Loose programming of GIS workflows with geo‐analytical concepts

Loose programming enables analysts to program with concepts instead of procedural code. Data transformations are left underspecified, leaving out procedural details and exploiting knowledge about the applicability of functions to data types. To synthesize workflows of high quality for a geo‐analytical task, the semantic type system needs to reflect knowledge of geographic information systems (GIS) at a level that is deep enough to capture geo‐analytical concepts and intentions, yet shallow enough to generalize over GIS implementations. Recently, core concepts of spatial information and related geo‐analytical concepts were proposed as a way to add the required abstraction level to current geodata models. The core concept data types (CCD) ontology is a semantic type system that can be used to constrain GIS functions for workflow synthesis. However, to date, it is unknown what gain in precision and workflow quality can be expected. In this article we synthesize workflows by annotating GIS tools with these types, specifying a range of common analytical tasks taken from an urban livability scenario. We measure the quality of automatically synthesized workflows against a benchmark generated from common data types. Results show that CCD concepts significantly improve the precision of workflow synthesis.     

GML模式匹配算法

提出了一个面向空间信息集成的GML模式匹配算法，其核心思想是将GML模式转化成树状结构．通过测度两个树状结构的相似度来判断两个对应模式的匹配程度。在GML规范基础上．给出了GML模式的匹配算法和匹配器结构，并实现了相关算法，进而完成GML文档的集成。     

空间服务语义模式的地理信息服务发现

如何从大规模地理信息服务集合中快速且准确地发现目标服务是地理信息服务应用中的一个关键问题。当前基于关键字的服务发现方式缺乏语义支持,搜索效率低。本文在WSMO/WSML框架下,提出了一种基于空间服务语义模式的服务发现方法,将地理信息从语法模式转换为语义模式,明确表达空间数据中隐含的知识,有效克服数据源之间的语义异构。该方法能够显著提高地理信息服务发现的查全率和查准率。     

GIS语义共享的实质及其实现途径

GIS技术下的地理信息共享表现为 GIS数据共享 ,在研究 GIS数据共享时 ,是以最终实现地理信息共享为目的的。为达到这一目的 ,首先必须解决数据本身的共享问题 ,再次要解决数据所表达的语义的共享问题 ,其中包括从数据中读取语义的过程 ,即语义翻译 ,以及所读取的语义与应用目的之间的融合过程 (主要是要解决语义冲突问题 ) ,即语义融合。为了实现 GIS语义共享 ,除要采用一定的技术实现数据本身的共享外 ,还必须选择合适的空间概念及其逻辑表达方法实现语义的共享 ,本文提出采用基于地理要素的空间概念并采用 GIS语义数据模型加以描述可以实现 GIS的语义共享。     

Using Ontologies for Integrated Geographic Information Systems

Today, there is a huge amount of data gathered about the Earth, not only from new spatial information systems, but also from new and more sophisticated data collection technologies. This scenario leads to a number of interesting research challenges, such as how to integrate geographic information of different kinds. The basic motivation of this paper is to introduce a GIS architecture that can enable geographic information integration in a seamless and flexible way based on its semantic value and regardless of its representation. The proposed solution is an ontology-driven geographic information system that acts as a system integrator. In this system, an ontology is a component, such as the database, cooperating to fulfill the system's objectives. By browsing through ontologies the users can be provided with information about the embedded knowledge of the system. Special emphasis is given to the case of remote sensing systems and geographic information systems. The levels of ontologies can be used to guide processes for the extraction of more general or more detailed information. The use of multiple ontologies allows the extraction of information in different stages of classification. The semantic integration of aerial images and GIS is a crucial step towards better geospatial modeling.     

应用描述词汇约简的OGC地理信息服务演绎推理

针对OGC地理信息服务在地理空间知识的有效组织和表达方面的能力比较弱,缺乏对服务信息的描述,数据丰富而知识缺乏,致使已有的数据在知识的表示和检索上存在缺陷,通过引入地理本体,按照基础地理信息要素分类,对地理信息服务的关键描述词汇进行提取,构建了地理信息服务本体库和实例数据库,应用粗糙集理论建立关键描述词汇约简模型,基于该模型实现了对地理信息服务实例数据库进行知识约简,形成最优实例数据库。最后应用地理信息服务本体库和实例数据库,基于演绎推理模型开发实例原型系统,实现了对地理信息服务对象的语义检索和推理,并通过试验从查全率和查准率两个指标验证了该方法的可行性、有效性和准确性。     

