Feodor F. Dragan, Anh Tran and Chenyu Yan - PowerPoint PPT Presentation

About This Presentation
Title:

Feodor F. Dragan, Anh Tran and Chenyu Yan

Description:

The Light Tree t-Flow Spanner approximation algorithm works better for small ... Experimental results for both approximation algorithms ... – PowerPoint PPT presentation

Number of Views:156
Avg rating:3.0/5.0
Slides: 2
Provided by: bonita4
Category:

less

Transcript and Presenter's Notes

Title: Feodor F. Dragan, Anh Tran and Chenyu Yan


1
Network Flow Spanners
  • Feodor F. Dragan, Anh Tran and Chenyu Yan
  • Algorithmics Lab, Spring 2006, Kent State
    University

EXAMPLE 2 denotes the capacity
3 denotes the price
In H, those 7 packages can be sent in two rounds
(52)
In G, we can send 7 packages from source to sink
at once
  • OUR RESULTS
  • The Light Flow-Spanner, Sparse Flow-Spanner,
    Light-Edge-Connectivity-Spanner and Sparse
    Edge-Connectivity-Spanner problems are
    NP-complete.
  • The Light Tree Flow-Spanner problem is
    NP-complete.
  • We give two approximation algorithms for the
    Light Tree Flow-Spanner problem
  • Our problems belong to the class of Network
    Design and Network Survivability problems
  • They take into account Fault Tolerance, Bandwidth
    Constraints and Link Failures

VARIATIONS OF LFSD
  • RELATED WORK
  • k-Edge-Connected-Spanning-Subgraph problem
  • Given a graph G along with an integer k, one
    seeks a spanning subgraph of G that is
    k-edge-connected
  • MAX SNP-hard Fernandes98, (12/k)-approx.
    algorithm Gabow et. al.05
  • Original edge-connectivities are not taking into
    account
  • Survivable-network-design problem (SNDP)
  • Given a graph G(V, E), a non-negative cost p(e)
    for every edge e?E and a non-negative
    connectivity requirement rij for every
    (unordered) pair of vertices i, j. One needs to
    find a minimum-cost subgraph in which each pair
    of vertices i, j is joined by at least rij
    edge-disjoint paths.
  • NP-hard problem, 2(11/21/31/k)-approximation
    algorithm Gabow et. al.98, Goemans et. al.94
  • By setting rij?FG(i, j)/t? for each pair of
    vertices i, j, our LECS problem can be reduced to
    SNDP.

EXPERIMENTAL RESULTS
Experimental results for both approximation
algorithms
Experimental results on Internet-like graphs
Experimental results on random graphs
CONCLUSION The Light Tree t-Flow Spanner
approximation algorithm works better for small
stretch factors t while the Light Tree Flow
Spanner approximation algorithm works better for
larger t.
Results were partially presented at LATIN 2006
Conference, March 20-24, Valdivia, Chile
Write a Comment
User Comments (0)
About PowerShow.com