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Existence, uniqueness and numerical solution of stochastic fractional differential equations with integer and non-integer orders

Abstract

The parametrized approach is extended in this study to find solutions to differential equations with fractal, fractional, fractal-fractional, and piecewise derivatives with the inclusion of a stochastic component. The existence and uniqueness of the solution to the stochastic Atangana-Baleanu fractional differential equation are established using Caratheodory's existence theorem. For the solution of differential equations using piecewise differential operators, which take into account combining deterministic and stochastic processes utilizing certain significant mathematical tools such as fractal and fractal-fractional derivatives, the applicability of the parametrized technique is being examined. We discuss the crossover behaviors of the model obtained by including these operators and we present some illustrative examples for some problems with piecewise differential operators.

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Existence, uniqueness and numerical solution of stochastic fractional differential equations with integer and non-integer orders

Author: Araz, Seda Igret
Publisher: AIMS Press
Year: 2024
DOI: 10.3934/era.2024035
Source: https://dspace.vsb.cz/bitstreams/94ff1e75-3713-43f1-934f-99d8e44d50bf/download
Elec onic
Resea ch A chi e
h p://www.aimsp ess.com/jou nal/e a
ERA, 32(2): 733–761.
DOI: 10.3934/e a.2024035
Recei ed: 26 Sep embe 2023
Re ised: 03 Decembe 2023
Accep ed: 15 Decembe 2023
Published: 10 Janua y 2024
Resea ch a icle
Exis ence, uniqueness and nume ical solu ion o s ochas ic ac ional
di e en ial equa ions wi h in ege and non-in ege o de s
Seda IGRET ARAZ1,2,*, Mehme Aki CETIN3and Abdon ATANGANA2,4,5
1Sii Uni e si y, Depa men o Ma hema ics Educa ion, Sii , Tu key
2Ins i u e o G oundwa e S udies, Facul y o Na u al and Ag icul u al Sciences, Uni e si y o he
F ee S a e, Sou h A ica
3ALTSO Voca ional School, Alanya Alaaddin Keykuba Uni e si y, An alya, Tu key
4Depa men o Medical Resea ch, China Medical Uni e si y Hospi al, China Medical Uni e si y,
Taichung, Taiwan
5IT4Inno a ions, VSB–Technical Uni e si y o Os a a, Os a a-Po uba 70800, Czech Republic
*Co espondence: Email: [email p o ec ed].
Abs ac : The pa ame ized app oach is ex ended in his s udy o ind solu ions o di e en ial equa ions
wi h ac al, ac ional, ac al- ac ional, and piecewise de i a i es wi h he inclusion o a s ochas ic
componen . The exis ence and uniqueness o he solu ion o he s ochas ic A angana-Baleanu ac-
ional di e en ial equa ion a e es ablished using Ca a heodo y’s exis ence heo em. Fo he solu ion
o di e en ial equa ions using piecewise di e en ial ope a o s, which ake in o accoun combining
de e minis ic and s ochas ic p ocesses u ilizing ce ain signi ican ma hema ical ools such as ac al and
ac al- ac ional de i a i es, he applicabili y o he pa ame ized echnique is being examined. We
discuss he c osso e beha io s o he model ob ained by including hese ope a o s and we p esen some
illus a i e examples o some p oblems wi h piecewise di e en ial ope a o s.
Keywo ds: Ca a heodo y’s condi ions; ac al- ac ional di e en ia ion; piecewise calculus;
pa ame ized me hod
1. In oduc ion
F ac ional analysis is a heo y ha s a ed wi h Leibniz asking i he e is a de i a i e o o de 1
/
2
o a unc ion. This heo y in e es ed many esea che s when di e en ypes o ac ional de i a i es
we e in oduced. One well-known de ini ion is he Riemann-Liou ille ac ional de i a i e whe e
he powe -law ke nel is inco po a ed. Capu o [1] in oduced a de i a i e wi h a modi ica ion on he
734
Riemann-Liou ille ac ional de i a i e [2] because i was use ul in heo y bu no app op ia e o
sol ing eal-li e p oblems. These ope a o s, which a e used o model powe law p ocesses, ha e
beha io ha is bo h nonlocal and singula . E en hough some p ocesses a e unique, ano he o m o
ma h is needed o desc ibe p ocesses ha beha e di e en ly. Capu o and Fab izio [3] ha e c ea ed
a ma hema ical concep called a de i a i e wi h ading memo y, which uses an exponen ial pa e n.
This de i a i e deals wi h p ocesses ha beha e p edic ably and wi hin a small a ea. Howe e , we
needed a de i a i e ha is p edic able bu ac s o e a la ge a ea. The A angana-Baleanu ac ional
de i a i e [4] is a ma hema ical ool ha mee s his equi emen , and i u ilizes he Mi ag-Le le
unc ion. The ac al de i a i e o Hausdo de i a i e [5] is a di e en kind o de i a i e used o
measu ing ac als in ac al geome y. F ac al de i a i es we e made o s udy how hings sp ead in a
s ange way when no mal ways o s udying do no conside he ac al shape o he hing ha hings a e
sp eading h ough. A ac al measu e
changes i s size in ela ion o
aised o he powe o
β
. This ype
o de i a i e is only used in a speci ic a ea, unlike he ac ional de i a i e, which is used in a simila
way. La e , A angana in oduced ac al- ac ional de i a i es [6] by combining he concep s o ac al
and ac ional de i a i es. Al hough he e is no doub ha ac ional di e en ial ope a o s a e use ul in
modeling ele an p ocesses [7–11], hese ope a o s canno be used o model c osso e p ocesses such
as om s ochas ic o powe -law o om ading memo y o s ochas ic [12–15]. Concluding ha a new
class o di e en ial ope a o s was needed o his, A angana and A az in oduced piecewise di e en ial
ope a o s [16], which can be c ea ed by including a ious di e en ial ope a o s o model such p ocesses.
