Applied Mechanics and Materials Vols. 385-386

Abstract: The existing background modelings are mostly color vision characteristics modeling based on single pixel, which are easily influenced by light shadow, weather and noise, and can easily cause foreground apertures and false alarm discrete noise. This paper presents the background modeling based on multiscale Gauss parameters against deficiencies. the experimental results shows that it can efficiently solve the problem of cavity and false alarm discrete noise.

Abstract: Brain-Computer Interface (BCI) is very useful for people who lose limb control such as amyotrophic lateral sclerosis (ALS) patients, stroke patients and patients with prosthetic limbs. Among all the brain signal acquisition devices, functional near-infrared spectroscopy (fNIRS) is an efficient approach to detect hemodynamic responses correlated with brain activities using optical method, and its spatial resolution is much higher than EEG. In this paper, we investigate the classification performance of both optical signal and hemodynic signal that both used in fNIRS-based BCI system using Hidden Markov Model (HMM). Our results show that hemodynamic signal has a much lower error rate than optical signal, especially the Oxy-hemoglobin (HbO) has the lowest error rate. This result is important for researchers who want to design an fNIRS-based BCI system and get better performance.

Abstract: Antenna has two response modes of co-polarization and cross-polarization as well as the serious amplitude and phase error, the alternate orthogonally polarization jamming is presented from the perspective of polarization domain according to the processing characteristics of typical open-loop adaptive side-lobe cancellation. The basic idea and principle are introduced and analyzed.

Abstract: In this study, we would like to improve the existing seam carving methods by using an more appropriate edge map and with the aid of Hough transform to select more appropriate seams for removal. This would allow seam carving to adapt to a variety of environments, providing desired results for users.

Abstract: The object of this paper is presenting a novel approach to classify the attention state and non-attention state. Firstly, the raw recorded electroencephalogram (EEG) data were decomposed by the algorithm of wavelet packet, several main EEG rhythms were extracted; then a complexity measure of these rhythm signal, approximate entropy (ApEn) was calculated respectively, and the values were used as input vector of a trained support vector machine (SVM), the output of this SVM will be the result of classification. The average performance obtained for the proposed scheme in classification is: sensitivity 73.7%, specificity 71.4% and accuracy 72.5%.

Abstract: The detection and tracking of cooperative targets are crucial significance in the rendezvous and docking of space targets. In this paper, a high performance detection and tracking method is proposed based on the combination of adaptive threshold sub-pixel detective positioning with the nearest neighbor clustering analysis of feature points in visual images. In order to enhance the accuracy of detective positioning the bilinear interpolation is employed to achieve sub-pixel coordinates positioning. And then the improved particle filter is used to carry out the prediction and tracking of cooperative targets so as to overcome stochasctic disturbances from stray light and noises. A series of experiment results indicate that the proposed method is characterized with its well performances of detection accuracy and real-time tracking and its outstanding simpleness and practicability so as to play important role in the implementation of cooperative target detection and tracking by visual measurement in the RVD of space exploration.

Abstract: In order to improve the detection accuracy of spliced images, a new blind detection based on visual saliency was proposed in this paper. Firstly, create the edge conspicuous map by an improved OSF-based method, and extract fixations by visual attention model. Then locate those fixations on conspicuous edges by conspicuous edge positioning method. Accordingly, key feature fragments can be captured. Secondly, extract Extended Hidden Markov Model features, and reduce their dimension by SVM-RFE. Finally, support vector machine was exploited to classify the authentic and spliced images. The experimental results showed that, when testing on the Columbia image splicing detection dataset, the detection accuracy of the proposed method was 96.68%.

Abstract: Based on analyzing and discussing the sand body CT fault image features in tectonic physical simulation experimental sand box, some technical schemes and methods of sand body CT image processing are proposed. Aiming at the characteristics of sand body CT sequence images, such as blurs, poor quality and obscure boundary between the layers, based on the correlation between pixels, fuzzy logic is applied to the edge detection of gray images, and an edge detection algorithm based on fuzzy similarity model is proposed. The experimental results show that the proposed algorithm has better performance than traditional edge detection operators.

Abstract: Analyzing the current developing status and actual problems of radar system simulation, based on continuous system simulation, combining signal simulation and function simulation, considering current development of simulation technique and the request of air battle to EW, the simulation system of phased array radar based on MATLAB/SIMULINK is presented and designed, which conquered the contradiction between simulation precision and real-time characteristic. And the key techniques of composition, modeling and exploitation of modules are studied in-depth. The simulation system is checked and tested by illustration of one jamming to phased array radar system in the end. Simulation is carried out whose result verifies the efficiency. The successful exploitation of the system will supply the analyses evaluation of the whole simulation system efficiency with platform and basis, which has instructive sense for the tactical use and simulation of phased array radar.

Abstract: This paper analyzes the distribution of breaks estimators and finite sample property of the method based on different mean break and long memory situations based on Bai and Perron (1998) multi-unknown breaks method. As to the distribution of the multiple break estimates, the property of the estimates under the alternative hypothesis is better when d is close to-0.5 that the bias and variance are smaller and the distribution are smoother even better than the BP (1998) case. Further work can be made on the limit distribution of break number test statistics in the case of d (-0.5, 0), d (0, 0.5) and to the case of three and more mean, trend breaks.