• 한국지반환경공학회 논문집
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• 제18권3호
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• pp.25-30
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• 2017

본 논문에서는 변형률 응답 곡선의 형상을 정량적으로 분석하는 새로운 기법을 소개하였다. 변형률 응답 곡선은 응력 공간에서 단위 응력을 입력하였을 때의 발생한 변형률을 변형률 공간에 작성한 이미지이다. 변형률 응답 곡선의 형상 변화 특성을 퓨리에 기술자를 이용하여 분석하였으며, 탄소성 모델 기반으로 그 의미를 해석하였다. 전산해석결과 응력 경로가 항복면 내부에 머물러 탄성 변형만 존재할 경우, 퓨리에 기술자는 일정하게 그 값을 유지하였으나 응력 경로가 항복면에 도달하여 소성변형이 발생하는 순간 퓨리에 기술자는 변화하였다. 불교란 자연 시료와 재성형 시료에 대해 실시한 응력 경로 시험 결과, 자연 시료에 대해서만 응력 경로가 항복면에 도달하였을 때 명확한 변형률 응답 곡선의 형태 변화가 발견되었으며, 퓨리에 기술자 값도 명확하게 변화하였다. 퓨리에 기술자 중, 비대칭성과 관련 있는 퓨리에 기술자 값이 항복 및 점성토 구조변화의 지표로 활용할 수 있는 것을 확인하였다.

• 식물분류학회지
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• 제39권2호
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• pp.89-99
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• 2009

한국산 꿩의다리속 식물의 계통 및 유연관계를 밝히기 위해 39개의 형태 형질을 바탕으로 Maximum parsimony와 Neighbor-joining을 분석하였다. 식물재료는 한국 고유종을 포함해 내군 21분류군과 외군 1분류군이 사용되었다. 좀꿩의다리절과 금꿩의다리절은 각각 100% 부트츠랩 값과 83% 부트츠랩 값으로 단계통군을 형성하였고, 금꿩의다리절은 좀꿩의다리절의 자매군으로 나타났다. 꽃꿩의다리절과 산꿩의다리절은 측계통군을 형성하였다. 그늘꿩의다리를 제외한 산꿩의다리절은 방사상분지로 나타났다. 꿩의다리절과 발톱꿩의다리절은 각각 독립적인 분계군를 형성하였다. 꿩의다리속 식물에서 주요한 형질인 수술의 모양은 곤봉형이 가장 원시적이며, 원시적인 곤봉형에서 봉형, 그리고 실형으로 파생되는 것으로 나타났다. 수술의 형태는 수분방법(충매, 풍매), 개화시 꽃받침의 존재유무 등 꿩의다리속 식물의 꽃 진화에도 관련되어 있다고 판단된다.

• 천문학회보
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• 제36권2호
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• pp.69.2-69.2
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• 2011

The discovery of dark energy from Type Ia supernovae (SN Ia) is based on the implicit assumption that the look-back time evolution of SN Ia luminosity, after light-curve corrections, would be negligible. A strong support for this assumption was the apparent insensitivity of SN Ia distances across the host galaxy morphologies. However, Hicken et al. 2009 (H09) shows a systematic difference in the Hubble residual (HR) of $0.144{\pm}0.070$ mag between the E-S0 and Scd/Sd/Irr galaxies, after light-curve corrections. If true, this indicates that the light-curve fitters used by the SN Ia community can not correct for the population age (and therefore the evolution) effect. In order to confirm this, we have combined nearby SN Ia samples and the first-year SDSS-II SN Survey. The SNANA package was used for analyzing SN Ia light-curve, both for the MLCS2k2 and SALT2 fitters. We find a systematic difference in the HR of $0.10-0.13{\pm}0.030$ mag between E-S0 and Scd/Sd/Irr galaxies, which is in agreement with the result of H09, but now at the 3-5 ${\sigma}$ level. Considering the significant difference in the mean age of stellar population between these morphological types, the difference in the HR reported here suggests that the evolution effect of SN Ia luminosity should be considered in the cosmological application of SN Ia data.

• 한국세라믹학회지
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• 제29권11호
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• pp.912-918
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• 1992

Microstructure evolution including morphological change in the vicinity of the electrodes, porosity change and grain boundary migration was observed in polycrystalline CoO subject to electric fields at 1100 and 121$0^{\circ}C$ in air. At the cathode, the transported cations react with oxygen in the surrounding to form new lattices, while, at the anode, the reverse reaction occurs leading to lattice annihilation. Lattice formation also takes place at the surface of pores near the cathode inducing pore-filling effect. Grain boundary migration was found bo be enhanced or retarded depending on the field direction. It is therefore implied that the driving force of grain boundary migration is the vectorial sum of the curvature-induced chemical potential gradient and the electric field applied.

