Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicato...Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicators of natural disaster risk monitoring are complex.How to achieve intelligent perception and monitoring of natural disaster risk for immovable cultural relics has always been a focus and a challenge for researchers.Based on the analysis of the concepts and issues related to the natural disaster risk of immovable cultural relics,this paper proposes a framework for natural disaster risk monitoring for immovable cultural relics based on the digital twin.This framework focuses on risk monitoring,including the physical entities of natural disaster risk for immovable cultural relics,monitoring indicators,and virtual entity construction.A platform for monitoring the natural disaster risk of immovable cultural relics is proposed.Using the Puzhou Ancient City Site as a test bed,the proposed concept can be used for monitoring the natural disaster risk of immovable cultural relics at different scales.展开更多
This study proposes a refined methodology for controlling building heights in heritage areas.In order to protect the visual integrity of the heritage area,buildings should not obstruct the view from important site poi...This study proposes a refined methodology for controlling building heights in heritage areas.In order to protect the visual integrity of the heritage area,buildings should not obstruct the view from important site points and viewpoints to the periphery.By calculating the building height thresholds that buildings should not obscure the view from each viewpoint,the results of which are weighted and superimposed,and the values are extracted to each building unit as a refined building height control guideline.This study takes the Zhoukoudian area as a case study,applies the refined building height control criterion to the Zhoukoudian Site,and relies on this refined criterion to assess the visual integrity of the Zhoukoudian area,so as to realize the scientific planning and monitoring of the Zhoukoudian area.The refined building height control method can be applied to building height planning and visual landscape protection in large heritage areas.展开更多
针对壁画部分区域被烟熏污染,人眼难以辨别的问题,现有的图像增强算法未能充分考虑壁画影像中的同质区域和空谱信息,因此,本文提出了基于空谱特征联合的烟熏壁画线条增强方法。首先,用地面高光谱成像仪采集壁画的原始高光谱数据进行数...针对壁画部分区域被烟熏污染,人眼难以辨别的问题,现有的图像增强算法未能充分考虑壁画影像中的同质区域和空谱信息,因此,本文提出了基于空谱特征联合的烟熏壁画线条增强方法。首先,用地面高光谱成像仪采集壁画的原始高光谱数据进行数据预处理,选取波段合成真彩色影像并利用多尺度模糊C均值算法进行图像分类,将分类后数据与高光谱影像一一对应得到分区高光谱数据,对各分区数据进行核主成分分析(kernel principal componentanalysis,KPCA)降维获取前几主成分,经平均梯度分析选出分区KPCA的最优主成分影像;其次,分析壁画每幅影像的行列相关性,对预处理后的高光谱影像进行二维主成分分析获取其行、列主成分,经图像重构和平均梯度分析获得二维主成分分析的最优主成分影像;最后,结合光谱特征分析与自适应伽马校正算法得到包含壁画线条增强信息和色彩信息的影像。结果表明,与已有的单尺度Retinex算法、带色彩恢复的多尺度Retinex算法及侯妙乐等(2014)方法进行对比,本方法得到的影像线条完整、清晰,具有更好的对比度。展开更多
建筑物作为城市中最主要的人工地物,其三维模型是智慧地球建设的重要数据支撑,实现精准自动化三维重建至关重要。机载激光雷达(Light Detection and Ranging,LiDAR)技术因具有环境约束小、操作成本低、采集速度快、数据精度高、可全天...建筑物作为城市中最主要的人工地物,其三维模型是智慧地球建设的重要数据支撑,实现精准自动化三维重建至关重要。机载激光雷达(Light Detection and Ranging,LiDAR)技术因具有环境约束小、操作成本低、采集速度快、数据精度高、可全天候获取地物空间信息等优势,已成为自动提取建筑屋顶轮廓线辅助建筑三维重建的主要数据源。首先对建筑屋顶轮廓线提取技术的发展历程进行简要回顾,再根据以往研究内容总结出一套较为通用的技术流程;该技术流程4个关键步骤为点云滤波、建筑物提取、屋顶轮廓线提取和轮廓线规则化;对每一步骤的实现方法、常用算法、发展现状以及面临问题进行详细阐述和对比分析。最后,对本技术面临的挑战和未来发展趋势进行讨论。展开更多
建筑信息模型(building information model, BIM)是我国古建筑遗产数字化保护与发展的重要有效手段,标准元件的多细节层级(level of details, LOD)模型是建立古建筑遗产BIM模型的先决条件,然而目前尚不存在各类元件的多LOD模型标准以及...建筑信息模型(building information model, BIM)是我国古建筑遗产数字化保护与发展的重要有效手段,标准元件的多细节层级(level of details, LOD)模型是建立古建筑遗产BIM模型的先决条件,然而目前尚不存在各类元件的多LOD模型标准以及与之匹配的参数获取方法。文章以古建筑为例,首先基于不同标准元件的几何特征,初步提出了相应的多LOD模型标准以及相应的参数。在此基础上,提出了基于三维激光扫描高保真点云数据的多LOD模型参数获取方法,并以典型结构构件(柱、梁),非典型结构构件(雀替、牌匾)为例,提取了上述构件的多LOD显著几何特征参数信息,建立了实验区的整体BIM模型,为古建筑日常运营维护管理提供可靠和有效的支撑。展开更多
基金National Natural Science Foundation of China(Nos.42171444,42301516)Beijing Natural Science Foundation Project-Municipal Education Commission Joint Fund Project(No.KZ202110016021)Beijing Municipal Education Commission Scientific Research Project-Science and Technology Plan General Project(No.KM202110016005).
