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Intelligent extraction of road cracks based on vehicle laser point cloud and panoramic sequence images

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Journal of Road Engineering 2024年第1期4卷 69-79页

作者： Ming Guo Li Zhu Ming Huang Jie Ji Xian Ren Yaxuan Wei Chutian Gao School of Geomatics and urban spatial informatics Beijing University of Civil Engineering and ArchitectureBeijing 102616China Engineering Research Centre of Representative Building and Architectural Heritage Database Ministry of EducationBeijing 100044China key laboratory of Modern urban Surveying and Mapping National Administration of SurveyingBeijing 102616China School of Civil and Transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing 102616China

In light of the limited efficacy of conventional methods for identifying pavement cracks and the absence of comprehensive depth and location data in two-dimensional photographs,this study presents an intelligent strategy for extracting road *** methodology involves the integration of laser point cloud data obtained from a vehicle-mounted system and a panoramic sequence of *** study employs a vehicle-mounted LiDAR measurement system to acquire laser point cloud and panoramic sequence image data simultaneously.A convolutional neural network is utilized to extract cracks from the panoramic sequence *** extracted sequence image is then aligned with the laser point cloud,enabling the assignment of RGB information to the vehicle-mounted three dimensional(3D)point cloud and location information to the two dimensional(2D)panoramic ***,a threshold value is set based on the crack elevation change to extract the aligned roadway point *** three-dimensional data pertaining to the cracks can be *** experimental findings demonstrate that the use of convolutional neural networks has yielded noteworthy outcomes in the extraction of road *** utilization of point cloud and image alignment techniques enables the extraction of precise location data pertaining to road *** approach exhibits superior accuracy when compared to conventional ***,it facilitates rapid and accurate identification and localization of road cracks,thereby playing a crucial role in ensuring road maintenance and traffic ***,this technique finds extensive application in the domains of intelligent transportation and urbanization *** technology exhibits significant promise for use in the domains of intelligent transportation and city development.

关键词： Road crack extraction Vehicle laser point cloud Panoramic sequence images Convolutional neural network

Hybrid ITO Algorithm for Large-Scale Colored Traveling Salesman Problem

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Chinese Journal of Electronics 2024年

作者： Xueshi DONG College of Computer Science and Technology Qingdao University Beijing key laboratory of urban spatial Information Engineering School of Computer Science Wuhan University

In the fields of intelligent transportation and multi-task cooperation, many practical problems can be modeled by colored traveling salesman problem (CTSP). When solving large-scale CTSP with a scale of more than 1000dimensions, their convergence speed and the quality of their solutions are limited. This paper proposes a new hybrid ITO(HITO) algorithm, which integrates two new strategies, crossover operator and mutation strategy, into the standard ITO. In the iteration process of HITO, the feasible solution of CTSP is represented by the double chromosome coding, and the random drift and wave operators are used to explore and develop new unknown regions. In this process, the drift operator is executed by the improved crossover operator, and the wave operator is performed by the optimized mutation strategy. Experiments show that HITOis superior to the known comparison algorithms in term of the quality solution.

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Sensitivity Simulations of the 30 March 2020 Xichang Wildfire in Southwest China Based on the WRF-Fire Model

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Journal of Meteorological Research 2024年第4期38卷 826-843页

作者： Yujue LIU Shiguang MIAO Hanbin ZHANG Institute of urban Meteorology China Meteorological AdministrationBeijing 100089 key laboratory of urban Meteorology China Meteorological AdministrationBeijing 100089

This paper describes a fire forecast system—Weather Research and Forecasting-Fire(WRF-Fire)—that is employed to simulate a real wildfire case in Xichang,Sichuan Province,Southwest China on 30 March 2020 at a 100-m resolution over the fire area,in order to provide a fine representation of the terrain and fuel heterogeneities and explicitly resolve the atmospheric *** sensitivity experiments were conducted to analyze the impacts of atmospheric model grid spacing and fire–atmosphere interaction on simulated meteorological fields and fire *** results indicate that finer horizontal grid spacing in the atmospheric model improves the accuracy of wind,temperature,and moisture simulations in the near surface ***,it can better describe local wind field characteristics,capture microscale wind speed fluctuations,and produce more significant effect from fire–atmosphere *** mass and energy released by the fire model and its feedback to the atmospheric model exhibit enhanced heterogeneous *** simulated fire area aligns well with the observation,with KAPPA coefficient(KC)of 0.56–0.59 and spatial correlation coefficient(SC) of 0.52–*** this real case,the influence of heterogeneous land surface on the fire behavior is much greater than the atmosphere–fire *** study suggests that WRFFire holds high potential as a real wildfire simulation tool,offering a new and feasible approach for fire prediction.

