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Practical Timing Synchronization for Network Dynamics in Large Machine-to-Machine Networks
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作者 Lei Gu Shih-Chun Lin 《China Communications》 SCIE CSCD 2016年第10期160-168,共9页
Efficient multi-machine cooperation and network dynamics still remain open that jeopardize great applications in largescale machine-to-machine(M2M) networks. Among all possible machine cooperation controls, to synchro... Efficient multi-machine cooperation and network dynamics still remain open that jeopardize great applications in largescale machine-to-machine(M2M) networks. Among all possible machine cooperation controls, to synchronize tremendous machines in a timing-efficient brings one of the greatest challenge and serves as the foundation for any other network control policies. In this paper, we propose a linear-time synchronization protocol in large M2M networks. Specifically, a closed-form of synchronization rate is provided by developing the statistical bounds of the second smallest eigenvalue of the graph Laplacian matrix. These bounds enable the efficient control of network dynamics, facilitating the timing synchronization in networks. Through a practical study in Metropolis, simulation results confirm our theoretical analysis and provide effective selection of wireless technologies, including Zigbee, Wi-Fi, and cellular systems, with respect to the deployed density of machines. Therefore, this paper successfully demonstrates a practical timing synchronization, to make a breakthrough of network dynamic control in real-world machine systems, such as Internet of Things. 展开更多
关键词 timing synchronization network dynamics graph Laplacian matrix distributed protocol internet of things(IoTs) machine-to-machine(M2M) communications
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Target layer state estimation in multi-layer complex dynamical networks considering nonlinear node dynamics
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作者 吴亚勇 王欣伟 蒋国平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期245-252,共8页
In many engineering networks, only a part of target state variables are required to be estimated.On the other hand,multi-layer complex network exists widely in practical situations.In this paper, the state estimation ... In many engineering networks, only a part of target state variables are required to be estimated.On the other hand,multi-layer complex network exists widely in practical situations.In this paper, the state estimation of target state variables in multi-layer complex dynamical networks with nonlinear node dynamics is studied.A suitable functional state observer is constructed with the limited measurement.The parameters of the designed functional observer are obtained from the algebraic method and the stability of the functional observer is proven by the Lyapunov theorem.Some necessary conditions that need to be satisfied for the design of the functional state observer are obtained.Different from previous studies, in the multi-layer complex dynamical network with nonlinear node dynamics, the proposed method can estimate the state of target variables on some layers directly instead of estimating all the individual states.Thus, it can greatly reduce the placement of observers and computational cost.Numerical simulations with the three-layer complex dynamical network composed of three-dimensional nonlinear dynamical nodes are developed to verify the effectiveness of the method. 展开更多
关键词 multi-layer complex dynamical network nonlinear node dynamics target state estimation functional state observer
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Network evolution driven by dynamics applied to graph coloring
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作者 吴建设 李力光 +2 位作者 王晓华 于昕 焦李成 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期262-267,共6页
An evolutionary network driven by dynamics is studied and applied to the graph coloring problem. From an initial structure, both the topology and the coupling weights evolve according to the dynamics. On the other han... An evolutionary network driven by dynamics is studied and applied to the graph coloring problem. From an initial structure, both the topology and the coupling weights evolve according to the dynamics. On the other hand, the dynamics of the network are determined by the topology and the coupling weights, so an interesting structure-dynamics co-evolutionary scheme appears. By providing two evolutionary strategies, a network described by the complement of a graph will evolve into several clusters of nodes according to their dynamics. The nodes in each cluster can be assigned the same color and nodes in different clusters assigned different colors. In this way, a co-evolution phenomenon is applied to the graph coloring problem. The proposed scheme is tested on several benchmark graphs for graph coloring. 展开更多
关键词 network dynamics evolution of network evolutionary strategies graph coloring problem
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Image super‐resolution via dynamic network 被引量:1
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作者 Chunwei Tian Xuanyu Zhang +2 位作者 Qi Zhang Mingming Yang Zhaojie Ju 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第4期837-849,共13页
Convolutional neural networks depend on deep network architectures to extract accurate information for image super‐resolution.However,obtained information of these con-volutional neural networks cannot completely exp... Convolutional neural networks depend on deep network architectures to extract accurate information for image super‐resolution.However,obtained information of these con-volutional neural networks cannot completely express predicted high‐quality images for complex scenes.A dynamic network for image super‐resolution(DSRNet)is presented,which contains a residual enhancement block,wide enhancement block,feature refine-ment block and construction block.The residual enhancement block is composed of a residual enhanced architecture to facilitate hierarchical features for image super‐resolution.To enhance robustness of obtained super‐resolution model for complex scenes,a wide enhancement block achieves a dynamic architecture to learn more robust information to enhance applicability of an obtained super‐resolution model for varying scenes.To prevent interference of components in a wide enhancement block,a refine-ment block utilises a stacked architecture to accurately learn obtained features.Also,a residual learning operation is embedded in the refinement block to prevent long‐term dependency problem.Finally,a construction block is responsible for reconstructing high‐quality images.Designed heterogeneous architecture can not only facilitate richer structural information,but also be lightweight,which is suitable for mobile digital devices.Experimental results show that our method is more competitive in terms of performance,recovering time of image super‐resolution and complexity.The code of DSRNet can be obtained at https://github.com/hellloxiaotian/DSRNet. 展开更多
关键词 CNN dynamic network image super‐resolution lightweight network
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Influencer identification of dynamical networks based on an information entropy dimension reduction method
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作者 段东立 纪思源 袁紫薇 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期375-384,共10页
Identifying critical nodes or sets in large-scale networks is a fundamental scientific problem and one of the key research directions in the fields of data mining and network science when implementing network attacks,... Identifying critical nodes or sets in large-scale networks is a fundamental scientific problem and one of the key research directions in the fields of data mining and network science when implementing network attacks, defense, repair and control.Traditional methods usually begin from the centrality, node location or the impact on the largest connected component after node destruction, mainly based on the network structure.However, these algorithms do not consider network state changes.We applied a model that combines a random connectivity matrix and minimal low-dimensional structures to represent network connectivity.By using mean field theory and information entropy to calculate node activity,we calculated the overlap between the random parts and fixed low-dimensional parts to quantify the influence of node impact on network state changes and ranked them by importance.We applied this algorithm and the proposed importance algorithm to the overall analysis and stratified analysis of the C.elegans neural network.We observed a change in the critical entropy of the network state and by utilizing the proposed method we can calculate the nodes that indirectly affect muscle cells through neural layers. 展开更多
关键词 dynamical networks network influencer low-dimensional dynamics network disintegration
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Spontaneous Recovery in Directed Dynamical Networks
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作者 Xueming Liu Xian Yan H.Eugene Stanley 《Engineering》 SCIE EI CAS CSCD 2024年第6期208-214,共7页
Complex networked systems,which range from biological systems in the natural world to infrastructure systems in the human-made world,can exhibit spontaneous recovery after a failure;for example,a brain may spontaneous... Complex networked systems,which range from biological systems in the natural world to infrastructure systems in the human-made world,can exhibit spontaneous recovery after a failure;for example,a brain may spontaneously return to normal after a seizure,and traffic flow can become smooth again after a jam.Previous studies on the spontaneous recovery of dynamical networks have been limited to undirected networks.However,most real-world networks are directed.To fill this gap,we build a model in which nodes may alternately fail and recover,and we develop a theoretical tool to analyze the recovery properties of directed dynamical networks.We find that the tool can accurately predict the final fraction of active nodes,and the prediction accuracy decreases as the fraction of bidirectional links in the network increases,which emphasizes the importance of directionality in network dynamics.Due to different initial states,directed dynamical networks may show alternative stable states under the same control parameter,exhibiting hysteresis behavior.In addition,for networks with finite sizes,the fraction of active nodes may jump back and forth between high and low states,mimicking repetitive failure-recovery processes.These findings could help clarify the system recovery mechanism and enable better design of networked systems with high resilience. 展开更多
关键词 network resilience Directed dynamical networks Spontaneous recovery
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FREQUENCY-DIFFERENTIATED BRAIN NETWORK DYNAMICS IN REAL WORDS AND PSEUDOWORDS PERCEPTION
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作者 Guo Taiyang ZHAO Bin +2 位作者 ZHANG Gaoyan Dang Jianwu UNOKI Masashi 《中国语音学报》 2020年第1期114-122,共9页
Brain mechanisms of lexical-semantic processing have been well researched using electroencephalography(EEG)technique with high temporal resolution.However,the detailed brain dynamics regarding spatial connectivity and... Brain mechanisms of lexical-semantic processing have been well researched using electroencephalography(EEG)technique with high temporal resolution.However,the detailed brain dynamics regarding spatial connectivity and the spectral characteristics remain to be clarified.For this reason,this study performed frequency-specific effective connectivity analysis for the EEG recordings during the processing of real and pseudowords.In addition,we introduced f MRI-based network templates into a representational similarity analysis to compare the functional differences between real and pseudowords in different frequency bands.Our results revealed that real words could rapidly activate the brain network for speech perception and complete its comprehension with efficiency,especially when the first syllable of the real word has clear categorical features.In contrast,the pseudowords were delayed in the initiation of speech perception and required a longer time span to retrieve its meaning.The frequency-specific analysis showed that the theta,alpha,and beta rhythms contribute more to semantic processing than the gamma oscillation.These results showed that semantic processing is frequency-specific and time-dependent on the word categories. 展开更多
关键词 Speech perception EEG Brain network Dynamic brain network Frequency specified brain network
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Study on Ecological Change Remote Sensing Monitoring Method Based on Elman Dynamic Recurrent Neural Network
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作者 Zhen Chen Yiyang Zheng 《Journal of Geoscience and Environment Protection》 2024年第4期31-44,共14页
In this paper, Hailin City of Heilongjiang Province, China is taken as the research area. As an important city in Heilongjiang Province, China, the sustainable development of its ecological environment is related to t... In this paper, Hailin City of Heilongjiang Province, China is taken as the research area. As an important city in Heilongjiang Province, China, the sustainable development of its ecological environment is related to the opening up, economic prosperity and social stability of Northeast China. In this paper, the remote sensing ecological index (RSEI) of Hailin City in recent 20 years was calculated by using Landsat 5/8/9 series satellite images, and the temporal and spatial changes of the ecological environment in Hailin City were further analyzed and the influencing factors were discussed. From 2003 to 2023, the mean value of RSEI in Hailin City decreased and increased, and the ecological environment decreased slightly as a whole. RSEI declined most significantly from 2003 to 2008, and it increased from 2008 to 2013, decreased from 2013 to 2018, and increased from 2018 to 2023 again, with higher RSEI value in the south and lower RSEI value in the northwest. It is suggested to appropriately increase vegetation coverage in the northwest to improve ecological quality. As a result, the predicted value of Elman dynamic recurrent neural network model is consistent with the change trend of the mean value, and the prediction error converges quickly, which can accurately predict the ecological environment quality in the future study area. 展开更多
关键词 Remote Sensing Ecological Index Long Time Series Space-Time Change Elman Dynamic Recurrent Neural network
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UltraStar:A Lightweight Simulator of Ultra-Dense LEO Satellite Constellation Networking for 6G 被引量:3
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作者 Xiaoyu Liu Ting Ma +3 位作者 Zhixuan Tang Xiaohan Qin Haibo Zhou Xuemin(Sherman)Shen 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第3期632-645,共14页
The mega-constellation network has gained significant attention recently due to its great potential in providing ubiquitous and high-capacity connectivity in sixth-generation(6G)wireless communication systems.However,... The mega-constellation network has gained significant attention recently due to its great potential in providing ubiquitous and high-capacity connectivity in sixth-generation(6G)wireless communication systems.However,the high dynamics of network topology and large scale of mega-constellation pose new challenges to the constellation simulation and performance evaluation.In this paper,we introduce UltraStar,a lightweight network simulator,which aims to facilitate the complicated simulation for the emerging mega-constellation of unprecedented scale.Particularly,a systematic and extensible architecture is proposed,where the joint requirement for network simulation,quantitative evaluation,data statistics and visualization is fully considered.For characterizing the network,we make lightweight abstractions of physical entities and models,which contain basic representatives of networking nodes,structures and protocol stacks.Then,to consider the high dynamics of Walker constellations,we give a two-stage topology maintenance method for constellation initialization and orbit prediction.Further,based on the discrete event simulation(DES)theory,a new set of discrete events is specifically designed for basic network processes,so as to maintain network state changes over time.Finally,taking the first-generation Starlink of 11927 low earth orbit(LEO)satellites as an example,we use UltraStar to fully evaluate its network performance for different deployment stages,such as characteristics of constellation topology,performance of end-to-end service and effects of network-wide traffic interaction.The simulation results not only demonstrate its superior performance,but also verify the effectiveness of UltraStar. 展开更多
关键词 Discrete event simulation(DES) mega-constellation network dynamics performance evaluation simulation architecture design
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Epidemic propagation on adaptive coevolutionary networks with preferential local-world reconnecting strategy 被引量:2
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作者 宋玉蓉 蒋国平 巩永旺 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第4期63-69,共7页
