d22ce344ca5834277bc333ccbde1b917.ppt
- Количество слайдов: 50
Nonnegative Matrix Factorization via Rank-one Downdate
Nonnegative Matrix Factorization
2 by 1965 560 by 2 -2. 19 -0. 02 20 by 28 -3. 19 1. 02 2 by 1
Singular Value Decomposition (SVD)
History
History
History
History
History (Algorithms)
History (Algorithms)
First observation
Power method • Computes the leading singular vectors/value (or eigenvector/value) of a matrix 1 2 while not converged 3 4 5 6 end
Example • Computes the leading singular vectors/value (or eigenvector/value) of a matrix 2 while not converged 3 4 5 6 end
Naive approach to NMF using this observation 1 2 3 4 5 6 for all end for set Without step 5, this will simply compute the SVD (Jordan's algorithm, Camille Jordan 1874. )
Second observation
Modified power iteration 1 2 while not converged 3 4 5 6 7 8 end
Modified power iteration: Demo A= Rank-1 submatrix
Modified power iteration: Demo v: 0. 14 0. 07 0. 64 0. 41 0. 55 Rank-1 submatrix
Modified power iteration: Demo v: 0. 0 0. 64 0. 41 0. 55 Rank-1 submatrix
Modified power iteration: Demo v: 0. 0 0. 64 0. 41 0. 55 Rank-1 submatrix
Modified power iteration: Demo v: u: 0. 16 0. 21 0. 22 0. 44 0. 74 0. 20 0. 64 0. 41 0. 55 Rank-1 submatrix
Modified power iteration: Demo v: u: 0. 0 0. 44 0. 74 0. 20 0. 64 0. 41 0. 55 Rank-1 submatrix
Modified power iteration: Demo v: u: 0. 0 0. 44 0. 74 0. 20 0. 64 0. 41 0. 55 Rank-1 submatrix
Modified power iteration: Demo v: u: 0. 0 0. 44 0. 74 0. 20 0. 60 0. 28 0. 59 Rank-1 submatrix
Modified power iteration: Demo v: u: 0. 0 0. 44 0. 74 0. 20 0. 60 0. 28 0. 59 Rank-1 submatrix
Modified power iteration: Demo v: u: 0. 0 0. 44 0. 74 0. 20 0. 60 0. 28 0. 59 Rank-1 submatrix Rank-1 Zero-out! submatrix
Modified power iteration: Demo Anew = Rank-1 submatrix
Rank-one Downdata (R 1 D) 1 2 3 4 5 end for
Objective function
Approx. Rank. One. Submatrix(A)
Rank-one Downdata (R 1 D)
Rank-one Downdata (R 1 D)
A simple model for text
Generating a corpus in the model
Theorem about text
LSI
R 1 D
Experimental results • Information retrieval task – TDT corpus (pilot study, v. 1. 3, 1997): news articles Identified topics (first few columns of ): Topic: president, clinton, house, white Topic: bosnian, serbs, bosnia, serb, nato, sarajevo, air, bihac Topic: haiti, military, aristide, haitian, troops, port, invasion, … Topic: simpson, defense, judge, case, jury, trial, angeles, los, court, … Topic: bill, today, senate, republicans, house, congress, republican, …
Experimental results • For topic: “OJ Simpson trial” (simpson, defense, judge, case, jury, trial) Document 1 Document 2 Document 3 Document 4 Allen Simpson Judge Gloves Kaelin Judge Defense Case Police Defence Statements Prosecution Defense Marcus Opening Defense Chicago Court Jury Roger Testimony Witness Legal Put Night Testify Yesterday Fit Knapsack Nicole Prosecution Today Cnn gloves Marc Problems Blood los jury Witness
Theorem about images
Experimental results
LSI
NMF-DIV
R 1 D
LSI
NMF_DIV
NMF_SC
R 1 D