基于语义网格的注册信息服务模型设计

作为下一代网络新架构,语义网格凭借其强大的语义分析能力及集合网格技术的特征,正逐步被人们认可和接受.尽管网格注册为发布、发现资源提供了用于存储和访问元数据的一些机制,如,元数据目录服务MDS,但是要将其扩展到语义网格上处理资源,这种注册机制还不够完善.因此将Web服务和元数据目录服务引入语义网格的资源管理的信息服务模型中,提出一个语义网格注册信息服务模型.定义该模型的信息模型和语义模型,以此得出语义推理结论,并给出具体的执行过程.     

语义聚集的P2P服务组织模型

针对集中式和传统分布式服务注册与发现机制中存在的问题,提出一种新的服务组织模型。该模型归纳服务系统中各服务功能来建立语义树,依据此语义树产生的语义串对服务进行标识,采用改进的Kademlia算法将服务组织起来,形成按语义树聚集的、使用语义串进行结点发现的P2P覆盖网络,从而解决了单点失效、性能瓶颈问题,实现了不依赖注册中心和注册操作的、自发现的服务调用。它具有高可扩展性,能够支撑动态调度、模糊搜索等应用形式, 已在某服务计算平台中成功应用,该平台已通过验收并连续运行近一年。     

基于SWE的无线传感器网络数据目录服务研究与实现

SWE (Sensor Web Enablement)是基于OGC组织的web服务框架及信息模型提出的针对无线传感器网络资源的框架,通过提供统一的接口及编码实现了异构网络中资源的管理.为实现传感资源的有效整合,在应用SWE基础上扩展了基于ebRIM模型的OGC CSW规范,提出以OGC的SWE框架内SOS服务和CSW规范的融合的方法,并从系统实现角度,讨论了系统设计及数据格式以及实现验证等关键问题.未来的传感应用依赖于海量传感数据处理,对于传感资源的整合需求也应覆盖SWE的全部服务.这也是下一步的努力方向.     

一种语义嫡的社区划分模型及其应用研究

根据复杂网络中整个网络由若干个社区组成和用户通常只对少数主题感兴趣的事实,通过社区语义墒和社区间语义间嫡,提出了一种基于语义信息的社区结构划分模型,将网络划分为几个语义社区,并将其应用在服务注册中心的具体问题中,同时通过社区负载容量等参数进行了实验分析。实验结果表明,该模型充分考虑到了社区间的语义特性,在应用中效率有显著提高,为语义社区结构中的服务注册中心部署提供了新的途径。     

ebXML注册库的一个语义互操作性扩展模型*

定义了注册对象的语义,将注册对象分为简单对象和复合对象;进一步地,针对复合对象的ebXML注册描述了一个基于MOF语义的模型,论述了如何利用它来增强现有的ebRIM的语义互操作,并用实例证明了此方法的正确性。     

基于WPS的空间计算网格技术研究

为解决以Web Services为核心的Globus等通用网格平台框架在异构空间计算资源的抽象整合、注册查找、远程访问协作方面的不足,提出了以OGC(open geospatial consortium)组织制定的WPS(web processing service)服务取代WebServices,构建空间信息领域的计算网格系统。以WPS服务为核心,分别设计了空间计算资源抽象整合、双层注册实体映射和异步服务机制。给出了完整的空间计算网格框架,并进行了相关的应用试验,实验结果表明了基于WPS的空间计算网格能够很好的实现空间计算资源的跨单位共享协作。     

基于Web Service和OWL-S的地理空间信息语义服务

在分析W eb Service服务协议和OGC的地理信息服务框架的基础上,通过引进本体及其语义服务,提出了基于服务本体的地理空间信息语义服务框架,并以缓冲区分析为例进行了地理空间信息W eb服务的语义表达和组合研究。     

语义网站点的发现与排序

随着语义网中RDF数据的大量涌现,语义搜索引擎为用户搜索RDF数据带来了便利.但是,如何自动地发现包含语义网信息资源的站点,并高效地在语义网站点中收集语义网信息资源,一直是语义搜索引擎所面临的问题.首先介绍了语义网站点的链接模型.该模型刻画了语义网站点、语义网信息资源、RDF模型和语义网实体之间的关系.基于该模型讨论了语义网实体的归属问题,并进一步定义了语义网站点的发现规则;另外,从站点链接模型出发,定义了语义网站点依赖图,并给出了对语义网站点进行排序的算法.将相关算法在一个真实的语义搜索引擎中进行了初步测试.实验结果表明,所提出的方法可以有效地发现语义网站点并对站点进行排序.     

