Difference between revisions of "CATS-May-13-2013"

From Theory
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== Abstract ==
 
== Abstract ==
 
The first part of this talk focuses on a network diffusion model
 
The first part of this talk focuses on a network diffusion model
  that was recently introduced by Goldberg & Liu (SODA'13). Goldberg &
+
that was recently introduced by Goldberg & Liu (SODA'13). Goldberg &
  Liu's model adapts the earlier linear threshold model of Kempe,
+
Liu's model adapts the earlier linear threshold model of Kempe,
  Kleinberg & Tardos (KDD'03) in an effort to capture aspects of
+
Kleinberg & Tardos (KDD'03) in an effort to capture aspects of
  technology adaptation processes in networks. We present new,
+
technology adaptation processes in networks. We present new,
  improved, yet simple algorithms for the so called Influence
+
improved, yet simple algorithms for the so called Influence
  Maximization problem in this setting.
+
Maximization problem in this setting.
  
  A key component of our algorithm is a Langrangean multiplier
+
A key component of our algorithm is a Langrangean multiplier
  preserving (LMP) algorithm for the Prize-collecting Node-weighted
+
preserving (LMP) algorithm for the Prize-collecting Node-weighted
  Steiner Tree problem (PC-NWST). This problem had been studied in
+
Steiner Tree problem (PC-NWST). This problem had been studied in
  prior work by Moss and Rabani (STOC'01 & SICOMP'07) who presented a
+
prior work by Moss and Rabani (STOC'01 & SICOMP'07) who presented a
  primal-dual O(log |V|) approximate and LMP algorithm, and showed
+
primal-dual O(log |V|) approximate and LMP algorithm, and showed
  that this is best possible unless NP=P.
+
that this is best possible unless NP=P.
  
  We demonstrate that Moss & Rabani's algorithm for PC-NWST is
+
We demonstrate that Moss & Rabani's algorithm for PC-NWST is
  seriously flawed. We then present a new, fundamentally different
+
seriously flawed. We then present a new, fundamentally different
  primal-dual method achieving the same performance guarantee. Our
+
primal-dual method achieving the same performance guarantee. Our
  algorithm introduces several novel features to the primal-dual
+
algorithm introduces several novel features to the primal-dual
  method that may be of independent interest.
+
method that may be of independent interest.
  
  Joint work with Laura Sanita and Sina Sadeghian
+
Joint work with Laura Sanita and Sina Sadeghian

Revision as of 20:16, 25 April 2013

Title[edit]

Network Diffusion & Node-Weighted Steiner Trees

Speaker[edit]

Evdokia Nikolova is an Assistant Professor at the Computer Science & Engineering Department at Texas A&M University. Previously she was a postdoctoral associate in the Computer Science and Artificial Intelligence Laboratory at MIT. She graduated with a BA in Applied Mathematics with Economics from Harvard University, MS in Mathematics from Cambridge University (U.K.) and Ph.D. in Computer Science from MIT. She is interested in risk analysis from an algorithmic perspective arising in stochastic optimization, networks, economics and complex systems. She has worked on applications to transportation and is also interested in energy and other domains where her work may apply.


Abstract[edit]

The first part of this talk focuses on a network diffusion model that was recently introduced by Goldberg & Liu (SODA'13). Goldberg & Liu's model adapts the earlier linear threshold model of Kempe, Kleinberg & Tardos (KDD'03) in an effort to capture aspects of technology adaptation processes in networks. We present new, improved, yet simple algorithms for the so called Influence Maximization problem in this setting.

A key component of our algorithm is a Langrangean multiplier preserving (LMP) algorithm for the Prize-collecting Node-weighted Steiner Tree problem (PC-NWST). This problem had been studied in prior work by Moss and Rabani (STOC'01 & SICOMP'07) who presented a primal-dual O(log |V|) approximate and LMP algorithm, and showed that this is best possible unless NP=P.

We demonstrate that Moss & Rabani's algorithm for PC-NWST is seriously flawed. We then present a new, fundamentally different primal-dual method achieving the same performance guarantee. Our algorithm introduces several novel features to the primal-dual method that may be of independent interest.

Joint work with Laura Sanita and Sina Sadeghian