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IEEE Conference on Decision and control

作者： Ricardo G. Sanfelice Andrew R. Teel Center for Control Dynamical Systems and Computation Electrical and Computer Engineering Department University of California Santa Barbara CA USA

ISBN: (纸本)1424401704;9781424401703

For hybrid closed-loop systems arising from hybrid control of nonlinear systems, we show that the sample-and-hold implementation of the hybrid controller preserves (semiglobally and practically) the stability properties of the closed-loop system. We provide a general model for the hybrid closed-loop system where the hybrid controller is implemented digitally and it is interfaced to the nonlinear system through sample and hold devices. We model the sample device and the digital controller/hold device as single asynchronous hybrid systems with independent timing constants and data. The main result is established by means of a Lyapunov function for the hybrid closed-loop system resulting from the interconnection of its hybrid and nonlinear subsystems

关键词： Feedback control systems Nonlinear control systems Nonlinear systems Digital control Stability analysis Emulation control system synthesis Military computing Asymptotic stability

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Experimental Quantum Key Distribution with Decoy States

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Physical Review Letters 2006年第7期96卷 070502-070502页

作者： Yi Zhao Bing Qi Xiongfeng Ma Hoi-Kwong Lo Li Qian Center for Quantum Information and Quantum Control Department of Physics and Department of Electrical and Computer Engineering University of Toronto Toronto Ontario M5S 3G4 Canada

To increase dramatically the distance and the secure key generation rate of quantum key distribution (QKD), the idea of quantum decoys—signals of different intensities—has recently been proposed. Here, we present the first experimental implementation of decoy state QKD. By making simple modifications to a commercial quantum key distribution system, we show that a secure key generation rate of 165 bit/s, which is 1/4 of the theoretical limit, can be obtained over 15 km of a telecommunication fiber. We also show that with the same experimental parameters, not even a single bit of secure key can be extracted with a non-decoy-state protocol. Compared to building single photon sources, decoy state QKD is a much simpler method for increasing the distance and key generation rate of unconditionally secure QKD.

关键词： Quantum theory

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Learning Distributed Object Pushing: Individual Learning and Distributed Cooperation Protocol

Learning Distributed Object Pushing: Individual Learning and...

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2006 IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Hossein Aminaiee Majid Nili Ahmadabadi Control and Intelligent Processing Center of Excellence Robotics and AI Lab Department of Electrical and Computer Engineering University of Tehran Iran

In this paper we study learning in cooperative object pushing systems. The proposed approach is based on the idea of learning individual skills and then mapping the required cooperative behaviors on the learned skills. The control point for each individual robot is chosen so as to simplify the design of the reinforcement signal and reduce the role of delayed reward on individual learning in addition to make cooperative protocol simpler. A fuzzy Q-learning system for learning individual object pushing is proposed, together with a method for coordination among the robots to push the object cooperatively. The coordination method takes into account the dynamics of the object and the learned individual skills. The idea of the coordination protocol is based on the notion of ability and active regions defined in this paper. In effect, the cooperation protocol is mapped to a Q-value based policy. Simulation results supportively show that the robots learn individual and cooperative object pushing efficiently

关键词： Protocols Robot kinematics Intelligent robots Fuzzy systems Learning Friction control systems Artificial intelligence Robot control Fuzzy control

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Unconditionally secure key distillation from multiphotons

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Physical Review A 2006年第1期73卷 010302(R)-010302(R)页

作者： Kiyoshi Tamaki Hoi-Kwong Lo Center for Quantum Information and Quantum Control Department of Electrical and Computer Engineering and Department of Physics University of Toronto Toronto Ontario Canada M5S 3G4

In this paper, we prove that the unconditionally secure key can be surprisingly extracted from multiphoton emission part in the photon polarization-based quantum key distribution. One example is shown by explicitly proving that one can indeed generate an unconditionally secure key from Alice’s two-photon emission part proposed by Scarani [ et al. Phys. Rev. Lett. 92, 057901 (2004)]. Which is called the Scarani-Acin-Ribordy-Gisin (SARG04) protocol. This protocol uses the same four states as in Bennett-Brassard 1984 (BB84) and differs only in the classical postprocessing protocol. It is, thus, interesting to see how the classical postprocessing of quantum key distribution might qualitatively change its security. We also show that one can generate an unconditionally secure key from the single to the four-photon part in a generalized SARG04 protocol that uses six states. Finally, we also compare the bit error rate threshold of these protocols with the one in the BB84 protocol and the original six-state protocol assuming a depolarizing channel.