These ope a o s, which can be used o desc ibe many p ocesses, om modeling he di e en a es (o
e en s opping) o an indi idual’s hea bea o e a pe iod o ime, o modeling he sp ead o a i us, i s
cumula i ely and hen daily, ha e become ocus o a en ion o esea che s.
In o de o be e unde s and and analyze he p ocesses discussed, i is necessa y o sol e he equa ions
ha ep esen hese p ocesses. Because i is di icul o sol e hese equa ions using analy ic me hods
when he ope a o s men ioned abo e and he nonlinea i y o he associa ed equa ions a e in ol ed, we
ha e o use nume ical me hods o ob ain solu ions o such equa ions. The pa ame ized me hod, which
deals wi h he app oxima ion o a unc ion wi h cons an s depending on a pa ame e , is one o he
well-known nume ical me hods. While he pa ame e ized me hod is p esen ed in he li e a u e [8–10]
o classical di e en ial equa ions, A angana and A az [17] ex ended his me hod o sol e ac ional and
ac al- ac ional di e en ial equa ions. The pa ame ized me hod was compa ed wi h exis ing me hods
in he li e a u e in [17] and i was shown ha he me hod is mo e e ec i e han o he me hods, especially
when he pa ame e is close o 1.
Howe e , in [17], he applica ion o he ele an me hod o s ochas ic di e en ial equa ions wi h
ac ional, ac al- ac ional and piecewise de i a i es [16] is no aken in o accoun . The e o e, in
his s udy, we p esen he de i a ion o his me hod o s ochas ic di e en ial equa ions wi h ac ional,
ac al- ac ional and piecewise de i a i es. We employ he pa ame ized me hod o sol e di e en
ypes o equa ions ob ained by inco po a ing hese ma hema ical ools in o di e en ial equa ions.
Be o e p esen ing he associa ed me hod, i s he de ini ions o he abo e-men ioned ac ional, ac al
ac ional and piecewise de i a i es will be p esen ed. In he ollowing sec ion, wi h he help o
Ca a h
´
eodo y condi ions [15,16], he exis ence and uniqueness o he solu ion o A angana-Baleanu
s ochas ic di e en ial equa ions [18] will be in es iga ed. In he emaining sec ions, in addi ion o
he de i a ion o he pa ame ized me hod wi h hese de i a i es, some illus a i e examples will be
included.
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
735
2. P elimina ies
In his sec ion, he de ini ions o ac ional de i a i es wi h powe law beha io , ading memo y
and exhibi ing powe law beha io a e ading memo y, ac al- ac ional de i a i es and piecewise
de i a i es, which can be ep esen ed in di e en ways by including ac ional and ac al- ac ional
de i a i es, will be discussed.
The Capu o-Fab izio ac ional de i a i e [3] o he unc ion ( )∈H1(0,T)is de ined by
CF
0Dα
( )=1
1−αZ
0
0(τ)exp −α
1−α( −τ)dτ, (2.1)
whe e 0 <α<1 and H1(0,T)desc ibes he Hilbe space. The associa ed in eg al is gi en as
CF
0Jα
( )=(1−α) ( )+αZ
0
(τ)dτ. (2.2)
The Capu o ac ional de i a i e [1] o he unc ion ( )∈H1(0,T)is de ined by
C
0Dα
( )=1
Γ(1−α)Z
0
0(τ) ( −τ)−αdτ, (2.3)
whe e 0
< α ≤
1 and he Riemann-Liou ille ac ional de i a i e o he unc ion
( )∈C(0,T)
is
de ined by
RL
0Dα
( )=1
Γ(1−α)
d
d Z
0
(τ) ( −τ)−αdτ. (2.4)
The in eg al wi h powe -law ke nel [2] is gi en by
RL
0Jα
( )=1
Γ(α)Z
0
(τ) ( −τ)α−1dτ. (2.5)
The ollowing o mulas desc ibe he A angana-Baleanu ac ional de i a i e [4], which has he c osso e
beha io om s e ched exponen ial o powe -law,
ABC
0Dα
( )=1
1−αZ
0
0(τ)Eα−α
1−α( −τ)αdτ, (2.6)
and
ABR
0Dα
( )=1
1−α
d
d Z
0
(τ)Eα−α
1−α( −τ)αdτ. (2.7)
The abo e ope a o s a e called A angana-Baleanu ac ional de i a i e in he Capu o sense and A angana-
Baleanu ac ional de i a i e in he Riemann-Liou ille sense [4], espec i ely. The associa ed in eg al is
gi en by
AB
0Jα
( )=(1−α) ( )+α
Γ(α)Z
0
(τ) ( −τ)α−1dτ. (2.8)
The concep o ac al- ac ional di e en ia ion and in eg a ion has appea ed p e iously wi h he idea o
combining he ac al and ac ional de i a i es. The ac al- ac ional de i a i e [6] wi h powe -law
ke nel is de ined by
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
736
FFP
0Dα,β
( )=1
Γ(1−α)
d
d βZ
0
(τ) ( −τ)−αdτ, (2.9)
whe e he de ini ion o ac al de i a i e [5] is
d
d β ( )=lim
→ 1
( )− ( 1)
β− β
1
.(2.10)
The associa ed ac al- ac ional in eg al [6] wi h powe -law ke nel is gi en by
FFP
0Jα
( )=1
Γ(α)Z
0
βτβ−1 (τ) ( −τ)α−1dτ. (2.11)
The ac al- ac ional de i a i e wi h Mi ag-Le le ke nel [6] is de ined by
FFM
0Dα,β
( )=1
1−α
d
d βZ
0
(τ)Eα−α
1−α( −τ)αdτ(2.12)
and he associa ed ac al- ac ional in eg al is gi en by
FFM
0Jα
( )=(1−α)β β−1 ( )+α
Γ(α)Z
0
βτβ−1 (τ) ( −τ)α−1dτ. (2.13)
The ac al- ac ional de i a i e wi h exponen ial decay ke nel [6] is de ined by
FFE
0Dα,β
( )=1
1−α
d
d βZ
0
(τ)exp −α
1−α( −τ)dτ(2.14)
and he associa ed ac al- ac ional in eg al is gi en by
FFE
0Jα
( )=(1−α)β β−1 ( )+αZ
0
βτβ−1 (τ)dτ. (2.15)
We now p esen he de ini ions o he piecewise de i a i e and in eg al ope a o s, which made signi ican
con ibu ion o li e a u e [16].
The piecewise de i a i e wi h classical and ac ional de i a i e wi h powe -law ke nel such ha i
can be aken as [16]
PRL
0Dα
y( )=(y0( )i 0 ≤ ≤ 0
RL
0Dα
y( )i 0≤ ≤T(2.16)
whe e
PRL
0Dα
ep esen s he classical de i a i e wi hin 0
≤ ≤ 0
and he Riemann-Liou ille ac ional
de i a i e wi hin 0≤ ≤T.
The piecewise wi h Capu o de i a i e is gi en as [16]
PC
0Dα
y( )=(y0( )i 0 ≤ ≤ 0
C
0Dα
y( )i 0≤ ≤T(2.17)
whe e he unc ion
y( )
is con inuous bu no necessa ily di e en iable in
[ 0,T].
He e,
PRL
0Dα
ep esen s
he classical de i a i e on 0
≤ ≤ 0
and he Capu o ac ional de i a i e [1] on
0≤ ≤T
. The
associa ed piecewise in eg al o yis gi en as [16]
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
737
PPLI y( )=





