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Fast computation of Zernike moments in polar coordinates

IET image processing 2012年第7期6卷 996-1004页

作者： Liu, C. Huang, X. -H. Wang, M. Huazhong Univ Sci & Technol Key Lab Image Proc & Intelligent Control Minist Educ China Dept Control Sci & Engn Wuhan 430074 Hubei Peoples R China

Zernike moments (ZMs) are widely used in many image analysis and pattern recognition problems because of their superiority compared with other moments. However, they suffer from high computation cost and inherent error. Previous researches have shown that the algorithm, computing ZMs in polar system, improves the ZMs accuracy of the reconstruction and invariance properties dramatically. In this study, the authors firstly modify a direct method for computing ZMs in polar coordinates and present a recursive relation. Then, this study presents an algorithm for fast computation of ZMs, based on the improved polar pixel tiling scheme. Owing to the symmetrical property, ZMs can be obtained by computing only one-sixteenth circle of the radial polynomials, which means that the number of pixels involved in the computation of ZMs is only 6.25% of the previous method. This leads to a significant reduction in the computational complexity requirements. A comparison with the other conventional method is performed in detail. The obtained results show the superiority of the proposed method.

关键词： COMPUTATIONAL complexity ZERNIKE polynomials POLAR coordinates (Mathematics) image analysis PATTERN recognition systems SYMMETRY (Mathematics)

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Nonlinear Internal Model control Using Echo State Network for Pneumatic Muscle System

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JOURNAL OF COMPUTERS 2012年第12期7卷 3060-3067页

作者： Wu, Jun Wang, Yongji Huang, Jian Zhou, Hanying Huazhong Univ Sci & Technol Dept Control Sci & Engn Key Lab Image Proc & Intelligent Control Wuhan 430074 Hubei Peoples R China

Pneumatic muscle (PM) has many advantages such as light weight, high power to weight ratio and low price. However, it has strong time varying characteristic. The complex nonlinear dynamics of PM system poses some challenges for achieving accurate modeling and control. To solve these problems, we propose nonlinear internal model control (IMC) using echo state network (ESN) for PM system in this paper. The ESN based IMC is termed ESNBIMC, which fully embodies the virtues of ESN and IMC. In ESNBIMC, the dynamic model of PM system is identified by an ESN. The other ESN is trained to learn the inverse dynamics of the system, and then it can be used as a nonlinear controller. Recursive Least Square (RLS) algorithm can be applied to online training the ESN without affecting the previous weight structure, which is very suitable for real-time control problems. By using the identification ability of ESN and RLS, high accurate plant model of PM system without detailed model information can be built. In addition, strong robustness also can be attained by online self-tuning of controller and internal model. Experiment demonstrates the effectiveness of the proposed control algorithm. The results show that ESNBIMC achieves satisfactory tracking performance for PM system.

关键词： internal model control echo state network pneumatic muscle nonlinear control

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Arithmetic computation using self-assembly of DNA tiles:subtraction and division

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Progress in Natural Science:Materials International 2009年第3期19卷 377-388页

作者： Xuncai Zhang a,b, Yanfeng Wang b, Zhihua Chen a, Jin Xu a,*, Guangzhao Cui b a The key laboratory of image processing and intelligent control, Department of control Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China b School of Electrical and Electronic Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, China [a]The Key Laboratory of Image Processing and Intelligent Control Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China [b]School of Electrical and Electronic Engineering Zhengzhou University of Light Industry Zhengzhou 450002 China

Recently, experiments have demonstrated that simple binary arithmetic and logical operations can be computed by the process of self- assembly of DNA tiles. In this paper, we show how the tile assembly process can be used for subtraction and division. In order to achieve this aim, four systems, including the comparator system, the duplicator system, the subtraction system, and the division system, are pro- posed to compute the difference and quotient of two input numbers using the tile assembly model. This work indicates that these systems can be carried out in polynomial time with optimal O(1) distinct tile types in parallel and at very low cost. Furthermore, we provide a scheme to factor the product of two prime numbers, and it is a breakthrough in basic biological operations using a molecular computer by self-assembly.

