Abstract:Periodic Vortex shedding from the structures coincides with the periodic forces on the structures.The vortices in the downstream of the structures can be detected by the method of snapshot proper orthogonal decomposition(POD)whether they can be seen obviously or not.The method in this paper combines the method of snapshot POD and small eddy decomposition methods together with part of the frozen turbulence hypothesis.The vortex shedding frequency can be obtained based on one-single-time velocity map alone through which the Strouhal number of the structure can be derived.Numerical simulation was done based on the examples of the square cylinder and twin box bridge deck.The results show the error is rather small of the strouhal number with that through the Fourier transform of the lift force coefficient,implying that the method is practicable.

Abstract:按场地类别和强震持时将水平向302条美国Northridge地震记录和339条台湾ChiChi地震记录的峰值进行规一化处理,分别采用双线型、半退化三线型和退化三线型3种恢复力模型,对单自由度(SDOF)体系进行弹塑性时程分析,研究结构动力特性和地震动参数对平均滞回耗能谱的影响.结果表明,平均滞回耗能值强烈地依赖于场地条件、强震持时和阻尼比等因素,恢复力模型和屈服强度系数对滞回耗能值的影响较小;滞回耗能值随强震持时的增长而增大,随场地特征周期的增长而增大,随阻尼比的增大而减小.Northridge地震和Ch

Abstract:The time-dependency of undrained behavior of the tested natural soft clay as well as the influence of pre-shearing stress history on the studied subject was examined based on experimental data.The tested clay was characterized by high water content and high plasticity with slight organic debris.Triaxial undrained constant strain rate(UCSR)tests were employed to study the strain-rate sensitivity of the undisturbed natural clay by using computerized testing system with stress-path controlled.The specimens were loaded to different stress state after re-consolidation with in-situ stress and pore pressure and before the UCSR tests were performed.The specimens were sheared at step-changing axial strain rates respectively to exclude the influence of instinctive heterogeneities of different specimens.The strain-rate dependent properties of undrained shear strength and effective stress path as well as the effect of pre-shearing stress history on the strain-rate dependent properties of the natural soft clay were examined based on triaxial UCSR experimental results.The results show that the undrained strength increases by 9.7% in compression tests and 7.2% in extension tests caused by the 10-times increased strain rates for the tested clay.

Abstract:Variation of seepage free surface with time is analyzed by finite element method that can perform the coupled analysis of soil mass deformation and pore water pressure dissipation,and the influence of variation of seepage free surface on excess pore water pressure,soil water potential and foundation pit deformations are also further investigated.It is indicated that excess pore water pressure and soil water potential will decrease when variation of seepage free surface outside the foundation pit is considered.Variation of seepage free surface causes the decrease of water pressure and the increase of effective stress outside the foundation pit,and also causes the decrease of the water head difference between the inside and outside of the foundation pit,and thus further results in the decrease of retaining structure horizontal displacement and pit base heave and the increase of ground surface settlement.

Abstract:A model test of the composite long-short pile foundation including single pile,three piles,nine piles and fifteen piles was put forward.Design of plan,measured instruments,methods and results about the model test,test results and factors of test error are also provided.The test data shows that the skin friction behavior of the short pile in the composite long-short pile foundation is almost the same as the single pile and that of the long pile is different from the single pile due to the significant effects by the short piles.At the beginning of loading the skin friction along the upper of the long pile does not work.By the end of the ultimate loading the skin friction along the upper of the long pile does fully play its role,the same as that of the single pile.

Abstract:This paper develops a practical and user-friendly approach for real-time service load condition assessment of cable-stayed bridges.In this approach,the spatial effect of stress distribution is considered in the establishment of a 3D solid finite element model,and then the model is used to obtain the stress envelope.The real-time measurement data from the field and the theoretic stress envelope from simulation are used in the assessment of the service load condition.The design and field data are the basis of the assessment and this method can be applied widely in real engineering.A Case study has also been conducted,showing that the detailed procedure of the proposed method and results have advantages over the previous methods.

