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A TRUST REGION-TYPE METHOD FOR SOLVINGMONOTONE VARIATIONAL INEQUALITY

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Journal of Computational Mathematics 2000年第1期18卷 13-24页

作者： Xi-ming Liang Cheng-Xian Xu ji-xin qian Institute of Industrial Process Control National Lab of Industrial Control TechnologyZhejiang UniversityHangzhou 310027China School of Science Xi’an Jiaotong UniversityXi’an 710049China

Presents a study which proposed to introduce a trust region-type modification of Newton method for the monotone inequality problem using merit function. Concepts of monotone mapping; Proof of convergence of algorithm ... 详细信息

关键词： variational inequality problem trust region method global convergence quadratic convergence

A closed-loop particle swarm optimizer for multivariable process controller design

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第8期9卷 1050-1060页

作者： Kai HAN Jun ZHAO Zu-hua XU ji-xin qian State Key Lab of Industrial Control Technology Institute of Industrial Process Control Zhejiang University Hangzhou 310027 China

Design of general multivariable process controllers is an attractive and practical alternative to optimizing design by evolutionary algorithms (EAs) since it can be formulated as an optimization problem. A closed-loop particle swarm optimization (CLPSO) algorithm is proposed by mapping PSO elements into the closed-loop system based on control theories. At each time step, a proportional integral (PI) controller is used to calculate an updated inertia weight for each particle in swarms from its last fitness. With this modification, limitations caused by a uniform inertia weight for the whole population are avoided, and the particles have enough diversity. After the effectiveness, efficiency and robustness are tested by benchmark functions, CLPSO is applied to design a multivariable proportional-integral-derivative (PID) controller for a solvent dehydration tower in a chemical plant and has improved its performances.

关键词： Multivariable process control Proportional-integral-derivative (PID) control Model predictive control (MPC) Particle swarm optimization (PSO) Closed-loop system

Characteristics of a magnetic fluid seal and its motion in an axial variable seal gap

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Journal of China University of Mining and Technology 2008年第4期18卷 634-636页

作者： qian ji-guo YANG Zhi-yi School of Mechanical and Electronic Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221116 China

With suitable assumptions a hydrodynamic model for the magnetic fluid motion in an axial variable gap seal was con- structed, and the solution to the equations of the model was deduced. The characteristics of a magnetic fluid seal and its motion, including the speed and pressure distribution, and the seal capacity of a magnetic fluid rotating seal were systematically described. The factors affecting seal capacity and ways to improve seal capacity based on the hydrodynamic model are discussed. The basic condition for dynamic seal availability is presented. The rotating speed and radius of the shafts should be decreased. The work can provide proof of a seal design or suggest ways to improve the seal capacity of magnetic fluid seals.

关键词： characteristics hydrodynamic model magnetic fluid seal axial variable gap

Expression patterns and action analysis of genes associated with drug-induced liver diseases during rat liver regeneration

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World Journal of Gastroenterology 2006年第43期12卷 6966-6972页

作者： qian-ji Ning Shao-Wei Qin Cun-Shuan Xu College of Life Science HenanNormal University Xinxiang 453007 Henan Province China Key Laboratory for Cell Differentiation Regulation Xinxiang 453007 Henan Province China

AIM: To study the action of the genes associated with drug-induced liver diseases at the gene transcriptional level during liver regeneration (LR) in rats. METHODS: The genes associated with drug-induced liver diseases were obtained by collecting the data from databases and literature, and the gene expression changes in the regenerating liver were checked by the Rat Genome 230 2.0 array. RESULTS: The initial and total expression numbers of genes occurring in phases of 0.5-4 h after partial hepatectomy (PH), 4-6 h after PH (G0/G1 transition), 6-66 h after PH (cell proliferation), 66-168 h after PH (cell differentiation and structure-function reconstruction) were 21, 3, 9, 2 and 21, 9, 19, 18, respectively. It is illustrated that the associated genes were mainly triggered at the initial stage of LR and worked at different phases. According to their expression similarity, these genes were classified into 5 types: only up- regulated (12 genes), predominantly up-regulated (4 genes), only down-regulated (11 genes), predominantly down-regulated (3 genes), and approximately up-/ down-regulated (2 genes). The total times of their up- and down-expression were 130 and 79, respectively, demonstrating that expression of most of the genes was increased during LR, while a few decreased. The cell physiological and biochemical activities during LR were staggered according to the time relevance and were diverse and complicated in gene expression patterns. CONCLUSION: Drug metabolic capacity in regenerating liver was enhanced. Thirty-two genes play important roles during liver regeneration in rats.

