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North-Holland

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    Spatio-temporal modelling and prediction of bus travel time using a higher-order traffic flow model

    Bharathi, DhivyaSubramanian, Shankar C.Vanajakshi, Lelitha
    16页
    查看更多>>摘要：Accurate bus travel time prediction in real-time is challenging, as numerous factors such as fluctuating travel demand, incidents, signals, bus stops, dwell times, and seasonal variations can affect travel time, a spatio-temporal variable. Literature that considered the spatio-temporal evolution of bus travel time adopting traffic flow theory-based models investigated one-equation models (also widely known as first-order model) predominantly while the two-equation models (commonly known as higher-order models) have not been sufficiently explored due to their complex structure, parameters to calibrate, hardship in obtaining the data, and difficulty in discretizing and solving. Motivated by this, the present study explores the suitability of higher order traffic flow models for the prediction of bus travel time. This study adopted a well-known two-equation model 'Aw-Rascle model' (Aw and Rascle, 2000), which addressed most of the limitations of the previous models, and discretized using a Finite volume method to preserve the conservational properties of Partial Differential Equations (PDE). As Global Positioning System (GPS) is a widespread data source for transit systems, the identified model was rewritten in terms of speed by adopting a suitable pressure function. The discretized model was represented in the state-state-space form and integrated with a filtering technique using appropriate inputs, to facilitate real-time implementation. The performance of the proposed methodology was evaluated and compared with a first order model (Lighthill Whittam Richards (LWR) model) based approach to understand the efficacy of the higher-order models in travel time prediction. The prediction accuracy in terms of Mean Absolute Percentage Error (MAPE) was around 14% for the proposed methodology with an absolute deviation of around +/-1.2 min, which was better than the existing LWR model-based prediction method. The developed real-time prediction methodology is a promising one to be integrated with Advanced Public Transportation Systems (APTS) applications. (C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Characterization of resilience in Aedes aegypti mosquito networks

    Macias Torres, M.Naranjo Mayorga, F.
    10页
    查看更多>>摘要：In this work, the resilience study of the Aedes aegypti mosquito network built in urban areas of Colombia is presented. We define the network based on the Skeeter-Buster model, where each node is represented by a mosquito habitat in each zone. The state that defines the population of each node depends on the gonotrophic cycle of the species and the environmental conditions. Interactions between nodes are defined by the probability that mosquitoes migrate from one node to another (P (d(ij))). The topology of the network is evaluated and the dynamic equation of the system is defined, through which the universal resilience function is obtained in the A. aegypti mosquito network. We found that the more heterogeneous networks are more likely to be resilient, so a strategy could be sought to manipulate this property in A. aegypti networks. The phase transitions have been located for each constructed network and the fixed points in the phase space were characterized. One of the most important contributions is the migration probability of the vector P (d(ij)), which offers a good approximation to the migratory behavior of the vector as a function of the mean flight distance and the distance between habitats. Finally, it is observed in the dynamics of the network that the population growth presents different values of effective mean degree (beta(eff)), with values between 1.6 and 5.57, highlighting the case of Villavicencio with a value of 1.6309. (C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Spatial early warning signals for tipping points using dynamic mode decomposition

    Donovan, G. M.Brand, C.
    8页
    查看更多>>摘要：Tipping points are abrupt transitions in time-varying systems which may be driven by noise, changes in the underlying system, or some combination of the two. Early warning signals of tipping points are potentially valuable leading indicators of these transitions. In low-dimensional systems, it is possible to characterize these indicators based on the expected type of the tipping point. In spatial systems, indicators which take account of changes in the spatial structure are in principle able to capture more information, compared with aggregate measures, and thus provide stronger leading indicators. Here we propose the use of dynamic mode decomposition (DMD), a dimensionality reduction technique first developed in a fluid dynamics context, as a method for extracting useful information about critical slowing down in the leading mode of a spatial system approaching a tipping point. To demonstrate its potential utility for this purpose we employ two models: one drawn from the physiology literature for the study of spatially-patterned ventilation distributions in asthma, and the other an ecological model previously used for the study of spatial early warning signals of tipping points. Together these show that the DMD leading eigenvalue may be a useful spatially-informed early warning signal. (c) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Evolution of cooperation in public goods games with segregated networks and periodic invasion

