• 제목/요약/키워드: Triplet

검색결과 345건 처리시간 0.022초

카메라 렌즈 설계에서 직교화 방법에 관한 연구 (A study on convergence and stabilization of SVD damped least squares method in the triplet camera lens-system design)

  • 정정복;이원진;김경찬
    • 한국안광학회지
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    • 제1권1호
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    • pp.29-39
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    • 1996
  • Triplet 카메라 렌즈계(f'=50mm, f/3.5)를 통하여 고유값의 중간값은 최적의 감쇠 계수임과, 정규 방정식을 풀 때 SVD 직교화 방법을 적용하면 불량 조건을 제거하여 계산의 정확도를 높일 수 있어서 merit 함수는 최소값에 안정하면서도 빠르게 수렴할 수 있다는 것을 조사하였다. 양호 조건인 triplet 카메라 렌즈계에서 SVD 직교화 방법을 적용한 DLS 법에서 얻은 최소 merit 함수는 가우스 소거법에서 얻은 최소 merit 함수의 97.86%로서 크게 개선되지는 못하였다. 따라서 SVD 직교화 방법을 적용한 DLS 법이 가우스 소거법을 적용한 DLS 법보다 감쇠 계수 적용에 대한 안정성과 수렴속도가 좋으며, 최적화 방법에 적절한 감쇠 계수를 적용시켜주면 최적화 과정의 수렴 속도가 개선됨을 알 수 있었다.

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Behaviour of twin- and triplet-born lambs and their dam 3 to 18 hours after birth is not a useful predictor of lamb survival to weaning

  • Gronqvist, G.V.;Hickson, R.E.;Kenyon, P.R.;Morris, S.T.;Stafford, K.J.;Corner-Thomas, R.A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권11호
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    • pp.1848-1857
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    • 2020
  • Objective: An experiment was designed to determine if behaviour traits expressed by twin- and triplet-bearing lambs and their dams at 3 to 18 hours of age (after the immediate ewe-lamb bonding had occurred) were associated with lamb survival to weaning. Methods: The behaviour of twin and triplet lambs and their dams was assessed in the paddock at 3 to 18 hours after birth. Observations were made of the number of high- and low-pitched bleats, time to stand, make contact with dam, suck from dam and follow dam were recorded for each lamb. The maternal behaviour score of each dam was assessed. A random sub-sample of lambs were assessed during a maternal-recognition test at 12 or 24 hours of age. Traits included time spent standing, sitting, walking, time taken to reach the ewes and time spent with the ewes as well as the number of high- and low-pitched bleats emitted by the lamb. Results: In the paddock, for each additional second required for twin-born lambs to follow their dam, lambs were 1.004 (95% confidence interval [CI] 1.000 to 1.008) times more likely to survive to weaning (p<0.05). The opposite relationship, however, was seen in triplet lambs. For each additional second required for triplet-born lambs to follow their dam, lambs were 0.996 (95% CI 0.993 to 0.999) times as likely to survive to weaning (p<0.05). During the maternal recognition test, twin-born lambs were 0.989 (95% CI 0.979 to 1.000) times as likely to survive to weaning for every additional second they took to reach the contact zone (p<0.05). Similarly, triplet-born lambs were 0.994 (95% CI 0.989 to 0.999) as likely to survive for every additional second they took to reach their dam (p<0.05). Conclusion: All ewe behaviours and the majority of lamb paddock and test behaviours were not associated with the survival of twin- or triplet-born lambs and, therefore, are of little use as indicators of lamb survival to weaning.

The Link Between Stereoselectivity and Spin Selectivity in Intermolecular and Intramolecular Photochemical Reactions

  • Griesbeck, Axel G.
    • Journal of Photoscience
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    • 제10권1호
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    • pp.49-60
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    • 2003
  • How stereo selectivity in singlet and triplet photocycloaddition and photocyclization reactions, respectively, is linked to spin selectivity and how this link affects our understanding of photochemical reaction mechanisms, is described in this review. As illustrative examples, the Paterno-Buchi reaction and the Norrish-Yang cyclization are described with emphasis on triplet biradical structure and dynamics.