• 한국균학회지
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• 제44권2호
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• pp.73-81
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• 2016

흰녹가루병균류(난균류)는 인공배양이 불가능한 순활물 병원균이다. 이들은 많은 속씨식물들에서 흰녹가루병을 일으키는데, 경제적으로 중요한 기주식물로는 해바라기, 와사비, 갓, 유채, 무, 배추, 시금치 등이 있다. 최근에 분자분석 방법과 분류학적으로 유용한 형태적 특징들이 제안되면서, 흰녹가루병균류의 다양성, 진화, 계통분류에 대한 연구에 큰 진척이 있었다. 본 논문은 국내에 덜 알려진 흰녹가루병 균류를 소개하고 최근의 연구성과에 대하여 고찰하였다.

• 한국미생물·생명공학회지
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• 제10권1호
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• pp.27-32
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• 1982

광합성세균에 의한 수소산을 목적으로 성남근교의 논 토양으로부터 수소를 다량 생산하는 비유황세균 1주를 분리하고 동정하였다. 이 균주의 생리적 형태적 및 배양상의 특성을 규명한 결과 Rhodopseudomonas gelatinosa K-13으로 동정되었다.

• Carbon letters
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• 제14권4호
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• pp.228-233
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• 2013

In this work, we report in-situ observations of changes in catalyst morphology, and of growth termination of individual carbon nanotubes (CNTs), by complete loss of the catalyst particle attached to it. The observations strongly support the growth-termination mechanism of CNT forests or carpets by dynamic morphological evolution of catalyst particles induced by Ostwald ripening, and sub-surface diffusion. We show that in the tip-growth mode, as well as in the base-growth mode, the growth termination of CNT by dissolution of catalyst particles is plausible. This may allow the growth termination mechanism by evolution of catalyst morphology to be applicable to not only CNT forest growth, but also to other growth methods (for example, floating-catalyst chemical vapor deposition), which do not use any supporting layer or substrate beneath a catalyst layer.

• Mycobiology
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• 제48권4호
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• pp.304-312
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• 2020

Over the past 15 years, downy mildew became the most destructive foliar disease in cultivated Impatiens species (Balsaminaceae) worldwide. A previous study had revealed that the causal agent was not Plasmopara obducens (Oomycota, Peronosporales) but Plasmopara destructor on Impatiens walleriana, and Plasmopara velutina on Impatiens balsamina. This hints to a relatively high degree of specialization of Plasmopara on Balsaminaceae. Therefore, it was the aim of the present study to perform multigene phylogenetic analysis and detailed morphological investigation for several Korean downy mildew samples parasitic to cultivated I. walleriana, and I. balsamina, but also to a northeast Asian wild plant, Impatiens textori. It was revealed that I. textori harbors a new species, which is introduced and described here as Plasmopara elegantissima.

• Animal Systematics, Evolution and Diversity
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• 제29권4호
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• pp.312-315
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• 2013

Sea urchins were collected from waters adjacent to Daludo Island and Mohang harbor in the Yellow Sea, and were identified into Glyptocidaris crenularis A. Agassiz, 1864, of the family Stomopneustidae within the order Stomopneustoida, based on morphological characteristics. This species has two unique morphological characteristics: the ambulacral plate is composed of three primary plates and two demi-plates, and a valve of globiferous pedicellaria consists of with a well-developed long terminal hook and a unique stalk equipped with one to six long lateral processes covering membranes, resembling fins. It is newly recorded in Korea and is described with photographs. This brings the total number of sea urchins reported from the Yellow Sea, Korea, to seven.

• Animal Systematics, Evolution and Diversity
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• 제29권4호
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• pp.308-311
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• 2013

A sea urchin was collected from Geomundo Island of Jeollanam-do, Korea on July 3, 2009. This specimen was classified as Spatangus luetkeni A. Agassiz 1872 belonging to the family Spatangidae of order Spatangoida based on the morphological characteristics. This genus and species are newly recorded in Korea. It is distinct morphological characters that test is thick and strong, six to eight primary tubercles are in 1 and 4 interambulacra, sternum is equipped with little keel, and color in alcohol is dark violet. This species inhabits tropical waters and usually distributes over the West Pacific from southern Japan to New Zealand.