检索结果-南通市图书馆

SnapshotPrune: A Novel Bitcoin-Based Protocol Toward efficient Pruning and Fast Node Bootstrapping

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第4期29卷 1037-1052页

作者： Pengfei Huang Xiaojun ren Teng Huang Arthur Sandor Voundi koe duncan S Wong Hai Jiang Institute of Artificial Intelligence and Blockchain Guangzhou UniversityGuangzhou 510006China Institute of Artificial Intelligence and Blockchain Guangzhou UniversityGuangzhou 510006Chinaand also with Pazhou LabGuangzhou 510330China

Node synchronization is essential for the stability of the Bitcoin network. Critics have raised doubts about the ability of a new node to quickly and efficiently synchronize with the Bitcoin network and alleviate the storage pressure from existing full nodes to stockpile new data. Basic pruning and other techniques have been explored to address these concerns but have been insufficient to reduce node synchronization delay and effectively suppress the growth of synchronized data. In this study, we propose SnapshotPrune, a novel pruning and synchronization protocol that achieves fast node bootstrapping in the Bitcoin blockchain. Real Bitcoin historical data are leveraged to measure the synchronization time and monitor the network traffic during node bootstrapping. The protocol requires data downloads that are 99.70% less than Bitcoin Core, 81% less than CoinPrune, and 60% less than SnapshotSave, thereby saving 97.23% of download time. Findings show that the proposed design enhances the storage efficiency and reduces the node synchronization delay compared with existing techniques. We hypothesize that the efficiency of this protocol increases with the block height.

关键词： synchronization blockchain Unspent Transaction Output(UTXO)pruning snapshot fast bootstrapping

event-triggered H_(∞) consensus control for input-constrained multi-agent systems via reinforcement learning

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第1期22卷 25-38页

作者： Jinxuan Zhang Chang-e ren College of Information engineering Capital Normal UniversityBeijing100089China

This article presents an event-triggered H_(∞) consensus control scheme using reinforcement learning (RL) for nonlinear second-order multi-agent systems (MASs) with control constraints. First, considering control constraints, the constrained H_(∞) consensus problem is transformed into a multi-player zero-sum game with non-quadratic performance functions. Then, an event-triggered control method is presented to conserve communication resources and a new triggering condition is developed for each agent to make the triggering threshold independent of the disturbance attenuation level. To derive the optimal controller that can minimize the cost function in the case of worst disturbance, a constrained Hamilton–Jacobi–Bellman (HJB) equation is defined. Since it is difficult to solve analytically due to its strongly non-linearity, reinforcement learning (RL) is implemented to obtain the optimal controller. In specific, the optimal performance function and the worst-case disturbance are approximated by a time-triggered critic network;meanwhile, the optimal controller is approximated by event-triggered actor network. After that, Lyapunov analysis is utilized to prove the uniformly ultimately bounded (UUB) stability of the system and that the network weight errors are UUB. Finally, a simulation example is utilized to demonstrate the effectiveness of the control strategy provided.

关键词： H_(∞)optimal control Input constrains Multi-agent systems(MASs) Reinforcement learning(RL)

Uncertainty-Aware Deep Learning: A Promising Tool for Trustworthy Fault Diagnosis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ieee/CAA Journal of Automatica Sinica 2024年第6期11卷 1317-1330页

作者： Jiaxin ren Jingcheng Wen Zhibin Zhao Ruqiang Yan Xuefeng Chen Asoke k.Nandi School of Mechanical engineering Xi’an Jiaotong UniversityXi’an 710049China Department of electronic and electrical engineering Brunel University LondonKingston LaneUxbridgeUB83PHUK Ieee

