haar wavelet

In this paper, we combine the two-dimensional (2D) Haar wavelet functions (HWFs) with the block-pulse functions (BPFs) to solve the 2D linearVolterra-Fredholm integral equations (2D-L(VF)IE), so we present a new hybrid computational effcient method based on the 2D-HWFs and 2D-BPFs to approximate the solution ofthe 2D linear Volterra-Fredholm integral equations. In fact, the HWFs and theirrelations to the BPFs are employed to derive a general procedure to formoperational matrix of Haar wavelets. Theoretical erroranalysis of the proposed method is done. Finally some examples arepresented to show the effectiveness of the proposed method.

A class of linear and nonlinear fractional differential equations (FDEs) in the Caputo sense is considered and studied through two novel techniques called the Homotopy analysis method (HAM). A reliable approach is proposed for solving fractional order nonlinear ordinary differential equations, and the Haar wavelet technique (HWT) is a numerical approach for both integer and noninteger orders. Perturbation techniques are widely applied to gain analytic approximations of nonlinear equations. However, perturbation methods are essentially based on small physical parameters (called perturbation quantity), but unfortunately, many nonlinear problems have no such kind of small physical parameters at all. HAM overcomes this, and HWT does not require any parameters. Due to this, we opt for HAM and HWT to study FDEs. We have drawn a semi-analytical solution in terms of a series of polynomials and numerical solutions for FDEs. First, we solve the models by HAM by choosing the preferred control parameter. Second, HWT is considered. Through this technique, the operational matrix of integration is used to convert the given FDEs into a set of algebraic equation systems. Four problems are discussed using both techniques. Obtained results are expressed in graphs and tables. Results on convergence have been discussed in terms of theorems.

This article uses the rational Haar wavelet and the successive methodto solve the nonlinear Fredholm integral differential equation. Additionally, wehave proved the convergence and order of convergence in this method by usingthe fixed point Banach theorem. In this way, numerical integration is not used.We also talk about two examples. We solved, drawing the absolute error, andplot of the exact and numerical solution. Finally, the results show that theproposed method is powerful for solving this equation.

The Haar wavelet collocation with iteration technique is applied for solving a class of time-fractional physical equations. The approximate solutions obtained by two dimensional Haar wavelet with iteration technique are compared with those obtained by analytical methods such as Adomian decomposition method (ADM) and variational iteration method (VIM). The results show that the present scheme is effective and appropriate for obtaining the numerical solution of the timefractional Modified Camassa-Holm equation and Time fractional Modified Degasperis-Procesi equation.

In this paper, we solve a class of nonlinear optimal control problems using a hybrid genetic algorithm (HGA) and a direct method based on the Haar wavelets where the performance index is Bolza-form and the dynamic system is linear‎. ‎First‎, ‎we change the problem by using HWs to a static optimization problem ‎in‎ ‎which the decision variables are the unknown coefficients of the state and control variables in the Haar series‎. ‎Next‎, ‎we apply HGA with a local search for higher power of GA in investigating the search space for solving optimization problems‎. ‎Finally‎, ‎we give some examples to illustrate the high accuracy of the proposed method.

In this paper, We studied an application of the Haar wavelet basis in solving a particular class of delay differential equations. We have extended the Haar wavelet series(HWS) method to develop a numerical technique to solve linear and nonlinear Dirichlet boundary value problems of proportional delay nature. Some problems are presented to test the efficiency of the proposed technique, where a remarkable agreement between approximate and analytic solutions is obtained. The numerical simulation indicates that error drops with the increase in the level of resolution. Also, it is observed that the rate of convergence tends to be 2.

A numerical method based on the Haar wavelet is introduced in this study for solving the partial differential equation which arises in the pricing of European options. In the first place, and due to the change of variables, the related partial differential equation (PDE) converts into a forward time problem with a spatial domain ranging from 0 to 1. In the following, the Haar wavelet basis is used to approximate the highest derivative order in the equation concerning the spatial variable. Then the lower derivative orders are approximated using the Haar wavelet basis. Finally, by substituting the obtained approximations in the main PDE and doing some computations using the finite differences approach, the problem reduces to a system of linear equations that can be solved to get an approximate solution. The provided examples demonstrate the effectiveness and precision of the method.

In this study, we present the existence of solutions for Urysohn integral equations. By using the techniques of noncompactness measures, we employ the basic fixed point theorems such as Petryshyn's fixed point theorem to obtain the mentioned aim in Banach algebra. Then this paper presents a numerical approach based on Haar wavelets to solve the equation. This numerical method does not lead to a nonlinear algebraic equations system. Conducting numerical experiments confirm the theoretical results of the applied method and endorse the accuracy of the method.

