• Journal of KIISE:Software and Applications
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• v.36 no.7
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• pp.509-522
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• 2009

The W3C Ontology Working Group has recently developed OWL as an ontology language for the Semantic Web. OWL, however, fails to perform the process of reasoning about temporal knowledge because it lacks full-pleadged semantics for temporal language. Entities in the real world are changing as time passes, while new facts are being introduced as new events occur. KBs without temporal information are incomplete and incorrect. In this paper, we propose an extended temporal ontology language called TL-OWL which provides an abstract syntax and semantics for representing and reasoning about temporal information in the Semantic Web.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.133-150
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• 2007

In this paper we investigate a trend analysis service using Semantic Web technology in a news domain. The trend analysis service can provide more intelligent answers rather than the answer given In current news search engines since it can analyze the passage of time and the relation among news. In order to provide the trend analysis service, the capability of temporal reasoning is required, but the Semantic Web language such as OWL does not support the reasoning capability. Therefore, we propose a language TL-OWL(Temporal Web Ontology Language) extending OWL with the temporal reasoning.

• Journal of information and communication convergence engineering
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• v.2 no.1
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• pp.26-31
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• 2004

In the last few years, The Semantic Web has increased the interest in ontologies. Ontology is an essential component of the semantic web. Ontologies continue to change and evolve. We consider the management of versions in ontology. We study a set of changes based on domain changes, changes in conceptualization, metadata changes, and temporal dimension. In many cases, we want to be able to search in historical versions, query changes in versions, retrieve versions on the temporal dimension. In order to support an ontology query language that supports temporal operations, we consider temporal dimension includes transaction time and valid time. Ontology versioning brings about massive amount of versions to be stored and maintained. We present the storage policies that are storing all the versions, all the sequence of changed element, all the change sets, the aggregation of change sets periodically, and the aggregation of change sets using a criterion. We conduct a set of experiments to compare the performance of each storage policies. We present the experimental results for evaluating the performance of different storage policies from scheme 1 to scheme 5.

• Spatial Information Research
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• v.22 no.5
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• pp.9-18
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• 2014

According to the recent development of the ubiquitous computing environment, the use of spatio-temporal data from sensors with GPS is increasing, and studies on the Semantic Sensor Web using spatio-temporal data for providing different kinds of services are being actively conducted. Especially, the W3C developed the SSNO(Semantic Sensor Network Ontology) which uses sensor-related standards such as the SWE(Sensor Web Enablement) of OGC and defines classes and properties for expressing sensor data. Since these studies are available for the query processing about non-spatio-temporal sensor data, it is hard to apply them to spatio-temporal sensor data processing which uses spatio-temporal data types and operators. Therefore, in this paper, we developed the SWE based on SSNO which supports the spatio-temporal sensor data types and operators expanding spatial data types and operators in "OpenGIS Simple Feature Specification for SQL" by OGC. The system receives SensorML(Sensor Model Language) and O&M (Observations and Measurements) Schema and converts the data into SSNO. It also performs the efficient query processing which supports spatio-temporal operators and reasoning rules. In addition, we have proved that this system can be utilized for the web service by applying it to a virtual scenario.