Applied Mechanics and Materials Vols. 599-601

Abstract: The mapping approach is a powerful tool to looking for the exact solutions for nonlinear partial differential equations. In this paper, using an improved mapping approach, a series of exact solutions (including solitary wave solutions and periodic wave solutions) of the (2+1)-dimensional dissipative Zabolotskaya Khokhlov (DZK) system is derived. Based on the derived solitary wave solution, we obtain some folded localized excitations of the DZK system.

Abstract: The speaker recognition technology and development of the basic concepts of history, lists and compares several commonly used feature extraction and pattern matching methods, summarize the current problems and its development were discussed.

Abstract: Based on the rapid development of information technology and wide application, using the SWOT analysis method, combined with the status quo of information development in our country, it is done that the strategic analysis of advantage factors, archives information development in the disadvantages, opportunities and threats, and some strategies and suggestions are put forward for the development of our country's archives information.

Abstract: For the devices with limited computing capacity and processing time, this paper proposes a new steady-state kalman filtering method based on thresholding optimal gain. The core algorithm is about improving the updating stage of the kalman filtering with a double-threshold optimal gain, which improves the dynamic tracking performance of the system steady-state while reducing the filtering algorithm computation. The results of the simulation prove that the algorithm has a better steady-state convergence effect than traditional kalman filtering algorithm. The method proposed in this paper can be widely used in many occasions, as it simplifies the computation of the optimal kalman gain and the a priori estimation.

Abstract: A scheme that can be used to generate UWB doublet and triplet signals simultaneously based on SOA-SGS and SOA-XGM is carried up, then the theory is analyzed. Simulated through Optisystem9.0, a UWB doublet signal whose central frequency is 6GHz and relative bandwidth is 143% and a triplet signal whose central frequency is 8GHz and relative bandwidth is 120% are generated. Then, the impacts that input pulse width and light source power impose on the results is analyzed.

Abstract: In synthetic aperture radar (SAR) inherent speckle will affect the legibility of image details; give the image target detection adverse effects. In order to reduce the SAR image speckles noise, this article provided an improved algorithm based on median filter and wavelet semi-soft threshold shrinkage. First, reduced the SAR image speckle with median filtering method, then, with the filtered image, filtering the image with wavelet half soft threshold value contraction algorithm to noise, Simulation results show that the algorithm based on median filtering and improved algorithm of wavelet half soft threshold shrinkage of SAR image can better remove the speckle noise of the SAR image, while keep better edge, in Equivalent Number of Looks (ENL) and edge keep ability (FOM) aspects, it would be better than median filtering.

Abstract: Although many wavelet de-noising methods have been studied and proposed, the parameters of them are obtained by experience mostly, which makes the de-noising effect instable. To solve the issues, the solutions, such as the selection of wavelet function and threshold function, the calculation of decomposition levels, the optimal wavelet packet basis and the thresholds obtained based on QPSO, have been studied in this paper. Every parameter is obtained by calculation. This method is applied to the de-noising experiment of sine and vibration signals. Through the experimental verification, the effect of this de-noising method is obvious.

Abstract: The resolution of ground-based large aperture adaptive telescope which is limited by diffraction and atmospheric turbulence can’t achieve the demand of high-orbit satellite imaging, while synthetic aperture imaging can get high resolution without using large telescope. In this paper, we analyzed the merits and demerits of several synthetic aperture imaging method such as amplitude interference imaging, intensity correlation imaging, and Fourier telescope which can be used in high-orbit satellite imaging. According to the analysis we prospected for the development of synthetic aperture imaging method towards high-orbit satellite in the future

Abstract: According to the analysis of text feature, the document with co-occurrence words expresses very stronger and more accurately topic information. So this paper puts forward a text clustering algorithm of word co-occurrence based on association-rule mining. The method uses the association-rule mining to extract those word co-occurrences of expressing the topic information in the document. According to the co-occurrence words to build the modeling and co-occurrence word similarity measure, then this paper uses the hierarchical clustering algorithm based on word co-occurrence to realize text clustering. Experimental results show the method proposed in this paper improves the efficiency and accuracy of text clustering compared with other algorithms.

Abstract: In order to achieve high accuracy, we present a new calibration technique aimed at blind steganalysis. The calibration can be considered as a preprocessing of stego image before extracting the features. The extracted features will be more effective for our classification [1] Moreover, the calibrated feature was used to train SVM (Support Vector Machine)[2], a nonlinear classifier, which is effective in class separation. For comparison, we conducted extensive experiments and drawn a conclusion that the steganalytic scheme based on our novel calibration can detect the stego information with high accuracy. Experimental results demonstrate that our proposed scheme outperforms the best effective JPEG steganalysis having been presented.