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1.
Navigation is a task performed in both large and small scale environments. Landmarks within an environment are of great benefit to these navigational tasks, but in large rural environments such landmarks may be sparse. It has been shown that landmarks need not be purely visual and that a change in context for a feature can make it become a landmark against its surroundings (such as being provided with significant meaning). Such meaning could be added through personal experience or by informing the observer via some form of communication. To investigate the effects of providing such contextual information on navigational performance, experiments were conducted in a large rural virtual environment where the delivery method of the information was varied between onscreen and PDA display. Users were instructed to perform a route tracing navigation task. In some instances users were presented with textual information about specific locations within the environment which appeared when they were in the vicinity of the location. Both quantitative and qualitative data were collected and analyzed, with results indicating that although the actual performance in the task was not significantly improved, users felt that their performance was better and the task easier when they were presented with the contextual information. 相似文献
2.
《制图学和地理信息科学》2013,40(2):232-242
Communication of natural hazard assessment results is crucial to protect people and infrastructure from devastating impacts of extreme events. While hazard maps provide important information on potential impacts, their interpretation and the general knowledge exchange between stakeholders is often difficult. Web-based information systems contain the potential to support hazard management tasks by fast distribution and customization of hazard visualizations through interactive functionality. Cartographic principles are, however, often ignored in existing web-based visualizations which leads to poor graphical results and consequently to an impairment of the information flow. While these issues need to be solved, a new task is already waiting: the integration of uncertainty information into hazard visualizations. Since many hazard management activities rely on hazard assessment results, communication of associated uncertainties among experts is vital. The challenge of this research is to overcome these existing shortcomings by combining high quality cartographic visualizations of natural hazard data as well as associated uncertainties with interactive functionality. The resulting web-based cartographic information system will convene the needs of natural hazard specialists by offering a high level of customization: the suggested visualizations include various cartographic techniques such as the application of textures, bars, and interpolated surfaces. The possibility to interactively select particular data sets, customize colors, choose dimensions, query attribute data, and include uncertainty information facilitates the interpretation of complex data and finally the communication among natural hazard specialists. In this article we summarize requirements that have to be considered, suggest functionalities necessary to perform natural hazards management tasks, and present a prototype of an expert system for the visualization and exploration of natural hazards assessments results and associated uncertainties. 相似文献
3.
The Climate Data Records (CDRs) of Essential Climate Variables (ECVs) that are based on satellite observations need to be precisely described. In particular, when these products are delivered to end-users, the error characteristics information and how this information is obtained (e.g., through a validation process) need to be documented. Such validation information is intended to help end-users understanding to what extent the product is suitable for their specific applications. Based on how different European initiatives approached the validation of CDR and ECV products, we reviewed several aspects of the current validation practices. Based on the analysis of current practices, essentials of validation are discussed. A generic validation process is subsequently proposed, together with a quality indicator. 相似文献
4.
Jeffrey T. Howarth 《制图学和地理信息科学》2015,42(4):6-10
There are now many opportunities to learn how to make maps through technical training with mapmaking tools, including geographic information systems and web-based mapping services. In cartographic education, two challenges with teaching through practice stem from the disruptive nature of mapmaking tools and the tradition of teaching cartographic principles by rule or convention. This article outlines a framework for a pattern language to organize and share practical information about principles for making maps. The article provides an example pattern for mapmaking and discusses how this framework addresses recurring problems with teaching through practice. 相似文献
5.
