Kim Ahlstrøm (Aalborg University) will talk in the LiU Semantic Web Seminars Series

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KimAhlstromOn February 7 (Tuesday), Kim Ahlstrøm of Aalborg University will give a talk in our series of Semantic Web seminars. The title of his talk is:

Towards Answering Provenance-Enabled SPARQL Queries over RDF Data Cubes

Abstract: The SPARQL 1.1 standard has made it possible to formulate analytical queries in SPARQL. While some approaches have become available for processing analytical queries on RDF data cubes, little attention has been paid to answering provenance-enabled queries over such data. Yet, considering provenance is a prerequisite to being able to validate if a query result is trustworthy. The main challenge for existing triple stores is the way provenance can be encoded in standard triple stores based on context values (named graphs). In this talk, I will present shortcomings in existing techniques, and we propose an index to handle the high number of context values that provenance encoding typically entails. Our experimental results using the Star Schema Benchmark show the feasibility and scalability of our index and query evaluation strategies.

Time and date: 3.15pm, February 7, 2017

Location: Campus Valla, Building B, Room “Charles Babbage”

LiU Semantic Web research in Semantic Web Special issue on ontology and linked data matching

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Two papers with co-authors from our group are published in a special issue on ontology and linked data matching of the Semantic Web journal:

Lambrix P, Kaliyaperumal R, A Session-based Ontology Alignment Approach enabling User Involvement, Semantic Web Journal, 8(2):225-251, 2017.

Zhang Z, Gentile A, Blomqvist E, Augenstein I, Ciravegna F, An unsupervised data-driven method to discover equivalent relations in large Linked Datasets, Semantic Web Journal, 8(2):197-223, 2017.

Marjan Alirezaie (Örebro University) will talk in the LiU Semantic Web Seminars Series

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PhotoMarjanAlirezaieOn Tuesday next week, January 24, Marjan Alirezaie of Örebro University will give a talk in our series of Semantic Web seminars. The title of her talk is:

Recent Developments in Bridging the Semantic Gap Problem

Abstract: In this talk, I will present a summary of my PhD thesis which is about bridging the semantic gap between sensor data and ontological knowledge. The focus will be on the recent developments in heterogeneous knowledge integration as a solution for the semantic gap issue. I will also introduce the two research projects: Semantic Robot and E-care@home, with the goal of addressing the knowledge integration problem. In Semantic Robot, we are aiming to provide a semantic layer to a 3D topographic map and making the objects in the 3D map reasoning ready for different purposes such as querying and navigation. Likewise, in Ecare@home which is a Swedish interdisciplinary distributed research environment, our focus is on the development of methods that provide interpretation of the heterogeneous data coming from different types of sensors in conjunction with both medical and environmental knowledge in order to provide e-services for the elderly residing in their homes.

Time and date: 3.15pm, January 24, 2017

Location: Campus Valla, Building B, Room “Alan Turing”

Survey on Ontology Engineering tooling

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Karl Hammar is running a survey on user preferences with regard to ontology tooling, specifically tooling supporting Ontology Design Patterns. As an incentive to take part, a lottery will be held in a few weeks, at which Amazon gift cards to the amount of 50 USD each (or the equivalent in local currency for local Amazon sites), will be awarded to one out of every ten participants in this survey.

Any SemWeb people who are interested in participating in the survey and the lottery are welcome to do so: just follow the instructions below.

Survey Instructions

  1. Surf to http://wp.xd-protege.com, where a customized WebProtégé environment awaits. Register for an account and start a new project.
  2. Look at the scenario described at https://goo.gl/5cXeUP and the corresponding data sets at http://karlhammar.com/ontologies/2016/10/ISWC2016TutorialData.zip
  3. In the WebProtégé install mentioned above, under the tab ”Design Patterns”, check out the listed ontology design patterns from the scenario description.
  4. Try to model a couple of the competency questions from that scenario by way of instantiating ontology design patterns. To do so, find a pattern that you wish to use in the browser, and click the ”Use this pattern” button at the top of the pattern description page, which starts up a pattern instantiation wizard. It should be enough if you run through this wizard once or twice.
  5. Finally, once you’ve run through the wizard once or twice (which should hopefully take no more than 10-15 minutes), please fill out the survey at https://goo.gl/I1MWT4.