基于语义Web的地理服务发现框架

在传统Web服务发现架构中,仅凭接口参数的结构化相似度计算匹配方法远远不能满足复杂地理服务的发现需求。本文结合语义Web知识,设计了地理服务发现框架,框架支持地理服务语义化描述、带有语义信息的服务注册、基于语义推理的服务发现。其中,服务匹配算法是服务发现的关键,本文基于传统的四级匹配算法,提出采用分级匹配思想,并在I/O匹配中利用本体分类树,将本体相似度求解转换为分类树中节点距离求解的方法的地理服务发现匹配算法。实例证明,改进的算法不但能区分匹配等级,而且能区分同一匹配等级之间的相似度大小,能较好地满足地理服务的发现的需求。     

基于OWL-S的地理信息服务描述和发现

本文建立了地理数据类型本体和地理服务类型本体,提出了基于OWL-S地理理信息服务发现方法。其核心思想是用OWL-S进行服务描述和发布,通过对服务语义描述中的输入、输出、服务分类进行分级匹配实现服务的自动发现。     

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。     

Identifying geospatial services across heterogeneous taxonomies

Geospatial services with different functions are assembled together to solve complex problems. Different taxonomies are developed to categorize these services into classes. As differences in granularity and semantics exist among these taxonomies, the identification of services across different taxonomies has become a challenge. In this paper, an approach to identify geospatial services across heterogeneous taxonomies is proposed. Using formal concept analysis, existing heterogeneous taxonomies are decomposed into semantic factors and their various combinations. With these semantic factors, a super taxonomy is established to integrate the original heterogeneous taxonomies. Finally, with the super taxonomy as a cross-referencing system, geospatial services with classes in original taxonomies are identifiable across taxonomies. Experiments in service registries and a social media-based spatial-temporal analysis project are presented to illustrate the effectiveness of this approach.     

顾及上下文的空间信息服务组合语义匹配方法

提出了一种顾及上下文的空间信息服务组合语义匹配方法。该方法根据空间信息服务组合的特点,充分考虑了空间信息组合服务对内部抽象原子服务匹配的约束,以及匹配过程中各抽象原子服务上下文之间的相互影响,应用回溯算法思想准确有效地将抽象的空间信息服务组合模型转换为工作流引擎可执行的空间信息服务链。     

多源地理空间矢量数据关联分析

针对多源地理空间矢量数据多来源、难以集成综合利用这一现状，本文提出了多源地理空间矢量数据关联方法，并以此为基础构建了多源地理空间矢量数据关联的可视与计算查询系统。首先，对多源地理空间矢量数据关联的概念及分类进行了定义。然后，以此为基础，提出了关联关系构建技术：自适应四叉树编码技术、扫描线技术、几何匹配及语义匹配技术。最后，为实现关联关系的直观展示，设计了原型系统。关联技术的提出可建立起多源地理空间矢量数据之间的关联关系，原型系统的构建也为用户综合利用多源地理空间矢量数据提供了平台，提高了数据的利用率及数据查询的效能。     

基于网格的空间信息原子服务互操作与集成框架

提出了空间信息原子服务的概念，阐述了其互操作模型与互操作层次结构，进而提出了空间信息原子服务的集成框架，包括服务分类框架、服务链接模式以及由空间信息原子服务、分子服务、流程服务和方案服务组成的服务集成模型。空间信息原子服务概念的提出，对于空间信息服务(GIService)的服务组织与管理、服务集成以及更好地实现软件复用和空间信息互操作等都具有重要的意义。     

A capability matching and ontology reasoning method for high precision OGC web service discovery

Finding the right spatially aware web service in a heterogeneous distributed environment using criteria such as service type, version, time, space, and scale has become a challenge in the integration of geospatial information services. A new method for retrieving Open Geospatial Consortium (OGC) Web Service (OWS) that deals with this challenge using page crawling, link detection, service capability matching, and ontology reasoning, is described in this paper. Its major components are distributed OWS, the OWS search engine, the OWS ontology generator, the ontology-based OWS catalog service, and the ontology-based multi-protocol OWS client. Experimental results show that the execution time of this proposed method equals only 0.26 of that of Nutch's method. In addition, the precision is much higher. Moreover, this proposed method can carry out complex OWS reasoning-based queries. It is being used successfully for the Antarctica multi-protocol OWS portal of the Geo-Information Web Service Portal of the Polar.     

