Applied Mechanics and Materials Vol. 742

Abstract: A General Feistal Structure based color image encryption and authentication algorithm is designed in this paper. The plain image is first permuted, then divided into groups of size pixels and encrypted by block encryption algorithm; finally the cipher image is obtained by performing inverse permutation on the image. In which, block encryption function is the kernel part of the encryption algorithm, and is designed with general feistel structure. To provide integrality authentication function, the last cipher block is the cipher of the sum of all plain blocks. It’s from experiments and analysis that the algorithm is secure and valid.

Abstract: This paper proposed a new face recognition algorithm based on Haar-Like features and Gentle Adaboost feature selection via sparse representation. Firstly, All the images including face images and non face images are normalized to size and then Haar-Like features are extracted . The number of Haar-Like features can be as large as 12,519. In order to reduce the feature dimension and retain the most effective features for face recognition, Gentle Adaboost algorithm is used for feature selection. Selected features are used for face recognition via sparse representation classification (SRC) algorithm. Testing experiments were carried out on the AR database to test the performance of the new proposed algorithm. Compared with traditional algorithms like NS, NN, SRC, and SVM, the new algorithm achieved a better recognition rate. The effect of face recognition rate changing with feature dimension showed that the new proposed algorithm performed a higher recognition rate than SRC algorithm all the time with the increasing of feature dimension, which fully proved the effectiveness and superiority of the new proposed algorithm.

Abstract: Working on low-contrast, extended, time-varying objects such as the solar granulation, solar adaptive optics (AO) system uses correlation algorithms to detect image shift of the Shack-Hartmann (SH) wavefront sensor (WFS) instead of centroid algorithm in night-time adaptive optics system. An real-time image shift detection processor, which consists of a Xilinx FPGA and a TI DSP, has been developed for a low-order solar AO system based on cross correlation coefficient algorithm. Image shift of integer pixels can be calculated in the FPGA and DSP is responsible for parabolic interpolation to obtain subpixel accuracy. The experimental results show that the processor can obtain correct image shift and satisfy the time latency requirement of the AO system.

Abstract: It is difficult to make the realization of synchronous sampling and the whole cycle truncation when we use the fast Fourier transform (FFT) for power system harmonic analysis .Once the FFT is used, the spectral leakage caused by it will affect the accuracy. Using Blackman window weighted to the harmonic signal, combined with the spectrum analysis of phase, An improved method for power harmonic analysis based on Blackman window and phase shifted difference correction is presented in this paper. The calculation equation of multiple fundamental harmonic signal frequency, amplitude and initial phase angle is derived and the conventional spectral phase correction method is improved. The simulation results show that the calculation accuracy using Blackman window phase correction signal harmonic analysis is improved significantly compared to Hanning window interpolation, Blackman window interpolation and Hanning window phase difference. The algorithm is simple, and has high precision and versatility, which can be applied to high-precision power metering and power quality analysis.

Abstract: In this paper, we present a hierarchical method of activity recognition for sleeping at the desk in business hall. The method consists of three steps. First, the reference points such as body joints are obtained from workers in business hall. Second, we build the dependency graph to represent the relationships between reference points. Third, the multidimensional output regressions along the dependency paths are used to estimate the positions of these reference body points. Experimental results demonstrate that our method achieves comparable accuracy to state-of-the-art results.

Abstract: Compare and analysis the transient identification in Nuclear Power Plant fault diagnosis method. According to how does these methods for nuclear power plant systems HTR effect, Further proposed to a problem that towards existing transient recognition of methods to verification effectiveness. Preliminary analysis of the three kinds of validation strategy, after a comparative demonstration, it is formed the preliminary research on the utility analysis framework. Utility to verify the framework for the Nuclear Power Plant fault diagnosis methods carry out intensive research provides a theoretical basis.

Abstract: In allusion to the need of analyzing complex system, we have proposed a method named multi-grade color Petri net. We for the first time use this new method to analyze a missile training simulator system. This model can accurately reflect the complex environments of the system and avoid the difficulty occurring often in developing accurate mathematics model by using classical research approach.

Abstract: The paper concentrates on bistatic polar format algorithm (PFA) for focusing the spotlight bistatic Synthetic aperture radar (SAR) data. Exploring the imaging geometry of spotlight mode, a wavenumber vector K_b is derived according to the original definition of wavenumber. The direction of the vector Kb corresponds to the path from the transmitter to the target in the scene to the receiver in the bistatic SAR configuration. Using the vector K_b, a point target position vector in the scene can be expressed as the same form as that of conventional monostatic spotlight SAR. Based on the vector K_b, the spotlight bistatic PFA is derived and is presented concisely. In the simulation experiments, the presented PFA and BP algorithm process the same area target respectively. The result of the experiments show the PFA mentioned in this paper is valid. The quality of the processing result achieved by the PFA is not worse than that by BP algorithm.

Abstract: Mathematical model of information retrieval algorithm retrieves digital libraries involved, it is very important to design an algorithm to make the best of the books, in order to extract the required information, including the association rules and classification method for from the database predicting the reader and potential use of fast and accurate information. In this paper, the intelligent data retrieval books mining algorithms to analyze, you can study the books of intelligent retrieval application, until the actual retrieval algorithm to solve the model first developed to meet the requirements, design a library of books intelligent information retrieval system .

Abstract: Thermal process usually has the characteristics of nonlinearity and uncertainty, so it is difficult to establish the nonlinear model by the traditional method of describing the dynamic mathematical model of thermal process and accurately implement optimal control of thermal process. This paper provides an identification method of thermal process based on relevance vector machine and firefly algorithm, and the modeling results are compared with those by minimal resource allocation network and support vector regression. The simulation results show that the method is effective, and the model has high accuracy and can be directly used in control algorithm based on the model.