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Fundamental Limits of Doppler Shift-Based, ToA-Based,and TDoA-Based Underwater Localization

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IEEE/CAA Journal of Automatica Sinica 2023年第7期10卷 1637-1639页

作者： Zijun gong cheng Li Ruoyu Su Hong Kong University of Science and Technology(Guangzhou) IOT ThrustGuangzhou 511400 Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyHong Kong 999077China Faculty of Engineering and Applied Science Memorial University of NewfoundlandNewfoundland A1B 3X5Canada School of Internet of Things Nanjing University of Posts and TelecommunicationsNanjing 210003China

Dear Editor,This paper is concerned with the underwater localization based on acoustic signals. Specifically, we will focus on the search of an underwater target that can constantly broadcast a beacon signal, such as a black box. Common measurements for localization are Doppler shift [1], time of arrival(ToA) [2]–[4], time difference of arrival(TDoA) [5], [6], angle of arrival(AoA) [7], etc.

关键词： TDoA ToA underwater

Permanent displacement models of earthquake-induced landslides considering near-fault pulse-like ground motions

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Journal of Mountain Science 2019年第6期16卷 1244-1265页

作者： ZHANG Ying-bin XIANG Chen-lin CHEN Yan-long cheng Qian-gong XIAO Li YU Peng-cheng CHANG Zhi-wang Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining&TechnologyXuzhou 221116China Department of Geotechnical Engineering School of Civil EngineeringSouthwest Jiaotong UniversityChengdu 610031China Department of Geological Engineering Southwest Jiaotong UniversityChengdu 610031China

The permanent displacement of seismic slopes can be regarded as an effective criterion for stability estimation. This paper studied the characteristics of permanent displacements induced by velocity pulse-like ground motions and developed an empirical model to readily evaluate the stability of seismic slopes in a near-fault region. We identified 264 velocity pulse-like ground motions from the Next Generation Attenuation(NGA) database using the latest improved energy-based approach. All selected ground motions were rotated to the orientation of the strongest observed pulse for considering the directivity of the pulse effect, so that the most dangerous condition for slopes was considered. The results show the velocity pulse-like ground motions have a much more significant effect on permanent displacement of slopes than non-pulse-like ground motions. A regression model based on a function of peak ground velocity(PGV), peak ground acceleration(PGA) and critical acceleration(ac), was generated. A significant difference was found by comparing the presented model with classical models from literatures. This model can be used to evaluate the seismic slope stability considering the effects of nearfault pulse-like characteristics.

关键词： Seismic slope Permanent displacement Pulse effect Earthquake-induced landslides Near-fault

Automatic Lane-Level Intersection Map Generation using Low-Channel Roadside LiDAR

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IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1209-1222页

作者： Hui Liu Ciyun lin Bowen gong Dayong Wu the Department of Traffic Information and Control Engineering Jilin UniversityChangchun 130022 the Texas A&M Transportation Institute Texas A&M UniversityCollege StationTexasTX 77843 USA

A lane-level intersection map is a cornerstone in high-definition(HD) traffic network maps for autonomous driving and high-precision intelligent transportation systems applications such as traffic management and control, and traffic accident evaluation and prevention. Mapping an HD intersection is time-consuming, labor-intensive, and expensive with conventional methods. In this paper, we used a low-channel roadside light detection and range sensor(LiDAR) to automatically and dynamically generate a lane-level intersection, including the signal phases, geometry, layout, and lane directions. First, a mathematical model was proposed to describe the topology and detail of a lane-level intersection. Second, continuous and discontinuous traffic object trajectories were extracted to identify the signal phases and times. Third, the layout, geometry, and lane direction were identified using the convex hull detection algorithm for trajectories. Fourth, a sliding window algorithm was presented to detect the lane marking and extract the lane, and the virtual lane connecting the inbound and outbound of the intersection were generated using the vehicle trajectories within the intersection and considering the traffic rules. In the field experiment, the mean absolute estimation error is 2 s for signal phase and time identification. The lane marking identification Precision and Recall are96% and 94.12%, respectively. Compared with the satellite-based,MMS-based, and crowdsourcing-based lane mapping methods,the average lane location deviation is 0.2 m and the update period is less than one hour by the proposed method with low-channel roadside LiDAR.

