This document summarizes an analysis of the 2009 Linked Open Data cloud graph. It describes that the graph had 86 vertices and 274 edges, with a diameter of 10 and average path length of 3.916. It also discusses that DBPedia, DBLP, ACM, GeneID, and Geonames had the highest in-degrees and out-degrees, referring to many other datasets. Finally, it concludes that the Linked Open Data provides useful data for reuse through a flexible graph structure compared to traditional databases.

1. Aristotle University of Thessaloniki
School of Computer Science - Master Studies - Spring Semester
Web Data Mining course - Instructor: Vakali Athena
Kouroupetroglou
Praxitelis Nikolaos
Master Student
Linked data and Graph properties

2. ● A Graph Analysis of the Linked Data Cloud (2009)
Overview

3. Open Linked Data Graph Analysis (1)
● Connected Components
○ Without SCC, 31 WCC
○ Top WCC Sizes: DBPedia, DBLP
● Degree Correlations
○ In-degree - Out-degree, statistical
significance
○ Degree assortativity: data sets tend to
connect to data sets with differing degrees.
● Pagerank Data Centrality
○ Top central datasets: DBLP Berlin, DBLP
Hannover, DBpedia, KEGG, UniProt, GeneID
● Communities
○ Communities based on datasets content
○ Datasets with similar content exist in the
same structural area of the graph.
● Open Linked Data Cloud 2009 analysis
● Graph Construction
○ G = (V, E) model, directed graph
● General Statistics
○ #edges: 274, #vertices: 86
○ diameter: 10, avg path length: 3.916
● Degrees - Datasets references
○ In-degree - references
■ Top Nodes: DBpedia (14), DBLP (13),
ACM (10), GeneID (10), Geonames (10)
○ Out-degree - references
■ Top Nodes: DBpedia (17), DBLP (14),
ACM (10), SiteSeer (9), EPrints (9)
● Degree Distribution
○ with log-log plot, a power law distribution fits
with a = 1.496

4. Open Linked Data Graph Analysis (2)
Figure from Source [1]
● Visualization:
○ Vertex: Data Sets
○ Edge: Dataset Links
○ Vertex color: denote the structural
communities
● Conclusions:
○ Open Linked Data with RDF
technologies provides data useful
for data reuse and distribution
leading to Web of Data
○ Graphs are becoming a flexible
representational data structure in
contrast to RDBMS tables

5. 1. Rodriguez, M. A. (2009). A graph analysis of the linked data cloud. arXiv
preprint arXiv:0903.0194.
References
Linked data and Graph properties
Thank you for listening
Kouroupetroglou
Praxitelis Nikolaos