检索结果-内蒙古大学图书馆

Design of Parallel Electrical Resistance Tomography System for Measuring Multiphase Flow

Chinese Journal of Chemical engineering 2012年第2期20卷 368-379页

作者：董峰许聪张志强任尚杰 Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and AutomationTianjin University

ERT(electrical resistance tomography) is effective method for visualization of multiphase flows,offering some advantages of rapid response and low cost,so as to explore the transient *** at this target,a fully programmable and reconfigurable FPGA(field programmable gate array)-based Compact PCI(peripheral component interconnect) bus linked sixteen-channel ERT system has been *** data acquisition system is carefully designed with function modules of signal generator module;Compact PCI transmission module and data processing module(including data sampling,filtering and demodulating).The processing module incorporates a powerful FPGA with Compact PCI bus for communication,and the measurement process management is conducted in *** reconstruction algorithms with different speed and accuracy are also coded for this *** system has been demonstrated in real time(1400 frames per second for 50 kHz excitation) with signal-noise-ratio above 62 dB and repeatability error below 0.7%.Static experiments have been conducted and the images manifested good resolution relative to the actual object *** parallel ERT system has provided alternative experimental platform for the multiphase flow measurements by the dynamic experiments in terms of concentration and velocity.

关键词： electrical resistance tomography data acquisition compact peripheral component interconnect field programmable gate array digital filter digital demodulation

来源：评论

学校读者我要写书评

暂无评论

L_2-gain Analysis and Anti-windup Design of Discretetime Switched Systems with Actuator Saturation

引用

International Journal of automation and computing 2012年第4期9卷 369-377页

作者： Zhang, Xin-Quan Zhao, Jun School of Information and Control Engineering Liaoning Shihua University Fushun 113001 China State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang 110819 China

This paper investigates L2-gain analysis and anti-windup compensation gains design for a class of discrete-time switched systems with saturating actuators and L2 bounded disturbances by using the switched Lyapunov function *** a given set of anti-windup compensation gains,we firstly give a sufficient condition on tolerable disturbances under which the state trajectory starting from the origin will remain inside a bounded set for the corresponding closed-loop switched system subject to L2 bounded ***,the upper bound on the restricted L2-gain is obtained over the set of tolerable ***,the antiwindup compensation gains aiming to determine the largest disturbance tolerance level and the smallest upper bound of the restricted L2-gain are presented by solving a convex optimization problem with linear matrix inequality(LMI) constraints.A numerical example is given to illustrate the effectiveness of the proposed design method.

关键词： L2-gain anti-windup switched systems saturating actuators switched Lyapunov function tolerable disturbances.

来源：评论

学校读者我要写书评

暂无评论

Undo the codebook bias by linear transformation for visual applications 13

Undo the codebook bias by linear transformation for visual a...

引用

21st ACM International Conference on Multimedia, MM 2013

作者： Zhang, Chunjie Zhang, Yifan Wang, Shuhui Pang, Junbiao Liang, Chao Huang, Qingming Tian, Qi School of Computer and Control Engineering University of Chinese Academy of Sciences 100049 Beijing China National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing China Key Lab of Intell. Info. Process Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China College of Computer Science and Technology Beijing University of Technology 100124 Beijing China School of Computer National Engineering Research Center for Multimedia Software Wuhan University 430072 Wuhan China Department of Computer Sciences University of Texas at San Antonio San Antonio TX 78249 United States

