18 Hits in 5.8 sec

A Survey of RDF Stores SPARQL Engines for Querying Knowledge Graphs [article]

Waqas Ali, Muhammad Saleem, Bin Yao, Aidan Hogan, Axel-Cyrille Ngonga Ngomo
2021 arXiv   pre-print
This survey paper provides a comprehensive review of techniques and systems for querying RDF knowledge graphs.  ...  RDF has seen increased adoption in recent years, prompting the standardization of the SPARQL query language for RDF, and the development of local and distributed engines for processing SPARQL queries.  ...  Sedge [254] (2012) is an RDF store based on Pregel: a distributed (vertex-centric) graph processing framework.  ... 
arXiv:2102.13027v4 fatcat:phontczhbfcvdjt5y75n3hfcge

A distributed query execution engine of big attributed graphs

Omar Batarfi, Radwa Elshawi, Ayman Fayoumi, Ahmed Barnawi, Sherif Sakr
2016 SpringerPlus  
G-SPARQL supports various types of graph querying operations including reachability, pattern matching and shortest path where any G-SPARQL query may include value-based predicates on the descriptive information  ...  , a popular distributed graph processing system, by orders of magnitudes.  ...  G-Path (Bai et al. 2013) has been introduced as a path-based query language on large graphs.  ... 
doi:10.1186/s40064-016-2251-0 pmid:27350905 pmcid:PMC4899405 fatcat:midt5lr2djg2jogjvpbmv4njly

Demystifying Graph Databases: Analysis and Taxonomy of Data Organization, System Designs, and Graph Queries [article]

Maciej Besta, Emanuel Peter, Robert Gerstenberger, Marc Fischer, Michał Podstawski, Claude Barthels, Gustavo Alonso, Torsten Hoefler
2021 arXiv   pre-print
(e.g., RDF or Labeled Property Graph), data organization techniques (e.g., storing graph data in indexing structures or dividing data into records), and different aspects of data distribution and query  ...  We outline graph database queries and relationships with associated domains (NoSQL stores, graph streaming, and dynamic graph algorithms).  ...  To the best of our knowledge, there are no efforts into developing a topology-aware or routing-aware data distribution scheme for graph databases, especially in the context of recently proposed data center  ... 
arXiv:1910.09017v5 fatcat:ta4pzurv3ndyngzjfpl7vhvcui

Knowledge Graphs: New Directions for Knowledge Representation on the Semantic Web (Dagstuhl Seminar 18371)

Piero Andrea Bonatti, Stefan Decker, Axel Polleres, Valentina Presutti, Michael Wagner
2019 Dagstuhl Reports  
and Processing at scale for the Semantic Web.  ...  This report documents the program and the outcomes of Dagstuhl Seminar 18371 "Knowledge Graphs: New Directions for Knowledge Representation on the Semantic Web", where a group of experts from academia  ...  Aidan Hogan is funded by the Millennium Institute for Foundational Research on Data (IMFD) and Fondecyt Grant No. 1181896.  ... 
doi:10.4230/dagrep.8.9.29 dblp:journals/dagstuhl-reports/BonattiDPP18 fatcat:z4lkmofnavf67c5v2sye2x2zle

One Algorithm to Evaluate Them All: Unified Linear Algebra Based Approach to Evaluate Both Regular and Context-Free Path Queries [article]

Ekaterina Shemetova, Rustam Azimov, Egor Orachev, Ilya Epelbaum, Semyon Grigorev
2021 arXiv   pre-print
The Kronecker product-based algorithm for context-free path querying (CFPQ) was proposed by Orachev et al. (2020).  ...  Our evaluation shows that our algorithm is a good candidate to be the universal algorithm for both regular and context-free path querying.  ...  A recent work by Wang et al. (2019) provides a Pregel-based provenance-aware RPQ algorithm which utilizes a Glushkov's construction (Glushkov, 1961) .  ... 
arXiv:2103.14688v1 fatcat:fy73vloj5zcmjbbwis37rbexte

Knowledge Graphs [article]

Aidan Hogan, Eva Blomqvist, Michael Cochez, Claudia d'Amato, Gerard de Melo, Claudio Gutierrez, José Emilio Labra Gayo, Sabrina Kirrane, Sebastian Neumaier, Axel Polleres, Roberto Navigli, Axel-Cyrille Ngonga Ngomo (+6 others)
2021 arXiv   pre-print
After some opening remarks, we motivate and contrast various graph-based data models and query languages that are used for knowledge graphs.  ...  We provide an overview of prominent open knowledge graphs and enterprise knowledge graphs, their applications, and how they use the aforementioned techniques.  ...  Acknowledgements: We thank the attendees of the Dagstuhl Seminar on "Knowledge Graphs" for discussions that inspired and influenced this paper, and all those that make such seminars possible.  ... 
arXiv:2003.02320v5 fatcat:ab4hmm2f2bbpvobwkjw4xbrz4u

Semantic Knowledge Graphs for the News: A Review

Andreas L. Opdahl, Tareq Al-Moslmi, Duc-Tien Dang-Nguyen, Marc Gallofré Ocaña, Bjørnar Tessem, Csaba Veres
2022 ACM Computing Surveys  
This paper reviews the research on using semantic knowledge graphs for production, distribution, and consumption of news.  ...  Semantic knowledge graphs (KGs) is an established technique for integrating such heterogeneous information.  ...  It is based on RDF-GL A61 , a SPARQL-based graphical query language for RDF, and also provides an algorithm for ranking search results.  ... 
doi:10.1145/3543508 fatcat:l4lwafoyuncdpmc4qhj3xxekwa