R 0
0y(τ)dτi 0 ≤ ≤ 0
1
Γ(α)R
0y(τ) ( −τ)α−1dτi 0≤ ≤T(2.18)
whe e
PPL
0Iα
ep esen s he classical in eg al on 0
≤ ≤ 0
and he in eg al wi h powe -law ke nel on
0≤ ≤T.
The piecewise de i a i e wi h classical de i a i e and exponen ial decay ke nel is gi en as [16]
PCF
0Dα
y( )=(y0( )i 0 ≤ ≤ 0
CF
0Dα
y( )i 0≤ ≤T(2.19)
whe e
PCF
0Dα
is he classical de i a i e on 0
≤ ≤ 0
and he Capu o-Fab izio ac ional de i a i e [3]
on
0≤ ≤T.
He e, i is assumed ha he unc ion
y( )
is di e en iable. A piecewise in eg al is gi en
as [16]
PCF I y( )=





R 0
0y(τ)dτi 0 ≤ ≤ 0
1−α
M(α)y( )+α
M(α)R
0y(τ)dτi 0≤ ≤T.(2.20)
The piecewise de i a i e wi h classical de i a i e and Mi ag-Le le ke nel is de ined by [16]
PAB
0Dα
y( )=(y0( )i 0 ≤ ≤ 0
ABC
0Dα
y( )i 0≤ ≤T(2.21)
whe e
PAB
0Dα
ep esen s he classical de i a i e on 0
≤ ≤ 0
and he A angana-Baleanu ac ional
de i a i e [4] on 0≤ ≤T.The associa ed piecewise in eg al is gi en as [16]
PABI y( )=





R 0
0y(τ)dτi 0 ≤ ≤ 0
(1−α)y( )+α
Γ(α)R
0y(τ) ( −τ)α−1dτi 0≤ ≤T.(2.22)
Lemma 1. (The gene aliza ion o he G onwall inequali y) Assume ha
b≥
0
, α >
0
,
and
x( )
is a
nonnega i e unc ion locally in eg able on 0
≤ <T,
and assume ha
y( )
is nonnega i e and locally
in eg able on 0≤ <T wi h
y( )≤x( )+bZ
0
y(τ) ( −τ)α−1dτ. (2.23)
Then,
y( )≤x( )+Z
0
∞
X
n=1
(bΓ(α))n
Γ(nα)y(τ) ( −τ)nα−1x(τ)dτ. (2.24)
De ini ion 1. (S i ling o mula) The S i ling o mula o he Gamma unc ion is o mula ed by
Γ(x)∼√2πe−xxx−1
2.(2.25)
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.

738
3. Ca a heodo y’s heo y o exis ence and uniqueness o a gene al Cauchy p oblem wi h
s ochas ic A angana-Baleanu ac ional de i a i e
In his sec ion, we p o e he exis ence and uniqueness o he solu ion o he A angana-Baleanu
s ochas ic di e en ial equa ion [18] by employing Ca a h
´
eodo y’s exis ence heo y [19,20], which is a
mo e gene al e sion o Peano’s exis ence heo em. I is wo h no ing ha he exis ence and uniqeness
o he solu ion o s ochas ic di e en ial equa ions wi h he Capu o ac ional de i a i e is p esen ed
in [21]. He e, we will examine he exis ence and uniqueness o he s ochas ic di e en ial equa ion wi h
A angana-Baleanu ac ional de i a i e. The di e en ial equa ion unde in es iga ion is ep esen ed in
he o m:
AB
0Dα
y( )= 1( ,y)d +σy( )dB ( ), ≥0 (3.1)
y( 0)=y0
unde he condi ions
E1) Fo all y,¯y∈H, he e is a cons an k>0 such ha
| 1( ,y)− 1( ,¯y)|2,| 2( ,y)− 2( ,¯y)|2≤k|y−¯y|2, ≥0.(3.2)
E2) Fo all y∈H, he e is a cons an ¯
k>0 such ha
| 1( ,y)|2,| 2( ,y)|2≤¯
k1+|y|2, ≥0 (3.3)
whe e
H
is a Banach space. No e ha condi ions E1 and E2 a e known as he Lipschi z condi ion and
he g ow h condi ion, espec i ely.
Theo em 1. Fo each
y0∈L2(Ω,H)
, Eq (26) has a unique mild solu ion
y∈C[0,T],L2(Ω,H)
=
S
such ha
sup
0≤ ≤T
E|y|2<∞.
P oo .
Fo he p oo , we will use he con ac ion mapping p inciple. Be o e p oceeding wi h he p oo ,
we de ine he no m
kηk2
γ=sup
0≤ ≤T
E|η( )|2(3.4)
whe e Edeno es he expec a ion.
Fo any
∈[0,T]
and
y∈S
, we de ine he mapping subjec o Ω =
C[0,T],L2(Ω,H)→
C[0,T],L2(Ω,H)
(Λy) ( )=y0+(1−α) 1( ,y)+(1−α)σy( )B0( )(3.5)
+α
Γ(α)Z
0
1(s,y) ( −s)α−1ds +ασ
Γ(α)Z
0
y(s) ( −s)α−1dB (s).
Thus, we w i e
E|(Λy) ( )−(Λ¯y) ( )|2=E
(1−α) ( 1( ,y)− 1( ,¯y))
+(1−α)σ(y( )−¯y( )) B0( )
+α
Γ(α)R
0( 1(s,y)− 1(s,¯y)) ( −s)α−1ds
+ασ
Γ(α)R
0(y(s)−¯y(s)) ( −s)α−1dB (s)

