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International Journal of Database Theory and Application 2014年第3期7卷 91-106页

作者： Wan, Jian Xuan, Huijia Zhang, Jilin School of Computer Science and Technology Hangzhou Dianzi University Hangzhou China Key Laboratory of Complex System Modeling and Simulation Ministry of Education Hangzhou China Electric Engineering School Zhejiang University Hangzhou China

With the advent of the information age, the data volumes of various industries are in explosive growth, which increasingly highlights the importance of data. When a disaster occurs, how to recover the data completely and rapidly is one of the important issues receiving common concerns throughout the current industrial and academic circles. Based on the traditional disaster recovery system, this paper researches and implements a PRS algorithm-based distributed disaster recovery system[1, 2] called OsnDDR, which ensures the high availability of the system under the circumstance of continuous disasters or multi-node damage. The system adopts PRS algorithm based on RS erasure code [3] to reduce the storage resource consumption caused by the data redundancy and designs the load balancing strategy to guarantee the load balancing of each disaster recovery center in the system. © 2014 SERSC.

关键词： Disasters

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Improved optimization for data disaster recovery system over low-bandwidth networks

International Journal of Database Theory and Application

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International Journal of Database Theory and Application 2014年第5期7卷 1-16页

作者： Wan, Jian Hong, Xiaolong Zhang, Jinlin School of Computer Science and Technology Hangzhou Dianzi University Hangzhou China Key Laboratory of Complex System Modeling and Simulation Ministry of Education Hangzhou China Electric Engineering School Zhejiang University Hangzhou China

Data generated by various fields are increasing exponentially and thus results in challenges for data performances in both scales of diversity and complexity. The problem how to solve the bottlenecks of low-bandwidth networks has been of fatal significance for all kinds of network status. We present a new approach on improved optimization for data disaster recovery system (DDRS) over low-bandwidth networks that not only aims to improve the defects and deficiencies of mainstream DDRS but also helps ensure the reliable network resources for operators to conduct multi-services. A novel bandwidth self-adaptive approach (BSAA) for data packing replication was essentially established to make contribution to the integral performance improvement. A Hidden Markov Model (HMM) for predicting network status was also built to ensure system availability and stability. Experiments showed that the DDRS over low-bandwidth networks named InfoDr can effectively optimize the workload with better performance and better application self-adaptability for multi-services.

关键词： Hidden Markov models

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A first-principles study of the structural and elastic properties of orthorhombic and tetragonal Ca_3Mn_2O_7

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Chinese Physics B 2013年第6期22卷 465-471页

作者：张玮童培庆 Department of Physics Institute of Theoretical PhysicsNanjing Normal University Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University

The structural and elastic properties of multiferroic Ca3Mn2O7 with ferroelectric orthorhombic （O-phase） and paraelectric tetragonal structures （T-phase） have been studied by first-principles calculations within the generalized gradient approximation （GGA） and the GGA plus Hubbard U approaches （GGA ＋ U）. The calculated theoretical structures are in good agreement with the experimental values. The T-phase is found to be antiferromagnetic （AFM） and the AFM O-phase is more stable than the T-phase, which also agree with the experiments. On these bases, the single-crystal elastic constants （Cijs） and elastic properties of polycrystalline aggregates are investigated for the two phases. Our elasticity calculations indicate Ca3Mn2O7 is mechanically stable against volume expansions. The AFM O-phase is found to be a ductile material, while the AFM T-phase shows brittle nature and tends to be elastically isotropic. We also investigate the influence of strong correlation effects on the elastic properties, qualitatively consistent results are obtained in a reasonable range of values of U. Finally, the ionicity is discussed by Bader analysis. Our work provides useful guidance for the experimental elasticity measurements of Ca3Mn2O7, and makes the strain energy calculation in multiferroic Ca3Mn2O7 thin films possible.