In the propagation of an epidemic in a population, individuals adaptively adjust their behavior to avoid the risk of an epidemic. Differently from existing studies where new links are established randomly, a local lin... In the propagation of an epidemic in a population, individuals adaptively adjust their behavior to avoid the risk of an epidemic. Differently from existing studies where new links are established randomly, a local link is established preferentially in this paper. We propose a new preferentially reconnecting edge strategy depending on spatial distance (PR- SD). For the PR-SD strategy, the new link is established at random with probability p and in a shortest distance with the probability 1 p. We establish the epidemic model on an adaptive network using Cellular Automata, and demonstrate the effectiveness of the proposed model by numerical simulations. The results show that the smaller the value of parameter p, the more difficult the epidemic spread is. The PR-SD strategy breaks long-range links and establishes as many short-range links as possible, which causes the network efficiency to decrease quickly and the propagation of the epidemic is restrained effectively. 展开更多
关键词 adaptive networks epidemic dynamics network dynamics cellular automata local-world reconnecting mechanism
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The effects of degree correlations on network topologies and robustness 被引量:1
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作者 赵静 陶林 +3 位作者 俞鸿 骆建华 曹志伟 李亦学 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第12期3571-3580,共10页
Complex networks have been applied to model numerous interactive nonlinear systems in the real world. Knowledge about network topology is crucial to an understanding of the function, performance and evolution of compl... Complex networks have been applied to model numerous interactive nonlinear systems in the real world. Knowledge about network topology is crucial to an understanding of the function, performance and evolution of complex systems. In the last few years, many network metrics and models have been proposed to investigate the network topology, dynamics and evolution. Since these network metrics and models are derived from a wide range of studies, a systematic study is required to investigate the correlations among them. The present paper explores the effect of degree correlation on the other network metrics through studying an ensemble of graphs where the degree sequence (set of degrees) is fixed. We show that to some extent, the characteristic path length, clustering coefficient, modular extent and robustness of networks are directly influenced by the degree correlation. 展开更多
关键词 network dynamics random graphs complex networks degree correlation
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3-D fracture network dynamic simulation based on error analysis in rock mass of dam foundation 被引量:4
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作者 ZHONG Deng-hua WU Han +2 位作者 WU Bin-ping ZHANG Yi-chi YUE Pan 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第4期919-935,共17页
Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network mode... Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network model and measured data,a 3-D fracture network dynamic modeling method based on error analysis was proposed.Firstly,errors of four fracture volume density estimation methods(proposed by ODA,KULATILAKE,MAULDON,and SONG)and that of four fracture size estimation methods(proposed by EINSTEIN,SONG and TONON)were respectively compared,and the optimal methods were determined.Additionally,error index representing the deviation between fracture network model and measured data was established with integrated use of fractal dimension and relative absolute error(RAE).On this basis,the downhill simplex method was used to build the dynamic modeling method,which takes the minimum of error index as objective function and dynamically adjusts the fracture density and size parameters to correct the error index.Finally,the 3-D fracture network model could be obtained which meets the requirements.The proposed method was applied for 3-D fractures simulation in Miao Wei hydropower project in China for feasibility verification and the error index reduced from 2.618 to 0.337. 展开更多
关键词 rock mass of dam foundation 3-D fracture network dynamic simulation fractal dimension error analysis relative absolute error(RAE) downhill simplex method
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Second-order consensus in networks of dynamic agents with communication time-delays 被引量:5
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作者 Bo Yang1,2, Huajing Fang3, and Hua Wang4 1. School of Navigation, Wuhan University of Technology, Wuhan 430063, P. R. China 2. Wuhan Second Ship Design and Research Institute, Wuhan 430064, P. R. China +1 位作者 3. Department of Control Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China 4. Department of Aerospace and Mechanical Engineering, Boston University, Boston MA02215, USA 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第1期88-94,共7页
This paper proposes second-order consensus protocols with time-delays and gives the measure of the robustness of the protocols to the time-delay existing in the network of agents with second-order dynamics. By employi... This paper proposes second-order consensus protocols with time-delays and gives the measure of the robustness of the protocols to the time-delay existing in the network of agents with second-order dynamics. By employing a frequency domain method, it is proven that the information states and their time derivatives of all the agents in the network achieve consensus asymptotically, respectively, for appropriate communication timedelay if the topology of weighted network is connected. Particularly, a tight upper bound on the communication time-delay that can be tolerated in the dynamic network is found. The consensus protocols are distributed in the sense that each agent only needs information from its neighboring agents, which reduces the complexity of connections between neighboring agents significantly. Numerical simulation results are provided to demonstrate the effectiveness and the sharpness of the theoretical results for second-order consensus in networks in the presence of communication time-delays. 展开更多
关键词 second-order consensus protocols dynamic networks algebraic graph theory frequency domain analysis com-munication constraints.