文摘Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicators of natural disaster risk monitoring are complex.How to achieve intelligent perception and monitoring of natural disaster risk for immovable cultural relics has always been a focus and a challenge for researchers.Based on the analysis of the concepts and issues related to the natural disaster risk of immovable cultural relics,this paper proposes a framework for natural disaster risk monitoring for immovable cultural relics based on the digital twin.This framework focuses on risk monitoring,including the physical entities of natural disaster risk for immovable cultural relics,monitoring indicators,and virtual entity construction.A platform for monitoring the natural disaster risk of immovable cultural relics is proposed.Using the Puzhou Ancient City Site as a test bed,the proposed concept can be used for monitoring the natural disaster risk of immovable cultural relics at different scales.
文摘This study proposes a refined methodology for controlling building heights in heritage areas.In order to protect the visual integrity of the heritage area,buildings should not obstruct the view from important site points and viewpoints to the periphery.By calculating the building height thresholds that buildings should not obscure the view from each viewpoint,the results of which are weighted and superimposed,and the values are extracted to each building unit as a refined building height control guideline.This study takes the Zhoukoudian area as a case study,applies the refined building height control criterion to the Zhoukoudian Site,and relies on this refined criterion to assess the visual integrity of the Zhoukoudian area,so as to realize the scientific planning and monitoring of the Zhoukoudian area.The refined building height control method can be applied to building height planning and visual landscape protection in large heritage areas.
文摘针对壁画部分区域被烟熏污染,人眼难以辨别的问题,现有的图像增强算法未能充分考虑壁画影像中的同质区域和空谱信息,因此,本文提出了基于空谱特征联合的烟熏壁画线条增强方法。首先,用地面高光谱成像仪采集壁画的原始高光谱数据进行数据预处理,选取波段合成真彩色影像并利用多尺度模糊C均值算法进行图像分类,将分类后数据与高光谱影像一一对应得到分区高光谱数据,对各分区数据进行核主成分分析(kernel principal componentanalysis,KPCA)降维获取前几主成分,经平均梯度分析选出分区KPCA的最优主成分影像;其次,分析壁画每幅影像的行列相关性,对预处理后的高光谱影像进行二维主成分分析获取其行、列主成分,经图像重构和平均梯度分析获得二维主成分分析的最优主成分影像;最后,结合光谱特征分析与自适应伽马校正算法得到包含壁画线条增强信息和色彩信息的影像。结果表明,与已有的单尺度Retinex算法、带色彩恢复的多尺度Retinex算法及侯妙乐等(2014)方法进行对比,本方法得到的影像线条完整、清晰,具有更好的对比度。
文摘建筑物作为城市中最主要的人工地物,其三维模型是智慧地球建设的重要数据支撑,实现精准自动化三维重建至关重要。机载激光雷达(Light Detection and Ranging,LiDAR)技术因具有环境约束小、操作成本低、采集速度快、数据精度高、可全天候获取地物空间信息等优势,已成为自动提取建筑屋顶轮廓线辅助建筑三维重建的主要数据源。首先对建筑屋顶轮廓线提取技术的发展历程进行简要回顾,再根据以往研究内容总结出一套较为通用的技术流程;该技术流程4个关键步骤为点云滤波、建筑物提取、屋顶轮廓线提取和轮廓线规则化;对每一步骤的实现方法、常用算法、发展现状以及面临问题进行详细阐述和对比分析。最后,对本技术面临的挑战和未来发展趋势进行讨论。
文摘建筑信息模型(building information model, BIM)是我国古建筑遗产数字化保护与发展的重要有效手段,标准元件的多细节层级(level of details, LOD)模型是建立古建筑遗产BIM模型的先决条件,然而目前尚不存在各类元件的多LOD模型标准以及与之匹配的参数获取方法。文章以古建筑为例,首先基于不同标准元件的几何特征,初步提出了相应的多LOD模型标准以及相应的参数。在此基础上,提出了基于三维激光扫描高保真点云数据的多LOD模型参数获取方法,并以典型结构构件(柱、梁),非典型结构构件(雀替、牌匾)为例,提取了上述构件的多LOD显著几何特征参数信息,建立了实验区的整体BIM模型,为古建筑日常运营维护管理提供可靠和有效的支撑。
