查看更多>>摘要：The saturated-constrained distributed filtering problem is discussed for a class of discrete nonlinear systems with random access protocol (RAP) and missing measurements (MMs) under uncertain missing probabilities (UMPs ). In order to prevent data congestions, the RAP is adopted to regulate the information transmission, where only one sensor is sched-uled to have the communication right and transmit the information at each time step through a shared network. In addition, the phenomenon of MMs is considered, in which the UMPs are characterized by means of the nominal means and error bounds. The main purpose of this paper is to design a distributed filter under saturation constraint such that, for both RAP and MMs under UMPs, there exists an upper bound (UB) matrix of filtering error covariance and the corresponding distributed filter gain is constructed to minimize the trace of the received UB matrix by resorting to the matrix simplifying technique. Be-sides, the filtering algorithm performances are discussed regarding the boundedness and monotonicity of the presented distributed filtering scheme from the mathematical perspec-tive. Finally, some comparisons are provided to illustrate the validity of the proposed time-varying distributed filtering algorithm.(c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this paper we consider a scalar linear delay equation with constant delay associated with an impulsive self-support condition. We define a numerical approximation scheme using a sequence of approximate delay equations with piecewise constant arguments, and we show its theoretical convergence. We present numerical examples to illustrate the applicability of the method, and we also observe existence of periodic solutions of the impulsive delay equation using numerical studies.(c) 2021 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/ )
查看更多>>摘要：This work is devoted to the study of spatiotemporal fault detection, estimation and control for nonlinear reaction-diffusion equations (RDEs). This strategy mainly includes the following three steps. Firstly, a fault detection observer is constructed by using average measurement, and the deviation signal generated by the observer is used to detect the existence of the fault. Secondly, a partial differential equation (PDE) fault estimator with a fault estimation algorithm is designed, which starts to perform only when the fault observer detects the existence of a fault. Thirdly, a feedback controller based on PDE fault estimator is designed to make the coupled system globally ultimately uniformly bounded (UUB). Sufficient conditions in terms of linear matrix inequalities (LMIs) are derived to ensure the coupled system globally UUB by using the Lyapunov-Krasovskii method. Finally, simulation examples are carried out to illustrate the validity of the proposed fault estimation algorithm and the designed controller.(c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：In this paper, we develop a fourth-order accurate compact difference scheme for the symmetric regularized long wave (SRLW) equation for a single nonlinear velocity form. The discrete conservation, priori estimate, solvability, convergence and stability of the present scheme are proved by the discrete energy method. Numerical examples are given to support the theoretical analysis.(c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：The dispersion and attenuation traits of Love-type waves propagating through a porous piezoelectric stratum imperfectly bonded to an anisotropic superficial stratum and a piezoelectric substratum have been irradiated through this analytical framework. With the aid of fundamental equations of motion and non-vanishing field equations, the electrical as well as mechanical displacements along with the constituents of electric potential have been obtained simultaneously. Applying stress free condition at the uppermost surface of the anisotropic stratum together with electro-mechanical boundary as well as continuity conditions at the common imperfect interfaces of the uppermost and intermediate strata as well as the intermediate stratum and piezoelectric substratum, the compact form of secular equation for the considered geometrical structure has been obtained. For better comprehension of the influence of the presumed parameters on the phase and attenuation phenomena of Love-type waves through the stratified Earth's structure with perfect and imperfect interfaces, a comparative graphical analysis has been accomplished by taking data corresponding to four different naturally occurring anisotropic rock samples namely, crystalline rock, North Sea sandstone, dry Vosges sandstone and saturated Lavoux limestone.(c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：Many various projects may exist in an enterprise in parallel, which leads to distinct group interactions. Team members cooperate in their respective projects, and sometimes it is possible to engage in several concurrent projects. Owing to practice makes perfect, the longer the duration of members participating in an identical project is, the higher benefits will be under same contribution. However, in a fiercely competitive environment, a huge conflict of interest between groups and individuals which results in social dilemma makes projects difficult to proceed smoothly. The experience of direct reciprocity shows that repeated interactions can alleviate this problem, but most multi-person dilemma studies consider a single game scenario, and public resources remain constant. Here we introduce a general framework of multiple public goods games. Taking the public goods game with threshold into consideration, public resource evolves with the persistence and transition of games. Our results suggest although collaborators are at a disadvantage in different game scenarios, our model can still effectively promote the overall cooperation in multiple public goods games. Especially, it performs better when public resource is relative scarce. (c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：An output feedback-based containment control strategy is proposed with an event triggered mechanism for a class of stochastic nonlinear multi-agent systems (MASs). For unavailable internal states of individual agent, a state observer is constructed for their estimations. The dynamic surface control (DSC) technology is employed to improve traditional backstepping, where a first-order filter is introduced for derivation calculation of virtual control laws. For the purpose of reducing communication resources, a fixed threshold based triggered strategy is presented to reduce data transmission bits over communication channels. It is proven that all signals in the closed-loop system are bounded in probability and the containment control is achieved. Finally, the effectiveness of the proposed control strategy is verified via two examples. (c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：The R-h-restricted connectivity & UKappa;(h) is a significant measurement to estimate the reliability of large-scale processor system. The arrangement graph A(n,k) is a generalization and also a competitive alternative of the star graph S-n. In this paper, for any non-negative integer h & LE; n - 2 , we determine that & UKappa;(h) (A(n, 2)) = n(n - 2) / 2 provided h is odd with h = n - 3 , otherwise & UKappa;(h) (A(n,2)) = (h + 2)(n - 2) - left perpendicularh(2)/2 + hright perpendicular. This result implies the upper bound of & UKappa;(h) (A(n,k)) given by Cheng et al. (J. Supercomput., 73(8)(2017) 3669-3682) is not optimal in a sense. (c) 2021 Elsevier Inc. All rights reserved.
Ehigie, Julius O.Luan, Vu ThaiOkunuga, Solomon A.You, Xiong...
23页
查看更多>>摘要：In this work, we construct and derive a new class of exponentially fitted two-derivative diagonally implicit Runge-Kutta (EFTDDIRK) methods for the numerical solution of differential equations with oscillatory solutions. First, a general format of so-called modified two-derivative diagonally implicit Runge-Kutta methods (TDDIRK) is proposed. Their order conditions up to order six are derived by introducing a set of bi-colored rooted trees and deriving new elementary weights. Next, we build exponential fitting conditions in order for these modified TDDIRK methods to treat oscillatory solutions, leading to EFTDDIRK methods. In particular, a family of 2-stage fourth-order, a fifth-order, and a 3-stage sixth-order EFTDDIRK schemes are derived. These can be considered as superconvergent methods. The stability and phase-lag analysis of the new methods are also investigated, leading to optimized fourth-order schemes, which turn out to be much more accurate and efficient than their non-optimized versions. Finally, we carry out numerical experiments on some oscillatory test problems. Our numerical results clearly demonstrate the accuracy and efficiency of the newly derived methods when compared with existing trigonometically/exponentially fitted implicit Runge-Kutta methods and two-derivative Runge-Kutta methods of the same order in the literature. (C) 2021 Elsevier Inc. All rights reserved.
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