    He, YujieRen, TianyuZheng, JunjunHuang, Yongchao...
    16页
    查看更多>>摘要：Despite the cost, rational individuals routinely modify their relationships in social networks to optimize their payoffs. To develop this observation, we propose a segregation strategy that impels individuals to sever the adverse ties between defectors and their group at some cost, and then we randomly rewire the link-broken cooperative individuals. Moreover, time-varying environmental factors impact the relationships between interacting individuals, in particular certain periodic changes such as the circadian rhythm and seasonality, thus affecting the evolution of cooperation in spatial public goods games. By this means, periodic invasion is taken into account, which allows defectors with lower degrees than the initial value to randomly restore links and invade the population again. Through simulation, we find that the segregation strategy involving periodic invasion can effectively facilitate cooperation by formatting assortative and heterogeneous topology. Furthermore, we observe a subtle interplay between the costly topology control strategy and the exogenous changes in temporal factors that alter the spatiotemporal dynamics of coevolution and promote cooperation. We conclude that a relatively low periodic invasion frequency contributes to increasing the level of cooperation, but the threshold of cooperation is not sensitive to the change in invasion period when at longer intervals. We present our interpretations of these phenomena, which thus allow us to better understand the role of this new machine in the emergence of cooperation. (C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Cascading failure analysis and critical node identification in complex networks

    Xiao, FengLi, JinWei, Bo
    13页
    查看更多>>摘要：Cascading failures in complex networks have attracted widespread attention in recent years. In this paper, a cascade model is proposed to analyze the potential overloads of nodes and edges simultaneously. First, some theoretical results for regular networks are detailed by the cascade model. The results show that in ring networks, as long as the capacity of each node or edge exceeds twice its initial load, the networks still work normally when an arbitrary node or edge breaks down, and in regular networks the failure of the farthest edges is most likely to induce cascades and the robustness of regular networks becomes stronger with the increase in the number of edges. Furthermore, an indicator evaluating the damage of the cascades is introduced. The analysis on the robustness of some typical networks indicates that WS networks can resist cascading failures more effectively and the robustness performance of WS networks can be improved by increasing rewiring probabilities. In BA networks, the failure of a critical node may pull down the whole networks, while the networks still function normally even if any edge breaks down. Finally, a forecasting indicator, called modified betweenness centrality, is proposed to identify critical nodes and experimental results show that the proposed indicator outperforms other typical indicators in identifying critical nodes.
      原文链接:
    • NSTL
    • Elsevier

    The effect of information literacy heterogeneity on epidemic spreading in information and epidemic coupled multiplex networks

    Wu, JiangZuo, RenxianHe, ChaochengXiong, Hang...
    16页
    查看更多>>摘要：With the COVID-19 pandemic, better understanding of the co-evolution of information and epidemic diffusion networks is important for pandemic-related policies. Using the microscopic Markov chain method, this study proposed an aware-susceptible-infected model (ASI) to explore the effect of information literacy on the spreading process in such multiplex networks. We first introduced a parameter that adjusts the self-protection related execution ability of aware individuals in order to emphasis the importance of protective behaviors compared to awareness in decreasing the infection probability. The model also captures individuals' heterogeneity in their information literacy. Simulation experiments found that the high information-literate individuals are more sensitive to information adoption. In addition, epidemic information can help to suppress the epidemic diffusion only when individuals' abilities of transforming awareness into actual protective behaviors attain a threshold. In communities dominated by highly literate individuals, a larger information literacy gap can improve awareness acquisition and thus help to suppress the epidemic among the whole group. By contrast, in communities dominated by low information-literate individuals, a smaller information literacy gap can better prevent the epidemic diffusion. This study contributes to the literature by revealing the importance of individuals' heterogeneity of information literacy on epidemic spreading in different communities and has implications for how to inform people when a new epidemic disease emerges.(C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Statistical properties of non-Gaussian quantum states generated via thermal state truncation

