• Title/Summary/Keyword: Climatic test

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Effects of Local Climatic Conditions on the Yearly Cone Production in Progeny Test Stands of Korean White Pine (국지기후가 잣나무 차대검정림의 년도별 구과 결실량에 미치는 영향)

  • 신만용;장용석;한상억;김영채
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.4 no.3
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    • pp.141-150
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    • 2002
  • This study was conducted to reveal the effects of local climatic conditions on the yearly cone production in progeny test stand of Korean white pine. For this, yearly cone production by locality of progeny test stands was first measured and analyzed. The effects of climatic conditions on the cone production was analyzed by the estimation of yearly local climates based on both a topoclimatological method and a spatial statistical technique. From yearly climatic estimates, 19 climatic indices affecting cone production were computed for each of the progeny test stand. The yearly cone productions were then correlated with and regressed to the climatic indices to examine effects of local climatic conditions on the reproductive growth. According to correlation analysis, it was found that some typical climatic indices by locality were significantly correlated with the cone production. Also, the optimal regression equations which can estimate cone production by local climatic conditions were provided for applying to each of the progeny test stand of Korean white pine.

Analysis and Investigation of International(UIC, EN, IEC) and Domestic Standards(Test Methods) for Climatic Wind Tunnel Test of Rolling Stock (철도차량 기후환경시험을 위한 국제 규격(UIC, EN, IEC) 및 국내 규격(시험방법) 분석 및 고찰)

  • Jang, Yong-Jun;Chung, Jong-Duk;Lee, Jae-Cheon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.782-789
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    • 2020
  • The demand for the development of rolling stock technology to maintain the best performance in various climatic environments has increased to expand the overseas market of rolling stock. In this study, international and domestic standards that must be applied to build a harsh climatic environment test system were investigated and compared. The way of improvement for domestic standards is proposed. The wind velocities and temperatures are specified in the UIC, EN, and IEC standards for climatic wind tunnel, and EN 50125-1 provides the velocity test up to 180km/h, the largest wind speed. UIC and EN provide the lowest temperature of -45℃, and IEC 62498-1 provides the highest temperature 55℃. The solar radiation test was specified up to 1200W/m2 in the UIC, EN, and IEC. The IEC, EN, and KS R 9145 provide the water tightness standards, which are different from each other in water capacity, pressure, and methods. The snow test method was not well specified. KRTS-VE-Part 31 provides pressurization test methods. The airtightness standards for high-speed rolling stock are defined and regulated for internal pressure change rate in UIC 660 and 779-11. The domestic standard for the wind tunnel test was not well prepared, and the solar radiation test and snow test do not exist in Korea. Therefore, it is necessary to improve domestic standards to an international level for the climatic wind tunnel test of rolling stock.

Analysis of Wetness/Dryness in Geum River Basin based on Climatic Water Balance (기후학적 물수지에 의한 금강유역의 습윤/건조 상태 분석)

  • Kim, Joo Cheol;Lee, Sang Jin
    • Journal of Korean Society on Water Environment
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    • v.26 no.2
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    • pp.243-251
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    • 2010
  • Evapotranspiration and rainfall-runoff are the major components of hydrological cycle and thereby the changes of them can directly affect the wetness/dryness or runoff characteristics of basins. In this study the wetness/dryness in Geum river basin are classified by dint of cumulative probability density function of monthly moisture index and the long term changes of them are analyzed based on climatic water balance concept. The drought events in Geum river basin are selected through evaluation of monthly moisture index and the various hydrological properties of them are investigated in detail. Also the trends of time-series of climatic water balance components are examined by Seasonal Kendall test and the variability of hydrological cycle in Geum river basin during the recent decade is inquired. It is judged that the results of this study can be contributed to establishment of the counter plan against the future drought events as the fundamental information.

Effects of Local Climatic Conditions on the Early Growth in Progeny Test Stands of Korean White Pine (지역별 잣나무 차대검정림의 초기생장에 미치는 미기후의 영향)

  • 신만용;김영채
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.4 no.1
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    • pp.1-11
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    • 2002
  • This study was conducted to reveal the effects of local climatic conditions on the early growth of Korean white pine progeny test stands. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age and locality were first measured and summarized for each stand. Based on these statistics, annual increments for 10 years from stand age 10 to 20 were calculated for each of stand variables. The effects of local climatic conditions as one of environmental factors on the growth were then analyzed by both a topoclimatological method and a spatial statistical technique. From yearly climatic estimates,30 climatic indices which affect the tree growth were computed for each of the progeny test stand. The annual increments were then correlated with and regressed on the climatic indices to examine effects of local climatic conditions on the growth. Gapyung area provided the best conditions for the early growth of Korean white pine and Kwangju area ranked second. On the other hand, the growth pattern in Youngdong ranked last overall as expected. It is also found that the local growth patterns of Korean white pine in juvenile stage were affected by typical weather conditions. The conditions such as low temperature and high relative humidity provide favor environment for the early growth of Korean white pine. Especially, it was concluded that the low temperature is a main factor influencing the early growth of Korean white pine based on the results of correlation analysis and regression equations developed far the prediction of annual increments of stand variables.

