Advanced Materials Research Vols. 756-759

Abstract: A improve robust watermarking algorithm is proposed for binary images. The primary focus of the proposed algorithm lies in finding more flippable pixels and enhancing the robustness of watermarking. Based on Haar Wavelet Transform, the more flippable pixels was found not only in the neighbourhood but also in the Wavelet Transform domain. The embedding mechanism based on dynamic step size was proposed for enhancing the robustness of watermarking. And the experiment results and analyses demonstrate that proposed algorithm can find more flippable pixels, and is has better in robustness and invisibility.

Abstract: In this paper we intend to apply a new method to predict tertiary structure. A novel hybrid feature adopted is composed of physicochemical composition (PCC), recurrence quantification analysis (RQA) and pseudo amino acid composition (PseAA). We use the Error Correcting Output Coding (ECOC) based on three flexible neural tree models as the classifiers. 640 dataset is selected to our experiment. The predict accuracy with our method on this data set is 60.23%, higher than some other methods on the 640 datasets. So, our method is feasible and effective in some extent.

Abstract: Expensiveness and lack of N-pixels sensor affect the application of terahertz imaging. New compressed sensing theory recently achieved a major breakthrough in the field of signal codec, making it possible to recover the original image by using the measured values, which have much smaller number than the pixels in the image. In this paper, by comparing the measurement matrices based on different reconstruction algorithms, such as Orthogonal Matching Pursuit, Compressive Sampling Matching Pursuit and Minimum L_1 Norm algorithms, we proposed a terahertz imaging method based on single detector of randomly moving measurement matrices, designed the mobile random templates and an automatically template changing mechanism, constructed a single detector imaging system, and completed the single terahertz detector imaging experiments.

Abstract: To study the model of plasma antenna, a system intended to establish and sustain plasma with RF power was described in this paper. This system was made as a modular design, a feature that facilitates changing of operating frequency, RF power. A univariate optimization algorithm was used to achieve impedance matching (coefficient< 5%) in the system, therefore some key experimental data were measured accurately. Experiments showed that there is a difference between establishing power and sustaining power of plasma, and indicated the function of the length of the plasma column vs. square root of RF power.

Abstract: This paper analysized the Ziegler-Nichols setting method based on the ideal relay feedback identification. There are errors in the method. So, we consider to adopt hysteresis relay feedback to countact the error generated by the load disturbances and improve the measurement accuracy to eliminate errors. We proposed a PID parameter setting method stability margin method based on the hysteresis relay feedback identification. It can be seen from a plenty of simulation experiments that the control performances of the methods in set value tracking and interference eliminating are very good.

Abstract: In order to improve the prediction accuracy of gas emission, propose a prediction method of evidence theory combining with neural network. According to the experimental data of gas emission, three different particle swarm optimization-neural network models are used for the initial prediction. And use the BP and RBF network to get the credibility of model by analyzing forecasting errors and its influence factors. Then the evidence theory is used to obtain the weights of combination model, realize the gas emission combination forecasting. Examples results show that the error of evidence theory is less than error of the neural network and equal weight method, and it is suitable for gas emission prediction of coal mine.

Abstract: In order to improve the accuracy of fault diagnosis of power transformer, in this paper, a method is proposed that optimize the weight of BP neural network by adaptive mutation particle swarm optimization (AMPSO). According to the characteristic of transformer fault, the optimized neural network is used to diagnose fault of the power transformer. Individual particles action is amended by this algorithm and local minima problems of the standard PSO and BP network are overcooked. The experimental results show that, the method can classify transformer faults, and effectively improve the fault recognition rate.

Abstract: for a parameter α that played an important role in the course of fuzzy decision tree creation ,there exists a specific interval, within which gradual increasing of the parameter α may have the same effect as the crisp decision tree post pruning on the size and test accuracy, and there exists a optimum value of α within this specific interval, When α gets the value, can make the fuzzy decision tree reach its performance optimal. To obtain α optimum value , this paper proposed a method of optimizing parameter based on genetic algorithm and proved the validity of the method through comparing with the relative experiment.

Abstract: We present a performance tool for Earth system models development to aid in analyzing the performance of the climate modeling applications. It is difficult for existing tools to handle with the complex, coupled structure and the long execution time of models. Our performance tool implements rapid analysis based on statistical sampling and grouping aggregation the calling relationship and the actual computing resource consumption excluding waiting losses. Using this tool, we study an ocean model POP in short-term sampling and analyze its scaling bottleneck and acceleration trend. The measuring results of its entire execution prove our predictions on the scaling efficiencies.

Abstract: A virtual space scene is established using visual simulation technology, describing the space target imaging geometric mapping relations and photometric properties. It covers focal plane size, pixel size, field of view (FOV), focal length, the apparent magnitude, the detection range, and other parameters. When the space target cannot form a clear image on the focal plane, an equivalent apparent magnitude is used to simulate the target brightness by calculating the space target photometric quantity. The method proposed proves to be a good reduction of the optical camera imaging.