Semantic Data Management
Coordinator: Prof. Vassilis Christophides
During last years we have witnessed a tremendous increase in the amount of semantic data that is available on the Web in almost every field of human activity (e.g. Wikipedia, U.S. Census, CIA World Factbook, open government sites in the US and the UK, news and entertainment sources, e-science ontologies and data) have been created and published online. Semantic data management refers to a range of techniques that can be employed for storing, querying, manipulating and integrating data based on its meaning. Current ISL activities in this area focus on two main topics: provenance and access control.
Provenance means the origin of data, and refers from where and how the piece of data was obtained and it is critical in applications such as trust assessment, access control, data cleaning and data/information quality. ISL activities in the domain of provenance for semantic web data target the following research activities:
- development of annotation and abstract provenance models for Semantic Web Data
- efficient storage and indexing schemes for the provenance of Semantic Web Data and
- provenance manipulation languages.
One of the aspects of the problem of secure data management is to enforce access control policies that have been defined to protect data of sensitive nature. Addressing such security concerns mandates the development of generic, flexible access control frameworks that can effectively support a variety of policies for controlling access to Web data in an efficient and effective manner. ISL activities in the domain of secure data management target the following research activities:
- specification languages for access control policies and formalization of their semantics;
- enforcement of access control policies; and
- consistency checking and repairs of access control policies.