• Title/Summary/Keyword: evolution program

Search Result 373, Processing Time 0.028 seconds

A study on an optimal design for a dual-band patch antenna with a shorting pin using the evolution strategy (진화 알고리즘을 이용한 단락핀이 있는 이중대역 패치 안테나 최적 설계 연구)

  • Ko, Jae-Hyeong;Kwon, So-Hyun;Kim, Hyeong-Seok
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 2009.08a
    • /
    • pp.221-224
    • /
    • 2009
  • In this paper, we deal with the development of an optimal design program for a dual-band of 0.92 GHz and 2.45 GHz with shorting pin and slot by using evolution strategy. the optimal shorting pin, coaxial feed and H-shaped patch are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The resonance frequencies of the dual-band antenna yielded by the optimal design program are 0.92 GHz and 2.45 GHz that show a good agreement to the design target values.

  • PDF

Analyzing the Effect of Argumentation Program for Improving Teachers' Conceptions of Evolution (교사들의 진화 개념 이해 향상을 위한 논변활동 프로그램 효과 분석)

  • Kwon, Jieun;Cha, Heeyoung
    • Journal of The Korean Association For Science Education
    • /
    • v.35 no.4
    • /
    • pp.691-707
    • /
    • 2015
  • This study aims to develop biology teachers' education program based on argumentation activity about core concepts of evolution and to analyze the characteristics of core concepts of evolution learned during the program. The eight core concepts of evolution in this study were variation, heritability of variation, competition, natural selection, adaptation, differential reproductive rate of individuals, changes in genetic pool within a population, and macroevolution. The performances of teachers participating in the program were compared before and after argumentation activities; consisting of seven sessions on the eight core concepts of evolution. The process of the program was specially designed by learning cycle model for teacher education, consisting of seven phases: identification of the task, production of a tentative argument, small group's written argument, share arguments with the other groups, reflective discussion, final written argument, and organization by an instructor. Participants in the study were two pre-service biology teachers and four in-service biology teachers. The results suggest that biology teachers reduced the teleological explanation for biological evolution and improve its adequacy after the intervention. Teachers lacked the opportunity to discuss variation, heritability of variation, competition, and macroevolution because science textbooks lack information on the concepts of biological evolution. The results of this study suggest that because the argumentation program developed for teachers helps to improve understanding the concepts of evolution and to reduce inadequate conceptions in biology, teacher education programs using argumentation activity and eight core concepts of evolution will play a role for efficient evolution education for biology teachers.

Development of a Program to Predict Recrystallizaion Behavior in the Hot Forming Process and Its Application (고온 성형에 있어서 재결정 거동 예측 프로그램 개발 및 적용)

  • Lee K. O.;Kang J. H.;Kang S. S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2001.05a
    • /
    • pp.136-142
    • /
    • 2001
  • Recently, a much amount of attention has been paid not only to produce products with precise dimensional accuracy, but also to predict and control the microstructural evolution and mechanical properties of parts. Especially, to do the latter through computer simulation, the history of states factors influencing on these evolution such as temperature, strain, strain rate etc., should be calculated and a appropriate mathematical models for the prediction of microstructural evolution must be developed. Thus, in this study thermo-viscoplastic finite element program including the model for predicting microstructural has been developed. Also for the verification of developed program warm forging process for the rotor pole was simulated and the comparison between the results calculated and ones in the literature was made.

  • PDF

A Study on an Optimal Design of a Triple-band PIFA using the Evolution Strategy (진화 알고리즘을 이용한 삼중대역 PIFA 최적 설계에 관한 연구)

  • Ko, Jae-Hyeong;Kim, Koon-Tae;Kim, Kyong-Ah;Kim, Hyeong-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.59 no.4
    • /
    • pp.768-773
    • /
    • 2010
  • In this paper, we study on an optimal design of a triple-band PIFA (Planar Inverted-F Antenna) of 433 MHz, 912 MHz and 2.45 GHz by using evolution strategy. Generally, the resonant frequency of the PIFA is determined by the width and length of a U-type slot used. However the resonant frequencies of the multiple U slots are varied by the mutual effect of the slots. Thus the optimal width and length of U-type slots are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The resonant frequencies of initial model are 439.5 MHz, 981.5 MHz and 2.563 GHz. However, the resonant frequencies of the triple-band PIFA yielded by the optimal design program are 430.5 MHz, 907 MHz and 2.4515 GHz. Measured resonant frequencies are 433.5 MHz, 905.5 MHz and 2.454GHz, which show a good agreement with the simulation results.

