• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.6
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• pp.977-987
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• 1997

The present study was designed to see what the local cooling of different body regions especially head and neck, hands and feet effect physiological responses in cold environment. Four male subjects wore garments covering whole body except face and rested for 20 min and then they rested for 40 min with uncovered head, neck, hands and feet, respectively in a cold environment(10$\pm$1$^{\circ}C$, 50$\pm$5%R.H.) 1. Rectal temperature increased when hands and feet were exposed to cold environment respectively, and when head and neck, hands and feet were exposed to cold environment together. 2. Exposed skin temperatures fell in cold environment. And hands temperature was lower than any other exposed skin temperatures. The hands temperature was significantly lower when head was exposed than when head was covered. And the feet temperature were significantly lower when hands were exposed than when hands were covered. 3. Mean skin temperature was the lowest when head and neck, hands and feet were exposed simultaneously, In conclusion, skin temperatures of extremities were decreased due to exposure to the cold environment. Especially upper extremities were lower than lower extremities by exposed parts of the body. It seemed that the extremities played the role of cold receptors but head and neck didn't. And there were large heat losses from the unprotected head and neck. In cold environment of 1$0^{\circ}C$ , thus, it is suggested for the purpose of thermoregulatory responses that head and neck would be covered and extremities would be exposed, especially upper extremities.

• Journal of the Korean GEO-environmental Society
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• v.18 no.3
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• pp.15-23
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• 2017

Gangwon Province, located in the northeastern part of South Korea, is the coldest area in South Korea with 90% of the total area as mountainous. Therefore, tunnel damage has been reported continuously in winter. But there has been lack of researches on frost heave occurring behind tunnel lining. In this study, numerical analysis was conducted to investigate the frost depth in road tunnel constructed in Gangwon province. Based on the database on road tunnel and weather in Gangwon province, a standard tunnel shape and geotechnical properties of ground was determined. And then thermal analysis for the frost depth according to the temperature change and ground conditions were conducted. Analysis result showed that the sensitivity to frost heave of metamorphic rock and sedimentary rock is higher than sand. Lower initial ground temperature leads to deeper frost depth and consequently increases frost damage. In addition, lining thickness, specific heat capacity, and thermal conductivity also affect greatly on the variation of frost depth.

• Journal of Wetlands Research
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• v.26 no.2
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• pp.168-181
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• 2024

Constructed wetlands (CWs) deliver a range of ecosystem services, including the removal of contaminants, sequestration and storage of carbon, and enhancement of biodiversity. These services are facilitated through hydrological and ecological processes such as infiltration, adsorption, water retention, and evapotranspiration by plants and microorganisms. This study investigated the correlations between microbial populations, soil physicochemical properties, and treatment efficiency in a horizontal subsurface flow constructed wetland (HSSF CW) treating runoff from roads and parking lots. The methods employed included storm event monitoring, water quality analysis, soil sampling, soil quality parameter analysis, and microbial analysis. The facility achieved its highest pollutant removal efficiencies during the warm season (>15℃), with rates ranging from 33% to 74% for TSS, COD, TN, TP, and specific heavy metals including Fe, Zn, and Cd. Meanwhile, the highest removal efficiency was 35% for TOC during the cold season (≤15℃). These high removal rates can be attributed to sedimentation, adsorption, precipitation, plant uptake, and microbial transformations within the CW. Soil analysis revealed that the soil from HSSF CW had a soil organic carbon content 3.3 times higher than that of soil collected from a nearby landscape. Stoichiometric ratios of carbon (C), nitrogen (N), and phosphorus (P) in the inflow and outflow were recorded as C:N:P of 120:1.5:1 and 135.2:0.4:1, respectively, indicating an extremely low proportion of N and P compared to C, which may challenge microbial remediation efficiency. Additionally, microbial analyses indicated that the warm season was more conducive to microorganism growth, with higher abundance, richness, diversity, homogeneity, and evenness of the microbial community, as manifested in the biodiversity indices, compared to the cold season. Pollutants in stormwater runoff entering the HSSF CW fostered microbial growth, particularly for dominant phyla such as Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroidetes, which have shown moderate to strong correlations with specific soil properties and changes in influent-effluent concentrations of water quality parameters.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.697-702
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• 2005

