Guidelines for representing complex cardinality constraints in binary and ternary relationships

Ternary relationships represent the association among three entities whose constraints database designers do not always know how to manage. In other words, it is very difficult for the designer to detect, represent and add constraints in a ternary relationship according to the domain requirements. To remedy the shortcomings in capturing the semantics required for the representation of this kind of relationship, the present paper discusses a practical method to motivate the designer's use of ternary relationships in a methodological framework. The method shows how to calculate cardinality constraints in binary and ternary relationships and to preserve the associated semantics until the implementation phase of the database development method.This work forms part of the ‘Thuban: Natural Interaction Platform for Virtual Attending in Real Environments’ project (TIN2008-02711), the Spanish Ministry of Industry, Tourism and Trade through the project Semants (TSI-020100-2009-419) and also by the Spanish research projects: MA2VICMR: Improving the access, analysis and visibility of the multilingual and multimedia information in web for the Region of Madrid (S2009/TIC-1542).Publicad

Educational experiences detecting, using, and representing ternary relationships in database design

Conceptual models are applied as the first step in software design methodologies for collecting the semantics involved in the universe of discourse. Nevertheless, the abstraction process creates some misunderstandings for novice designers, such as difficulties in modeling some constructs and in understanding the semantics that they represent. This paper presents a thorough study of errors detected among Database Design students in Computer Science Engineering when they apply the abstraction process to generate a conceptual schema using a specific model. Specifically, the paper focuses on errors made in the design of ternary relationships. Some heuristics are proposed in order to help novice designers avoid these common errors, and an experimental study is presented to compare the number of errors made by the students before and after applying these heuristics. (Contains 10 figures, 2 tables, and 3 footnotes.)This work was supported in part by the Software Process Management platform project Modeling, Reuse and Measurement (TIN2004/07083), by the Spanish Ministry of Science and Innovation, and by the Universidad Carlos III de Madrid, which supports the APEINTA research and innovation project.Publicad

Large-scale database modeling: Discovering attributes, entities, and relationships

This thesis is concerned with the team efforts to develop a, large database to track medical information. Entity relational model approach is taken to study an extensive set of forms for structure discovery. This approach has led to thousands of attributes and hundreds of entities and relationships. A meta-database is used to manipulate this data for further design

Lenguajes austeros de modelado conceptual de datos basados en evidencias

Multiple logic-based reconstructions of UML class diagram, Entity Relationship diagrams, and Obect-Role Model diagrams exists. They mainly cover various fragments of these Conceptual Data Modelling Languages and none are formalised such that the logic applies simultaneously for the three language families as a unifying mechanism. This hampers interchangeability, interoperability, and tooling support. In addition, due to the lack of a systematic design process of the logic used for the formalisation, hidden choices permeate the formalisations that have rendered them incompatible. We aim to address these problems, first, by structuring the logic design process in a methodological way. We generalise and extend the DSL design process to logic language design. In particular, a new phase of ontological analysis of language features is included, to apply to logic language design more generally and, in particular, by incorporating an ontological analysis of language features in the process. Second, we specify minimal logic profiles availing of this extended process, including the ontological commitments embedded in the languages, of evidence gathered of language feature usage, and of computational complexity insights from Description Logics (DL). The profiles characterise the essential logic structure needed to handle the semantics of conceptual models, therewith enabling the development of interoperability tools. No known DL language matches exactly the features of those profiles and the common core is in the tractable DL ACJfl. Although hardly any inconsistencies can be derived with the profiles, it is promising for scalable runtime use of conceptual data models.Existen varias reconstrucciones basadas en lógica de lenguajes de modelado conceptual como EER, diagramas de clases UML y ORM. Principalmente cubren fragmentos de estos lenguajes, y sus formalizaciones no están hechas para que se apliquen simultáneamente a estas tres familias de lenguajes como un mecanismo de unificación. Este hecho atenta contra el intercambio y la interoperabilidad de los modelos y el desarrollo de herramientas de soporte. Además, dada la falta de un proceso sistemático de diseño, ciertas decisiones ocultas en la representación lógica hacen que las formalizaciones sean incompatibles. En este trabajo nos proponemos atacar este problema, proponiendo primero un proceso de diseño lógico que puede ser aplicado en forma metodológica. Se generaliza y extiende el proceso DSL para que se pueda aplicar al diseño de lenguajes lógicos en general, incorporando análisis ontológico de las características del lenguaje. Segundo, se especifican perfiles lógicos minimales que sacan provecho de este proceso extendido, incluyendo los compromisos ontológicos asumidos, de evidencia de uso de las características del lenguaje, y de los propiedades computacionales de las Lógicas Descriptivas (DL, description logics). Estos perfiles caracterizan la estructura lógica esencial que se necesita para manejar la semántica de los modelos conceptuales, habilitando el desarrollo de herramientas automáticas de interoperabilidad. No existe correspondencia exacta directa entre estos perfiles y fragmentos conocidos de lenguajes DL, y el núcleo común es pequeño (la lógica tratable ACNT). Aunque es muy poca la posibilidad de derivar inconsistencias dentro de estos perfiles, es prometedor su uso en modelos conceptuales dado su complejidad en tiempo escalable.Facultad de Informátic