关键词： QUANTUM ERROR-CORRECTION DISTRIBUTION PROTOCOL CRYPTOGRAPHY STATES PROOF

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Learning Individual Skills and Team Behaviors for Distributed Object Pushing

Learning Individual Skills and Team Behaviors for Distribute...

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IEEE International Conference on Mechatronics and Automation

作者： Hossein Aminaiee Majid Nili Ahmadabadi Control and Intelligent Processing Center of Excellence Robotics Laboratory Department of Electrical and Computer Engineering University of Tehran Tehran Iran

In this paper we discuss a learning approach to distributed object pushing. In the proposed approach, first the required individual skills for single-robot object pushing are learned using a fuzzy reinforcement learning method. Then, the robots learn how to coordinate their actions to push the object to the desired configuration cooperatively in a distributed manner. The proposed team-level learning benefits from the knowledge, which is in the form of a Q-table, that the agent has gained in its individual learning phase by a special design of reward signal and state-action representation. Each robot learns a threshold on its Q-value using a single state reinforcement learning method and pushes the object when the Q-value of its best action in the current state is above this threshold. The reward signal is designed based on the robots' Q-tables and no external critic is needed for learning cooperation. Simulation results show that the robots learn their individual skills and a cooperation protocol to push the object cooperatively

关键词： Robot kinematics Learning Protocols Robot control Robotics and automation Intelligent robots Signal design Mechatronics Process control Intelligent control

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Design and simulation of an adaptive load shedding algorithm using a real network

Design and simulation of an adaptive load shedding algorithm...

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IEEE Power India Conference

作者： H. Seyedi M. Sanaye-Pasand M.R. Dadashzadeh School of Electrical and Computer Engineering University of Tehran Iran Control and Intelligent Processing Center of Excellence University of Tehran Iran Department of Electrical Engineering University of Western Ontario Canada

ISBN: (纸本)0780395255

In this paper a new adaptive under frequency load shedding algorithm is designed. The purpose of this method is to enhance the adaptability of under frequency relays and increase the security of power system during large disturbances. A suitable method to design the proposed adaptive under frequency load shedding scheme is described in detail. After completing the design, it is tested on a real power system by modeling the network in a power system studies software. Simulation results indicate that the proposed method has an improved performance for large disturbances while its response is similar to the conventional scheme for small disturbances

关键词： Algorithm design and analysis Power system simulation Power system relaying Power system security Power system modeling Frequency Design methodology Software testing System testing Software systems

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Anti-windup control for an air-breathing hypersonic vehicle model

Anti-windup control for an air-breathing hypersonic vehicle ...

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AIAA Guidance, Navigation, and control Conference 2006

作者： Groves, Kevin P. Serrani, Andrea Yurkovich, Stephen Bolender, Michael A. Doman, David B. Collaborative Center of Control Science Ohio State University Columbus OH 43210 United States Air Force Research Laboratory Wright-Patterson AFB OH 45433 United States Harris Corporation FL United States Department of Electrical and Computer Engineering 2015 Neil Ave. AIAA United States Department of Electrical and Computer Engineering 2015 Neil Ave. Columbus OH United States AFRL/VACA 2210 Eighth St. United States

ISBN: (纸本)1563478196

An anti-windup controller modification is implemented in control system design for a model of the longitudinal dynamics of an air-breathing hypersonic vehicle. Anti-windup control allows the input constraints to be considered explicitly in the design of linear controllers to track a reference trajectory for the vehicle velocity, altitude, and angle of attack. The presence of anti-windup alleviates the need of keeping large penalties on the magnitude of the control input to avoid the occurrence of saturation. This, in turn, allows tighter tuning of the controller gains to obtain faster and more accurate trajectory tracking. The paper employs recent developments in anti-windup design to deal with the presence of exponentially unstable dynamics, which are typically encountered in air-breathing vehicle models. Simulation results on a fully nonlinear model are presented to validate the controller design. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Hypersonic aerodynamics

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Adaptive failure compensation for aircraft tracking control using engine differential based model

Adaptive failure compensation for aircraft tracking control ...

