检索结果-内蒙古大学图书馆

7th International Symposium on Advanced control of Chemical processes, ADCHEM 2003

作者： Mulder, Pieter Morris, Julian Martin, Elaine B. Centre for Process Analytics and Control Technology School of Chemical Engineering and Advanced Materials University of Newcastle Newcastle upon TyneNE1 7RU United Kingdom

The performance of a control chart in statistical process control is often quantified in terms of the Average Run Length (ARL). The ARL enables a comparison to be undertaken between various monitoring strategies. These are often determined through Monte Carlo simulation studies. Monte Carlo simulations are time consuming and if too few runs are performed then the results will be inaccurate. An alternative approach is proposed based on analytical computation. The analytical results are compared with those of the Monte Carlo simulations for three case studies. Copyright © IFAC 2003

关键词： control charts

来源：评论

学校读者我要写书评

暂无评论

Towards the robust application of PAT in real time control

Towards the robust application of PAT in real time control

引用

作者： Morris, Julian Chen, Zengping Lovett, David Centre for Process Analytics and Control Technology Newcastle University United Kingdom State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan University China Perceptive Engineering Daresbury Innovation Centre Daresbury Cheshire United Kingdom

ISBN: (纸本)9783902661708

process Analytical Technologies (PAT) are increasingly being explored and adopted by pharma-chem and bio-pharma companies for enhanced process understanding, Quality by Design (QbD) and Real-time-Release (RTR). To achieve these aspirations there is a critical need to extract the most information, and hence understanding, from complex and often very 'messy' spectroscopic data data. A number of new approaches will be shown to overcome the limitations of existing calibration/modelling methodologies and algorithms and their use in some industrial applications will be presented. © 2010 IFAC.

关键词： Calibration

来源：评论

学校读者我要写书评

暂无评论

Modeling and optimal control of fed-batch processes using control affine feedforward neural networks

Modeling and optimal control of fed-batch processes using co...

引用

American control Conference (ACC)

作者： Zhihua Xiong Jie Zhang Centre for Process Analytics and Control Technology Department of Chemical and Process Engineering University of Newcastle UK

ISBN: (纸本)0780372980

Many fed-batch processes can be considered as a class of control-affine nonlinear systems. In this paper, a new methodology of neural networks, called the control Affine Feedforward Neural Network (CAFNN), is proposed. It can be trained easily. For constrained nonlinear optimization problems, it offers an effective and simple optimal control strategy by sequential quadratic programming in which the analytic gradient information can be computed directly. The proposed modeling and optimal control schemes are illustrated on an ethanol fermentation process. Compared with a general multilayer neural network, the nonlinear programming problem based on a CAFNN model is solved more accurately and efficiently.

关键词： Optimal control process control Neural networks Feedforward neural networks Multi-layer neural network Nonlinear control systems control systems Nonlinear systems Constraint optimization Quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Detection of process model changes in PCA based performance monitoring

Detection of process model changes in PCA based performance ...

引用

American control Conference (ACC)

作者： S. Kumar E.B. Martin J. Morris Centre for Process Analytics & Control Technology Merz Court University of Newcastle UK

The detection of process changes through a principal component analysis based monitoring scheme can be achieved through the interrogation of two metrics, Hotelling's T/sup 2/ and the Q-statistic. The Q-statistic has been shown to be insensitive to small changes in the process model parameters. In this paper, a modified statistic based on the local approach is proposed to detect changes in model parameters in a principal component analysis monitoring scheme. The performance of the more traditional Q-statistic is compared with the modified statistic through their application to fault detection in a continuous stiffed tank reactor.

关键词： Principal component analysis Statistics Condition monitoring Network-on-a-chip process control Statistical analysis Fault detection Continuous-stirred tank reactor Predictive models Covariance matrix

来源：评论

学校读者我要写书评

暂无评论

Analysis of nonlinear partial least squares algorithms 7th

Analysis of nonlinear partial least squares algorithms

引用

7th IFAC Symposium on Dynamics and control of process Systems, DYCOPS 2004

作者： Kumar, S. Kruger, U. Martin, E.B. Morris, A.J. Centre of Process Analytics and Process Technology University of Newcastle NE1 7RU United Kingdom Intelligent Systems and Control Group Queen's University Belfast BT9 5AH United Kingdom

This paper presents an analysis of nonlinear extensions to Partial Least Squares (PLS) using error-based minimization techniques. The analysis revealed that such algorithms are maximizing the accuracy with which the response variables are predicted. Therefore, such algorithms are nonlinear reduced rank regression algorithms rather than nonlinear PLS algorithms. © IFAC Dynamics and control of process Systems, Cambridge, Massachusetts, USA, 2004

关键词： Least squares approximations

来源：评论

学校读者我要写书评

暂无评论

Classifying green teas with near infrared hyperspectral imaging

引用

NIR news 2019年第1-2期31卷 20 - 23页

作者： Puneet Mishra Alison Nordon WestCHEM Department of Pure and Applied Chemistry and Centre for Process Analytics and Control Technology University of Strathclyde Glasgow UK

来源：评论

学校读者我要写书评

暂无评论

Investigation of calibration-free resolution techniques and independent component analysis 7th

Investigation of calibration-free resolution techniques and ...

