Raster type of forest inventory data with site and growing stock variables interpreted for small squareshaped grid cells are increasingly available for forest planning.In Finland,there are two sources of this type of ...Raster type of forest inventory data with site and growing stock variables interpreted for small squareshaped grid cells are increasingly available for forest planning.In Finland,there are two sources of this type of lattice data:the multisource national forest inventory and the inventory that is based on airborne laser scanning(ALS).In both cases,stand variables are interpreted for 16 m×16 m cells.Both data sources cover all private forests of Finland and are freely available for forest planning.This study analyzed different ways to use the ALS raster data in forest planning.The analyses were conducted for a grid of 375×375 cells(140,625 cells,of which 97,893 were productive forest).The basic alternatives were to use the cells as calculation units throughout the planning process,or aggregate the cells into segments before planning calculations.The use of cells made it necessary to use spatial optimization to aggregate cuttings and other treatments into blocks that were large enough for the practical implementation of the plan.In addition,allowing premature cuttings in a part of the cells was a prerequisite for compact treatment areas.The use of segments led to 5–9%higher growth predictions than calculations based on cells.In addition,the areas of the most common fertility classes were overestimated and the areas of rare site classes were underestimated when segments were used.The shape of the treatment blocks was more irregular in cell-based planning.Using cells as calculation units instead of segments led to 20 times longer computing time of the whole planning process than the use of segments when the number of grid cells was approximately 100,000.展开更多
The purpose of this paper is to study the RS data web services and related subjects of data storage and data management. Based on an analysis of the present situation and development trend of storage and management of...The purpose of this paper is to study the RS data web services and related subjects of data storage and data management. Based on an analysis of the present situation and development trend of storage and management of raster data and web service technology, a management and service system architecture for Remote Sensing raster data based on web service technologies was developed, the implementation methodologies of the key technology of the system were explored and a prototype of the system was illustrated.展开更多
This paper studies urban waterlog_draining decision support system based on the 4D data fusion technique.4D data includes DEM,DOQ,DLG and DRG.It supplies entire databases for waterlog forecast and analysis together wi...This paper studies urban waterlog_draining decision support system based on the 4D data fusion technique.4D data includes DEM,DOQ,DLG and DRG.It supplies entire databases for waterlog forecast and analysis together with non_spatial fundamental database.Data composition and reasoning are two key steps of 4D data fusion.Finally,this paper gives a real case: Ezhou Waterlog_Draining Decision Support System (EWDSS) with two application models,i.e.,DEM application model,water generating and draining model.展开更多
The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from min...The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from mine to geology and their complicated relations, and proposes several new kinds of spatial objects including cross-section, column body and digital surface model to represent some special spatial phenomena like tunnels and irregular surfaces of an ore body. An integrated data structure including vector, raster and object-oriented data models is used to represent various 3-D spatial objects and their relations. The integrated data structure and object-oriented data model can be used as bases to design and realize a 3-D geographic information system.展开更多
【目的】建筑物是地图上的重要组成要素,其形状识别既是空间认知和相似关系领域的研究热点和难点,也可以为地图制图综合的自动化实现提供技术支持。针对目前基于监督学习的栅格化建筑物形状识别方法需要大量标注样本的缺陷,本文融合了...【目的】建筑物是地图上的重要组成要素,其形状识别既是空间认知和相似关系领域的研究热点和难点,也可以为地图制图综合的自动化实现提供技术支持。针对目前基于监督学习的栅格化建筑物形状识别方法需要大量标注样本的缺陷,本文融合了对比学习的自监督特征提取策略和迁移学习的监督分类技术,提出了一种基于对比迁移模型(Contrastive Learning Transfer Model,CLTM)的栅格化建筑物形状识别方法。【方法】首先,提取建筑物的形状并对其进行二值化和尺寸标准化处理,消除尺度与像素等因素的干扰;然后,构建对比学习模型对建筑物形状进行编码,获得高维特征向量,利用设计的对比损失函数优化模型;最后,以对比损失进行梯度更新,使用迁移参数预测建筑物形状以验证模型性能。【结果】实验结果表明,该方法的建筑物形状分类准确率达到93.79%,高于AlexNet方法的93.11%,但低于ResNet50方法的96.10%。在形状识别应用中运用t-SNE可视化技术,清晰展示了不同形状类别在特征空间中的聚类趋势,直观显示了形状识别效果,进一步验证了模型的有效性。【结论】尽管该方法的分类准确率低于监督的ResNet50方法,但该模型显著减少了分类准确率对大量标注数据的依赖,同时降低了人工视觉偏差的影响,是一种有效可靠的建筑物识别方法。展开更多
