ASKW Colloquium, 31 August, 3pm, Dockerizing Linked Data

In this colloquium, Natanael Arndt will present his paper “Knowledge Base Shipping to the Linked Open Data Cloud“.

Abstract: Popular knowledge bases that provide SPARQL endpoints for the web are usually experiencing a high number of requests, which often results in low availability of their interfaces. A common approach to counter the availability issue is to run a local mirror of the knowledge base. Running a SPARQL endpoint is currently a complex task which requires a lot of effort and technical support for domain experts who just want to use the SPARQL interface. With our approach of containerised knowledge base shipping we are introducing a simple to setup methodology for running a local mirror of an RDF knowledge base and SPARQL endpoint with interchangeable exploration components. The flexibility of the presented approach further helps maintaining the publication infrastructure for dataset projects. We are demonstrating and evaluating the presented methodology at the example of the dataset projects DBpedia, Catalogus Professorum Lipsiensium and Sächsisches Pfarrerbuch.

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

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ASKW Colloquium, 24 August, 3pm, Lucene, SOLR, FEASIBLE

In this colloquium, first, Kay Müller and Nilesh Chakraborty will give an overview of Lucene and SOLR and how they can be used in information retrieval scenarios, along with a short peek into ElasticSearch, introducing a few recent features, their respective use-cases and how they compare with SOLR.

Then, Muhammed Saleem will present his paper “FEASIBLE: A Featured-Based SPARQL Benchmark Generation Framework

Abstract: Benchmarking is indispensable when aiming to assess technologies with respect to their suitability for given tasks. While several benchmarks and benchmark generation frameworks have been developed to evaluate triple stores, they mostly provide a one-fits-all solution to the benchmarking problem. This approach to benchmarking is however unsuitable to evaluate the performance of a triple store for a given application with particular requirements. We address this drawback by presenting FEASIBLE, an automatic approach for the generation of benchmarks out of the query history of applications, i.e., query logs. The generation is achieved by selecting prototypical queries of a user-defined size from the input set of queries. We evaluate our approach on two query logs and show that the benchmarks it generates are accurate approximations of the input query logs. Moreover, we compare four different triple stores with benchmarks generated using our approach and show that they behave differently based on the data they contain and the types of queries posed. Our results suggest that FEASIBLE generates better sample queries than the state of the art. In addition, the better query selection and the larger set of query types used lead to triple store rankings which partly differ from the rankings generated by previous works.

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

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AKSW has 10 accepted publications in Semantics’2015 conference

The Semantics‘2015 conference will take place in Vienna, Austria on September 15-17, 2015. AKSW is happy to announce 10 accepted publications: 6 for research track and 4 for demos/posters track. Semantics’2015 has received 93 submissions for research track, out of which 24 were accepted (an acceptance rate of 26%).

For the research track our accepted papers are:

For the poster/demo track:

See you at the conference in September!

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AKSW Colloquium, 17-08-2015, Relational Machine Learning for Knowledge Graphs, Zoo Keeper, Apache Mesos

Relational Machine Learning for Knowledge Graphs

In this colloquium Patrick Westphal will present the paper “A Review of Relational Machine Learning for Knowledge Graphs” by Nickel, Murphy, Tresp and Gabrilovich.

Abstract: Relational machine learning studies methods for the statistical analysis of relational, or graph-structured, data. In this paper, we provide a review of how such statistical models can be “trained” on large knowledge graphs, and then used to predict new facts about the world (which is equivalent to predicting new edges in the graph). In particular, we discuss two different kinds of statistical relational models, both of which can scale to massive datasets. The first is based on tensor factorization methods and related latent variable models. The second is based on mining observable patterns in the graph. We also show how to combine these latent and observable models to get improved modeling power at decreased computational cost. Finally, we discuss how such statistical models of graphs can be combined with text-based information extraction methods for automatically constructing knowledge graphs from the Web. In particular, we discuss Google’s Knowledge Vault project.

Zoo Keeper, Apache Mesos

A short introduction to the coordination system ‘ZooKeeper’ and cluster manager ‘Apache Mesos’ will be presented by Hajira.
Mesos provides efficient resource isolation and sharing across distributed applications and frameworks. It can run a multitude of applications on a dynamically shared pool of resources being coordinated by zookeeper.

