Search

In this paper, the adaptive tracking problem for a class of strictly feedback nonlinear time‐delay systems with output constraints, actuator failures, and input dead zones is studied. First, in the design of controller, the absolute value function and integral term are introduced into the candidate functions to deal with nonlinear factors and distributed time‐varying delays in the system. In addition, an adaptive neural network controller is designed to ensure the stability of the controlled system, and the system tracking error can converge to the origin without violating the constraints. Finally, simulation results verify the feasibility of the proposed control strategy. [ABSTRACT FROM AUTHOR]

This paper investigates the bifurcations of the following difference equations xn+1=axn+byne−xn,yn+1=cyn+dxne−yn,xn+1=ayn+bxne−yn,yn+1=cxn+dyne−xn,where a,b,c, and d are positive constants and the initial conditions x0 and y0 are positive numbers. Psarros, Papaschinopoulos, and Schinas (Math. Methods Appl. Sci., 2016, 39: 5216–5222) presented the semistability of the fixed point (0,0) when one eigenvalue is equal to 1 and the other eigenvalue has absolute value less than 1. In this paper, we consider another case: one eigenvalue is equal to −1. With the aid of the center manifold reduction theorem, we rigorously show that these two systems undergo flip bifurcations or generalized flip bifurcations. Moreover, the stability of the fixed point (0,0) and the existence of period‐two cycles are also given. [ABSTRACT FROM AUTHOR]

The present paper first establishes that an identity involving generalized fractional integrals is proved for differentiable functions by using two parameters. By utilizing this identity, we obtain several parameterized inequalities for the functions whose derivatives in absolute value are convex. Finally, we show that our main inequalities reduce to Ostrowski type inequalities, Simpson type inequalities and trapezoid type inequalities which are proved in earlier published papers. [ABSTRACT FROM AUTHOR]

In this paper, we study the stability of the zero equilibrium and the occurrence of flip bifurcation of the following system of difference equations: xn+1=a1ynb1+yn+c1xnek1−d1xn1+ek1−d1xn,yn+1=a2znb2+zn+c2ynek2−d2yn1+ek2−d2yn,zn+1=a3xnb3+xn+c3znek3−d3zn1+ek3−d3zn,where ai, bi, ci, di, and ki, for i=1, 2, and 3, are real constants and the initial values x0, y0, and z0 are real numbers. We study the stability of this system in the special case when one of the eigenvalues is equal to −1 and the remaining eigenvalues have absolute value less than 1, using the center manifold theory. [ABSTRACT FROM AUTHOR]

This paper investigates the analytical and semi‐analytical solutions of the time‐fractional Cahn–Allen equation, which describes the structure of dynamic for phase separation in Fe‐Cr‐X (X = Mo, Cu) ternary alloys. We apply a modified auxiliary equation method and the Adomian decomposition method to get distinct solutions to our suggested model. These solutions describe the dynamic of the phase separation in iron alloys and use in solidification and nucleation problems. The applications of this method arise in many various fields such as plasma physics, quantum mechanics, mathematical biology, and fluid dynamics. We apply a conformable fractional derivative to this fractional model to convert it into a nonlinear partial differential equation with integer order. We obtain many analytical wave solutions and also apply a semi‐analytical scheme to calculate the absolute value of error. All solutions are verified by using Mathematica software. [ABSTRACT FROM AUTHOR]

An innovative numerical procedure for solving the viscoelastic arch problem based on variable fractional rheological models, directly in time domain, is proposed and investigated. First, the nonlinear integral‐differential governing equation is established according to the variable fractional constitutive relation and geometrical relationship. Second, the nonlinear integral‐differential governing equation is transformed into algebraic equations and solved by using the shifted Legendre polynomials. Furthermore, the accuracy and effectiveness of the algorithm are verified according to the mathematical example. A small value of the absolute error between numerical and accurate solution is obtained. Finally, the dynamic analysis of viscoelastic arch is investigated to determine the displacement at different times and positions. The displacement of the viscoelastic arch is compared under various loading (uniformly distributed load and linear load). The displacement of the viscoelastic arch of different materials under the same load conditions is also investigated. The results in the paper show the efficiency of the proposed numerical algorithm in the dynamical analysis of the viscoelastic arch. [ABSTRACT FROM AUTHOR]

In the present manuscript, we define the concept of GA$$ GA $$‐ s$$ s $$‐convex functions in the fourth sense. We obtain the Hermite–Hadamard inequality for the newly introduced class of functions. We also establish some inequalities of the Hermite–Hadamard type for functions whose first derivative in absolute value at certain powers is a GA$$ GA $$‐ s$$ s $$‐convex function in the fourth sense. In the last, some applications to special means of real numbers are given. [ABSTRACT FROM AUTHOR]

This manuscript employs the trigonometric Quintic B‐spline (TQBS) scheme for investigating the numerical solution of the conformable fractional nonlinear time‐space telegraph equation. This model is derived by Oliver Heaviside 1880 to describe the cutting‐edge or voltage of an electrified transmission range with the day yet distance from an electrified transmission or electromagnetic wave's application. In Hamed and Khater, three recent computational schemes (sech–tanh expansion method; extended sinh–Gorden expansion method; and extended simplest equation method) have been applied to the fractional model for constructing the exact traveling wave solutions. Many distinct solutions have been obtained, and some of them have been sketched in two, three‐dimensional, and density plots. Here, these solutions are investigated to evaluate the initial and boundary conditions that apply the suggested numerical scheme. The accuracy of the constructed exact solutions is investigated by calculating the absolute value of error. The most accurate numerical schemes of the three applied computational schemes have been illustrated. [ABSTRACT FROM AUTHOR]