Applied Mechanics and Materials Vols. 513-517

Abstract: In order to develop an anti-broadband electromagnetic interference wired phone, speech enhancement, electromagnetic shielding, PCB board electromagnetic compatibility and filtering are the usual measures. Realization of speech enhancement can resolve practical problems of SLT dialing error in strong electromagnetic interference, voice unclear and intermittent communication. The experiment shows that in 50m radiating field of high-power VHF radar or shortwave radio, speech intelligibility of phone designed was higher than that of general phone and had no whistling or ringing.

Abstract: According to the problem that train operation process costs much more energy in rail transit. Multi-objective optimization model is formulated on multiple objective optimization methods. The model aims to energy-efficient, punctuality and stopping at adequate position. In order to solve the basic PSO relapsing into local extremum and slow convergence in the late evolutionary, a method is put forward to improve the acceleration coefficient of PSO. Experiments result shows that the modified algorithm can get a more accurate global optimal value.

Abstract: With some residual coal and much leaking air in gob area, fire happens frequently in those areas. Thus, it has become one of main factors of restricting mine development. With the technology of optical fiber pyrometer, the monitoring system has been designed for temperature distribution in coalmine gob area. In addition, by combining it with line laying system, power supply system, data collection system and data analysis system, temperature distribution in coalmine gob area could be monitored in time to provide firing warning of the spontaneous fire happening in the residual coal and fire would be reduced effectively. By comparing optical fiber thermometric system with the temperature measurement system, it shows that the former have a clear advantage in the aspects of time, the location of ignition point, reaction speed and costs maintenance.

Abstract: This paper presents a novel low-power digital baseband for UHF RFID tag. The design is complied with a modified ISO 18000-6C protocol. In order to reduce the peak power, module-reuse and other advanced low power techniques are applied. And a novel baseband architecture is discussed, which fulfills the protocol functions and reduces power consumption. The whole tag chip, including digital baseband, RF/analog frontend and memory, has been taped out using TSMC 0.18um CMOS process. The chip area is 89234 um² excluding test pads. Its power consumption is 11.63uw under 1.1v power supply.

Abstract: Radiation characteristics and mutual coupling are the important factors to the integration design and arrangement for airborne antennas. And the study of them is significant to the EMC of airborne electronic systems. Therefore, by using UTD, a study of predicting the far field pattern of a monopole mounted on the fuselage of an aircraft is described, and the method of computing isolation between airborne antennas is referred to. Initially simple model of large airplane is given by the principle that configuration should be simplified while electromagnetic radiation characteristics should not be neglected. Furthermore, single order, two orders as well as higher orders ray tracing are discussed based on the basic modals such as cylinder, taper and flat. The analytical solution of ray tracing is given out when it exists. If the analytical solution of ray tracing doesnt exist, faster numerical searching method is recommended. Then shadow judgment is introduced briefly. Lastly programs are made, and the results are proved true by comparing them with relative referencesv [1].

Abstract: The detection of flocculation in the thickener has a significant impact on the realization of the closed-loop control of the thickener production. In this paper, a slurry concentration detector is designed based on a parallel plate capacitive sensor. The relation between the slurry concentration and the measurement of the capacitive sensor is obtained for mass percentage concentration of the slurry between 5% and 25% through a large amount of experiments. The results are compared and verified by a known relation experimentally and the errors are less than 5%. The reliability of the relation and the feasibility of the detector equipment are verified, which provides a reliable detection method for the realization of closed-loop control of the thickener production.

Abstract: In order to diminish the simulation granularity of phased array radar simulation system, modeling the target track is really necessary. This paper adds the target track simulation module and coordinate conversion module to the original functional simulation system of the phased array radar, thereby presents the frame construction, additional mathematical modules and simulate procedure of the improved simulation system. The phased array radars functional simulation system is proposed for the realization of the actual simulation software system. The simulation result verifies the efficiency of modeling method and mathematical modules.

Abstract: In order to determine the electromagnetic compatibility between radars better, this paper deduced the distribution character of signal+ noise+ jamming and the signal passing narrowband linear filtering system based on the signal detection theory, and established the quantitative relationship of the radar detection probability and jamming noise ratio on this basis, the detection probability was used to judge the electromagnetic compatibility between radars directly. The simulation experimental results showed that the detection probability was reduced with the increase of interference intensity, when the interference power exceeded the threshold of 1.7 dB, radar detection probability dropped to 50%.

Abstract: In practical applications, the DSSS signal has very low power spectral density, and its application range is very wide, so in the non cooperative communication, if on the premise that the spread spectrum sequence is unaware, how to detect and estimate the existence of DSSS signal is very important, this has very strong application background. This paper introduces the time domain correlation detection method of DSSS signal, through the simulation can validate that this way can detect the existence of signal; it lays the theoretical foundation for practical application.

Abstract: In this paper, a multi-resolution wavelet threshold denoising method which can achieve radar weak single detection is proposed. The method and the way of the radar weak signal detection which based on the Wavelets transform are described. The simulation to real radar signal is verified by MATLAB. The good results are obtained that the proposed method effectively improves the signal noise rate of the weak signal detection.