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Improvements in the sensibility of MSA-GA tool using COFFEE objective function

Journal of Physics: Conference Series 2015年第1期574卷

作者： A R Amorim G F D Zafalon L A Neves A R Pinto C R Valêncio J M Machado Department of Computer Science and Statistics (DCCE) São Paulo State University (UNESP) São José do Rio Preto Brazil Department of Control Engineering and Automation Federal University of Santa Catarina Blumenau Brazil

The sequence alignment is one of the most important tasks in Bioinformatics, playing an important role in the sequences analysis. There are many strategies to perform sequence alignment, since those use deterministic algorithms, as dynamic programming, until those ones, which use heuristic algorithms, as Progressive, Ant Colony (ACO), Genetic Algorithms (GA), Simulated Annealing (SA), among others. In this work, we have implemented the objective function COFFEE in the MSA-GA tool, in substitution of Weighted Sum-of-Pairs (WSP), to improve the final results. In the tests, we were able to verify the approach using COFFEE function achieved better results in 81% of the lower similarity alignments when compared with WSP approach. Moreover, even in the tests with more similar sets, the approach using COFFEE was better in 43% of the times.

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Finite abstractions of networked control systems 53

Finite abstractions of networked control systems

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2014 53rd IEEE Annual Conference on Decision and control, CDC 2014

作者： Zamani, Majid Mazo, Manuel Abate, Alessandro Department of Electrical Engineering and Information Technology Technische Universität München MunichD-80290 Germany Delft Center for Systems and Control Delft University of Technology Delft CD2628 Netherlands Department of Computer Science University of Oxford OxfordOX1 3QD United Kingdom

ISBN: (纸本)9781479977468

In networked control systems (NCS), the communication between sensors, controllers, and actuators is supported by a shared communication channel that is subject to variable communication delays, limited bandwidth, packet losses, quantization errors, and other practical non-idealities. This work investigates the problem of constructively deriving symbolic models of NCS by simultaneously considering the mentioned network non-idealities. By employing the obtained symbolic models, one can completely automate the design of controllers enforcing rich logical specifications, e.g. formulae in linear temporal logic, over NCS. © 2014 IEEE.

关键词： Networked control systems

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On overcoming limitations of a class of linear systems with first-order reset elements

On overcoming limitations of a class of linear systems with ...

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World Congress on Intelligent control and Automation (WCICA)

作者： Guanglei Zhao Jingcheng Wang Kang Li Department of Automation Key Laboratory of System Control and Information Processing China Electrical Engineering and Computer Science Queens University Belfast UK

This paper considers using reset control to improve transient performance and overcome some fundamental limitations of linear systems. First, an auxiliary system is presented, then, based on which, a new reset control model is proposed, such that the non-overshoot performance specification can be met for any minimum phase relative degree one plants, the results imply some limitations of linear systems are overcome and clearly illustrate the advantages of reset control. A numerical example is given to show the effectiveness.

关键词： Closed loop systems Stability analysis Gold Linear systems Steady-state Educational institutions

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An Improved BET Method for Brain Segmentation

An Improved BET Method for Brain Segmentation

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International Conference on Pattern Recognition

作者： Liping Wang Ziming Zeng Reyer Zwiggelaar Department of Computer Science Aberystwyth University Aberystwyth United Kingdom Information and Control Engineering Faculty Shenyang Jianzhu University Liaoning China

ISBN: (纸本)9781479952106

The Brain Extraction Tool (BET) developed by Smith is widely used for brain segmentation due to its simplicity, accuracy and insensitivity to parameter settings. However, it typically requires a large number of iterations to generate acceptable results. It also sometimes fails to recognize boundaries of the brain. Moreover, obvious under-segmentation occurs for some datasets. In this paper, we present an improved BET method where at each iteration, we enhance the vertex displacement, add a new search path and embed an independent surface reconstruction process. These strategies lead to much faster convergence. Furthermore, a scheme based on fuzzy c-means is proposed to refine the segmentation. Experimental results based on various datsets demonstrated that the proposed method significantly outperforms the original BET and other competing methods.

