检索结果-内蒙古大学图书馆

作者： Eckhard, Diego

Data-based control design methods consist of adjusting the parameters of the controller directly from batches of input-output data of the process; no process model is used. The adjustment is done by solving an optimization problem, which searches the argument that minimizes a specific cost function. Iterative algorithms based on the gradient are applied to solve the optimization problem, like the steepest descent algorithm, Newton algorithm and some variations. The only information utilized for the steepest descent algorithm is the gradient of the cost function, while the others need more information like the hessian. Longer and more complex experiments are used to obtain more informations, that turns the application more complicated. For this reason, the steepest descent method was chosen to be studied in this work. The convergence of the steepest descent algorithm to the global minimum is not fully studied in the literature. This convergence depends on the initial conditions of the algorithm and on the step size. The initial conditions must be inside a specific domain of attraction, and how to enlarge this domain is treated by the methodology Cost Function Shaping. The main contribution of this work is a method to compute efficiently the step size, to ensure convergence to the global minimum. Some informations about the process are utilized, and this work presents how to estimate these informations. Simulations and experiments demonstrate how the methods work. ...

关键词： Data-based tuning Controle automático H2 criterium Otimização matemática steepest descent algorithm Controle de processos Global minimum Dissertação

来源：评论

学校读者我要写书评

暂无评论

Coordinated Optimization of Parameters of PSS and UPFC-PODCs to Improve Small-Signal Stability of a Power System with Renewable Energy Generation

引用

JOURNAL OF ENERGY ENGINEERING 2021年第2期147卷 04020089-04020089页

作者： He, Ping Shen, Runjie Wen, Fushuan Pan, Qi Zhengzhou Univ Light Ind Coll Elect & Informat Engn Zhengzhou 450002 Peoples R China Tallinn Univ Technol Dept Elect Power Engn & Mechatron EE-19086 Thilinn Estonia

The ever-increasing penetration of intermittent renewable energy generation from wind farms (WFs) and photovoltaic (PV) plants has significant impacts on the stability of the power system concerned. This paper examined the effect of the power oscillation damping controller (PODC), consisting of a power system stabilizer (PSS) and a unified power flow controller (UPFC), on the stability of a power system with doubly fed induction generators (DFIGs) based WFs and PV plants. The small-signal stability of a power system with intermittent renewable energy generation was enhanced by coordinately adjusting the parameters of damping controllers of the PSS and UPFC-PODC, as formulated as a multiobjective optimization and solved by the steepest descent algorithm (SDA). The well-coordinated application can suppress significantly the low-frequency oscillation (LFO). In addition, an index based on eigenvalues and damping ratios is proposed to measure the damping change of the power system. A four-machine, two-area sample power system was employed to test the proposed method through several designed scenarios, including changing the tie-line transmission power, increasing wind power and PV outputs, and changing WF and PV plant access points. The performance of the proposed method was demonstrated through small-disturbance eigenvalue analysis and short-circuit fault dynamic time-domain simulation. Simulation results showed that simultaneous optimization of parameters among different controllers effectively suppresses local and interarea oscillations.

关键词： Power system Renewable energy generation Small-signal stability steepest descent algorithm Power system stabilizer (PSS) Unified power flow controller (UPFC) Power oscillation damping controller (PODC)

来源：评论

学校读者我要写书评

暂无评论

Frequency estimation of multiple complex sinusoids using noise suppressing predictive FIR filter

引用

DIGITAL SIGNAL PROCESSING 2023年 143卷

作者： Kukrer, Osman Ince, Erhan A. Eastern Mediterranean Univ Dept Elect & Elect Engn Mersin Turkiye

The paper presents a predictive filter based frequency estimation algorithm (PF-FE) for multiple complex sinusoids corrupted by additive white Gaussian noise. The proposed frequency estimator combines the noise suppression capability of an FIR filter with a least squares approach minimizing the sum of the squared errors of a prediction filter. The FIR filter coefficients are chosen such that the sinusoidal components are predicted with minimum distortion. Computer simulation results are given to contrast the performance of the proposed PF-FE method with six other state-of-the-art frequency-estimators and the Cramer-Rao lower bound. Furthermore, the paper provides a complexity analysis of the PF-FE method and compares it with those of the conventional MUltiple SIgnal Classification algorithm and some selected state-of-the-art methods from the literature. Performance of the proposed PF-FE method is validated with effective mean square error (EMSE) plots for model orders of three and five and under different observation lengths and signal-to-noise ratio values. Finally, the paper demonstrates how EMSE varies for the proposed method when the prediction filter length is increased from 20 to 75. After extensive simulations, it is observed that when filter length is larger than half the observation length the EMSE will start to degrade.