ISBN: (纸本)9781450324045

The bag of visual words model (BoW) and its variants have demonstrate their effectiveness for visual applications and have been widely used by researchers. The BoW model first extracts local features and generates the corresponding codebook, the elements of a codebook are viewed as visual words. The local features within each image are then encoded to get the final histogram representation. However, the codebook is dataset dependent and has to be generated for each image dataset. This costs a lot of computational time and weakens the generalization power of the BoW model. To solve these problems, in this paper, we propose to undo the dataset bias by codebook linear transformation. To represent every points within the local feature space using Euclidean distance, the number of bases should be no less than the space dimensions. Hence, each codebook can be viewed as a linear transformation of these bases. In this way, we can transform the pre-learned codebooks for a new dataset. However, not all of the visual words are equally important for the new dataset, it would be more effective if we can make some selection using sparsity constraints and choose the most discriminative visual words for transformation. We propose an alternative optimization algorithm to jointly search for the optimal linear transformation matrixes and the encoding parameters. Image classification experimental results on several image datasets show the effectiveness of the proposed method. Copyright © 2013 ACM.

关键词： Linear transformations

来源：评论

学校读者我要写书评

暂无评论

Dual-modality data acquisition system based on CPCI industrial computer

Dual-modality data acquisition system based on CPCI industri...

引用

2012 IEEE International Conference on Imaging Systems and Techniques, IST 2012

作者： Xu, Cong Dong, Feng Zhang, Zhiqiang Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin China

ISBN: (纸本)9781457717741

As a non-radiant and unperturbed 2D/3D boundary measurement technique, Electrical resistance tomography (ERT) provides an effective way of monitoring and on-line measurements for multi-phase fluid. However, the spatial resolution and accuracy are very poor due to the ill-posed nature of inverse problems. A combination of electrical and ultrasonic dual-modality system based on CPCI industrial computer was developed for increasing the resolution and accuracy. The fusion system was with strong expansibility and high stability due to the CPCI bus and adoption of FPGA. The system has been tested and verified with good SNR and consistence. Preliminary static experiments have been conducted, and this system is an appealing way to improve spatial resolution and accuracy. © 2012 IEEE.

关键词： Field programmable gate arrays (FPGA)

来源：评论

学校读者我要写书评

暂无评论

Two phase flow visualization in an annular tube by an electrical resistance tomography

Two phase flow visualization in an annular tube by an electr...

引用

2012 IEEE International Conference on Imaging Systems and Techniques, IST 2012

作者： Ren, Shang-Jie Tan, Chao Dong, Feng Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China

ISBN: (纸本)9781457717741

Phase distribution within an annular channel is desired to know as precise as possible for industrial processes like cooling system and etc. Electrical Resistance Tomography (ERT) can be used to achieve this task since it is a non-invasive visualization technique. However, the internal structure which forms the annulus with the pipe wall makes the reconstruction of phase distribution different from the conventional application of ERT, especially when the diameter of the internal structure is big. The case of a non-conductive internal structure with the diameter ratio of 0.76 is studied on the electric field distribution and sensitivity distribution. Small bubbles within the annulus and a stratified flow occupied half of the cross section are numerically simulated and reconstructed with one-step Gauss-Newton method which provides good resolution on the bubbles location but overestimates their size. © 2012 IEEE.

关键词： Electric resistance

来源：评论

学校读者我要写书评

暂无评论

Nonlinear modeling and global sliding mode control of main drive system torsional vibration in cold rollling mill

Nonlinear modeling and global sliding mode control of main d...

引用

2012 5th International Conference on Intelligent Computation Technology and automation, ICICTA 2012

作者： Yang, Xu Tong, Chao-Nan Key Laboratory of Advanced Control of Iron and Steel Process School of Automation and Electrical Engineering University of Science and Technology Beijing Beijing China

ISBN: (纸本)9780769546377

the torsional vibration model in main drive system of cold rolling mill is built with the consideration of nonlinear stiffness and nonlinear friction coefficient. The global sliding mode controller is designed for rolling mill drive system for rejecting plants with rolling parameters' uncertainties, as well as a better tracking behavior. Simulation results show the validity of the nonlinear model and the strong robustness, good dynamic characteristic of control algorithms. © 2012 IEEE.