    Yu, Zhao-XianWang, LeiWang, Ji-SuoZhang, Xiao-Yan...
    12页
    查看更多>>摘要：Quantum scissors devices proposed by Pegg are beneficial to obtain highly nonclassical quantum states and indispensable for meeting the requirements of quantum information and computation. In this paper, via inputting and detecting single photon states, quantum scissor operation is equivalent to a mixed superposition of three pure state projection operators, which means that the output states are always truncated for any input state. We theoretically prepare a class of non-Gaussian quantum states via thermal state truncation and investigate their statistical properties using average photon number, gain intensity and signal to noise ratio. It is shown that the intensity gain and signal to noise ratio greater than one can be achieved by modulating the thermal parameter and the transmissivity, which realizes the signal amplification and enhancement. Besides, quantum scissor operation can generate the highly non-classical quantum state by investigating the negativity volume of Wigner function. These results indicate that the usage of the new non-Gaussian states may have potential applications in certain quantum information processing. (C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Protecting quantum coherence and entanglement in a correlated environment

    Sk, RajiuddinPanigrahi, Prasanta K.
    13页
    查看更多>>摘要：Long-term preservation of quantum coherence and entanglement is indispensable for practical quantum computation. We study the evolution of quantum coherence and genuine multipartite concurrence of extended Werner like states transmitted through correlated amplitude damping (AD), phase damping (PD) and depolarizing (DP) channels. The results show that the decay rate of coherence is curtailed in the presence of correlation between successive actions of the channel. It is shown that the fragility of genuine multipartite entanglement due to decoherence can be protected to some significant amount by using the correlated channels. In fact, for even qubit Werner like states, coherence and entanglement exhibit freezing phenomenon, in which it remains intact against decohering environment in perfectly correlated phase damping and depolarizing channels. For multipartite GHZ-class states in a perfectly correlated channel, it is shown that entanglement sudden death (ESD) is circumvented in amplitude damping channel, and there is an entanglement sudden birth (ESB) for odd qubit systems in depolarizing channel. Further, we have established analytical relation between coherence and entanglement for completely uncorrelated and fully correlated quantum channels. (C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Monte Carlo study of site disordered 3d Heisenberg models in the presence of a magnetic field and a weak random anisotropy

    Belkhatir, S.Bekhechi, S.Southern, B. W.
    9页
    查看更多>>摘要：We study the 3d Heisenberg site disordered model with and without weak random anisotropy D in the presence of a uniform external longitudinal magnetic field using Monte Carlo methods. The spin and the chirality correlation lengths are measured. We provide evidence that the "mixed chiral " phase is a chiral glass at a finite temperature transition TCG > 0, whereas the spin glass temperature transition is at T-SG = 0 for D = 0. In the anisotropic case we find that the model exhibited a strong evidence the occurrence of finite temperature transitions in the both sectors the spin and the chirality. Our estimate of the spin and chirality correlation-length exponents are compatible with our previous values obtained for the same model without anisotropy and the 3d Heisenberg spin glass.(C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Teleporting quantum Fisher information under Davies-Markovian dynamics

    El Anouz, K.El Allati, A.
    12页
    查看更多>>摘要：The estimation degree of a teleported state using two different quantum channels by means of quantum Fisher information is discussed. It consists of using two different noisy channels generated from an interaction between an open quantum system and its surrounding environment under Davies-Markovian dynamics. However, when small interacted system-environment parameters and a small number of detuning parameters are taken into account, a robust estimation degree is obtained. Moreover, it is possible to estimate various system-environment parameters related to the energy relaxation time and dephasing time. By controlling these parameters, we conclude that maximally entangled channels and robust estimation degrees by means of quantum Fisher information are achieved when the energy relaxation and dephasing times vanish. (c) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier