Advanced Materials Research Vols. 846-847

Abstract: On the question of solving lower triangular matrices or symmetric matrix by a type of matrix equation, we obtain the necessary and sufficient conditions for its only solution and design a recursive algorithm to compute the solution. With finite domain multiplicative inverse technology and Differ-Hellman protocol, a new cryptosystem is designed based on finite fields matrix equations. Numerical experiments demonstrate the correctness of the new cryptosystem and feasibility.

Abstract: For the problem of sparse recovery, an approximation algorithm, termed Squarewave-Like Sum Function Minimization (abr. SLSFM), is proposed. Firstly, norm is appro-ximated by squarewave-like sum function. Then sparse recovery is cast as Squarewave-Like Sum Function Minimization problem, which is solved by a fast iterative method. Finally, simulation results show that our algorithm has some advantages over most existing methods: it is more robust to noise and needs less measurement.

Abstract: In this study, we proposed a simple and effective approach for feature extraction of motor imagery (MI) data. Aside from the original use of continuous wavelet transform (CWT), the Blackman filter is proposed to further refine the selection of active segments. In the time domain we compute the energy feature by squared-amplitude of EEG; in the frequency domain BT method power spectrum density (PSD) is used to get energy feature. The method is simple and the classification accuracy is satisfactory, especially for classification 2.

Abstract: When the chaos is degenerating, the unary polynomial transformation can make the chaotic signal more complicated. Therefore, the transformed chaotic signal is more suitable for image encryption. In this paper, the image is respectively encrypted by the chaotic signal transformed by different unary polynomials and the chaotic signal without transformation. And then their encryption effects are compared and analyzed by various criteria. Experiments and research results indicate that, after unary polynomial transformation, the effect of chaos-based image encryption is improved. Furthermore, different unary polynomials have different effects on the cipher image. It can make the effect of image encryption better by changing the form of unary polynomial.

Abstract: In terms of the chaotic signal needed by encryption, it is the more complicate the better. In addition, the frequency range of chaos should be wider than that of signal to be encrypted. However, chaotic spectrum usually is a narrow area in the low frequency region, and the complexity is not high enough. The signals encryption effects are affected. In order to solve this problem, this paper used the chaos transformed by unary polynomial to encrypt signals. Under the Matlab simulation environment, it is confirmed from time-domain and frequency-domain perspectives that the encryption effect of transformed chaos is better. Even the higher frequency signal can also be covered up completely. At the same time, the difficulty of decoding the encrypted signals is greatly increased, and the anti-attacking capability is strengthened.

Abstract: this article uses Power Spectrum Density Theory and The Monte Carlo Simulation Method to analyze the effect of blanket jamming on the bit error rate of satellite navigation signal, and emulate, analyze and compare suppress interference interference effect on PSK-R signal and BOC signal. All the analyses are based on the research on blanket jamming and PSK-R signal and BOC signal.

Abstract: In some cases, MFCC will fail to effectively demonstrate the real voice quality. In order to achieve speech quality effectively, a new speech feature extraction method are proposed on the base of MFCC. We use Gammatone filter bank instead of triangle filter bank, which is not sensitive to the excursion of formant, and we use RASTA filter to further process the results of the previous step; the experimental results show that the proposed algorithm is effectively in speech evaluation.

Abstract: One limitation on the performance of optical tweezers (abbreviated as OT) is the noise inherently present in each setup. Therefore, it is the desire to minimize and possibly eliminate the noise from the OT experiments. In this paper, a filter method based on wavelet analysis is proposed. At first we investigate the properties of OT outputs noise, and introduce the wavelet filtering method in simply. Following, we study on the OTs drift signal using different base: db4 and Haar. And also study on the signal using different filter algorithm: the soft,the hard threshold,and compulsive filter. These main conclusions based on foregoing analysis are reached: more larger the resolving scale is, more perfect the filtering effect is. The soft threshold value filtering effect is better than that of the hard threshold value filtering at the cost of calculation when the threshold value is same. The variance of the compulsive filtering is least when both the wavelet and the resolving scale are same for these filtering methods. For the compulsive filtering with same wavelets, the filtering effect of harr is better than that of db4 and the calculation of the former is fewer. Analysis the dynamic output of OT with different algorithm, it also shows that the effect of filter with the compulsive filtering is better than others. Accordingly, we found that applying the compulsive filtering with the Harr wavelet base and suitable resolving scale to the signal processing of OT outputs signal is helpful for the OT design and construction.

Abstract: The key to the performance test system for hydraulic components is to realize real, fast and accurate signal acquisition and processing. By analysis the analog and digital signal processing during hydraulic components Performance testing, a new signal flow scheme is proposed. It described in detail the acquisition and processing method of serial signals and PLC signals, thus solving the lag and distortion during signal processing and realizing the real-time display of data and the automatic report of performance parameters during hydraulic components testing process.

Abstract: The thesis uses data in the database of campus card platform as the analysis object, combined with statistical methods and data mining technology to analyze the students consumption and the situation of the canteens. We use the Microsoft .NET and SQL Server 2008 business intelligence development tools to mine and analyze these data; know canteens consumption and learn about the business status and the popular shops of the canteen by using the K-means algorithm; analyze and predict students behavior and the situation of the canteen by using time series algorithm. It is convenient to manage the college students, and provide data support for university policy makers and shoppers to make plans.