检索结果-内蒙古大学图书馆

Dynamic output-feedback control for continuous-time interval positive systems under L₁ performance

APPLIED MATHEMATICS AND COMPUTATION 2016年 289卷 48-59页

作者： Chen, Xiaoming Chen, Mou Qi, Wenhai Shen, Jun Nanjing Univ Aeronaut & Astronaut Coll Automat Engn Nanjing 210016 Jiangsu Peoples R China Northeastern Univ Coll Informat Sci & Engn Shenyang 110819 Peoples R China

This paper is concerned with the design of L-1-induced dynamic output-feedback controller for continuous-time positive systems with interval uncertainties. A necessary and sufficient condition for stability and L-1-induced performance of positive linear systems is proposed in terms of linear inequalities. Based on this, conditions for the existence of robust dynamic output-feedback controllers are established and an iterative convex optimization approach is developed to solve the conditions. One illustrative example is provided to show the effectiveness and applicability of the theoretical results. (C) 2016 Elsevier Inc. All rights reserved.

关键词： Interval uncertainties iterative algorithm Linear Lyapunov functions L-1-induced performance Output-feedback Positive systems

来源：评论

学校读者我要写书评

暂无评论

Off-grid fast relevance vector machine algorithm for direction of arrival estimation

引用

IET RADAR SONAR AND NAVIGATION 2016年第4期10卷 718-725页

作者： Lin, Jincheng Ma, Xiaochuan Yan, Shefeng Hao, Chengpeng Lin, Geping Chinese Acad Sci Inst Acoust Key Lab Informat Technol Autonomous Underwater Ve Beijing 100190 Peoples R China

Direction of arrival (DOA) estimation is a basic and important problem in signal processing and has been widely applied. Its research has been advanced by the recently developed methods based on Bayesian compressive sensing (BCS). Among these methods, the ones combined with an off-grid (OG) model have been proved to be more accurate than the on-grid ones. However, the conventional BCS-based methods have a disadvantage of the slow speed. In this study, a high-efficiency iterative algorithm, based on the fast relevance vector machine and the OG model, is developed. This new approach applies to both the single- and multiple-snapshot cases. Numerical simulations show that the proposed method estimates DOAs more accurately than the l(1)-penalisation method and computes more efficiently than the conventional BCS-based methods. Finally, comparisons with state-of-the-art methods and Cramer-Rao bound are also reported.

关键词： direction-of-arrival estimation Bayes methods compressed sensing iterative methods learning (artificial intelligence) off-grid fast relevance vector machine algorithm direction of arrival estimation DOA estimation signal processing Bayesian compressive sensing BCS method iterative algorithm OG model multiple-snapshot case single-snapshot case penalisation method Cramer-Rao bound

来源：评论

学校读者我要写书评

暂无评论

Energy efficiency maximisation for WPCN with distributed massive MIMO system

引用

ELECTRONICS LETTERS 2016年第19期52卷 1642-1644页

作者： Kim, W. Yoon, W. Ajou Univ Dept Elect & Comp Engn Suwon South Korea

A joint time allocation and energy beamforming method for the maximisation of the system energy efficiency (EE) in multi-user multi-cell wireless powered communication network (WPCN) with distributed massive multi-input multi-output (DM-MIMO) system is proposed. An iterative algorithm to solve the EE maximisation problem is proposed. The simulation results show that the proposed scheme can achieve a significant EE gain. Further, it reveals that the achievable sum capacity of the DM-MIMO is considerably higher than that of a conventional centralised massive multi-input multi-output system.

关键词： iterative methods cellular radio multi-access systems telecommunication power management MIMO communication energy conservation optimisation WPCN distributed massive MIMO system joint time allocation and energy beamforming method system energy efficiency maximisation system EE maximisation multiuser multicell wireless powered communication network distributed massive multiinput multioutput system iterative algorithm DM-MIMO achievable sum capacity

来源：评论

学校读者我要写书评

暂无评论

The inverse kinematics of a 7R 6-degree-of-freedom robot with non-spherical wrist

引用

ADVANCES IN MECHANICAL ENGINEERING 2017年第8期9卷 1-11页

作者： Wang, Xuhao Zhang, Dawei Zhao, Chen Tianjin Univ Sch Mech Engn Key Lab Mech Theory & Equipment Design Minist Educ Tianjin 300072 Peoples R China

