Ning, DiChen, JuanJiang, Meiying
12页查看更多>>摘要：This article mainly investigates pinning impulsive synchronization of the two-layer delayed network with unidirectional interlayer coupling and transmission delays. The intralayer topologies of different layers are independent each other, and the nodal dynamics in each layer are different as well. Using the Lyapunov stability theory and the auxiliary system method, several pinning impulsive strategies for guaranteeing interlayer generalized synchronization of two-layer delayed networks are put forward. When the impulse interval is fixed as a constant value, the smallest number of pinned nodes and largest impulse interval needed theoretically for ensuring interlayer generalized synchronization are obtained. Specially, when the impulse strengths, the impulse interval, and the number of pinned nodes are respectively set to constant values independent of the impulsive instant, the influences of these parameters on the synchronized region are further discussed. Furthermore, it is found that the relatively small interlayer transmission delay is beneficial to interlayer generalized synchronization. Numerical simulations are presented to verify the effectiveness and correctness of the proposed schemes. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:
NSTL
Elsevier
Feng, JiaojiaoWang, JinghongLi, JiaLi, Jiachen...
15页查看更多>>摘要：With the increasing density of people in buildings and complexity of building structures, pedestrians will inevitably be affected by social relationships during vertical evacuation when an earthquake occurs. However, empirical data on the evacuation of pedestrians on stairs in small groups are lacking in the current research. This study aims to analyze and discuss the impact of social relations between pedestrians on the evacuation efficiency and individual behavior after an earthquake. Field experiments were conducted in a university campus with 84 volunteers, and the variables considered were social relationships, speed, and obstacles. After tracking the pedestrian trajectory using the PeTrack software, the interpersonal angle and distance, average speed, time-space relationship, step frequency, offset angle, and pedestrian lateral oscillation were calculated and analyzed. The results show that pedestrian groups with close social relationships have smaller interpersonal angles and distances, and their speed of evacuation is faster than that of pedestrian groups with unfamiliar social relationships. A subjective increase in pedestrian speed increases the evacuation speed and step frequency, whereas road obstacles produce the opposite results. The findings of this study can provide basic data for modeling the vertical evacuation of pedestrian groups as well as a reference for studying the complex characteristics of pedestrian movement during earthquakes. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Shoreh, A. A-HKuznetsov, N., VMokaev, T. N.
16页查看更多>>摘要：The aim of this report is to investigate an adaptive synchronization (AS) for the general class of complex hyperchaotic models with unknown parameters and a new algorithm to achieve this type of synchronization is proposed. Owing to the intricacy behavior of hyperchaotic models that could be effective in secure communications, the special control based on adaptive laws of parameters is constructed analytically, and the corresponding simulated results are performed to validate the algorithm's accuracy. The complex Rabinovich model is utilized as an enticing example to examine the proposed synchronization technique. A strategy for secure communication improving the overall cryptosystem is proposed; the scheme is designed to split the message and insert some bit of information signal into the modulation parameters and the other bit into the transmitter system's states, making decryption by intruders more difficult. Meanwhile, adaptive techniques and a decryption function on the receiver side can accurately retrieve the message. Different types of encoded messages are examined for testing the robustness of the proposed scheme (e.g., text and gray images with diverse scales of white Gaussian noise). (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Zhang, PanpanWang, TiandongYan, Jun
14页查看更多>>摘要：PageRank (PR) is a fundamental tool for assessing the relative importance of the nodes in a network. In this paper, we propose a measure, weighted PageRank (WPR), extended from the classical PR for weighted, directed networks with possible non-uniform node-specific information that is dependent or independent of network structure. A tuning parameter leveraging node degree and strength is introduced. An efficient algorithm based on R program has been developed for computing WPR in large-scale networks. We have tested the proposed WPR on widely used simulated network models, and found it outperformed the classical PR. Additionally, we apply the proposed WPR to the real network data generated from World Input-Output Tables as an example, and have seen the results that are consistent with the global economic trends, which renders it a preferred measure in the analysis. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Jiang, Jiu-LeiFang, HuiLi, Sheng-QingLi, Wei-Min...
13页查看更多>>摘要：The identification of important nodes in a temporal network is of great significance for the analysis and control of the information dissemination process. In this work, the multi-layer coupled network analysis method is employed to identify important nodes in a temporal network. First, to overcome the problem of a fixed constant being unable to reflect differences in the inter-layer coupling relationship, and by combining a node's own neighbors and common neighbors of nodes in two-time layers, a new Enhanced Similarity Index (ESI) is proposed to measure the inter-layer coupling relationship. Secondly, the attenuation factor is introduced to more accurately describe the inter-layer coupling relationship. Finally, an Attenuation-Based Supra-Adjacency Matrix (ASAM) temporal network modeling method based on the attenuation of the inter-layer coupling strength is proposed. The importance of nodes in the temporal network is evaluated by calculating the eigenvector centrality of the nodes in each time layer in the temporal network. It is found that after deleting a certain percentage of the important nodes identified by the ASAM method, the temporal Largest Connected Component (LCC) of the network becomes smaller, and the network performance is improved as compared with the SAM and SSAM methods. The results indicate that the important nodes identified by the ASAM are at the core of the network and have a greater impact on the network structure and functions. This demonstrates that the proposed ASAM model can more effectively identify important nodes in the temporal network, and has significant application value in this research field. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Chen, WenhaoLi, JichaoJiang, JiangChen, Gang...
