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Joint power and admission control based on channel distribution information: A novel two-timescale approach

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arXiv 2017年

作者： Chen, Qitian Kang, Dong He, Yichu Chang, Tsung-Hui Liu, Ya-Feng School of Mathematical Sciences Peking University Beijing100871 China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China School of Science and Engineering Chinese University of Hong Kong Shenzhen Research Institute of Big Data Shenzhen518172 China

In this letter, we consider the joint power and admission control (JPAC) problem by assuming that only the channel distribution information (CDI) is available. Under this assumption, we formulate a new chance (probabilistic) constrained JPAC problem, where the signal to interference plus noise ratio (SINR) outage probability of the supported links is enforced to be not greater than a prespecified tolerance. To efficiently deal with the chance SINR constraint, we employ the sample approximation method to convert them into finitely many linear constraints. Then, we propose a convex approximation based deflation algorithm for solving the sample approximation JPAC problem. Compared to the existing works, this letter proposes a novel two-timescale JPAC approach, where admission control is performed by the proposed deflation algorithm based on the CDI in a large timescale and transmission power is adapted instantly with fast fadings in a small timescale. The effectiveness of the proposed algorithm is illustrated by simulations. Copyright © 2017, The Authors. All rights reserved.

关键词： Signal interference

A monotone finite volume method for time fractional Fokker-Planck equations

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arXiv 2017年

作者： Jiang, Yingjun Xu, Xuejun Department of Mathematics and Scientific Computing Changsha University of Science and Technology Changsha410076 China Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences P.O. Box 2719 Beijing100190 China School of Mathematical Sciences Tongji University Shanghai China

We develop a monotone finite volume method for the time fractional Fokker-Planck equations and theoretically prove its unconditional stability. We show that the convergence rate of this method is order 1 in space and if the space grid becomes sufficiently fine, the convergence rate can be improved to order 2. Numerical results are given to support our theoretical findings. One characteristic of our method is that it has monotone property such that it keeps the nonnegativity of some physical variables such as density, concentration, etc.65M12, 65M06, 35S1065M12, 65M06, 35S10 Copyright © 2017, The Authors. All rights reserved.

关键词： Finite volume method

A Navier-Stokes-Korteweg Model for Dynamic Wetting based on the PeTS Equation of State

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PAMM 2019年第1期19卷

作者： Felix Diewald Michaela Heier Martin Lautenschläger Martin Horsch Charlotte Kuhn Kai Langenbach Hans Hasse Ralf Müller Institute of Applied Mechanics TU Kaiserslautern 67653 Kaiserslautern Germany Laboratory of Engineering Thermodynamics TU Kaiserslautern 67653 Kaiserslautern Germany Scientific Computing Department Daresbury Laboratory Warrington WA4 4AD UK Computational Mechanics TU Kaiserslautern 67653 Kaiserslautern Germany

Dynamic wetting of component surfaces can be investigated by finite element phase field simulations. Often these models use a double-well potential or the van der Waals equation to define the local part of the free energy density at a point of the computational domain. In order to give the present model a stronger physical background the molecular dynamics based perturbed Lennard-Jones truncated and shifted (PeTS) equation of state is used instead. This results in phase field liquid-vapor interfaces that agree with the physical density gradient between the two phases. In order to investigate dynamic scenarios, the phase field description is coupled to the compressible Navier-Stokes equations. This coupling requires a constitutive equation that complies with the surface tension of the liquid-vapor interface resulting from the PeTS equation of state and is comparable to the so-called Korteweg tensor.

