检索结果-南通市图书馆

Designing Proportional-Integral Consensus Protocols for Second-Order Multi-Agent Systems Using Delayed and Memorized State Information

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 878-892页

作者： Honghai Wang Qing-long Han the College of Information Science and Engineering State Key Laboratory of Synthetical Automation for Process IndustriesNortheastern UniversityShenyang 110819China the School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourneVIC 3122Australia

This paper is concerned with consensus of a secondorder linear time-invariant multi-agent system in the situation that there exists a communication delay among the agents in the network.A proportional-integral consensus protocol is designed by using delayed and memorized state *** the proportional-integral consensus protocol,the consensus problem of the multi-agent system is transformed into the problem of asymptotic stability of the corresponding linear time-invariant time-delay *** that the location of the eigenvalues of the corresponding characteristic function of the linear time-invariant time-delay system not only determines the stability of the system,but also plays a critical role in the dynamic performance of the *** this paper,based on recent results on the distribution of roots of quasi-polynomials,several necessary conditions for Hurwitz stability for a class of quasi-polynomials are first *** allowable regions of consensus protocol parameters are *** necessary and sufficient conditions for determining effective protocol parameters are *** designed protocol can achieve consensus and improve the dynamic performance of the second-order multi-agent ***,the effects of delays on consensus of systems of harmonic oscillators/double integrators under proportional-integral consensus protocols are ***,some results on proportional-integral consensus are derived for a class of high-order linear time-invariant multi-agent systems.

关键词： Consensus protocol Hurwitz stability multi-agent systems quasi-polynomials time delay

When Electronically Inert Polymers Meet Conjugated Polymers:Emerging Opportunities in Organic Photovoltaics

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2022年第8期40卷 861-869,I0006页

作者： Jing-Jing Wang long Ye School of Materials Science&Engineering Tianjin Key Laboratory of Molecular Optoelectronic SciencesTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin300350China State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun130033China

Insulating polymers(commodity plastics in particular)are a major category of polymeric materials widely used in our daily life,but they exhibit abysmal electrical ***,conjugated polymers are gaining tremendous interest due to their excellent electrical properties and versatile applications in organic *** this perspective,we provide a concise account of the added value in organic solar cells,as brought by the combined use of conjugated and insulating *** challenging tasks and prospective directions are given to the potential benefits of employing insulating polymer additives,which spans from common commodity plastics to high-temperature resistant resins and thermoplastic ***,the inert polymers can improve many important properties such as mechanical and thermal robustness but not sacrifice optoelectronic performance.

关键词： Organic solar cells Insulating polymers Photovoltaic polymers Miscibility Morphology

Certifying the Global Optimality of Quartic Minimization over the Sphere

在线全文

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2022年第2期10卷 241-287页

作者： Sheng-long Hu Department of Mathematics School of ScienceHangzhou Dianzi UniversityHangzhou 310018ZhejiangChina

The quartic minimization over the sphere is an NP-hard problem in the general *** exist various methods for computing an approximate solution for any given *** practice,it is quite often that a global optimal solution was found but without a *** will present in this article two classes of methods which are able to certify the global optimality,i.e.,algebraic methods and semidefinite program(SDP)relaxation *** advances on these topics are summarized,accompanied with some emerged new *** want to emphasize that for mediumor large-scaled instances,the problem is still a challenging one,due to an apparent limitation on the current force for solving SDP problems and the intrinsic one on the approximation techniques for the problem.

关键词： Quartic minimization Tensor Sphere Global optimality Elimination method Critical points Eigenvectors Determinant Nondegenerate Characteristic polynomial SDP relaxations Moment matrix Flatness Positivstellensatz Nonnegative polynomial Sums of squares Duality

Potential Hydrodynamic Performance Enhancement of Hydrokinetic Turbine with Hydrophobic Coatings

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

China Ocean Engineering 2021年第6期35卷 924-932页

作者： CHEN long NG Kai-Wern School of Hydraulic and Environmental Engineering Changsha University of Science and TechnologyChangsha 410114China Department of Civil Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha University of Science and TechnologyChangsha 410114China

