Solution of the Nonlinear Mixed Volterra-Fredholm Integral Equations by Hybrid of Block-Pulse Functions and Bernoulli Polynomials

A new numerical method for solving the nonlinear mixed Volterra-Fredholm integral equations is presented. This method is based upon hybrid functions approximation. The properties of hybrid functions consisting of block-pulse functions and Bernoulli polynomials are presented. The operational matrices of integration and product are given. These matrices are then utilized to reduce the nonlinear mixed Volterra-Fredholm integral equations to the solution of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of the technique

Numerical Approximate Methods for Solving Linear and Nonlinear Integral Equations

Integral equation has been one of the essential tools for various area of applied mathematics. In this work, we employed different numerical methods for solving both linear and nonlinear Fredholm integral equations. A goal is to categorize the selected methods and assess their accuracy and efficiency. We discuss challenges faced by researchers in this field, and we emphasize the importance of interdisciplinary effort for advancing the study on numerical methods for solving integral equations. Integral equations can be viewed as equations which are results of transformation of points in a given vector spaces of integrable functions by the use of certain specific integral operators to points in the same space. If, in particular, one is concerned with function spaces spanned by polynomials for which the kernel of the corresponding transforming integral operator is separable being comprised of polynomial functions only, then several approximate methods of solution of integral equations can be developed. This work, specially, deals with the development of different wavelet methods for solving integral and intgro-differential equations. Wavelets theory is a relatively new and emerging area in mathematical research. It has been applied in a wide range of engineering disciplines; particularly, wavelets are very successfully used in signal analysis for waveform representations and segmentations, time frequency analysis, and fast algorithms for easy implementation. Wavelets permit the accurate representation of a variety of functions and operators. Moreover, wavelets establish a connection with fast numerical algorithms. Wavelets can be separated into two distinct types, orthogonal and semi-orthogonal. The preliminary concept of integral equations and wavelets are first presented in Chapter 1. Classification of integral equations, construction of wavelets and multi-resolution analysis (MRA) have been briefly discussed and provided in this chapter. In Chapter 2, different wavelet methods are constructed and function approximation by these methods with convergence analysis have been presented. In Chapter 3, linear semi-orthogonal compactly supported B-spline wavelets together with their dual wavelets have been applied to approximate the solutions of Fredholm integral equations (both linear and nonlinear) of the second kind and their systems. Properties of these wavelets are first presented; these properties are then utilized to reduce the computation of integral equations to some algebraic equations. Convergence analysis of B-spline method has been discussed in this chapter. Again, in Chapter 4, system of nonlinear Fredholm integral equations have been solved by using hybrid Legendre Block-Pulse functions and xiii Bernstein collocation method. In Chapter 5, two practical problems arising from chemical phenomenon, have been modeled as Fredholm- Hammerstein integral equations and solved numerically by different numerical techniques. First, COSMO-RS model has been solved by Bernstein collocation method, Haar wavelet method and Sinc collocation method. Second, Hammerstein integral equation arising from chemical reactor theory has been solved by B-spline wavelet method. Comparison of results have been demonstrated through illustrative examples. In Chapter 6, Legendre wavelet method and Bernoulli wavelet method have been developed to solve system of integro-differential equations. Legendre wavelets along with their operational matrices are developed to approximate the solutions of system of nonlinear Volterra integro-differential equations. Also, nonlinear Volterra weakly singular integro-differential equations system has been solved by Bernoulli wavelet method. The properties of these wavelets are used to reduce the system of integral equations to a system of algebraic equations which can be solved numerically by Newton's method. Rigorous convergence analysis has been done for these wavelet methods. Illustrative examples have been included to demonstrate the validity and applicability of the proposed techniques. In Chapter 7, we have solved the second order Lane-Emden type singular differential equation. First, the second order differential equation is transformed into integro-differential equation and then solved by Legendre multi-wavelet method and Chebyshev wavelet method. Convergence of these wavelet methods have been discussed in this chapter. In Chapter 8, we have developed a efficient collocation technique called Legendre spectral collocation method to solve the Fredholm integro-differential-difference equations with variable coefficients and system of two nonlinear integro-differential equations which arise in biological model. The proposed method is based on the Gauss-Legendre points with the basis functions of Lagrange polynomials. The present method reduces this model to a system of nonlinear algebraic equations and again this algebraic system has been solved numerically by Newton's method. The study of fuzzy integral equations and fuzzy differential equations is an emerging area of research for many authors. In Chapter 9, we have proposed some numerical techniques for solving fuzzy integral equations and fuzzy integro-differential equations. Fundamentals of fuzzy calculus have been discussed in this chapter. Nonlinear fuzzy Hammerstein integral equation has been solved by Bernstein polynomials and Legendre wavelets, and then compared with homotopy analysis method. We have solved nonlinear fuzzy Hammerstein Volterra integral equations with constant delay by Bernoulli wavelet method and then compared with B-spline wavelet method. Finally, fuzzy integro-differential equation has been solved by Legendre wavelet method and compared with homotopy analysis method. In fuzzy case, we have applied two-dimensional numerical methods which are discussed in chapter 2. Convergence analysis and error estimate have been also provided for Bernoulli wavelet method. xiv The study of fractional calculus, fractional differential equations and fractional integral equations has a great importance in the field of science and engineering. Most of the physical phenomenon can be best modeled by using fractional calculus. Applications of fractional differential equations and fractional integral equations create a wide area of research for many researchers. This motivates to work on fractional integral equations, which results in the form of Chapter 10. First, the preliminary definitions and theorems of fractional calculus have been presented in this chapter. The nonlinear fractional mixed Volterra-Fredholm integro-differential equations along with mixed boundary conditions have been solved by Legendre wavelet method. A numerical scheme has been developed by using Petrov-Galerkin method where the trial and test functions are Legendre wavelets basis functions. Also, this method has been applied to solve fractional Volterra integro-differential equations. Uniqueness and existence of the problem have been discussed and the error estimate of the proposed method has been presented in this work. Sinc Galerkin method is developed to approximate the solution of fractional Volterra-Fredholm integro-differential equations with weakly singular kernels. The proposed method is based on the Sinc function approximation. Uniqueness and existence of the problem have been discussed and the error analysis of the proposed method have been presented in this chapte