Recently,intelligent fault diagnosis based on deep learning has been extensively investigated,exhibiting state-of-the-art ***,the deep learning model is often not truly trusted by users due to the lack of interpretability of“black box”,which limits its deployment in safety-critical applications.A trusted fault diagnosis system requires that the faults can be accurately diagnosed in most cases,and the human in the deci-sion-making loop can be found to deal with the abnormal situa-tion when the models *** this paper,we explore a simplified method for quantifying both aleatoric and epistemic uncertainty in deterministic networks,called *** SAeU,Multivariate Gaussian distribution is employed in the deep architecture to compensate for the shortcomings of complexity and applicability of Bayesian neural *** on the SAeU,we propose a unified uncertainty-aware deep learning framework(UU-DLF)to realize the grand vision of trustworthy fault ***,our UU-DLF effectively embodies the idea of“humans in the loop”,which not only allows for manual intervention in abnor-mal situations of diagnostic models,but also makes correspond-ing improvements on existing models based on traceability ***,two experiments conducted on the gearbox and aero-engine bevel gears are used to demonstrate the effectiveness of UU-DLF and explore the effective reasons behind.

关键词： Out-of-distribution detection traceability analysis trustworthy fault diagnosis uncertainty quantification.

A FAS approach for stabilization of generalized chained forms: part 1. Discontinuous control laws

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第2期67卷 118-143页

作者： Guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology Center for Control Science and Technology Southern University of Science and Technology

In this paper, a type of general nonholonomic systems is proposed, which contains both the Brockett’s two example systems, and their extended n-dimensional chained forms, as special cases. For the stabilization of such systems, a stabilizing controller is proposed based on the fully actuated system(FAS)approach, which is discontinuous at the origin but time-invariant when the open-loop system is time-invariant,and drives the feasible trajectories of the system to the origin exponentially. Furthermore, the proposed FAS approach is also extended to the sub-normal system case and the time-delay system case.

关键词： nonholonomic systems feedback stabilization exponential convergence sub-fully actuated systems time-delay systems

A FAS approach for stabilization of generalized chained forms: part 2. Continuous control laws

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第3期67卷 114-135页

作者： Guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology Shenzhen key Laboratory of Control Theory and Intelligent Systems Southern University of Science and Technology

In this paper, continuous time-varying stabilizing controllers for the type of general nonholonomic systems proposed and treated in part 1 are designed using the fully actuated system(FAS) approach. The key step is to differentiate the first scalar equation, and by control of the obtained second-order scalar system, a proportional plus integral feedback form for the first control variable is obtained. With the solution to this designed second-order scalar system, the rest equations in the nonholonomic system form an independent time-varying subsystem which is then handled by the FAS approach. The overall designed controller contains an almost arbitrarily chosen design parameter, and is proven to guarantee the uniformly and globally exponential stability of the closed-loop system. The proposed approach is simple and effective,and is demonstrated with a practical example of ship control.

关键词： nonholonomic systems feedback stabilization fully actuated systems Lyapunov stability continuous controllers

Resilient control of flexible hypersonic vehicles against unmatched distributed faults

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 60-70页

作者： Dong ZHAO Wenjing ren School of Artificial Intelligence Anhui UniversityHefei 230601China key Laboratory of System Control and Information Processing Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China School of electrical engineering and Automation Hefei University of TechnologyHefei 230009China

This paper studies a robust fault compensation and vibration suppression problem of flexible hypersonic *** controlled plant is represented by a cascade system composed of a nonlinear Ordinary Differential equation(ODe)and an euler-Bernoulli Beam equation(eBBe),in which the vibration dynamics is coupled with the rigid dynamics and suffers from distributed faults.A state differential transformation is introduced to transfer distributed faults to an eBBe boundary and a longitudinal dynamics is refined by utilizing T-S fuzzy IF-THeN rules.A novel T-S fuzzy based fault-tolerant control algorithm is developed and related stability conditions are *** robust exponential stability and well-posedness are proved by using the modified l_(0)-semigroup based Lyapunov direct approach.A simulation study on the longitudinal dynamics of flexible hypersonic vehicles effectively verifies the validity of the developed theoretical results.

