• Title/Summary/Keyword: 하절기

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The consideration of the electronic cooling device for outside panel (옥외 자립형 PANEL에 적용한 전자냉각장치 고찰)

  • Ok, Yeon-Ho;Lim, Jae-Il;Park, Ji-Kun;Kwak, Won-Ku;Lee, Jae-Heung;Kim, Byung-Ki
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.353-354
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    • 2008

  • 옥외 현장에 설치되어 있는 PANEL은 하절기에 내부 온도가 높아져 PANEL 내부에 설치되어 있는 제어장치의 정상 동작을 방해 할 수 있다. 실제로 하절기 오후 $2{\sim}3$시경 PANEL 내부의 온도는 약 $60{\sim}75^{\circ}C$ 정도의 고온을 유지한다. 근래에는 현장 PANEL 내부에 PLC 및 컨트롤러등 전자화된 제어 장치의 설치 비중이 증가하고 있고 대부분의 컨트롤러 사용 온도는 약 $0{\sim}55^{\circ}C$ 이므로 하절기 고온 상태에서 정상적인 동작을 기대하기는 어렵다. 본 논문에서는 옥외 자립형 PANEL의 냉각 장치를 개발하여 운영하고 그 효과를 분석, 검토함으로써 하절기 고온 상태에서도 안정적으로 설비가 정상 동작하기 위한 방안 제시를 주요 목적으로 한다.

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Winterkill and Strategy of Golf Course Management: A Review (동절기 피해의 이해와 겨울철 골프장 관리: 리뷰)

  • Lee, Sang-Kook
    • Asian Journal of Turfgrass Science
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    • v.25 no.2
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    • pp.133-137
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    • 2011

  • Winterkill can be defined as any injury including freeze stress kill, winter desiccation, and low temperature disease to turfgrass plants that occurs during the winter period. The major damages from winterkill were low temperature kill, crown hydration, and winter desiccation. Low temperature kill is caused by air and soil temperature. Soil temperature affect more severe to turfgrass than air temperature because low soil temperature cause fetal damage to turfgrass crown. Crown hydration is a form of winter injury in which intercellular water within the plant freezes and causes physical injury to the cell membrane and wall. This is eventually resulted in dehydration of cell. Winter desiccation is the death of leaves or whole plants due to drought during the winter period. To reduce winterkill damage, cultivar selection is very important. If changing cultivar is not allowed, cold temperature hardiness needs to be increased by providing nutrients especially phosphorus and potassium in the late fall. Turf cover is effective way to reduce winterkill damage. Remaining snow is positive process to reduce winterkill damage by insulating soil temperature. The previous researches reported many materials as turf cover such as straw, polypropylene, polyester, and wood mat. Aeration and topdressing is one of the process against winterkill. Both methods are mainly conducted to reduce thickness of thatch layer. In recent, relatively new materials called black or winter topdressing sand are used to protect soil temperature from low air temperature and thaw ice crystal that may remain in soil.

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Economic Analysis of Chives for Packaging (쪽파 포장을 위한 경제성 고찰)

  • Park, HyungWoo;Jang, Jongkun;Kim, SangHee;Kim, Suil
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.18 no.1_2
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    • pp.15-20
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    • 2012

  • Economic feasibility was analyzed for packaging of chives, which are currently distributed without packaging. The additional revenue from packaging of chives was estimated to be 3,471 million won in summer season (May to September in Korea) and 3,083 million won in winter season (October to April). But, the additional cost due to packaging was estimated to be 1,926 million won in summer season and 1,254 million won in Winter season. Thus, net profits were estimated to be 1,545 million won and 1,829 million won respectively. In terms of unit (1.4 kg), the net profit with packaged distribution estimated to be 247.9 won/unit in summer season and 226.5 won/unit in winter season, respectively. therefore, total profit through packaging was estimated to be 2,799 million won per year.

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