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Duality for robust multi-dimensional vector variational control problem under invexity
                               subject to                     ξ(t, σ, ζ, σ κ , ζ κ , ω, ϱ)=1, the invexity of function-
                                                              als follows as below :
                         2b+σ−7≦0, b∈[1, 2]
                             −5ω =0, µ∈[0, 1]
                         µσ t 1
                                                                                                          2
                                  1          3                    (i) To show that    R  Ψ 1 (., ¯ a 1 )dν =  R  (σ +
                         σ(0, 0)= , σ(1, 1)= ,                                         Ω              Ω
                                  2          2                       ¯ a 1 ω)dν is invex w.r.t. η and ξ at (ζ, ϱ).
                        1                                            Consider
                     h    i
                 a 1 ∈ 0,  , a 2 ∈[0, 3], [t 1 , t 2 ]∈[0, 0]×[1, 1].  Z                 Z
                        2
                                                                A 1 =   Ψ 1 (Λ, σ κ , ¯a 1 )dν −  Ψ 1 (Π, ζ κ , ¯a 1 )dν
            Thus, the set of feasible solutions for (RUVP1) will
                                                                      Ω                   Ω
            be                                                       Z
                                                                   −   η(t, σ, ζ, σ κ , ζ κ , ω, ϱ)(Ψ 1 ) σ (Π, ζ κ , ¯a 1 )dν
                                               −5ω =0,
                                                                      Ω
               T 1 ={(σ, ω)∈K ×Υ : σ ≤3, µσ t 1
                                                                Z
                     1           3
             σ(0, 0)= , σ(1, 1)= , t∈Ω, b∈[1, 2], µ∈[0, 1]}.  −    D κ η((t, σ, ζ, σ κ , ζ κ , ω, ϱ))(Ψ 1 ) σ κ (Π, ζ κ ¯a 1 )dν
                     2           2                               Ω
            To obtain a feasible point (σ, ω), sufficiency con-   Z
            dition (2) gives                                     −   ξ(t, σ, ζ, σ κ , ζ κ , ω, ϱ)(Ψ 1 ) ω (Π, ζ κ , ¯a 1 )dν
                                                                    Ω
                                 χ 1   5τ                        Z       1       Z          Z
                                                                       2
                             ω =    −     .                    =     σ + ω dν −      2.35dν −    8ωσdν
                                 4χ 2  2χ 2                        Ω      2         Ω          Ω
                      ∗
            Solving (2 ), we get                                                              Z  1
                                                                                            −     dν
                                                                                               2
                          χ 1    5τ               +                                            Ω
                    σ =5      −      t 1 +d 1 , d 1 ∈R .          Z        1   2  3        Z
                          4χ 2  2χ 2                            =      3t 1  +  2  +  40  dt 1 dt 2 −  2.35dt 1 dt 2
                                                                        4
                         1
                                1
                                    ∗
            Taking χ 1 = , χ 2 = , (3 ) gives d 1 =  1 2  and τ =  Ω           Z              Z  Ω 1
                         2
                                2
             1                                                                −   8ωσdt 1 dt 2 −  dt 1 dt 2
             50  . Thus,                                                         Ω             Ω  2
                                       1 3
                                  3t 1                             =0.0875≧0
                         (σ, ω)=      + ,
                                   4    2 20                         and
              is obtained as the robust feasible solution to         Z                   Z
                                                                A 2 =   Ψ 2 (Λ, σ κ , ¯a 2 )dν −  Ψ 2 (Π, ζ κ , ¯a 2 )dν
            (RUVP1), which is shown graphically in figure 1.          Ω                   Ω
                                                                     Z
            Now the Wolfe type dual to the problem (RUVP1)         −   η(t, σ, ζ, σ κ , ζ κ , ω, ϱ)(Ψ 2 ) σ (Π, ζ κ , ¯a 2 )dν
            is given by :                                             Ω
                                                                 Z
                            Z
                                    1
                                 2
                 (WD1) max      ζ + ϱ+λ(2b+ζ −7)+              −   D κ η(t, σ, ζ, σ κ , ζ κ , ω, ϱ)(Ψ 2 ) σ κ (Π, ζ κ , ¯a 2 )dν
                        (ζ,ϱ)  Ω     2                            Ω  Z
                                    2
                         −5ϱ), 3−ϱ +λ(2b+ζ −7)+                    −   ξ(t, σ, ζ, σ κ , ζ κ , ω, ϱ)(Ψ 2 ) ω (Π, ζ κ , ¯a 2 )dν
                   τ(µζ t 1
                                                                      Ω

                                            −5ϱ) dν                Z             Z  74     Z
                                      τ(µζ t 1                              2
                                                                 =     3−ω    dν −      dν +   2ξωdν
                                                                    Ω               Ω  25     Ω
                               subject to                         Z                Z             Z
                                                                =    2.9775dt 1 dt 2 −  2.96dt 1 dt 2 +  0.4dt 1 dt 2
                                                         ∗
                                               =0      (4 )
                                                                   Ω                Ω              Ω
                     χ 1 (2ζ +λ)+χ 2 λ+λ−(τ) t 1
                     1
                                                         ∗
                  χ 1 ( −5τ)+χ 2 (−2ϱ−5τ)−5τ =0        (5 )
                     2                                           =0.4175≧0
                                                                                             R
                                  1          3                       Therefore, the invexity of  Ω Ψ i (., ¯ a i )dν,i=
                                                         ∗
                         ζ(0, 0)= , ζ(1, 1)= ,         (6 )                           3 1
                                  2          2                       1, 2 at (ζ, ϱ)= − ,    holds.
                                                                                       2 5
                                2                                                    Z
                               X                                                         T
                                                         ∗
                         χ≧0,     χ i =1, λ≧0.         (7 )      (ii) To show that     λ θ(., ., b)dν is invex
                                                                                      Ω
                               i=1                                   w.r.t. η and ξ at (ζ, ϱ).
            Solving    dual    constraints,    using    χ=
                                                                     Z                   Z

                                                                         T
                                                                                             T
            (χ 1 , χ 2 )=  2 1  , τ =  1  , λ=1, we get (ζ, ϱ)=  A 3 =  λ θ(Λ, σ κ , b)dν −  λ θ(Π, ζ κ , b)dν
                         ,
                        3 3      50
               3 1
             − ,    .      Hence,     (ζ, ϱ, χ, λ, τ, ¯ a, b, µ)=    Z Ω                 Ω
               2 5
                                                                                             T
                              1
               3 1 2 1
             − , , , , 1,   1  , , 3, 2,  1  is a robust feasible   −   η(t, σ, ζ, σ κ , ζ κ , ω, ϱ)λ θ σ (Π, ζ κ , b)dν
               2 5 3 3     50 2      2
            solution to (WD1).                                     Z   Ω
                                                                                             T
            To validate Theorem 3, the invexity of function-     −    D κ η(t, σ, ζ, σ κ , ζ κ , ω, ϱ)λ θ σ κ (Π, ζ κ b)dν
                                                                  Ω
                                                3 1
            als is to be explored at (ζ, ϱ)= − ,      w.r.t.          Z
                                                2 5                 −                        T
            η and ζ. Taking η(t, σ, ζ, σ κ , ζ κ , ω, ϱ)=4ω and         ξ(t, σ, ζ, σ κ , ζ κ , ω, ϱ)λ θ ω (Π, ζ κ , b)dν
                                                                       Ω
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