This paper presents a voxel-based region growing method for automatic road surface extraction from mobile laser scanning point clouds in an expressway environment.The proposed method has three major steps:constructing...This paper presents a voxel-based region growing method for automatic road surface extraction from mobile laser scanning point clouds in an expressway environment.The proposed method has three major steps:constructing a voxel model;extracting the road surface points by employing the voxel-based segmentation algorithm;refining the road boundary using the curb-based segmentation algorithm.To evaluate the accuracy of the proposed method,the two-point cloud datasets of two typical test sites in an expressway environment consisting of flat and bumpy surfaces with a high slope were used.The proposed algorithm extracted the road surface successfully with high accuracy.There was an average recall of 99.5%,the precision was 96.3%,and the F1 score was 97.9%.From the extracted road surface,a framework for the estimation of road roughness was proposed.Good agreement was achieved when comparing the results of the road roughness map with the visual image,indicating the feasibility and effectiveness of the proposed framework.展开更多
In order to obtain a compact and exact representation of 2D range scans,UKF(unscented Kalman filter) and CDKF(central difference Kalman filter) were proposed for extracting the breakpoint of the laser data. Line extra...In order to obtain a compact and exact representation of 2D range scans,UKF(unscented Kalman filter) and CDKF(central difference Kalman filter) were proposed for extracting the breakpoint of the laser data. Line extraction was performed in every continuous breakpoint region by detecting the optimal angle and the optimal distance in polar coordinates,and every breakpoint area was constructed with two points. As a proof to the method,an experiment was performed by a mobile robot equipped with one SICK laser rangefinder,and the results of UKF/CDKF in breakpoint detection and line extraction were compared with those of the EKF(extended Kalman filter) . The results show that the exact geometry of the raw laser data of the environments can be obtained by segmented raw measurements(combining the proposed breakpoint detection approach with the line extraction method) ,and method UKF is the best one compared with CDKF and EKF.展开更多
AIM： To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection （LCM）. METHODS： Tissues are complex structures compri...AIM： To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection （LCM）. METHODS： Tissues are complex structures comprised of a heterogeneous population of interconnected cells. LCM offers a method of isolating a single cell type from specific regions of a tissue section. LCM is an essential approach used in conjunction with molecular analysis to study the functional interaction of cells in their native tissue environment. The process of labeling and acquiring cells by LCM prior to mRNA isolation can be elaborate, thereby subjecting the RNA to considerable degradation. Kupffer cell labeling is achieved by injecting India ink intravenously, thus circumventing the need for in vitro staining. The significance of this novel approach was validated using a cholestatic liver injury model. RESULTS： mRNA extracted from the microdissected cell population displayed marked increases in colonystimulating factor-1 receptor and Kupffer cell receptor message expression, which demonstrated Kupffer cell enrichment. Gene expression by Kupffer ceils derived from bile-duct-ligated, versus sham-operated, mice was compared. Microarray analysis revealed a significant （2.5-fold, q value 〈 10） change in 493 genes. Based on this fold-change and a standardized PubMed search, 10 genes were identified that were relevant to the ability of Kupffer cells to suppress liver injury. CONCLUSION; The methodology outlined herein provides an approach to isolating high quality RNA from Kupffer cells, without altering the tissue integrity.展开更多
基金Project(SIIT-AUN/SEED-Net-G-S1 Y16/018)supported by the Doctoral Asean University Network ProgramProject supported by the Metropolitan Expressway Co.,Ltd.,Japan+2 种基金Project supported by Elysium Co.Ltd.Project supported by Aero Asahi Corporation,Co.,Ltd.Project supported by the Expressway Authority of Thailand。
文摘This paper presents a voxel-based region growing method for automatic road surface extraction from mobile laser scanning point clouds in an expressway environment.The proposed method has three major steps:constructing a voxel model;extracting the road surface points by employing the voxel-based segmentation algorithm;refining the road boundary using the curb-based segmentation algorithm.To evaluate the accuracy of the proposed method,the two-point cloud datasets of two typical test sites in an expressway environment consisting of flat and bumpy surfaces with a high slope were used.The proposed algorithm extracted the road surface successfully with high accuracy.There was an average recall of 99.5%,the precision was 96.3%,and the F1 score was 97.9%.From the extracted road surface,a framework for the estimation of road roughness was proposed.Good agreement was achieved when comparing the results of the road roughness map with the visual image,indicating the feasibility and effectiveness of the proposed framework.
基金Project(2003AA1Z2130)supported by the National High-Tech Research and Development Program of ChinaProject(2005C11001-02)supported by the Science and Technology Project of Zhejiang Province,China
文摘In order to obtain a compact and exact representation of 2D range scans,UKF(unscented Kalman filter) and CDKF(central difference Kalman filter) were proposed for extracting the breakpoint of the laser data. Line extraction was performed in every continuous breakpoint region by detecting the optimal angle and the optimal distance in polar coordinates,and every breakpoint area was constructed with two points. As a proof to the method,an experiment was performed by a mobile robot equipped with one SICK laser rangefinder,and the results of UKF/CDKF in breakpoint detection and line extraction were compared with those of the EKF(extended Kalman filter) . The results show that the exact geometry of the raw laser data of the environments can be obtained by segmented raw measurements(combining the proposed breakpoint detection approach with the line extraction method) ,and method UKF is the best one compared with CDKF and EKF.
基金Supported by NIH Grant DK068097funds provided by Rhode Island Hospital+1 种基金the Deutsche Forschungsgemeinschaft grant (DFG) grant GE1193/1-1NIH COBRE Award (RR-P20 RR17695)
文摘AIM： To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection （LCM）. METHODS： Tissues are complex structures comprised of a heterogeneous population of interconnected cells. LCM offers a method of isolating a single cell type from specific regions of a tissue section. LCM is an essential approach used in conjunction with molecular analysis to study the functional interaction of cells in their native tissue environment. The process of labeling and acquiring cells by LCM prior to mRNA isolation can be elaborate, thereby subjecting the RNA to considerable degradation. Kupffer cell labeling is achieved by injecting India ink intravenously, thus circumventing the need for in vitro staining. The significance of this novel approach was validated using a cholestatic liver injury model. RESULTS： mRNA extracted from the microdissected cell population displayed marked increases in colonystimulating factor-1 receptor and Kupffer cell receptor message expression, which demonstrated Kupffer cell enrichment. Gene expression by Kupffer ceils derived from bile-duct-ligated, versus sham-operated, mice was compared. Microarray analysis revealed a significant （2.5-fold, q value 〈 10） change in 493 genes. Based on this fold-change and a standardized PubMed search, 10 genes were identified that were relevant to the ability of Kupffer cells to suppress liver injury. CONCLUSION; The methodology outlined herein provides an approach to isolating high quality RNA from Kupffer cells, without altering the tissue integrity.
