检索结果-内蒙古大学图书馆

arXiv 2017年

作者： Chen, Minghua Bu, Weiping Qi, Wenya Wang, Yantao School of Mathematics and Statistics Gansu Key Laboratory of Applied Mathematics and Complex Systems Lanzhou University Lanzhou730000 China School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan University Xiangtan411105 China South University of Science and Technology of China Shenzhen518055 China

In this article a theoretical framework for the Galerkin finite element approximation to the time-dependent Riesz tempered fractional problem is provided without the fractional regularity assumption. Because the time-dependent problems should become easier to solve as the time step τ → 0, which correspond to the mass matrix dominant [R. E. Bank and T. Dupont, Math. Comp., 153 (1981), pp. 35-51]. Based on the introduced and analysis of the fractional τ-norm, the uniform convergence estimates of the V-cycle multigrid method with the time-dependent fractional problem is strictly proved, which means that the convergence rate of the V-cycle MGM is independent of the mesh size h and the time step τ. The numerical experiments are performed to verify the convergence with only O(NlogN) complexity by the fast Fourier transform method, where N is the number of the grid points. To the best of our knowledge, this is the first proof for the convergence rate of the V-cycle multigrid finite element method with τ → 0. Copyright © 2017, The Authors. All rights reserved.

关键词： Fast Fourier transforms

来源：评论

学校读者我要写书评

暂无评论

LPI radar signal detection based on radial integration of Choi-Williams time-frequency image

引用

Journal of systems Engineering and Electronics 2015年第5期26卷 973-981页

作者： Yongjian Liu Peng Xiao Hongchao Wu Weihua Xiao Science and Technology on Complex Aviation Systems Simulation Laboratory Aviation University of Air Force

This paper mainly revolves the time-frequency image of low probability of intercept(LPI) radar signals and carries out research work on image features selection and extraction and recognition. Since Choi-Williams distribution(CWD) uses the exponential kernel of bilinear generalized class of time-frequency distribution, it has an excellent time-frequency aggregation. And it is suitable for detecting LPI radar signals in a low signal-to-noise ratio(SNR) condition. A radial integration method based on the integral rotating factor is proposed to detect LPI radar signals when the signals’ time-frequency image is obtained. First, the digital image processing method is used to preprocess the LPI radar signals’ time-frequency images after CWD transformation; then, the radial integration method based on the integral rotating factor is used to detect LPI radar signals in the binary images. The analytic results of real data show that the method has a good performance on detecting LPI radar signals in a low SNR condition. Additionally,the method is simple and takes less logic resources and has the potential of real-time detection of LPI radar signals.

关键词： low probability of intercept(LPI) integral rotating factor signal detection image processing

来源：评论

学校读者我要写书评

暂无评论

Energy efficiency analysis of heterogeneous platforms: Early experiences 7

Energy efficiency analysis of heterogeneous platforms: Early...

引用

7th International Green and Sustainable Computing Conference, IGSC 2016

作者： Li, Youhuizi Shi, Weisong Jiang, Congfeng Zhang, Jilin Wan, Jian Key Laboratory of Complex Systems Modeling and Simulation Hangzhou Dianzi University China Mobile and Internet Systems Laboratory Wayne State University United States School of Information and Electronic Engineering Zhejiang University of Science and Technology China

ISBN: (纸本)9781509051175

Heterogeneous multi-core platforms, e.g., ARM's ***, are a promising trend to improve the performance and energy efficiency of future mobile systems. However, the immediate benefits and the challenges to take advantage of the heterogeneity are still not clear. In this paper, we present our early experiences about the energy efficiency of the two *** heterogeneous platforms: ODROID XU+E and ODROID XU3. We quantified compared them with homogeneous platforms through multiple benchmarks which include popular mobile applications and high-performance parallel benchmarks. Besides, we analyzed the scheduling impact on the energy consumption of the heterogeneous platforms and the migration cost is also discussed. Based on the results, several insights, such as fine-granularity power control and thread level parallelism, related to hardware, application and system design are derived. © 2016 IEEE.

