Project Team

George Papastefanatos

Dr. George Papastefanatos

Scientific Coordinator

Nikos Bikakis

Dr. Nikos Bikakis

PostDoc Researcher

Marios Meimaris

Dr. Marios Meimaris

PostDoc Researcher

Giorgos Alexiou

Giorgos Alexiou

PhD Researcher

Stavros Maroulis

Stavros Maroulis

PhD Researcher

Vasilis Stamatopoulos

Vasilis Stamatopoulos

Scientific Associate

Panos Vasiliadis

Panos Vassiliadis

Professor in Computer Science - Scientific Advisor

Team Bios

George Papastefanatos

Dr. George Papastefanatos is a research associate at the Information Management Systems Institute (IMSI) of the ATHENA Research Centre, since 2009. George obtained his Diploma on Electrical and Computer Engineering and his PhD in Computer Science from the Department of Electrical and Computer Engineering of the National Technical University of Athens (NTUA) in 2000 and 2009, respectively. George has been involved as a senior researcher or scientific coordinator in the implementation of more than 15 EU and national research projects. He has also worked as an external IT expert in various private and public organizations such as National Statistical Service of Greece, ETVA VI.PE. S.A., Citibank, Greek Ministry of Education in the implementation of IT projects. During 2007 and 2011, he was an adjunct lecturer in University of Peloponnese and National School of Public Administration and in 2018 he was a visiting lecturer in University of Aegean. George has more 60 publications in international conferences and journals and has co-authored 3 chapters in books in the areas of big data management and analytics and specifically in issues related to semantic web data modelling, indexing and query optimization, data integration, data visualization and visual analytics. Three of his articles has been selected as Best Papers in International conferences. He has supervised and contributed to the development of more than 5 prototype tools related to the management and visualization of Linked Data. In 2018, George was one of the receivers of a grant from the Hellenic Foundation for Research and Innovation for postdoc research on the area of data visualization and visual analytics. He is co-organizing the International Workshop on Big Data Visual Exploration and Analytics, an annual event providing a forum for researchers and practitioners to discuss exchange and disseminate their work in the research areas of Data Management, Information Visualization and Human-Computer Interaction. George has given several invited talks in conferences and events, and served as a keynote speaker in the 8th International Workshop on “Data Engineering meets the Semantic Web (DESWeb2017)”, in conjunction with ICDE 2017, giving a talk for "Visual Exploration in the Web of Data".

Nikos Bikakis

Dr. Nikos Bikakis is a postdoctoral researcher at the Information Management Systems Institute (IMSI) of the ATHENA Research Centre. Before that, he was a Data Engineer at ATYPON Inc. and RedLink Inc., a Postdoctoral Researcher at Univ. of Ioannina and Athens Univ. of Economics & Business, as well as an Adjunct Lecturer at Univ. of West Attica. He received his PhD in Computer Science from the Nat. Techn. Univ. of Athens (NTUA) and his Diploma in Computer Engineering from the Techn. Univ. of Crete, Greece. Dr. Bikakis has been published one book ["Linked Data Visualization: Techniques, Tools & Big Data", Morgan & Claypool , 2020] and more than 25 international research papers (Encyclopedia chapters, Journal articles & Conference papers). He has been awarded with two Best Paper Awards in international conferences. In 2017, his research in the field of Big Data Visual Analytics, was supported by a Young Researchers Nat/EU Research Grand. He is co-organizing the annual international workshop on "Big Data Visual Exploration & Analytics" (BigVis 2020, 2019, 2018). He has served as a Guest Editor at special issues on "Interactive Big Data Visualization & Analytics" and "Big Data Visualization, Exploration & Analytics", Big Data Research, Elsevier, 2020 & 2018; PC and (external) Reviewer for various top-tier international journals and conferences, e.g., EDBT [Senior PC], TKDD, TVCG, TKDE, VLDBJ, SIGMOD, ICDE, IEEE VIS, CKIM, TWEB, ect. His research interests include: Human-Data Interaction, Visual Analytics, Personalized Data Management, Data Structures, Hard Computational Problems, Spatial & Social Data and Web of Data.

