Unification of Concept Terms in Description Logics: Revised Version

Unification of concept terms is a new kind of inference problem for Description Logics, which extends the equivalence problem by allowing to replace certain concept names by concept terms before testing for equivalence. We show that this inference problem is of interest for applications, and present first decidability and complexity results for a small concept description language.This revised version of LTCS-Report 97-02 provides a stronger complexity result in Section 6. An abridged version will appear in Proc. ECAI'98

Unfication of Concept Terms in Description Logics

Unification of concept terms is a new kind of inference problem for Description Logics, which extends the equivalence problem by allowing to replace certain concept names by concept terms before testing for equivalence. We show that this inference problem is of interest for applications, and present first decidability and complexity results for a small concept description language

Unification in the Description Logic EL Without Top Constructor

Unification in Description Logics has been proposed as a novel inference service that can, for example, be used to detect redundancies in ontologies. The inexpressive Description Logic EL is of particular interest in this context since, on the one hand, several large biomedical ontologies are defined using EL. On the other hand, unification in EL has recently been shown to be NP-complete, and thus of considerably lower complexity than unification in other DLs of similarly restricted expressive power. However, EL allows the use of the top concept (>), which represents the whole interpretation domain, whereas the large medical ontology SNOMEDCT makes no use of this feature. Surprisingly, removing the top concept from EL makes the unification problem considerably harder. More precisely, we will show that unification in EL without the top concept is PSpace-complete.This is an updated version of the original report that includes Appendix A on locality of unifiers

DCU at the NTCIR-13 Lifelog-2 Task

In this work, we outline the submissions of Dublin City University (DCU) team, the organisers, to the NTCIR-13 Lifelog-2 Task. We submitted runs to the Lifelog Semantics Access (LSAT) and the Lifelog Insight (LIT) sub-tasks

Re-thinking public library spaces with diversity and essential roles

Abstract. After the Internet was developed, public libraries started providing opportunities for many kinds of activities in addition to their traditional services, such as console games, making something in maker space, free Internet connection, and so on. Public library spaces have become more diverse to facilitate this change, and people can use them as free spaces. While this is an excellent way to increase the number of patrons, it seems that the share of people reading books is decreasing among the visitors. As libraries become more convenient and many people use them as free spaces, user interest in library materials is fading away, and thousands of materials have become just decoration. My diploma thesis aims to reorganize public library spaces to promote the essential roles of a library along with the embraced diverse new functions of the public library. Today, when the public library becomes freely used for a broader array of uses than simply reading and borrowing books, we need to rethink the spaces connecting patrons and literature because just placing books on rows of shelves in the library is no longer enough to make anyone read them. In the first part, I refer to current public library designs, concepts, and trends after the Internet has been commonized. I also discuss the future prospection of public libraries through a literature review to consider new public library designs. Secondly, I provide a brief review of design methodology, which approaches the interior and urban aspects to consider the optimal balance between diverse functions and essential roles. In the end, I show the new public library design in Fukushima City as an example of applying the methodology of my design approach. Through this diploma thesis, I suggest a design approach from both interior and urban perspectives as one of the ways to rethink the library space and attempt to see how it creates architecture in the actual site

SNOMED CT standard ontology based on the ontology for general medical science

Background: Systematized Nomenclature of Medicine—Clinical Terms (SNOMED CT, hereafter abbreviated SCT) is acomprehensive medical terminology used for standardizing the storage, retrieval, and exchange of electronic healthdata. Some efforts have been made to capture the contents of SCT as Web Ontology Language (OWL), but theseefforts have been hampered by the size and complexity of SCT. Method: Our proposal here is to develop an upper-level ontology and to use it as the basis for defining the termsin SCT in a way that will support quality assurance of SCT, for example, by allowing consistency checks ofdefinitions and the identification and elimination of redundancies in the SCT vocabulary. Our proposed upper-levelSCT ontology (SCTO) is based on the Ontology for General Medical Science (OGMS). Results: The SCTO is implemented in OWL 2, to support automatic inference and consistency checking. Theapproach will allow integration of SCT data with data annotated using Open Biomedical Ontologies (OBO) Foundryontologies, since the use of OGMS will ensure consistency with the Basic Formal Ontology, which is the top-levelontology of the OBO Foundry. Currently, the SCTO contains 304 classes, 28 properties, 2400 axioms, and 1555annotations. It is publicly available through the bioportal athttp://bioportal.bioontology.org/ontologies/SCTO/. Conclusion: The resulting ontology can enhance the semantics of clinical decision support systems and semanticinteroperability among distributed electronic health records. In addition, the populated ontology can be used forthe automation of mobile health applications

Dismatching and Local Disunification in EL

Unification in Description Logics has been introduced as a means to detect redundancies in ontologies. We try to extend the known decidability results for unification in the Description Logic EL to disunification since negative constraints on unifiers can be used to avoid unwanted unifiers. While decidability of the solvability of general EL-disunification problems remains an open problem, we obtain NP-completeness results for two interesting special cases: dismatching problems, where one side of each negative constraint must be ground, and local solvability of disunification problems, where we restrict the attention to solutions that are built from so-called atoms occurring in the input problem. More precisely, we first show that dismatching can be reduced to local disunification, and then provide two complementary NP-algorithms for finding local solutions of (general) disunification problems

Constructing SNOMED CT Concepts via Disunification

Description Logics (DLs) [BCM+07] are prominent modeling formalisms underlying the Web Ontology Language (OWL). The lightweight DL EL in particular is used to formulate many biomedical ontologies. DLs allow to represent subconcept-superconcept relationships between concepts, e.g., diseases, as well as more complex correspondences. Unification in DLs has been proposed as a non-standard reasoning task to detect redundant concepts in ontologies [BN01, BM10b]. Recently, disunification in EL has been investigated and several algorithms were proposed to solve disunification problems [BBM16]