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54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： El-Hajj, Ahmad M. Dawy, Zaher Amer Univ Beirut Dept Elect & Comp Engn Beirut Lebanon

ISBN: (纸本)9781424492688

The development of the Time Division Duplexing (TDD) mode in next generation OFDMA-based wireless standards has brought some major advantages but at the same time raised several critical design requirements. Among others, the introduced flexibility in splitting resources between the uplink and downlink directions makes of the uplink/downlink switching point configuration a major design problem, especially that it is directly connected to other design aspects such as resource allocation and interference mitigation. In this paper, we propose a dynamic joint uplink/downlink resource allocation and switching point configuration algorithm. The proposed algorithm is channel-aware, traffic-aware, and service-aware. The resource allocation problem is formulated as an optimization problem that captures the different network parameters. Resulting instantaneous uplink and downlink rates are utilized in a dynamic estimation of the uplink and downlink time shares. A fast implementation using sequential quadratic programming is presented. Simulation results demonstrate the efficiency of the proposed approach in responding dynamically to varying network conditions and the improved performance when compared to fixed uplink/downlink switching point configurations.

关键词： Downlink Estimation Indexes Interference OFDM modulation Optimization Resource management Switches TDD-OFDMA wireless networks channel-aware downlink directions dynamic estimation dynamic joint switching point configuration dynamic joint uplink/downlink resource allocation major design problem next generation OFDMA-based wireless standards next generation networks optimization problem radio links radio networks resource allocation resource allocation problem sequential quadratic programming service-aware switching point configuration algorithm time division duplexing mode traffic-aware uplink directions uplink/downlink switching point configuration

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A Multi-objective Optimization Method for Thin-walled Tube NC Bending

A Multi-objective Optimization Method for Thin-walled Tube N...

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International Conference on Advanced Material Research

作者： Xu, Jie Yang, He Li, Heng NW Polytech Univ State Key Lab Solidificat Proc Sch Mat Sci & Engn Xian 710072 Peoples R China

ISBN: (纸本)9783037850619

A multi-objective optimization method for thin-walled tube NC bending is presented. Firstly, a half-symmetry 3D elastic-plastic FEM model is established based on the initial design values, applying the dynamic explicit code ABAQUS/Explicit. Secondly, virtual orthogonal arrays are designed to optimize friction coefficients, with minimizing the maximum wall-thinning ratio, the maximum cross section distortion ratio and the maximum height of wrinkling waves as the multi-objectives. Lastly, the mandrel radius is optimized by sequential quadratic programming with approximate regressive models fit from uniform design values in the allowed range. Application is put forward for Phi 50x1x100 (tube outside diameter xtube wall thickness x central line bending radius) and Phi 100x1.5x200 aluminum alloy tube bending. It is proved that the forming quality has been improved by the method.

关键词： Multi-objective optimization Thin-walled tube NC bending Orthogonal arrays FEM sequential quadratic programming

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Hybrid DE-SQP algorithm for non-convex short term hydrothermal scheduling problem

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ENERGY CONVERSION AND MANAGEMENT 2011年第1期52卷 757-761页

作者： Sivasubramani, S. Swarup, K. Shanti Indian Inst Technol Dept Elect Engn Madras 600036 Tamil Nadu India

This paper proposes a hybrid method combining differential evolution (DE) and sequential quadratic programming (SQP) for solving short term hydrothermal scheduling problem with non-convex fuel cost function. In this paper, differential evolution (DE) is used as a global optimizer and sequential quadratic programming (SQP) method as a local optimizer to fine tune the solution. The proposed method has been tested on a multichain cascaded reservoir with an equivalent thermal test system and the simulation results are compared with existing methods reported in literatures. From the results, it clearly shows that the proposed method is giving better quality solutions than existing methods. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Differential evolution sequential quadratic programming Hydrothermal system

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Classification-assisted Memetic Algorithms for Solving Optimization Problems with Restricted Equality Constraint Function Mapping

Classification-assisted Memetic Algorithms for Solving Optim...

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IEEE Congress on Evolutionary Computation (CEC)

作者： Handoko, Stephanus Daniel Keong, Kwoh Chee Soon, Ong Yew Chan, Jonathan Nanyang Technol Univ Sch Comp Engn Singapore 639798 Singapore King Mongkuts Univ Technol Thonburi Sch Informat Technol Bangkok Thailand

ISBN: (纸本)9781424478354

The success of Memetic Algorithms (MAs) has driven many researchers to be more focused on the efficiency aspect of the algorithms such that it would be possible to effectively employ MAs to solve computationally expensive optimization problems where single evaluation of the objective and constraint functions may require minutes to hours of CPU time. One of the important design issues in MAs is the choice of the individuals upon which local search procedure should be applied. Selecting only some potential individuals lessens the demand for functional evaluations hence accelerates convergence to the global optimum. In recent years, advances have been made targeting optimization problems with single equality constraint h(x) = 0. The presence of previously evaluated candidate solutions with different signs of constraint values within some localities thus allows the estimation of the constraint boundary. An individual will undergo local search only if it is sufficiently close to the approximated boundary. Elegant as it may seem, the approach had unfortunately assumed that every constraint function maps the design variables to optimize into unbounded real values. This, however, may not always be the case in practice. In this paper, we present a strategy to efficiently solve constrained problems with a single equality constraint;the function of which maps the design variables into restricted (either strictly non-negative or strictly non-positive) real values only.

