Abstract:Based on the wind pressure distribution mode in which mean wind pressures are used together with RMS pressures,weighted constrained least squares method is adopted to calculate equivalent static wind loads for large-span roofs.In order to limit the range of the equivalent static wind loads,the constraint conditions are employed.Further,weighting factors are introduced to improve the accuracy of typical responses.The equivalent static wind loads in the paper can reproduce simultaneously several peak responses,whereas traditional methods just lead to equivalent loads which only target one certain response.Finally,the method is applied to a real large-span roof,and high accuracy is found for responses the absolute values of which are large to some extent.It is also found that typical responses have higher accuracy than non-typical ones for the usage of weighting factor.Meanwhile,the distribution of equivalent static wind loading calculated through the method is found to be reasonable,in which the gradient of wind loading are small and no oscillating results are observed.

Abstract:By applying high frequency balance technique on rigid section models in wind tunnel,aerodynamic force characteristics of cylinder,bare conductor and six quasi-oval shape iced conductor models were investigated in different turbulence intensities and wind directions.Galloping instability of quasi-oval shape iced conductor models were also studied.The analysis shows that absolute values of the force coefficients decrease with the increasing turbulence intensities and the shape of the iced conductors,wind directions have great influences on the force coefficients acting on the conductors and galloping of quasi-oval shape iced conductors can occur in some wind direction.The results could be used as the basis of analysis of their wind induced response and failure mechanism.

Abstract:Based on Sap2000,two different concrete-timber hybrid structural models:detailed timber floor model and simplified timber floor model were established and used to do numerical simulation for a test of a one-storey hybrid structure under lateral load.At last,simplified floor model and rigid floor model were used to build up two 6-storey structural models and were analyzed under seismic load.Results show that,both of detailed timber floor model and simplified floor model can simulate well the hybrid structure test; in order to simplify the analysis of hybrid structure,the simplified floor model can take place of the detailed floor model; according to the seismic analysis results of simplified floor model of 6-storey building,the mid-frame takes more lateral load than side-frame;the time history seismic analysis results show that,the time-displacement curves on the top of simplified wood diaphragm model and rigid floor model are very close.

Abstract:This paper evaluates the shear behavior of hybrid GFRP/steel-reinforced concrete beams without transverse reinforcement.All beams were subjected to four-point loading,with shear span-to-effective depth ratio of 2.54 and 2.67 respectively.The test variables were effective reinforcement ratio and axial stiffness ratio between GFRP and steel bars.The test beams included three beams reinforced with steel bars,three beams reinforced with GFRP bars and six beams reinforced with GFRP and steel bars.An analysis was made of the load-midspan deflection curves,cracking behavior and shear strength of tested beams.The test results were compared with the predictions provided by different codes and design guidelines available.The test result shows that beams designed with the same effective reinforcement ratio,exhibits similar shear strength regardless of reinforcement arrangement (steel，GFRP，or combination of steel and GFRP).Axial stiffness ratio between GFRP and steel bars has little influence on shear behavior of hybrid GFRP/steel-reinforced concrete beams.Eurocode 2—04 and CSA A23.3—04 design method provids reasonable predictions,whereas the ACI440.1R—06,JSCE and CSA S6—06 results in conservative shear strength estimates.

Abstract:The finite element models for rib-to-deck joints of Sutong Yangtze River bridge are established,the hot-spot stress along the weld toe and the stress concentration factor at weld toe are studied with several methods for determinig hot-spot stress,and the influence of element type and meshing requirement on computing results are comprehensively analyzed.In order to validate numerical analysis results,the test for stress distribution along the weld toe is carried out.As a result,the effective methods for computing hot-spot are founded,the stress distribution along weld toe and its stress concentration factor are gained.At last,the effect of some geometrical parameters on the stress concentration in the hot spots tress region is investigated.

Abstract:Reverse engineering CAD technique was used to establish the mechanical simulation model of Cangzhou Iron Lion.The flow field of Cangzhou iron lion was studied under the load of wind.An analysis was made of the stress,strain and displacement of iron lion by the load of gravity,wind and temperature,the results show that iron lion is safe at present.

Abstract:The unsaturated permeability of compacted Gaomiaozi-bentonite was tested under unconfined conditions on the basis of the instantaneous profile method.Results show that under unconfined conditions,the unsaturated permeability of Gaomiaozi bentonite ranges from 1.0×10-12 to 1.0×10-15 m·s-1 and groups around 1.0×10-14 m·s-1,and the maximum value reaches when the specimen is saturated.Compared to the confined conditions,the unsaturated permeability under confined conditions is lower than that under unconfined conditions,and the shapes of curves between unsaturated permeability and suction under different confining conditions are different.This may because that the swelling mechanism is different under different confining conditions.

