• 제목/요약/키워드: degree-days

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HadCM3를 이용한 서울 및 울산지역의 미래 냉.난방도일 예측 (The expectation of future cooling and heating degree day of the Seoul and Ulsan using HadCM3)

  • 이관호;유호천;노경환
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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    • pp.160-165
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    • 2008
  • The concern in energy reduction in the field of architecture which takes up a big weight in domestic energy consumption is gradually increasing. For this reason, a lot of research work on this matter is being carried out. Particularly, it is generally required that currently used system in a structure for energy reduction should be maximized in its efficiency. In addition, research on several energy reduction typed systems is underway. Such a research work should not only include the one in time of the present but also keep up with the trend for future-oriented research. This research paper forecasted and analyzed the trend for global warming and demand of a structure for energy in the future by applying climate scenarios to cooling degree-day and heating degree-day. Also, this research found out the decrease in heating degree-days and increase in cooling degree-days until this moment due to the progress of global warming. In addition, as for heating degree-days in the future forecasted on the basis of HadCM3, it is estimated that the range of decrease could be ever bigger starting 2040 in case of Seoul and also starting 2010 in case of Ulsan ever after respectively. In case of cooling degree-days, it is estimated that its increase range could be bigger abruptly starting 2050, and after 2080, its increase range would be much bigger.

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기후 온난화의 영향에 의한 건물의 냉.난방에너지 수요량 예측 (The Demand Expectation of Heating & Cooling Energy in Buildings According to Climate Warming)

  • 김지혜;서승직
    • 한국태양에너지학회 논문집
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    • 제26권3호
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    • pp.119-125
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    • 2006
  • The impacts of climate changes on building energy demand were investigated by means of the degree-days method. Future trends for the 21st century was assessed based on climate change scenarios with 7 global climate models(GCMs). We constructed hourly weather data from monthly temperatures by Trnsys 16. A procedure to estimate heating degree-days (HDD) and cooling degree-days (CDD) from monthly temperature data was developed and applied to three scenarios for Inchon. In the period 1995-2080, HDD would fall by up to 70%. A significant increase in cooling energy demand was found to occur between 1995-2004(70% based on CDD). During 1995-2080, CDD would Increase by up to 120%. Our analysis shows widely varying shifts in future energy demand depending on season. Heating costs in winter will significantly decrease whereas more expensive electrical cooling energy will be needed.

NCDC데이터를 활용한 냉난방도일 산정 및 계산방법에 관한 연구 (A Study on Heating and Cooling Degree-Days Calculation Methods with NCDC Data)

  • 서동현;송유진
    • 한국태양에너지학회 논문집
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    • 제33권6호
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    • pp.77-84
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    • 2013
  • Degree-day method is very simple but essential index to estimate heating and cooling energy demand in buildings. It has been neglected, however, for the simplicity so it is difficult to find any DB for south Korean cities. Even meteorological department of S. Korea doesn't report the data officially. In this study, current methods that are being used in many countries are investigated and used to calculate degree-days of 35 south Korean cities with 30 years(1981~2010) historical data. The calculation result indicates that the error among 4 major methods are dependent on how daily or hourly temperature are treated in the calculation and how balance point temperature is defined. The errors of the methods are no larger than 6% relative to hourly degree-day method.

기후변화를 고려한 외벽 최적단열두께 검토 (Examination of the Optimal Insulation Thickness of Exterior Walls for Climate Change)

  • 정재훈
    • KIEAE Journal
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    • 제11권6호
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    • pp.81-86
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    • 2011
  • By strengthening the insulation performance of a building, a great deal of energy can be saved and a comfortable indoor environment can be offered to people. On the other hand, the climate, which has a great influence on the indoor environment, is changed by global warming. Therefore, in planning building envelope structure and design, climate change should be considered. In this paper, the optimal insulation thickness of exterior walls was calculated by an economic assessment method using heating degree-days. Additionally, how much influence climate change has on planning building insulation was investigated. The examination showed that heating degree-days have decreased by about 10% due to climate change in the past few decades. It was also shown that the optimal insulation thickness of exterior walls was thin, at about 6%, in three representative Korean cities (Seoul, Daejeon, Jeju).