Comparison of Climatic Environmental Test Standards of MIL-STD-810 and IEC Pub. 60068 (MIL-STD-810과 IEC Pub. 60068 기후적 환경시험 규격의 비교)

  • Kim, H.J.;Kim, M.S.
    • Journal of Applied Reliability
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    • v.9 no.2
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    • pp.81-91
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    • 2009
  • This paper presents the comparison of climatic environmental tests of IEC Pub. 60068 and MIL-STD-810. Cold, dry heat, change of temperature, and heat-humidity cyclic tests are compared in terms of the types of tests and test severities. This study shows the difference between the standards, which will provide the useful information to the industries and be helpful in applying the standards.

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Trend Analysis of Wetness/Dryness in Geum River Basin (금강유역의 습윤/건조 상태에 대한 경향성 분석)

  • Kim, Joo-Cheol;Lee, Sang-Jin;Hwang, Man-Ha;Ahn, Jung-Min
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.1640-1644
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    • 2010
  • In this study the wetness/dryness in Geum river basin are classified by dint of cumulative probability density function of monthly moisture index and the long term changes of them are analyzed based on climatic water balance concept. The drought events in Geum river basin are selected through evaluation of monthly moisture index and the various hydrological properties of them are investigated in detail. Also the trends of time-series of climatic water balance components are examined by Seasonal Kendall test and the variability of hydrological cycle in Geum river basin during the recent decade is inquired. It is judged that the results of this study can be contributed to establishment of the counter plan against the future drought events as the fundamental information.

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Modeling of Daily Pan Evaporation using the Limited Climatic Variables and Polynomial Networks Approach (제한된 기상변수와 Polynomial Networks Approach를 이용한 일 증발접시 증발량의 모형화)

  • Kim, Seong-Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.1596-1599
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    • 2010
  • Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily pan evaporation (PE) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it is composed of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily PE data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as pan evaporation modeling can be generalized using GMDH-NNM.

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Ground High/Low Temperature Test for FA-50 Aircraft (FA-50 경공격기 전기체 지상 고/저온시험)

  • Ahn, Jong Hoon;Kim, Tae Ho;Woo, Seung Cheol;Cho, Young Kyun;Kim, Do Wan
    • Journal of the Korean Society of Systems Engineering
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    • v.6 no.1
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    • pp.41-46
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    • 2010
  • The ground high/low temperature test objective is to check the normal ground operation of FA-50 aircraft in the extreme ground ambient conditions. The aircraft was exposed in climatic conditions of the basic climatic category according to the MIL-HDBK-310. For verified normal operation in the extreme high temperature, the high temperature test was performed in the hot regional type conditions and accentuated solar radiation heat. This test was performed at the test chamber in ADD where is in Haemi. This paper was described about the test procedure of FA-50 high/low temperature including preparation, testing and results.

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Energy self-sufficiency of office buildings in four Asian cities

  • Kim, Jong-Jin
    • Advances in Energy Research
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    • v.2 no.1
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    • pp.11-20
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    • 2014
  • This paper examines the climatic and technical feasibilities of zero energy buildings in Seoul, Shanghai, Singapore and Riyadh. Annual and seasonal energy demands of office buildings of various scales in the above cities were compared. Using optimally tilted rooftop PV panels, solar energy production potentials of the buildings were estimated. Based on the estimates of onsite renewable energy production and building energy consumption, the energy self-sufficiencies of the test buildings were assessed. The economic feasibilities of the PV systems in the four locations were analyzed. Strategies for achieving zero energy buildings are suggested.

Thermal and subjective responses by sun hats for farmer in a hot climatic chamber (서열 환경에서 농작업 모자 착용에 따른 체온 조절 및 주관적 반응)

  • 김명주;최정화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.5
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    • pp.713-722
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    • 2004
  • This study examined the effects of two kinds of functional sun hats through a head-manikin test and a climatic chamber trial for farm workers in summer. Experiment was composed of four conditions. The first condition was the condition without any hat (Control). The second was the condition with a sun hat on the market (Hat A). The third was the condition with a functional sun hat made of reflective fabric (Hat B). The last was the condition with a functional sun hat having a ventilating structure as well as reflective fabric (Hat C). For the subjects in the climatic chamber trials, 12 healthy males volunteered. Air temperature, relative humidity and globe temperature in the chamber was maintained at $33{\pm}0.5^{\circ}C,\;65{\pm}5%RH\;and\;39{\pm}1^{\circ}C\;(WBGT\;33^{\circ}C)$. Subjects did a simulated red pepper-work (50-min work and 10-min rest, twice repetition) for 120 min. As the result of head-manikin test, the surface temperature on middle of back-neck was the lowest in Hat B of four conditions and the surface temperature on top of head was the lowest in Hat C. As the result of climatic chamber trials, there were apparent differences between with (Hat A, Hat B, Hat C) and without a sun hat (Control). In rectal temperature ($T_{re}$), mean skin temperature ($\={T}_{sk}$), heart rate (HR), total sweat rate (TSR), The physiological heat strain was less in the condition with hats than in the condition without a sun hat. As the increasing rate in Tre, Hat B is the most effective hat for alleviation heat strain. As the subjective responses, Hat B was the most effective hat for thermal comfort even though the difference was not significant. Hat C was less effective than Hat B and the reason might be the increase of weight due to inserting the ventilating structure.