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Dynamical thermalization of Frenkel-Kontorova model in the thermodynamic limit

Physical Review E 2016年第2期93卷 022216-022216页

作者： Zhenjun Zhang Chunmei Tang Peiqing Tong College of Science Hohai University Nanjing Jiangsu 210098 People's Republic of China School of Physics Science and Technology Nanjing Normal University Nanjing Jiangsu 210023 People's Republic of China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu 210023 People's Republic of China

We study numerically the process of dynamical thermalization in the Frenkel-Kontorova (FK) model with weak nonlinearity. The total energy has initially equidistributed among some of the lowest frequency linear modes. It is found that the energy transfers continuously to the high-frequency modes and finally evolves towards energy equipartition in the FK model. However, the metastable state, which was found in Fermi-Pasta-Ulam (FPU) model and φ4 model in a relatively short time scale, is not found in the FK model. We further perform a very accurate systematic study of the equipartition time Teq as functions of the particle number N, the nonlinear parameter β, and the energy density ɛ. In the thermodynamic limit, the dependence of Teq on β and ɛ is found to display a power law behavior: Teq∝βaɛb. The exponents a and b are numerically found to be approximately −2.0 and 1.43. This scaling law is also quite different from those of the FPU-β model and φ4 model.

关键词： Lattice dynamics Lattice models in statistical physics Lattice models in condensed matter

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Autonomous migration of virtual machine based on OpenStack

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International Journal of Hybrid Information Technology 2016年第8期9卷 65-84页

作者： Zhou, Li Yu, Zhuoer Zhang, Jilin Wan, Jian Wu, Yusen School of Computer and Technology Hangzhou Dianzi University Hangzhou310018 China Key Laboratory of Complex Systems Modeling and Simulation Ministry of Education Hangzhou China College of Electrical Engineering Zhejiang University Hangzhou310058 China School of Information and Electronic engineering Zhejiang University of Science & Technology Hangzhou310023 China Zhejiang Provincial Engineering Center on Media Data Cloud Processing and Analysis HangzhouZhejiang China

For the problem of compute nodes load unbalance leads to the overload node impact VM performance and the underload node waste electrical energy. Dynamic VM consolidation is an efficient approach for improving the utilization of servers and reducing energy costs. In this paper, we introduce dynamic consolidation into OpenStack and implement AMVM based on OpenStack. AMVM collect and analyze all performance data of VM and compute node in OpenStack. Then AMVM automatically schedules VM live migrate to the most appropriate node according to the real-time load of all compute nodes. Then we use hybrid-copy instead of pre-copy in AMVM to improve the efficiency of VM live migration. Finally, we analyze the performance of hybrid-copy, hybrid-copy can reduce page faults compared with post-copy and reduce total data transferred compared with pre-copy. © 2016 SERSC.

关键词： Virtual machine

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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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An efficient storage technology for object-based distributed storage system

International Journal of Control and Automation

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International Journal of Control and Automation 2015年第11期8卷 337-348页

作者： Zhang, Jilin Su, Yucheng Wan, Jian Zhou, Li Wang, Jue Zhang, Lei College of Electrical Engineering Zhejiang University Hangzhou China School of Computer Science and Technology Hangzhou Dianzi University Hangzhou China Key Laboratory of Complex Systems Modeling and Simulation Ministry of Education China Supercomputing Center of Computer Network Information Center Chinese Academy of Sciences Beijing China Computer Science Department Beijing University of Civil Engineering and Architecture Beijing China

There have two effective ways to improve the overall efficiency of the object-based distributed storage system, one is network caching technology and the other is metadata server cluster load balancing strategy. Under the heterogeneous storage environments, object-based distributed file system face the key challenge of lacking caching mechanism for the high-frequency access files, metadata server load imbalance also reduce the overall efficiency. To address these challenges, we discuss the design and implementation of an object-based distributed file storage caching system, and propose a weight-based metadata server cluster load balancing strategy. It effectively improve the metadata processing capacity. Based on the results, it demonstrated the feasibility and the efficiency of our methods. © 2015 SERSC.

