الفهرس | Only 14 pages are availabe for public view |
Abstract Integral equations are encountered in various elds of science and numerous applications (in elasticity, plasticity, heat and mass transfer, oscillation theory, uid dynamics, ltration theory, electrostatics, electrodynamics, biomechanics, game theory, control, queuing theory, electrical engineering, economics, medicine, etc.). Exact (closed-form) solutions of integral equations play an important role in the proper understanding of qualitative features of many phenomena and processes in various areas of natural science. Lots of equations of physics, chemistry, and biology contain functions or parameters which are obtained from experiments and hence are not strictly xed. Therefore, it is expedient to choose the structure of these functions so that it would be easier to analyze and solve the equation. As a possible selection criterion, one may adopt the requirement that the model integral equation admits a solution in a closed form. Exact solutions can be used to verify the consistency and estimate errors of various numerical, asymptotic, and approximate methods. Through out this thesis we come across many subjects that handle the linear integral and nonlinear integro-di¤erential equations by using the modern mathematical methods, and some of the powerful traditional methods. This thesis will be powerful tool for those who are concerned by applied mathematics, physical science, and engineering, attempts are made so that it presents both analytical and numerical approaches in a clear and systematic fashion to make this thesis accessible to those who work in these elds. Also there will be a part that is devoted to thoroughly examine the nonlinear integral equations and its applications. Mathematical physics models, such as di¤raction problems, scattering in quantum mechanics, conformal mapping, and water waves also contributed to the creation of nonlinear integral equations. Because it is not always possible to nd exact solutions to problems of physical science that are posed, much work is devoted to obtaining qualitative approximations that highlight the structure of the solution and we worked to search for new methods to become closer or to obtain the exact solution. Summarizing this thesis demonstrates the following ve chapters Chapter 1: This chapter is an introduction to the basic de nitions and concepts of in-tegral and integro-di¤erential equations with some important de nitions and theorems which are necessary for studying the properties of integral and integro-di¤erential equations. It also contains an introduction to some methods used in solving integral equations. Chapter 2: In this chapter, we introduce the basic de nitions and theorems of the Dif- ferential transform method (DTM) for some linear and non-linear functions, it also contains di¤erential transform for convolution theorem and error analysis. Also, we investigate the di¤erential transform method for the Fresnel integrals, Singularly perturbed Volterra integral equations, Volterra population model and a system of di¤erential equations. Exact and approximate solutions were obtained by the mentioned method and we compared those solutions with previous work that used other methods for the same model. Chapter 3: In this chapter, we apply the di¤erential transform method for solving quadratic integral equations to nd the exact solutions for some models and problems, also we study the existence and uniqueness theorem for quadratic integral equations. It also contains applications like singularly perturbed Volterra integral equations and Heat Radiation in a Semi-In nite Solid and their solution using di¤erential transform method. On the other hand, we introduce the basic idea of Homotopy Perturbation Method (HPM) and investigate the method for Singularly perturbed Volterra integral equations, quadratic Sin- gularly perturbed Volterra integral equations, heat radiation in a semi-in nite solid application, and Volterra population model to nd exact and approximate solutions for these applications. The method showed remarkable resulted and was compared to the results of another methods used to solve the same applications. Chapter 4: In this chapter, we study the di¤erential transform method to nd the approx- imate solutions of nonlinear delay di¤erential equations (DDEs) and delay integro-di¤erential equations of type u(qt ) and u(qt). Also, we prove theorems related to the di¤erential trans- formation of the delay functions u(qt ) and u(qt). The results of some examples were tested by applying the DTM showed remarkable performance through a comparison with the pervious results. Chapter 5: This chapter introduces the basic de nitions and theorems of two and three- dimensional di¤erential transform for integral equations. By applying the di¤erential transform method, the integral equations can be transformed to an algebraic equations and solving this equations, we nd the approximate solutions of the integral equations. Also, we apply two and three-dimensional di¤erential transform on some Integral equations and we compared the results with the exact solutions. Two papers were published from the work in this chapter entitled: 1- ”Applications on Di¤erential Transform Method for Solving Singularly Perturbed Volterra Integral Equation, Volterra Integral Equation and Integro-di¤erential Equation.” in the International Journal of Mathematics Trends and Technology (IJMTT), (2015) [41]. 2- ”Applications on Di¤erential Transform method for solving Singularly Perturbed Volterra integral equation, Volterra integral equation and integro-di¤erential equation.” in the Journal of Fractional Calculus and Applications, (2014) [42]. A third paper was accepted containing some work from these chapters entitled: 3- ”Exact Solutions of Quadratic Integral and Integro-di¤erential equations.” in the Journal of Nonlinear Analysis and Optimization, (2015) [43]. |