Satin, Y. A.Razumchik, R., VZeifman, A., IKovalev, I. A....
12页
查看更多>>摘要：We consider the well-known problem of the computation of the (limiting) time-dependent performance characteristics of one-dimensional continuous-time birth and death processes on Z with the time-varying and possibly state-dependent intensities. First in the literature upper bounds on the rate of convergence are provided. Upper bounds for the truncation errors are also given. The condition under which a limiting (time-dependent) distribution exists is formulated but relies on the quantities that need to be guessed in each use-case. The developed theory is illustrated by two numerical examples within the queueing theory context. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：Control theory of one dimensional (1-D) systems is not directly applicable to two dimensional (2-D) systems due to involvement of complex dynamics in space and time. This paper deals with the control of nonlinear Roesser systems by employing feedback strategies with multiple constraints on the input signal. The input constraints are slope restriction, quantization, and generalized nonlinearities related to actuator overflow. Modeling deficiencies are also handled with the generalized actuator nonlinearities in a robust fashion. Novel results for state and output feedback topologies are furnished. Local stability criteria are developed for both feedback topologies by considering intrinsic nonlinearity as one-sided Lipschitz and generalized nonlinearity in a bounded sector. To the best of our knowledge, the outcomes of present paper are novel for nonlinear Roesser discrete-time systems while considering such nested restrictions on input signal. The results are verified by applying the proposed method on different 2-D practical systems. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：In engineering and manufacturing processes, heat transmission is unavoidable. Because of the two-part nanomaterials, the hybrid nanofluid has an efficient heat transfer approach which helps to increase the heat transport capacity of standard nanofluids. The flow, heat transport, and entropy of a high conductivity hybrid nanofluid and a stretching surface with velocity slip effects are investigated numerically in this study. The fluid model de-picts understanding the thermodynamic efficiency of nanomaterials. The numerical frame-work for the hybrid nanofluid model is formed and similarity transformations are used to transform the PDEs into nonlinear ordinary differential equations. These equations are numerically calculated for different parameters in the computational tool MATLAB using the shooting (bvp4c) method. The most significant consequences of this investigation are the impacts of various physical flow parameters on the velocity, entropy and tempera -ture profiles including the permeability parameter, velocity slip parameter, magnetic pa-rameter, heat source-sink parameter, Biot number, volume fraction of nanoparticles, ther-mal radiation parameter, Brinkman number and temperature ratio parameter. For velocity, temperature, and entropy generation profiles, the magnetic parameter performs inversely. Moreover, the system's entropy generation profile is enriched with the incorporation of nanoparticles percentage by volume fraction of nanoparticles and Brinkman number. The authors confirm that all of their findings are unique and have not been previously pub-lished.(c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this paper, the stability analysis of continuous-time switched affine systems (CTSASs) is addressed via dwell time switching. The main purpose of this note is to design a time-dependent switching signal assuring the global exponential stability of a desire limit cycle (which is selected from a set of attainable limit cycles). By constructing a discretized Lyapunov function and using the linear matrix inequalities technique, a set of conditions in the framework of dwell time are designed. For CTSASs, the performance indexes of the system in this neighborhood cannot be analyzed because most of the proposed controllers drive the system trajectory into a small enough neighborhood. Differently, the technique proposed in this note leads the CTSAS's trajectory to the limit cycle so that the resulting conditions can consider the weighted H-infinity performance level of the system. More specifically, the design conditions can be applied to open-loop subsystems that are unstable. At last, a numerical example and a practical example are given to illustrate our method. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：We prove that for every tree T with t vertices ( t > 2 ), the signed line graph (K-t) pound has (T) pound as a star complement for the eigenvalue -2 ; in other words, T is a foundation for K-t (regarded as a signed graph with all edges positive). In fact, (K-t) pound is, to within switching equivalence, the unique maximal signed line graph having such a star complement. It follows that if t is not an element of{7, 8, 9 } then, to within switching equivalence, K-t is the unique maximal signed graph with T as a foundation. We obtain analogous results for a signed unicyclic graph as a foundation, and then provide a classification of signed graphs with spectrum in [ -2, infinity). We note various consequences, and review cospectrality and strong regularity in signed graphs with least eigenvalue >=-2. (c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this paper, we focus on Perron pairs of a nonnegative tensor, which have wide applications in many areas, such as higher order Markov chains and hypergraph theory. We first propose a SemiDefinite Programming (SDP) relaxation algorithm to directly compute all Perron eigenvectors of a nonnegative tensor with finite Perron eigenvectors, where all Perron eigenvectors associated with monotonous Perron eigenvalues are generated by solving finite SDP problems. Then, the convergence of the proposed algorithm is proved. Finally, numerical experiments illustrate the efficiency of the proposed algorithm.(c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this paper, a regional sampled-data synchronization criterion is proposed for the chaotic neural networks (CNNs) with input saturation using the piecewise-continuous delay dependent Lyapunov functional (PDDLF) approach. The aim of this work is to enlarge the region of attraction (ROA) of the synchronous state for CNNs with input saturation. Unlike existing works, the Lyapunov functional in the proposed approach is constructed from a polynomial with respect to the piecewise-continuous delay. Moreover, the proposed Lyapunov functional is combined with looped-functionals to derive the sufficient condition. The synchronization criterion is formulated in terms of sum of squares (SOS) programs, which reduces the infinite-dimensional linear matrix inequality (LMI) conditions to a finite number of SOS conditions. A numerical example is presented to illustrate the effectiveness and advantages of the proposed approach.(c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this paper, we propose a conservative scheme to solve the time-dependent twodimensional nonlinear Schrodinger equation, which plays an important role in many fields of physics. We discretize the equation using the multiquadric trigonometric quasi interpolation method in space and the Crank-Nicolson scheme in time. The quasiinterpolant is constructed through a linear combination of function values and node translations of a kernel function. It is very simple to compute since it doesn't need to solve any linear system. We adopt two different approaches to approximate second order spatial derivatives and analyze the symmetric or anti-symmetric properties of differentiation matrices. Moreover, the convergence and conservation properties including the total mass and energy conservation laws are also investigated in detail. Numerical experiments are performed to illustrate the accuracy and efficiency of the proposed method.(c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this study, we construct Kantorovich variant of max-min kind operators, which are nonlinear. By using these new operators, we obtain some uniform approximation results in N dimension ( N >= 1 ). Then, we estimate the error with the help of Holder continuous functions and modulus of continuity. Furthermore, we give some illustrative applications to verify our theory and also investigate some shape-preserving properties of Kantorovichtype max-min Bernstein operator. Lastly, we examine the image processing implementation of our results via Kantorovich-type max-min Shepard operator.(c) 2022 Elsevier Inc. All rights reserved.
查看更多>>摘要：A B S T R A C T In this paper, the ratio-dependent impulsive control is used in an SIQS epidemic model with non-linear incidence. Compared with most of existing results, there are two advantages. On the one hand, the impulsive control strategy is economical, efficient and simple. On the other hand, the ratio-dependent impulsive control can deal with the changing population well. Besides, by using analogue of the Poincare criterion, vector field analysis, Poincare map and the method of qualitative analysis, the stability of the disease-free equilibrium and the existence and stability of positive order-k periodic solution of the SIQS epidemic model under ratio-dependent impulsive control are studied. Moreover, our results show that order-k ( k > 2 ) periodic solutions don't exist. Finally, some simple numerical examples are used to verify our theoretical results.(c) 2022 Elsevier Inc. All rights reserved.
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