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ViziQuer: A Web-Based Tool for Visual Diagrammatic Queries Over RDF Data [chapter]

Kārlis Čerāns, Agris Šostaks, Uldis Bojārs, Jūlija Ovčiņņikova, Lelde Lāce, Mikus Grasmanis, Aiga Romāne, Artūrs Sproģis, Juris Bārzdiņš
2018 Lecture Notes in Computer Science  
A query environment can be created over a user-supplied SPARQL endpoint with known data schema (a data schema exploration service is available, as well).  ...  We demonstrate the open source ViziQuer tool for web-based creation and execution of visual diagrammatic queries over RDF/SPARQL data.  ...  Acknowledgements This work has been partially supported by research organization base financing at Institute of Mathematics and Computer Science, University of Latvia and the University of Latvia project  ... 
doi:10.1007/978-3-319-98192-5_30 fatcat:ungvwredfzduvbgj4zpatuuw64

A Framework for Exploration and Visualization of SPARQL Endpoint Information

Maria Krommyda
2020 International Journal of Graph Computing  
The platform handles each query result independently based only on its characteristics, offering an endpoint and data schema agnostic solution.  ...  We present here an integrated platform that supports the users to the querying, exploration and visualization of information contained in SPARQL endpoints.  ...  The Linked Data Query Wizard [50] is a web-based tool for displaying, accessing, ltering, exploring, and navigating Linked Data stored in SPARQL endpoints.  ... 
doi:10.35708/gc1868-126723 fatcat:nc5n6fwkjne2rofkajcpz4oczu

Fusion – Visually Exploring and Eliciting Relationships in Linked Data [chapter]

Samur Araujo, Geert-Jan Houben, Daniel Schwabe, Jan Hidders
2010 Lecture Notes in Computer Science  
Building applications over Linked Data often requires a mapping between the application model and the ontology underlying the source dataset in the Linked Data cloud.  ...  Its architecture allows the creation of new applications through the extension of existing Linked Data with additional data.  ...  queries, since the most direct way to search in an RDF graph in the Linked Data cloud is by issuing SPARQL queries over its remote SPARQL endpoint.  ... 
doi:10.1007/978-3-642-17746-0_1 fatcat:msa5lb22dncuhfrbfwckclttsq

Towards Exploratory OLAP Over Linked Open Data – A Case Study [chapter]

Dilshod Ibragimov, Katja Hose, Torben Bach Pedersen, Esteban Zimányi
2015 Lecture Notes in Business Information Processing  
Based on this information the system is able to query data sources, extract and aggregate data, and build a cube.  ...  In this paper we describe a framework for so-called Exploratory OLAP over RDF sources. We propose a system that uses a multidimensional schema of the OLAP cube expressed in RDF vocabularies.  ...  Data from such knowledge bases are usually freely accessible over SPARQL endpoints.  ... 
doi:10.1007/978-3-662-46839-5_8 fatcat:viwmlikm7rfmfocuhtk34kqbhi

Towards Graphical Query Notation for Semantic Databases [chapter]

Kārlis Čerāns, Jūlija Ovčiņņikova, Mārtiņš Zviedris
2015 Lecture Notes in Business Information Processing  
We describe a notation and a tool for schema-enabled visual/diagrammatic creation of SPARQL queries over RDF databases.  ...  The notation and the tool support both the standard basic query pattern comprising a main query class and possibly linked condition classes and means for aggregate query definition and placing conditions  ...  Acknowledgements This work has been supported by European Union within the ERDF project 'Granular ontology tools for data analysis' (Project No. 2DP/2.1.1.1.0/14/APIA/VIAA/072) and Latvian State Research  ... 
doi:10.1007/978-3-319-21915-8_19 fatcat:2mjzaa7agrcczg4yyeffkxt7nq

Optimizing Analytical Queries over Semantic Web Sources [article]

Dilshod Ibragimov
2017 PhD series, Technical Faculty of IT and Design, ˜Aalborg=ålborgœ University  
[69] presents cost-based optimization strategies for aggregate queries over linked data that are suitable for a single endpoint and does not support the integration of similar data from various endpoints  ...  Data from such knowledge bases are usually freely accessible over SPARQL endpoints.  ... 
doi:10.5278/vbn.phd.tech.00022 fatcat:5d2lmnicazgmze2qhe5cikowwm

An Empirical Meta-analysis of the Life Sciences (Linked?) Open Data on the Web [article]

Maulik R. Kamdar, Mark A. Musen
2020 arXiv   pre-print
In this paper, we extract schemas from more than 80 publicly available biomedical linked data graphs into an LSLOD schema graph and conduct an empirical meta-analysis to evaluate the extent of semantic  ...  We envision that the LSLOD schema graph and the findings from this research will aid researchers who wish to query and integrate data and knowledge from multiple biomedical sources simultaneously on the  ...  Amrapali Zaveri, a staunch advocate for data quality issues  ... 
arXiv:2006.04161v1 fatcat:e2b35ti4cbguhgj3rwf4wml7zq

Result Optimisation for Federated SPARQL Queries

Arooj Fatima, Cristina Luca, George Wilson, Mohamed Kettouch
2015 2015 17th UKSim-AMSS International Conference on Modelling and Simulation (UKSim)  
The focus of this paper is the result optimisation for the data received as a result of running queries over different SPARQL end-points.  ...  Linked open data end-points are accessible to users and applications to exploit semantic data. However it is not very usable for non-expert users.  ...  SPARQL endpoints are the access points for Linked Open Data.  ... 
doi:10.1109/uksim.2015.50 dblp:conf/uksim/FatimaLWK15 fatcat:wvldtxt3nnchlpieanoitcweju

