Applied Mechanics and Materials Vols. 687-691

Abstract: This paper puts forward a new scheme of remote data acquisition system based on GPRS to solve various problems people encounter in the process of production and living. The scheme adopts GPRS’s Internet access function; hardware system CPU chooses microcontroller AT89S51; GPRS module chooses SIM100 to solve the problem of real time and reliability of data transmission, at the same time build the acquisition system with strong real-time communication, and high reliability. The application results show the effectiveness of the proposed scheme.

Abstract: This paper has introduced a kind of method which can simulate the echo signal of radar receiver by the use of the Digital Radio Frequency Memory (DRFM) and Programable Logic Device (PLD).With the realization of actual circuit,the echo simulator can produce intermediate frequency and video signals.Therefore,with the help of the echo simulator, we can raise the detection ability of radar receiver system considerably. The structure of the simulator is simple but its function is great.The echo simulator can simulate intermediate frequency signals of radar receiver system for the first time.So the simulator can locate where isn’t work well of the radar receive system.

Abstract: In order to verify whether the piezoelectric impedance technology can be applied to detect the physiological signals of human body, the principle of piezoelectric coupling impedance theory and piezoelectric impedance technology using for human physiological signal detection was introduced in this paper. With an experiment platform set up, detection experiments based on the piezoelectric impedance technology were created. And the experimental1 was improved to avoid the influence of man-made factors on experiment result. Two methods were used to deal with the experimental data. The results show that the piezoelectric impedance technique can be applied to identify the human body physiological signal, and offers a totally new idea to detect the physiological signals of human body.

Abstract: At present, in the digital audio processing sampling rate is respectively 32 kHz, 44.1 kHz, 48 kHz [1]. Because of the different criteria, there is much inconvenience in the process of research. Therefore, the sampling rate converter is a must, between any two kinds of sampling rate. In synchronous sampling rate conversion, you can use decimation and interpolation for sampling rate conversion, but in the asynchronous sampling rate system, due to the different input clock pulse with the output clock pulse, the above method cannot achieve. Therefore we introduce the fractional delay filter sampling rate conversion. This article introduces the principle of the sampling rate conversion and the fractional delay filter based on Farrow structure. At last, we simulate asynchronous sampling rate conversion of audio signal through the MATLAB.

Abstract: the temporal correlation exists between the frame and the frame in a video message, in order to solve temporal redundancy.This paper adopts motion-compensated temporal filtering method for removing temporal correlation, motion-compensated temporal filtering and Haar wavelet lifting techniques are studied and discussed; finally presented the improved motion compensated temporal filtering methods. Results show the new method improves coding efficiency and scalability.

Abstract: Large area real terrain modeling is the key technology in visual simulation system. This thesis discusses the terrain modeling technology based on the GeoTIFF data, which transform the GeoTIFF data to DEM using the Global Mapper. And then, the three dimensional terrain models are established through Creator environment, the real terrain modeling is implemented quickly.

Abstract: A novel indoor positioning algorithm named BPNN-LANDMARC is proposed in this paper to increase the positioning accuracy and reduce the high time complexity of classical LANDMARC algorithm. Simulation results prove that the proposed BPNN-LANDMARC algorithm can improve the average positioning accuracy by 24.35%. In addition, the improved algorithm reduces the time complexity of algorithm obviously.

Abstract: In MU-MIMO system when a base station sometimes has not enough resources to satisfy the service application from each user, we should arrange to communicate selectively for a certain number of users according to some appropriate method, i.e. multiuser scheduling. Given necessary channel state information this paper investigated the relationship between the norm of channel matrix and channel quality and studied multiuser scheduling algorithm typically based on the Frobenius-norm of channel matrix which was simulated respectively for equal power distribution and water-filling power distribution in MU-MIMO system model. The simulation result showed that at the same transmitted signal-to-noise ratio (SNR) such scheduling algorithm could be able to lower the bit error rate (BER) effectively and improve the receive capability in comparison to random scheduling.

Abstract: For dynamical changed network topology and unstable links, this paper proposes a mobility prediction-based weighted clustering algorithm for vehicular ad-hoc network with high mobility nodes. In the CH election stage, it computes vehicle’s priority through the similarity, intimacy and centrality, the vehicles with the highest priority in their neighborhoods are selected as the CHs, this scheme suitable for large scale network. NS2 simulation results show that the proposed clustering scheme improves the stability of cluster structure, prolongs the CH duration time, improves the delivery ratio.

Abstract: Scale invariant feature transform matching algorithm and Maximally Stable Extremal Regions matching algorithm have been widely used because of their good performance. The two local feature matching algorithms were compared through numbers of experiments in this paper. The experiment results showed that SIFT is good at dealing with the image distortion from shooting distance difference and small shooting viewpoint deviation; MSER is good at handling the complicated affine distortion from big shooting viewpoint deviation. From the aspect of scene types, the performance of SIFT is good both to structure images and texture images. MSER is suitable for the matching of structure images, but not so successful to that of texture images.