Generally, the interactivity provided by web applications is carried out through surfing, as a result of a server’s response at the request of a workstation. This is an essential characteristic of this type of software, although in some circumstances it…

Most information in science, engineering and business has been recorded in form of text. This information can be found online in the World-Wide-Web. One of the major tools to support information access are the search engines which usually use information…

Since huge amounts of spatial data can be easily collected from various applications, ranging from remote sensing technology to geographical information system, the extraction and comprehension of spatial knowledge is a more and more important task. Many excellent studies on…

Ontologies serve as a mean to establish a conceptually concise basis for communicating knowledge for many purposes. Within the information integration area, ontologies are useful to solve heterogeneity problems. They provide a set of knowledge terms, including the vocabulary, the…

The Semantic Web attempts to reach a state in the future where everything on the Web will no longer be only machine-readable, but also machine-understandable. An ontology is an explicit specification of a conceptualization. A conceptualization is an abstract, simplified…

A data warehouse efficiently processes a given set of queries by utilizing the multiple materialized views. Owing to the constraint on space and maintenance cost, the materialization of all views is unfeasible. One of the critical decisions involved in the…

Vertical partitioning, in which attributes of a relation are
assigned to partitions, is aimed at improving database
performance. We extend previous research that is based on
a single relation to multi-relation database environment,
by including referential integrity constraints, access time

This paper is an attempt to define how a
specific data structure might be used to
store, in a persistent manner, temporal
information during a computer simulation.
In particular, it considers the sort of
temporal information generated during a
discrete…

We describe the design, implementation and deployment of the multi-level agent-based system architecture developed for the SEWASIE project. The aim of the system is to help the user in querying heterogeneous data sources which are integrated by means of ontologies.…

Similarity search is a fundamental operation for applications that deal with unstructured data sources. In this paper we propose a new pivot-based method for similarity search, called Sparse Spatial Selection (SSS).
The main characteristic of this method is that it…