• Issue 11,2010 Table of Contents
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    • >土木工程与建筑学
    • An Elastoplastic Doublehardening Constitutive Model for Shanghai Fine Sand Based on Modified Plastic Work

      2010, 38(11):1561-1567. DOI: 10.3969/j.issn.0253-374x.2010.11.001

      Abstract (1155) HTML (36) PDF 1.18 M (913) Comment (0) Favorites

      Abstract:Based on the results from a series of drained plane strain compression (PSC) tests along different stress path and isotropic loadingunloading triaxial tests on Shanghai fine sand,the modified plastic work shearvolumetric double hardening function is proposed,which is independent of stress history and stress path.Then an elastoplastic doublehardening constitutive model for Shanghai fine sand is formulated on the basis of the modified plastic work hardening function.The comparison between calculation results from the numerical method incorporating the proposed constitutive model and experimental data shows that the proposed constitutive model can reflect the deformation and strength behavior on Shanghai fine sand reasonably.

    • Anisotropic Creep Test of Greenchist Under Uniaxial Compression

      2010, 38(11):1568-1573. DOI: 10.3969/j.issn.0253-374x.2010.11.002

      Abstract (887) HTML (41) PDF 1.94 M (713) Comment (0) Favorites

      Abstract:The uniaxial creep tests of green schist from auxiliary tunnel at Jinping second stage hydropower station were carried out.An analysis was made of the influence of relationship between axial loading orientation and bedding plane on instantaneous strain,stress strain relation,axial strain rate,time duration of transient creep phase and creep breach mechanism.The instantaneous strain increment when axial loading orientation is perpendicular to bedding plane is larger than that when parallel to bedding plane under the same lower stress level,while,the result is on the contrary under the same higher stress levels.The axial strain rate and time duration of transient creep phase when axial loading orientation is perpendicular to bedding plane is smaller than that when the parallel to bedding plane under the same stress level.Meanwhile,the stress strain relation curve has initial crack closing stage,elastic deformation stage,crack extending stage and post failure stage when axial loading orientation is perpendicular or parallel to bedding plane,and the creep failure patterns under two kinds of conditions are both brittle.

    • Experimental Study on Environment Friendly Slurry for Slurry Shield Tunnelling

      2010, 38(11):1574-1578. DOI: 10.3969/j.issn.0253-374x.2010.11.003

      Abstract (884) HTML (40) PDF 1.52 M (744) Comment (0) Favorites

      Abstract:Based on water,clay,starch and minor solid alkali,an environment friendly slurry for slurry shields driving in sandy soils was invented by using the gelatinization property of starch.The true triaxial test coupled SteREO Discovery (V12) were performed to explore the mechanical property of an environment friendly slurry under the complicated stress state.And the mesostructure of a tight membrane and filter cake even in sandy soils were also observed.Experimental results indicate that the environment friendly slurry is characterized by short formation time,compact structure,strong infiltration capacity and wide area with respect to effective support pressure of the slurry.Furthermore,under the drained or undrained condition,the permeability of slurries has great effect on the strength and deformation of sandy soil,and the effective support pressure of slurries has an upper and lower limit value.

    • Experimental Study on BondSlip Behavior of Postinstalled Rebar at High Temperature

      2010, 38(11):1579-1585. DOI: 10.3969/j.issn.0253-374x.2010.11.004

      Abstract (839) HTML (27) PDF 3.62 M (854) Comment (0) Favorites

      Abstract:Specimens with 3d embedment depth were tested under different temperatures to study the bondslip behavior of postinstalled rebar.The specimens were heated by the electric furnace,and the test temperature ranged from 25 ℃ to 350 ℃.Records had been made on specimen temperatures,rebar slips and loads.When the specimen temperature reached to the design temperature,the specimen was tested and 5 specimens were tested at each design temperature.Based on the test results,the fitting model about ultimate strength and temperature and the fitting model about peak slip and temperature were obtained.While the fitting model about bond stress,temperature and slip was achieved,anchorage adhesive constitutive relationship at high temperature was obtained.The test results show that the ultimate strength decreases with the temperature increase,especially the ultimate strength is 4% of that of ambient temperature when the temperature is above 350 ℃.

