Panagiotis Liakos

Panagiotis Liakos

Doctoral Researcher, Network Analysis and MADgIK groups

Οἶδά σου τὰ ἔργα, ὅτι οὔτε ψυχρὸς εἶ οὔτε ζεστός. ὄφελον ψυχρὸς ἦς ἢ ζεστός.
Οὕτως, ὅτι χλιαρὸς εἶ καὶ οὔτε ζεστὸς οὔτε ψυχρός, μέλλω σε ἐμέσαι ἐκ τοῦ στόματός μου.

About Me

Welcome to my homepage!

I am currently a Doctoral Researcher at the University of Athens under the guidance of Prof. Alex Delis. My research focus is on developing graph mining techniques for large-scale networks.
In addition, I have over 8 years of professional experience in developing software using Java, Python, and Ruby on Rails. Currently, I participate in the GALENA project.

I hold a Ptychion (4-year degree) in Informatics and Telecommunications and an MSc. in Computer Systems' Technology, both from the University of Athens.



Doctor of Philosophy (2015 - )

University of Athens, Department of Informatics and Telecommunications
Thesis: Development of Graph Mining Techniques for Large Scale Networks
Advisor: Prof. Alex Delis

M.Sc. in Computer Systems' Technology (2008 - 2011)

University of Athens, Department of Informatics and Telecommunications
Thesis: Topic-Sensitive Hidden Web Crawling
M.Sc. Thesis Advisor: Prof. Alex Delis

Ptychion in Informatics and Telecommunications (2004 - 2008)

University of Athens, Department of Informatics and Telecommunications
Thesis: VHDL design and FPGA implementation of the ICEBERG encryption algorithm
Thesis Advisor: Prof. Antonis Paschalis


Scalable link community detection: A local dispersion-aware approach

P. Liakos, A. Ntoulas, and A. Delis

In IEEE Big Data 2016, Washington D.C., USA.

Memory-Optimized Distributed Graph Processing through Novel Compression Techniques

P. Liakos, K. Papakonstantinopoulou, and A. Delis

In CIKM 2016, Indianapolis, USA.

Pinpointing Influence in Pinterest (pdf)

P. Liakos, K. Papakonstantinopoulou, M. Sioutis, K. Tsakalozos, and A. Delis

In SocInf 2016 (co-located with IJCAI 2016), New York, USA.

On the impact of social cost in opinion dynamics (pdf)

P. Liakos and K. Papakonstantinopoulou

In Tenth International AAAI Conference on Web and Social Media, May, 2016, Cologne, Germany.

Focused crawling for the hidden web (pdf)

P. Liakos, A. Ntoulas, A. Labrinidis, and A. Delis

In Proceedings of the World Wide Web Journal, pages 1--27, May, 2015

Pushing the Envelope in Graph Compression (pdf)

P. Liakos, K. Papakonstantinopoulou, and M. Sioutis

In Proceedings of the 23rd ACM International Conference on Conference on Information and Knowledge Management (CIKM), pages 1549--1558, Shanghai, China, November 2014.

On the Effect of Locality in Compressing Social Networks (pdf, poster)

P. Liakos, K. Papakonstantinopoulou, and M. Sioutis

In Advances in Information Retrieval - 36th European Conference on IR Research (ECIR), pages 650--655, Amsterdam, The Netherlands, April 2014.

Topic Sensitive Hidden-Web Crawling (pdf, slides)

P. Liakos, A. Ntoulas

In Proceedings of the International Conference on Web Information System Engineering, 2012, Paphos, Cyprus.


Researcher/Developer at the University of Athens (Feb. 2010 - Oct. 2011, Sept. 2012 - present)

  • Design and development of software components for:

Developer for the Hellenic Army (Nov. 2011 - Aug. 2012)

Database Administrator (Jun. 2005 - Sept. 2005)

  • Set up and maintanance of the database of a book import company.

Teaching Assistantships


Programming Languages


Ruby on Rails






Operating Systems








  • English:
  • Greek:  
  • French: 


IEEE Big Data Student Travel Grant 2016

Scholarship to cover travel expenses to IEEE Big Data 2016, to be held during December 5-8, 2016 in Washington D.C., USA.

SIGIR Student Travel Grant 2016

Scholarship to cover travel expenses to CIKM-16, to be held during October 24-28, 2016 in Indianapolis, USA.

ICWSM-16 Student Grant Award 2016

Scholarship to cover travel expenses to ICWSM-16, held during May 17-20, 2016 in Cologne, Germany.

WSDM '13 Data Challenge 1st place - 2013

SiVaC*: An Efficient Graph Compression Algorithm

With Katia Papakonstantinopoulou and Michael Sioutis we have developed a graph compression algorithm that allows efficient compression of the graph's elements.
Our approach is outlined in this poster. The source code is available here.

Greek State Scholarships Foundation (IKY) 2006-2007

Academic performance award.

Under construction