Taking TM images, SPOT photos and DEM images as the basic information, this paper had not only put forward a kind of manual controlled computer-automatic extraction method, but also completed the task of extracting th...Taking TM images, SPOT photos and DEM images as the basic information, this paper had not only put forward a kind of manual controlled computer-automatic extraction method, but also completed the task of extracting the main types of ground objects in the Three Gorges Reservoir area under relatively high accuracy, after finishing such preprocessing tasks as correcting the topographical spectrum and synthesizing the data. Taking the specialized image analysis software-eCognition as the platform, the research achieved the goal of classifying through choosing samples, picking out the best wave bands, and producing the identifying functions. At the same time the extraction process partly dispelled the influence of such phenomena as the same thing with different spectrums, different things with the same spectrum, border transitions, etc. The research did certain exploration in the aspect of technological route and method of using automatic extraction of the remote sensing image to obtain the information of land cover for the regions whose ground objects have complicated spectrums.展开更多
A novel cast shadow detection approach was proposed.A stereo vision system was used to capture images instead of traditional single camera.It was based on an assumption that cast shadows were on a special plane.The im...A novel cast shadow detection approach was proposed.A stereo vision system was used to capture images instead of traditional single camera.It was based on an assumption that cast shadows were on a special plane.The image obtained from one camera was inversely projected to the plane and then transformed to the view from another camera.The points on the plane shared the same position between original image and the transformed image.As a result,the cast shadows can be detected.In order to improve the efficiency of cast shadow detection and decrease computational complexity,the obvious object areas in CIELAB color space were removed and the potential shadow areas were obtained.Experimental results demonstrate that the proposed approach can detect cast shadows accurately even under various illuminations.展开更多
Hyperspectral remote sensing has become one of the research frontiers in ground object identification and classification. On the basis of reviewing the application of hyperspectral remote sensing in identification and...Hyperspectral remote sensing has become one of the research frontiers in ground object identification and classification. On the basis of reviewing the application of hyperspectral remote sensing in identification and classification of ground objects at home and abroad. The research results of identification and classification of forest tree species, grassland and urban land features were summarized. Then the researches of classification methods were summarized. Finally the prospects of hyperspectral remote sensing in ground object identification and classification were prospected.展开更多
针对现有的三维视觉定位方法依赖昂贵传感器设备、系统成本高且在复杂多目标定位中准确度和鲁棒性不足的问题,提出一种基于单目图像的多目标三维视觉定位方法。该方法结合自然语言描述,在单个RGB图像中实现对多个三维目标的识别。为此,...针对现有的三维视觉定位方法依赖昂贵传感器设备、系统成本高且在复杂多目标定位中准确度和鲁棒性不足的问题,提出一种基于单目图像的多目标三维视觉定位方法。该方法结合自然语言描述,在单个RGB图像中实现对多个三维目标的识别。为此,构建一个多目标视觉定位数据集Mmo3DRefer,并设计跨模态匹配网络TextVizNet。TextVizNet通过预训练的单目检测器生成目标的三维边界框,并借助信息融合模块与信息对齐模块实现视觉与语言信息的深度整合,进而实现文本指导下的多目标三维检测。与CORE-3DVG(Contextual Objects and RElations for 3D Visual Grounding)、3DVG-Transformer和Multi3DRefer(Multiple 3D object Referencing dataset and task)等5种方法对比的实验结果表明,与次优方法Multi3DRefer相比,TextVizNet在Mmo3DRefer数据集上的F1-score、精确度和召回率分别提升了8.92%、8.39%和9.57%,显著提升了复杂场景下基于文本的多目标定位精度,为自动驾驶和智能机器人等实际应用提供了有效支持。展开更多
[目的/意义]玉米是主要粮食作物,果穗作为玉米关键表型性状,其形态、大小及颜色特征能够有效反映植株生长状态及潜在产量。传统的田间玉米果穗检测依赖人工,效率低且劳动强度大。随着密植栽培模式的推广,玉米冠层结构愈发密集,人工进入...[目的/意义]玉米是主要粮食作物,果穗作为玉米关键表型性状,其形态、大小及颜色特征能够有效反映植株生长状态及潜在产量。传统的田间玉米果穗检测依赖人工,效率低且劳动强度大。随着密植栽培模式的推广,玉米冠层结构愈发密集,人工进入田间开展果穗测量不仅操作困难,还容易对植株造成机械损伤,进一步限制了数据的准确性与代表性。因此,亟需高效的自动化检测技术。[方法]为实现复杂田间环境下玉米果穗的高效精准检测,提出一种基于改进YOLO11n(You Only Look Once 11)的CornYOLO模型。创新性地采用无人车搭载全景相机进行图像采集,构建了高质量的田间数据集,并在此基础上提出了3项核心模型改进:1)采用动态点空间注意力的跨阶段部分网络(Cross Stage Partial Network with Dynamic Pointwise Spatial Attention,C2PDA)以提升对遮挡目标的识别鲁棒性;2)引入特征优化模块(Feature Refinement Module,FRM)以增强多尺度目标检测能力;3)使用统一交并比(Unified Intersection Over Union,UIoU)损失函数以优化边界框回归精度。为作物田间表型高通量获取提供了一种从数据采集到智能识别的端到端解决方案。[结果和讨论]CornYOLO在复杂田间环境下表现出优异的检测性能,在验证集上mAP@50达到89.3%,相较于YOLO11n,F1分数提升2.5个百分点。相较于其余基线模型,其mAP@50提升显著,最高达12.6个百分点。消融实验表明,C2PDA、FRM与UIoU这3个模块均对性能提升有积极贡献,其中C2PDA作用最为关键。[结论]CornYOLO模型能够高效精准地识别田间玉米果穗,为玉米育种表型分析和产量预测提供可靠的技术支持,推动玉米果穗信息提取的智能化发展。展开更多