Abstract:Humdrum static load experiment and fatigue experiment were made on two groups of carbon fiber,the carbon fiber reinforced with plastics and the carbon fiber reinforced with girder,under different pre-stress levels to investigate fatigue load of fatigue experiment girder and the expansion of crack under each load rank acting,the strain and displacement.And the crack load,yielding load and ultimate load are obtained.Results show that with the increasing of pre-stress level,width and length of the crack decrease.Meanwhile,the displacement decreases obviously too.The yielding load and the ultimate load and the ultimate load have different increments.

Abstract:以巴黎香榭丽舍大街为应用背景,提出了一种实时、基于规则、反应式的交通走廊公交信号优先算法.该算法定义了优先方法初选、可行性验证和优先方案实施3个紧密联系的步骤.在优先方法初选阶段,根据既定的规则选择当前情况下最合适的一种优先方式.然后,在可行性验证阶段对所选优先方案是否可以实施进行验证.如果可行性验证通过,则在方案实施阶段生成新的控制方案,并在当前信号周期的下一时刻实施.该算法能灵活地描述优先灯组与冲突灯组、上/下游相容灯组、对向相容灯组间的逻辑关系,并基于此实现绿灯延长、绿灯重启、绿灯早启等常用公交信号

Abstract:采用动态心电仪和地理信息系统(GPS)对高速公路不同交通流状况下驾驶员心率和车速进行行车实验测试,通过运用医学、心生理学、交通流等理论,分析结果发现:高速公路平直路段自由流条件下车速超过100km.h-1时,心率增长率与车速呈线性增长关系;非自由流条件下超车等驾驶行为对驾驶心理影响显著,心率平均增长率较自由流条件下高.确定心率增长率32%为驾驶员心理紧张的生理评价标准,42%为行车中应避免的心理安全阈值.

Abstract:Based on the economic and road freight traffic volume data of Shanghai between 1990 and 2005,a study is made of the relationship between road freight traffic volume and economy growth with the cointegration theory and Eviews software.A conclusion is drawn that there exists the long-term equilibrium between the road freight traffic and economy.The Granger causality test results show that there exists single Granger causality between road freight traffic volume and total road operation mileage,the total industrial enterprises,GDP.The impact of road transport on the economy growth is not remarkable.And the government should make more industry policy and road freight transport policy adjustment which can guide a more rational development for the road transport.

Abstract:采用实测轮胎荷载建立有限元模型,分析了满足长寿命路面要求的沥青路面结构组合.首先提出采用最大剪应力包络线来代替剖面线.其次,对3种不同类型结构组合原则进行了探讨.通过计算,提出了柔性基层薄面层结构不宜采用高模量混合料.认为厚沥青层结构采用高模量层对整个结构的抗剪是有利的,中间层模量2000～3000MPa、基层模量1000～4000MPa时结构受力较为均衡,建议下基层或垫层采用高质量的级配碎石层或者添加微剂量的稳定材料.对于半刚性基层结构,中间层模量和基层模量可以适当提高,但不能太大.研究最后认为,无论采

Abstract:Fatigue tests of 6063 aluminium alloy were performed under multiaxial proportional loading,and the fatigue characterristics and microcosmic mechanism were analyzed.Results indicate that the fatigue life is lower;the cyclic hardening is more obvious and the dislocation density is higher under higher effective stress amplitude,and dislocation structure changes from cross slipping to notable labyrinth.The fatigue life of aluminium alloy can be exactly forecasted by using equation Manson-Coffin under multiaxial proportional loading.The dislocation seriously affects the cyclic hardening and fatigue life of 6063 aluminum alloy.

