Applied Mechanics and Materials Vols. 220-223

Abstract: In order to satisfy the needs in engineering practice，a new type of nonlinear viscous damper with conical valves is developed. There is a through hole and two valves in the piston of the damper. When the damper work, the fluid flows throw the hole and the regulators, then the energy is consumed. The regulators open because of the pressure difference and adjust their sizes to control the damping force to get just the effect we wanted.

Abstract: Metal-oxide semiconductor gas-sensitive sensors have various advantages as the basic devices of gas detection systems, such as high sensitivity, fast responsibility and low cost, etc. They are widely applied to many fields. Amplifier circuit is an important section of gas detection system. A new type of amplifier circuit including a three-stage operational amplifier was designed in the paper which can effectively eliminate the influence of the follow-up circuit on the sensor output. Theory analysis and experimental simulations were performed. The results show that the output voltage signals have a linear relation with the concentrations of the detected gas.

Abstract: This letter presents a circularly polarized antenna with a printed monopole structure fed by a coplanar waveguide (CPW) line. Circular polarization (CP) radiation of the proposed design is achieved by introducing an inverted L-shaped strip connected to the square radiation loop and an L-shaped slit embedded in the ground plane. A parametric study has been carried out to investigate the effects caused by different widths and lengths of both the strip and the slit. Both simulated and measured results are provided to validate the CP performance of the monopole antenna.

Abstract: Smart antenna is the critical technique of the third mobile communication, and will become the key technology in the fourth generation communication. The benefits of pattern diversity increase as the incoming pattern distribution becomes more isotropic, so that the research on correlation coefficient in antenna diversity is very critical. This research reviews the related definitions of antenna diversity as well as the related parameters, and then introduces our algorithm to develop closed form solution to calculate correlation coefficient, which provides a generalized method of determining the efficacy of an antenna diversity system. The correlation coefficient calculation is simulated with MATLAB. The simulation results show that the method is efficient and flexible, which will serve as a design tool when constructing pattern diversity systems.

Abstract: Antenna gain is one of the most important electrical characteristics that are of interest to obtain by direct measurement in laboratory experiment. This paper introduced a laboratory measurement method of antenna gain, and demonstrated this experiment in detailed steps such as measurement environment surrounding the antenna, measurement preparation, measurement points for attention, etc. A quarter wave omnidirectional antenna, a collinear omnidirectional antenna, a biquad antenna and a cantenna were shown as models, and the measurement result is fully consistent with theoretical value.

Abstract: According to the current situation of domestic passenger cars’ battery quick change equipment and its overall development trend, we first research on the key module technology of passenger cars’ battery quick change system. Then, this paper researches on network information control mode, internal dynamic management mode of the battery quick change system, radio frequency identification (RFID) and storage charging system mode, respectively. Thus, they can provide passenger cars’ battery quick change system with some references realizing the system’s network, intelligence and high efficiency.

Abstract: According to the demands of power supply system of microwave power module (MPM), ZVS push-pull dual-voltage resonant converter is present. High-voltage can be achieved in this new novel converter topology. The paper introduces the structure of the converter. Then the steady-state and operation characteristic of the converter is analyzed and deduced. A Pspice simulation is carried out to verify the theoretical analysis, the results and conclusions are given in the end. The results show that the ZVS push-pull dual-voltage resonant converter can realize the soft-switch and double voltage well. The structure of the converter is simple and easy to implementation, so it suitable for low input voltage and high output voltage power supply system.

Abstract: This paper considers a tradeoff between maximizing the user’s signal interference noise ratio and minimizing interference leakage in preprocessing for multi-cell MIMO system. A sub-optimal precodingalgorithm based on game theory is proposed to deal with it. A game-based algorithm mathematics model is constructed and interference pricing function is also introduced in the solution to the precoding vector by Lagrange equation. Implement step of the proposed algorithm is also summarized in the paper. Finally in simulation the proposed algorithm is compared with conventional algorithms and convergence of utility function is also discussed. The simulation results show that the proposed algorithm provide improvement over existing schemes.

Abstract: Embedded computer vision is a relatively new concept, it is only in the past few years that embedded devices have become fast enough and the component cost low enough that they can be used in small low power systems. In this paper, the design and development of a vision-based detection system with smart devices features is proposed. The main functionality of the equipment is introduced as well as the additional features it should provide to be integrated into a smart environment.

Abstract: In order to make prosthetic work in unstructured environments in real time to solve the inverse kinematics problem, the coordinates of the location of the end of the workspace of the manipulator rod needed to know. The spatial orientation value of random object relative to prosthesis basic coordinates be calculated in real time is realized in the embedded system by means of two three-dimensional attitude sensors and one laser ranging sensor.This method can provide the necessary raw information for the multiple degree of freedom prosthesis which works in an unstructured environment to complete the operational tasks assigned.