Keyphrases
- principal components
- information retrieval
- principal component analysis
- dimensionality reduction
- information retrieval systems
- multivariate data
- principal components analysis
- hyperplane
- covariance matrix
- search engine
- spectral data
- query expansion
- kernel space
- language model
- correlation coefficient
- question answering
- information extraction
- test collection
- neural network
- document collections
- kernel principal component analysis
- text mining
- principal component regression