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24th Annual Joint Conference of the IEEE Computer and Communications Societies

作者： Andrews, M Qian, LJ Stolyar, A Lucent Technol Bell Labs Murray Hill NJ 07974 USA

ISBN: (纸本)0780389689

We consider the problem of scheduling multiple users sharing a time-varying wireless channel. (As an example, this is a model of scheduling in 3G wireless technologies, such as CDMA2000 3G1xEV-DO downlink scheduling.) We introduce an algorithm which seeks to optimize a concave utility function Sigma(i) H-i (R-i) of the user throughputs Ri, subject to certain lower and upper throughput bounds: R-i(min) <= Ri <= R-i(max). The algorithm, which we call the gradient algorithm with Minimum/Maximum Rate constraints (GMR) uses a token counter mechanism, which modifies an algorithm solving the corresponding unconstrained problem, to produce the algorithm solving the problem with throughput constraints. Two important special cases of the utility functions are Sigma(i) log Ri and Sigma R-i, corresponding to the common Proportional Fairness and Throughput Maximization objectives. We study the dynamics of user throughputs under GMR algorithm, and show that GMR is asymptotically optimal in the following sense. If, under an appropriate scaling, the throughput vector R(t) converges to a fixed vector R* as time t -> infinity then R* is an optimal solution to the optimization problem described above. We also present simulation results showing the algorithm performance.

关键词： scheduling wireless CDMA 3G time varying channel QoS gradient algorithm proportional fair maximum throughput rate constraints guaranteed fate

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A double-integrator system for distributed optimization of convex cost functions 29

A double-integrator system for distributed optimization of c...

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第29届中国控制与决策会议

作者： Ngoc-Tu Tran Xuan Feng Wen-Yuan Xu Na Zhan Xi Wang School of Automation Huazhong University of Science and Technology Key Laboratory of Image Processing and Intelligent Control(Huazhong University of Science and Technology) Ministry of Education Hubei Electric Power Company

ISBN: (纸本)9781509046584

In this paper,the distributed optimization problem is investigated under a second-order multi-agent *** the proposed algorithm,each agent solves the optimization via local computation and information exchange with its neighbors through the communication ***,in comparison with the existing second-order distributed optimization algorithms,the proposed algorithm is much simpler due to one coupled information exchange among the agents is *** achieve the optimization,the distributed algorithm is proposed based on the consensus method and the gradient *** optimal solution of the problem is thus obtained with the design of Lyapunov function and the help of LaSallel's Invariance Principle.A numerical simulation example and comparison of proposed algorithm with existing works are presented to illustrate the effectiveness of the theoretical result.

关键词： Second-order multi-agent systems Distributed optimization Consensus Lyapunov function gradient algorithm

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Route Control for Freeway Networks via Nonlinear Optimization Approach

Route Control for Freeway Networks via Nonlinear Optimizatio...

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7th World Congress on Intelligent Control and Automation

作者： Xie, Jinsong Fan, Bingquan Gan, Hongcheng Yang, Jin Shanghai Univ Sci & Technol Ctr Res Transports Syst Sch Business Shanghai 201800 Peoples R China Shanghai Univ Sci & Technol Coll Sci Shanghai Peoples R China

ISBN: (纸本)9781424421138

This paper is concerned with route control for freeway networks. The freeway network with multi-origin and multi-destination was modeled using a second order macroscopic traffic flow model. The nonlinear optimization method for traffic control was presented. The considered control measure was route diversion by Variable Message Signs (VMS). The control task was formulated as a dynamic, nonlinear, discrete-time optimal control problem with constrained control variables. Considering the characteristic of nonlinearity of this control problem, a gradient algorithm, which was imbedded by a Quasi-Newton search algorithm, was presented. A simulation result for route diversion was given through a test example. From the result, we prove the presented gradient algorithm is efficient and applicable in increasing the network performance.

