A New Technique for Numerical Solution of System of Volterra Integral ...

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Jul 16, 2017 - In the present paper, we propose Simpson's quadrature rule to solve the system of linear Volterra Integral Equations of the second kind.
Journal of Computer and Mathematical Sciences, Vol.8(7), 332-339 July 2017 (An International Research Journal), www.compmath-journal.org

ISSN 0976-5727 (Print) ISSN 2319-8133 (Online)

A New Technique for Numerical Solution of System of Volterra Integral Equations of the Second Kind by Simpson’s Quadrature Rule Irin Rahman, M. M. Parvez and Sumita Ghosh Department of Mathematics, Dhaka University of Engineering & Technology, Gazipur Gazipur-1700, BANGLADESH. (Received on: July 15, Accepted: July 16, 2017) ABSTRACT In the present paper, we propose Simpson’s quadrature rule to solve the system of linear Volterra Integral Equations of the second kind. We convert the system of linear Volterra Integral Equation of the second kind to a recurrence relation and an approximation solution of them is obtained. We show that our estimates have a good degree of accuracy. Keywords: Simpson’s quadrature rule, System of linear Volterra Integral Equations of the Second Kind.

1. INTRODUCTION In recent years, there has been a growing interest in the Volterra integral equations arising in various fields of physics and engineering, e.g. potential theory and Dirichlet problems, electrostatics, the particle transport problems of astrophysics and reactor theory, contact problems, diffusion problems, and heat transfer problems. Also, many initial and boundary value problems associated with the ordinary and partial differential equations can be cast into the Volterra integral equations. The problem of finding a numerical solution of Fredholm and Volterra integral equations of the second kinds is one of the oldest problems in the applied Mathematics literature and many computational methods are introduced in this field. In the recent paper, we apply repeated Simpson's quadrature rule to solve the system of linear Volterra integral equations of the second kind. By using this method we convert the system of linear Volterra integral equations of the second kind of a recurrence relation and find an approximate solution for them. 332

Irin Rahman, et al., Comp. & Math. Sci. Vol.8 (7), 332-339 (2017)

2. SIMPSON’S QUADRATURE RULE If N is even, then Simpson’s quadrature rule may be applied to each subinterval  ଶ௜ , ଶ௜ାଵ , ଶ௜ାଶ ;  = 0, 1, … … … … … . , − 1 2 individually yielding the approximations ℎ ଶ௜ + 4ଶ௜ାଵ + (ଶ௜ାଶ ) 3 ே Summing these approximation result in the composite version of Simpson’s quadrature ଶ ℎ

ℎ =  + 4 + ℎ + 2 + 2ℎ + 4 + 3ℎ + ⋯ + 2 − 2ℎ 3 + 4 − ℎ + ( ) ே For the entire interval. The error of S(h) is the sum of all individual errors

ℎ =  () − ℎ = − ௕

And we conclude that ℎ = For further information, see [10] ௔

ಿ ିଵ మ



ℎହ   ସ ƺ௜ ƺ௜ ∈ ଶ௜ , ଶ௜ାଶ  90

௜ୀ଴ ௕ି௔ ସ ସ − ℎ  ƺ ; ƺ ∈ ଵ଼଴

( , )

3. METHOD OF SOLUTION A linear system of Volterra integral equation of the second kind is considered in the following way,    +  ଵ ,  ଵ   = ଵ   ଵ ௔  ௧   ଶ  +  ଶ ,  ଶ   = ଶ  ௧

, <  < , (1) ௔ .  .  .  ௧  ௡  +  ௡ ,  ௡   = ௡   ௔ where௜  , ௜ ,  are known functions with ௜  , ≠ 0   = 1,2, … . and ௜    = 1,2, … .  are unknown functions. Let the interval  ,  be finite and partitioned by N equally spaced points. ଴ = ; ே = ; 333

Irin Rahman, et al., Comp. & Math. Sci. Vol.8 (7), 332-339 (2017)

