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Fractional calculus is an important branch of mathematical analysis and played a fundamental role in different fields including signal processing and image processing. In this paper, we proposed a sparse super-resolution (SR) technique by using the Grünwald-Letnikov (G–L) fractional differential operator, which aims to reconstruct high-resolution images by recovering pixel information from low-resolution images. We suggested a modified fractional derivative mask based on G–L for image enhancement. The proposed method suppresses block artifacts, staircase edges, and false edges near the edges. The proposed method is very flexible and preserves detailed features. The obtained experiments demonstrated that fractional operator can nonlinearly preserve the low-frequency contour information in the smooth region and also nonlinearly improve well the high-frequency edge and texture of the image. In sparse SR images, the dictionary is constructed by texture information of the images by using integer derivatives. In this work, we computed dictionary matrices by applying the fractional masks. In fact, the extracted features based on fractional derivatives are utilized in the dictionary training procedure and sparse coding. The experimental results and analysis on natural images indicated that the proposed method achieved much better results than other algorithms in terms of both quantitative measures and visual perception. [ABSTRACT FROM AUTHOR]

There has been considerable academic interest in the study of nonlinear dynamical models and their exact traveling waves over the past few years. The main aim of the present paper is to consider a nonlinear dynamical model known as the nonlinear Konno–Oono model and derive its exact traveling waves. Specifically, after applying a universal transformation, periodic and solitary waves of the governing model with applications in the electromagnetic field are derived using generalized methods. Through the consideration of two- and three-dimensional simulations, several case studies are considered to represent the dynamical behavior of soliton solutions. [ABSTRACT FROM AUTHOR]

This research derives the shifted Jacobi operational matrix (JOM) with respect to fractional derivatives, implemented with the spectral tau method for the numerical solution of the Atangana-Baleanu Caputo (ABC) derivative. The major aspect of this method is that it considerably simplifies problems by reducing them to ones that can be solved by solving a set of algebraic equations. The main advantage of this method is its high robustness and accuracy gained by a small number of Jacobi functions. The suggested approaches are applied in solving non-linear and linear ABC problems according to initial conditions, and the efficiency and applicability of the proposed method are proved by several test examples. A lot of focus is placed on contrasting the numerical outcomes discovered by the new algorithm together with those discovered by previously well-known methods. [ABSTRACT FROM AUTHOR]

The major goal of the current paper is to conduct a detailed study on a generalized KdV equation (gKdVE) and its non-singular multi-complexiton wave. More precisely, first the multi-shock wave of the governing model is retrieved using the principle of linear superposition. Based on the multi-shock wave and the techniques adopted by Zhou and Manukure, the non-singular multi-complexiton wave to the gKdVE is then constructed with the help of symbolic computations. The dynamical properties of single and double shock waves as well as non-singular single and double complexiton waves are analyzed by representing a group of 3D-plots. The achievements of the present paper take an important step in completing the research on the generalized KdV equation. [ABSTRACT FROM AUTHOR]

In this paper, the symmetry reduction method and Nucci's reduction method are used to obtain exact solutions to the Triki–Biswas equation. Furthermore, the new conservation theorem is utilized for finding the conservation laws of the given model. The conservation laws are derived for each admitted symmetry of the Triki–Biswas equation and satisfy the divergence condition. The 3D, contour and 2D figures are finally plotted to show the dynamics of the obtained exact solutions. [ABSTRACT FROM AUTHOR]

In this relativistic consideration, the energy integral unlike others has been derived in a weakly relativistic plasma in terms of Sagdeev potential. Both compressive and rarefactive subsonic solitary waves are found to exist, depending on wave speeds in various directions of propagation. It is found that compressive relativistic solitons have potential depths that are higher than non-relativistic solitons in all directions of propagation, allowing for the presence of denser plasma particles in the potential well. Furthermore, it shows how compressive soliton amplitude grows as the propagation direction gets closer to the magnetic field's direction. [ABSTRACT FROM AUTHOR]

A new generalized KdV equation, describing the motions of long waves in shallow water under the gravity field, is considered in this paper. By adopting a series of well-organized methods, the Bäcklund transformation, the bilinear form and diverse wave structures of the governing model are formally extracted. The exact solutions listed in this paper are categorized as lump-type, complexiton, and soliton solutions. To exhibit the physical mechanism of the obtained solutions, several graphical illustrations are given for particular choices of the involved parameters. As a direct consequence, diverse wave structures given in this paper enrich the studies on the KdV-type equations. [ABSTRACT FROM AUTHOR]

