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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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Task jitter measurement under RTLinux and RTX operating systems, comparison of RTLinux and RTX operating environments

Task jitter measurement under RTLinux and RTX operating syst...

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International Multiconference on computer science and Information Technology, IMCSIT

作者： Pavel Moryc Jindrich Cernohorsky Faculty of Electrical Engineering and Computer Science Department of Measurement and Control Centre for Applied Cybernetics Technical University of Ostrava Ostrava Czech Republic

This paper compares task jitter measurement performed under RTLinux and RTX hard real-time operating systems. Both the operating environments represent hardware abstraction layer extensions to general-purpose operating systems, and make possible to create a real-time system according to the POSIX 1003.13 PSE 54 profile (multipurpose system). The paper is focused on discussion of experimental results, obtained on PC hardware, and their interpretation.

关键词： Jitter Operating systems

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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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A new artificial intelligence approach for 2D path planning for underwater vehicles avoiding static and energized obstacles

A new artificial intelligence approach for 2D path planning ...

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Congress on Evolutionary Computation

作者： S. Khanmohammadi G. Alizadeh J. Jassbi M. Pourmahmood Control Engineering Department Faculty of Electrical and Computer Engineering University of Tabriz Tabriz Iran Industrial Management Department Azad University Science and Research Branch Tehran Iran

Optimal trajectories in energetic environment for underwater vehicles can be computed using a numerical solution of the optimal control problem (OCP). An underwater vehicle is modeled with the six dimensional nonlinear and coupled equations of motion, controlled by DC motors in all degrees of freedom. An energy performance index that should be minimized may be considered. This leads to a two point boundary value problem (TPBVP). The resulting TPBVP is generally solved using iterative methods. In this paper, the applications of two different intelligent algorithms are briefly studied and compared versus the generally acceptable conjugate gradient penalty (CGP) method for the OCP. Genetic algorithm (GA) and particle swarm optimization (PSO) methods are applied to solve OCP. Two approaches for performance index minimization, using GA and PSO, are proposed. CGP method is used to solve the TPBVP, by applying Euler-Lagrange equation. The simulation results show that the trajectories obtained by the intelligent methods were better than that of conjugate gradient penalty. After analyzing the simple path planning problem, the problem energetic environments consisting some energy sources is propounded. The optimal paths are found using GA and PSO algorithms. The problem of collision avoidance in an energetic environment is solved and energy avoidance paths are computed.

关键词： Underwater vehicles Trajectory Optimal control Mathematical model Propellers Damping Gallium

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Hybridized GPS/DR Positioning System With Unknown Initial Heading For Land Vehicles

Hybridized GPS/DR Positioning System With Unknown Initial He...

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International Conference on Intelligent Transportation

作者： A. Dumitrache M.A. Zamora R. Toledo-Moreo A.G. Skarmeta Centre for Research and Training Industrial Control Robotics and Material Engineering Technical University of Bucharest Romania Faculty of Computer Science Department of Information and Communication Engineering University of Murcia Spain

In the intelligent transportation systems (ITS) field, the number of applications that demand a high integrity positioning system is growing. In order to improve the integrity of localization systems, GPS is usually hybridized with additional proprioceptive sensors. In this paper, a new hybridization algorithm based on GPS plus odometry and a gyro is proposed as an improvement of the most common extended Kalman filter (EKF) approach. In concrete, these investigations focus on the performance of the system under bad initial conditions. Results show the suitability of the proposed system for navigation under bad initial values of heading, and its benefits as compared to two state-of-the-art methods of the literature: an EKF, and a particle filter based solution.

关键词： Global Positioning System Land vehicles Intelligent transportation systems Navigation Particle filters Road vehicles Intelligent sensors Sensor systems Costs Sensor fusion

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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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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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Stability analysis of time-delayed single-input sliding mode control systems

Stability analysis of time-delayed single-input sliding mode...

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Annual Conference of Industrial Electronics Society

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

This paper presents stability analysis of the time-delayed equivalent control based single input sliding mode control systems using an LMI approach. Conditions to guarantee the boundedness of the control system trajectories under the time-delayed equivalent control based sliding mode control are obtained. Maximum upper bound of the delay time to guarantee stability is estimated. Digital simulations are conducted to verify the theoretical results.

关键词： Stability analysis Sliding mode control control systems Delay estimation Upper bound Delay effects Communication system control Digital simulation Electrical equipment industry Industrial control

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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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Reliable Adaptive control for Switched Fuzzy Systems

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IFAC Proceedings Volumes 2008年第2期41卷 7636-7641页

作者： Le Zhang Cvetko Andreeski Georgi M. Dimirovski Yuan-Wei Jing Control Science Institute of the School of Information Science and Engineering Northeastern University Shenyang 110004 P.R. China Faculty of Tourism and Hospitality in Ohrid St Clement Ohridski University 6000 Ohrid Rep of Macedonia Department of Computer Engineering Dogus University Kadikoy TR-34722 Istanbul Turkey

A model of a kind of uncertain switched fuzzy systems is presented first, in which each subsystem is an uncertain fuzzy system. Then the robust stabilization problem to the system is studied and a solution proposed. When the upper bounds of the disturbances are unknown, and the actuator is serious failure and the residual part of actuator can not make original system stable, a reliable robust adaptive controller is constructed to guarantee the closed-loop system is uniformly ultimately bounded via using switching technique and multiple Lyapunov function approach. The switching strategy achieving system uniformly ultimately bounded of the uncertain switched fuzzy system is given. An illustrative example is given that demonstrates the feasibility and the effectiveness of the proposed method.

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