关键词： elastic constant elastic anisotropy strong correlation effect multiferroic

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The effects of the Dzyaloshinskii-Moriya interaction on the ground-state properties of the XY chain in a transverse field

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Chinese Physics B 2013年第9期22卷 285-291页

作者：钟鸣徐卉刘小贤童培庆 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

The effects of the Dzyaloshinski-Moriya （DM） interaction on the ground-state properties of the anisotropic XY chain in a transverse field have been studied by means of correlation functions and entanglement. Different from the case without the DM interaction, the excitation spectra ek of this model are not symmetrical in the momentum space and are not always positive. As a result, besides the ferromagnetic （FM） and the paramagnetic （PM） phases, a gapless chiral phase is induced. In the chiral phase, the von Neumann entropy is proportional to log2 L （L is the length of a subchain） with the coefficient A ~ 1/3, which is the same as that of the XY chain in a transverse field without the DM interaction for 7 = 0 and 0 〈 h 〈 1. And in the vicinity of the critical point between the chiral phase and the FM （or PM） phase, the behaviors of the nearest- neighbor concurrence and its derivative are like those for the anisotropy transition.

关键词： Dzyaloshinskii-Moriya interaction the XY chain in a transverse field quantum entanglement,ground-state properties

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Unified information modeling for achieving high-performance information sharing in the information grid

Unified information modeling for achieving high-performance ...

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2012 2nd International Conference on Management, Manufacturing and Materials Engineering, ICMMM 2012

作者： Zhang, Ying-chao Zhang, Jing Qin-Zhang, Yu Feng, Ye Wei, Li Zhi-Ming, Shen National Key Laboratory of Science and Technology on Complex Systems Simulation Beijing China

ISBN: (纸本)9783037855423

In this paper, an unified information description model ("UIDM" for short) is proposed to model information from multiple sources in the Information Grid uniformly. In the UIDM: 1) An unified information description language derived from the ODLI 3 is presented to describe information uniformly to resolve the information heterogeneity;2) A set of diagrammatized information modeling symbols are defined to model the information diagrammatically to illustrate the semantic relationships between information classes;3) An information capability model is advanced to model the capability of information from different information sources, based on which the high-performance global views for information sharing are to be constructed. © (2013) Trans Tech Publications, Switzerland.

关键词： Semantics

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An iterative space alternative tiling parallel algorithm for 3D finite difference stencil computations

International Journal of Database Theory and Application

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International Journal of Database Theory and Application 2014年第6期7卷 105-120页

作者： Shen, Jing Zhang, Jilin Wan, Jian Zhou, Li Jiang, Ming School of Computer Science and Technology Hangzhou Dianzi University Hangzhou Zhejiang China Key Laboratory of Complex Systems Modeling and Simulation Ministry of Education China Zhejiang Provincial Engineering Center on Media Data Cloud Processing and Analysis Hangzhou China School of Information Engineering Hangzhou Dianzi University Hangzhou Zhejiang China

Stencils are finite-difference algorithms for solving large-scale and high-dimension partial differential equations. Due to the data dependences among the iterative statements in Stencils, traditional Stencil computations are be executed serially, rather than in parallel. It's challenging to design an effective and scalable Stencil parallelized method. To address the issue of 3D data space computing, we present a serial execution model based on multi-layers symmetric Stencil method and time skewing techniques. Within this model, the iteration space is divided to multiple tiles based on time skewing, where the executive process is ordered by the sequence of tiles, and the nodes in each individual tile can be swept repeatedly to improve the data locality. In addition, we propose a novel 3D iterative space alternate tiling Stencil parallel method, which subdivides the iteration space along high dimension, and changes the execution sequence of tiles to reduce the data dependency and communication cost, where the partial order of tiles is still guaranteed. Experimental results demonstrate our proposed alternative tiling parallel method achieves better parallel efficiency and scalability compared with the domain-decomposition methods.

关键词： Iterative methods

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Feedback control of wave segments in an excitable medium

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Chinese Physics B 2013年第5期22卷 187-190页

作者：吴宁杰高洪俊应和平 Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical SciencesNanjing Normal University Institute of Modern Physics and Department of Physics Zhejiang University

Depending on the excitability of the medium, a propagating wave segment will either contract or expand to fill the medium with spiral waves. This paper aims to introduce a simple mechanism of feedback control to stabilize such an expansion or contraction. To do this, we lay out a feedback control system in a block diagram and reduce it into a bare, universal formula. Analytical and experimental findings are compared through a series of numerical simulations of the Barkley model.