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CP2K: An electronic structure and molecular dynamics software package quickstep: Efficient and accurate electronic structure calculations

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arXiv 2020年

作者： Kühne, Thomas D. Iannuzzi, Marcella Ben, Mauro Del Rybkin, Vladimir V. Seewald, Patrick Stein, Frederick Laino, Teodoro Khaliullin, Rustam Z. Schütt, Ole Schiffmann, Florian Golze, Dorothea Wilhelm, Jan Chulkov, Sergey Bani-Hashemian, Mohammad Hossein Weber, Valéry Borštnik, Urban Taillefumier, Mathieu Jakobovits, Alice Shoshana Lazzaro, Alfio Pabst, Hans Müller, Tiziano Schade, Robert Guidon, Manuel Andermatt, Samuel Holmberg, Nico Schenter, Gregory K. Hehn, Anna Bussy, Augustin Belleflamme, Fabian Tabacchi, Gloria Glöß, Andreas Lass, Michael Bethune, Iain Mundy, Christopher J. Plessl, Christian Watkins, Matt VandeVondele, Joost Krack, Matthias Hutter, Jürg Dynamics of Condensed Matter and Center for Sustainable Systems Design Chair of Theoretical Chemistry Paderborn University Warburger Str. 100 PaderbornD-33098 Germany Department of Chemistry University of Zurich Winterthurerstrasse 190 ZürichCH-8057 Switzerland Computational Research Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States IBM Research - Zurich Säumerstrasse 4 RüschlikonCH-8803 Switzerland Department of Chemistry McGill University CH-801 Sherbrooke St. West MontrealQCH3A 0B8 Canada Department of Materials ETH Zürich ZürichCH-8092 Switzerland Centre of Policy Studies Victoria University Melbourne Australia Department of Applied Physics Aalto University Otakaari 1 EspooFI-02150 Finland Institute of Theoretical Physics University of Regensburg Universitätsstraße 31 RegensburgD-93053 Germany School of Mathematics and Physics University of Lincoln Brayford Pool Lincoln United Kingdom Integrated Systems Laboratory ETH Zürich ZürichCH-8092 Switzerland Scientific IT Services ETH Zürich Zürich Switzerland ETH Zürich HPE Switzerland GmbH Basel Switzerland Intel Extreme Computing Software and Systems Zürich Switzerland Department of Computer Science and Paderborn Center for Parallel Computing Paderborn University Warburger Str. 100 PaderbornD-33098 Germany Department of Chemistry and Materials Science Aalto University P.O. Box 16100 Aalto00076 Finland Physical Science Division Pacific Northwest National Laboratory P. O. Box 999 RichlandWA99352 United States Department of Science and High Technology University of Insubria INSTM via Valleggio 9 ComoI-22100 Italy BASF SE Carl-Bosch-Straße 38 Ludwigshafen am RheinD-67056 Germany Hartree Centre Science and Technology Facilities Council United Kingdom Laboratory for Scientific Computing and Modelling Paul Scherrer Institute Villigen PSICH-5232 Switzerland

CP2K is an open source electronic structure and molecular dynamics software package to perform atomistic simulations of solid-state, liquid, molecular and biological systems. It is especially aimed at massively-parallel and linear-scaling electronic structure methods and state-of-the-art ab-initio molecular dynamics simulations. Excellent performance for electronic structure calculations is achieved using novel algorithms implemented for modern high-performance computing systems. This review revisits the main capabilities of CP2K to perform efficient and accurate electronic structure simulations. The emphasis is put on density functional theory and multiple post-Hartree-Fock methods using the Gaussian and plane wave approach and its augmented all-electron extension. Copyright © 2020, The Authors. All rights reserved.

关键词： Electronic structure

A Mathematical Aspect of Hohenberg-Kohn Theorem∗

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arXiv 2017年

作者： Zhou, Aihui LSEC Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing100049 China

The Hohenberg-Kohn theorem plays a fundamental role in density functional theory, which has become a basic tool for the study of electronic structure of matter. In this article, we study the Hohenberg-Kohn theorem for a class of external potentials based on a unique continuation *** Codes 81V70 Copyright © 2017, The Authors. All rights reserved.

关键词： Electronic structure

New characterizations for the variation of the spectrum of an arbitrary matrix

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arXiv 2017年

作者： Xu, Xuefeng LSEC Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing100049 China

The celebrated Hoffman–Wielandt theorem reveals the strong stability of the spectrum of a normal matrix under perturbations. Over the past decades, some analogs of the Hoffman–Wielandt theorem have been developed to characterize the stability of the spectrum of an arbitrary matrix. In this paper, we establish new perturbation bounds to characterize the variation of the spectrum of an arbitrary matrix. The counterparts of the existing results are also given, which are sharper than the existing ones. Moreover, our results have generalized some perturbation bounds for the spectrum of a normal matrix. Copyright © 2017, The Authors. All rights reserved.