The principal goal of the presented paper is to investigate the dynamics of optical solitons for the generalized Sasa–Satsuma (GSS) equation describing the propagation of the femtosecond pulses in the systems of optical fiber transmission. More precisely, the governing model, which is a generalized version of the classical Sasa–Satsuma equation, is firstly reduced in a one-dimensional real regime through a specific transformation; then, its bright and dark optical solitons are established using the modified Kudryashov (MK) method. The changes in the amplitude of the bright and dark solitons are analyzed as a case study for various classes of free parameters. Considerable changes are observed in the optical solitons amplitude from the results presented in the current study. [ABSTRACT FROM AUTHOR]

The major goal of the present paper is to construct optical solitons of the Ginzburg–Landau equation including the parabolic nonlinearity. Such an ultimate goal is formally achieved with the aid of symbolic computation, a complex transformation, and Kudryashov and exponential methods. Several numerical simulations are given to explore the influence of the coefficients of nonlinear terms on the dynamical features of the obtained optical solitons. To the best of the authors' knowledge, the results reported in the current study, classified as bright and kink solitons, have a significant role in completing studies on the Ginzburg–Landau equation including the parabolic nonlinearity. [ABSTRACT FROM AUTHOR]

The main goal of the current paper is to analyze the impact of the Coriolis parameter on nonlinear waves by studying the geophysical KdV equation. More precisely, specific transformations are first adopted to derive one-dimensional and operator forms of the governing model. Solitons and complexiton of the geophysical KdV equation are then retrieved with the help of several well-established approaches such as the Kudryashov and Hirota methods. In the end, the new conservation theorem given by Ibragimov is formally employed to extract conservation laws of the governing model. It is shown that by increasing the Coriolis parameter, based on the selected parameter regimes, less time is needed for tending the free surface elevation to zero. [ABSTRACT FROM AUTHOR]

The main aim of this paper is to conduct a detailed study on a high-order nonlinear Schrödinger (HONLS) equation involving nonlinear dispersions and the Kerr effect. More precisely, after reducing the governing model describing ultra-short pulses in optical fibers in a one-dimensional domain, its optical solitons including the bright and dark solitons are derived through the modified Kudryashov (MK) method. The dynamical behavior of the bright and dark solitons is formally investigated for different sets of the involved parameters. It is shown that increasing and decreasing nonlinear dispersions lead to significant changes in the amplitude of the bright and dark solitons. [ABSTRACT FROM AUTHOR]

The search for soliton structures plays a pivotal role in many scientific disciplines particularly in nonlinear optics. The main concern of the present paper is to explore the dynamics of soliton structures in a nonlinear Schrödinger (NLS) equation with the parabolic law. In this respect, the reduced form of the NLS equation is firstly extracted; then, its soliton structures are derived in the presence of spatio-temporal dispersions using the Kudryashov method. As the completion of studies, the impact of increasing and decreasing the coefficients of the parabolic law on the dynamics of soliton structures is formally addressed through representing several two- and three-dimensional figures. [ABSTRACT FROM AUTHOR]

In this paper, a numerical method is presented using a Dickson-based collocations method to solve a fractional model of computer virus propagation. The model presented in this paper is a system of differential equations of fraction. By using the Dickson-based collocation method and using Chebyshev's spatial points, we transform the system of deficit differential equations into a system of algebraic equations. In this way, an approximate solution can be found for the proposed model. By introducing the error functions for the expressed fractional model, the accuracy and convergence of the obtained solutions are investigated. Some of the approximate results obtained using this method is displayed in the numerical results section. [ABSTRACT FROM AUTHOR]

In the present work, the generalized complex Ginzburg–Landau (GCGL) model is considered and its 1-soliton solutions involving different wave structures are retrieved through a series of newly well-organized methods. More exactly, after considering the GCGL model, its 1-soliton solutions are obtained using the exponential and Kudryashov methods in the presence of perturbation effects. As a case study, the effect of various parameter regimes on the dynamics of the dark and bright soliton solutions is analyzed in three- and two-dimensional postures. The validity of all the exact solutions presented in this study has been examined successfully through the use of the symbolic computation system. [ABSTRACT FROM AUTHOR]

Starting flows of a viscous incompressible fluid, modeled by the time-fractional derivatives, within a rotating channel due to an impulsive pressure gradient are studied. Using the eigenfunction expansion, the analytic solutions in series form are obtained. The flow of the ordinary fluid is studied as a special case of the time-fractional problem. The convergence of series solutions is proved. In addition, using the classical analytical method, coupled with the Laplace transform and Stehfest's algorithm, an approximate solution is found. The flow rates in x- and y-directions are determined. In the case of the ordinary fluid, the steady-state and transient components of velocities are obtained. The numerical calculations are carried out by using the Mathcad software. It is found that, for fractional fluids, the reversal flow is much attenuated if the values of the fractional parameter are less than 1. [ABSTRACT FROM AUTHOR]

