Ramadoss, JanarthananKengne, JacquesTelem, Adelaide Nicole KengnouRajagopal, Karthikeyan...
20页查看更多>>摘要：Y We investigate the impact of a broken symmetry on the dynamics of the well-known Shinriki oscillator. The broken symmetry is caused by the memristive diodes bridge with an asymmetric pinched hysteresis loop current-voltage characteristic designed by selecting two pairs of semiconductor diodes with different electrical properties. We examine how the broken symmetry affects the topology of attractors, the nature of fixed points, the bifurcation structures, the number and types of coexisting solutions, and the topology of the basins of attraction as well. These features are highlighted by utilizing plots of Lyapunov exponents, bifurcation diagrams, basins of attraction and phase portraits. As sample results, up to four coexisting asymmetric chaotic and periodic attractors are reported following changes in both initial conditions and parameters. Moreover, some sets of parameters are revealed where the system develops the striking feature of coexisting bubbles of bifurcation. Breadboard experiments are carried out to support the theoretical investigations. Although the breaking of symmetry may be seen as a common practice to discover new nonlinear events, the results obtained in this work may help for a better understanding of the impact of a real memristor on the global behavior of chaotic oscillators including a memristor as nonlinear device. (C) 2021 Elsevier B.V. All rights reserved.
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NSTL
Elsevier
Ribeiro, H. V.Lenzi, M. K.Lenzi, E. K.Guilherme, L. M. S....
8页查看更多>>摘要：We investigate a diffusion process in heterogeneous media where particles stochastically reset to their initial positions at a constant rate. The heterogeneous media is modeled using a spatial-dependent diffusion coefficient with a power-law dependence on particles' positions. We use the Green function approach to obtain exact solutions for the probability distribution of particles' positions and the mean square displacement. These results are further compared and agree with numerical simulations of a Langevin equation. We also study the first-passage time problem associated with this diffusion process and obtain an exact expression for the mean first-passage time. Our findings show that this system exhibits non-Gaussian distributions, transient anomalous diffusion (sub- or superdiffusion) and stationary states that simultaneously depend on the media heterogeneity and the resetting rate. We further demonstrate that the media heterogeneity non-trivially affect the mean first-passage time, yielding an optimal resetting rate for which this quantity displays a minimum. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Lu, XinbiaoZhang, ChiHuang, ChenQin, Buzhi...
8页查看更多>>摘要：In the classical Vicsek model, it was found that the emergence of self-ordered motion in systems of particles when the direction of each particles' motion of at the next moment is updated according to its all neighbors' mean direction. However, the rapid increase of the number of particles and the complexity of particles' interaction will lead to this progress's time become too long. Therefore, in order to reduce the time from disorder to order, a novel strategy is proposed to make the directions of all particles' motions reach consensus more quickly. In this rule, we introduce the value of neighbors' degree according to the degree value, and select only part of the neighbor particles with larger degree. When the initial particles of swarm are connected, simulation results show that the emergence of consistent direction earlier in the improved Vicsek model than that in classical Vicsek model. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Wang, ChaoMeng, XinGuo, MingxueLi, Hao...
15页查看更多>>摘要：Subway is considered to be one of the most energy-intensive transportation modes for its high operating frequency. However, energy-efficient operations for the subway system are of great importance yet have not been paid much attention to. In this study, we first develop an integrated energy-efficient and transfer-accessible model to minimize the tractive energy consumption and maximize the number of last train connections, which could contribute to the development of high energy-efficient strategies and the construction of wide-accessibility timetables for the subway system. Four tractive modes, which are accelerating-braking (A-B) mode, accelerating-coasting-braking (A-Co-B) mode, accelerating-cruising-braking (A-Cr-B) mode, and the mixed mode, are proposed to facilitate the last train operations. A real-life case study of the Beijing subway network is solved by a tailored genetic algorithm. Results show that the A-B mode is the most energy-intensive with an energy consumption of 466.9 kWh, while the A-Co-B mode becomes the most energy-efficient (402.5 kWh). The A-Cr-B and the mixed modes consume 442.2 kWh and 412.8 kWh, respectively. The findings are of significant value for subway companies in addition to their academic merits. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Zubillaga, Bernardo J.Vilela, Andre L. M.Wang, ChaoNelson, Kenric P....