关键词： Frequency estimation Predictive FIR filtering steepest descent algorithm Line search via quadratic fit

来源：评论

学校读者我要写书评

暂无评论

M-Convex Function Minimization Under L1-Distance Constraint and Its Application to Dock Reallocation in Bike-Sharing System

引用

MATHEMATICS OF OPERATIONS RESEARCH 2022年第2期47卷 1566-1611页

作者： Shioura, Akiyoshi Tokyo Inst Technol Dept Ind Engn & Econ Tokyo 1528550 Japan

In this paper, we consider a problem of minimizing an M-convex function under an L1-distance constraint (MML1);the constraint is given by an upper bound for L1-distance between a feasible solution and a given "center." This is motivated by a nonlinear integer programming problem for reallocation of dock capacity in a bike-sharing system discussed by Freund et al. (2017). The main aim of this paper is to better understand the combinatorial structure of the dock reallocation problem through the connection with M-convexity and show its polynomial-time solvability using this connection. For this, we first show that the dock reallocation problem and its generalizations can be reformulated in the form of (MML1). We then present a pseudo-polynomial-time algorithm for (MML1) based on the steepest descent approach. We also propose two polynomial-time algorithms for (MML1) by replacing the L1-distance constraint with a simple linear constraint. Finally, we apply the results for (MML1) to the dock reallocation problem to obtain a pseudo-polynomial-time steepest descent algorithm and also polynomial-time algorithms for this problem. For this purpose, we develop a polynomial-time algorithm for a relaxation of the dock reallocation problem by using a proximity-scaling approach, which is of interest in its own right.

关键词： discrete convex function discrete convex analysis resource allocation problem steepest descent algorithm proximity-scaling algorithm

来源：评论

学校读者我要写书评

暂无评论

Adaptive Feedforward Compensating Self-Sensing Method for Active Flutter Suppression

引用

SENSORS 2018年第10期18卷 3447-3447页

作者： Wang, Yizhe Xu, Zhiwei Nanjing Univ Aeronaut & Astronaut State Key Lab Mech & Control Mech Struct Nanjing 211106 Jiangsu Peoples R China

A single piezoelectric patch can be used as both a sensor and an actuator by means of the self-sensing piezoelectric actuator, and the function of self-sensing shows several advantages in many application fields. However, some problems exist in practical application. First, a capacitance bridge circuit is set up to realize the function of self-sensing, but the precise matching of the capacitance of the bridge circuit is hard to obtain due to the standardization of electric components and variations of environmental conditions. Second, a local strain is induced by the self-sensing actuator that is not related to the global vibration of the structure, which would affect the performance of applications, especially in active vibration control. The above problems can be tackled by the feedforward compensation method that is proposed in this paper. A configured piezoelectric self-sensing circuit is improved by a feedforward compensation tunnel, and a gain of compensation voltage is adjusted by the time domain and frequency domain's steepest descent algorithms to alleviate the capacitance mismatching and local strain problems. The effectiveness of the method is verified in the experiment of the active vibration control in a wind tunnel, and the control performance of compensated self-sensing actuation is compared to the performance with capacitance mismatching and local strain. It is found that the above problems have negative effects on the stability and performance of the vibration control and can be significantly eliminated by the proposed method.

关键词： self-sensing actuation feedforward compensation capacitance mismatching local strain steepest descent algorithm active flutter suppression

来源：评论

学校读者我要写书评

暂无评论

Improved RBF network application in analog circuit fault isolation

引用

Journal of Measurement Science and Instrumentation 2012年第1期3卷 70-74页

作者：禹航肖明清赵鑫 ATS Lab Engineering CollegeAir Force Engineering University

One kind of steepest descent incremental projection learning algorithm for improving the training of radial basis function(RBF)neural network is proposed,which is applied to analog circuit fault *** algorithm simplified the structure of network through optimum output layer coefficient with incremental projection learning(IPL)algorithm,and adjusted the parameters of the neural activation function to control the network scale and improve the network approximation *** to the traditional algorithm,the improved algorithm has quicker convergence rate and higher isolation *** results show that this improved RBF network has much better performance,which can be used in analog circuit fault isolation field.

关键词： analog circuit fault isolation RBF network IPL algorithm steepest descent algorithm

来源：评论

学校读者我要写书评

暂无评论

Optimization on the space of rigid and flexible motions: an alternative manifold optimization approach

Optimization on the space of rigid and flexible motions: an ...