基于Ontology的网络教育资源语义检索模型研究

针对传统网络教育资源检索中存在的问题,提出了基于Ontology的网络教育资源语义检索模型,详细论述了模型的实现机制。给出了一套有效的语义检索模型实现方案,从而为语义检索原型系统的开发提供理论和技术支持。     

基于Web Service和OWL—S的地理空间信息语义服务

在分析Web Service服务协议和OGC的地理信息服务框架的基础上，通过引进本体及其语义服务，提出了基于服务本体的地理空间信息语义服务框架，并以缓冲区分析为例进行了地理空间信息Web服务的语义表达和组合研究。     

Sharing geospatial provenance in a service-oriented environment

One of the earliest investigations of provenance was inspired by applications in GIS in the early 1990’s. Provenance records the processing history of a data product. It provides an information context to help users determine the reliability of data products. Conventional provenance applications in GIS focus on provenance capture, representation, and usage in a stand-alone environment such as a desktop-based GIS software system. They cannot support wide sharing and open access of provenance in a distributed environment. The growth of service-oriented sharing and processing of geospatial data brings some new challenges in provenance-aware applications. One is how to share geospatial provenance in an interoperable way. This paper describes the development of provenance service for geospatial data products using the ebXML Registry Information Model (ebRIM) of a geospatial catalog service, which follows the interface specifications of the OGC Catalogue Services for the Web (CSW). This approach fits well the current service stack of the GIS domain and facilitates the management of geospatial data provenance in an open and distributed environment.     

Semantic integration of enterprise information systems using meta-metadata ontology

This paper proposes a non-domain-specific metadata ontology as a core component in a semantic model-based document management system (DMS), a potential contender towards the enterprise information systems of the next generation. What we developed is the core semantic component of an ontology-driven DMS, providing a robust semantic base for describing documents’ metadata. We also enabled semantic services such as automated semantic translation of metadata from one domain to another. The core semantic base consists of three semantic layers, each one serving a different view of documents’ metadata. The core semantic component’s base layer represents a non-domain-specific metadata ontology founded on ebRIM specification. The main purpose of this ontology is to serve as a meta-metadata ontology for other domain-specific metadata ontologies. The base semantic layer provides a generic metadata view. For the sake of enabling domain-specific views of documents’ metadata, we implemented two domain-specific metadata ontologies, semantically layered on top of ebRIM, serving domain-specific views of the metadata. In order to enable semantic translation of metadata from one domain to another, we established model-to-model mappings between these semantic layers by introducing SWRL rules. Having the semantic translation of metadata automated not only allows for effortless switching between different metadata views, but also opens the door for automating the process of documents long-term archiving. For the case study, we chose judicial domain as a promising ground for improving the efficiency of the judiciary by introducing the semantics in this field.     

Use of ebRIM-based CSW with sensor observation services for registry and discovery of remote-sensing observations

Recent advances in Sensor Web geospatial data capture, such as high-resolution in satellite imagery and Web-ready data processing and modeling technologies, have led to the generation of large numbers of datasets from real-time or near real-time observations and measurements. Finding which sensor or data complies with criteria such as specific times, locations, and scales has become a bottleneck for Sensor Web-based applications, especially remote-sensing observations. In this paper, an architecture for use of the integration Sensor Observation Service (SOS) with the Open Geospatial Consortium (OGC) Catalogue Service-Web profile (CSW) is put forward. The architecture consists of a distributed geospatial sensor observation service, a geospatial catalogue service based on the ebXML Registry Information Model (ebRIM), SOS search and registry middleware, and a geospatial sensor portal. The SOS search and registry middleware finds the potential SOS, generating data granule information and inserting the records into CSW. The contents and sequence of the services, the available observations, and the metadata of the observations registry are described. A prototype system is designed and implemented using the service middleware technology and a standard interface and protocol. The feasibility and the response time of registry and retrieval of observations are evaluated using a realistic Earth Observing-1 (EO-1) SOS scenario. Extracting information from SOS requires the same execution time as record generation for CSW. The average data retrieval response time in SOS+CSW mode is 17.6% of that of the SOS-alone mode. The proposed architecture has the more advantages of SOS search and observation data retrieval than the existing sensor Web enabled systems.     