세시풍속 및 세시음식의 실태에 관한 연구 (A Study on the Present State of for Seasonally Special Days and Dishes)

  • 허성미;한재숙
    • 동아시아식생활학회지
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    • 제3권2호
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    • pp.83-97
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    • 1993
  • The purpose of this study is to serve as the basic data for the possible effort of succeeding to traditional culture. The major findings of this study are as follows : On the question about [the importance of Special Days] was shown to average score of 3.8 On the question about [helpfulness degree of Seasonally Special Days] was shown to average score of 3,4 Regarding to the kinds of Seasonally Special days that people celebrate most, [The New Year's Day], [Chusok(Chinese Thanks-giving day)], [Dried Vegetables and mixed bowl of five-sort grains(Chusok:The 1st Full-Moon Day)], [Red beans Gruel (The Winter Solstice)] were shown to enjoy most. In preparation of dishes for Seasonally Special Days, about 58% of the respendants answered that they prepared them at their own homes. [Rice Cake] was shown to the highest among the kinds of ready-made deshes for Seasonally Special Days. On the hand down to foods for Seasonally Special Days, about 38% of respondants answered that they do want to their daughters, The significant variable on family environment for this if family religion. On the prospect for succession of the Seasonally Special Days' customs including the dishes, about 80% of respondants answered that a part of them would be handed down to next generations. The significant variable on family environment for this is subjects' religion. On the degree of recognition of the Seasonally Special Days, mothers's group was predominent(compared with daughters')

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야외 실험 수조에서 추정한 연못하루살이($Cloeon$ $dipterum$)(Ephemeroptera: Baetidae)의 발육 유효적산온도 (Estimation of Accumulated Degree Days Required for the Development of $Cloeon$ $dipterum$ (Ephemeroptera: Baetidae) in an Experimental Tub Under Field Conditions.)

  • 이차영;김동건;최락중;백민정;윤태중;배연재
    • 생태와환경
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    • 제45권1호
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    • pp.123-128
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    • 2012
  • 연못하루살이의 성장에 필요한 유효적산온도를 구하고자 2011년 8월 7일부터 10월 10일까지 야외에 설치한 실험 수조에서 실험을 수행하였다. 실험 수조 설치일로부터 4일 경과 후 수면에서 죽은 암컷 성충 한 개체가 발견되어 산란이 이루어졌을 것으로 추정하였으며, 산란추정일로부터 39일째부터 성충이 우화하기 시작하여 61일째에 마지막 개체가 우화하였다. 우화한 성충은 총 229개체였고, 성비(암컷 수/전체 수)는 0.45로 수컷이 많았으나 통계적으로 유의하지 않았으며($p$ >0.05), 전체적으로 수컷이 먼저 우화하는 경향을 보였다. 최저 발육임계온도를 $0^{\circ}C$로 하여 유효적산온도를 산출한 값은 $1,221.8{\pm}116.0$ DD였으며, 대조습지의 연간 유효적산온도가 5,650.0 DD임을 고려할 때, 연못하루살이는 본 연구결과를 적용할 경우 야외 서식처에서 최대 1년 4세대의 생활사를 가질 가능성이 있다.

Factors Affecting In vitro True Digestibility of Napiergrass

  • Chen, Chia-Sheng;Wang, Su-Min;Hsu, Jih-Tay
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권4호
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    • pp.507-513
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    • 2006
  • Changes of in vitro true digestibility (IVTD) of Napiergrass (Pennisetum purpureum) were determined by a filter bag system, and their relationships to chemical composition, leaf to stem ratio, plant height, geographic location, climatic factors and harvest interval were studied and used to develop prediction models for the crude protein (CP), acid-detergent fiber (ADF), and neutral-detergent fiber (NDF) contents and IVTD. Partitioning the total variance of IVTD of Napiergrass showed that 80% was attributable to the effect of harvest interval. Days of growth, plant height, leaf/stem ratio, CP, ADF and NDF of Napiergrass had highly significant relationships (p<0.01) with IVTD. The highest coefficient of correlation between the ADF, NDF, and IVTD of Napiergrass and growth degree days was obtained when the base temperature was set at $0^{\circ}C$. Growth degree days could predict ADF, NDF, and IVTD of Napiergrass more accurately than plant height, and plant height is not suitable to predict IVTD.

