Ensemble prediction model of solar proton events associated with solar flares and coronal mass ejections     

Xin Huang  Hua-Ning Wang  Le-Ping Li 《天体物理学报》2012,(3):313-321

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基于深度学习的高分辨率遥感影像光伏用地提取   总被引：1，自引：0，他引：1  

吴永静  吴锦超  林超  窦宝成  黎珂 《测绘通报》2021,(5):96-101

近年来我国光伏产业发展迅猛,随之也产生了诸多用地问题,通过遥感技术提取光伏用地,监测光伏用地分布与用地状况,对于光伏产业健康发展具有重要意义。本文提出一套基于深度学习方法的高分辨率遥感影像光伏用地自动提取方法,该方法利用GF-1等卫星影像和Google Earth影像构建光伏用地样本,基于ResNeSt-50作为骨干网络的DeepLab V3+模型实现深度学习语义分割算法,并结合计算机图形学方法对深度学习结果进行后处理,实现了面向高分辨率遥感影像较通用的且高精度的光伏用地自动提取。该方法的深度学习模型验证精度mIoU值达0.899 2,提取结果具有良好的边缘精度且具有广泛的适用性,支持GF-1、ZY-3、GF-6、GF-2和Google Earth等影像。  相似文献   

时间序列SAR图像不可移动文物水域淹没监测     

吴樊  李娟娟  张波  王超  张红  陈富龙  李璐  许璐 《遥感学报》2021,25(12):2431-2440

全球气候变化引起的极端降雨、洪涝灾害是导致不可移动文物受损的重要破坏因素。合成孔径雷达SAR（Synthetic Aperture Radar）具有全天时、全天候、大范围周期性对地观测的优势,是大区域水体监测的重要手段,对不可移动文物水域淹没及风险监测具有重要意义。本文利用时间序列SAR图像提出基于残差U-Net的不可移动文物水域淹没及风险监测框架。首先,基于双峰阈值分割法结合专家知识辅助进行水体样本生成,提高样本制作效率;其次,引入残差模块建立U型卷积网络,综合残差结构及U-Net的特点,缓解梯度更新时的弥散、消失等现象,通过卷积层之间累加和跳跃链接,保留多尺度的地物特征信息,以实现水体快速、高精度的语义分割;最后通过将结果与不可移动文物点位进行空间叠加分析,实现对不可移动文物水淹状况的监测。选取鄱阳湖及南昌市昌邑北垱遗址作为试验研究对象。获取了21景覆盖鄱阳湖区域不同时相Sentinel-1 SAR图像,并结合Sentinel-2光学图像进行结果分析与评价。实验结果表明：本文方法在鄱阳湖试验区对水体提取总精度优于95%,相较于FCN（Fully Convolutional Networks）与U-Net方法具有更好的精度。利用不同时相SAR图像获得时间序列水体分布范围变化图,与昌邑北垱遗址点位进行空间叠加分析,得到不可移动文物水域淹没长时间序列监测结果。实验结果表明本文提出的方法可以有效提取水体范围,对不可移动文物水域淹没及风险监测可以提供有力支撑。  相似文献   

AMSR-E地表温度数据重建深度学习方法   总被引：1，自引：0，他引：1  

苏扬  吴鹏海  程洁  殷志祥  马晓双  杨辉 《遥感学报》2022,26(4):739-751

地表温度对于全球气候变化等研究具有重要意义。被动微波遥感传感器AMSR-E（Advanced Microwave Scanning Radiometer for EOS）可以获得全天候地表温度,可作为多云条件下热红外地表温度数据的补充;但轨道扫描间隙限制了该数据在全球或区域尺度上的实际应用。鉴于地表温度的高时空异质性和AMSR-E LST轨道间隙数据的特点,本文提出了一种多时相特征连接卷积神经网络地表温度双向重建模型（MTFC-CNN）,利用深度学习在处理复杂非线性问题上的优势,重建轨道间隙区域的地表温度值。将2010年中国大陆四季的AMSR-E LST数据（数据未含港澳台区域）,分为白天和夜晚,形成共8个数据子集进行实验。在模拟实验中,重建结果与原始反演地表温度值平均均方根误差在1.0 K左右,决定系数R²在0.88以上,优于传统的样条空间插值和时间线性回归方法;真实实验结果具有较好的目视效果,且与对应MODIS LST产品对比发现,重建区LST值和未重建区LST值与MODIS LST产品间具有相近的平均均方根误差和决定系数。因此,本文提出的MTFC-CNN方法能有效重建AMSR-E LST轨道间隙数据,且优于传统方法。  相似文献   