关键词： Multi-origin multi-destination non-linear optimization traffic control gradient algorithm

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Sensitivity control of a semi-active suspension system equipped with MR-dampers

Sensitivity control of a semi-active suspension system equip...

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International Conference on Control, Automation and Systems

作者： Hong, Keum-Shik Kim, Tae-Shik Kim, Rae-Kwan Pusan Natl Univ Sch Mech Engn San 30 Jangjeon Dong Pusan 609735 South Korea Pusan Natl Univ Dept Mech & Intelligent Syst Engn Pusan 609735 South Korea

ISBN: (纸本)9788995003879

In this paper, numerical aspects of a sensitivity control for the semi-active suspension system with a magneto-rheological (MR) damper are investigated. A 2-dof quarter-car model together with a 6th order polynomial model for the MR damper are considered. For the purpose of suppressing the vertical acceleration of the sprung mass, the square of the vertical acceleration is defined as a cost function and the current input to the MR damper is adjusted in the fashion that the current is updated in the negative gradient of the cost function. Also, for improving the handling performance, a weighted absolute velocity of the sprung mass is added to the control law. The implementation of the proposed algorithm requires only the measurement of the relative displacement of the suspension deflection. The local stability of the equilibrium point of the closed loop nonlinear system is proved by investigating the eigenvalues of the linearized me. Through simulations, the passive suspension, the skyhook control, and the proposed sensitivity control are compared.

关键词： gradient algorithm sensitivity MR damper semi-active polynomial model ride comport

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Accurate focusing technology for the coronal images 2

Accurate focusing technology for the coronal images

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Symposium on Astronomical Optics - Design, Manufacture, and Test of Space and Ground Systems II held at SPIE Optical Engineering + Applications Conference

作者： Zhang, X. F. Liu, Y. Li, X. B. Song, T. F. Zhao, M. Y. Wang, J. X. Chinese Acad Sci Yunnan Observ Kunming 650011 Yunnan Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Chinese Acad Sci Univ Sci & Technol China Key Lab Geospace Environm Hefei 230026 Peoples R China

ISBN: (数字)9781510629264

ISBN: (纸本)9781510629257;9781510629264

Optical imaging has been widely used in many fields as a tool for acquiring images, which can be used in microscopic observation, medical analysis, remote sensing, and astronomical observation. In the field of astronomical observations, it is very important to adjust the focus of the coronagraph. Due to the significant differences of the intensity between the corona and the solar photosphere, the ground-based coronagraph usually adopt an occulter, which is a little larger than the solar disk, to shield the light from the solar photosphere. In absence of the Sun as reference, focusing of the coronagraph is much harder than usual optical system. For the ground-based coronagraph, we developed a method of focusing using the solar disk image behind this disk occulter. Based on a series of images collected by shifting the center of the solar disk, we extract edge information of the solar disk and use the edge gradient algorithm to fit the focal length. This method can reduce the error of manual focusing. We can precisely find out the coronagraph focal point and obtain a clear coronal image, which lays a foundation for the technical support aboutremote control system of the coronagraph.

关键词： Image focusing gradient algorithm Coronagraph Occulter

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Collaborative Tracking Systems Using Decentralized Iterative Learning Control 39

Collaborative Tracking Systems Using Decentralized Iterative...

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39th Chinese Control Conference (CCC)

作者： Shen, Dong Liu, Yanze Song, Qijiang Renmin Univ China Sch Math Beijing 100872 Peoples R China Beijing Univ Chem Technol Coll Informat Sci & Technol Beijing 100029 Peoples R China

ISBN: (纸本)9789881563903

This study addresses the collaborative tracking problem for a set of linear systems with noisy measurements using decentralized iterative learning control. The collaborative tracking problem indicates that the desired reference trajectory over a finite time interval is required to be precisely tracked by a combination of the outputs of several independent subsystems. A description of the achievable tracking reference and its corresponding input is elaborated. Two decentralized learning schemes are then provided to solve the collaborative tracking problem iteratively. Numerical simulations are given to verify the derived results.