௜ = ଴ + ℎ ;  = 1,2, …  ே The approximations of system of VIE (1) in the even nodes ଶ௠ where  = 1,2, … … , are మ೘  ଵ ଶ௠ + ௔ ଵ ,  ଵ   = ଵ ଶ௠





௧మ೘   ଶ ଶ௠ + ௔ ଶ ,  ଶ   = ଶ ଶ௠ . given by (2) .   .  ௧మ೘ ௡ ଶ௠ + ௔ ௡ ,  ௡   = ௡ ଶ௠

Instead of a system of VIE (2), consider the following equation:

 ଵ ଶ௠ +   ଵ ଶ௠ ,  ଵ   = ଵ (ଶ௠ ) ௟ୀ଴ ௧మ೗   ௠ିଵ ௧మ೗శమ   ଶ ଶ௠ +   ଶ ଶ௠ ,  ଶ   = ଶ (ଶ௠ ) ௠ିଵ ௧మ೗శమ

మ೗ .  .   .  ௠ିଵ ௧మ೗శమ   ௡ ଶ௠ +   ௡ ଶ௠ ,  ௡   = ௡ (ଶ௠ ) ௟ୀ଴ ௧మ೗ 

௟ୀ଴ ௧

(3)

And applying repeated Simpson’s quadrature rule, we have

ℎ  ଵ ଶ௠ +  ଵ ଶ௠,ଶ௟ ଵ ଶ௟ + 4ଵ ଶ௠,ଶ௟ାଵ ଵ ଶ௟ାଵ + ଵ ଶ௠,ଶ௟ାଶ ଵ ଶ௟ାଶ  = ଵ ଶ௠  3 ௟ୀ଴  ௠ିଵ  ℎ  ଶ ଶ௠ +  ଶ ଶ௠,ଶ௟ ଶ ଶ௟ + 4ଶ ଶ௠,ଶ௟ାଵ ଶ ଶ௟ାଵ + ଶ ଶ௠,ଶ௟ାଶ ଶ ଶ௟ାଶ  = ଶ ଶ௠ 3 ௟ୀ଴ .  .  .  ௠ିଵ  ℎ ௡ ଶ௠ +  ௡ ଶ௠,ଶ௟ ௡ ଶ௟ + 4௡ ଶ௠,ଶ௟ାଵ ௡ ଶ௟ାଵ + ௡ ଶ௠,ଶ௟ାଶ ௡ ଶ௟ାଶ  = ௡ ଶ௠ 3  ௠ିଵ

We set ௜ ଶ௟ାଵ = ௟ୀ଴

௬೔ మ೗ ା௬೔ మ೗శమ ଶ

for  = 1,2, … … … 

334

Irin Rahman, et al., Comp. & Math. Sci. Vol.8 (7), 332-339 (2017)

ଵ ଶ௟ + ଵ ଶ௟ାଶ ℎ  + ଵ ଶ௠,ଶ௟ାଶ ଵ ଶ௟ାଶ = ଵ ଶ௠ ଵ ଶ௠ +  ଵ ଶ௠,ଶ௟ ଵ ଶ௟ + 4ଵ ଶ௠,ଶ௟ାଵ  3 2 ௟ୀ଴  ௠ିଵ  ଶ + ଶ ଶ௟ାଶ ℎ  ଶ ଶ௠ +  ଶ ଶ௠,ଶ௟ ଶ ଶ௟ + 4ଶ ଶ௠,ଶ௟ାଵ ଶ௟ + ଶ ଶ௠,ଶ௟ାଶ ଶ ଶ௟ାଶ = ଶ ଶ௠ 3 2 ௟ୀ଴ .  .  .  ௠ିଵ  ௡ + ௡ ଶ௟ାଶ ℎ ௡ ଶ௠ +  ௡ ଶ௠,ଶ௟ ௡ ଶ௟ + 4௡ ଶ௠,ଶ௟ାଵ ଶ௟ + ௡ ଶ௠,ଶ௟ାଶ ௡ ଶ௟ାଶ = ௡ ଶ௠ 3 2  ௠ିଵ

