• Volume 39,Issue 5,2011 Table of Contents
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    • >土木工程与建筑学
    • Study on an Equivalent Cross Brace Model of Steel Plate Wall with Slits

      2011, 39(5):625. DOI: 10.3969/j.issn.0253-374x.2011.05.001

      Abstract (881) HTML (22) PDF 2.11 M (1090) Comment (0) Favorites

      Abstract:A full-scale composite slit steel plate walls(CSSPW) specimen was tested,which further verified the cyclic strain hardening phenomenon.In the meanwhile,a unified model of equivalent cross brace(ECB) model and corresponding hysteretic models were proposed to simulate the hysteresis behavior of steel plate shear walls with slits and CSSPW.Numerical simulation was conducted for four specimens of steel plate shear walls and three specimens of CSSPWs,showing good accuracy of the proposed model.

    • Development And Experimental Study on Domestic TJI Buck-restrained Brace

      2011, 39(5):631-636. DOI: 10.3969/j.issn.0253-374x.2011.05.002

      Abstract (851) HTML (43) PDF 1.30 M (1085) Comment (0) Favorites

      Abstract:Domestic Q195/235 steel was adopted to produce a new type of buckling-restrained brace,TJI buck-restrained brace.The design and structural requirements of brace were proposed.Moreover,the performance requirements of steel core and testing standards of TJI buck-restrained brace were put forward,too.Cyclic loading test was conducted on TJI buckling-restrained brace.The experimental result shows that the buckling-restrained brace has better hysteretic characteristic and ability of seismic resistance,which is an effective member for energy dissipation.As a result,the ability for seismic resistance of structure improves greatly.

    • Dynamic-instability-based Equivalent Static Wind Loads on Spatial Structures

      2011, 39(5):637-642. DOI: 10.3969/j.issn.0253-374x.2011.05.003

      Abstract (959) HTML (47) PDF 1.65 M (1108) Comment (0) Favorites

      Abstract:The paper presents the concept of dynamic-instability-based equivalent static wind loads and the elementary method to obtain them and then the method is applied to studying the stability of a single-layer reticulated cylindrical shell.The unsteady aerodynamic forces on the shell are obtained from the wind tunnel test,the dynamic instability of the shell are investigated by the Budiansky-Roth criterion,and then the dynamic-instability-based equivalent static wind loads on the shell are gained.Comparison of stability of the shell under two kinds of equivalent static wind loads,the dynamic-instability-based and the displacement-based,shows that it’s necessary to adopt the dynamic-instability-based equivalent static wind loads to consider the wind actions in the stability analysis of large-span spatial structures.

    • Analysis on Seismic Performance of Folded-slab Stair

      2011, 39(5):643-649. DOI: 10.3969/j.issn.0253-374x.2011.05.004

      Abstract (992) HTML (52) PDF 1.76 M (1272) Comment (0) Favorites

      Abstract:A comparative study was made of the vibration performances of frame structures without stair tread,with straight stair tread or with folded stair tread by ANSYS numerical simulation.The stair with folded slab was proposed to adopt while designing stair in frame structure.Landing board and frame column were proposed to be separated as well.With the method,the K-effect of stairs during earthquake would be weakened and the stairs’ capability to take part in the whole structure decreases,too.The mal-distribution of seismic force among frames would be lightened.As a result,the internal force of the stair components and the difficulty of design would diminish.However,frame columns would not be changed into short columns.Meanwhile,the conservative degree of allowable value of drift angle would be reduced.Based on a lot of data,the variation law of stress was investigated,and proposals on dimensions of folded stair were put forward.

    • Seismic Hydrodynamic Effects on Group-pile Foundations with Caps Merged in Water

      2011, 39(5):650-655. DOI: 10.3969/j.issn.0253-374x.2011.05.005

      Abstract (1166) HTML (35) PDF 1.06 M (1201) Comment (0) Favorites

      Abstract:To meet the seismic design demands of bridges in deep water in China,an investigation was made into the hydrodynamic effects on seismic response of bridges.The cap of group-pile foundation was idealized as a truncated cylinder at first,and theoretical solutions of the added mass matrix and the added damping matrix for the truncated cylinder were developed.Approximate methods were proposed to obtain the added mass matrix and the added damping matrix for the truncated prism with arbitrary section by modifying the ones for truncated cylinder.The seismic motion equation was developed for bridges with group-pile foundation in deep water in frequency domain,and a software was coded for the computation of seismic response of bridges in deep water.The seismic responses of a bridge were obtained by the proposed methods and the software.The results show that the hydrodynamic effects may increase or decrease the seismic response by a percentage of ±20%.

