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GridNet-3D: A Novel Real-Time 3D Object Detection Algorithm Based on Point Cloud

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Chinese Journal of Electronics 2021年第5期30卷 931-939页

作者： YUE Yuanchen CAI Yunfei wang dongsheng School of Computer Science and Engineering Nanjing University of Science and Technology

3D object detection based on point cloud has an important application prospect in automatic driving technology. Aiming at the low precision of 3D object detection based on point cloud and the poor real-time performance caused by large numbers of 3D convolutions, a novel end-to-end real-time object detection algorithm named GridNet-3D is proposed. In the work, 2D gridmapping is used to preprocess the original point *** a novel structure grid encoding layer is adopted to encode point cloud features and is gotten grid feature maps in bird's eye view which is connected to region proposal network module to generate detections. Despite only using point clouds, the results on the KITTI 3D detection benchmark show that our algorithm has higher detection precision and better real-time performance on the detection of cars, pedestrians and cyclists, which has high practical value.

关键词： GridNet-3D point cloud features region proposal network module structure grid encoding layer grid feature maps 2D gridmapping intelligent transportation systems end-to-end real-time object detection algorithm KITTI 3D detection benchmark feature extraction automatic driving technology object detection 3D convolution

Distribution of heavy metals in the water column,suspended particulate matters and the sediment under hydrodynamic conditions using an annular flume

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Journal of Environmental Sciences 2012年第12期24卷 2051-2059页

作者： Jianzhi Huang Xiaopeng Ge dongsheng wang State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Sediment resuspension plays an important role in the transport and fate of heavy metals in the aquatic environment. In the present study, the release and binding forms of Cr, Cu, Zn, Pb under hydrodynamic conditions were investigated using an annular flume. Two sediments located at YLZ and GBD from Liangshui River, Beijing were resuspended for 10 hr at 0.159 and 0.267 m/see, respectively. The concentrations of suspended particulate matters of YLZ were higher than those of GBD during resuspension, indicating that the former sediment is more sensitive to the velocity. Cr in the dissolved phase stayed nearly constant at about 2.25 and 1.84 I^g/L for YLZ and GBD, respectively, due to the high percentage of its stable binding fractions in both sediments, while Cu, Zn, and Pb showed a fast release in the initial period of time. However, their concentrations in SPM generally decreased with time and were higher at the lower velocity of 0.159 m/see, which resulted from the entrainment and depressing effect of larger size particles with lower heavy metal content, commonly referred to as the ＂particle concentration effect＂. In addition, the binding form and heavy metal fractions were also found to vary during the resuspension event. A decrease in the sulphide/organic matters bounded form in GBD sediment was observed, whereas no visible changes were perceived in YLZ site samples. This phenomenon is due to the oxidation of heavy metal-sulphide binding forms, which originated from its high acid volatile sulphide content in GBD sediment.

关键词： heavy metals sediment resuspension suspended particulate matters annular flume

Banian: A Cross-Platform Interactive Query System for Structured Big Data

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Tsinghua Science and Technology 2015年第1期20卷 62-71页

作者： Tao Xu dongsheng wang Guodong Liu the Department of Computer Science and Technology Tsinghua University the Department of Computer Science and Technology and Tsinghua National Laboratory for Information Science and Technology Tsinghua University Tsinghua National Laboratory for Information Science and Technology Tsinghua University

The rapid growth of structured data has presented new technological challenges in the research fields of big data and relational database. In this paper, we present an efficient system for managing and analyzing PB level structured data called Banian. Banian overcomes the storage structure limitation of relational database and effectively integrates interactive query with large-scale storage management. It provides a uniform query interface for cross-platform datasets and thus shows favorable compatibility and scalability. Banian＇s system architecture mainly includes three layers：（1） a storage layer using HDFS for the distributed storage of massive data;（2） a scheduling and execution layer employing the splitting and scheduling technology of parallel database; and（3）an application layer providing a cross-platform query interface and supporting standard SQL. We evaluate Banian using PB level Internet data and the TPC-H benchmark. The results show that when compared with Hive, Banian improves the query performance to a maximum of 30 times and achieves better scalability and concurrency.

