The LNCS journal Transactions on Large-Scale Data- and Knowledge-Centered Systems focuses on
data management knowledge discovery and knowledge processing which are core and hot topics
in computer science. Since the 1990s the Internet has become the main driving force behind
application development in all domains. An increase in the demand for resource sharing across
different sites connected through networks has led to an evolution of data- and
knowledge-management systems from centralized systems to decentralized systems enabling
large-scale distributed applications providing high scalability. Current decentralized systems
still focus on data and knowledge as their main resource. Feasibility of these systems relies
basically on P2P (peer-to-peer) techniques and the support of agent systems with scaling and
decentralized control. Synergy between grids P2P systems and agent technologies is the key to
data- and knowledge-centered systems in large-scale environments. This the 18th issue of
Transactions on Large-Scale Data- and Knowledge-Centered Systems contains extended and revised
versions of seven papers presented at the 24th International Conference on Database and Expert
Systems Applications DEXA 2013 held in Prague in the Czech Republic in August 2013.
Following the conference and two further rounds of reviewing and selection five extended
papers and two invited keynote papers were chosen for inclusion in this special issue. The
subject areas covered include argumentation e-government business processes predictive
traffic estimation semantic model integration top-k query processing uncertainty handling
graph comparison community detection genetic programming and web services.
