Grey wolf optimizer (GWO) is an effective meta-heuristic technique which has been widely utilized to solve numerical optimization as well as real-world applications. However, GWO has some shortcomings, i.e., low solution accuracy, slow convergence, and easy stagnation at local optima in solving complex problems. To tackle these shortcomings, an enhanced GWO called EGWO is developed in this study. This enhancement is achieved by embedding three novel strategies into the basic GWO to improve its performance. Firstly, a new transition mechanism is designed instead of the original strategy to obtain a good transition from the exploration to exploitation. Secondly, the cuckoo search algorithm is... More >

The paper discusses the dynamical characteristics of solutions to a model with quadratic term. More precisely, an exponential-type fuzzy difference equation is proposed as follows $$ a_{n+1}=\frac{D+Pe^{-a_n}}{T+a^2_{n-1}},\ \ n=0,1,\cdots ,$$ here $D, P, T$ and $a_0, a_{-1}$ belong to positive fuzzy numbers. This model can be used to characterize the diffusion modeling of a class of infectious diseases with uncertainty, such as the transmission prediction of dengue fever, monkeypox, and other infectious diseases. In addition, by highlighting the advantages of using Stefanini's the generalization of division of fuzzy number (it is also known as g-division) and constructing a Lyapunov functi... More >

Releasing amount of natural enemy generally depends on its population data, while impulsive releasing natural enemy usually brings about a time delay after the data is observed in the practical pest management. Therefore, it is very important for pest managers to assess the impact of the time delay in pest management. In this paper, we construct a pest-natural enemy model with time delay in impulsive releasing natural enemy. We prove that the pest-free periodic solution of model $(2.1)$ is globally attractive with $\eta \tau<\frac{\zeta y^{\ast}(1-e^{-\lambda \tau})}{\lambda}$. We also prove that model $(2.1)$ is permanent with $\eta \tau>\frac{\zeta y^{\ast}(1-e^{-\lambda \tau})}{\lambda}$.... More >

This paper deals with continuous piecewise linear differential systems with three zones separated by two parallel straight lines (for short, CPWL3). The number of limit cycles of CPWL3 systems with two degenerate subsystems is not clear. In the paper, we provide a complete study on the maximum number of limit cycles by geometric techniques when the continuous piecewise linear systems with three zones have two degenerate subsystems. During our analysis, we also detect some bifurcation phenomena, such as boundary equilibrium bifurcation, scabbard bifurcation, grazing bifurcation, heteroclinic bifurcation and Hopf bifurcation. More >

Presents the introductory editorial for this issue of the publication. More >