权限扩展RBAC模型的本体表示和实现

针对基于角色的访问控制(RBAC)模型对权限实体的刻画能力不足,提出了带权限层次扩展的RBAC模型。为结合本体在知识表示和推理方面的优势,提出了该模型的本体表示和实现方法。该方法使用Web本体语言(OWL)表示该扩展模型,借助语义Web规则语言(SWRL)定义模型中应用逻辑规则,隐式授权知识经规则推理获得。在此基础上,通过SPARQL协议和RDF查询语言(SPARQL)查询命令生成显式和隐式授权视图,实现系统安全状态分析。最后,给出了具体应用示例,表明该方法的可行性。     

Bridging the gap between OWL and relational databases

Despite similarities between the Web Ontology Language (OWL) and schema languages traditionally used in relational databases, systems based on these languages exhibit quite different behavior in practice. The schema statements in relational databases are usually interpreted as integrity constraints and are used to check whether the data is structured according to the schema. OWL allows for axioms that resemble integrity constraints; however, these axioms are interpreted under the standard first-order semantics and not as checks. This often leads to confusion and is inappropriate in certain data-centric applications. To explain the source of this confusion, in this paper we compare OWL and relational databases w.r.t. their schema languages and basic computational problems. Based on this comparison, we extend OWL with integrity constraints that capture the intuition behind similar statements in relational databases. We show that, if the integrity constraints are satisfied, they need not be considered while answering a broad range of positive queries. Finally, we discuss several algorithms for checking integrity constraint satisfaction, each of which is suitable to different types of OWL knowledge bases.     

OWL rules: A proposal and prototype implementation

Although the OWL Web Ontology Language adds considerable expressive power to the Semantic Web it does have expressive limitations, particularly with respect to what can be said about properties. We present the Semantic Web Rule Language (SWRL), a Horn clause rules extension to OWL that overcomes many of these limitations. SWRL extends OWL in a syntactically and semantically coherent manner: the basic syntax for SWRL rules is an extension of the abstract syntax for OWL DL and OWL Lite; SWRL rules are given formal meaning via an extension of the OWL DL model-theoretic semantics; SWRL rules are given an XML syntax based on the OWL XML presentation syntax; and a mapping from SWRL rules to RDF graphs is given based on the OWL RDF/XML exchange syntax. We discuss the expressive power of SWRL, showing that the ontology consistency problem is undecidable, provide several examples of SWRL usage, and discuss a prototype implementation of reasoning support for SWRL.     

XSWRL,an Extended Semantic Web Rule Language and prototype implementation

Although the OWL (Web Ontology Language) and SWRL (Semantic Web Rule Language) add considerable expressiveness to the Semantic Web they do have expressive limitations. For some reasoning problems it is necessary to infer the existence of new individuals satisfying stated condition. This kind of problems can not be fully resolved by OWL and SWRL. We present the XSWRL (Extended Semantic Web Rule Language), an extension to SWRL, to overcome these problems. XSWRL introduces existentially quantified variables to rules. XSWRL extends SWRL in a syntactically and semantically coherent manner. We show that while the expressiveness of the Semantic Web language is improved, the undecidability and infinite chains are brought on. We define the inseparable set of atoms to separate XSWRL rules, and discuss a prototype implementation of reasoning support for XSWRL.     

Expressing inter-link constraints in OWL knowledge bases

Abstract: In this paper the Web Ontology Language (OWL) is examined to instantiate expert system knowledge bases intended for semantic Web applications. In particular, OWL is analyzed for expressing Unified Modeling Language (UML) representations that have been augmented with propositional logic asserted as inter‐link constraints. The motivation is ultimately to provide declarative propositional logic constraints that can be represented in UML and declaratively implemented using OWL and other constructs to realize semantic Web knowledge base repositories and databases to facilitate expert system applications. The results of this paper show that OWL is sufficient for capturing most inter‐link constraints asserted on generalization/specialization instances; however, OWL alone is inadequate for representing some inter‐link constraints asserted on associations. We propose enhancements to OWL via RDF extensions for the reification of associations into classes. These extensions mitigate all concerns that were identified in OWL as part of this study. The result is increased support of declarative constraint representations, which can be expressed in knowledge bases in the context of the semantic Web.     

