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
Khlifi, Y.Seddik, S.El Allati, A.
9页查看更多>>摘要：An entangled steady-state behavior between two quantum thermal refrigeration machines is evaluated. Each machine is made up of three qubits of two-level, where each qubit interacts with its proper reservoir. The coupling between the qubits and the reservoirs is investigated with weak interaction. In addition, thermodynamic quantities such as heat flux are examined as a function of entanglement. The effect of temperature on entanglement is also studied in the cases of resonance and non-resonance. The obtained results show that the steady-state entanglement is more robust in the case of resonance than in the case of non-resonance. However, the maintenance in this case corresponds to the higher cooling power of the machine. (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Eftekhari, F.Tavassoly, M. K.Behjat, A.
17页查看更多>>摘要：In this paper we investigate the dynamics of f-deformed interaction (nonlinear atom field coupling) of a three-level atom in V-configuration with a two-mode quantized field in the presence and absence of Kerr medium as well as the phonon and photon dissipations in an optomechanical cavity. We solve the associated time-dependent Schrodinger equation and arrive at the corresponding state vector at arbitrary time. In the continuation, we evaluate several nonclassical properties including atomic von Neumann entropy, atomic information entropy squeezing, sub-Poissonian statistics and atomic squeezing, numerically. Our numerical results show that, with the parameters at our disposal, we can adjust the above-mentioned properties according to our purposes. For instance, significant amount of von Neumann entropy may be achieved, in the linear and nonlinear atom-field coupling, without or even with considered dissipations. However, atomic information entropy squeezing can be observed only in the presence of nonlinear atom-field coupling by tuning the proper values of Lamb-Dicke parameter. Atomic squeezing can be seen in the presence or absence of linear and nonlinear atom-field coupling. Negative values of Mandel parameter, showing the sub-Poissonian statistics as the nonclassicality of the field can be observed with and without nonlinear atom-field coupling, however, the presence of Lamb-Dicke nonlinearity can make this effect more visible. Unless the atomic information entropy squeezing, in all above mentioned physical phenomena stability of the evaluated parameters can be accessible via choosing appropriate parameters containing Lamb-Dicke parameter, Kerr effects, dissipation parameters, laser pumps and photon-phonon coupling. (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
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
Aragie, BerhanuDaba, TesemaPellicane, Giuseppe
9页查看更多>>摘要：We study a stochastic model for the dynamics of charge carriers hopping from a lattice site to a neighboring one, in a one-dimensional (1D) semiconductor layer. Charge carriers are forced to migrate toward the central region by an external, harmonic potential. We also apply a non-uniform temperature, which is a linear combination of the temperature profiles generated by two heat sources. The first one is hot at the two ends of the semiconductor layer and pushes the charge carriers to stay around the center. The second one is hot around the center and produces the opposite effect. The composition of the two temperature profiles across the semiconductor layer generates two symmetric minima with respect to the central region. We show that this model is a bistable system, and by using both analytical and numerical methods we analyze the effect of different controlling parameters on the diffusion of charge carriers. We also study the crossing rate of charge carriers through the thermally activated barrier, and the stochastic resonance (SR) arising in the presence of a time-varying signal. Our results show that the application of an external potential provides a strong spectral amplification peak eta, which occurs at a even lower temperature than the one we reported recently in Aragie (2020). (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Luo, YunLi, YukeSun, ChudiCheng, Chun...
13页查看更多>>摘要：It is noted in the psychology literature that a discrepancy may exist between individuals' implicit opinions and their explicit opinions (or beliefs) on a matter due to political correctness or peer pressures. This study proposes an adaptation of the Deffuant- Weisbuch model that incorporates both implicit and explicit opinions to investigate the evolution of opinions in a population. In our proposed model, we also consider the scenario where an opinion leader exists. We present a theoretical analysis of opinion convergence and consensus in our proposed model and prove a result on the occurrence of "strong diversity"in opinions. We further show that with the existence of an opinion leader, the model will predict a convergence to consensus. Finally, we show the emergence of a strong diversity of opinions in the population for model-based networks and square networks using Monte Carlo simulations. (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Zhou, ShiruiLing, ShuaiZhu, ChenqiangTian, Junfang...