关键词： Partial hepatectomy Rat Genome 230 2.0array Drug-induced liver diseases Genes associatedwith liver regeneration

Experimental study on wire breakage detection by acoustic emission

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Frontiers of Structural and Civil Engineering 2011年第4期5卷 503-509页

作者： Limin SUN ji qian State Key Laboratory for Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

This paper experimentally investigated wire breakage detection in a steel cable by acoustic emission(AE)*** the experiments,the attenuation laws of waveform amplitudes were discussed based on stress wave propagation in the wire,which was generated by kNocking and wire *** the wave velocity was calculated based on the reach time of the stress wave from each ***,based on the waveform attenuation laws and the linear position method,the amplitude and energy of the source were confirmed through the measured waveform to identify the source *** experimental results illustrated that the stress wave from different sources has a different frequency spectrum,and the amplitude attenuation factor varied with the stress wave frequency;high frequency waves had a greater attenuation *** with the other source,the wire breakage source contained a much higher energy,and thus,the wire breakage signal can be distinguished from the other source by comparing the non-attenuation energy at the source position.

关键词： acoustic emission(AE) waveform wire breakage attenuation factor wave velocity

Enhanced Synchronization of Intercellular Calcium Oscillations by Noise Contaminated Signals

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Communications in Theoretical Physics 2008年第10期50卷 903-906页

作者： ZHANG ji-qian CHEN Han-Shuang WANG Mao-Sheng College of Physics and Electronic Information Anhui Normal University Wuhu 241000 China

We consider the dynamics of locally coupled calcium oscillation systems,each cell is subjected to extracel-lular contaminated signal,which contains common sub-threshold signal and independent Gaussian *** is found thatintermediate noise can enhance synchronized oscillations of calcium ions,where the frequency of noise-induced oscilla-tions is matched with the one of sub-threshold external *** show that synchronization is enhanced as a result ofthe entrainment of external signal Furthermore,the effect of coupling strength is *** find above-mentionedphenomenon exists only when coupling strength is very *** findings may exhibit that noise can enhance thedetection of feeble external signal through the mechanism of synchronization of intercellular calcium ions.

关键词： synchronization noise coupled oscillators random processes

Chaotic Identification and Prediction of Silicon Content in Hot Metal

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Journal of Iron and Steel Research International 2005年第5期12卷 3-5,46页

作者： GAO Chuan-hou ZHOU Zhi-min qian ji-xin Zhejiang University Hangzhou 310027 China

The time series data of silicon content in hot metal were identified to have the chaotic feature because of the positive maximum Lyapunov exponent, and then the time scales to predict future were estimated. Finally a chaotic local-region model was constructed to predict silicon content in hot metal with good performance due to high hitting rate.

关键词： blast furnace silicon content hot metal chaos Lyapunov spectra prediction

Simultaneous approach for simulation of a high-temperature gas-cooled reactor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第7期12卷 567-574页

作者： Yang CHEN jiang-hong YOU Zhi-jiang SHAO Ke-xin WANG ji-xin qian State Key Laboratory of Industrial Control Technology Zhejiang University Hangzhou 310027 China

The simulation of a high-temperature gas-cooled reactor pebble-bed module(HTR-PM) plant is *** lumped parameter model has the form of a set differential algebraic equations(DAEs) that include stiff equations to model point neutron *** nested approach is the most common method to solve DAE,but this approach is very expensive and time-consuming due to inner *** paper deals with an alternative approach in which a simultaneous solution method is *** DAEs are discretized over a time horizon using collocation on finite elements,and Radau collocation points are *** resulting nonlinear algebraic equations can be solved by existing *** discrete algorithm is discussed in detail;both accuracy and stability issues are ***,the simulation results are presented to validate the efficiency and accuracy of the simultaneous approach that takes much less time than the nested one.

关键词： Differential algebraic equations(DAEs) High-temperature gas-cooled reactor(HTR) Simulation Simultaneous approach

Model predictive control with an on-line identification model of a supply chain unit

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第5期11卷 394-400页

作者： jian NIU Zu-hua XU Jun ZHAO Zhi-jiang SHAO ji-xin qian State Key Lab of Industrial Control Technology Zhejiang University Hangzhou 310027 China

A model predictive controller was designed in this study for a single supply chain unit.A demand model was described using an autoregressive integrated moving average(ARIMA) model,one that is identified on-line to forecast the future *** was used to modify the demand prediction,and profit was chosen as the control *** imitate reality,the purchase price was assumed to be a piecewise linear form,whereby the control objective became a nonlinear *** addition,a genetic algorithm was introduced to solve the *** were put on the predictive inventory to control the inventory fluctuation,that is,the bullwhip effect was *** model predictive control(MPC) method was compared with the order-up-to-level(OUL) method in *** results revealed that using the MPC method can result in more profit and make the bullwhip effect controllable.

关键词： Supply chain Model predictive control On-line identification Optimization with constraint Piecewise linear price