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American control Conference

作者： Su Liu Jinfeng Liu Yiping Feng Gang Ron State Key Laboratory of Industrial Control Technology Institute of Cyber-System and Control Zhejiang University Hangzhou 310027 China Department of Chemical & Materials Engineering University of Alberta Edmonton AB T6G 2V4 Canada

ISBN: (纸本)9781479901777

In this work, an efficient approach for the assessment of achievable performance of decentralized control systems based on a general quadratic performance index involving both system states and inputs is proposed. The performance assessment problem is formulated as an optimization problem subject to constraints in the form of linear/bilinear matrix inequalities which explicitly take the block-diagonal structural constraint on decentralized control systems into account. In order to deal with the block-diagonal constraint, an iterative approach based on the original optimization problem and an equivalent transformation of the original one with parameter space constraint is proposed. The proposed approach solves for both the best achievable performance and the corresponding controller (and observer) gains. The application to one example illustrates the applicability and effectiveness of the proposed approach.

关键词： Distributed control systems decentralised control control systems realizable equivalent transformation Constraint quadratic performance index

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Nonlinear system identification with multiple and correlated scheduling variables *

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IFAC Proceedings Volumes 2013年第32期46卷 319-324页

作者： Lei Chen Biao Huang Fei Liu Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education) Institute of Automation Jiangnan University Wuxi 214122 P.R. China Department of Chemical and Materials Engineering University of Alberta Edmonton AB T6G 2G6 Canada

This paper is concerned with identification of nonlinear systems with multiple and correlated scheduling variables. Multiple auto regressive exogenous (ARX) models are identified on different process operating conditions, and a normalized exponential function as the probability density function associated with each of the local ARX models taking effect is then used to combine all the local models to represent the complete dynamics of a nonlinear system. The parameters of the local ARX models and the exponential functions are estimated simultaneously under the framework of the expectation maximization (EM) algorithm. A numerical example is applied to demonstrate the proposed identification method.

关键词： System identification Nonlinear process Multiple models Expectation maximization algorithm Multiple scheduling variables

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Effect of silver concentration on bioactivity and antibacterial properties of SiO2-CaO-P2O5 sol-gel derived bioactive glass

Effect of silver concentration on bioactivity and antibacter...

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23rd Symposium and Annual Meeting of International Society for Ceramics in Medicine, ISCM 2011

作者： Nezafati, Nader Moztarzadeh, Fathollah Hesaraki, Saeed Mozafari, Masoud Samadikuchaksaraei, Ali Hajibaki, Leila Gholipour, Mazaher Faculty of Biomedical Engineering Amirkabir University of Technology Tehran Iran Ceramic Department Materials and Energy Research Center Karaj Iran Department of Biotechnology and Cellular Faculty of Allied Medicine Tehran University of Medical Sciences Tehran Iran Biological Systems Engineering Laboratory Centre for Process Systems Engineering Department of Chemical Engineering London United Kingdom Department of Biotechnology Shahid Beheshti University of Medical Science Tehran Iran

ISBN: (纸本)9783037852552

Human beings are often infected by microorganisms in the living environment. Among various natural and inorganic substances, silver or silver ions have a powerful antibacterial activity. In the present study, the bioactivity and antibacterial activity of the SiO2-CaO-P 2O5-Ag2O was compared with that of its ternary counterpart glass system (as a control sample) in vitro. The molar ratio of silver oxide in the bioactive glass composition was considered as different amount (0.5%, 1% and 2%). The surface characterization was evaluated after soaking in simulated body fluid (SBF). The sharpest apatite peak in X-ray diffraction (XRD) analyse after 7 days soaking in SBF was observed for 2% Ag sample (2%Ag-BG). Hence, the antibacterial effects of 2%Ag-BG sample against 2 gram negatives bacterium were examined by agar plate test. The result showed that the amount of silver did not prevent the HAp formation. Also, the antibacterial properties of 2%Ag-BG sample indicated near 100% bactericidal ratio (according to the width of antibacterial halo). © (2012) Trans Tech Publications.

