检索结果-内蒙古大学图书馆

Deep reinforcement learning based controller with dynamic feature extraction for an industrial claus process

JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS 2023年第1期146卷

作者： Liu, Jialin Tsai, Bing -Yen Chen, Ding -Sou Tunghai Univ Res Ctr Smart Sustainable Circular Econ 1727Sec4Taiwan Blvd Taichung Taiwan Tunghai Univ Dept Chem & Mat Engn 1727Sec4Taiwan Blvd Taichung Taiwan China Steel Corp Green Energy & Syst Integrat Res & Dev Dept 1 Chung Kang Rd Kaohsiung Taiwan

Background: The significant time delay between the manipulated and controlled variables introduces challenges in the task of system identification when implementing model predictive control (MPC) for an industrial process. Recently, deep reinforcement learning (DRL) with model-free characteristics has attracted considerable attention from the process control community. However, the model-free assumption in DRL is based on the property of the Markov decision process (MDP), in which all state variables must be observed. This assumption is not true for an industrial process. Methods: In this study, the sequence-to-sequence (Seq2seq) network was employed to build a surrogate model based on the industrial Claus process data. Meanwhile, the hidden state output from the encoder of the Seq2seq network, which represents the dynamic feature of the process, connects to the DRL-based controller to compensate for the partial observabilities of a real *** findings: The results show that the standard deviation of the control variable, which refers to the H2S to SO2 concentration ratio in the tail gas, can be reduced by up to 55% using the proposed DRL-based controller comparing with the current control strategy.

关键词： Deep reinforcement learning industrial Claus process Sequence-to-sequence network Actor-critic networks Twin delayed deep deterministic policy gradient algorithm

来源：评论

学校读者我要写书评

暂无评论

Study on Large-Scale Urban Water Distribution Network Computation Method Based on a GPU Framework

引用

WATER 2024年第18期16卷 2642页

作者： Zhang, Rongbin Hou, Jingming Li, Jingsi Wang, Tian Imran, Muhammad Xian Univ Technol State Key Lab Ecohydraul Xian 710048 Peoples R China Shaanxi Prov Inst Water Resources & Elect Power In Xian 710048 Peoples R China

Large-scale urban water distribution network simulation plays a critical role in the construction, monitoring, and maintenance of urban water distribution systems. However, during the simulation process, matrix inversion calculations generate a large amount of computational data and consume significant amounts of time, posing challenges for practical applications. To address this issue, this paper proposes a parallel gradient calculation algorithm based on GPU hardware and the CUDA Toolkit library and compares it with the EPANET model and a model based on CPU hardware and the Armadillo library. The results show that the GPU-based model not only achieves a precision level very close to the EPANET model, reaching 99% accuracy, but also significantly outperforms the CPU-based model. Furthermore, during the simulation, the GPU architecture is able to efficiently handle large-scale data and achieve faster convergence, significantly reducing the overall simulation time. Particularly in handling larger-scale water distribution networks, the GPU architecture can improve computational efficiency by up to 13 times. Further analysis reveals that different GPU models exhibit significant differences in computational efficiency, with memory capacity being a key factor affecting performance. GPU devices with larger memory capacity demonstrate higher computational efficiency when processing large-scale water distribution networks. This study demonstrates the advantages of GPU acceleration technology in the simulation of large-scale urban water distribution networks and provides important theoretical and technical support for practical applications in this field. By carefully selecting and configuring GPU devices, the computational efficiency of large-scale water distribution networks can be significantly improved, providing more efficient solutions for future urban water resource management and planning.

关键词： large water supply network GPU parallel computing gradient algorithm matrix inversion

来源：评论

学校读者我要写书评

暂无评论

Regression Model-Based Flux Observer for IPMSM Sensorless Control with Wide Speed Range

引用

ENERGIES 2021年第19期14卷 6249页

作者： Choi, Jongwon Hannam Univ Dept Elect & Elect Engn Daejeon 34430 South Korea

A new linear regression form is derived for a flux observer and a position observer is designed. In general, the observability of the permanent-magnet synchronous motor is lost at zero speed. In this work, the proposed regressor vector contains current derivative terms in both directions (dq-axis), and it gives the chance for the model-based flux observer to operate at zero speed. When an excitation signal is injected into d and q axes with the proposed flux observer, it helps to satisfy the persistent excitation condition in the low-speed range. Therefore, the sensorless performance of the model-based is improved greatly, even at zero speed. However, it appears with a disturbance term, which depends on the derivative of the d-axis current. Thus, the disturbance does not vanish when an excitation signal is injected. In this work, the disturbance term is also taken care of in constructing an observer. It results in an observer which allows signal injection. Thus, high frequency signal can be injected in the low speed region and turned off when it is unnecessary as the speed increases. This model-based approach utilizes the signal injection directly without recurring to a separate high frequency model. In other words, it provides a seamless transition without switching to the other algorithm. The validity is demonstrated by simulation and experimental results under various load conditions near zero speed.