Abstract:Representative sample of soft soil in Tianjin Binhai new district under different consolidation pressures are made by chill-sublimating and SEM(scanning electron microscopy).The change of pore structure parameter of sample SEM images under the applied consolidation stress level is systematically analyzed and the integrity and average equitability of pore distribution is studied with the simple plane fractal (Dp),and Pore Structure Factor (PSF) is presented which can reflect the scale,shape,distribution,orientation of pore.The research indicates that there is a fine corresponding relationship between structural parameters of internal pore and external loading.The internal characteristics of void are quite different before and after structural yielding pressure.

Abstract:To find an effective method to control an oversaturated network,it is essential for the traffic control system to make a quick response to the oversaturated circumstance.Accordingly,the traffic signal control subarea related to the oversaturated link should be delimited at the very beginning.The oversaturated link was identified at first,and then the connection model was presented and verified on the basis of quantizing the connection index between intersections.A dynamic method was proposed to delimit the coordinate control subarea under oversaturated condition by defining the congested area,interim area,normal-state area and dissipated area.The threshold values of connection index for subarea delimitation were calibrated and the detailed steps of delimitation were also explained via a case study.The research of delimiting signal coordinate subarea under oversaturated state lays the foundation for the research of traffic control strategies for an oversaturated urban traffic signalized network.

Abstract:Based on the user perceptions,the level of services(LOS) of individual components and the overall station were evaluated by surveying the passengers.The linear regression model was used to obtain a mathematical relationship between the overall arriving LOS ratings and the LOS of individual components,which could identify the main important attributes and the degree of their importance.The questionnaires data analysis of the arriving passengers in Xinzhuang rail station shows that transfer facilities,walking environment outside,rail station platform,checking in and total walking distance are the five significant impact facilities for the arriving passengers,and the degrees of importation are:0.205,0.196,0.196,0.140,0.126,which correspond to the actual situation,and the model proves to be of good applicability and operability.The model provides a good method for evaluating overall LOS of urban rail station.

Abstract:This paper presents four test methods,with emphasis on the contradiction of workability with durability,for evaluate performance of cold patch asphalt mixture based on related research at home and abroad.The methods are adhesion test,penetration test,cohesion test and modified Marshall test.Several kinds of cold mix with three additives and two material gradations are prepared by varying contents of separant,and then some tests are made.The test results show that both workability performance and Marshall strength should be taken into consideration,and attentions should be paid to the cohesion performance and moisture susceptibility in the evaluations of cold mix performance.At last,recommendations for evaluation indices and technical requirements of cold patch asphalt mixture are given.

Abstract:An integrated nitrogen and phosphorus removal process(AmOn) was developed based on the traditional theory of wastewater nutrients treatment process.A reactor was operated in a pilot-scale study,by using activated sludge model No.2D(ASM2D)to optimize the process.The results show that the treatment efficiency of CODCr,NH3N,TN and TP of domestic wastewater achieved by AmOn are up to 74.40%,93.15%,73.35% and 33.20% respectively.Mathematics model established based on experimental results simulated the effect of reactor well,and the combination of anaerobic/anoxic/aerobic districts smartly could accomplish design optimization.AmOn process occupies less space,and effluent could reach the second national discharge standard.After optimization the effluent quality can be further improved.

Abstract:The compounds containing structural Fe(Ⅱ) including sulphate Green Rust(GRSO4) and carbonate Green Rust(GRCO3) used in this study were synthesized in laboratory.The reducing capacity of GR for o-chloronitrobenzene(CNB) as well as the reaction pathway and products was investigated.Results show that reductive transformation of o-chloronitrobenzene by GRSO4 and GRCO3 is effective and the reducing capacity of GRSO4 is more than GRCO3,the structural Fe(Ⅱ) as the main active material.O-chloronitrobenzene is mainly transformed to o-chloroaniline after reaction,GR becomes the magnetite and goethite by oxidation reaction.pH is the important influence factor on the reducing capacity of GR and the rise of pH value can increase the reduction rate of CNB by GR.

Abstract:Five automated transmissions popular in international automobile market are introduced systematically.Transmission principle of five transmissions is expatiated,and development history and state-of-art of the automated transmissions are advanced.From the perspective of simulation skill,launch control,shifting schedule establishment,shifting quality optimized,actuator design,and product manufacture,the same key techniques of automated transmissions are proposed.Representative manufacturers and the application status in China market are listed.Advantages and disadvantages of automated transmissions are compared,and development perspective is presented.

