Reproducing Kernel Method Research Articles

A new approach for Solving a nonlinear system of second-order BVPs

In this paper, we introduce a new approach based on the Reproducing Kernel Method (RKM) for solving a nonlinear system of second-order Boundary Value Problems (BVPs) without the Gram-Schmidt orthogonalization process. What motivates us to use the RKM without the Gram-Schmidt orthogonalization process is its easy implementation, elimination of the Gram-Schmidt process, fewer calculations, and high accuracy. Finally, the compatibility of numerical results and theorems demonstrates that the Present method is effective.

Functional quantile regression with missing data in reproducing kernel Hilbert space

We, in this article, focus on functional partially linear quantile regression, where the observations are missing at random, which allows the response or covariates or response and covariates simultaneously missing. Estimation of the unknown function is done based on reproducing kernel method. Under suitable assumptions, we discuss consistency with rates of the estimators, and establish asymptotic normality of the estimator for the parameter. At the same time, we study hypothesis test of the parameter, and prove asymptotic distributions of restricted estimators of the parameter and test statistic under null hypothesis and local alternative hypothesis, respectively. Also, we study variable selection of the linear part of the model. By simulation and real data, finite sample performance of the proposed methods is analyzed.

A novel numerical approach for the third order Emden–Fowler type equations

AbstractThis article aims to achieve robust numerical results by applying the Chebyshev reproducing kernel method without homogenizing the initial‐boundary conditions of the Emden–Fowler (E‐F) equation, thereby introducing a new perspective to the literature. A novel numerical approach is presented for solving the initial‐boundary value problem of third‐order E‐F equations using Chebyshev reproducing kernel theory. Unlike previous applications, which were confined to homogeneous initial‐boundary value problems or required homogenization, the proposed method is effective for both homogeneous and nonhomogeneous cases. To handle the initial‐boundary conditions of the E‐F equations, additional basis functions are introduced rather than imposing conditions on the reproducing kernel Hilbert space. The method's effectiveness is demonstrated through five examples, which validate the theoretical analysis. Overall, the results emphasize the method's efficiency.

The Approximate Integrals by the Reproducing Kernel Method on the Elliptical Region Eₙ In the Space Rⁿ

In this paper, we applied the reproducing kernel method on elliptical region, we establish the formulas of the reproducing kernel from several degrees and generalized those formulas whatever the dimension of space, we obtained all surfaces, points, and their constants for compensation in the cubature formula, tables are included to show our results and examples to show the approximation solution in this method.

Solving an electrically conducting nanofluid over an impermeable stretching cylinder problem with a spectral reproducing kernel method

In this paper, a nonlinear mechanical system of ordinary differential equations (ODEs) with multi-point boundary conditions is considered by a novel type of reproducing kernel Hilbert space method (RKHSM). To begin, we define the unknown variables in terms of the reproducing kernel function. The roots of the Shifted Chebyshev polynomials (SCPs) are then utilized to collocate the resulting system. Finally, Newton’s iterative method is employed to find the unknown expansion coefficients. The solutions of this system of equations, which arise from the flow of an electrically conducting nanofluid over an impermeable stretching cylinder, are numerically analyzed, and convergence analysis is discussed to demonstrate the reliability of the presented method (PM). Tables and figures are provided to further discuss the solutions and assess the effectiveness of the method in comparison to other techniques in the literature.

A new application of the reproducing kernel method for solving linear systems of fractional order Volterra integro-differential equations

In this article, a new implementation of the reproducing kernel method is presented for solving systems of fractional-order Volterra integro-differential equations. Unlike previous implementations, this method does not rely on the Gram-Schmidt process. The reproducing kernel method utilizes various components, including space, inner product, bases, and points. Furthermore, the system of fractional-order Volterra integro-differential equations involves Caputo’s fractional derivative and Volterra integral. However, when using the reproducing kernel method to solve these systems, challenges such as longer execution time and lower accuracy may arise compared to other methods. The present method has overcome these challenges with features such as easy implementation, high accuracy, and lower execution time.

Application of the reproducing kernel method for solving linear Volterra integral equations with variable coefficients

This article proposes a new approach for solving linear Volterra integral equations with variable coefficients using the Reproducing Kernel Method (RKM). This method eliminates the need for the Gram-Schmidt process. However, the accuracy of RKM is influenced by various factors, including the selection of points, bases, space, and implementation method. The main objective of this article is to introduce a generalized method based on the Reproducing Kernel, which is successful in solving a special type of singular weakly nonlinear boundary value problems (BVPs). The easy implementation, elimination of the Gram-Schmidt process, fewer calculations, and high accuracy of the present method are interesting. The conformity of numerical results, including tables and figures, with theorems related to error analysis and convergence order, confirms the practicality of the present method.

