Zdenek Kouba

On Data Warehouse and GIS Integration

A system composed of a data warehouse (DWH) integrated with geographical information system (GIS) yields significant advantages and introduces a new decision making support quality. The advantages, drawbacks and implementation strategies of the integrated system are discussed. This paper attempts to identify necessary requirements for functionality of the integration module in order to provide complete and consistent system interconnection. The solution should be general enough to be easily reimplemented for a large family of GIS and DWH. Within the project, special attention should be dedicated to the methodology of spatial data aggregation. It is necessary to keep in mind that two different types of information can be used to describe spatial data, namely geometric properties (location, area etc.) and topological ones. A software component, which interconnects these two technologies, is under development within the GOAL research project.

Ontology-Driven Information System Design

Conventional information systems are built on top of a relational database that requires its data model to be stable. This lack of adaptability is very restrictive for systems that manipulate evolving or heterogenous knowledge. The authors of this paper faced this issue at the time of the development of an information system of structural failures. As knowledge on structural failures is very heterogeneous and dynamic, it is practically impossible to define a stable database schema ahead. The widely accepted alternative to relational databases are semantic web ontologies. However, software developers miss adequate frameworks and design methodologies in this area. This paper tries to fill the gap by proposing a methodology for designing ontology-backed software applications that make the ontology possible to evolve while being exploited by one or more applications at the same time. The methodology relies on a contract between the ontology and the application that is formally expressed in terms of integrity constraints. Violation of the contract means either that the ontology evolved in a way that is incompatible with the particular application or the application produced invalid data. In the first case, the ontology change must either be rolled back, or the application needs to be upgraded. In the second case, the user has to modify entered data to fulfill the contract. Furthermore, this paper elaborates an object ontological mapping, transaction management, and efficient querying API. A reference Java implementation of the methodology and the proof-of-concept application in the civil engineering domain is introduced at the end of the paper.

OWLDiff: A Practical Tool for Comparison and Merge of OWL Ontologies

As the semantic web is becoming more mature, the need for complex, large, formally described ontologies grows. Developing such ontologies is rather nontrivial and complex task requiring collaboration among knowledge engineers and domain experts. To support ontology sharing we introduce OWLDiff, an OWL 2 ontology comparison/merge tool, its algorithms, implementation details and usage examples. OWLDiff can be used for syntactic, explanation-based and semantic comparison and merging of OWL 2 ontologies and integrates also a Subversion client for ontology versioning. The system is open-source and is available as a standalone application, Protégé plugin and NeOn toolkit plugin.

GOLAP - Geographical Online Analytical Processing

Current geographical information systems (GIS) handle large amounts of geographical data stored usually in relational databases. Database vendors developed special database plug-ins in order to make retrieval of geographical data more efficient. Basically, they implement spatial indexing techniques aimed at speeding-up spatial query processing. This approach is suitable for those spatial queries, which select objects in certain user-defined area. Similarly as on-line transaction processing (OLTP) systems evolved into on-line analytical processing (OLAP) systems for supporting more complicated analytical tasks, similar evolution can be expected in the context of geographical information analytical processing. This paper describes the GOLAP system consisting of a commercial OLAP system enriched with a spatial index. Experiments comparing efficiency of original OLAP and the extended one are presented.

On Updating the Data Warehouse from Multiple Data Sources

The paper discusses various problems related to feeding the data warehouse with data originated in various data sources. The main focus is concentrated on describing and handling of uncertainty, which comes from merging imperfect data sources. Uncertainty measures and their implementation approaches are suggested.

Tools for personalised annotation and organisation of diverse Web resources

The CIPHER project is concerned with developing tools and methodologies to support the exploration of cultural heritage via Web-based Cultural Heritage Forums. As part of the project, a resource annotation tool (RAT) is being developed to support the collection, annotation and retrieval of diverse Web resources to provide content for personal or shared spaces within a forum. Interaction with the RAT tool will enable a user to reuse and personalise an official site ontology, based on personal interests and for a group of users to identify overlapping areas of interest. Tools will further be provided to facilitate users in the construction of coherent stories using their personal content, based on narrative principles. This paper describes the existing functionality of the RAT tool and plans for future development.

A CIM application of a multi-agent system

The paper consists of three parts. In the first one it introduces some general remarks on multi-agent technology, in the second one the modular kit of multi-agent systems developed in the Gerstner Lab is introduced.

On-Line Analysis of Utility Networks

Geographical information systems (GIS) are often used as visualization and analytical means for utility networks applications, because they enable to store information on geographical objects together with their topological and geographical relations. They handle large amounts of geographical data and provide spatial query evaluation on this data. The computationally expensive spatial queries may be improved thanks to the development of on-line analytical processing systems (OLAP) speeding-up the analysis of huge amounts of data stored in large databases. An integration of data warehouse and GIS technologies is the way to enable on-line analysis of geographical information and present its results in geographical contents by native means of the GIS system.

ODCA - Ontology-Based Document and Content Annotation in Structural Health Monitoring

This paper describes an approach and a software tool for document and content annotation in the area of structural health monitoring. By providing domain ontology and reasoning capabilities, it enables to organize large document sets in a way that in situations of need, relevant cases of prior similar situations can be found in an efficient way.

Resource Annotation and Outline Creation Tool (RAT-0)

This paper describes an intelligent approach to annotating information resources identified by Universal Resource Identifiers (URI). It is based on mapping of both the resources and descriptive keywords to concepts defined by existing ontologies. Having ready a database of such annotations, the author of a Web presentation can use it later for fast search of relevant information resources. Resource Annotation and Outline Creation Tool (RAT-O) is a client/server software application based on this approach. It allows annotating resources, as well as to search the database of annotations. Web presentations can be created by defining their outline, which is later enriched by associating text paragraphs or pictures with the appro0priate nodes of the tree representing the outline.