关键词： Self-assembly Subtractor Divider Tile assembly model DNA tiles DNA computing

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Mem Brain: An Easy-to-Use Online Webserver for Transmembrane Protein Structure Prediction

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Nano-Micro Letters 2018年第1期10卷 12-19页

作者： Xi Yin Jing Yang Feng Xiao Yang Yang Hong-Bin Shen Institute of Image Processing and Pattern Recognition Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China Department of Computer Science Shanghai Jiao Tong University Key Laboratory of Shanghai Education Commission for Intelligent Interaction and Cognitive Engineering

Membrane proteins are an important kind of proteins embedded in the membranes of cells and play crucial roles in living organisms, such as ion channels,transporters, receptors. Because it is difficult to determinate the membrane protein's structure by wet-lab experiments,accurate and fast amino acid sequence-based computational methods are highly desired. In this paper, we report an online prediction tool called Mem Brain, whose input is the amino acid sequence. Mem Brain consists of specialized modules for predicting transmembrane helices, residue–residue contacts and relative accessible surface area of a-helical membrane proteins. Mem Brain achieves aprediction accuracy of 97.9% of ATMH, 87.1% of AP,3.2 ± 3.0 of N-score, 3.1 ± 2.8 of C-score. Mem BrainContact obtains 62%/64.1% prediction accuracy on training and independent dataset on top L/5 contact prediction,respectively. And Mem Brain-Rasa achieves Pearson correlation coefficient of 0.733 and its mean absolute error of13.593. These prediction results provide valuable hints for revealing the structure and function of membrane *** Brain web server is free for academic use and available at ***/bioinf/Mem Brain/.

关键词： Transmembrane a-helices Structure prediction Machine learning Contact map prediction Relative accessible surface area

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Consensus in second-order multi-agent systems via impulsive control using position-only information with heterogeneous delays

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IET control Theory and Applications 2015年第3期9卷 336-345页

作者： Wang, Yan-Wu Yi, Jing-Wen School of Automation Huazhong University of Science and Technology Wuhan430074 China Key Laboratory of Image Processing and Intelligent Control Huazhong University of Science AndTechnology Ministry of China China

This study investigates the consensus problem of second-order multi-agent systems (MASs) via impulsive control using position-only information with communication delays. The communication delays between any two distinct agents are different which can be larger than one impulsive period. A distributed impulsive consensus protocol is designed, in which only the delayed sampled relative positions to neighbours and the relative position to the last sampling state are utilised. By introducing some virtual subgraphs and performing three steps of model transformation, the consensus problem of original continuous-time system is converted to the stability problem of a discrete-time expanded error system. Some necessary and sufficient criteria are derived to grantee the dynamic average-consensus of the MAS. Furthermore, a special case, that is, the delays less than one impulsive period, is discussed, and the bounds of impulsive periods for the dynamic average-consensus are obtained in explicit expressions for both the undirected and directed communication graphs, respectively. Two numerical simulation examples are given to illustrate the effectiveness of theoretical results. © 2015 The Institution of Engineering and Technology.

关键词： Multi agent systems

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Tracking control of pneumatic muscle using Lyapunov based control method

Tracking control of pneumatic muscle using Lyapunov based co...

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2012 International Conference on Modelling, Identification and control, ICMIC 2012

作者： Elobaid, Youssif M. T. Huang, Jian Wang, Yongji Wu, Jun Key Laboratory of Image Processing and Intelligent Control Department of Control Science and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9780956715715

Presently pneumatic muscles (PMs) are used in various applications due to their simple construction, lightweight and high force to weight ratio. However, pneumatic muscles are facing various problems due to their nonlinear characteristic in various mechanical applications. The model of PM is nonlinear and time-varying. In this paper, a Lyapunov-based control (LBC) approach is proposed for the control of PM. Based on the nonlinear characteristic of PM, a dynamic model of the PM actuator with pulling a mass against gravity is formed. control objectives are both a regulation and an asymptotic tracking of a desired trajectory. Stability analysis based on Lyapunov method with respect to our proposed control law is discussed. The simulation results show the validity, effectiveness and enhancing robustness of the proposed method. © 2012 Huazhong Univ of Sci & Tec.

关键词： Lyapunov methods

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Refine for Semantic Segmentation Based on Parallel Convolutional Network with Attention Model

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NEURAL processing LETTERS 2021年第6期53卷 4177-4188页

作者： Peng, Gang Yang, Shiqi Wang, Hao Huazhong Univ Sci & Technol Sch Artificial Intelligence & Automat Minist Educ Key Lab Image Proc & Intelligent Control Wuhan Peoples R China

High-precision semantic segmentation methods require global information and more detailed local features. It is difficult for ordinary convolutional neural networks to efficiently use this information. In response to the above issues, this paper uses the attention to scale method and proposes a novel attention model for semantic segmentation, which aggregates multi-scale and context features to refine prediction. Specifically, the skeleton convolutional neural network framework takes in multiple different scales inputs, by which means the CNN can get representations in different scales. The proposed attention model will handle the features from different scale streams respectively and integrate them. Then location attention branch of the model learns to softly weight the multi-scale features at each pixel location. Moreover, we add an recalibrating branch, parallel to where location attention comes out, to recalibrate the score map per class. We achieve quite competitive results on PASCAL VOC 2012 and ADE20K datasets, which surpass baseline and related works.

