.Therefore,the variation rate of the first modal is taken as the signature for damage detection,and multiple damage state is transformed into superposition of single damage states.The procedure of the proposed method was presented.A simply-supported beam and a square plate fixed at four sides were taken as example.The results show that the method can precisely determine the damage state with a simple procedure.

Dynamic Three-Dimensional Game about Advertisement,Service and Price

WANG Zhenhui, TAN Deqing, YAN Honglin

2006, 19(2): 227-230.

[Abstract](1395)

Abstract:
According to the characteristics of dynamic multidimensional game,a model of dynamic multidimensional game with complete information between two firms about product pricing and expenditures on advertisement and services was established,and its equilibrium solution was obtained.The two-dimensional equilibrium for advertisement-price or service-price games can also be easily obtained by setting the corresponding parameter in the solved equilibrium to zero.The equilibrium indicates that the characteristic of equilibrium solutions to static and dynamic multidimensional game accords with that to one-dimensional game.

Axiomatic Analysis of Serial Cost Pricing

ZHENG Liqun, WU Yuhua, XIA Qing

2006, 19(2): 231-235.

[Abstract](1235)

Abstract:
Axiomatic system of the homogeneous cost sharing was proposed,and serial cost pricing was analyzed axiomatically.The axiomatic characters of this cost sharing method are proven.The relation between the serial cost pricing and the axioms of upper bound,lower bound,free lunch,controllability of demand and consistency was discussed in detail.It is indicated that serial cost pricing meets all the axioms in the homogeneous axiomatic system except monotony of cost function,control of demand and consistency.Serial cost pricing was compared with average cost pricing in terms of meeting the atoms of upper bound,lower bound,free lunch and control of demand.The result shows that serial cost pricing is obviously better when the needs of agents are easily controlled.Otherwise,average cost pricing is better.

Consistency Improvement of Comparison Matrix Based on Geometric Consistency Index

ZHOU Qunyan, TIAN Peng, TIAN Zhiyou

2006, 19(2): 236-240.

[Abstract](1351)

Abstract:
A new criterion,consistency-credibility degree,of comparison matrix was defined by introducing the principle of "possibility-satisfiability degree" to overcome the deficiencies of available consistency improving methods.Row geometric mean method (RGMM) was taken for determining weights,and geometric consistency index (GCI) was taken as consistency measure.Then a new consistency improving method was proposed.An example was presented to show that this method abstains from the unreasonableness of traditional improving criterions,and the optimal improved matrix obtained preserves the original preference information as much as possible as well as improving the consistency of comparison matrix.

Order Allocation Model Based on Profit Maximization of Horizontal Conglomerate

XIANG Jinqian, HUANG Peiqing, WANG Ziping

2006, 19(2): 241-244.

[Abstract](1548)

Abstract:
Order allocation among member enterprises of a horizontal conglomerate is the key problem when the conglomerate headquarter is responsible for obtaining all market orders.A 0-1 programming model was established for allocation of market orders by taking maximum profit as the objective.In the model,the factors,such as stock share,capital cost and operation fixed cost,etc.,are taken into account.Optimum allocation of the market orders,as well as the production and transportation plans for the member enterprises,can be obtained by solve the 0-1 programming model.An example was presented to show the procedure of solving the model.

Computer Aided Decision-Making System for Staff Promotion Based on Fuzzy Neural Network

REN Xinxin, LI Qiang, WU Zhenye

2006, 19(2): 245-249.

[Abstract](1343)

Abstract:
To analyze the factors influencing staff promotion,the Takagi-Sugen model,a method of fuzzy neural network,was modified.The input variables in the modified model include fuzzy and non-fuzzy ones.An extended pi-sigma artificial neural network algorithm,in which summation,multiplication and minimization nodes are available,was used to determine conclusion and premise parameters,and to summarize the fuzzy logic from staff databases adaptively.An example shows that the accurate rate of the method is over 75%.

Entropy,Information and Evolution of Structure of Enterprise Organization

XIN Zhihong, HU Pei, YU Xiang

2006, 19(2): 250-252.

[Abstract](1358)

Abstract:
The correlations between an open system and its subsystems were analyzed quantitatively based on the theories of entropy and information.A model was established for describing the evolution of enterprise organizations.As the development of an enterprise,it has to find a new organizational structure to decrease the entropy of organizational structure and advance to a new state of orderliness.

Asymptotic Analysis of Nonlinear Two Species Competition in a Reaction-Diffusion System

WANG Geng

2006, 19(2): 253-255,263.

[Abstract](1305)

Abstract:
A class of nonlinear two species competition singularly perturbed initial-boundary-value problems in a reaction-diffusion system in biomathematics was studies using the modern method of differential equation.The existence and asymptotic behavior of the solution for the initial-boundary-value problem were discussed using the theory of differential inequalities under the assumption that the degenerate problem has a positive solution and the functions in the system are continuous.The uniformly efficient estimate of the solution for the system was obtained.

Rules of Inference in Lattice-Valued Propositional Logic Lvpl

CHEN Shuwei, XU Yang

2006, 19(2): 256-258.

[Abstract](1151)

Abstract:
To describe reasoning methods such as minimizing,multiple reasoning,multi-dimensional reasoning etc.,corresponding rules of inference in lattice-valued propositional logic Lvpl are introduced.These rules are composed of two parts,semantics and syntax,and there exists a certain consistency between the two parts.It is proved that,with an appropriate level of consistency between semantics and syntax,L-type fuzzy subsets of the set of all formulae of Lvpl are closed to a certain extent with respect to these rules of inference when they are homomorphic.

Construction Method of Fuzzy Concept Lattices Based on Residual Implication

SUN Shibao, QIN Keyun

2006, 19(2): 259-263.

[Abstract](1166)

Abstract:
The residual implication generated from lower semi-continuous triangular norm was introduced.Fuzzy concept lattices with respect to a fuzzy formal context was derived,and their hierarchical structure,fuzzy concept generated from fuzzy set and the fix point of Wille operator were discussed.Examples were presented to illustrate the constructing method of fuzzy concept lattices based on Godel residual implication.

Performances of Dominant Strains for Degradation of COD in Leachate

QIU Zhongping, YANG Lizhong, LIU Dan, LIU Yuanyue, WU Min, WANG Yanjie

2006, 19(2): 264-268.

[Abstract](1381)

Abstract:
Five dominant strains that can effectively degrade COD in leachate were selected based on a series of experiments,in which the concentration of leachate was increased step by step.The performances of the five dominant strains for degradation of COD were studied.The experimental results show that the degradation rate of the composite strains is 45.3% under the condition of 30℃ and pH 7.All the five strains are aerobic.The optimum time of degradation of COD in leachate is 120 h, and the best pH is 7 for all of five strains.The degradation performances of the composite strains are better than those of single ones.Carbon source has positive effect on leachate degradation,while nitrogen source negative.

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2006 Vol. 19, No. 2