检索结果-内蒙古大学图书馆

decomposition by Successive Convex Approximation: A Unifying Approach for Linear Transceiver Design in Heterogeneous Networks

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2016年第2期15卷 1377-1392页

作者： Hong, Mingyi Li, Qiang Liu, Ya-Feng Iowa State Univ Dept Ind & Mfg Syst Engn Ames IA USA Univ Elect Sci & Technol China Sch Commun & Informat Engn Chengdu 610054 Peoples R China Chinese Acad Sci Acad Math & Syst Sci Inst Computat Math & Sci Engn Comp State Key Lab Sci & Engn Comp Beijing 100190 Peoples R China

We study the downlink linear precoder design problem in a multicell dense heterogeneous network (HetNet). The problem is formulated as a general sum-utility maximization (SUM) problem, which includes as special cases many practical precoder design problems such as multicell coordinated linear precoding, full and partial per-cell coordinated multipoint transmission, zero-forcing precoding, and joint BS clustering and beamforming/precoding. The SUM problem is difficult due to its nonconvexity and the tight coupling of the users' precoders. In this paper, we propose a novel convex approximation technique to approximate the original problem by a series of convex subproblems, each of which decomposes across all the cells. The convexity of the subproblems allows for efficient computation, while their decomposability leads to distributed implementation. Our approach hinges upon the identification of certain key convexity properties of the sum-utility objective, which allows us to transform the problem into a form that can be solved using a popular algorithmic framework called block successive upper-bound minimization (BSUM). Simulation experiments show that the proposed framework is effective for solving interference management problems in large HetNet.

关键词： BSUM decomposition algorithms HetNet Precoder Design SCA

来源：评论

学校读者我要写书评

暂无评论

New decomposition methods for solving variational inequality problems

引用

MATHEMATICAL AND COMPUTER MODELLING 2003年第3-4期37卷 405-418页

作者： Han, DR Sun, WY Nanjing Normal Univ Sch Math & Comp Sci Nanjing 210097 Peoples R China

For solving large-scale constrained separable variational inequality problems, the de-composition methods are attractive, since they solve the original problems via solving a series of small-scale problems, which may be much easier to solve than the original problems. In this paper, we-propose some new decomposition methods, which axe based on the Lagrange and the augmented Lagrange mappings of the problems, respectively. For the global convergence, the first method needs the partial cocoercivity of the underlying mapping, while the second one just requires monotonicity, a condition which is much weaker than partial cocoercivity. The cost for this weaker condition is to perform two additional projection steps on the dual variables and the primal-dual variables. We then extend the method to a more practical one, which just solves the subproblem approximately. We also report some computational results of the inexact method to show its promise. (C) 2003 Elsevier Science Ltd. All rights reserved.

关键词： variational inequality problems decomposition algorithms partial cocoercive mappings monotone mappings global convergence

来源：评论

学校读者我要写书评

暂无评论

Comparison of conventional and decomposition-enhanced spike triggered averaging techniques

引用

CLINICAL NEUROPHYSIOLOGY 2004年第3期115卷 564-568页

作者： Lawson, VH Bromberg, MB Stashuk, D Univ Utah Dept Neurol Salt Lake City UT 84132 USA Univ Waterloo Dept Biomed Med Engn Waterloo ON N2L 3G1 Canada

Objective: Spike triggered averaging (STA) is a technique to extract an estimate of a recurring motor unit potential from a complex electromyographic (EMG) signal. In conventional STA (C-STA), potentials related to the discharges of single intramuscular motor units are isolated and used to trigger an averager to obtain an individual surface-detected motor unit potential (S-MUP) from an EMG signal. In decomposition-enhanced STA (DE-STA), EMG signal decomposition algorithms determine discharges of a number of different motor units (4 to 10) that can be used to trigger an averager to obtain their corresponding S-MUPs. We tested the accuracy of extracting and averaging SMUPs using DE-STA compared to C-STA for the same EMG signals. Methods: We compared the intramuscular potentials used for triggering and the resultant averaged S-MUPs that were common in both techniques. Results: We found no statistically significant differences in the metrics used to describe the triggering potentials and S-MUPs. Conclusions: We conclude that DE-STA is an accurate and efficient method to obtain a large number of intramuscular motor unit potentials and their corresponding S-MUP in proximal and distal muscles. (C) 2004 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

关键词： spike triggered averaging decomposition algorithms motor unit number estimation

来源：评论

学校读者我要写书评

暂无评论

An Improved decomposition and Drawing Process for Optimal Topological Visualization of Directed Graphs 15

An Improved Decomposition and Drawing Process for Optimal To...

