Dear Researcher

please refer to this attachments if it is helpful for you.

Regards

http://link.springer.com/article/10.1631%2Fjzus.C1300088

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6076327&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6076327

http://www.aensiweb.com/old/jasa/rjfh/2015/May/94-104.pdf

Dear Researcher,

you can optimize fuzzy membership functions by editing the fis file using readfis and writefis commands in MATLAB. you can also read the HELP doc of this commands.

refering to this paper ( doi:10.1016/j.conengprac.2007.10.003 ) may also be helpful.

regards

In order to optimize the membership function, you first define an error measure e.g. MSE. 

Then, your input variables should be set on different types of membership functions. The membership function with minimum error is the best one. It can involve in ICA main loop. 

Good Luck