引用

IEEE Annual Conference on Decision and Control

作者： Pirooz Vakili Hanieh Mirzaei Shahrooz Zarbafian Ioannis Ch. Paschalidis Dima Kozakov Sandor Vajda Dept. of Mechanical Eng. and Division of Systems Eng. Boston University Division of Systems Eng. Boston University Dept. of Mechanical Eng. Boston University Dept. of Electrical & Computer Eng. and Division of Systems Eng. Boston University Dept. of Biomedical Eng. Boston University

ISBN: (纸本)9781467360890

In this paper we consider the problem of minimization of a cost function that depends on the location and poses of one or more rigid bodies, or bodies that consist of rigid parts hinged together. We present a unified setting for formulating this problem as an optimization on an appropriately defined manifold for which efficient manifold optimizations can be developed. This setting is based on a Lie group representation of the rigid movements of a body that is different from what is commonly used for this purpose. We illustrate this approach by using the steepest descent algorithm on the manifold of the search space and specify conditions for its convergence.

关键词： Manifolds Rigid steepest descent algorithm Body Posing

来源：评论

学校读者我要写书评

暂无评论

An interference alignment based on joint projector interference distances

An interference alignment based on joint projector interfere...

引用

11th International Conference on Wireless Communications, Networking and Mobile Computing (WiCOM 2015)

作者： Fang Ye Junchao Yao Yibing Li College of Information and Communication Engineering Harbin Engineering University China

ISBN: (纸本)9781510821279

Interference alignment (IA) effectively improves the capacity of interference channel by overlapping the interference and eliminating at the receivers. At present, most algorithms of the distributed interference alignments design precoder and receiver filter at both transmitters and receivers which causes overhead. This paper presents an improved interference alignment based on minimizing projector interference distances, introduces joint distance and optimizes the subspace projector distances between interference and desired signals to achieve interference alignment by steepest descent algorithm based on complex Grassmann manifold. The proposed algorithm alleviates the overhead for designing precoding matrixes at one side. Simulation results suggest that the proposed approach obtains higher sum rate compared with the previous algorithms and faster rate of convergence compared with the old approach only based on the projector interference distances.

关键词： Interference Alignment Interference Channel Multi-User Orthogonal Projector Interference channels interference interference Receivers multi-user steepest descent algorithm desired signal

来源：评论

学校读者我要写书评

暂无评论

IMPROVED ONLINE IDENTIFICATION OF ACOUSTIC MISO SYSTEMS BASED ON SEPARATED INPUT SIGNAL COMPONENTS

IMPROVED ONLINE IDENTIFICATION OF ACOUSTIC MISO SYSTEMS BASE...

引用

IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Philipp Thune Gerald Enzner Institute of Communication Acoustics (IKA) Ruhr-Universit?t Bochum Germany

ISBN: (纸本)9781479903573

Creating an immersive listening experience and providing the audience with improved spatial realism is the goal of many adaptive audio reproduction techniques such as room equalization or crosstalk cancellation. The majority of these approaches currently relies on acoustic impulse responses (AIRs) that have been measured prior to the actual audio reproduction. In order to maintain a high degree of adaptivity, however, the AIRs need to be estimated online during the reproduction process, which turns out to be a severely ill-conditioned problem due to the high inter-channel correlation of the loudspeaker signals. In this paper, we present a novel approach to MISO system identification with realistically correlated excitation. Based on the idea of separate treatment of correlated and uncorrelated signal components, we propose two extended filter structures for gradient-descent-based adaptive system identification and provide theoretical analysis and experimental validation of their effectiveness.

关键词： room acoustics multichannel acoustic system identification nonuniqueness gradient descent algorithm room acoustics multiple-input single-output signals ENTERING steepest descent algorithm System identification Audio

来源：评论

学校读者我要写书评

暂无评论

Forward-Decoding Kernel-Based Phone Sequence Recognition 02

Forward-Decoding Kernel-Based Phone Sequence Recognition

引用

Annual Conference on Neural Information Processing Systems

作者： Shantanu Chakrabartty Gert Cauwenberghs Center for Language and Speech Processing Department of Electrical and Computer Engineering Johns Hopkins University Baltimore MD 21218

ISBN: (纸本)0262025507

Forward decoding kernel machines (FDKM) combine large-margin classifiers with hidden Markov models (HMM) for maximum a posteriori (MAP) adaptive sequence estimation. State transitions in the sequence are conditioned on observed data using a kernel-based probability model trained with a recursive scheme that deals effectively with noisy and partially labeled data. Training over very large datasets is accomplished using a sparse probabilistic support vector machine (SVM) model based on quadratic entropy, and an on-line stochastic steepest descent algorithm. For speaker-independent continuous phone recognition, FDKM trained over 177, 080 samples of the TIMIT database achieves 80.6% recognition accuracy over the full test set, without use of a prior phonetic language model.

关键词： Telephone modelling languages Support Vector Network observational data label data steepest descent algorithm speaker-independent

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：