The neutral grounding mode of medium-voltage distribution network decides the reliability, overvoltage, relay protection and electrical safety. Therefore, a comprehensive consideration of the reliability, safety and e...The neutral grounding mode of medium-voltage distribution network decides the reliability, overvoltage, relay protection and electrical safety. Therefore, a comprehensive consideration of the reliability, safety and economy is particularly important for the decision of neutral grounding mode. This paper proposes a new decision method of neutral point grounding mode for mediumvoltage distribution network. The objective function is constructed for the decision according the life cycle cost. The reliability of the neutral point grounding mode is taken into account through treating the outage cost as an operating cost. The safety condition of the neutral point grounding mode is preserved as the constraint condition of decision models, so the decision method can generate the most economical and reliable scheme of neutral point grounding mode within a safe limit. The example is used to verify the feasibility and effectiveness of the decision method.展开更多
According to the frequency property of Phasedarray ground penetrating radar(PGPR),this paper gives a frequency point slice method based on Wigner time-frequency analysis.This method solves the problem of analysis for ...According to the frequency property of Phasedarray ground penetrating radar(PGPR),this paper gives a frequency point slice method based on Wigner time-frequency analysis.This method solves the problem of analysis for the PGPR's superposition data and makes detecting outcome simpler and detecting target more recognizable.At last,the analytical results of road test data of the Three Gorges prove the analytical method efficient.展开更多
In the last century, there has been a significant development in the evaluation of methods to predict ground movement due to underground extraction. Some remarkable developments in three-dimensional computational meth...In the last century, there has been a significant development in the evaluation of methods to predict ground movement due to underground extraction. Some remarkable developments in three-dimensional computational methods have been supported in civil engineering, subsidence engineering and mining engineering practice. However, ground movement problem due to mining extraction sequence is effectively four dimensional （4D）. A rational prediction is getting more and more important for long-term underground mining planning. Hence, computer-based analytical methods that realistically simulate spatially distributed time-dependent ground movement process are needed for the reliable long-term underground mining planning to minimize the surface environmental damages. In this research, a new computational system is developed to simulate four-dimensional （4D） ground movement by combining a stochastic medium theory, Knothe time-delay model and geographic information system （GIS） technology. All the calculations are implemented by a computational program, in which the components of GIS are used to fulfill the spatial-temporal analysis model. In this paper a tight coupling strategy based on component object model of GIS technology is used to overcome the problems of complex three-dimensional extraction model and spatial data integration. Moreover, the implementation of computational of the interfaces of the developed tool is described. The GIS based developed tool is validated by two study cases. The developed computational tool and models are achieved within the GIS system so the effective and efficient calculation methodology can be obtained, so the simulation problems of 4D ground movement due to underground mining extraction sequence can be solved by implementation of the developed tool in GIS.展开更多
The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spec...The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spectrum to select ground motion records based on the target spectrum.This research demonstrates the influence of adopting different weighted factors for various period ranges during matching selected ground motions with the target hazard spectrum.The event data from the Next Generation Attenuation West 2(NGA-West 2)database is used as the basis for ground motion selection,and hazard de-aggregation is conducted to estimate the event parameters of interest,which are then used to construct the target intensity measure(IM).The target IMs are then used to select ground motion records with different