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On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 2001年第6期49卷 1050-1059页

作者： Chakravarty, S Mittra, R Williams, NR Penn State Univ Electromagnet Commun Lab University Pk PA 16802 USA WL Gore & Associates Adv Electromagnet Prod Newark DE 19714 USA

In this paper, we present a procedure for synthesizing broad-band microwave absorbers incorporating frequency-selective surface (FSS) screens embedded in dielectric media using a binary coded genetic algorithm (GA) [1], [2].The GA simultaneously and optimally chooses the material in each layer, thickness of each layer, FSS screen periodicity in the x- and y-directions, its placement within the dielectric composite, and the FSS screen material, Additionally, the GA generates the cell structure of the FSS screen. The result is a multilayer composite that provides maximum absorption of both TE and TM waves for a prescribed range of frequencies and incident angles. This technique automatically places an upper bound on the total thickness of the composite.

关键词： frequency-selective surfaces genetic algorithm microgenetic algorithm microwave absorbers multilayer dielectrics

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Detection of stiffness reductions in laminated composite plates from their dynamic response using the microgenetic algorithm

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COMPUTATIONAL MECHANICS 2005年第4期36卷 320-330页

作者： Lee, SY Wooh, SC Remos Technol Inc Bedford MA 01730 USA Univ Granada Dept Struct Mech Politecn Fuentenueva E-18071 Granada Spain

In this study, we investigate a method to detect damage in a laminated composite structure by analyzing its dynamic response to impact loads. The combined finite element method (FEM) with seven degrees of freedom (DOF) and the advanced microgenetic algorithm described in this paper may allow us not only to detect the damaged elements but also to find their locations and the extent of damage. A high order shear deformation theory (HSDT) is used to predict the structural behavior and to detect damage of laminated composite plates. The effects of noise associated with the uncertainty of measurements due to the complex nature of composites are considered for [0/90](s) and [+/- 45](s) layup sequences. The results indicate that the new method is computationally efficient in characterizing damage for complex structures such as laminated composites.

关键词： inverse problem damage assessment dynamic response finite element method laminated composite plate microgenetic algorithm noise effect

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Optimization of multilayered ZnO whisker radar absorbing coatings using microgenetic algorithm

Optimization of multilayered ZnO whisker radar absorbing coa...

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Asia-Pacific Microwave Conference

作者： Chao, Kun Liu, Yunlin Yang, Rugui SW Jiaotong Univ Inst Electromagnet Chengdu 610031 Peoples R China

ISBN: (纸本)078039433X

An optimization technique based on the microgenetic algorithm (MGA) is presented for the design of multilayered radar absorbing materials made of tetrapod-shaped ZnO whisker in this paper. The fast optimization procedure is designed for a given maximum thickness and the optimization conditions are different in order to meet the practical requirements in the different frequency bands (the range of 2 similar to 18GHz). The effects of the thickness, the number of layers, and the restrained conditions on the optimization results are discussed in detail.

关键词： tetrapod-shaped ZnO whisker multilayered radar absorbing materials microgenetic algorithm

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Application of the hybrid algorithm combining ant colony optimization algorithm with microgenetic algorithm to the optimization of multilayered radar absorbing coating

Application of the hybrid algorithm combining ant colony opt...

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International Conference on Microwave and Millimeter Wave Technology

作者： Chao, Kun Liu, Yunlin Yang, Rugui SW Jiaotong Univ Inst Electromagnet Chengdu 610031 Peoples R China

ISBN: (纸本)9781424418794

A new optimization technique based on the hybrid algorithm combining ant colony optimization algorithm with microgenetic algorithm is presented for the design of multilayered radar absorbing materials. During the optimization procedure the optimization constrained conditions are different in order to meet the practical requirements in the different frequency bands between 2 GHz and 18 GHz, and the multilayered radar absorbing materials is also designed for a given maximum total thickness. The effects of the thickness and the number of layers on the optimization results are discussed in detail. The numerical results show that this new hybrid algorithm can obtain a better solution than that of the genetic algorithm.

