• 제목/요약/키워드: Lightening

검색결과 252건 처리시간 0.022초

분포형 광섬유 센서를 이용한 복합소재 대차 사이드프레임의 변형 모니터링 (Strain monitoring of composite bogie side-frame using distributed optical fiber sensor)

  • 윤혁진;김정석;송광용;김승철;나희승
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.627-632
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    • 2010
  • Recently the research for lightening the railway vehicle is actively made according to the demand of the environment-friendly technology development contributing to the energy cost reduction and the green growth. The railway vehicle lightweight research is expanded to the load-supporting first structure from the secondary structure which doesn't support the load. After the composite car body development used in the Korean tilting train is completed, the composite bogie frame development in which the weight reduction efficiency is large is progressed. In this paper, distributed strain was monitored when the train load was added to the central part of the composite bogie side-frame. By using the optical fiber which was attached to the lower part of the side-frame and the developed Brillouin correlation domain analysis (BOCDA) system, the strain distribution could be measured with 3cm step over 3m section. This strain distribution was compared with the design value by the FE analysis when the load of 14ton and 18ton added. This experiment can verify the manufactured composite bogie side-frame.

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복합재 태양광 무인기 날개 일체성형 제작기법 연구 (A Study on Manufacturing Methods of Cocuring Composite Wings of Solar-Powered UAV)

  • 양용만;권정식;김진성;이수용
    • 항공우주시스템공학회지
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    • 제10권1호
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    • pp.43-50
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    • 2016
  • In order to suggest the optimal manufacturing technology of composite wings of solar-powered unmanned aerial vehicles, this study compared forming technologies to reduce wing weight for long-endurance flight and to improve the manufacturing process for cost-saving and mass production. It compared the manufacturing time and weight of various composite wing molding technologies, including cocuring, secondary bonding, and manufacturing by balsa. As a result, wing weight was reduced through cocuring methods such as band type composite fiber/tape lamination technology, which enabled prolonged flight duration. In addition, the reduced manufacturing time led to a lower cost, which is a good example of weight lightening for not only small solar-powered UAVs, but also composite aircraft.

물푸레나무로부터 분리된 Esculetin와 Esculin의 미백 효능 (Depigmenting Effects of Esculetin and Esculin Isolated from Fraxinus rhynchophyllaHance)

  • 홍용덕;남미희;이창석;신송석;박영호
    • 대한화장품학회지
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    • 제40권1호
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    • pp.89-94
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    • 2014
  • 물푸레나무 수피 추출물은 주요 생활성 물질로서 esculetin과 esculin을 포함하고 있다. 이 가운데, Esculetin은 B16F10 melanoma cells에서 $IC_{50}$ value $2.8{\mu}M$의 아주 좋은 melanogenesis 억제 활성을 나타내며, 이를 통해 Melan-A cell에서 melanin 합성을 감소시킨다. 더욱이, esculetin은 mushroom tyrosinase에서도 $IC_{50}$ value $40{\mu}M$의 억제 활성을 나타내어 melanin biosynthesis를 저해한다. 위의 결과들로서, 우리는 melanogenic enzyme 활성 조절에 의해 melanin 생성을 저해하는 효과적인 피부미백 물질로서 esculetin을 제안하고자 한다.

임베디드 리눅스 기반의 눈 영역 비교법을 이용한 얼굴인식 (Face Recognition System Based on the Embedded LINUX)

  • 배은대;김석민;남부희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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    • pp.120-121
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    • 2006
  • In this paper, We have designed a face recognition system based on the embedded Linux. This paper has an aim in embedded system to recognize the face more exactly. At first, the contrast of the face image is adjusted with lightening compensation method, the skin and lip color is founded based on YCbCr values from the compensated image. To take advantage of the method based on feature and appearance, these methods are applied to the eyes which has the most highly recognition rate of all the part of the human face. For eyes detecting, which is the most important component of the face recognition, we calculate the horizontal gradient of the face image and the maximum value. This part of the face is resized for fitting the eye image. The image, which is resized for fit to the eye image stored to be compared, is extracted to be the feature vectors using the continuous wavelet transform and these vectors are decided to be whether the same person or not with PNN, to miminize the error rate, the accuracy is analyzed due to the rotation or movement of the face. Also last part of this paper we represent many cases to prove the algorithm contains the feature vector extraction and accuracy of the comparison method.