௟ୀ଴

Then we have

ℎ ℎ  +  (ଵ ଶ௠,ଶ௟ + 2ଵ ଶ௠,ଶ௟ାଵ )ଵ ଶ௟ +  (2ଵ ଶ௠,ଶ௟ିଵ + ଵ ଶ௠,ଶ௟ ) ଵ ଶ௟ = ଵ ଶ௠  ଵ ଶ௠ 3 3 ௟ୀ଴ ௟ୀଵ  ௠ିଵ ௠  ℎ ℎ  ଶ ଶ௠ +  (ଶ ଶ௠,ଶ௟ + 2ଶ ଶ௠,ଶ௟ାଵ )ଶ ଶ௟ +  (2ଶ ଶ௠,ଶ௟ିଵ + ଶ ଶ௠,ଶ௟ ) ଶ ଶ௟ = ଶ ଶ௠ 3 3 ௟ୀଵ ௟ୀ଴ .  .  .  ௠ିଵ ௠  ℎ ℎ ௡ ଶ௠ +  (௡ ଶ௠,ଶ௟ + 2௡ ଶ௠,ଶ௟ାଵ )௡ ଶ௟ +  (2௡ ଶ௠,ଶ௟ିଵ + ௡ ଶ௠,ଶ௟ ) ௡ ଶ௟ = ௡ ଶ௠ 3 3  ௠ିଵ



By expanding every row of above system for  = 1,2, … … … . ଶ , we have ௟ୀଵ

௟ୀ଴



ଵ ଶ௠ − ∑௠ିଵ ௟ୀଵ  ଵ ଶ௠,ଶ௟ିଵ + ଵ ଶ௠,ଶ௟ + ଵ ଶ௠,ଶ௟ାଵ ଵ ଶ௟ − ଷ ( ଵ ଶ௠,଴ + 2 ଵ ଶ௠,ଵ )ଵ ଴  ଷ  = ଵ ଶ௠ ௛  1 + 2 ଵ ଶ௠,ଶ௠ିଵ + ଵ ଶ௠,ଶ௠

 ଷ  ଶ௛ ௠ିଵ ௛ ∑  −  +  ଶ ଶ௠ ଶ ଶ௠,ଶ௟ିଵ ଶ ଶ௠,ଶ௟ + ଶ ଶ௠,ଶ௟ାଵ ଶ ଶ௟ − ଷ ( ଶ ଶ௠,଴ + 2 ଶ ଶ௠,ଵ )ଶ ଴ ௟ୀଵ ଷ  ଶ ଶ௠ = ௛ 1 + 2 ଶ ଶ௠,ଶ௠ିଵ + ଶ ଶ௠,ଶ௠

(4) ଷ .  .   .  ଶ௛ ௠ିଵ ௛ ∑  −  + ௡ ଶ௠ ௡ ଶ௠,ଶ௟ିଵ ௡ ଶ௠,ଶ௟ + ௡ ଶ௠,ଶ௟ାଵ ௡ ଶ௟ − ଷ ( ௡ ଶ௠,଴ + 2 ௡ ଶ௠,ଵ )௡ ଴ ௟ୀଵ  ଷ ௡ ଶ௠ = ௛ 1 + 2 ௡ ଶ௠,ଶ௠ିଵ + ௡ ଶ௠,ଶ௠

 ଷ ଶ௛



Now taking the initial value ଴ = in system (1) we obtain

 = ଵ ଴ = ଵ  = ଵ ()  ଵ଴  = ଶ ଴ = ଶ  = ଶ ()   ଶ଴ . (5) .  .   ௡ ଴ = ௡ ଴ = ௡  = ௡ () 335

Irin Rahman, et al., Comp. & Math. Sci. Vol.8 (7), 332-339 (2017)