Kathleen Hornsby 《Transactions in GIS》2001,5(3):255-272
Spatio-temporal knowledge representation often requires changing from one level of detail or granularity to another so users can carry out a desired task. Meteorological occurrences, geological processes, or population movements, for example, can be examined at different granularities. This includes different spatial perspectives as well as temporal views where phenomena may be examined under real time conditions, or over hourly, daily, weekly, or longer periods. Moving back and forth among granularities is a necessary routine for many domain scientists. Changing to a more detailed view uncovers information that otherwise is unknown. Conversely, moving to a simpler view can improve our understanding of phenomena. Although people routinely abstract information from their environment at different granularities and perform mental shifts that increase or decrease detail, formalization of these alterations for use in information systems has proved difficult. Geographic information systems typically treat changes in granularity from the perspective of changes to the geometric properties of objects through graphic zooming. None of the current approaches to zooming offer support for performing this operation over time. This work focuses on the temporal aspects of changing granularity or temporal zooming . The approach is based on a model of change to identifiable objects. In this paper, temporal zooming involves expanding or collapsing the transitions among identity states of the same object as well as revealing or omitting other objects that are linked through transitions. A set of operations to support refining and coarsening the evolution of objects over time is presented. This work offers a new perspective on zooming important for spatio-temporal query languages and for users of large spatio-temporal databases who require the means to shift back and forth among simpler or summarized views of data and more detailed views. 相似文献
6.
Seamless integration of spatial statistics and GIS: The S-PLUS for ArcView and the S+Grassland Links
Shuming Bao Luc Anselin Doug Martin Diana Stralberg 《Journal of Geographical Systems》2000,2(3):287-306
The extension of the functional capacity of geographic information systems (GIS) with tools for statistical analysis in general
and exploratory spatial data analysis (ESDA) in particular has been an increasingly active area of research in recent years.
In this paper, two operational implementations that combine the functionality of spatial data analysis software with a GIS
are considered more closely. They consist of linkages between the S-PLUS software for data analysis and two different GIS implementations, the ArcView desktop system, which is mostly vector-oriented, and the primarily raster-based Grassland open GIS environment. We emphasize conceptual and technical issues related to the software implementation of these approaches
and suggest future directions for linking spatial statistics and GIS.
Received: 14 January 1999 / Accepted: 11 May 1999 相似文献
7.
《制图学和地理信息科学》2013,40(4):257-268
Much progress has been made in the field of web-based cartography through standards developed by the Open Geospatial Consortium (OGC). While automated access and presentation of cartographic data have been defined, the services for automated generalization are yet to be standardized. This paper aims to show advantages of applying the service concept to generalization and suggests several classification schemas of generalization services at different levels of granularity. A detailed explanation of a real implemented Generalization Service is provided. We show how software developers can make their generalization functionality available as a service and how these services can be accessed dynamically. For the implementation, the open source Java Unified Mapping Platform (JUMP) was extended to work as a framework for generalization. Generalization services could be used in different application scenarios, for instance as a middleware component extending a web map service with adaptive zooming or as stand-alone services supporting the production of topographic maps by national mapping agencies. They may also allow the development of a common research platform, where researchers would have access to a common generalization framework. 相似文献
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9.
Sepehr Honarparvar Rouzbeh Forouzandeh Jonaghani Ali Asghar Alesheikh Behnam Atazadeh 《国际地球制图》2013,28(13):1496-1513
AbstractRecommender systems (RS), as supportive tools, filter information from a massive amount of data based on the determined preferences. Most of the RS require information about the context of users such as their locations. In such cases, location-aware recommender systems (LARS) can be employed to suggest more personalized items to the users. The most current research projects on LARS focus on the development of algorithms, evaluation methods and applications. However, the role of up-to-date spatial databases in LARS is not a well-researched area. The up-to-date spatial information would potentially improve the accuracy of items which are recommended by LARS. Volunteered geographic information (VGI) could be a low-cost source of up-to-date spatial information for LARS. This article proposes an approach to enrich spatial databases of LARS by VGI. Since not all records of VGI are fitted for use in LARS, a mechanism is developed to identify useful information. Some VGI data sets refer to existing spatial data in the database while other VGI data sets are shared for the first time. Therefore, the proposed method assessed the quality of VGI with reference source (for VGI which is existed in the database) and VGI without reference source (for VGI which is shared for the first time). To demonstrate the feasibility of the proposed approach, a mobile application has been developed to recommend suitable restaurants to the users based on their geospatial locations. The evaluation of the method indicates that VGI can potentially enhance the functionality of the LARS in predicting the users’ interests. 相似文献
10.