基于本体的大规模定制产品配置模型

依据产品配置领域的相关知识,提出一种基于本体的大规模定制产品配置概念模型,其中包括配置类型和约束类。定义模型中每个概念及其关系,运用Web本体语言对其进行形式化的描述,使用语义Web规则语言表达特定的约束规则,基于Protégé对该模型进行有效性检验。     

Identification and resolution of conflicts during ontological integration using rules

Abstract: Integration of ontologies of information sources and consumers is an important phase in achieving web‐based interoperability. The present work describes an approach for identifying certain semantic conflicts while integrating ontologies of heterogeneous information sources. This paper is focused on the identification of homonymy and synonymy between elements in ontologies. In the present work the concepts of homonymy and synonymy are synonymous to naming conflicts and entity identifier conflicts, respectively, and partial synonymy is synonymous to schema isomorphism conflicts. The concept of the mask of interoperability is introduced for the identification of synonymy. The mask of interoperability is expressed in a declarative way as a set of rules, which can then be used for resolution of conflicts during integration of ontologies. As proof of concept, ontologies are implemented using the XML‐based ontology language Ontology Web Language (OWL), and the rules are implemented using the emerging rule language Semantic Web Rule Language (SWRL). This representation in OWL and SWRL allows the ontology to be executable, flexibly extendable and platform‐independent. The OWL facts and SWRL rules are used by the Jess and Bossam reasoning engine to identify semantic homonymy and synonymy.     

基于语义的访问控制模型及其推理机制

对语义Web上资源进行访问要求授权决策充分考虑实体之间的语义关系,但传统的访问控制模型不能处理该问题。结合基于本体的语义描述技术和基于语义规则的推理机制,将不同的语义内部关系归纳为包含关系,提出一种面向语义Web的基于语义的访问控制模型,研究其语义授权推理机制,并提出一个推理实现系统。     

基于语义Web的受控自然语言系统推理模型

虽然相关研究组织提供了语义Web的一些简化工具,但是对不具备相关背景知识的领域专家来说,语义Web的可用性较低。提出了基于语义Web的受控自然语言系统推理模型,以解决这个问题。首先给出受控自然语言系统推理模型框架;然后分析受控自然语言的语言处理部分,提出基于WordNct的受控自然语言系统的本体词库模型和基于本体词库的受控自然语言解释器,把受控自然语言转换成中间表达语言篇章表述结构;最后通过推理部分把篇章表述结构转换成语义Web的本体和规则,通过模板工具映射成Jess的事实和规则,根据预定义的语义Web的公理和定理对受控自然语言进行推理。试验证明此模型大大提高了知识表示建模的效率,也基本满足简单推理任务,具有实用价值。     

基于上下文推理的指挥所业务交互研究

基于指挥所操作业务的应用需求,定义适用于指挥所中人机交互的上下文信息。在选取该上下文信息的过程中,利用OWL语言完成指挥所业务上下文描述,建立交互信息上下文感知模型。运用SWRL逻辑规则对交互信息上下文进行推理,获得业务交互过程中高层上下文语义后进行自适应调整。以一个师指挥所作战指挥业务想定为例,说明计算机通过用户交互位置和上级指令上下文信息进行调整,从而满足当前用户的交互位置和交互业务。     

Development of a product configuration system with an ontology-based approach

Product configuration is a crucial means to implement the mass customization paradigm by assembling a set of customizable components to satisfy both customers’ needs and technical constraints. With the aim of enabling efficient and effective development of product configuration systems by reusing configuration knowledge, an ontology-based approach to modeling product configuration knowledge is presented in this paper. The ontology-based product configuration models are hierarchically organized. At the lower level, a configuration meta-model is defined. Based on this meta-model, domain-specific configuration knowledge can be derived by reusing or inheriting the classes or relations in the meta-model. Configuration models are formalized using OWL (Ontology Web Language), an ontology representation language developed by W3C. As a result, configuration models have well-defined semantics due to the logic semantics of OWL, making it possible to automatically detect inconsistencies of configuration knowledge bases. Furthermore, configuration constraints are represented in SWRL, a rule language based on OWL. Finally, actual configuration processes are carried out using JESS, a rule engine for the Java platform, by mapping OWL-based configuration facts and SWRL-based configuration constraints into JESS facts and JESS rules, respectively. The proposed methodology is illustrated with an example for configuring the ranger drilling machine.     

