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A Global optimization algorithm for Nonlinear Biological Systems Using a Hierarchical Model of Evolution and Consciousness

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IFAC Proceedings Volumes 1998年第5期31卷 121-125页

作者： M. Hirafuji S. Hagan K. Otobe K. Tanaka Computational Modeling Lab. Department of Information Science and Technology National Agriculture Research Center 3-1-1 Kannondai Tsukuba 305-8666 Japan

Global optimization algorithms are required for optimal control of complex systems such as plant growth and crop yield. Processes for global optimization, selfprogramming and the determination of accurate fitness (evaluation) functions are indispensable to modeling in the strong AI and strong A-Life projects. The modeling of complex processes like consciousness and evolution will be applied towards the development of global optimization algorithms. To date several models of the microscopic mechanisms involved in brain function have been proposed that are based on quantum dynamics. However biological systems comprise a hierarchy from the microscopic to the macroscopic level. Here we employ both quantum dynamics and a systems theoretical approach based on techniques derived from the modeling of consciousness and evolution to propose a global optimization algorithm that can avoid locally optimal states of non-linear functions.

关键词： optimization algorithm Evolution Genetic algorithm Quantum mechanics Hierarchical model Consciousness

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Reduced-order design-oriented stress analysis using combined direct and adjoint solutions

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AIAA JOURNAL 2000年第5期38卷 898-909页

作者： Livne, E Blando, GD Univ Washington Dept Aeronaut & Astronaut Seattle WA 98195 USA

A new method for extracting accurate stress information from reduced-order structural and aeroelastic models is presented. The method has second-order accuracy when approximate reduced-order direct and adjoint solutions (based on different reduced-order bases) are used simultaneously to obtain approximate stresses, The method is applicable to both static and dynamic linear analysis. A review of four common methods for structural model order reduction [two variants of the mode displacement method (standard mode displacement and the fictitious mass method), the mode acceleration method, and the Ritz vector method] identifies sources of difficulty and causes of errors in stress behavior sensitivity calculations. Considerations used for selection of the reduced-order direct and adjoint bases are discussed. A series of static and dynamic test cases is used to assess accuracy of the new method in an analysis mode. Accuracy studies of sensitivity calculations follow. We hope to contribute to the held of design-oriented structural dynamics in terms of both insight and practice.

关键词： Stress Analysis Structural Dynamics Model Order Reduction Aeroelastic Analysis Isoparametric Elements Structural Analysis Sensitivity Analysis Structural Modeling optimization algorithm Static Deformation

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Model refinement using eigensystem assignment

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2000年第4期23卷 683-692页

作者： Maghami, PG NASA Langley Res Ctr Guidance & Control Branch Hampton VA 23681 USA

A novel approach for the refinement of finite-element-based analytical models elf flexible structures is presented. The proposed approach models the possible refinements in the mass, damping, and stiffness matrices of the finite element model in the form of a constant gain feedback with acceleration, velocity, and displacement measurements, respectively. Once the free elements of the structural matrices have been defined, the problem of model refinement reduces to obtaining position, velocity, and acceleration gain matrices with appropriate sparsity that reassign a desired subset of the eigenvalues of the model, along with partial mode shapes, from their baseline values to those obtained from system identification test data. A sequential procedure is used to assign one conjugate pair of eigenvalues at each step using symmetric output feedback gain matrices, and the eigenvectors are partially assigned, while ensuring that the eigenvalues assigned in the previous steps are not disturbed. The procedure can also impose that gain matrices be dissipative to guarantee the stability of the refined model. A numerical example, involving finite element model refinement for a structural testbed at NASA Langley Research Center (Controls-Structures-Interaction Evolutionary model) is presented to demonstrate the feasibility of the proposed approach.

关键词： Stiffness Matrices Output Feedback NASA Langley Research Center Damping Ratio Control System Design Computing Newton's Method Closed Loop System Stress Strain Analysis optimization algorithm

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Novel beetle algorithm for Cartesian grid generation in two dimensions

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JOURNAL OF AIRCRAFT 2000年第5期37卷 927-929页

作者： Srivastava, A Ravichandran, KS Natl Aerosp Labs Computat & Theoret Fluid Dynam Div Bangalore 560017 Karnataka India

A Cartesian grid generator has been coded to obtain a Cartesian grid around an arbitrary geometry in 2D. The grid generation is accomplished by a novel technique employing a Beetle algorithm. The significant parameters in defining the movement of the Beetle and its capture of intersection points are ascertained and implemented within the code. The sample grid generated around several shapes demonstrates the code's versatility. (CSA)