基于本体的网络空间决策支持系统研究*

为了不同的空间决策,往往需要建立相应的空间决策支持系统,在这些空间决策支持系统中,大量的空间数据和模型是可以被重复使用的,因此提出了一种基于本体的空间决策支持系统。该系统能够高效、自动地利用互联网中存在的各类异构空间信息与分析资源来支持空间决策;此外,本系统还提出了一种灵活的体系架构来解决空间决策中存在的语义问题。     

An investigation into the applicability of building information models in geospatial environment in support of site selection and fire response management processes

Some tasks in the construction industry and urban management field such as site selection and fire response management are usually managed by using a Geographical Information System (GIS), as the tasks in these processes require a high level and amount of integrated geospatial information. Recently, a key element of this integrated geospatial information to emerge is detailed geometrical and semantic information about buildings. In parallel, Building Information Models (BIMs) of today have the capacity for storing and representing such detailed geometrical and semantic information. In this context, the research aimed to investigate the applicability of BIMs in geospatial environment by focusing specifically on these two domains; site selection and fire response management. In the first phase of the research two use case scenarios were developed in order to understand the processes in these domains in a more detailed manner and to establish the scope of a possible software development for transferring information from BIMs into the geospatial environment. In the following phase of the research two data models were developed - a Schema-Level Model View and a geospatial data model. The Schema-Level Model View was used in simplifying the information acquired from the BIM, while the geospatial data model acted as the template for creating physical files and databases in the geospatial environment. Following this, three software components to transfer building information into the geospatial environment were designed, developed, and validated. The first component served for acquiring the building information from the BIM, while the latter two served for transforming the information into the geospatial environment.The overall research demonstrated that it is possible to transfer (high level of geometric and semantic) information acquired from BIMs into the geospatial environment. The results also demonstrated that BIMs provide a sufficient level and amount of (geometric and semantic) information (about the building) for the seamless automation of data management tasks in the site selection and fire response management processes.     

Real time query propagation strategies with Lightweight Coordination Calculus (LCC) for ad hoc networks of geospatial databases

Large volumes of geospatial data are increasingly made available through dynamic networks, such as ad hoc networks. Consequently, new adapted query propagation approaches that take into account geospatial aspects of data are needed. Different existing query propagation approaches use various criteria to select relevant sources. In addition, many approaches rely on existing semantic mappings between sources; however, in ad hoc networks, sources move autonomously and in a dynamic fashion. Our goal is rather to reduce the number of sources that must be accessed to answer a query and, therefore, to reduce the volume of semantic mappings that needs to be computed to answer the query. In this paper, we propose three real time query propagation strategies to address this issue. Those strategies reproduce the behavior of members of a social network. The strategies are designed to be part of a real time semantic interoperability framework for ad hoc networks of geospatial databases. The strategies have been formalized with the Lightweight Coordination Calculus (LCC), which support distributed interactions based on social norms and constraints. The implementation and testing of the strategies show that they complement each other to provide optimal query answers.     

Generating Semantic 3D Models of Underground Infrastructure

By combining semantic scene-graph markups with generative modeling, this framework retains semantic information late in the rendering pipeline. It can thus enhance visualization effects and interactive behavior without compromising interactive frame rates. Large geospatial databases are populated with the results of hundreds of person-years of surveying effort. Utility workers access these databases during fieldwork to help them determine asset location. Real-time rendering engines are highly advanced and optimized software toolkits that interactively display 3D information to users.To connect geospatial databases and rendering engines, we must transcode raw 2D geospatial data into 3D models suitable for standard rendering engines. Thus, transcoding isn't simply a one-to-one conversion from one format to another; we obtain 3D models from 2D information through procedural 3D modeling. Transcoding the geospatial database information's semantic attributes into visual primitives entails information loss. We must therefore find the right point in the pipeline to perform transcoding.     

地理空间约束的业务流程建模方法

明晰了受地理空间约束的业务流程的两个基本概念:地理位置与地理空间信息.首先,提出了地理空间约束思想,分析了地理空间约束的内涵,并在工作流元模型的知识基础上构建了地理空间约束的UML语义框架;其次,以形式化的方式提出了地理空间约束的业务流程建模方法(LAWF-net),并描述了LAWF-net模型转化为CPN可执行模型的规则,探讨了地理空间约束对流程建模的影响;最后,通过案例结合GIS系统来扩展CPN Tools,不仅验证了LAWF-net建模方法的可行性,而且实现了地理空间约束的业务流程的可视化.