关键词： Flexible hypersonic vehicles ODe-eBBe cascade Robust exponential stability Unmatched distributed fault compensation Vibration suppression

Progress in modeling and control of probe-and-drogue autonomous aerial refueling

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 6-26,I0001页

作者： Jinrui ren Quan QUAN School of Automation Xi’an University of Posts&TelecommunicationsXi'an 710072China School of Automation Science and electrical engineering Beihang UniversityBeijing 100191China

By refueling aircraft while they are in flight,aerial refueling is an efficient technique to extend their endurance and *** Aerial Refueling(AAR)is anticipated to be used to complete aerial refueling for unmanned *** are three aerial refueling methods:the Probe-and-Drogue Refueling(PDR)refueling method,the flying-boom refueling method,and the boom-drogue-adapter refueling *** paper considers the PDR approach,the most challenging of the three,because the flexible hose-drogue assembly has fast dynamics and is susceptible to various kinds of winds,which makes the probe docking with the drogue *** is divided into four phases,namely the rendezvous phase,joining phase,refueling phase,and reform phase,with the refueling phase being the most *** controller design faces the greatest challenge during the docking control of the refueling phase since it calls for a high level of safety,precision,and *** a result,the modeling and control issues encountered during the refueling phase are typical and *** fundamental idea of AAR is presented in the paper first,after which the characteristics and requirements of AAR are *** progress in modeling and control techniques for the AAR’s refueling phase is then systematically ***,potential future work for high safety,precision,and efficiency requirements is examined and suggested.

关键词： Aerial refueling Probe-and-drogue refueling Docking Flight controlsystems Unmanned Aerial Vehicles

Sparse identification-assisted exploration of the atomic-scale deformation mechanism in multiphase CoCrFeNi high-entropy alloys

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第4期67卷 1124-1132页

作者： XIAO Lu GUO XiaoXiang SUN YuTong WANG Gang LONG WeiMin LIAW Peter k. ren JingLi School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Institute of Materials Shanghai UniversityShanghai 200444China SkL of Advanced Brazing Metals&Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001China Department of Materials Science and engineering The University of TennesseeKnoxvilleTN 37996USA

This study investigated the atomic-scale deformation mechanism of multiphase CoCrFeNi high-entropy alloys(HeAs)at liquid helium,liquid nitrogen,and room temperatures.A million-atom multiphase HeA was prepared using molecular dynamics simulation involving melt and quench *** HeA exhibited high-density dislocations and some twins,consistent with experimental *** analysis revealed an inconsistent evolution of the microstructure under tensile *** particular,the elastic and initial plastic stages exhibited an increase in the disordered structure at the expense of the face-centered cubic and hexagonal close-packed structures,followed by a subsequent transformation involving multiple structural ***,through sparse identification,a model depicting microstructural evolution during tension was extracted for the CoCrFeNi HeA at three typical temperatures and three tensile *** model highlighted the importance of the body-centered cubic structure in the evolutionary process.

关键词： high-entropy alloy data-driven method microstructure evolution multiphase structure molecular dynamics simulation

Nonlocal symmetries,soliton-cnoidal wave solution and soliton molecules to a(2+1)-dimensional modified kdV system

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 14-21页

作者： Jianyong Wang Bo ren Department of Mathematics and Physics Quzhou UniversityQuzhou 324000China Department of Mathematics Zhejiang University of TechnologyHangzhou 310014China

A(2+1)-dimensional modified kdV(2DmkdV)system is considered from several ***,residue symmetry,a type of nonlocal symmetry,and the Bäcklund transformation are obtained via the truncated Painlevéexpansion ***,the residue symmetry is localized to a Lie point symmetry of a prolonged system,from which the finite transformation group is ***,the integrability of the 2DmkdV system is examined under the sense of consistent tanh expansion ***,explicit soliton-cnoidal wave solutions are ***,abundant patterns of soliton molecules are presented by imposing the velocity resonance condition on the multiple-soliton solution.

关键词： soliton-cnoidal wave solution nonlocal symmetry soliton molecule (2+1)-dimensional modified kdV system