Abstract:针对我国电气化铁路和磁浮交通对受流器滑块材料的性能要求,采用冷压烧结粉末冶金法制备了铜石墨材料,考察了该材料的载流磨损行为.结果表明:试样的磨损率随着试验载荷、速度、电流密度的增加而增大.载流条件下电流产生的电弧热是磨损率增加的主要因素.建立了摩擦磨损试验参数与磨损率之间的人工神经网络模型.以载荷、速度、电流密度作为网络的3个输入,以运行100km后试样的磨损率作为网络的1个输出,调试设计了一个3×3×1的反向传播(BP)神经网络.对神经网络的训练和检验表明该BP神经网络能够较好地预测影响因素对材料载流滑

Abstract:The paper presents a special design of water-cooling device for power control unit(PCU),a combination of DC/DC,DC/AC,which is characterized by its high efficiency and low resistance.According to the principle of heat transfer enhancement,the heat will be conducted to the inside of the water-cooling device by pasting up the water-cooling device with the heating component,and then be transferred to the outer cooling system through convection with the coolant.The design to adopt the rhombus ribs enlarges the heating area,and increases the velocity of coolant due to the decrease of the flow tunnel area.As a result,the efficiency of PCU and the working condition are improved,and the service life is prolonged.A test platform is established and validates the design.

Abstract:This paper presents an automatic reading system for electrical power meters based on the structure of the media access control(MAC)wireless bus.The data characteristic of electrical power terminals and the factors influencing packet loss rate in wireless channels are analyzed for this structure.The transmission format of the data frame is proposed.Finally,the communication protocol,the terminal software and hardware are designed.

Abstract:An optimized high-precision registering method of multi-source remote sensing images is discussed.The feature points are quickly extracted by using the operators of gradient and Forstner,and the grid technique based on the entropy is adopted to control the homogeneity of feature points.Based on some exact control points and the matching rule of the invariant moment similarity measurement and the matching strategy of the global relaxation,the homonymy points are obtained by quickly registering the remote sensing images.Then the error points are eliminated by using the quadratic polynomial model.Experiment results show that the method,with quick registering speed and highly accurate and evenly distributing points,can meet the need of the image fusion and quick updating of the remote sensing images.

Abstract:Numerical simulations of radar wave performance in typical fault models of shield tunneling back-filled grouting layer were conducted.The simulation algorithm we used was the finite difference time domain solution over a 2D space,with a perfectly matched layer(PML)absorbing boundary conditions for these attenuation models.Simulated results indicate that the wave field observed at free interface consists of strong scattering induced by steel-bars in concrete lining,so it is difficult to recognize the reflection of objects.A new method is proposed for removing the scattering field,and it is named as coincidence information removing method.The scattering field of steer-bars can be calculated in advance.By subtracting the scattering field from total field observed at free interface,reflection of objects could be abstracted.Numerical computing results show that this technique is effective for removing scattering wave.

Abstract:A filter QP-free infeasible method is proposed for minimizing a smooth function subject to smooth inequality constraints.This method is introduced by solving nonsmooth equations which are equivalent to the KKT first-order optimality conditions that are constructed by the multiplier and some NCP functions.Locally,each iteration of this method can be viewed as a perturbation of a Newton or quasi-Newton iteration on both the primal and dual variables for the solution of the KKT optimality conditions.The filter method is also used in linear search.This method is implementable and globally convergent.The method proves to have superlinear convergence rate under some mild conditions.The computational results show that this algorithm is efficient and reliable.

Abstract:Based on the partial differential equation(PDE)method,a closed form solution of the perpetual Bermudan option considered as a solution of a periodic of Black-Scholes option is given in the theoretical frame of Black-Scholes.Moreover,a nonlinear equation satisfied by the optimal exercise boundary of the perpetual Bermudan option is obtained.

Abstract:"3-Zone Interaction" is a new interactive model of regional innovation system which links up university,science park and public community.In this innovation model,university is regarded as the innovation source,science park the innovation body and public community the innovation support system.And then based on the division theory and model,an analysis is made of the driving mechanism of "3-Zone Interaction".The result shows that the urgent role-transition requirements of university,science park and public community strongly drive "3-Zone Interaction" foundation,and the foundation of "3-Zone Interaction" will further drive the smooth transition of the above 3 players.So this driving mechanism will help the "3-Zone Interaction" mode become a healthy and spiral-rising innovation model.