查看更多>>摘要：In this paper, the interval stability/stabilization of linear stochastic switched time-varying delay systems are considered. Firstly, the interval stability is defined and the sufficient conditions for the interval stability of linear stochastic switched systems are addressed. Different from current stability conditions, the interval stability criterion can make more accurate judgment than stability of linear stochastic switched time-varying delay systems. Secondly, the criterion of interval stabilization is gained by linear matrix inequalities, which can not merely ensure the stability of the system, but also accelerate or slow down the convergence of the system. Finally, the validity of the theoretical results is verified by a digital simulation and water quality preservation problem. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：To maintain biodiversity and ecological balance, studying population dynamics of species by establishing different mathematical models is quite important. In this paper, we deal with a reaction-diffusion predation model with mixed functional responses. We are mainly concerned with the coexistence of the species. We firstly give the long-time behaviors of parabolic dynamical system. Secondly, we consider the steady state system, including the priori estimate, existence, uniqueness and asymptotic stability of positive solutions to the system. The result shows that the coexistence of the species depends to a great extent on their intrinsic growth rates, diffusion situations and the predation pressure imposed to preys by predators. The uniqueness and stability results show that the functional response has important effects on the model, which is mainly reflected by the predation behavior of predators. Finally, some numerical simulations are presented to illustrate the theoretical results. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this paper, we introduce a linearized projection scheme for non-stationary incompressible coupled the MHD with heat equations, which buoyancy affects because temperature differences in the flow cannot be neglected. The projection algorithm naturally preserves the Gauss's law and overcomes many shortcomings of previous approaches, which also preserves the electrical field e . Firstly, we establish certain discrete energy estimates based on the projection scheme. Next, we testify the unconditional stability and error estimates of the velocity, pressure, magnetic field and temperature. The regularity of the projection scheme will be given. The numerical results show the method has an optimal convergence order, and can keep Gauss's law well. The numerical results are consistent with our theoretical analysis, and our method is effective. The numerical method has a good robustness for different cases.(c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：This paper aims to design an improved sampled-data control for T-S fuzzy systems under mismatch of the actual fuzzy-basis function and the sampled fuzzy-basis function. To this end, an enhanced two-sided looped-functional method is proposed so that the chosen Lyapunov-Krasovskii functional can contain two new time-integrated states. In addition, a less conservative relaxation process is devised in such a way that (1) the error bounds of the mismatched fuzzy-basis functions can be imposed on the stabilization conditions, and (2) the required computational complexity can be reduced when relaxing the mismatched fuzzy-basis functions. Finally, through two illustrative examples, the effectiveness of the proposed method is verified by comparing our results with those of other existing methods.
Vadivoo, B. S.Jothilakshmi, G.Almalki, Y.Debbouche, A....
25页
查看更多>>摘要：This paper is concerned with the relative controllability for a class of fractional differential equations with multiple time delays. The solution representation is introduced for this system via multiple delayed perturbations of Mittag-Leffler function. Necessary and sufficient conditions for the indicated problem to be relatively controllable are established for linear and non-linear systems. For non-linear case, the existence result is proved by using Krasnoselskii's fixed point theorem. Numerical examples are given to illustrate the theoretical results, and its diagrammatic formulations are done by MATLAB.(c) 2022 Elsevier Inc. All rights reserved.
Froguel, Lucas BelasquePrado, Thiago de LimaCorso, GilbertoLima, Gustavo Zampier dos Santos...
13页
查看更多>>摘要：Recurrence plot (RP) is a powerful tool in the study of nonlinear dynamics, being successfully applied in economics, medicine, geophysics, and astronomy. The Recurrence Quantification Analysis (RQA) consists of a methodology to compute RP quantifiers based on statistics over vertical/diagonal recurrent lines, densities, and other features of the RP. The traditional way to calculate the quantifiers computes each recurrent point individually and builds the histogram of the whole RP. Here we propose a new, statistical approach to calculate the quantifiers using the (recurrence) microstates, which are small representative chunks of the RP. The new way of statistically calculating the quantifiers converges fast and brings a computational gain. In particular, it reduces the time complexity from O(K-2) to O(K), for K the size of the time-series. Moreover, we show that our results are independent of the system and series size. (C) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：We analyze the structure of losses in individual flows, in a multi-flow, finite-buffer queue-ing system. Namely, a model with many separate flows (streams) of jobs arriving to a shared buffer, where they are subject to losses due to buffer overflows, is considered. (Such systems are common, for instance, in computer networking, where flows of packets arrive to the same router's buffer from different network users). Assuming a general service time distribution and Poisson flows, we study the burst ratio parameter, which reflects the ten-dency of losses to cluster together, in long series. In particular, an explicit formula for the burst ratio in each individual flow is derived. Using this formula we show, among other things, that the per-flow burst ratio may vary significantly among flows and differ from the global burst ratio. This distinguishes the per-flow burst ratio from the per-flow loss ra -tio, which is the same for all flows. We demonstrate also the dependence of the per-flow burst ratio on the flow rate, number of flows, buffer size, system load and variance of the service time. (c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )
Park, SangbeomKim, PhilsuJeon, YonghyeonBak, Soyoon...
20页
查看更多>>摘要：In this study, we propose an efficient algorithm for solving one-dimensional coupled viscous Burgers' equations. One of the main accomplishments of this study is to develop a stable high-order algorithm for the system of reaction-diffusion equations. The algorithm is "robust" because it is designed to prevent non-physical oscillations through an iteration procedure of a block Gauss-Seidel type. The other is to develop an efficient algorithm for the Cauchy problem. For this, we first find half of the upstream points by adopting a multi-step q th-order (q = 2 , 3) error correction method. The algorithm is also "economical" in the sense that an interpolation strategy for finding the remaining upstream points is designed to dramatically reduce the high computational cost for solving the nonlinear Cauchy problem without damage to the order of accuracy. Three benchmark problems are simulated to investigate the accuracy and the superiority of the proposed method. It turns out that the proposed method numerically has the q th-order temporal and 4th-order spatial accuracies. In addition, the numerical experiments show that the proposed method is superior to the compared methods in the sense of the computational cost. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：The practical stability problem of switched homogeneous positive nonlinear systems (SHPNS) is addressed in this study, which includes two instances in terms of continuous-time and discrete-time. Sufficient conditions are presented by using the max-separable Lyapunov function (MSLF) approach, such that each solution of SHPNS is practically stable. The distinction between the existing results and the obtained results is that ours are not only relatively concise but also easily verifiable, and the theoretical results are also extended to a more general case without restricting the systems to be positive. Eventually, a pair of examples are proposed to explain the approach's validity. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：This paper studied a generalized case of the constant elasticity of variance diffusion (CEV) process whereas the drift term is substantially nonlinear in the short rate. Well-known instances deduced by this process are the extended Cox-Ingersoll-Ross (ECIR) process and the extended inverse Feller (EIF) process or 3/2-stochastic volatility model (SVM). We found particular sufficient conditions of existence and uniqueness of a positive pathwise strong solution for time-dependent parameter functions, and obtained closed-form formulas for conditional moments based on Feynman-Kac theorem. The accuracy and validity of the formulas were further investigated based on Monte Carlo simulations. (c) 2022 Elsevier Inc. All rights reserved.
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