引用

31st Spring Conference on Computer Graphics

作者： Abuthawabeh, Ala Zeckzer, Dirk TU Kaiserslautern Kaiserslautern Germany Univ Leipzig D-04109 Leipzig Germany

ISBN: (纸本)9781450336932

Important information in application areas like Bio-Informatics, Biology, and Software Engineering is encoded in directed graphs. Typically, these graphs are represented using node-link diagrams. In these areas differentiating between cyclic and acyclic subgraphs shows important information about the structure and eases the analysis of these graphs. However, existing approaches are uniform and do not differentiate between different structures while computing the layout of the directed graph. We propose a topology-based approach that decomposes directed graphs into subgraphs for different topological structures, builds a two-level hierarchy of coarse grained graphs, and applies optimized area-aware layout algorithms to draw them. We applied our approach to one synthetic data set for illustration purposes and to one real data set showing usage dependencies in a software system. The results show that the different structural components of the directed graphs can be clearly identified.

关键词： topological visualization directed graphs graph drawing cyclic area-aware layout decomposition algorithms

来源：评论

学校读者我要写书评

暂无评论

STRUCTURAL-PROPERTIES AND RECOGNITION OF RESTRICTED AND STRONGLY UNIMODULAR MATRICES

引用

MATHEMATICAL PROGRAMMING 1987年第1期38卷 17-27页

作者： CONFORTI, M RAO, MR New York University New York USA

A (0, ±1) matrix A is restricted unimodular if every matrix obtained from A by setting to zero any subset of its entries is totally unimodular. Restricted unimodular matrices are also known as matrices without odd cycles. They have been studied by Commoner and recently Yannakakis has given a polynomial algorithm to recognize when a matrix belongs to this class. A matrix A is strongly unimodular if any matrix obtained from A by setting at most one of its entries to zero is totally unimodular. Crama et al. have shown that (0,1) matrix A is strongly unimodular if and only if any basis of (A, 1) is triangular, whereI is an identity matrix of suitable dimensions. In this paper we give a very simple algorithm to test whether a matrix is restricted unimodular and we show that all strongly unimodular matrices can be obtained by composing restricted unimodular matrices with a simple operation.

关键词： decomposition algorithms Integer programming totally unimodular matrices

来源：评论

学校读者我要写书评

暂无评论

SDDP for multistage stochastic linear programs based on spectral risk measures

引用

OPERATIONS RESEARCH LETTERS 2012年第5期40卷 313-318页

作者： Guigues, Vincent Roemisch, Werner Univ Berlin Inst Math D-10099 Berlin Germany IMPA Rio De Janeiro Brazil Univ Fed Rio de Janeiro Escola Politecn Dept Engn Ind Ilha FundaoCT Rio de Janeiro Brazil

We consider risk-averse formulations of multistage stochastic linear programs. For these formulations, based on convex combinations of spectral risk measures, risk-averse dynamic programming equations can be written. As a result, the Stochastic Dual Dynamic Programming (SDDP) algorithm can be used to obtain approximations of the corresponding risk-averse recourse functions. This allows us to define a risk-averse nonanticipative feasible policy for the stochastic linear program. Formulas for the cuts that approximate the recourse functions are given. In particular, we show that some cut coefficients have analytic formulas. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Spectral risk measure Stochastic programming Risk-averse optimization decomposition algorithms Monte Carlo sampling

来源：评论

学校读者我要写书评

暂无评论

A CASCADE IMPLEMENTATION OF DIGITAL-SYSTEMS

MICROPROCESSING AND MICROPROGRAMMING

引用

MICROPROCESSING AND MICROPROGRAMMING 1990年第3期29卷 151-163页

作者： DVORAK, V TECH UNIV BRNO DEPT COMPCS-61266 BRNOCZECHOSLOVAKIA

This paper presents a new synthesis technique of multiple-output combinational networks based on iterative decomposition that results in implementation of digital systems in a form of a cascade of subsystems with regular interconnections. Some new theorems are proven and a figure of merit of cascade implementations is introduced in order to compare cost-effectiveness of different configurations. The technique is illustrated on several examples. Applications of cascade synthesis are found in multi-level partitioning of ROMs, in designing pipelined structures, and also in simulation of large multiple output Boolean function in software, which is several times faster than evaluation of Boolean expressions.