基于本体的公差规范的自动生成

针对目前公差规范依靠人工指定带来不确定性的问题,在基于本体的公差类型自动生成方法的基础上,研究基于本体的公差规范的自动生成。通过分析公差规范领域知识,提取其中涉及的概念和关系,以此构建公差规范本体,并采用Web本体语言（Web Ontology Language,OWL）编码实现该本体。在所实现本体的基础上,采用语义Web规则语言（Semantic Web Rule Language,SWRL）定义公差规范的生成规则,进而设计公差规范的自动生成算法。应用所设计算法,说明减速器中间传动轴的公差规范自动生成的过程。将为CAD系统中公差规范自动生成的研究提供有效的思路和方法。     

Salient object detection using biogeography-based optimization to combine features

In recent studies, ontology related concepts have been introduced into FIPA ACL content language to convey information for agent communication. However, these works have only applied ontology-based knowledge representation in communication message and then demonstrated the advantage of this association. In fact, although ontology can represent semantic implications needed for decidable reasoning support, it has no mechanism for defining complex rule-based representation to support inference. The motivation of this study is to address this issue by developing a semantic-based infrastructure to integrate Semantic Web technologies into ACL message contents. This semantic-based infrastructure defines two different semantic frameworks: the three-tier knowledge representation framework for message content and the Multi-layer Ontology Architecture for content language. The former is developed based on Semantic Web stack to support ontology-based reasoning and rule-based inference. The latter is adopted to develop a Lightweight Ontology-based Content Language (LOCL) to describe agent communication messages in an unambiguous and computer-interpretable way Jena reasoner is used in an application scenario that exploits agent communication with LOCL as content language, OWL as ontology language, and SWRL as rule language to demonstrate the feasibility of the proposed infrastructure.     

Data exchange and schema mappings in open and closed worlds

In the study of data exchange one usually assumes an open-world semantics, making it possible to extend instances of target schemas. An alternative closed-world semantics only moves ‘as much data as needed’ from the source to the target to satisfy constraints of a schema mapping. It avoids some of the problems exhibited by the open-world semantics, but limits the expressivity of schema mappings. Here we propose a mixed approach: one can designate different attributes of target schemas as open or closed, to combine the additional expressivity of the open-world semantics with the better behavior of query answering in closed worlds. We define such schema mappings, and show that they cover a large space of data exchange solutions with two extremes being the known open and closed-world semantics. We investigate the problems of query answering and schema mapping composition, and prove two trichotomy theorems, classifying their complexity based on the number of open attributes. We find conditions under which schema mappings compose, extending known results to a wide range of closed-world mappings. We also provide results for restricted classes of queries and mappings guaranteeing lower complexity.     

Semantic-based approach for route determination and ontologyupdating

This paper presents a semantic approach for route determination and support for several vehicles sharing the same environment. This approach relies on designing ontologies that use a semantically rich mark-up language (OWL – Ontology Web Language) and the SWRL (Semantic Web Rule Language) rule expression set. A real-time ontology update procedure is also proposed to face unforeseen circumstances. In particular, it has been implemented in a real prototype using an ACO (Ant Colony Optimization) metaheuristic to detect road width variations. Several road crossing configurations have been tested in order to check the performance of the system. The times to calculate the route and resolve priorities at crossings allow the vehicles to navigate in real-time.     

基于本体的语义Web服务QoS描述和发现

WS-QMO是提出的一个用来对Web服务及其QoS信息进行建模和发现的顶层本体,它既可用于对服务QoS信息的描述和发布,也可用于对服务QoS需求的描述.WS-QMO本体基本满足了当前对Web服务QoS语义建模的普遍要求,并且由于适当地加入SWRL规则,它不但可以灵活地自定义单个QoS属性,描述一个QoS属性在不同务件下...