关键词： feedback control wave segments excitable medium

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Predicting web service QoS via combining matrix factorization with network location

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International Journal of u- and e- Service, Science and Technology 2014年第3期7卷 303-318页

作者： Zhou, Li Song, Zhibo Zhai, Suichu Xiao, Tan Yin, Yuyu School of Computer Science and Technology Hangzhou Dianzi University Hangzhou China Key Laboratory of Complex System Modeling and Simulation Ministry of Education China Hangzhou Power Supply Cooperation Hangzhou China Electric Engineering School Zhejiang University Hangzhou China

With the increasing abundance of Web Services across Internet, Quality of Service (QoS)-based service recommendation has become a hot issue. It is necessary to predict the missing values of QoS for service recommendation. Because Web services run on the Internet, their network locations may be anther critical factor for QoS prediction. Although there have existed many works on QoS prediction, few consider the influence of the network locations of users or Web Services. In this paper, we propose a novel collaborative QoS prediction framework with network location-based regularization (NLBR). We first elaborate the popular Matrix Factorization (MF) model for missing values prediction. Then, by taking advantage of the local connectivity between Web services users, we incorporate network location information to identify the neighborhood. We conduct the experiments on a public large-scale real-world QoS dataset, Experiments show that our proposed approaches have the better prediction performance compared with the existed approaches. © 2014 SERSC.

关键词： Web services

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Metastable States and Wetting Transition of Submerged Superhydrophobic Structures

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Physical Review Letters 2014年第19期112卷 196101-196101页

作者： Pengyu Lv Yahui Xue Yipeng Shi Hao Lin Huiling Duan State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering Science College of Engineering Peking University Beijing 100871 China Key Laboratory of High Energy Density Physics Simulation Center for Applied Physics and Technology Peking University Beijing 100871 China Mechanical and Aerospace Engineering Rutgers The State University of New Jersey 98 Brett Road Piscataway New Jersey 08854 USA

Superhydrophobicity on structured surfaces is frequently achieved via the maintenance of liquid-air interfaces adjacent to the trapped air pockets. These interfaces, however, are subject to instabilities due to the Cassie-Baxter-to-Wenzel transition and total wetting. The current work examines in situ liquid-air interfaces on a submerged surface patterned with cylindrical micropores using confocal microscopy. Both the pinned Cassie-Baxter and depinned metastable states are directly observed and measured. The metastable state dynamically evolves, leading to a transition to the Wenzel state. This process is extensively quantified under different ambient pressure conditions, and the data are in good agreement with a diffusion-based model prediction. A similarity law along with a characteristic time scale is derived which governs the lifetime of the air pockets and which can be used to predict the longevity of underwater superhydrophobicity.

关键词： HYDROPHOBIC surfaces RESEARCH METASTABLE states WETTING LIQUID air PHYSICS research

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Theoretical study of a d* resonance in the coupled 3D3−3G3 partial waves of nucleon-nucleon scattering

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Physical Review C 2014年第6期90卷 064003-064003页

作者： Hongxia Huang Jialun Ping Chengrong Deng Fan Wang Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 China School of Mathematics and Physics Chongqing Jiaotong University Chongqing 400074 China Department of Physics Nanjing University Nanjing 210093 China

We calculated the phase shifts of the coupled 3D3−3G3 partial waves of nucleon-nucleon scattering taking into account the 7S3 Δ−Δ channel coupling in the framework of two constituent quark models: the quark delocalization color screening model and the chiral quark model. Our results show that there is a resonance from 7S3ΔΔ coupling to the 3D3NN and 3G3NN partial waves in both of these two models, which is consistent with the d* resonance observed by WASA-at-COSY collaboration. The resonance structure in the 3D3NN partial wave is remarkable, whereas in the 3G3NN phase shifts there is only a small bump around the resonance energy. This result is in agreement with the recent experimental results of WASA-at-COSY Collaboration.

关键词： NUCLEON-nucleon scattering NEUTRON resonance QUARK models DELOCALIZATION energy QUANTUM chromodynamics

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