Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized charact...Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.展开更多
Objective:To evaluate the safety,efficacy and feasibility of laser with suction device in mini-percutaneous nephrolithotomy(mini-PCNL).Methods:A retrospective study was conducted including 200 patients who underwent m...Objective:To evaluate the safety,efficacy and feasibility of laser with suction device in mini-percutaneous nephrolithotomy(mini-PCNL).Methods:A retrospective study was conducted including 200 patients who underwent mini-PCNL for renal stones.All patients underwent PCNL using Electro-Medical Systems laser.In addition to the laser in 100 patients,a suction device was used(laser with suction[LWS]).In the other 100,suction device was not used(laser with no additional suction[LOS]).Mini-PCNL was performed using standard technique and Karl Storz minimally invasive PCNL-medium system was used.Primary end point was stone clearance.Results:Both the groups were comparable in terms of demographic data.Mean stone size was 15.24±5.90 mm and 16.16±5.53 mm in LWS and LOS,respectively.Mean Hounsfield unit of stone was 1285.64 and 1206.79 in LWS and LOS,respectively.Operative time was less in LWS group(56.89±19.65 min)as compared to LOS(62.01±28.81 min).At one-month follow-up,radiological complete clearance was 96%in LWS and 92%in LOS.On subgroup analysis of stones larger than 18 mm,the clearance rate was in favour of LWS(85.7%vs.100%)and also the need for nephrostomy placement was less in LWS group.Conclusions:LWS device is safe and efficacious when used with mini-PCNL.For stones greater than 18 mm,it has a better stone free rate as compared to using no suction.展开更多
基金funded by National Natural Science Foundation of China(Grant Nos.42272333,42277147).
文摘Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.
文摘Objective:To evaluate the safety,efficacy and feasibility of laser with suction device in mini-percutaneous nephrolithotomy(mini-PCNL).Methods:A retrospective study was conducted including 200 patients who underwent mini-PCNL for renal stones.All patients underwent PCNL using Electro-Medical Systems laser.In addition to the laser in 100 patients,a suction device was used(laser with suction[LWS]).In the other 100,suction device was not used(laser with no additional suction[LOS]).Mini-PCNL was performed using standard technique and Karl Storz minimally invasive PCNL-medium system was used.Primary end point was stone clearance.Results:Both the groups were comparable in terms of demographic data.Mean stone size was 15.24±5.90 mm and 16.16±5.53 mm in LWS and LOS,respectively.Mean Hounsfield unit of stone was 1285.64 and 1206.79 in LWS and LOS,respectively.Operative time was less in LWS group(56.89±19.65 min)as compared to LOS(62.01±28.81 min).At one-month follow-up,radiological complete clearance was 96%in LWS and 92%in LOS.On subgroup analysis of stones larger than 18 mm,the clearance rate was in favour of LWS(85.7%vs.100%)and also the need for nephrostomy placement was less in LWS group.Conclusions:LWS device is safe and efficacious when used with mini-PCNL.For stones greater than 18 mm,it has a better stone free rate as compared to using no suction.