关键词： Energy utilization

来源：评论

学校读者我要写书评

暂无评论

Grand-canonical Monte-Carlo simulation of solutions of salt mixtures: theory and implementation

arXiv

引用

arXiv 2017年

作者： Nguyen, Toan T. VNU Key Laboratory"Multiscale Simulation of Complex Systems" Faculty of Physics VNU University of Science Vietnam National University 334 Nguyen Trai Street Thanh Xuan Hanoi School of Physics Georgia Institute of Technology 837 State Street AtlantaGA30332-0430 United States

A Grand-canonical Monte-Carlo simulation method extended to simulate a mixture of salts is presented. Due to charge neutrality requirement of electrolyte solutions, ions must be added to or removed from the system in groups. This leads to some complications compared to regular Grand Canonical simulation. Here, a recipe for simulation of electrolyte solution of salt mixture is presented. It is then implemented to simulate solution of 1:1, 2:1 and 2:2 salts or their mixtures at different concentrations using the primitive ion model. The osmotic pressures of the electrolyte solutions are calculated and shown to depend linearly on the salt concentrations within the concentration range simulated. We also show that at the same concentration of divalent anions, the presence of divalent cations make it easier to insert monovalent cations into the system. This can explain some quantitative differences observed in experiments of the MgCl2 salt mixture and MgSO4 salt mixture. Copyright © 2017, The Authors. All rights reserved.

关键词： Magnesium compounds

来源：评论

学校读者我要写书评

暂无评论

Beyond bilinear: Generalized multimodal factorized high-order pooling for visual question answering

arXiv

引用

arXiv 2017年

作者： Yu, Zhou Yu, Jun Xiang, Chenchao Fan, Jianping Tao, Dacheng Key Laboratory of Complex Systems Modeling and Simulation School of Computer Science and Technology Hangzhou Dianzi University China Department of Computer Science University of North Carolina Charlotte United States UBTECH Sydney Artificial Intelligence Centre School of Information Technologies Faculty of Engineering and Information Technologies University of Sydney DarlingtonNSW2008 Australia

Visual question answering (VQA) is challenging because it requires a simultaneous understanding of both visual content of images and textual content of questions. To support the VQA task, we need to find good solutions for the following three issues: 1) fine-grained feature representations for both the image and the question;2) multi-modal feature fusion that is able to capture the complex interactions between multi-modal features;3) automatic answer prediction that is able to consider the complex correlations between multiple diverse answers for the same question. For fine-grained image and question representations, a 'co-attention' mechanism is developed by using a deep neural network architecture to jointly learn the attentions for both the image and the question, which can allow us to reduce the irrelevant features effectively and obtain more discriminative features for image and question representations. For multi-modal feature fusion, a generalized Multi-modal Factorized High-order pooling approach (MFH) is developed to achieve more effective fusion of multi-modal features by exploiting their correlations sufficiently, which can further result in superior VQA performance as compared with the state-of-the-art approaches. For answer prediction, the KL (Kullback-Leibler) divergence is used as the loss function to achieve precise characterization of the complex correlations between multiple diverse answers with same or similar meaning, which can allow us to achieve faster convergence rate and obtain slightly better accuracy on answer prediction. A deep neural network architecture is designed to integrate all these aforementioned modules into a unified model for achieving superior VQA performance. With an ensemble of our MFH models, we achieve the state-of-the-art performance on the large-scale VQA datasets and win the runner-up in VQA Challenge 2017. Copyright © 2017, The Authors. All rights reserved.

