• 제목/요약/키워드: ESO

검색결과 113건 처리시간 0.032초

자동차 후드의 정강성을 고려한 위상 최적화 (Topology Optimization of a Vehicle's Hood Considering Static Stiffness)

  • 한석영;최상혁;박재용;황준성;김민수
    • 한국공작기계학회논문집
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    • 제16권1호
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    • pp.69-74
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    • 2007
  • Topology optimization of the inner reinforcement for a vehicle's hood has been performed by evolutionary structural optimization(ESO) using a smoothing scheme. The purpose of this study is to obtain optimal topology of the inner reinforcement for a vehicle's hood considering the static stiffness of bending and torsion simultaneously. To do this, the multiobjective optimization technique was implemented. Optimal topologies were obtained by the ESO method. From several combinations of weighting factors, a Pareto-optimal solution was obtained. Also, a smoothing scheme was implemented to suppress the checkerboard pattern in the procedure of topology optimization. It is concluded that ESO method with a smoothing scheme is effectively applied to topology optimization of the inner reinforcement of a vehicle's hood considering the static stiffness of bending and torsion.

A study of a tidally interacting BCD pair, ESO 435-IG20 and ESO 435-IG16

  • Kim, Jinhyub;Sung, Eon-Chang;Chung, Aeree
    • 천문학회보
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    • 제39권1호
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    • pp.44.1-44.1
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    • 2014
  • Blue Compact Dwarf galaxies (BCDs) are systems that recently have experienced the burst of star formation. As one of the causes for active star formation in BCDs, tidal interaction (fly-by or merger) has been suggested. A pair of BCDs, ESO 435-IG20 and ESO 435-IG16 are separated by only ~80 kpc in projection at a similar redshift (at a ~9 Mpc distance), and hence suspected to be a good example of such case. Intergalactic atomic hydrogen gas found in HIPASS survey is also suggestive of this hypothesis. In this study, we probe the HI morphology and kinematics of this BCD pair using ATCA HI data to study detailed interaction history. We investigate various star formation tracers of the pair to study how responsible tidal interaction is for triggering star formation in these galaxies.

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열 컴플라이언트 메커니즘의 위상 최적설계 (Topology Optimization of Thermal Actuated Compliant Mechanisms)

  • 이원구;임민규;박재용;한석영
    • 한국생산제조학회지
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    • 제19권4호
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    • pp.434-439
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    • 2010
  • A compliant mechanism is a mechanism that produces its motion by the flexibility of some or all of its members when input force or thermal load is applied. Whereas the topology optimizations based on homogenization and SIMP parameterization have been successfully applied for compliant mechanism design, ESO approach has been hardly considered yet for the optimization of these types of systems. In this paper, traditional ESO method is adopted to achieve the optimum design of a compliant mechanism for thermal load, since AESO method cannot consider the effect of both heat conduction and convection. Sensitivity number, a criterion for element removal in traditional ESO, was newly defined for input thermal loading. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.

점진적 구조 최적화 기법을 응용한 철근콘크리트 부재의 배근 (A Study on the Reinforcement of Reinforced Concrete using Evolutionary Structural Optimization)

  • 윤성수;이정재
    • 한국농공학회지
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    • 제44권2호
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    • pp.127-135
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    • 2002
  • Due to the fact that the design of a reinforced concrete structure changes in accordance with its shape and assigned load, total automation of the design system has not been achieved. For instance, since there is no general rule about setting up reinforcing steel quantity and arrangement location, it is simply not feasible to automatically decide the reinforcing arrangement location. In this study, the ESO(evolutionary structural optimization) technique and its related issues will be discussed. The ESO techniques is determined the reasonable load path which is traveling of load between in-flow and out-flow at a concrete structure using numerical analysis. And the results applied to the steel arrangement in reinforced concrete structures. The optimal algorithm, which determines the terminal criteria during ESO process, has been updated by using the obtained results. And the load path within the member has been determined automatically.