引用

7th International Symposium on Advanced control of Chemical processes, ADCHEM 2003

作者： Triadaphillou, S. Wells, I. Morris, A.J. Martin, E.B. Centre for Process Analytics and Control Technology School of Chemical Engineering and Advanced Materials University of Newcastle Newcastle upon TyneNE1 7RU United Kingdom Avecia Process Technology Department GrangemouthFK3 8XG United Kingdom

Calibration-free resolution techniques provide an alternative approach to the development of a calibration model. These combine spectroscopic measurement coupled with mathematical and statistical assumptions and give spectral profiles and non-quantitative concentration profiles for the unknown mixture. In this paper, a number of calibration free techniques including VARIMAX, ITTFA, EFA, FSWEFA, SIMPLISMA are described and applied to a synthetic spectral data set and the results are compared with the complementary technique of Independent Component Analysis (ICA) in particular FastICA and JADE. The results were comparable in all cases with ICA separating the signal from the constituent components successfully. Copyright © IFAC 2003

关键词： Independent component analysis

来源：评论

学校读者我要写书评

暂无评论

A Revised State Space Modelling Approach and Improved Fault Detection Using Combined Index Monitoring for Dynamic processes

引用

IFAC Proceedings Volumes 2010年第5期43卷 805-810页

作者： S. Stubbs J. Zhang J. Morris Centre for Process Analytics and Control Technology Newcastle University Newcastle NE1 7RU UK (Tel: +***)

Larimore's state space model derivation and stochastic estimation algorithm, first published in 1983, have been the adopted standard for deriving the state variables and parameters of the five (5) matrices state space model representation which continues to be applied extensively in the literature for applications ranging from controls, system identification and process monitoring. This paper presents an alternate derivation and stochastic estimation algorithm. The paper also discusses how strategic classification of the process inputs may, for some applications, facilitate the use of a simplified stochastic estimation algorithm. The alternative state space modeling approaches demonstrated better fault monitoring statistic performance for specific types of faults simulated. The canonical variate based state space modeling approaches were evaluated on a simulate CSTR process – with recycle through a heat exchanger. The results demonstrates the potential benefits to be derived from using a combined monitoring index based upon monitoring statistics derived from independent state space models for improved overall fault detecting capabilities and reliability of the fault monitoring scheme.

关键词： Dynamic modeling Stochastic modeling State space modeling Fault detection Canonical Variate Analysis Combined Index

来源：评论

学校读者我要写书评

暂无评论

On-line re-optimisation control of a batch polymerisation reactor based on a hybrid recurrent neural network model

On-line re-optimisation control of a batch polymerisation re...

引用

American control Conference (ACC)

作者： Yuan Tian Jie Zhang J. Morris Centre for Process Analytics and Control Technology Department of Chemical & Process Engineering University of Newcastle Newcastle-upon-Tyne UK

A hybrid recurrent neural network model based on-line re-optimisation control strategy is developed for batch polymerisation reactors. The hybrid model contains a simplified mechanistic model covering material balance and simplified reaction kinetics only and recurrent neural networks. Based on this hybrid neural network model, optimal control policy can be calculated. A difficulty in the optimal control of batch polymerisation reactors is that optimisation effort can be seriously hampered by unknown disturbances such as reactive impurities and reactor fouling. A technique for on-line estimation of reactive impurity and reactor fouling has been developed by Zhang et al. (1999). In this contribution, on-line reactive impurity estimation is combined with batch reactor optimal control to form a novel re-optimisation control strategy. When there exists an unknown amount of reactive impurities, the off-line calculated optimal control profile will be no longer optimal. On-line impurity estimation is applied to estimate the amount of reactive impurities during the early stage of the batch. Based on the estimated amount of reactive impurities, on-line re-optimisation is applied to calculate the optimal reactor temperature profile for the remaining time period of the batch reactor operation. This approach is illustrated on the optimisation control of a simulated batch MMA polymerisation process.

关键词： Polymers Inductors Optimal control Impurities Neural networks Recurrent neural networks Chemical analysis process control Chemical technology Kinetic theory

来源：评论

学校读者我要写书评

暂无评论

A training method for enhancing neural network model generalisation

A training method for enhancing neural network model general...

引用

International Joint Conference on Neural Networks (IJCNN)

作者： J. Zhang Centre for Process Analytics and Control Technology Department of Chemical & Process Engineering University of Newcastle Newcastle-upon-Tyne UK

A training method for enhancing neural network model generalisation is proposed. In this method, a neural network is trained and tested alternatively on a training data set and a testing data set. Unlike in conventional neural network training where the training and testing data sets are fixed, the training and testing data sets swap roles continuously during network training. Training is terminated when the network prediction errors on both data sets cannot be further reduced. Application examples demonstrate that this neural network training strategy can significantly improve the neural tu network model prediction accuracy, especially the long range prediction accuracy.

关键词： Neural networks Testing Training data Chemical analysis process control Chemical technology Accuracy Partitioning algorithms Chemical processes Chemical engineering

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：