关键词： big data interactive query relational database HDFS cross platform

Sustainable water environment and water use： A perspective on water resource utilization

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Journal of Environmental Sciences 2016年第12期28卷 1-2页

作者： Huijuan Liu dongsheng wang Baoling Yuan State Key Laboratory of Environmental Aquatic Chemistry Research Center of Eco-Environment Sciences Chinese Academy of Sciences Beijing 100085 China Institute of Municipal and Environmental Engineering College of Civil Engineering Huaqiao University Xiamen 361021 China

The 6th International Water Association Asia Pacific Regional Grouping （IWA-ASPIRE） Conference and Exhibition was held on September 20-24, 2015, in Beijing. The conference was hosted by the Research Center for Eco-Environmental Sciences （RCEES） of Chinese Academy of Sciences （CAS）; with strong support provided by CAS, Chinese Academy of Engineering （CAE）, National Science Foundation of China （NSFC）,

关键词： Sustainable water environment and water use CAS

Characterization of changes in extracellular polymeric substances and heavy metal speciation of waste activated sludge during typical oxidation solubilization processes

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Journal of Environmental Sciences 2019年第6期31卷 146-158页

作者： Qiongying Xu Huidi wang Qiandi wang Weijun Zhang dongsheng wang Faculty of Materials Science and Chemistry China University of Geosciences School of Environmental Studies China University of Geosciences Hubei Provincial Engineering Research Center of Systematic Water Pollution Control State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

Biopolymer solubilization is considered to be the rate-limiting stage of anaerobic digestion of waste activated sludge(WAS). Oxidation processes have been proven to be effective in disrupting sludge flocs and causing solubilization of the solid biopolymers. In this study,WAS was treated by NaNO2 or H2 O2 oxidation at p H of 2. The changes in extracellular polymeric substances properties and the speciation of heavy metals were investigated. The results revealed that both NaNO2 and H2 O2 treatments were effective in solubilizing organics in WAS, while the conversion of biopolymers in the two treatment processes was different. Free nitrous acid destroyed the gel network structure of EPS, and organic materials were released from the solid phase to the supernatant. Indigenous peroxidase catalyzed H2 O2 to produce hydroxyl radicals which caused significant solubilization of biopolymers, and the protein-like substances were further degraded into micro-molecule polypeptides or amino acids at high dosages of H2 O2. During the oxidation processes, Zn, Cd and Cu, with excellent mobility, tended to migrate to the supernatant, and thus were easy to remove through the liquid–solid separation process. Ni and As showed moderate migration ability, of which the residual fraction tended to transform into reducible and soluble fractions. With poor mobility, Cr and Pb mainly existed in the forms of residual and oxidizable fractions, which were difficult to dissolve and remove from WAS. Both NaNO2 and H2 O2 treatment resulted in the enhancement of sludge solubilization efficiency and heavy metal mobility in WAS, but different heavy metals showed distinct migration and transformation behaviors.

关键词： Extracellular polymeric substances(EPS) Oxidation Biopolymers solubilization Biodegradability Heavy metals

Selection and modification of ground motion records using Newmark-Hall spectrum as target spectrum for long-period structures

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Earthquake Engineering and Engineering Vibration 2023年第1期22卷 117-134页

作者： Fu Jianyu wang dongsheng Zhang Rui Chen Xiaoyu School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China School of Civil Engineering Dalian Jiaotong UniversityDalian 116028China Institute of Road and Bridge Engineering Dalian Maritime UniversityDalian 116026China

Input ground motions have significant impacts on the uncertainty of structural responses in time-history *** this study,records were selected and scaled for the evaluation of mean structural responses according to the target *** Newmark-Hall spectrum is closely related to seismic response of short,medium and long-period structures,so it was taken as the target spectrum *** nonlinear time-history analyses of 9-story and 20-story steel moment-resisting frame structures were carried out as *** represent medium and long-period buildings,*** target spectra with risk of 50%,10%and 2%probabilities for exceedance in 50 years were calculated by the average Newmark-Hall spectrum method for three ground motion sets developed in the SAC Steel *** predicted structural mean responses of these Newmark-Hall spectra were compared with those calculated by the average spectral acceleration method for the same record *** is found that both methods have similar accuracy for estimating the structural mean ***,the method proposed herein is more effective in reducing the variability of the structural ***,the proposed method is more advantageous for the time-history analysis of long-period structures or structures with more severe nonlinear responses under strong seismic excitations.

关键词： time-history analysis selection and modification of ground motions target spectrum Newmark-Hall spectrum steel moment resisting frame structure

Nanomechanical Behaviour of the Membranous Wings of Dragonfly Pantala flavescens Fabricius

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Journal of Bionic Engineering 2016年第3期13卷 388-396页

作者： Yanru Zhao dongsheng wang Jin Tong Jiyu Sun The College of Mechanical and Power Engineering Henan Polytechnic University Jiaozuo 454000 China The Key Laboratory of Bionic Engineering (Ministry of Education China) and the College of Biological and Agricultural Engineering Jilin University (Nanling Campus) Changchun 130022 China