Approximate Analytical Methods For Solving Fredholm Integral Equations

Persamaan kamiran memainkan peranan penting dalam banyak bidang sains seperti matematik, biologi, kimia, fizik, mekanik dan kejuruteraan. Oleh yang demikian,pelbagai teknik berbeza telah digunakan untuk menyelesaikan persamaan jenis ini. Kajian ini, memfokus kepada analisis secara matematik dan berangka bagi beberapa kes persamaan kamiran Fredholm yang linear dan bukan linear. Kes-kes ini termasuklah persamaan kamiran Fredholm satu dimensi jenis pertama dan kedua, persamaan kamiran Fredholm dua dimensi jenis pertama dan kedua dan sistem persamaan kamiran Fredholm satu dimensi dan dua dimensi. Integral equations play an important role in many branches of sciences such as mathematics, biology, chemistry, physics, mechanics and engineering. Therefore, many different techniques are used to solve these types of equations. This study focuses on the mathematical and numerical analysis of some cases of linear and nonlinear Fredholm integral equations. These cases are one-dimensional Fredholm integral equations of the first kind and second kind, two-dimensional Fredholm integral equations of the first kind and second kind and systems of one and two-dimensional Fredholm integral equations

Fractional Calculus and Special Functions with Applications

The study of fractional integrals and fractional derivatives has a long history, and they have many real-world applications because of their properties of interpolation between integer-order operators. This field includes classical fractional operators such as Riemann–Liouville, Weyl, Caputo, and Grunwald–Letnikov; nevertheless, especially in the last two decades, many new operators have also appeared that often define using integrals with special functions in the kernel, such as Atangana–Baleanu, Prabhakar, Marichev–Saigo–Maeda, and the tempered fractional equation, as well as their extended or multivariable forms. These have been intensively studied because they can also be useful in modelling and analysing real-world processes, due to their different properties and behaviours from those of the classical cases.Special functions, such as Mittag–Leffler functions, hypergeometric functions, Fox's H-functions, Wright functions, and Bessel and hyper-Bessel functions, also have important connections with fractional calculus. Some of them, such as the Mittag–Leffler function and its generalisations, appear naturally as solutions of fractional differential equations. Furthermore, many interesting relationships between different special functions are found by using the operators of fractional calculus. Certain special functions have also been applied to analyse the qualitative properties of fractional differential equations, e.g., the concept of Mittag–Leffler stability.The aim of this reprint is to explore and highlight the diverse connections between fractional calculus and special functions, and their associated applications

Abstract book

Welcome at the International Conference on Differential and Difference Equations & Applications 2015. The main aim of this conference is to promote, encourage, cooperate, and bring together researchers in the fields of differential and difference equations. All areas of differential & difference equations will be represented with special emphasis on applications. It will be mathematically enriching and socially exciting event. List of registered participants consists of 169 persons from 45 countries. The five-day scientific program runs from May 18 (Monday) till May 22, 2015 (Friday). It consists of invited lectures (plenary lectures and invited lectures in sections) and contributed talks in the following areas: Ordinary differential equations, Partial differential equations, Numerical methods and applications, other topics

