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Aerodynamic optimization of essentially three-dimensional shapes for wing-body fairing

AIAA JOURNAL 2008年第7期46卷 1814-1825页

作者： Peigin, Sergey Epstein, Boris Israel Aerosp Ind Ltd IL-70100 Ben Gurion Israel Acad Coll Tel Aviv Yaffo IL-64044 Tel Aviv Israel

A new approach for the optimization of essentially three-dimensional aerodynamic shapes for minimum drag is proposed. The method allows the handling of the nonlinear surfaces that are typical of complex aircraft junctions such as a wing-body fairing. The optimization framework OPTIMAS, previously proposed and developed by the authors for the solution of the drag-minimization problem for two-dimensional airfoils, three-dimensional isolated wings, and three-dimensional wings in the presence of a body in succession, is extended in this paper to a significantly higher level of geometrical complexity of optimized aerodynamic configurations. The method is driven by accurate full Navier-Stokes evaluations of the objective function, and the optimization engine is based on genetic algorithms. The important features of the method are the ability to accurately handle multiple geometrical/aerodynamic constraints and a high level of computational efficiency, achieved through massive multilevel parallelization and a reduced-order-model approach. The method was applied to the optimization of a wing-body fairing for a generic business jet configuration at realistic transonic cruise flight conditions. The results demonstrate that the proposed approach achieves significant drag reduction in on- and offdesign conditions and can be used in an engineering environment.

关键词： Aerodynamic Shape optimization Generic Business Jet Configuration Genetic algorithm Two Dimensional Airfoil Numerical Simulation Aircraft Configurations Aerodynamic Performance Navier Stokes Equations Euler Equations optimization algorithm

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A constrained line search optimization method for discriminative training of HMMs

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IEEE TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING 2008年第5期16卷 900-909页

作者： Liu, Peng Liu, Cong Jiang, Hui Soong, Frank Wang, Ren-Hua Microsoft Res Asia Beijing 100080 Peoples R China Univ Sci & Technol China Hefei 230026 Peoples R China York Univ Toronto ON M3J 1P3 Canada

In this paper, we propose a novel optimization algorithm called constrained line search (CLS) for discriminative training (DT) of Gaussian mixture continuous density hidden Markov model (CDHMM) in speech recognition. The CLS method is formulated under a general framework for optimizing any discriminative objective functions including maximum mutual information (MMI), minimum classification error (MCE), minimum phone error (MPE)/minimum word error (MWE), etc. In this method, discriminative training of HMM is first cast as a constrained optimization problem, where Kullback-Leibler divergence (KLD) between models is explicitly imposed as a constraint during optimization. Based upon the idea of line search, we show that a simple formula of HMM parameters can be found by constraining the KLD between HMM of two successive iterations in an quadratic form. The proposed CLS method can be applied to optimize all model parameters in Gaussian mixture CDHMMs, including means, covariances, and mixture weights. We have investigated the proposed CLS approach on several benchmark speech recognition databases, including TIDIGITS, Resource Management (RM), and Switchboard. Experimental results show that the new CLS optimization method consistently outperforms the conventional EBW method in both recognition performance and convergence behavior.

关键词： discriminative training (DT) optimization algorithm line search Kullback-Leibler divergence (KLD)

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Resulted word counts optimization - A new approach for better automatic image annotation

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PATTERN RECOGNITION 2008年第12期41卷 3562-3571页

作者： Kwasnicka, Halina Paradowski, Mariusz Wroclaw Univ Technol Inst Appl Informat PL-50370 Wroclaw Poland

One of major problems in image auto-annotation is the difference between the expected word counts vector and the resulted word counts vector. This paper presents a new approach to automatic image annotation-an algorithm called resulted word counts optimizer which is an extension to existing methods. An ideal annotator is defined in terms of recall quality measure. On the basis of the ideal annotator an optimization criterion is defined. it allows to reduce the difference between resulted and expected word counts vectors. The proposed algorithm can be used with various image auto-annotation algorithms because its generic nature. Additionally, it does not increase the computational complexity of the original annotation method processing phase. It changes output word probabilities according to a pre-calculated vector of correction coefficients. (C) 2008 Elsevier Ltd. All rights reserved.

关键词： automatic image annotation ideal image annotator recall quality measure optimization algorithm

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A Directed Quantile Cross-Entropy Method for 0/1 Knapsack Problems

A Directed Quantile Cross-Entropy Method for 0/1 Knapsack Pr...

