Abstract:A topology optimization design method for the thick plate transition structure was proposed. The optimization mathematical model was established in such a form that structure types were design variables, the deletion ratio of volume was constrain condition and the minimum structural flexibility was the objective function. Based on the strain energy criterion, the method of evolutionary structure optimization (ESO) was applied to achieve structural optimization model by deleting elements with low strain energy. Thick plates of various layout of shearing walls and columns subjected to vertical loads were studied, and then space truss model with strut and tie was obtained, which reflected the shortest path of the load transferring in thick plate. Furthermore, the behavior of the tie rod and strut bracing for the thick plate optimized was analyzed，and the formula of bearing capacity was deduced. The result has indicated that the proposed optimization design method is feasible.

Abstract:In order to discuss the progressive collapse of long-span space structures with the alternate path method (AP method), a practical method for the evaluation of elements to be removed was presented. The elementary scope of important elements was selected through concept analysis, and then the importance coefficient of these elements was calculated through simplified sensitivity analysis to choose the important elements. The effects of the removal of elements, the variation of cross-section of elements and the change of pre-stress of cables on the structural response were considered in the sensitivity analysis. A space grid structure and a cable-arch structure were analyzed in this method. The results have shown that the method is suitable for the evaluation of important structural components of long-span space structures. The problem that the elements to be removed for other non-frame structures are not given in codes has been solved, and then the AP method will have extensive applications.

Abstract:On the basis of the Xupu connecting line of Shao-Huai Expressway and with the help of finite element program, the Drucker-Prager theory of elastoplastic model and four-node Goodman friction element was used. Simulation tests were done for reinforced cut and fill sub-grade distortion factors sensitivity analysis. By defining the sensitivity factor and analyzing the test results, the sensitivity was sorted out. The result has shown that, for the sensitivity priority of each factor to stability of reinforced cut and fill sub-grad, the top three factors for the settlement of subgrade are foundation strength, embankment height and geocell, and the top three factors for the lateral displacement of subgrade are foundation strength, geocell and embankment height. This experiment has revealed the real work condition of the reinforced cut and fill sub-grade, and the results shown here have given a good reference for the succeeding research and similar engineering practice.

Abstract:The equilibrium differential equation and the corresponding boundary conditions of laterally loaded long-piles under double-parameter foundation on double-layered soil were deduced by means of energy variation principle. Meanwhile, the condition of moment equilibrium, shear equilibrium and the continuity condition of displacement and corner were used to relate the medium ground of layered soil. The coefficients of piecewise displacement function were derived by substituting the solution of equilibrium differential equation into the conditions of moment equilibrium, shear equilibrium and the continuity condition of displacement and corner, thus identifying the displacement curve of laterally loaded long-piles.Case study indicates, the stiffer layer on the earth surface can exert an influence on the displacement of pile, and as the diameter increases to some extent, its effect on the displacement of the pile is smaller.

Abstract:Offshore wind turbines are mainly built in shallow water, so the nonlinear characteristics of the wave forces are significant. The high order nonlinear wave velocity fields and acceleration fields were studied on the basis of the stream function wave theory. The nonlinear wave forces of offshore wind turbines were calculated with the Morison equation and the Stream Function Wave Theory. The free surface influences on the nonlinear wave forces of offshore wind turbines were studied. The characteristics of the nonlinear wave forces of piles of different diameters in shallow water were also investigated. To verify the correctness of the calculation results and compare the characteristics of the nonlinear wave force, the calculation results were compared with the linear wave calculation results. The results show that the maximum nonlinear wave force is 26.6% larger than the maximum linear wave force, and the free surface influences generate 14.7% relative errors. In offshore wind turbine design, the application of the nonlinear wave theory will lead to more accurate wave forces on offshore wind turbines.

Abstract:A hydro-pneumatic interconnected suspension system was proposed to overcome the deterioration of the automotive ride and driving performance due to the uneven load distribution among the wheels. The structure and principle of the system were introduced firstly, and the dynamic model was built up using Matlab/Simulink subsequently. Finally, the co-simulation was carried out by integrating the interconnected system into the vehicle dynamics simulation software, Carsim. The comparison between the vehicle with this system and without demonstrates that the hydro-pneumatic interconnected suspension system could enhance the vehicle ride, traction ability and trafficability.