基于语义映射的空间数据转换及其应用研究

数据转换是GIS工程建设中的一个十分重要的内容,传统的方法往往只是进行数据格式的转换,忽略了空间数据之间的内在联系,本文将语义映射和空间操作相结合,实现空间数据和属性数据的重构,从而实现异构数据的快速转换。     

移动轨迹的尺度特征

移动轨迹是移动对象在地理空间环境中移动而留下的痕迹。移动轨迹数据是一类特殊的地理时空数据,它具有时间尺度、空间尺度和语义尺度特征。本文首先分析了轨迹数据的空间尺度特征与时间尺度特征,建立了轨迹空间尺度与时间尺度转换关系式;然后论述了轨迹的语义内涵和语义尺度特征,将轨迹语义分为移动对象语义、地理空间环境语义、采集设备语义、移动方式语义,并从地理空间环境语义的角度分析了轨迹的语义多尺度;最后探讨了轨迹语义尺度与时空尺度之间的一致性关系。     

基于本体语义的地理信息服务发现

基于本体语义研究地理信息服务发现问题.将加权语义距离和Wu-Palmer法相结合并进行改进计算本体概念语义相似度.引入服务接口依赖关系,提出支持接口多态性的本体语义地理信息服务输入输出匹配方法.最后开发实验原型对基于本体的地理信息服务匹配方法进行实验与分析.     

基于三维GIS的铁路BIM空间信息系统构建及其工程应用

铁路工程是带状工程,具有范围广、与地形地貌结合紧密的特点。传统BIM设计对海量模型及地理空间分析的支持较弱,难以解决大范围地理环境下铁路工程多专业集成的问题。本文以三维地理信息系统为基础,研究了大范围地理环境下面向铁路BIM多专业设计融合的关键技术,从铁路地理信息数据发布、地理环境下的线路设计、多专业BIM模型无缝拼接、海量模型数据的轻量化与显示策略等方面进行了深入地分析和研究,提出了一套完整的铁路设计BIM+GIS解决方案。在此基础上,构建了基于三维GIS的BIM空间信息平台,在西成高铁BIM试点工程中进行了应用和验证。     

基于FME实现AutoCAD Dwg向Shape数据转换

数据转换是实现GIS(Geographic information system)数据间互操作的重要手段之一。详细阐述目前实现数据转换的几种方法及存在问题,并以AutoCAD dwg数据格式为例,介绍如何利用FME(FeatrueManipulate Engine)语义转换实现AutoCAD dwg数据向GIS shape数据格式转换,并利用脚本程序进行批量处理,这在很大程度上提高了地籍数据入库的效率。     

Ontological Engineering for Interpreting Geospatial Queries

Despite advancements in geographic information system (GIS) technology, the efficient and effective utilization of GIS to solve geospatial problems is a daunting process requiring specialized knowledge and skills. Two of the most important and burdensome tasks in this process are interpretation of geospatial queries and mapping the interpreted results into geospatial data models and geoprocessing operations. With the current state of GIS, there exists a gap between the knowledge user's possess and the knowledge and skills they need to utilize GIS for solving problems. Currently, users resort to training and practice on GIS technology or involving GIS experts. Neither of these options is optimal and there is a need for a new approach that automates geoprocessing tasks using GIS technology. This paper presents an ontological engineering methodology that uses multiple ontologies and the mappings among them to automate certain tasks related to interpretation of geospatial queries and mapping the interpreted results into geospatial data models and geoprocessing operations. The presented methodology includes conceptualization of geospatial queries, knowledge representation for queries, techniques for relating elements in different ontologies, and an algorithm that uses ontologies to map queries to geoprocessing operations.     

当代地理信息系统进展综述

综述当代地理信息技术的发展现状与趋势,涉及地理信息的获取与处理,地理空间数据的管理,地理信息应用服务,地理信息共享技术以及新型GIS如WebGIS、组件GIS、三维GIS和移动GIS等方面的内容。     

Multidimensional Similarity Measuring for Semantic Trajectories

Most existing approaches aiming at measuring trajectory similarity are focused on two‐dimensional sequences of points, called raw trajectories. However, recent proposals have used background geographic information and social media data to enrich these trajectories with a semantic dimension, giving rise to the concept of semantic trajectories. Only a few works have proposed similarity measures for semantic trajectories or multidimensional sequences, having limitations such as predefined weight of the dimensions, sensitivity to noise, tolerance for gaps with different sizes, and the prevalence of the worst dimension similarity. In this article we propose MSM, a novel similarity measure for multidimensional sequences that overcomes the aforementioned limitations by considering and weighting the similarity in all dimensions. MSM is evaluated through an extensive experimental study that, based on a seed trajectory, creates sets of semantic trajectories with controlled transformations to introduce different kinds and levels of dissimilarity. For each set, we compute the similarity between the seed and the transformed trajectories, using different measures. The results showed that MSM was more robust and efficient than related approaches in the domain of semantic trajectories.     