The dragonfly has excellent flying capacity and its wings are typical 2-dimensional composite materials in micro-scale or nano-scale. The nanomechanical behavior of dragonfly membranous wings was investigated with a nanoindenter. It was shown that the maxima of the reduced modulus and nanohardness of the in-vivo and fresh dragonfly wings are about at position of 0.7L, where L is the wing length. It was found that the reduced modulus and nanohardness of radius of the wings of dragonfly are large. The reduced modulus and nanohardness of Costa, Radius and Postal veins of the in-vivo dragonfly wings are larger than those of the fresh ones. The deformation, stress and strain under the uniform load were analyzed with finite element simulation software ANSYS. The deformation is little and the distribution trend of the strain is probably in agreement with that of the stress. It is shown that the main veins have better stabilities and load-bearing capacities. The understanding of dragonfly wings＇ nanomechanical properties would provide some references for improving some properties of 2-dimentional composite materials through the biomimetic designs. The realization of nanomechanical properties of dragonfly wings will provide inspirations for designing some new structures and materials of mechanical parts.

关键词： Pantala flavescens Fabricius membranous wing experimental optimization design nanoindentation nanome-chanieal property

Laser cladding of Al+Ir powders on ZM5 magnesium base alloy

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Rare Metals 2007年第5期26卷 420-425页

作者： CHEN Changjun wang Maocai wang dongsheng JIN Ren LIU Yiming State Key Laboratory for Corrosion and Protection Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education College of Materials ＆ Metallurgy Wuhan University of Science ＆ Technology Wuhan 430081 China Shenyang Liming Aero-engine Corporation Shenyang 110043 China

Laser cladding of preplaced Al ＋ Ir powders on a ZM5 magnesium alloy was performed to enhance the corrosion resistance of the ZM5 magnesium alloy. A metallurgical bond was obtained at the coating/substrate interface. The corrosion potential （Ecorr） of the laser cladded sample was 169 mV positive to that of the untreated ZM5 substrate,while the corrosion current （Icorr） was some one order of magnitude lower. The laser cladded sample,unlike the untreated ZM5 substrate,showed a passive region in the polarization plot. Immersion tests confirmed that the corrosion resistance of the laser cladded ZM5 sample was significantly enhanced in 3.5 wt.% NaCl solution. The Al-rich phases of AlIr,Mg17Al12,and Al formed in the cladding layer and the rapid solid characteristics were contributed to the improved corrosion behavior of the coating.

关键词： laser cladding magnesium alloys Ir corrosion

Fractal analysis of polyferric chloride-humic acid(PFC-HA) flocs in different topological spaces

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Journal of Environmental Sciences 2009年第1期21卷 41-48页

作者： wang Yili LU Jia DU Baiyu SHI Baoyou wang dongsheng College of Environmental Science and Engineering The Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry University Beijing 100083 China. State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beifing 100085 China

The fractal dimensions in different topological spaces of polyferric chloride-humic acid （PFC-HA） flocs, formed in flocculating different kinds of humic acids （HA） water at different initial pH （9.0, 7.0, 5.0） and PFC dosages, were calculated by effective densitymaximum diameter, image analysis, and N2 absorption-desorption methods, respectively. The mass fractal dimensions （De） of PFC-HA floes were calculated by bi-logarithm relation of effective density with maximum diameter and Logan empirical equation. The Df value was more than 2.0 at initial pH of 7,0, which was 11% and 13% higher than those at pH 9.0 and 5.0, respecively, indicating the most compact flocs formed in flocculated HA water at initial pH of 7.0. The image analysis for those flocs indicates that after flocculating the HA water at initial pH greater than 7.0 with PFC flocculant, the fractal dimensions of D2 （logA vs. logdL） and D3 （logVsphere vs. logdL） of PFC-HA floes decreased with the increase of PFC dosages, and PFC-HA floes showed a gradually looser structure. At the optimum dosage of PFC, the D2 （logA vs. logdL） values of the flocs show 14%-43% difference with their corresponding Dr, and they even had different tendency with the change of initial pH values. However, the D2 values of the floes formed at three different initial pH in HA solution had a same tendency with the corresponding Df. Based on fractal Frenkel-Halsey-HiU （FHH） adsorption and desorption equations, the pore surface fractal dimensions （Ds） for dried powders of PFC-HA flocs formed in HA water with initial pH 9.0 and 7.0 were all close to 2.9421, and the Ds values of flocs formed at initial pH 5.0 were less than 2.3746. It indicated that the pore surface fractal dimensions of PFC-HA floes dried powder mainly show the irregularity from the mesopore-size distribution and marcopore-size distribution.

关键词： polyferric chloride-humic acid (PFC-HA) flocs topological spaces fractal dimensions effective density image analysis pore surface fractal