• Title/Summary/Keyword: Humidity variation

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Humidity Variation by Green Space Calculation Method (녹지의 산출방법이 습도변화에 미치는 영향)

  • Yoon, Yong-Han;Park, Heon
    • Asian Journal of Turfgrass Science
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    • v.16 no.1
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    • pp.41-47
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    • 2002
  • For this study grasp quantitative humidity variation with planting stratification to various green space of calculation method, observed humidity distribution in the green space. with this data, coverage condition and humidity distribution, planting calculation method and humidity, planting stratification calculation method and humidity, analyzed by revolution analysis. In this result, as well as coverage condition, planting stratification effect humidity variation. increasing planting ratio (area) and planting volume (capacity) effect higher humidity. especially, if we compared between planting stratification calculation method and higher humidity, effect by a revolution coefficient and a correlation coefficient, effect relatively planting volume (capacity) higher than stratification ratio (area). today, in the index of higher humidity, planting calculation propose application of capacity method.

A Study on the Variation of Physiology Signals based on EEG with Humidity (습도 변화에 따른 뇌파 기반 생체신호 변화에 관한 연구)

  • Kim, Myung-Ho;Kim, Jung-Min
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.1
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    • pp.50-55
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    • 2013
  • Subjects with 0.7[clo]'s amount of clothing were estimated on their thermal comfort, concentrativeness, heart rate variability, stress and fatigue degree when given variation in relative humidity to 30, 40, 50, 60, 70, and 80[RH%], in an environmental test room of temperature 25[$^{\circ}C$], illumination 1000[lux] and air velocity 0.02[m/sec], by using EEG, learning ability and HRV. At the result, it was at 50~60[RH%] of relative humidity that subject's thermal comfort and concentrativeness were at the highest while stress were at the lowest, and it was at 60[RH%] of relative humidity that heart rate variability was most stabilized. It was found that when temperature and humidity of the environmental test room are at 25[$^{\circ}C$] and 50~60[RH%], subject's productivity and psychological state are least affected.

Effect of inlet air humidity on the combustion process of the spark-ignition engine (흡입습도가 스파아크 점화기관의 연소과정에 미치는 영향)

  • 김문헌;이성열
    • Journal of the korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.41-47
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    • 1983
  • The analysis shows that the variation of maximum pressure of the cycle, rate of hear release, rate of mass burned, and combustion delay are influenced by the inlet air humidity in the spark-ignition engine. The quantitative combustion delay can be obtained from the rate of mass burned. Also, the variation of time loss and effective compression ratio with the change of inlet air humidity are dominated by the development of rate of heat release.

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Characteristics of Meteorological Environment Variation Before and After Construction of Nak-dong River Estuary Barrage (낙동강 하구둑 건설 전·후의 기상환경 변화 특성)

  • Jeon, Byung-Il
    • Journal of Environmental Impact Assessment
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    • v.14 no.3
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    • pp.135-145
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    • 2005
  • This study was conducted to investigate the characteristics of meteorological environment variation before and after construction of Nak-dong river estuary barrage. We used meteorological data(air temperature, precipitation, relative humidity, visibility, wind) at Gimhae airport meteorological station. The construction of river estuary barrage can change climate at the neighboring districts and influence human's health and vegetable. The construction of Nakdong river estuary barrage brought rise of temperature, decrease of relative humidity and increase of poor visibility frequency.

A study on indoor environmental elements of the granite model dome in different envelope materials during summer season (하절기, 석재 모형돔의 외피 유형별 실내환경 요소에 관한 연구)

  • 공성훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.6
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    • pp.898-902
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    • 1999
  • During summer season, the weather condition of Korea is hot and humid. So humidity elements are very important relating to building envelope condition. The purpose of this investigation is to measure and analyze characteristics of summer's environmental elements such as relative humidity, dry bulb temperature and air velocity in the clay/cement envelope materials using a granite dome model. According to the variation of exterior humidity, the state of interior relative humidity for clay model has an equal tendency, although a little range of variation is shown in comparison to the cement model.

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A study on the characteristics of environmental factors of granite dome models with different envelope structures in winter (외피 유형별 석재 모형돔의 동절기 환경 특성에 관한 연구)

  • 공성훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.5
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    • pp.642-646
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    • 1999
  • Factors governing the rate of heat exchange comprise the air temperature, the speed of air movement, relative humidity, and relation indoors. Recently, there are many researches on the transient analysis of indoor environmental factors such as the dry bulb temperature, relative humidity and air velocity in miniature models. The purpose of this study is to measure the environmental factors and to analyze and evaluate the characteristics of indoor environment with the different envelope structures using a granite dome model. According to the variation of humidity, the state of interior relative humidity for clay model has an equal tendency, although a little range of variation is shown in comparison to the cement model.