    • Wind Tunnel Test Study on Wind Pressure on Typical Gable Roofs of Lowrise Buildings

      2010, 38(11):1586-1592. DOI: 10.3969/j.issn.0253-374x.2010.11.005

      Abstract (1077) HTML (51) PDF 1.66 M (1140) Comment (0) Favorites

      Abstract:The wind pressure distribution on four types of typical gable roofs of lowrise building models are studied with pressure measurement wind tunnel tests.Three aspects are respectively discussed:the distribution characteristics of mean and fluctuating wind pressure coefficient on four types of gable roofs and eaves at different wind angles,the influence of turbulence intensity on the fluctuating wind pressure distribution and the influence of different roof types on the wind pressure spatial distribution.A detailed analysis of the experimental results show that absolute values of mean wind pressure coefficients are larger at roof ridge and near the edge of roof than on internal areas of roof.Fluctuating wind pressure coefficients increase with the turbulence intensities,which are larger on upwind roof than those on leeward roof.Generally,there are larger fluctuating wind pressure coefficients near the windward eaves.The changes of eave shapes only have more obvious influences on local wind pressure coefficients than those on overall wind pressure coefficients.These conclusions provide reference for modifying clauses about wind loads on lowrise buildings.

    • >交通运输工程
    • United Evaluation Model of Traffic Operation Level for Different Types of Urban Road

      2010, 38(11):1593-1598. DOI: 10.3969/j.issn.0253-374x.2010.11.006

      Abstract (714) HTML (29) PDF 943.44 K (704) Comment (0) Favorites

      Abstract:New concept of road level of service (LOS) is proposed,which defines LOS into two parts:level of facility supply and level of traffic operation.Under the direction of this new concept,the ratio of travel speed to free flow speed (FFS) is selected as the evaluation index of traffic operation.Then,a test of traffic operation evaluation for urban expressway and streets,in which the experts are invited to grade different traffic operation level,is carried out.The result shows that,by introducing the FFS into the evaluation index to consider the difference of facilities,the evaluation methods of operation level for urban expressway and streets can be united.Finally,based on the concept of fuzzy set,the functions of degree of subordination is given for different level of traffic operation with the threshold value for each level following.

    • Pedestrian Flow Simulation Study at Main Entrance Square of Shanghai World Expo Park

      2010, 38(11):1599-1604. DOI: 10.3969/j.issn.0253-374x.2010.11.007

      Abstract (931) HTML (27) PDF 1.01 M (946) Comment (0) Favorites

      Abstract:Passenger flow of over 20 thousand in ShangNan Road Entrance Square (30 thousand square meters) of Shanghai World Expo Park was simulated by selfdeveloped passenger distribution simulation system.Pedestrian movement simulation model was established according to pedestrians’ admission characteristics which include random arrival and multistage controlled queue,irregular queue of various forms,and combination of queuing resting stage and walking dynamic stage.The model is composed of “behavior flow management layer” and “walking process control layer”,which can search route intelligently for passengers.Based on simulation results and queuing psychology,some suggestions were proposed on passenger flow organization,guiding facility layout,safe capacity of square and reasonable security inspection time.

    • Analysis of Social Equity in Congestion Pricing

      2010, 38(11):1605-1609. DOI: 10.3969/j.issn.0253-374x.2010.11.008

      Abstract (1044) HTML (14) PDF 930.73 K (933) Comment (0) Favorites

      Abstract:In both thecretical and practical studies,models are constructed to analyze the inequity impact to different travelers from congestion pricing.It is assumed that value of time of travelers follows continuous distribution.In an example network,the equilibrium behavior of travelers in choosing travel mode and route is established.Then the variation of travel mode,travel route and travel cost after congestion pricing is investigated,and it is found that travel time and travel cost decrease after congestion pricing for the majority of travelers.Specifically,most bus passengers and drivers with high VOT benefit from congestion pricing,but few drivers with lower VOT suffer from congestion pricing.

