Wu, YanqiZhang, JunfengLin, Peng
14页查看更多>>摘要：Faults of components may deteriorate the system performances and stochastic cyber attacks may destroy the state measurements of systems and obstruct control commands. This paper proposes a non-fragile hybrid-triggered control design for networked positive switched systems to deal with the faults and cyber attacks. Bernoulli distribution is employed for describing cyber attacks. Based on the property of cyber attacks, a hybrid-triggered strategy is introduced. The corresponding hybrid-triggered mechanism consists of time- and event-triggered schemes. The event-triggering condition is established in a linear form. By combining a matrix decomposition approach and switched co-positive Lyapunov functions, a non-fragile hybrid-triggered controller is designed for positive switched systems with actuator faults. Then, a stochastic hybrid control strategy is used for the systems subject to stochastic cyber attacks. Under the hybrid-triggered controller, the systems can resist the risk from the attacks and actuator faults. Meanwhile, the risk of communication congestion from the limited bandwidth is reduced by virtue of the hybrid-triggered control strategy. All the presented conditions can be solved via linear programming. Finally, two examples are given to verify the effectiveness of the designed controller. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:
NSTL
Elsevier
Liu, WeiChang, ZhenhaiJia, CaiyanZheng, Yimei...
14页查看更多>>摘要：A challenge of community detection in attributed networks is how we can design an effective and efficient clustering method that can not only discover a wide of structure types but also have good community semantic annotations. To this end, by sharing the latent position of nodes, a mathematically principled model (named GNAN) that fuses topological information and node-attribute information is developed. Using the expectation-maximization algorithm, the latent position of each node and the model parameters are learned. The new model detects communities more accurately than can be done with topology information alone. And a case study is provided to show the ability of our model in the semantic interpretability of communities. In detail, firstly, inspired by the idea of NMM (Newman's Mixture Models), a group of parameters that characterize the link behaviors of nodes is introduced into the topological model. In the probabilistic sense, nodes with the same link pattern form a community. Therefore, the combined model can generate not only traditional communities, i.e., groupings of nodes with dense internal connections and sparse external ones, but also a range of other types of structure in networks, such as bipartite structure, core-periphery structure, and their mixture structure, which are collectively referred to as generalized structure. Secondly, based on the homogeneity assumption, another group of parameters describing the distribution of attributes in a community is introduced into the attributed model. Under the control of these parameters, the united model can generate different attributes according to the probability, and automatically discover the critical attributes of the community. Finally, experiments on both synthetic and real-world networks with various network structures show that the new model can detect communities more accurately than the related state-of-the-art models. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Wang, JingWang, ChunyangXiao, LidongMa, Haijun...
9页查看更多>>摘要：The diffusion of passing over the saddle point of a three-dimensional quadric potential energy surface was studied by analytically solving a set of coupled generalized Langevin equations. An accurate expression of the passing probability was obtained. The effect of the coupling between different degrees of freedom which is represented by the off diagonal elements of the inertia, friction and potential-curvature tensors was analyzed in detail. It is found that some of the coupling have great influence on the diffusion process, while others not. The combination of them results in an optimal injecting direction of the diffusing particles, revealing an optimal three-dimensional diffusion path. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Fu, XinXu, ChengyaoLiu, YutengChen, Chi-Hua...
17页查看更多>>摘要：It is of great reference significance to exploring spatial dependence of urban traffic activities and researching internal causes of regional traffic state changes for road network optimization and residents' travel behavior analysis. Based on trajectory data of taxis in Ningbo city of China, this study calculates average driving speed of taxis in different blocks during characteristic period and generates the global Moran's I and the LISA clustering diagram. On this basis, the spatial clustering characteristics of congestion on working days and non-working days are analyzed. Furthermore, in order to further characterize the changes of congestion from the perspective of spatial migration, a method of measuring geometric displacement is adopted to describe spatio-temporal migration trend of traffic states, four indicators designed to identify urban frequently congested areas, including migration direction, angle, distance, and low-value area. The results show that the high-clustering area are located urban fringe and the low-clustering area are located at geometric center of major urban areas. Spatial-temporal migration law of low-value areas in city-center is obvious. Difference between trend is compared with non-working days, the offset and azimuth of low-value area in downtown on working days are even bigger. The accurate capture of the characteristics of congestion space migration at the urban scale will help to formulate more targeted congestion management strategies. (C) 2021 Published by Elsevier B.V.
原文链接:- NSTL
- Elsevier
Pacheco-Martinez, H. A.Peraza-Mues, G.Penunuri, F.Carvente, O....
8页查看更多>>摘要：Kinetic energy is transferred through collisions to the millimeter particles that are in contact with the base of a vertically vibrated 3D container. In the early stages of a vibrational annealing process where the dimensionless acceleration is kept constant, the spontaneous appearance and disappearance of unstable clusters of ordered particles near the bottom surface of the container is observed. In later stages of this vibra-tional annealing process, the precursor nuclei stabilize becoming stable crystal seeds which resembles a thermal phase transition. Molecular Dynamics simulations based on these experimental observations are used to study the unstable-stable transition. The Ornstein-Zernike equation using the Percus-Yevick closure is applied to the stages be-fore and after the observation of the stable crystal seeds in order to extract the effective potentials associated with the phase transition. Both the radial distribution function and the effective potentials show a clear correspondence of the spatial correlation as the crystallization phase begins to appear. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Tilfani, OussamaKristoufek, LadislavFerreira, PauloBoukfaoui, My Youssef El...
16页查看更多>>摘要：Heterogeneity of effects between economic variables has been a frequently discussed topic for many years now. However, the estimation of such scale-dependent effects has proved challenging. Here, we propose a multivariate multiscale regression approach based on the combination of detrended fluctuation analysis and detrended cross-correlation analysis, but the idea can be easily translated into other time and frequency domain frameworks. As illustrations, we pick two classic economic models - the Taylor's rule and the money demand function for the USA and Japan - and we uncover evident scale-dependence in the individual effects not visible by the simple regression tools. Importantly, the proposed framework can be used in any discipline where studying the effects at various scales is of interest. Further applications are thus certainly at hand. (C) 2021 Published by Elsevier B.V.
原文链接:- NSTL
- Elsevier
Jindal, A.Bhatia, N.Kolomeisky, A. B.Gupta, A. K....
16页查看更多>>摘要：Motor proteins or biological molecular motors belong to a class of active enzymatic molecules that are responsible for transport and force generation in living cells. They typically operate in large teams and individual protein molecules interact with each other while moving along linear cytoskeleton filaments. Moreover, during their transportation the motors can reversibly dissociate from their tracks. Motivated by these observations, we propose a one dimensional totally asymmetric simple exclusion model for interacting particles that are allowed to reversibly dissociate/associate from a particular site far away from the system boundaries. A theoretical analysis of the model is based on cluster mean-field approximation that allows for a comprehensive description of the stationary properties in the system. It is found that the topology and nature of stationary phase diagrams for varying association/dissociation rates strongly depend on the sign and strength of interactions. Extensive Monte Carlo simulations are implemented to test our theoretical predictions. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