关键词： Weather Research and Forecasting-Fire wildfire coupled fire–atmosphere modeling fire behavior large-eddy simulation(LES)

Mapping upland crop–rice cropping systems for targeted sustainable intensification in South China

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The Crop Journal 2024年第2期12卷 614-629页

作者： Bingwen Qiu Linhai Yu Peng Yang Wenbin Wu Jianfeng Chen Xiaolin Zhu Mingjie Duan key laboratory of spatial Data Mining&Information Sharing of Ministry of Education Academy of Digital China(Fujian)Fuzhou UniversityFuzhou 350116FujianChina key laboratory of Agricultural Remote Sensing Ministry of Agriculture and Rural AffairsBeijing 100081China Department of Land Surveying and Geo-informatics The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina

Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural *** UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural ***,datasets describing cropping systems are limited in spatial coverage and crop *** UCR is more challenging than crop identification and most existing approaches rely heavily on accurate phenology calendars and representative training samples,which limits its applications over large *** describe a novel algorithm(RRSS)for automatic mapping of upland crop-rice cropping systems using Sentinel-1 Synthetic Aperture Radar(SAR)and Sentinel-2 Multispectral Instrument(MSI)*** indicator,the VV backscatter range,was proposed to discriminate UCR and another two indicators were designed by coupling greenness and pigment indices to further discriminate tobacco or oilseed *** RRSS algorithm was applied to South China characterized by complex smallholder rice cropping systems and diverse topographic *** study developed 10-m UCR maps of a major rice bowl in South China,the Xiang-Gan-Min(XGM)*** performance of the RRSS algorithm was validated based on 5197 ground-truth reference sites,with an overall accuracy of 91.92%.There were7348 km^(2) areas of UCR,roughly one-half of them located in *** UCR was represented mainly by oilseed-UCR and tobacco-UCR,which contributed respectively 69%and 15%of UCR *** patterns accounted for only one-tenth of rice production,which can be tripled by intensification from single rice *** to complex and fragmented subtropical regions suggested the spatiotemporal robustness of the RRSS algorithm,which could be further applied to generate 10-m UCR datasets for application at national or global scales.

关键词： Cropping-pattern mapping Paddy rice Sentinel-1/2 China Sustainable intensification

Wavelet-domain feature decoupling for weakly supervised multi-object tracking

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Science China(Information Sciences) 2024年第8期67卷 339-340页

作者： Yu-Lei LI Yan YAN Yang LU Hanzi WANG Fujian key laboratory of Sensing and Computing for Smart City School of InformaticsXiamen University

Multi-object tracking(MOT) aims to discover interesting foreground targets and meanwhile generate robust trajectories of these targets with different data association algorithms based on identity embedding features(Re-ID features) [1] or motion cues [2]. During the past few decades,some advanced MOT methods have achieved considerable progress due to their wide range of applications in modern autonomous driving and intelligent video analysis.

关键词： Tracking (position)

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Ultra-highly sensitive dual gases detection based on photoacoustic spectroscopy by exploiting a long-wave,high-power,wide-tunable,singlelongitudinal-mode solid-state laser

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Light(Science & Applications) 2024年第5期13卷 941-956页

作者： Shunda Qiao Ying He Haiyue Sun Pietro Patimisco Angelo Sampaolo Vincenzo Spagnolo Yufei Ma National key laboratory of Laser spatial Information Harbin Institute of TechnologyHarbinChina PolySense Lab Dipartimento Interateneo di FisicaUniversity and Politecnico of BariVia AmendolaBariItaly

Photoacoustic spectroscopy(PAS)as a highly sensitive and selective trace gas detection technique has extremely broad application in many ***,the laser sources currently used in PAS limit the sensing *** to diode laser and quantum cascade laser,the solid-state laser has the merits of high optical power,excellent beam quality,and wide tuning *** we present a long-wave,high-power,wide-tunable,singlelongitudinal-mode solid-state laser used as light source in a PAS sensor for trace gas *** self-built solid-state laser had an emission wavelength of~2μm with Tm:YAP crystal as the gain material,with an excellent wavelength and optical power stability as well as a high beam *** wide wavelength tuning range of 9.44 nm covers the absorption spectra of water and ammonia,with a maximum optical power of~130 mW,allowing dual gas detection with a single laser *** solid-state laser was used as light source in three different photoacoustic detection techniques:standard PAS with microphone,and external-and intra-cavity quartz-enhanced photoacoustic spectroscopy(QEPAS),proving that solid-state laser is an attractive excitation source in photoacoustic spectroscopy.