13页查看更多>>摘要：The problem of network disintegration is one of the core topics in the field of network science. Currently, most of the existing research is based on homogeneous and single layer networks of nodes. However, the various components of complex systems in the real world are often interdependent, and the cost of attacking different units is diverse, causing the traditional network disintegration method to lack good applicability. This paper establishes a weighted interdependent network (WIN) model, and based on this, a WIN disintegration strategy based on Q-learning is proposed. First, the network nodes are divided into multiple node sets according to the dependencies between the nodes, and the state and action space of Q-learning are determined. Next, the disintegration cost constraints and Q-learning parameters are defined to perform iterative learning. Then, the optimal network disintegration strategy is calculated according to the iterative Q-table. The results show that when the cost sensitivity factor (p) is fixed, DSQ can maintain good results in disintegrating different types of networks under different cost constraints, while the baseline methods have difficulty guaranteeing the disintegration effect in the face of different types of networks. Furthermore, we perform a sensitivity analysis on the p value and find that the effect of most of the baseline methods worsens as the p value increases, while DSQ maintains a good effect. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Zheng, PengjunHuang, ZhaodongChien, StevenZhu, Wei...
15页查看更多>>摘要：Scheduling the wheel inspection is critical to ensure the safety and sustainability of urban rail transit (URT) operation. The common wheel inspection is conducted on a fixed-interval basis, determined by empirical practices. However, the relationship between the distance of wheel travel and wheel wearing condition subject to track alignment is uncertain. A Bayesian model is developed to schedule the timings of wheel inspections which meet the safety thresholds for sustainable train operation. In the case study, the historic wheel inspection data of a real-world URT line was collected and analyzed, which indicates that wheel reprofiling follows a Weibull distribution. The suggested wheel inspection plan by the proposed model is compared with fix-interval inspection. The results show that the inspection frequency can be significantly reduced before yielding 180,900 km wheel travel, which satisfies the wheel reliability as 0.95. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Manimaran, P.Panigrahi, Prasanta K.Pal, Mayukha
17页查看更多>>摘要：It is well known, the Electroencephalogram (EEG) signals are non-stationary signals which helps us in understanding the complex brain dynamics, cognitive processes, etc. In this paper, we have analysed the healthy and Epilepsy seizure subjects through continuous wavelet transform using Morlet wavelet function. We identify the key differences between healthy and epilepsy seizure EEG signals' low frequency periodic modulations and transient time varying patterns. Persistent intermixing of alpha and beta waves is found to be a key characteristic feature of the patients. The frequency intermixing is completely absent in signals from the hippocampal formation of the opposite hemisphere of the brain for the patients without seizure, akin to the healthy subjects. Our study further reveals dominance of frequency broadened gamma waves for seizure patients as compared to the low frequency regular alpha and beta waves for the healthy subjects. The time-frequency localization of wavelet transform clearly shows transfer of power to high frequency beta waves from the low frequency alpha waves in the signals of the epileptogenic zone of the patients. The observed frequency intermixing, reported here, is analogous to the bi-stability behaviour of dynamical systems. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Yin, YongChen, JinquLiu, JiePeng, Qiyuan...
16页查看更多>>摘要：Existing studies seldom consider network structure and passenger travel demand jointly, and certain impractical assumptions are generally considered for assessing the resilience of an urban rail transit (URT) network. To address the abovementioned limitations, we have proposed a performance indicator called the demand-impedance (DI) indicator, in which demand and impedance are reflected by passenger trips and travel time. By considering effective travel paths (ETPs) and passengers' path choice behavior, we have proposed a node centrality called effective path betweenness (EPB) by modifying the betweenness centrality (BC) to evaluate the importance of stations. The performance curve of a URT network during the attack and repair processes is depicted using the DI indicator, and a modified resilience metric is formulated by referring to the resilience triangle. The model application in the Chengdu subway network demonstrates that the correlation coefficient between the EPB and BC of stations is 0.901, which indicates that stations with a higher EPB are inclined to have a higher BC. The Chengdu subway network demonstrates a higher resilience under random disturbances than it does under malicious disturbances. Disturbance duration, passengers' tolerance time, and rescue ability on the Chengdu subway network significantly affect its resilience. Several practical suggestions involving the management of disturbances, shortening the emergency response time, providing passenger services, and improving emergency rescue ability are provided for managing the Chengdu subway system under disturbances. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