As two-dimensional coupled system of nonlinear partial differential equations does not give enough smooth solutions, when approximated by linear, quadratic and cubic polynomials and gives poor convergence or no convergence. In such cases, approximation by zero degree polynomials like Haar wavelets (continuous functions with finite jumps) are most suitable and reliable. Therefore, modified numerical method based on Taylor series expansion and Haar wavelets is presented for solving coupled system of nonlinear partial differential equations. Efficiency and accuracy of the proposed method is depicted by comparing with classical methods.

In this paper, a new method for calculating the numerical approximation of the nonlinear Urysohn integral equations is proposed based on Haar wavelets. Also, the convergence analysis and numerical stability of these method are discussed. Conducting numerical experiments confirm the theoretical results of the applied method and endorse the accuracy of the method.

We successively apply the rational Haar wavelet  to solve the nonlinear Volterra integro-differential equations and nonlinear Fredholm integro-differential equations. Using the Banach fixed point theorem for these equations, we prove the convergence. In this method, no numerical integration is used. Numerical results are presented to show the effectiveness of this method.

In this work, we investigate fractional version of the Fisher equation and solve it by using an efficient iteration technique based on the Haar wavelet operational matrices. In fact, we convert the nonlinear equation into a Sylvester equation by the Haar wavelet collocation iteration method (HWCIM) to obtain the solution. We provide four numerical examples to illustrate the simplicity and efficiency of the technique.

For {φ_n(x)}, x ε [0,1] an orthonormalsystem of uniformly bounded functions, ||φ_n||_{∞}≤ M

We present a method for calculating the numerical approximation of the   two-dimensional mixed Volterra Fredholm integral equations, using the properties of the rationalized Haar (RH) wavelets and the matrix operator.  Attaining this purpose, first, an operator and then an orthogonal projection should be defined. Regarding the characteristics of Haar wavelet, we solve the integral equation without using common mathematical methods. An upper bound and the convergence of the mentioned method have been proved, by using the Banach fixed point. Moreover, the rate of the convergence  method is  $O(n(2q) ^n)$. Finally, several examples of different kinds of functions are presented and solved by this method.

We present here, three- dimensional Haar wavelet based method for solving well known two- dimensional telegraph equation, by approximating higher order mixed derivatives by a series of higher dimensional Haar wavelet functions, which are integrated subsequently to get wavelet approximation of the solution. Numerical examples have been solved to illustrate the accuracy and efficiency of the proposed Haar wavelet method. High accuracy of the results even in the case of a small number of collocation points have been observed.

In this paper we present a new and efficient method by combining pseudo differential operators and Haar wavelet to solve the linear and nonlinear differential equations. The present method performs extremely well in terms of efficiency and simplicity.

‎In this paper‎, ‎Haar wavelets are performed for solving continuous time-variant linear-quadratic optimal control problems‎. ‎Firstly‎, ‎using necessary conditions for optimality‎, ‎the problem is changed into a two-boundary value problem (TBVP)‎. ‎Next‎, ‎Haar wavelets are applied for converting the TBVP‎, ‎as a system of differential equations‎, ‎in to a system of matrix algebraic equations‎, ‎as Haar matrix equations using Kronecker product‎. ‎Then the error analysis of the proposed method is presented‎. ‎Some numerical examples are given to demonstrate the efficiency of the method‎. ‎The solutions converge as the number of approximate terms increase.

In this paper a robust and accurate algorithm based on Haar wavelet collocation method (HWCM) is proposed for solving eighth order boundary value problems. We used the Haar direct method for calculating multiple integrals of Haar functions. To illustrate the efficiency and accuracy of the concerned method, few examples are considered which arise in the mathematical modeling of fluid dynamics and hydromagnetic stability. Convergence and error bound estimation of the method are discussed. The comparison of results with exact solution and existing numerical methods such as Quintic B-spline collocation method and Galerkin method with Quintic B-splines as basis functions shown that the HWCM is a powerful numerical method for solution of above mentioned problems.

In recent years, there has been greater attempt to find numerical solutions of differential equations using wavelet''s methods. The following method is based on vector forms of Haar-wavelet functions. In this paper, we will introduce one dimensional Haar-wavelet functions and the Haar-wavelet operational matrices of the fractional order integration. Also the Haar-wavelet operational matrices of the fractional order differentiation are obtained. Then we propose the Haar-wavelet operational matrix method to achieve the Haar-wavelet time response output solution of fractional order linear systems where a fractional derivative is defined in the Caputo sense. Using collocation points, we have a Sylvester equation which can be solve by Block Krylov subspace methods. So we have analyzed the errors. The method has been tested by a numerical example. Since wavelet representations of a vector function can be more accurate and take less computer time, they are often more useful.