    • Simplified Analysis for Drainage System of Composite Foundation Improved by Cement-mixing Columns and Vertical Drains

      2011, 39(5):656-660. DOI: 10.3969/j.issn.0253-374x.2011.05.006

      Abstract (939) HTML (37) PDF 1.11 M (892) Comment (0) Favorites

      Abstract:he simplified analysis model was first established to get its analytical solution;and then the conversion function of soil permeability was conducted on the basis of equivalent drainage relationship between its drainage and sand well.Finally,the analysis results were verified to be reasonable and feasible by finite element method and actual project application.

    • Experimental Study on Influence of Foundation Pit Dewatering on Lateral Pressure Coefficient of Soil

      2011, 39(5):661-665. DOI: 10.3969/j.issn.0253-374x.2011.05.007

      Abstract (696) HTML (36) PDF 1.30 M (1077) Comment (0) Favorites

      Abstract:Aiming at the layer 3 mucky silty clay,the layer 4 mucky clay,the layer 5-1 silty clay and the layer 5-2 clayey silt involved in the process of excavation and dewatering of deep foundation fit in soft soil stratum of Shanghai,a study was made on the variation characteristics of the lateral pressure coefficient for the soil layers in different drawdown through the two step consolidation method and K0 test.The test results show that the lateral pressure coefficient value of the clay is larger than that of the silt before and after dewatering.The lateral pressure coefficient of the soil decreases with the increasing of the drawdown,and the lateral pressure efficient value of the layer 5-1,the layer 5-2,the layer 3 and the layer 4 decreases about 3.1%,2.5%,2.3% and 1.3% per meter drawdown respectively.As the drawdown increases,the influence of dewatering on the lateral pressure coefficient is decreasing gradually,and finally the lateral pressure coefficient tends to be stable.In the end,the simple calculation formulas of the lateral pressure coefficient were obtained based on the theory of regression analysis,providing reference for the determination on the lateral pressure coefficient of the soil after dewatering of the deep foundation pit in Shanghai.

    • Nonlinear Vibration of Coupled Structure of Cable-stayed Beam

      2011, 39(5):666-674. DOI: 10.3969/j.issn.0253-374x.2011.05.008

      Abstract (914) HTML (25) PDF 1.15 M (1151) Comment (0) Favorites

      Abstract:Based on a series of partial differential equations describing the effect of curvature of the main cables and deformation of the stay cables on the structure,the non-linear ordinary differential equations of the first order approximation on time-domain are obtained by Galerkin method and studied by multi-scale method.An analysis is made of the principal resonance and 1∶2 internal resonance.The analytical solutions of the first order approximation and the vibration amplitude response curves for the amplitude of excitation as a parameter are derived.The results indicate the first order approximate analytical solutions have a higher accuracy.In the internal resonance condition,there are jump phenomena of the vibration amplitudes of the main cables and the beam.But the low-order resonance bifurcation values of the jump phenomena are less than the high-order resonance bifurcation values,which indicates that the low-frequency resonance vibration is easier to generate substantial vibrations than the low-frequency.The study results are significant for engineering applications

    • Nonlinear Analysis of Flexible Giant Ferris Wheel

      2011, 39(5):675-681. DOI: 10.3969/j.issn.0253-374x.2011.05.009

      Abstract (738) HTML (57) PDF 1.63 M (1859) Comment (0) Favorites

      Abstract:Combined with a project example of flexible giant Ferris wheel,mechanical performance of rim and cable was analyzed.The rational initial prestressing force was chosen to optimize the structural behaviour.The initial imperfection was considered to perform the stability analysis of rim and overall structure.Nonlinear buckling characteristics was researched.Taking both the geometrical and material nonlinearity into account,the elasto-plastic limit bearing capacity analysis was carried out and its results comprehensively revealed the structural characteristics.The results of analytical study indicate that nonlinear characteristics of flexible giant Ferris wheel is obvious due to the introduction of prestressed cable.Mechanical performance of the structure depends on the initial prestressing force.The wheel consisting of radiate spoke cables and space truss provides strong lateral stiffness as well as torsional stiffness and the stability performance is favorable.The mechanism of plastic development is appropriate and its failure mode belongs to the strength failure.The elasto-plastic limit bearing capacity is so large that the wheel can satisfy the need both for operating condition and for storm condition.