2
.(3.6)
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
739
Taking 2
α−
1
>
0, by he Cauchy-Schwa z inequali y, I o’s isome y o mula and he Lipschi z
condi ion [22], we ha e
E|(Λy) ( )−(Λ¯y) ( )|2≤4(1−α)2kσ1+|B0|2E|y−¯y|2(3.7)
+(T+1)4α2k
Γ2(α)Z
0
E|y−¯y|2( −s)2α−2ds
≤4(1−α)2σk1+|B0|2ky−¯ykγ
+(T+1)4α2k
Γ2(α)
2α−1
(2α−1)ky−¯ykγ
≤4σ(1−α)2k 1+sup
∈[0,T]|B0|2!ky−¯ykγ
+(T+1)4α2k
Γ2(α)
2α−1
(2α−1)ky−¯ykγ
≤4σ(1−α)2k1+kB0k∞ky−¯ykγ
+(T+1)4σα2k
Γ2(α)
2α−1
(2α−1)ky−¯ykγ
≤˜
kky−¯ykγ,
whe e
˜
k=4σ(1−α)2k1+kB0k∞+(T+1)4σα2k
Γ2(α)
2α−1
(2α−1).(3.8)
Using he gene alized G onwall inequali y [23], we w i e
EΛ2y( )−Λ2¯y( )≤4σ(1−α)2k1+kB0k∞E|Λy−Λ¯y|2(3.9)
+4σα2k(T+1)
Γ2(α)Z
0
( −s)2α−2E|Λy−Λ¯y|2ds
≤4σ(1−α)2k1+kB0k∞"4(1−α)2k(1+kB0k∞)
+(T+1)4α2k
Γ2(α)
2α−1
(2α−1)#(3.10)
+4σα2k(T+1)
Γ2(α)Z
0
( −s)2α−2"4(1−α)2k(1+kB0k∞)
+(T+1)4α2k
Γ2(α)
s2α−1
(2α−1)#ds(3.11)
≤

4σ(1−α)2k(1+kB0k∞)2
+(T+1)4σα2k
Γ2(α)
T2α−1
(2α−1)4(1−α)2(1+kB0k∞)
+4σ(1−α)2k(1+kB0k∞)4α2k(T+1)
Γ2(α)T2α−1
(2α−1)
+4σα2k(T+1)
Γ2(α)2Γ2(2α−1)
Γ(4α−2)
T4α−2
(2α−1)


ky−¯ykγ.
By he induc ion o mula o n, we can hen w i e
E|(Λny) ( )−(Λn¯y) ( )|≤

4σ(1−α)2(1+kB0k∞)n
+4σ(1−α)2(1+kB0k∞) (T+1)4α2k
Γ2(α)
T2α−1
(2α−1)n−1
+4σ(1−α)2(1+kB0k∞)n−14σα2k(T+1)
Γ2(α)Tn(2α−1)
Γ(n(2α−1))
+4σα2k(T+1)
Γ2(α)nTn(2α−1)
(2α−1)
Γn(2α−1)
Γ(n(2α−1))

ky−¯ykγ(3.12)
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
740
≤Lky−¯ykγ
whe e
L=

4σ(1−α)2(1+kB0k∞)n
+4σ(1−α)2(1+kB0k∞) (T+1)4α2k
Γ2(α)
T2α−1
(2α−1)n−1
+4σ(1−α)2(1+kB0k∞)n−14σα2k(T+1)
Γ2(α)Tn(2α−1)
Γ(n(2α−1))
+4σα2k(T+1)
Γ2(α)nTn(2α−1)
(2α−1)
Γn(2α−1)
Γ(n(2α−1))

.(3.13)
To p o e he heo em holds, we will show ha
L<
1 o su icien la ge
n
. Le us conside he ollowing
se ies o posi i e e ms
∞
n=1

4σ(1−α)2(1+kB0k∞)n
+4σ(1−α)2(1+kB0k∞) (T+1)4α2k
Γ2(α)
T2α−1
(2α−1)n−1
+4σ(1−α)2(1+kB0k∞)n−14σα2k(T+1)
Γ2(α)Tn(2α−1)
Γ(n(2α−1))
+4σα2k(T+1)
Γ2(α)nTn(2α−1)
(2α−1)
Γn(2α−1)
Γ(n(2α−1))

.(3.14)
Using he d’Alembe disc iminan me hod
lim
n→∞ 4α2k(T+1)
Γ2(α)n+1T(n+1)(2α−1)
(2α−1)
Γn+1(2α−1)
Γ((n+1)(2α−1))
4σα2k(T+1)
Γ2(α)nTn(2α−1)
(2α−1)
Γn(2α−1)
Γ(n(2α−1))
<1 (3.15)
which is equi alen o
lim
n→∞ 4σα2k(T+1)
Γ2(α)T(2α−1)Γ(2α−1)Γ(n(2α−1))
Γ((n+1) (2α−1)) <1.(3.16)
Using he S i ling o mula [21], we ha e he ollowing o las e m
lim
n→∞ 4σα2k(T+1)
Γ2(α)Γ(2α−1)T(2α−1)e(2α−1)
√n+1
√nn
n+1n(2α−1)1
((n+1)(2α−1))(2α−1)=0 (3.17)
and knowing ha α < 1,we can ha e
lim
n→∞

4σ(1−α)2(1+kB0k∞)n
+4σ(1−α)2(1+kB0k∞) (T+1)4α2k
Γ2(α)
T2α−1
(2α−1)n−1
+4σ(1−α)2(1+kB0k∞)n−14σα2k(T+1)
Γ2(α)Tn(2α−1)
Γ(n(2α−1))
+4σα2k(T+1)
Γ2(α)nTn(2α−1)
(2α−1)
Γn(2α−1)
Γ(n(2α−1))

