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International Conference on Conduction and Breakdown in Dielectric Liquids

作者： S. Wolny M. Zdanowski Faculty of Electrical Engineering Automatic Control and Computer Science Chair of Electrical Power Engineering Opole University of Technology Opole Poland

The paper presents the application of the Cole-Cole model for determining the runs of the return voltage of the paper-oil insulation sample through a computer simulation. Different insulation conditions were simulated through an adequate selection of parameters alpha and tau of the Cole-Cole model. For calculation purposes, a series-parallel substitute scheme, obtained through approximation of a discrete characteristic operator impedance Z a of the model applied, was used. The diagnostics of the simulated insulation condition was based on the analysis of a few selected parameters of the return voltage, obtained from time characteristics.

关键词： Insulation Impedance Mathematical model Approximation methods Voltage measurement Frequency measurement Computational modeling

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Evaluating a Mobile Emergency Response System

Evaluating a Mobile Emergency Response System

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14th International Workshop of Groupware

作者： Sapateiro, Claudio Antunes, Pedro Zurita, Gustavo Vogt, Rodrigo Baloian, Nelson Systems and Informatics Department Superior School of Technology Polytechnic Institute of Setúbal Portugal Department of Informatics Faculty of Sciences University of Lisbon Portugal Management Control and Information Systems Department Business School Universidad de Chile Chile Computer Science Department Engineering School Universidad de Chile Chile

ISBN: (纸本)9783540928300

Existing information systems often lack support to crisis and emergency situations. In such scenarios, the involved actors often engage in ad hoc collaborations necessary to understand and respond to the emerging events. We propose a collaboration model and a prototype aiming to improve the consistency and effectiveness of emergent work activities. Our approach defends the requirement to construct shared situation awareness (SA). To support SA, we developed a collaborative artifact named situation matrixes (SM), which relates different situation dimensions (SD) of the crisis/emergency scenario. A method was also developed to construct and evaluate concrete SM and SD. This method was applied in two organizations' IT service desk teams, which often have to deal with emergency situations. The target organizations found our approach very relevant in organizing their response to emergencies.

关键词： Emergency services

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A sensorless speed control strategy for a low-cost full-closed-loop servo driver system

A sensorless speed control strategy for a low-cost full-clos...

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World Congress on Intelligent control and Automation (WCICA)

作者： Nanhu Chen Zexiang Li Division of Control and Mechatronics Engineering Harbin Institute of Technology Shenzhen Guangdong China Department of Electronic and Computer Engineering Hong Kong University of Science and Technology Kowloon Hong Kong China

In digital system, a full-closed-loop configuration using a tachometers and an analog-digital converter with low resolution results in bad speed control and therefore influences the positioning performance in a high-precision positioning system. However, on the other hand, speed information cannot be accurately obtained through the encoder using traditional estimations. In this paper, we proposed a speed estimator - Kalman Filter by getting the position information through the encoder. The rules of selecting key parameters such as noise covariance in Kalman Filtering were modified to avoid trial-and-error. Experimental results in a control point of view showed a good performance both in normal and low speed range so that a full-closed-loop high-precision servo drive system could be achieved with a low-cost configuration.

关键词： Noise Kalman filters Torque Estimation Noise measurement Gain Filtering algorithms

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Adaptive observer based actuator fault diagnosis for ASV

Adaptive observer based actuator fault diagnosis for ASV

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3rd International Conference on Innovative Computing Information and control, ICICIC'08

作者： Wang, Jianfei Jiang, Bin Shi, Peng Wang, Hankang College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Faculty of Advanced Technology University of Glamorgan Pontypridd CF37 1DL United Kingdom Department of Computer Science VII: Robotics and Telematics Universtity of Würzburg 97074 Würzburg Germany

ISBN: (纸本)9780769531618

This paper deals with the actuator fault diagnosis and accommodation problem for the aero space vehicle (ASV). A novel nonlinear robust adaptive observer is developed for estimation of the actuator fault under the lipschitz condition on the nonlinear part of such systems, which is used to continuously accommodate the control signal, so as to ensure the stability of faulty system. Finally, simulation results about ASV are presented to illustrate the feasibility and effectiveness of the proposed methods. © 2008 IEEE.

