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Safety Assessment of Networked Vehicle Platoon Controllers – Practical Experiences With Available Tools

IFAC Proceedings Volumes 2009年第17期42卷 292-297页

作者： Martín Guillermo Ibtissem Ben Makhlouf Stefan Kowalewski Chavez Grunewald Dirk Abel RWTH Aachen University Computer Science Chair XI – Embedded Software Laboratory Ahornstr. 55 52074 Aachen Germany RWTH Aachen University Institute of Automatic Control Steinbachstr. 54 52074 Aachen Germany

Vehicle platoons are usually modelled as continuous dynamic systems. But the parameters of the embedded controllers require particular adaptation depending on the quality and changes commonly occurring in communication networks. These changes may lead to delays or in extreme cases to loss of information. Hence, these changes trigger the jump from one continuous state to another and may be considered as discrete events arising, in general, spontaneously. In this work, we use the formalism of hybrid automata to carry out a safety analysis of controlled vehicle platoons. We are interested in the safety verification of a platoon of vehicles, which communicate with each other via a wireless network. Our aim is to check, if a collision could take place within the platoon under a predefined control law including mode switches. In this paper, we report on results for the non-switching case and for pre-defined switching times. In addition, using different verification tools for this case study allows for the assessment of the performance of these tools and their limitations.

关键词： Hybrid systems reachability analysis platoon of vehicles control law PHAVer Hsolver KeYmaera

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Dynamic application of slicing technique in grid calling and network resources

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WSEAS Transactions on Circuits and Systems 2009年第1期8卷 73-83页

作者： Wang, Lixia Yang, Aimin Li, Yaohui Gao, Liting Liu, Tieying Department of Computer Science Hebei Institute of Architecture and Civil Engineering No.33 Jianguo Road Zhang Jiakou City Hebei Province China Computer Science and Information Technology College Zhejiang Wanli University No.8 South Qian Hu Road Ningbo Zhejiang Province China HebeiCAIDA Securities Co Ltd China

The grid links all resources in different structures widespread geographically into one logical system via internet, characterized with complexity of network structure, dynamism of network resources and autonomy of each LAN. The high-efficient management of grid resources and high-efficient scheduling of tasks are the important contents in today's net grid research. Slices technology is the present quite popular popular technology, the application domain is widespread. The grid technology and the slice technology fuse in together, may create the more reasonable task scheduling and the scheduling of resources. In this article we divide the tasks into some small tasks assigned with scheduling priorities for each level, and then slice all resources in network into some time slices assigned with resource priorities according to trust mechanism. It promotes the effectiveness and high-efficiency by arranging task scheduling and resource scheduling in priority.

关键词： Grid computing

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Nonlinear measurement update and prediction: Prior Density Splitting Mixture Estimator

Nonlinear measurement update and prediction: Prior Density S...

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IEEE Conference on Control Technology and Applications (CCTA)

作者： Andreas Rauh Kai Briechle Uwe D. Hanebeck Chair of Mechatronics University of Rostock Rostock Germany Dr. Johannes Heidenhain GmbH Traunreut Germany Institute of Computer Science and Engineering Universität Karlsruhe Karlsruhe Germany

In this paper, the Prior Density Splitting Mixture Estimator (PDSME), a new Gaussian mixture filtering algorithm for nonlinear dynamical systems and nonlinear measurement equations, is introduced. This filter reduces the linearization error which typically arises if nonlinear state and measurement equations are linearized to apply linear filtering techniques. For that purpose, the PDSME splits the prior probability density into several components of a Gaussian mixture with smaller covariances. The PDSME is applicable to both prediction and filter steps. A measure for the linearization error similar to the Kullback-Leibler distance is introduced allowing the user to specify the desired estimation quality. An upper bound for the computational effort can be given by limiting the maximum number of Gaussian mixture components.

关键词： Density measurement Nonlinear equations State estimation Nonlinear filters Filtering algorithms Nonlinear systems State-space methods Nonlinear control systems Control systems Noise measurement

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A two-step method for estimating the parameters of induction machine models

A two-step method for estimating the parameters of induction...