关键词： multilayered radar absorbing materials hybrid algorithm ant colony optimization algorithm microgenetic algorithm

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Application of the Hybrid algorithm Combining Ant Colony Optimization algorithm with microgenetic algorithm to the Optimization of Multilayered Radar Absorbing Coating

Application of the Hybrid Algorithm Combining Ant Colony Opt...

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2008 International Conference on Microwave and Millimeter Wave Technology(2008国际微波毫米波技术会议)

作者： Kun Chao Yunlin Liu Rugui Yang Electromagnetics Institute Southwest Jiaotong University Chengdu 610031China

A new optimization technique based on the hybrid algorithm combining ant colony optimization algorithm with microgenetic algorithm is presented for the design of muitilayered radar absorbing materials. During the optimization procedure the optimization constrained conditions are different in order to meet the practical requirementsInthe different frequency bands between 2 GHz and 18 GHz,and the muitilayered radar absorbing materials is also designed for a given maximum total thickness. The effects of the thickness and the number of layers on the optimization results are discussedIndetail. The numerical results show thatThis new hybrid algorithm can obtain a better solution than that of the genetic algorithm.

关键词： Index Terms-multilayered radar absorbing materials hybrid algorithm ant colony optimization algorithm microgenetic algorithm

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Application of The microgenetic algorithm to The Optimization of Multilayered ZnO Whisker Radar Absorbing Coating

Application of The Microgenetic Algorithm to The Optimizatio...

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2006 7th International Symposium on Antennas, Propagation and EM Theory

作者： Kun Chao Yunlin Liu Rugui Yang Electromagnetics Institute Southwest Jiaotong Universit

An optimization method based on the microgenetic algorithm(MGA) is presented for the design of multilayered radar absorbing materials made of tetrapod-shaped ZnO *** optimization procedure is designed for a given thickness and the optimization conditions,which are different in order to meet the practical requirements in the different frequency bands(the range of 2～18GHz).The effects of the thickness,the number of layers,and the restrained conditions on the optimization results are discussed in detail.

关键词： microgenetic algorithm multilayered radar absorbing materials tetrapod-shaped ZnO whisker

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Delamination identification and response prediction in composites using bivariate Gamma function-based microgenetic algorithms

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INVERSE PROBLEMS IN SCIENCE AND ENGINEERING 2019年第8期27卷 1038-1056页

作者： Lee, Sang-Youl Andong Natl Univ Dept Civil Engn Andong Gyeongsangbuk D South Korea

This study deals with an identification of stiffness reduction and response predictions occurred by the delamination damage in laminated composite plates under impact loads. Combined bivariate Gamma function and microgenetic algorithms are developed to determine the crack region due to the delamination and predict future responses. The validity of the proposed method was verified using impact-induced data obtained from a two-dimensional delamination finite element model. Examples indicated that the proposed approach is a feasible and advantageous method through which future dynamic responses can be predicted and the distribution of the degraded stiffness of laminated composite structures can be inspected for different measuring locations and fibre angles.

关键词： Delamination crack detection 2D-composite damage model bivariate Gamma function microgenetic algorithm response prediction

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An adaptive overcurrent protection system applied to distribution systems

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COMPUTERS & ELECTRICAL ENGINEERING 2020年第0期81卷 106545-000页

作者： Nascimento, Jamile P. Brito, Nubia S. D. Souza, Benemar A. Univ Fed Campina Grande Dept Elect Engn Campina Grande Paraiba Brazil