关键词： Semantic segmentation Parallel convolutional network Attention model Multi-scale Multi-dilation

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On the stability and bullwhip effect of a production and inventory control system

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INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2013年第1期51卷 154-171页

作者： Wei, Yongchang Wang, Hongwei Qi, Chao Huazhong Univ Sci & Technol Inst Syst Engn Key Lab Educ Minist Image Proc & Intelligent Control Wuhan 430074 Peoples R China

This paper focuses on the discrete-time automatic pipeline, inventory and order-based production control system (APIOBPCS), a well-established production and inventory control model. The feedback mechanism within the replenishment rule enables the model to mitigate the bullwhip effect, but introduces a stability problem. In this research, a comprehensive stability analysis is conducted for arbitrary lead times using difference equation theory. On the basis of stability, a state space approach is advocated to analyse the impact of replenishment parameters, demand processes, and lead times on the robustness of the bullwhip effect. The stability results demonstrate that the production control system can easily be destabilised without incorporating the work-in-progress (WIP) feedback loop. Furthermore, it reveals that the stability problem for long lead times can be simplified with the stability condition independent of the lead time. The results obtained in this study provide useful guidelines for the selection of replenishment parameters to guarantee stability and mitigate the bullwhip effect.

关键词： manufacturing control systems production planning production control

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Model-Predictive control Scheme of Five-Leg AC-DC-AC Converter-Fed Induction Motor Drive

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2016年第7期63卷 4517-4526页

作者： Zhou, Dehong Zhao, Jin Li, Yunhua Huazhong Univ Sci & Technol Sch Automat Minist Educ China Key Lab Image Proc & Intelligent Control Wuhan 430074 Peoples R China

AC-DC-AC converter-fed induction motor (IM) drive is mainly realized by back-to-back three-phase converters. However, fault in a single semiconductor switch will make it inoperative. To enable continued controllable operation in case of the faults occurring in the converter, the five-leg converter with a shared leg between the grid and load sides is a possible solution. However, this topology poses an inherent two-objective control problem, because its grid and load sides should be controlled simultaneously. More importantly, the potential increase of the shared-leg current may destroy the converters. In this paper, a new control scheme based on the FCS-MPC combined with intrinsic characteristic of the five-leg converter is proposed for independent control of the rectifier and inverter subsystem with the shared-leg overcurrent constraint. The condition for independent control is analyzed. In order to give a complete evaluation of the proposed control scheme, the conventional pulsewidth modulation (PWM) control scheme is conducted for comparison. Experimental results are provided to validate the effectiveness of the proposed scheme.

关键词： Fault-tolerant five-leg converter induction motor (IM) model-predictive control

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Design of a fault-tolerant system for a multi-motor drive with multiple inverter leg faults

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JOURNAL OF POWER ELECTRONICS 2022年第11期22卷 1848-1859页

作者： Song, Yujin Zhao, Jin Sun, Jiajiang Huazhong Univ Sci & Technol Sch Artificial Intelligence & Automat Key Lab Image Proc & Intelligent Control Minist Educ Wuhan Peoples R China

A novel fault-tolerant system for a multi-motor drive with one-leg, two-leg, and secondary faults is designed in this study. Fault tolerance is realized from pre-fault to post-fault via a topology reconstruction scheme and an integrated control law. The scheme develops a reconstructible topology and its reconstruction algorithm. The multi-motor drive can be reconstructed into appropriate tolerant topologies on the basis of the diagnosis results. The control law based on the predictive torque control method is universal under any topology by designing a unified voltage vector model and an optimal switching state decision. The proposed system can cope with more types of faults and effectively switch from a healthy state to a fault-tolerant state under any fault. The effectiveness and performance of the fault-tolerant system are verified and demonstrated by simulation and experiment results.

关键词： Two-leg fault Secondary fault Fault-tolerant system Topology reconstruction Integrated control law

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