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2009 9th International Conference on Electronic Measurement & Instruments(第九届电子测量与仪器国际会议 ICEMI'2009)

作者： Libao Deng Liyan Qiao Xiyuan Peng Department of Automatic Test and Control Harbin Institute of Technology Harbin150080P.O.Box 3033China

ISBN: (纸本)9781424438631;9781424438624

Cross-entropy method is base on probability density function. It is robust, easy to use. With analysis of advantages and disadvantages of the cross-entropy method, a directed quantile method based on crossentropy is proposed. The main idea of the directed quantile cross-entropy method is to select alterable quantity vectors using for producing a "better" sample in the next iteration. The convergence speed and search best result of the directed quantile cross-entropy are tested using 0/1 knapsack problems. The experiments show that the search efficiency of the modified cross-entropy method is more significantly improved than quantum-inspired evolutionary algorithm and cross-entropy method.

关键词： cross-entropy method optimization algorithm 0/1 knapsack problems.

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Reactive Power optimization for Distribution Systems Based on Dual Population Ant Colony optimization

Reactive Power Optimization for Distribution Systems Based o...

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27th Chinese Control Conference

作者： Guo Lirui Huo Limin Zhang Liguo Liu Weina Hu Jie Agr Univ Hebei Dept Mech & Elect Engn Baoding 071001 Peoples R China Agr Univ Hebei Coll Informat Sci & Technol Baoding 071001 Peoples R China

ISBN: (纸本)9787900719706

The Dual Population Ant Colony optimization(DPACO) was tried to be applied to Power System Dynamic Reactive Power optimization. The installation positions of capacitors were taken as obstacles, the capacities of capacitors installed were taken-as the paths through which the ants climb over the obstacles and the mathematical models of the reactive power planning under the multiple load state were adopted. In running process, the pheromone was adjusted according to the ant's search results and the principle of pheromone modification and the convergence speed was fastened. At the same time, the Dual Population Ant Colony optimization (DPACO) avoided trapping in local optimum and increased the precision of Reactive Power optimization for doing well in global optimization. After optimization, the voltage quality was enhanced obviously and comprehensive fees decrease significantly. The running results show that Dual Population Ant Colony optimization (DPACO) applied to Power System Dynamic Reactive Power optimization is feasible and effective.

关键词： Reactive Power optimization Dual Population Ant Colony optimization (DPACO) Distribution system optimization algorithm

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Interconnect sizing and spacing with consideration of buffer insertion for simultaneous crosstalk-delay optimization

Interconnect sizing and spacing with consideration of buffer...

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3rd International Conference on Design and Technology of Integrated Systems in Nanoscale Era (DTIS)

作者： Hasani, Fargol Masoumi, Nasser Univ Tehran Sch ECE VLSI Res Grp POB 14395-515 Tehran Iran

ISBN: (纸本)9781424415762

As integrated circuits (ICs) are scaled into nanometre dimensions and operate in gigahertz frequencies, interconnects have become critical in determining system performance and reliability. In this paper we propose a new approach to investigate crosstalk reduction techniques which helps to have simultaneous optimization of interconnect delay and crosstalk noise in deep submicron VLSI circuits. The optimization problem is modelled by solving a new cost function to find a minimum cost for both crosstalk noise and delay which are conflicting in nature. Through MATLAB software, a system of three coupled wires is modelled as a RC distributed network. The results indicate the number of optimum available solutions including wire sizing, wire spacing and buffer insertion in which crosstalk reduction techniques can be useful for both crosstalk noise and delay.

关键词： nano scale Interconnect optimization wire sizing wire spacing buffer insertion optimization algorithm coupling capacitance delay crosstalk

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Enhanced self-adaptive search capability Particle Swarm optimization

Enhanced self-adaptive search capability Particle Swarm Opti...

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8th International Conference on Intelligent Systems Design and Applications (ISDA 2008)

作者： Hu Juan Yu Laihang Zou Kaiqi Dalian Univ Technol Univ Key Lab Informat Sci & Engn Coll Informat Engn Dalian 116622 Peoples R China

ISBN: (纸本)9780769533827

A new particle swarm optimization characterized by sensation is presented to improve the limited capability of regular particle swarm optimization in exploiting history experience (iwPSO). It guides individuals to behave reasonably with the capability of self-adaptation in activities of self-cognition according to the sensation model. Considering the complexity of a swarm intelligent system at the level of sensation brings about optimization of the comprehensive capability of global, local searching and cooperating with each other It is compared with the regular particle swarm optimizer (PSO) invented by Kennedy and Eberhart in 1995 based on three different benchmark functions. In the iwPSO proposed here, each particle adjusting the inertia weight omega value when its position changes, it enhances the search capability of single particle. The strategy here is to avoid the local minimum problems of PSO algorithm. Under all test cases, simulation shows that the iwPSO always finds better solutions than PSO.