关键词： MDO optimization algorithm High Performance Computing Annealing Process Stochastic optimization Sensitivity Analysis Aircraft Wing Design Parallel Computing Sorting algorithms Genetic algorithm

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Hemivariational inequality modeling of hybrid laminates with unidirectional composite constituents

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AIAA JOURNAL 2000年第4期38卷 680-686页

作者： Stavroulakis, GE Mistakidis, ES Tech Univ Braunschweig Inst Appl Mech Dept Civil Engn D-38106 Braunschweig Germany Aristotelian Univ Salonika Inst Steel Struct Dept Civil Engn GR-54006 Salonika Greece

The overall tensile and bending behavior of unidirectional composite elements with monotone and nonmonotone, possibly multivalued, constitutive laws for each constituent are studied within a nonsmooth mechanics framework. A nondifferentiable and possibly nonconvex, caused by degradation effects, potential energy is formulated for the whole mechanical system. For the structural analysis problem the potential energy minimization problem is considered. The arising variational or hemivariational (in the case of nonmonotone laws) inequality problems are solved by appropriate nonconvex-nonsmooth computational mechanics techniques. Parametric numerical investigations of typical composite elements are presented, which shed light into the complex behavior of the composite structural elements. On the other hand, the arising overall laws can he used as phenomenological laws for structural analysis of large-scale structures incorporating the studied composite elements.

关键词： Structural Analysis Techniques Composite Materials Composite Structures Material Properties Computer Programs optimization algorithm Iterative algorithm Elastic Structure Stiffness Matrices Plasticity

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Parameterization of model validating sets for uncertainty bound optimizations

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2000年第2期23卷 222-230页

作者： Lim, KB Giesy, DP NASA Langley Res Ctr Hampton VA 23681 USA

Given measurement data, a nominal model, and a linear fractional transformation uncertainty structure with an allowance on unknown but bounded exogenous disturbances, easily computable tests for the existence of a model validating uncertainty. set are given. Under mild conditions, these tests are necessary and sufficient far the case of complex. nonrepeated, block-diagonal structure. For the more general case that includes repeated and/or real scalar uncertainties, the tests are only necessary but become sufficient if a collinearity condition is also satisfied. With the satisfaction of these tests, it is shown that a parameterization of all model validating sets of plant models is possible. The nea parameterization is used as a basis for a systematic way to construct or perform uncertainty tradeoff with model validating uncertainty sets that hare specific linear fractional transformation structure for use in robust control design and analysis. An illustrative example is given that includes a comparison of candidate model validating sets.

关键词： Closed Loop Transfer Function NASA Langley Research Center Spacecraft Guidance and Control Control System Design Optimal Control Singular Value Decomposition optimization algorithm White Noise Aeroservoelasticity Structural Dynamics

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Developments towards a fully automated AMS system

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NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 2000年 161卷 250-254页

作者： Steier, P Puchegger, S Golser, R Kutschera, W Priller, A Rom, W Wallner, A Wild, E Univ Vienna Inst Radiumforsch & Kernphys A-1090 Vienna Austria

The possibilities of computer-assisted and automated accelerator mass spectrometry (AMS) measurements were explored. The goal of these efforts is to develop fully automated procedures for "routine" measurements at the Vienna Environmental Research Accelerator (VERA), a dedicated 3-MV Pelletron tandem AMS facility. As a new tool for automatic tuning of the ion optics we developed a multi-dimensional optimization algorithm robust to noise, which was applied for C-14 and Be-10. The actual isotope ratio measurements are performed in a fully automated fashion and do not require the presence of an operator. Incoming data are evaluated online and the results can be accessed via Internet. The system was used for C-14,Be-10,Al-26 and I-129 measurements. (C) 2000 Elsevier Science B.V. All rights reserved.