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Cycloaddition Reaction on 1,4,5,8-Tetraazaphenanthrene Photoexcited Triplet State to Some Olefins

  • Park, Seung-Ki;Shim, Sang-Chul
    • Bulletin of the Korean Chemical Society
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    • 제8권1호
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    • pp.27-30
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    • 1987
  • Photocycloaddition of 1,4,5,8-tetraazaphenanthrene to olefins proceeds through a biradical triplet-state intermediate as proven by the photoproduct stereochemistry, quantum yield measurements, sensitization, quenching, and fluorescence and phosphorescence quenching studies.

Photosystem I and II Reaction Centers in a New Type Oxygenic Photosynthesis of Acaryochloris marina Based on Chlorophyll d: Studies of Delayed Fluorescence and Triplet State ESR

  • Itoh, Shigeru;Fukushima, Yoshimasa;Itoh, Kunihiro;Maeda, Masanori;Mino, Hiroyuki;Kumazaki, Shigeichi
    • Journal of Photoscience
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    • 제9권2호
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    • pp.70-73
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    • 2002
  • A cyanobacteria-like organism Aaryochloris marina performs oxygenic photosynthesis with near far-red light by the use of chlorophyll d. Reaction center chlorophyll (Chl) of Photosystem (PS) II of A. marina was studied by analysis of millisecond-delayed fluorescence. Delayed fluorescence is emitted by Chi d indicating efficient energy transfer between antenna Chi d molecules and the unknown primary electron donor of PS II. P740 a reaction center Chl of PS I of A. marina is shown to give a dimer type cation, and triplet state with a D value of 245xlO$\^$-4/ cm$\^$-l/ in contrast to the 280-290 xlO$\^$-4/cm$\^$-l/ values of P700 suggesting triplet spins interacting at a 5% larger distance in P740 than in P700.

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CCTV 카메라용 광학계 설계 (Optical System Design for CCTV Camera)

  • 이수천
    • 한국안광학회지
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    • 제13권1호
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    • pp.31-35
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    • 2008
  • 목적: 본 논문은 CCTV 카메라용 렌즈 설계를 triplet형으로 광학 설계를 하였다. 방법: 초점거리를 56 mm, 유효경을 20 mm 그리고 화각을 $5^{\circ}$로 한 망원 렌즈 형태이고, 설계하고자 하는 카메라의 CCD array detector의 크기를 2/3인치로 하였다. 결과: 광학계의 성능은 ray-fan과 spot diagram 그리고 회절 광학적인 MTF를 계산하여 평가하였고, 파장은 Fraunhofer C, d 및 F-line에 대해 achromat 되었으며 MTF 값도 tangential과 sagittal MTF 모두 50 line pairs/mm의 공간 주파수에 70% 정도가 나왔다. 결론: triplet형으로 비교적 저가 보급형 감시용 목적 CCTV 카메라를 설계하였고 충분히 실용적이라 생각된다.

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충돌형(F-O-F, O-F-O) 실물형 분사기의 분무특성 및 혼합특성에 관한 연구 (A Study on Spray and Mixing Characteristics of Unlike Impinging Triplet Injector (F-O-F, O-F-O))

  • 김종규;김승한;문일윤;이광진;서성현;한영민
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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    • pp.195-203
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    • 2003
  • 실물형 Unlike 충돌형 triplet 분사기인 F-O-F형과 O-F-O형의 분무특성 및 혼합특성을 실험적으로 알아보았다. 각각의 분사기에 대해 산화제와 연료의 운동량비의 변화에 따라 분무형상과 케로신/물을 이용한 혼합효율을 측정하였다. 분무형상은 Stroboscope와 CCD camera를 이용한 직접사진기법으로, 혼합효율은 Mechanical Patternator를 이용하였다. O-F-O형 분사기가 미립화 특성이 우수함을 알 수 있었고, 운동량비가 증가함에 따라 혼합효율이 급격히 감소함을 알 수 있었다.

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