    • >交通运输工程
    • Virtual Reality Experiment on Pedestrian Crossing Behaviors At Signalized Intersections

      2011, 39(5):682-687. DOI: 10.3969/j.issn.0253-374x.2011.05.010

      Abstract (959) HTML (47) PDF 2.06 M (915) Comment (0) Favorites

      Abstract:A pedestrian crossing behavior virtual reality system (PCBVRS) was developed on the basis of the micro traffic simulation Software VISSIM and VR technology.29 typical travelers from Zhongyuan Community and Tongji University were recruited and 230 crossing samples were obtained with PCBVRS in Shanghai.Reliability and validity theory in experimental science was adopted to comparatively analyze the data obtained respectively from field survey and PCBVRS experiment,which proved that PCBVRS could effectively catch pedestrian’s crossing behavior.The characteristics of VR system,such as immersion,interaction and reality was satisfied by PCBVRS,and apart from that,PCBVRS was of the virtue of low building cost,high portability,which,therefore,can acted as a training tool to promote safety awareness during pedestrian crossing after a further improvement.

    • An Edge Detection Method Designed for Pavement Distress Images

      2011, 39(5):688-692. DOI: 10.3969/j.issn.0253-374x.2011.05.011

      Abstract (1140) HTML (67) PDF 0.00 Byte (1481) Comment (0) Favorites

      Abstract:An edge detection method designed for pavement images was presented in this study to overcome the difficulties in traditional methods of edge detection for pavement images such as nonuniform background illumination,low proportion of distress pixels and irregular directions of distress.The method offered in this study brought image preprocessing and edge enhancement to traditional edge detection methods.The image preprocessing was composed of background correction,Gaussian smoothing and histogram transformation based on the conception of effective range of gray levels which was proposed by this study for the first time,while the edge enhancement included the morphological dilation and median filtering operation.A pavement distress image was tested by Sobel detector of eight directions and Otsu method following the procedure above.The result shows that the proposed procedure can dramatically dampen the impact of noise on edge detection,and the background corrections as well as the histogram transformation based on effective range of gray levels are the key components of the method.Besides,Otsu method can provide good segmented edge maps if the images have been preprocessed.

    • Simplified Methods for Calculating Aircraft Load Repetition

      2011, 39(5):693-698. DOI: 10.3969/j.issn.0253-374x.2011.05.012

      Abstract (877) HTML (33) PDF 1001.14 K (1121) Comment (0) Favorites

      Abstract:The paper presents a discussion on the simplified methods for calculating aircraft load repetition,which is used in mechanistic-empirical pavement design procedure.A simplified concept based on stress/strain spread angle and equivalent width is put forward as the basis of load repletion calculation.The results based on double pavement layers analysis show that the equivalent width is the function of top layer thickness and relative stiffness of the layers.Then,the simplified equations for calculating equivalent width are put forward.The width differences between simplified method and spatial response-based method are within 5%.The pavement with more than two layers can be transferred to two layers according the equivalent approach.With the equivalent width,load repetition methods are developed for single tire,and a detailed analysis is made of the multiple tires and multiple axles as well.Furthermore,the equations with a consideration of the mixed traffic are put forward.

    • Simulation Method of Mechanical Properties of Graded Broken Stone Based on Particle Flow Code

      2011, 39(5):699-704. DOI: 10.3969/j.issn.0253-374x.2011.05.013

      Abstract (1177) HTML (43) PDF 1.17 M (1438) Comment (0) Favorites

      Abstract:In order to reveal the intrinsic relation between composition and mechanical properties of graded broken stone,the simulation method for mechanical properties of graded broken stone is put forward on the basis of particle flow code (PFC2D).A case study of Yinghu Limestone aggregate shows that the measured values of California bearing ratio (CBR),shear strength and compressive strength of graded broken stone under different graduations are 495%~692%,592~802 kPa,1.29~1.54 MPa,respectively.The corresponding simulation values are 525%~736%,636~839 kPa and 1.34~1.54 MPa,with respective average errors of 4.50%,5.07% and 5.15%,and the simulation results are basically consistent with the measured results.Finally,particle flow numerical simulation method proves to be feasible in the study of mechanical properties of graded broken stone.

