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Ju H.,Systems Engineering Research Institute of CSSC
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

In this paper, a novel salient object detection method based on modeling the spatial anomalies is presented. The proposed framework is inspired by the biological mechanism that human eyes are sensitive to the unusual and anomalous objects among complex background. It is supposed that a natural image can be seen as a combination of some similar or dissimilar basic patches, and there is a direct relationship between its saliency and anomaly. Some patches share high degree of similarity and have a vast number of quantity. They usually make up the background of an image. On the other hand, some patches present strong rarity and specificity. We name these patches a€anomaliesa Generally, anomalous patch is a reflection of the edge or some special colors and textures in an image, and these pattern cannot be well a€explaineda by their surroundings. Human eyes show great interests in these anomalous patterns, and will automatically pick out the anomalous parts of an image as the salient regions. To better evaluate the anomaly degree of the basic patches and exploit their nonlinear statistical characteristics, a multivariate Gaussian distribution saliency evaluation model is proposed. In this way, objects with anomalous patterns usually appear as the outliers in the Gaussian distribution, and we identify these anomalous objects as salient ones. Experiments are conducted on the well-known MSRA saliency detection dataset. Compared with other recent developed visual saliency detection methods, our method suggests significant advantages. © SPIE. Downloading of the abstract is permitted for personal use only 2015. Source

Ju H.,Systems Engineering Research Institute of CSSC
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

Ship detection is important due to both its civil and military use. In this paper, we propose a novel ship detection method, Adaptive Target Filter (ATF), for high resolution optical imagery. The proposed framework can be grouped into two stages, where in the first stage, a test image is densely divided into different detection windows and each window is transformed to a feature vector in its feature space. The Histograms of Oriented Gradients (HOG) is accumulated as a basic feature descriptor. In the second stage, the proposed ATF highlights all the ship regions and suppresses the undesired backgrounds adaptively. Each detection window is assigned a score, which represents the degree of the window belonging to a certain ship category. The ATF can be adaptively obtained by the weighted Logistic Regression (WLR) according to the distribution of backgrounds and targets of the input image. The main innovation of our method is that we only need to collect positive training samples to build the filter, while the negative training samples are adaptively generated by the input image. This is different to other classification method such as Support Vector Machine (SVM) and Logistic Regression (LR), which need to collect both positive and negative training samples. The experimental result on 1-m high resolution optical images shows the proposed method achieves a desired ship detection performance with higher quality and robustness than other methods, e.g., SVM and LR. © Copyright 2015 SPIE. Source

Xiao F.,Systems Engineering Research Institute of CSSC | Song M.-Y.,Systems Engineering Research Institute of CSSC | Guo X.,CAS Beijing Institute of Acoustics | Ge F.-X.,Beijing Normal University
OCEANS 2015 - MTS/IEEE Washington | Year: 2015

Robust weak signal detection is quite a difficult problem in the presence of interferences and noise. Generally, adaptive beamforming is an efficient way of interference suppression. However, conventional adaptive beamforming, e.g. MVDR may degrade significantly due to mismatch in the practical applications. In this paper, a robust adaptive interference suppression method is presented and then the worst-case performance optimization is implemented on the eigenanalysis-based re-constructed covariance matrix. Experimental results show the proposed method can efficiently suppress the interferences and then be for robust adaptive beamforming and weak signal detection. © 2015 MTS. Source

Zhang Q.,Northwestern Polytechnical University | Tong Y.,Systems Engineering Research Institute of CSSC | Ren H.,Systems Engineering Research Institute of CSSC | Liu Y.,Systems Engineering Research Institute of CSSC | Chen Z.,Systems Engineering Research Institute of CSSC
Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University | Year: 2013

We have come to believe that falling film will be widely applied to various industries in the near future to obtain high heat and mass transfer performance. We now report our exploratory study results on the flow field of the falling film down a vertical plate at high Reynolds number. In the full paper, we explain in some detail our exploration; in this abstract, we just add some pertinent remarks to two topics of our explanation: (1) computational method and model; Fig. 1 shows the computational model and boundary conditions, and Fig. 2 shows the physical structure of a wavy liquid film based on experimental and numerical observations; (2) computational results and their analysis; we use the volume of fluid (VOF) method and k-ε turbulence model to carry out the numerical simulation of the flow field of the falling film and then compare the simulation results with experimental data. We analyze the variation laws of some important characteristic parameters such as velocity distribution, average thickness and base thickness of the falling film and the amplitude and the length of surface wave and then discuss the effects of wave characteristics on mass transfer and stability of falling film. The computational results indicate that the flow fields have very complicated structures as shown in Figs. 3 and 5. The average thickness of falling film decreases first quickly, then slowly and finally tends to be constant as the flow goes downstream, as shown in Fig. 4. As the film falls downstream, the amplitude and length of surface wave increase gradually, but the thickness of base film decreases gradually; the mass transfer is enhanced at the same time, however, the stability of falling film becomes worse. we compare the VOF-computational results with the high speed photography measurements. Fig. 7 indicates that the VOF method accurately captures most of flow characteristics and predicts better the flow field of the film falling down a vertical plate at high Reynolds number. Source

Yuan J.,Tianjin University | Yan H.,Systems Engineering Research Institute of CSSC | Hua B.,Systems Engineering Research Institute of CSSC | Jiang J.,Tianjin University | And 4 more authors.
Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering | Year: 2016

The serial-to-parallel conversion and byte alignment of data is an important step in high speed serial communication. In order to meet the requirement that the output parallel data after serial-to-parallel conversion is a complete byte, a high speed data serial-to-parallel conversion and byte alignment method is designed based on FPGA. At first, K28.5 synchronous code including 8B/10B code was embedded into data; and then, the data was serialized to be sent. Serial-to-parallel conversion module and code pattern test module were designed based on Verilog HDL.The serial-to-parallel conversion module is responsible for generating parallel clock and desializing serial data for output. The method achieved functions of 1:10 serial-to-parallel conversion and the parallel data bit shifting test and adjustment. According to experimental results of different transmission rates, the method can satisfy the requirement of high speed serial data communication, reducing the complexity of hardware circuit design. © 2016, Editorial Office of Nanotechnology and Precision Engineering. All right reserved. Source

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