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2005 IEEE Pulsed Power Conference, PPC

作者： Holt, S. Dickens, J. Walter, J. Calico, S. Center for Pulsed Power and Power Electronics Research Departments of Electrical and Computer Engineering and Physics Texas Tech. University Lubbock TX 79409-3102 United States Lockheed Martin Missiles and Fire Control Dallas TX 75265-0003 United States

ISBN: (纸本)078039190X

The design and testing of explosive-driven ferroelectric generators (FEGs) with output voltages exceeding 200 kV is presented. The generator design is aimed at achieving high voltages in a compact device by explosively compressing stacks of ferroelectric ceramic discs. The ferroelectric used in this application is EC-64 lead zirconatetitanate (PZT), a hard ferroelectric ceramic with a high dielectric constant and a good piezoelectric coupling coefficient in the direction of polarization. The pressure impulse is generated by high explosive detonating cord and travels longitudinally along the polarization vector in the PZT. The effect of variations in the rise-time, width, and magnitude of the pressure pulse on the peak voltage has been experimentally studied by modifying the ferroelectric stack and explosive driver geometries. Different dielectric insulations are experimentally evaluated for good compatibility with the ferroelectrics and maximum hold-off voltage. © 2005 IEEE.

关键词： Ferroelectric ceramics

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control of discrete linear repetitive processes with ℋ ∞ and 2 - ∞ performance

Control of discrete linear repetitive processes with ℋ ∞ a...

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2007 American control Conference, ACC

作者： Wu, Ligang Lam, James Paszke, Wojciech Galkowski, Krzysztof Rogers, Eric Space Control and Inertial Technology Research Center Harbin Institute of Technology Harbin 150001 China Department of Mechanical Engineering University of Hong Kong Pokfulam Road Hong Kong Hong Kong Institute of Control and Computation Engineering University of Zielona Góra ul. Podgórna 50 65-246 Zielona Góra Poland School of Electronics and Computer Science University of Southampton Southampton SO17 1BJ United Kingdom

ISBN: (纸本)1424409888

This paper considers the control of discrete linear repetitive processes, which are a distinct class of two-dimensional (2-D) discrete linear systems, i.e. information propagation in two independent directions, which are of both system-theoretic and applications interest. In this paper we report new results on the design of control laws with guaranteed levels of performance. In particular, develop algorithms for the design of an ℋ∞ and 2-∞ dynamic output feedback controller which guarantees that the resulting controlled process is stable and has prescribed disturbance attenuation performance as measured by ℋ∞ and 2-∞ norms. © 2007 IEEE.

关键词： Linear systems

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Predicting secret keys via branch prediction

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Cryptographers Track at the RSA Conference, CT-RSA 2007

作者： Acıiçmez, Onur Koç, Çetin Kaya Seifert, Jean-Pierre School of Electrical Engineering and Computer Science Oregon State University CorvallisOR97331 United States Information Security Research Center Istanbul Commerce University Eminönü Istanbul34112 Turkey Applied Security Research Group The Center for Computational Mathematics and Scientific Computation Faculty of Science and Science Education University of Haifa Haifa31905 Israel Institute for Computer Science University of Innsbruck Innsbruck6020 Austria

ISBN: (纸本)9783540693277

This paper announces a new software side-channel attack — enabled by the branch prediction capability common to all modern high-performance CPUs. The penalty paid (extra clock cycles) for a mispredicted branch can be used for cryptanalysis of cryptographic primitives that employ a data-dependent program flow. Analogous to the recently described cache-based side-channel attacks our attacks also allow an unprivileged process to attack other processes running in parallel on the same processor, despite sophisticated partitioning methods such as memory protection, sandboxing or even virtualization. In this paper, we will discuss several such attacks for the example of RSA, and experimentally show their applicability to real systems, such as OpenSSL and Linux. Moreover, we will also demonstrate the strength of the branch prediction side-channel attack by rendering the obvious countermeasure in this context (Montgomery Multiplication with dummy-reduction) as useless. Although the deeper consequences of the latter result make the task of writing an efficient and secure modular exponentiation (or scalar multiplication on an elliptic curve) a challenging task, we will eventually suggest some countermeasures to mitigate branch prediction side-channel attacks. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Side channel attack

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LANDING AN UNMANNED AIR VEHICLE: VISION BASED MOTION ESTIMATION AND NONLINEAR control

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Asian Journal of control 2008年第3期1卷