《制图学和地理信息科学》2013,40(2):133-136
Over the recent years, spatial data have become more accessible to members of the public, and there is an increased awareness that spatial data are an essential ingredient in the development of governance policies. In parallel, computing devices that can render real-time 3D environments in nearly photo-realistic quality have become a common household item. Integrating spatial data and virtual environments opens the possibility of presenting spatial data in a highly visual way—the same way we experience our everyday world. We have developed a landscape planning tool called SIEVE (Spatial Information and Visualization Environment), which allows users to explore existing spatial data and hypothetical future scenarios in a real-time 3D environment, links to environmental process models outcomes, and also provides a collaborative decision-making environment. SIEVE has an automatic model-building component that allows users to select a region on a 2D map using a web portal and to download automatically generated 3D landscape environments. SIEVE not only models above-ground features but also incorporates underground features. This allows users to see the connection between below- and above-ground processes. Lastly, SIEVE incorporates a multi-user environment that allows users from different locations to gather in the virtual landscapes for exploring and decision-making purposes. 相似文献
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12.
ABSTRACTUsing Artl@s as an example of a project that relies on volunteered geographic information (VGI), this article examines the specific challenges that exist, beyond those frequently discussed in general VGI systems (e.g., participants’ motivation and data quality control) in regard to sharing research data in humanities: (1) most data from the humanities is qualitative and collected from multiple data sources which are often inconsistent and unmappable; (2) data is usually interconnected with multiple relationships among different tables which creates challenges for both mapping and query functionality; (3) data is both geographical and historical. Consequently addresses that no longer exist have to be geolocated and visualized on historical basemaps and spaces must be represented diachronically; (4) the design of web map application needs to balance both sophisticated research requirements and a user-friendly interface; (5) finally contributors expect their data to be cited or acknowledged when used in other studies and users need metadata and citation information in order to reuse and repurpose datasets.In this article, we discuss how Artl@s, a project which developed a georeferenced historical database of exhibition catalogues, addresses these challenges. Artl@s provides a case study for VGI adoption by digital humanities scholars for research data sharing, as it offers features, such as flexible batch data contribution, interrelated spatial query, automatic geolocalization of historical addresses, and data citation mechanisms. 相似文献
13.
《ISPRS Journal of Photogrammetry and Remote Sensing》1999,54(4):234-243
A geologic map is typically a 2D representation of 3D subsurface structures in a given area. It is based on the currently accepted geologists' model explaining the observed phenomena and the processes that shaped them in the geologic past. For historical reasons, this model is recorded in a geologic map with an explanatory booklet that describes the authors' conclusions as well as relevant field observations and other data such as tectonic measurements, drill hole logs or fossil records. Today, however, this variety of information can be better handled by converting it into digital and even hypermedial format. This necessitates the prior conception, development and implementation of a suitable geologic “hypermap model”. The main objective of this study is to design models and tools well-suited for the interaction between users and geologic hypermaps. The unique aspect of this family of applications is that users, in general, are both end-users (e.g., engineers) and designers (e.g., mapmakers). Objectives, concepts and methods for developing a human interface to geologic hypermaps have been tested using a prototype (i.e., GeoHyp) within the GIS environment of ArcView from ESRI. Tools to access the underlying background database via hyperlinks have been implemented, as well as functions especially developed to meet specific geologic requirements. Tests with various types of users have shown that the prototype matches their expectations and serves as a good basis for further development. In this article, we report on our design choices for GeoHyp and the current status of our project. 相似文献
14.
自适应空间信息移动服务 总被引：4，自引：0，他引：4
空间信息移动服务系统是空间信息系统继由传统PC计算环境向有线Web分布式计算环境扩展后，向移动计算环境的新发展。文中在分析移动计算环境概念和特点的基础上，讨论了空间信息移动服务的若干特点及关键技术，研究了自适应空间信息移动服务方案。 相似文献
15.
Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed “virtual organizations”. The heterogeneous, dynamic and multi-domain nature of these environments makes challenging security issues that demand new technical approaches. Despite the recent advances in access control approaches applicable to Grid computing, there remain issues that impede the development of effective access control models for Grid applications. Among them there are the lack of context-based models for access control, and reliance on identity or capability-based access control schemes. An access control scheme that resolve these issues is presented, and a dynamically authorized role-based access control (D-RBAC) model extending the RBAC with context constraints is proposed. The D-RABC mechanisms dynamically grant permissions to users based on a set of contextual information collected from the system and user's environments, while retaining the advantages of RBAC model. The implementation architecture of D-RBAC for the Grid aplication is also described. 相似文献
16.