An Optimal Design of a 19.05GHz High Gain 4X4 Array Antenna Using the Evolution Strategy (진화전략 기법을 이용한 19.05GHz 고이득 4X4 배열 안테나 최적설계)

  • Kim, Koon-Tae;Kwon, So-Hyun;Ko, Jae-Hyeong;Kim, Hyeong-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.60 no.4
    • /
    • pp.811-816
    • /
    • 2011
  • In this paper, we propose a optimal design using the Evolution Strategy of a high gain $4\times4$ array antenna that have the resonant frequency of a 19.05GHz with 18.86GHz~19.26GHz bandwidth. The proposed array antenna structure is designed to be allocated equally electric power by microstrip patch power splitter. Thus the optimal array antenna with power splitter are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The simulation result of $4\times4$ array antenna is confirmed that the Gain is 19.36 dBi at resonance frequency 19.05GHz.

Development of an Optimal Design Program for a Triple-Band PIFA Using the Evolution Strategy (진화 알고리즘을 이용한 삼중 대역 PIFA 최적 설계 프로그램의 구현)

  • Ko, Jae-Hyeong;Kim, Koon-Tae;Kim, Dong-Hun;Kim, Hyeong-Seok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.20 no.8
    • /
    • pp.746-752
    • /
    • 2009
  • In this paper, we deal with the development of an optimal design program for a triple-band PTFA(Planar Inverted-F Antenna) of 433 MHz, 912 MHz and 2.45 GHz by using evolution strategy. Generally, the resonance frequency of the PIFA is determined by the width and length of a U-type slot used. However the resonance frequencies of the multiple U slots are varied by the mutual effect of the slots. Thus the optimal width and length of U-type slots are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The resonance frequencies of the triple-band PIFA yielded by the optimal design program are 430 MHz, 910.5 MHz and 2.458 GHz that show a good agreement to the design target values.

Synthesis of GBSB-based Neural Associative Memories Using Evolution Program

  • Hyuk Cho;Park, Joo-young;Moon, Jong-sub;Park, Dai-hee
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.11 no.7
    • /
    • pp.680-688
    • /
    • 2001
  • In this paper, we propose a reliable method for searching the optimally performing generalized brain-state-in-a-box (GBSB) neural associative memory using an evolution program (EP) given a set of prototype patterns to be stored as stable equilibrium points. First, we exploit some qualitative guidelines necessary to synthesize the GBSB model. Next, we parameterize the solution space utilizing the limited number of parameters to represent the solution space. Then, we recast the synthesis of GBSB neural associative memories as two constrained optimization problems, which are equivalent to finding a solution to the original synthesis problem. Finally, we employ an evolution program (EP), which enables us to find an optimal set of parameters related to the size of domains of attraction (DOA) for prototype patterns. The validity of this approach is illustrated by a design example and computer simulations.

  • PDF

Fuzzy Clustering using Evolution Program (진화 프로그램을 이용한 퍼지 클러스터링)

  • 정창호;임영희;박주영;박대희
    • Journal of KIISE:Software and Applications
    • /
    • v.26 no.1
    • /
    • pp.130-130
    • /
    • 1999
  • In this paper, we propose a novel design method for improving performance of existing FCM-type clustering algorithms. First, we define the performance measure which focuses on bothcompactness and separation of clusters. Next, we optimize this measure using evolution program.Especially the proposed method has following merits: ① using evolution program, it solves suchproblems as initialization, number of clusters, and convergence to local optimum ② it reduces searchspace and improves convergence speed of algorithm since it represents chromosome with possiblepotential centers which are selected possible candidates of centers by density measure ③ it improvesperformance of clustering algorithm with the performance index which embedded both compactnessand separation Properties ④ it is robust to noise data since it minimizes its effect on center search.

An Affordable Implementation of Kalman Filter by Eliminating the Explicit Temporal Evolution of the Background Error Covariance Matrix (칼만필터의 자료동화 활용을 위한 배경오차 공분산의 명시적 시간 진전 제거)

  • Lim, Gyu-Ho;Suh, Ae-Sook;Ha, Ji-Hyun
    • Atmosphere
    • /
    • v.23 no.1
    • /
    • pp.33-37
    • /
    • 2013
  • In meteorology, exploitation of Kalman filter as a data assimilation system is virtually impossible due to simultaneous requirements of adjoint model and large computer resource. The other substitute of utilizing ensemble Kalman filter is only affordable by compensating an enormous usage of computing resource. Furthermore, the latter employs ensemble integration sets for evolving the background error covariance matrix by compensating the dynamical feature of the temporal evolution of weather conditions. We propose a new implementation method that works without the adjoint model by utilizing the explicit expression of the background error covariance matrix in backward evolution. It will also break a barrier in the evolution of the covariance matrix. The method may be applied with a slight modification to the real time assimilation or the retrospective analysis.