关键词： bioactive glass

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A comparison of information theoretic functions for tracking maneuvering targets

A comparison of information theoretic functions for tracking...

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IEEE/SP Workshop on Statistical Signal Processing (SSP)

作者： W. Lu G. Zhang S. Ferrari Laboratory for Intelligent Systems and Control (LISC) Department of Mechanical Engineering and Materials Science Duke University Durham NC USA

Several information theoretic functions have been proposed in the literature to assess the information value of sensor measurements a posteriori, that is, after measurements have been obtained from one or more targets. Sensor planning algorithms, however, require that the value of future sensor measurements be computed a priori, based on available models and prior information. An approach was recently presented by the authors for estimating the expected information value of future sensor measurements in target classification problems. The approach derives expected information theoretic functions from probabilistic models of the sensors and the targets, conditioned on prior information. In this paper, the approach is extended to the problem of sensor planning for tracking maneuvering targets. The approach is illustrated for a sensor that obeys an exponential power law model of received isotropic energy, and a target that obeys a Markov motion model. The performance of five information theoretic functions is compared through numerical simulations, and the results show that the objective function based on conditional mutual information leads to the most effective sensor planning strategy.

关键词： Target tracking Planning Mutual information Entropy Random variables Time measurement Measurement uncertainty

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Pinch Point Calculations and Its Implications on Robust Distillation Design

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Chinese Journal of chemical engineering 2011年第6期19卷 911-925页

作者： Daniel A. Beneke Seon B. Kim Andreas A. Linninger Laboratory for Product and Process Design Department of Chemical and Bio Engineering University of Illinois at Chicago Chicago IL 60607 USA Centre of Materials and Process Synthesis （COMPS） School of Process and Materials Engineering University of the Witwatersrand Johannesburg South Africa

Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.

关键词： pinch point column profile map phase equilibrium model temperature collocation

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A Radial Basis Function Spike Model for Indirect Learning via Integrate-and-Fire Sampling and Reconstruction Techniques

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Advances in Artificial Neural systems 2012年第1期2012卷

作者： X. Zhang G. Foderaro C. Henriquez A. M. J. VanDongen S. Ferrari Laboratory for Intelligent Systems and Control (LISC) Department of Mechanical Engineering and Materials Science Duke University Durham NC 27708 USAduke.edu Department of Biomedical Engineering and Department of Computer Science Duke University Durham NC 27708 USAduke.edu Program in Neuroscience & Behavioral Disorders Duke-NUS Graduate Medical School Singapore Singapore

This paper presents a deterministic and adaptive spike model derived from radial basis functions and a leaky integrate-and-fire sampler developed for training spiking neural networks without direct weight manipulation. Several algorithms have been proposed for training spiking neural networks through biologically-plausible learning mechanisms, such as spike-timing-dependent synaptic plasticity and Hebbian plasticity. These algorithms typically rely on the ability to update the synaptic strengths, or weights, directly, through a weight update rule in which the weight increment can be decided and implemented based on the training equations. However, in several potential applications of adaptive spiking neural networks, including neuroprosthetic devices and CMOS/memristor nanoscale neuromorphic chips, the weights cannot be manipulated directly and, instead, tend to change over time by virtue of the pre- and postsynaptic neural activity. This paper presents an indirect learning method that induces changes in the synaptic weights by modulating spike-timing-dependent plasticity by means of controlled input spike trains. In place of the weights, the algorithm manipulates the input spike trains used to stimulate the input neurons by determining a sequence of spike timings that minimize a desired objective function and, indirectly, induce the desired synaptic plasticity in the network.

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Size control of Block Polymer Templated Mesoporous Silicate materials

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MRS Online Proceedings Library 2011年第1期628卷 1-6页

作者： Takeo Yamada Keisuke Asai Kenkichi Ishigure Akira Endo Hao S. Zhou Itaru Honma Department of Quantum Engineering and Systems Science Graduate School of Engineering The University of Tokyo Tokyo Japan Department of Chemical Systems National Institute of Materials and Chemicals Research Tsukuba Ibaraki Japan Energy Fundamentals Division Electrotechnical Laboratory Tsukuba Ibaraki Japan

Mesoporous materials have attracted considerable interest because of applications in molecular sieve, catalyst, and adsorbent. It will be useful for new functional device if functional molecules can be incorporated into the pore of mesoporous material. However, it is necessary to synthesize new mesoporous materials with controlled large pore size. Recently, new class of mesoporous materials has been prepared using triblock copolymer as a template. In this paper, we reported that hexagonal and cubic structure silicate mesoporous materials can be synthesized through triblock copolymer templating, and their size was controlled by synthesis condition at condensation.

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Output error method for identification of multiple-model process with transition

Output error method for identification of multiple-model pro...

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International Symposium on Advanced control of Industrial Processes (ADCONIP)

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

This paper is concerned with the identification of multiple model process with transition using the output error (OE) method. Local multiple linear models with output error model structure are identified at fixed operating points first and then a global nonlinear model is approximated by interpolating the multiple linear models with exponential weighting functions. With all the obtained initial values of the system's parameters, nonlinear optimization strategy is implemented to find the optimal values of the parameters for both the local multiple models and their corresponding weighting functions. Finally a more accurate global model can be obtained. The effectiveness of the proposed approach is demonstrated through simulation examples.

关键词： Interpolation Spline Optimization Data models Coolants Numerical models Zinc

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Soft Sensing of Sodium Aluminate Solution Component Concentrations via On-line Clustering and Fuzzy Modeling

Soft Sensing of Sodium Aluminate Solution Component Concentr...

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2011 American control Conference (ACC)

作者： Wei Wang Tianyou Chai Lijie Zhao S. Joe Qin State Key Laboratory of Integrated Automation for Process Industry Northeastern University Shenyang China Key Laboratory of Integrated Automation of Process Industry Ministry of Education and Information Engineering School Shenyang Institute of Chemical Technology China Department of Chemical Engineering and Materials Science Daniel J. Epstein Department of Industrial and Systems Engineering University of Southern California Los Angeles CA USA

The component concentrations measurement of sodium aluminate solution are critical to the process of alumina production, they affect the product quality. However, they can not be measured online at present, thus the control and optimal operation is hardly to be achieved. This paper presents an on-line fuzzy modeling method to predict the component concentrations. It includes an on-line clustering approach which can be applied in a general class of fuzzy TKS models. Stable learning algorithms for the premise and the consequence parts of fuzzy rules are also given. A measuring device is developed to achieve the proposed method and industry experiments are conducted in the alumina production process, the predicted results show the effectiveness of the proposed method.

关键词： Conductivity Temperature measurement Production Predictive models Laboratories Temperature sensors

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Mixing of particles and powders:Where next?

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Particuology 2010年第6期8卷 563-567页

作者： John Bridgwater University of Cambridge Department of Chemical Engineering and BiotechnologyCambridge CB2 3RAUK Laboratory for Simulation and Modeling of Particulate Systems School of Materials Science and EngineeringUniversity of New South WalesSydneyNSW 2052Australia

Industrial mixers for powders and granular materials operate with no effective control of mixture quality and lack scientific design. The last twenty years have seen growth in understanding of mixing and mixers. However, research falls far short of what is needed for on-line characterisation of mixture quality. Secondly, although theoretical descriptions of a few mixer types have been reported, these fall far short of what is needed for equipment design. Two thrusts could revolutionise this situation. One is a scientific characterisation of mixer structure applicable to industrial scale as well as laboratory scale equipment; this is now within our grasp using digital imaging. The other is the development of ideas to overcome the restricted number of particles that can be used in the Distinct Element Method （DEM） for mixers. The goal should be to take the designer through a sequence of steps to the most appropriate mixer size, configuration and operating conditions for a given process duty.

关键词： Design Granular materials Mixing Mixers Powders Quality characterisation Quality measurement

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