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A man-made object detection algorithm based on contour complexity evaluation

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Chinese Journal of Aeronautics 2017年第6期30卷 1931-1957页

作者： Guili XU Zhengbing WANG Yuehua CHENG yupeng tian Chao ZHANG College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Astronautics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Man-made object detection is of great significance in both military and civil areas, such as search-and-rescue missions at sea, traffic signs recognition during visual navigation, and targets location in a military strike. Contours of man-made objects usually consist of straight lines, corner points, and simple curves. Motivated by this observation, a man-made object detection method is proposed based on complexity evaluation of object contours. After salient contours which keep the crucial information of objects are accurately extracted using an improved mean-shift clustering algorithm, a novel approach is presented to evaluate the complexity of contours. By comparing the entropy values of contours before/after sampling and linear interpolation, it is easy to distinguish between man-made objects and natural ones according to the complexity of their *** results show that the presented method can effectively detect man-made objects when compared to the existing ones.

关键词： Complexity evaluation Contour chain code Contour detection Man-made object detection Salient contour

A salient edges detection algorithm of multi-sensor images and its rapid calculation based on PFCM kernel clustering

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Chinese Journal of Aeronautics 2014年第1期27卷 102-109页

作者： Xu Guili Zhao Yan Guo Ruipeng Wang Biao tian yupeng Li Kaiyu College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Multi-sensor image matching based on salient edges has broad prospect in applications, but it is difficult to extract salient edges of real multi-sensor images with noises fast and accurately by using common algorithms. According to the analysis of the features of salient edges, a novel salient edges detection algorithm and its rapid calculation are proposed based on possibility fuzzy C-means （PFCM） kernel clustering using two-dimensional vectors composed of the values of gray and texture. PFCM clustering can overcome the shortcomings that fuzzy C-means （FCM） cluster- ing is sensitive to noises and possibility C-means （PCM） clustering tends to find identical clusters. On this basis, a method is proposed to improve real-time performance by compressing data sets based on the idea of data reduction in the field of mathematical analysis. In addition, the idea that kernel-space is linearly separable is used to enhance robustness further. Experimental results show that this method extracts salient edges for real multi-sensor images with noises more accurately than the algorithm based on force fields and the FCM algorithm; and the proposed method is on average about 56 times faster than the PFCM algorithm in real time and has better robustness.

关键词： DaM reduction Edge detection Fuzzy clustering Possibility fuzzy C2means(PFCM)

Use of land's cooperative object to estimate UAV's pose for autonomous landing

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Chinese Journal of Aeronautics 2013年第6期26卷 1498-1505页

作者： Xu Guili Qi Xiaopeng Zeng Qinghua tian yupeng Guo Ruipeng Wang Biao College of Automation Engineering Nanjing University of Aeronautics and Astronautics

The research of unmanned aerial vehicles＇（UAVs＇）autonomy navigation and landing guidance with computer vision has important ***,because of the image blurring,the position of the cooperative points cannot be obtained accurately,and the pose estimation algorithms based on the feature points have low *** this research,the pose estimation algorithm of UAV is proposed based on feature lines of the cooperative object for autonomous *** method uses the actual shape of the cooperative-target on ground and the principle of vanishing *** angle is calculated from the vanishing *** angle is calculated from the location of the target in the ***,the remaining extrinsic parameters are calculated by the coordinates *** results show that the pose estimation algorithm based on line feature has a higher precision and is more reliable than the pose estimation algorithm based on points ***,the error of the algorithm we proposed is small enough when the UAV is near to the landing strip,and it can meet the basic requirements of UAV＇s autonomous landing.