关键词： Surface morphology Surface treatment Surface reconstruction Brain modeling Image segmentation Measurement

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Fault Tolerant Barrier Coverage for Wireless Sensor Networks

Fault Tolerant Barrier Coverage for Wireless Sensor Networks

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IEEE International Conference on computer Communications

作者： Zhibo Wang Honglong Chen Qing Cao Hairong Qi Zhi Wang Department of Control Science and Engineering Zhejiang University Hangzhou P.R. China College of Information and Control Engineering China University of Petroleum Qingdao P.R. China Depattment of Electrical Engineering and Computer Science University of Tennessee Knoxville USA

Barrier coverage is a critical issue in wireless sensor networks for security applications (e.g., border protection), the performance of which is highly related with locations of sensor nodes. Existing work on barrier coverage mainly assume that sensor nodes have accurate location information, however, little work explores the effects of location errors on barrier coverage. In this paper, we study the barrier coverage problem when sensor nodes have location errors and deploy mobile sensor nodes to improve barrier coverage if the network is not barrier covered after initial deployment. We analyze the relationship between the true distance and the measured distance of two stationary sensor nodes and derive the minimum number of mobile sensor nodes needed to connect them with a guarantee when nodes location errors. Furthermore, we propose a fault tolerant weighted barrier graph, based on which we prove that the minimum number of mobile sensor nodes needed to form barrier coverage with a guarantee is the length of the shortest path on the graph. Simulation results validate the correctness of our analysis.

关键词： Mobile nodes Robot sensing systems Fault tolerance Fault tolerant systems Measurement uncertainty

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Embedded Model Predictive control on a PLC using a primal-dual first-order method for a subsea separation process

Embedded Model Predictive Control on a PLC using a primal-du...

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Mediterranean Conference on control and Automation (MED)

作者： D. K. M. Kufoalor S. Richter L. Imsland T. A. Johansen M. Morari G. O. Eikrem Department of Engineering Cybernetics Norwegian University of Science and Technology Norway Automatic Control Laboratory ETH Zurich Zurich Switzerland. FD ER SF Statoil ASA Rotvoll Norway

The results of a PLC implementation of embedded Model Predictive control (MPC) for an industrial problem are presented in this paper. The embedded MPC developed is based on the linear MPC module in SEPTIC (Statoil Estimation and Prediction Tool for Identification and control), and it combines custom ANSI C code generation with problem size reduction methods, embedded real-time considerations, and a primal-dual first-order method that provides a fast and light QP solver obtained from the FiOrdOs code generator toolbox. Since the primal-dual first-order method proposed in this paper is new in the control community, an extensive comparison study with other state-of-the-art first-order methods is conducted to underline its potential. The embedded MPC was implemented on the ABB AC500 PLC, and its performance was tested using hardware-in-the-loop simulation of Statoil's newly patented subsea compact separation process. A warm-start variant of the proposed first-order method outperforms a tailored interior-point method by a factor of 4 while occupying 40% less memory.

关键词： Convergence Real-time systems Software Liquids IP networks Separation processes Predictive control

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A Novel control Method for Neutral Point Clamped Inverters with a Single Z-Source Network

A Novel Control Method for Neutral Point Clamped Inverters w...

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Annual Conference of the IEEE Industrial Electronics Society

作者： Xiangyang Xing Alian Chen Weisheng Wang Chenghui Zhang Vahid Najmi School of Control Science and Engineering Shandong University Center for Power Electronics Systems The Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University

ISBN: (纸本)9781479940318

The Z-source neutral point clamped (NPC) inverters can realize buck-boost energy conversion with all satisfying advantages of the three-level inverters. A significant problem related to this topology is the fluctuation of the neutral-point potential (NP). However, the previous modulation techniques for this topology cannot achieve the considerate stable voltage. In this paper, based on the analysis of the relationship among the shoot-through duty cycle and the NP voltage, the average NP current, switching frequency capacitor value, a new feed-forward compensator by modifying the shoot-through duty cycle which can improve to balance the NP voltage balancing is proposed. Meanwhile, in consideration of a low voltage gain caused by the NP voltage balance method, a new control method based on a maximum constant boost control method is proposed, which brings the benefits in both high voltage gain and low-frequency ripple. The considerate stable NP voltage and the high voltage gain have been proven in simulation and through experimental results from a prototype converter.

关键词： Z-source neutral point clamped (NPC) inverter High voltage gain Balance the neutral-point potential (NP) voltage

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Adaptive cubature strong tracking information filter using variational Bayesian method 19

Adaptive cubature strong tracking information filter using v...