关键词： Metadata

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Research and implementation of CDP disaster recovery system based on oracle

International Journal of Control and Automation

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International Journal of Control and Automation 2015年第11期8卷 325-336页

作者： Ren, Yongjian Ye, Jiaolong Zhang, Jilin Zhou, Li Wang, Jue Zhang, Lei School of Computer Science and Technology Hangzhou Dianzi University Hangzhou China Key Laboratory of Complex Systems Modeling and Simulation Ministry of Education China College of Electrical Engineering Zhejiang University Hangzhou China Supercomputing Center of Computer Network Information Center Chinese Academy of Sciences Beijing China Computer Science Department Beijing University of Civil Engineering and Architecture Beijing China

The OraCDP disaster recovery system uses CDP disaster recovery technology based on the combination of block level, combining with the communication coupling between the underlying I/O and Oracle database. The experimental results show that the OraCDP system can not only maintain the normal operation of the original system without any negative influence, but also guarantee the recovery of data and service at specific time quickly, fully and accurately. © 2015 SERSC.

关键词： Recovery

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RETRACTED: Graphic and haptic simulation for transvaginal cholecystectomy training in NOTES

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Journal of Biomedical Informatics 2016年 60卷 410-421页

作者： Jun J. Pan Woojin Ahn Saurabh Dargar Tansel Halic Bai C. Li Ganesh Sankaranarayanan Kurt Roberts Steven Schwaitzberg Suvranu De State Key Laboratory of Virtual Reality Technology and Systems Beihang University Beijing China Center for Modeling Simulation and Imaging in Medicine Rensselaer Polytechnic Institute Troy USA Computer Science Department University of Central Arkansas Conway USA Gastrointestinal Surgery Yale School of Medicine Yale University New Heaven USA Department of Surgery Cambridge Health Alliance Harvard Medical School Boston USA

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( http://***/locate/withdrawalpolicy ). This article has been retracted at the request of the Editor-in-Chief. The Publisher and Editor have been informed that the article was submitted to the journal without the consent of all the coauthors. The coauthor Suvranu De expressed concerns regarding the validity of some of the techniques and data reported in the paper, particularly in Figure 18 and Table 3. In addition, we identified in the article a significant portion of copied text that came from the following publications: Metaballs-based physical modeling and deformation of organs for virtual surgery Junjun Pan, Chengkai Zhao, Xin Zhao, Aimin Hao, Hong Qin The Visual Computer , June 2015, Volume 31, Issue 6, pp 947–957 DOI: 10.1007/s00371-015-1106-y Virtual reality training and assessment in laparoscopic rectum surgery Jun J. Pan, Jian Chang, Xiaosong Yang, Hui Liang, Jian J. Zhang, Tahseen Qureshi, Robert Howell and Tamas Hickish The International Journal of Medical Robotics and Computer Assisted Surgery , Volume 11, Issue 2, pages 194–209 DOI: 10.1002/rcs.1582 As such, this article represents an abuse of the scientific publishing system, which we believe warrants the retraction of the article. The scientific community takes a very strong view on this matter and apologies are offered to the readers of the journal that our processes, which have since been updated, did not adequately verify the assent of the coauthors and their approval of the paper’s content.

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Perturbative QCD factorization of ργ⋆→ρ

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Physical Review D 2016年第3期93卷 036002-036002页

作者： Ya-lan Zhang Shan Cheng Jun Hua Zhen-Jun Xiao Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu 210023 People’s Republic of China Theoretische Elementarteilchenphysik Naturwissenschaftlich Technische Fakultät Universiät Siegen 57068 Siegen Germany Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People’s Republic of China

In this paper we first demonstrate step by step that the factorization hypothesis is valid at the next-to-leading order (NLO) for the exclusive process ργ⋆→ρ by employing the collinear factorization approach, and then extend this proof to the case of the kT factorization by taking into account the transversal momentum of the light external quark (antiquark) lines in the ρ meson. At the NLO level, we then show that the soft divergences from different subdiagrams will cancel each other in the quark level, while the remaining collinear divergences can be absorbed into the NLO meson wave functions. The full NLO amplitudes can therefore be factorized as the convolution of the NLO wave functions Φρ(1) and the infrared-finite leading order (LO) hard kernels GX,IJ,kl0 in the kT factorization. We also write down the polarized NLO ρ meson wave functions in the form of nonlocal hadron matrix elements with the gauge factor integral path deviating from the light cone. These NLO ρ meson wave functions can be used to calculate the NLO hard corrections to some relevant exclusive processes, such as B→ρ transition.

