• Title/Summary/Keyword: 다목적

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Multi-Objective Integrated Optimal Design of Hybrid Structure-Damper System Satisfying Target Reliability (목표신뢰성을 만족하는 구조물-감쇠기 복합시스템의 다목적 통합최적설계)

  • Ok, Seung-Yong;Park, Kwan-Soon;Song, Jun-Ho;Koh, Hyun-Moo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.2
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    • pp.9-22
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    • 2008
  • This paper presents an integrated optimal design technique of a hybrid structure-damper system for improving the seismic performance of the structure. The proposed technique corresponds to the optimal distribution of the stiffness and dampers. The multi-objective optimization technique is introduced to deal with the optimal design problem of the hybrid system, which is reformulated into the multi-objective optimization problem with a constraint of target reliability in an efficient manner. An illustrative example shows that the proposed technique can provide a set of Pareto optimal solutions embracing the solutions obtained by the conventional sequential design method and single-objective optimization method based on weighted summation scheme. Based on the stiffness and damping capacities, three representative designs are selected among the Pareto optimal solutions and their seismic performances are investigated through the parametric studies on the dynamic characteristics of the seismic events. The comparative results demonstrate that the proposed approach can be efficiently applied to the optimal design problem for improving the seismic performance of the structure.

Analysis on the Orbit Accuracy of KOMPSAT-5 (다목적실용위성 5호 궤도정밀도 분석)

  • Jung, Okchul;Chung, Deawon;Kim, Eunkyou;Yoon, Jaecheol;Hwang, Yoola
    • Aerospace Engineering and Technology
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    • v.13 no.2
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    • pp.108-114
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    • 2014
  • This paper describes the orbit accuracy of KOMPSAT-5, which has been in normal operations since the launch on Aug. 22, 2013. The analysis on the various GPS related data and the different methodologies for orbit estimation are carried out and compared with each other. The accuracy of precise orbit is confirmed to be 12.8cm($1{\sigma}$) on average using data from the in-flight dual frequency GPS receiver, GPS precise ephemeris, and IGS stations. In addition, the orbit estimation using single frequency GPS receiver provides the orbit solution around 2m level. And, the accuracy of orbit processing is 5m using on-board navigation solution, which has about 10m accuracy.

Impact Performance Optimization of Auto-Sensing Breaker using Multi-objective Function (다목적함수를 이용한 지능형 브레이커의 타격성능 최적화)

  • Lee, Dae-Hee;Noh, Dae-Kyung;Park, Sung-Su;Lee, Geun-Ho;Kang, Young-Ky;Cho, Jae-Sang;Jang, Joo-Sup
    • Journal of the Korea Society for Simulation
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    • v.26 no.4
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    • pp.11-21
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    • 2017
  • This paper discusses the design parameter sensitivity analysis and multi-objective function optimization for improving the impact performance of an auto-sensing breaker based on the analytical model of the same, which secured reliability in a previous research. The study aims to improve both impact power and stability by complementing the existing research that only improved the impact power. The study sequence is as follows: first, the analysis scenarios for the accurate sensitivity analysis and optimization are set up. Second, the sensitivity of the design parameter of the auto-sensing breaker is analyzed, and the variables with high sensitivity are extracted. Third, the extracted variables are used to optimize the multi-objective functions, and the optimized performance is compared with the initial performance to see how the impact performance on the existing auto-sensing breaker has improved. This study is based on domestic technology, and will allow the development of products with a better blowing performance than their existing overseas counterparts.