The main purpose of this study was to investigate employees and managers' satisfaction of transportation system in the steal and rolling Units of Saba in Mobarakeh Steel Company using the intuitionistic fuzzy data. The statistical population included the personnel of Saba Steel and Rolling Units from Mobarakeh Steel Company including 1800 people. The sample size included 325 people. In this study, a new method was used to defuzzifying the intuitionistic fuzzy numbers so that the equivalent of every intuitionistic fuzzy number was a real number. This method was also used to rank intuitionistic fuzzy numbers. In this regard, features of the proposed method have been investigated for defuzzyfying and ranking. To measure satisfaction with such data, a questionnaire containing 26 questions was used for collecting field data with a reliability coeffcient of 0:95: To analyze the results, one-sample t-test, binomial test and Friedman test were used. [ABSTRACT FROM AUTHOR]

Realizing the behavior of the solution in the asymptotic situations is essential for repetitive applications in the control theory and modeling of the real-world systems. This study discusses a robust and definitive attitude to find the interval approximate asymptotic solutions of fractional differential equations (FDEs) with the Atangana-Baleanu (A-B) derivative. In fact, such critical tasks require to observe precisely the behavior of the noninterval case at first. In this regard, we initially shed light on the noninterval cases and analyze the behavior of the approximate asymptotic solutions, and then, we introduce the A-B derivative for FDEs under interval arithmetic and develop a new and reliable approximation approach for fractional interval differential equations with the interval A-B derivative to get the interval approximate asymptotic solutions. We exploit Laplace transforms to get the asymptotic approximate solution based on the interval asymptotic A-B fractional derivatives under interval arithmetic. The techniques developed here provide essential tools for finding interval approximation asymptotic solutions under interval fractional derivatives with nonsingular Mittag-Leffler kernels. Two cases arising in the real-world systems are modeled under interval notion and given to interpret the behavior of the interval approximate asymptotic solutions under different conditions as well as to validate this new approach. This study highlights the importance of the asymptotic solutions for FDEs regardless of interval or noninterval parameters. 1 --> a --> [ABSTRACT FROM AUTHOR]

In the recent years some efforts were made to propose simple and well-behaved fractional derivatives that inherits the classical properties from the first order derivative. Therefore, we propose in this research a new strategy to acquire interval solution of fractional interval differential equations (FIDEs) under interval fractional conformable derivative. This scheme is developed based on a variation of the constant formula to achieve the solution explicitly. The important characteristic of this technique is that it helps us to find a solution with decreasing length of its support which is critical for the solutions based on the interval or fuzzy notions. Two examples are experienced to illustrate our approach and validate it. [ABSTRACT FROM AUTHOR]

Fuzzy control systems have had various applications in a wide range of science and engineering in recent years. Since an unstable control system is typically useless and potentially dangerous, stability is the most important requirement for any control system (including fuzzy control system). Conceptually, there are two types of stability for control systems: Lyapunov stability (a special case of which is exponential stability) and input-output stability. This paper develops fuzzy Lyapunov stability through investigating the concept of stability for finite-dimensional systems under uncertainty and provides some related theorems. Considering the capability of fuzzy differential systems for modeling uncertainty and processing vague or subjective information in mathematical models, exponential stability and Lyapunov stability of fuzzy differential systems are presented. Also, numerical examples are given to support the theoretical results. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a new method for approximating solutions of fully fuzzy linear systems in the dual form. For this purpose, we solve the original problem in the 1-cut position (we assumed that the 1-cut is a crisp linear system), then some unknown symmetric spreads are allocated to each row of the crisp system, which leads to convert the original problem to 2 * n linear equations in order to find the symmetric spreads. Consequently, we suggested some extensions of the united solution set, the tolerable solution set and the controllable solution set. Simultaneously, we clarify between the classic hull solution sets and the extended hull solution sets in which finally leads to characterize the inner and outer estimations. Then, a financial example is solved to show the ability of proposed method. [ABSTRACT FROM AUTHOR]

Large scale integration of wind generation capacity into power systems introduces operational challenges due to wind power uncertainty and variability. Therefore, accurate wind power forecast is important for reliable and economic operation of the power systems. Complexities and nonlinearities exhibited by wind power time series necessitate use of elaborative and sophisticated approaches for wind power forecasting. In this paper, a local neurofuzzy (LNF) approach, trained by the polynomial model tree (POLYMOT) learning algorithm, is proposed for short-term wind power forecasting. The LNF approach is constructed based on the contribution of local polynomial models which can efficiently model wind power generation. Data from Sotavento wind farm in Spain was used to validate the proposed LNF approach. Comparison between performance of the proposed approach and several recently published approaches illustrates capability of the LNF model for accurate wind power forecasting. [ABSTRACT FROM AUTHOR]

