• Title/Summary/Keyword: outdoor climatic conditions

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Leakage Current Properties Analysis of Outdoor Insulator on Climatic.Environmental Factor (기후.환경 인자에 의한 옥외 절연물의 누설전류 특성 분석)

  • Lee, Won-Yeong;Shim, Kyu-Il;Han, Sang-Ok;Park, Gang-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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    • pp.27-30
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    • 2002
  • In this paper, we were investigated leakage current properties of outdoor insulator on climatic environmental factor. Contamination is one of the most important factor to determine the performance of insulator. Thus, it is very important to exam the contamination degree on the outdoor insulator. There are many limits, such as reliability of data, interval of measurement and similarity of environmental conditions, in conventional method. So, we measured phase and leakage current of outdoor insulator using the temperature & humidity chamber. In this investigation, phase difference was measured to compare the variance of phase difference with the contamination degree and relative humidity.

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Pollution Cycle Method with NSDD Contaminant (불용성 오손물을 이용한 오손주기시험법)

  • Lee, Won-Yeong;Choi, Nam-Ho;Park, Gang-Sik;Han, Sang-Ok
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1481-1483
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    • 2001
  • There is a wide climatic difference between Korea and foreign countries. Thus, the pollution cycle method, based on the climatic condition of Korea, is needed to evaluate the electrical properties of outdoor insulators. We make a analysis on the cycle methods of foreign countries, climatic conditions of Korea and failure data to make the cycle method. From the result, we can design a good pollution cycle method to evaluate the electrical properties of outdoor insulators.

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Human Solar Heat Load and Thermal Comfort in an Outdoor Environment (건축외부공간에 있어서 인체의 일사열부하(日射熱負荷) 및 열적(熱的) 쾌적성(快適性)에 관한 실험적 연구)

  • Jeong, Chang-Won;Yoon, In
    • Journal of the Korean Society of Industry Convergence
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    • v.1 no.2
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    • pp.65-74
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    • 1998
  • The purpose of this paper is to investigate the mount of relief of human solar heat load and thermal comfort in outdoor environment in summer, Six different types of sites, T garden and its neighboring area in Japan, were selected as the experiment sites. The experiments were conducted from 22 to 29 August, 1994 to find the relationship between climatic conditions and human responses, Climatic conditions, subjects's thermal sensation and skin temperature were measured. Radiant heat exchange on the human body was estimated on the basis of the measured air and surface temperature and solar radiation. Thermal index Operative Temperature and New Effective Temperature was modified with the effect of the radiant heat exchange. Human thermal comfort and skin temperature is affected by the solar radiation and the sky factor in an outdoor environment. The effect of tree shade was verified on thermal comfort, The mount of relief of human solar heat load is relation to the existence of shade a solar radiation and the sky factor. The urban garden is one of the effective design element in an urban environmental planning.

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Analysis on the Thermal Comfort Aspect of a Locally-Cooled Room in Warm and Humid Environments : PPD-Based Evaluation of Human Responses (중온 고습 환경조건에서 부분적으로 냉방되는 실내의 열쾌적성에 대한 분석 : 인체반응에 대한 PPD 기준의 평가)

  • Kim, Bong-Hun;Seo, Seung-Rok
    • Journal of the Ergonomics Society of Korea
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    • v.17 no.3
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    • pp.41-59
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    • 1998
  • Thermal comfort aspect of a locally-cooled target space in warm and humid environments(typically in the rainy summer season) was studied in view of PPD index. First. theoretical analyses were conducted to examine the effect of the governing parameters(such as air temperature, relative humidity and air velocity, etc.) using a computer model. Secondly, experimental investigations were also performed in a climatic room designed to simulate corresponding thermal conditions of outdoor environments. During the tests, temporal variation of PPD was recorded as functions of climatic variables(outdoor and indoor temperatures, relative humidity and air velocity) for the given human factors(metabolic heat generation and clothing). From both theoretical and experimental investigations, air temperature and air velocity were found to be the most dominant parameters affecting PPD of the target space. Results were summarized as: 1. Relative humidity of the locally-cooled target space tends to approach that of outdoor's as the space is subjected to an ON-OFF mode of cooling, since moisture potential of the two rooms reaches an equalized state as a result of moisture diffusion. 2. It was recognized that changes in relative humidity did not show any significance in view of thermal comfort as was reported in the previous studies, while variations of both temperature and air velocity caused relatively large changes in the degree of thermal comfort. 3. In-door environment should be evaluated in terms of PPD instead of relative humidity commonly recognized as an important climatic variable particularly in warm and humid environments.

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The Impact of Comfort of built Environment and Microclimate on Outdoor Activities in Urban Space (건조환경의 쾌적성과 미기후가 도시공간의 외부활동 지속에 미치는 영향 분석)

  • Jeong, Yunnam;Lee, Gunwon
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.5
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    • pp.565-575
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    • 2019
  • This study aimed to examine the influence of physical environment, microclimate, and comfort on sustaining outdoor activities. This study has identified the main factors that influence sustaining outdoor activities as physical environment, comfort in the physical environment, microclimate and microclimate comfort. For analysis, the study conducted the investigation on pedestrian walkability during spring, summer and winter of the year 2017. The microclimate levels were also recorded at the same time. The method of logit regression analysis was used to analyze these outcomes. The result showed that the comfort and safety of the physical environment as well as the ideal climatic conditions, in terms of temperature, wind level, and solar insolation, were related to sustaining outdoor activities. Also, walking and shopping in the physical and climatic environment were the factors that were found to be more influenced than the act of remaining in a place and forming conversations.

