• Title/Summary/Keyword: Evolution strategy

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Sliding Mode Control for Robot Manipulator Usin Evolution Strategy (Evolution Strategy를 이용한 로봇 매니퓰레이터의 슬라이딩 모드 제어)

  • 김현식;박진현;최영규
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.379-382
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    • 1996
  • Evolution Strategy is used as an effective search algorithm in optimization problems and Sliding Mode Control is well known as a robust control algorithm. In this paper, we propose a Sliding Mode Control Method for robot manipulator using Evolution Strategy. Evolution Strategy is used to estimate Sliding Mode Control Parameters such as sliding surface gradient, continuous function boundary layer, unknown plant parameters and switching gain. Experimental results show the proposed control scheme has accurate and robust performances with effective search ability.

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A variable PID controller for robots using evolution strategy and neural network (Evolution strategy와 신경회로망에 의한 로봇의 가변 PID제어기)

  • 최상구;김현식;최영규
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1585-1588
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    • 1997
  • In this paper, divide total workspace of robot manipulator into several subspaces and construct PID controller ineach subspace. Using EvolutionSTrategy we optimize the gains of PID controller in each subspace. But the gains may have a large difference on the boundary of subspaces, which can cause bad oscillatory performance. So we use Aritificial Neural Network to have continuous gain curves htrough the entire subspaces. Simualtion results show that the proposed method is quite useful.

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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
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    • 2009.08a
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    • pp.221-224
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    • 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.

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BLDC Motor Position Control by Variable Structure Control with Evolution Strategy (Evolution Strategy를 이용한 가변구조제어기의 BLDC motor 위치제어)

  • Kim, Hyun-Sik;Park, Jin-Hyun;Choi, Young-Kiu
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.655-657
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    • 1995
  • Variable Structure Controller is well known to be a robust controller. Recently, Evolution Strategy is used as a effective search algorithm. In this paper, we propose a Variable Structure Controller combined with Evolution Strategy. Evolution Strategy is used to estimate the unknown parameters, the control gain and the thickness of saturation function boundary layer of Variable Structure Controller. From the experiment, we found the proposed Variable Structure Controller shows accurate tracking ability and robust performance in the BLOC motor position control system.

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Development of an Effective Strategy to Teach Evolution

  • Ha, Min-Su;Cha, Hee-Young
    • Journal of The Korean Association For Science Education
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    • v.31 no.3
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    • pp.440-454
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    • 2011
  • This study proposes a new instructional strategy and corresponding materials designed from various alternative frameworks to help students understand evolution as a biologically acceptable theory. Biology teachers have normally taught the evolutionary mechanism by means of comparing Lamarckism with natural selection. In this study, a new instructional strategy in which the Lamarckian explanation is first excluded because Lamarckism is known to be subsumed in a learner's cognitive structure as a strong preconception of evolution is suggested for teaching evolution. After mutation theory is introduced, Darwinism including natural selection is explained separately during the next class hour. Corresponding instructional materials that aid student understanding of the evolutionary mechanism were developed using recently published articles on human genetic traits as scientific evolutionary evidence instead of the traditional evolutionary subject matter, giraffe neck. Evolutionary evidence from human genetic traits allows students to exclude anthropocentric thoughts effectively and raise concern for the phenomenon of evolution positively. The administered instructional strategy and materials in this research improved student conception, concern, and belief of evolution and it is believed that they helped students understand the evolutionary mechanism effectively.

A Study on Auto-Tuning of Robust Pill using Evolution Strategy (Evolution Strategy를 이용한 강인한 PID 자동동조에 관한 연구)

  • Bae, Geun-Shin;Kim, Seong-Hoon;Lee, Young-Jin;Lee, Kwon-Soon
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1110-1112
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    • 1996
  • In this paper, we propose a new approach for robust auto-tuning of PID gains using Evolution Strategy. Evolution Strategy is searching algorithm which imitate the principles of natural evolution as a method to solve parameter optimization problem and easy to use without any other special mathematical theory. Through the simulation of the speed control of a series-connected de motor, our proposed method shows more improved performance by finding optimal parameters of PID controller than a classical Ziegler-Nichols method.

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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
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    • v.59 no.4
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    • pp.768-773
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    • 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
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    • v.60 no.4
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    • pp.811-816
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    • 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.

Feasibility Test for Hydraulic Conductivity Characterization of Small Basin-Scale Aquifers Based on Geostatistical Evolution Strategy Using Naturally Imposed Hydraulic Stress (자연 수리자극을 이용한 소유역 규모 대수층 수리전도도 특성화: 지구통계 진화전략 역산해석 기법의 적용 가능성 시험)

  • Park, Eungyu
    • Journal of Soil and Groundwater Environment
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    • v.25 no.4
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    • pp.87-97
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    • 2020
  • In this study, the applicability of the geostatistical evolution strategy as an inverse analysis method of estimating hydraulic properties of small-scale basin was tested. The geostatistical evolution strategy is a type of data assimilation method that can effectively estimate aquifer hydraulic conductivity by combining a global optimization model of the evolution strategy and a local optimization model of the ensemble Kalman filtering. In the applicability test, the geometry, hydraulic boundary conditions, and the distribution of groundwater monitoring wells of Hanlim-Eup were employed. On the other hand, a synthetic hydraulic conductivity distribution was generated and used as the reference property for ease of estimation quality assessment. In the estimations, two different cases were tested where, in Case I, both groundwater levels and hydraulic conductivity measurements were assumed to be available, and only the groundwater levels were available, in Case II. In both cases, the reference and estimated hydraulic conductivity fields were found to show reasonable similarity, even though the prior information for estimation was not accurate. The ability to estimate hydraulic conductivity without accurate prior information suggests that this method can be used effectively to estimate mathematical properties in real-world cases, many of which little prior information is available for the aquifer conditions.

Homogeneous Magnet Design Technique Using Evolution Strategy (진화알고리즘을 이용한 균즐자장 발생용 마그네트의 최적설계)

  • 송명곤;김동훈;이상진
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.114-118
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    • 2002
  • We introduce a design technique for homogeneous magnets using evolution strategy. The method has several advantages over existing techniques including: it allows complete flexibility in geometric constraints on the shape of both the coil and the homogeneous volume; it guarantees a globally optimal solution, and it automatically searches the minimum number of coils that satisfies given constraints.