    • >机械、车辆与能源工程
    • Rule of Aerodynamics Braking Force in Longitudinal Different Position of High-speed Train

      2011, 39(5):705-709. DOI: 10.3969/j.issn.0253-374x.2011.05.014

      Abstract (807) HTML (37) PDF 1.28 M (1345) Comment (0) Favorites

      Abstract:Characteristics of the flow field around the brake panels are analyzed when all carriages of the train are equipped with aerodynamic brake.The kinetic rule is acquired that the first windward brake panel produces the largest drag,and the drag is reduced step by step in the windward.Then,principle of the braking force is also studied by taking a high-speed train model as an example,when the vehicles with the pantographs are not equipped with brake panels in order to reduce the impact of brake panels on the pantograph.This principle of braking force is compared with the rule of braking force when all carriages are equipped with brake panels.Finally,an analysis is made of the braking force effect generated by aerodynamic brake.

    • Optimization for High-speed Wheel Profiles

      2011, 39(5):710-715. DOI: 10.3969/j.issn.0253-374x.2011.05.015

      Abstract (1817) HTML (72) PDF 1.43 M (1382) Comment (0) Favorites

      Abstract:A target-oriented method for the design of railway wheel profiles is presented.The target chosen is the rolling radii difference function which plays an important role in the dynamics of railway vehicles especially for high speed performances.A computer program based on this method is also developed and validated by examples in which wheel profiles LMa,S1002G and XP55 are investigated.An optimization process for selecting a suitable profile for high-speed vehicle is put forward.

    • Simulation of Flow Field and Heat Transfer in Passenger Compartment

      2011, 39(5):716-720. DOI: 10.3969/j.issn.0253-374x.2011.05.016

      Abstract (1313) HTML (49) PDF 3.30 M (1203) Comment (0) Favorites

      Abstract:The thermal environment in a vehicle cabin with passengers is simulated.Boundary temperatures for computational fluid dynamics (CFD) calculation are provided by numerical human model created with lumped-heat-capacity method.In the CFD simulation,hexahedral mesh and SIMPLE algorithm is applied.Natural convection and wall radiation are taken into consideration.An experiment on a real car is executed to validate the simulation.

    • A structural Optimization Design for Wear-out Life of Concrete Sealing

      2011, 39(5):721-725. DOI: 10.3969/j.issn.0253-374x.2011.05.017

      Abstract (750) HTML (24) PDF 1.63 M (911) Comment (0) Favorites

      Abstract:In order to solve the problem of lifetime of concrete sealing during the pumping process of concrete under the condition of multiphase fluid and variable load,this paper presents a design for structure parameters optimization of concrete sealing based on the homogenizing evaluation of the contact pressure of friction pair.That is to say,on the basis of the generalized physical model of elastic contact friction and wear,the paper analyzes the main elements which affect abrasion.Reference to the actual working conditions,this paper establishes the contact mechanical model of concrete sealing and carries out the multi-parameter optimization of the structure by Taguchi method.This study provides theoretical support for the design of concrete sealing under complex working conditions,and presents an engineering guide for reverse research of the similar contact wear damage.

    • >电子、计算机、控制与系统
    • Scheduling Optimization in Re-entrant Lines Based on a GA and PSO Hybrid Algorithm

      2011, 39(5):726-730. DOI: 10.3969/j.issn.0253-374x.2011.05.018

      Abstract (997) HTML (31) PDF 931.54 K (1091) Comment (0) Favorites

      Abstract:Scheduling optimization in re-entrant lines proves to be more difficult than in other manufacturing systems,which is well known as a NP-hard problem.A mathematical programming model was established and corresponded with a digraph via several definitions for an intelligent algorithm.A hybrid algorithm was proposed to optimize the objective function,which took the advantages of genetic algorithm and particle swarm algorithm,so this hybrid algorithm integrated global searching ability with high convergence speed.Compared to the results of the normal GA or PSO,simulation results show that the hybrid algorithm is an effective method for scheduling optimization.