=0.(3.18)
This gua an ees ha
L<
1 holds. This p o es ha Λ
y( )
is a con ac ion mapping, which comple es he
p oo .
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
741
4. Pa ame ized me hod o a gene al Cauchy p oblem wi h s ochas ic ac ional de i a i es
In his sec ion, we de elop he pa ame ized app oach o nume ically sol ing di e en ial equa ions
wi h ac ional de i a i es ha inco po a e s ochas ic componen s. Be o e p esen ing he ex ension o
he me hod o he solu ions o di e en di e en ial equa ions, we shall ecall he o mula ion o he
pa ame ized app oach [17,24–26]. The app oach is o mula ed by he ollowing:
ϕ1( ,y)≈" 1−1
2ξ!ϕ1 k,yk+1
2ξϕ1 k+1,˜yk+1#.(4.1)
4.1. Pa ame ized me hod o a gene al Cauchy p oblem wi h s ochas ic componen
To de i e he associa ed me hod, in his subsec ion, we conside a gene al Cauchy p oblem wi h
s ochas ic componen gi en by
dy ( )=ϕ1( ,y)d +σy( )dB ( ).(4.2)
We con e he abo e in o an in eg al equa ion, by applying on bo h sides he classical in eg al
y( )=y(0)+Z
0
ϕ1(τ, y)dτ+Z
0
σy(τ)dB (τ).(4.3)
A = k+1,we w i e
y( k+1)=y(0)+Z k+1
0
ϕ1(τ, y)dτ+Z k+1
0
σy(τ)dB (τ)(4.4)
and a = k
y( k)=y(0)+Z k
0
ϕ1(τ, y)dτ+Z k
0
σy(τ)dB (τ).(4.5)
Subs ac ing hese wo equali ies gi es
y( k+1)=y( k)+Z k+1
k
ϕ1(τ, y)dτ+Z k+1
k
σy(τ)dB (τ).(4.6)
The unc ion
ϕ1(τ, y)
can be app oxima ed by using he pa ame ized app oach [17,24
–
26] p esen ed
ea lie . A e simpli ica ion, we ha e he p edic o -co ec o o mula [27]
yk+1=yk+h" 1−1
2ξ!ϕ1 k,yk+1
2ξϕ1 k+1,˜yk+1#(4.7)
+σy(ck) (B( k+1)−B( k)) ,
whe e ck∈[ k, k+1]and he p edic o e m
˜yk+1=yk+hϕ1 k,yk.(4.8)
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
748
5.3. Pa ame ized me hod o a gene al Cauchy p oblem wi h s ochas ic ac al- ac ional de i a i e
wi h powe -law ke nel
In his sec ion, we ob ain he nume ical solu ion o a gene al Cauchy p oblem wi h s ochas ic
ac al- ac ional de i a i e [18] wi h powe -law ke nel by using he pa ame ized me hod [17]. The
associa ed p oblem unde conside a ion is ep esen ed by
(FFP
0Dα
y( )=ϕ1( ,y)+σy( )dB ( ),i >0,
y(0)=y0,i =0.(5.11)
Applying he ac al- ac ional de i a i e [6] wi h powe -law ke nel, we ha e
y( )=β
Γ(α)Z
0
τβ−1ϕ1(τ, y) ( −τ)α−1dτ+β
Γ(α)Z
0
σy(τ)τβ−1( −τ)α−1dB (τ).(5.12)
A = k+1,we ha e
y( k+1)=β
Γ(α)
k
X
n=0Z n+1
n
τβ−1ϕ1(τ, y) ( k+1−τ)α−1dτ(5.13)
+β
Γ(α)
k
X
n=0Z n+1
n
τβ−1σy(τ) ( k+1−τ)α−1B0(τ)dτ.
Replacing he unc ion ϕ1(τ, y)by i s pa ame ized app oxima ion, we ha e
yk+1=β
Γ(α)
k
X
n=0" 1−1
2ξ!ϕ1( n,yn)+1
2ξϕ1 n+1,˜yn+1#(5.14)
×Z n+1
n
τβ−1( k+1−τ)α−1dτ
+β
hΓ(α)
k
X
n=0
σy(cn) (B( n+1)−B( n))
×Z n+1
n
τβ−1( k+1−τ)α−1dτ.
The in eg al on he igh hand side o he abo e equa ion is calcula ed by using he change o a iables
τ= k+1uand dτ= k+1du as ollows:
Z n+1
n
τβ−1( k+1−τ)α−1dτ= α+β−1
k+1Z n+1
n
uβ−1(1−u)α−1du
= α+β−1
k+1 B n+1
k+1
, β, α!−B n
k+1
, β, α!!,
whe e he unc ion
B(·,·,·)
is he incomple e Be a unc ion. By calcula ion o hese in eg als, he
ollowing nume ical scheme is ob ained:
yk+1=β
Γ(α)
k
X
n=0" 1−1
2ξ!ϕ1( n,yn)+1
2ξϕ1 n+1,˜yn+1#(5.15)
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.

