• 디지털콘텐츠학회 논문지
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• 제7권1호
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• pp.47-52
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• 2006

본 논문에서는 전두엽과 두정엽의 4채널 뇌파를 이용하여 인간의 쾌적성 평가를 위한 알고리즘을 개발하고자 한다. 알고리즘은 선형 예측 분석과 신경회로망으로 구성되며, 많은 피검자들의 템플릿(template)을 활용한다. 먼저 다양한 실험 환경을 조성하여 쾌적 및 불쾌적한 상태의 뇌파를 수집하였다. 그리고 나서 개발된 알고리즘을 이용하여 쾌적성 평가 실험을 수행하였으며, 전두엽의 a파 전력비(power ratio)를 이용한 기존의 감성 평가 방법과 성능을 비교해 보았다. 온도와 습도를 이용한 쾌적성 평가를 위해 여러 방법으로 수집된 뇌파를 통해 적은 채널을 이용하면서 감성을 평가할 수 있는 전극의 위치를 확인하고자 실시한 여러 가지 조합의 2채널, 4채널 실험에서는 쾌적성 평가 결과가 제시한 task와 80%가 일치하여 Heller의 감정 모델에 근거한 4채널이 가장 변별력을 나타내는 전극의 위치임을 알 수 있었다. 또한 기존의 a파 전력을 통하여 뇌의 활성 영역을 구분하여 감성을 평가하는 방법에서는 상당히 저조한 성능을 나타내어 감성과의 상관성을 확인할 수 없었다.

• 산업기술연구
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• 제25권A호
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• pp.151-156
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• 2005

Auto exhausts and air pollution can become trapped in the cabin of vehicle, reducing the amount of oxygen available for breathing. Driver may feel sleepy, headaches, nausea, confusion, dizziness and lower levels of oxygen can damage the driver's general health. Consequently, oxygen generator purified oxygen into the car to help driver get the oxygen driver's body needs. In this study, in order to evaluate the oxygen generator performance, the samples that the various conditions(humidity(50%, 100%), flow and oxygen concentration) were examined. There were three types of oxygen generator; sample 1($2.5{\ell}/min$, $36%O_2$), sample 2($4.5{\ell}/min$, $41%O_2$) and sample 3($5{\ell}/min$, $39%O_2$). As the humidity increased from 50% to 100%, the oxygen concentration of the sample 1(36%), 2(41%) and 3(39%) was reduced $31%O_2$, $38%O_2$ and $38%O_2$, respectively. Also, the each sample measured that effect of human in car on oxygen concentration, if the oxygen concentration is one person in car, each sample of oxygen concentration was $20.8%O_2$, $23.7%O_2$ and $21.2%O_2$. From the above results, it was shown that oxygen generator for car, if the oxygen concentration is increased, effect of humidity is reduced, and that in the sample of supplying a high-rate of oxygen, the oxygen concentration is increased. It was suggested that effect of humidity on oxygen generator for car can be reduced according to the supply of oxygen.

• 한국의류산업학회지
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• 제2권3호
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• pp.265-271
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• 2000

Heat stress results in fatigue, a decline in strength, alertness., and mental capacity. The problem is compounded when high humidity exists. To help relieve worker heat stress, many types of cooling units are marketed. While workers may experience some cooling, critical body core temperatures often continue to elevate. This study was designed to find the effects of three kinds of cooling vest with portable frozen gel strips on thermophysiological parameters and on temperature and humidity within clothing. The heart rate, rectal, and skin temperature as well as sweat rate and clothing microclimate were measured during 80 min in 5 healthy males. Inquiries were also made into the subjective rating thermal, humidity comfort, and fatigue sensations. The main findings in our experiments are as follows: (a) Physiological parameters such as rectal temperature was the lowest in garb A1, intermediate in garb A, and the highest in garb A2 throughout the experiment. And mean skin temperature was the lowest in garb A, intermediate in garb A1, and the highest in garb A2; (b) Temperature and humidity within clothing (back) were garb in Al, intermediate in garb A, and the highest in garb A2. But the temperature and humidity within clothing (chest) were garb in A, intermediate in garb A1, and the highest in garb A2; (c) Most participants (4 out of 5 persons) answered that they felt more comfortable and fatigueless in garb A1 than in garb A and A2. It is concluded that local cooling in garb A1 of the upper torso could physiological reduce the thermal strain in participants wearing cooling vest.