Abstract:In this study,the FCV (fuel cell vehicle) structure-borne noise reduction by the control of body vibration based on FEM/BEM is studied.As to acoustic analysis,in order to get the dynamic behavior of the auto-body structure,a frequency response of body structure is calculated by using FEM.And then,the pressure response of the interior acoustic domain is solved by boundary element method(BEM).Test results show good agreement with simulation results and the error analysis between those is made.As to body panel noise contribution analysis (PNCA),the thoughts and principles of PNCA are set forth and analyzed.Then,the governing principle of selected frequency is determined.Based on the above analysis,PNCA is carried out to point out the direction for body panel improvement.At last,constrained damping treatments are adopted to control body panel vibration.Based on PNCA results,the panel modifications are developed and validated virtually by the above-mentioned method.The simulation results show that the amplitude of low-frequency interior noise reduces and the control of rear seat and front floor improves in FCV structure-borne noise reduction.

Abstract:Assembling low pressure economizer is one of the important measures for energy-saving and emission reduction in power plants.An analysis is made of the 350 MW Unit installed with low pressure economizer,which consists of two linking models,series and parallel way.As exhaust gas temperature is lowered by 25 ℃,and steam state changes according to isentropic process in extraction hole,the relative internal efficiency decreases by 0.012 9% in series and 0.007 2% in parallel,and the cycle efficiency increases by 0.606 2% and 0.656 7%,respectively,and absolute internal efficiency 0.615 2% and 0.691 8%,respectively.As the extraction hole steam state is in isothermal process,the relative internal efficiency relative increases by 0.020 6% in series and 0.042 7% in parallel;cycle efficiency increases by 0.602 5% and 0.651 4% respectively,and absolute internal efficiency by 0.645 2% and 0.736 5%,respectively.

Abstract:Based on elastic-plastic theory,autofrettage technology can improve the life of tube with high-pressure.The residual stress of three-dimensional tube was obtained via an elastic-plastic finite element analysis,research and application on how to improve life of tube by autofrettage technology was discussed.Through comparing the maximum stress of the tube under different levels of autofrettaged pressure,the best level was determined.Based upon the prediction of stress-life methods,a prediction of life of tube was conducted using MSC.Fatigue package.Results show that after autofrettage of three-dimensional tube,the life has an obviously different distribution,the region of the lowest life lies in inner of tube before it is autofrettaged,but the region of the lowest life moves between inner and outer of tube after it is autofrettaged,autofrettage technology makes the lowest life of tube increase more than quintupling.

Abstract:Problems of turbulent flow and heat transfer in concentric annuli with moving inner hot rod are solved by the proposed steady equation method,and cost of computation is,therefore,cut down.Simulation is made to achieve the flow field and temperature field of whole computation area,which is approximate to what is achieved by classical experience equation.Partial wall Nu and wall temperature of hot rod as well as air temperature distribution near rod front and bottom are compared in three work conditions.Results indicate that enhanced heat release effect takes on when annuli flow has the reverse direction of rod,however when flow having the same moving direction,effect weaken.

Abstract:Based on the principle of thermodynamics,a new concept of the relative irreversibility is put forward to describe the internal irreversibility.An irreversible thermodynamic model of four reservoirs absorption refrigeration based on this concept is derived,and numerical examples are given.The differences of the new model and the traditional model are discussed.

Abstract:The urban gas consumption time series was analyzed with phase space reconstruction based on chaos theory.The chaotic characters of urban gas consumption were identified by calculating the correlation dimension and largest Lyapunov exponent.Then,several methods including weighted one-rank local-region method,largest Lyapunov exponent method and Bayesian regularization neural network model were applied on forecasting of daily urban gas consumption.The test results indicate that the chaotic time series analysis method is feasible to be used in urban gas consumption forecasting.Combined with the advantages of chaos theory,neural network and Bayesian regularization method,the forecasting performance of Bayesian regularization neural network model based on phase space reconstruction is especially good.

Abstract:In the transformer differential protection,the second harmonic restraint and the dead angle restraint principles are the two major criterions to discriminate inrush current from fault currents.But in the super-high voltage system,there is also plenty of second harmonic in the fault current.The second harmonic here is of great probability to result in the tripping delay.Meanwhile,the dead angle restraint principle would result in misjudge due to the disappearance of dead angle during the CT saturation.To overcome these shortages,this paper presents a new method to discern inrush current from fault currents using energy dissipation criterion.The least square curve-fitting is adopted to fit the inrush current so as to overcome the shortage of the Fourier algorithm which is sensitive to frequency change.The results of dynamic simulation verify the feasibility of the proposed method.

