Shang, RonghuaZhang, WeitongZhang, JingwenFeng, Jie...
15页查看更多>>摘要：Local community detection is to discover local community where the seed is located. Most algorithms extend local community by edge information, without considering high-order information in network. The high-order information which is also named as network motif is very important for forming a community. There are also methods that focus on higher-order structure but ignore the sparsely connected edges, resulting in that fail to extend some edge points. In addition, when the seed is the edge node, how to choose the first node to integrate into the community will determine whether the community expands in a right direction. Therefore, a local community detection algorithm based on higher-order structure and edge information (HSEI) is proposed. Firstly, different ways selecting the first node joining local community according to the motif degree of seed are used. Secondly, a new motif-based modularity function is proposed to extend local community, so that the extended community will be connected more tightly. A new motif-based community central node is defined to help extend the central part of local community. For the edge of community and the area with sparse connections, edge information is used to mine the membership strength between nodes and communities, so as to obtain more complete local community members. Compared with five state-of-the-art algorithms, the proposed method achieves better results on the generated networks with different parameters and six real networks. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:
NSTL
Elsevier
Borsche, RaulKlar, AxelZanella, Mattia
17页查看更多>>摘要：We study the application of a recently introduced hierarchical description of traffic flow control by driver-assist vehicles to include lane changing dynamics. Lane-dependent feedback control strategies are implemented at the level of vehicles and the aggregate trends are studied by means of Boltzmann-type equations determining three different hydrodynamics based on the lane switching frequency. System of first order macroscopic equations describing the evolution of densities along the lanes are then consistently determined through a suitable closure strategy. Numerical examples are then presented to illustrate the features of the proposed hierarchical approach. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Rehman, Mobeen UrAhmad, NasirVo, Xuan Vinh
19页查看更多>>摘要：Energy market is witnessed to have high integration with international equity markets ranging from traditional assets to newly introduced asset classes, especially after increased financialization during the last decade. We compare the connectedness between international oil market and socially responsible stocks before and during the recent pandemic COVID-19. Socially responsible stocks are increasingly becoming popular because of their social cause as well as less integration with other assets, however since their acceptance, have never been tested against the contagion phenomena. We utilize daily data ranging from March 2016 to June 2020 to investigate integration and spillover before and during COVID-19 period. Our methodological framework includes asymmetric multifractal detrended approach, network connectedness and conditional diversification measures. Our sampled SRI funds exhibit multifractal behaviour and share bidirectional spillover with oil. The SRI funds demonstrate good hedging abilities during normal and COVID-19 period and for similar reason are suggested as optimal asset together with oil futures in a portfolio. Furthermore, these SRI funds yield optimal diversification benefits with oil futures under bearish market conditions. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Thomas, Gilberto L.Fortuna, IsmaelPerrone, Gabriel C.Graner, Francois...
12页查看更多>>摘要：Cell migration plays essential roles in development, wound healing, diseases, and in the maintenance of a complex body. Experiments in collective cell migration generally measure quantities such as cell displacement and velocity. The observed short-time diffusion regime for mean square displacement in single-cell migration experiments on flat surfaces calls into question the definition of cell velocity and the measurement protocol. Theoretical results in stochastic modeling for single-cell migration have shown that this fast diffusive regime is explained by a white noise acting on displacement on the direction perpendicular to the migrating cell polarization axis (not on velocity). The prediction is that only the component of velocity parallel to the polarization axis is a well-defined quantity, with a robust measurement protocol. Here, we ask whether we can find a definition of a migrating-cell polarization that is able to predict the cell's subsequent displacement, based on measurements of its shape. Supported by experimental evidence that cell nucleus lags behind the cell center of mass in a migrating cell, we propose a robust parametrization for cell migration where the distance between cell nucleus and the cell's center of mass defines cell shape polarization. We tested the proposed methods by applying to a simulation model for three-dimensional cells performed in the CompuCell3D environment, previously shown to reproduce biological cells kinematics migrating on a flat surface. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Ding, HengQian, YuZheng, XiaoyanBai, Haijian...
