Now showing items 21-34 of 34

    • OBDA with the Ontop Framework 

      Calvanese D; Cogrel B; Guzel Kalayci E; Komla Ebri S; Kontchakov R; Lanti D; Rezk M; Rodriguez-Muro M; Xiao G (Curran, 2015)
      Ontology-based data access (OBDA) has become a popular paradigm for accessing data stored in legacy sources using Semantic Web technologies. In the OBDA setting, users access the data through a conceptual layer, which ...
    • Ontology-based data access for Maritime Security 

      Brüggemann S; Bereta K; Xiao G; Koubarakis M (Springer, 2016)
      The maritime security domain is challenged by a number of data analysis needs focusing on increasing the maritime situation awareness, i.e., detection and analysis of abnormal vessel behaviors and suspicious vessel movements. ...
    • Ontology-Based Data Access: A Survey 

      Xiao G; Calvanese D; Kontchakov R; Lembo D; Poggi A; Rosati R; Zakharyaschev M (IJCAI Organization, 2018)
      We present the framework of ontology-based data access, a semantic paradigm for providing a convenient and user-friendly access to data repositories, which has been actively developed and studied in the past decade.  ...
    • Ontop-temporal: A Tool for Ontology-based Query Answering over Temporal Data 

      Güzel Kalayci E; Xiao G; Ryzhikov V; Kalayci TE; Calvanese D (ACM, 2018)
      We present Ontop-temporal, an extension of the ontology-based data access system Ontop for query answering with temporal data and ontologies. Ontop is a system to answer SPARQL queries over various data stores, using ...
    • A Rule-based Framework for Creating Instance Data from OpenStreetMap 

      Eiter T; Pan JZ; Schneider P; Simkus M; Xiao G (Springer, 2015)
      Reasoning engines for ontological and rule-based knowledge bases are becoming increasingly important in areas like the Semantic Web or information integration. It has been acknowledged however that judging the performance ...
    • A Semantic Approach to Polystores 

      Kharlamov E; Mailis TP; Bereta K; Bilidas D; Brandt S; Jimènez-Ruiz E; Lamparter S; Neuenstadt C; Özcep ÖL; Soylu A; Svingos C; Xiao G; Zheleznyakov D; Calvanese D; Horrocks I; Giese M; Ioannidis YE; Kotidis Y; Möller R; Waaler A (IEEE, 2016)
      In the database community Polystores is an emerging and promising approach for data federation that aims at designing a unified querying layer over multiple data models. In the Semantic Web community a similar in spirit ...
    • Semantic Rule-Based Equipment Diagnostics 

      Mehdi G; Kharlamov E; Savkovic O; Xiao G; Güzel Kalayci E; Brandt S; Horrocks I; Roshchin M; Runkler TA (Springer, 2017)
      Industrial rule-based diagnostic systems are often data-dependant in the sense that they rely on specific characteristics of individual pieces of equipment. This dependence poses significant challenges in rule authoring, ...
    • Semantic Rules for Machine Diagnostics: Execution and Management 

      Kharlamov E; Savkovic O; Xiao G; Penaloza R; Mehdi G; Roshchin M; Horrocks I (ACM, 2017)
      Rule-based diagnostics of equipment is an important task in industry. In this paper we present how semantic technologies can enhance diagnostics. In particular, we present our semantic rule language sigRL that is inspired ...
    • SemDia: Semantic Rule-Based Equipment Diagnostics Tool 

      Mehdi G; Kharlamov E; Savkovic O; Xiao G; Güzel Kalayci E; Brandt S; Horrocks I; Roshchin M; Runkler TA (ACM, 2017)
      Rule-based diagnostics of power generating equipment is an important task in industry. In this demo we present how semantic technologies can enhance diagnostics. In particular, we present our semantic rule language sigRL ...
    • Theoretical Characterization of Signal Diagnostic Processing Language 

      Savkovic O; Kharlamov E; Xiao G; Mehdi G; Güzel Kalayci E; Nutt W; Roshchin M; Horrocks I (CEUR Workshop Proceedings, 2018)
      In this paper we analyze the theoretical aspects of our semantic rule language, SDRL. Inspired with an industrial collaboration, SDRL is designed to process signals from sensors installed in industrial equipment by filtering, ...
    • Towards practical OBDA with temporal ontologies (position paper) 

      Calvanese D; Güzel Kalayci E; Ryzhikov V; Xiao G (Springer, 2016)
      The temporal dimension of data, which contains such important information as duration or sequence of events and is present in many applications of ontology-based data access (OBDA) concerned with logs or streams, is getting ...
    • Towards Simplification of Analytical Workflows With Semantics at Siemens (Extended Abstract) 

      Kharlamov E; Mehdi G; Savkovic O; Xiao G; Lamparter S; Horrocks I; Waaler A (IEEE, 2018)
      Analytical workflows are heavily used in large and data intensive companies. An important application of such workflows in Siemens is equipment analytics when equipment KPIs and reports are computed by aggregating equipment's ...
    • Virtual OBDA over Expressive Ontologies: Rewritings and Approximations 

      Botoeva E; Calvanese D; Santarelli V; Savo DF; Solimando A; Xiao G (CEUR-WS, 2016)
      In this paper we extend virtual OBDA to more expressive ontology languages than that of DL-Lite_R, which is the logic underpinning the W3C ontology language OWL 2 QL. We achieve this by relying on two well-known mechanisms, ...
    • Visual exploration of multivariate movement events in space-time cube 

      Ding L; Krisp JM; Meng L; Xiao G; Keler A (AGILE, 2016)
      Analyzing large amounts of complex movement data requires appropriate visual and analytical methods. This paper proposes a 2-D star-icon based visualization technique for the visual exploration of multivariate movement ...