The computation of ௜ ଶ௠ , for  = 1,2, … … … ଶ will facilitate the recurrence relation (4) and the above mentioned relation. ே

4. NUMERICAL EXAMPLES Consider the system of Volterra integral equation of the second kind

 ଵ  = 1 + 2 −  () ௢   ௧

   

ଶ  =

+1+





ିሺ௧ି௦ሻ

ଷ  =  + 2  ଴





௧ି௦

  0 ≤  ≤ 1

()

ଵ  = " +  ଶ  =  + 2

! ଵ ଷ  = ହ 2 − " +

The exact solution is

ଷ௧ 

And numerical approximations by using repeated Simpson’s quadrature rule with the figure are shown in the following tables: Table 01: Exact and approximate solution of example for h=0.05 Node

Exact

Approximate

Solution

Solution

‫ݕ‬ଵ (‫)ݐ‬

‫ݕ‬ଶ (‫)ݐ‬

0.0

1.000000000000

2.000000000000

‫ݕ‬ଵ (‫)ݐ‬

‫ݕ‬ଶ (‫)ݐ‬

1.000000000000

2.000000000000

000

000

0.1

1.094837581924

2.100000000000

0.110904295118

000

000

1.094920793613

2.100000021001

0.111348905940

854

000

0.2

1.178735908636

2.200000000000

327

006

523

018

0.247878176827

1.178901506884

2.200000042350

0.249058956929

303 0.3

1.250856695786

000

878

592

166

904

2.300000000000

0.419061407070

1.251103031688

2.300000064045

0.421422368013

0.4

946

000

805

495

927

042

1.310479336311

2.400000000000

0.635578522670

1.310803953713

2.400000086088

0.639787397943

0.5

536

000

193

040

808

493

1.357008100494

2.500000000000

0.912591517131

1.357407760589

2.500000108478

0.919642247684

0.6

576

000

220

041

807

724

1.389978088304

2.600000000000

1.270719359258

1.390448802039

2.600000131215

1.282078926564

714

000

667

289

926

233

t

‫ݕ‬ଷ (‫)ݐ‬ 0

336

‫ݕ‬ଷ (‫)ݐ‬ 0

Irin Rahman, et al., Comp. & Math. Sci. Vol.8 (7), 332-339 (2017) 0.7

1.409059874522

2.700000000000

1.737952619951

1.409596942497

2.700000154300

1.755770729178

180

000

708

748

164

693

0.8

1.414062800246

2.800000000000

2.352236370618

1.414660859710

2.800000177731

2.379644011296

688

000

697

975

520

994

0.9

1.404936877898

2.900000000000

3.164955115171

1.405589956363

2.900000201509

3.206488554188

148

000

428

188

996

789

1.0

1.381773290676

3.000000000000

4.245635317387

1.382474865624

3.000000225635

4.307836790024

036

000

064

624

591

433

Table 02: Calculating error by comparing the results of exact and approximate solution for h=0.05 Node t 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Error calculation, |௜ |  |   , ௜       , ௜ |;   1,2,3. |ଵ | |ଶ | |ଷ | 0 0 0 0.000083211688152 0.000000021001523 0.000444610821691 0.000165598248289 0.000000042350166 0.001180780102026 0.000246335901449 0.000000064045927 0.002360960942237 0.000324617401504 0.000000086088808 0.004208875273300 0.000399660094465 0.000000108478807 0.007050730553504 0.000470714734575 0.000000131215926 0.011359567305566 0.000537067975568 0.000000154300164 0.017828109226985 0.000598059464287 0.000000177731520 0.027407640678297 0.000653078465040 0.000000201509996 0.031533441017361 0.000701574948588 0.000000225635591 0.062201472637369

