查看更多>>摘要：? 2022This paper investigates the distributed filtering (DF) issue for a class of time-varying state-saturated systems with packet disorders (PDs) via the event-triggered communication mechanism (ETCM). The random transmission delays, which can be characterized by a set of random variables obeying certain probability distribution, cause the phenomenon of PDs. In addition, for the sake of decreasing the consumption of network resources, the ETCM is used to arrange the data transmission. On the basis of the measurable data information, a novel distributed filter is constructed that can ensure the existence of the upper bound matrix (UBM) regarding the filtering error (FE) covariance and then the trace of the presented UBM is minimized via constructing the suitable filter gain. Afterwards, the boundedness analysis of FE dynamics is provided to evaluate the filtering algorithm performance. Finally, the validity of the designed DF scheme is illustrated through a numerical experiment.
查看更多>>摘要：? 2022 Elsevier Inc.In this study, the problem of noise-input-to-state stability for switching stochastic nonlinear systems with impulses is investigated. There are two outstanding features of the investigated systems: (a) the occurrences of swithcings and impulses are allowed to be asynchronous; (b) the impulsive maps not only depend on the subsystems but also are different for the different impulsive instants. The noise-input-to-state stability problem is first considered for systems, where switching instants and impulsive intervals are confined by the mode-dependent average dwell time and impulsive interval, respectively. Then, we revisit the noise-input-to-state stability for nonlinear systems with stochastic switching and impulsive densities. To derive less conservative sufficient conditions, multiple Lyapunov functions with the indefinite weak infinitesimal generator and some fundamental stochastic techniques are applied. A simulation example is proposed to illustrate the effectiveness of the provided criteria.
查看更多>>摘要：? 2022 Elsevier Inc.Let X be a Cayley graph whose diameter is 2. Set R:=Aut(X) and w∈V(X). In this paper, it is shown that: for every positive integer m at least 6, there is a such Cayley graph X of m points such that Rw acts transitively in X2(w) but not in X(w); for every positive integer k at least 3, there is a such graph X of valency k such that Rw is transitive in X2(w) but not in X(w).
查看更多>>摘要：? 2022 Elsevier Inc.In this paper, the problem of incipient fault detection is investigated for linear time-varying (LTV) systems with stochastic noises. The fault detectability in a probabilistic sense is defined for LTV stochastic systems by considering false alarm rate (FAR) and missed detection rate (MDR) simultaneously. Necessary and sufficient conditions are derived to reveal the relationship among the fault amplitude, FAR and MDR, and the reason why incipient faults are difficult to detect is quantitatively analyzed in the model-based framework. To improve the sensibility of the residual to incipient faults, the weighted moving average approach is introduced and its parameters, the optimal weight and the smallest window length, are accurately analyzed in theory. Moreover, the concept of average fault detectability is introduced, which is conducive to providing a feasible scheme for incipient fault detection. Finally, a numerical example and an experiment are given to show the effectiveness of the derived results.
查看更多>>摘要：? 2022 Elsevier Inc.Credit sales not only help sellers expand sale size and promote competitiveness, but also relieve the pressure of customers cash flow, but inevitably increases channel conflict and generates capital opportunity cost. This article attempts to consider a dual-channel supply chain operation decision and coordination under credit sales transactions for the first time, in which the supplier and the retailer compete on the credit period provided to the final customers, and the market demand is random and depends on credit period. This paper develops and analyzes the mathematical models of the dual-channel supply chain expected profit maximization under centralized, decentralized and coordinated decision making structures. A decision framework for a dual-channel supply chain considering credit sales competition and random demand is given, in which the supplier decides on wholesale price and online direct sales channel credit period, and the retailer decides on traditional retail channel credit period. This study finds that the fierce credit sales competition is bad for the dual-channel supply chain, and classical coordination contracts such as wholesale price joint trade credit contract have limitations in the dual-channel supply chain coordination considering credit sales competition. To stimulate channel members to make optimal decisions while optimizing their expected profits, a two-part credit contract based on asymmetric Nash bargaining is proposed. The research results reveal that the proposed contract can not only achieve the dual-channel supply chain coordination considering credit sales competition, but also achieve Pareto improvements of all members. Finally, the performance of different models is compared by numerical examples and sensitivity analyses, the effectiveness of the proposed contract is proved, and some managerial insights are given.