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Influence of Temperature and Relative Humidity in Infection of Nosema bombycis (Microsporidia: Nosematidae) and Cross-infection of N. mylitta on Growth and Development of Mulberry Silkworm, Bombyx mori

  • Chakrabarti, Satadal;Manna, Buddhadeb
    • International Journal of Industrial Entomology and Biomaterials
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    • v.17 no.2
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    • pp.173-180
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    • 2008
  • The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

Computational Fluid Dynamics Study on Performance Variation of PEMFC with Serpentine Flow Fields According to Humidity Condition (가습조건이 사형유로를 채택한 고분자 전해질 연료전지의 성능에 미치는 영향에 대한 전산유체역학 해석 연구)

  • Oh, Gyu-Hwan;Lee, Kyu-Jin;Nam, Jin-Hyun;Kim, Charn-Jung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.8
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    • pp.604-612
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    • 2009
  • Water management has been recognized as a crucial factor for achieving better performance and stability in polymer electrolyte membrane fuel cells (PEMFCs). Proper water management should provide favorable water conditions, including the local humidity, membrane water content, and liquid water saturation in PEMFCs, thereby leading to more uniform electrochemical reaction and current generation. In this study, computational fluid dynamics (CFD) simulation was conducted to investigate the effects of the cathode relative humidity (RH) on the performance of a 3 by $3\;cm^2$ PEMFC with serpentine flow fields. The CFD results showed that the best performance of the PEMFC was obtained for the cathode RH of 80%, but the performance variation was small for the cathode RH range of $60{\sim}100%$. However, the loss of the PEMFC performance was significant when the cathode RH was reduced below 40%. The reason for such performance variation was investigated through the detailed inspection of ohmic loss, activation and concentration overpotential, and water and current distributions.

A Surface Humidity Model of Drying Concrete Immediately after Placement (타설 직후 건조하는 콘크리트의 표면습도 모형)

  • Jeong, Jin-Hoon
    • International Journal of Highway Engineering
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    • v.7 no.3 s.25
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    • pp.23-30
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    • 2005
  • Predicting distribution and variation of humidity inside concrete is essential to improve curing quality of concrete at field. The concrete humidity is predicted by numerical analysis using surface humidity as boundary condition. However, ambient humidity has been used instead of the surface humidity because the surface humidity could not be ccurately measured. Because it is hard to accurately measure the surface humidity, owever, the ambient humidity has been used instead of the surface humidity in the numerical analysis. In this paper, a methodology to accurately measure the surface humidity is suggested, and the ambient humidity and the humidity at the surface and inside the concrete measured by a series of laboratory tests are presented. The cause of low concrete humidity immediately after placement was investigated by a separately performed test. A surface humidity prediction model was developed using the measured humidity, and consequently validated through an additional test.

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Gas Detecting Characteristics Using Catalytic Combustion Type Gas Sensor (접촉연소식 가스 센서를 이용한 감도특성)

  • Yoon, Hun-Ju;Ko, Keel-Young;Lee, Jong-Pil;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.773-777
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    • 2002
  • In this study, we analyzed the LPG and LNG sensitivity measurement and voltage variation using catalytic type gas sensor characteristics in catalytic combustion type gas detecter sensors. gas detector shall operate as intended when exposed for 24 hours to air having a relative humidity of 0~85 percent at a temperature of $20[{\mu}m]$ and humidity of 45 percent at a temperature of $-10{\sim}40[^{\circ}C]$ the gas detecter sensors are to be subjected to operation for 210 days in an area that has been detemined to be equivalent to a typical residential atmosphere with an air velocity of 50 [cm/sec]. The source of energy for a gas detector sensors employing a supplementary basic circuit is energized from a separate source of supply direct applied voltage 2.1[V], 2.2[V], 2.3[V]. As a result, it was confirmed that the relative humidity and temperature by regression each analysis, compared to the LPG characteristic graph and methane characteristics graph by a relative humidity of 0 ~ 85 [%] at a temperature range of $-10{\sim}40[^{\circ}C]$ show a similar linear pattern on the whore.

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