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System structural analysis of communication networks based on DEMATEL-ISM and entropy

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Journal of Central South University 2017年第7期24卷 1594-1601页

作者： FU Kai XIA Jing-bo ZHANG Xiao-yan SHEN Jian Information and Navigation College Air Force Engineering UniversityXi’an 710077China Tan Kah Kee College Xiamen UniversityZhangzhou 363105China

A method of system structural analysis based on decision making trial and evaluation laboratory together with interpretative structural modeling(DEMATEL-ISM) and entropy is proposed to clarify system structure of communication networks and analyze mutual influencing degree between different *** influencing degree and importance degree of elements are both considered to determine weights of elements,and the entropy of expert judgment results is used to omit unimportant influence relation and simplify system *** analysis on communication networks system shows that the proposed method can quantificationally present weights and mutual influencing degree of elements,and reasonably simplify system *** results indicate the rationality and feasibility of the method.

关键词： communication networks system structural analysis decision making trial and evaluation laboratory (DEMATEL) interpretative structural modeling (ISM) entropy

Symmetry-adapted graph neural networks for constructing molecular dynamics force fields

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Science China(Physics,Mechanics & Astronomy) 2021年第11期64卷 118-126页

作者： Zun Wang Chong Wang SiBo Zhao ShiQiao Du Yong Xu Bing-Lin Gu WenHui Duan State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China Department of Physics Carnegie Mellon UniversityPittsburgh 15213USA Institute for Advanced Study Tsinghua UniversityBeijing 100084China Frontier Science Center for Quantum Information Beijing 100084China RIKEN Center for Emergent Matter Science(CEMS) WakoSaitama 351-0198Japan

Molecular dynamics is a powerful simulation tool to explore material *** realistic material systems are too large to be simulated using first-principles molecular *** molecular dynamics has a lower computational cost but requires accurate force fields to achieve chemical *** this work,we develop a symmetry-adapted graph neural network framework called the molecular dynamics graph neural network(MDGNN)to construct force fields automatically for molecular dynamics simulations for both molecules and *** architecture consistently preserves translation,rotation,and permutation invariance in the *** also propose a new feature engineering method that includes high-order terms of interatomic distances and demonstrate that the MDGNN accurately reproduces the results of both classical and first-principles molecular *** addition,we demonstrate that force fields constructed by the proposed model have good *** MDGNN is thus an efficient and promising option for performing molecular dynamics simulations of large-scale systems with high accuracy.

关键词： graph neural networks molecular dynamics force fields

iSeeBetter: Spatio-temporal video super-resolution using recurrent generative back-projection networks

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Computational Visual Media 2020年第3期6卷 307-317页

作者： Aman Chadha John Britto M.Mani Roja Department of Computer Science Stanford University450 Serra MallStanfordCA 94305USA Department of Computer Science University of Massachusetts AmherstAmherstMA 01003USA Department of Electronics and Telecommunication Engineering University of MumbaiMumbaiMaharashtra 400032India

Recently,learning-based models have enhanced the performance of single-image superresolution(SISR).However,applying SISR successively to each video frame leads to a lack of temporal *** neural networks(CNNs)outperform traditional approaches in terms of image quality metrics such as peak signal to noise ratio(PSNR)and structural similarity(SSIM).On the other hand,generative adversarial networks(GANs)offer a competitive advantage by being able to mitigate the issue of a lack of finer texture details,usually seen with CNNs when super-resolving at large upscaling *** present i See Better,a novel GAN-based spatio-temporal approach to video super-resolution(VSR)that renders temporally consistent super-resolution videos.i See Better extracts spatial and temporal information from the current and neighboring frames using the concept of recurrent back-projection networks as its ***,to improve the"naturality"of the superresolved output while eliminating artifacts seen with traditional algorithms,we utilize the discriminator from super-resolution generative adversarial *** mean squared error(MSE)as a primary loss-minimization objective improves PSNR/SSIM,these metrics may not capture fine details in the image resulting in misrepresentation of perceptual *** address this,we use a four-fold(MSE),perceptual,adversarial,and total-variation loss *** results demonstrate that i See Better offers superior VSR fidelity and surpasses state-of-the-art performance.

关键词： networks resolution projection

A Disturbance Rejection Control Approach for Clock Synchronization in IEEE 1588 networks

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Journal of Systems Science & Complexity 2018年第6期31卷 1437-1448页

作者： ZHANG Junhao ZHANG Wenan College of Information Engineering Zhejiang University of TechnologyHangzhou 310023China Zhejiang Provincial United Key Laboratory of Embedded Systems Hangzhou 310023China

This paper is concerned with the clock synchronization problem for IEEE 1588 ***,the synchronization error is described as a bounded disturbance,and a linear extended state observer (LESO)is designed to estimate the lumped disturbance induced by the oscillator frequency drift and timestamps quantization ***,the lumped disturbance is compensated by the proposed *** proposed approach has the advantage that it's able to deal with non-Gaussian disturbance induced by accumulated quantization *** are Drovided to validate the effectiveness and superiority of the proposed approach.

关键词： Feedback control IEEE 1588 linear extended state observer peer-to-peer networks syn-chronization.

