Dear Yong Peng;

Here is an interesting paper on aligning Thai and English text using
statistical methods based on word frequency. Uses minimal info and is
very simple. Used to align bible text:

http://www.iait2007.org/Proceedings/P00192.pdf

There are probably some review of the literature papers that summarize
these algorithms.

Dan Malamed publishes a lot in this area:

http://www.cs.nyu.edu/~melamed/pubs.html

Good articles in following book at Google books:
Parallel Text Processing By Jean Véronis
http://books.google.com/books?id=I_4FPNS-RrEC&pg=PA25&lpg=PA25&dq=parallel+corpus+bitext+dan+melamed&source=web&ots=PcruOHrGTV&sig=EWNAc82On72khdWf36cfCEuNF_A&hl=en&sa=X&oi=book_result&resnum=6&ct=result#PPA4,M1

With metta,
Jon