• Environmental Engineering Research
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• 제22권4호
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• pp.347-355
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• 2017

This study investigated how the combined changes in environmental conditions and nitrogen (N) deposition influence the mineralization processes and carbon (C) dynamics of wetland soil. For this objective, we conducted a growth chamber experiment to examine the effects of combined changes in environmental conditions and N deposition on the anaerobic decomposition of organic carbon and the emission of greenhouse gases from wetland soil. A chamber with elevated $CO_2$ and temperature showed almost twice the reduction of total decomposition rate compared to the chamber with ambient atmospheric conditions. In addition, $CO_2$ fluxes decreased during the incubation under the conditions of ambient $CO_2$ and temperature. The decrease in anaerobic microbial metabolism resulted from the presence of vegetation, which influences the litter quality of soils. This can be supported by the increase in C/N ratio over the experimental duration. Principle component analysis results demonstrated the opposite locations of loadings for the cases at the initial time and after three months of incubation, which indicates a reduction in the decomposition rate and an increasing C/N ratio during the incubation. From the distribution between the decomposition rate and gas fluxes, we concluded that anaerobic decomposition rates do not have a significantly positive relationship with the fluxes of greenhouse gas emissions from the soil.

• 한국철도학회논문집
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• 제15권6호
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• pp.558-565
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• 2012

최근 기후변화에 따른 이상 기상현상이 증가하고 있는데, 특히 동절기의 혹한은 승객의 열적 쾌적성을 크게 저하할 우려가 있다. 이에 본 연구에서는 철도차량 실대형 환경챔버를 이용하여 저온 조건에서 철도차량의 난방장치 가동시 객실 내부의 온도변화 및 분포를 알아보았다. 실험결과 난방시스템 가동 직후에는 객실 내부온도가 급격하게 증가하였으나, 일정 시간 경과 후에는 더 이상 증가하지 않았으며, 객실의 위쪽이 아래쪽보다 온도가 더 높게 나타났다. 이러한 결과들을 통해 승객의 온열 쾌적감 저하를 최소화할 수 있는 방안을 제시하고자 하였다.

• 한국작물학회지
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• 제64권3호
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• pp.246-268
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• 2019

Soybean [Glycine max (L.) Merr.] is a species of legume native to East Asia. The interactions between climatic conditions and genetic characteristics are known to affect the agricultural performance of soybean. Therefore, the present investigation was conducted to identify the main elements affecting the agricultural performances of 11 soybean varieties/lines from China [Harbin ($45^{\circ}12^{\prime}N$), Yanji ($42^{\circ}53^{\prime}N$), Dalian ($39^{\circ}30^{\prime}N$), Qingdao ($36^{\circ}26^{\prime}N$)] and the Republic of Korea [Suwon ($37^{\circ}16^{\prime}N$), and Jeonju ($35^{\circ}49^{\prime}N$)]. The days to flowering (DTF) of soybeans with the e1-nf and e1-as alleles and the E1e2e3e4 genotype, except in 'Keumgangkong', 'Tawonkong', and 'Duyoukong', were relatively short compared to those of soybeans with other alleles. Although DTF of the soybeans was highly correlated with all climatic conditions [negative: precipitation, average temperature (AVT), accumulated temperature; positive: day-length (DL)], days to maturity and 100-seed weight of the soybeans showed no significant correlation with any climatic conditions. The soybeans with a dominant Dt1 allele, except 'Tawonkong', had the longest stem length (STL). Moreover, STL of the soybeans grown in the test fields showed a positive correlation with only DL; however, the results of our chamber test that was conducted to complement the field tests showed that STL of soybean was positively affected by AVT and DL. Although soybean yield (YLD) showed positive correlations with latitude and DL (except L62-667, OT89-5, and OT89-6), the response of YLD to the climatic conditions was cultivar-specific. Our results show that DTF and STL of soybeans grown in six different latitudes are highly affected by DL, and AVT and genetic characteristic also affect DTF and STL.

• Ecology and Resilient Infrastructure
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• 제5권4호
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• pp.257-263
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• 2018

본 연구는 도시의 열섬을 저감하기 위해 그린인프라시설의 표면온도 저감 성능시험 장비를 개발하고, 대표적인 그린인프라시설 제품을 포함하여 실험을 수행하였다. 기존문헌을 고찰하여 장비를 개발하였으며, 개발된 장비의 특징은 다음과 같다. 표면온도의 측정방법은 비접촉식인 적외선온도센서를 활용하였으며, 시편의 중앙 온도만 측정하는 것이 아닌 모서리 부분 온도를 포함하여 전체적인 평균온도를 측정하도록 개선하였다. 개발된 장비 (GSTM)를 활용하여 대조군인 아스팔트와 그린인프라시설 제품을 비교하여 성능평가를 수행하였다. 그 결과 식생블록이 $18.4^{\circ}C$의 높은 차이를 보이며, 표면온도 저감에 기여하는 것으로 나타났다.