Finite-Time Synchronization for a Class of Dynamical Complex networks with Nonidentical Nodes and Uncertain Disturbance

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Journal of Systems Science & Complexity 2019年第3期32卷 818-834页

作者： LI Qingbo GUO Jin SUN Changyin WU Yuanyuan DING Zhengtao School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083 China College of Mathematics and Information Science Zhengzhou University of Light Industry Zhengzhou 450002 China Key Laboratory of Knowledge Automation for Industrial Processes Ministry of Education Beijing 100083 China School of Automation Southeast University Nanjing 210096 China College of Electric and Information Engineering Zhengzhou University of Light Industry Zhengzhou 450002 China School of Electrical and Electronic Engineering University of Manchester Manchester M139PL UK

This paper investigates the finite-time synchronization for a class of linearly coupled dynamical complex networks with both nonidentical nodes and uncertain disturbance. A set of controllers are designed such that the considered system can be finite-timely synchronized onto the target node. Based on the stability of the error equation, the Lyapunov function method and the linear matrix inequality technique, several sufficient conditions are derived to ensure the finite-time synchronization, and applied to the case of identical nodes and tlie one without uncertain disturbance. Also the adaptive finite-time synchronization is discussed. A numerical example is given to show the effectiveness of the main results obtained.

关键词： Disturbance dynamical complex networks finite-time synchronization nonidentical nodes

Nodes and layers PageRank centrality for multilayer networks

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Chinese Physics B 2019年第2期28卷 129-136页

作者： Lai-Shui Lv Kun Zhang Ting Zhang Meng-Yue Ma Nanjing University of Science and Technology

In this paper, we propose a new centrality algorithm that can simultaneously rank the nodes and layers of multilayer networks, referred to as the MRFNL centrality. The centrality of nodes and layers are obtained by developing a novel iterative algorithm for computing a set of tensor equations. Under some conditions, the existence and uniqueness of this centrality were proven by applying the Brouwer fixed point theorem. Furthermore, the convergence of the proposed iterative algorithm was established. Finally, numerical experiments on a simple multilayer network and two real-world multilayer networks(i.e., Pierre Auger Collaboration and European Air Transportation networks) are proposed to illustrate the effectiveness of the proposed algorithm and to compare it to other existing centrality measures.

关键词： multilayer networks PageRank centrality random walks transition probability tensors

Traffic dynamics considering packet loss in finite buffer networks

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Chinese Physics B 2019年第4期28卷 433-438页

作者： Jie Chen Jin-Yong Chen Ming Li Mao-Bin Hu School of Engineering Science University of Science and Technology of China Civil Architectural and Environmental Engineering University of Texas at Austin

In real complex systems, the limited storage capacity of physical devices often results in the loss of data. We study the effect of buffer size on packet loss threshold in scale-free networks. A new order parameter is proposed to characterize the packet loss threshold. Our results show that the packet loss threshold can be optimized with a relative small buffer size. Meanwhile, a large buffer size will increase the travel time. Furthermore, we propose a Buffered-Shortest-Path-First(BSPF) queuing strategy. Compared to the traditional First-In-First-Out(FIFO) strategy, BSPF can not only increase the packet loss threshold but can also significantly decrease the travel length and travel time in both identical and heterogeneous node capacity cases. Our study will help to improve the traffic performance in finite buffer networks.

关键词： finite buffer networks loss threshold queuing strategy

Task-Aware Flow Scheduling with Heterogeneous Utility Characteristics for Data Center networks

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Tsinghua Science and Technology 2019年第4期24卷 400-411页

作者： Fang Dong Xiaolin Guo Pengcheng Zhou Dian Shen the School of Computer Science and Engineering Southeast University

With the continuous enrichment of cloud services, an increasing number of applications are being deployed in data centers. These emerging applications are often communication-intensive and data-parallel, and their performance is closely related to the underlying network. With their distributed nature, the applications consist of tasks that involve a collection of parallel flows. Traditional techniques to optimize flow-level metrics are agnostic to task-level requirements, leading to poor application-level performance. In this paper, we address the heterogeneous task-level requirements of applications and propose task-aware flow scheduling. First, we model tasks' sensitivity to their completion time by utilities. Second, on the basis of Nash bargaining theory, we establish a flow scheduling model with heterogeneous utility characteristics, and analyze it using Lagrange multiplier method and KKT condition. Third, we propose two utility-aware bandwidth allocation algorithms with different practical constraints. Finally, we present Tasch, a system that enables tasks to maintain high utilities and guarantees the fairness of utilities. To demonstrate the feasibility of our system, we conduct comprehensive evaluations with realworld traffic trace. Communication stages complete up to 1.4 faster on average, task utilities increase up to 2.26,and the fairness of tasks improves up to 8.66 using Tasch in comparison to per-flow mechanisms.

关键词： data center networks coflow flow scheduling data-intensive applications

Distributed control and optimization of process system networks:A review and perspective

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Chinese Journal of Chemical Engineering 2019年第7期27卷 1461-1473页

作者： Wentao Tang Prodromos Daoutidis Department of Chemical Engineering and Materials Science University of Minnesota Minneapolis

Large-scale and complex process systems are essentially interconnected *** automated operation of such process networks requires the solution of control and optimization problems in a distributed *** this approach,the network is decomposed into several subsystems,each of which is under the supervision of a corresponding computing agent(controller,optimizer).The agents coordinate their control and optimization decisions based on information communication among *** recent years,algorithms and methods for distributed control and optimization are undergoing rapid *** this paper,we provide a comprehensive,up-to-date review with perspectives and discussions on possible future directions.

关键词： Distributed control Distributed optimization Process networks Decision making