The aim of this study was to divide vocalizations of laying hens (Hy-Line Brown) into general vocalizations (GVs), heat stress-related vocalization (HSV), and cold stress-related vocalizations (CSVs) and to determine if they are classified by the discriminant function analysis method. Thirty laying hens, 65-wk-old, were recorded using digital video recorders 2 times from 10:00 to 14:00 h in each thermal environment (thermoneutral: $22.0{\pm}1.8^{\circ}C$, too hot: $32.0{\pm}2.0^{\circ}C$, too cold: $8.0{\pm}1.9^{\circ}C)$ after a 7 day acclimation period. When the laying hens were not recorded, they were kept in thermoneutral conditions. The GVs, HSV, and CSVs were divided based on the shapes of spectrums and spectrograms. The GVs, HSV, and CSVs were identified as 5, 1, and 3 types, respectively. Pitch, intensity, duration, formant 1, formant 2, formant 3, and formant 4 among the thermal environment-related vocalizations were significantly different (P<0.001). The discrimination rate determined by discriminant function analysis was 86.2%. These results suggest that HSV and CSVs are present and may be used as an indicator of the thermal environment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.4
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• pp.300-304
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• 1993

This experiment was carried out to increase the utility and productivity of forage crop as to investigate the rotation system which is suitable to cultivat at the alpine area. The treatments were 9 crops combinations including corn - rye treatment. The results obtained were as follows: 1. Rye can be cultivated satisfactorily at cold and high altitude areas such as Tae Kwan Ryong. 2. Corn, to be raised as a second crop after rye in the same year, does not have to be early (short) or medium maturity varieties in the high alpine area. 3. It is possible to increase the harvest by 30% in terms of dry melter or green crop yield through raising two crops, rye and corn, in the same year. 4. Maturity period or growth conditions of corn. as a tropical crop and the best forage crop, can improve or worsen acording to the external circumstance, such as low temperature resulting from high atitude.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.6
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• pp.866-876
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• 2019

This study examined the physiological and psychological effects of wearing gloves at rest in a cold environment. Seven elderly females participated in two separate trials: wearing gloves (WG) and bare hands (BH). The experiment was conducted for 60 min in a climatic chamber (air temperature 7.8±0.3℃ with 44±2%RH) with a sedentary posture. Microclimate temperature on the left palm was 4.16℃ higher in WG compared to that in BH (p<.1). Microclimate temperature on the chest during the last 5 min increased compared to the initial 5 min only in WG (p<.05). During the last 5 min, skin temperatures at the arm and hand in WG were higher than those in BH (p<.05). There was no statistical difference in the change of rectal temperature between WG and BH. Heart rate in BH was significantly higher compared to the WG (p<.05). Subjects also felt less cold on the whole body and hand in WG than those in BH (p<.05). The findings indicate that wearing gloves for elderly females affected the distribution of skin temperature and cardiovascular response in cold environments. Elderly females should be informed about the importance of wearing gloves through the clothing guideline in winter.

• Maritime Security
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• v.1 no.1
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• pp.311-343
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• 2020

Because of the global warming, the Arctic Ocean is expected to be ice-free by the year 2035. When the Arctic Ocean will be opened, a number of national interests will become more salient as experiencing a shortened sailing distance and decreasing navigation expense, possibility of natural resources transport by sea from Arctic Circle, and indirect-profit making by building a herb port in Asia. To secure the national interests and support the free activities of people in this region, R.O.K government is trying to make advanced policies. In order to carry out the naval tasks in the Arctic Ocean, using the operational characteristics(mobility, flexibility, sustainability, presence of capabilities, projection) is necessary. To this end, ROK Navy should analyze the operational environment (O.E.) by its capability(weakness and strength), opportunity, and threat. R.O.K. Navy should make an effort over the following issues to implement the tasks in the Arctic Ocean: first, Navy needs to map out her own plan (Roadmap) under the direction of government policies and makes crews participate in the education·training programs in home and abroad for future polar experts. Third, to develop the forces and materials for the tasks in cold, far operations area, Navy should use domestic well-experienced shipbuilding skills and techniques of the fourth industrial revolution. Next, improving the combined operations capabilities and military trust with other countries in the Arctic region to cover the large area with lack of forces' number and to resolve the ports of call issues. Lastly, preparation in advance to execute a variety of missions against military and non-traditional threats such as epidemics, HA/DR, SOLAS, in the future operation area is required.