13页查看更多>>摘要：We propose a three-state microscopic opinion formation model for the purpose of simulating the dynamics of financial markets. In order to mimic the heterogeneous composition of the mass of investors in a market, the agent-based model considers two different types of traders: noise traders and noise contrarians. Agents are represented as nodes in a network of interactions and they can assume any of three distinct possible states. The time evolution of the state of an agent is dictated by probabilistic dynamics that include both local and global influences. A noise trader is subject to local interactions, tending to assume the majority state of its nearest neighbors, whilst a noise contrarian is subject to a global interaction with the behavior of the market as a whole, tending to assume the state of the global minority of the market. The model exhibits the typical qualitative and quantitative features of real financial time series, including distributions of returns with heavy tails, volatility clustering and long-time memory for the absolute values of the returns. The distributions of returns are fitted by means of coupled Gaussian distributions, quantitatively revealing transitions between leptokurtic, mesokurtic and platykurtic regimes in terms of a non-linear statistical coupling which describes the complexity of the system. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Cornes, F. E.Frank, G. A.Dorso, C. O.
18页查看更多>>摘要：We propose an epidemiological model that explores the effect of human mobility on the spatio-temporal dynamics of the COVID-19 outbreak, in the spirit to those considered in Refs. Barmak et al. (2011, 2016) and Medus and Dorso (2011) [1]. We assume that people move around in a city of 120 x 120 blocks with 300 inhabitants in each block. The mobility pattern is associated to a complex network in which nodes represent blocks while the links represent the traveling path of the individuals (see below). We implemented three confinement strategies in order to mitigate the disease spreading: (1) global confinement, (2) partial restriction to mobility, and (3) localized confinement. In the first case, it was observed that a global isolation policy prevents the massive outbreak of the disease. In the second case, a partial restriction to mobility could lead to a massive contagion if this was not complemented with sanitary measures such as the use of masks and social distancing. Finally, a local isolation policy was proposed, conditioned to the health status of each block. It was observed that this mitigation strategy was able to contain and even reduce the outbreak of the disease by intervening in specific regions of the city according to their level of contagion. It was also observed that this strategy is capable of controlling the epidemic in the case that a certain proportion of those infected are asymptomatic. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Zhou, ShuangWang, XingyuanZhang, ChuanZhou, Wenjie...
11页查看更多>>摘要：Identifying the scale-free interval is an important step in calculating the correlation dimension. In this paper, we propose a method using machine learning known as density peak based clustering algorithm to recognize the scale-free interval. First, the GP algorithm is used for computing the correlation integral index. Then, the density peak based clustering algorithm is used for classifying the second-order derivative data sets of the correlation integral curve, the zero-fluctuation data are selected to be retained, and then the gross errors are excluded from the selected data. Finally, the coefficient of determination is used to identify the scale-free interval. Some examples are provided to verify the proposed method effective. The calculated results show that our method is feasible. In addition, this research proposes a new method to identify the scale-free interval for fractional dimension calculation theory. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Shang, Xue-ChengLi, Xin-GangXie, Dong-FanJia, Bin...
14页查看更多>>摘要：In this paper, a data-driven two-lane traffic flow model based on cellular automata is proposed. Long Short-Term Memory (LSTM) and Support Vector Machine (SVM) are used to learn the characteristics of car following behavior and lane changing behavior, respectively, from real operation data of vehicles. Under optimal network parameters, the mean absolute errors of the LSTM network for training and testing data are only 0.001 and 0.006, respectively; while the prediction accuracy of the SVM classifier for both data reaches higher than 0.99. Moreover, forward rules and lane changing rules which are more consistent with actual situation are designed. The simulation results show that: (1) the new model can reflect the first-order phase transition from free flow to synchronized flow; (2) the frequency of unsuccessful lane changing is near zero in low-density traffic areas, but increases sharply in high-density regions; and (3) the lane changing duration and unsuccessful lane changing frequency display similar trends as traffic densities increase. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Kuikka, VesaMonsivais, DanielKaski, Kimmo K.
9页查看更多>>摘要：In an earlier study one of us had developed a model of influence spreading for analysing human behaviour and interaction with others in a social network. Here we apply this model and corresponding influence centrality measures to real data of mobile phone call detail records. From this we get structures of human ego-centric networks and use a simple model, based on the number of phone calls, to describe the strengths of social relationships. To analyse 48,000 egos in their ego-centric networks we define normalised out-centrality and in-centrality influence measures, by dividing with out-degree and in-degree, respectively. With these and the betweenness centrality measures, we analyse the influence spreading in the ego-centric networks under different scenarios of link strengths between individuals reflecting the network structure being either interaction or connectivity oriented. The model reveals characteristics of social behaviour that are not obvious from the data analysis of raw empirical data or from the results of standard centrality measures. A transition is discovered in behaviour from young to older age groups for both genders and in both normalised out-centrality and in-centrality as well as betweenness centrality results. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
