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NURBS-based DEM for non-spherical particles

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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Consistent Distributed Cooperative Localization: A Coordinate Transformation Approach

arXiv

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arXiv 2023年

作者： Tian, Chungeng Hao, Ning He, Fenghua Yao, Haodi National Key Laboratory of Modeling and Simulation for Complex Systems School of Astronautics Harbin Institute of Technology Harbin150001 China

This paper addresses the consistency issue of multi-robot distributed cooperative localization. We introduce a consistent distributed cooperative localization algorithm conducting state estimation in a transformed coordinate. The core idea involves a linear time-varying coordinated transformation to render the propagation Jacobian independent of the state and make it suitable for a distributed manner. This transformation is seamlessly integrated into a server-based distributed cooperative localization framework, in which each robot estimates its own state while the server maintains the cross-correlations. The transformation ensures the correct observability property of the entire framework. Moreover, the algorithm accommodates various types of robot-to-robot relative measurements, broadening its applicability. Through simulations and real-world dataset experiments, the proposed algorithm has demonstrated better performance in terms of both consistency and accuracy compared to existing algorithms. Copyright © 2023, The Authors. All rights reserved.

关键词： Multipurpose robots

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The semileptonic decays of B/B_s meson in the perturbative QCD approach:a short review

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Chinese Science Bulletin 2014年第29期59卷 3787-3800页

作者： Zhen-Jun Xiao Ying-Ying Fan Wen-Fei Wang Shan Cheng Department of Physics and Institute of Theoretical Physics Nanjing Normal University Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Institute of High Energy Physics and Theoretical Physics Center for Science Facilities Chinese Academy of Sciences

In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=*** firstly gave a brief introduction for the experimental measurements for B=Bs!Peltl;l ml;m mT decays,the BaBar’s ReDT and ReD T anomaly,the P05deviation for B0!K 0ltl *** then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule,the heavy quark effective theory,and the perturbative QCD factorization *** using the form factors calculated in the perturbative(pQCD)approach,we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of B=*** also made careful phenomenological analysis for these pQCD predictions and found,in general,the following points:(a)For all the considered B=Bssemileptonic decays,the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods;(b)For ReDT and ReD T,the pQCD predictions agree very well with the data,the BaBar’s anomaly of ReDe TT are therefore explained successfully in the standard model by employing the pQCD approach;and(c)We defined several new ratios Rl;s Dand Rl;s Ds,they may be more sensitive to the QCD dynamics which controls the B=Bs!eDe T;De T sT transitions than the old ratios,we therefore strongly suggest LHCb and the forthcoming Super-B experiments to measure these new ratios.

关键词：微扰QCD 衰变率 BS 介子光锥QCD求和规则实验测量评论 QCD因子化

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The Effect of Quantum Coins on the Spreading of Binary Disordered Quantum Walk

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Chinese Physics Letters 2015年第6期32卷 20-23页

作者：赵静胡亚运童培庆 Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 Kavli Institute for Theoretical Physics China Chinese Academy of Sciences Beijing 100190

The dynamical and static disordered quantum walks were extensively studied recently. It is found that, for the dynamicM disorder case, the transport behavior of particles is diffusive, and for the static disorder ease the transport behavior is localized. In this work, we study the effect of quantum coins on the transport behaviors of the binary disordered quantum walks. We lind that once the coins satisfy certain conditions, the sub-ballistic spreading could be found in binary dynamical disorder quantum walks, and the sub-ballistic, diffusive and sub- diffusive spreadings could be found in binary static disorder quantum walks. We obtain the necessary conditions for those abnormal diffusive behaviors.

关键词： The Effect of Quantum Coins on the Spreading of Binary Disordered Quantum Walk

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