运用社交网络分析淹水空间信息之关联性     

周天颖  赖顺仁  黄崇典  杨龙士  叶美伶  吴政庭  方耀民 《遥感学报》2016,20(5):1299-1307

随着社交网络的普遍发展,大量的讯息透过智能手机发布在个人的微博或其他社交网站。台湾地区的社交网站以脸书(Facebook)的使用量最大,平均每天有近千万笔的讯息量,大多数的讯息多以食衣住行或个人讯息为主,但从本研究所撷取自2010年至2015年的数据中显示,公众在社交网站所分享的信息中具有降雨、淹水或相关灾情的讯息,而这些讯息具有极高比例的正确性。由于社交网站无法提供私人讯息,故本研究将从社交信息中,以地点为单位撷取大量的数据信息再辅以语意关键词萃取出有关可作为淹水预判的讯息数据。为检核资料的可性度,本研究透过历史台风数据FLO-2D仿真重建淹水之空间信息进行检核。从研究比对分析中发现,经萃取后的公众信息其与灾害的关联性及正确性相当显着,故透过社交网站中大量的非结构讯息,透过语意及空间的转换,可萃取转化为防灾信息,对广域的都市治理而言,此一讯息将可作为预判区域淹水或防救灾情报之有效参考。  相似文献   

结合投影变换和相位相关的海冰运动监测     

胡迎迎  郎文辉  张盼  杨学志 《遥感学报》2016,20(4):579-589

为提高对渤海海冰旋转和平移运动的监测精度,提出一种基于投影变换的相位相关跟踪方法。选取连续8景静止水色成像仪(GOCI)图像序列,根据特征图像窗口的投影变换构造辅助函数,通过寻求函数最优解得到旋转角度集合,选择修正相关系数确定最佳旋转角度,同时根据相位信息实现海冰样本间亚像素级别的平移跟踪,消除传统相位相关法中因忽略图像相频特性所造成的匹配误差。实验结果表明,以手动测量的旋转角度为基准,该方法和传统相位相关法的旋转监测均方根误差的最大值/平均值分别为0.59/0.50与1.41/0.94,跟踪速度提高了50.6%;海冰平移运动的速度矢量与辽东湾的现场实测数据及历史资料记录数据基本一致。该方法对渤海海冰旋转和平移运动具有较好的跟踪效果。  相似文献   

Representation and discovery of building patterns: a three-level relational approach     

Shihong Du  Mi Shu  Chen-Chieh Feng 《International journal of geographical information science》2016,30(6):1161-1186

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Semantic and syntactic interoperability in online processing of big Earth observation data     

Martin Sudmanns  Dirk Tiede  Stefan Lang  Andrea Baraldi 《International Journal of Digital Earth》2018,11(1):95-112

ABSTRACT

The challenge of enabling syntactic and semantic interoperability for comprehensive and reproducible online processing of big Earth observation (EO) data is still unsolved. Supporting both types of interoperability is one of the requirements to efficiently extract valuable information from the large amount of available multi-temporal gridded data sets. The proposed system wraps world models, (semantic interoperability) into OGC Web Processing Services (syntactic interoperability) for semantic online analyses. World models describe spatio-temporal entities and their relationships in a formal way. The proposed system serves as enabler for (1) technical interoperability using a standardised interface to be used by all types of clients and (2) allowing experts from different domains to develop complex analyses together as collaborative effort. Users are connecting the world models online to the data, which are maintained in a centralised storage as 3D spatio-temporal data cubes. It allows also non-experts to extract valuable information from EO data because data management, low-level interactions or specific software issues can be ignored. We discuss the concept of the proposed system, provide a technical implementation example and describe three use cases for extracting changes from EO images and demonstrate the usability also for non-EO, gridded, multi-temporal data sets (CORINE land cover).  相似文献   