Hydrokinetic energy is a promising technology to harness predictable renewable energy from free-flowing water,tides and ocean *** studies have been conducted by researchers and engineers to find out ways to enhance the performance of the hydrokinetic *** current paper reports the experimental study of using hydrophobic coating as an alternative way to improve the performance of hydrokinetic turbine.A hydrophobic coating can lower the friction drag of a surface that is in contact with *** hydrokinetic turbine blade,reduction in friction drag may allow a blade section to have a better lift/drag ratio and have its efficiency *** this study,a formula to predict the pattern of drag reduction over a hydrophobic surface has been *** hydrophobic coatings were applied on NACA 63418 hydrofoils and their performances were *** was found that NACA 63418 hydrofoil with the hydrophobic coatings had its drag reduced by an average of 3%−4.0%.When the coatings were applied on a 350 mm diameter three-bladed turbine,the maximum increment of rotational speed of the turbine was found to be 2.5%.The performance of the two coatings against marine fouling was also *** weight of plate with and without the coatings increased by 10%and 100%,respectively.

关键词： hydrophobic coating hydrokinetic energy marine fouling

Experimental demonstration of concatenated composite pulses robustness to non-static errors

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2016年第9期59卷 46-51页

作者： Xing-long Zhen Tao Xin Fei-Hao Zhang Gui-Lu long State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua University Beijing 100084 China Innovation Centre of Quantum Matter Beijing 100084 China Tsinghua National Laboratory For Information Science and Technology Tsinghua University Beijing 100084 China

We examine the robustness of composite pulses to non-static classic noise in the NMR facility. Though these pulses are proposed to eliminate static, systematic errors, they are shown to be robust to time-varying noise with high-cut frequency up to near 10% of the Rabi frequency in a recent theoretical work. The CP pulses that are only robust to one kind of error have been implemented in various experiment platforms. In this paper we have compared the performance of reduced CinSK rc pulse, which is designed to cancel both the pulse length error and the off resonance error, to that of the primitive n pulse in a hybrid error environment. In order to achieve this target we have simultaneously injected noise to the RF output wave. The filter function formalism is employed to predict the evolution fidelity decay, which shows great consistency with the experiment data. Our work not only validates the superiority of reduced CinSK pulse but also indicates its sensitivity to the initial states, providing practical guidance in the noise suppression domain.

关键词： composite pulse filter function quantum control NMR

Numerical Investigation on the Influence of Nozzle Lip Thickness on the Flow Field and Performance of an Annular Jet Pump

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2014年第3期21卷 59-67页

作者： long-Zhou Xiao Xin-Ping long Xue-long Yang School of Power and Mechanical Engineering Wuhan University Key Lab of Jet Theory and New Technology of Hubei Province

The performance of an annular jet pump( AJP) is determined by its area ratio A( ratio of cross sectional area of throat and annular nozzle) and flow rate ratio q( ratio of primary and secondary flow rate,Qs/Qj),while the nozzle lip thickness is neglected in the present studies. This paper presents a study on the effect of the thickness on the flow field and performance of an AJP with A = 1. 75. With the increasing flow rate ratio and nozzle lip thickness,a small vortex forms at the nozzle lip and keeps on growing. However,as the flow rate ratio or nozzle lip thickness is extremely low,the vortex at the lip vanishes thoroughly. Moreover,the recirculation width varies conversely with the nozzle lip thickness when the flow rate ratio q ≤ 0. 13. While the deviation of the recirculation width with different nozzle lip thickness is negligible with q ≥ 0. 13. Additionally the existence of nozzle lip hinders the momentum exchange between the primary and secondary flow and leads to a mutation of velocity gradient near the nozzle exit,which shift the recirculation downstream. Finally,based on the numerical results of the streamwise and spanwise vortex distributions in the suction chamber, the characteristics of the mixing process and the main factors accounting for the AJP performance are clarified.