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펄스 Nd:YAG 레이저를 이용한 모터용 스테이터 적층코어의 용접특성 [ I ] - 레이저 용접성에 미치는 가공변수의 영향 - (The Weldability of Laminated Stator Core for Motor by Pulsed Nd:YAG Laser [ I ] - The Effect of Processing Parameter on Weldability of Laser -)

  • 김종도;유승조;김장수
    • Journal of Advanced Marine Engineering and Technology
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    • 제30권5호
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    • pp.629-635
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    • 2006
  • Manufacture of motor by laser has been studying realization that was demands on market for lightening and miniaturization. Moreover. early in the 1980s. manufacture of parts for automobiles by laser welding was already successfully introduced. The purpose of this study was to develop production technology of the high quality laminated stator core for motor by pulsed Nd:YAG laser heat source. In the event of adjusting defocus and voltage to control humping in laser welding of the laminated core. sound bead could be obtained. but deep penetration was not. Therefore. explosive evaporating plasma was controlled by adjustment of peak power on pulse width. Particularly, because explosive evaporating plasma induced high peak power, made molten metal in keyhole scatter. a suitable adjustment of peak power was required to obtain sound bead. As a results of experiment. sound bead and deep penetration could be obtained.

의료과오소송에 있어서 인과관계의 판단과 입증책임에 관한 판례의 최근 경향 - 일본 판례와의 비교를 중심으로 - (Judgement of causation and burden of proof in medical malpractice litigation)

  • 백경희
    • 의료법학
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    • 제8권1호
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    • pp.179-211
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    • 2007
  • To succeed the claim of medical malpractice litigation, the patient as a plaintiff should establish the medical fault of a physician as a defendant, and the causation between the fault and damages. Because of the extraordinary nature of medical province, however, this application of a legal principles is rigorous with the patient. In addition, given the causation between the validation of physician's fault and damage is not attested, patient is not awarded anything. In order to overcome a difficulty of patient's verification and ensure the right to fair process, it was demonstrated the lightening of burden of proof in medical malpractice litigation and the acceptance of the responsibility for an illegal act in a prescribed range in the absence of the causation between the physician's fault and damage. This paper deals with the judgement of causation and burden of proof in medical malpractice litigation, and the acceptance of responsibility in the absence of the causation between the physician's fault and damage. Also, this study recommends a tendency of our precedent through the comparative case method of ours and Japan.

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이차전지용 니켈 다층 박판의 레이저 용접 보호가스의 영향 (Effects of Different Shielding Gases in Laser Welding of Secondary Ni battery with Multi-thin Plates)

  • 유영태;이가람;김진우
    • 한국생산제조학회지
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    • 제25권5호
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    • pp.329-337
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    • 2016
  • The demand for the eco-friendly vehicles is skyrocketing because of the increasing $CO_2$ emissions and global warming. In the industrial field, the battery process, a core part of an eco-friendly vehicle, is drawing increased attention; its weight lightening as well as high energy density are becoming increasingly important. In this study, pure Ni plates that were used as the battery pole plate were welded using the laser. The lab joint welding was conducted on ten pure Ni plates at a laser power of 1900 W and a feed speed of 2.8-3.4 m/min. As observed in the experiment, a faster feed speed reduced the bead width, but the laser did not penetrate all ten specimen plates. In addition, pores were trapped when protective gas was used, but they were not trapped when the welding was conducted in atmospheric condition.