关键词： Computer vision Cooperative object Landing Position measurement UAV Vanishing line

Plasmon coupling-driven enhanced high-order multiphoton excited fluorescent performance of metal-organic frameworks

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Nano Research 2024年第7期17卷 6502-6508页

作者： Tong Meng Bo Li Linlin Zeng Xianshun Sun yupeng tian Hongping Zhou Meng Zhou Dandan Li Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid MaterialsMinistry of EducationAnhui UniversityHefei 230601China School of Chemistry and Chemical Engineering Anhui UniversityHefei 230601China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Accessing high-order multiphoton excited fluorescence(H-MPEF)materials is challenging yet and needs complicated synthesis *** this study,we successfully assembled plasmonic Au nanorods(Au NRs)with multiphoton responsive metalorganic frameworks(MOFs),resulting in a significant several-fold enhancement of *** extent of multiphoton enhancement was found to be strongly dependent on the degree of overlap between the multiphoton excitation wavelength of MOFs and the localized surface plasmon resonance absorbance of Au NRs,indicating the importance of plasmon-induced resonance energy ***,plasmon-induced hot electron transfer played a vital role in enhanced multiphoton activity as ***,the optimum H-MPEF enhancement occurs at the second near-infrared(NIR-II)region,which provides a promising platform for fluorescent *** findings provide a feasible and practical method to fabricate optimized H-MPEF materials for biological imaging using tissue-penetrating NIR-II light.

关键词： metal-organic framework(MOF) plasmon resonance multiphoton activity fluorescence imaging

Visible light-driven superoxide generation by conjugated polymers for organic synthesis

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Nano Research 2018年第2期11卷 1099-1108页

作者： Feili Lai Yue Wang Dandan Li Xianshun Sun Juan Peng Xiaodong Zhang yupeng tian tianxi Liu Hefei National Laboratory for Physical Science at Microscale Collaborative Innovation Center of Chemistry for Energy Materials University of Science and Technology of China Hefei China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University Shanghai China Department of Chemistry Anhui University Hefei China State Key Laboratory of Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University Shanghai China

Benefiting from their unique delocalized electronic structure, conjugated polymer-based semiconductors are widely applied in the fields of organic electronics, sensors, and biomedical applications. However, the photocatalytic properties of conjugated polymers have been seldom studied because of their unsuitable band structures. Herein, we creatively demonstrate that the band structures of conjugated polymers are strongly related to their degree of polymerization （DP）, offering an effective strategy for the design of metal-free photocatalysts with tunable light absorption properties. Taking poly（3- hexylthiophene）（PHT） as an example, we show that PHT nanofibers with a suitable DP are a novel visible light-driven photocatalyst, which can readily convert molecular oxygen into superoxide ions. Benefiting from the high selectivity of the generated superoxides, the PHT nanofibers display outstanding activity for the aerobic oxidation of amines into imines with nearly 100% conversion and selectivity. This study offers a new strategy for the design of advanced coniugated Dolvrner-based Dhotocatalvsts.

关键词： visible light poly(3-hexylthiophene)(PHT) superoxide selective aerobic oxidation photocatalysis

Hydrothermal Synthesis and Capacitance Property of Cobalt Sulfide/Graphene Oxide Nanocomposite

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Journal of Wuhan University of Technology(Materials Science) 2017年第1期32卷 80-84页

作者：韦莹张胜义 NIU Helin MAO Changjie SONG Jiming JIN Baokang tian yupeng Department of Chemistry Anhui UniversityHefei 230601China Anhui Provincial Center for Disease Control and Prevention Hefei 230601China

The cobalt sulfide/graphene oxide（CoS/GO） nanocomposite was synthesized by a simple hydrothermal *** products as-synthesized were characterized by XRD,SEM,TEM,BET-BJH and *** electrochemical property and impedance of the CoS/GO nanocomposite were studied by cyclic voltammetry and EIS analysis,*** results show that the presence of the GO enhances the electrode conductivity,and then improves the capacitance property of the CoS/GO *** galvanostatic charge/discharge measurement results show that the CoS/GO nanocomposite has a high specific capacitance（550Fg^-1） and long cycle life（over 1 000 cycles）.