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American control Conference (ACC)

作者： Yu Liu Xidong Tang Gang Tao S.M. Joshi Department of Electrical and Computer Engineering University of Virginia Charlottesville VA USA NASA-Langley Research Center Hampton VA USA

An aircraft model that incorporates independently adjustable engine throttles and ailerons is employed to develop an adaptive control scheme in the presence of actuator failures. This model captures the key features of aircraft flight dynamics when in the engine differential mode. Based on this model an adaptive feedback control scheme for asymptotic state tracking is developed and applied to a transport aircraft model in the presence of two types of failures during operation, rudder failure and aileron failure. Simulation results are presented to demonstrate the adaptive failure compensation scheme

关键词： Programmable control Adaptive control Aerospace control Aircraft propulsion Engines Actuators control systems Military aircraft Postal services nasa

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Security proof of a three-state quantum-key-distribution protocol without rotational symmetry

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Physical Review A 2006年第4期74卷 042342-042342页

作者： Chi-Hang Fred Fung Hoi-Kwong Lo Center for Quantum Information and Quantum Control Department of Electrical and Computer Engineering University of Toronto Toronto Ont. M5S 3G4 Canada

Standard security proofs of quantum-key-distribution (QKD) protocols often rely on symmetry arguments. In this paper, we prove the security of a three-state protocol that does not possess rotational symmetry. The three-state QKD protocol we consider involves three qubit states, where the first two states ∣0z⟩ and ∣1z⟩ can contribute to key generation, and the third state ∣+⟩=(∣0z⟩+∣1z⟩)∕2 is for channel estimation. This protocol has been proposed and implemented experimentally in some frequency-based QKD systems where the three states can be prepared easily. Thus, by founding on the security of this three-state protocol, we prove that these QKD schemes are, in fact, unconditionally secure against any attacks allowed by quantum mechanics. The main task in our proof is to upper bound the phase error rate of the qubits given the bit error rates observed. Unconditional security can then be proved not only for the ideal case of a single-photon source and perfect detectors, but also for the realistic case of a phase-randomized weak coherent light source and imperfect threshold detectors. Our result in the phase error rate upper bound is independent of the loss in the channel. Also, we compare the three-state protocol with the Bennett-Brassard 1984 (BB84) protocol. For the single-photon source case, our result proves that the BB84 protocol strictly tolerates a higher quantum bit error rate than the three-state protocol, while for the coherent-source case, the BB84 protocol achieves a higher key generation rate and secure distance than the three-state protocol when a decoy-state method is used.

关键词： UNCONDITIONAL SECURITY CRYPTOGRAPHY

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A survey of techniques for detection and tracking of airport runways

A survey of techniques for detection and tracking of airport...

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44th AIAA Aerospace Sciences Meeting 2006

作者： Gong, Xiaojin Abbott, A. Lynn Fleming, Gary A. Virginia Tech. Blacksburg VA 24061 United States NASA Langley Research Center Hampton VA 23681 United States Bradley Department of Electrical and Computer Engineering United States AIAA United States Advanced Sensing and Optical Measurement Branch United States

ISBN: (纸本)1563478072

This paper is concerned with autonomous and semiautonomous landing of aircraft. This survey presents an overview of systems and techniques that can be used for this purpose, with an emphasis on computer vision systems that are appropriate for use with General Aviation (GA) class aircraft. If the runway can be located in digital images, using one or more cameras mounted on the aircraft, then this information can be used to estimate the relative position, orientation, and velocity of the aircraft. These estimates, in turn, can be used by a flight-control system to guide landing operations. Although many techniques have been developed for the analysis of high-altitude imagery, relatively few researchers have considered image analysis as an aid to aircraft landing. In one system, image intensity edges are used to detect the sides of a runway in a monocular image sequence, and these are used to estimate the 3-dimensional position and orientation of the runway. In another system, the analysis of optical flow is used to search for obstacles on a runway during an approach. Ultimately, high-speed image analysis will provide an important new source of information for use in automatic aircraft control.

关键词： Airport runways

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