• 제목/요약/키워드: thermal index

검색결과 851건 처리시간 0.029초

Development of a thermal perception index

  • Kown, Young-G.;Jerry D. Ramsey
    • 대한인간공학회:학술대회논문집
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    • 대한인간공학회 1998년도 춘계학술대회논문집
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    • pp.111-116
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    • 1998
  • This study aims to develop an easy and practical simple heat index (SHI) using climatic parameters. This simple heat index was named as a thermal perception index. Most of thermal indices are difficult to calculate or interpret for most normal person. Newly developed thermal perception index (THI) was used only a few variables for input.

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남한의 연 누적 온습도 지수에 따른 생리기후유형의 특성 (The Characteristics of Bioclimatic Types According to Annual Cumulative Temperature-Humidity Index in South Korea)

  • 강철성
    • 대한지리학회지
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    • 제43권3호
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    • pp.312-323
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    • 2008
  • 본 논문에서는 인간 생활에 기본이 되는 온도, 상대습도를 기초로 하여 인간의 온열감을 측정하여 남한의 온열감 분포의 특성과 기후유형을 파악하였다. 연구 방법은 설문지 검사를 통하여 온습도 지수 공식을 이용, 월별 온열감, 연 누적 온열감 지수를 계산하였다. 월별 온열감 지수 분석 결과 온열감의 지역적 차이는 위도 및 고도, 지형적 요인, 기단체계에 따른 영향으로 나타났다. 연 누적 온열감 지수분포는 대체로 남쪽에서 북쪽으로 갈수록, 해안에서 내륙으로 갈수록 기후 스트레스가 증가하였다. 이러한 원인으로 겨울의 추위 스트레스와 여름의 더위 스트레스가 높기 때문에 나타나는 현상으로 사료된다. 연 생리 기후유형은 쾌적함(M)기후유형, 극히 무더움(ES)유형, 쾌적함-극히 무더움(M-ES)유형, 쾌적함-무더움(M-S)유형, 더움-극히 무더움(W-ES)유형, 서늘함-극히 무더움(C-ES)유형, 서늘함-쾌적함(C-M)유형, 서늘함-쾌적함-극히 무더움(C-M-ES)유형으로 도합 8개의 기후유형으로 구분된다.

급기구 형상에 따른 겨울철 실내 온열환경의 비교 (Comparison of Indoor Thermal Environments in Winter depending on Supply Vent Configurations)

  • 한화택;정영균
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.970-975
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    • 2008
  • This study considers indoor thermal comfort in an ondol space by supply vent configurations to prevent cold draft in winter. A specially-designed vent cap has been investigated in comparison with a round pan-type vent and a simple opening without a cap. Numerical simulations have been conducted using CFD to analyze thermal comfort indices such as Predicted Mean Vote (PMV) and Effective Draft Temperature (EDT) as well as air distribution index i.e. Air Diffusion Performance Index (ADPI). Results show the new vent cap provides improved thermal comfort conditions especially near ondol heated floor, as the cold outdoor air spreads upwards along the vertical wall before reaching occupant region near floor. This paper includes discussions on the flow and comfort distributions created by the thermal jets from the vents.

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상변화 냉각시스템의 정량적 성능지수 연구 (A Study on Quantitative Performance Index for Phase-Change Cooling Systems)

  • 장명언;송혜은
    • 한국군사과학기술학회지
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    • 제23권3호
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    • pp.237-245
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    • 2020
  • In this paper, I introduce Phase-Change Cooling for thermal management of high power devices that can be applied to High Power Laser and Electric Propulsion Systems which are composed of multiple distributed superheat sources. Phase-Change Cooling can be good used to efficient cooling of their heat sources. Phase-Change Cooling has extremely high efficiency of two-phase heat transport by utilizing heat of vaporization, relatively low flow rates and reduced pumps power. And I suggest TPI(Thermal Performance Index) which is a quantitative performance index of Phase-Change Cooling for thermal management. I quantify the performance of Phase-Change Cooling by introducing TPI. I present the test results of TPI's changing refrigerant, heat sink and flow rate of the Phase-Change Cooling system through the experiments and analyze these results.

수치분석을 통한 내부구속 매스콘크리트의 온도균열지수 결정 (Determination of Thermal Cracking Index of Internal Restricted Mass Concrete Using a Numerical Analysis)

  • 서기영;김희성;진치섭
    • 한국구조물진단유지관리공학회 논문집
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    • 제11권1호
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    • pp.57-67
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    • 2007
  • 콘크리트 구조물의 사용수명은 콘크리트의 초기에 발생하는 균열에 큰 영향을 받는다. 특히 매스콘크리트 구조물에서는 수화열이 초기 온도균열의 주요한 원인이 된다. 이러한 온도균열은 콘크리트 표준시방서에 제시된 온도균열지수를 통해 분석할 수 있다. 따라서 본 논문은 내부구속이 지배적인 매스콘크리트에서 여러변수(시멘트종류, 타설높이, 양생조건, 타설온도, 단위시멘트량)에 따른 온도균열지수를 해석적으로 분석하였고, 분석결과는 변수의 변화에 따른 온도균열지수의 증감률로 나타내었다. 이러한 결과는 시공이나 설계시 온도균열을 파악하는 데 도움을 주어 경제적이고 안정적인 매스콘크리트 구조물의 설계에 유용하게 활용될 것으로 판단된다.