基于随机补片和DeepLabV3+的建筑物遥感图像变化检测     

王民水  孔祥明  陈学业  杨国东  王明常  张海明 《吉林大学学报(地球科学版)》2021,51(6):1932-1938

为有效解决传统遥感图像变化检测预处理复杂的问题,提出一种基于随机补片和DeepLabV3+的建筑物遥感图像变化检测方法。以ResNet50特征提取网络为基础,创建DeepLabV3+语义分割网络,并在图像和标签中创建大小为224像素×224像素的随机补片作为网络输入,训练建筑物提取网络;修改建筑物提取网络输入层为6通道,通过矩阵运算将两期遥感图像转换为一幅6通道非RGB图像,利用转换后的非RGB图像进行网络训练并验证变化检测精度。实验1利用ENVI5.3软件,采用马氏距离法进行变化检测;实验2采用改进的U-Net网络和随机补片,完成网络训练和精度验证;实验3使用实验2的训练数据和验证数据,采用随机补片和DeepLabV3+网络进行变化检测网络训练及精度验证。实验结果表明,该方法实验1、实验2、实验3建筑物变化检测平均交并比分别为24.43%、83.14%、89.90%,边界轮廓匹配分数分别为61.47%,80.24%、96.51%。  相似文献   

面向对象的语义数据模型及其在空间数据库中的应用     

朱欣焰  许云涛  张银州  李锦祥 《武汉大学学报(信息科学版)》1993,(4)

传统的数据库模型适合于表示数字字母数据,难以处理复杂的空间数据。面向对象的语义数据模型克服了传统数据模型的许多不足,越来越多地应用于计算机科学各个领域。本文先描述了面向对象的语义数据模型,然后介绍了建立于这种模型基础上的空间数据库实验系统 spobase。  相似文献   

基于语义网络的知识表示的形式转换及推理   总被引：8，自引：0，他引：8  

夏幼明  徐天伟  刘海庆 《武汉大学学报(信息科学版)》2001,26(4):369-373

介绍了基于语义网络的知识表示，并利用基于知识的方法将SNetL的知表示转换为谓词逻辑的表现形式，将其用于推理。本文讨论知识表示的交互式输入方法及中间模型的设计。按SNetL语言的描述机制，确定了用户描述的控制、导航方式，并研究转换中的规则和算法。  相似文献   

从灰度变化获取表面形状的研究     

王新华  傅晓云 《武汉大学学报(信息科学版)》1995,(3)

提出了一种基于可信度操作的从灰度变化信息获取表面形状的方法，并结合在频率域的强制可积约束，把对表面梯度空间（ｐ，ｑ）的处理经过高斯球变换到（ｆ，ｇ）空间处理，不仅较好地保证了算法的收敛性和可靠性，而且有利于边界条件的确定。  相似文献   

An IEEE value loop of human-technology collaboration in geospatial information science     

Liqiu Meng 《地球空间信息科学学报》2020,23(1):61-67

ABSTRACT

Geosensing and social sensing as two digitalization mainstreams in big data era are increasingly converging toward an integrated system for the creation of semantically enriched digital Earth. Along with the rapid developments of AI technologies, this convergence has inevitably brought about a number of transformations. On the one hand, value-adding chains from raw data to products and services are becoming value-adding loops composed of four successive stages – Informing, Enabling, Engaging and Empowering (IEEE). Each stage is a dynamic loop for itself. On the other hand, the “human versus technology” relationship is upgraded toward a game-changing “human and technology” collaboration. The information loop is essentially shaped by the omnipresent reciprocity between humans and technologies as equal partners, co-learners and co-creators of new values.

The paper gives an analytical review on the mutually changing roles and responsibilities of humans and technologies in the individual stages of the IEEE loop, with the aim to promote a holistic understanding of the state of the art of geospatial information science. Meanwhile, the author elicits a number of challenges facing the interwoven human-technology collaboration. The transformation to a growth mind-set may take time to realize and consolidate. Research works on large-scale semantic data integration are just in the beginning. User experiences of geovisual analytic approaches are far from being systematically studied. Finally, the ethical concerns for the handling of semantically enriched digital Earth cover not only the sensitive issues related to privacy violation, copyright infringement, abuse, etc. but also the questions of how to make technologies as controllable and understandable as possible for humans and how to keep the technological ethos within its constructive sphere of societal influence.  相似文献   

从三个平面看概数词“好多”与“好几”     

蔡晓 《广东海洋大学学报》2003,23(5):72-77

概数词“好多”与“好几”在分布、语义辖域、和语用倾向等方面既具有其相同的一面 ,也有相对的一面 ,还有相交叉的一面。它们所能出现的语法位置有异有同 ,“好几”表数范围具有定性和“好多”表数范围则无定性 ,同时还“好几”具有显示个体作用的性质  相似文献