The 7R 6-degree-of-freedom robots with hollow non-spherical wrist have been proven more suitable to spray painting. However, the inverse kinematics of this robot is still imperfect due to the coupling between position and orientation of the end-effector. In this article, a reliable numerical iterative algorithm for the inverse kinematics of a 7R 6-degree-of-freedom robot is proposed. Based on the geometry of the robot, the inverse kinematics is converted into a one-dimensional iterative research problem. Since the Jacobian matrix is not utilized, the proposed algorithm possesses good convergence, even for singular configurations. Moreover, the multiple-solution problem in the inverse kinematics is also discussed. By introducing three robot configuration indicators which are prespecified by a user, the correct solution could be chosen from all the possible solutions. In order to verify the accuracy and efficiency of the proposed algorithm, several simulations are implemented on a practical 7R 6-degree-of-freedom painting robot. The result shows that the proposed algorithm is more advantageous for a continuous trajectory.

关键词： Inverse kinematics iterative algorithm 7R 6-degree-of-freedom robot non-spherical wrist

来源：评论

学校读者我要写书评

暂无评论

Robust power control for femtocell networks with imperfect channel state information

引用

IET COMMUNICATIONS 2016年第8期10卷 882-890页

作者： Liu, Zhixin Zhang, Peng Guan, Xinping Li, Xinbin Yang, Hongjiu Yanshan Univ Inst Elect Engn Qinhuangdao 066004 Peoples R China Shanghai Jiao Tong Univ Sch Elect Informat & Elect Engn Shanghai 200240 Peoples R China

In this study, the authors study the power control for a two-tier network system which is comprised of a central macrocell and several femtocells. In practice, the communication environment is fairly complex and dynamic which leads to the imperfect channel state information (CSI). To enhance the robustness of the two-tier network system, the imperfect CSI in both signal links and interference links are considered and the uncertainties of the CSI are uniformly distributed in an ellipsoid uncertainty set. Then, a probability-constrained optimisation problem is formulated to deal with the uncertainties and protect the quality-of-service of all users. A novel method is provided to convert probability constraints into deterministic ones. Based on them, they propose an iterative algorithm and an admission control algorithm to enhance the network efficiency. They also investigate the case when the distributions of the uncertainties of the CSI are unknown. Finally, numerical results are given to illustrate the effectiveness of the authors' power control scheme.

关键词： robust control power control femtocellular radio radiofrequency interference optimisation probability iterative methods telecommunication congestion control quality of service robust power control imperfect channel state information femtocell networks two-tier network system central macrocell network CSI signal links interference links ellipsoid uncertainty set probability-constrained optimisation problem quality-of-service iterative algorithm admission control algorithm network efficiency communication environment

来源：评论

学校读者我要写书评

暂无评论

Kalman state filtering based least squares iterative parameter estimation for observer canonical state space systems using decomposition

引用

JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2016年 301卷 135-143页

作者： Ding, Feng Liu, Ximei Ma, Xingyun Qingdao Univ Sci & Technol Coll Automat & Elect Engn Qingdao 266042 Peoples R China

This paper focuses on the parameter and state estimation problems for observer canonical state space systems from measurement information, derives a Kalman filter based least squares iterative (KF-LSI) algorithm to estimate the parameters and states, and a model decomposition based KF-LSI algorithm to enhance computational efficiency. An example is provided to confirm the effectiveness of the proposed algorithms. (C) 2016 Elsevier B.V. All rights reserved.

关键词： Kalman filter iterative algorithm Least squares State space system

来源：评论

学校读者我要写书评

暂无评论

Robust adaptive beamforming based on sparse reconstruction using a non-convex optimisation algorithm

引用

ELECTRONICS LETTERS 2016年第19期52卷 1584-1586页

作者： Chen, Pei Zhao, Yongjun Liu, Chengcheng Natl Digital Switching Syst Engn & Technol Res Ct Nav & Aerosp Target Engn Dept Zhengzhou 450001 Peoples R China

A novel robust adaptive beamforming technique is proposed to solve the problem of performance degradation with one single snapshot. A sparse signal recovery model under the non-convex optimisation framework is first established, which dispenses with the mismatched sample covariance matrix, an indispensable part of most existing beamformers. Then, an iterative algorithm is designed to solve the optimisation problem by using the p-shrinkage operator and the alternating direction method of multipliers. The iteration steps are closed form and convenient to apply in practice. Simulation results demonstrate the effectiveness and robustness of the proposed algorithm.