关键词： power tunable tuning

Impact of Local Climate Zones on the urban Heat and Dry Islands in Beijing:spatial Heterogeneity and Relative Contributions

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Journal of Meteorological Research 2024年第1期38卷 126-137页

作者： Zuofang ZHENG Fu LUO Nana LI Hua GAO Yuanjian YANG Institute of urban Meteorology China Meteorological AdministrationBeijing 100089 School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 key laboratory of urban Meteorology China Meteorological AdministrationBeijing 100089

Based on the building height and density data on a 100-m resolution,hourly 2-m temperature and humidity data at83 automatic weather stations,and gridded local climate zone(LCZ)data on a 120-m resolution in urban Beijing in2020,this study first employs the semivariogram combined with building parameters to calculate spatial correlations and has identified an LCZ grid resolution of 500 m suitable for best usage of the available observation ***,how the spatially heterogeneous LCZs affect and contribute to the canopy urban heat island intensity(UHII)and urban dry island intensity(UDII)are quantitatively *** is found that UHII is high in winter and low in summer with a unimodal diurnal variation while UDI is low in winter but high in summer with a bimodal diurnal *** LCZ with compact mid-rise(open high-rise)buildings exhibits the highest UHII(UDII),followed by the compact high-rise(compact low-rise),while the LCZ of scattered trees presents both the lowest UHII and the lowest *** most significant difference in the UHII(UDII)among the nine LCZ types in the urban area of Beijing is2.62℃(1.1 g kg^(-1)).Area-weighted averaging analysis reveals that the open mid-rise LCZ is the most significant contributor to the UHII(UDII),immediately followed by compact mid-rise(open low-rise),with the least contribution from bare rock or paved(scattered trees).The results also indicate that beyond the intrinsic physical properties of the LCZs of a city,their area proportions cannot be overlooked in evaluating their impact on the UHI and *** quantitatively findings could help urban planners to create a livable urban climate and environment by adjusting the relevant land use.

关键词： local climate zone(LCZ) urban heat island(UHI) urban dry island(UDI) distribution pattern contribution rate Beijing

Reassessing the contributions of terrestrial waters to sea level variations in the South China Sea and its response to alternating ENSO events

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Science China Earth Sciences 2024年第7期67卷 2253-2267页

作者： Pengfei YANG Hok Sum FOK Zhongtian MA MOE key laboratory of Geospace Environment and Geodesy&MNR key laboratory of Geophysical Geodesy School of Geodesy and GeomaticsWuhan UniversityWuhan 430079China Hubei Luojia laboratory Wuhan 730079China Department of Land Surveying and Geo-informatics The Hong Kong Polytechnic UniversityHong Kong 999077China

Regional sea level variability is linked to regional terrestrial water and the El Ni?o-Southern Oscillation(ENSO).This study assessed the relationships between the sea level variations in the South China Sea(SCS)and ENSO,the impact of terrestrial water storage(TWS)on non-steric sea level(NSSL),and the contributions of steric sea level(SSL)and NSSL to sea level anomaly(SLA),*** 2003 to 2015,the SLAs exhibited a long-term trend of 6.65±0.78 mm/yr,which was primarily attributed to the ***,during 2003-2015,ENSO events alternating with varying intensities might also be responsible for the unusually high SLA *** to the SSLs,the NSSLs contributed the seasonal signals to the SLAs,while the NSSLs changes were largely explained by the TWS in the Mekong River Basin at the seasonal scale and in the Pearl River Basin and Red River Basin at other time *** contrast to the TWS,the contributions of precipitation and evapotranspiration were relatively minor.A negative correlation between the sea level variations and ENSO was also found,with cross-correlation coefficients between the oceanic Ni?o index and SLAs/SSLs/NSSLs of -0.36/-0.37/-0.62 with lags of 2/3/2 months,*** findings systematically reassessed the contributions of different components to the sea level *** study provided a benchmark for in-depth analysis of the impacts of terrestrial water and other potential causes on sea level rise in the SCS.

关键词： South China Sea Sea level variations Terrestrial water storage ENSO

Automatic Sensing and Detection for Subway Tunnel Pathologies

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Journal of World Architecture 2024年第1期8卷 54-62页

作者： Xingyu Wang Zhengkun Zhu School of Geomatics and urban spatial informatics Beijing University of Civil Engineering and ArchitectureBeijing 102616China

Subway tunnels often suffer from surface pathologies such as cracks,corrosion,fractures,peeling,water and sand infiltration,and sudden hazards caused by foreign object *** a mobile visual pathology sensing system at the front end of operating trains is a critical measure to ensure subway *** leakage as the typical pathology,a tunnel pathology automatic visual detection method based on Deeplabv3+(ASTPDS)was proposed to achieve automatic and high-precision detection and pixel-level morphology extraction of *** with similar methods,this approach showed significant advantages and achieved a detection accuracy of 93.12%,surpassing FCN and ***,it also exceeded the recall rates for detecting leaks of FCN and U-Net by 8.33%and 8.19%,respectively.

关键词： Visual detection Neural network Health monitoring Image segmentation Water leakage Subway tunnel.