关键词： High-definition map lane-level intersection map roadside LiDAR sliding window traffic object trajectory

Temporal and Spatial Variations of Microbial Carbon Utilization in Water Bodies from the Dajiuhu Peatland, Central China

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Journal of Earth Science 2018年第4期29卷 969-976页

作者： Rui-cheng Wang Hong-Mei Wang Xing Xiang Yu Gao Qing-Wei Song lin-Feng gong State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Wuhan 430074 China State Key Laboratory Breeding Base of Marine Genetic Resources Key Laboratory of Marine Genetic Resources Third Institute of Oceanography SOA Key Laboratory of Marine Genetic Resources of Fujian Province Xiamen 361005 China

To investigate the microbial utilization of organic carbon in peatland ecosystem, water samples were collected from the Dajiuhu Peatland and nearby lakes, central China across the year of 2014. The acridine orange （AO） staining and Biolog Eco microplates were used to numerate microbial counts and determine the carbon utilization of microbial communities. Meanwhile, physicochemical characteristics were measured for subsequent analysis of the correlation between microbial carbon utilization and environmental factors. Results indicated that total microbial counts were between 106107 cells/L. Microbial diversities and carbon utilization rates showed a similar pattern, highest in September and lowest in November. Microbial communities in the peat pore waters preferred to utilize N-bearing carbon sources such as amines and amino acids compared with microbial communities in lakes. The network analysis of microbial utilization of 31 carbon substrates clearly distinguished microbial communities from peat pore waters and those from lakes. Redundancy analysis （RDA） showed the total organic nitrogen content （P=-0.03, F=2.5） and daily average temperature （P=0.034, F=2.4） significantly controlled microbial carbon utilization throughout the sampling period. Our report is the first one to address the temporal and spatial variations of carbon uti- lization of microbial communities which are closely related to the decomposition of organic matter in the Dajiuhu Peatland in context of climate warming.

关键词： carbon source microbial carbon utilization average temperature Dajiuhu Peatland.

Effect of Stress Ratio on the Fatigue Crack Propagation Behavior of the Nickel-based GH4169 Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 809-821页

作者： Shen Ye Jian-Guo gong Xian-cheng Zhang Shan-Tung Tu cheng-cheng Zhang Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyMeilongRoad 130Xuhui DistrictShanghai 200237People'sRepublic of China AECC Commercial Aircraft Engine Co.LTD ShanghaiEngineering Research Center for Commercial Aircraft EngineShanghai 201108People's Republic of China

The fatigue crack growth behavior of the newly developed GH4169 nickel-based alloy at a maximum stress of 700 MPa and different stress ratios was investigated in the present work employing the specimens with a single micro- notch at a frequency of 129 Hz at room temperature. The results demonstrate a typical three-stage process of fatigue crack propagation processing from the microstructurally small crack （MSC） stage to the physically small crack （PSC） stage, and finally to the long crack stage. The crack growth rate in the MSC stage is relatively high, while the crack growth rate in the PSC stage is relatively low. A linear function of crack-tip reversible plastic zone size was proposed to predict the crack growth rate, indicating an adequate prediction solution.

关键词： Fatigue crack Crack growth rate Stress ratio Nickel-based alloy

Comparative effect of allopolyploidy on transposable element composition and gene expression between Gossypium hirsutum and its two diploid progenitors

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Journal of Integrative Plant Biology 2019年第1期61卷 45-59页

作者： Hua cheng Gaofei Sun Shoupu He Wenfang gong Zhen Peng Ruiping Wang Zhongxu lin Xiongming Du Research Base Anyang Institute of TechnologyState Key Laboratory of Cotton BiologyInstitute of Cotton Researchthe Chinese Academy of Agricultural Science College of Plant Science & Technology of Huazhong Agricultural University Department of Computer Science and Information Engineering Anyang Institute of Technology

An allopolyploidization event formed allotetraploid Gossypium species from an A-genome diploid species and a D-genome diploid species. To explore the responses of transposable elements(TEs) to allopolyploidy, we assembled parallel TE datasets from G. hirsutum, G. arboreum and G. raimondii and analyzed the TE types and the effects of TEs on orthologous gene expression in the three Gossypium *** was the most abundant TE type and most TEs were located $500 bp from genes in all three genomes. In G. hirsutum, 35.6% of genes harbored TE insertions, whereas insertions were more frequent in G. arboreum and G. raimondii. G. hirsutum had the highest proportion of uniquely matching 24-nt small interfering RNAs(siRNAs) that targeted TEs. TEs,particularly those targeted by 24-nt siRNAs, were associated with reduced gene expression, but the effect of TEs on orthologous gene expression varied substantially among species. Orthologous gene expression levels in G. hirsutum were intermediate between those of G. arboreum and G. raimondii, which did not experience TE expansion or reduction resulting from allopolyploidization. This study underscores the diversity of TEs co-opted by host genes and provides insights into the roles of TEs in regulating gene expression in Gossypium.