In this paper, we study existence and uniqueness of solutions of second-order fuzzy integro-differential equations with fuzzy kernel under strongly generalized differentiability. To this end, four cases are considered to show the existence of the fuzzy solution mentioned equation. Some theorems are proved, and the uniqueness of the fuzzy solution is discussed step by step. Finally, the illustrated examples are solved to investigate the conditions of theorems. [ABSTRACT FROM AUTHOR]

A natural way to model dynamic systems under uncertainty is to use fuzzy initial value problems (FIVPs) and related uncertain systems. In this paper, we express the fuzzy Laplace transform and then some of its well-known properties are investigated. In addition, an existence theorem is given for fuzzy-valued function which possess the fuzzy Laplace transform. Consequently, we investigate the solutions of FIVPs and the solutions in state-space description of fuzzy linear continuous-time systems under generalized H-differentiability as two new applications of fuzzy Laplace transforms. Finally, some examples are given to show the efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

A new method is proposed for solving systems of fuzzy fractional differential equations (SFFDEs) with fuzzy initial conditions involving fuzzy Caputo differentiability. For this purpose, three cases are introduced based on the eigenvalue-eigenvector approach; then it is shown that the solution of system of fuzzy fractional differential equations is vector of fuzzy-valued functions. Then the method is validated by solving several examples. [ABSTRACT FROM AUTHOR]

We propose a new distance measure for the space of all trapezoidal fuzzy numbers using centroid point and left/right spread of trapezoidal fuzzy numbers. Moreover, the metric properties of suggested distance measure are investigated. Indeed, we show that for two arbitrary trapezoidal fuzzy numbers if the distance between centroid points and also the distance between left spreads and right spreads go to zero, then two given fuzzy numbers are equal. Consequently, we complete discussion about the relation between fuzzy number and its centroid which is the firstly discussed by Hadi-Vencheh and Allame (2010). To the best of our knowledge, this is first time in the literature that such metric is applied by centroid point. [ABSTRACT FROM AUTHOR]

We propose a method to approximate the solutions of fully fuzzy linear system (FFLS), the so-called general solutions. So, we firstly solve the 1-cut position of a system, then some unknown spreads are allocated to each row of an FFLS. Using this methodology, we obtain some general solutions which are placed in the well-known solution sets like Tolerable solution set (TSS) and Controllable solution set (CSS). Finally, we solved two examples in order to demonstrate the ability of the proposed method. [ABSTRACT FROM AUTHOR]

We give the explicit solutions of uncertain fractional differential equations (UFDEs) under Riemann-Liouville H-differentiability using Mittag-Leffler functions. To this end, Riemann-Liouville H-differentiability is introduced which is a direct generalization of the concept of Riemann-Liouville differentiability in deterministic sense to the fuzzy context. Moreover, equivalent integral forms of UFDEs are determined which are applied to derive the explicit solutions. Finally, some illustrative examples are given. [ABSTRACT FROM AUTHOR]

Using fuzzy Laplace transform method, the solution of fuzzy convolution Volterra integral equation (FCVIE) of the second kind with convolution fuzzy and crisp kernel is investigated. So, fuzzy convolution operator is proposed and related theorem is submitted which is useful for solving FCVIEs. Finally, several illustrative examples with fuzzy and crisp convolution kernels are given to show the ability of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, we study the numerical method for solving hybrid fuzzy differential using Euler method under generalized Hukuhara differentiability. To this end, we determine the Euler method for both cases of H-differentiability. Also, the convergence of the proposed method is studied and the characteristic theorem is given for both cases. Finally, some numerical examples are given to illustrate the efficiency of the proposed method under generalized Hukuhara differentiability instead of suing Hukuhara differentiability. [ABSTRACT FROM AUTHOR]

In this paper, a novel operator method is proposed for solving fuzzy linear differential equations under the assumption of strongly generalized differentiability. To this end, the equivalent integral form of the original problem is obtained then by using its lower and upper functions the solutions in the parametric forms are determined. The proposed method is illustrated with numerical examples. [ABSTRACT FROM AUTHOR]

In this paper, a novel coronavirus infection system with a fuzzy fractional differential equation defined in Caputo's sense is developed. By using the fuzzy Laplace method coupled with Adomian decomposition transform, numerical results are obtained for better understanding of the dynamical structures of the physical behavior of COVID-19. Such behavior on the general properties of RNA in COVID-19 is also investigated for the governing model. The results demonstrate the efficiency of the proposed approach to address the uncertainty condition in the pandemic situation. [ABSTRACT FROM AUTHOR]

In [1], the authors claimed by a counterexample that the cross product definition in [2] is not correct and thus the proposed technique is false. In this note, we show that this assertion is incorrect. [ABSTRACT FROM AUTHOR]