Yin, ShaoyingSong, JieLiu, ShutianWang, Yueyuan...
10页查看更多>>摘要：Basis-independent coherence of spin-pairs and its distribution (collective and localized coherence) are studied in spin chains with three-site interaction. Firstly, we demonstrate that three kinds of coherence can correctly characterize the first-order quantum phase transition (QPT) induced by the anisotropy parameter, and the second-order QPT induced by the magnetic field and three-site interaction by their critical behaviors. Secondly, The triangle inequality between the basis-independent coherence and its distribution is verified, and the trade-off relations between the collective and localized coherence are captured by regulating the magnetic field. Lastly, we find that the collective coherence mainly contain the contributions from the classical and quantum correlations by virtue of the anisotropy parameter. (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
Chehardoli, HosseinGhasemi, Ali
12页查看更多>>摘要：The adaptive robust size-independent consensus problem of leader following multi-agent systems (MASs) with unknown dynamics based on only onboard relative dis-placement information is studied. It is assumed that all followers only can measure the relative displacement regarding their adjacent agents. Due to lack of communication tools, each follower must estimate its uncertain dynamics and the leader acceleration simultaneously. A decentralized adaptive robust consensus law is presented to achieve the global state consensus for uncertain second-order multi-agent systems by employing only relative displacement information. According to the Lyapunov theorem, it is proved that without any knowledge about the number of followers and communication graph, the global state consensus is attained. The control and adaptive gains are tuned independently of the number of followers and communication topology. Therefore, the controller is robust against size-changing and can be applied to large-scale uncertain MASs. Afterward, it is verified that if the basis vectors are persistently exciting (PE), the estimation errors of uncertain vectors tend to zero. Several numerical scenarios are prepared to confirm the efficiency of this method. (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
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
Lee, Ji-HyeJo, JunghyoKim, Jong WonLee, Keumsook...
9页查看更多>>摘要：We analyze the spatial distributions of restaurants in Seoul to examine the effects of the proximity to a transportation system as well as online information sharing on urban living facilities. Despite its complexity, restaurants are spread in a selfsimilar manner, forming clusters with the fractal dimension approximately given by 1.62. The probability density of distances between each restaurant and the nearest station shows that the locations of restaurants are associated extensively with the Seoul metropolitan subway system. Moreover, we explore the effects of online information sharing by choosing a subset of restaurants having a large number of online reviews. The distribution of these most-reviewed restaurants exhibits similar but somewhat different geographical patterns. To explain observed features based on data analysis, we propose a mathematical model taking into account the pedestrians and exploration paths as well as land prices around subway stations. Parametrization in terms of the characteristic distance and scaling exponents makes it possible to understand, with a single formula, the seemingly different spatial patterns between all restaurants and most-reviewed ones, manifesting universality in such phenomena. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Zhai, CongWu, WeitiaoXiao, YingpingLuo, Qiang...
15页查看更多>>摘要：Pedestrian flow models contribute to the effective design and operation of pedestrian spaces. In real traffic, pedestrians usually adjust their walking state in the movement procession according to perceptual information. Subject to the human capability, certain errors would exist between the perceptual information and the real traffic information, which can greatly affect the pedestrian flow performance. This paper proposes a bidirectional pedestrian flow model considering the effect of perceived uncertainty of preceding pedestrian information. In the linear and nonlinear stability analysis, we derive the stability criterion and modified Korteweg-de Vries (mKdV) equation of the proposed model. The kink-antikink solitary wave solution can be acquired via solving the above mKdV equations, which provides insight into the essential property of the formation and propagation of traffic jams near the neutral stability curve. Numerical examples demonstrate that the uncertainty terms and the perception time of pedestrians directly affect the pedestrian congestion. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
de Lacerda, K. J. C. C.da Silva, L. R.Viswanathan, G. M.Cressoni, J. C....
6页查看更多>>摘要：The theory of Markovian random walks is consolidated and very well understood, however the theory of non-Markovian random walks presents many challenges due to its remarkably rich phenomenology. An important open problem in this context is to study how the diffusive properties of random walk processes change when memoryinduced correlations are introduced. In this work we propose a model of a random walk that evolves in time according to past memories selected from rectangular (flat) and exponentially decaying memory profiles. In this mixed memory profile model, the walker remembers either the last B steps with equal a priori probability or the steps A prior to B with exponentially decaying probability, for a total number of steps equal to A + B. The diffusive behavior of the walk is numerically examined through the Hurst exponent (H). Even in the lack of exact solutions, we are still able to show that the model can be mapped onto a RW model with rectangular memory profile. (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Nezhadhaghighi, M. Ghasemi
9页查看更多>>摘要：In two-dimensional statistical mechanics, the Stochastic Loewner equation, introduced by Oded Schramm, provides a powerful technique to study and categorize critical random curves and interfaces. For the first time, a new type of stochastic Loewner equation entitled fractional stochastic Loewner evolution (FSLE) has been proposed. We introduce a wide class of fractal curves using the fractional time series as the driving function of the Loewner equation and local fractional integrodifferential operators. We suggest that, in addition to fractal dimension estimations, the Hurst index of the driving function leads significant differences in the FSLE curves. This modification introduces a new approach to categorize different types of scaling curves based on the Hurst index of the driving function. Such formalizations appear to be appropriate for studying a wide range of two-dimensional curves seen in statistical mechanics and natural phenomena. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