关键词： Perturbative QCD Scattering amplitudes Mesons

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Grand−canonical Monte−Carlo simulation of DNA condensation in equilibrium with a salt mixture containing 2:2 salt

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Journal of Physics: Conference Series 2017年第1期865卷

作者： Nguyen V Duc Toan T Nguyen Faculty of Physics VNU University of Science Vietnam National University 334 Nguyen Trai Street Thanh Xuan Hanoi Vietnam VNU Key Laboratory for Multiscale Simulation of Complex Systems Vietnam National University 334 Nguyen Trai Street Thanh Xuan Hanoi Vietnam School of Physics Georgia Institute of Technology 837 State Street Atlanta Georgia 30332-0430 USA

The Grand–canonical Monte–Carlo simulation method is used to simulate DNA hexagonal condensate in the presence of a mixture of 1:1, 2:1, 2:2 salts using the primitive ion model. Previous results show that DNA can be condensed by divalent counterions in restricted environment, such as inside viruses. In this work, we study the effects of divalent co-ions on condensation of DNA by divalent counterions. It is shown that divalent co–ions lead to weaker DNA condensation free energy and DNA de–condensation at smaller counterions concentration.

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Graphic and haptic simulation for transvaginal cholecystectomy training in NOTES

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Journal of Biomedical Informatics 2016年 60卷 410-421页

作者： Pan, Jun J. Ahn, Woojin Dargar, Saurabh Halic, Tansel Li, Bai C. Sankaranarayanan, Ganesh Roberts, Kurt Schwaitzberg, Steven De, Suvranu State Key Laboratory of Virtual Reality Technology and Systems Beihang University Beijing China Center for Modeling Simulation and Imaging in Medicine Rensselaer Polytechnic Institute Troy United States Computer Science Department University of Central Arkansas Conway United States Gastrointestinal Surgery Yale School of Medicine Yale University New Heaven United States Department of Surgery Cambridge Health Alliance Harvard Medical School Boston United States

Background: Natural Orifice Transluminal Endoscopic Surgery (NOTES) provides an emerging surgical technique which usually needs a long learning curve for surgeons. Virtual reality (VR) medical simulators with vision and haptic feedback can usually offer an efficient and cost-effective alternative without risk to the traditional training approaches. Under this motivation, we developed the first virtual reality simulator for transvaginal cholecystectomy in NOTES (VTEST™). Methods: This VR-based surgical simulator aims to simulate the hybrid NOTES of cholecystectomy. We use a 6DOF haptic device and a tracking sensor to construct the core hardware component of simulator. For software, an innovative approach based on the inner-spheres is presented to deform the organs in real time. To handle the frequent collision between soft tissue and surgical instruments, an adaptive collision detection method based on GPU is designed and implemented. To give a realistic visual performance of gallbladder fat tissue removal by cautery hook, a multi-layer hexahedral model is presented to simulate the electric dissection of fat tissue. Results: From the experimental results, trainees can operate in real time with high degree of stability and fidelity. A preliminary study was also performed to evaluate the realism and the usefulness of this hybrid NOTES simulator. Conclusions: This prototyped simulation system has been verified by surgeons through a pilot study. Some items of its visual performance and the utility were rated fairly high by the participants during testing. It exhibits the potential to improve the surgical skills of trainee and effectively shorten their learning curve. © 2016 Elsevier Inc.

关键词： Virtual reality

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Research on Prediction Method for Pivotal Indicator of Hospital Medical Quality Using Decision Tree

Research on Prediction Method for Pivotal Indicator of Hospi...

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2015 6th IEEE International Conference on Software Engineering and Service Science(ICSESS 2015)

作者： Liujian Chen Lujia Bi Huayou Si Jilin Zhang Yongjian Ren Key Laboratory of Complex System Modeling and Simulation Ministry of Education Department of Computer Science and Technology Hangzhou Dianzi University Department of Information First Hospital of Jiaxing

Indicators of medical quality is the main basis of medical quality evaluation, predictive analyzing the indicators by using data mining technology, we can find and solve the problems of hospital quality management more timely. The study, basing on the medical homepage records, analyzes the key indicators of the hospital medical quality by decision tree C4.5 algorithm. Decision tree is a prediction model which can assist hospital to make related decision on medical quality management issues. By using decision tree C4.5 algorithm with appropriate modification, a high quality model of decision tree can be made. It can not only do the statistic of medical quality indicators, but also predict the indicators with high relative accuracy to improve hospital’s medical quality management.

关键词： medical quality data mining decision tree C4.5

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