Yu, ZhenhuaGao, HongxiaWang, DanAlnuaim, Abeer Ali...
12页查看更多>>摘要：Cyber-physical systems (CPSs) are new types of intelligent systems that integrate computing, control, and communication technologies, and bridge cyberspace and physical world. CPSs are widely used in many security-critical areas, but they are vulnerable to virus infections and malicious code attacks, which can cause damage to their functions and security incidents. To study the influence of malware on CPSs, this paper proposes a Susceptible-Exposed-Infected(1)-Infected(2)-Removed ((SEIRS)-R-2) model with different infection rates to study malware propagation in CPSs. First, we establish the nonlinear dynamic equation of malware propagation, and calculate the equilibria and basic reproduction number of the model. In addition, the local asymptotic stability and global asymptotic stability at the equilibria are proved by using Lyapunov theorem and Routh-Hurwitz criterion, and the transcritical bifurcation phenomenon is analyzed. Finally, we also carry out some simulations to simulate malware spreading in CPSs. The simulation results illustrate the existence of the equilibria, the stability and the transcritical bifurcation, which verify the effectiveness of the theoretical results. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:
NSTL
Elsevier
Cheng, W. W.Li, B.Gong, L. Y.Zhao, S. M....
9页查看更多>>摘要：We explore quantum speed limit time tQSL of a qubit system coupling to a spin chain environment which is described by an extended Ising model associated with non-trivial topological characterization. For an initial pure state, we find that tQSL exhibits a behavior of local maximum around all critical points when the environment spin chain undergoes a topological quantum phase transition driven by external magnetic field. or the anisotropy. of nearest-neighbor interaction. And the value of local maximum would increase by strengthening the coupling between the system and environment around the critical points. However, the behavior of tQSL are both driving parameters and critical points dependent when the topological quantum phase transition is driven by the threesite interaction a or its anisotropy d. Additionally, we also investigate tQSL for arbitrary time-evolution state in the whole dynamics process and find that tQSL exhibits a behavior of oscillation at non-critical points. However, tQSL will decay rapidly to zero around all critical points, and such trend accompany with oscillation behavior at some critical points. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Wei, XiaodanZhao, XuZhou, Wenshu
14页查看更多>>摘要：We study global stability of a network-based SIS epidemic model with a saturated treatment function. The model was proposed by Huang and Li (2019). They obtained a threshold R-0, depending on the network structure and some parameters (except the parameter alpha used to measure the extent of the effect of the infected being delayed for treatment), and some sufficient conditions on the stability of the equilibria. The aim of the present paper is to conduct a further analysis on the global stability of the equilibria by means of an iterative technique. For the case when R-0 < 1, it is proved that if the disease-free equilibrium is the unique one, then it is globally asymptotically stable. In addition, we give some new conditions guaranteeing that the disease-free equilibrium is the unique one, and show the existence of two endemic equilibria if alpha is sufficiently large, which verifies partially their numerical observation. For the case when R-0 > 1, it is proved that if the model admits a unique endemic equilibrium, then the unique endemic equilibrium is globally attractive, and is globally asymptotically stable if alpha is sufficiently large or small. In particular, we present a condition such that the threshold R0 determines the global stability of the disease-free equilibrium and the endemic equilibrium. Numerical experiment is also performed to illustrate our theoretical results.(C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Kassenova, T. K.Tsyba, P. YuRazina, O., VMyrzakulov, R....
11页查看更多>>摘要：This work is dedicated to the consideration of the construction of a representation of braid group generators from vertex models with N-states, which provides a great way to study the knot invariant. An algebraic formula is proposed for the knot invariant when different spins (N - 1)/2 are located on all components of the knot. The work summarizes procedure outputting braid generator representations from three-partite vertex model. This representation made it possible to study the invariant of a knot with multi-colored links, where the components of the knot have different spins. The formula for the invariant of knot with a multi-colored link is studied from the point of view of the braid generators obtained from the R-matrices of three-partite vertex models. The resulting knot invariant 52 corresponds to the Jones polynomial and HOMFLY-PT. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Batac, Rene C.Cirunay, Michelle T.