关键词： Deep neural networks

来源：评论

学校读者我要写书评

暂无评论

Quasi-two-body decays B → ηc(1S, 2S) [ρ(770), ρ(1450), ρ(1700) →] ππ in the perturbative QCD approach

arXiv

引用

arXiv 2017年

作者： Li, Ya Ma, Ai-Jun Rui, Zhou Xiao, Zhen-Jun Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu210023 China College of Sciences North China University of Science and Technology Tangshan063009 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China

In this paper, we calculated the branching ratios of the quasi-two-body decays B → ηc(1S, 2S) [ρ(770), ρ(1450), ρ(1700) →]ππ by employing the perturbative QCD (PQCD) approach. The contributions from the P -wave resonances ρ(770), ρ(1450) and ρ(1700) were taken into account. The two-pion distribution amplitude ΦPππ is parameterized by the vector current time-like form factor Fπ to study the considered decay modes. We found that (a) the PQCD predictions for the branching ratios of the considered quasi-two-body decays are in the order of 10−7 ∼ 10−6, while the two-body decay rates B(B → ηc(1S, 2S)(ρ(1450), ρ(1700))) are extracted from those for the corresponding quasi-two-body decays;(b) the whole pattern of the pion form factor-squared |Fπ|2 measured by the BABAR Collaboration could be understood based on our theoretical results;(c) the general expectation based on the similarity between B → ηcππ and B → J/ψππ decays are confirmed: R2(ηc) ≈ 0.45 is consistent with the measured R2(J/ψ) ≈ 0.56 ± 0.09 within errors;and (d) new ratios R3(ηc(1S)) and R4(ηc(2S)) among the branching ratios of the considered decay modes are defined and could be tested by future experiments. Copyright © 2017, The Authors. All rights reserved.

关键词： Hadrons

来源：评论

学校读者我要写书评

暂无评论

Author Correction: Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic

引用

Nature communications 2020年第1期11卷 6292页

作者： Zhu Liu Philippe Ciais Zhu Deng Ruixue Lei Steven J Davis Sha Feng Bo Zheng Duo Cui Xinyu Dou Biqing Zhu Rui Guo Piyu Ke Taochun Sun Chenxi Lu Pan He Yuan Wang Xu Yue Yilong Wang Yadong Lei Hao Zhou Zhaonan Cai Yuhui Wu Runtao Guo Tingxuan Han Jinjun Xue Olivier Boucher Eulalie Boucher Frédéric Chevallier Katsumasa Tanaka Yiming Wei Haiwang Zhong Chongqing Kang Ning Zhang Bin Chen Fengming Xi Miaomiao Liu François-Marie Bréon Yonglong Lu Qiang Zhang Dabo Guan Peng Gong Daniel M Kammen Kebin He Hans Joachim Schellnhuber Department of Earth System Science Tsinghua University Beijing China. zhuliu@***. Laboratoire des Sciences du Climat et de l'Environnement LSCE CEA CNRS UVSQ Centre d'Etudes Orme de Merisiers Gif-sur-Yvette France. Department of Earth System Science Tsinghua University Beijing China. Department of Meteorology and Atmospheric Science The Pennsylvania State University University Park PA USA. Department of Earth System Science University of California Irvine 3232Croul Hall Irvine CA USA. Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA USA. Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA. Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University of Information Science and Technology Nanjing China. Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China. Climate Change Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China. Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China. School of Environment Tsinghua University Beijing China. School of Mathematical School Tsinghua University Beijing China. Department of Mathematical Sciences Tsinghua University Beijing China. Center of Hubei Cooperative Innovation for Emissions Trading System Wuhan China. Faculty of Management and Economics Kunming University of Science and Technology 13 Kunming China. Economic Research Centre of Nagoya University Furo-cho Chikusa-ku Nagoya Japan. Institut Pierre-Simon Laplace Sorbonne Université/CNRS Paris France. Université Paris Dauphine Place du Maréchal de Lattre de Tassigny 75016 Paris France.

A Correction to this paper has been published: https://***/10.1038/s41467-020-20254-5.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Explore K-Anycast Information Dissemination in Mobile Opportunistic Networks

Explore K-Anycast Information Dissemination in Mobile Opport...

