Page 207 - Mathematical Techniques of Fractional Order Systems
P. 207

196  Mathematical Techniques of Fractional Order Systems


               Let 0 # λ # 1, then for each tAJ, one can get

                                  Ð t        Ð t                    b 21
                ðλρ 1 ð1 2 λÞρ ÞðtÞ 5  0  S α ðsÞx 1 ds 1  0  S α ðt 2 sÞBB S ðb 2 sÞðEI1Π Þ

                                                         α
                            2
                   1
                                                                    0
                                          ~
                                 n     Ð  b                 Ð  b
                                  E~ x b 1  φðsÞdWðsÞ 2 S α ðbÞφð0Þ 2  S α ðsÞx 1 ds
                                        0                    0
                                 2  Ð b  S α ðb 2 sÞ½λf 1 ðsÞ 1 ð1 2 λÞf 2 ðsފds
                                    0
                                                                o
                                   Ð  b      Ð  s   ^
                                 2   S α ðb 2 sÞ  σðs; τ; φ 1 y τ ÞdWðτÞ ds ds
                                    0         0      τ
                                   Ð t
                                 1   S α ðt 2 sÞ½λf 1 ðsÞ 1 ð1 2 λÞf 2 ðsފds
                                    0

                                   Ð  t     Ð  s   ^
                                 1   S α ðt 2 sÞ  σðs; τ; φ 1 y τ ÞdWðτÞ ds
                                    0        0      τ
               It is easy to see that N F;x is convex, since F has convex values, so
            λf 1 1 ð1 2 λÞf 2 AN F;x . Thus λρ 1 ð1 2 λÞρ AΨy:
                                     1
                                               2
               Step 2: Next, one can show that there exists a positive number r such
            that ΨðB r ÞDB r . If it is not true, then there exists E . 0 such that for every
                                                         r
            positive number r and tAJ, there exists a function y ðUÞAB r but Ψðy r Þ=2B r ,
                                r 2
                                          r
                                     r
                         2
                     r
            i.e., EOðΨy ÞðtÞO  fOρ O : ρ AðΨy Þg . r. For such E . 0,
                                  b
              r # EOðΨy ÞðtÞO 2
                      r
                              2
                                              ε
                                                 ^
               # 4E:  Ð  t  S α ðsÞx 1 ds: 1 4E:  Ð  t  S α ðt2sÞBu ðs; φ1y Þds: 2
                                                    r
                     0               0
                                                  Ð  s                2
                                                        ^
                     t
                                  2
                                         t
               1 4E:  S α ðt2sÞf ðsÞds: 1 4E:  S α ðt2sÞ  σðs; τ; φ 1y ÞdWðτÞ ds:  ð7:7Þ
                                        Ð
                             r
                                                            r
                    Ð
                                                         τ
                     0                   0        0         τ
                 4
                X
                   I i :
                 i51
               By using ðH 1 Þ 2 ðH 5 Þ, one can obtain
                                                    0  2ωb  1
                                           2
                           I 1 5 4E:  Ð  t  S α ðsÞx 1 ds: # 4M bx 1 @ e  2 1 A
                                                 2
                                  0                    2ω
                                                                        ð7:8Þ
                                              ^
                           I 2 5 4E:  Ð  t  S α ðt2sÞBu ðs; φ1y Þds: 2
                                           E
                                                  r
                                  0
                                                   ^
                                                E
                                                         2
                                                       r
                             # 4M bOBO 2  Ð  t  e 2ωðt2sÞ EOu ðs; φ 1 y ÞO ds:
                                 2
                                       0
               Now, in view of ðH 4 Þ, there exist positive constants, β; γ, such that, for
                                          ^
                                   ^
                                      2
                   2
                                                  2
                                                                      2
            all OφO . γ, EOFðt; φ; LφÞO # ðd 1 βÞOφO . Let F 1 5 fφ: OφO # γg;
                   B                              B                   B
                       2
            F 2 5 fφ: OφO . γg thus
                       B
                                                 ^
                                        2
                                                         2
                              EOFðt; φ; ^ LφÞO # μðγÞ 1 ðd 1 βÞOφO :
                                                         B
            and
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