A methodology for computationally efficient simulation-driven design of microstrip antenna subarrays is presented. Our approach takes into account the effect of the feed (here, a corporate network) on the subarray sid...
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ISBN:
(纸本)9788393152520
A methodology for computationally efficient simulation-driven design of microstrip antenna subarrays is presented. Our approach takes into account the effect of the feed (here, a corporate network) on the subarray side-lobe level and allows adjustment of both radiation and reflection responses of the structure under design within a single automated process. This process is realized as surrogate-based optimization that produces designs meeting requirements imposed on both radiation and reflection at the cost of just a few simulations of the high-fidelity model of the structure of interest. Selected optimal designs of microstrip subarrays operating at 10 GHz have been manufactured and validated by measuring their radiation patterns and reflection coefficients.
In this paper, computationally efficient design optimization of a miniaturized dual-band microstrip branch-line coupler is presented. Our optimization approach relies on suitably extracted features of a highly nonline...
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ISBN:
(纸本)9781479968121
In this paper, computationally efficient design optimization of a miniaturized dual-band microstrip branch-line coupler is presented. Our optimization approach relies on suitably extracted features of a highly nonlinear response of the coupler structure under design. By formulating the design objectives in terms of the feature point locations, we carry out iterative optimization of the linear model of the features, embedded in the trust-region framework. Due to only slightly nonlinear dependence of the features on the designable parameters of the circuit, the optimized design satisfying prescribed performance requirements is obtained at the low computational cost of only 24 high-fidelity EM simulations of the structure.
Genetic algorithm(GA) is a powerful tool for the analysis of the mechanism and dynamic responses of the fermentation process,and for process optimization and automatic *** this research,the structured and unstructured...
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Aiming at the problem that the steering tires were seriously wore on a 8x8 in-wheel motor driven vehicle, a model of McPherson suspension and double-front axle steering system was established by ADAMS. Considering the...
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ISBN:
(纸本)9781479942398
Aiming at the problem that the steering tires were seriously wore on a 8x8 in-wheel motor driven vehicle, a model of McPherson suspension and double-front axle steering system was established by ADAMS. Considering the influences on steering errors caused by wheel jump and using parametric analysis method, the error accumulation between theoretical value and actual value of steering angle, and the sum of variation of toe-in angle were added up for forming the objective optimization function. The simulation and optimization results indicate that this design improves the steering performance and reduces the motion interference between the suspension and steering linkage.
Stochasticity, noisiness, and ergodicity are the key concepts behind many natural processes and its modeling is an important part of their implementation. There is a handful of soft-computing methods that are directly...
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Stochasticity, noisiness, and ergodicity are the key concepts behind many natural processes and its modeling is an important part of their implementation. There is a handful of soft-computing methods that are directly inspired by nature or stochastic natural processes. The implementation of such a nature-inspired optimization and search methods usually depends on streams of integer and floating point numbers generated in course of their execution. The pseudo-random numbers are utilized for in-silico emulation of probability-driven natural processes such as arbitrary modification of genetic information (mutation, crossover), partner selection, and survival of the fittest (selection, migration) and environmental effects (small random changes in motion direction and velocity). Deterministic chaos is a well known mathematical concept that can be used to generate sequences of seemingly random real numbers within selected interval in a predictable and well controllable way. In the past, it has been used as a basis for various pseudo-random number generators (PRNGs) with interesting properties. This work provides an empirical comparison of the behavior of selected nature-inspired optimization algorithms using different PRNGs and chaotic systems as sources of stochasticity.
Computationally efficient and reliable procedure for antenna design using electromagnetic (EM) simulation models is proposed. Our approach exploits trust-region-based gradient search and adjoint sensitivities for fast...
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ISBN:
(纸本)9781479936625
Computationally efficient and reliable procedure for antenna design using electromagnetic (EM) simulation models is proposed. Our approach exploits trust-region-based gradient search and adjoint sensitivities for fast derivative evaluation. Derivative data allows for constructing the approximation model of the antenna responses. Computational cost of the design process can be further reduced by utilizing variable-fidelity EM simulations and adaptive procedure of switching between EM antenna models of increasing accuracy. We demonstrated the proposed methodology using a dielectric resonator antenna. The overall design cost using the proposed approach corresponds to less than eight antenna simulations at fine discretization and it is 50 percent lower than direct high-fidelity model optimization (also exploiting adjoint sensitivities).
