像元尺度上分类不确定性评价及可视化表达     

竞霞  张竞成  琚存勇  边宗攀  魏曼 《测绘科学》2014,39(9)

传统的地物类别尺度上的遥感影像分类不确定性评价仅能实现分类精度的数学度量,无法反映分类不确定性的空间分布,难以完整、准确地描述和理解遥感影像分类信息的不确定性.文章首先在像元尺度上对遥感影像分类的不确定性进行评价,并在此基础上利用计算机技术从彩色可视化、用户交互式可视化和用户选择性可视化模式3个方面在空间域上对分类不确定性进行描述,从视觉感知角度表达遥感影像分类的不确定性信息,从而使用户更加形象直观地理解不确定性信息数据的大小及其空间分布.  相似文献   

在ArcToolbox中实现用户自定义工具     

徐国庆  顾钰培  赵明瑜 《测绘与空间地理信息》2014,(8):131-132

简要介绍了ArcToolbox的相关概念以及在ArcToolbox中开发实现用户自定义工具的方法与技巧;并以一个常见的应用场景为例,使用Python脚本语言在ArcToolbox中实现了一个用户自定义工具;最后经实践验证,在ArcToolbox中开发实现用户自定义工具的方法能显著提高测绘生产中地理信息数据处理的效率。  相似文献   

Influential Visual Design Parameters on TV Weather Maps     

《The Cartographic journal》2013,50(4):311-323

Abstract

Information transformation on television weather maps (TVWMs) is influenced by visual elements for a broad range of viewers. This research emphasizes the cartographic aspects of TVWMs through evaluating their visual variables. Currently defined visual variables including basic, dynamic and motion variables are investigated and some suggestions are made to improve their application on TVWMs. The rates of the represented visual information within different frames and the related standard deviation are proposed as measures to improve the performance of the ‘duration’ dynamic variable. The concept of ‘visual expressions’ is introduced, and their applications at the organisational level of map design are discussed. Such expressions (including background, boundary, spatial order, zoom and overview maps) are examined as tools for ‘user orientation’ in particular, and their role as dominant parameters in TVWMs’ cartographic communication is considered. Their incorporation in TVWMs of a number of global news channels is evaluated. Firstly, the concepts of visual design parameters are utilized as a foundation for an analytical evaluation, then an empirical evaluation is carried out based on a statistical investigation of a sample of TV viewers. The resulting ranking order and correlation coefficients for each of the elements shows a firm agreement, corroborating views on the importance and proficiency of the visual elements in communicating weather information. As a result, TVWMs of well-known global TV channels (BBC, Euronews, France24, PressTV) are ranked with respect to the effectiveness of their designs.  相似文献   

Investigating the Effectiveness of an Efficient Label Placement Method Using Eye Movement Data   总被引：1，自引：0，他引：1  

《The Cartographic journal》2013,50(3):234-246

Abstract

This paper focuses on improving the efficiency and effectiveness of dynamic and interactive maps in relation to the user. A label placement method with an improved algorithmic efficiency is presented. Since this algorithm has an influence on the actual placement of the name labels on the map, it is tested if this efficient algorithms also creates more effective maps: how well is the information processed by the user. We tested 30 participants while they were working on a dynamic and interactive map display. Their task was to locate geographical names on each of the presented maps. Their eye movements were registered together with the time at which a given label was found. The gathered data reveal no difference in the user’s response times, neither in the number and the duration of the fixations between both map designs. The results of this study show that the efficiency of label placement algorithms can be improved without disturbing the user’s cognitive map. Consequently, we created a more efficient map without affecting its effectiveness towards the user.  相似文献   

Study of the attentive behavior of novice and expert map users using eye tracking   总被引：1，自引：0，他引：1  

K. Ooms  P. De Maeyer  V. Fack 《制图学和地理信息科学》2013,40(1):37-54

The aim of this paper is to gain better understanding of the way map users read and interpret the visual stimuli presented to them and how this can be influenced. In particular, the difference between expert and novice map users is considered. In a user study, the participants studied four screen maps which had been manipulated to introduce deviations. The eye movements of 24 expert and novice participants were tracked, recorded, and analyzed (both visually and statistically) based on a grid of Areas of Interest. These visual analyses are essential for studying the spatial dimension of maps to identify problems in design. In this research, we used visualization of eye movement metrics (fixation count and duration) in a 2D and 3D grid and a statistical comparison of the grid cells. The results show that the users’ eye movements clearly reflect the main elements on the map. The users’ attentive behavior is influenced by deviating colors, as their attention is drawn to it. This could also influence the users’ interpretation process. Both user groups encountered difficulties when trying to interpret and store map objects that were mirrored. Insights into how different types of map users read and interpret map content are essential in this fast-evolving era of digital cartographic products.  相似文献   

Visual clutter reduction in zoomable proportional point symbol maps     

Tomasz Opach  J. Korycka-Skorupa  I. Karsznia  T. Nowacki  I. Gołębiowska  J. K. Rød 《制图学和地理信息科学》2013,40(4):347-367