• 공업화학
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• 제31권1호
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• pp.57-60
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• 2020

An acetaldehyde, a representative food waste odor, was decomposed using a hybrid system comprised of a non-thermal plasma and catalyst at an ambient temperature under high humidity. A five wt.% Mn was impregnated on two differently structured microporous zeolites, namely Beta and ZSM-5, with a different molar ratio of SiO₂/Al₂O₃. Under high humidity conditions, the acetaldehyde degradation was higher in zeolites with the high ratio of SiO₂/Al₂O₃. Among studied catalysts, a five wt.% Mn/Beta (SiO₂/Al₂O₃ = 300) showed the highest acetaldehyde removal activity owing to its high hydrophobicity and reducibility. During long term stability test using the same catalyst for 110 hours, the acetaldehyde removal activity was relatively well-maintained.

• 한국농공학회논문집
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• 제54권5호
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• pp.49-55
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• 2012

In order to derive the efficient utilization of low pressure compressed air fogging system, cooling efficiencies with control types were analyzed through cooling experiments in tomato greenhouses. The control types were set up with temperature control, humidity control, temperature and humidity control, and time control. It showed that the cooling effects were 0.7 to $3.3^{\circ}C$ on average and maximum of 4.3 to $7.0^{\circ}C$, the humidification effects were 3.5 to 13.5 % on average and maximum of 14.3 to 24.4 %. Both the cooling and humidification effect were the highest in the time control method. The cooling efficiency of the air fogging system was not high with 8.3 to 27.3 % on average. However, the cooling efficiency of 24.6 to 27.3 % which appears from the time control is similar to the cooling efficiency of high pressure fogging system experimented in Japan. The air fogging system is operated by low pressure, but its efficiency is similar to high pressure. We think because it uses compressed air. From this point of view, we suggest that the air fogging system can get the cooling efficiency of similar levels to that of high pressure fogging system and it will have an advantage from clogging problem of nozzle etc.

• 한국환경과학회지
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• 제30권11호
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• pp.925-936
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• 2021

The study was aimed to investigate the correlation between tidal effects and fog occurrence in Incheon and Mokpo, which are located in the middle and southern coasts of the West Sea of Korea, respectively. The investigation used meteorological data obtained from the automated synoptic observing systems and automatic weather stations and ocean data from tide stations from 2010 to 2019. Fog occurrence frequency was highest at high tide (Incheon, 41%; Mokpo, 45%). During fog event days at high tide, the dew-point depression was low (Incheon, 0.5℃; Mokpo, 0.4℃) and the relative humidity was high (Incheon, 97%; Mokpo, 98%). The wind speed was 2.4 m/s in Incheon and 2.0 m/s in Mokpo, and the main wind directions were west-southwesterly from Incheon and southwesterly from Mokpo. In the fog case study, tidal flats were covered with water before and after the fog started. During the fog period, both stations experienced negative air-sea temperature differences, low dew-point depression, and high relative humidity were maintained, with weak winds forming from the tidal flats to the shore.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.286-286
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• 2009

A small PEM fuel cell has two different stack configurations such as active and passive stacks. The active stack has a distintion of high power density although it makes system complex by using alr blower and related BOPs resulting in large system volume. On the contrary, passive stack has an advantage of compact system because it doesn't need air supplying devices although it reveals relatively low stack power density. In this study we fabricated two 10W PEMFC stacks with different stack configurations, active and passive stacks, and tested their performance and stability. The active stack consists of 13cells with an active area of $5cm^2$. The passive stack has 12cells with an active area of $16cm^2$. When we compared the stack performance of those stacks, the active stack showed higher power density compared to the passive stack, particularly at high voltage regions. However, at low voltage and high current regions, the passive stack performance was comparable to the active stack. The stack stability was largely dependent on the fuel humidity, particularly for active stack. At low humidity conditions, the active stack performance was decreased continuously and the cell voltage distribution was not uniform showing seriously low cell voltage at center cells mainly due to the cell drying. The passive stack showed relatively stable behavior at low humidity and the stack performance was largely dependent on the atmospheric conditions.