The proceedings contain 14 papers. The special focus in this conference is on Solving Computationally Expensive Engineering Problems. The topics include: Surrogate-based and one-shot optimization methods for PDE-const...
ISBN:
(纸本)9783319089843
The proceedings contain 14 papers. The special focus in this conference is on Solving Computationally Expensive Engineering Problems. The topics include: Surrogate-based and one-shot optimization methods for PDE-constrained problems with an application in climate models;shape-preserving response prediction for surrogate modeling and engineering design optimization;nested space mapping technique for design and optimization of complex microwave structures with enhanced functionality;automated low-fidelity model setup for surrogate-based aerodynamic optimization;design space reduction for expedited multi-objective design optimization of antennas in highly dimensional spaces;numerically efficient approach to simulation-driven design of planar microstrip antenna arrays by means of surrogate-based optimization;optimal design of computationally expensive EM-based systems;atomistic surrogate-based optimization for simulation-driven design of computationally expensive microwave circuits with compact footprints;knowledge based three-step modeling strategy exploiting artificial neural network;large-scale global optimization via swarm intelligence;evolutionary clustering for synthetic aperture radar images;automated classification of airborne laser scanning point clouds;a novel approach to the common due-date problem on single and parallel machines and on gaussian process NARX models and their higher-order frequency response functions.
Accurate high-fidelity Computational Fluid Dynamics (CFD) models may be computationally too expensive for simulation-driven design optimization. Variable-fidelity optimization algorithms have been utilized to reduce h...
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ISBN:
(数字)9781624102882
ISBN:
(纸本)9781624102882
Accurate high-fidelity Computational Fluid Dynamics (CFD) models may be computationally too expensive for simulation-driven design optimization. Variable-fidelity optimization algorithms have been utilized to reduce high CPU-cost related to the design process solely based on accurate CFD models. The most critical components of such algorithms are the low-fidelity models. Typically, the low-fidelity models employ the same CFD solver as the high-fidelity one, but with reduced discretization density and reduced number of flow solver iterations. The performance of the optimization algorithm strongly depends on the quality of the low-fidelity models. The low-fidelity model grid setup has been based on hands-on parametric studies. In this work, an automated low-fidelity CFD model setup technique is developed. The model setup task is defined as a constrained nonlinear optimization problem and suitable grid and flow solver parameters are obtained numerically. Comparison of the standard and the proposed approach is carried out in the context of aerodynamic design of transonic airfoils. Two variable-fidelity optimization algorithms are used in the study. One algorithm is based on a single corrected low-fidelity CFD model and the other utilizes a family of such models. The results suggest that the automated model generation may lead to significant computational savings of the CFDbased aerodynamic design process.
In this paper, computationally efficient multi-objective optimization of antenna structures is discussed. As a design case, we consider a multi-parameter planar Yagi-Uda antenna structure, featuring a driven element, ...
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Many problems in dynamic data drivenmodeling deals with distributed rather than lumped observations. In this paper, we show that the Monge-Kantorovich optimal transport theory provides a unifying framework to tackle ...
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ISBN:
(纸本)9781479932740
Many problems in dynamic data drivenmodeling deals with distributed rather than lumped observations. In this paper, we show that the Monge-Kantorovich optimal transport theory provides a unifying framework to tackle such problems in the systems-control parlance. Specifically, given distributional measurements at arbitrary instances of measurement availability, we show how to derive dynamical systems that interpolate the observed distributions along the geodesics. We demonstrate the framework in the context of three specific problems: (i) finding a feedback control to track observed ensembles over finite-horizon, (ii) finding a model whose prediction matches the observed distributional data, and (iii) refining a baseline model that results a distribution-level prediction-observation mismatch. We emphasize how the three problems can be posed as variants of the optimal transport problem, but lead to different types of numerical methods.
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