As one of the most important urban lifeline systems,a water distribution system can be damaged under a strong earthquake,and the damage cannot easily be located,especially immediately after the event.This often causes...As one of the most important urban lifeline systems,a water distribution system can be damaged under a strong earthquake,and the damage cannot easily be located,especially immediately after the event.This often causes tremendous difficulties to post-earthquake emergency response and recovery activities.This paper proposes a methodology to locate seismic damage to a water distribution system by monitoring water head online at some nodes in the water distribution system.An artificial neural network-based inverse analysis method is developed to estimate the water head variations at all nodes that are not monitored based on the water head variations at the nodes that are monitored.The methodology provides a quick,effective,and practical way to locate seismic damage to a water distribution system.展开更多
The main goal of this study was to investigate the effects of selected ship collision parameter values on the characteristics of the absorbed energy in several ship collision scenarios. Non-linear simulations were per...The main goal of this study was to investigate the effects of selected ship collision parameter values on the characteristics of the absorbed energy in several ship collision scenarios. Non-linear simulations were performed using a finite element method （FEM） to obtain virtual experiment data. In the present research, the size of the side damage from a collision phenomenon were measured and used to verify the numerical configuration together with the calculation results using an empirical equation. Parameters in the external dynamics of a ship collision such as the location of the contact point and velocity of the striking ship were taken into consideration. The internal energy and deformation size on the side structure were discussed further in a comparative study. The effects of the selected parameters on several structural behaviors, namely energy, force, and damage extent were also observed and evaluated in this section. Stiffener on side hull was found to contribute significantly into resistance capability of the target ship against penetration of the striking bow. Remarkable force during penetration was observed to occur when inner shell was crushed as certain velocity was applied in the striking bow.展开更多
The principal of preferred plane analysis is a new research view and model of rock slope engineering geology. It advocates that the rock slope stability, boundary conditions and failure model are controlled by preferr...The principal of preferred plane analysis is a new research view and model of rock slope engineering geology. It advocates that the rock slope stability, boundary conditions and failure model are controlled by preferred planes. Therefore, the problem of slope stability evaluation can be converted into the search for preferred planes and determination of preferred separating bodies. The organic combination of the deterministic model and the indeterministic model can be realized by applying the systems engineering principle and the research model and method of reliability analysis in the quantitative evaluation and prediction of rock slope stability. Finally, the paper presents the case studies of slopes of the Yangtze Gorge Project and the Ma'anshan openpit mine.展开更多
A road network is essential to a country’s transportation and socio-economic development.Its maintenance requires regular monitoring to guide maintenance decisions.Artificial intelligence now enables the automatic de...A road network is essential to a country’s transportation and socio-economic development.Its maintenance requires regular monitoring to guide maintenance decisions.Artificial intelligence now enables the automatic detection of damage,but monitoring a roadway does not end with detection.It also involves estimating the severity and extent of damage and determining the Is index.Therefore,this study allowed the development of a digital tool based on artificial intelligence and image processing for complete monitoring.This consists of detecting the roadway damages,then estimating their severity and extent to calculate the index Is.Four databases were designed from videos of damaged roads collected on different roads in Benin.These data were used in transfer learning to train the YOLOv9 and Roboflow 3.0 Object Detection models.A script was developed to estimate the extent of the degradations,setting a collection speed of 10 km/h,a picking height of 1.20 m and a viewing angle equal to 45˚,covering the entire width of the roadway.Another script determines the index Is by estimating the cracking and deformation indices,with possible corrections depending on the repairs present.The best model obtained,ROCNN4,results from training Roboflow 3.0 Object Detection with the fourth base.It detects 19 classes of degradations with a precision P of 90.8%,a mAP of 91.8%and a recall R of 89.5%.These results pave the way for better road maintenance planning by providing managers with a reliable and automated decision-support tool.They thus help optimize intervention costs and improve the durability of the road network.展开更多
基金National Natural Science Foundation of China under Grant No.59878032
文摘As one of the most important urban lifeline systems,a water distribution system can be damaged under a strong earthquake,and the damage cannot easily be located,especially immediately after the event.This often causes tremendous difficulties to post-earthquake emergency response and recovery activities.This paper proposes a methodology to locate seismic damage to a water distribution system by monitoring water head online at some nodes in the water distribution system.An artificial neural network-based inverse analysis method is developed to estimate the water head variations at all nodes that are not monitored based on the water head variations at the nodes that are monitored.The methodology provides a quick,effective,and practical way to locate seismic damage to a water distribution system.
文摘The main goal of this study was to investigate the effects of selected ship collision parameter values on the characteristics of the absorbed energy in several ship collision scenarios. Non-linear simulations were performed using a finite element method （FEM） to obtain virtual experiment data. In the present research, the size of the side damage from a collision phenomenon were measured and used to verify the numerical configuration together with the calculation results using an empirical equation. Parameters in the external dynamics of a ship collision such as the location of the contact point and velocity of the striking ship were taken into consideration. The internal energy and deformation size on the side structure were discussed further in a comparative study. The effects of the selected parameters on several structural behaviors, namely energy, force, and damage extent were also observed and evaluated in this section. Stiffener on side hull was found to contribute significantly into resistance capability of the target ship against penetration of the striking bow. Remarkable force during penetration was observed to occur when inner shell was crushed as certain velocity was applied in the striking bow.
基金Chen Zhengzhou, Yang Weidong, Wang Peiqing and Wu Hao also took part in this study
文摘The principal of preferred plane analysis is a new research view and model of rock slope engineering geology. It advocates that the rock slope stability, boundary conditions and failure model are controlled by preferred planes. Therefore, the problem of slope stability evaluation can be converted into the search for preferred planes and determination of preferred separating bodies. The organic combination of the deterministic model and the indeterministic model can be realized by applying the systems engineering principle and the research model and method of reliability analysis in the quantitative evaluation and prediction of rock slope stability. Finally, the paper presents the case studies of slopes of the Yangtze Gorge Project and the Ma'anshan openpit mine.
文摘A road network is essential to a country’s transportation and socio-economic development.Its maintenance requires regular monitoring to guide maintenance decisions.Artificial intelligence now enables the automatic detection of damage,but monitoring a roadway does not end with detection.It also involves estimating the severity and extent of damage and determining the Is index.Therefore,this study allowed the development of a digital tool based on artificial intelligence and image processing for complete monitoring.This consists of detecting the roadway damages,then estimating their severity and extent to calculate the index Is.Four databases were designed from videos of damaged roads collected on different roads in Benin.These data were used in transfer learning to train the YOLOv9 and Roboflow 3.0 Object Detection models.A script was developed to estimate the extent of the degradations,setting a collection speed of 10 km/h,a picking height of 1.20 m and a viewing angle equal to 45˚,covering the entire width of the roadway.Another script determines the index Is by estimating the cracking and deformation indices,with possible corrections depending on the repairs present.The best model obtained,ROCNN4,results from training Roboflow 3.0 Object Detection with the fourth base.It detects 19 classes of degradations with a precision P of 90.8%,a mAP of 91.8%and a recall R of 89.5%.These results pave the way for better road maintenance planning by providing managers with a reliable and automated decision-support tool.They thus help optimize intervention costs and improve the durability of the road network.
