• 제목/요약/키워드: pattern shape

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극저하중(極低荷重)사이클을 받는 강부재(鋼部材) 및 요소(要素)의 파괴거동(破壞擧動)에 관한 실험적(實驗的) 연구(硏究) (Experimental Study on Failure Behavior of Steel Members and Elements under Very Low Load-Cycles)

  • 박연수
    • 대한토목학회논문집
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    • 제14권2호
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    • pp.257-268
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    • 1994
  • 강진과 같은 큰 반복하중하에서 강부재 및 그들요소의 균열과 파단에 영향을 미치는 중요한 물리적 인자들을 찾아내어, 그 인자들간의 정량적인 관계를 규명하기 위해 실험적 연구를 수행하였다. 9개의 강판요소와 28개의 앵글 강부재를 시험체로서 사용하였으며, 비탄성 좌굴이 포함된 축방향의 반복하중을 5~20회 정도 받았다. 본 실험은 극저사이클 파괴거동에 있어서 제하이력과 파괴형태 및 단면형상의 영향평가에 특히 촛점을 두었다. 실험결과, 에너지 소산능력은 실험변수에 크게 의존하였으며, 균열의 발생 또는 파단과 에너지 소산능력 사이에 단순한 정량적 관계가 성립되지 않았다. 그러나, 실험변수에 관계없이 균열발생부에 있어서 잔류변형률의 최대치는 일정한 값을 보여주었다.

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Fabrication of Optically Active Nanostructures for Nanoimprinting

  • Jang, Suk-Jin;Cho, Eun-Byurl;Park, Ji-Yun;Yeo, Jong-Souk
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.393-393
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    • 2012
  • Optically active nanostructures such as subwavelength moth-eye antireflective structures or surface enhanced Raman spectroscopy (SERS) active structures have been demonstrated to provide the effective suppression of unwanted reflections as in subwavelength structure (SWS) or effective enhancement of selective signals as in SERS. While various nanopatterning techniques such as photolithography, electron-beam lithography, wafer level nanoimprinting lithography, and interference lithography can be employed to fabricate these nanostructures, roll-to-roll (R2R) nanoimprinting is gaining interests due to its low cost, continuous, and scalable process. R2R nanoimprinting requires a master to produce a stamp that can be wrapped around a quartz roller for repeated nanoimprinting process. Among many possibilities, two different types of mask can be employed to fabricate optically active nanostructures. One is self-assembled Au nanoparticles on Si substrate by depositing Au film with sputtering followed by annealing process. The other is monolayer silica particles dissolved in ethanol spread on the wafer by spin-coating method. The process is optimized by considering the density of Au and silica nano particles, depth and shape of the patterns. The depth of the pattern can be controlled with dry etch process using reactive ion etching (RIE) with the mixture of SF6 and CHF3. The resultant nanostructures are characterized for their reflectance using UV-Vis-NIR spectrophotometer (Agilent technology, Cary 5000) and for surface morphology using scanning electron microscope (SEM, JEOL JSM-7100F). Once optimized, these optically active nanostructures can be used to replicate with roll-to-roll process or soft lithography for various applications including displays, solar cells, and biosensors.

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금속 마이그레이션에 의한 화재 위험성 연구 (A Study on Fire Hazard by Metallic Migration)

  • 최경원;현병수;김선재;임규영;우승우;이동규;조영진;박종택;고재모;박남규
    • 한국화재소방학회논문지
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    • 제33권6호
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    • pp.114-119
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    • 2019
  • 우리는 LED등기구의 Printed circuit board (PCB)에서 화재의 원인으로 특정할 수 있는 금속 마이그레이션(Metallic migration) 현상을 발견하고, 본 연구를 진행하였다. 금속 마이그레이션 현상 가속화 실험인 물방울 시험을 소량의 물과 저전압(3 V)로 진행하고 절연되어있는 양극에서 직접적으로 금속 마이그레이션의 성장과 회로의 단락을 확인하였다. 그리고 전자주사현미경(SEM)을 통해 형태를 관찰하고 에너지 분산형 분광기(EDS)를 이용하여 성분을 분석한 결과, 절연된 부분에서 전극을 이루고 있는 구리의 성분을 검출하였다.

열처리가 냉간가공한 stainless steel wire의 복원양상에 미치는 영향 (EFFECTS OF LOW-TEMPERATURE HEAT TREATMENT ON ELASTIC MEMORY PROCESS OF COLD WORKED STAINLESS STEEL WIRE)