The Early Chemical Enrichment Histories of Two Sculptor Group Dwarf Galaxies as Revealed by RR Lyrae Variables

  • Yang, Soung-Chul;Wagner-Kaiser, Rachel;Sarajedini, Ata;Kim, Sang Chul;Kyeong, Jaemann
    • 천문학회보
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    • 제39권1호
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    • pp.39.1-39.1
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    • 2014
  • We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys (ACS) onboard the Hubble Space Telescope (HST), we have identified a sample of RR Lyrae candidates in both dTrans galaxies [219 RRab (RR0) and 13 RRc (RR1) variables in ESO294-G010; 225 RRab and 44 RRc stars in ESO410-G005]. The metallicities of the individual RRab stars are calculated via the period-amplitude-[Fe/H] relation derived by Alcock et al. This yields mean metallicities of <[Fe/H]>_{ESO294} = -1.77 +/- 0.03 and <[Fe/H]>_{ESO410} = -1.64+/- 0.03. The RRL metallicity distribution functions (MDFs) are investigated further via simple chemical evolution models; these reveal the relics of the early chemical enrichment processes for these two dTrans galaxies. In the case of both galaxies, the shapes of the RRL MDFs are well-described by pre-enrichment models. This suggests two possible channels for the early chemical evolution for these Sculptor group dTrans galaxies: 1) The ancient stellar populations of our target dwarf galaxies might have formed from the star forming gas which was already enriched through "prompt initial enrichment" or an "initial nucleosynthetic spike" from the very first massive stars, or 2) this pre-enrichment state might have been achieved by the end products from more evolved systems of their nearest neighbor, NGC 55.

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한국 유방암 환자에서 cancer/testis antigen의 발현분석 (A comprehensive Analysis of a Large Panel of Cancer/Testis (CT) Antigens in Korea Breast Cancer)

  • 배재호;김민주;박해림;송명하;김지연;이창훈;곽희숙;이상률
    • 생명과학회지
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    • 제19권7호
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    • pp.886-891
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    • 2009
  • Cancer/testis(CT) antigens은 여러 종료의 암에서는 발현이 되지만, 정상조직에서는 고환에서만 발현이 되는 특이성을 가지고 있다. 이러한 특이성은 immunotherapy을 하기 위한 항암백신 개발에 매력적인 유전자로 알려져 있다. 본 연구에서는 29개의 한국유방암조직에서 13개의 CT antigens (NY-SAR35, SCP-1, SSX-1, SSX-2, SSX-4, MAGE-1, MAGE-3, MAGE-4, MAGE-10, CT-7, NY-TLU57, NY-ESO-1, and LAGE-1)의 발현빈도를 RT-PCR을 통하여 조사하고 환자의 임상학적 분류와 CT antigens의 발현빈도에 대하여 조사하였다. 29개의 유방암조직에 RT-PCR결과, 13개의 CT antigen중에 MAGE-3 (66%)와 MAGE-1(57%)에서 발현빈도가 가장 높았고 LAGE-1 (55%),NY-SAR-35 (49%),MAGE-4(41%), NY-ESO-1(38%), CT-7(24%), SSX-4(24%)순으로 발현빈도를 보였다. 그러나 SSX-1, SSX-2. MAGE-10와 NY-TLU-57의 발현은 3-7%로 매우 낮았고 특히 SCP-1는 발현되지 않았다. 29 유방암 조직에서 적어도 하나 이상의 CT antigen이 발현되는 샘플은 28(98%)이였다. 그러나 환자의 임상학적 분류와 CT antigens의 발현빈도와는 특징적인 관꼐가 없음을 알수있었다. 29개의 유방암조직에서 MAGE-3와 NY-ESO-1의 Protein level에서의 발현을 알아보기 위하여monoclonal antibody를 이용하여 면역조직염색을 하였다. MAGE-3은 29개 조직중에서 12개의 조직에서 발현되었으며 NY-ESO-1은 11개의 조직에서 발현되었다. 그러므로 CT antigens은 한국 유방암 조직에서 빈번하게 발현된 것을 알 수 있었으며 CT antigens을 기반으로 한 암 백신개발의 잠재적인 표적이 될 수 있을 것이라 사료된다.