A fuzzy logic system to evaluate levels of trust on linked open data resources

Paulo Alonso Gaona-García, Jhon Francined Herrera-Cubides, Jorge Iván Alonso-Echeverri, Kevin Alexandre Riaño-Vargas, Adriana Carolina Gómez-Acosta
2018 Revista Facultad de Ingeniería  
One of the strategies used to perform linked resources queries is through the consumption of SPARQL Endpoints.  ...  Linked Data is a way of using the network by creating links among data from different information sources in order to improve search processes, semantic interoperability among other functionalities.  ...  This research has been developed within the framework of the doctoral research project on Linked Data, at the District University Francisco José de Caldas.  ... 
doi:10.17533/udea.redin.n86a06 fatcat:c6lrhhk2s5gazdo4pb45dbxrei

An empirical meta-analysis of the life sciences linked open data on the web

Maulik R. Kamdar, Mark A. Musen
2021 Scientific Data  
In this paper, we extract schemas from more than 80 biomedical linked open data sources into an LSLOD schema graph and conduct an empirical meta-analysis to evaluate the extent of semantic heterogeneity  ...  We envision that the LSLOD schema graph and the findings from this research will aid researchers who wish to query and integrate data and knowledge from multiple biomedical sources simultaneously on the  ...  However, the linked data profiling algorithms have, in many cases, only been implemented over some of the popular SPARQL endpoints, do not account for variable SPARQL versions, require the retrieval of  ... 
doi:10.1038/s41597-021-00797-y pmid:33479214 fatcat:iealrgcwwbhjlicg7m43mj4mee

PepeSearch: Semantic Data for the Masses

Guillermo Vega-Gorgojo, Martin Giese, Simen Heggestøyl, Ahmet Soylu, Arild Waaler, Jaap Kamps
2016 PLoS ONE  
We also assessed its portability by configuring PepeSearch to query other SPARQL endpoints.  ...  We have tested PepeSearch with 15 participants searching a Linked Open Data version of the Norwegian Register of Business Enterprises for non-trivial challenges.  ...  Visual Graph-based query editors Medium High/Medium NITELIGHT [13], QueryVOWL [14] Natural choice for RDF data Not very usable for mainstream users Form-based query editors High Medium  ... 
doi:10.1371/journal.pone.0151573 pmid:26967899 pmcid:PMC4788387 fatcat:p4rgzcvdjbepzhxkzi74fhumyq

Automatic Bootstrapping of GraphQL Endpoints for RDF Triple Stores

Lars Christoph Gleim, Tim Holzheim, István Koren, Stefan Josef Decker
2020 CEUR Workshop Proceedings  
GraphQL is a query language for graph-structured Web APIs, increasingly popular among Web developers and recently explored as an alternative query language for Linked Data and its underlying RDF data model  ...  the underlying RDF data.We present Ultra-GraphQL (UGQL), an open source tool enabling the automatic bootstrapping of GraphQL endpoints for existing RDF triple stores, based on an adaptable SPARQL schema  ...  extraction for data structure visualization.  ... 
doi:10.18154/rwth-conv-242785 fatcat:ig7ssod575g4rmlkzbb6zxtiyu

Ornithology Based on Linking Bird Observations with Weather Data [chapter]

Mikko Koho, Eero Hyvönen, Aleksi Lehikoinen
2014 Lecture Notes in Computer Science  
To support data exploration, the data is published in a SPARQL endpoint service using the RDF Data Cube model, on which semantic search and visualization tools are built. 12  ...  This paper presents the first results of a use case of Linked Data for eScience, where 0.5 million rows of bird migration observations over 30 years time span are linked with 0.1 million rows of related  ...  ., National Research Data Initiative (TTA) 25 , and the Linked Data Finland project 26 funded by the Finnish Funding Agency for Innovation (Tekes) of 20 partners.  ... 
doi:10.1007/978-3-319-11955-7_7 fatcat:g5zjc73dpjcxjgint7qryzss5i

TranQL: An Interactive Query and Visualization Environment for Federated Knowledge Graphs (Preprint)

Steven Cox, Stanley C. Ahalt, James Balhoff, Chris Bizon, Karamarie Fecho, Yaphet Kebede, Kenneth Morton, Alexander Tropsha, Patrick Wang, Hao Xu
2020 JMIR Medical Informatics  
The use cases posed questions that traversed 2 federated Translator API endpoints: Integrated Clinical and Environmental Exposures Service (ICEES) and Reasoning Over Biomedical Objects linked in Knowledge  ...  We successfully posed queries to TranQL that traversed these endpoints and retrieved answers that we visualized and evaluated.  ...  The authors thank Matt Brush and Chris Mungall for creating and publishing the Biolink data model, and Eric Deutch and David Koslicki for contributing to the Translator KGS API specification.  ... 
doi:10.2196/17964 pmid:33226347 fatcat:catqasmnhrdrxid4hvmsax2ox4

ReVeaLD: A user-driven domain-specific interactive search platform for biomedical research

Maulik R. Kamdar, Dimitris Zeginis, Ali Hasnain, Stefan Decker, Helena F. Deus
2014 Journal of Biomedical Informatics  
In this report we present ReVeaLD (a Real-time Visual Explorer and Aggregator of Linked Data), a user-centered visual analytics platform devised to increase intuitive interaction with data from distributed  ...  ReVeaLD was implemented in a cancer research setting; queries included retrieving data from in silico experiments, protein modeling and gene expression.  ...  The authors would also like to acknowledge Claude Warren, for the development of the GRANATUM Query Engine, Panagiotis Hasapis, for the provision of sample use cases and scenarios in cancer chemoprevention  ... 
doi:10.1016/j.jbi.2013.10.001 pmid:24135450 fatcat:kkbnap7ocfgkhhyi64nycjlaz4
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