    • Activity-based Technical Risk Identification Modeling for Complex Products Developing Process

      2011, 39(5):731-737. DOI: 10.3969/j.issn.0253-374x.2011.05.019

      Abstract (628) HTML (31) PDF 1.28 M (883) Comment (0) Favorites

      Abstract:The technical risk of complex products developing is classified as the inner technical risk of activities and the technical risk among activities.Then,based on the decomposition of activities and the risk identification of inner activities,the technical risk of inner activities is obtained with the analytic hierarchy process (AHP).Finally,from the view of risk analysis,the technical risks of the various relations among activities are categorized as the sequential relations and the dependent relations,and the identification model of technical risk among activities is constructed.The method is successfully applied to the risk identification in developing the micro-electronics equipments.

    • >计算机与信息工程
    • Fast ChanVese Segmentation Algorithm Based on Image Entropy

      2011, 39(5):738-744. DOI: 10.3969/j.issn.0253-374x.2011.05.020

      Abstract (1086) HTML (45) PDF 1.55 M (846) Comment (0) Favorites

      Abstract:A fast ChanVese segmentation algorithm based on image entropy is presented.The image entropy was computed as the fitting term parameters to speed up the evolution.Meanwhile,the evolutionary stability was determined by analyzing the change of the entropy.The experiments on a variety of infrared images show its superiority in effectiveness and efficiency on noisy,object blurred and edge discontinuous image detection.

    • Dynamic Evolution of Software Architectures Based on Hypergraph Grammars

      2011, 39(5):745-750. DOI: 10.3969/j.issn.0253-374x.2011.05.021

      Abstract (863) HTML (25) PDF 1.16 M (1014) Comment (0) Favorites

      Abstract:Hypergraphs with constraints was proposed to represent software architectures.The formal semantics and operations of dynamic evolution production rules of software architectures were presented based on hypergraph morphisms.A software architecture style was defined as a type hypergraph,and the dynamic evolution of software architectures was modeled by applying hypergraph grammars and the architecture style.Model checking technique was used to verify the correctness of dynamic evolution of software architectures,an algorithm was designed to verify the property of dynamic evolution of software architectures.Experimental analysis was made by using a model checker.The approach provides a graphical representation of dynamic evolution of software architectures,and displays a formal theoretical framework based on grammars.

    • Modified BP Algorithm Based On Random Adjustment of Parameters

      2011, 39(5):751-757. DOI: 10.3969/j.issn.0253-374x.2011.05.022

      Abstract (833) HTML (70) PDF 862.48 K (953) Comment (0) Favorites

      Abstract:A modified BP algorithm of neural network,random adjustment of parameters (RMBP) algorithm,is proposed to overcome the defect of easy going into local minimum of BP neural network.By adding randomization to the progress of parameters adjustment,RMBP helps BP neural network jump out of local minimum point easily,and get to global minimum point along gradient descent direction.Result of study experiment of XOR problem shows that RMBP has advantages of high study speed,high study precision and low resource occupation in comparison with other modified or unmodified BP algorithm.Finally,in combination with study of real-time flight simulation system of civil aviation airplane,a study is made of a group of aircraft aerodynamic force character parameters to verify the effectiveness of RMBP algorithm.

    • >测绘科学与技术
    • Geography Ontology Fusion Model Based on Statistical Machine Learning

      2011, 39(5):758-763. DOI: 10.3969/j.issn.0253-374x.2011.05.023

      Abstract (1001) HTML (40) PDF 1.38 M (813) Comment (0) Favorites

      Abstract:The ubiquity of geography ontology heterogeneity is caused by multiple cognitive systems for geographical object.Geography ontology fusion model was proposed by introducing the method of automatic statistical machine learning for processing relationship within the concepts.The credibility was produced according to emergence frequency of relationship between concepts in different ontology and finally a large-scale integrated geographic concept space with statistic and field information was generated.Cumbersome concept mapping process is circumvented through this model,and all the knowledge expressed in ontologies is fused while information within each field is preserved in this concept space which realize sharing between multiple cognitive systems.