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.7-18
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• 2006

Samples were collected from five stations monthly from October 2003 to September 2004 to investigate seasonal variation of size structure of phytoplankton and relationship between size-fractionated phytoplankton and environmental factors in the Asan Bay. The contribution of large cells (microphytoplankton, $>20\;{\mu}m$) to total concentrations of chlorophyll $\alpha$ was higher than small cells (nanophytoplankton, $3\sim20\;{\mu}m$; picophytoplankton, $<3\;{\mu}m$) during the sampling period. Especially, large cells contributed 80% to the total chlorophyll a from February, 2004 to April 2004 when chlorophyll $\alpha$ concentrations were high. The size structure of phytoplankton shifted from micro-size class to nano-size class and picophytoplankton rapidly increased when phytoplankton biomass decreased in May 2004. Microphytoplankton exhibited a high biomass in the upper region during winter-spring season whereas nano- and picophytoplankton showed two peaks in the middle-lower regions (Station 3,5) during spring and summer. Microphytoplankton are most likely controlled by water temperature and nutrient supply during the cold season whereas nano- and picophytoplankton may be affected by stratification, light exposure during the warm season.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.101-108
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• 2023

Recently, in relation to climate change, many studies have been conducted to predict the potential habitat area and distribution range of tilapia and the suitability of habitat for each species. Most tilapia are tropical fish that cannot survive at water temperatures below 10 to 12℃, although some tilapia can survive at 6 to 8℃. This study predicted habitable areas and the possibility of spreading of habitat ranges of tilapia (Oreochromis niloticus and Oreochromis aureus) known to inhabit domestic streams. Due to climate change, it was found that habitats in the Geum River, Mangyeong River, Dongjin River, Seomjin River, Taehwa River, Hyeongsan River, and the flowing in East Sea were possible by 2050. In addition, it was confirmed that tilapia could inhabit the preferred lentic ecosystem such as Tamjin Lake, Naju Lake, Juam Lake, Sangsa Lake, Jinyang Lake, Junam Reservoir, and Hoedong Reservoir. In particular, in the case of tilapia, which lives in tributaries of the Geumho River, Dalseo Stream, and the Nakdong River, its range of habitat is expected to expand to the middle and lower of the Nakdong River system. Therefore, it is judged that it is necessary to prepare physical and institutional management measures to prevent the spread of the local population where tilapia currently inhabits and to prevent introduction to new habitats.

• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.47-56
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• 2011

The research was conducted to find optimal habitats of warm-temperate evergreen broad-leaved trees, and to investigate climate factors to determine their distribution using classification tree (CT) analysis. The warm-temperate evergreen broad-leaved trees model (EG-model) constructed by CT analysis showed that Mean minimum temperature of the coldest month (TMC) is a major climate factor in determining distribution of warm-temperate evergreen broad-leaved trees. The areas above the $-5.95^{\circ}C$ of TMC revealed the optimal habitats of the trees. The coldest month mean temperature (CMT) equitable to $-5.95^{\circ}C$ of TMC is $-1.7^{\circ}C$, which is lower than $-1^{\circ}C$ of CMT of warm-temperate evergreen broad-leaved trees. Suitable habitats were defined for warm-temperate evergreen broad-leaved trees in Korea. These habitats were classified into two areas according to the value of TMC. One area with more than$-5.95^{\circ}C$ of TMC was favorable to trees if the summer precipitation (PRS) is above 826.5mm; the other one with less than $-5.95^{\circ}C$ of TMC was favorable if PRS is above 1219mm. These favorable conditions of habitats were similar to those of warm-temperate evergreen broad-leaved trees in Japan. We figured out from these results that distribution of warm-temperate evergreen broad-leaved trees were expanded to inland areas of southern parts of Korean peninsula, and ares with the higher latitude. Finally, the northern limits of warm-temperate evergreen broad-leaved trees might be adjusted accordingly.