749
× α+β−1
k+1 B n+1
k+1
, β, α!−B n
k+1
, β, α!!
+β
hΓ(α)
k
X
n=0
σy(cn) (B( n+1)−B( n))
× α+β−1
k+1 B n+1
k+1
, β, α!−B n
k+1
, β, α!!.
We know ha he e m ˜yn+1is p edic ed by he ollowing:
˜yn+1=y0+β
Γ(α)
k
X
n=0
ϕ1( n,yn) α+β−1
k+1 B n+1
k+1
, β, α!−B n
k+1
, β, α!!.(5.16)
5.4. Pa ame ized me hod o a gene al Cauchy p oblem wi h s ochas ic ac al- ac ional de i a i e
wi h Mi ag-Le le ke nel
To examine he solu ion o a gene al Cauchy p oblem wi h s ochas ic ac al- ac ional de i a i e
wi h Mi ag-Le le ke nel [18], we conside he ollowing p oblem:
(FFM
0Dα
y( )=ϕ1( ,y)+σy( )dB ( ),i >0,
y(0)=y0,i =0(5.17)
A e aking he associa ed in eg al, he abo e can be a anged as ollows:
y( )=(1−α)ϕ1( ,y)+(1−α)σy( )dB ( )(5.18)
+αβ
Γ(α)Z
0
τβ−1ϕ1(τ, y) ( −τ)α−1dτ
+αβ
Γ(α)Z
0
σy(τ)τβ−1( −τ)α−1B0(τ)dτ.
A = k+1,we ha e
y( )=(1−α)ϕ1 k+1,yk+1+(1−α)σy( k+1)dB ( k+1)(5.19)
+αβ
Γ(α)Z k+1
0
τβ−1ϕ1(τ, y) ( k+1−τ)α−1dτ
+αβ
Γ(α)Z k+1
0
σy(τ)τβ−1( k+1−τ)α−1dB (τ).
Using he ϕ1(τ, y)app oxima ions, we ha e
yk+1=(1−α)ϕ1 k+1,yk+1+(1−α)σy(ck+1) (B( k+1)−B( k)) (5.20)
+αβ
Γ(α)
k
X
n=0" 1−1
2ξ!ϕ1( n,yn)+1
2ξϕ1 n+1,˜yn+1#
×Z n+1
n
τβ−1( k+1−τ)α−1dτ
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
750
+αβ
hΓ(α)
k
X
n=0
σy(cn) (B( n+1)−B( n))
×Z n+1
n
τβ−1( k+1−τ)α−1dτ.
Using he calcula ions o hese in eg als and a anging he abo e, we ha e
yk+1=(1−α)ϕ1 k+1,yk+1+(1−α)σy(ck+1) B( k+1)−B( k)
h!(5.21)
+αβ
Γ(α)
k
X
n=0" 1−1
2ξ!ϕ1( n,yn)+1
2ξϕ1 n+1,˜yn+1#
× α+β−1
k+1 B n+1
k+1
, β, α!−B n
k+1
, β, α!!
+αβ
hΓ(α)
k
X
n=0
σy(cn) (B( n+1)−B( n))
× α+β−1
k+1 B n+1
k+1
, β, α!−B n
k+1
, β, α!!,
whe e he p edic o o mula is s a ed as:
˜yk+1=y0+(1−α)β β−1
k+1ϕ1 k+1,yk+1+αβ
Γ(α)
k
X
n=0
ϕ1( n,yn)(5.22)
× α+β−1
k+1 B n+1
k+1
, β, α!−B n
k+1
, β, α!!.
6. Pa ame ized me hod o a gene al Cauchy p oblem wi h piecewise de i a i e
In his sec ion, we de i e he pa ame ized me hod [17] o some e sions o nonlinea di e en ial
equa ions wi h piecewise di e en ia ion. We shall s a wi h he e sion o nonlinea di e en ial
equa ions wi h piecewise de i a i e [16], in which classical p ocesses can be used in he i s ime
in e al, p ocesses wi h powe -law a e ading memo y in he second ime in e al, and s ochas ic
p ocesses can be used in he hi d ime in e al. The associa ed model is ep esen ed by he ollowing:



























dy
d =ϕ( ,y), i 0 ≤ ≤ 1
y(0)=y0,
ABC
1Dα
y=ϕ( ,y),i 1≤ ≤ 2
y( 1)=y1,
dy ( )=ϕ( ,y)d +σydB ( ), i 2≤ ≤T
y( 2)=y2
.(6.1)
The unc ion
ϕ( ,y)
can be app oxima ed by employing he pa ame ized o mula ion [17], hus in e-
g a ing wi hin [ n, n+1], we ha e he ollowing co ec o o mula wi h p edic o e m:
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
751
yk+1=








y0+hk1
j1=0h1−1
2ξϕ1 j1,yj1+1
2ξϕ1 j1+1,˜yj1+1i,
i 0 ≤ ≤ 1
,(6.2)





































y1+(1−α)ϕ1 k2+1,˜yk2+1
+(1−α)σyck2+1B k2+1−B k2
+hα
Γ(α)
k2
j2=k1+1h1−1
2ξϕ1 j2,yj2+1
2ξϕ1 j2+1,˜yj2+1i
×(k2−j2+1)α−(k2−j2)α
+hα−1
Γ(α)
k2
j2=k1+1σycj2B j2+1−B j2
×(k2−j2+1)α−(k2−j2)α,
i 1≤ ≤ 2,











y2+hk
j3=k2+1h1−1
2ξϕ1 j3,yj3+1
2ξϕ1 j3+1,˜yj3+1i
+σy(ck) (B( k+1)−B( k)) ,
i 2≤ ≤T.
The p edic o componen s o each in e al a e calcula ed as



















n˜yk1+1=y0+hk1
j1=0ϕ1 j1,yj1,i 0 ≤ ≤ 1,







˜yk2+1=y1+(1−α)ϕ1 k2,yk2+hα
Γ(α)
k2
j2=k1+1ϕ1 j2,yj2
×(k2−j2+1)α−(k2−j2)α,i 1≤ ≤ 2,
n˜yk3+1=y2+hk
j3=k2+1ϕ1 j3,yj3,i 2≤ ≤T.
(6.3)
Now, we p oceed wi h an ano he e sion o nonlinea di e en ial equa ions wi h piecewise de i a i es
[16]. In he i s ime in e al, ading memo y p ocesses can be u ilized, while s ochas ic p ocesses
can be used in he second ime in e al. Fo he hi d ime in e al, p ocesses ha deal wi h powe -law
beha io s ha ing ac al p ope ies can be employed. The model ha explains he p ocess p esen ed
he e is shown as ollows:



























CF
0Dα
y=ϕ( ,y), i 0 ≤ ≤ 1
y(0)=y0,
dy ( )=ϕ( ,y)d +σydB ( ),i 1≤ ≤ 2
y( 1)=y1,
FFP
2Dα
y=ϕ( ,y), i 2≤ ≤T
y( 2)=y2.
(6.4)
Using he a o emen ioned concep o nume ical scheme, he nume ical scheme o he Cauchy p oblem
in he amewo k o piecewise de i a i e [16] is achie ed as
yk+1=





















y0+(1−α)ϕ1 k1+1,yk1+1
+αhk1
j1=0h1−1
2ξϕ1 j1,yj1+1
2ξϕ1 j1+1,˜yj1+1i,
i 0 ≤ ≤ 1
(6.5)











y1+hk2
j2=k1+1h1−1
2ξϕ1 j2,yj2+1
2ξϕ1 j2+1,˜yj2+1i
+σyck2B k2+1−B k2,
i 1≤ ≤ 2
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
752



