关键词： linear regression form sensorless algorithm IPMSM active flux nonlinear observer gradient algorithm persistence of excitation signal injection

来源：评论

学校读者我要写书评

暂无评论

Reconstruction of discontinuous parameters in a second order impedance boundary operator

引用

INVERSE PROBLEMS 2016年第10期32卷 105004-105004页

作者： Chaabane, S. Charfi, B. Haddar, H. Sfax Univ Fac Sci Sfax Dept Math Lab Appl Math & Harmon AnalLAMHA LR 11ES52 BP 1171 Sfax 3000 Tunisia Univ Paris Saclay Ecole Polytech INRIA Route Saclay F-91128 Palaiseau France

We consider the inverse problem of retrieving the coefficients of a second order boundary operator from Cauchy data associated with the Laplace operator at a measurement curve. We study the identifiability and reconstruction in the case of piecewise continuous parameters. We prove in particular the differentiability of the Kohn-Vogelius functional with respect to the discontinuity points and employ the result in a gradient type minimizing algorithm. We provide validating numerical results discussing in particular the case of an unknown number of discontinuity points.

关键词： discontinuous parameters generalized boundary conditions identifiability identification gradient algorithm

来源：评论

学校读者我要写书评

暂无评论

Convergence performance of adaptive filter having a restricted linear sum of moment of weight and application to design of filter

引用

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE 2005年第3期88卷 11-20页

作者： Kobayashi, M Eguchi, O Itoh, Y Chuba Univ Coll Engn Kasugai Aichi 4878501 Japan Kinseki Ltd Komae Tokyo 2018648 Japan Tottori Univ Fac Engn Tottori 6808552 Japan

This paper studies an adaptive filter with a restricted linear sum of the moments of tap coefficients and investigates its applications. In general, when a sampled value filter or a digital filter represented by a surface acoustic filter is realized, the maximum absolute values or the variances of the tap coefficients are restricted. In this paper, restrictions on the maximum values or the variances are imposed by means of a restricted linear sum of several moments around an arbitrary positive number, facilitating the realization of the filter. The number of the moments and the weights are determined in such a way that the frequency characteristics of the filter after restriction satisfy the given specifications. The adaptive system consists of an ideal filter without restriction on the tap coefficients and an adaptive filter placed in parallel. The adaptive filter consists of a transversal filter. Its adaptive algorithm is a gradient algorithm with a small amount of processing, with a restricted linear sum of the moments of the tap coefficients. Since the proof of uniqueness of the converged value of the adaptive algorithm and the upper limit of the loop gain in the algorithm are formulated, the filter designer can easily obtain filter parameters with restricted tap coefficients. Finally, verification of the discussed results is rigorously carried out by computer simulations. (C) 2004 Wiley Periodicals, Inc.

关键词： moment variance of tap coefficients convergence characteristics gradient algorithm estimation

来源：评论

学校读者我要写书评

暂无评论

Steady-state analysis of complex adaptive IIR notch filters for the detection of single sinusoid

引用

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE 2002年第1期85卷 32-40页

作者： Jiang, HY Nishimura, S Hinamoto, T Hiroshima Univ Fac Engn Higashihiroshima 7398527 Japan Shimane Univ Dept Elect & Control Syst Engn Matsue Shimane 6908504 Japan

In this paper, we present a new structure for a complex adaptive infinite impulse response (IIR) notch filter which is useful for the detection of complex sinusoids in communication and radar systems. The proposed structure is based on the gradient algorithm. The adaptive detection of a complex sinusoid with additive complex white noise has been investigated. A quantitative analysis for the steady-state coefficient fluctuation has been developed. Analytical expressions for the steady-state variance of complex variable coefficient fluctuation have been obtained. It has been shown that the variance of the complex coefficient fluctuation does not depend on the angular frequency of the input sinusoid. Finally, the results of computer simulations which confirm the theoretical predictions are presented. (C) 2001 Scripta Technica.