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Topology identification for a class of complex dynamical networks using output variables 被引量:4
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作者 Fan Chun-Xia Wan You-Hong Jiang Guo-Ping 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期193-201,共9页
A problem of topology identification for complex dynamical networks is investigated in this paper. An adaptive observer is proposed to identify the topology of a complex dynamical networks based on the Lyapunov stabil... A problem of topology identification for complex dynamical networks is investigated in this paper. An adaptive observer is proposed to identify the topology of a complex dynamical networks based on the Lyapunov stability theory. Here the output of the network and the states of the observer are used to construct the updating law of the topology such that the communication resources from the network to its observer are saved. Some convergent criteria of the adaptive observer are derived in the form of linear inequality matrices. Several numerical examples are shown to demonstrate the effectiveness of the proposed observer. 展开更多
关键词 complex dynamical networks topology identification adaptive observer output variables
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Research on the self-defence electronic jamming decision-making based on the discrete dynamic Bayesian network 被引量:6
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作者 Tang Zheng Gao Xiaoguang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第4期702-708,共7页
The manner and conditions of running the decision-making system with self-defense electronic jamming are given. After proposing the scenario of applying discrete dynamic Bayesian network to the decision making with se... The manner and conditions of running the decision-making system with self-defense electronic jamming are given. After proposing the scenario of applying discrete dynamic Bayesian network to the decision making with self-defense electronic jamming, a decision-making model with self-defense electronic jamming based on the discrete dynamic Bayesian network is established. Then jamming decision inferences by the aid of the algorithm of discrete dynamic Bayesian network are carried on. The simulating result shows that this method is able to synthesize different targets which are not predominant. In this way, various features at the same time, as well as the same feature appearing at different time complement mutually; in addition, the accuracy and reliability of electronic jamming decision making are enhanced significantly. 展开更多
关键词 self-defense electronic jamming discrete dynamic Bayesian network decision-making model
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SYNCHRONIZATION OF MASTER-SLAVE MARKOVIAN SWITCHING COMPLEX DYNAMICAL NETWORKS WITH TIME-VARYING DELAYS IN NONLINEAR FUNCTION VIA SLIDING MODE CONTROL 被引量:4
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作者 M.Syed ALI J.YOGAMBIGAI 曹进德 《Acta Mathematica Scientia》 SCIE CSCD 2017年第2期368-384,共17页
In this article, a synchronization problem for master-slave Markovian switching complex dynamical networks with time-varying delays in nonlinear function via sliding mode control is investigated. On the basis of the a... In this article, a synchronization problem for master-slave Markovian switching complex dynamical networks with time-varying delays in nonlinear function via sliding mode control is investigated. On the basis of the appropriate Lyapunov-Krasovskii functional, introducing some free weighting matrices, new synchronization criteria are derived in terms of linear matrix inequalities (LMIs). Then, an integral sliding surface is designed to guarantee synchronization of master-slave Markovian switching complex dynamical networks, and the suitable controller is synthesized to ensure that the trajectory of the closed-loop error system can be driven onto the prescribed sliding mode surface. By using Dynkin's formula, we established the stochastic stablity of master-slave system. Finally, numerical example is provided to demonstrate the effectiveness of the obtained theoretical results. 展开更多
关键词 Markovian switching complex dynamical networks Lyapunov-Krasovskii method sliding mode control Linear Matrix Inequality
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Complete synchronization of uncertain chaotic dynamical network via a simple adaptive control 被引量:3
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作者 肖玉柱 徐伟 +1 位作者 李秀春 唐素芳 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第1期80-86,共7页
In this paper, based on the invaxiance principle of differential equations, we propose a simple adaptive control method to synchronize the network with coupling of the general form. Comparing with other control approa... In this paper, based on the invaxiance principle of differential equations, we propose a simple adaptive control method to synchronize the network with coupling of the general form. Comparing with other control approaches, this scheme only depends on each node's state output. So we need not to know the concrete network structure and the solutions of the isolate nodes of the network in advance. In order to demonstrate the effectiveness of the method, a special example is provided and numerical simulations are performed. The numerical results show that our control scheme is very effective and robust against the weak noise. 展开更多