关键词： Evolutionary computation memetic algorithms genetic algorithms sequential quadratic programming equality-constrained optimization computationally-expensive problems classification support vector machine

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Bilevel Multi-objective Optimization Problem Solving Using Progressively Interactive EMO

Bilevel Multi-objective Optimization Problem Solving Using P...

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6th International Conference on Evolutionary Multi-Criterion Optimization

作者： Sinha, Ankur Aalto Univ Sch Econ Dept Business Technol FIN-00076 Helsinki Finland

ISBN: (纸本)9783642198922

Bilevel multi-objective optimization problems are known to be highly complex optimization tasks which require every feasible upper-level solution to satisfy optimality of a lower-level optimization problem. Multi-objective bilevel problems are commonly found in practice and high computation cost needed to solve such problems motivates to use multi-criterion decision making ideas to efficiently handle such problems. Multi-objective bilevel problems have been previously handled using an evolutionary multi-objective optimization (EMO) algorithm where the entire Pareto set is produced. In order to save the computational expense, a progressively interactive EMO for bilevel problems has been presented where preference information from the decision maker at the upper level of the bilevel problem is used to guide the algorithm towards the most preferred solution (a single solution point). The procedure has been evaluated on a set of five DS test problems suggested by Deb and Sinha. A comparison for the number of function evaluations has been done with a recently suggested Hybrid Bilevel Evolutionary Multi-objective Optimization algorithm which produces the entire upper level Pareto-front for a bilevel problem.

关键词： Genetic algorithms evolutionary algorithms bilevel optimization multi-objective optimization evolutionary programming multi-criteria decision making hybrid evolutionary algorithms sequential quadratic programming

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Seismic displacement control of multiple-degree-of-freedom structures using tuned viscous mass dampers 8

Seismic displacement control of multiple-degree-of-freedom s...

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8th International Conference on Structural Dynamics (EURODYN)

作者： Ikago, Kohju Sugimura, Yoshifumi Saito, Kenji Inoue, Norio Tohoku Univ Grad Sch Engn Aoba Ku Sendai Miyagi 980 Japan NTT Facil Inc Res & Dev Headquarters Toshima Ku Tokyo Japan NTT Facil Inc Bldg Engn Headquarters Minato Ku Tokyo Japan

ISBN: (纸本)9789076019314

The authors have presented a new seismic control device the tuned viscous mass damper (TVMD). The TVMD consists of a viscous mass damper with an apparent mass amplifier and a soft spring which connects the damper to the primary system. The mass amplifier has allowed us to make the additional mass and device itself smaller compared with a conventional tuned mass damper (TMD). The design method to determine an optimum set of damper parameters has not yet been presented for the vibration control system of a damped MDOF structure, while that of an undamped SDOF structure is obtained by the fixed point method. In this paper, we present a design method to obtain a set of optimum damper parameters for the seismic control system of a damped MDOF structure using sequential quadratic programming (SQP).

关键词： Tuned viscous mass damper Dynamic vibration absorber Optimum vibration control Fixed point method sequential quadratic programming Seismic control

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Nonlinear Optimization for Human-Like Movements of a High Degree of Freedom Robotics Arm-Hand System

Nonlinear Optimization for Human-Like Movements of a High De...

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11th International Conference on Computational Science and Its Applications (ICCSA)

作者： Costa e Silva, Eliana Costa, Fernanda Bicho, Estela Erlhagen, Wolfram Univ Minho Dept Ind Elect P-4719 Braga Portugal Univ Minho Dept Math Appl P-4719 Braga Portugal

ISBN: (纸本)9783642219306;9783642219313

The design of autonomous robots, able to closely cooperate with human users in shared tasks, provides many new challenges for robotics research. Compared to industrial applications, robots working in human environments will need to have human-like abilities in their cognitive and motor behaviors. Here we present a model for generating trajectories of a high degree of freedom robotics arm-hand system that reflects optimality principles of human motor control. The process of finding a human-like trajectory among all possible solutions is formalized as a large-scale nonlinear optimization problem. We compare numerically three existing solvers, IPOPT, KNITRO and SNOPT, in terms of their real-time performance in different reach-to-grasp problems that are part of a human-robot interaction task. The results show that the SQP methods obtain better results than the IP methods. SNOPT finds optimal solutions for all tested problems in competitive computational times, thus being the one that best serves our purpose.