8页查看更多>>摘要：Studies on road networks, especially on highly-urban areas, have to account not only for the topological (i.e. network structure) but, more so, for the actual physical and geographical constraints that affect the efficiency of transport within the system. Here, we investigate the set of shortest paths across low-betweenness centrality nodes, which are found at the periphery of the network. Travel from one peripheral node to another is characterized by highly sinuous paths, which is expected due to the fact that these nodes represent the most highly inaccessible points in the network. Interestingly, short is not simple, i.e. the shorter paths are more likely to have a broad range of sinuosity values, while longer paths are generally more straight. We propose a categorization of the inaccessibility of peripheral nodes based on topological (network centrality) and spatial (physical dimensions) properties, to determine the most highly-inaccessible locations of the network. Unlike other networked architectures where the nodes and edges can be easily replaced or removed, it is impractical, if not impossible, to flatten down cities to give way for new roads. Studies such as this one can give useful insights for management and improvement of city transportation networks given the current conditions. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Cornes, F. E.Sticco, I. M.Dorso, C. O.Rozan, E. A....
21页查看更多>>摘要：This research explores the dynamics of emergency evacuations in the presence of social groups. The investigation was carried out in the context of the Social Force Model (SFM). We included attractive feelings between individuals belonging to the same social group, as proposed in Ref. Frank and Dorso (2016). We focused on the escaping dynamics through an emergency exit and through a corridor. We confirmed the results appearing in Ref. Frank and Dorso (2016) for a desired velocity of 4 m/s, but further extended the analysis on the emergency exit to the range 1-8 m/s. We noticed that the presence of groups worsens the evacuation performance. However, very strong feelings can improve the escaping time with respect to moderate feelings. We call this phenomenon "Closer Is-Faster ", in analogy to the "Faster-Is-Slower " effect. The presence of social groups also affects the dynamics within a corridor by introducing an additional slow-down in the moving crowd.(C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Deng, Zheng-HongXu, Ji-WeiCao, Run-Hua
13页查看更多>>摘要：Most of the existing studies on the characteristics of precipitation in Shanghai only focus on the statistical characteristics of the precipitation series rather than the internal dynamic characteristic. The visibility graph algorithm has been proven to be an effective algorithm for grasping the internal dynamics characteristics of time series. Therefore, this paper exploits the visibility graph algorithm to analyze the daily precipitation time series in Shanghai from 2000 to 2020. Some characteristics of precipitation during this period are obtained: Typhoon Mesa and Typhoon Fitow had a profound impact on Shanghai's precipitation; There is a certain similarity of the precipitation structure in different periods; Only a few nodes in the precipitation network have a profound impact on the precipitation in Shanghai. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Wei, FengyingLiu, Fangfang
15页查看更多>>摘要：An epidemic model with the saturated incidence rate and the environmental fluctuations is investigated in this paper. We study the extinction and the persistence in the mean, and stationary distribution of the solution as well. By contradiction, we firstly show that stochastic epidemic model admits a unique global positive solution for any given positive initial value. Further, when (sic)(0) > 1 is valid, we derive the persistence in the mean, and also prove the existence of an ergodic stationary distribution by constructing moderate functions. By comparison theorem of stochastic differential equations and properties of inequalities, the extinction of the solution is finally derived when R-0 < 1 and nu < 0 hold, where nu indicates the exponential rate for decline. Meanwhile, the distribution for the density of the susceptible is estimated. As a consequence, numerical simulations and illustrative examples are separately carried out to support the main results of this paper. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Gomes, P. F.Fernandes, H. A.Costa, A. A.
11页查看更多>>摘要：In this work, we study the topological transition on the associated networks in a model proposed by Saeedian et al. (Scientific Reports 2019 9:9726), which considers a coupled dynamics of node and link states. Our goal was to better understand the two observed phases, so we use another network structure (the so called random geometric graph - RGG) together with other metrics borrowed from network science. We observed a topological transition on the two associated networks, which are subgraphs of the full network. As the links have two possible states (friendly and non-friendly), we defined each associated network as composed of only one type of link. The (non) friendly associated network has (non) friendly links only. This topological transition was observed from the domain distribution of each associated network between the two phases of the system (absorbing and active). We also showed that another metric from network science called modularity (or assortative coefficient) can also be used as order parameter, giving the same phase diagram as the original order parameter from the seminal work. On the absorbing phase the absolute value of the modularity for each associated network reaches a maximum value, while on the active phase they fall to the minimum value. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