关键词： progenitors allopolyploidization

The Exhumation History of North Qaidam Thrust Belt Constrained by Apatite Fission Track Thermochronology:Implication for the Evolution of the Tibetan Plateau

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Acta Geologica Sinica(English Edition) 2016年第3期90卷 870-883页

作者： cheng Xiaogan lin Xiubin WU Lei CHEN Hanlin XIAO Ancheng gong Junfeng ZHANG Fengqi YANG Shufeng School of Earth Sciences Zhejiang UniversityHangzhou 310027ZhejiangChina Research Center for Structures in Oil-and Gas-Bearing Basins Ministry of EducationHangzhou 310027ZhejiangChina

Determining the spatio-temporal distribution of the deformation tied to the India-Eurasian convergence and the impact of pre-existing weaknesses on the Cenozoic crustal deformation is significant for understanding how the convergence between India and Eurasia contributed to the development of the Tibetan Plateau. The exhumation history of the northeastern Tibetan Plateau was addressed in this research using a new apatite fission track （AFT） study in the North Qaidam thrust belt （NQTB）. Three granite samples collected from the Qaidam Shan pluton in the north tied to the Qaidam Shan thrust, with AFT ages clustering in the Eocene to Miocene. The other thirteen samples obtained from the Luliang Shan and Yuka plutons in the south related to the Luliang Shan thrust and they have showed predominantly the Cretaceous AFT ages. Related thermal history modeling based on grain ages and track lengths indicates rapid cooling events during the Eocene-early Oligocene and since late Miocene within the Qaidam Shan, in contrast to those in the Cretaceous and since the Oligocene-Miocene in the Luliang Shan and Yuka region. The results, combined with published the Cretaceous thermochronological ages in the Qaidam Shan region, suggest that the NQTB had undergo rapid exhumation during the accretions along the southern Asian Andean-type margin prior to the India-Eurasian collision. The Cenozoic deformation initially took place in the North Qaidam thrust belt by the Eocene, which is consistent with the recent claim that the deformation of the northeastern Tibetan Plateau initiated in the Eocene as a response to continental collision between India and Eurasia. The immediate deformation responding to the collision is tentatively attributed to the preexisting weaknesses of the lithosphere, and therefore the deformation of the northeastern Tibetan Plateau should be regarded as a boundary-condition-dependent process.

关键词： apatite fission track Qaidam Shan Luliang Shan North Qaidam thrust belt Tibetan plateau

Damping of Magnetorheological Elastomers

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Chinese Journal of Chemical Physics 2008年第6期21卷 581-585页

作者： lin Chen Xing-long gong Wei-hua Li CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Me- chanics University of Science and Technology of China Hefei 230027 China School of Mechanical Materials and Mechatronic Engineering University of Wollongong Wollongong NSW 2522 Australia

The damping property of magnetorheological （MR） elastomers is characterized by a modified dynamic mechanical-magnetic coupled analyzer. The influences of the external magnetic flux density, damping of the matrix, content of iron particles, dynamic strain, and driving frequency on the damping properties of MR elastomers were investigated experimentally. The experimental results indicate that the damping properties of MR elastomers greatly depend on the interfacial slipping between the inner particles and the matrix. Different from general composite materials, the interracial slipping in MR elastomers is affected by the external applied magnetic field.

关键词： Magnetorheological elastomers Damping property Interfacial slipping

Contribution of phylogenetics to understanding the evolution and epidemiology of dengue virus

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Animal Models and Experimental Medicine 2022年第5期5卷 410-417页

作者： Xi Yu gong cheng Tsinghua-Peking Center for Life Sciences School of MedicineTsinghua UniversityBeijingChina Institute of Infectious Diseases Shenzhen Bay LaboratoryShenzhenChina Institute of Pathogenic Organisms Shenzhen Center for Disease Control and PreventionShenzhenChina School of Life Sciences Tsinghua UniversityBeijingChina

Dengue virus(DENV)is one of the most important arboviral pathogens in the tropics and subtropics,and nearly one-third of the world's population is at risk of *** transmission of DENV involves a sylvatic cycle between nonhuman primates(NHP)and Aedes genus mosquitoes,and an endemic cycle between human hosts and predominantly Aedes *** belongs to the genus Flavivirus of the family Flaviviridae and consists of four antigenically distinct serotypes(DENV-1-4).Phylogenetic analyses of DENV have revealed its origin,epidemiology,and the drivers that determine its molecular evolution in *** review discusses how phyloge-netic research has improved our understanding of DENV evolution and how it affects viral ecology and improved our ability to analyze and predict future DENV emergence.

关键词： dengue virus(DENV) evolution flavivirus phylogenetics