Applied Mechanics and Materials Vols. 513-517

Abstract: DFT-S OFDM, short for DFT Spread OFDM, is employed in LTE uplink to reduce the Peak-To-Average Power Ratio (PAPR) introduced by multicarrier transmission. In this paper, we compare the maximum achievable data rate, i.e. the Shannon capacity, of DFT-S-OFDM and OFDM under Rayleigh and with clipping. Our results indicate that, in terms of Shannon Capcity, OFDM outperforms DFT-S-OFDM with ZF or MMSE.

Abstract: On the basis of actuated control method, the number of car arrived of the current phase and the number of car arrived of the next phase are considered altogether. It is decided to prolong the green time of the current phase according to the relationship of the number of cars arrived of the current phase and the next phase. The experience and principle of traffic control are described as knowledge here. The entire condition of intersection is consisted from classified arrived car number. The knowledge face to the controlling of isolate intersection is applied in the space of intersection state. Then a rough set is formed. Finally, signal control rule set face to every situation is made after some work was done to make one condition corresponding to one action of signal control. The results of simulation indicates that the total stop delay of cars of this signal control method based on rough set reduces 23.1% averagely than the fixed-time approach and reduces 9.5% averagely than the actuated approach in the same condition.

Abstract: To avoid the defects of physical detection methods, such as road spoiling, complex algorithms and equipment maintenance, SVM (Support Vector Machine) and PHOW (Pyramid Histogram of Words) are explored to detect the traffic and road condition. Experimental results show that the average accuracies go beyond 82.5% in the case of different weather. The proposed method can effectively classify 4 types of traffic and road condition images.

Abstract: Static random-dot stereograms (RDS) were used as stimuli to investigate the uncrossed disparity in 15 normal subjects. The response of every subject was recorded with different disparities of 3.27 arc min, 6.54 arc min, 8.18 arc min, 11.45 arc min, 14.72 arc min, 17.99 arc min, 21.26 arc min and 24.53 arc min. The results showed that the human visual system was the most sensitive to stereo images at disparity of 8.18 arc min. Disparity of 21.26 arc min had significant differences with other small disparities in reaction times, as supported the viewpoint that it was reasonable to limit the fine disparity in 20 arc min.

Abstract: Among the main geological factors to cause the disasters of mine safety production in deep mining, coal and gas outburst is the first major calamity that restricts colliery exploiting. Aiming at this problem, current geophysical methods were reviewed and compared, and the velocity tomography technology using ground penetrating radar was studied. Two models with ground stress anomaly and collapse columns were built and inverted using LSQR algorithm, respectively. The results show that the proposed method gives very consistent results with respect to the models information, and uncertain features of inverted models were identified accurately. This verified radar velocity tomography is effective and practical.

Abstract: Among the digital monitoring system, MPEG4 encoding compression technology and embedded technologies are widely used, chemical embedded MPEG4 video surveillance system has a broad market prospect and highly advanced technology. In this paper, the MPEG coding standards and on the basis of analysis of the characteristics, given a set of MPEG4 video surveillance system design, and implementation are integrated MPEG4 exposition, after the actual chemical application shows that the system performance stable, real good, do not need to assign someone to manage, scalability is also very good.

Abstract: With the popularization of digital radio system, radio has also entered the digital age from the original analogue system. On the basis of the digital radio chip TEA5767 which used in the current widespread use of electronic products, this paper proposes and designs a digital broadcast receiving system based on STM32. The hardware circuit uses STM32F103VE as the main controller, with the configuration of digital radio chip TEA5767 and corresponding SD card storage module, LCD module, power module and so on; the software design adopts I²C bus to communicate and coordinate between the main controller and FM chip, achieving FM frequency and volume adjusting function. Meanwhile the μC/GUI is used to design the human-machine interactive interface. The digital broadcasting radio system has the advantages of small volume, multiple functions, low power consumption and easy to use.

Abstract: The additive noise is a common type of noise in signal processing. Although its existence does not depend on the input signal, it has a great interference on the useful signal. In the field of information hiding, additive noise and de-noising is also an important research direction and is crucial for the security. In this paper, different information hiding methods of linear carrier are analyzed and the pros and cons of each way are compared. Beside this, a deep research is carried on the effect of Gaussian noise and Salt & Pepper noise on each method. The simulation comparison shows that additive noise has a great influence on information hiding, and under the same noise intensity, the method of hiding information based on the difference of concave and convex square waves has stronger robustness.

Abstract: Different styles (invariable amplitude, sweep frequency, amplitude modulation) of continuous wave irradiation experiments are done on a certain radio fuze, and the failure regularity are summarized. The accidental explosion reasons are generally illuminated, and the failure mechanism under different irradiation conditions are particular analyzed. Finally, the failure regularity and mechanism of different irradiation conditions are compared. The results show that different electromagnetic environment will have different effects on the same fuze, and the failure regularity and mechanism are also different.

Abstract: As the first step in 3D point cloud process, registration plays an critical role in determining the quality of subsequent results. In this paper, an initial registration algorithm of point clouds based on random sampling is proposed. In the proposed algorithm, the base points set is first extracted randomly in the target point cloud, next an optimal corresponding points set is got from the source point cloud, then a transform matrix is estimated based on the two sets with least square methods, finally the matrix is applied on the source point cloud. Experimental results show that this algorithm has ideal precision as well as good robustness.