Panagiotis Liakos

Panagiotis Liakos

Postdoctoral 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 Researcher at the University of Athens after recently defending my Ph.D. dissertation that I was fortunate enough to complete 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 12 years of professional experience in developing software using Java, Python, and Ruby on Rails.

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

Hobbies

Education

Doctor of Philosophy (2015 - 2018)

University of Athens, Department of Informatics and Telecommunications
Thesis: Distributed and Streaming Graph Processing Techniques
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

Publications

Sim-Piece: Highly Accurate Piecewise Linear Approximation through Similar Segment Merging (pdf)

X. Kitsios, P. Liakos, K. Papakonstantinopoulou, and Y. Kotidis

In 49th International Conference on Very Large Databases, Vancouver, Canada.

Chimp: Efficient Lossless Floating Point Compression for Time Series Databases (pdf)

P. Liakos, K. Papakonstantinopoulou, and Y. Kotidis

In 48th International Conference on Very Large Databases, Sydeny, Australia.

On Compressing Temporal Graphs (pdf)

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

In 38th IEEE International Conference on Data Engineering (ICDE 2022), Kuala Lumpur, Malaysia.

Rapid Detection of Local Communities in Graph Streams (pdf)

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

In IEEE TKDE.

Uncovering Local Hierarchical OverlappingCommunities at Scale (pdf)

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

In IEEE Transactions on Big Data.

DiCeS: Detecting Communities in Network Streams Over the Cloud (pdf)

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

In IEEE CLOUD 2019, Milan, Italy.

Realizing Memory-Optimized Distributed Graph Processing (pdf)

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

IEEE TKDE, vol. 30, no. 4, April 2018

CoEuS: Community Detection via Seed-set Expansion on Graph Streams (pdf)

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

In IEEE Big Data 2017, Boston, MA.

Rhea: Adaptively Sampling Authoritative Content from Social Activity Streams (pdf)

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

In IEEE Big Data 2017, Boston, MA.

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.

Experience

Software Engineer at App-Art (Apr. 2017 - present)

  • Design and development of software applications and solutions targeted to diversified industries such as Telecoms, Health and Energy.

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.

Theses' supervision

  • Foodie: An Online Hybrid Recommendation System for Recipes Using Spring-Boot and Neo4j,
    Konstantina K. Stamoulou
  • Efficient Queries in MongoDB with Encrypted Fields,
    Andriani G. Triantafyllou and Eleni G. Mantzana
  • Ανάπτυξη Εφαρμογής Αναπαράστασης της κίνησης σε μεγάλους δρόμους με Storm Framework , Redis DB και Leaflet JS,
    Christina I. Chatzialioti
  • Analytics over Basketball Statistics using SlamData and MongoDB,
    Gerasimos Alexandros Panagiotopoulos and Athanasios Michail Karampatsis
  • CarShare: Αναπτύσσοντας μια πλατφόρμα συνεπιβατισμού με PHP, AngularJS και MongoDB,
    Themistoklis N. Beris
  • Δρομολόγηση Οχημάτων Περιορισμένης Χωρητικότητας με Χρονικά Όρια,
    Iosif E. Angelidis
  • Web application development using Ruby on Rails,
    Ioannis A. Efthymiou

Teaching Assistantships

Skills

Programming Languages

Java

Ruby on Rails

Python

Databases

PostgreSQL

MongoDB

elasticSearch

Operating Systems

Linux

BSD

Windows

Other

LaTeX

TikZ

Languages

  • English:
  • Greek:  
  • French: 

Awards

IEEE Big Data Student Travel Grant 2017

Scholarship to cover travel expenses to IEEE Big Data 2017, to be held during December 11-14, 2017 in Boston, MA, USA.

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