  • 오정세;박수병;손우성
    • 대한치과교정학회지
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    • 제22권3호
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    • pp.647-656
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    • 1992
  • The purpose of this study was to evaluate the elastic memory process in cold worked stainless steel wire and the effect of heat treatment on it. 0.018 inch round and $0.019\times0.025$ inch rectangular wire (ORMCO stainless wire) were used in this study. Each wire type had 4 groups: non-heat treatment group, furnace heat treatment group, electric current heat treatment group, and bending after heat treatment group. Each group was consisted of 10 specimens. With the Jig, each wire was bent into v-shape uniformly, and width of two free ends of each v-shaped wire was measured by caliper (to the point of 0.1 mm correctly) at time interval of offjig, after heat treatment, 1, 2, 3, 4 hours, 1, 2, 3, 4, 5, 6 days, 1, 2, 3, 4 weeks after. The results were as follows: 1. In non-heat treatment group and bending after heat treatment group, elastic memory process was occured $60\%$ within 1 hour, and more than $90\%$ within 1 week. 2. In furnace and electric current heat treatment group, almost all elastic memory process was occured during teat treatment, and then specimen was stabilized dimensionally. 3. Magnitude of deformation by elastic memory was greater in heat treatment group than non heat treatment group and bending after heat treatment group. 4. There was no remarkable difference in deformation pattern between 0.018 inch round wire and $0.019\times0.025$ inch rectangular wire.

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쉬땅나무족(장미과) 화판표피의 미세형태학적 특성에 관한 연구 (A Study on the Petal Micromorphological Characteristics of the Tribe Sorbarieae (Rosaceae))

  • 송준호;홍석표
    • 한국자원식물학회지
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    • 제29권4호
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    • pp.376-384
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    • 2016
  • 쉬땅나무족 15분류군의 화판의 미세형태학적 형질을 주사 전자현미경으로 관찰하여 화판 향축면, 배축면의 세포 외형, 배열, 수층벽, 큐티클의 미세형태를 자세히 기재하였으며, 분류학적, 계통학적 유용성을 검토하였다. 쉬땅나무족의 화판은 유두상 또는 원추형 유두상(PCS), 직사각형의 주름판상(TRS)로 확인되었으며, 향축면, 배축면의 화판 구조에 따라 크게 세 유형으로 구분하였다. Type I. PCS-TRS, Type II. PCS-PCS, Type III. TRS-TRS (향축면-배축면). 구분된 이들 유형과 수층벽, 큐티클 표면의 형태는 족 내 속간/종간 진단 형질로 유용하였을 뿐 아니라, 계통학적으로도 그 유용성이 확인되었다. 또한, 화판 표면의 세포의 미세형태와 수분매개자(곤충을 통한 충매)와의 연관성을 나타내는 추가적인 사례로 제시하였다.

새로운 곤충병원성 Bacillus thuringiensis subsp. aizawai 균주의 유전학적 특성 (Genetic characteristics of the novel insect pathogenic Bacillus thuringiensis subsp. aizawai strain)

  • 서미자;윤영남;유용만;김기수
    • 농업과학연구
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    • 제41권4호
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    • pp.351-359
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    • 2014
  • For identifying the plasmid DNA coding cry gene of Bacillus thuringiensis subsp. aizawai KB098 with high insecticidal activity against Spodoptera exigua, mutant isolates with no crystal protein were produced by $42^{\circ}C$ incubation condition and then mutant plasmid DNA band patterns were compared with those of KB098. KB098 isolates had 4 cry genes, cry1Aa, cry1Ab, cry1C, cry1D, and also had been found seven plasmid DNA. Though the SDS-PAGE experiment, it was confirmed that mutant didn't produce 130~145kDa protein band involved in bipyramidal shape crystal. Also, five mutant isolates had no cry genes coding plasmid DNA in PCR. In result of comparison the plasmid DNA of KB098 and 5 mutant isolates, only 1 plasmid DNA band was left out in mutant plasmid DNA pattern, so that the missing band was extracted from the gel. The missing(disappeared) plasmid DNA was the largest molecular size among the 7 plasmid DNA of KB098 and it was also confirmed this plasmid DNA had all 4 cry genes through PCR.

Base Plate로 보강된 기둥-기초 접합부의 뚫림전단강도 연구 (A Study on Punching Shear of Column-Foundation Joint Connection for Reinforced Steel Base Plate)

  • 김성겸;박종권;한상희;김병철;장일영
    • 한국구조물진단유지관리공학회 논문집
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    • 제19권2호
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    • pp.1-9
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    • 2015
  • 본 논문에서는 RC 기둥-기초 접합부분을 중공형 및 확장형 강재 Base Plate로 보강한 실험체에 대한 하중 재하 실험을 실시하여, 강재 Base Plate가 부착된 RC 기둥-기초에서의 뚫림전단에 대한 보강효과를 정량화 하기 위한 구조해석 및 기초적 실험 연구를 수행하였다. 실험은 각 실험체별 부착된 Base Plate의 두께, 내민길이, 치수, 형식 등의 변수에 따라 수행하였으며 실험을 통하여 응력분산에 적합한 적정 Base Plate의 모양 및 치수를 확인하였고, 보강효과에 대하여 분석하였다. 실험을 통해 Base Plate가 기초에 전해지는 수직하중의 응력분산에 효과적이었으며 폐쇄형보다 중공형 보강이 효율적인 것을 확인하였다. 보강을 통해 변위연성 능력의 향상으로 기존의 기초두께보다 두께가 감소한 실험체에서도 기존보다 높은 성능을 나타냈다. 보강 후의 실험체로부터 구조물의 거동특성을 취성으로부터 연성으로 유도 할 수 있었으며, 실험체를 파괴시까지 가력함으로써 파괴시 보강 전, 후에 대한 균열 및 파괴양상을 확인 하였다.