• 한국입자에어로졸학회지
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• 제20권2호
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• pp.25-33
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• 2024

Suspension of particulate matter (PM) in indoor spaces, which increases risk of negative impact on occupants' health from exposure to PM, is influenced by humidity level in the indoor environment. The goal of this study is to investigate the property of size-resolved PM suspension in accordance with the relative humidity through simulation chamber experiments which reflect the indoor environmental characteristics. The relative humidity of simulation chamber is adjusted to 35%, 55% and 75% by placing it inside a real-size environmental chamber which allows artificial control of climatic conditions (e.g., temperature, humidity). At the respective humidity conditions, PM suspension concentration caused by occupant walking is analyzed by particle size (0.5-0.8, 0.8-1.0, 1.0-2.5, 2.5-3.5, 3.5-4.5, 4.5-5.5, 5.5-8.0, and 8.0-10 ㎛). Irrespective of the particle size, the suspension concentration reveals a decreasing tendency as the relative humidity increases. Furthermore, a one-way analysis of variance (one-way ANOVA) test statistically verifies that the suspension concentration has a significant difference depending on the indoor relative humidity level. In addition, as the relative humidity increases, a proportion of the suspended particles with 0.5-2.5 ㎛ diameter decreases, while that with 2.5-3.5 ㎛ diameter increases. The reason is considered that the humidity has an effect on adhesion and coagulation forces of the particles.

• 안보군사학연구
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• 통권1호
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• pp.231-247
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• 2003

To get the basic data for making comfortable military uniforms and to examine the distribution of clothing microclimate, seasonal fluctuations of skin temperature, subjective sensation, and clothing microclimate were measured from 10 males. The subject were questioned on thermal comfort in experiment. Clothing microclimate temperature at breast, skin temperature at four sites (breast, upper arm, thigh, leg), deep body temperature at eardrum( tympanic temperature), and subjective sensation were measured for an hour in the controlled climatic chamber. The subjects felt comfortable when skin temperature were recorded $34.43^{\circ}C$ at breast, $33.53^{\circ}C$ at upper arm, $32.9^{\circ}C$ at thigh, and 32.50 at leg. Then mean skin temperature was $33.55\pm$$0.63^{\circ}C$. Clothing microclimate temperature ranged from 31.2 to $33.8^{\circ}C$, and clothing microclimate humidity ranged from 49.80～52.41%. In the comparison of these results with the microclimate of military uniforms, it needs more insulation in clothing for military uniforms. It also says that military uniforms should be made of the textiles which can control humidity.

• 한국생활과학회지
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• 제7권1호
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• pp.139-146
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• 1998

The actual clothing conditions of male collegian were surveyed to analyse clothing contents and the rate of wearing underwear. Then, clothing microclimate, physiological responses, and subjective sensations were investigated through wearing trials on human body in climatic chamber based on the results from the survey. The results were follows: 1. Male collegian wore T-shirts, jeans, and socks in summer, and total clothing weight per body surface area was $561g/m^2$. The number of clothes for upper body were 1 layer, but the number of clothes for lower body were 2 layers. Subjective sensations have no significant difference with wearing underwear. 2. Most physiological responses including temperature inside clothing, mean skin temperature, skin temperature of chest, abdomen, thigh, and lower leg, and sweat rate, were higher in with-underwear than in without-underwear. But pulse rates were not significantly different between with-and without-underwear.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.67-73
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• 1995

This study was undertaken to investigate the effect of heat treatment on the dynamic viscoelasticity of three species of Phyllostachys bambusoides, Phyllostachys nigra var. henonis and Phyllostachys pubescens, grown in southern Korea. The bamboo was treated for 3~24 hours at $60{\sim}180^{\circ}C$, and then was treated in a climatic chamber for 3~48 hours at $40^{\circ}C$ and 95% relative humidity. The results obtained are summarized as follows : 1. Dynamic Young's modulus decreased with increasing temperature and duration of the heat treatment. 2. Internal friction decreased with increasing treatment duration. 3. Moisture absorption decreased with increasing temperature and duration of the heat treatment. 4. Dynamic viscoelasticity decreased, whereas internal friction slowly increased, with increasing moisture content.

• 한국지역사회생활과학회지
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• 제21권4호
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• pp.633-639
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• 2010

This study was carried out to compare human thermoregulatory responses and preferred air temperature by feet immersion between summer and winter in terms of thermal comfort. Five healthy female university students participated in the study as subjects. They experienced feet immersion at $40^{\circ}C$ of water in the climatic chamber of $24^{\circ}C$, 50%RH from 19:30 to 21:00 in the summer and winter, respectively. Rectal temperature gradually decreased and maintained $0.08^{\circ}C$ lower in winter than summer, while mean skin temperature changed $0.4^{\circ}C$ greater in winter than summer(p=0.00). Air temperature selected by each subject for their thermal comfort revealed $0.8^{\circ}C$ higher in summer than winter(p=0.06). The results obtained suggest an increase in human thermoregulation and be used as preliminary data to maintain optimal indoor temperature in summer and winter.

• 한국의류학회지
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• 제1권1호
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• pp.7-13
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• 1977

The insulating values of 7 kinds of woman's Korean-styled clothes were examined on the instrumented copper mannequin standing upright under still air condition in a climatic chamber at $20^{\circ}C$ and $60\%$ R.H.. Results obtained are as follows: 1) High correlation coefficients were found in both between total insulating values of clothing (IT) and total clothing weight. and between IT and total clothing thickness while no significant difference was found between total clothing weight and total clothing thickness. 2) It seems possible to predict the approximate insulating value of woman's Korean styled clothes on still air condition by the total clothing weight.