9,847 research outputs found

    X-ray Astronomical Point Sources Recognition Using Granular Binary-tree SVM

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    The study on point sources in astronomical images is of special importance, since most energetic celestial objects in the Universe exhibit a point-like appearance. An approach to recognize the point sources (PS) in the X-ray astronomical images using our newly designed granular binary-tree support vector machine (GBT-SVM) classifier is proposed. First, all potential point sources are located by peak detection on the image. The image and spectral features of these potential point sources are then extracted. Finally, a classifier to recognize the true point sources is build through the extracted features. Experiments and applications of our approach on real X-ray astronomical images are demonstrated. comparisons between our approach and other SVM-based classifiers are also carried out by evaluating the precision and recall rates, which prove that our approach is better and achieves a higher accuracy of around 89%.Comment: Accepted by ICSP201

    Learning a Dilated Residual Network for SAR Image Despeckling

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    In this paper, to break the limit of the traditional linear models for synthetic aperture radar (SAR) image despeckling, we propose a novel deep learning approach by learning a non-linear end-to-end mapping between the noisy and clean SAR images with a dilated residual network (SAR-DRN). SAR-DRN is based on dilated convolutions, which can both enlarge the receptive field and maintain the filter size and layer depth with a lightweight structure. In addition, skip connections and residual learning strategy are added to the despeckling model to maintain the image details and reduce the vanishing gradient problem. Compared with the traditional despeckling methods, the proposed method shows superior performance over the state-of-the-art methods on both quantitative and visual assessments, especially for strong speckle noise.Comment: 18 pages, 13 figures, 7 table

    Establishment and Analysis of Chinese Judges’ Occupational Stress Scale

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    As the decision makers of cases, judges’ physical and mental health directly affects the outcome of the cases, and is related to the fairness and efficiency of the judiciary. Some studies have shown that the current level of mental health of judges is lower than people in general, and the rise of judges’ turnover rate in recent years also reflects their occupational stress from one aspect. This study selected 1,159 judges from seven regions including Beijing, Tianjin, Jilin, Liaoning, Shanxi, Hubei, and Henan for test, and conducted the questionnaire of occupational stress inventory-revised (OSI-R), established the occupational stress scale of Chinese judges, and conversed crude points to T points to grade the tension degree. Test results have showed that compared to groups of professionals and lawyers, the group of judges has a higher degree of tension, and seniority, gender, geography, age are the variables which affect the results of OSI-R questionnaire the most, and education and marital status affect secondly

    Thermoelastic properties and thermal evolution of the Martian core from ab initio calculated ferromagnetic Fe-S liquid

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    The accurate thermoelastic properties and thermal conductivity are crucial in understanding the thermal evolution of the Martian core. A fitting method based on the ab initio calculated pressure-volume-temperature data is proposed in the formulation of the equation of state with high accuracy, by which the pressure and temperature dependent thermoelastic properties can be directly calculated by definitions. The ab initio results show that the liquid Fe0.75S0.25 under Martian core condition is thoroughly in the ferromagnetic state, without existing spin crossover. The liquid Fe0.75S0.25 in magnetic calculation owns a low thermal conductivity (21~23 W/m/K) when compared with non-magnetic calculation at the same state. Based on the Insight estimated and ab initio calculated properties of the Martian core, the iron snow model is verified when the current temperature at the core-mantle boundary is below the core melting temperature, and the simply secular cooling model is verified on the contrary
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