    • Calculation Method for Reasonable Fare Based on Operating Efficiency

      2010, 38(11):1610-1614. DOI: 10.3969/j.issn.0253-374x.2010.11.009

      Abstract (929) HTML (49) PDF 832.55 K (700) Comment (0) Favorites

      Abstract:An analysis is made of the farerelated factors of existing lines of URT,including passenger traffic volume,ticket revenue,transportation cost and exterior benefit to make the fare of urban rail transit (URT) more reasonable.A calculation method of reasonable fare is proposed based on the idea to maximize the operating efficiency.Taking the passenger traffic and fares data of Shanghai Metro Line 5 as the case data,the method is applied to finding the reasonable fare of Line 5.The empirical study results show that although high price can increase the ticket revenue of URT,the cost per passenger and the operation cost gradually increase along the ticket price; although lower price results in the ticket revenue reduction,the unit passenger’s transportation cost and the operation cost decrease gradually and the operation efficiency increases simultaneously.Therefore,it’s proposed that mazimizing operation efficiency of URT should be set as the basis of a reasonable fare.

    • >环境科学与工程
    • Total Chlorides and Bromines in Sewage Sludge and Variation of Total Bromines in Hydrolysis and Acidification Processes

      2010, 38(11):1615-1620. DOI: 10.3969/j.issn.0253-374x.2010.11.010

      Abstract (612) HTML (37) PDF 916.47 K (661) Comment (0) Favorites

      Abstract:The combined method of automatic quick furnace and ion chromatography was applied to investigating total chlorides and bromines in sewage sludge from eight wastewater treatment plants as well as total bromines in the degraded samples collected from hydrolysis and acidification processes.The results show that the content of total chlorides (0.63~3.6 mg·g-1) in sewage sludge is about one order of magnitude higher than that of total bromines (0.04~0.20 mg·g-1).Meanwhile,the content of total chlorides in this study is 2~4 orders of magnitude higher than that of organic chlorides in literature (0.08~6.9 mg·g-1).As for the hydrolysis and acidification processes,total bromines of sludge flocs are significantly degraded at pH 10.0 when compared with pH 5.5.However,the superiority of thermophilic condition on the degradation of total bromines of sludge flocs is uncertain when compared with mesophilic condition.This study reveals for the first time that the hydrolysis and acidification processes at pH 10.0 could reduce the total bromines of sludge flocs and thereby reduce the risk of sludge disposal (i.e.,land application,incineration).However,the volatile fatty acids (VFA) produced in the fermentation process at pH 10.0 may increase the risk as the carbon sources of tertiary treatment in WWTP,owing to the total bromines transferring from the solid state to the liquid state.

    • Electrokinetic Remediation Experimental Study of Heavy Metal Contaminated Soil

      2010, 38(11):1626-1630. DOI: 10.3969/j.issn.0253-374x.2010.11.012

      Abstract (756) HTML (18) PDF 1.22 M (889) Comment (0) Favorites

      Abstract:Electrokinetic remediation capability was researched by selfdesigned device.The interval power breaking method and voltage improving method were used to increase removal efficiency of single iron contaminated soil,and soil contaminated by three ions recovery through electrokinetic remediation was also done.The result shows that Cd removal efficiency of interval power breaking and voltage improving are respectively 6.17% and 0.56% higher than that of common experiment,and power consumption are 51.86% and 12.4% less.Removal efficiency of Cu,Pb and Cd are 68.56%,75.31% and 69.90%,respectively,which are lower than that of the same single iron,and power consumption are 5.0612 kJ·g-1,which is more than that of the same single one.

    • >机械、车辆与能源工程
    • Reliability Analysis of Railway Vehicle Structure Based on Stochastic Finite Element

      2010, 38(11):1631-1634. DOI: 10.3969/j.issn.0253-374x.2010.11.013

      Abstract (1015) HTML (19) PDF 933.81 K (931) Comment (0) Favorites

      Abstract:A method is put forward which combines the modified first order second moment method (MFOSM) of reliability theory and finite element method in the research.Based on a case study of the bogie framework,the reliability of the concerned part of the side beam is analyzed.The stochastic properties of materials,geometry and loads are considered in this study.The reliability index is obtained by iterating calculation.Further,the sensitivity indexes of reliability index with respect to the random variables are analyzed and the extent of the impact to structure design and manufacture reliability can be obtained.