weighted vector-valued objective functions.The weights are altered to account for the relative importance of IM in accordance with the structural analysis application of steel moment resisting frame(SMRF)buildings.Instead of an ordinary objective function for the matching spectrum,a novel model is introduced and compared with the conventional cost function.The results indicate that when applying the new cost function for ground motion selection,it places higher demands on structures compared to the conventional cost function.Moreover,submitting more weights to the first-mode period of structures increases engineering demand parameters.Findings demonstrate that weight factors allocated to different period ranges can successfully account for period elongation and higher mode effects.展开更多
Generating ground truth data for developing object detection algorithms of intelligent surveillance systems is a considerably important yet time-consuming task; therefore, a user-friendly tool to annotate videos effic...Generating ground truth data for developing object detection algorithms of intelligent surveillance systems is a considerably important yet time-consuming task; therefore, a user-friendly tool to annotate videos efficiently and accurately is required. In this paper, the development of a semi-automatic video annotation tool is described. For efficiency, the developed tool can automatically generate the initial annotation data for the input videos utilizing automatic object detection modules, which are developed independently and registered in the tool. To guarantee the accuracy of the ground truth data, the system also has several user-friendly functions to help users check and edit the initial annotation data generated by the automatic object detection modules. According to the experiment＇s results, employing the developed annotation tool is considerably beneficial for reducing annotation time; when compared to manual annotation schemes, using the tool resulted in an annotation time reduction of up to 2.3 times.展开更多
海岸带是陆地、海洋、大气相互作用的地球生态关键带,汇集了大量的物质和能量,正经历着高强度人类活动、全球气候变化和物种入侵的叠加影响,面临着前所未有的挑战。遥感科学与技术是全面、系统、深入监测海岸带资源、生态、环境的有效...海岸带是陆地、海洋、大气相互作用的地球生态关键带,汇集了大量的物质和能量,正经历着高强度人类活动、全球气候变化和物种入侵的叠加影响,面临着前所未有的挑战。遥感科学与技术是全面、系统、深入监测海岸带资源、生态、环境的有效手段。本文从海岸带独特性和遥感技术优势出发,借助Web of Science和CNKI数据库,分析了海岸带遥感国内外研究现状,探讨了海岸带遥感所面临的科学技术问题,综述了研究进展,明确了机遇与挑战,讨论了未来发展方向。本文可为科学认识海岸带遥感中存在的问题,把握海岸带遥感发展方向提供参考。展开更多
基金Under the auspices of the Construction Committeeof Three GorgesR eservoirProject(No .SX [2002]00401) andChineseAcademy ofSciences(No .KZCX2-SW-319-01 )
文摘Taking TM images, SPOT photos and DEM images as the basic information, this paper had not only put forward a kind of manual controlled computer-automatic extraction method, but also completed the task of extracting the main types of ground objects in the Three Gorges Reservoir area under relatively high accuracy, after finishing such preprocessing tasks as correcting the topographical spectrum and synthesizing the data. Taking the specialized image analysis software-eCognition as the platform, the research achieved the goal of classifying through choosing samples, picking out the best wave bands, and producing the identifying functions. At the same time the extraction process partly dispelled the influence of such phenomena as the same thing with different spectrums, different things with the same spectrum, border transitions, etc. The research did certain exploration in the aspect of technological route and method of using automatic extraction of the remote sensing image to obtain the information of land cover for the regions whose ground objects have complicated spectrums.
基金Project(40971219)supported by the Natural Science Foundation of ChinaProjects(201121202020005,T201221207)supported by the Fundamental Research Fund for the Central Universities,China
文摘A novel cast shadow detection approach was proposed.A stereo vision system was used to capture images instead of traditional single camera.It was based on an assumption that cast shadows were on a special plane.The image obtained from one camera was inversely projected to the plane and then transformed to the view from another camera.The points on the plane shared the same position between original image and the transformed image.As a result,the cast shadows can be detected.In order to improve the efficiency of cast shadow detection and decrease computational complexity,the obvious object areas in CIELAB color space were removed and the potential shadow areas were obtained.Experimental results demonstrate that the proposed approach can detect cast shadows accurately even under various illuminations.
文摘Hyperspectral remote sensing has become one of the research frontiers in ground object identification and classification. On the basis of reviewing the application of hyperspectral remote sensing in identification and classification of ground objects at home and abroad. The research results of identification and classification of forest tree species, grassland and urban land features were summarized. Then the researches of classification methods were summarized. Finally the prospects of hyperspectral remote sensing in ground object identification and classification were prospected.
文摘针对现有的三维视觉定位方法依赖昂贵传感器设备、系统成本高且在复杂多目标定位中准确度和鲁棒性不足的问题,提出一种基于单目图像的多目标三维视觉定位方法。该方法结合自然语言描述,在单个RGB图像中实现对多个三维目标的识别。为此,构建一个多目标视觉定位数据集Mmo3DRefer,并设计跨模态匹配网络TextVizNet。TextVizNet通过预训练的单目检测器生成目标的三维边界框,并借助信息融合模块与信息对齐模块实现视觉与语言信息的深度整合,进而实现文本指导下的多目标三维检测。与CORE-3DVG(Contextual Objects and RElations for 3D Visual Grounding)、3DVG-Transformer和Multi3DRefer(Multiple 3D object Referencing dataset and task)等5种方法对比的实验结果表明,与次优方法Multi3DRefer相比,TextVizNet在Mmo3DRefer数据集上的F1-score、精确度和召回率分别提升了8.92%、8.39%和9.57%,显著提升了复杂场景下基于文本的多目标定位精度,为自动驾驶和智能机器人等实际应用提供了有效支持。
文摘[目的/意义]玉米是主要粮食作物,果穗作为玉米关键表型性状,其形态、大小及颜色特征能够有效反映植株生长状态及潜在产量。传统的田间玉米果穗检测依赖人工,效率低且劳动强度大。随着密植栽培模式的推广,玉米冠层结构愈发密集,人工进入田间开展果穗测量不仅操作困难,还容易对植株造成机械损伤,进一步限制了数据的准确性与代表性。因此,亟需高效的自动化检测技术。[方法]为实现复杂田间环境下玉米果穗的高效精准检测,提出一种基于改进YOLO11n(You Only Look Once 11)的CornYOLO模型。创新性地采用无人车搭载全景相机进行图像采集,构建了高质量的田间数据集,并在此基础上提出了3项核心模型改进:1)采用动态点空间注意力的跨阶段部分网络(Cross Stage Partial Network with Dynamic Pointwise Spatial Attention,C2PDA)以提升对遮挡目标的识别鲁棒性;2)引入特征优化模块(Feature Refinement Module,FRM)以增强多尺度目标检测能力;3)使用统一交并比(Unified Intersection Over Union,UIoU)损失函数以优化边界框回归精度。为作物田间表型高通量获取提供了一种从数据采集到智能识别的端到端解决方案。[结果和讨论]CornYOLO在复杂田间环境下表现出优异的检测性能,在验证集上mAP@50达到89.3%,相较于YOLO11n,F1分数提升2.5个百分点。相较于其余基线模型,其mAP@50提升显著,最高达12.6个百分点。消融实验表明,C2PDA、FRM与UIoU这3个模块均对性能提升有积极贡献,其中C2PDA作用最为关键。[结论]CornYOLO模型能够高效精准地识别田间玉米果穗,为玉米育种表型分析和产量预测提供可靠的技术支持,推动玉米果穗信息提取的智能化发展。
文摘The neutral grounding mode of medium-voltage distribution network decides the reliability, overvoltage, relay protection and electrical safety. Therefore, a comprehensive consideration of the reliability, safety and economy is particularly important for the decision of neutral grounding mode. This paper proposes a new decision method of neutral point grounding mode for mediumvoltage distribution network. The objective function is constructed for the decision according the life cycle cost. The reliability of the neutral point grounding mode is taken into account through treating the outage cost as an operating cost. The safety condition of the neutral point grounding mode is preserved as the constraint condition of decision models, so the decision method can generate the most economical and reliable scheme of neutral point grounding mode within a safe limit. The example is used to verify the feasibility and effectiveness of the decision method.
