Abstract:The modified method of equivalent linear model was proposed when performing pile-soil-structure interaction. The dimension of near region was solved and the modified equivalent linear model was obtained. Then, the extensive numbers of the models were analyzed and the modified parameters were solved. Finally, the regression analysis was performed to obtain the empirical equation based on the extensive modified parameters. It is shown that the accuracy of pilesoilstructure interaction analysis under strong earthquake is improved with the modified method.

Abstract:To simulate the degradation of cast-in-situ piles exposed to sulfate saline soil environments, a corrosion experiment of cast-in-situ specimen was conducted. The deterioration mechanism of fresh concrete specimen was studied. The difference of deterioration mechanism between precast concrete specimen and fresh concrete specimen was analyzed with comparison experiments. The effect of watercement ratio and concentration of sulfate solution on the durability of cast-in-situ concrete specimen was analyzed. The mass change rate and the relative value of compressive strength were used to quantify the degradation rule of fresh concrete specimen. The results show that both the concrete mass and the compressive strength increases firstly and then decreases. In the same condition, the fresh concrete specimen is the first to show the mass and compressive strength loss. The loss rate is 0.4% and 15%, respectively. The increase of sulfate concentration has not obvious effect on the degradation law of the fresh concrete specimen. However, with the watercement ratio increases, the fresh concrete specimen is prone to deterioration.

Abstract:Considering the asymmetry, nonuniformity and local characteristics of load in the near field, the expression of lateral load was derived by geometrical relation. According to the different bearing modes of structural section, the plastic failure criterion under the joint action of axial force and bending moment was given. Based on the fourhinge failure mechanism, a simplified calculation method for the plastic damage of shallow buried arch structures was proposed. The bearing mode of circular arch plastic failure was calculated based on Matlab, then the distribution of structure plastic hinge was obtained. It is shown that plastic hinges are produced near two arches, at peak load, and at the shoulder of backside blast surface. When the bias angle is small, the plastic hinge firstly appears at the arch of backside blast surface and the position of projection point of explosion source. As the blast angle increases, the first plastic hinge appears at the arch of front blast surface. In practical engineering, large bias is an ideal failure mode.

Abstract:The multi-constrained optimization problem of regular high-rise structures based on inter-story displacement constraints was transformed into a single constraint problem. On this basis, the single-step optimization method（SOM） based on virtual work was proposed. The optimization results of SOM were compared with the optimization results of SAP2000. The results show that SOM based on virtual work can reduce the mass of material by 10%.

Abstract:The nonlinear analytical model of an external prestressed concrete wind tower was developed based on fiber beamcolumn element. Four damage states were defined based on the results obtained from pushover analysis. Twenty recorded ground motions were selected as the basis of incremental dynamic analysis. The peak ground acceleration and the horizontal displacement ratio were chosen as the intensity measure and the structural seismic demand parameter, respectively. Nonlinear incremental dynamic analysis was then performed and the probabilistic model of seismic demand was built through regression analysis based on lognormal assumptions. Subsequently, the fragility analyses were produced. The seismic fragility of the tower was evaluated, proving that the wind tower meets the requirements of 7degree seismic fortification intensity. For 8degree earthquakes, however, the probabilities of serious or complete damage significantly increase, according to the proposed analyses.

Abstract:An automatic traffic incident detection algorithm based on discrete time signal correlation was proposed. Traffic information data were converted to discrete-time signals and the correlation was calculated to locate the same traffic stream passing the upper and lower sections. The characteristics of correlation coefficients was explained. The results show that the algorithm is visual and easy to understand. The algorithm performs well under low-saturated traffic conditions and has better adaptability.

Abstract:Based on China naturalistic driving data, a driver model for emergency braking was set up and the general characteristics of driver’s braking behavior were analyzed. The results show that the driver’s emergency braking response time is related to the urgency of emergency scenario. By taking the inverse of time to collision 0.2 s-1 as dangerous trigger threshold, the driver’s emergency braking reaction time is the normal distribution of mean 0.5 s. The maximum braking deceleration do not vary with the urgency of the scenarios. The maximum braking deceleration jerk increases with the urgency of the scenarios.