Komparativ analyse av heterogene og homogene nevrale feltmodeller

The present thesis is devoted to the comparative analysis of heterogeneous and homogeneous neural field models. The motivation for this work stems from the fact that there is considerable interest in processes in neural tissue, which can underlie both natural and pathological neurobiological phenomena (e.g., orientation tuning in primary visual cortex, short term working memory, control of head direction, motion perception, visual hallucinations and EEG rhythms). The main aim of this thesis is to investigate the outcome of the analysis of a heterogeneous neural field model and its homogeneous counterpart. Another goal is to get more realistic dynamical models for the brain function which takes into account microscopic effects. Mathematically, this approach is formulated in terms of (a system of) nonlinear integro-differential equations. These models describe nonlinear interactions between neuron populations. They are used as a starting point to study traveling wave fronts, localized stationary solutions (bumps) and pattern formation. The first part of the thesis consists of the introduction. Here we first give a short review of the neurophysical background. Secondly, we introduce the key mathematical objects of the present thesis, namely a neural field model of the Amari type and a 2-population homogenized neural field model. We also review the basic ideas of homogenization theory and the two-scale convergence method. Then we summarize the results and give ideas for future works. The second part of the thesis consists of three papers. Paper I deals with the existence and linear stability of stationary periodic bump solutions to a neural field model of the Amari type. In Paper II and III we focus on 2-population homogenized neural field models where the cortical microstructure is taken into account in the connectivity strength. We study the existence and stability of localized stationary single bump solutions (Paper II). In Paper III we investigate pattern forming processes in the same neural field model. The key methods in the present study are a pinning function technique for the existence of bumps, spectral methods and properties, block diagonalization and the Fourier decomposition method in the stability assessment and numerical simulations. We believe that the present thesis contributes to the understanding of the brain functions, both in normal and pathological cases.I denne avhandlingen utføres en komparativ analyse av heterogene og homogene nevrale nettverksmodeller. Motivasjonen for dette arbeidet er interessen for prosesser i hjernebarken, som kan være grunnlag for både naturlige og patologiske nevrobiologiske fenomener (for eksempel i orienteringsinnstilling i den primære visuelle hjernebarken, korttidsminne, kontroll av hoderetning, bevegelsesoppfattelse, visuelle hallusinasjoner og EEG-rytmer). Hovedformålet med denne avhandlingen er å analysere en heterogen nevral nettverksmodell og dens homogene motstykke. Et annet mål er å få mer realistiske dynamiske modeller for hjernefunksjonen, som tar hensyn til mikroskopiske effekter. Disse modellene er gitt som (et system av) ikke-lineære integro-differensiallikninger. Disse modellene beskriver ikke-lineære interaksjoner mellom nevronpopulasjoner. De brukes som utgangspunkt for å studere bølgeforplantning, lokaliserte stasjonære løsninger (bumps) og mønsterdannelse. I introduksjonen presenterer vi en oversikt over den nevrofysiologiske bakgrunnen. Videre introduserer vi de matematiske modellene som er sentrale i denne avhandlingen, det vil si en nevral nettverksmodell av Amari- typen og en homogenisert 2-populasjon nevral nettverksmodell. Vi gjennomgår også grunnbegrepene i homogeniseringsteori og toskala konvergensmetoden. Deretter oppsummerer vi resultatene og fremlegger ideer for videre arbeid. Den andre delen av denne avhandlingen består av tre artikler. Artikkel I omhandler eksistensen og den lineære stabiliteten til stasjonære periodiske bump-løsninger i en nettverksmodell av Amari-typen. I artikkel II og III fokuserer vi på en homogenisert 2-populasjons nevral nettverksmodell, hvor mikrostrukturen i hjernebarken tas med i beregningen av konnektivitetsstyrken. Vi undersøker eksistensen og stabiliteten til lokaliserte stasjonære bump-løsninger (artikkel II). I artikkel III studerer vi mønsterdannende prosesser i den samme nevrale nettverksmodellen. De sentrale metodene i denne studien er en pinning-funksjonsteknikk for eksistens av bumps. Stabilitetsanalysen er gjennomført ved hjelp av spektral metoder , blokk diagonalisering og Fouriertransformasjon og numeriske simuleringer. Vi mener at denne avhandlingen bidrar til forståelsen av hjernens funksjoner, både under normale og patologiske omstendigheter

International Conference on Mathematical Analysis and Applications in Science and Engineering – Book of Extended Abstracts

The present volume on Mathematical Analysis and Applications in Science and Engineering - Book of Extended Abstracts of the ICMASC’2022 collects the extended abstracts of the talks presented at the International Conference on Mathematical Analysis and Applications in Science and Engineering – ICMA2SC'22 that took place at the beautiful city of Porto, Portugal, in June 27th-June 29th 2022 (3 days). Its aim was to bring together researchers in every discipline of applied mathematics, science, engineering, industry, and technology, to discuss the development of new mathematical models, theories, and applications that contribute to the advancement of scientific knowledge and practice. Authors proposed research in topics including partial and ordinary differential equations, integer and fractional order equations, linear algebra, numerical analysis, operations research, discrete mathematics, optimization, control, probability, computational mathematics, amongst others. The conference was designed to maximize the involvement of all participants and will present the state-of- the-art research and the latest achievements.info:eu-repo/semantics/publishedVersio