    • Adaptive Synchronization Control of Diaphragm Wall Grab Crane with Double Main Hoist

      2010, 38(11):1635-1640. DOI: 10.3969/j.issn.0253-374x.2010.11.014

      Abstract (890) HTML (2) PDF 1.06 M (979) Comment (0) Favorites

      Abstract:A double hoist hydraulic system of diaphragm wall grab crane was introduced.A mathematic model was built for the double hoist synchronous system.Synchronous control strategy of proportional integral derivation(PID) with masterslave mode was adopted,and an online adaptive genetic algorithms (GA) was employed to optimize the parameter of PID.The simulation results show that the proposed algorithm has better control performance than traditional GA.Field test data indicate that there are good synchronizing effects by applying the proposed control strategy,and the synchronization precision can be controlled within±0.35°,which can meet the working requirements in engineering,and it is more capable of improving precision of synchronism driving than the PID control with traditional GA.

    • Energy Saving Analyses on Envelope Thermal Properties in Hot Summer and Cold Winter Region

      2010, 38(11):1641-1646. DOI: 10.3969/j.issn.0253-374x.2010.11.015

      Abstract (1076) HTML (26) PDF 1.08 M (1136) Comment (0) Favorites

      Abstract:Residential buildings were selected as the research object in the seven typical cities of hotsummer and coldwinter region.The model of sixstorey residential building was set up.Firstly,the effect of thermal properties of enclosure each component on energy consumption of residential buildings was analyzed by energy consumption software VisualDOE 4.0.Enclosures include roof,window,sunshade and exterior wall,et,al.Secondly,comprehensive measures schemes of energy saving were designed by the orthogonal experiment.Then,the building energy consumption and energy efficiency rates of different enclosures combination schemes were compared and analyzed.Finally,the optimize combination scheme is determined,exceeding the goal of enclosures saving 25% of energy.Simulation results are accordant with the experimental results.It is fully verified the correctness of the simulation calculations.

    • >电子、计算机、控制与系统
    • Mobile Robot Optimal Path Planning Based on Smoothing A* Algorithm

      2010, 38(11):1647-1650. DOI: 10.3969/j.issn.0253-374x.2010.11.016

      Abstract (1919) HTML (35) PDF 1.12 M (1586) Comment (0) Favorites

      Abstract:Path planned by A* algorithm for mobile robot under grid environment is flaw with much broken lines,frequently turning points,large cumulative turning angle.Smoothing A* is proposed in order to obtain optimum path.Based on the initial path planned by A*,traversing all the nodes on initial path,deleting the node which prolong the length of initial path as no obstacle existing on the line connected by forward and after nodes.Smoothing A* model is established after initial path processed.Simulation results show that smoothing A* exceeds Ant,Anytime D*.Length,total turning points,cumulative turning angle of path are almost reduced by 5%,50%,30%~60% respectively when smoothing A* algorithm is adopted.Path planning problem under different complex environment with random obstacles distribution can be achieved by smoothing A* algorithm.

    • Predictive Controller Design Based on Subspace Identification with Varying Forgetting Factor

      2010, 38(11):1651-1655. DOI: 10.3969/j.issn.0253-374x.2010.11.017

      Abstract (944) HTML (26) PDF 879.57 K (855) Comment (0) Favorites

      Abstract:In the existence of unpredictable disturbance and large changes in dynamic characteristics,a complete datadriven method based on subspace identification with variable forgetting factor is proposed for LTV multivariable system,without any priori structural information and identification of system parameters matrix.Predictive control is a modelbased control method.In order to establish better system model,the variable forgetting factor is structured by error of the real and predictive output value based on on-line identification.Thus the weight of the collection data is adjusted and identification sensitivity and control effect is improved.Finally,a simulation example is given to demonstrate the efficiency of the proposed algorithm.

    • An Adaptive Filter Method of LFM Signal Based on Swept Filter

      2010, 38(11):1656-1658. DOI: 10.3969/j.issn.0253-374x.2010.11.018

      Abstract (1130) HTML (45) PDF 879.32 K (902) Comment (0) Favorites

      Abstract:An adaptive filter method of linear frequency modulation(LFM) signal in white noise is discussed,and a LFM signal is produced.The LFM signal is transformed to sinusoid signal by Fourier reverse transform(FRFT).The adaptive filter,which can be replaced by swept filter,is implemented in domain u,and the filtered signal is gained with the fractional FRFT.A detailed analysis of the method performance proves that the method performance depends on adaptive filter.When LMS algorithm is used,the performance of ALE is decided by step parameter,and the step parameter is selected in practice.At last,Simulation results show that this filtering algorithm is simple to computated and easy to implement.