关键词： annular jet pump nozzle lip recirculation streamwise vortex spanwise vortex

The Security of Using Large Language Models:A Survey With Emphasis on ChatGPT

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2025年第1期 1-26页

作者： Wei Zhou Xiaogang Zhu Qing-long Han Lin Li Xiao Chen Sheng Wen Yang Xiang the School of Science Computing and Engineering Technologies Swinburne University of Technology IEEE the School of Computer and Mathematical Sciences the University of Adelaide Adelaide the Faculty of Science and Engineering Southern Cross University the School of Information and Physical Sciences the University of Newcastle

ChatGPT is a powerful artificial intelligence(AI)language model that has demonstrated significant improvements in various natural language processing(NLP) tasks. However, like any technology, it presents potential security risks that need to be carefully evaluated and addressed. In this survey, we provide an overview of the current state of research on security of using ChatGPT, with aspects of bias, disinformation, ethics, misuse,attacks and privacy. We review and discuss the literature on these topics and highlight open research questions and future *** this survey, we aim to contribute to the academic discourse on AI security, enriching the understanding of potential risks and mitigations. We anticipate that this survey will be valuable for various stakeholders involved in AI development and usage, including AI researchers, developers, policy makers, and end-users.

关键词：

Effect of the inclined weak interlayers on the rainfall response of a bedded rock slope

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2016年第9期13卷 1663-1674页

作者： LI long-qi State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Environment and Civil Engineering Chengdu University of TechnologyChengdu 610059China

Engineering experience shows that outward dipping bedded rock slopes, especially including weak interlayers, are prone to slide under rainfall conditions. To investigate the effect of inclined weak interlayers at various levels of depth below the surface on the variation of displacements and stresses in bedded rock slopes, four geo- mechanical model tests with artificial rainfall have been conducted. Displacements, water content as well as earth pressure in the model were monitored by means of various FBG （Fiber Bragg Grating） sensors. The results showed that the amount of displacement of a slope with a weak interlayer is 2.8 to 6.2 times larger than that of a slope without a weak interlayer during one rainfall event. Furthermore, the position of the weak interlayer in terms of depth below the surface has a significant effect on the zone of deformation in the model. In the slope with a high position weak interlayer, the recorded deformation was larger in the superficial layer of the model and smaller in the frontal portion than in the slope with a low position weak interlayer. The slope with two weak interlayers has the largest deformation at all locations of all test slopes. The slope without a weak interlayer was only saturated in its superficial layer, while the displacement decreased with depth. That was different from all slopes with a weak interlayer in which the largest displacement shifted from the superficial layer to the weak interlayer when rainfall persisted. Plastic deformation of the weak interlayer promoted the formation of cracks which caused more water to flow into the slope, thus causing larger deformation in the slope with weak interlayers. In addition, the slide thrust pressure showed a vibration phenomenon o.5 to 1 hour ahead of an abrupt increase of the deformation, which was interpreted as a predictor for rainfall-induced failure of bedded rock slopes.

关键词： Bedded rock slope Inclined weakinterlayer Rainfall Model test

An Improved Differential Fault Analysis on Block Cipher KLEIN-64

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2020年第11期65卷 1425-1436页

作者： Min long Man Kong Sai long Xiang Zhang Changsha University of Science and Technology Changsha410014China School of Computing National University of SingaporeSingapore

KLEIN-64 is a lightweight block cipher designed for resource-constrained environment,and it has advantages in software performance and hardware *** investigation shows that KLEIN-64 is vulnerable to differential fault attack(DFA).In this paper,an improved DFA is performed to *** is found that the differential propagation path and the distribution of the S-box can be fully utilized to distinguish the correct and wrong keys when a half-byte fault is injected in the 10th *** analyzing the difference matrix before the last round of S-box,the location of fault injection can be limited to a small ***,this improved analysis can greatly improve the attack *** the best case,the scale of brute-force attack is only *** for the worst case,the scale of brute-force attack is far less than 232 with another half byte fault injection,and the probability for this case is 1/***,the measures for KLEIN-64 in resisting the improved DFA are proposed.

关键词： Block cipher KLEIN-64 differential fault analysis half-byte fault injection