A binary Caputo–Fabrizio fractional reproducing kernel method for the time-fractional Cattaneo equation

A binary Caputo–Fabrizio fractional reproducing kernel method for the time-fractional Cattaneo equation

Gohar Fractional Derivative: Theory and Applications

The local fractional derivatives marked the beginning of a new era in fractional calculus. Due to their that have never been observed before in the field, they are able to fill in the gaps left by the nonlocal fractional derivatives and substantially increase the field’s theoretical and applied potential. In this article, we introduce a new local fractional derivative that possesses some classical properties of the integer-order calculus, such as the product rule, the quotient rule, the linearity, and the chain rule. It meets the fractional extensions of Rolle’s theorem and the mean value theorem and has more properties beyond those of previously defined local fractional derivatives. We reveal its geometric interpretation and physical meaning. We prove that a function can be differentiable in its sense without being classically differentiable. Moreover, we apply it to solve the Riccati fractional differential equations to demonstrate that it provides more accurate results with less error in comparison with the previously defined local fractional derivatives when applied to solve fractional differential equations. The numerical results obtained in this work by our local fractional derivative are shown to be in excellent agreement with those produced by other analytical and numerical methods such as the enhanced homotopy perturbation method (EHPM), the improved Adams-Bashforth-Moulton method(IABMM), the modified homotopy perturbation method (MHPM), the Bernstein polynomial method (BPM), the fractional Taylor basis method (FTBM), and the reproducing kernel method (RKM).

Reproducing Kernel Method with Global Derivative

Ordinary differential equations describe several phenomena in different fields of engineering and physics. Our aim is to use the reproducing kernel Hilbert space method (RKHSM) to find a solution to some ordinary differential equations (ODEs) that are described by using the global derivative. In this research, we used the RKHSM to construct new numerical solutions for nonlinear ODEs with global derivative. The used method systematically produces analytic and approximate solutions in the series’s form. We tested three applications for showing the performance of the RKHSM.

STABILITY,ERROR ESTIMATE AND APPROXIMATION OF SOLUTIONS OF NON-LINEAR SYSTEM INTEGRAL EQUATIONS IN DIRECT SUM OF HILBERT SPACE

In this research, we study stability of solutions with respect to the driver of a system of nonlinear Volterrs integral equations in reproducing Kernel Hilbert space. We study error estimate of solutions in terms of uniform grid numbers of subintervals of [a, b]. Furthermore, we use the reproducing kernel method to approximate the solutions of the problem. Finally, we give some examples to show the power of the method

APPROXIMATI OF SOLUTIONS OF 2D NON-LINEAR INTEGRAL EQUATIONS IN A BINARY HILBERT SPACE

In this work, we investigate stability of solutions relative to the driver to a general class of nonlinear integral equations in two dimensions in binary reproducing kernel Hilbert space. Next, we analyze estimate error of solutions in terms of uniform grid numbers of compact subintervals of [a, b] × [c, d]. In addition, we use the reproducing kernel method to approximate the solutions of the problem. Finally, we provide an example to illustration the reliability of the method

The reproducing kernel method for nonlinear fourth-order BVPs

<abstract><p>Based on the reproducing kernel theory, we solve the nonlinear fourth order boundary value problem in the reproducing kernel space $ W_{2}^{5}[0, 1] $. Its approximate solution is obtained by truncating the n-term of the exact solution and using the $ \varepsilon $-best approximate method. Meanwhile, the approximate solution $ u^{(i)}_{n}(x) $ converges uniformly to the exact solution $ u^{(i)}(x), (i, 0, 1, 2, 3, 4) $. The validity and accuracy of this method are verified by some examples.</p></abstract>

The Bernoulli polynomials reproducing kernel method for nonlinear Volterra integro-differential equations of fractional order with convergence analysis

The Bernoulli polynomials reproducing kernel method for nonlinear Volterra integro-differential equations of fractional order with convergence analysis

Adaptive multi-step piecewise interpolation reproducing kernel method for solving the nonlinear time-fractional partial differential equation arising from financial economics

This paper is aimed at solving the nonlinear time-fractional partial differential equation with two small parameters arising from option pricing model in financial economics. The traditional reproducing kernel (RK) method which deals with this problem is very troublesome. This paper proposes a new method by adaptive multi-step piecewise interpolation reproducing kernel (AMPIRK) method for the first time. This method has three obvious advantages which are as follows. Firstly, the piecewise number is reduced. Secondly, the calculation accuracy is improved. Finally, the waste time caused by too many fragments is avoided. Then four numerical examples show that this new method has a higher precision and it is a more timesaving numerical method than the others. The research in this paper provides a powerful mathematical tool for solving time-fractional option pricing model which will play an important role in financial economics.

