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116 results on '"Luo, Dapeng"'

8. Learning Scene-specific Object Detectors Based on a Generative-Discriminative Model with Minimal Supervision

Author

Luo, Dapeng, Zeng, Zhipeng, Sang, Nong, Wu, Xiang, Wei, Longsheng, Mou, Quanzheng, Cheng, Jun, and Luo, Chen

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

One object class may show large variations due to diverse illuminations, backgrounds and camera viewpoints. Traditional object detection methods often perform worse under unconstrained video environments. To address this problem, many modern approaches model deep hierarchical appearance representations for object detection. Most of these methods require a timeconsuming training process on large manual labelling sample set. In this paper, the proposed framework takes a remarkably different direction to resolve the multi-scene detection problem in a bottom-up fashion. First, a scene-specific objector is obtained from a fully autonomous learning process triggered by marking several bounding boxes around the object in the first video frame via a mouse. Here the human labeled training data or a generic detector are not needed. Second, this learning process is conveniently replicated many times in different surveillance scenes and results in particular detectors under various camera viewpoints. Thus, the proposed framework can be employed in multi-scene object detection applications with minimal supervision. Obviously, the initial scene-specific detector, initialized by several bounding boxes, exhibits poor detection performance and is difficult to improve with traditional online learning algorithm. Consequently, we propose Generative-Discriminative model to partition detection response space and assign each partition an individual descriptor that progressively achieves high classification accuracy. A novel online gradual optimized process is proposed to optimize the Generative-Discriminative model and focus on the hard samples.Experimental results on six video datasets show our approach achieves comparable performance to robust supervised methods, and outperforms the state of the art self-learning methods under varying imaging conditions.

Published
2016

13. Controllable sulfidation of polymetallic nickel cobalt molybdenum layered double hydroxides on Ni foam for high-performance hybrid supercapacitors.

Author

Luo, Dapeng, Zou, Jinping, Wei, Zhaohui, Ye, Xiaoyun, Wang, Qianting, and Ma, Li-An

Subjects
*LAYERED double hydroxides, *SULFIDATION, *MOLYBDENUM, *SUPERCAPACITORS, *COBALT, *OXIDATION-reduction reaction
Abstract

In situ construction of polymetallic layered double hydroxide (LDH) @sulfide heterostructures (LDH@sulfides) is a promising strategy to achieve excellent electrochemical performance by providing more redox active sites and facilitating ion/electron pathways. Herein, nickel cobalt molybdenum based LDH@sulfide core–shell composites (NCM-LDH@NCMS) grown on Ni foam have been successfully prepared via a facile hydrothermal method, followed by controllable sulfidation methods. The effect of sulfidation time on the electrochemical performance of NCM-LDH@NCMS was investigated. The NCM-LDH nanosheets minimized the diffusion path of electrolyte ions and accelerated the kinetics of redox reactions, and the outer Ni–Co–Mo sulfides effectively improved the conductivity of LDHs and exposed more active sites. With sulfidation for 2 h, the obtained NCM-LDH@NCMS-2 exhibited excellent electrochemical performance, with a specific capacitance of ∼7.73 F cm−2 at 10 mA cm−2, and better capacitance rate performance of 56.7% at 50 mA cm−2. Furthermore, hybrid NCM-LDH@NCMS-2//activated carbon supercapacitors provided a high energy density of 0.25 mW h cm−2 at 40 mW cm−2 and excellent cycling stability of 89.82% after 8000 cycles at 8 mA−2. [ABSTRACT FROM AUTHOR]

Published
2023
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23. Responses to Solar UV-B Exclusion and Drought Stress in Two Cultivars of Chestnut Rose with Different Leaf Thickness.

Author

Luo, Dapeng, Li, Jielin, Luo, Jianxun, Ma, Yan, Wang, Yongzhi, Liu, Wei, Rodriguez, Lucas Gutierrez, and Yao, Yinan

Subjects
CASTANEA, DROUGHTS, SOLAR radiation, CULTIVARS, CHESTNUT, RESTORATION ecology
Abstract

Plants adopt a series of strategies to tolerate solar UV-B radiation (with the side effects of growth reduction), but the positive effects of solar UV-B radiation have not been yet clarified. In this study, two cultivars with different leaf thickness for Chestnut rose (Rosa roxburghii Tratt), a pioneering species for ecological restoration in Karst region of Southwest China, were employed to investigate its responses to ultraviolet-B (UV-B) exclusion, moderate drought, and their combination in an outdoor experiment. Thin-leaf cultivars (Gui 2) adopt an opportunistic growth strategy, growing better than Gui 7 under UV-B exclusion combined with well-watered conditions. To avoid the penetration of solar UV-B wavelengths into the underlying leaf tissues, Gui 2 exhibited higher enhancements in leaf thickness, palisade/spongy tissue ratio, antioxidant responses such as the leaf concentration of flavonols compounds catalyse activity under solar UV-B exposure. Moreover, ambient solar UV-B radiation alleviated the adverse impact caused by drought in both cultivars, improving total biomass and reducing membrane penetration. This alleviation may be related with two potential explanations. First, solar UV-B radiation primes chestnut rose plants with increased antioxidative capacity against drought stress, shown in both antioxidative enzyme activity and non-enzyme antioxidants (in particular, with total flavonols and flavonol ratio [(quercetin+myricetin)/kaempferol]). Second, to avoid nutrition insufficiency, solar UV-B radiation and drought endows chestnut rose plants with complementary effects on nutrition balance. Overall, solar UV-B radiation helps the chestnut tolerate drought stress that occurs frequently in the Karst region by modulating its antioxidative capacity and nutrition balance. [ABSTRACT FROM AUTHOR]

Published
2023
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25. 基于马赫-曾德干涉仪的色散转折效应及其传感性能模拟研究

Author

Huang Tianye, 黄田野, primary, Lei Rongrong, 雷蓉蓉, additional, Cheng Zhuo, 程卓, additional, Zhang Xiangli, 张祥莉, additional, Wang Yong, 王勇, additional, Luo Dapeng, 罗大鹏, additional, Xu Guizhen, 许桂珍, additional, Zhang Gangshun, 张港顺, additional, Wu Yiheng, 吴易恒, additional, and Pan Jianxing, 潘建行, additional

Published
2022
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30. Construction of Hierarchical NiCo2O4@NiFe‐LDH Core‐Shell Heterostructure for High‐performance Positive Electrode for Supercapacitor.

Author

Luo, Dapeng, Yong, Yi, Hou, Jiang, Guo, Weiguang, Liu, Hengbo, Zhao, Xue, Xiang, Jingrong, ZongZong, Nima, Han, Yuqi, and Yan, Minglei

Subjects
HEAT treatment, CHARGE exchange, NANOSTRUCTURED materials, SUPERCAPACITORS, ELECTRODES, SUPERCAPACITOR electrodes
Abstract

In this work, the hierarchical NiCo2O4@NiFe‐layered double hydroxide (NiCo2O4@NiFe‐LDH) heterostructure has been successfully synthesized by sequential hydrothermal method, heat treatment and electrodeposition, which is investigated as high‐performance positive electrode for supercapacitor. In this unique structure, on the one hand, the NiCo2O4 as the scaffold provide high conductivity, which accelerates the electron transfer. On other hand, the NiFe‐LDH nanosheets increase the surface area, which offers abundant active sites for electrochemical reaction. Furthermore, the three‐dimensional (3D) hierarchical structures are beneficial to the diffusion for electrolyte ions. Hence, the synergistic effect between NiCo2O4 and NiFe‐LDH endows the optimal NiCo2O4@NiFe‐LDH‐150/CC with excellent electrochemical performance, such as high areal specific capacitance (1.09 F cm−2@1 mA cm−2), small charge‐transfer resistance (0.35 Ω) and superior cycling stability. This study demonstrates the NiCo2O4@NiFe‐LDH core‐shell heterostructures are promising positive electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

Published
2022
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31. 基于马赫-曾德干涉仪的色散转折效应及其传感性能模拟研究

Author

黄田野 Huang Tianye, 雷蓉蓉 Lei Rongrong, 程卓 Cheng Zhuo, 张祥莉 Zhang Xiangli, 王勇 Wang Yong, 罗大鹏 Luo Dapeng, 许桂珍 Xu Guizhen, 张港顺 Zhang Gangshun, 吴易恒 Wu Yiheng, and 潘建行 Pan Jianxing

Subjects
Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials
Published
2022

32. From H5N1 to HxNy: An epidemiologic overview of human infections with avian influenza in the Western Pacific Region, 2003–2017

Author

Hamid, Sarah, Arima, Yuzo, Dueger, Erica, Konings, Frank, Bell, Leila, Lee, Chin-Kei, Luo, Dapeng, Otsu, Satoko, Olowokure, Babatunde, and Li, Ailan

Subjects
Adult, Male, Asia, Adolescent, Infant, Newborn, Infant, Middle Aged, Poultry, Regional Analysis, Young Adult, Age Distribution, Influenza A virus, Child, Preschool, Influenza in Birds, Influenza, Human, Animals, Humans, Female, Sex Distribution, Child, Epidemics, Non theme issue, Aged
Published
2018

36. Objective Image Quality Assessment Based on Saliency Map

Author

Longsheng Wei, Feng Liu, Wei Liu, Luo Dapeng, and Xinmei Wang

Subjects
business.industry, Computer science, Image quality, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Objective analysis, 02 engineering and technology, 01 natural sciences, 010309 optics, Human-Computer Interaction, Seam carving, Artificial Intelligence, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Computer vision, Saliency map, Computer Vision and Pattern Recognition, Artificial intelligence, business
Abstract