제1회 한국물리탐구토론대회에 출제된 "접착 테이프(Adhesive tape)" 문제 풀이에 대한 분석 (An Analysis of Students' Reports on an Assigned Problem for 'Adhesive Tape' in the first Korean Youth Physics Tournament)

  • 육근철;이희복;김명환
    • 영재교육연구
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    • 제12권4호
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    • pp.108-119
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    • 2002
  • 제1회 한국물리탐구토론대회에는 10개의 문제가 출제되었는데 본 연구에서는 이들 10개의 문제 중 ${\ulcorner}$접착 테이프(Adhesive tape)${\lrcorner}$ 문제를 해결한 5개 팀의 보고서를 비교 분석하였다. 그 결과 학생들은 접착 테이프를 갑자기 뗄때 빛이 발생하는 원인을 정전기 발생, 전자의 이동, 에너지의 변환 등으로 해석하였다. 그러나 탐구의 과정에서 확산적 사고를 가지고 창의적 아이디어를 제시한 팀은 소수에 불과하였다. 본 대회는 탐구 토론대회이므로 탐구의 과정별로 새로운 아이디어를 제안하여 결론에 이르는 창의적 탐구의 과정이 제안되어야 한다.

알루미늄 5182-폴리프로필렌 샌드위치 판재의 소성변형비 및 집합조직의 발달 (Pastic Strain Ratio and Texture Evolution of Aluminum/Polypropylene/Aluminum Sandwich Sheets)

  • 김기주;정효태
    • 한국자동차공학회논문집
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    • 제14권2호
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    • pp.57-66
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    • 2006
  • AA5182-polypropylene sandwich sheet was manufactured, and the mechanical properties evaluation was executed in order to identify $L{\ddot{u}}ders$ band that causes fabrication process problem and especially surface roughness. To identify formability, deformation behavior, plastic strain ratio (R-value) and pole figure were measured, and texture analysis was performed. In the case of sandwich sheet, the unstable deformation behavior has decreased. As well, for sandwich sheet, A1 skin could manage the most of load, and the elongation has improved about 45% more than that of A1 skin. The plastic strain ratio of A1 skin and sandwich panel, which indicates serration behavior, was obtained from instantaneous plastic strain ratio evaluation. Also, the planar anisotropy of sandwich sheet has decreased more than that of A1 skin. According to these results, the sandwich sheet produced lightening effect and could control unstable deformation characteristic, that is, surface roughness caused by $L{\ddot{u}}ders$ band. Furthermore, it was proved that the texture control of the rolling attachment of A1 skin is necessary to improve the formability of the sandwich panel.

$\beta-cyclodextrin$ 및 유도체의 포접체 형성에 의한 LG 106W의 유용성 및 안정성 개선에 관한 연구 (Improvement in availability and stability of to 106w by inclusion with $\beta-cyclodextrin$ and its derivatives)

  • 정성훈;이천구;조완구;강세훈
    • 대한화장품학회지
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    • 제25권1호
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    • pp.120-136
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    • 1999
  • A newly synthesized polyhydroxy aromatic compound(LG 106w) has good skin lightening effect. Inclusion complexation of LG 106w with $\beta$-cyclodextrin and its hydroxypropyl and dimethyl derivatives was studied by the solubility method, scanning electron microscopy and differential thermal analysis. A relationship between host and guest was clearly reflected in the magnitude of the stability constant(DM-$\beta$> HP-$\beta$>$\beta$ -cyclodextrin). Formulation problems, which resulted from its very low solubility in aqueous solution, were resolved by the inclusion formation. LG 106W from inclusions is much more water-soluble than pure one. The improvement of pH and temperature stability correlated with the increased solubility was also observed. Inclusion complex of LG 106w had similar activity to pure LG 106w on the inhibition of melanin synthesis in B-16 melanoma cell but showed lower irritation on cultured cell test in vitro. According to the results, cyclodextrins might be one of the reliable candidates for improving the availability of LG 106w.

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