关键词： complex adaptive IIR notch filter steady-state characteristics gradient algorithm variance of coefficient fluctuation

来源：评论

学校读者我要写书评

暂无评论

Second-Order vs. First-Order algorithms: New Perspectives

引用

IFAC Proceedings Volumes 2000年第15期33卷 1169-1174页

作者： Heikki Hyötyniemi Helsinki University of Technology Control Engineering Laboratory Konemiehentie 2 FIN-02150 Espoo Finland

This paper presents an approach how the first-order (gradient) parameter estimation algorithm can be enhanced to behave like a second-order algorithm; the key to achieve this is to apply "virtual whitening" to the data. This approach allows one to introduce more complex optimization criteria efficiently; as an example, it is demonstrated how an algorithm that is based on the kurtosis of the distribution can remarkably enhance the parameter estimation performance when unmodeled noise is present in the system.

关键词： Least squares gradient algorithm data distributions independent component analysis

来源：评论

学校读者我要写书评

暂无评论

New Wavelet Threshold Denoising Method in Noisy Blind Source Separation

引用

Journal of Electronic Science and Technology 2010年第4期8卷 356-361页

作者： Xuan-Sen He Tian-Jiao Zhao College of Computer and Communication Hunan University Changsha 410082 China

In general conditions, most blind source separation algorithms are established on noisy-free model and ignore the noise that affects the quality of separated sources. Firstly, this paper introduces an improved natural gradient algorithm based on bias removal technology to estimate the demixing matrix under noisy environment. Then the discrete wavelet transform technology is applied to the separated signals to further remove noise. In order to improve the separation effect, this paper analyzes the deficiency of hard threshold and soft threshold, and proposes a new wavelet threshold function based on the wavelet decomposition and reconfiguration. The simulations have verified that this method improves the signal noise ratio （SNR） of the separation results and the separation precision.

关键词： Bias removal blind source separation gradient algorithm wavelet threshold denoising.

来源：评论

学校读者我要写书评

暂无评论

Steady-state analysis of complex adaptive IIR notch filter and its application to QPSK communication systems

引用

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2002年第5期E85A卷 1088-1095页

作者： Jiang, HY Nishimura, S Hinamoto, T Hiroshima Univ Fac Engn Higashihiroshima 7398527 Japan Shimane Univ Dept Elect & Control Syst Engn Matsue Shimane 6908504 Japan

In this paper, we present a method to analyze the steady-state performance of a, complex coefficient adaptive IIR notch filter which is useful for the rejection of multiple narrow-band interferences from broad-band signals in quadrature phase shift keying (QPSK) spread-spectrum communication systems. The adaptive notch filter based on the simplified gradient algorithm is considered. Analytical expressions have been developed for the conditional mean and variance of notch filter output. The signal-to-noise ratio improvement factor is also obtained from which the validity of the use of the notch filter can be concluded. Finally, the results of computer simulations are shown which confirm the theoretical predictions.

关键词： adaptive notch filter interference rejection. QPSK gradient algorithm steady-state characteristics

来源：评论

学校读者我要写书评

暂无评论

Network utility maximisation framework with multiclass traffic

引用

IET NETWORKS 2013年第3期2卷 152-161页

作者： Vo, Phuong Luu Tran, Nguyen Hoang Hong, Choong Seon Lee, Sungwon Kyung Hee Univ Dept Comp Engn 1 Seocheon Yongin 446701 Gyeonggi South Korea

The concave utilities in the basic network utility maximisation (NUM) problem are only suitable for elastic flows. In networks with both elastic and inelastic traffic, the utilities of inelastic traffic are usually modelled by the sigmoidal functions which are non-concave functions. Hence, the basic NUM problem becomes a non-convex optimisation problem. To address the non-convex NUM, the authors approximate the problem which is equivalent to the original one to a strictly convex problem. The approximation problem is solved efficiently via its dual by the gradient algorithm. After a series of approximations, the sequence of solutions to the approximation problems converges to a local optimal solution satisfying the Karush-Kuhn-Tucker conditions of the original problem. The proposed algorithm converges with any value of link capacity. The authors also extend their work to jointly allocate the rate and the power in a multihop wireless network with elastic and inelastic traffic. Their framework can be used for any log-concave utilities.

关键词： approximation theory convex programming gradient methods radio networks telecommunication traffic network utility maximisation framework multiclass traffic NUM elastic flows inelastic traffic sigmoidal functions nonconcave functions nonconvex optimisation problem approximation problem gradient algorithm multihop wireless network

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：