1 Learning from Shadows Dimensionality Reduction and its Application in Artificial Intelligence, Signal Processing and Robotics Ali Ghodsi Department of Statistics and Actuarial Science University of Waterloo October 2006
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3 Dimensionality Reduction
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5 Manifold and Hidden Variables
6 Data Representation
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by by 2 2 by by by 1
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16 Hastie, Tibshirani, Friedman 2001
17 The Big Picture
18 Uses of Dimensionality Reduction (Manifold Learning)
19 Denoising Mika et. al Zhu and Ghodsi 2005
20 Tenenbaum, V de Silva, Langford 2001
21 Roweis and. Saul 2000
22 Arranging words: Each word was initially represented by a high-dimensional vector that counted the number of times it appeared in different encyclopedia articles. Words with similar contexts are collocated Roweis and Saul 2000
23 Hinton and Roweis 2002
24 Embedding of Sparse Music Similarity Graph Platt, 2004
25 Pattern Recognition Ghodsi, Huang, Schuurmans 2004
26 Pattern Recognition
27 Clustering
28 Glasses vs. No Glasses
29 Beard vs. No Beard
30 Beard Distinction Ghodsi, Wilkinson, Southey 2006
31 Glasses Distinction
32 Multiple-Attribute Metric
33 Reinforcement Learning Mahadevan and Maggioini, 2005
34 Semi-supervised Learning Use graph-based discretization of manifold to infer missing labels. Build classifiers from bottom eigenvectors of graph Laplacian. Belkin & Niyogi, 2004; Zien et al, Eds., 2005
35 Learning Correspondences How can we learn manifold structure that is shared across multiple data sets? Ham et al, 2003, 2005
36 Mapping and Robot Localization Bowling, Ghodsi, Wilkinson 2005 Ham, Lin, D.D. 2005
37 Action Respecting Embedding Joint Work with Michael Bowling and Dana Wilkinson
38 Modelling Temporal Data and Actions
39 Outline Background –PCA –Kernel PCA Action Respecting Embedding (ARE) –Prediction and Planning –Probabilistic Actions Future Work
40 Principal Component Analysis (PCA)
41 Principal Component Analysis (PCA)
42 Kernel Methods
43 Kernel Trick
44 Observed, Feature and Embedded Spaces
45 Kernel PCA
46 Problem
47 Idea
48 Action Respecting Embedding (ARE)
49 Action Respecting Constraint
50 Preserve distances between each point and its k nearest neighbors. Local Distances Constraint
51 Preserve local distances Local Distances Constraint
52 Semidefinite Programming
53 Experiment
54 Experiment 1
55 Experiment 2
56 Experiment 3
57 Experiment 4
58 Experiment 5
59 Planning
60 Planning
61 Planning
62 Experiment
63 Probabilistic Actions
64 Future work
65 Related Papers