[Couenne] Couenne_reformulation PDF file

[Pietro Belotti]

Dear Sismail,

these two problems look equivalent to me, the only difference is that  
P' explicitly introduces auxiliary variables that would be created by  
Couenne.

I'm not sure of how the g() functions look like, but this is in  
general a nonconvex problem. If you are interested in understanding  
why the solutions you get are different (which is the problem you had  
in the beginning, if I remember correctly), then a more precise  
formulation is needed. Do you have an AMPL model, or a .nl file  
produced by AMPL?

Hope this helps.

Pietro

_________________________________________
Pietro Belotti, Lehigh University
Dept. of Industrial & Systems Engineering
200 W Packer Ave, Bethlehem PA 18015.
phone: 610-758-3865   fax: 610-758-4886
email: belotti at lehigh.edu
web:   http://www.lehigh.edu/~pib208


On 06/17/2009, ksismail <ksismail1 at gmail.com> wrote:

> I apologize for the bad file. I send it now in pdf format.
>
> Best Regards,
>
> Sismail
>
>
> Dear Pietro,
>
>  I completely agree with you that global solutions in Couenne for  problem
> (P) to problem (P')  must be the same with the same value for the 2
> objective functions.
>
>  I am surely mistaken when I  reformulated  problem (P) to problem (P').
>
>  Can you please take one minute tell me what it is wrong in the
> reformulation for the following example ?
>
>  Reformulation seems to be not evident.
>
> Thank you very much in advance.
>
> Sismail
>
> PS/  if you can give some links for the kind of problems
>



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