Internet-Based GIS in an Inductive Learning Environment: A Case Study of Ninth-Grade Geography Students   总被引：2，自引：2，他引：0  

《The Journal of geography》2012,111(6):227-237

Abstract

This article reports the results of a qualitative case study that explored the use of Internet-based geographic information systems (IGIS) with ninth-grade geography students. The students worked in teams to examine the geography of Africa using IGIS resources with the instructional goal of developing a presentation on a significant issue facing one region or country. The purpose of this study was to explore the use of IGIS as a tool for integrating geospatial technologies into ninth-grade geography curriculum and instruction within an inductive learning environment. The findings for this study indicate that IGIS can be a successful tool for geography education in an inductive learning environment. Based on qualitative data collected through classroom observations, focus group interviews with students, student work samples, and a teacher journal, two assertions are offered: students perceived expanded freedom as a positive aspect of this IGIS project and IGIS projects such as this can lead to gains in students' cultural awareness and empathy for distant others.  相似文献   

Problem-Based Learning for Promoting Student Learning in High School Geography     

《The Journal of geography》2012,111(5):190-200

ABSTRACT

This study determines the impact of problem-based learning on a preuniversity geography class. Learning activities include problem analysis, information collection, an examination of concepts, oral presentations, and group summaries in relation to current and perennial geographical issues of local and/or global concern. Assessment for learning and assessment of learning were done by the teacher, classmates, and students themselves. Results showed that students could analyze problem statements and present their understanding systematically but varied considerably in organization, argument, and quality of thinking. To seek improvements, teachers should become more active facilitators while encouraging students to learn as problem solvers. Teacher training and school-based support are needed for creating a collaborative inquiry-oriented atmosphere in the classroom.  相似文献   

Positionality and Active Learning: Confronting Privilege in Field-Exercise Design     

《The Journal of geography》2012,111(4-5):186-193

Abstract

University instructors are increasingly drawing on active learning exercises to engender critical thinking skills among students. In this article, we introduce the design and implementation of an active learning exercise about mobility and transportation that we assigned in an introductory human geography class at the University of Georgia. The students' responses and the survey instrument we used to assess the effectiveness of the exercise revealed disappointing results and caused us to think carefully about the role of positionality in designing active learning exercises. In this article, we argue that we need to understand privilege—particularly class privilege—in order to design effective assignments.  相似文献   

Concept Learning through Writing for Learning: Using Journals in an Introductory Geography Course     

《The Journal of geography》2012,111(5):196-206

Abstract

To effectively use journals and other writing for learning tasks as critical thinking and learning tools, geographic educators need to draw from the education literature on concept learning. Using the literature on concept learning and critical thinking, geographic educators can construct different kinds of journal assignments that give students opportunities to personalize and understand concepts. I demonstrate that students, regardless of their sex, level of education, or previous coursework in geography, found journal assignments helpful in understanding human geographic concepts.  相似文献   

Exploring Youth Cultures Geographically Through Active Learning     

《The Journal of geography》2012,111(1):9-16

Abstract

This paper presents strategies for actively involving students in studying cultural geography through a research project on youth cultures. It provides a basic framework to investigate selected “subcultures” focusing on the origin and diffusion of each culture, its material and non-material aspects and the attributes and meanings of spaces used by each cultural group and youth cultures in the context of change. Students used a variety of methodologies to gather data and to describe and analyze the cultures selected. Of the eleven youth cultures investigated by the class, examples from the cultures of raves, skateboarding, and the Boy Scouts of America (BSA) are selectively presented to elucidate their geographic characteristics.  相似文献   

Editorial     

《The Journal of geography》2012,111(5):217-218

Abstract

Project GeoSim is a multidisciplinary effort by members of Virginia Tech's Departments of Geography and Computer Science, College of Education, and Learning Resources Center to develop computer-aided education (CAE) software for introductory geography and related classes. GeoSim laboratory exercises draw on the five fundamental themes of geography for their subject matter. The programs emphasize interactive learning combining the information capabilities of Geographic Information Systems (GIS) with the techniques of computer simulation. The result is a series of geographic explorations that will make available some of the most exciting aspects of geography to a potential audience of 425,000 introductory geography students per year.  相似文献