关键词： Particle Swarm optimization evolutionary computation self-adaptive optimization algorithm

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Amplitude-only Shaping optimization Method for Circular Planar Slot Array Antennas

Amplitude-only Shaping Optimization Method for Circular Plan...

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11th IEEE Singapore International Conference on Communication Systems

作者： Zha, Xiaochen Wang, Jian Ren, Lixia Univ Elect Sci & Technol China Sch Elect Engn Chengdu 610054 Peoples R China

ISBN: (纸本)9781424424238

A new method for amplitude -only optimization of circular planar slot array antennas is presented. In order to form a given three-dimensional antenna pattern for array antennas, variable metric algorithms, Davidon- Fletcher- Powell(DFP) and Broyden- Fletcher- Goldfarb-Shanno (BFGS) were jointly used to optimize the amplitude distribution of the current excitations. Thus, the optimized main lobe of the antenna pattern is fitted for the given and the side lobe level is efficiently controlled. This method solves N-dimensional unrestricted function;it shows fast convergence and small amount of computing. It is a valuable beam shaping method for array antennas.

关键词： shaped three-dimensional pattern circular slot array antennas amplitude-only method optimization algorithm

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Research on optimization of Wind and PV Hybrid Power Systems

Research on Optimization of Wind and PV Hybrid Power Systems

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7th World Congress on Intelligent Control and Automation

作者： Li, Mingliang Wang, Cong China Univ Min & Technol Sch Mech Elect & Informat Engn Beijing 100083 Peoples R China

ISBN: (纸本)9781424421138

To effectively and reliably utilize renewable resources then achieve the wind/PV (photovoltaic) hybrid generator, a new type wind/PV hybrid generator was designed, which adopts the auto-interference controller designed by utilizing the nonlinear transform of aerodynamic force to capture wind to the highest degree, and also other technologies as brushless double-fed wind generator, extremum, control on solar inverter. Considering the multi-input and multi-output of the distributed hybrid power system, using the theory of linear relationship between the hierarchical fuzzy controller's totalities and variables, here give the hierarchical fuzzy controller algorithm to control the loading and unloading of wind generators, solar cells and the grid. The experiments show that: on the premise of utilizing renewable resources to the greatest extent, system can realize the equilibrium between the supply and demand of the electric energy automatically according to its load.

关键词： Hybrid power systems Fuzzy control optimization algorithm System design

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Unsteady discrete adjoint formulation for two-dimensional flow problems with deforming meshes

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AIAA JOURNAL 2008年第6期46卷 1351-1364页

作者： Mani, Karthik Mavriplis, Dimitri J. Univ Wyoming Dept Mech Engn Laramie WY 82071 USA

A method to apply the discrete adjoint for computing sensitivity derivatives in two-dimensional unsteady flow problems is presented. The approach is to first develop a forward or tangent linearization of the nonlinear flow problem in which each individual component building up the complete flow solution is differentiated against the design variables using the chain rule. The reverse or adjoint linearization is then constructed by transposing and reversing the order of multiplication of the forward problem. The developed algorithm is very general in that it applies directly to the arbitrary Lagrangian-Eulerian form of the governing equations and includes the effect of deforming meshes in unsteady flows. It is shown that an unsteady adjoint formulation is essentially a single backward integration in time and that the cost of constructing the final sensitivity vector is close to that of solving the unsteady flow problem integrated forward in time. It is also shown that the unsteady adjoint formulation can be applied to time-integration schemes of different orders of accuracy with minimal changes to the base formulation. The developed technique is then applied to three optimization examples, the first in which the shape of a pitching airfoil is morphed to match a target time-dependent load profile, the second in which the shape is optimized to match a target time-dependent pressure profile, and the last in which the time-dependent drag profile is minimized without any loss in lift.

关键词： Two Dimensional Flow Arbitrary Lagrangian Eulerian Symmetric Airfoil Edge Computing Freestream Mach Number Angle of Attack Euler Equations Roe Approximate Riemann Solver optimization algorithm Computational Fluid Dynamics

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