关键词： automation AMS optimization algorithm noisy data beam tuning

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Response surface techniques for diffuser shape optimization

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AIAA JOURNAL 2000年第9期38卷 1512-1518页

作者： Madsen, JI Shyy, W Haftka, RT Univ Aalborg Inst Engn Mech DK-9220 Aalborg E Denmark Univ Florida Dept Aerosp Engn Mech & Engn Sci Gainesville FL 32611 USA

The design of incompressible diffusers for maximum pressure recovery is used to demonstrate the utility of response surface approximations for design optimization of flow devices. Two examples involving two and five design variables are treated, with the diffuser wall shapes described by polynomials and B-splines. In both erases monotonicity conditions drastically reduce the design space. In this irregularly shaped space, a pool of designs is selected by a D-optimality criterion and analyzed by a finite volume computational fluid dynamics (CFD) code. Quadratic polynomial response surfaces are then fitted to the pressure recovery coefficients. To improve the prediction accuracy, uncertain regressor terms and possible outlier design points are excluded based on statistical tests. A standard optimization algorithm is used to find the optimal diffuser design from the response surface approximations. The optimum diffusers exhibit minimal flow separation and yield similar wall shapes fur the two parameterizations. A main asset of the response surface optimization approach lies in the smoothing of noisy response functions. Therefore, the issue of numerical noise in CFD results based on the use of two different analysis codes is addressed.

关键词： Diffusers Shape optimization Numerical Modeling optimization algorithm Reynolds Averaged Navier Stokes Numerical Simulation Design of Experiments Static Pressure Surface Modeling Regression Analysis

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Mathematical Methods in Defense Analyses 3rd ed.

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丛书名： AIAA Education Series

2000年

作者： J.S. Przemieniecki

ISBN: (数字)9781600862137

ISBN: (纸本)9781563473975

This text presents the various mathematical methods used in military operations research in one easy-to-use reference volume. The reader will find the calculations necessary to analyze all aspects of defense operations, from weapon performance to combat modeling. The text is so clearly written and organized that even newcomers to the field will find it useful. Included with the text is an updated version of Defense Analyses Software, a compendium of software subroutines that allow the reader to compute numerical values for functions or tables derived in the text. Each subroutine is provided with a detailed reference to the equation from which it was derived to ensure that its intended application is consistent with the assumptions used in the derivation. The third edition has a new chapter on theater missile defense based on the concept of layered defense with different strategies of allocating defense interceptors against short- or mid-range ballistic missiles. This text is a highly recommended reference for defense analysts, researchers, and professionals entering the field of military operations research.

关键词： Aerodromes Aeronautics Air Forces Aircraft Collision Avoidance Systems Aircraft Operations and Technology Aircraft Radars Aircraft Tracking Aircrafts Airfields algorithms and Data Structures Anti-Ballistic Missile Anti-Submarine Warfare Applied Mathematics Artificial Intelligence Artillery Systems Aviation Aviation Communication Aviation Risk Aviation Safety Ballistic Missile Ballistics Combat Aircraft Communication System Computational Fluid Dynamics Computer Programming and Language Computing and Informatics Computing, Information, and Communication Cruise Missiles Data Science Elementary Algebra Energy Weapons Fluid Dynamics General Physics Guidance, Navigation, and Control Systems Guided Missiles Helicopters Mathematical Analysis Mathematical optimization Military Airbases Military Aircraft Military Aviation Military Science Military Technology Missile Defense Missile Guidance and Control Missile Systems, Dynamics and Technology Missiles Navigational Guidance Nuclear Weapons Numerical Analysis Operating Systems optimization algorithm Projectiles RADAR Rotorcrafts Search algorithm Software Systems Space Weapons Statistical Analysis Surface-to-Air Missile Systems Software Tracking and Positioning Systems Warfare and Military Operations Weapon Systems

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Euler/Navier-Stokes optimization of supersonic wing design eased on evolutionary algorithm

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AIAA JOURNAL 1999年第10期37卷 1327-1328页

作者： Oyama, A Obayashi, S Nakahashi, K Nakamura, T Tohoku Univ Dept Aeronaut & Space Engn Nakahashi Lab Sendai Miyagi 9808579 Japan Natl Aerosp Lab Dept Aeronaut & Space Engn Tokyo 1828522 Japan

An evolutionary algorithm (EA) coupled with a Euler/Navier-Stokes code has been applied to supersonic wing shape design. Aerodynamic evaluations are distributed to the processing elements (PE) of the numerical wind tunnel (NWT) to overcome the enormous computational time necessary for the optimization. The design yields both the minimum drag and the minimum volume wave drag in the given design space. The important features of supersonic wing design as compared with conventional transonic wing design are presented.

关键词： Evolutionary algorithm Aerodynamic Design Aerodynamic Performance Wing Root National Aerospace Laboratories optimization algorithm Aeroplane Camber Numerical optimization Spline Interpolation

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