ABSTRACT

Proportional point symbols are commonly used in map displays. However, when such displays are zoomed out, the available map space shrinks and consequently symbols overlap and the display suffers from visual clutter. Therefore, solutions are needed to reduce visual clutter in zoomable map displays that contain proportional point symbols. The authors add to the body of knowledge through the investigation of the performance of three solutions: aggregation of unit areas, the displacement of overlapping symbols, and modified symbolization; four variations of modified symbolization are examined in detail. The original study begins with a consideration of the strengths and weaknesses of the solutions, with an emphasis on information loss. Thereafter, user sessions with 165 participants are arranged to gain empirical evidence of the performance of the solutions. The results reveal that although participants zoom out the map to zoom levels that implement visual clutter reduction techniques, they tend to zoom in the map and pan it to examine specific areas. Moreover, they willingly use the map with aggregated unit areas in cases when the solution facilitates task accomplishment. A certain amount of skepticism attaches to the solution that displaces overlapping symbols.  相似文献   

Ontologies of geographic information     

Helen Couclelis 《International journal of geographical information science》2013,27(12):1785-1809

This article explores the notion of a system of ontologies specifically designed for the needs of an information science. A framework for geographic information ontologies is outlined that focuses on geographic information constructs rather than on the direct representation of real-world entities or on linguistic terms. The framework takes the form of a generative hierarchy anchored by the notion of intentionality at one end and of a spatiotemporal field of potentially relevant information at the other. Two theoretical notions are used in the generation of the hierarchy. The first is the principle of semantic contraction, whereby, starting from a level of geographic information constructs specified so as to reflect user intentionality, semantically coherent domains of properties are removed over several steps until only the rudiments of a spatiotemporal information system are left. The second notion is that of object of discourse, which allows entities to be represented as the composites of geographic information constructs at the higher levels of the hierarchy, explicitly reflecting the connections between the purpose, function, appropriate internal constitution, and ensuing categorization of the entities represented. The framework's main contribution is thus twofold: first, it allows the notions of user purpose and object function to be directly built into geographic representations; second, it proposes a hierarchy of ontological levels that are linked by systematic semantic relations. Further, the framework presents an integrated view of object and field representations. It may also provide a novel perspective on a number of issues of ongoing interest in geographic information science.  相似文献   

Web环境下地学数据共享用户行为模式分析   总被引：1，自引：0，他引：1  

王末  王卷乐 《地球信息科学学报》2016,18(9):1174-1183

了解科学数据共享用户行为特征对实现高效、精准的数据共享服务具有重要的参考意义。本文基于国家地球系统科学数据共享平台网站服务器日志及服务记录数据,利用空间数据挖掘及Web使用挖掘技术,探索地球系统科学数据共享用户行为模式。在数据预处理阶段,完成用户识别、会话识别、位置识别,并对数据进行空间建模、空间数据库建库。在数据挖掘阶段,分别对用户产生的网页浏览数、会话数、数据集浏览数为对象进行空间“热点”分析,识别用户行为的地域差异。针对用户数据浏览和下载行为,采用FP-growth算法对用户——数据之间进行关联规则挖掘,发现用户对数据关注和使用的高频规律。分析结果表明：（1）该共享平台用户地在国内各省市均有分布,用户最多的3个省（市）分别为北京市、山东省、江苏省,该分布与国内高校学生分布相关程度不高,但与“211工程”高校学生的空间分布相关度较高;（2）空间“热点”分析表明,北京、天津及河北北部无论在网页浏览、数据浏览还是会话量上都是“热点”区域,但识别的“冷点”区域有较大不同,尤其是数据访问“冷点”分布较广,如南方沿海省份、河南省、山东省、四川省等;（3）关联规则挖掘发现多个数据浏览高频项目集以及关联规则。数据下载高频项与数据浏览高频模式较好吻合,但下载行为未表现出明显关联规则。本文提供了一种结合Web使用挖掘和空间数据挖掘的用户行为模式挖掘方法,该方法也可用于其他类型网站的数据挖掘。  相似文献   

位置服务的上下文信息模型     

齐凌艳  陈荣国 《地球信息科学学报》2014,16(2):191-198

在位置服务领域,用户所处环境的上下文信息在分析、处理请求,以及推送相应的位置信息服务方面发挥着至关重要的作用。目前,如何存储和管理上下文位置信息缺乏统一的模型和标准,本文对此提出了一种全新的位置服务的上下文信息模型。利用User Context（< User >,< Time >,< Location >,< Surroundings >,< Demand >）5元素模型描述位置服务上下文信息中5个信息元素（用户信息、时间信息、位置信息、环境信息、用户需求信息）,这5个信息元素均是直接因素,彼此独立且获取方便,人为干预少;同时,利用数据库技术可将5元素模型抽象成5元素表形式存储于数据表中,以便高效检索。最后,通过分析5元素模型中的不同信息元素,可推理出基于搜索关键词的用户需求偏好及基于时间和位置信息的用户轨迹（用户行为、热点区域、用户兴趣）。  相似文献   

北斗系统与GPS应用比较分析   总被引：1，自引：0，他引：1  

周兵  陈向东  赵齐乐 《全球定位系统》2012,37(4):6-8

我国自主建设的北斗卫星导航区域系统已投入试运行服务。从国内用户应用方面具体分析了北斗卫星导航系统相比美国GPS的优势,包括定位精度、信号的载噪比、定位速度和应用模式等,给出了北斗卫星导航区域系统在试运行阶段的一些应用测试数据。同时指出了对北斗系统未来发展趋势。  相似文献