Figure: Table 01

337

Irin Rahman, et al., Comp. & Math. Sci. Vol.8 (7), 332-339 (2017) Table 03: Exact and approximate solution of example for h=0.01 Node

t 0.0 0.02 0.04 0.06 0.08 0.1

Exact Solution

‫ݕ‬ଵ (‫)ݐ‬ 1.00000000000 0000 1.01979867335 9911 1.03918944084 7612 1.05816454641 4649 1.07671640027 1792 1.09483758192 4854

‫ݕ‬ଶ (‫)ݐ‬ 2.00000000000 0000 2.02000000000 0000 2.04000000000 0000 2.06000000000 0000 2.08000000000 0000 2.10000000000 0000

Approximate Solution

‫ݕ‬ଷ (‫)ݐ‬ 0 0.02040677465 3090 0.04165508265 8333 0.06378896722 9099 0.08685536639 1426 0.11090429511 8327

‫ݕ‬ଵ (‫)ݐ‬ 1.00000000000 0000 1.01979933998 6798 1.03919077383 5181 1.05816654523 0148 1.07671906411 6142 1.09484090973 2961

‫ݕ‬ଶ (‫)ݐ‬ 2.00000000000 0000 2.02000000000 6678 2.04000000001 3377 2.06000000002 0100 2.08000000002 6844 2.10000000003 3611

‫ݕ‬ଷ (‫)ݐ‬ 0 0.02040959349 4214 0.04166104123 1650 0.06379841591 7822 0.08686868750 2286 0.11092190550 0630

Table 04: Calculating error by comparing the results of exact and approximate solution for h=0.01 Node T 0.01 0.02 0.04 0.06 0.08 0.1

Error calculation, |௜ | = |   , ௜ −      , ௜ |; = 1,2,3. |ଵ | |ଶ | |ଷ | 0 0 0 0.000000666626887 0.000000000006678 0.000002818841124 0.000001332987469 0.000000000013377 0.000005958573317 0.000001998815499 0.000000000020100 0.000009448688723 0.000002663844350 0.000000000026844 0.000013321110860 0.000003427808107 0.000000000033611 0.000017610282303

5. CONCLUSION In this paper, we applied an application of repeated Simpson’s quadrature rule for solving the system of linear Volterra integral equations of the second kind. According to the numerical results which obtaining from the illustrative example, we conclude that for sufficiently small h we get a good accuracy, since by reducing the step size length the least square error will be reduced. The same approach can be used to solve other problems like: - Nonlinear Volterra integral equations. - Linear Fredholm integral equations with Cauchy kernel, Abel kernel. - Volterra- Fredholm integral equations. REFERENCES 1. Mostafa Safavi, A New Technique for Numerical Solution of System of Volterra Integral Equations of the first kind via Quadrature Rule, ACMA, (2012). 338

Irin Rahman, et al., Comp. & Math. Sci. Vol.8 (7), 332-339 (2017)

2. A.J. Jerri, Introduction to Integral Equations with Applications, second edition, John Wiley and Sons, (1999). 3. A.D. Polyanin, A.V. Manzhirov, Handbook of Integral Equations, CRC Press, (2008). 4. C.T.H. Baker, G.F. Miller, Treatment of Integral Equations by Numerical Methods, Academic Press Inc., London, (1982). 5. L. M. Delves, J. L. Mohammad, Computational methods for integral equations, Cambridge University Press, (1985). 6. R. P Kanwal, Linear integral equations theory and technique, Academic Press, New York and London, (1971). 7. R. Kress, Linear Integral Equations, Springer-Verlag, Berlin, Heidelbarg, 1989. 8. P.K Kyte, P. Puri, E. Computational methods for integral equations, Birkhauser, Boston, (2002). 9. M. Nadir, A. Rahmoune, P.P. Zabrejko, Modified Method for solving linear Volterra integral equations of the second kind using Simpson’s rule, Int. J. Math. Manus., 1(1), 141-146 (2007). 10. G. M. Philips, P. J. Taylor, Theory and applications of numerical analysis, Academic press, New York, (1973).

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