14页查看更多>>摘要：As the important spatiotemporal state of traffic flow discovered by Kerner's three-phase traffic theory, the synchronized traffic flow describes a new traffic phase in congested traffic. However, until now most models within the standard traffic theories cannot reproduce it. The average space gap model (ASGM) is a simple cellular automaton model aimed to reproduce various empirical findings discovered by Kerner's three-phase traffic theory by incorporating the influence of the multi-anticipative effect on vehicle's deceleration. However, this paper shows that the simulated synchronized flow by ASGM is not consistent with the reality. To this end, the Multi-Anticipative Model (MAM) based on ASGM is proposed, which describes the influence of the multi-anticipative effect on both the accelerations and the decelerations. Simulations indicate that the empirical consistent synchronized flow and related congested patterns can be well reproduced by MAM. Moreover, MAM can reproduce the speed drop in the car following vehicle platoons reported by the empirical observations. Generally, MAM indicates that the multi-anticipative effect can shed light on the understanding and capturing the complex characteristics of traffic flow especially reported by Kerner's three-phase traffic theory. (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Pan, HaoBai, HaijianZheng, XiaoyanChen, Jin...
19页查看更多>>摘要：In the near future, connected and autonomous vehicles (CAVs) will share road space with human-driven vehicles (HVs). In this mixed vehicular traffic, effective following cooperation among multiple vehicles is an important basis for improving traffic efficiency and safety. However, CAVs are unable to communicate with HVs to acquire information. Therefore, how to obtain HV information and realize cooperative car-following has become an urgent problem for CAVs. This paper proposes a CAV driving strategy that considers multiple preceding vehicles, including HVs. The strategy first uses a large amount of real car-following data to build an upgraded Elman neural network (ENN) model optimized with the sparrow search algorithm (SSA), which is utilized to obtain HV information. Then, we combine the SSA-ENN with the classical car-following model and use a time-varying weighting model to analyze the impact of the different states of multiple preceding cars at various moments on the host car, so as to achieve car following driving control. Numerical simulations are carried out, and the results show that the driving strategy can improve road capacity and suppress traffic oscillations. With the increase in CAV penetration, traffic efficiency, safety, and driving comfort are improved accordingly. (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Kopsidas, AthanasiosKepaptsoglou, Konstantinos
13页查看更多>>摘要：Metro systems are critical public transport elements in several metropolitan areas around the world. Unexpected disruptions may undermine service provision of metro systems, and thus addressing their negative impacts is of primary importance. A first step towards developing mitigation measures involves the identification of those critical metro stations, whose operation must be preserved. Complex Network Theory (CNT) provides valuable methodological tools for this purpose, as a topological analysis based on centrality measures combined with real-world spatiotemporal data can be used for critical station identification. The objective of this paper is to develop a measure for evaluating metro station criticality based on CNT, considering substitute services during a disruption. A substitute network is defined as the network consisting of the metro stations as nodes and all alternative public transport routes potentially serving those stations outside the metro system, as edges. The form of the substitute network depends on a pre-selected service level. Two graphs are constructed, the metro and the substitute, using an L-space and a P-space representation, respectively. A combination of centrality measures of both networks is utilized for evaluating the stations' criticality. The methodology proposed is applied to a real-world metro system, that of Athens, Greece. A sensitivity analysis is conducted suggesting that the proposed measures manage to capture the tradeoff between centrality and availability of alternatives, considering a station's topological criticality. On top of that, the criticality measure seems to be robust against changes at service levels, but sensitive enough, so that it can be adaptable to each operator's needs. The methodology proposed can be utilized for identifying critical metro stations a priori and thus achieving a more efficient planning, considering metro disruptions.(c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Sun, Peng GangWu, XunlianQuan, YiningMiao, Qiguang...
14页查看更多>>摘要：Communities in social networks represent social circles, and people within same circles often highly interact and strongly influence one another, and hence individual behaviors percolate quickly, and tend to invoke a resonance phenomenon, i.e., collective behaviors. Nowadays, boundaries between circles are more and more indistinct because people probably involve more than one circle. This paper develops an influence percolation method (IPM) for identifying overlapping communities. In IPM, we first determine the influenced area of each node through many times of simulations for influence percolation so that activated nodes with a frequency belong to the area, and those as clusters can initialize a cover for a network. Then, the cover is further refined through three stages, i.e., filtration, absorbtion and selection to determine communities. We systematically evaluate our method on plenty of artificial networks with various network characteristics as well as real-world networks. The results indicate that our method achieves the best performance on the networks with stronger overlaps, e.g., up to 50% overlapping nodes, each of which belongs to more than four communities, compared with the state of the art algorithms. An interesting finding is that two nodes tend to be indivisible if one is a seed, influence percolates into the other exceeding a certain frequency, and this threshold is mainly determined by the networks' density. (c) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