The development of objective image quality assessment metrics aligned with human perception is of fundamental importance to numerous image processing applications. In this paper, an objective image quality assessment approach based on saliency map is proposed. By local shift estimation method, the retargeted image is resized to the same size as the reference image. A gradient magnitude similarity map is computed by comparing the retargeted and reference images. The more similarly, the brighter of pixels in the gradient magnitude similarity map. At the same time, a saliency map of reference image is achieved by visual attention. Finally, an overall image quality score is computed from the gradient magnitude similarity map via saliency pooling strategy. The most important step in our approach is to generate a gradient magnitude similarity map that indicates at each spatial location in the source image how the structural information is preserved in the retargeted image. There are two key contributions in this paper, one is that we add the texture feature in computing saliency map because image gradient is very sensitive to texture information, and the other is that we propose a new objective image quality metrics by introducing saliency map into image quality evaluation. Experimental results indicate that the evaluation indexes of our approach are better than existing methods in the literature.

Published
2016

40. Depth Estimation of 2-D Magnetic Anomalous Sources by Using Euler Deconvolution Method

Author

M.G. El Dawi, Liu Tianyou, Shi Hui, and Luo Dapeng

Subjects
Mathematical optimization, Multidisciplinary, Mathematical analysis, Window (computing), Interference (wave propagation), Magnetic field, Magnetization, symbols.namesake, Feature (computer vision), Euler's formula, symbols, Cluster (physics), Cluster analysis, Mathematics
Abstract

Euler deconvolution method is the method of depth estimation which is best suited for anomalies caused by isolating and multiple anomalous sources. In the present study, algorithmic programs based on generalizing linear inverse theory, uses a least square sense to solve for Euler’s equation is being written. The Euler technique that can estimate the location of a simple body from measurements of the magnetic field could be applied to a long profile of measurements, by dividing the profile into the windows of consecutive measurements, each window providing a single estimate of depth and source location. Acceptable solutions for features of interest may involve some trial and error by adjusting the structural index and the window size. When all such measurements are plotted they tend to cluster around magnetization of geologic interest. Some indication of the source type can be gained by varying the structural index for any particular feature. Shallow features can be deconvolved well by using small window to reduce source interference. By using n = 1 and n = 1. 5, and deconvolved with small window sizes, our program yields good tight clustering and acceptable depths of the anomalous igneous body located along aeromagnetic profile in the south of Amenzi area, Inner Mongolia, North China. The depths obtained by using the structural index of n = 1. 5 varying between 700-900 m. The method yielded useful solutions with an acceptable depth estimate.

Published
2004

43. Lymphatic filariasis in Papua New Guinea: distribution at district level and impact of mass drug administration, 1980 to 2011

Author

Patricia M. Graves, Leo Makita, Masayo Ozaki, Moses J. Bockarie, Frederick Michna, Wayne Melrose, Luo Dapeng, David Reeve, Corinne Capuano, Louise A. Kelly-Hope, Molly Brady, Zaixing Zhang, Melinda Susapu, Kazuyo Ichimori, and Walter M Kazadi

Subjects
medicine.medical_specialty, Veterinary medicine, Endemic Diseases, Population, Elephantiasis, medicine.disease_cause, Microfilaria, Papua New Guinea, Elephantiasis, Filarial, Environmental health, Prevalence, medicine, Animals, Humans, Wuchereria bancrofti, education, Mass drug administration, Lymphatic filariasis, Estimation, education.field_of_study, business.industry, Data Collection, Research, medicine.disease, Filaricides, Treatment Outcome, Infectious Diseases, Mapping, Communicable Disease Control, Tropical medicine, Parasitology, business
Abstract

Background Lymphatic filariasis (LF) caused by Wuchereria bancrofti is present at high prevalence in some parts of Papua New Guinea. However, there has been no rigorous data-based representative assessment of nationwide prevalence of LF. The LF programme has been daunted by the scope of the problem, and progress on mass drug administration (MDA) has been slow and lacking in resources. Methods A systematic literature review identified LF surveys in Papua New Guinea between 1980 and 2011. Results were extracted by location, time period and test used (blood slide, immunochromatographic test (ICT) or Og4C3 ELISA) and combined by district. Three criteria schemes based on the Global Programme to Eliminate Lymphatic Filariasis guidelines, with modifications, were developed to classify and prioritize districts by prevalence level. Results of repeated surveys in the same sites were used to investigate the impact of MDA on LF prevalence over the time period. Results There were 312 distinct survey sites identified in 80 of the 89 districts over the 31-year period. The overall LF prevalence in the sites tested was estimated at 18.5 to 27.5% by blood slide for microfilariae (Mf), 10.1% to 12.9% by ICT and 45.4% to 48.8% by Og4C3. Biases in site selection towards areas with LF, and change in type of assay used, affected the prevalence estimates, but overall decline in prevalence over the time period was observed. Depending on the criteria used, 34 to 36 districts (population 2.7 to 2.9 million) were classed as high endemic (≥5% prevalence), 15 to 25 districts (1.7 to 1.9 million) as low endemic (

Published
2013

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