April 01, 2019

An O(NlogN) algorithm for clustering mixture of two Gaussians

  • Jalali S.
  • Kushnir D.
  • Saniee I.

Mixtures of Gaussians are ubiquitous for modeling high dimensional data. In this paper we tackle the problem of clustering to recover the assignment of points to different Gaussians. We show that in the 2-Gaussian mixture a very efficient algorithm can be used to cluster the data in 1D while using only a handful of random projections to recover the clusters with high accuracy. We provide rigorous probabilistic analysis and guarantees on the error that can be achieved by our algorithm as well as the number of projection required. Our analysis is validated with empirical results in which our algorithm is shown to perform within the provided bounds with running time that is linear in the dimension and number of data points.

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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 ...