关键词： Nonlinear systems

来源：评论

学校读者我要写书评

暂无评论

Computer system for process control based on data-driven

Computer system for process control based on data-driven

引用

2012 IEEE Symposium on Electrical and Electronics engineering, EEESYM 2012

作者： Li, Jiangyun Liu, Yan Tong, Chaonan School of Automation and Electrical Engineering University of Science and Technology Beijing Key Laboratory of Advanced Control of Iron and Steel Process Beijing China

ISBN: (纸本)9781467323659

It presents a computer control system for process control based on data-driven. The system focuses on process data and is able to deal with the complex problems such as nonlinearity, significant delay, strong coupling and stochastic uncertainty, which are ubiquitous in process control. It adopts both modeling method based on data and learning control theory. The computer control system is composed of PC servers and high performance embedded special controllers. control network adopts fully-distributed automation islands based on industrial Ethernet. So the powerful ability of data process is provided for the system and can satisfy the requirement of modeling and controlling based on data-driven. © 2012 IEEE.

关键词： Computer control systems

来源：评论

学校读者我要写书评

暂无评论

A water flow control method of quenching cooling system based on smith predictor

A water flow control method of quenching cooling system base...

引用

2012 IEEE Symposium on Electrical and Electronics engineering, EEESYM 2012

作者： Li, Jiangyun Yao, Yunyun Tong, Chaonan School of Automation and Electrical Engineering University of Science and Technology Beijing Key Laboratory of Advanced Control of Iron and Steel Process Beijing China

ISBN: (纸本)9781467323659

The computer control system of a steel plant is composed of Siemens S7-400 PLC and configuration software WinCC. In order to achieve real-time control of water flow accurately in quenching process, this paper uses a combination of Smith predictor and PID controller to compensate time delay of system and overcome problems caused by the delay. MATLAB simulation verifies that this method can solve the time delay problem in quenching process, and provide a solution for real-time control of water flow. © 2012 IEEE.

关键词： Flow of water

来源：评论

学校读者我要写书评

暂无评论

Empirical numerical study on denoising by wavelet and by second kind of Fourier analysis

Empirical numerical study on denoising by wavelet and by sec...

引用

International Conference on Automatic control and Artificial Intelligence, ACAI 2012

作者： Yang, Zheng-Ling Duan, Zhi-Feng Song, Yan-Wen Wang, Teng School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China Tianjin Key Laboratory of Process Measurement and Control Tianjin 300072 China

ISBN: (纸本)9781849195379

As the wavelet bases usually have relative small support sets, three defects of wavelet denoising for a complex time series can be deduced. The first defect is that for in large sample size, the wavelet denoising is not better than the second kind, Fourier analysis denoising. The second is that wavelet denoising has the worse reconstructive capacity for the high frequency signal. The last defect is that the wavelet denoising is not better when there are many outliers. The numerical experiments are carried out to make sure the three deductions.

关键词： Fourier analysis

来源：评论

学校读者我要写书评

暂无评论

Empirical study of robust combination of forecasts for short-term highway traffic flow forecast

Empirical study of robust combination of forecasts for short...

引用

2012 International Conference on Machine Learning and Cybernetics, ICMLC 2012

作者： Yang, Zheng-Ling Li, Yan Song, Yan-Wen Chen, Xi Zhang, Jun School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China Tianjin Key Laboratory of Process Measurement and Control Tianjin 300072 China

ISBN: (纸本)9781467314855

In order to improve forecast accuracy and reliability of expressway traffic flows, the variance reciprocal weighting methods in linear combination of forecasts are compared numerically with the simple average. Ten individual methods for combination include the autoregression, exponential smoothing models, moving average models, and cybernetics method. Six variance estimators for the variance reciprocal weighting methods are the standard deviation, mean absolute deviation, median absolute deviation from median, fourth-spread, biweight estimator and Andrews wave M-estimator of scale. The empirical results show that the variance reciprocal weighting methods are usually better than the simple average, and they can be further improved by robust scale estimators. © 2012 IEEE.

关键词： Time series

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：