21页查看更多>>摘要：Homogeneous traffic density is the precondition of macroscopic fundamental diagrams (MFDs) that exist in a regional road network. However, traffic density may be transformed by the effects of traffic flow transmission and parking generation in a dynamic system. Once the homogeneous and uniform traffic density is changed, the shape of the MFD curve is likely affected, and thus, the output efficiency of the road network decreases. Based on the existing research of the aggregation evaluation model of parking generation in a regional road network, the study analyses the relationship between the variation in parking generation aggregation and the variation ratio in the trip completion flow of the network through further analysis. On this basis, a dynamic parking charge-perimeter control coupled (DPCPCC) method in a macro road network is proposed to balance the traffic flow density in a dynamically congested sub-region that exists in multiple public parking lots and to improve the efficiency of traffic flow for the entire road network. Furthermore, the method optimizes the entire parking charge rate of each MFD sub-region, aiming for the lowest generalized cost, reduces the delay time of the road network by adjusting the perimeter control rate, and changes the traffic aggregation index by dynamic charging strategies to improve the congested sub-region outflow efficiency. Finally, the regional road network in the Binhu New District of Hefei is taken as an example, and three control scenarios consisting of the DPCPCC method, the static parking charge-perimeter control coupled (SPCPCC) method, and the proportional-integral (PI) method are analysed and compared. According to the analysis of the relationship between the parking generation aggregation index and MFD changes and the application of this relationship to verify the regional road network dynamic charging model, the results reveal that the DPCPCC method can reduce the marginal social cost and improve the operation efficiency of the road network compared with the SPCPCC and PI control methods. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Safaeesirat, AminMoghimi-Araghi, Saman
14页查看更多>>摘要：It has been observed experimentally that the neural tissues generate highly variable and scale-free distributed outbursts of activity both in vivo and in vitro. Understanding whether these heterogeneous patterns of activity come from operation of the brain at the edge of a phase transition is an interesting possibility. Therefore, constructing simple model that exhibits such behavior is of great interest. Additionally, the presence of both critical behavior and oscillatory patterns in brain dynamics is a very interesting phenomenon: Oscillatory patterns define a temporal scale, while criticality imposes scale-free characteristics. In this paper, we consider a model for a neuronal population where each neuron is modeled by an over-damped rotator. We find that there are some regions in the space of external parameters where the system shows synchronization. Interestingly, just at the transition point, the avalanche statistics show power-law behavior. Also, in the case of small systems, the (partial) synchronization and power-law behavior can occur simultaneously. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Zafer, Ayturk HamdiAkguc, Gursoy B.
10页查看更多>>摘要：Active spherical particles in a water film form aggregate on two neighboring water bubbles, where one of the bubbles' half surface is heated by a laser source, creating a convective flow field. The specific geometry is similar to the experimental setup we used for colloidal particles (Ilday et al., 2017). Water flow is considered reactive during the simulation due to changing flow field, as well as temperature field. A feedback interaction is introduced, which may be due to the concentration of particles in some region of fluid, effectively a time-dependent accumulation. We show the effect of attractive and repulsive feedback forces, and observe, under attractive feedback, the formation of patches of aggregate distributed all over the space, and eventually a greater aggregate formation on the bubble surface. Reactive flow effects, with and without feedback effects, are analyzed, by examining the pair correlation and mean square displacement indicators, as well as the single-particle trajectories. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Lu, XinbiaoZhang, ChiQin, Buzhi
9页查看更多>>摘要：In the original Vicsek model, the motion direction of a particle is updated according to its all neighbors' mean direction. However, the convergence speed of the system is usually low due to the too many interacting particles, which is especially true when the particle densities are high. Therefore, a new rule is proposed to make the motion direction of all particles reach consensus more quickly. The Euclidean distances between its neighbors and the particle are arranged from far to near, and we only take the average direction of the farthest part neighbors as the motion direction of the particle at the next moment, which replace the original Vicsek model. The simulation results demonstrate that the improved Vicsek model has faster convergence speed than the original Vicsek model under different particle number and different system parameters. Furthermore, the convergence speed will reach the fastest with an appropriate number of neighbors according to the new rule, and the improved model is much easier to obtain consensus even for the noise disturbance. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
