Applied Mechanics and Materials Vols. 380-384

Abstract: LTE is accepted worldwide as the Long Term Evolution Perspective for todays 3G and 4G networks. Cell search time synchronization is an important physical layer procedure by which a user equipment (UE) acquires synchronization with a cell and detects the physical layer cell ID of that cell. Timing synchronization is consisted of the symbol timing synchronization and frame synchronization. This paper supplies the introduction of synchronization signals, presents the detection method, and analyzes the design based on FPGA platform and finally simulated on the Modelsim 6.5 and implemented in Xilinx Virtex-6 kit.

Abstract: Radio Frequency Identification (RFID) is an automatic identification technology that can identify the objects at a distance.This paper presents the design of remote attenance system based RFID. The system is implemented for the automation of time and attenance using a new mode of barrer-free channel. With a simple setting, the attendance system is capable of recording real time attendance, counting attendance and attenance statistics analysis. Reports and charts will be provided for the top management to make decision, annual review, and planning on man power. The applied result of the system shows that it is simple and effective.

Abstract: Nowadays Radio Frequency Identification (RFID) technology is becoming more and more common in neonatal department. This paper proposes a patient Electronic Medical Record (EMR) System based on RFID technology in neonatal intensive care unit (NICU). The system is such a proactive step to enable fast sharing of medical information with the clinical staff and families and avoid human-based errors that it makes the management of the NICU more effective and efficient. Besides the system architecture and functions are described, the database design and several key features of the software development are introduced too.

Abstract: In this research, an identification method of harmonic source, based on independent component analysis, was proposed. An unknown harmonic source in the equivalent circuit of power system was regarded as the signal source in the independent component analysis. The known voltage and current of PCC were taken as observed quantities. The independent component analysis and the optimization algorithm were utilized to construct a matrix that could linearly transform voltage and current of PCC into mutually independent signal sources. The harmonic impedance and harmonic source of both the user side and system side were obtained. Then the contribution of users to the harmonic distortion at PCC could be identified. With a good anti-jamming property, this algorithm only needs a condition that variations in the harmonic voltage sources at system side and user side are independent to each other. Simulation results indicated the effectiveness of the method to identify the harmonic source of PCC.

Abstract: A new HDMI data transmission system is proposed in this paper. To achieve a better data transmission performance, the TMDS codec algorithm of HDMI transmitter and receiver are optimized, thus the precision and practical applicability is improved. Moreover, a color enhanced module and an error correction module are added to the system. The proposed system is implemented using Verilog DHL language and simulated in Modelsim software. The simulation results show that the proposed system exhibits better performance on the functions of data sending and receiving.

Abstract: A new derivation of Transient Grounding Resistance (TGR) has been proposed in this paper. Take grounding system as naked antenna in lossy medium, and then get the input resistance of naked antenna in a given frequency based on Helen current integral equations. With inverse Fourier transform, the resistance calculation equations can be translated from frequency domain to time domain. The result can be applied to design a new grounding system and to calculate its TGR .

Abstract: Due to the excellent spectral efficiency and inherent resistance to multipath fading effect, OFDM has been widely adopted in Digital video broadcasting-terrestrial (DVB-T). However, as a multi-carrier transmission technique, there is sampling frequency offset (SFO) in the OFDM systems, which will seriously degrade performance of demodulation by resulting in interference between adjacent sub-carriers (ICI) and demodulated phase deviation. In this paper, to achieve correction of phase errors and solve the problem that OFDM signals cannot be correctly demodulated for complex constellation when SFO exists, we propose an adaptive sampling frequency tracking and demodulated phase error compensation scheme based on synchronization symbol information of OFDM signals. Numerical results supported by simulations are provided to show that the proposed scheme in an ADSL environment indicate great performance improvement of demodulation.

Abstract: DC offset of the input analog signal I and Q of quadrature modulator which is as DAC and RF channel interface will affect bit error rate (BER) of the system, the quality of the emission signals and the overall effect of DPD[. This paper focuses on the influences of non-ideal characteristics quadradure modulator on DPD technology.

Abstract: This paper proposes a method of segmentation of hand signal, based on the skin color model in YCbCr space and background subtraction under complex background. This paper discussed the reasonable threshold selection of Cb, Cr in the skin color model and the segmentation selection of skin area combining the background segmentation. Finally, an inequality of hands outline feature is proposed to complete the division processing of the palm part of the area of skin. Experiments show the accurate segmentation of gesture under a complex static background.

Abstract: In the process of network transmission, when an exception occurs (such as forgery, tampering, information confusion), digital medical image, as a diagnostic basis, can not serve as the evidence of medical accident case. And the ROI of medical image is unable to tolerate significant changes. In order to deal these problems, we have proposed a multiple watermarks algorithm that uses Arnold scrambling to preprocess the original multiple watermarks, improving the security of watermarking, and combining the visual feature vector of image with the encryption technology and the concept of third-party. Moreover, the sophisticated process is needless to find the Region of Interest (ROI) of medical images. So compared with the existing medical watermarking techniques, it can embed much more data, with less complexity. The experimental results show that the scheme has strong robustness against common attacks and geometric attacks.