Advanced Materials Research Vols. 765-767

Abstract: This paper presents a novel approach in order to construct low-loss reconfigurable impedance matching networks and tuners using MEMS series-contact switches and periodic defected-ground-structures (DGSs) implemented on coplanar waveguide (CPW) transmission lines. The application of DGSs results in an improved insertion loss and power handling capability compared to the conventional RF MEMS impedance tuning networks. The proposed structure consists of 12 DGSs and RF MEMS series-contact switches. The tunable matching network was fabricated on a silicon substrate and is only 1.4×̃˾̈˰̽̽˰̹̾˰̵̹̓͊˾˰̸̵̤˰̵̵̴̱̽̓͂ͅ˰̼̿̓̓˰̶̿˰̸̵̈́˰̵͇̻̾̈́̿͂˰̸̵͇̾˰̵̴̓ͅ˰̈́̿˰̸̱̳̽̈́˰̱˰́̀˰Ω˰̴̼̱̿˰̈́̿˰̅̀˰Ω˰̶͂̿m 5GHz up to 40 GHz is only 0.8 dB. The results show that the tuner can achieve a broadband impedance match for a wide variety of loads that are either purely resistive or that have a large reactance as well.

Abstract: The high penetration of doubly-fed induction generators (DFIGs) entails a change in dynamics and operational characteristics of the power system, thus this paper investigates the small signal stability of the large-scale wind farm with DFIGs. The GE 1.5MW DFIG is modeled in power system analysis software package (PSASP), and a large-scale wind farm with DFIGs is established. Then, the two-area test system with four generators is applied to assess the effect of the large wind farm on power system inter-area oscillatory mode in which the penetration and the installation site of the wind farm are considered. Finally, the simulation results indicate that abundant penetration of DFIG-based wind power will improve the inter-area oscillatory, and the integration of wind farms with DFIGs in the receiving area makes the inter-area mode highly damped.

Abstract: Aiming at the reliability of real-time industrial Ethernet, the L2 Industrial Ethernet switch is designed using VSC7429. With the respect of real-time capacity, it is based on the IEEE1588 standard by adding logic modules between MAC £ ̈Medium Access Control£© layer and PHY £ ̈physical£© layer to process the clock stamp. It eliminates the delay and uncertainty of the protocol stack and provides the accurate synchronous clock. In terms of reliability, dual hot backup power supplies were applied. Owing to the harsh environment of the industrial field, the EMC (Electro Magnetic Compatibility) protection design was considered. The performance of the switch was tested including packet loss rate and bit error rate. Experimental results showed it met the requirement of industrial Ethernet standard.

Abstract: Multi-core processor has been a hot topic since it improves operation speed. It is not easy to get efficient parallel processing data algorithms because of waste of hardware resources. In this paper, a novel multitask parallel algorithm based on getting common substring of two strings is described in order to improve the data-handling capacity of the multi-processor. Firstly, this algorithm performs Task Parallel Library (TPL) in VS.NET, and then schedule the algorithm proposed in this paper to process data. This algorithm is tested by actual parallel data. The results demonstrate that this algorithm overcomes the problem of waste of hardware resource, can take full advantage of the features of multi-core parallel processing data thereby enhancing the parallel speedup, greatly improving the efficiency of data processing.

Abstract: The sensor technology is applied to the discus sports, which can be called digital discus, a real-time data acquisition of the moving discus information can be easily gained. The system uses statistical analysis and data mining to do analysis with these collected data. It's solved the problem on getting the accurate kinetic data and kinematics data of the moving discus for the sports like discus, and proved significant data for study athlete's technical movement and achievement.

Abstract: t has been shown that the traditional seven Hu invariant moment does not have scaling invariance with low recognition rate in human behavior recognition. In order to improve the recognition rate, a human behavior recognition method will be put forward in this paper based on weighted modified Hu moments. Firstly, the traditional seven Hu moments will be extended to ten Hu moments to get more image details. Then, the extended Hu moments will be modified to make the Hu moments has the feature of scaling invariance. Lastly, the weighted modified Hu moment will be obtained through least squares method based on minimum variance criterion. The simulation of the sequence images shows that the weighted modified Hu moment can improve the recognition rate effectively.

Abstract: The wheel load measuring plate is a force sensor based on strain measurement, it can bear simultaneously multidimensional force load and identify radial wheel load by decoupling. The measuring plate can output multichannel voltage signal, usually each channel has the properties of weak signal, strong noise, poor anti-jamming ability. The paper discusses the development of a multichannel data acquisition system for the wheel load measuring plate and conducts the experimental verification, through the data acquisition system achieve time-sharing acquisition of multichannel data, improving the precision and anti-jamming ability of wheel load measurement system.

Abstract: The gyro stabilization loop is very important part in the Ship-borne Servo system to keep stable tracking. Based on the controlling structure of the gyro stabilization loop of Ship-borne Servo system, the theory of stabilizing the ships shaking is introduced and the signal of Gyroscopes is analyzed. The Kalman filter used in the gyro stabilization loop is put forward based on the famous Singer Model. The simulation on the real measured data is carried on. The result of simulation shows that this method can highly decrease random error in the Gyroscopes output and the ability of isolating the ships shaking can be improved more.

Abstract: A new method for encoding and reconstruction high quality video image is given in this paper which uses the theory of compressed sensing. First the image frame of video is transformed into DCT domain. Then Image coding and decoding process using CS theory is given, frame I in image sequences is coded by frame coding mode after doing CS sampling to the DCT coefficients and the difference vector dv of the t-th fame for fame P. CS reconstruction and IDCT are done during decoding. Finally, the high quality reconstructed image is obtained. The experimental results shows that for images with sparseness, the image coding and decoding system integrated with CS theory and its methods can be used to obtain reconstructed images with high quality, and comparing with DCT and IDCT method, the method has some improvement in the term of PSNR for general images.

Abstract: To improve the throughput performance of the Wireless Access in Vehicular Environment (WAVE) system, we propose a multi-channel MAC protocol that is able to adaptively adjust the intervals of Control Channel (CCH) and Service Channel (SCH) according to the probability distribution of the reservation time for service packet in CCH Interval. Numerical results show that our protocol can significantly improve the performance of WAVE system.