检索结果-南通市图书馆

Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

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

Defence Technology（防务技术） 2024年第3期33卷 518-531页

作者： Chenggang Wang Jianhu Yan Wenlong Li Liang Shan Le Sun School of Automation Nanjing University of Science and TechnologyNanjing 210094China

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear *** order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter *** models that consider total disturbances are developed to design the TDOF-LADRC speed controller ***,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is *** on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting ***,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

关键词： Permanent magnet synchronous motor(PMSM) Active disturbance rejection control(ADRC) Disturbance observer Two-degree-of-freedom control Anti-disturbance

One-step quantum dialogue

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 95-104页

作者：朱鹏辉钟伟杜明明李喜云周澜盛宇波 College of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China Institute of Quantum Information and Technology Nanjing University of Posts and TelecommunicationsNanjing 210003China

Quantum dialogue(QD)enables two communication parties to directly exchange secret messages *** conventional QD protocols,photons need to transmit in the quantum channel for two *** this paper,we propose a one-step QD protocol based on the *** the help of the non-local hyperentanglement-assisted Bell state measurement(BSM),the photons only need to transmit in the quantum channel *** prove that our one-step QD protocol is secure in theory and numerically simulate its secret message capacity under practical experimental *** with previous QD protocols,the one-step QD protocol can effectively simplify the experiment operations and reduce the message loss caused by the photon transmission ***,the non-local hyperentanglement-assisted BSM has a success probability of 100%and is feasible with linear optical ***,combined with the hyperentanglement heralded amplification and purification,our protocol is possible to realize long-distance one-step QD.

关键词： one-step quantum dialogue hyperentanglement hyperentanglement distribution non-local Bell-state measurement

An Empirical Study on Automated Test Generation Tools for Java:Effectiveness and Challenges

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2024年第3期39卷 715-736页

作者：刘相君余萍马晓星 State Key Laboratory for Novel Software Technology Nanjing UniversityNanjing 210023China Department of Computer Science and Technology Nanjing UniversityNanjing 210023China CCF ACM IEEE

Automated test generation tools enable test automation and further alleviate the low efficiency caused by writing hand-crafted test ***,existing automated tools are not mature enough to be widely used by software testing *** paper conducts an empirical study on the state-of-the-art automated tools for Java,i.e.,EvoSuite,Randoop,JDoop,JTeXpert,T3,and *** design a test workflow to facilitate the process,which can automatically run tools for test generation,collect data,and evaluate various ***,we conduct empirical analysis on these six tools and their related techniques from different aspects,i.e.,code coverage,mutation score,test suite size,readability,and real fault detection *** discuss about the benefits and drawbacks of hybrid techniques based on experimental ***,we introduce our experience in setting up and executing these tools,and summarize their usability and ***,we give some insights into automated tools in terms of test suite readability improvement,meaningful assertion generation,test suite reduction for random testing tools,and symbolic execution integration.

关键词： automated test generation search-based software testing random testing symbolic execution

Effective dynamics for a spin-1/2 particle constrained to a curved layer with inhomogeneous thickness

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

Chinese Physics B 2024年第2期33卷 78-83页

作者：梁国华尹佩林 School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China

We derive an effective Hamiltonian for a spin-1/2 particle confined within a curved thin layer with non-uniform thickness using the confining potential *** analysis reveals the presence of a pseudo-magnetic field and effective spin–orbit interaction(SOI)arising from the curvature,as well as an effective scalar potential resulting from variations in ***,we demonstrate that the physical effect of additional SOI from thickness fluctuations vanishes in low-dimensional systems,thus guaranteeing the robustness of spin interference measurements to thickness ***,we establish the applicability of the effective Hamiltonian in both symmetric and asymmetric confinement scenarios,which is crucial for its utilization in one-side etching systems.