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19th IFAC World Congress on International Federation of automatic control, IFAC 2014

作者： Ge, Quanbo Wen, Chenglin Chen, Shaodong Sun, Ruoyu Li, Yuan Institute of Systems Science and Control Engineering School of Automation Hangzhou Dianzi University Hangzhou Zhejiang310018 China Luoyang Institute of Electro Optical Equipment of AVIC Luoyang Henan471000 China Department of Electrical and Computer Engineering University of Minnesota MinneapolisMN55414 United States Information Engineering School Shenyang University of Chemical Technology Shenyang Liaoning100142 China

ISBN: (纸本)9783902823625

For most practical nonlinear state estimation problems, the conventional nonlinear filters do not usually work well for some cases, such as inaccurate system model, sudden change of state-interested and unknown variance of measurement noise. In this paper, an adaptive cubature strong tracking information filter using variational Bayesian (VB) method is proposed to cope with these complex cases. Firstly, the strong tracking filtering (STF) technology is used to integrally improve performance of cubature information filter (CIF) aiming at the first two cases and an iterative scheme is presented to effectively evaluate a strong tracking fading factor. Secondly, the VB method is introduced to iteratively evaluate the unknown variance of measurement noise. Finally, the novel adaptive cubature information filter is obtained by perfectly combining the STF technology with the VB method, where the variance estimation provided by the VB method guarantees normal running of the strong tracking functionality. © IFAC.

关键词： Information filtering

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Ambulatory estimation of 3D walking trajectory and knee joint angle using MARG Sensors

Ambulatory estimation of 3D walking trajectory and knee join...

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International Conference on Innovative Computing Technology (INTECH)

作者： Sen Qiu Yu Yang Jijian Hou Ran Ji Huosheng Hu Zhelong Wang Department of Computer Science and Electronic Engineering University of Essex Colchester UK School of Control Science and Engineering Dalian University of Technology Dalian China Dalian University of Technology Dalian Liaoning CN

This paper presents a MARG Sensors based walking motion analysis method that can be used for rehabilitation treatment evaluation under ambulatory conditions in daily lives. A commercial inertial measure unit MTx is fixed on human shank segment. Then digital data box worn on the waist transmits the raw data to laptop with Blue-tooth for post processing. Subjects are required to perform level walking and upstairs walking respectively. After the initial alignment and quaternion convergence, the proposed method fuses the inertial data using Kalman filter based on quaternion. Walking trajectory and knee joint angle are estimated and validated by available ground truth. Experiment results demonstrate that the proposed method has a good performance at both motion patterns. It also shows that no significant drifts exist in the overall results presented in the paper. The method can also be adapted to measure other sites of articulation such as ankle and elbow.

关键词： Legged locomotion Sensors Quaternions Gyroscopes Kalman filters Estimation Accelerometers

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ANN-based DTC scheme to improve the dynamic performance of an IM drive

ANN-based DTC scheme to improve the dynamic performance of a...

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7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014

作者： Bouhoune, K. Yazid, K. Boucherit, M.S. Power and Industrial Systems Laboratory Faculty of Electronics and Computer Science University of Science and Technology Houari Boumediene PO Box 32 El Alia Bab Ezzouar 16111 Algiers Algeria Process Control Laboratory Department of Electrical Engineering Polytechnic National School PO Box 182 10 Hassan Badi El-Harrach 16200 Algiers Algeria

ISBN: (纸本)9781849198158

In addition to simplicity, the DTC of the IM allows a good torque control in steady-state and transient operating conditions. However, high torque ripple is produced, which is reflected in speed estimation responses. It also increases acoustical noise and makes the voltage source inverter operated in high and variable switching frequency, requiring a high sampling frequency. In this paper, a simple effective ANN-based DTC of the induction machine is proposed. Neural networks with a simple architecture are designed and implemented in influential points of the direct torque control block of the three phase induction machine in order to improve its dynamic performance while preserving the DTC structure simplicity as much as possible. In particular, this paper proposes to reduce, on the one hand, the torque ripple and commutation frequency. Neural comparators are used to select the appropriate bandwidth for the torque and flux hysteresis controllers. Their aim is to optimize the ripple level in the developed torque and flux. On the other hand, a neural speed controller is designed in order to improve the system ability to respond rapidly to changes in process variables and mitigate the effects of external perturbations. The performance of the proposed control are tested in simulation and highlighted by comparing to the conventional DTC control based on conventional hysteresis comparators and conventional PI speed controller. The obtained results show the feasibility and good performances of the proposed control.

关键词： Neural networks

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