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Modeling of Isomerization of C_8 Aromatics by Online Least Squares Support Vector Machine

Chinese Journal of Chemical engineering 2009年第3期17卷 437-444页

作者：李丽娟苏宏业褚建 College of Automation and Electrical Engineering Nanjing University of Technology State Key Lab. of Industrial Control Technology Institute of Cyber-systems and ControlZhejiang University

The least squares support vector regression (LS-SVR) is usually used for the modeling of single output system, but it is not well suitable for the actual multi-input-multi-output system. The paper aims at the modeling of multi-output systems by LS-SVR. The multi-output LS-SVR is derived in detail. To avoid the inversion of large matrix, the recursive algorithm of the parameters is given, which makes the online algorithm of LS-SVR practical. Since the computing time increases with the number of training samples, the sparseness is studied based on the pro-jection of online LS-SVR. The residual of projection less than a threshold is omitted, so that a lot of samples are kept out of the training set and the sparseness is obtained. The standard LS-SVR, nonsparse online LS-SVR and sparse online LS-SVR with different threshold are used for modeling the isomerization of C8 aromatics. The root-mean-square-error (RMSE), number of support vectors and running time of three algorithms are compared and the result indicates that the performance of sparse online LS-SVR is more favorable.

关键词： least squares support vector machine multi-variable online sparseness isomerization

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Soft Sensor for Distillation Column Feeds

Soft Sensor for Distillation Column Feeds

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2009年中国控制与决策会议(2009 Chinese control and Decision Conference)

作者： Lingyu Zhu Jixin Qian Zhijiang Shao Xi Chen State Key Laboratory of Industrial Control Technology Department of Control Science & EngineeringZ State Key Laboratory of Industrial Control Technology Department of Control Science & EngineeringZ

Distillation columns are normally controlled at a pre-designed condition, which is the optimal for a specified feed condition. In reality, however, the feeds may vary in their flow rates, temperatures, or compositions, which results in the distillation process operating at non-optimal values. Therefore, it is ideal to optimally adjust the operations in conjunction with the real feed variation. The online hardware measurement of the feed status, however, is basically impossible for most columns. A method using the temperature measurements along the distillation column to detect the feed variations is proposed in this paper. Verification is conducted through simulations under different conditions. Both derivative-based and derivative-free optimization methods are discussed for the soft-sensor establishment.

关键词： distillation column optimal operation feed variation temperature distribution soft-sensor.

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Periodic Disturbance Rejection Method Using Iterative Learning Predictive Function control

Periodic Disturbance Rejection Method Using Iterative Learni...

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International Conference on Fuzzy Systems and Knowledge Discovery (FSKD)

作者： Jing Wang Jun Zhao Zuhua Xu Jixin Qian State Key Lab of Industrial Control Technology Department of Control Science and Engineering University of Zhejiang Hangzhou China

In this paper, a robust control method is proposed for rejecting the periodic disturbance. Cooperating with predictive function control (PFC), iterative learning (IL) is used to deal with the period mismatch, that is, iterative learning control (ILC) is used to handle the periodic errors while PFC doing its job of system process control. Simulation results shows that the IL-PFC algorithm achieves significant improvement in rejecting periodic disturbance over the repetitive control scheme.

关键词： Iterative methods control systems Radio control Optical control Error correction Process control Signal generators Fuzzy systems industrial control Knowledge engineering

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Multi-step prediction error approach for MPC performance monitoring

Multi-step prediction error approach for MPC performance mon...

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作者： Zhao, Yu Chu, Jian Su, Hongye Huang, Biao State Key Lab. of Industrial Control Technology Institute of Cyber Systems and Control Zhejiang University Hangzhou China Department of Chemical and Materials Engineering University of Alberta Edmonton AB T6G 2G6 Canada

ISBN: (纸本)9783902661548

Performance monitoring of model predictive control systems (MPC) has received a great interest from both academia and industry. In recent years some novel approaches for multivariate control performance monitoring have been developed without the requirement of process models or interactor matrices. Among them the prediction error approach has been shown to be a promising one, but it is k-step prediction based and may not be fully comparable with the MPC objective that is multi-step prediction based. This paper develops a multi-step prediction error approach for performance monitoring of model predictive control systems, and demonstrates its application in an industrial MPC performance monitoring and diagnosis problem.