    • Design of Remote Environmental Monitoring System

      2010, 38(11):1659-1663. DOI: 10.3969/j.issn.0253-374x.2010.11.019

      Abstract (898) HTML (39) PDF 1023.89 K (635) Comment (0) Favorites

      Abstract:A remote environment online monitor system was designed to replace traditional environmental data monitoring systems,which collected monitoring data manully and whose monitoring effects were not ideal.Field data can be collected and restored by Siemens S7-200 PLC,and the realtime data of equipment’s state can be sent to the host computer automatically through the GPRS DTU,and receive the host computer’s instruction and send the history data within a specific time.The host computer receives and processes the data of remote terminals with the Winsock control of VB6.0.This system is applied to Nanhai District of Foshan City to improve the efficiency of environmental regulation.

    • Parameters Tuning and Poles Designation for Sensorless Induction Motor Drive

      2010, 38(11):1664-1668. DOI: 10.3969/j.issn.0253-374x.2010.11.020

      Abstract (780) HTML (42) PDF 999.20 K (715) Comment (0) Favorites

      Abstract:This paper presents a completely analysis for the state observer whose state variables are stator currents and rotor fluxes and a new poles designation method is proposed and a detailed process of designing is also described.Then the adaption laws for stator resistant and rotor resistant and speed are given.The proposed method is verified with simulation and experiments.

    • Soft Sensor Modeling of Leaf Water Potential Based on Improved Support Vector Machine

      2010, 38(11):1669-1674. DOI: 10.3969/j.issn.0253-374x.2010.11.021

      Abstract (973) HTML (44) PDF 931.13 K (598) Comment (0) Favorites

      Abstract:Based on study on least square support vector machine(LSSVM),the paper presents an improved particle swarm optimization (IPSO) algorithm to select the parameters of LSSVM.The soft sensor modeling of the leaf water potential is established based on IPSOLSSVM.Simulation results indicate that the method based on IPSOLSSVM is of a higher accuracy than the basic LSSVM and LSSVM based on PSO,which can well predict leaf water potential.

    • Survey on 5.8 GHz Electronic Toll Collection Technologies

      2010, 38(11):1675-1681. DOI: 10.3969/j.issn.0253-374x.2010.11.022

      Abstract (793) HTML (9) PDF 967.02 K (587) Comment (0) Favorites

      Abstract:Electronic toll collection(ETC) system is an important component of the intelligent transportation systems(ITS).5.8 GHz band,the mainstream of the international standard of ETC,was adopted by the national specifications of China on ETC that promulgated in 2007.Principles and composition of 5.8 GHz ETC system were described based on domestic ETC standard,and the key technologies of 5.8 GHz ETC system were summarized and analyzed.Then future research and development orientation were pointed out.The aim of the paper is to provide reference for a further study in 5.8 GHz ETC technology.

    • >计算机与信息工程
    • Dynamic Threshold Method of Establishing Trust in Open Environment

      2010, 38(11):1682-1688. DOI: 10.3969/j.issn.0253-374x.2010.11.023

      Abstract (810) HTML (32) PDF 1.01 M (735) Comment (0) Favorites

      Abstract:In incomplete information environment,there are many optimization problems in the process of automated trust negotiation (ATN) based on exchanging digital credentials,like how to disclose minimum credentials and obtain maximum authorized,negotiation optimization,et al.Based on an analysis of the ATN process by game theory,a quantitative approach of trust is proposed to compute trust value of each credential in the ATN process a trust negotiation system is established on the basis of the dynamic strategy.The dynamicthreshold,fluctuating with the negotiation process,is proposed for further optimization to reduce credentials disclosure.The case analysis and simulations show that the dynamicthreshold strategy can restrict the amount of disclosed credentials and improve efficiency of the negotiation process in the incomplete information environment.