An efficient technique based on least-squares method for fractional integro-differential equations

In this paper, we investigate an efficient technique for solving fractional integro-differential equations (FIDEs) that have numerous applications in various fields of science. The proposed technique is based upon the Legendre orthonormal polynomial and least Csquares method (LSM). By dividing the domain into n cells, a k-th order polynomial approximate solution in each cell can be obtained by LSM. The unique solvability and stability of the proposed numerical scheme are proven by analyzing the condition number of the matrix of the linear system. Moreover, the optimal convergence order under W22–norm is provided as well. Numerical examples are studied to verify our theoretical discovery. Comparison with the traditional reproducing kernel method and C3-spline method illustrates that our algorithm can obtain a more accurate approximating solution.

Solving Two-Sided Fractional Super-Diffusive Partial Differential Equations with Variable Coefficients in a Class of New Reproducing Kernel Spaces

Fractional-order calculus has become a useful mathematical framework to describe the complex super-diffusive process; however, numerical solutions of the two-sided space-fractional super-diffusive model with variable coefficients are difficult to obtain, and almost no method can obtain an analytical solution. In this paper, a class of new fractional dimensional reproducing kernel spaces (RKS) based on Caputo fractional derivatives is given, and we give analytical and numerical solutions of the two-sided space-fractional super-diffusive model based on the class of new RKS. The analytical solution is represented in the form of series in the reproducing kernel space. Numerical experiments indicate that the piecewise reproducing kernel method is more accurate than the traditional reproducing kernel method (RKM), and these new fractional reproducing kernel spaces are efficient for the two-sided space-fractional super-diffusive model.

Benchtop characterization of the tricuspid valve leaflet pre-strains

The pre-strains of biological soft tissues are important when relating their in vitro and in vivo mechanical behaviors. In this study, we present the first-of-its-kind experimental characterization of the tricuspid valve leaflet pre-strains. We use 3D photogrammetry and the reproducing kernel method to calculate the pre-strains within the central 10×10 mm region of the tricuspid valve leaflets from n=8 porcine hearts. In agreement with previous pre-strain studies for heart valve leaflets, our results show that all the three tricuspid valve leaflets shrink after being explanted from the ex vivo heart. These calculated strains are leaflet-specific and the septal leaflet experiences the most compressive changes. Furthermore, the strains observed after dissection of the central 10×10 mm region of the leaflet are smaller than when the valve is explanted, suggesting that our computed pre-strains are mainly due to the release of in situ annulus and chordae connections. The leaflets are then mounted on a biaxial testing device and preconditioned using force-controlled equibiaxial loading. We show that the employed preconditioning protocol does not 100% restore the leaflet pre-strains as removed during tissue dissection, and future studies are warranted to explore alternative preconditioning methods. Finally, we compare the calculated biomechanically oriented metrics considering five stress-free reference configurations. Interestingly, the radial tissue stretches and material anisotropies are significantly smaller compared to the post-preconditioning configuration. Extensions of this work can further explore the role of this unique leaflet-specific leaflet pre-strains on in vivo valve behavior via high-fidelity in-silico models. Statement of significanceThis study provides a first of its kind benchtop characterization of tricuspid valve leaflet pre-strains. We used 3D photogrammetry to reconstruct the central region of the tricuspid valve leaflets in three configurations. The associated configurational changes revealed compressive, leaflet-specific strains after dissection of the valve from its in situ environment. Interestingly, we found that biaxial preconditioning did not restore the measured pre-strains of the leaflets. Depending on the selection of the stress-free reference configuration, this led to substantial differences in the leaflet mechanics. Our findings and methodology are crucial when it comes to relating in vitro mechanical behaviors to valve function in vivo. Future studies can integrate our quantified pre-strains into in-silico simulations to get more realistic predictions about the valve function.

A broken reproducing kernel method for the multiple interface problems

A broken reproducing kernel method for the multiple interface problems

A new reproducing kernel-based collocation method with optimal convergence rate for some classes of BVPs

In this paper, we present a new reproducing kernel-based collocation (RKBC) approach with optimal convergence rate for some classes of boundary value problems (BVPs). The reproducing kernel function (RKF) of the reproducing kernel space (RKS) W2m is a piecewise polynomial of degree 2m−1. We observe that the global convergence orders under L∞, L2, H1 and H2-norms of our method in W2m(m=2,3,4) is 2m, 2m, 2m−1, and 2m−2, which are more efficient than existing reproducing kernel methods (RKMs). Besides, our method can also be easily extended to solve interface problems without losing accuracy. Numerical experiments with detailed discussions on the figures and tables confirm the stability and convergence associated with our proposed numerical approach.