Bronius Paradauskas

REVERSIBLE LOSSLESS TRANSFORMATION FROM OWL 2 ONTOLOGIES INTO RELATIONAL DATABASES

The goal of the paper is to define reversible, information preserving transformation from OWL 2 ontologies into relational databases using our proposed hybrid approach, when a part of ontology constructs is directly represented by relational database structures and another part having no direct correspondences in a relational database is stored in metadata tables. The desirable transformation is defined in QVT Relations language following additional requirements under which such transformation is reversible and does not lose semantic information when performing from ontology to database and backward.

Developing SBVR Vocabularies and Business Rules from OWL2 Ontologies

Semantics of Business Vocabulary and Business Rules (SBVR) is OMG adopted metamodel allowing defining noun concepts, verb concepts and business rules of a problem domain in structured natural language based on formal logics. SBVR business vocabulary and business rules are capable of representing ontologies. There are some research works devoted to transforming SBVR into Web Ontology Language OWL2. The reverse way of representing ontology concepts with SBVR structured language was not investigated though there are much more ontologies than SBVR vocabularies. Our research is concentrated on methodology for creating SBVR vocabularies and rules from OWL2 ontologies without a loss of the expressive power, characteristic for ontologies, as some ontology-specific concepts have no direct representation in SBVR. The particular attention is devoted to applying SBVR vocabulary in semantic search.

Preserving Semantics of Owl 2 Ontologies in Relational Databases Using Hybrid Approach

The goal of the paper is to define conditions, under which semantics of OWL 2 ontologies may be preserved in relational database, and to demonstrate that the hybrid approach for transforming OWL 2 ontologies into relational databases possesses such capability. The paper analyzes requirements for ontologies under transformation as ontology normalization and integrity rules, and presents an example model of Vehicle ontology, conforming to these rules. A schema of a database generated by applying the hybrid approach maps part of ontology concepts to relational database concepts on the base of their common semantics; ontology constructs having no direct equivalents in databases are stored in metatables. SQL queries are presented that demonstrate how metatables may be used for extracting rich information covering semantics of source ontology. DOI: http://dx.doi.org/10.5755/j01.itc.41.2.833

Representing and Transforming SBVR Question Patterns into SPARQL

The goal of the paper is to present question patterns in structured natural language and their transformations into ontology query language SPARQL for allowing business participants to communicate with business software services and data in more flexible and friendly way. The structured language is based on Semantics of Business Vocabulary and Business Rules (SBVR) metamodel, which allows creating and managing business vocabularies and business rules in specific domains. The current paper is focused on transforming question patterns, including usage of synonyms and synonymous forms; projecting formulations constrained by atomic formulations based on facts and fact types; projections on several variables; restricting query results by auxiliary variables constrained by various logical formulations; supplementing questions with derivation rules from SBVR vocabulary of business rules, etc. Patterns are followed by examples, proved by implemented SBVR query editor and SBVR to SPARQL transformations.

Model driven development of data warehouses

Long lasting and heavyweight data warehouse development processes may be far more automated using set of standard schema and data transformations based on relevant conceptual models. Model-driven method for development of data warehouses is proposed based on primary concept model and warehouse concept model. The primary concept model treats object types and their properties as individual concepts and enables direct conversion to warehouse schema; it may be easily extracted from normalized relational schema of database. The concept model enables to get warehouse schema in multi-dimensional normal form that ensures avoiding of aggregation anomalies. It suggests extracting of operational data to warehouse in their original fine-grained form thus allowing flexibility of queries. Transformations between primary concept model and warehouse concept model enable automatic or semi-automatic development of warehouse schema. Important issue from this research is in the fact that normalization of operational databases not only secures from update anomalies but also makes it possible to easy using of operational data in warehousing

Experimental investigation of transformations from SBVR business vocabularies and business rules to owl 2 ontologies

The goal of the paper is to analyse the relevance of the proposed transformation from SBVR business vocabularies and business rules to the corresponding OWL 2 ontologies. The transformation was aimed to be model driven, lossless and reversible; covering transformable SBVR concepts and as much as possible OWL 2 concepts, especially those that are important for inference; supporting the consistency and normalization of resulting ontologies. The paper presents the detailed comparison of the proposed solution with the most advanced, to our knowledge, related works and experimental investigation of the implemented transformation prototype with nine SBVR business vocabularies and business rule sets with regards to defined desirable criteria. DOI: http://dx.doi.org/10.5755/j01.itc.45.2.8873

A Grammar for ADVANCED SBVR Editor

SBVR is the richest knowledge model allowing to create specifications that are understandable for business people and also interpretable by computers. Existing SBVR editors still lack capabilities that could allow generating formal SBVR models, adapting SBVR to several languages or making SBVR extensions for various purposes without changing SBVR metamodel.The goal of the paper is to present the Xtext grammar for SBVR structured language and the prototype of SBVR editor, created on the base of this grammar. The experiment conducted with the prototype has shown that it allows defining business vocabularies, business rules and questions in SBVR structured English and Lithuanian languages; produxing formal SBVR models; using concepts from several vocabularies , and extending SBVR without changing its metamodel. DOI: http://dx.doi.org/10.5755/j01.itc.45.1.9219

Rules for Transforming OWL 2 Ontology into SBVR

Our research is concentrated on defining transformation rules from OWL 2 ontologies into SBVR vocabularies and rules without a loss of information and the expressive power, characteristic for ontologies, overcoming the fact that some ontology-specific concepts have no direct representation in SBVR. Our focus is on generic transformation rules, but the particular attention is devoted to ontologies and vocabularies related with semantic search in Lithuanian Internet corpus. Therefore, we consider some particular constructs related with our application domain, including the idea of creating domain-specific lexical ontologies, related with domain ontologies and capable to support semantic annotating and search.

Conceptual object–relationship–property approach: three different interpretations of the same entity

In this paper the universal structural type of entities is presented by recursive applications of two operators, i.e., operator which constructs positioned subsets of entity name universum and operator which constructs a functional set on the entity name universum. The object subtype is determined using an especial commutational diagram with the compositions of inner functions. The main integration rule of conceptual object-relationship-property scheme is determined by means of external containment function. A compositions of inner and external functions serve as a tool for normalization of entities systems. The advantages of proposed approach to the modelling of entities system are pointed out.