Foundations of Data Management (Dagstuhl Perspectives Workshop 16151)

Marcelo Arenas, Richard Hull, Wim Marten, Tova Milo, Thomas Schwentick, Marc Herbstritt
2016 Dagstuhl Reports  
Graph data, RDF / Tree data, XML, JSON (tree automata). Approximate query answering, top-k. Stream-based processing. External memory. Incomplete information / Probabilistic databases.  ...  We then concentrate on the case of RDF and its query language SPARQL.  ...  Graph problems: There is a lot of work on page rank, shortest path, mining, etc. Still many more needs to be solved at scale.  ... 
doi:10.4230/dagrep.6.4.39 dblp:journals/dagstuhl-reports/ArenasHMMS16 fatcat:gpdqvqbhr5futlluo3qqdvg5hu

Gravitate Project D3.1 Report On Shape Analysis And Matching And On Semantic Matching

Silvia Biasotti, Andrea Cerri, Chiara Catalano E., Bianca Falcidieno, Maria Laura Torrente, Stuart Middleton E., Leo Dorst, Ilan Shimshoni, Ayellet Tal, Dominic Oldman
2016 Zenodo  
After the review of the current literature on these fields, we end the report with common remarks on possible or plausible cross connections that suggest themselves.  ...  Then, each part is connected to an instance that can be stored in a knowledge base to ease the retrieval process based on semantics.  ...  Google's Pregel is a large scale graph processing system where stateful graph vertices are stored in memory and can exchange messages to connected verticies.  ... 
doi:10.5281/zenodo.55432 fatcat:tc3rsykiufezxeper7ldew2ibu

Toward Scalable Systems for Big Data Analytics: A Technology Tutorial

Han Hu, Yonggang Wen, Tat-Seng Chua, Xuelong Li
2014 IEEE Access  
Google's Pregel specializes in large-scale graph computing, such as web graph and social network analysis.  ...  In contrast to flow-type models, graph processing iterative by nature, and the same dataset may have to be revisited many times. We mainly consider Pregel [43] and GraphLab [172] .  ... 
doi:10.1109/access.2014.2332453 fatcat:6unxlocbmnhs7mfctlvphdyqtu

GIS Mashups [chapter]

Ilya Zaslavsky
2017 Encyclopedia of GIS  
Definition Gaussian processes (GPs) are local approximation techniques that model spatial data by placing (and updating) priors on the covariance structures underlying the data.  ...  Kriging in this literature was used to model response variables (e.g., ozone concentrations) over 2D spatial fields as realizations of a stochastic process.  ...  that knowledge based approaches (expert systems) could be used to model the process -using a rule based approach.  ... 
doi:10.1007/978-3-319-17885-1_530 fatcat:rrr5buo3zrevpigdtjwhewipvm

Algorithmic building blocks for relationship analysis over large graphs [article]

Stephan Seufert, Universität Des Saarlandes, Universität Des Saarlandes
Qi et al. (2013) study seed-based indexing for distance query processing in a distributed setting.  ...  For efficient processing of SPARQL queries, RDF-3X is relying primarily on merge-joins, with a query optimizer concentrating on the join order.  ...  Connection to Query Entities 6.5 with 1 to |Q| (depending on the scenario) of the query entities, employing a dynamic programming algorithm to identify good paths.  ... 
doi:10.22028/d291-25420 fatcat:p53vkf4c3zgrfme2emwwzyjb2y

Dagstuhl Reports, Volume 8, Issue 9, September 2018, Complete Issue [article]

If we focus on the automatic handling of domain knowledge, there has been significant progress (e.g., NELL, Watson, etc.), but this is still poorly integrated with some other techniques.  ...  Some standards, such as CRISP-DM (and extensions) recognise processes, but not competences or skills.  ...  Additionally, extensions of such regular path queries with more complex conditions on properties have been defined, which are particularly important when dealing with graph data beyond "flat" RDF, such  ... 
doi:10.4230/dagrep.8.9 fatcat:5qvmtdru7banpoucejfabfjqdu

The International Symposium on Challenges for Designing and Using Datasets Brussels, Belgium IMMM 2015 Editors IMMM 2015 COMMITTEE IMMM Advisory Committee

Christian Ernst, Andreas Schmidt, Philip Davis, Andreas Schmidt, David Newell, Bournemouth University -Bournemouth, Kuan-Ching Li, Abdulrahman Yarali, Alain Casali, Christian Ernst, Paolo Garza, Di Torino (+135 others)
Korea DATASETS   unpublished
The amount of information and its complexity makes it difficult for our society to take advantage of the distributed knowledge value.  ...  a series of academic and industrial events focusing on advances in all aspects related to information mining, management, and use.  ...  RDF is a desirable choice for annotation, because its pairing with ontologies is understood [8] , and RDF has been already been useful in provenance research, such as my Grid.  ... 

Knowledge discovery from evolving social media data

Μαρια Κ. Γιάτσογλου
Social data mining addresses this challenge through the proposal of methods for harvesting knowledge based on content, activities, and / or structure.  ...  Challenges in social data mining impose the need for scalable, online methodologies that can process structure, content and activities in a time-aware approach.  ...  Apache Giraph is another graph processing framework implemented on top of Hadoop, which is an open-source implementation of Pregel, a graph processing architecture proposed by Malewicz et al. [2010] .  ... 
doi:10.26262/ fatcat:jm2pc2hdnnfmjgvi65r2lwhfba
« Previous Showing results 1 — 15 out of 18 results