Abstract:By taking two simply supported box girder bridges of 30 m as example, a systematic dynamic simulation model of vehicletrackbridge was established, with a consideration of the coupling mechanism of multilayer vibration isolation system. The finite element model(FEM) was verified by a set of field tests. Good agreement between measurement and predicted results proved the effectiveness and accuracy of the model. With the validated simulation model, the effect of resilient parameters on the dynamic response of vehicle, track, slab, bridge wing plate, web plate, bottom plate and bridge pier, was obtained. Finally, parameter matching principle was presented. The results indicate that an optimized elastic parameters matching design of viaducts may improve the isolation efficiency for the vibration environment along railway lines, and ameliorate the dynamic properties of each substructure of vehiclerailbridge systems.

Abstract:In this paper, the idea of ‘semidecoupling’ is introduced to construct an ethanolgasoline chemical reaction model, which uses the small molecule mechanism of H2/CO/C1 as the ‘core’ with coupling the ethanol skeleton oxidation mechanism and the gasoline toluene reference fuel(TRF) mechanism. By comparing with experimental results available in published literature, the numerical simulation results calculated by CHEMIKIN software can accurately reflect the combustion characteristics of ethanolgasoline fuel. Furthermore, based on the sensitivity analysis of H2O, a hydrous ethanolgasoline reduced chemical kinetic model is established through integrating the chemical reactions of H2O. And the reduced model is verified by the experimental results of ethanolgasoline fuel ignition characteristics.

Abstract:Based on a semiphysical range extender experimental system, the control strategies of both start/stop and power following of range extender were optimized. Results show: with the increase of motor dragged torque and dragged end speed, the time of start process decreases to 1.01 s, the number of ultrafine particles for warm start is about 2.0×108 per cm-3; during the engine stop with load from generator, the speed fluctuation decreases obviously; with the fast start and the increase of rise limit for range extender output electric power, the bus power performance is improved; the number of ultrafine particles is about 2.5×108 per cm-3 during swithover process; the power output of engine speed control method is smoother compared with the generator speed control method, but tends to deviate from the optimum fuel consumption curve.

Abstract:In this paper, the parallel ventilation structure of battery box for hybrid electric vehicle is improved by optimizing the original parallel ventilation structure. Uniform cooling between the front surface and the rear surface of battery can be ensured. According to the air inlet mode and flow path structure, three kinds of structures, i.e., wedgeshaped structure, trapezoid structure and circular hole baffle structure, are designed. It is shown that the circular hole baffle structure is the best. Meanwhile, the structure of the circular hole baffle is improved in cooling dimension. Parallel cooling and vertical cooling are demonstrated. The results show that the dualchannel vertical cooling structure is the better. In the condition of ambient temperature less than 30 ℃, cooling effect is the best at medium and low discharge status when the outlet flow velocity is 6 m?s-1 and the battery gap is 4 ~ 6 mm.

Abstract:By using computational fluid dynamics(CFD), this paper studies the effect of rotating wheels with different filling ratios on the aerodynamic characteristics of wheel housings of a sedan. The results are compared with the existing experimental data. It is concluded that while the filling ratio drops by 27%, the total drag coefficient rises nearly by 20% and the lift coefficient drops almost by 30%. The main reason for the drag coefficient reduction is the increased flow rate inside the wheel housings, which generates more flow separations, higher vorticity and lower car base pressure. The lower lift coefficient results from the accelerated flow near the underbody, which leads to lower local pressure.

Abstract:The behaviors of flow and aerodynamic noise produced around a highspeed train bogie are studied numerically at a scaled model based on the theory of vortex sound and the acoustic analogy method in this paper. The effect of bogie cavity on the flow and flowinduced noise performance is investigated. Results show that for isolated bogie and bogieinsidecavity cases, the volume dipole is the predominate source of nearfield quadrpole noise generated in the wake region close to the geometries. Moreover, as the main aerodynamic noise source for farfield noise radiation, the surface dipole noise is produced from the pressure fluctuation on the wall surfaces around the bogie areas. Compared with the isolated bogie configuration, the bogie cavity changes the flow around the bogie for the bogieinsidecavity case and consequently the directivity of the noise generated from the bogie wall surfaces is altered and the radiated aerodynamic noise level is reduced. However, the strong noise is generated on the rear wall of the bogie cavity.

Abstract:Based on the electrically driven inertial vibration exciter, a twopoint excitation fatigue test system of wind turbine blade was constructed. The virtual master synchronization control algorithm was put forward. The PID algorithm was used to design the error compensator, then the stability of the control algorithm was proved by using Lyapunov function. The control simulation model was established, and the convergence and the robustness of the control algorithm were analyzed by numerical simulation. Finally, the effectiveness of the control algorithm of electromechanical coupling was verified. The results show that the control algorithm can make the exciter follow quickly, the fluctuation of phase difference between the exciters is very small, the blade amplitude is stable, and the stable and effective loading of wind turbine blades is realized.

