The unconsolidated soils of the Indo-Gangetic Plains(IGP)contribute significantly to the amplification of seismic damage during earthquakes.Site-specific effects play a critical role in intensifying groundmotion and s...The unconsolidated soils of the Indo-Gangetic Plains(IGP)contribute significantly to the amplification of seismic damage during earthquakes.Site-specific effects play a critical role in intensifying groundmotion and shaping the spatial distribution of seismic hazards.This study aims to investigate the spatial variability of seismic hazards using geophysical and geological parameters such as lithology,shear wave velocity,soil texture,basement depth,and proximity to fault lines.Training data were derived from common hazard points identified in earthquake catalogues.Several machine learning(ML)models,including Logistic Regression(LR),K-Nearest Neighbors,Random Forest,and Decision Tree,were employed to analyze the variability of seismic hazards in North Bihar.These models achieved classification accuracies of 65%,67%,87%,and 77%,respectively,in identifying hazard patterns.Thegeneralized hazard map generated using the Random Forest algorithm can serve as a valuable tool for estimating the extent of seismic risk when integrated with ground motion parameters following an earthquake.展开更多
Single Pilot Operations(SPO)for commercial aircraft has been planned to be the core development direction of the next generation civil aircraft operating mode in 2030 by International Civil Aviation Organization(ICAO)...Single Pilot Operations(SPO)for commercial aircraft has been planned to be the core development direction of the next generation civil aircraft operating mode in 2030 by International Civil Aviation Organization(ICAO).Safety is a key airworthiness factor in the design of commercial aircraft.However,the increasing system integrity and a higher degree of air-ground task collaboration make safety the main challenge in implementing SPO,it is extremely hard to effectively identify potential hazard elements in the system using the traditional dual-pilot safety analysis methods.To address the above problems,this paper introduces the hazard pattern mining method and proposes different hazard pattern mining algorithms to identify potential hazard patterns implied in air-ground resource sharing,function fusion,and task collaboration.And a model-based simulation verification platform has been proposed to complete the safety assessment and verification of SPO air-ground task collaboration.It can provide a theoretical basis of safety analysis for further developing commercial aircraft based on SPO mode.展开更多
Various types of geological hazards exist in the South China Sea. In dynamics sense, they can be categorized into 5 principal genetic types related to effects of hydraulic dynamics, gaseous activity, soil mechanics, g...Various types of geological hazards exist in the South China Sea. In dynamics sense, they can be categorized into 5 principal genetic types related to effects of hydraulic dynamics, gaseous activity, soil mechanics, gravity and tectonism, respectively. Integrated analyses indicate that the geological hazards associated with volcanoes, earthquakes and fractures are mainly distributed in tectonically active regions, whereas those resulting from mudflows, landslides and diapirs are usually concentrated in the region of slope, that shallow gas, high pressure gas pockets and soft intercalations are major potential geological hazards in the inner shelf, and that strong hydraulic dynamics, especially storm tide, is one of the major causes of geological hazards in the littoral areas. The geological hazards that occurred in the South China Sea are also characterized by periodicity, succession and, to a certain extent, unpredictability in addition to regionalization.展开更多
文摘The unconsolidated soils of the Indo-Gangetic Plains(IGP)contribute significantly to the amplification of seismic damage during earthquakes.Site-specific effects play a critical role in intensifying groundmotion and shaping the spatial distribution of seismic hazards.This study aims to investigate the spatial variability of seismic hazards using geophysical and geological parameters such as lithology,shear wave velocity,soil texture,basement depth,and proximity to fault lines.Training data were derived from common hazard points identified in earthquake catalogues.Several machine learning(ML)models,including Logistic Regression(LR),K-Nearest Neighbors,Random Forest,and Decision Tree,were employed to analyze the variability of seismic hazards in North Bihar.These models achieved classification accuracies of 65%,67%,87%,and 77%,respectively,in identifying hazard patterns.Thegeneralized hazard map generated using the Random Forest algorithm can serve as a valuable tool for estimating the extent of seismic risk when integrated with ground motion parameters following an earthquake.
基金supported by Natural Science Foundation of Shanghai(20ZR1427800)New Young Teachers Launch Program of Shanghai Jiao Tong University(20X100040036).
文摘Single Pilot Operations(SPO)for commercial aircraft has been planned to be the core development direction of the next generation civil aircraft operating mode in 2030 by International Civil Aviation Organization(ICAO).Safety is a key airworthiness factor in the design of commercial aircraft.However,the increasing system integrity and a higher degree of air-ground task collaboration make safety the main challenge in implementing SPO,it is extremely hard to effectively identify potential hazard elements in the system using the traditional dual-pilot safety analysis methods.To address the above problems,this paper introduces the hazard pattern mining method and proposes different hazard pattern mining algorithms to identify potential hazard patterns implied in air-ground resource sharing,function fusion,and task collaboration.And a model-based simulation verification platform has been proposed to complete the safety assessment and verification of SPO air-ground task collaboration.It can provide a theoretical basis of safety analysis for further developing commercial aircraft based on SPO mode.
文摘Various types of geological hazards exist in the South China Sea. In dynamics sense, they can be categorized into 5 principal genetic types related to effects of hydraulic dynamics, gaseous activity, soil mechanics, gravity and tectonism, respectively. Integrated analyses indicate that the geological hazards associated with volcanoes, earthquakes and fractures are mainly distributed in tectonically active regions, whereas those resulting from mudflows, landslides and diapirs are usually concentrated in the region of slope, that shallow gas, high pressure gas pockets and soft intercalations are major potential geological hazards in the inner shelf, and that strong hydraulic dynamics, especially storm tide, is one of the major causes of geological hazards in the littoral areas. The geological hazards that occurred in the South China Sea are also characterized by periodicity, succession and, to a certain extent, unpredictability in addition to regionalization.
