Modeling Topical Trends over *Continuous Time *with Priors

1. Modeling Topical Trends over Continuous Time with Priors Tomonari MASADA 正田备也 Nagasaki University 长崎大学 [email_address] Tomonari MASADA ISNN 2010

5. Tomonari MASADA ISNN 2010 Shanghai is the largest city in China, located in her eastern coast at the outlet of the Yangtze River. Originally a fishing and textiles town, Shanghai grew to importance in the 19th century. In 2005 Shanghai became the world's busiest cargo port. The city is an emerging tourist destination renowned for its historical landmarks such as the Bund and Xintiandi, its modern and 63 7 7 41 63 7 63 41 7 7 41 41 7 7 41 7 7 63 22 41 7 22 7 41 41 63 41 7 41 7 7 50 50 7 50 63 41 7 41 41 22 22 7 41 7 7 41 41 41 41 7 7 41 41 7 7 7 63 7 63 7 41 7

6. Topic Re-assignment Probabilities Tomonari MASADA ISNN 2010 How many tokens of word w are assigned to topic k How many tokens in doc j are assigned to topic k Introduce time-dependency!

7. Topics over Time [Wang et al. KDD06] Tomonari MASADA ISNN 2010

8. Tomonari MASADA ISNN 2010 TOT Beta densities

9. Tomonari MASADA ISNN 2010 LDA: no time-dependency TOT: too heavy time-dependency

10. LYNDA [Masada et al. CIKM09] L atent d YN amical D irichlet A llocation Tomonari MASADA ISNN 2010

11. Tomonari MASADA ISNN 2010 LYNDA unnormalized Gaussian densities

14. x y z θ α φ s τ η γ β b a

16. Tomonari MASADA ISNN 2010 entire document set ground-truth document set “ Yes!” “ No!”

22. Tomonari MASADA ISNN 2010 http://www.cis.nagasaki-u.ac.jp/~masada/researches.html DBLP 1990 ~ 2009 LDA BTOT

23. Tomonari MASADA ISNN 2010 http://www.cis.nagasaki-u.ac.jp/~masada/researches.html Xinhua net May 5, 2009 ~ Dec. 17, 2009 LDA BTOT

24. Tomonari MASADA ISNN 2010 http://www.cis.nagasaki-u.ac.jp/~masada/researches.html Yomiuri Newspaper 2002 ~ 2005 LDA BTOT