Qian-Ping Gu, Shietung Peng, Hal Sudborough: A 2-approximation algorithm for genome rearrangements by reversals and transpositions, Journal of Theoretical Computer Science 210 (1999), 327--339.  Home/Search   Document Not in Database   Summary   Related Articles

....What is the minimal number of operations (reversals, transpositions and inverted transpositions) needed to transform a genome into the identity genome The function giving this value is denoted d comb . Using the breakpoint graph theory, this problem has been attacked by Gu, Peng and Sudborough [36]. They have found an approximation within a factor 2 using the inequalities d comb (#) c odd (#) This is very similar to the case with transpositions alone and this is no coincidence. In the choice between transpositions and reversals, the transpositions generally come out on top, ....

....and d appr (# 1 ) h # (# 1 ) d appr (# 2 ) h # (# 2 ) 13 if the pair constitutes a strong super hurdle. The worst case is when we are totally ignorant of the type of each of the three pairs, and the components are as small as possible. In that case, we get d(#) 3 12, 3 13 1] [36, 40] , and since this is the worst case, we have a (10 9) approximation, which is better than 7 6. Again, this ratio will be significantly smaller in most applications. 4.2.3 The (1 #) approximation In order to improve on the (7 6) approximation, we need to be able to identify strong hurdles ....

Qian-Ping Gu, Shietung Peng, Hal Sudborough: A 2-approximation algorithm for genome rearrangements by reversals and transpositions, Journal of Theoretical Computer Science 210 (1999), 327--339.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC