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  1. Jan Vondrak Professor of Mathematics Dept. of Mathematics Stanford University 450 Jane Lanthrop Way, building 380 Stanford, CA 94305 E-mail: jvondrak-at-stanford-dot-edu.

    • My Papers

      Shahar Dobzinski, Jan Vondrak: Impossibility results for...

    • CS369P

      Course description: This is a graduate-level course in...

    • Some Presentations

      Some presentations Lectures/tutorials Submodular functions...

    • Math 113

      Tuesday 3-5 pm, 383-J (Jan) Friday 2-4 pm, 380-T (Joj)...

    • Discrete analogy?
    • Cut function:
    • In contrast:
    • Why is it possible to minimize submodular functions?
    • Maximization of submodular functions:
    • Questions that don’t seem to be answered by combinatorial algorithms:

    Not so obvious... f is now a set function, or equivalently

    (T ) = je(T ; T )j So, is submodularity more like concavity or convexity?

    Maximizing a submodular function (e.g. Max Cut) is NP-hard.

    The combinatorial algorithms are sophisticated... But there is a simple explanation: the Lovász extension. Why is it possible to minimize submodular functions? The combinatorial algorithms are sophisticated... But there is a simple explanation: the Lovász extension. Submodular function

    comes up naturally in allocation / welfare maximization settings (S) = value of a set of items S ... often submodular due to combinatorial structure or property of diminishing returns in these settings, f (S) is often assumed to be monotone: T =) f (S) f (T ): Maximization of submodular functions: comes up naturally in allocation / welfare maximiza...

    What is the optimal approximation for maxff (S) : S 2 Ig, in particular the Submodular Welfare Problem? What is the optimal approximation for multiple constraints, e.g. multiple knapsack constraints? In general, how can we combine different types of constraints? Questions that don’t seem to be answered by combinatorial algorithms: What is the optim...

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  2. Jan Vondrák1 1IBM Almaden Research Center San Jose, CA SIAM Discrete Math conference, Minneapolis, MN June 2014 Jan Vondrák (IBM Almaden) Submodular Functions and Applications 1 / 28 . Discrete optimization What is a discrete optimization problem? Find ...

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  3. Department of Mathematics Building 380, Stanford, California 94305 Phone: (650) 725-6284 mathfrontdesk [at] stanford.edu (E-mail)

  4. Jan Vondrák. IBM Almaden Research Center. Simons Institute, Berkeley, October 2013. Junta approximations. How can we simplify a function f : f0; 1gn ! R? In this talk: How well can we approximate f by a function g of few variables? Def.: g approximates f within. in Lp, if. kf. gkp = (E[jf (x) g(x)jp])1=p. (in this talk, the uniform distribution)

  5. en.wikipedia.org › wiki › Jan_VondrákJan Vondrák - Wikipedia

    Jan Vondrák is a Czech applied mathematician and theoretical computer scientist. He has been a professor of mathematics at Stanford University since 2015. He was a research staff member in the theory group at the IBM Almaden Research Center from 2009 to 2015.

  6. Authors: Ashwinkumar Badanidiyuru and Jan Vondrák Authors Info & Affiliations. Pages 1497 - 1514. https://doi.org/10.1137/1.9781611973402.110. PDF. BibTeX. Tools. Abstract. There has been much progress recently on improved approximations for problems involving submodular objective functions, and many interesting techniques have been developed.