• Title/Summary/Keyword: Narcissus

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Occurrence of Narcissus Smoulder Caused by Botrytis narcissicola in Korea

  • Hong, Sung-Kee;Kim, Wan-Gyu;Cho, Weon-Dae;Kim, Hong-Gi
    • Mycobiology
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    • v.35 no.4
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    • pp.235-237
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    • 2007
  • Leaf blight and bulb rot symptoms were observed on narcissus plants grown in Yongin, Cheongwon and Namhae areas in Korea during disease survey from 1999 to 2002. A total of 15 isolates of Botrytis sp. were obtained from the infected plant parts of narcissus. All the isolates were identified as Botrytis narcissicola based on their morphological and cultural characteristics. Three isolates of B. narcissicola were tested for their pathogenicity to leaves and bulbs of narcissus by artificial inoculation. All the isolates induced leaf blight and bulb rot symptoms on the plants of narcissus by artificial inoculation. The symptoms induced by artificial inoculation were similar to those observed in the fields. This is the first report of narcissus smoulder caused by B. narcissicola in Korea.

Design of Cooled Infrared Optical System Considering Narcissus (나르시서스를 고려한 냉각형 적외선 광학계 설계)

  • Jeong, Su Seong;Kim, Young Soo;Hong, Jin Suk;Lee, Kyoung Muk;Yoon, Jee Yeon
    • Korean Journal of Optics and Photonics
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    • v.30 no.6
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    • pp.219-225
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    • 2019
  • In an infrared optical system, using a cooled detector generates a phenomenon called a narcissus, in which the focal-plane array cooled to very low temperatures is reflected at the lens surface and detected. The narcissus can be removed by non-uniformity correction of the detector pixel, so narcissus is generally ignored in infrared optics. However, non-uniformity correction reduces the sensitivity of the system. Also, as the housing temperature varies due to an environmental temperature change, or a lens is moved for focusing or athermalization purposes, a narcissus may occur even after non-uniformity correction. To minimize such a narcissus, the amount of the effect must be controlled in the lens-design stage. In this paper we designed a midinfrared optical system and analyzed the narcissus by setting the lens surface reflectance to 1%. In addition, the design was divided into stages of an initial design, an improved design, and a minimum design, and the narcissus was improved to about 56% of that in the initial design.

Effect of Growth Regulators and Chilling Treatment on Bulblet Increment of Narcissus pseudo-narcissus 'King Alfred' in Vitro (수선의 기내 구 비대에 미치는 생장조절제와 저온처리의 영향)

  • 정향영;신학기;김의영
    • Korean Journal of Plant Tissue Culture
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    • v.24 no.2
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    • pp.99-101
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    • 1997
  • This experiments were conducted to investigate growth regulator concentrations and a period of chilling treatment for increasing the size of bulblets of Narcissus pseudo-narcissus cv King Alfred. Combination of 2.5 mg/L BA and 2.5 mg/L NAA remarkedly increased the diameter and growth of regenerated bulblets. Chilling period favorable for the growth of regenerated bulblets was found to be 8 weeks, and addition of 1.0 mg/L NAA alone to MS medium was the most effective for increasing the size of bulblet for the culture after the chilling treatment.

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Design of Infrared Refractive Collimator for Reduce Narcissi Effect (나르시스현상 감소를 위한 적외선용 굴절식 시준기 설계)

  • Park, Sang-Woo;Kim, Jong-Jin;Won, Jea-Hak;Yun, Seok-Jae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.712-715
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    • 2011
  • When simulate long distance infrared image in the laboratory the Infrared Refractive Collimator is used. In this case, infrared light reflected from the surface of the lens and target. The reflected infrared light causes Narcissus. Narcissus degrades the quality of the infrared image. To minimize Narcissus optimize the reflective index and placement of the lenses, lenses and target surface coated.

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Discovery of the large narcissus fly, Merodon equestris (Fabricius), (Diptera, Syrphidae) in South Korea

  • Han, Taeman;Park, Haechul;Kim, Seung-Hyun;Park, In Gyun;Choi, Deuk-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.36 no.2
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    • pp.42-48
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    • 2018
  • We found the large narcissus fly, Merodon equestris (Fabricius), which has been doubted to occur in Korea. This species is an economically important in management of narcissus and also of quarantine pests. We therefore provide the morphological diagnosis and DNA barcode sequences for rapid species identification of M. equestris based on the five Korean specimens.

Athermalization and Narcissus Analysis of Mid-IR Dual-FOV IR Optics (이중 시야 중적외선 광학계 비열화·나르시서스 분석)

  • Jeong, Do Hwan;Lee, Jun Ho;Jeong, Ho;Ok, Chang Min;Park, Hyun-Woo
    • Korean Journal of Optics and Photonics
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    • v.29 no.3
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    • pp.110-118
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    • 2018
  • We have designed a mid-infrared optical system for an airborne electro-optical targeting system. The mid-IR optical system is a dual-field-of-view (FOV) optics for an airborne electro-optical targeting system. The optics consists of a beam-reducer, a zoom lens group, a relay lens group, a cold stop conjugation optics, and an IR detector. The IR detector is an f/5.3 cooled detector with a resolution of $1280{\times}1024$ square pixels, with a pixel size of $15{\times}15{\mu}m$. The optics provides two stepwise FOVs ($1.50^{\circ}{\times}1.20^{\circ}$ and $5.40^{\circ}{\times}4.23^{\circ}$) by the insertion of two lenses into the zoom lens group. The IR optical system was designed in such a way that the working f-number (f/5.3) of the cold stop internally provided by the IR detector is maintained over the entire FOV when changing the zoom. We performed two analyses to investigate thermal effects on the image quality: athermalization analysis and Narcissus analysis. Athermalization analysis investigated the image focus shift and residual high-order wavefront aberrations as the working temperature changes from $-55^{\circ}C$ to $50^{\circ}C$. We first identified the best compensator for the thermal focus drift, using the Zernike polynomial decomposition method. With the selected compensator, the optics was shown to maintain the on-axis MTF at the Nyquist frequency of the detector over 10%, throughout the temperature range. Narcissus analysis investigated the existence of the thermal ghost images of the cold detector formed by the optics itself, which is quantified by the Narcissus Induced Temperature Difference (NITD). The reported design was shown to have an NITD of less than $1.5^{\circ}C$.