• 마이크로전자및패키징학회지
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• 제23권3호
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• pp.43-49
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• 2016

박형 package-on-package에 대해 T/H (temperature/humidity) 시험, TC (temperature cycling) 시험과 HTS(high temperature storage) 시험을 사용하여 신뢰성을 분석하였다. T/H 시험은 $85^{\circ}C/85%$의 조건으로 500시간, TC 시험은 $-40{\sim}100^{\circ}C$의 조건으로 1000회, HTS 시험은 $155^{\circ}C$의 조건으로 1,000시간 범위에서 평가하였다. 폴리이미드 써멀테이프를 사용하여 제작한 24개의 package-on-package (PoP) 시편에 대해 신뢰성 시험 전에 측정한 솔더접속 배선의 평균저항은 $0.56{\pm}0.05{\Omega}$이었으며, 24개 시편에서 모두 유사한 값이 측정되었다. 500시간까지의 T/H 시험, 1000회의 TC 시험 및 1,000시간까지의 HTS 시험후에도 솔더 접속부의 오픈 불량은 발생하지 않았다.

• 대기
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• 제30권4호
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• pp.391-404
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• 2020

To understand the characteristics of the relationship between visibility and particulate matter (PM) in different meteorological conditions, we investigated the contributions of PM and relative humidity (RH) to visibility in Seoul, South Korea. For the period from 2001 to 2018, both PM and RH show descending trends, resulting in a visibility increase. PM has little impact on the hourly variation of visibility, which could be explained more by the RH variability. Meanwhile, the daily change of PM accounts for daily visibility variation. For the monthly variation of visibility, both PM and RH showed similar influence. The correlation coefficients of PM10, PM2.5, and RH with visibility was -0.486, -0.644, and -0.556, respectively, which became higher during the high PM seasons of spring and winter. The correlation coefficient between PM2.5 and visibility was -0.454 for RH higher than 80%, and -0.780 for RH between 40% and 60%. From 2017 to 2018, there were 10 cases of extreme visibility impairment, among which five cases were incurred by high PM pollution, and two cases were by high humidity. Further analysis with PM chemical composition measurements is required to better understand the characteristics of visibility in Seoul.

• 한국식품과학회지
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• 제41권6호
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• pp.681-686
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• 2009

Cronobacter spp.(Enterbacter sakazakii)의 건조저항성은 다른 장내 세균들보다 강한 특성을 가지고 있는 것으로 알려져 있다. 본 연구는 국내 식품으로부터 분리한 110개의 Cronobacter균주로부터 건조내성 특성을 분석하고 여러 상대습도에서의 생존특성을 연구하고자 하였다. 국내 식품에서 분리한 Cronobacter 110균주중 8시간 금속표면 건조노출에 대하여 초기균수의 약 절반정도 생존하는 고내성그룹이 30%, 대부분이 사멸하는 저내성그룹이 약 10%를 차지하여 전체 균주 중 중간정도 이상의 내성을 가지는 균주가 90% 이상을 차지하고 있었다. 15일간 장기 건조노출에 경우도 비슷한 경향을 보여 주었다. 조제분유에서 Cronobacter 건조 노출의 경우 고내성그룹과 중간내성그룹은 30일 이후에도 5 log CFU/mL에서 3 log CFU/mL 이상의 생균수를 나타내었다. 오히려 금속 표면건조 때보다 더 생존율이 높아 조제분유에서는 더 내성이 증가함을 할 수가 있었다. 따라서 국내 식품에서 분리한 대부분의 Cronobacter도 건조에 강한 내성을 가지고 있는 것으로 보인다. 건조환경에서의 biofilm 형성능력은 고내성과 중간 내성그룹 균주는 노출초기에서부터 biofilm 생성이 이루어졌다. 그러나 저내성그룹 균주의 경우에는 biofilm의 형성이 증가하지 않다가 7일 후 biofilm 생성이 많아지는 것으로 분석되었다. 따라서 Cronobacter의 biofilm 형성능은 각 그룹간 biofilm 생성의 시간적인 차이만 존재하고 대부분의 Cronobacter는 건조스트레스에서 biofilm 형성능이 비슷한 것으로 보인다. Cronobacter는 건조금속표면의 75%의 상대습도에서 24-48시간 내에 모두 사멸하는 것으로 나타났으나 40% 상대습도에서는 초기균수의 60% 생균수를 유지하여 낮은 상대습도에 강한 저항특성을 보여주었다. 대부분의 Cronobacter는 건조에 강한 내성을 가지고 있어 조제분유등의 건조식품에서 오랫동안 살아 있을 수 있으나 습도가 높은 환경에서는 사멸이 많이 일어나는 것으로 사료된다. 그러므로 식품생산현장에서 습도를 조절하여 Cronobacter를 제어할 수 있을 것으로 보인다.