July 22, 2009
In the following paper published on ISMIR 2008:
the authors present their work using NMF (Non-negative Matrix Factorization) to analyze semantic topics from song lyrics. In Section 3.4:
“We decide to use NMF for automatic topic detection as it is a clustering technique that results in additive representation of items (e.g., song X is represented as 10% topci A, 30% topic B and 60% topic C), a property that distinguishes it from most other clustering techniques.”
However, “most other techniques” including pLSA, LDA and Mix-Noisy-OR models all have the “distinguishing property” stated by the authors. In addition, the equivalence between NMF and pLSA has been well studied in the following papers:
The authors also criticize that LSA cannot process large sparse matrices. However, LSA is in fact applying SVD on term-document-matrix (TDM), and there are many SVD algorithms that can decompose large sparse matrices.
July 15, 2009
An apple everyday, keeps doctor away.
I recently wrote a Braille translator, which converts English text into Braille rendered using pretty dots — only people with well eye-sight can percieve.
July 8, 2009
To enable the “Lock Screen” function of Mac OS X, open your Keychain Access utility in the Applications / Utility folder. In the preference dialog, select “Show Status in Menu Bar.” A black padlock will appear in your taskbar in the upper right-hand corner. Close Keychain Access. Now when you click on the padlock, you have a “Lock Screen” option in the drop-down.