    • Convergence Analysis of Invasive Weed Optimization Algorithm and Its Application in Engineering

      2010, 38(11):1689-1693. DOI: 10.3969/j.issn.0253-374x.2010.11.024

      Abstract (720) HTML (34) PDF 800.77 K (784) Comment (0) Favorites

      Abstract:This paper introduces a novel numerical stochastic optimization algorithm,the invasive weed optimization (IWO),inspired from colonizing weeds,which mimics the robustness,adaptation and randomness of weeds in a simple but effective optimizing algorithm.Its global convergence is analyzed with Markov chain.Compared to other heuristic algorithms,the biggest advantage of IWO is its directed search based on the species of outstanding individuals within the group.Additionally,the offspring individuals are being randomly spread near their parents according to Gauss normal distribution with the standard deviation of the random function adjusted dynamically during the evolution process.Thus,the algorithm explores new areas aggressively to maintain the diversity of the species in the early and middle iterations,and then enhance the local search near optimal individuals in final iterations.Such mechanism ensures the steady convergence of the algorithm to global optimal solution.Simulation results of the optimal design of a typical complex machinery show that IWO algorithm can effectively search global optimum to avoid falling into a local optimal solution.

    • >测绘科学与技术
    • Geopositioning Capability of Highresolution Satellite Stereo Imagery for Highrise Buildings in Urban Area

      2010, 38(11):1694-1700. DOI: 10.3969/j.issn.0253-374x.2010.11.025

      Abstract (801) HTML (10) PDF 1.48 M (754) Comment (0) Favorites

      Abstract:This paper focuses on the geopositioning capability and accuracy evaluation of highresolution satellite stereo imagery for highrise buildings in urban area.The experimental result shows that ground control points (GCPs) are needed in order to improve the geopositioning accuracy derived from the rational function model (RFM).The traditional geometric correction model in object space is effective when GCPs and independent check points (ICPs) are both on flat ground,but the computation error caused by elevation extrapolation appears when ICPs are on high building rooftops.A modified geometric correction model in object space is then proposed to eliminate the error introduced by huge elevation difference on high buildings.The result shows that a geopositioning accuracy of 0.6m in horizontal direction and 0.8m in vertical direction was achieved in Shanghai central district with high buildings involved,proving the effectiveness of this modified model.

    • Applications of ObjectOriented for Metadata Research

      2010, 38(11):1701-1707. DOI: 10.3969/j.issn.0253-374x.2010.11.026

      Abstract (892) HTML (35) PDF 1.19 M (750) Comment (0) Favorites

      Abstract:Multistandard coexistence and metadata management system reconstruction are presented in metadata research.The paper presents object models of metadata standard and metadata management system based on objectoriented design.Metadata section,metadata entity and metadata element are abstracted to be classes and properties,and the objects involved in management system are abstracted to be classes.In this way,compatibility between standards is strengthened.Management system extensibility and code reuse is improved.

    • >经济与管理科学
    • Calibration of CDO Model by Market Data and LGD Distribution

      2010, 38(11):1708-1713. DOI: 10.3969/j.issn.0253-374x.2010.11.027

      Abstract (722) HTML (22) PDF 877.97 K (565) Comment (0) Favorites

      Abstract:This paper deals with the calibration of collateralized debt obligation(CDO) model and loss given default(LGD) distribution on the basis of the market data by minimizing the relative entropy.Stochastic recovery and generalized twofactors GaussCopula model are supposed.The computational result,which shows the skewed distribution of the default,can be considered as an modification of classical GaussCopula model.The iteration techniques are adopted to avoid the nonlinearity and nonsmooth of target function.The numerical results prove the stability and convergence of the algorithm.

    • Analysis on Mechanism of International Portfolio Arbitrage and Its Optimal Strategy

      2010, 38(11):1714-1718. DOI: 10.3969/j.issn.0253-374x.2010.11.028

      Abstract (772) HTML (3) PDF 806.42 K (590) Comment (0) Favorites

      Abstract:Based on the extended international arbitrage pricing theory (IAPT),an international multiple factors model is established.Through relative mathematical analysis,the behavior of international portfolio arbitrage is defined,and the trigger conditions and determinants are described by the numbers.The mechanism of the international portfolio arbitrage behavior is revealed as: through establishing portfolio to increase relativity of the assets,the assets used for arbitrage can be matched.Under the condition without any transaction cost,an optimal weight of portfolio arbitrage can be solved with the meanvariance method.

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