Colloquia and Seminars

Upcoming Colloquia & Seminars

  • Synthesizing Concurrent Relational Data Structures

    Speaker:
    Roman Manevich
    Date:
    Tuesday, 14.2.2012, 14:30
    Place:
    Room 337-8 Taub Bld.
    Link:
    http://www.cs.technion.ac.il/~colloq/20120214_14_30_Manevich.html

  • On the Complexity of the Regenerator Location Problem - Treewidth and Other Parameters

    Speaker:
    Itamar Hartstein, M.Sc. Thesis Seminar
    Date:
    Sunday, 19.2.2012, 11:30
    Place:
    Taub 701
    Advisor:
    Prof. S. Zaks and Dr. M. Shalom

    We deal with the Regenerator Location Problem in optical networks. We are given a network G = (V, E), and a set Q of communication requests between pairs of terminals in V. We investigate two variations: one in which we are given a routing P of the requests in Q, and one in which we are required to find also the routing. In both cases, each path in P must contain a regenerator after every d edges in order to deal with loss of signal quality for some d > 0. The goal is to minimize the number of vertices that contain regenerators used by the solution. Both variations of the problem are NP-Hard in the general case. In this work we investigate the parameterized complexity of the problem. We introduce several fixed parameter tractability results and polynomial algorithms for fixed parameter values, as well as several NP-Hardness results. The main parameters under consideration are the treewidth of the input graph, and the number of connections.

  • Pixel Club: Hierarchical Invariant Sparse Modeling for Image Analysis

    Speaker:
    Leah Bar (University of Minnesota)
    Date:
    Tuesday, 21.2.2012, 11:30
    Place:
    EE Meyer Building 1061

    Sparse representation theory has been increasingly used in signal processing and machine learning. In this work we introduce a hierarchical sparse modeling approach which integrates information from the image patch level to derive a mid-level invariant image and pattern representation. The proposed framework is based on a hierarchical architecture of dictionary learning for sparse coding in a cortical (log-polar) space, combined with a novel pooling operator which incorporates the Rapid transform and max pooling to attain rotation and scale invariance. The invariant sparse representation of patterns here presented- can be used in different object recognition tasks. Promising results are obtained for three applications -- 2D shapes classification, texture recognition and object detection.

    joint work with Guillermo Sapiro, University of Minnesota.

  • Polar codes: construction and improved decoding

    Speaker:
    Ido Tal
    Date:
    Tuesday, 28.2.2012, 14:30
    Place:
    Room 337-8 Taub Bld.
    Link:
    http://www.cs.technion.ac.il/~colloq/20120228_14_30_Tal.html