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IEEE Energy Conversion Congress and Exposition, ECCE

作者： Christopher Laughman Steven B. Leeb Leslie K. Norford Steven R. Shaw Peter R. Armstrong Mitsubishi Electric Research Laboratories Inc. Cambridge MA USA Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA Department of Architecture Massachusetts Institute of Technology Cambridge MA USA Department of Electrical and Computer Engineering Montana State University Bozemon MT USA Masdar Institute of Science and Technology Abu Dhabi UAE

ISBN: (纸本)9781424428922

This paper describes and demonstrates a mathematical algorithm that can monitor the physical parameters of the motor solely by observing the stator electrical currents. This method uses measurements of transient stator currents to identify the parameters of an electromechanical model of the induction motor. These parameters are obtained from a relatively poor initial guess, which is constrained only to be within an order of magnitude of the physical parameters, by using a two-step strategy based upon nonlinear least-squares regression techniques. This makes the approach in this paper useful for diagnostic monitoring and energy scorekeeping. Experimental results are presented which demonstrate the effectiveness of this method on identifying the parameters of a 1 HP induction motor connected to a squirrel cage fan in an air-handling unit.

关键词： Parameter estimation Induction machines Condition monitoring Paper technology Induction motors Current measurement Sensor arrays Velocity measurement Voltage Hardware

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Shape optimization of shell roofs subjected to strong wind using multigrid method and variable complexity model

Journal of Structural and Construction Engineering

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Journal of Structural and Construction Engineering 2009年第636期74卷 297-304页

作者： Yamashita, Takuzo Kumagai, Tomohiko Ogawa, Toshiyuki Mjyamura, Tomoshi Ohsaki, Makoto Dept. of Archi. and Build. Eng. Tokyo Institute of Technology Japan Dept. of Computer Science College of Engineering Nihon University Japan Dept. of Architecture and Architectural Engineering Kyoto University Japan

Shape optimization of shell roofs subjected to strong wind is camed out to mimmize the maximum vertical displacement. The three dimensional (3D) fluid flow analysis is performed to obtain highly precise dynamic wind load. To reduce the large computational cost of the 3D analysis, the multignd method is employed to solve the pressure Poisson equation. The objective function of the optimization problem is expected to have strong nonlineanty. Employing Response Surface Model (RSM), the objective function is approximated as a smooth function so that computational cost of the optimization is reduced. Analyses for several experimental points are required to generate RSM. It is not practical to perform 3D analyses for all experimental points due to huge computational cost. Vanable Complexity Model (VCM) is useful for generating RSM. VCM is the method combining a high-fidelity model and a low-fidelity model. As the method of generating RSM, two kinds of methods are employed;(1) VCM (2) 3D analyses for all the experimental points. Optimized shapes are obtained by both methods. Although the value of the objective function of (1) is slightly larger than that of (2), the computation for (1) is much faster than that for (2).

关键词： Shape optimization

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Multi-objective particle swarm optimization algorithm for engineering constrained optimization problems

Multi-objective particle swarm optimization algorithm for en...

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IEEE International Conference on Granular Computing (GRC)

作者： Dekun Tan Wenhai Luo Qing Liu Department of Computer Science & Technology Nanchang Institute of Technology Nanchang Jiangxi China Department of Civil Engineering & Architecture Nanchang Institute of Technology Nanchang Jiangxi China School of Information Engineering University of Nanchang Nanchang Jiangxi China

This paper proposes a modified particle swarm optimization algorithm for engineering optimization problems with constraints, in which the penalty function is employed to the traditional PSO algorithm, and at the same time adjusts the personal optimum and global optimum to make PSO being able to solve the non-linear programming problems, then the multi-objective problem can be converted into single objective problem. Moreover, the constraint term played its role in the process of generating particles, those pariticles which don't meet the constraint condition are eliminated. The actual engineering design optimization problem is tested and the results show that the multi-objective particle swarm optimization algorithm can be used to solve the multi-objective constrained optimization problem. Comparison with Genetic Algorithm confirms that the proposed algorithm can find better solutions, and converge quickly.