Abstract:According to system switching nonlinear characteristic,the paper utilizes generalized state space averaging (GSSA) method,decomposes system model in frequency domain and transform system nonlinear model to approximate linear continuous model.With the model,system static and transient dynamic behaviors are analyzed in detail.Simulation results are consistent with SIMULINK model.Furthermore,system efficiency computing method is presented.And analyses among system efficiency,DC inductor and load parameters are proposed for system design as well.

Abstract:This paper presents a data acquisition system of dynamic track scale with field programmable gate array(FPGA).The system takes the AD7703 as the ADC，and samples 8 sensor signals by using FPGA as the sampling controller,then the sampled values are transmitted in asynchronous serial mode to the upper computer through RS232 interface.The logical design of the whole system is completed with the QuartusII 9.0.The results of hardware testing show that the system can efficiently solve the problem of zero drift and gain error which occurred in the process of data acquisition by using the self-calibration of AD7703.Utilizing the parallel processing capabilities of FPGA,8 channel signals can be sampled in parallel,which increases the data acquisition rate.Therefore,it satisfies the requirements of high resolution and high rate for the track scale designing.

Abstract:Based on Lyapunov function method together with linear matrix inequality (LMI),the non-fragile stabilization and H∞ control problems for a class of stochastic delay system are investigated.The time-delay exists not only in the system state but also in the system control input.Under the two kind of controller gain disturbance,the memory state feedback non-fragile H∞ controller of stochastic delay system is designed by solving LMI.Finally,a numerical simulation is given to show the effectiveness of the proposed approach and the validity of the results.

Abstract:Central pattern generator (CPG) plays an important role in rhythmic motion of animals and is available for biological motion control studies of robots.In this paper,by using Kimura neuron oscillators,a distributed CPG control network is constructed to realize the locomotion control of quadruped robot AIBO.The parameters of the network are adjusted by multi-object genetic algorithm (MOGA) and an animal-like walking gait of AIBO can be realized.Both simulations in Webots and experiments on real AIBO validate the feasibility and efficiency of the constructed CPG control network.

Abstract:In attribute-based extended delegation model(ABDMA),delegatee must satisfy both delegation prerequisite condition(CR) and delegation attribute expression(DAE) when assigned to a delegation role.We extended ABDMA to make delegation more safe and easy to revoke delegation role form delegateee.This paper first defines user revocations,by which delegator can revoke delegate role from delegate.Then an auto-revocation mechanism is introduced and four types of auto-revocations are defined as revocation caused by delegation duration,the change of delegatee’s CR,the change of user’s DAE and the changed of delegation role’s DAE.System cost and security in multi-step delegation caused by auto revocation are also discussed.An auto revocation algorithm and a system architecture are proposed in this paper.

Abstract:An approximation-exact penalty function method for solving single stage stochastic programming is presented.Firstly,the determinate nonlinear programming sequences are obtained by means of discretizing random variable.Secondly,an exact penalty function and an unconstrained optimization are constructed correspondingly.Under lenient conditions,some equivalent properties between the determinate nonlinear programming and the unconstrained optimization are proved,and the solution sequence of the determinate nonlinear programming converges to solution to the original problem in some sense.

Abstract:Based on Black-Scholes Model, the pricing of SIPs was investigated with PDE method.With the double-factor model,a pricing model for the SIPs was established with an earlier exercise condition according to hedging techniques and Ito Lemma.And the numerical solution was obtained with the difference method.The value of the liquidity was analyzed by comparing the models with or without the early open condition.Finally,a case study was made of Guangda SIP.The roles the model in pricing and its limits were discussed as well.

Abstract:Quantitative assessment model of low cost element is first established by dividing rural energy system cost into economic cost and environmental cost.And the latter is determined based on output data of life cycle inventory.With 15 years as a life cycle,12 energy system schemes of 3 typical villages from freezing zone,cold zone in China are compared synthetically as case studies.From the quantitative result,the fossil energy(coal,LPG) system schemes have higher economic and environmental cost; straw and fuel wood energy system schemes have lower economic cost but higher environmental cost; straw gas and methane energy system schemes have lower economic and environmental cost,and the integrated cost is below 5 000 yuan·capita-1,which are the optimum schemes for the future rural energ