Flexible Standardization: Making Interoperability Accessible to Agencies with Limited Resources

Semantic standardization is an integral part of sharing data for GIS and spatial analysis. It is part of a broader rubric of interoperability or the ability to share geographic information across multiple platforms and contexts. GIScience researchers have made considerable progress towards understanding and addressing the multiple challenges involved in achieving interoperability. For local government agencies interested in sharing spatial data, however, current interoperability approaches based on object-oriented data models represent idealistic solutions to problems of semantic heterogeneity that often exceed the level of sophistication and funding available. They are waiting for the market to decide how interoperability should be resolved. In order to assist in this transition, this paper presents a rule-based Visual Basic application to standardize the semantics of simple spatial entities using several classification systems. We use the example of well-log data, and argue that this approach enables agencies to share and structure data effectively in an interim period during which market and research standards for semantic interoperability are being determined. It contributes to a geospatial data infrastructure, while allowing agencies to share spatial data in a manner consistent with their level of expertise and existing data structures.     

基于Oracle语义城市地图分类信息智能查询

面对万维网日益增长的地图信息查询需求,利用对行政区划、地理要素分类及用户添加等地理要素的语义信息进行辅助地图分类查询。根据相关的标准建立了中国行政区划本体和基础地理要素分类本体,将这两个本体存储到Oracle语义库中,采用SPAQEL完成语义信息查询,以提高地理要素检索的智能性。最后,通过建立的原型系统进行查询试验,验证了语义信息辅助地图分类查询可以提高信息检索的查全率和查准率。     

A Rule-Based Strategy for the Semantic Annotation of Geodata

The ability to represent geospatial semantics is of great importance when building geospatial applications for the Web. This ability will enhance discovery, retrieval and translation of geographic information as well as the reuse of geographic information in different contexts. The problem of generating semantic annotations has been recognized as one of the most serious obstacles for realizing the Geospatial Semantic Web vision. We present a rule‐based strategy for the semantic annotation of geodata that combines Semantic Web and Geospatial Web Services technology. In our approach, rules are employed to partially automate the annotation process. Rules define conditions for identifying geospatial concepts. Based on these rules, spatial analysis procedures are implemented that allow for inferring whether or not a feature in a dataset represents an instance of a geospatial concept. This automated evaluation of features in the dataset generates valuable information for the creation and refinement of semantic annotations on the concept level. The approach is illustrated by a case study on annotating data sources containing representations of lowlands. The presented strategy lays the foundations for the specification of a semantic annotation tool for geospatial web services that supports data providers in annotating their sources according to multiple domain views.     

Ontology‐supported Querying of Geographical Databases

Querying geographical information systems has been recognized as a difficult task for non‐expert users. Furthermore, user queries are often characterized by semantic aspects not directly managed by traditional spatial databases or GIS. Examples of such semantic geospatial queries are the use of implicit spatial relations between objects, or the reference of domain concepts not explicitly represented in data. To handle such queries, we envisage a system that translates natural language queries into spatial SQL statements on a database, thus improving standard GIS with new semantic capabilities. Within this general objective, the contribution of this article is to introduce a methodology to handle semantic geospatial queries issued over a spatial database. This approach captures semantics from an ontology built upon the spatial database and enriched by domain concepts and properties specifically defined to represent the localization of objects. Some examples of the use of the methodology in the urban domain are presented.     

概念格在基础地理本体层次构建中的应用

本文通过研究基础地理信息中概念间的语义层次来改进现有分类标准。文中分析了基础地理信息中存在的三种概念间的层次关系(Hierarchy):a-kind-of、a-part-of和appertaining-to;重点介绍了使用概念格的思想获取a-kind-of(上下位)关系的方法,并通过推理得到了基础地理信息概念的语义体系,分析实验结果表明了概念格方法建立本体层次的有效性。     

面状地图空间信息度量方法研究

如何计算地图的空间信息含量是评价制图质量、地图综合算法以及实现空间信息有效传输的重要基础。本文在详细分析现有的空间信息度量方法的基础上,提出了一种度量面状地图空间信息的新方法。该方法分别从几何、专题、拓扑以及专题拓扑四个方面来度量地图空间信息。通过算例分析发现,本文方法便于定量计算和分析地图空间的信息量。