I received my Ph.D. from the Department of Combinatorics and Optimization at the University of Waterloo. I was very fortunate to have Prof. Swamy as my supervisor. I am the recipient of a 2017 University of Waterloo Outstanding Achievement in Graduate Studies (Ph.D.) designation.

My main research interest is in the design and implementation of efficient algorithms for the optimization problems that arise in machine learning, and big data analysis. My recent work mainly focuses on facility location and clustering problems. In my research, I use techniques from the fields of approximation/online algorithms and algorithmic game theory. My latest publication on the k-means problem, the most fundamental problem in unsupervised learning, presents the first algorithmic improvement in over a decade.

Email: sahmadian [at] uwaterloo [dot] ca

History

May 2017-Sept 2017: Research assistant, University of Waterloo, Waterloo, Canada.
May 2012-April 2017: Gradute student (Ph.D.) in Combinatorics and Optimization, University of Waterloo, Waterloo, Canada.
Nov 2016-Dec 2016: Visiting research scholar, University of Alberta, Edmonton, Canada.
Nov 2015-Dec 2015: Visiting research scholar, Hausdorff Research Institute for Mathematics, Bonn, Germany.
Sept 2015-Nov 2015: Visiting research scholar, École polytechnique fédérale de Lausanne, Lausanne, Switzerland.
Sept 2010-Mar 2012: Gradute student (Master's) in Combinatorics and Optimization, Waterloo, Canada.
Sept 2004-Aug 2008: Undergradute student (Bsc.) in Computer Engineering, Sharif University of Technology, Tehran, Iran.

Publications

  • Algorithms for Inverse Optimization Problems (with Umang Bhaskar, Laura Sanità, and Chaitanya Swamy)
  •     Submitted .
  • Better Guarantees for k-Means and Euclidean k-Median by Primal-Dual Algorithms (with Ashkan Norouzi-fard, Ola Svensson, and Justin Ward)
  •     In proceedings of IEEE 58th Annual Symposium on Foundations of Computer Science (FOCS).
        Invited to a special issue of SIAM Journal on Computing (SICOMP).
  • Further Approximations for Demand Matching: Matroid Constraints and Minor-Closed Graphs (with Zachary Friggstad)
  •     In proceedings of the 44th International Colloquium on Automata, Languages, and Programming (ICALP 2017).,
  • Approximation Algorithms for Clustering Problems with Lower Bounds and Outliers (with Chaitanya Swamy)
  •     In proceedings of the 43th International Colloquium on Automata, Languages, and Programming (ICALP 2016),
  • Stabilizing Network Bargaining Games by Blocking Players (with Laura Sanità and Hamideh Hosseinzadeh)
  •     In proceedings of the 18th International Conference on Integer Programming and Combinatorial Optimization (IPCO 2016),
  • Approximation Algorithm for Minimum-Load k-Facility Location (with Babak Behsaz, Zachary Friggstad, Amin Jorati, Mohammad Salavatipour, and Chaitanya Swamy)
  •    In proceedings of the 17th International Workshop on Approximation Algorithms for Combinatorial Optimization Problems (APPROX 2014).
       To appear in The ACM Transactions on Algorithms (TALG).
  • Local-Search Approximation Algorithms for Mobile Facility Location Problems (with Zachary Friggstad and Chaitanya Swamy)
  •    In proceedings of ACM-SIAM Symposium on Discrete Algorithms (SODA 2013),
  • Improved Approximation Guarantees for Lower-Bounded Facility Location (with Chaitanya Swamy)
  •    In proceedings of the 10th Workshop on Approximation and Online Algorithms (WAOA 2012).
  • Construction of a Random Perfect Phylogeny Matrix (with Changiz Eslahchi, Sepideh Mahabadi, Hanieh Mirzaei, Hamid Pezeshk, and Mehdi Sadeghi)
  •     Advances and Applications in Bioinformatics and Chemistry, 2010.
  • An Algorithm for Construction of all Perfect Phylogeny Matrices (with Changiz Eslahchi, Sepideh Mahabadi, Hanieh Mirzaei, Hamid Pezeshk, and Mehdi Sadeghi)
  •    MATCH Communications in Mathematical and in Computer Chemistry, 2009.

    Theses