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2021 China Automation Congress, CAC 2021

作者： Xu, Liang Wang, Hao Liu, Ying Xue, Wei Li, Ningning Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems School of Electrical Engineering and Automation Tianjin University of Technology Tianjin China National Key Laboratory for Complex Systems Simulation Beijing China BeijingAerospace Propulsion Institute Beijing China

ISBN: (纸本)9781665426473

To address the problem of aeroengine PID parameter optimization and tuning, this work employs the excellent performance of the sparrow search algorithm (SSA) with high convergence accuracy and fast convergence speed to propose a self-tuning PID control method (SSA-PID) for aeroengine parameters. Considering that the oil supply output by the actuator may have a substantial overshoot, the proposed technique adds a penalty mechanism for the overshoot at the output, designs and improves the fitness function weighted by performance indicators, and effectively avoids the possible excessive overshoot and sharp oil supply phenomenon of the engine oil supply. The SSA-PID simulates and verifies the mathematical models of the turbofan engine ' s steady-state operating points on the ground and at high altitudes. The results show that the SSA-PID control method has better parameter tuning and optimization effects, a faster speed step response, and generates a fuel supply that does not have a large overshoot, thereby proving its effectiveness and feasibility. © 2021 IEEE

关键词： Three term control systems

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Effects of phonon bandgap on phonon-phonon scattering in ultrahigh thermal conductivityθ-phase TaN

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Chinese Physics B 2023年第4期32卷 543-548页

作者：吴超刘晨晗 Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China Micro-and Nano-scale Thermal Measurement and Thermal Management Laboratory School of Energy and Mechanical EngineeringNanjing Normal UniversityNanjing 210023China Jiangsu Key Laboratory for Numerical Simulation of Large-Scale Complex Systems Nanjing Normal UniversityNanjing 210023China Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments School of Mechanical EngineeringSoutheast UniversityNanjing 211100China

Phonon bandgap typically has a significant effect on phonon-phonon scattering *** this work,the effects of mass modified phonon bandgap inθ-phase Ta N are systemically investigated by the means of first-principles calculations with linearized Boltzmann transport *** detailed calculations,we find that phonon bandgap has a significant effect on three-phonon process while exhibits a much weaker effect on four-phonon *** reason for the ultrahigh thermal conductivity ofθ-phase Ta N is the long lifetime of phonons including both three-phonon and four-phonon processes,which originates from the weak phonon anharmonicity and large phonon bandgap-induced small phonon-phonon scattering phase *** work advances the understanding of phonon bandgap effects on phonon transport.

关键词： ultrahigh thermal conductivity phonon-phonon scattering phase space first-principles calculation phonon bandgap

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Skyrmion stability at finite isospin chemical potential and temperature

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Chinese Physics C 2020年第1期44卷 105-110页

作者： Wen-Li Yuan Zhen-Ni Xu Jin-Li Zhang Hong-Shi Zong Department of Physics Nanjing UniversityNanjing 210093China Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal UniversityNanjing 210023China Joint Center for Particle Nuclear Physics and CosmologyNanjing 210093China State Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsCASBeijing 100190China

The skyrmion stability at finite isospin chemical potentialμ_I is studied using the Skyrme Lagrangian with a finite pion mass m_π.A critical valueμ_(Ic)=■,above which a stable soliton does not exist,is *** also explore some properties of the skyrmion as function of i.e.,the isoscalar rms radius and the isoscalar magnetic rms ***,considering the finite temperature effect on the skyrmion mass,we obtain a critical temperature T_c,using the profile function of the skyrmion,above which the skyrmion mass does not have a minimum,which can be interpreted as the occurrence of the deconfinement phase transition.