作者： Omid Shakernia Yi Ma T. John Koo Shankar Sastry Dept. of Electrical Engineering & Computer Science University of California at Berkeley Berkeley CA94720-1774 U.S.A. Tak-Kuen John Koo received the B.Eng. degree in 1992 in Electronic Engineering and the M.Phil. in 1994 in Information Engineering both from the Chinese University of Hong Kong. From 1994 to 1995 he was a graduate student in Signal and Image Processing Institute at the University of Southern California. He is currently a Ph.D. Candidate in Electrical Engineering and Computer Sciences at the University of California at Berkeley. His research interests include nonlinear control theory hybrid systems inertial navigation systems with applications to unmanned aerial vehicles. He received the Distinguished M.Phil. Thesis Award of the Faculty of Engineering The Chinese University of Hong Kong in 1994. He was a consultant of SRI International in 1998. Currently he is the team leader of the Berkeley AeRobot Team and a delegate of The Graduate Assembly University of California at Berkeley. He is a student member of IEEE and SIAM. S. Shankar Sastry received his Ph.D. degree in 1981 from the University of California Berkeley. He was on the faculty of MIT from 1980-82 and Harvard University as a Gordon McKay professor in 1994. He is currently a Professor of Electrical Engineering and Computer Sciences and Bioengineering and Director of the Electronics Research Laboratory at Berkeley. He has held visiting appointments at the Australian National University Canberra the University of Rome Scuola Normale and University of Pisa the CNRS laboratory LAAS in Toulouse (poste rouge) and as a Vinton Hayes Visiting fellow at the Center for Intelligent Control Systems at MIT. His areas of research are nonlinear and adaptive control robotic telesurgery control of hybrid systems and biological motor control. He is a coauthor (with M. Bodson) of “Adaptive Control: Stability Convergence and Robustness Prentice Hall 1989.” and (with R. Murray and Z. Li) of “A Mathematical Introduction to Robotic Manipulati

In this paper, we use computer vision as a feedback sensor in a control loop for landing an unmanned air vehicle (UAV) on a landing pad. The vision problem we address here is then a special case of the classic ego-motion estimation problem since all feature points lie on a planar surface (the landing pad). We study together the discrete and differential versions of the ego-motion estimation, in order to obtain both position and velocity of the UAV relative to the landing pad. After briefly reviewing existing algorithm for the discrete case, we present, in a unified geometric framework, a new estimation scheme for solving the differential case. We further show how the obtained algorithms enable the vision sensor to be placed in the feedback loop as a state observer for landing control. These algorithms are linear, numerically robust, and computationally inexpensive hence suitable for real-time implementation. We present a thorough performance evaluation of the motion estimation algorithms under varying levels of image measurement noise, altitudes of the camera above the landing pad, and different camera motions relative to the landing pad. A landing controller is then designed for a full dynamic model of the UAV. Using geometric nonlinear control theory, the dynamics of the UAV are decoupled into an inner system and outer system. The proposed control scheme is then based on the differential flatness of the outer system. For the overall closed-loop system, conditions are provided under which exponential stability can be guaranteed. In the closed-loop system, the controller is tightly coupled with the vision based state estimation and the only auxiliary sensor are accelerometers for measuring acceleration of the UAV. Finally, we show through simulation results that the designed vision-in-the-loop controller generates stable landing maneuvers even for large levels of image measurement noise. Experiments on a real UAV will be presented in future work.

关键词： Motion estimation computer vision based control unmanned air vehicle differential flatness

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The Kalman Filter Information Fusion for Cement Mill control Based on Local Linear Neuro-Fuzzy Model

The Kalman Filter Information Fusion for Cement Mill Control...

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International Conference on Innovations in Information Technology

作者： Amin Ramezani Hamed Ramezani B. Moshiri Faculty of Electrical and Computer Engineering University of Tehran Iran Faculty of Electrical and Computer Engineering Shahid Beheshti University Tehran Iran ECE and the Control and Intelligent Processing Center of Excellence (CIPCE) University of Tehran Tehran Iran

In this paper, to improve quality control system and being in the competition at a cement production line, we proposed a novel approach for model reference control of a cement milling circuit by implementing local linear neuro-fuzzy model (LLNFM) and Kalman filter information fusion (KFIF). To do so, first gathered information from distributed sensor network (DSN), deployed in the plant, is used to model under-control process based on the LLNFM approach. This LLNFM is used to prepare data for a KFIF system to derive the form of the control vector with the goal of driving the response of the system to that of a desired model in a noisy operating environment. The paper demonstrates the extraction of the reference models and the derivation of the control laws and the results observed justify the tracking and stability claims of the paper.

关键词： Milling machines State estimation Circuits Robust stability Process control Intelligent control Quality control Production systems Working environment noise Data mining

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Decoy state protocols for quantum cryptography with parametric down conversion sources

Decoy state protocols for quantum cryptography with parametr...