Evidence-based lean conceptual data modelling languages

Multiple logic-based reconstructions of conceptual data modelling languages such as EER, UML Class Diagrams, and ORM exist. They mainly cover various fragments of the languages and none are formalised such that the logic applies simultaneously for all three modelling language families as unifying mechanism. This hampers interchangeability, interoperability, and tooling support. In addition, due to the lack of a systematic design process of the logic used for the formalisation, hidden choices permeate the formalisations that have rendered them incompatible. We aim to address these problems, first, by structuring the logic design process in a methodological way. We generalise and extend the DSL design process to apply to logic language design more generally and, in particular, by incorporating an ontological analysis of language features in the process. Second, we specify minimal logic profiles availing of this extended process, including the ontological commitments embedded in the languages, of evidence gathered of language feature usage, and of computational complexity insights from Description Logics (DL). The profiles characterise the essential logic structure needed to handle the semantics of conceptual models, therewith enabling the development of interoperability tools. There is no known DL language that matches exactly the features of those profiles and the common core is small (in the tractable DL ALNI). Although hardly any inconsistencies can be derived with the profiles, it is promising for scalable runtime use of conceptual data models

Evidence-based lean logic profiles for conceptual data modelling languages

Multiple logic-based reconstruction of conceptual data modelling languages such as EER, UML Class Diagrams, and ORM exists. They mainly cover various fragments of the languages and none are formalised such that the logic applies simultaneously for all three modelling language families as unifying mechanism. This hampers interchangeability, interoperability, and tooling support. In addition, due to the lack of a systematic design process of the logic used for the formalisation, hidden choices permeate the formalisations that have rendered them incompatible. We aim to address these problems, first, by structuring the logic design process in a methodological way. We generalise and extend the DSL design process to apply to logic language design more generally and, in particular, by incorporating an ontological analysis of language features in the process. Second, availing of this extended process, of evidence gathered of language feature usage, and of computational complexity insights from Description Logics (DL), we specify logic profiles taking into account the ontological commitments embedded in the languages. The profiles characterise the minimum logic structure needed to handle the semantics of conceptual models, enabling the development of interoperability tools. There is no known DL language that matches exactly the features of those profiles and the common core is small (in the tractable ALNI). Although hardly any inconsistencies can be derived with the profiles, it is promising for scalable runtime use of conceptual data models

Transforming semi-structured life science diagrams into meaningful domain ontologies with DiDOn

AbstractBio-ontology development is a resource-consuming task despite the many open source ontologies available for reuse. Various strategies and tools for bottom-up ontology development have been proposed from a computing angle, yet the most obvious one from a domain expert perspective is unexplored: the abundant diagrams in the sciences. To speed up and simplify bio-ontology development, we propose a detailed, micro-level, procedure, DiDOn, to formalise such semi-structured biological diagrams availing also of a foundational ontology for more precise and interoperable subject domain semantics. The approach is illustrated using Pathway Studio as case study

XML documents schema design

The eXtensible Markup Language (XML) is fast emerging as the dominant standard for storing, describing and interchanging data among various systems and databases on the intemet. It offers schema such as Document Type Definition (DTD) or XML Schema Definition (XSD) for defining the syntax and structure of XML documents. To enable efficient usage of XML documents in any application in large scale electronic environment, it is necessary to avoid data redundancies and update anomalies. Redundancy and anomalies in XML documents can lead not only to higher data storage cost but also to increased costs for data transfer and data manipulation.To overcome this problem, this thesis proposes to establish a formal framework of XML document schema design. To achieve this aim, we propose a method to improve and simplify XML schema design by incorporating a conceptual model of the DTD with a theory of database normalization. A conceptual diagram, Graph-Document Type Definition (G-DTD) is proposed to describe the structure of XML documents at the schema level. For G- DTD itself, we define a structure which incorporates attributes, simple elements, complex elements, and relationship types among them. Furthermore, semantic constraints are also precisely defined in order to capture semantic meanings among the defined XML objects.In addition, to provide a guideline to a well-designed schema for XML documents, we propose a set of normal forms for G-DTD on the basis of rules proposed by Arenas and Libkin and Lv. et al. The corresponding normalization rules to transform from a G- DTD into a normal form schema are also discussed. A case study is given to illustrate the applicability of the concept. As a result, we found that the new normal forms are more concise and practical, in particular as they allow the user to find an 'optimal' structure of XML elements/attributes at the schema level. To prove that our approach is applicable for the database designer, we develop a prototype of XML document schema design using a Z formal specification language. Finally, using the same case study, this formal specification is tested to check for correctness and consistency of the specification. Thus, this gives a confidence that our prototype can be implemented successfully to generate an automatic XML schema design