关键词： skyrme model isospin chemical potential skyrmion stability

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NURBS-based DEM for non-spherical particles

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Particuology 2020年第2期18卷 65-76页

作者： Shiwen Liu Feiguo Chen Wei Ge Philippe Ricoux State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesP.O.Box 353Beijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Data Processing and Modeling TOTAL Scientific DivisionFrance

The discrete element method(DEM)is used to analyze complex practical granular systems;however,the representation of real shapes is an important consideration because behavior of non-spherical particles is unlike that of spherical particles both individually and *** this study,we use non-uniform rational basis-splines(NURBS)to describe the shapes of non-spherical particles and introduce a contact detection scheme based on quadratic convergence,to simulate the behaviors of elliptical *** simulation results are compared with those based on polygons,in terms of the shape description and contact treatment,to demonstrate the high accuracy and efficiency of NURBS-based DEM.

关键词： Non-spherical particle Discrete element method NURBS Facet-based DEM Granular system

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Resonance contributions fromχ_(c0)in charmless three-body hadronic B meson decays

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Chinese Physics C 2023年第4期47卷 148-154页

作者：张亚兰王超林毅肖振军 Faculty of Mathematics and Physics Huaiyin Institute of TechnologyHuaian 223200China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal UniversityNanjing 210023China

Within the framework of perturbative QCD factorization,we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=π,*** compare our predicted branching ratios for the B_(()(s))→K_(χc0)→Kπ^(+)π-(K^(+)K^(-))decay with available experiment data as well as predictions by other theoretical *** branching ratios of these decays are consistent with data and other theoretical ***,in the Cabibbo-suppressed decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=K^(0),π,the values of the branching ratios are of the order of 10^(-7)and 10^(-8).The ratio R_((χ)_(c0))between the decays B^(+)→π^(+)χ_(c0)→π^(+)π^(+)π^(-)and B^(+)→K^(+)χc0→K^(+)π^(+)π^(-)and the distribution of branching ratios for different decay modes in invariant mass are considered in this study.

关键词： three-body B meson decays resonance contributions perturbative QCD factorization approach

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Integrated water resource security evaluation of Beijing based on grey relation analysis and TOPSIS

Integrated water resource security evaluation of Beijing bas...

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5th Biennial Conference of the International Environmental Modelling and Software Society: Modelling for Environment's Sake, iEMSs 2010

作者： Dai, Jing Chi, Jingjing Chen, Bin Ju, Liping State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China

ISBN: (纸本)9788890357411

Security evaluation has become a hot topic in the research field of water resource management. In this paper, we established a novel water resource security indicator system based on the Pressure-Status-Response (PSR) framework using grey relation analysis and technique for order preference by similarity to ideal solution (TOPSIS). A case study of Beijing from 1996 to 2007 was conducted to verify the evaluation system. Results showed that the grey relative closeness degrees of water resource security to the positive ideal solution were low, with the least one of 0.360 in 1999 and largest one of 0.527 in 2007, implying that Beijing was facing severer challenges with water resources during the concerned time. Also, the analysis of water resource security indicated that the pressure of water resource was constantly increasing. Finally, factor analysis was employed to calculate the grey relation degrees of evaluating indices with the ideal solutions so as to reveal the relativity of water resource security of Beijing, which may contribute to a better understanding of the urban water resource management and regulation.

关键词： Factor analysis

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Foreword

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Particuology 2011年第4期9卷 319-319页

作者： Ning Yang Wei Ge Jinghai Li State key laboratory of Multiphase complex systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China Aibing Yu laboratory for simulation and modeling of Particulate systems, School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Laboratory for Simulation and Modeling of Particulate Systems School of Materials Science and Engineering The University of New South Wales Sydney NSW 2052 Australia

Granular materials are ubiquitous in nature and engineering. They display both fluid- and solid-like behavior with fascinating complexity and remarkable uniqueness. Their behavior at different scales is strongly coupl... 详细信息

关键词： materials different Understanding size effects structures complexity challenge products display nature high

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S-wave resonance contributions to B(s)^0→ηc(2S)π^+π^-in the perturbative QCD factorization approach

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Chinese Physics C 2017年第8期41卷 47-52页

作者： Ai-Jun Ma Ya Li Wen-Fei Wang Zhen-Jun Xiao Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China Institute of Theoretical Physics Shanxi UniversityTaiyuanShanxi 030006China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal UniversityNanjing 210023China