查看更多>>摘要：? 2022 Elsevier Inc.In this paper, we present a game-theoretic model describing voluntary social distancing during the spread of an epidemic. The payoffs of the agents depend on the social distancing they practice and on the probability of getting infected. We consider two types of agents: the non-vulnerable agents with a small cost if they get infected and the vulnerable agents with a higher cost. For the modeling of the epidemic outbreak, we consider a variant of the SIR (Susceptible-Infected-Removed) model involving populations of susceptible, infected, and removed persons of vulnerable and non-vulnerable types. The Nash equilibria of this social distancing game are studied. The main contribution of this work is the analysis of the case where the players, desiring to achieve a low social inequality, pose a bound on the variance of the payoffs. In this case, we introduce and characterize a notion of Generalized Nash Equilibrium (GNE) for games with a continuum of players and provide characterizations for this type of GNE. It turns out that often there is a continuum of GNE. However, among the GNE, for a given value of the variance bound, there is one that Pareto dominates the others. We also provide conditions under which a more restrictive variance constraint benefits all the game participants. Furthermore, we describe a bargaining-based algorithm for choosing the variance constraint. Through numerical studies, we show that inequality constraints result in a slower spread of the epidemic and an improved cost for the vulnerable players. Furthermore, we present some examples where inequality constraints are also beneficial for non-vulnerable players.
查看更多>>摘要：? 2022 Elsevier Inc.In this article, an efficient two-grid finite element method is proposed for solving the nonlinear time fractional variable coefficient diffusion equations. This algorithm firstly solves a nonlinear system to get the numerical solution uHn on the coarse grid with size H, then based on the initial iterative solution uHn on the coarse grid, the linearized finite element system is solved on the fine grid with size h to get the numerical solution Uhn, in which the temporal direction is approximated by the L2?1σ scheme. Besides, the stability and priori error estimates of standard finite element method and two-grid method are given. Finally, the validity and efficiency of the two-grid algorithm are verified by two numerical experiments.
查看更多>>摘要：? 2022 The Author(s)The choice of age as a physiological parameter to structure a population and to describe its dynamics involves the election of the life-span. The analysis of an unbounded life-span age-structured population model is motivated because, not only new models continue to appear in this framework, but also it is required by the study of the asymptotic behaviour of its dynamics. The numerical integration of the corresponding model is usually performed in bounded domains through the truncation of the age life-span. Here, we propose a new numerical method that avoids the truncation of the unbounded age domain. It is completely analyzed and second order of convergence is established. We report some experiments to exhibit numerically the theoretical results and the behaviour of the problem in the simulation of the evolution of the Nicholson's blowflies model.
查看更多>>摘要：? 2022We investigate the behavior of the numerical solutions of the p-Laplacian Allen–Cahn equation. Because of the p-Laplacian's challenging numerical properties, many different methods have been proposed for the discretized p-Laplacian. In this paper, we provide and analyze a numerical scheme for the boundedness of solutions and energy decay properties. For a comprehensive understanding of the effect of p-Laplacian and its relationship in the context of phase-field modeling, we compare the temporal evolution and compute the eigenpairs of the classical, fractional, and p-Laplacian in the Allen–Cahn equations. As for the p-Laplacian Allen–Cahn equation, we characterize different morphological changes of numerical solutions under various numerical tests such as phase separation, equilibrium profile, boundedness of solution, energy decay, traveling wave solution, geometric motions, and comparison of the Allen–Cahn equations with the three different Laplacians. Our results imply that the interface profile along the two-phase boundary lines changes more steeply than classical one as the p order decreases, therefore, the p-Laplacian Allen–Cahn equation can be applied for the description of phase interface where it is important to maintain sharply.
查看更多>>摘要：? 2022 Elsevier Inc.In this paper, the dynamic of inertial capsules into microfluidic bifurcations is studied. The fluid evolution is based on the solution of the BGK – lattice Boltzmann scheme including a forcing term accounting for immersed geometries. The dynamic-Immersed Boundary forcing strategy is adopted for imposing no-slip boundary conditions on moving deformable or rigid structures, while, on fixed immersed geometries the Bouzidi–Firdaouss–Lallemand second-order bounce back technique is implemented. The proposed computational framework is employed to detail dynamics and deformation of rigid and deformable capsules traveling into a branching duct. This journey is characterized in terms of i) the capsule/bifurcation interaction depending on the sharpness of the branching channels junction; ii) daughter branches aperture angle; iii) occlusion ratio, the ratio between capsule size and main channel diameter; iv) flowing capsules stiffness; v) number of flowing particles.
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