    • Development and Application of GPS Precise Positioning Software

      2011, 39(5):764-767. DOI: 10.3969/j.issn.0253-374x.2011.05.024

      Abstract (999) HTML (39) PDF 906.04 K (1525) Comment (0) Favorites

      Abstract:Correction models,data preprocessing,and solving approach of GPS precise positioning software LTW_BS are introduced.Two-year-data from Shanghai CORS network and data from Jiangsu CORS network composed of 70 stations are processed.Results show that LTW_BS is reliable and stable.With LTW_BS,millimeter level accuracy for a 100 km regional static network and 2 cm accuracy for a large scale network up to a thousand of kilometer are expected.

    • >数理科学与化学
    • Randomly Weighted Estimators for Parametric Component in Semi-linear Errors-in-variables Models

      2011, 39(5):768-772. DOI: 10.3969/j.issn.0253-374x.2011.05.025

      Abstract (603) HTML (4) PDF 865.52 K (771) Comment (0) Favorites

      Abstract:The randomly weighted method is used to approximate the distribution of the least square estimators,and it is demonstrated that the approximation is asymptotically valid with probability one.Finally,simulated example is given to illustrate the performance of the proposed method.

    • Synthesis and Characterization of Complexes of Calix[8] Arene Ketone Derivative with Praseodymium or Europium

      2011, 39(5):773-777. DOI: 10.3969/j.issn.0253-374x.2011.05.026

      Abstract (892) HTML (24) PDF 1.03 M (1036) Comment (0) Favorites

      Abstract:Calix[8]arene ketone derivative was prepared by using electrophilic reagent chloroacetone and p-tert-butyl phenol through etectrophilic substitution reaction.And then the solid complexes of calix[8]arene ketone derivative with Praseodymium or Europium were further synthesized.Elemental analysis,infrared spectra,13CNMR,XRD and thermal spectra were used to characterize the products.The results show that two kinds of the solid complexes are mononuclear molecules,central rare earth metal ions are coordinated by six oxygen atoms from two calix[8]arene ketone derivative and three nitrogen atoms from three N,N-Dimethylformamide molecules,leading to formation of nine-coordinated solid complexes with symmetrical tricapped trigonal prism structure.

    • >经济与管理科学
    • Indicator System of Quality of Urban Development from Perspective of Urban Functions

      2011, 39(5):778-784. DOI: 10.3969/j.issn.0253-374x.2011.05.027

      Abstract (799) HTML (31) PDF 826.04 K (729) Comment (0) Favorites

      Abstract:The paper attempts to evaluate the quality of urban development through objective urban functions development and subjective public satisfaction.Four types of basic urban function are proposed such as production,shelter,cultivation and connection.Then,the relationship between urban functions and public satisfaction is revealed.Regression models show that all these elements are important factors in explaining overall public satisfaction as a whole or individually and together can explain about 60% of the variation in overall public satisfaction,which implies that it is not enough for the urban policy-makers only to concentrate on the development of urban function of production, all urban functions are of importance and should be boosted equally.At last, an indicator system is set up.

    • Comprehensive Evaluation on Performance of Existing Residential Buildings Based on Fuzzy and Analytic Hierarchy Process

      2011, 39(5):785-790. DOI: 10.3969/j.issn.0253-374x.2011.05.028

      Abstract (741) HTML (56) PDF 961.10 K (918) Comment (0) Favorites

      Abstract:On the purpose of improving performance of buildings through complex refurbishment,the performance of existing residential buildings in this paper is measured by six indicators such as security,intactness,fittingness,energy-saving,dwelling environment,and coordination.In order to overcome the shortcomings of random and subjectivity in the traditional evaluation method and to eliminate the uncertainty during the evaluation process,a comprehensive model for evaluating performance of residential buildings is proposed,where the weight of each indicator is determinate based on an improved analytic hierarchy process (AHP) method combined with fuzzy analysis of the relevant relationship of each indicator.The case of 30 different residential buildings is evaluated and then reveals many advantages in this model that evaluation is comprehensive,objective,and operational.By discussion of case study in the end,several reconstruction approaches are proposed in improving performance of existing residential buildings.

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