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18 AKSW Papers at ISWC 2015

logoWe are very pleased to announce that AKSW will be presenting 18 papers in the upcoming International Semantic Web Conference (ISWC) 2015.  Following are the details:

Research track:

  1. TITLE: FEASIBLE: A Featured-Based SPARQL Benchmarks Generation Framework
    AUTHORS: Muhammad Saleem, Qaiser Mehmood, Axel-Cyrille Ngonga Ngomo
  2. TITLE: LANCE: Piercing to the Heart of Instance Matching Tools
    AUTHORS: Tzanina Saveta, Evangelia Daskalaki, Giorgos Flouris, Irini Fundulaki, Melanie Herschel, Axel-Cyrille Ngonga Ngomo

  In-Use and Software track

  1. TITLE: ASSESS —Automatic Self-Assessment Using Linked Data
    AUTHORS: Lorenz Bühmann, Ricardo Usbeck,  Axel-Cyrille Ngonga Ngomo 
  2. TITLE: Assessing and Refining Mappings to RDF to Improve Data Quality
    AUTHORS: Anastasia Dimou, Dimitris Kontokostas, Markus Freudenberg, Ruben Verborgh, Jens Lehmann, Erik Mannens, Sebastian Hellmann, Rik Van de Walle

  Data Sets and Ontologies

  1. TITLE: LSQ: Linked SPARQL Queries Dataset
    AUTHORS: Muhammad Saleem, Muhammad Intizar Ali, Aidan Hogan, Qaiser Mehmood, Axel-Cyrille Ngonga Ngomo
  2. TITLE: DBpedia Commons: Structured Multimedia Metadata for Wikimedia Commons
    AUTHORS: Gaurav Vaidya, Dimitris Kontokostas, Magnus Knuth, Jens Lehmann, Sebastian Hellmann

  Posters and Demos

  1. TITLE: Enhancing Dataset Quality Using Keys          [demo]
    AUTHORS: Tommaso Soru, Edgard Marx, Axel-Cyrille Ngonga Ngomo
  2. TITLE: The DBpedia Events Dataset          [demo]
    AUTHORS: Magnus Knuth, Jens Lehmann, Dimitris Kontokostas, Thomas Steiner, Harald Sack
  3. TITLE: Test-driven Assessment of [R2]RML Mappings to Improve Dataset Quality
    AUTHORS: Anastasia Dimou, Dimitris Kontokostas, Markus Freudenberg, Ruben Verborgh, Jens Lehmann, Erik Mannens, Sebastian Hellmann, Rik Van de Walle
  4. TITLE: Interoperable Machine Learning Metadata using MEX          [demo]
    AUTHORS: Diego Esteves, Diego Moussallem, Jens Lehmann, Maria Claudia, J.Cesar Duarte
  5. TITLE: Automatic SPARQL Benchmark Generation Using FEASIBLE          [demo]
    AUTHORS: Muhammad Saleem, Qaiser Mehmood, Axel-Cyrille Ngonga Ngomo
  6. TITLE: The LSQ Dataset: Querying for Queries          [demo]
    AUTHORS: Muhammad Saleem, Muhammad Intizar Ali, Aidan Hogan, Qaiser Mehmood, Axel-Cyrille Ngonga Ngomo
  7. TITLE: openQA: An Open-Source Question Answering Framework          [demo]
    AUTHORS: Edgard MarxAxel-Cyrille Ngonga Ngomo 
  8. TITLE: LANCE: A Generic Benchmark Generator for Linked Data
    AUTHORS: Tzanina Saveta, Evangelia Daskalaki, Giorgos Flouris, Irini Fundulaki, Melanie Herschel, Axel-Cyrille Ngonga Ngomo
  9. TITLE: SPARQL Query Formulation and Execution using FedViz          [demo]
    AUTHORS: Syeda Sana e Zainab, Ali Hasnain, Muhammad Saleem, Qaiser Mehmood, Durre Zehra, Stefan Decker

  Workshops

  1. TITLE: FedViz: A Visual Interface for SPARQL Queries Formulation and Execution
    AUTHORS: Syeda Sana e Zainab, Ali Hasnain, Muhammad Saleem, Qaiser Mehmood, Durre Zehra, Stefan Decker
  2. TITLE: Answering Boolean Hybrid Questions with HAWK
    AUTHORS: Ricardo Usbeck, Erik Körner,  Axel-Cyrille Ngonga Ngomo

  Tutorial

TITLE: Federated Query Processing over Linked Data
AUTHORS: Muhammad Saleem, Muhammad Intizar Ali, Ruben Verborgh, Axel-Cyrille Ngonga Ngomo

 

Come over to ISWC 2015 and enjoy the talks.