PDP의 격벽 형성 공정인 감광성 공법에서 $B_2O_3-Al_2O_3-SiO_2$계 유리 조성의 열적 특성과 굴절률 변화 (Thermal Properties and Refractive Index of $B_2O_3-Al_2O_3-SiO_2$ Glasses for Photolithographic Process of Barrier Ribs in PDP)

  • 황성진;원주연;김형순
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.321-321
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    • 2008
  • To obtaingood resolution in PDP, one of the important factors is to achieve the accuracy of barrier ribs. The photolithographic process can be used to form patterns of barrier rib with high accuracy and a high aspect ratio. The composition for photolithography is based on the $B_2O_3-SiO_2-Al_2O_3$ glass system including additives such as alkali oxides and alkali earth oxides. The refractive index and thermal properties in glass system are changed by amount of alkali oxides and alkali earth oxides. Therefore, it is important that additives are controlled to have proper refractive index and thermal properties. The additives are contributed to non-bridging oxygen within the glass network, causing a change of density. In addition to a change of the structural cross-link density, the refractive index, dielectric and thermal properties glass are correlated with ionic radius and polarizability of cations. In this study, we investigated the refractive index and the thermal properties such as glass transition temperature, glass softening temperature and coefficient of thermal expansion by changing composition in the $B_2O_3-SiO_2-Al_2O_3$ glass system.

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학교건물에서 냉방부하에 따른 열적 쾌적성 평가지표 비교 연구 (A Study on the Comparison of Thermal Comport Performance Indices for Cooling Loads in the Classroom)

  • 노광철;오명도
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1274-1279
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    • 2004
  • We performed the numerical study on the comparison of thermal comport performance indices for cooling loads in the classroom when the 4-way cassette air-conditioner is mounted on the ceiling. We investigated the velocity and the temperature distribution of the classroom as with respect to the variation of the air diffusion angle of the air-conditioner. Air diffusion performance index and Predicted mean vote were used for analyzing the characteristics of the thermal comport in the classroom and comparing their values each other. From the numerical results, we knew that the thermal comport is largely affected by the air diffusion angle and velocity of the air-conditioner. And we also found out that the qualitative tendency of the distribution between Air diffusion performance index and Predicted mean vote is very similar in all occupied zone.

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A Study on the Suggestion of Thermal Comfort Range in Radiant Floor Ondol Heating System

  • Chung, Kwang-Seop
    • International Journal of Air-Conditioning and Refrigeration
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    • 제12권2호
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    • pp.108-112
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    • 2004
  • The purpose of this study is to investigate the characteristics of thermal comfort index and to present the thermal comfort range through regression analyses and experiment in a radiant floor heating system laboratory. The results were compared to the comfort zone of ISO-7730, and the applicability of the thermal comfort index to a radiant floor heating system was studied. On comparing the sedentary posture on the floor to sitting on the chair, the comfort zone and the neutral point of comfort index showed different values. It is considered that the influence of conduction from floor to the human is sufficient. Moreover, we could find a correlation between the thermal sensation votes of subjects, and the comfort indexes were lower than those by calculation.

기후변화 대응 건축물 기화냉각시스템 적용에 따른 외부 열환경 변화 연구 (Changes in the External Heat Environment of Building Evaporative Cooling Systems in Response to Climate Change)

  • 윤용한;권기욱
    • 한국환경과학회지
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    • 제27권12호
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    • pp.1261-1269
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    • 2018
  • The purpose of this study was to investigate changes in the external thermal environment, following the application of evaporative cooling systems in buildings, in response to climate change. In order to verify changes in the external thermal environment, a T-test was performed on the microclimate, Thermal Comfort Index (TCI), and building surface temperature. Differences in microclimate, following the application of the evaporative cooling system in the building, were significant in terms of temperature and relative humidity. In particular, temperature decreased by more than 7% when the evaporative cooling system was applied. According to the results of the Thermal Comfort Index analysis, the Wet-Bulb Globe Temperature (WBGT) was below the limit of outdoor activities, indicating that outdoor activities were possible. The Universal Thermal Climate Index (UTCI) values were within the very strong heat stress range when the evaporative cooling system was not applied, When the system was applied, the UTCI values were within the strong heat stress range, indicating that they were lowered by one level. The building surface temperature decreased by ~10% or more when the evaporative cooling system was applied, compared to when it was not applied. Finally, the outside surface temperature of the building decreased by ~12% or more when the system was applied, compared to when it was not applied. We conclude that the energy saving effect of the building was significant.