지방산을 이용한 고리형 에스터 화합물의 합성 및 그의 가소 특성 연구 (Synthesis and Plasticity of Cyclic Ester Compounds Using Fatty Acids)

  • 이한나;장혜진;우제완
    • 공업화학
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    • 제34권3호
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    • pp.252-257
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    • 2023
  • 본 연구에서는 내분비계 교란 물질로 알려진 프탈레이트계 가소제를 대체하기 위하여 동·식물성 오일로부터 추출되는 지방산과 고리를 포함하는 알코올을 이용하여 가소제 후보물질을 합성하고, 가소화 효율을 포함한 가소제로서의 특성을 평가하였다. 지방산 3종(caprylic acid, capric acid, lauric acid)과 알코올 3종(solketal, benzyl alcohol, cyclohexanol)의 에스터화 반응으로 합성한 9종의 화합물의 구조는 1H-NMR을 이용하여 확인하였다. 합성한 9종의 가소제 후보물질은 PVC 수지에 첨가하여 가소 특성을 평가하였고, 상용 가소제인 di-2-ethylhexyl phthalate (DEHP), di(isononyl)cyclohexane-1,2-dicarboxylates (DINCH), epoxidized soybean oil (ESO)과 비교·분석하여 대체 가소제로서의 가능성을 평가하였다. 결과에 따르면 가소화 효율은 DEHP 대비 0.96~1.02 배, ESO 대비 0.94~0.98 배로 비슷한 결과를 얻었으며, DINCH의 경우보다는 1.05~1.10 배 우수한 결과를 보였다. 열적 안정성은 DEHP, DINCH보다 다소 떨어지나 ESO의 경우보다는 우수한 결과를 나타내었다. 용출성 시험 결과, 수성용매인 물과 유성용매인 노말 헥세인에서 DEHP, DINCH보다 다소 높은 결과를 보였으나 ESO 대비 유사하거나 우수한 특성을 나타내는 것을 확인하였다.

A Multi-wavelength Study of a Pair of Interacting BCDs: ESO 435-IG20 and ESO 435-IG16

  • Kim, Jinhyub;Chung, Aeree;Sung, Eon-Chang;Staveley-Smtih, Lister
    • 천문학회보
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    • 제39권2호
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    • pp.49-49
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    • 2014
  • Blue Compact Dwarf galaxies (BCDs) are low-mass galaxies with recently enhanced star formation activity. Since the discovery of old stellar population in the BCDs, a number of hypotheses have been suggested as the origin of the current active star formation. One theory is tidal interactions such as fly-by and merger. In this study we test this hypothesis using a pair of BCDs, ESO 435-IG20 and ESO 435-IG16 that are separate by only ~80 kpc in projection at a similar redshift (at a ~9 Mpc distance). In the HIPASS survey, intergalactic atomic hydrogen envelope has been found to be covering both galaxies, making the pair a good candidate for the case where the star formation has been triggered by tidal interaction. We probe the gas morphology and kinematics of the BCD pair using ATCA HI data in order to find the evidence of tidal interaction. We also estimate star formation rates in the pair based on Ha emission and UV continuum, and compare with other dwarf galaxies to investigate how responsible the tidal interaction is for the enhanced star formation in this case.

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점진적 최적화 기법에서 불규칙 삼각망을 이용한 평면구조의 응력경로 탐색모델의 개발 (Development of a Stress Path Search Model of Evolutionary Structural Optimization Using TIN)

  • 김남수;이정재;윤성수;김윤순
    • 한국농공학회논문집
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    • 제46권4호
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    • pp.65-71
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    • 2004
  • Stress Path Search Model of Evolutionary Structural Successive Optimization (SPSMESO) using Triangular Irregular Network(TIN) was developed for improving over burden at initial design of ESO and strict stress direction of strut-and-tie model and truss model. TIN was applied for discretizing structures in flexible stress path and segments of TIN was analyzed as one-dimensional line element for calculating stress. Finally, stress path was searched using ESO algorithm. SPSMESO was efficient to express the direction of stress for 2D structure and time saving.