《International Journal of Digital Earth》2013,6(5):434-443
Abstract Historical soil survey paper maps are valuable resources that underpin strategies to support soil protection and promote sustainable land use practices, especially in developing countries where digital soil information is often missing. However, many of the soil maps, in particular those for developing countries, are held in traditional archives that are not easily accessible to potential users. Additionally, many of these documents are over 50 years old and are beginning to deteriorate. Realising the need to conserve this information, the Joint Research Centre (JRC) and the ISRIC-World Soil Information foundation have created the European Digital Archive of Soil Maps (EuDASM), through which all archived paper maps of ISRIC has been made accessible to the public through the Internet. The immediate objective is to transfer paper-based soil maps into a digital format with the maximum possible resolution and to ensure their preservation and easy disclosure. More than 6,000 maps from 135 countries have been captured and are freely available to users through a user-friendly web-based interface. Initial feedback has been very positive, especially from users in Africa, South America and Asia to whom archived soil maps were made available to local users, often for the first time. Link: http://eusoils.jrc.ec.europa.eu/library/maps/country_maps/list_countries.cfm 相似文献
17.
YAO Hanbing HU Heping LU Zhengding LI Ruixuan 《地球空间信息科学学报》2006,9(3):223-228
IntroductionThe Grid security infrastructure ( GSI) hasbeen accepted as the pri mary authenticationmechanismfor the Grid computing. GSI devel-oped as part of the Globus project defines singlesign-on algorithms and protocols , cross-domainauthentication pr… 相似文献
18.
随着地理信息存储量的飞速增长,传统的单进程、集中式的数据处理方式已不能满足基于网络的地理信息服务的效能要求。分析对比了OpenMP,MPI和MapReduce等主流并行编程模式,将关系型数据库与分布式空间数据管理系统相结合,提出了面向并行处理的地理信息存储模型和数据组织模型,将该模型与传统模型进行了对比分析,并基于MapReduce实现了地理空间数据并行处理框架,选取了矢量数据装载、影像数据装载以及数据切片作为典型数据处理案例开展对比实验,该技术方案的处理效率均数倍于传统技术方案。实验表明,该模型能够很好地支持并行处理框架,可为分布式环境下数据处理中心构建提供一个有效解决方案。 相似文献
19.
准确及时的农情信息是国家与地方政府保障粮食安全与社会稳定的必要条件。云计算的出现为这一需求的实现提供了契机。本文阐述了农情遥感监测云服务平台建设的重要意义、设计思想、总体架构、组成部分以及建设内容。在此基础上,以农情遥感监测产品信息服务为例,开发了一个农情遥感监测信息在线原型系统。该系统是农情遥感监测云服务平台的重要组成部分,负责多尺度时间序列农情遥感监测结果与信息的管理、存储和维护,并且向用户提供查询与下载服务。农情遥感监测云服务平台建设框架的设计为全面整合专家智慧、IT技术、数据资源、服务方式以及平台的实现提供理论指导与建设依据。该平台的建立,将深刻改变农情遥感应用的模式,推动农情遥感的广泛应用与产业化发展。 相似文献
20.
Matt Duckham 《Transactions in GIS》2002,6(2):179-193
The current lack of error-sensitive functionality found in commercial GIS is at odds with the research focus error-sensitive GIS development has enjoyed over recent years. In an attempt to address this undesirable situation, this paper explores the development of error handling capabilities within GIS from the perspective of GIS users. Increasingly, GIS users need to fulfil a variety of different roles, from database designers and data capture personnel through to decision makers, each of which may require an awareness of data quality issues. The user-oriented approach taken here contrasts with the predominately developer-oriented perspective in the literature. The paper concludes that from a user's perspective it is possible to identify a number of simple reformulations of current research that would help bring about the desired increase in availability and use of error-sensitive functionality within commercial GIS technology and applications. 相似文献