关键词： Fault detection

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CNC Machine Scheduling Problems with the Tool Aging

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IFAC Proceedings Volumes 2008年第3期41卷 122-126页

作者： Adam Janiak Wladyslaw Janiak Radoslaw Rudek Agnieszka Wielgus Institute of Computer Engineering Control and Robotics Wroclaw University of Technology Janiszewskiego 11/17 50-372 Wroclaw Poland Faculty of Computer Science and Management Wroclaw University of Technology Lukasiewicza 5 50-371 Wroclaw Poland

The aging effect can be understood as a deterioration of a machine (tool) that increases a time required to manufacture products. It is highly desirable to minimize the negative influence of this effect, which in case of CNC machine is usually compensated by the increasing of its working speed. Therefore, although a tool efficiency decreases the processing times of jobs (products) can be still kept on the desired level. On the other hand, the increasing of a working speed cases the faster decreasing of a durability of a tool and its premature failure. In this paper, we focus on optimization problems in manufacturing systems, where occur the tool wear of CNC drilling/cutting machine and its compensation at the cost of a durability of a tool. We model such problems by single machine scheduling problems with the aging effect and additional resources with two criteria: time criterion (makespan and maximum lateness) and resource consumption penalty. The objectives are the minimization of time criteria under a given resource consumption and the minimization of resource consumption under a given time criteria. Computational analysis of these problems together with solution algorithms are provided.

关键词： Scheduling Deteriorating Resource allocation CNC Tool wear

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Dealing with redundancies and dependencies in normalization of XML data

Dealing with redundancies and dependencies in normalization ...

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International Multiconference on computer science and Information technology, IMCSIT

作者： Tadeusz Pankowski Tomasz Pilka Institute of Control and Information Engineering PoznaD University of Technology Poznan Poland Faculty of Mathematics and Computer Science Adam Mickiewicz University Poznan Poland

In this paper we discuss the problem of redundancies and data dependencies in XML data while an XML schema is to be normalized. Normalization is one of the main tasks in relational database design, where 3NF or BCNF, is to be reached. However, neither of them is ideal: 3NF preserves dependencies but may not always eliminate redundancies, BCNF on the contrary-always eliminates redundancies but may not preserve constraints. We discuss the possibility of achieving both redundancy-free and dependency preserving form of XML schema. We show how the XML normal form can be obtained for a class of XML schemas and a class of XML functional dependencies.

关键词： XML Relational databases computer science Data models Costs Information technology Data engineering Mathematics Memory Algorithm design and analysis

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Quotient kinematics machines: Concept, analysis and synthesis

Quotient kinematics machines: Concept, analysis and synthesi...

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2008 IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Yuanqing Wu Zexiang Li Han Ding Yunjiang Lou Mechanical Engineering School Shanghai Jiaotong University Shanghai China Department of Electrical Engineering and Computer Science University of Science and Technology of Hong Kong Kowloon Hong Kong China Shenzhen Graduate School Control and Mechatronics Engineering Harbin Institute of Technology China

ISBN: (纸本)9781424420575

In mechanism and machine design, the notion of serial kinematics machine (SKM), parallel kinematics machine (PKM) and hybrid kinematics machine (HKM) is well understood. In this paper, we introduce a fourth type of kinematics machine, known as quotient kinematics machine(QKM). A QKM generating a subgroup motion G consists of two mechanisms (or motion modules) acting in unison, one synthesizing a subgroup H of G, and another that of a complement of G/H. Apparently, the two motion modules of a QKM have simpler kinematic structures than that of a SKM, PKM or HKM with the same motion type G, and thus is expected to have performance advantages in terms of stiffness (speed and accuracy), modularity and etc, over its SKM/PKM/HKM counterparts. The formulation of the QKM concept and its analysis and synthesis are considered in this paper.

