17347401
RDF-based schema mediation for database grid
In presence of grid where a huge amount of databases can be involved in sharing cycle, database tools and middlewares should be well suited for schema mediation and query processing in a semantically meaningful way. Dart is an implemented prototype system whose goal is to provide a semantic solution for database resource sharing capable of deployment in grid settings. This paper particularly concerns the problems of schema mediation in DartGrid. Our approach mainly involves the following notions: a) we use RDF/OWL to define the mediated ontologies for integration, b) we devise a set of rules for automatically converting the relational schema to RDF/OWL description called source data semantic, c) we define the source data semantic (source schema) as the view of shared ontologies (mediated schema), d) query is formulated and posed on the shared ontologies. A set of grid services is developed for the implementation of above functionalities.
1463101
RDF/RDFS-based Relational Database Integration
We study the problem of answering queries through a RDF/RDFS ontology, given a set of view-based mappings between one or more relational schemas and this target ontology. Particularly, we consider a set of RDFS semantic constraints such as rdfs:subClassof, rdfs:subPropertyof, rdfs:domain, and rdfs:range, which are present in RDF model but neither XML nor relational models. We formally define the query semantics in such an integration scenario, and design a novel query rewriting algorithm to implement the semantics. On our approach, we highlight the important role played by RDF Blank Node in representing incomplete semantics of relational data. A set of semantic tools supporting relational data integration by RDF are also introduced. The approach have been used to integrate 70 relational databases at China Academy of Traditional Chinese Medicine.
3121075
Parameterized Compilability
Compilability is a measure of how effectively compilation (or preprocessing) can be applied to knowledge bases specified in a particular knowledge representation formalism; the aim of compilation is to allow for efficient, on-line query processing. A theory of compilability has been established for organizing knowledge representation formalisms according to a scheme of "compilability classes", and bears strong analogies to the classical theory of complexity, which permits the organization of computational problems according to complexity classes. We develop a novel theory of compilability, called parameterized compilability, which incorporates the notion of parameterization as used in parameterized complexity and permits for refined analysis of compilability.
10326556
Orthogonal and Straight-Line Drawings of Graphs with Succinct Representations
The concept of a hierarchical design has played an important role in various areas of computer science and engineering, including software engineering, CAD, among others. Graphs with hierarchical structures, which are capable of describing large-scale regular structures in a succinct manner, have naturally become an interesting and important modeling tool for facilitating such a hierarchical design. In the literature, a number of succinct models for representing graphs with hierarchical structures have been proposed. See, e.g., [4,5]. In each of such hierarchical graph models, a succinct description is capable of representing a graph (which can be thought of as the expansion of the description) whose size is exponential in the length of the description.
44852271
Managing Misalignments between Business and IT Architectures: A BITAM Case Study
8713624
Intelligent agents meet semantic web in a smart meeting room
We describe a new smart meeting room system called EasyMeeting that explores the use of FIPA agent technologies, Semantic Web ontologies, logic reasoning, and security and privacy policies. Building on a pervasive computing system that we have developed previously, EasyMeeting can provide relevant services and information to meeting participants based on their situational needs. Our system exploits the context-aware support provided by the Context Broker Architecture (CoBrA). Central to CoBrA is an intelligent broker agent that maintains a shared model of context for all computing entities in the space and enforces the privacy policies defined by the users. We also describe the use of CoBrA ontologies, logic reasoning, and privacy protection mechanisms, and evaluate our initial user experience studies.
14330906
Creating Context-Aware Software Agents
Sharing ontologies, sensing context and reasoning are crucial to the realization of context-aware software agents. This document de- scribes our efforts in using the Resource Description Framework (RDF) and Prolog Forward Chaining (Pfc) system to provide support for ontology sharing and reasoning in the CoolAgent Recommendation System (CoolAgent RS), a context-aware multi-agent system. We also describes the implementation of the CoolAgent RS document and cuisine recommendation services that provide tailored services by exploiting user's context.