关键词： array signal processing signal reconstruction concave programming covariance matrices iterative methods sparse reconstruction nonconvex optimisation algorithm robust adaptive beamforming technique sparse signal recovery model mismatched sample covariance matrix iterative algorithm p-shrinkage operator multiplier

来源：评论

学校读者我要写书评

暂无评论

Encoding of quantisation partitions optimised for distributed estimation

引用

ELECTRONICS LETTERS 2016年第8期52卷 611-612页

作者： Kim, Y. H. Chosun Univ Dept Elect Engn 309 Pilmum Daero Kwangju 61452 South Korea

A novel algorithm of designing independently operating quantisers at each node that optimise the system-wide metric (i.e. estimation error) for distributed estimation systems is presented. Assuming that each node can collect only its local measurement, the quantisation partitions constructed based on minimisation of the estimation error are not independently encodable at each node. To ensure a perfect independent encoding, a new concept of assigning multiple codewords to each partition is introduced and a simple iterative algorithm that generates a set of such codewords for each partition is proposed and demonstrated through experiments to achieve a significant performance improvement over typical designs and distributed novel designs recently published. Furthermore, the codeword set optimisation rules are suggested to reduce the cardinality of the sets for practical applications.

关键词： quantisation (signal) iterative methods minimisation encoding estimation theory distributed estimation systems quantisation partitions estimation error minimisation perfect independent encoding iterative algorithm codeword set optimisation rules

来源：评论

学校读者我要写书评

暂无评论

A spatially variant total variational model for chromatic aberration correction

引用

JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2016年 41卷 296-304页

作者： Pi, Ling Wang, Wei Ng, Michael Shanghai Jiao Tong Univ Dept Math Shanghai Peoples R China Tongji Univ Dept Math Shanghai Peoples R China Hong Kong Baptist Univ Dept Math Hong Kong Hong Kong Peoples R China

In this paper, we propose a spatially variant total variational model to correct chromatic aberration (CA) that causes false color artifacts near edges in captured images. In general, it may be very difficult to determine suitably CA regions in captured images. Instead of using local image processing methods, our idea is to make use of spatially variant model to control the gradient and intensity matching between the red and blue color channels and the green color channel at the edges. The total variation regularization is also employed to constraint the change of the intensity of red and blue color channels during the gradient and intensity matching. We present both theoretical results and algorithms for the proposed model. Experimental results are given to illustrate the effectiveness of the proposed model and algorithm and show that their corrected images are visually better than those corrected by the other testing methods. (C) 2016 Elsevier Inc. All rights reserved.

关键词： Chromatic aberration Spatially variant Total variational iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

iterative Learning Control for RF Power Amplifier Linearization

引用

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 2016年第9期64卷 2778-2789页

作者： Chani-Cahuana, Jessica Landin, Per Niklas Fager, Christian Eriksson, Thomas Chalmers Univ Technol Dept Signals & Syst S-41296 Gothenburg Sweden Ericsson AB S-69233 Kumla Sweden Chalmers Univ Technol Dept Microtechnol & Nanosci S-41296 Gothenburg Sweden

This paper proposes a new technique to identify the parameters of a digital predistorter based on iterative learning control (ILC). ILC is a well-established control theory technique that can obtain the inverse of a system. Instead of focusing on identifying the predistorter parameters, the technique proposed here first uses an iterative learning algorithm to identify the optimal power amplifier (PA) input signal that drives the PA to the desired linear output response. Once the optimal PA input signal is identified, the parameters of the predistorter are estimated using standard modeling approaches, e.g., least squares. To this end, in this paper, we present a complete derivation of an ILC scheme suitable for the linearization of PAs, which includes convergence conditions and the derivation of two learning algorithms. The proposed ILC scheme and parameter identification technique were demonstrated experimentally and compared with the indirect learning architecture (ILA) and direct learning architecture (DLA). The experimental results show that, even for the most difficult cases, the proposed ILC scheme can successfully linearize the PA. The experimental results also indicate that the proposed parameter identification technique is more robust to measurement noise than ILA and can provide better linearity performance when the PA nonlinearities are strong. In addition, the proposed parameter identification technique can achieve similar or better linearity performance than DLA but with a simpler identification process.

关键词： Digital predistortion (DPD) iterative algorithm linearization nonlinear distortion nonlinear systems nonlinearity power amplifier (PA)

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：