여아의 원피스 드레스 디테일 선호도 - 만 3~6세를 중심으로 - (A Study on the Detail Preference of Girls One-piece Dress - Focus on 3 to 6 Years Old -)

  • 김은영;권수애
    • 한국의상디자인학회지
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    • 제17권1호
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    • pp.167-182
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    • 2015
  • This study was to investigate the preference tendency by detail and material preference of summer one-piece dresses for the children, and evaluation standard of children's wear in purchasing one-piece dresses as an object of mothers who have girls as buying representatives of children's wear in order to supply real information of design about the one-piece dresses for the girls in accordance with the consumers' demands. The results of this study revealed that the one-piece dress was favorite one to them in purchasing their summer wear. This study showed tendency that the more the mother's fashion interest was, the more the mother's preference on the one-piece dress was. As to the material preference of one-piece dress, it preferred the natural fiber to the synthetic fiber much, and the preferred customer order in purchasing one-piece dresses for their children was analyzed as activity, material, design collar, and pattern. As to the preference by form factor of one-piece dress, it preferred A-line silhouette in the silhouette, natural waist in the waist position, 5~7cm from the knee in the length of one-piece dress, and flared skirt in shape of skirt. The preference on the collar type was soutien collar, and the preference on the neckline type was round neckline. In addition, the preference on sleeve form was shirtsleeve, and the preference on trimming was lace trimming.

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남성 요실금 팬티에 관한 연구 (A Study on Male Panties for Urinary Incontinence)

  • 이정순
    • 한국의상디자인학회지
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    • 제17권1호
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    • pp.39-52
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    • 2015
  • This study aims to analyze the characteristics of the male products for urinary incontinence by examining the types and characteristics of those registered in KIPO (Korean Industrial Property Office). Additionally, the types and characteristics, especially for the cloth products and the pads, of male panties for urinary incontinence on the market are analyzed. Men in their 60s with minor symptoms were selected as the subjects to evaluate the wearability. The results are as follows. 11 male products for urinary incontinence, registered in KIPO, are structurally different from those for women by having a separate pocket mainly for absorption. There are one disposable type and 7 cloth types, and the cloth panties can be classified as either united or separable type depending on the detachability of pads from the panties. The types of the panties vary according to the position, shape, and size of the attached pads on normal male panties (boxer, briefs, drawers). The fabrics for the urinary incontinence are usually piled in 3 to 5 layers by having the most absorptive layer on the top, the next with deodorizing characteristics, and the bottom with the waterproof fabric as basics with some additional layers of antibiotic or breathable fabrics. From the wearability test, it has been determined that the panties are not distinguishable in external appearance and the fitness is also not a problem since the size varies as the normal panties. It has been evaluated that the fitness of the panties is an important factor since the pad should be worn in any form; the pad sewed in the middle of the panties was evaluated to be more wearable than having a long pad. In case of separable panties, when the pattern and fabric is similar to the functional panties and the options such as the thickness of the pads or detachability are given to the users, it tends to be more satisfactory.

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한국산 미기록 양치식물 : 흰비늘고사리, 남도톱지네고사리, 애기지네고사리 (관중과) (Unrecorded fern species from Korean flora : Ctenitis maximowicziana, Dryopteris lunanensis and D. decipiens var. diplazioides (Dryopteridaceae))

  • 김철환;선병윤;김용복
    • 식물분류학회지
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    • 제34권1호
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    • pp.27-35
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    • 2004
  • 광주시 월각산 (275 m)의 계곡 주변에서 관중과의 남방고사리속과 관중속에 포함되는 미기록 양치식물 세 분류군을 발견하였다. 흰비늘고사리 [Ctenitis maximowicziana (Miq.) Ching]는 엽병 기부 인편의 색깔과 형태, 엽신의 형태, 둥근 신장형의 포막의 유무 등의 특상에 의해 남방고사리 [C. sinii (Ching) Ohwi]를 포함한 속내 다른 분류군들과 식별되었다. 남도톱지네고사리[Dryopteris lunanensis (H. Christ) C. Chr.]는 측우편의 수, 중부 이하의 우편의 제 1열편 혹은 2열편의 분열정도와 포자낭군의 분포양상에 의해 유사 분류군인 톱지네고사리 [D. atrata (Wall. ex Kunze) Ching]와 구별되었다. 애기지네고사리 [Dryopteris decipiens (Hook.) Kuntze var. diplazioides (H. Christ) Ching]는 중부 이하 우편의 분열 정도에 의해 원변종 var. decipiens와 식별되었으며 잎의 형태로 볼때 원변종과 큰지네고사리 (D. fuscipes C. Chr.)의 중간형처럼 보였다. 이들 세 분류군은 월각산의 해발 200-250 m에 국한하여 10개체 내외가 자생하고 있었다.