By employing the perturbative QCD（PQCD） factorization approach, we study the quasi-two-body B（s）^0→ηc（2S）π^＋π^- decays, where the pion pair comes from the S-wave resonance f0（X）. The Breit-Wigner formula for the f0（500） and f0（1500） resonances and the Flatt′e model for the f0（980） resonance are adopted to parameterize the time-like scalar form factors in the two-pion distribution amplitudes. As a comparison, Bugg＇s model is also used for the wide f0（500） in this work. For decay rates, we found the following PQCD predictions：（a）-B（Bs^0 →ηc（2S）f0（X）[π^＋π^-]s）= 2.67-1.08^＋1.78 ×10^-5 when the contributions from f0（980） and f0（1500） are all taken into account;（b）B（B0→η-c（2S）f0（500）[π^＋π^-]s） = 1.40（-0.56）（＋0.92） ×10^-6 in the Breit-Wigner model and 1.53（-0.61）^（＋0.97） ×10^-6 in Bugg＇s model.

关键词： PQCD factorization approach two-pion distribution amplitudes quasi-two-body decay

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Coevolution of Opinion Dynamics and Recommendation System: modeling Analysis and Reinforcement Learning Based Manipulation

arXiv

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arXiv 2024年

作者： Chen, Yuhong Dai, Xiaobing Buss, Martin Liu, Fangzhou Munich80333 Germany National Key Laboratory of Modeling and Simulation for Complex Systems Harbin Institute of Technology 150001 China

In this work, we develop an analytical framework that integrates opinion dynamics with a recommendation system. By incorporating elements such as collaborative filtering, we provide a precise characterization of how recommendation systems shape interpersonal interactions and influence opinion formation. Moreover, the property of the coevolution of both opinion dynamics and recommendation systems is also shown. Specifically, the convergence of this coevolutionary system is theoretically proved, and the mechanisms behind filter bubble formation are elucidated. Our analysis of the maximum number of opinion clusters shows how recommendation system parameters affect opinion grouping and polarization. Additionally, we incorporate the influence of propagators into our model and propose a reinforcement learning-based solution. The analysis and the propagation solution are demonstrated in simulation using the Yelp data set. Copyright © 2024, The Authors. All rights reserved.

关键词： Collaborative filtering

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PARDA: A dataset for scholarly PDF document metadata extraction evaluation 14th

PARDA: A dataset for scholarly PDF document metadata extract...

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14th EAI International Conference on Collaborative Computing: Networking, Applications and Worksharing, CollaborateCom 2018

作者： Fan, Tiantian Liu, Junming Qiu, Yeliang Jiang, Congfeng Zhang, Jilin Zhang, Wei Wan, Jian School of Computer Science and Technology Hangzhou Dianzi University Hangzhou310018 China Key Laboratory of Complex Systems Modeling and Simulation Ministry of Education Hangzhou310018 China School of Information and Electronic Engineering Zhejiang University of Science and Technology Hangzhou310023 China

ISBN: (纸本)9783030129804

Metadata extraction from scholarly PDF documents is the fundamental work of publishing, archiving, digital library construction, bibliometrics, and scientific competitiveness analysis and evaluations. However, different scholarly PDF documents have different layout and document elements, which make it impossible to compare different extract approaches since testers use different source of test documents even if the documents are from the same journal or conference. Therefore, standard datasets based performance evaluation of various extraction approaches can setup a fair and reproducible comparison. In this paper we present a dataset, namely, PARDA(Pdf Analysis and Recognition DAtaset), for performance evaluation and analysis of scholarly documents, especially on metadata extraction, such as title, authors, affiliation, author-affiliation-email matching, year, date, etc. The dataset covers computer science, physics, life science, management, mathematics, and humanities from various publishers including ACM, IEEE, Springer, Elsevier, arXiv, etc. And each document has distinct layouts and appearance in terms of formatting of metadata. We also construct the ground truth metadata in Dublin Core XML format and BibTex format file associated this dataset. © 2019, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

关键词： Metadata

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