GraphPropagation

From Cohen Courses
Revision as of 17:15, 1 February 2011 by Wcohen (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigationJump to search

Method

According to Velikovich_et_al,_NAACL_2010, this is a technique for propagating weights/flow over a graph, from say, a set of seeds.

You have a graph defined from data; for example, in Blair-Goldensohn_et_al,_2008 it's WordNet synonyms and antonyms; or in Velikovich_et_al,_NAACL_2010 it's web-derived distributional similarities. Starting with seed nodes' scores, the algorithm involves repeated matrix-multiplications with the edge matrix to propagate the flow. So at each step, a node's new flow strength (weight? score?) is the discounted sum of incoming flow:

for node with incoming neighbors and graph edge weights and per-node flow , and a discount factor .

(My apologies if this is bad terminology, I'm not sure the right way to do it)

This method is related to many other techniques in the literature; for example, PageRank and random walks.