基础地理知识服务的基本问题与研究方向

基础地理数据具有空间载体和知识存量两大作用。以往人们主要关注其空间载体作用，研发和提供了丰富多样的基础地理数据服务与信息服务，但对其知识存量挖掘不够，提供的地理空间知识服务极少。近年来，“数据海量，信息爆炸，知识难求”现象愈加突出，从地理数据信息服务走向知识服务势在必行，已成为测绘科技转型升级的一项重要任务。借鉴知识图谱的最新研究进展，讨论了基础地理数据、信息和知识的基本内涵，提出了以结构化和关联化为重要特征的基础地理知识服务总体思路，分析了由此带来的4方面问题；继而从领域知识体系构建、关键技术、应用服务3个方面讨论了基础地理知识服务的研究方向与重点；以GlobeLand30知识服务为例，介绍了初步研究进展。     

基于Agent的空间信息服务组合研究

首先简要介绍了空间信息服务的研究现状,然后分析了空间信息服务组合的3种主要形式。总结了Agent技术实现聚合式空间信息服务组合的优势,指出Agent的自主性、交互性等特性是解决开放环境下空间信息服务的发现、选择以及组合问题的最佳途径之一。详细设计了基于Agent的空间信息服务模型,阐述了服务发现、服务组合、用户交互3部分的结构和功能,引入词频向量的方法解决服务发现和匹配问题,最后构造了一个基于Agent的空间信息服务组合的用例。     

Using Federated Catalogs to Improve Semantic Integration among Spatial Data Infrastructures

Nowadays, Spatial Data Infrastructures (SDIs) play an important role in government agencies, at different levels: global, national, and local. They aim to improve the management and sharing of geospatial data. Nonetheless, these SDIs have been developed as information islands, in which a user's query is compared to metadata described only in their own catalog services. The lack of interaction among SDIs limits the potential of these infrastructures in providing geospatial data to a larger audience. This article presents a distributed architecture, based on a federation of SDIs which interact among themselves, using query propagation. This propagation facilitates data discovery and sharing. We also describe a distributed query processing service used to enable the resource discovery in distributed infrastructures.     

A framework for connecting two interoperability universes: OGC Web Feature Services and Linked Data

Diverse studies have shown that about 80% of all available data are related to a spatial location. Most of these geospatial data are available as structured and semi‐structured datasets, and often use distinct data models, are encoded using ad‐hoc vocabularies, and sometimes are being published in non‐standard formats. Hence, these data are isolated within silos and cannot be shared and integrated across organizations and communities. Spatial Data Infrastructures (SDIs) have emerged and contributed to significantly enhance data discovery and accessibility based on OGC (Open Geospatial Consortium) Web services. However, finding, accessing, and using data disseminated through SDIs are still difficult for non‐expert users. Overcoming the current geospatial data challenges involves adopting the best practices to expose, share, and integrate data on the Web, that is, Linked Data. In this article, we have developed a framework for generating, enriching, and exploiting geospatial Linked Data from multiple and heterogeneous geospatial data sources. This proposal allows connecting two interoperability universes (SDIs, more specifically Web Feature Services, WFS, and Semantic Web technologies), which is evaluated through a study case in the (geo)biodiversity domain.     

基于Petri网的地理信息服务组合模型研究

地理信息服务应用中,单一的功能服务往往无法独立完成复杂的地理信息应用,需要不同粒度的服务组合及协调机制。本文重点研究地理信息服务的组合建模方法,提出基于Petri网的地理信息服务组合建模理论。首先,给出基于Petri网的地理信息服务的定义和图形化描述,然后结合三维地理信息的应用,给出了三维空间分析服务组合的实例分析,最后通过烟草行业的地理信息服务应用验证基于Petri网的服务组合模型的可行性。     

The framework of a geospatial semantic web-based spatial decision support system for Digital Earth

Abstract

While significant progress has been made to implement the Digital Earth vision, current implementation only makes it easy to integrate and share spatial data from distributed sources and has limited capabilities to integrate data and models for simulating social and physical processes. To achieve effectiveness of decision-making using Digital Earth for understanding the Earth and its systems, new infrastructures that provide capabilities of computational simulation are needed. This paper proposed a framework of geospatial semantic web-based interoperable spatial decision support systems (SDSSs) to expand capabilities of the currently implemented infrastructure of Digital Earth. Main technologies applied in the framework such as heterogeneous ontology integration, ontology-based catalog service, and web service composition were introduced. We proposed a partition-refinement algorithm for ontology matching and integration, and an algorithm for web service discovery and composition. The proposed interoperable SDSS enables decision-makers to reuse and integrate geospatial data and geoprocessing resources from heterogeneous sources across the Internet. Based on the proposed framework, a prototype to assist in protective boundary delimitation for Lunan Stone Forest conservation was implemented to demonstrate how ontology-based web services and the services-oriented architecture can contribute to the development of interoperable SDSSs in support of Digital Earth for decision-making.     

空间服务网格元服务体系的研究

基于服务域技术为空间服务网格构建了一个服务路由树状结构的元服务体系,提供了符合空间信息领域特点的基本元服务和高级元服务,实现了该元服务体系。