Abstract:Improved collaborative optimization based on support vector regression and particle swarm optimization algorithm was researched. The basic principle of collaborative optimization and support vector regression was represented, and in order to resolve the difficulty in system-level coordination, improve convergence performance and efficiency, approximate models of constraint conditions in system-level were constructed using support vector regression, and particle swarm optimization algorithm was introduced to the system-level optimization and disciplinary-level optimization. Simulation results show that the improved collaborative optimization can effectively resolve multidisciplinary design optimization problems, and compared to standard collaborative optimization, optimization accuracy is higher, system-level iterative operation is less, and the stability is better. All those can provide theoretical reference for the research of multidisciplinary design optimization.

Abstract:This paper presented a method of leading angle flux-weakening control for interior permanent magnet synchronous motor (IPMSM) on the electric vehicles, and achieved the purposes of high times, smooth and wide-speed operation and low cost of control systems. The control algorithm based on the utilization of inverter's DC bus voltage determines the deviation degree of the rotor synchronization rotation angle by constructing a new index loop of voltage and achieves the purpose of extending the operation speed range. The transition of flux-weakening is smooth, and the algorithm of leading angle flux-weakening control has nothing with parameters and realizes the high-time flux-weakening control of IPMSM. It not only meets the requirements of wide speed operation, but also reduces the cost of the whole system. The effectiveness of the proposed control scheme is verified by computer simulation and experimental results.

Abstract:A new approach based on modified S-transform (MST) was proposed to detect and classify the voltage sags. The average power spectrum of white noise was deduced on the S transform and MST, and the results showed the MST'restraint upon noise. The selection thinking of adjusting parameter in MST was described, the method to get the amplitude was obtained, and the time and phases of the sag were given. Then the voltage sags in short-circuit fault , induction-motor starting and transformer exciting without load were analyzed, six feature parameters were extracted and decision rules were obtained to recognize the sag disturbance sources. The simulation results show that the amplitude and time of the voltage sags by using MST are more accurate than those by using S transform, and the classification method has a high classification ratio.

Abstract:A new video inpainting method based on three-dimensional Poisson equation was presented. The gradient fields of video frame were extracted first. Then, the target areas of every gradient fields were filled in the patch-by-patch inpainting methods. Afterwards, to repair the video, a three-dimensional Poisson equation was built and solved in the gradient field of the target area. Experiment results have shown that the proposed method can achieve the desired results and perform better than the existing methods in color, light and shade consistency.

Abstract:The mechanism of the cogging torque generated in permanent magnet machines and some measures to reduce cogging torque were studied. Taking a rare earth type, permanent magnet synchronous motor with four poles, forty-eight slots, surface-mounted as an example, this paper analyzed the influence of pole arc coefficient, magnet pole displacement and adding supplementary slot on cogging torque in a two-dimensional finite element analysis method. The computed cogging torque values were compared with the experiment values of the sample machine, both of which agree with each other well. The research results have indicated that, with the appropriate choice of these methods, the cogging torque can be reduced effectively. 

Abstract:The thermal fatigue crack propagation behavior of WC-8Co cemented carbide in different quenching agents was investigated. The pH of the aqueous solutions varied between 5.2, 7.4 and 8.8. This study was in the temperature range of 650 ℃ to 10 ℃ by using V-notch plate specimens.The results have shown that a corrosive environment has a strong influence on the thermal fatigue crack propagation behavior of the material test. Acidic and alkali environment can reduce the thermal fatigue crack initial life and increase the crack propagation rate. In addition, in the neutral environment, the thermal fatigue crack propagates along the WC / Co phase boundary, and in acidic and alkali environment, the crack propagates through the pits and the large size of the reunion things.