关键词： curved surface inhomogeneous thickness spin-1/2 particle effective Hamiltonian

The value of toxicological analysis in acute poisoning patients with uncertain exposure histories:a retrospective and descriptive study from an institute of poisoning

在线全文

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2024年第2期15卷 98-104页

作者： Qifang Shi Gen Ba Zhenyu Xia Zhengsheng Mao Hao Sun Jinsong Zhang Institute of Poisoning Nanjing Medical UniversityNanjing 211100China Department of Emergency Medicine the First Affiliated Hospital of Nanjing Medical UniversityNanjing 210029China Department of Forensic Medicine Nanjing Medical UniversityNanjing 211166China The Key Laboratory of Modern Toxicology of Ministry of Education Nanjing Medical UniversityNanjing 211166China

BACKGROUND:In clinical practice,some patients might not be able or unwilling to provide a thorough history of medication and poison *** aim of this study was to use toxicological analysis to examine the clinical characteristics of patients with acute poisoning whose exposure history was uncertain from a toxicological analysis ***:This was a retrospective and descriptive study from an institute of *** registration information and test reports spanning the period from April 1,2020 to March 31,2022,were *** with uncertain exposure histories and who underwent toxicological analysis were *** manifestations and categories of toxics were ***:Among the 195 patients with positive toxicological analysis results,the main causes of uncertain exposure history was disturbance of consciousness(62.6%),unawareness(23.6%)and unwillingness or lack of cooperation(13.8%).The predominant clinical manifestations were disturbed consciousness(62.6%),followed by vomiting and nausea(14.4%)and liver function abnormalities(8.7%).A comparison of clinical manifestations between patients with positive and negative(n=99)toxicological analyses results revealed significantly different proportions of disturbances in consciousness(63%vs.21%),dizziness(1.5%vs.5.1%),multi-organ failure(1.5%vs.7.1%),and local pain(0 vs 4%).The main categories of substances involved were psychiatric medications(23.1%),sedatives(20.5%),insecticides(13.8%),and herbicides(12.8%).CONCLUSION:The clinical manifestations of acute poisoning in patients with an uncertain exposure history are diverse and nonspecific,and toxicological analysis plays a pivotal role in the diagnosis and differential diagnosis of such patients.

关键词： Acute poisoning Toxic exposure Toxicological analysis Clinical manifestation

Sustainable management of campus fallen leaves through low-temperature pyrolysis and application in Pb immobilization

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第5期139卷 281-292页

作者： Rongli Tan Ke Li Yue Sun Xiaoliang Fan Zhengtao Shen Lingyi Tang School of Environment Nanjing UniversityNanjing 210023China School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210023China School of Earth and Engineering Sciences Nanjing UniversityNanjing 210023China Department of Earth and Atmospheric Sciences University of AlbertaEdmonton T6G 2E3Canada

Realizing campus sustainability requires the environmental-friendly and economical treatment of tremendous fallen *** fallen leaf biochar at a low temperature is a candidate *** this study,six common types of fallen leaves on the campus were pyrolyzed at 300℃.The obtained biochars were characterized and the adsorption mechanisms of lead(Pb)by the fallen leaf biochars were *** adsorption capacity of leaf biochar for Pb was relatively high,up to 209 mg/g(Yulania denudata leaf biochar).Adsorption of Pb onto active sites was the rate-limiting step for most leaf *** for Platanus leaf biochar,intraparticle diffusion of Pb^(2+)dominated owing to the lowest adsorption ***,the highest exchangeable Pb fraction(27%)indicated its potential for removing aqueous Pb^(2+).Ginkgo and Prunus cerasifera leaf biochar immobilized Pb by surface complexation and precipitation as lead ***,they were suitable for soil heavy metal *** study shed the light on the sustainable utilization of campus fallen leaves and the application of fallen leaf biochars in heavy metal remediation.