关键词 complete synchronization adaptive control dynamical network
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Synchronization of complex switched delay dynamical networks with simultaneously diagonalizable coupling matrices 被引量:4
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作者 Tao LIU Jun ZHAO 《控制理论与应用(英文版)》 EI 2008年第4期351-356,共6页
This paper studies local exponential synchronization of complex delayed networks with switching topology via switched system stability theory. First, by a common unitary matrix, the problem of synchronization is trans... This paper studies local exponential synchronization of complex delayed networks with switching topology via switched system stability theory. First, by a common unitary matrix, the problem of synchronization is transformed into the stability analysis of some linear switched delay systems. Then, when all subnetworks are synchronizable, a delay-dependent sufficient condition is given in terms of linear matrix inequalities (LMIs) which guarantees the solvability of the synchronization problem under an average dwell time scheme. We extend this result to the case that not all subnetworks are synchronizable. It is shown that in addition to average dwell time, if the ratio of the total activation time of synchronizable and non-synchronizable subnetworks satisfy an extra condition, then the problem is also solvable. Two numerical examples of delayed dynamical networks with switching topology are given, which demonstrate the effectiveness of obtained results. 展开更多
关键词 Exponential synchronization Complex dynamical network Switching topology Switched systems Av-erage dwell time Coupling delays Simultaneously diagonalizable matrices
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Multi-constraint quality of service routing algorithm for dynamic topology networks 被引量:3
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作者 Wang Ping Chen Bingcai +1 位作者 Gu Xuemai Liu Gongliang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第1期58-64,共7页
An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks, such as satellite networks and Ad-hoc networks. The AMQRA is a distributed and mobile-agents-based routing algorithm, whi... An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks, such as satellite networks and Ad-hoc networks. The AMQRA is a distributed and mobile-agents-based routing algorithm, which combines ant quantity system (AQS) with ant colony optimization (ACO) that is used in AntNet routing algorithm. In dynamic topology networks, the AMQRA achieves timely optimization for concave metric QoS constraint and fast convergence. The proposed routing algorithm is simulated in Iridium satellite constellation on OPNET. The results show that AMQRA not only outperforms the AntNet in convergence rate in dynamic topology networks but also can optimize concave metric QoS constraint and reasonably allot bandwidth to the load to avoid networks congestion. 展开更多
关键词 ROUTING QOS dynamic topology networks
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A Dynamic-Bayesian-Networks-Based Resilience Assessment Approach of Structure Systems: Subsea Oil and Gas Pipelines as A Case Study 被引量:3
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作者 CAI Bao-ping ZHANG Yan-ping +5 位作者 YUAN Xiao-bing GAO Chun-tan LIU Yong-hong CHEN Guo-ming LIU Zeng-kai JI Ren-jie 《China Ocean Engineering》 SCIE EI CSCD 2020年第5期597-607,共11页
Under unanticipated natural disasters, any failure of structure components may cause the crash of an entire structure system. Resilience is an important metric for the structure system. Although many resilience metric... Under unanticipated natural disasters, any failure of structure components may cause the crash of an entire structure system. Resilience is an important metric for the structure system. Although many resilience metrics and assessment approaches are proposed for engineering system, they are not suitable for complex structure systems, since the failure mechanisms of them are different under the influences of natural disasters. This paper proposes a novel resilience assessment metric for structure system from a macroscopic perspective, named structure resilience, and develops a corresponding assessment approach based on remaining useful life of key components. Dynamic Bayesian networks(DBNs) and Markov are applied to establish the resilience assessment model. In the degradation process, natural degradation and accelerated degradation are modelled by using Bayesian networks, and then coupled by using DBNs. In the recovery process, the model is established by combining Markov and DBNs. Subsea oil and gas pipelines are adopted to demonstrate the application of the proposed structure metric and assessment approach. 展开更多
关键词 structure resilience structure system remaining useful life dynamic Bayesian networks
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