关键词： Particle swarm optimization Constraint optimization Design optimization Design engineering Functional programming Mathematical model Space exploration Iterative algorithms Testing Genetic algorithms

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PerFlows for the computers of the 21st century

PerFlows for the computers of the 21st century

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IEEE International Conference on Pervasive Computing and Communications (PerCom)

作者： Stephan Urbanski Eduard Huber Matthias Wieland Frank Leymann Daniela Nicklas Reichenbach/Fils Taimos GmbH Germany Institute of Architecture of Application Systems (IAAS) Universität Stuttgart Germany Computer Science Department Carl von Ossietzky Universität Oldenburg Oldenburg Germany

In 1995, Mark Weiser introduced a scenario about the future life, where everyday objects are equipped with smart functions and the environment helps us to fulfill our everyday tasks. This paper shows how Weiser's scenario can be realized by today's available technologies. We combine PerFlows (to model the flow of daily tasks) and the Nexus context provisioning platform (to model and provide necessary context information to applications and devices). Furthermore, we present SmartGPS, which is able to provide fused location information even if the device is disconnected.

关键词： Context modeling Application software Sections computer architecture computer science Context awareness computer vision Embedded computing Radiofrequency identification Handheld computers

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Bidirectionalizing programs with duplication through complementary function derivation

Computer Software

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computer Software 2009年第2期26卷 56-75页

作者： Matsuda, Kazutaka Hu, Zhenjiang Nakano, Keisuke Hamana, Makoto Takeichi, Masato DC Graduate School of Information Science and Technology University of Tokyo Japan Society for the Promotion of Science Japan Information System Architecture Research Division National Institute of Informatics Japan University of Electro-Communications Japan Dept. of Computer Science Gunma University Japan Graduate School of Information Science and Technology University of Tokyo Japan

A bidirectional transformation consists of a pair of unidirectional transformations: a forward transformation that maps one data structure called source to another called view, and a backward transformation that reflects changes in the view to the source. Bidirectional transformation has many useful applications such as replicated data synchronization, presentation-oriented editor development, and software artifact synchronization. In a previous work, we proposed a framework in which a backward transformation is automatically generated from a forward transformation by derivation of a complementary function if the forward transformation is given by a program in a simple functional language. However, the language has a severe restriction that no variable is allowed to be used more than once. In this paper, we show that tupling transformation relaxes this restriction, allowing us to handle a wider class of bidirectional transformations that may contain duplications.

关键词： Functions

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Benefit and evaluation of interactive 3D process data visualization in operator training of plant manufacturing industry

Benefit and evaluation of interactive 3D process data visual...

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IEEE International Conference on Systems, Man and Cybernetics

作者： Dorothea Pantförder Birgit Vogel-Heuser Chair of Embedded Systems Faculty of Electrical Engineering/Computer Science University of Kassel Kassel Germany Institute of Information Technology in Mechanical Engineering Faculty of Mechanical Engineering Technische Universität München Munich Germany

Operator training without a process model is necessary in certain plant manufacturing industry's applications because the process models from the control theory perspective are still not available. This paper describes an experiment that analyzed the benefits of 3D data visualization integrated in HMI for process control in combination with different types of operator training to obtain process knowledge. The benefits of interactive 3D slider training in identifying errors during operation could be proven.

关键词： Data visualization Industrial training Manufacturing industries Process control Mechanical engineering Libraries Data analysis Cybernetics USA Councils Embedded system

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Combined fragile watermark and digital signature for H.264/AVC video authentication

Combined fragile watermark and digital signature for H.264/A...

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17th European Signal Processing Conference, EUSIPCO 2009

作者： Saadi, K. Ait Bouridane, A. Guessoum, A. Centre de Développement des Technologies Avancées Division Architecture des Systèmes Cité 20 Août 1956 Baba Hassen 16303 Alger Algeria School of Electronics Electrical Engineering and Computer Science Institute of Electronics Communications and Information Technology Queen's University Belfast United Kingdom Université Saad Dahlab Institut d'Electronique Route de Soumaa Blida Algeria

Currently the demand of security is getting higher due to easy reproduction of digitally created multimedia data. Digital watermarking aims to embed secret information into content for copyright protection and authentication. This paper proposes a combined digital watermarking and digital signature based on video content to authenticate and to verify the integrity of the compressed H.264/AVC video. Features are extracted as the authentication data from transform domain to generate a unique digital signature using an MD5hash function. The authentication information treated as fragile watermark is embedded in a set of motion vectors belonging to higher motion activities with the best partition mode in a tree-structured motion compensation approach. Watermark detection is blind and does not require an original video. Experimental results show that the proposed watermarking technique can not only achieve the goal of fragility but also verify the authenticity and the integrity of the video. © EURASIP, 2009.

关键词： Motion compensation

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