关键词： Fallen leaves Waste management Biochar Lead removal Sorption Circular campus

Reinforcement learning based adaptive control for uncertain mechanical systems with asymptotic tracking

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第4期34卷 19-28页

作者： Xiang-long Liang Zhi-kai Yao Yao-wen Ge Jian-yong Yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Automation&College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing210023China

This paper mainly focuses on the development of a learning-based controller for a class of uncertain mechanical systems modeled by the Euler-Lagrange *** considered system can depict the behavior of a large class of engineering systems,such as vehicular systems,robot manipulators and *** these systems are often characterized by highly nonlinear characteristics,heavy modeling uncertainties and unknown perturbations,therefore,accurate-model-based nonlinear control approaches become *** by the challenge,a reinforcement learning(RL)adaptive control methodology based on the actor-critic framework is investigated to compensate the uncertain mechanical *** approximation inaccuracies caused by RL and the exogenous unknown disturbances are circumvented via a continuous robust integral of the sign of the error(RISE)control *** from a classical RISE control law,a tanh(·)function is utilized instead of a sign(·)function to acquire a more smooth control *** developed controller requires very little prior knowledge of the dynamic model,is robust to unknown dynamics and exogenous disturbances,and can achieve asymptotic output ***,co-simulations through ADAMS and MATLAB/Simulink on a three degrees-of-freedom(3-DOF)manipulator and experiments on a real-time electromechanical servo system are performed to verify the performance of the proposed approach.

关键词： Adaptive control Reinforcement learning Uncertain mechanical systems Asymptotic tracking

QoE oriented intelligent online learning evaluation technology in B5G scenario

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第1期10卷 7-15页

作者： Mingzi Chen Xin Wei Peizhong Xie Zhe Zhang School of Communications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology(nanjing university of Posts and Telecommunications) Ministry of EducationNanjing210003China Institute of Higher Education Nanjing University of Posts and TelecommunicationsNanjing210003China

Students'demand for online learning has exploded during the post-COvID-19 pandemic ***,due to their poor learning experience,students'dropout rate and learning performance of online learning are not always *** technical advantages of Beyond Fifth Generation(B5G)can guarantee a good multimedia Quality of Experience(QoE).As a special case of multimedia services,online learning takes into account both the usability of the service and the cognitive development of the *** that affect the Quality of Online Learning Experience(OL-QoE)become more *** get over this dilemma,we propose a systematic scheme by integrating big data,Machine Learning(ML)technologies,and educational psychology ***,we first formulate a general definition of OL-QoE by data analysis and experimental *** formula considers both the subjective and objective factors(i.e.,video watching ratio and test scores)that most affect ***,we induce an extended layer to the classic Broad Learning System(BLS)to construct an Extended Broad Learning System(EBLS)for the students'OL-QoE *** the extended layer can increase the width of the BLS model and reduce the redundant nodes of BLS,the proposed EBLS can achieve a trade-off between the prediction accuracy and computation ***,we provide a series of early intervention suggestions for different types of students according to their predicted OL-QoE *** timely interventions,their OL-QoE and learning performance can be *** results verify the effectiveness oftheproposed scheme.

关键词： B5G Online learning Quality of experience

Magnetic Nonreciprocity in a Hybrid Device of Asymmetric Artificial Spin-Ice-Superconductors

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

Chinese Physics Letters 2024年第6期41卷 119-127页

作者：李冲黄培源王晨光李浩杰吕阳阳岳文诚袁子雄李甜雨涂学凑陶涛董思宁何亮贾小氢孙国柱康琳王华兵吴培亨王永磊 Research Institute of Superconductor Electronics Nanjing UniversityNanjing 210093China Purple Mountain Laboratories Nanjing 211111China National Key Laboratory of Spintronics Nanjing UniversitySuzhou 215163China

Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative *** introduce a unique superconducting hybrid device using a novel artificial spin ice structure composed of asymmetric *** structure forms a distinctive superconducting pinning potential that steers unconventional motion of superconducting vortices,thereby inducing a magnetic nonreciprocal effect,in contrast to the electric nonreciprocal effect commonly observed in superconducting ***,the polarity of the magnetic nonreciprocity is in situ reversible through the tunable magnetic patterns of artificial spin *** findings demonstrate that artificial spin ice not only precisely modulates superconducting characteristics but also opens the door to novel functionalities,offering a groundbreaking paradigm for superconducting electronics.

关键词： artificial collective reciprocal