随着铁路网络规模的迅速扩展及安全管理压力的日益增加,传统人工巡检模式的局限性愈加凸显,促使各铁路局采用无人机技术替代部分人工巡检作业。针对现有铁路无人机巡检过程中存在的管理缺失、安全风险高等问题,本文设计并搭建了一种基于...随着铁路网络规模的迅速扩展及安全管理压力的日益增加,传统人工巡检模式的局限性愈加凸显,促使各铁路局采用无人机技术替代部分人工巡检作业。针对现有铁路无人机巡检过程中存在的管理缺失、安全风险高等问题,本文设计并搭建了一种基于B/S架构的铁路无人机巡检管理平台。该平台结合GIS(Geographic Information System)技术、深度学习算法与数据可视化方法,开发了基础数据管理、飞行计划管理、病害隐患统计监管、信息综合展示等七大核心功能模块,为无人机飞行作业管控、巡检数据管理、铁路设备病害及外部环境隐患排查提供全面技术支持。现场应用表明,铁路无人机巡检管理平台为铁路无人机巡检作业的数字化转型奠定了基础,提升了作业的智能化、标准化与精细化水平,为铁路安全运行提供了保障。展开更多
In the paper a referral system to assist the medical experts in the screening/referral of diabetic retinopathy is suggested. The system has been developed by a sequential use of different existing mathematical techniq...In the paper a referral system to assist the medical experts in the screening/referral of diabetic retinopathy is suggested. The system has been developed by a sequential use of different existing mathematical techniques. These techniques involve speeded up robust features（SURF）, K-means clustering and visual dictionaries（VD）. Three databases are mixed to test the working of the system when the sources are dissimilar. When experiments were performed an area under the curve（AUC） of 0.9343 was attained. The results acquired from the system are promising.展开更多
The characteristics of low-speed fluid streaks occurring under sheared air-water interfaces were examined by means of hydrogen bubble visualization technique. A critical shear condition under which the streaky structu...The characteristics of low-speed fluid streaks occurring under sheared air-water interfaces were examined by means of hydrogen bubble visualization technique. A critical shear condition under which the streaky structure first appears was determined to be u(tau) approximate to 0.19 cm/s. The mean spanwise streak spacing increases with distance from the water surface owing to merging and bursting processes, and a linear relationship describing variation of non-dimensional spacing <(<lambda>+)over bar> versus y(+) was found essentially independent of shear stress on the interface. Values of <(<lambda>+)over bar>, however, are remarkably smaller than their counterparts in the near-wall region of turbulent boundary layers. Though low-speed streaks occur randomly in time and space, the streak spacing exhibits a lognormal probability distribution behavior. A tentative explanation concerning the formation of streaky structure is suggested, and the fact that <(<lambda>+)over bar> takes rather smaller values than that in wall turbulence is briefly discussed.展开更多
随着铁路行业加速向数字化、智能化、信息化转型,传统路基建、运、维监测中的数据管理方法和可视化水平已无法满足未来发展的需求。为解决这一困境,提出1套基于3层浏览器/服务器(Browser/Server,B/S)架构的高铁路基监测展示平台总体构...随着铁路行业加速向数字化、智能化、信息化转型,传统路基建、运、维监测中的数据管理方法和可视化水平已无法满足未来发展的需求。为解决这一困境,提出1套基于3层浏览器/服务器(Browser/Server,B/S)架构的高铁路基监测展示平台总体构建方案,以实现监测数据和工程数据的高效集成;使用Revit软件建立传感器实体模型,基于工业基础类(Industry Foundation Classes,IFC)标准实现传感器属性信息扩展,以Java语言为中介实现IFC文件与MySQL数据库表的精准映射,并通过设置约束关联其他工程信息;利用建筑信息模型(Building Information Modeling,BIM)软件创建集成传感器的高铁路基模型,通过轻量化处理并利用Three.js引擎实现该模型在网页端的可视化展示;通过进一步关联传感器模型和数据库中的监测信息,实现监测数据的实时展示和超限示警定位功能。结果表明:该展示平台的建立可帮助相关人员快速掌握监测项目资料,动态精准评估建、运、维过程中路基的状态,从而达到促进各方交流协作和辅助决策实施的目的。展开更多
文摘随着铁路网络规模的迅速扩展及安全管理压力的日益增加,传统人工巡检模式的局限性愈加凸显,促使各铁路局采用无人机技术替代部分人工巡检作业。针对现有铁路无人机巡检过程中存在的管理缺失、安全风险高等问题,本文设计并搭建了一种基于B/S架构的铁路无人机巡检管理平台。该平台结合GIS(Geographic Information System)技术、深度学习算法与数据可视化方法,开发了基础数据管理、飞行计划管理、病害隐患统计监管、信息综合展示等七大核心功能模块,为无人机飞行作业管控、巡检数据管理、铁路设备病害及外部环境隐患排查提供全面技术支持。现场应用表明,铁路无人机巡检管理平台为铁路无人机巡检作业的数字化转型奠定了基础,提升了作业的智能化、标准化与精细化水平,为铁路安全运行提供了保障。
文摘In the paper a referral system to assist the medical experts in the screening/referral of diabetic retinopathy is suggested. The system has been developed by a sequential use of different existing mathematical techniques. These techniques involve speeded up robust features（SURF）, K-means clustering and visual dictionaries（VD）. Three databases are mixed to test the working of the system when the sources are dissimilar. When experiments were performed an area under the curve（AUC） of 0.9343 was attained. The results acquired from the system are promising.
基金The project supported by the National Natural Science Foundation of China (19672070)
文摘The characteristics of low-speed fluid streaks occurring under sheared air-water interfaces were examined by means of hydrogen bubble visualization technique. A critical shear condition under which the streaky structure first appears was determined to be u(tau) approximate to 0.19 cm/s. The mean spanwise streak spacing increases with distance from the water surface owing to merging and bursting processes, and a linear relationship describing variation of non-dimensional spacing <(<lambda>+)over bar> versus y(+) was found essentially independent of shear stress on the interface. Values of <(<lambda>+)over bar>, however, are remarkably smaller than their counterparts in the near-wall region of turbulent boundary layers. Though low-speed streaks occur randomly in time and space, the streak spacing exhibits a lognormal probability distribution behavior. A tentative explanation concerning the formation of streaky structure is suggested, and the fact that <(<lambda>+)over bar> takes rather smaller values than that in wall turbulence is briefly discussed.
文摘随着铁路行业加速向数字化、智能化、信息化转型,传统路基建、运、维监测中的数据管理方法和可视化水平已无法满足未来发展的需求。为解决这一困境,提出1套基于3层浏览器/服务器(Browser/Server,B/S)架构的高铁路基监测展示平台总体构建方案,以实现监测数据和工程数据的高效集成;使用Revit软件建立传感器实体模型,基于工业基础类(Industry Foundation Classes,IFC)标准实现传感器属性信息扩展,以Java语言为中介实现IFC文件与MySQL数据库表的精准映射,并通过设置约束关联其他工程信息;利用建筑信息模型(Building Information Modeling,BIM)软件创建集成传感器的高铁路基模型,通过轻量化处理并利用Three.js引擎实现该模型在网页端的可视化展示;通过进一步关联传感器模型和数据库中的监测信息,实现监测数据的实时展示和超限示警定位功能。结果表明:该展示平台的建立可帮助相关人员快速掌握监测项目资料,动态精准评估建、运、维过程中路基的状态,从而达到促进各方交流协作和辅助决策实施的目的。
