Applied Mechanics and Materials Vol. 340

Abstract: The numerical simulation is made to the wind field of the assembled steel truss bridge by means of computational fluid mechanics. Based on N-S equation, Reynolds closure equation of "two-layer" turbulence model is regarded as the basic governing equation. Regarding numerical calculation, SIMPLE algorithm that is based on staggered mesh is adopted to the basic governing equation. The calculation of wind speed and pressure distribution of the assembled steel truss bridge provides technical support for its wind-resistant design.

Abstract: Collected a large number of data from 2003to 2011 of maintenance cost for mining dump truck, established the mathematical models of maintenance cost and forecast of economic life of mining dump truck through the method of mathematical statistics regression analysis, found the rule of operation, maintenance cost overhaul and renew, forecasted the economic life of mining dump truck scientifically for 11 years, according to the economic principle of overhaul , judged whether need third overhaul and provided a basis for evaluating the economic life of domestic mine use electric wheel trucks.

Abstract: To study pumping unit of operating state in practical work, permanent magnet synchronous motor of direct torque control was used to model and simulate based on Matlab/Simulink software, and analyzed the waveforms change under normal operation and intermissive pumping. The results indicate that permanent magnet synchronous motor can operate smoothly under low speed and high torque condition, and can transit smoothly with different torque and acceleration. The proposed simulation system can achieve stable control, and its effectiveness is confirmed experimentally. Results of simulation analysis have some certain practical value for pumping unit driven by permanent magnet synchronous motor of direct torque control.

Abstract: Withdrawn at author request.

Abstract: In the paper, we present a linearized mathematical model of a small scale coaxial helicopter with Bell-Hiller stabilizer bar, which is extracted from numerical linearization of a non-linear mathematical model with small perturbation theory. Stability and control derivatives calculated by numerical method are compared and analyzed for stability and control analysis on coaxial helicopters equipped with different type stabilizer bar. The study indicates that the coaxial helicopter with stabilizer bar fixed on the upper rotors has better capability on stability and control.

Abstract: The research of visualization will be carried out in the aspects of parameters distribution, dynamic history matching and geological models and numerical simulation of reservoirs respectively. In terms of the research on reservoir parameters, we can improve the accuracy of the prediction through comparing, analyzing and modeling the data of old wells and the secondary explained data. As to dynamic history matching and numerical simulation, by combination of dynamic and statistic methods, we can modify the deficiency of the traditional method. As for geological modeling, we can utilize the characters of logging responses and current mathematical theory to establish modeling. Only by combination of the dynamic and static methods, we can achieve actual visualization of oil-field development.

Abstract: In order to improve the detection performance of ultra wideband (UWB) system, a nonlinear scaling UWB pulse based on generalized Gaussian pulse (GGP) was proposed in this paper. Then wideband ambiguity function (WBAF) of the pulse was derived and analyzed to show the relationship between its range ambiguity function and nonlinear scaling characteristic parameters. The simulation demonstrate that such UWB pulse can achieve the thumbtack WBAF, low side lobes and high range resolution can be achieved by increasing modulation frequency offset and decreasing modulation frequency. The simulation result can provide theoretic guidance to UWB pulse design.

Abstract: In this paper was based on Kyle (1985) model, considering the conduction problem of the value of internal information, and established a single term insider trading by trading model to consider the case of signal distortions for the true value of the risky assets. And studied the effect of internal information has on the nature of internal trading strategies and market under a more general assumption condition. And compare the conclusion with Kyle (1985) model.

Abstract: With the increases of signal transmission rate in digital systems, the signal integrity becomes increasingly important in high-speed circuit design. During the hardware design of high-speed serial Rapid IO, signal integrity simulation of 5Gbps high-speed serial bus had been carried out by using Channel Analysis tools. Reliable data was formed by effectively analysis and evaluation of pre-simulation, the signal quality of high-speed serial Rapid IO was verified by post-simulation. The non-ideal design parameters were optimized by referring to the effective data obtained in pre-simulation. Signal quality has been greatly improved by parameters optimization. Signal integrity simulation analysis and verification of serial Rapid IO provides strong support for the design and significantly improves the efficiency of hardware design.

Abstract: To study the effect of blood perfusion rate and air convection boundary condition upon heat transfer of liver tissues by establishing heat conduction model of liver tissues under laser irradiation.The analytical solution of the model was solved by homogenizing boundary condition and the numerical solution of the bio-heat transfer model under the two-dimensional cylindrical coordinate was calculated by the Finite Element Method (FEM).The results show that the highest temperature irradiated by laser is on the center point of the surface tissue, and decreases in the radial and axial direction, the temperature in the axial degrades more seriously than that in the radial.This study provides a theoretic bases for laser applications in medicine.