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International Quantum Electronics Conference, IQEC 2007

作者： Ma, Xiongfeng Fung, Chi-Hang Fred Lo, Hoi-Kwong Center for Quantum Information and Quantum Control Department of Electrical and Computer Engineering University of Toronto Toronto ON M5S 1A7 Canada Department of Physics University of Toronto Toronto ON M5S 1A7 Canada

No abstract available

ISBN: (纸本)1424409306

No abstract available

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Decoy state protocols for quantum cryptography with parametric down conversion sources

Decoy state protocols for quantum cryptography with parametr...

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Conference on Lasers and Electro-Optics Europe (CLEO EUROPE)

作者： Xiongfeng Ma Chi-Hang Fred Fung Hoi-Kwong Lo Center for Quantum Information and Quantum Control Department of Electrical & Computer Engineering and Department of Physics University of Toronto Toronto ONT Canada

In this paper, we show that decoy states are very simple to implement for quantum key distribution (QKD) with parametric down conversion (PDC) sources. Indeed, with no modification in the hardware at all, by using the AYKI scheme, one can achieve a key generation rate that is close to the theoretical limit of infinite decoy states. Therefore, we expect decoy state QKD to become a standard technique not only in the coherent state QKD, but also in QKD with PDC sources.

关键词： Cryptographic protocols Cryptography Quantum computing Security Hardware Proposals Optical control Distributed computing Optical computing Physics computing

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Initial Rotor Position Estimation for Sensorless Brushless DC Drives

Initial Rotor Position Estimation for Sensorless Brushless D...

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International Conference on electrical Machines and Systems 2007(ICEMS2007)(第十届国际电机与系统会议)

作者： P. Champa P. Somsiri P. Wipasuramonton P. Nakmahachalasint Industrial Control and Automation Lab National Electronics and Computer Technology Center Thailand Industrial Control and Automation Lab National Electronics and Computer Technology Center Thailand Department of Electrical Engineering Thammasat University Thailand

This paper presents a method to determine the initial rotor position of a brushless DC machine at standstill without a position sensor. The key principle of the rotor position estimation is based on the simple detection and comparison of phase voltage and current responses relating to the stator inductance varied with the position of the rotor magnet. In the proposed method, only three pulse voltage injections are applied and 30 degree resolution can be achieved. Moreover, no knowledge of machine parameters is required. The effectiveness of the proposed method is validated by experimental results.

关键词： Voltage Rotors Phase detection Position measurement Current measurement Inductance measurement Drives Phase estimation Stators Brushless DC motors

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RELAXED CHARACTERIZATIONS OF SMOOTH PATCHY control LYAPUNOV FUNCTIONS

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IFAC Proceedings Volumes 2007年第12期40卷 486-491页

作者： Rafal Goebel Christophe Prieur Andrew R. Teel Department of Mathematics University of Washington Seattle WA 98195-4350 LAAS–CNRS 7 Avenue du Colonel Roche 31077 Toulouse Cedex 4 France Center for Control Dynamical Systems & Computation Department of Electrical and Computer Engineering University of California Santa Barbara CA 93106-9560

A smooth patchy control Lyapunov function for a nonlinear control system consists of an ordered family of smooth local control Lyapunov functions, whose open domains form a locally finite cover of the state space of the system, and which satisfy a certain arrangement property. In contrast to (Goebel et al., IEEE CDC, 2006), on each intersection of the domains, we do not impose a decrease condition of the local control Lyapunov functions when the index increases. We show a construction, based on such a patchy control Lyapunov function, of a stabilizing hybrid feedback that is robust to measurement noise. Copyrighte 2007 IFAC

关键词： hybrid systems control Lyapunov function stabilization

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A genetic-fuzzy control application to ramp metering and variable speed limit control

A genetic-fuzzy control application to ramp metering and var...

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IEEE International Conference on Systems, Man and Cybernetics

作者： Amir Hosein Ghods Ashkan Rahimi Kian Masoud Tabibi Control and Intelligent Processing Center of Excellence Department of Electrical and Computer Engineering University of Tehran Tehran Iran Department of Civil Engineering University of Amir-Kabir Tehran Iran

This paper proposes a fuzzy control approach for the traffic-responsive ramp metering and variable speed limits control, in order to reduce the peak-hour congestion on freeways. The objective of control is to minimize the total time spent in the traffic network. To ease the calibration process of fuzzy controller and improve the overall performance of ramp metering and variable speed limits, genetic algorithm is applied for tuning the fuzzy sets parameters. In order to evaluate the controller's efficiency and applicability, a comparison is made with traditional ALINEA based controller and the fuzzy ramp metering only case by a case-study. The macroscopic traffic model METANET and its extension for dynamic speed limits are used for optimization procedure and presenting the simulation results. The paper concludes that genetic fuzzy control of ramp metering and speed limits is expected to enhance the performance of the freeway traffic network.

关键词： Traffic control Fuzzy control Communication system traffic control Electric breakdown Fuzzy logic Fuzzy sets Nonlinear control systems Velocity control Safety Fuzzy systems

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