基金Open access funding provided by University of Eastern Finland (UEF) including Kuopio University Hospital
文摘Raster type of forest inventory data with site and growing stock variables interpreted for small squareshaped grid cells are increasingly available for forest planning.In Finland,there are two sources of this type of lattice data:the multisource national forest inventory and the inventory that is based on airborne laser scanning(ALS).In both cases,stand variables are interpreted for 16 m×16 m cells.Both data sources cover all private forests of Finland and are freely available for forest planning.This study analyzed different ways to use the ALS raster data in forest planning.The analyses were conducted for a grid of 375×375 cells(140,625 cells,of which 97,893 were productive forest).The basic alternatives were to use the cells as calculation units throughout the planning process,or aggregate the cells into segments before planning calculations.The use of cells made it necessary to use spatial optimization to aggregate cuttings and other treatments into blocks that were large enough for the practical implementation of the plan.In addition,allowing premature cuttings in a part of the cells was a prerequisite for compact treatment areas.The use of segments led to 5–9%higher growth predictions than calculations based on cells.In addition,the areas of the most common fertility classes were overestimated and the areas of rare site classes were underestimated when segments were used.The shape of the treatment blocks was more irregular in cell-based planning.Using cells as calculation units instead of segments led to 20 times longer computing time of the whole planning process than the use of segments when the number of grid cells was approximately 100,000.
基金The study subject of the National "863" Plan-The study of distributed management technology of multi-structured forestry resourcedata in forestry center(No. 2006AA10Z240).
文摘The purpose of this paper is to study the RS data web services and related subjects of data storage and data management. Based on an analysis of the present situation and development trend of storage and management of raster data and web service technology, a management and service system architecture for Remote Sensing raster data based on web service technologies was developed, the implementation methodologies of the key technology of the system were explored and a prototype of the system was illustrated.
文摘This paper studies urban waterlog_draining decision support system based on the 4D data fusion technique.4D data includes DEM,DOQ,DLG and DRG.It supplies entire databases for waterlog forecast and analysis together with non_spatial fundamental database.Data composition and reasoning are two key steps of 4D data fusion.Finally,this paper gives a real case: Ezhou Waterlog_Draining Decision Support System (EWDSS) with two application models,i.e.,DEM application model,water generating and draining model.
基金Project supported by the National Natural Science Foundation of China (No.49871066)
文摘The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from mine to geology and their complicated relations, and proposes several new kinds of spatial objects including cross-section, column body and digital surface model to represent some special spatial phenomena like tunnels and irregular surfaces of an ore body. An integrated data structure including vector, raster and object-oriented data models is used to represent various 3-D spatial objects and their relations. The integrated data structure and object-oriented data model can be used as bases to design and realize a 3-D geographic information system.
文摘【目的】建筑物是地图上的重要组成要素,其形状识别既是空间认知和相似关系领域的研究热点和难点,也可以为地图制图综合的自动化实现提供技术支持。针对目前基于监督学习的栅格化建筑物形状识别方法需要大量标注样本的缺陷,本文融合了对比学习的自监督特征提取策略和迁移学习的监督分类技术,提出了一种基于对比迁移模型(Contrastive Learning Transfer Model,CLTM)的栅格化建筑物形状识别方法。【方法】首先,提取建筑物的形状并对其进行二值化和尺寸标准化处理,消除尺度与像素等因素的干扰;然后,构建对比学习模型对建筑物形状进行编码,获得高维特征向量,利用设计的对比损失函数优化模型;最后,以对比损失进行梯度更新,使用迁移参数预测建筑物形状以验证模型性能。【结果】实验结果表明,该方法的建筑物形状分类准确率达到93.79%,高于AlexNet方法的93.11%,但低于ResNet50方法的96.10%。在形状识别应用中运用t-SNE可视化技术,清晰展示了不同形状类别在特征空间中的聚类趋势,直观显示了形状识别效果,进一步验证了模型的有效性。【结论】尽管该方法的分类准确率低于监督的ResNet50方法,但该模型显著减少了分类准确率对大量标注数据的依赖,同时降低了人工视觉偏差的影响,是一种有效可靠的建筑物识别方法。