β
Γ(α)
k
j3=k2+1h1−1
2ξϕ1 j3,yj3+1
2ξϕ1 j3+1,˜yj3+1i
× α+β−1
k+1B j3+1
k+1, β, α−B j3
k+1, β, α
+β
hΓ(α)
k
j3=k2+1σycj3B j3+1−B j3
× α+β−1
k+1B j3+1
k+1, β, α−B j3
k+1, β, α,
i 2≤ ≤T.
The p edic o componen s o each in e al a e de e mined as























n˜yk1+1=y0+hk1
j1=0ϕ1 j1,yj1,i 0 ≤ ≤ 1,
n˜yk2+1=y1+hk2
j2=k1+1ϕ1 j2,yj2,i 1≤ ≤ 2,









˜yk1+1=(1−α)β β−1
k1ϕ1 k1,yk1+αβ
Γ(α)
k
j3=k2+1ϕ1 j3,yj3
× α+β−1
k1+1B j3+1
k1+1, β, α−B j3
k1+1, β, α,i 2≤ ≤T.
(6.6)
7. Illus a i e examples
In his sec ion, we will in es iga e he applicabili y o he pa ame ized me hod o di e en ial
equa ions wi h piecewise de i a i es wi h he help o some illus a i e examples. This will be pe o med
wi h he combina ion o de e minis ic and s ochas ic p ocesses whe e he concep s o classical, s ochas ic,
ac ional, and ac al- ac ional a e added. We will s a wi h a simple piecewise Cauchy p oblem in
which he i s pa is wi h classical de e minis ic, he second pa is wi h A angana-Baleanu de i a i e
and las pa is wi h he classical s ochas ic. Ano he simple scena io will be p esen ed wi h classical
de e minis ic, Capu o ac ional de i a i e and he classical s ochas ic. Finally, we will conside an
anxie y model [28] employing he di e en e sions o he piecewise de i a i e.
Example 1. We conside a gene al Cauchy p oblem wi h piecewise de i a i e



























dy
d =− , i 0 ≤ ≤ 1
y(0)=0,
ABC
1Dα
y=− ,i 1≤ ≤ 2
y( 1)=y1,
dy ( )=− d +σydB ( ), i 2≤ ≤T
y( 2)=y2.
(7.1)
The nume ical solu ion o abo e p oblem is ep esen ed by
yk+1=








y0+hk1
j1=0h−1−1
2ξ j1−1
2ξ j1+1i,
i 0 ≤ ≤ 1
,(7.2)































y1−(1−α) k2+1+(1−α)σyck2+1B k2+1−B k2
+hα
Γ(α)
k2
j2=k1+1h−1−1
2ξ j2−1
2ξ j2+1i
×(k2−j2+1)α−(k2−j2)α
+hα−1
Γ(α)
k2
j2=k1+1σycj2B j2+1−B j2
×(k2−j2+1)α−(k2−j2)α,
i 1≤ ≤ 2,
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
753











y2+hk
j3=k2+1h−1−1
2ξ j3−1
2ξ j3+1i
+σy(ck) (B( k+1)−B( k)) ,
i 2≤ ≤T.
The p edic o e ms a e as ollows:



















n˜yk1+1=y0+hk1
j1=0− j1,i 0 ≤ ≤ 1,







˜yk2+1=y1−(1−α) k2+1−hα
Γ(α)
k2
j2=k1+1 j2
×(k2−j2+1)α−(k2−j2)α,i 1≤ ≤ 2,
n˜yk3+1=y2−hk
j3=k2+1 j3,i 2≤ ≤ .
(7.3)
No ing ha he s ochas ic cons an σis aken as 0.1, he ollowing ini ial condi ions a e as ollows:
y(0)=0,(7.4)





















y( 1)=−45 i α=0.9
y( 1)=−47.9 i α=0.8
y( 1)=−48.49 i α=0.6
y( 1)=−48.8 i α=0.4
y( 1)=−48.2 i α=0.2
,





















y( 2)=−145 i α=0.9
y( 2)=−123.6 i α=0.8
y( 2)=−85.2 i α=0.6
y( 2)=−76 i α=0.4
y( 2)=−60.2 i α=0.2
.
In Figu e 1, he nume ical simula ion o he conside ed p oblem wi h piecewise de i a i e is pe o med
by conside ing di e en alues o ac ional o de s.
Figu e 1. The g aphical isualiza ion o he piecewise Cauchy p oblem.
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.

754
Example 2. We conside a gene al Cauchy p oblem wi h piecewise de i a i e



























dy
d =sin , i 0 ≤ ≤ 1
y(0)=1,
ABC
1Dα
y=sin ,i 1≤ ≤ 2
y( 1)=y1,
dy ( )=sin d +σydB ( ), i 2≤ ≤T
y( 2)=y2.
(7.5)
The nume ical solu ion o abo e p oblem is ep esen ed by
yk+1=








y0+hk1
j1=0h1−1
2ξsin  j1+1
2ξsin  j1+1i,
i 0 ≤ ≤ 1
,(7.6)































y1+(1−α)sin  k2+1+(1−α)σyck2+1B k2+1−B k2
+hα
Γ(α)
k2
j2=k1+1h1−1
2ξsin  j2+1
2ξsin  j2+1i
×(k2−j2+1)α−(k2−j2)α
+hα−1
Γ(α)
k2
j2=k1+1σycj2B j2+1−B j2
×(k2−j2+1)α−(k2−j2)α,
i 1≤ ≤ 2,











y2+hk
j3=k2+1h1−1
2ξsin  j3+1
2ξsin  j3+1i
+σy(ck) (B( k+1)−B( k)) ,
i 2≤ ≤T.
The p edic o componen s o each in e al a e calcula ed as



















