Page 193 - Complementarity and Variational Inequalities in Electronics
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184  Complementarity and Variational Inequalities in Electronics


                           It results in
                                                                 2
                                                         2
                                                                      ∗ 2
                                            (∀t ≥ 0) :|z 3 (t)| =|z 3 (0)| =|z | .
                                                                      3
                           Here (∀t ≥ 0) : z 3 (t) ≤ 0, and thus
                                                                   ∗
                                             (∀t ≥ 0) : z 3 (t) = z 3 (0) = z ≤ 0.
                                                                   3
                           Thus any invariant subset of E(M, ,V ) is a subset of S(M, ). Therefore, for
                           any z 0 ∈ K,wehave

                                              lim d(z(t;0,z 0 ),S(M, )) = 0.
                                            t→+∞
                           Example 71. Suppose, for example, that R 1 > 0, R 2 > 0, and R 3 > 0. We have

                                                     0     0        0
                                                   ⎛                     ⎞
                                               T   ⎜ 0   2(R 1 +R 3 )  2R 1  ⎟
                                                   ⎜
                                         M + M =           L 3   − √     ⎟ .
                                                   ⎝                 L 2 L 3 ⎠
                                                     0  − √ 2R 1  2(R 1 +R 2 )
                                                            L 2 L 3  L 2
                           The matrix M is positive semidefinite, and

                                                    T
                                                             3
                                          ker(M + M ) ={z ∈ R : z 2 = z 3 = 0}.
                           We set
                                                                1   2
                                                      3
                                               (∀ z ∈ R ) : V(z) = ||z|| .
                                                                2
                           Thus
                                          (∀ z ∈ K) :
Mz,∇V(z) =
Mz,z ≥ 0
                           and

                                                            T
                                                                      3
                                  E(M, ,V ) = K ∩ ker(M + M ) ={z ∈ R : z 2 = z 3 = 0}.
                           A stationary solution z has to satisfy
                                             ∗
                                                                 ∗
                                                             ∗
                                                       ∗
                                                  K   z ⊥ Mz ∈ K ,
                           where
                                    ∗        3
                                  K ={w ∈ R : w 1 = 0,w 2 ≥ 0,w 3 ≤ 0 and w 2 + αw 3 ≥ 0}

                                    L 2
                           with α =   .Wehave
                                    L 3
                                                                    ∗
                                                               ∗
                                                         ∗
                                                ∗
                                               z ∈ K ⇔ z ≥ 0,z ≤ αz ,
                                                         2     3    2
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