关键词： Collaborative Tracking Iterative Learning Control gradient algorithm Stochastic Control

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Simultaneous Estimation of Time Delays Systems 5

Simultaneous Estimation of Time Delays Systems

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5th IEEE International Conference on Advanced Systems and Emergent Technologies (IC_ASET)

作者： Ghoul, Yamna Ibn Taarit, Kaouther Ksouri, Moufida Univ Tunis El Manar Natl Engn Sch Tunis Concept & Control Syst Lab LR11ES20 Anal BP 37 Le Belvedere Tunis 1002 Tunisia

ISBN: (纸本)9781665427357

This research proposes a gradient technique to identify, jointly, the parameters and the time delays of systems based on sampled data. The initial parameters values can be estimated using another algorithm. The proposed scheme uses a simultaneous procedure with the presence of a white noise. A numerical instance is proposed to confirm the effectiveness of the developed technique.

关键词： simultaneous identification gradient algorithm

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Adaptive synchronization of discrete-time T-S fuzzy chaotic systems using output tracking control

Adaptive synchronization of discrete-time T-S fuzzy chaotic ...

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SICE-ICASE International Joint Conference

作者： Lee, Won-Ki Hyun, Chang-Ho Kim, Euntai Park, Mignon Yonsei Univ Dept Elect & Elect Engn Seoul 120749 South Korea

ISBN: (纸本)9788995003848

This paper presents a model reference adaptive control approach for the synchronization of a discrete-time chaotic systems using output tracking control. Takagi-Sugeno (T-S) fuzzy model is employed to represent the discrete-time chaotic system. Then, the reference model system is chosen using the output of master system and design the control input so that the controlled slave system achieves asymptotic synchronization with the reference system given that two systems start from different initial conditions, different parameters and/or different type of model. Using a gradient algorithm, the ideal controller gains which can stabilize the error equation are estimated. Simulation examples of two cases are given to demonstrate the validity of our proposed adaptive method.

关键词： synchronization output tracking control T-S fuzzy model reference model system gradient algorithm

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Design and Testing of a Generalized Reduced gradient Code for Nonlinear Programming

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ACM Transactions on Mathematical Software (TOMS) 1978年第1期4卷 34-50页

作者： Lasdon, L.S. Waren, A.D. Jain, A. Ratner, M. Department of General Business School of Business Administration University of Texas Austin TX 78712 United States Department of Computer and Information Science Cleveland State University Cleveland OH 44115 United States Energy Systems Group Stanford Research Institute Menlo Park CA 94025 United States Department of Systems and Computer Science Case Western Reserve University Cleveland OH 44106 United States

An algorithm for solving nonlinear optimization problems is described along with its implementation as a Fortran program. Computational results are provided which compare its performance with that of other algorithms. The generalized reduced gradient (GRG) algorithm used is a nonlinear extension of the simplex method for linear programming. It is shown thatthe implementation is both robust and efficient. © 1978, ACM. All rights reserved.

关键词： constrained optimization gradient algorithm GRG mathematical programming nonlinear programming optimization reduced gradient software engineering

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Watermark Detection in Impulsive Noise Environment Based on the Compressive Sensing Reconstruction

Watermark Detection in Impulsive Noise Environment Based on ...

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作者： Lutovac, B. Brno University of Technology

The watermark detection procedure for images corrupted by impulsive noise is proposed. The procedure is based on the compressive sensing (CS) method for the reconstruction of corrupted pixels. It is shown that the proposed procedure can extract watermark with a moderate impulsive noise level. It is well known that most of the images are approximately sparse in the 2D DCT domain. Moreover, we can force sparsity in the watermarking procedure and obtain almost strictly sparse image as a desirable input to the CS based reconstruction algorithms. Compared to the state-of-the-art methods for impulse noise removal, the proposed solution provides much better performance in watermark extraction.

关键词： Image watermarking impulsive noise compressive sensing sparse reconstruction gradient algorithm

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