Marios Meimaris

Dr. Marios Meimaris is a postdoctoral researcher at the Information Management Systems Institute (IMSI) of the ATHENA Research Centre. Marios holds a Diploma in Electrical and Computer Engineering and an MBA from NTUA, as well as an MSc in Artificial Intelligence from the University of Edinburgh. He has worked as a research associate at the Multimedia Technology Laboratory of NTUA's Electrical and Computer Engineering department, where he has participated in a number of projects and publications on Linked Data, Business Intelligence and the Semantic Web. He is currently a research assistant in the Information Management Systems Institute (IMSI) of RC 'Athena' since 2013, where he works on Linked Data, Evolving Data, the Semantic Web and Multidimensional Data. He is the core engineer of the publicspending project, the first effort to semantically structure, interlink and publish government spending data as Linked Open Data in Greece. He is a tutor in ontology engineering, linked data practices and RDF/SPARQL at the PG level at NTUA. He has served as an invited expert at the W3C Government Linked Data working group, where he worked on standards, recommendations and best practices for governments to open up and publish data and was co-editor for the W3C Registered Organization Vocabulary.

Giorgos Alexiou

Giorgos Alexiou holds a Degree in Cultural Informatics from the University of the Aegean and a M.Sc. in Web Science from Aristotle University of Thessaloniki. From 2011, he is a research associate of the Multimedia Technology Laboratory at the National Technical University of Athens, where he is mainly focusing on research projects and publications on Linked Data, Semantic Web, Business Intelligence, as well as on infrastructure and software development. Besides that, from 2014, he is a Ph.D. candidate under the supervision of prof. Vassili Loumos and he is also tutoring (Ontology Engineering, Linked Data, RDF/SPARQL) the course at the Engineering-Economic Systems MBA program.Along with that, he has extensive experience in Semantic Web (web 3.0) technologies, knowledge engineering, system administration and cloud computing infrastructure. He is currently a research assistant in the Information Management Systems Institute (IMSI) of R.C. ATHENA, where he works on Linked Data, Entity/Record Matching and Multidimensional Data, since 2013.Over the recent years, he has worked as a software developer (internship) at the Information Systems Laboratory at the Foundation of Research and Technology Hellas (I.S.L./FO.R.T.H.) at the <> platform project and he was among the core engineers of the <> project, the first effort to semantically structure, interlink and publish government-spending data as Linked Open Data in Greece.

Stavros Maroulis

Stavros Maroulis is a phd candidate at the National Technical Univerity of Athens and a research assistant at at the Information Management Systems Institute (IMSI) of the ATHENA Research Centre. His research interest is on data visualization and has published a conference paper in this area, which received the best paper award. He has obtained considerable experience in visual exploration and analytics methods through the development of the www.socioscope.gr platform for the visualization and analysis of social and political data, and in H2020 –SlideWiki EU project where he was responsible for developing a visual analytics module for the analysis of learning content and activities.

Vasilis Stamatopoulos

Vasilis Stamatopoulos holds a degree in Computer Science and Telecommunications from the University Of Athens (NKUA) and is currently employed at the Information Management Systems Institute (IMSI) of the ATHENA Research Centre as a Software Engineer. He has collaborated with researchers at IMSI by providing technical solutions and expertise in both research and industry projects. Before this, along with his studies he worked in industry for 4 years, implementing software solutions for Pharmaceutical companies.

Prof. Panos Vassiliadis

Panos Vassiliadis is an associate professor in the Department of Computer Science & Engineering, at the University of Ioannina, Greece and adjunct researcher with IMIS, ATHENA. He has conducted research in the area of big data and data warehousing (metadata management, OLAP, and quite emphatically, ETL) for more than 15 years. He has also worked on database evolution, top-k and context-based querying as well as on web service management. Following a common thread in his work, he is currently investigating how the rigorous modeling of data, software and their interdependence can be exploited for the design, visualization and smooth evolution of data-intensive software ecosystems. Prof. Vassiliadis has more than 140 publications in international journals and conferences. He is also the co-editor of the book “Fundamentals of Data Warehouses” (Springer). Moreover, he has an active service to the scientific community as a reviewer and PC chair (with notable distinctions as PC-chair of important data warehousing venues, specifically DMDW’ 03, DOLAP’06, and track co-chair in important database venues such as CIKM’09 and ICDE’09). He has been involved in several national and EU funded R&D projects.