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Structured Quasi-Newton methods for optimization with orthogonality constraints

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arXiv 2018年

作者： Hu, Jiang Jiang, Bo Lin, Lin Wen, Zaiwen Yuan, Yaxiang Beijing International Center for Mathematical Research Peking University China School of Mathematical Sciences Key Laboratory for NSLSCS of Jiangsu Province Nanjing Normal University China Department of Mathematics University of California Berkeley BerkeleyCA94720 United States Computational Research Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States State Key Laboratory of Scientific and Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences China

In this paper, we study structured quasi-Newton methods for optimization problems with orthogonality constraints. Note that the Riemannian Hessian of the objective function requires both the Euclidean Hessian and the Euclidean gradient. In particular, we are interested in applications that the Euclidean Hessian itself consists of a computational cheap part and a significantly expensive part. Our basic idea is to keep these parts of lower computational costs but substitute those parts of higher computational costs by the limited-memory quasi-Newton update. More specically, the part related to Euclidean gradient and the cheaper parts in the Euclidean Hessian are preserved. The initial quasi-Newton matrix is further constructed from a limited-memory Nyström approximation to the expensive part. Consequently, our subproblems approximate the original objective function in the Euclidean space and preserve the orthogonality constraints without performing the so-called vector transports. When the subproblems are solved to sufficient accuracy, both global and local q-superlinear convergence can be established under mild conditions. Preliminary numerical experiments on the linear eigenvalue problem and the electronic structure calculation show the effectiveness of our method compared with the state-of-art algorithms. Copyright © 2018, The Authors. All rights reserved.

关键词： Eigenvalues and eigenfunctions

Performance Prediction Based on Statistics of Sparse Matrix-Vector Multiplication on GPUs

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Journal of Computer and Communications 2017年第6期5卷 65-83页

作者： Ruixing Wang Tongxiang Gu Ming Li Country Graduate School of Chinese Academy of Engineering Physics Beijing China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing China Country Xi’an Aeronautics Computing Technique Research Institute AVIC Xi’an China

As one of the most essential and important operations in linear algebra, the performance prediction of sparse matrix-vector multiplication (SpMV) on GPUs has got more and more attention in recent years. In 2012, Guo and Wang put forward a new idea to predict the performance of SpMV on GPUs. However, they didn’t consider the matrix structure completely, so the execution time predicted by their model tends to be inaccurate for general sparse matrix. To address this problem, we proposed two new similar models, which take into account the structure of the matrices and make the performance prediction model more accurate. In addition, we predict the execution time of SpMV for CSR-V, CSR-S, ELL and JAD sparse matrix storage formats by the new models on the CUDA platform. Our experimental results show that the accuracy of prediction by our models is 1.69 times better than Guo and Wang’s model on average for most general matrices.

关键词： Sparse Matrix-Vector Multiplication Performance Prediction GPU Normal Distribution Uniform Distribution

Flexible multiple base station association and activation for downlink heterogeneous networks

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arXiv 2017年

作者： Shen, Kaiming Liu, Ya-Feng Ding, David Yiwei Yu, Wei Edward S. Rogers Sr. Department of Electrical and Computer Engineering University of Toronto TorontoONM5S 3G4 Canada State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China

This letter shows that the flexible association of possibly multiple base stations (BSs) to each user over multiple frequency bands, along with the joint optimization of BS transmit power that encourages the turning-off of the BSs at off-peak time, can significantly improve the performance of a downlink heterogeneous wireless cellular network. We propose a gradient projection algorithm for optimizing BS association and an iteratively reweighting scheme together with a novel proximal gradient method for optimizing power in order to find the optimal tradeoff between network utility and power consumption. Simulation results reveal significant performance improvement as compared to the conventional single-BS association. Copyright © 2017, The Authors. All rights reserved.

关键词： Chemical activation