December 01, 2018

Fast Approximation Algorithms for p-Centers in Large ? -Hyperbolic Graphs

  • Edwards K.
  • Kennedy W.
  • Saniee I.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. We provide a quasilinear time algorithm for the p-center problem with an additive error less than or equal to 3 times the input graph?s hyperbolic constant. Specifically, for the graph G= (V, E) with n vertices, m edges and hyperbolic constant ?, we construct an algorithm for p-centers in time O(p(?+ 1) (n+ m) log (n)) with radius not exceeding rp+ ? when p? 2 and rp+ 3 ? when p? 3 , where rp are the optimal radii. Prior work identified p-centers with accuracy rp+ ? but with time complexity O((n3log n+ n2m) log (diam (G))) which is impractical for large graphs.

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Recent Publications

January 01, 2019

Friendly, appealing or both? Characterising user experience in sponsored search landing pages

  • Bron M.
  • Chute M.
  • Evans H.
  • Lalmas M.
  • Redi M.
  • Silvestri F.

© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Many of today's websites have recognised the importance of mobile friendly pages to keep users engaged and to provide a satisfying user experience. However, next to the experience provided by the sites themselves, ...

January 01, 2019

Analyzing uber's ride-sharing economy

  • Aiello L.
  • Djuric N.
  • Grbovic M.
  • Kooti F.
  • Lerman K.
  • Radosavljevic V.

© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Uber is a popular ride-sharing application that matches people who need a ride (or riders) with drivers who are willing to provide it using their personal vehicles. Despite its growing popularity, there exist ...

January 01, 2019

The paradigm-shift of social spambots: Evidence, theories, and tools for the arms race

  • Cresci S.
  • Petrocchi M.
  • Pietro R.
  • Spognardi A.
  • Tesconi M.

© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Recent studies in social media spam and automation provide anecdotal argumentation of the rise of a new generation of spambots, so-called social spambots. Here, for the first time, we extensively study this novel ...