Best Regards,
Saleem on behalf of AKSW

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Michael Röder at AKSW Colloquium, Monday, 10th August 2015, 3pm

Crawling the Linked Open Data Cloud by Michael Röder

Michael RoederIn the recent years the Linked Open Data Cloud matured to support various applications, e.g., question answering, knowledge inference or database enrichment. Such applications have to be supported by the recent data, which is impossible to retrieve without constant crawling, due to the dynamic nature of the World Wide Web and the cloud as a part of it. On this colloquium Michael is going to talk about the state of the art for Linked Data Crawling as well as the future work that will be done by Ivan Ermilov, Axel-Cyrille Ngonga Ngomo and himself.

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Hajira Jabeen and Ricardo Usbeck at AKSW Colloquium, Monday, 3rd August 2015, 3pm

Hybrid Question Answering at QALD 5 challenge by Ricardo Usbeck

The plethora of datasets on the web, both structured and unstructured, enables answering complex questions such as “Which anti-apartheid activist was born in Mvezo?” Some of those hybrid (source) question answering system have been benchmarked at the QALD 5 challenge at CLEF conference. Ricardo is going to present some of the results and give future research directions.

Slides: https://docs.google.com/presentation/d/1dccMwbPMIeOpzvV1PNCKKxg96xZBSdK2Gav9JynAJjo/edit?usp=sharing

BDE, Hadoop MapR and HDFS by Hajira Jabeen

Hajira will present brief introduction to BigData Europe project (BDE). Followed by , Hadoop HDFS and map reduce for distributed processing of large data sets on compute clusters of commodity hardware. Hadoop is one of the many Big Data components being used in the BDE project.

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

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DL-Learner 1.1 (Supervised Structured Machine Learning Framework) Released

Dear all,

we are happy to announce DL-Learner 1.1.

DL-Learner is a framework containing algorithms for supervised machine learning in RDF and OWL. DL-Learner can use various RDF and OWL serialization formats as well as SPARQL endpoints as input, can connect to most popular OWL reasoners and is easily and flexibly configurable. It extends concepts of Inductive Logic Programming and Relational Learning to the Semantic Web in order to allow powerful data analysis.

Website: http://dl-learner.org
GitHub page: https://github.com/AKSW/DL-Learner
Download: https://github.com/AKSW/DL-Learner/releases
ChangeLog: http://dl-learner.org/development/changelog/

DL-Learner is used for data analysis in other tools such as ORE and RDFUnit. Technically, it uses refinement operator based, pattern based and evolutionary techniques for learning on structured data. For a practical example, see http://dl-learner.org/community/carcinogenesis/. It also offers a plugin for Protege, which can give suggestions for axioms to add. DL-Learner is part of the Linked Data Stack – a repository for Linked Data management tools.

In the current release, we improved the support for SPARQL endpoints as knowledge sources. You can now directly use a SPARQL endpoint for learning without an OWL reasoner on top of it. Moreover, we extended DL-Learner to also consider dates and inverse properties for learning. Further efforts were made to improve our Query Tree Learning algorithms (those are used to learn SPARQL queries rather than OWL class expressions).

We want to thank everyone who helped to create this release, in particular Robert Höhndorf and Giuseppe Rizzo. We also acknowledge support by the recently started SAKE project, in which DL-Learner will be applied to event analysis in manufacturing use cases, as well as the GeoKnow and Big Data Europe projects where it is part of the respective platforms.

Kind regards,

Lorenz Bühmann, Jens Lehmann, Patrick Westphal and Simon Bin

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AKSW Colloquium, 20-07-2015, Enterprise Linked Data Networks

Enterprise Linked Data Networks (PhD progress report) by Marvin Frommhold

marvinFrommholdThe topic of the thesis is the scientific utilization of the LUCID research project, in particular the LUCID Endpoint Prototype. In LUCID we research and develop on Linked Data technologies in order to allow partners in supply chains to describe their work, their companies and their products for other participants. This allows for building distributed networks of supply chain partners on the Web without a centralized infrastructure.

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

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AKSW Colloquium, 13-07-2015

Philipp Frischmuth will give a brief presentation regarding the current state of his PhD thesis and Lukas Eipert will present the topic of his upcoming internship:

As part of an internship at eccenca a configurable graphical RDF editor will be developed. Graphical components such as shapes and arrows will be translated to triples depending on the configuration of the editor. This talk outlines the idea and motivation of this task.

About the AKSW Colloquium

This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw.org/Colloquium for further information about previous and future events. As always, Bachelor and Master students are able to get points for attendance and there is complimentary coffee and cake after the session.

 

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