Nikos Sarkas

Somewhere here I was born, and there I died. It was only a moment for you; you took no notice.

Research Interests

I am primarily interested in the development of techniques for querying, exploring and analyzing textual data, in particular user-generated content such as blogs. Consequently, I am also interested in web searching and mining, collaborative tagging systems and social network analysis. In the past I have also worked on top-k and skyline processing, as well as on qualitative spatial representation and reasoning.

Grapevine

I am part of the team behind Grapevine. Ever wondered what the world is talking about? Grapevine conducts large scale data analysis on the social media collective, distilling and extracting information in real time.

Publications (click on paper title to view abstract)

Query, Exploration, Analysis of Textual Data

• Nikos Sarkas, Gautam Das, Nick Koudas: Improved Search for Socially Annotated Data. VLDB 2009.

• Nikos Sarkas, Nilesh Bansal, Gautam Das, Nick Koudas: Measure-driven Keyword-Query Expansion. VLDB 2009.

• Albert Angel, Nick Koudas, Divesh Srivastava, Nikos Sarkas: What's on the Grapevine? SIGMOD 2009 Demo.

Top-k and Skyline Processing

• Nikos Sarkas, Gautam Das, Nick Koudas, Anthony K. H. Tung: Categorical Skylines for Streaming Data. SIGMOD 2008.

• Gautam Das, Dimitrios Gunopulos, Nick Koudas, Nikos Sarkas: Ad-hoc Top-k Query Answering for Data Streams. VLDB 2007.

Qualititave Spatial Representation and Reasoning

• Spiros Skiadopoulos, Nikos Sarkas, Timos Sellis and Manolis Koubarakis: A Family of Directional Relation Models for Extended Regions. IEEE TKDE, August 2007.

• Spiros Skiadopoulos, Christos Giannoukos, Nikos Sarkas, Panos Vassiliadis, Timos Sellis and Manolis Koubarakis: Computing and Managing Cardinal Direction Relations. IEEE TKDE, December 2005.

Education

• PhD student, Department of Computer Science, University of Toronto, supervised by Nick Koudas, 2007-Present.

• MSc student, Department of Computer Science, University of Toronto, supervised by Nick Koudas, 2005-2007.

• Undergraduate student, School of Electrical and Computer Engineering, National Technical University of Athens, supervised by Spiros Skiadopoulos and Timos Selis, 1999-2004.

Work Experience / Internships

• Search Labs - Microsoft Research, Summer 2009