진주조의 파종기이동에 따른 유효적산온도 및 생산성 (Growing Degree Days and Productivity by Shifting Planting Dates in Pearl Millet)

  • 최병한;박근용;박래경
    • 한국작물학회지
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    • 제35권2호
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    • pp.122-125
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    • 1990
  • 양질 다수성 신사료작물 진주조의 파종적기 및 파종기 이동에 따른 유효적산온도 및 생산성의 변이를 구명하기 위하여 시험 I(Australia), II(Suwon 1)로 나누어 1986-88년에 수원, 춘천, 대전, 진주, 무안, 제주에서 4월 15일부터 7월 15일까지 15일 간격으로 시험하였던 바 그 결과의 개요는 다음과 같다. 1. 파종기가 늦어짐에 따라서 출아일수가 12일에서 3일까지 단축되었고 유효적산온도는 평균 32.1$^{\circ}C$였다. 2. 출수일수는 파종기가 늦어짐에 따라서 96일에서 54일까지 크게 단축되었으나 유효적산온도는 평균 697$^{\circ}C$였으며 변이계수도 6으로 매우 낮았다. 3. 종실용 진주조의 경제적 파종시기는 5월 상순부터 6월 하순까지였다. 수확지수도 6월 하순까지는 큰 변이가 없었으나 7월 15일 파종구는 급격히 낮아졌다. 4. 청예용 진주조의 경제적 파종시기는 5월 중순부터 6월 중순까지였으며 파종적기는 5월중순이었다. 특히 7월 상순 파종부터는 청예수량이 급격히 낮아졌다.

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장기 저장 김치 맛 평가에 적합한 관능 척도에 대한 연구 (A Study on Sensory Measures Suitable for an Evaluation of Taste of Long-term Stored Kimchi)

  • 권수호;이명석;이동하
    • 산업공학
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    • 제13권4호
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    • pp.745-750
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    • 2000
  • This paper evaluated the 12 sensory measures suitable for evaluating taste of kimchi stored for 64 maturing days in the three kimchi refrigerators each made by the three different electronics companies respectively. The panel composed of 6 married women and 6 married man tasted sample of kimchi 8 times during the 64 maturing days. Analysis of variance results showed that among the 12 sensory measures sour smell, fresh smell, fermenting smell, sour taste, fresh taste, sensory satisfaction, and maturing degree were sensitive to differentiate both maturing days and refrigerators. Among sensory measures, maturing degree showed the most consistently increasing pattern during maturing days and the most consistently differentiating pattern for the refrigerators.

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22.9kV 트리억제형 전력케이블의 성능평가 (Efficiency appraisal of 22.9kV tree retardant power cable)

  • 김위영;윤대혁;박태곤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.179-182
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    • 2002
  • XLPE compound have used for insulation of 22.9(kV) power cable. But tree retardant power cable has developed and is going to br used commonly. TR XLPE compound retard production and growth of water tree. In this paper, tensile strength, elongation at break, degree of crosslinking, lightning impulse test, AC breakdown test, cyclic aging for 14days and accelerated water treeing test of TR XLPE insulated power cable were examined according to the KEPCO buying spec. & AEIC CS 5-94 standards. before and after As the result, tensile strength, elongation at break and degree of crosslinking test results of TR XLPE insulation were higher than requirement values. After accelerated water treeing test for 120 days, 240 days and 360 days, AC breakdown voltages were not decreased for accelerated water treeing aging duration

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