关键词： anthropomorphic robotic system reach-to-grasp human-like collision-free arm movements large-scale nonlinear optimization interior-point methods sequential quadratic programming

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Optimal Notch Filter for Active Magnetic Bearing Controllers

Optimal Notch Filter for Active Magnetic Bearing Controllers

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IEEE/ASME International Conference on Advanced Intelligent Mechatronics

作者： Yoo, Seong-yeol Lee, Wook-ryun Bae, Yong-chae Noh, Myounggyu D. Chungnam Natl Univ Dept Mechatron Engn Taejon South Korea Korea Elect Power Res Inst Taejon South Korea

ISBN: (纸本)9781457708398

This paper describes an optimal design of a notch filter for the active magnetic bearing (AMB) system which has unstable poles. A Notch filter is designed as 2(nd) order standard transfer function with two zeros and two poles. We performed optimization to design a notch filter using sequential quadratic programming (SQP) and evaluate the closed loop stability with a designed notch filter. The designed notch filter is optimized to have the lowest peak sensitivity with respect to the disturbance closed loop system. The designed notch filter is examined for the compensation effect for the unstable 2(nd) order system. We applied the design optimization to large scale flywheel energy storage system (FESS). FESS can store up to 5kWh of usable energy at the maximum speed of 18,000 rpm. The effect of the designed filter from optimization is simulated using simulation model of FESS and the simulation model is validated against experiments.

关键词： FESS Flywheels Magnetic levitation Magnetic separation Optimization Rotors SQP Sensitivity Transfer functions active magnetic bearing controllers closed loop stability closed loop systems disturbance closed loop system flywheels large scale flywheel energy storage system magnetic bearings notch filters optimal notch filter poles and zeros poles and zeros quadratic programming sequential quadratic programming stability transfer function

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Motion Planning for Vibration Reducing of Free-floating Redundant Manipulators Based on Hybrid Optimization Approach

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Chinese Journal of Aeronautics 2011年第4期24卷 533-540页

作者： LIAO Yihuan LI Daokui TANG Guojin College of Aerospace and Materials Engineering National University of Defense Technology Changsha 410073 China

This paper is concerned with optimal motion planning for vibration reducing of free-floating flexible redundant manipulators. Firstly, dynamic model of the system is established based on Lagrange method, and the motion planning model for vibration reducing is proposed. Secondly, a hybrid optimization approach employing Gauss pseudospectral method （GPM） and direct shooting method （DSM）, is proposed to solve the motion planning problem. In this approach, the motion planning problem is transformed into a non-linear parameter optimization problem using GPM, and genetic algorithm （GA） is employed to locate the approximate solution. Subsequently, an optimization model is formulated based on DSM, and sequential quadratic programming （SQP） algorithm is used to obtain the accurate solution, with the approximate solution as an initial reference solution. Finally, several numerical simulations are investigated, and the global vibration or residual vibration of flexible link is obviously reduced by the joint trajectory which is obtained by the hybrid optimization approach. The numerical simulation results indicate that the approach is effective and stable to the motion planning problem of vibration reducing.

关键词： flexible manipulator dynamic modeling motion planning Gauss pseudospectral method direct shooting method genetic algorithm sequential quadratic programming

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Design optimization for relative bandwidth of left-handed metamaterials with split-ring resonators

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JOURNAL OF OPTICS 2011年第1期13卷 015102-015102页

作者： Liu, Shutian Dong, Yanzhang Xu, Weikai Dalian Univ Technol State Key Lab Struct Anal Ind Equipment Dept Engn Mech Dalian 116024 Peoples R China

Due to their special properties, left-handed metamaterials have important potential applications in engineering. When an incident wave propagates through a periodic material with the dimension of its microstructure much smaller than the wavelength, the metamaterial can be regarded as a homogeneous medium, and its effective electromagnetic parameters (permittivity and permeability) in the frequency domain can be obtained with the S-parameters retrieval method. From this perspective, the design of a material with the desired left-handed characteristics becomes possible. By establishing automatic parametric modeling technology, we can study the transmission and reflection properties of left-handed metamaterials with arrays of split-ring resonators. Next, a whole flow chart of design optimization for improving left-handed metamaterial performance is proposed. Finally, the design method is illustrated through a numerical example including the shape and the size design of split-ring resonators to max relative bandwidth, based on parametric analysis of the left-handed relative bandwidths. sequential quadratic programming and enumeration optimization are applied to solve the optimization problem.

关键词： left-handed metamaterials material design relative bandwidth S-parameters retrieval methods sequential quadratic programming split-ring resonators

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