引用

IEEE Wireless Communications and Networking Conference

作者： Peng Liu Jia Xu Biao Xu Key Laboratory of Complex Systems Modeling and Simulation School of Computer Science and Technology Hangzhou Dianzi University

ISBN: (纸本)9781467398152

In Mobile Opportunistic Networks, there are special cases of multicast in which destinations (except the total number) are not predetermined. E.g., a person tries to find another three players to play poker without knowing them. Achieving efficient data routing in this scenario (target any k destinations among m of them) can be very challenge due to (1) no predetermined destinations, (2) extra delay cost by the destinations collision, and (3) difficulty of the receiver quantity control. We define this as a K-Anycast problem, the goal is to route copies of the message to any k destinations with the shortest average delay. In this paper, we first propose a matching method to solve the problem in a centralized way. We then bring forward a layered hierarchical structure where nodes are organized according to their degree of activities. Based on the structure, two routing algorithms are proposed where K-Cast initializes exactly k copies of the message without replication in the middle, K-Epidemic performs epidemic routing only in a controlled range. Both algorithms will first forward copies upwards along the structure and then downwards to the destinations. Experiments on real data trace show that the proposed algorithms achieve much better delay, delivery ratio and lower forwarding numbers.

关键词： Mobile Opportunistic Network Anycast Data routing Destination collision

来源：评论

学校读者我要写书评

暂无评论

A study on formation configuration design for long rang anti-radiation loitering munitions 27

A study on formation configuration design for long rang anti...

引用

27th Chinese Control and Decision Conference, CCDC 2015

作者： Tang, Xue-Mei Yuan, Cao Bo, Pu Bin, Gan Science and Technology on Complex Land Systems Simulation Laboratory Beijing China

ISBN: (纸本)9781479970179

Aiming at improving the target positioning accuracy, the formation configuration of anti-radiation loitering munitions is optimized. Firstly the time difference measuring error and positioning error of the loitering munitions are analyzed and the error propagation model is developed. Then the formation configuration design model is established based on the proposed time difference localization algorithm and the formation flying boundary conditions. Finally, considering the nonlinear features of optimization function for configuration optimization design, the genetic algorithm is introduced to obtain the optimal configuration. The simulation results show that, compared with the traditional formation configurations, the optimization design of configuration can acquire higher estimation accuracy of target position. Besides, the designed configuration has strong robustness. High accuracy estimations of target position can be obtained under a wide range of target position changes. © 2015 IEEE.

关键词： formation configuration loitering munitions optimization design time difference localization

来源：评论

学校读者我要写书评

暂无评论

A system-of-systems architecture-driven modeling method for combat system effectiveness simulation 2

A system-of-systems architecture-driven modeling method for ...

引用

2nd Annual IEEE International Symposium on systems Engineering, ISSE 2016

作者： Li, Xiaobo Wang, Weiping Shu, Zhe Zhu, Ning He, Hua Liao, Tianjun College of Information Systems and Management National University of Defense Technology Changsha Hunan410073 China Department of Mathematics and Computer Science University of Antwerp Antwerp2020 Belgium State Key Laboratory of Complex System Simulation Beijing Institute of Systems Engineering Beijing China

ISBN: (纸本)9781509007936

Under the background of system-of-systems (SoS) counterwork, it is more apparent that the simulation modeling of the equipment should be domain-specific, formal, automatic and composable. Current equipment effectiveness simulation modeling approaches are mainly based on the methods and techniques from the modeling and simulation (M&S) community and software engineering community, and they are not capable to satisfy these four requirements systematically. Thus the systems engineering architecture model and domain knowledge should be used to support effectiveness simulation modeling more effectively. In this research, we propose an architecture-driven modeling method which conforms to the principle of architecture-driven development, uses ontology techniques to build equipment SoS architecture model and sub-domain ontology. This method performs architecture driven simulation modeling to realize the transformation from architecture models to simulation model frameworks;employs ontological metamodeling to design domain-specific modeling languages (DSML) based on the comprehensive usage of architecture models, sub-domain ontologies and M&S formalisms;integrates domain-specific simulation models from various domains using the model framework, and supports the composable development of simulation applications. © 2016 IEEE.

关键词： System of systems

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：