基金Foundation item:Supported by the National Nature Science Founda-tion of China(50099620)and 863 Program Foundation of China(2001AA132050-03)
文摘According to the frequency property of Phasedarray ground penetrating radar(PGPR),this paper gives a frequency point slice method based on Wigner time-frequency analysis.This method solves the problem of analysis for the PGPR's superposition data and makes detecting outcome simpler and detecting target more recognizable.At last,the analytical results of road test data of the Three Gorges prove the analytical method efficient.
文摘In the last century, there has been a significant development in the evaluation of methods to predict ground movement due to underground extraction. Some remarkable developments in three-dimensional computational methods have been supported in civil engineering, subsidence engineering and mining engineering practice. However, ground movement problem due to mining extraction sequence is effectively four dimensional （4D）. A rational prediction is getting more and more important for long-term underground mining planning. Hence, computer-based analytical methods that realistically simulate spatially distributed time-dependent ground movement process are needed for the reliable long-term underground mining planning to minimize the surface environmental damages. In this research, a new computational system is developed to simulate four-dimensional （4D） ground movement by combining a stochastic medium theory, Knothe time-delay model and geographic information system （GIS） technology. All the calculations are implemented by a computational program, in which the components of GIS are used to fulfill the spatial-temporal analysis model. In this paper a tight coupling strategy based on component object model of GIS technology is used to overcome the problems of complex three-dimensional extraction model and spatial data integration. Moreover, the implementation of computational of the interfaces of the developed tool is described. The GIS based developed tool is validated by two study cases. The developed computational tool and models are achieved within the GIS system so the effective and efficient calculation methodology can be obtained, so the simulation problems of 4D ground movement due to underground mining extraction sequence can be solved by implementation of the developed tool in GIS.
基金financial support from Teesside University to support the Ph.D. program of the first author.
文摘The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spectrum to select ground motion records based on the target spectrum.This research demonstrates the influence of adopting different weighted factors for various period ranges during matching selected ground motions with the target hazard spectrum.The event data from the Next Generation Attenuation West 2(NGA-West 2)database is used as the basis for ground motion selection,and hazard de-aggregation is conducted to estimate the event parameters of interest,which are then used to construct the target intensity measure(IM).The target IMs are then used to select ground motion records with different weighted vector-valued objective functions.The weights are altered to account for the relative importance of IM in accordance with the structural analysis application of steel moment resisting frame(SMRF)buildings.Instead of an ordinary objective function for the matching spectrum,a novel model is introduced and compared with the conventional cost function.The results indicate that when applying the new cost function for ground motion selection,it places higher demands on structures compared to the conventional cost function.Moreover,submitting more weights to the first-mode period of structures increases engineering demand parameters.Findings demonstrate that weight factors allocated to different period ranges can successfully account for period elongation and higher mode effects.
文摘Generating ground truth data for developing object detection algorithms of intelligent surveillance systems is a considerably important yet time-consuming task; therefore, a user-friendly tool to annotate videos efficiently and accurately is required. In this paper, the development of a semi-automatic video annotation tool is described. For efficiency, the developed tool can automatically generate the initial annotation data for the input videos utilizing automatic object detection modules, which are developed independently and registered in the tool. To guarantee the accuracy of the ground truth data, the system also has several user-friendly functions to help users check and edit the initial annotation data generated by the automatic object detection modules. According to the experiment＇s results, employing the developed annotation tool is considerably beneficial for reducing annotation time; when compared to manual annotation schemes, using the tool resulted in an annotation time reduction of up to 2.3 times.
文摘海岸带是陆地、海洋、大气相互作用的地球生态关键带,汇集了大量的物质和能量,正经历着高强度人类活动、全球气候变化和物种入侵的叠加影响,面临着前所未有的挑战。遥感科学与技术是全面、系统、深入监测海岸带资源、生态、环境的有效手段。本文从海岸带独特性和遥感技术优势出发,借助Web of Science和CNKI数据库,分析了海岸带遥感国内外研究现状,探讨了海岸带遥感所面临的科学技术问题,综述了研究进展,明确了机遇与挑战,讨论了未来发展方向。本文可为科学认识海岸带遥感中存在的问题,把握海岸带遥感发展方向提供参考。