关键词： Kinematics Joints Generators Robots Manifolds Geometry Educational institutions

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Effects of average luminance level of displayed images, viewers age, and screen illuminance on preferred luminance of LCDs

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Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers 2008年第6期62卷 931-936页

作者： Kubota, Satoru Hanehara, Ryo Nakamura, Yoshitomo Nomoto, Kohei Yamakawa, Masaki Faculty of Science and Technology Seikei University 3-3-1 Kichijoji-kitamachi Musashino-shi Tokyo 180-8633 Japan Advanced Technology R and D Center Mitsubishi Electric Corporation 1 Zusho Baba Nagaokakyo-shi Kyoto 617-8550 Japan Industrial Design Center Mitsubishi Electric Corporation 5-1-1 Ofuna Kamakura-shi Kanagawa 247-8501 Japan Computer and Consumer Application Engineering Dept. Renesas Technology Corporation 4-1 Mizuhara Itami-shi Hyogo 664-0005 Japan

We investigated what influences the average luminance level (ALL) of displayed images, screen illuminance, and viewers ages had on the preferred luminance of LCDs. Twenty young subjects (mean age: 21.8) and 24 seniors (mean age: 68.9) adjusted the luminance of a 17-inch 1000: 1 LCD monitor to their preferred levels under different experimental conditions. The results indicate that the preferred luminance of LCDs corresponded to the following formula: Lp=k x ALLα. This is where Lp is the peak white luminance of the LCDs, k is a constant, and ALL is the average luminance level of the displayed images. Here, α is a constant from -0.19 to -0.20 for the seniors and from -0.14 to -0.17 for the young subjects. The influences of age-related changes in vision and ambient lighting on the luminance requirements for LCDs are also discussed. These results can be applied to the design of luminance-control systems for LCDs.

关键词： Liquid crystal displays

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Trajectory Tracking of Underactuated Skid-Steering Robot

Trajectory Tracking of Underactuated Skid-Steering Robot

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2008 American control Conference, Pages 3088-3529

作者： Dariusz Pazderski Krzysztof Kozlowski Faculty of Computer Science and Management Chair of Control and Systems Engineering Poznan University of Technology ul. Piotrowo 3a 60-965 Poznan Poland

ISBN: (纸本)9781424420780

This paper considers problem of approximation of admissible trajectory for skid-steering mobile robot at kinematic level. Nonholonomic constraints at kinematic and dynamic level are taken into account. The trajectory tracking control problem is solved using practical stabilizer using tunable oscillator with novel method of tuning. The stability result is proved using Lyapunov analysis and takes into account uncertainty of kinematics. In order to ensure stable motion of the robot the scaling method is used. Theoretical considerations are illustrated by simulation results.

关键词： Trajectory Kinematics Mobile robots Vehicle dynamics Vehicles Oscillators Wheels Acceleration Angular velocity control Tuning

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Time-delay effect on equivalent control based single-input sliding mode control systems

Time-delay effect on equivalent control based single-input s...

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International Workshop on Variable Structure Systems, VSS

作者： Xinghuo Yu Qinglong Han Xiangjun Li Changhong Wang School of Electrical and Computer Engineering RMIT University Melbourne Australia Faculty of Business and Informatics Central Queensland University Rockhampton Australia Department of Control Science and Engineering Harbin Institute of Technology China

This paper studies the time-delay effect on the equivalent control based sliding mode control. Conditions to guarantee the boundedness of the control system steady states under the time delayed equivalent control based sliding mode control are obtained. Maximum upper bound of the delay time to guarantee boundedness is estimated. Simulations are conducted to verify the theoretical results.

关键词： Sliding mode control control systems Delay effects Delay estimation Upper bound Communication system control Stability Steady-state Electrical equipment industry Industrial control

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