关键词： Model predictive control

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Flowrate measurement of air-water two-phase flow using an Electrical Resistance Tomography sensor and a Venturi meter

Flowrate measurement of air-water two-phase flow using an El...

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IEEE Instrumentation and Measurement technology Conference

作者： Zhenzhen Meng Zhiyao Huang Baoliang Wang Haifeng Ji Haiqing Li State Key Laboratory of Industrial Control Technology Department of Control Science and Engineering University of Zhejiang Hangzhou China

ISBN: (纸本)9781424433520

A flowrate measurement method for air-water two-phase flow is developed using an Electrical Resistance Tomography (ERT) sensor and a Venturi meter. With the conductance values measured by the ERT sensor, the real-time flow pattern is identified and the voidage is also calculated. The Butterworth correlation is applied to calculate the mass quality from the voidage value, and then six Venturi measurement correlations are introduced to predict the mass flowrate of two-phase flow. The flow pattern classifier is constructed by using the partial least square (PLS) method and the Least Squares Support Vector Machine (LS-SVM) classification method. The voidage measurement models are developed by using the PLS method and the LS-SVM regression method for different flow patterns. Experiment results verify that this measurement method is effective. The research work also shows that among the six Venturi measurement correlations the Collins correlation always performs the best for the flow condition in this work.

关键词： Electrical resistance measurement Fluid flow measurement Electric variables measurement Electric resistance Tomography Pressure measurement Electromagnetic measurements Least squares methods Electrodes Support vector machines

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Measurement system for characterization of gas-liquid two-phase flow in micro-channel

Measurement system for characterization of gas-liquid two-ph...

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IEEE Instrumentation and Measurement technology Conference

作者： Haifeng Ji Zhiyao Huang Baoliang Wang Haiqing Li State Key Laboratory of Industrial Control Technology Department of Control Science and Engineering University of Zhejiang Hangzhou China

ISBN: (纸本)9781424433520

A measurement system is developed for the parameter detection and flow characterization of gas-liquid two-phase flow in micro-channel. Electrical capacitance measurement system and optical measurement system are designed for the micro-channels with different inner diameters of 4.0 mm, 3.1 mm and 1.8 mm respectively. In experiment, bubble flow, stratified flow, slug flow and annular flow are observed. PSD (Power Spectrum Density) and PDF (Probability Density Function) methods are used to analyze the capacitance and optical signals. The results show that the stratified flow can not be observed in the pipe with inner diameter of 1.8 mm, and that the PSD and PDF curve can be used to characterize different flow regimes of gas-liquid two-phase flow in micro-channel. So the constructed measurement system is effective, and can be used to analyze flow characteristics and identify flow regime of gas-liquid two-phase flow in micro-channel.

关键词： Fluid flow measurement Capacitance measurement Image motion analysis Optical sensors Electric variables measurement Nitrogen Pressure measurement Optical design Microchannel Signal analysis

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Quantitative determination of cyfluthrin in n-hexane by terahertz time-domain spectroscopy with chemometrics methods

Quantitative determination of cyfluthrin in n-hexane by tera...

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IEEE Instrumentation and Measurement technology Conference

作者： Yuefang Hua Hongjian Zhang Hongliang Zhou State Key Laboratory of Industrial Control Technology Department of Control Science and Engineering University of Zhejiang Hangzhou China

Terahertz time-domain spectroscopy (THz-TDS) was used for the detection of cyfluthrin content in N-hexane solvent with the concentration range of 0.5-10 μg/mL. The absorbance of the solution form cyfluthrin was obtained in the frequency range between 0.5-1.5 THz. Two kinds of multivariate linear regression models were then built between the absorbance and the concentration of 15 samples, using partial least squares (PLS) and principle component regression (PCR) methods. The number of factors leading to the least root-mean-square error of cross validation (RMSECV) was 2 for PCR and 9 for PLS respectively. Compared to the PCR model, the PLS model proves to be more effective, with the RMSECV as low as 0.565 μg/mL. Results show that the THz-TDS plus PLS method is very promising for the further pesticide residue detection in food safety control, with the characteristics of being nondestructive and laborsaving compared to other analytical tools.