n˜yk1+1=y0+hk1
j1=0sin  j1,i 0 ≤ ≤ 1,







˜yk2+1=y1+(1−α)sin  k2+1+hα
Γ(α)
k2
j2=k1+1sin  j2
×(k2−j2+1)α−(k2−j2)α,i 1≤ ≤ 2,
n˜yk3+1=y2+hk
j3=k2+1sin  j3,i 2≤ ≤T.
(7.7)
No ing ha he s ochas ic cons an σis aken as 0.1, he ini ial condi ions a e as ollows:
y(0)=1,(7.8)





















y( 1)=1.6 i α=0.9
y( 1)=2 i α=0.8
y( 1)=2.5 i α=0.6
y( 1)=3.2 i α=0.4
y( 1)=3.4 i α=0.2
,





















y( 2)=2 i α=0.9
y( 2)=2.48 i α=0.8
y( 2)=3.36 i α=0.6
y( 2)=4.7 i α=0.4
y( 2)=4.27 i α=0.2
.
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
755
In Figu e 2, he nume ical simula ion o he conside ed p oblem wi h piecewise de i a i e is
pe o med by conside ing di e en alues o ac ional o de s.
Figu e 2. The g aphical isualiza ion o he piecewise Cauchy p oblem.
Example 3. (Ma hema ical modeling o anxie y o ma hema ics) Ins uc ional and social psychologi-
cal en i onmen a e some o he a i ude a ibu e o s uden s and possible ac o s a ec ing he s uden s’
disliking o liking o ma hema ics and ma hema ics anxie y is closely ela ed o a b oad spec um o
cogni i e, psychological, and beha io al p oblems [28,29]. We nex conside a ma hema ical model as-
socia ed wi h he anxie y o ma hema ics [28]. The ma hema ical model unde in es iga ion is p esen ed
by he ollowing:
dS
d =(1−ε)χ+ωR+ρ(1−η)P−θ
N(A+ϕQ)+κS(7.9)
dP
d =εχ −(κ+(1−η)ρ)P
dE
d =θ
N(A+ϕQ)S−(κ+υ)E
dA
d =(1−%)υE−(κ+δ+ς)A
dQ
d =δA−κQ
dR
d =ςA+%υE−(κ+ω)R
and he ini ial condi ions a e aken as
S(0)≥0,P(0)≥0,E(0)≥0,A(0)≥0,Q(0)≥0,R(0)≥0.(7.10)
He e,
S
: anxie y owa ds ma hema ics suscep ible s uden s;
P
: anxie y owa ds ma hema ics p o ec ed
s uden s;
E
: anxie y owa ds ma hema ics exposed s uden s;
A
: s uden s who ha e anxie y owa ds
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
756
ma hema ics;
Q
: s uden s who ha e pe manen anxie y owa ds ma hema ics;
R
: s uden s eco e ed
om anxie y owa ds ma hema ics.
Replacing he classical de i a i e by he piecewise di e en ial ope a o s and simpli ying he model
wi h piecewise de i a i e, we ge he ollowing modi ied model o anxie y:



























dU
d =ψ( ,U), i 0 ≤ ≤ 1
U(0)=U0,
C
1Dα
U=ψ( ,U),i 1≤ ≤ 2
U( i)=U1,
dU ( )=ψ( ,U)d +σiUdBi( ), i 2≤ ≤T
U( 2)=U2,
(7.11)
whe e
U=

S
P
E
A
Q
R

, ψ ( ,U)=

(1−ε)χ+ωR+ρ(1−η)P−θ
N(A+ϕQ)+κS
εχ −(κ+(1−η)ρ)P
θ
N(A+ϕQ)S−(κ+υ)E
(1−%)υE−(κ+δ+ς)A
δA−κQ
ςA+%υE−(κ+ω)R

.(7.12)
Using he sugges ed me hod o each in e al, he nume ical solu ion can be ob ained as
Uk+1=








U0+hk1
j1=0h1−1
2ξψ j1,Uj1+1
2ξψ j1+1,e
Uj1+1i,
i 0 ≤ ≤ 1
,(7.13)

























U1+hα
Γ(α+1)
k2
j2=k1+1h1−1
2ξψ j2,Uj2+1
2ξψ j2+1,e
Uj2+1i
×(k2−j2+1)α−(k2−j2)α
+hα−1
Γ(α+1)
k2
j2=k1+1σiUcj2Bi j2+1−Bi j2
×(k2−j2+1)α−(k2−j2)α,
i 1≤ ≤ 2,











U2+hk
j3=k2+1h1−1
2ξψ j3,Uj3+1
2ξψ j3+1,e
Uj3+1i
+σy(ck) (B( k+1)−B( k)) ,
i 2≤ ≤T.
The p edic o componen s o each in e al a e calcula ed as























ne
Uk1+1=U0+hk1
j1=0ψ j1,Uj1,i 0 ≤ ≤ 1,










e
Uk2+1=U1+hα
Γ(α+1)
k2
j2=k1+1ψ j2,Uj2"(k2−j2+1)α
−(k2−j2)α#,
i 1≤ ≤ 2,
ne
Uk3+1=U2+hk
j3=k2+1ψ j3,Uj3,i 2≤ ≤T.
(7.14)
In Figu e 3, we simula e he nume ical solu ion o he anxie y model wi h piecewise de i a i e o
α=0.9.
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.
757
Figu e 3. The g aphical isualiza ion o he anxie y model wi h piecewise se ing.
We p esen ano he case o ou model since we know ha he model can be modi ied wi h di e en
de i a i es in each in e als. Fo ano he case o ou model, i can be w i en as ollows:



























CF
0Dα
U=ψ( ,U), i 0 ≤ ≤ 1
U(0)=U0,
dU ( )=ψ( ,U)d +σUdB ( ),i 1≤ ≤ 2
U( 1)=U1,
FFP
2Dα,β
U=ψ( ,U), i 2≤ ≤T
U( 2)=U2.
(7.15)
Fo such a model, we ob ain
Uk+1=





















U0+(1−α)ψ k1+1,Uk1+1
+αhk1
j1=0h1−1
2ξψ j1,Uj1+1
2ξψ j1+1,e
Uj1+1i,
i 0 ≤ ≤ 1
(7.16)
Elec onic Resea ch A chi e Volume 32, Issue 2, 733–761.