In this paper, an innovative adaptive directional overcurrent protection system for electric power distribution systems with respect to distributed generation is proposed. The proposed system supervises network topology based on the monitoring functionality of numerical relays. The system detects any changes in the configuration and recalculates the directional overcurrent protection settings by using a microgenetic algorithm. The proposed system was evaluated for several operating scenarios and insertion levels of distributed generation, and then compared with both conventional and adaptive protection systems by means of a traditional genetic algorithm. The results showed that the performance of the proposed system is superior to the other two methods in terms of both speed and selectivity. This shows that this is a promising proposal for the protection of modern electric power distribution systems. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Adaptive protection system Distributed generation Directional overcurrent relay microgenetic algorithm

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STUDY AND OPTIMIZATION OF PARAMETERS THAT INFLUENCE THERMOHYDRAULIC PERFORMANCE OF FLOW IN A DUCT WITH TWISTED TAPE INSERT IN CONJUNCTION WITH DIMPLES OVER ITS SURFACE

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JOURNAL OF ENHANCED HEAT TRANSFER 2016年第6期23卷 499-512页

作者： Kishore, P. S. Reddy, V. Koteswara Dheeraj, M. Prem Kumar, K. Pavan Andhra Univ Coll Engn Dept Mech Engn Visakhapatnam 530003 Andhra Pradesh India Govt Polytech Dept Mech Engn Vizianagaram 535002 India Anil Neerukonda Inst Technol & Sci Dept Mech Engn Visakhapatnam 531162 Andhra Pradesh India Gayatri Vidhya Parishad Tech Campus Dept Mech Engn Visakhapatnam 530045 Andhra Pradesh India

Transport of energy across fluids is facilitated within a device called a heat exchanger. The ability to exchange thermal energy within this device is further enhanced by applying various passive and active techniques. In this work, a group of passive techniques were merged to improve the performance of a heat exchanger. A square duct is considered to represent the tube of a heat exchanger as water flows inside the duct. A spiral insert is placed within a square duct and two opposite walls of the duct are dented to impinge hemispherical dimples. The effect of a spiral insert and dimples on heat exchanger performance was observed in ANSYS at various configurations of dimples by keeping the spiral insert unaltered. This study is further extended to analyze and predict the best dimple configuration using optimization techniques such as genetic algorithms (GAs) and microgenetic algorithms (mu GAs). Using a GA, the best thermohydraulic performance is observed when spacing between the dimples is 7.5 mm, 5.5 mm, and 7.5 mm from the edge of the duct surface. The result suggested by a mu GA is also in close agreement with the result of the GA. According to the mu GA, the best thermohydraulic performance is predicted at 7.4 mm, 5.6 mm, and 7.4 mm from the edge of the duct surface.

关键词： square duct with dimples twisted tape insert thermal hydraulic performance factor Nusselt number dimple pattern dimple size genetic algorithm microgenetic algorithm optimization laminar flow heat transfer augmentation

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Optimization of composite sandwich cylinders for underwater vehicle application

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COMPOSITE STRUCTURES 2013年第Feb.期96卷 691-697页

作者： Lee, Gyeong-Chan Kweon, Jin-Hwe Choi, Jin-Ho Gyeongsang Natl Univ Dept Aerosp Engn Res Ctr Aircraft Parts Technol Jinju 660701 Gyeognam South Korea Gyeongsang Natl Univ Sch Mech Engn Res Ctr Aircraft Parts Technol Jinju 660701 Gyeognam South Korea

This study aims to use optimization to increase the design load of composite sandwich cylinders under external hydrostatic pressure. Unlike other studies that only consider buckling, this study took into account both buckling and material failure. *** was used for the finite element analysis, while a micro-genetic algorithm was used for the optimization. The finite element model was validated by comparison with the experiment results, and the result of the optimization using the finite element method was validated by comparison with the result of the feasible region analysis. Based on the optimization, as the thickness of the sandwich increases, the buckling load becomes larger than the material failure. Consequently, the optimum point is determined by material failure. The current results suggest that both the buckling and the static material failure should be considered in the design of the composite sandwich cylinder. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Sandwich Composite cylinders Optimization microgenetic algorithm

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