Applied Mechanics and Materials Vols. 239-240

Abstract: With the communication environment of RFID system developing from near field communication to long distance communication, Rayleigh fading with Doppler frequency shift emerges from multipath effect between the readers and electronic tags. A systemic study was focused on modeling and analysis of channel transmission for Type A tag signals in the multipath Rayleigh fading channel. Furthermore, the OFDM system was added to the RFID tag signals to improve the sensitivity of SNR in the Rayleigh fading channel. The SNR of tag signal is not sensitive in the multipath Rayleigh fading channel. However, the sensitivity increases after OFDM is added to the RFID system and the anti-interference ability is highly improved.

Abstract: Applying many electrodes is undesirable for real-life brain-computer interface (BCI) application since the recording preparation can be troublesome and time-consuming. Multi-objective particle swarm optimization (MOPSO) has been widely utilized to solve multi-objective optimization problems and thus can be employed for channel selection. This paper presented a novel method named cultural-based MOPSO (CMOPSO) for channel selection in motor imagery based BCI. The CMOPSO method introduces a cultural framework to adapt the personalized flight parameters of the mutated particles. A comparison between the proposed algorithm and typical L1-norm algorithm was conducted, and the results showed that the proposed approach is more effective in selecting a smaller subset of channels while maintaining the classification accuracy unreduced.

Abstract: Common spatial pattern (CSP) is a highly successful algorithm in motor imagery based brain-computer interfaces (BCIs). The performance of the algorithm, however, depends largely on the operational frequency bands. To address the problem, a filter bank was applied to find optimal frequency bands. In filter bank, CSP was applied in all sub-band signals for feature extraction. The feature selection is the key of filter bank method for increasing classification performance. In this study, coefficient decimation (CD) technique was used to devise filter bank, while Fisher score and Laplacian score were proposed as feature selection criterion. In off-line analysis, the proposed method yielded relatively better cross-validation classification accuracies.

Abstract: Local mean decomposition(LMD) as a new demodulating approach has some problems needing study and solution.This paper analyzed the overlapping phenomenon of product functions(PFs) generated when LMD decomposes signals through studying the adaptive filtering characteristic of LMD and numerical simulation. The results show that the overlapping phenomenon of PFs is general. Then in order to improve the demodulating effect of LMD, a new demodulating method based on LMD and combined Morlet wavelets was proposed and applied in gear fault diagnosis. The results show that this method is efficient.

Abstract: The purpose of detecting trace concentrations of analytes often is hindered by occurring noise in the signal curves of analytical methods. This is also a problem when different arsenic species (organic arsenic species such as arsanilic acid, nitarsone and roxarsone) are to be determined in animal meat by HPLC-UV-HG-AFS, which is the basis of this work. In order to improve the detection power, methods of signal treatment may be applied. We show a comparison of convolution with Gaussian distribution curves, Fourier transform, and wavelet transform. It is illustrated how to estimate decisive parameters for these techniques. All methods result in improved limits of detection. Furthermore, applying baselines and evaluating peaks thoroughly is facilitated. However, there are differences. Fourier transform may be applied, but convolution with Gaussian distribution curves shows better results of improvement. The best of the three is wavelet transform, whereby the detection power is improved by factors of about 2.4.

Abstract: On the requirement of fast signal processing and transmitting in time in digital substation, this paper presents an approach of lifting wavelet for extracting online monitoring signals of the electrical plants in digital substation. The lifting wavelet de-nosing algorithm is based on a threshold estimation formula based on Stain unbiased risk estimation (SURE). The de-noising experiments of stationary signals and non-stationary signal, i.e. simulative partial discharge (PD) signal are presented. The results show that the white noise can be removed effectively by the proposed lifting wavelet. Meanwhile, the lifting wavelet is a much less time-consuming scheme and exhibits a promising prospect in practical application.

Abstract: In order to resolve the problem of echo signal threshold detection about LFMCW lidar system, a new signal threshold detection method based on the constant false alarm rate(CFAR) detecting technology is put forward. This method constructed the CFAR detection model from the analysis about the noise’s statistics characteristic in frequency domain, and then analyzed the relation between the false alarm rate and threshold, at last contrasted CFAR threshold with constant threshold under the condition that the noise intensity changes by simulating technique. The simulated experiment result indicates, the CFAR detecting technology applies to an echo signal threshold detecting is able to ensure that the false alarm rate size is constant invariable when the threshold value follows the noise intensity changes, thereby this method is not only improved the lidar’s acclimatization, but also enhanced the systematic detecting function of LFMCW lidar effectively.

Abstract: Implantable wireless system is a suitable way for the animal model research, especially for the small animal monitoring. In this paper, an implantable wireless system for the mouse monitoring was developed and a data transmission strategy based on the multiple pulse position modulation (MPPM) method was adopted for this system. The physiological signal(s) was/were first modulated by the MPPM and then transmitted by the antenna. The outside receiver demodulated the signals from the antenna and then digitalized the analogy signals to the PC by the micro-controller. In the PC, the digital values were restored to the origin signal(s) using a decoding process according to the MPPM scheme. This strategy ensures the low power consumption of the implantable module and multichannel monitoring for small animals.

Abstract: This article discusses the requirements and implementation of feather image enhancement. Feather image enhancement need correct the uneven illumination, maintain color constancy and preserve texture details. Experiments are taken with four typical enhancement algorithms. The result shows that MSRCR algorithm can preferable meet the requirements. A novel improvement on MSRCR is proposed, that can get better effect.

Abstract: This paper uses Matlab7.0 software development tool, using Hough transformation and other technical means in the pictures are linear structure information extraction, for future research and deployment to provide reference. But there are still some limitations, such as image segmentation dependence, from nonroad factors affecting such. firstly using the road seed point spectrum information is way of regional growth, extracted from the spectral information consistent with the road area, get a contains road information two value image, and then this two value image filtering, in the extracted road strip on a regional basis, according to the road has the shape characteristics, using morphological thinning and a certain number of form pruning treatment, get a single pixel wide road center line information. The last image based on Hough transform linear feature extraction, The high resolution remote sensing image experiments were carried out to verify the validity of the method[1].