关键词： Time domain analysis Spectroscopy Safety Least squares methods Chemical technology Submillimeter wave technology Solvents Linear regression Infrared spectra Frequency domain analysis

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Oil-water two-phase flow measurement based on a hybrid flowmeter and dominant phase identification

Oil-water two-phase flow measurement based on a hybrid flowm...

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IEEE Instrumentation and Measurement technology Conference

作者： Zhiyao Huang Xia Li Haifeng Ji Baoliang Wang Haiqing Li State Key Laboratory of Industrial Control Technology Department of Control Science and Engineering University of Zhejiang Hangzhou China

Based on a hybrid flowmeter and a dominant phase identifier, a new system is proposed for oil-water two-phase flow measurement. The hybrid flowmeter consists of an oval gear flowmeter and a Venturi meter. The dominant phase identifier is utilized to overcome the influence of oil fraction on the measurement results. In the practical measurement process, the total volume flowrate and the differential pressure of the two-phase flow are firstly obtained by the oval gear flowmeter and the Venturi meter, respectively. Meanwhile, the dominant phase of the oil-water two-phase flow is identified. Then the meter coefficient of the Venturi meter is selected according to the dominant phase identification result. Finally, the total volume flowrate and the total mass flowrate of the two-phase flow are obtained. The preliminary research results show that the proposed system is effective in measuring oil-water two-phase flow.

关键词： Fluid flow measurement Phase measurement Gears Fluid flow Petroleum Volume measurement Equations Chemical industry Instrumentation and measurement laboratories

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Application of DNA self-assembly on maximum clique problem

Application of DNA self-assembly on maximum clique problem

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2nd International Workshop on Advanced Computational Intelligence, IWACI 2009

作者： Cui, Guangzhao Li, Cuiling Li, Haobin Zhang, Xuncai Li, Xiaoguang Henan Key Lab of Information-based Electrical Appliances 450002 Zhengzhou China Department of Control Science and Engineering Huazhong University of Science and Technology 430074 Wuhan China

ISBN: (纸本)9783642031557

Computation by self-assembly of DNA is an efficient method of executing parallel DNA computing, in which information is encoded in DNA tiles and a large number of tiles can be self-assembled via sticky end associations. Here, we investigate how basic ideas on tiling can be applied to solve maximum clique problem (MCP). We suggest that these procedures can be realized on the molecular scale through the medium of self-assembled DNA tiles. By creating billions of copies of the participating DNA tiles, the algorithmic will run in parallel on all possible cliques. The potential of DNA computing by self-assembly for this problem is promising given the operational time complexity of Θ(n). This work shows further evidence for the ability of DNA computing to solve NP-Complete problems. © 2009 Springer-Verlag Berlin Heidelberg.

关键词： Self assembly

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Research of feedback control of lighting system based on DALI

Research of feedback control of lighting system based on DAL...

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IEEE International Conference on industrial Informatics (INDIN)

作者： Yufang Zhong Huadong Li Mingguang Wu State Key Laboratory of Industrial Control Technology Department of Control Science and Engineering University of Zhejiang Hangzhou Zhejiang China

ISBN: (纸本)9781424437597

The remarkable characteristic of lighting system based on digital addressable lighting interface is panorama supervised which results from feedback control. This paper proposes the three-state feedback mechanism and the relative system consists of master units, slave units and a graphical user interface (GUI) for inputting parameters and supervising the detail of system. Slave units include standard slave units and feedback slave units which have AT90PWM2 controller. Built upon this system, the three-state feedback mechanism takes the feedback comprising the states of controller unit, implementation unit and controlled object unit according to the requirement of lighting protocol. Experimental results will be provided to verify the effectiveness of the proposed system.

关键词： Feedback control Electronic ballasts state feedback control systems Lighting control Master-slave Communication system control Protocols IEC standards industrial control

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