Abstract:A gate-level software-based self-testing method based on bounded model checking is proposed in this paper. The module in processor is abstracted and simplified into a constrained module to alleviate the state explosion problem. Then, the trigger conditions for unpredictable faults are transformed into properties one by one, and the bounded model checking is used to search violations which trigger these properties. Finally, the violation is mapped into the sequence of test instructions, and a sequence of observation instructions is added to form a self-test program. The experimental results show that the method can effectively test the faults which are difficult to be tested in the controller but without causing the state explosion problem, and improve the test quality of online test.

Abstract:A load-aware time division multiple access (LATDMA) protocol is proposed in this paper, by considering the avoidance of symbol collisions in the time spread on-off keying (TSOOK) based communication system combined with load-unbalanced application scenarios. This protocol adopts a dynamic TDMA-based time slot allocation mechanism according to the current number of source nodes, their corresponding traffic and the transmission peculiarities of Terahertz channel. The simulation results show that LATDMA is energy efficient and gains obvious advantages in average end-to-end delay and average throughput, which proves suitable to support low-delay and load-unbalanced wireless nanosensor networks (WNSNs).

Abstract:In this paper, event related potential (ERP) technology is used to identify public spatial identities and explore the effect of semantic consistency or inconsistency on user identification. The experimental materials are derived from GB/T 10001 “Public Information Graphical Symbols for Sign”. Matlab13b and Stata14 are used to process electroencephalograph (EEG) and behavioral data. It is shown that N170, P200, N300 and N400 are induced in the cognitive process of identification, indicating that the subjects experience 4 stages of classification, emotional arousal, logical judgment and semantic judgment in the process of identifying brain cognition. The statistical results show that the differences of N300 induced by the two conditions are significant in the frontal top areas, and the difference in the N400 is significant in the frontal top area, the central top area and the top area. N300 and N400 can be used as a neurometric index to judge whether the identification graph is consistent with the expected semantics.

Abstract:Based on moving least squares, an algorithm of trajectory tangent azimuth calculation is presented in this paper. The feasibility of the algorithm is tested by measured data and the setting of key parameters including dilatation parameter and weight function is discussed. The results show: the algorithm is practical and can be applied to small bended trajectory; the value of dilatation parameter should satisfy the requirement of calculation, but it should not be too big; the precision of trajectory fitting can be promoted by weight function but the precision of azimuth will not be affected.

Abstract:A scene model based stereo-camera calibration method is presented in this paper. The initial calibration process firstly constructs a global scene model, and based on this, both intrinsic and extrinsic parameters of the stereocamera are estimated separately and optimized jointly. The update calibration utilizes the established scene model to restore three dimentiontwo dimention relation between model coordinate and image coordinate, with the relation, stereocamera parameters are updated through joint optimization. The experiments in realworld show that the method calibrates all the parameters while SLAMbased method only solves a part, and the accuracy of the method is better than the chessboard based method.

Abstract:Assuming that the energy consumption unit is willing to agree to the contract for energy performance contracting (EPC) when the expected net present value of profit is equal or greater than the threshold value, a contract parameter decision model of EPC is developed from the point of profit maximization of energy service company (ESCo). The effects of financing, registered capital and other factors on the contract parameter and energysaving performance are explored based on the statistical analysis of 179 EPC contracts. The analytic results demonstrate that the financing and the registered capital of ESCo have significant positive effects on the contract parameter and energysaving performance. It is consistent with the fact that the financing difficulty is one of the present obstacles to the development of EPC, indicating that the proposed method is feasible.

Abstract:Considering the valuation of a protected swap on credit rating migration, under the framework of structural methods, a pricing model was established for protecting the loss caused by the first credit rating migration, where the credit ratings depend on the interest rate and have two grades. In the pricing model, an independent variable of the model was defined by the value of lowgrade zerocoupon, which is a new perspective. A partial differential equation(PDE) pricing model was derived by the hedging method. A semiclosed solution was obtained by dimensionality reduction technique. The numerical solution was calculated by the explicit finite difference method. Finally, the dependency of parameters of the model was discussed and the results show that there is a monotonically decreasing relationship between premium value and each parameter.