10. The topic modeling system as recited in claim 1 , wherein the minimizing the first equation while holding the topic-document matrix V fixed includes the regularization of column vectors of the term-topic matrix U, and the minimizing the first equation while holding the term-topic matrix U fixed includes the regularization of column vectors of the topic-document matrix V.
10. The topic modeling system as recited in claim 1 , wherein the minimizing the first equation while holding the topic-document matrix V fixed includes the regularization of column vectors of the term-topic matrix U, and the minimizing the first equation while holding the term-topic matrix U fixed includes the regularization of column vectors of the topic-document matrix V. 11. The topic modeling system as recited in claim 10 , wherein the regularization of column vectors of the term-topic matrix U is based on an l 1 norm and the regularization column vectors of the topic-document matrix V is based on an l 2 norm.