关键词： CoS graphene nanocomposite synthesis capacitance

Synthesis, crystal structures and electrochemical properties of two new metal-centered ferrocene complexes

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Science China Chemistry 2009年第7期52卷 930-936页

作者： WANG XuChun WU JieYing ZHOU HongPing tian yupeng LI Lin YANG JiaXiang JIN BaoKang ZHANG ShengYi Department of Chemistry Anhui Province Key Laboratory of Function Inorganic Material ChemistryAnhui UniversityHefei 230039China Department of Chemistry Anhui Science and Technology UniversityFengyang 233100China State Key Laboratory of Crystal Materials Institute of Crystal Materials of Shandong UniversityJinan 250100China

Two new metal-centered ferrocene complexes Ni(SCN)2(L)4 (1) and Cu(OAc)2(L)2 (2) (L = 1-[1-ferrocenylmethyl]imidazole) have been synthesized and characterized by elemental analysis, single crystal X-ray diffraction analysis, spectroscopic and cyclic voltammetric measurements. The geometry of Ni(II) in 1 is octahedral, with four ligands in the equatorial plan and two thiocyanate anions at the axial site, while that of Cu(II) in 2 is a distorted octahedron formed by two chealted OAc? and two ligands. Single crystal X-ray diffraction studies reveal that there is partial electron delocalization from ferrocene to imidazole in the two complexes. Electrochemical measurements exhibit that complexes 1 and 2 undergo similar reversible one electron redox processes, suggesting that the ferrocene moieties are equivalent and there are no interactions among them.

关键词： ferrocene imidazole complex crystal structure electrochemistry

Synthesis,structure and nonlinear optical properties of two novel two-photon absorption chromophores

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Science China Chemistry 2009年第4期52卷 529-534页

作者： CHENG LeHua LI Lin SUN PingPing ZHOU HongPing tian yupeng TANG HuoHong Department of Chemistry Key Laboratory Functional Inorganic Materials of Anhui ProvinceAnhui UniversityHefei 230039China Department of Chemistry Chaohu CollegeChaohu 238000China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China

Two triphenylamine-based derivatives that can be used as two-photon absorption chromophore,tris{4-[4-(3-trifluoromethyl-3-oxopanoyl)]phenyl}amine (1) and tris{4-[4-(3-phenyl-3-oxopanoyl)] phenyl} amine (2) were successfully synthesized and fully characterized by elemental analysis,IR,1H NMR and MS. The single crystal X-ray diffraction analysis showed that the molecules possess D-(π-A)3 structures. One-and two-photon absorption and fluorescence in various solvents were experimentally investigated. A data recording experiment proved the potential application of these chromophores.

关键词： two-photon absorption triphenylamine derivative chromophore crystal structure

Synthesis of two carbazole-based dyes and application of two-photon initiating polymerization

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Science China Chemistry 2009年第8期52卷 1210-1215页

作者： HU RenTao LüLiangFei RUAN BanFeng WANG Peng ZHANG MingLiang ZHOU HongPing LI ShengLi WU JieYing tian yupeng Department of Chemistry and Chemical Engineering Key Laboratory of Functional Inorganic Materials Chemistry of Anhui ProvinceAnhui UniversityHefei 230039China

Two carbazole-based polymerization initiators possessing blue fluorescence emission have been synthesized via Wittig reaction in the solid phase at room ***-photon excited fluorescence(TPEF) spectra for them were investigated under 800 nm fs laser pulse and two-photon absorption cross sections were determined by the Z-scan *** two-photon initiating polymerization(TPIP) microfabrication experiments were successfully carried ***-dimensional lattice and artificial defects were gained,indicating that they were viable candidates for the two-photon polymerization initiator in practical application of microfabrication.

关键词： carbazole-based dye two-photon excited fluorescence(TPEF) two-photon initiating polymerization(TPIP) microfabrication