Evaluation of thermal stability of quasi-isotropic composite/polymeric cylindrical structures under extreme climatic conditions

  • Gadalla, Mohamed;El Kadi, Hany
    • Structural Engineering and Mechanics
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    • v.32 no.3
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    • pp.429-445
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    • 2009
  • Thermal stability of quasi-isotropic composite and polymeric structures is considered one of the most important criteria in predicting life span of building structures. The outdoor applications of these structures have raised some legitimate concerns about their durability including moisture resistance and thermal stability. Exposure of such quasi-isotropic composite/polymeric structures to various and severe climatic conditions such as heat flux and frigid climate would change the material behavior and thermal viability and may lead to the degradation of material properties and building durability. This paper presents an analytical model for the generalized problem. This model accommodates the non-linearity and the non-homogeneity of the internal heat generated within the structure and the changes, modification to the material constants, and the structural size. The paper also investigates the effect of the incorporation of the temperature and/or material constant sensitive internal heat generation with four encountered climatic conditions on thermal stability of infinite cylindrical quasi-isotropic composite/polymeric structures. This can eventually result in the failure of such structures. Detailed critical analyses for four case studies which consider the population of the internal heat generation, cylindrical size, material constants, and four different climatic conditions are carried out. For each case of the proposed boundary conditions, the critical thermal stability parameter is determined. The results of this paper indicate that the thermal stability parameter is critically dependent on the cylinder size, material constants/selection, the convective heat transfer coefficient, subjected heat flux and other constants accrued from the structure environment.

Correlation Analysis between Climate and Contamination Degree through Multiple Regression Analysis (다중회귀 분석을 통한 기후 및 오손도 간의 상관관계 분석)

  • Kim, Do-Young;Lee, Won-Young;Shim, Kyu-Il;Han, Sang-Ok;Park, Kang-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05e
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    • pp.49-52
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    • 2003
  • The performance of insulators under contaminated conditions is the underlying and the most factor that determines insulation design for outdoor applications, Among the contamination factors, The sea salt is the most dangerous factor, and the salt factor have closed relation with climatic conditions, such as wind, temperature, humidity and so on, Effect of these factors to insulation system is different of each other, and need to show the correlation by multiple regression analysis techniques. In this paper, predicted and analyzed equivalent salt deposit density (ESDD) by change climatic condition through multiple regression analysis.

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A Study on relation to the Climatic Adaptation and Clothing Weight - In the Case of High School Students - (기후적응과 착의량의 관계에 관한 연구 -고등학교 학생을 중심으로-)

  • Ahn Pil-ja;Choi Jeong-Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.16 no.4 s.44
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    • pp.417-430
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    • 1992
  • To examine the effects of clothes upon human's physiological adaptation to the changes of climatic conditions, clothing weight was examined. The results are as follows; 1. According to the change in temperature, the total, upper and outer clothing weight showed remarked change. Clothing weight change was greatest between the July and October, the change was greater in the coast land and the girl students. 2. The clothing weight tends to be light under outdoor in both regions in all seasons except in July, it is remarked in inland and December. 3. The correlation between $R\"{o}hrer$ Index, Body Fat and clothing weight was recognised to be significantly reversed. 4. Positive correlation between health conditions and clothing weight was recognized in December 5. The correlation between exercise hours and clothing weight was negatively significant in December.

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Automatic Measurement of the Degree of Contamination with Electric Conductivity and Oscillating Frequency (발진주파수 및 전도도를 통한 오손도 자동측정)

  • 최남호;구경완;이명섭;한상옥;정재기
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.153-156
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    • 2000
  • To reduce the maintenance expense, and the possibility of electric outage and accident, we should optimize the outdoor insulation system. And for the optimization, accurate measurement for the degree of contamination with climatic conditions, such as wind, rain, and drought, should be carried. However the classical measuring method, brush wiping, has some problems in the aspect of man power, reliability, and expense. In this paper, we propose two type apparatus, which could detect the degree of contamination on insulators in outdoor insulation system, such as transmission and distribution line insulator and bushing. One use the leakage current, and the other use the oscillating frequency to check the degree of contamination. To avoid the oxidation of electrode AC source, and the low degree of contamination was applied. From the result of this investigation we could get the good relationship between the degree of contamination and the leakage current and oscillating frequency

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Analysis of Outdoor Design Temperatures for Heating and Cooling Greenhouses Based on Annual Percentiles (연간 백분위 방식에 의한 온실 냉난방 설계기온의 분석)

  • Nam, Sang-Woon;Shin, Hyun-Ho
    • Journal of Bio-Environment Control
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    • v.27 no.3
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    • pp.269-275
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    • 2018
  • In order to establish the criterion for analyzing outdoor weather conditions in the greenhouse heating and cooling system design, we analyzed heating and cooling design outdoor temperatures by the annual percentile method and compared with design outdoor temperatures by the existing seasonal percentile method. In the annual percentile method, 0.4%, 1% and 2% of the total 8,760 hours per year are presented as cooling design outdoor temperatures and 99.6% and 99% as heating design outdoor temperatures. When the annual percentile method was adopted, heating design outdoor temperatures increased by 6.7 to 9.6% compared with the seasonal percentile method, and cooling design outdoor temperatures decreased by 0.6 to 1.1%. The maximum heating load in the same greenhouse condition decreased by 3.0 to 3.6% when the annual percentile method was adopted, but the effect on the maximum cooling load was insignificant. Therefore, it is necessary to consider the change of heating design outdoor temperatures to the annual percentile method, but it is not necessary to change the cooling design outdoor temperatures since there is little difference between the two methods.