14.30, room 445, PCRI
The skyline operator (aka Pareto front) extracts relevant records from multidimensional databases according to multiple criteria. This operator has received a lot of attention because of its ability to identify the best records in a database without requiring to specify complex parameters like the relative importance of each criterion (as it is done in ranking methods). However, recent attempts to apply the operator to real data analysis tasks have revealed some weaknesses of the original definition.
In this presentation I will introduce the skyline operator, indicate some recent research trends related to these weaknesses and focus on the so-called aggregate skyline queries, where the skyline is executed on sets of records instead of single items. This operator can be used to express queries in the form: return the best groups depending on the features of their elements, and thus provides a powerful combination of grouping and skyline functionality.
I will conclude the presentation by showing an application of the skyline operator to complex data representing multiple social networks.
Matteo Magnani graduated in Computer Science at the University of Bologna in 2002. He studied at the University of Marne la Vallée (undergraduate level) and the Imperial College London (postgraduate research level). In 2006 he obtained a PhD in Computer Science (Bologna) where in 2011 he also graduated in Violin. He has received a Rotary Prize for the best student of the Science Faculty (UniBO), a Best Paper Award at ASONAM 2011, a Funniest Presentation award at SBP 2010 and his mother is very proud of him (or at least this is what she officially says). Until May 2012 he was a researcher (RTD) at the Dept. of Computer Science, University of Bologna and he currently holds a position at research assistant professor level at the Data Intensive Systems group, Dept. of Computer Science, Aarhus University, Denmark.
His main research interests span Database and Information Management systems, specifically uncertain information management and multidimensional database queries, and Social Computing/Complex Network Science. He has written around 1.5 Kg of papers on these topics (when printed on heavy A4 size sheets). He is currently the joint coordinator of the #sigsna research group on social network analysis, and has successfully attracted funding from Working Capital (Telecom Italia), PRIN and FIRB (MIUR – Italian Ministry for education, University and Research) schemes.