关键词： Cellular cascades decomposition algorithms Evaluation of logic functions Iterative decomposition Partial functions Pipelined processing ROM-based logic design

来源：评论

学校读者我要写书评

暂无评论

Obtaining lower bounds from the progressive hedging algorithm for stochastic mixed-integer programs

引用

MATHEMATICAL PROGRAMMING 2016年第1期157卷 47-67页

作者： Gade, Dinakar Hackebeil, Gabriel Ryan, Sarah M. Watson, Jean-Paul Wets, Roger J. -B. Woodruff, David L. Sabre Holdings Southlake TX 76092 USA Sandia Natl Labs POB 5800 Albuquerque NM 87185 USA Texas A&M Univ College Stn TX 77843 USA Iowa State Univ Ames IA 50011 USA Univ Calif Davis Davis CA 95616 USA

We present a method for computing lower bounds in the progressive hedging algorithm (PHA) for two-stage and multi-stage stochastic mixed-integer programs. Computing lower bounds in the PHA allows one to assess the quality of the solutions generated by the algorithm contemporaneously. The lower bounds can be computed in any iteration of the algorithm by using dual prices that are calculated during execution of the standard PHA. We report computational results on stochastic unit commitment and stochastic server location problem instances, and explore the relationship between key PHA parameters and the quality of the resulting lower bounds.

关键词： Stochastic mixed-integer programming decomposition algorithms Lower bounding

来源：评论

学校读者我要写书评

暂无评论

Computing call-blocking probabilities in LEO satellite networks: The single-orbit case

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2002年第2期51卷 332-347页

作者： Zaim, AH Rouskas, GN Perros, HG N Carolina State Univ Dept Comp Sci Raleigh NC 27695 USA

We study the problem of carrying voice calls over a low-earth-orbit satellite network and present an analytical model for computing call-blocking probabilities for a single orbit of a satellite constellation. We have devised a method to solve the corresponding Markov process efficiently for orbits of up to five satellites. For orbits consisting of a larger number of satellites, we have developed an approximate decomposition algorithm to compute the call-blocking probabilities by decomposing the system into smaller subsystems and iteratively solving each subsystem in isolation using the exact Markov process. Our approach can capture blocking due to handoffs for both satellite-fixed and earth-fixed constellations. Numerical results demonstrate that our method is accurate for a wide range of traffic patterns and for orbits with a number of satellites that is representative of commercial satellite systems.

关键词： call blocking probability decomposition algorithms handoffs low-earth-orbit (LEO) satellite networks

来源：评论

学校读者我要写书评

暂无评论

SDDP for some interstage dependent risk-averse problems and application to hydro-thermal planning

引用

COMPUTATIONAL OPTIMIZATION AND APPLICATIONS 2014年第1期57卷 167-203页

作者： Guigues, Vincent Fundacao Getulio Vargas Escola Matemat Aplicada Rio De Janeiro Brazil IMPA Rio De Janeiro Brazil Univ Fed Rio de Janeiro Escola Politecn Dept Engn Ind Ilha Fundao Rio de Janeiro Brazil

We consider interstage dependent stochastic linear programs where both the random right-hand side and the model of the underlying stochastic process have a special structure. Namely, for equality constraints (resp. inequality constraints) the right-hand side is an affine function (resp. a given function b (t) ) of the process value for the current time step t. As for m-th component of the process at time step t, it depends on previous values of the process through a function h (tm) . For this type of problem, to obtain an approximate policy under some assumptions for functions b (t) and h (tm) , we detail a stochastic dual dynamic programming algorithm. Our analysis includes some enhancements of this algorithm such as the definition of a state vector of minimal size, the computation of feasibility cuts without the assumption of relatively complete recourse, as well as efficient formulas for sharing optimality and feasibility cuts between nodes of the same stage. The algorithm is given for both a non-risk-averse and a risk-averse model. We finally provide preliminary results comparing the performances of the recourse functions corresponding to these two models for a real-life application.

关键词： Stochastic programming Risk-averse optimization decomposition algorithms Interstage dependency Monte Carlo sampling

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：