Decision Optimization

Decision Optimization

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  • 1.  Linearization

    Posted 07/29/16 06:36 AM

    Originally posted by: sandeepsinghchauhan


    I have a doubt regarding Linearization of constraint like:

    1) In Decentralization example Linearization done by:

    forall(ordered d1,d2 in Depts, c1, c2 in Cities) {
          Link[d1][c1][d2][c2] - IsIn[d1][c1] <= 0;
          Link[d1][c1][d2][c2] - IsIn[d2][c2] <= 0;
          IsIn[d1][c1] + IsIn[d2][c2] - Link[d1][c1][d2][c2] <= 1;
       }

    linearization of IsIn[d1][c1]xIsIn[d2][c2]

    Very clear even validating inequality conditions (when IsIn[d2][c2]=0 ->Link[d1][c1][d2][c2] =0   and   IsIn[d2][c2] =0 ->Link[d1][c1][d2][c2] = IsIn[d1][c1])

    2) But, the linearization in Yield management is very different :

    forall (s1 in scenarios, c in classes, o in options) {
          Revenue1[s1][c][o] - priceOptions[1][c][o]*Seats1[s1][c][o] <= 0;
          priceOptions[1][c][o]*Seats1[s1][c][o] - Revenue1[s1][c][o] + priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= priceOptions[1][c][o]*demand[1][s1][c][o];
       }

    not validating inequality condition ( PriceLevel1[c][o] = 0 -> Revenue1[s1][c][o] = 0)

    Please help me to clearify this confusion i will really thankful to you

    please help

    //      Revenue1[s1][c][o] - priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= 0;


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  • 2.  Re: Linearization

    Posted 07/29/16 09:03 AM

    Hi,

    Revenue1[s1][c][o] - priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= 0;

    if

    PriceLevel1[c][o]

    is 0 then

    Revenue1[s1][c][o]  <= 0;

    else

    Revenue1[s1][c][o] - priceOptions[1][c][o]*demand[1][s1][c][o] <= 0;

    Right ?

    So where is the confusion ?

    regards


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    #OPLusingCPLEXOptimizer


  • 3.  Re: Linearization

    Posted 07/29/16 09:40 AM

    Originally posted by: sandeepsinghchauhan


    But In yield management problem they not mentioned this equation

    Revenue1[s1][c][o] - priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= 0;

    This is my confusion


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  • 4.  Re: Linearization

    Posted 07/29/16 09:54 AM

    Originally posted by: sandeepsinghchauhan


    This is my confusion without including  Revenue1[s1][c][o] - priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= 0;

    How they formulate it ?


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  • 5.  Re: Linearization

    Posted 07/29/16 10:15 AM

    hi,

    in the .mod

    we have

    Revenue1[s1][c][o] - priceOptions[1][c][o]*Seats1[s1][c][o] <= 0;

    and in the book we see

    It is the same

    regards


    #DecisionOptimization
    #OPLusingCPLEXOptimizer


  • 6.  Re: Linearization

    Posted 07/29/16 01:27 PM

    Originally posted by: sandeepsinghchauhan


    Yes in book also they have
    forall (s1 in scenarios, c in classes, o in options) {
          Revenue1[s1][c][o] - priceOptions[1][c][o]*Seats1[s1][c][o] <= 0;
          priceOptions[1][c][o]*Seats1[s1][c][o] - Revenue1[s1][c][o] + priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= priceOptions[1][c][o]*demand[1][s1][c][o];
       }

    this they also not included

    Revenue1[s1][c][o] - priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= 0;

    I want to know why this is happening means how this linearization working even when it not able to satisfy my inequality condition (PriceLevel1[c][o] = 0 -> Revenue1[s1][c][o] = 0)

    please help me to clarify how yield management model is working correctly?

    Is any other thing in yield management taking care of this (Revenue1[s1][c][o] - priceOptions[1][c][o]*demand[1][s1][c][o]*PriceLevel1[c][o] <= 0; ) or PriceLevel1[c][o] = 0 -> Revenue1[s1][c][o] = 0 condition, which i am lacking?

    please help me

     


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    #OPLusingCPLEXOptimizer