Abstract:Thermodynamic analysis indicated that Li-3+.x.V-1-.x.Si-.x.O-4 film was difficult to be synthesized in aqueous solution, while Li-3V-1-.x.P-.x.O-4 could be prepared in aqueous solution. In certain alkaline aqueous solution, SiO-2 reacted with OH- and Li+ to produce Li-4SiO-4. At the same time, V-2O-5 reacted with OH- and Li+ to produce Li-3VO-4, and then Li-3VO-4 reacted with Li-4SiO-4 to produce Li-3+.x.V-1-.x.Si-.x.O-4. In this process, the reaction that produces SiO4--4 was the key step and .a.-OH-≥1.0 mol/L was a necessary condition. .a.-Li+>1.0 mol/l was a necessary condition for Li+ to react with SiO4--4 to produce Li-4SiO-4. In another alkaline aqueous solution, H-2PO--4 reacted with OH- and Li+ to produce Li-3PO-4. At the same time, V-2O-5 reacted with OH- and Li+ to produce Li-3VO-4, and then Li-3VO-4 reacted with Li-3PO-4 to produce Li-3V-1-.x.P-.x.O-4. In this process, .a.-OH->0.15 mol/L was a necessary condition for the production of VO3--4 and PO3--4. .a.-Li+>0.5 mol/L was a necessary condition for Li+ to react with VO3--4 and PO3--4 to produce Li-3VO-4 and Li-3PO-4.

Abstract:The mass transfer coefficient (.K.-Ga-v) and the removal efficiency of carbon dioxide for aqueous MEA-based absorption process were investigated in a packed absorber filled with θ-ring stainless steel packing. The experiment results showed that .K.-Ga-v decreased with the increase of CO-2 lean-loading, and increased with the rise of MEA concentration and liquid flow rate. In addition, an increase in feed temperature from 30 to 50 ℃ led to an increase in .K.-Ga-v.

Abstract:Seeds of .Arabidopsis. were planted separately in the medium of different nutrient element deficiency of N, P, K, Ca, Mg, Fe and Sucrose, in the condition of 22 ℃ long-day (16 h light / 8 h dark) 10 days. The .Arabidopsis. seedings had the corresponding phenotype. Histochemical assay of .GUS. activity and Q-PCR were used to analyze and examine the expression of the 4.CL1, 4CL2. and 4.CL3. gene. The research results have showed that the potassium (K) can induct the expression of the 4.CL. gene involved in the synthesis pathway of the lignin and flavonoid.

Abstract:To address the limited computing power of the nodes in Ad Hoc networks, this paper proposed a new session key agreement protocol based on one-way hash chains and mutual authentication technologies. The main contribution of this paper is the achievement of a higher efficiency than other similar protocols. It adopts hash function to avoid the complexity of the traditional public key algorithm, so it noticeably reduces the computational overhead. Meanwhile, this protocol has many secure properties, such as reliability of the node's identity, message integrity, forward security and session key independence. It can also resist the man-in-the-middle attack by using mutual authentication technology.

Abstract:To utilize sample' information in different stages and solve the parameter uncertainty risk in statistical process control, this paper introduces a reference prior distribution for the parameters in quality models, and constructed the warning lines and action lines to monitor the mean vector's change according the predictive distribution as well as the relationship between the multivariate .t. distribution and .F. distribution. When the current stage is under control, the parametric posterior distribution is considered to be their priori distribution in the next stage, in which the sequential Bayesian mean vector control method is established.

Abstract:As an important parameter for the credit risk management, default probability is the basis for the calculation of expected default loss, bond pricing and credit portfolio management. In order to estimate default probability more accurately and effectively, this paper defines the incomplete information with the delayed filtrations to change the information structure and filtrate the noise so as to increase the accuracy of the estimation of default probability and replaces martingale with respect to the natural filtration produced by the Brownian motion with the delayed filtration produced by the doubly stochastic Poisson process to calculate the default probability so as to avoid the limitation that the movement of some financial assets is not a martingale. With this key of the credit model, default intensity can be estimated from market information. The method put forward in this paper can be applied for emerging markets without sufficient historical default data.