Knowledge Engineering in a Temporal Semantic Web Context

2015

Several semantic web-based applications (e.g., ecommerce, e-government and e-health applications) require temporal versioning of ontology instances, in order to represent, store and retrieve time-varying ontologies. However, commercial systems do not provide any support for creating and updating temporal ontologies. In this paper, we propose a prototype system, named Temporal OWL 2 Web Ontology Language Manager (τOWL-Manager), which implements our τOWL framework and supports temporal versioning of ontology instances. It allows (i) creating and validating a temporal semantic web document, by augmenting an OWL 2 ontology schema with a set of logical and physical annotations, and (ii) creating and maintaining time-varying ontology instance documents, by generating a new timestamped version of each ontology instance document when updates are applied. Keywords–Semantic Web; Ontology; OWL 2; τXSchema; Logical annotations; Physical annotations; Temporal database; XML Schema; XML

An important challenge in the Knowledge Representation area is on representing and reasoning over temporally changing information. Particularly, a number of authors have been investigating approaches to extend the expressivity beyond what is currently supported by the DL (Description Logics) based languages in order to address this issue, while maintaining compatibility with subclasses of DLs adopted in the Semantic Web. This is mainly due to the increasing popularity of the Semantic Web initiative as well as the role played by DL in that context. In this paper we defend the need of a higher-level foundational framework based on results coming from the discipline of Formal Ontology. We present two complementary proposals for modeling temporally changing information in OWL, based on the most discussed strategy in the literature to address this problem, namely, the use of a perdurantist (or 4D) view of domain entities. Moreover we compare the results with some related work and discuss its limitations and further improvements.

Proceedings of the 9th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management

Representing time over the Semantic Web has always been a challenging issue that many scientific works were interested to address. To the best of our knowledge, the most important ones focused on models, whereas Semantic Web and especially OWL 2 offers semantics that can be efficiently used to describe qualitative diachronic information (i.e. information evolving in time and which start and/or end time is unknown). In this work, we show the relationship between the OWL 2 semantics and the representation of time intervals; then we introduce a qualitative representation of temporal information based on a set of SWRL rules, that allows a sound and complete reasoning mechanism.

2004

We present our experience on reusing time ontologies in Fund Finder, a semantic web application of the EU Esperonto project. On the one hand, we show a set of time ontologies implemented in different machine readable languages. Such ontologies are analyzed considering a series of features typical of time models (e.g., if they consider different granularities or different time zones). On the other hand, we present the specification of time modeling necessities for Fund Finder. Finally, we choose the ontology which fits best with the specifications.

Information Technology, 2000

Ontologies play an important role in semantic web applications and are often developed by different groups and continues to evolve over time. The knowledge in ontologies changes very rapidly that make the applications outdated if they continue to use old versions or unstable if they jump to new versions. Temporal frames using frame versioning and slot versioning are used to take care of dynamic nature of the ontologies. The paper proposes new tags and restructured OWL format enabling the applications to work with the old or new version of ontologies. Gene Ontology, a very dynamic ontology, has been used as a case study to explain the OWL Ontology with Temporal Tags.

2003

Abstract This paper reports on enriching a (logic-based) query and transformation language for the Web, called Xcerpt, with temporal constructs and temporal reasoning capabilities. Advanced Web applications often refer to temporal data, especially to time points, complex time intervals, and durations. Salient to many advanced Web applications is that they often refer to various calendars. However, current Web languages and formalisms have rather primitive temporal constructs and temporal data processing capabilities–if any.

2019

We present, FT-SWRL, a fuzzy temporal extension to the Semantic Web Rule Language (SWRL), which combines fuzzy theories based on the valid-time temporal model to provide a standard approach for modeling imprecise temporal domain knowledge in OWL ontologies. The proposal introduces a fuzzy temporal model for the semantic web, which is syntactically defined as a fuzzy temporal SWRL ontology (SWRL-FTO) with a new set of fuzzy temporal SWRL built-ins for defining their semantics. The SWRL-FTO hierarchically defines the necessary linguistic terminologies and variables for the fuzzy temporal model. An example model demonstrating the usefulness of the fuzzy temporal SWRL built-ins to model imprecise temporal information is also represented. Fuzzification process of interval-based temporal logic is further discussed as a reasoning paradigm for our FT-SWRL rules, with the aim of achieving a complete OWL-based fuzzy temporal reasoning. Literature review on fuzzy temporal representation approa...

Lecture Notes in Computer Science, 2009

We introduce TOQL, a query language for querying time information in ontologies. TOQL is a high level query language that handles ontologies almost like relational databases. Queries are issued as SQL-like statements involving time (i.e., time points or intervals) or high-level ontology concepts that vary in time. Although independent from TOQL, this work suggests a mechanism for representing time evolving concepts in ontologies based on the four-dimensional perdurantist mechanism. However, TOQL prevents users from being familiar with the representation of time in ontologies. To show proof of concept, an application has been developed that supports translation and execution of TOQL queries on temporal ontologies combined with a reasoning mechanism based on event calculus. A real world temporal ontology is also implemented on which several TOQL example queries are processed and discussed.

2014 UKSim-AMSS 16th International Conference on Computer Modelling and Simulation, 2014

The increasing adoption of Semantic Web technology by several classes of applications in recent years, has made ontology engineering a crucial part of application development. Nowadays, the abundant accessibility of interdependent information from multiple resources and representing various fields such as health, transport, and banking etc., further evidence the growing need for utilising ontology for the development of Web applications. While there have been several advances in the adoption of the ontology for application development, less emphasis is being made on the modelling methodologies for representing modern-day application that are characterised by the temporal nature of the data they process, which is captured from multiple sources. Taking into account the benefits of a methodology in the system development, we propose a novel methodology for modelling ontologies representing Context-Aware Temporal and Interdependent Systems (CATIS). CATIS is an ontology development methodology for modelling temporal interdependent applications in order to achieve the desired results when modelling sophisticated applications with temporal and interdependent attributes to suit today's application requirements.