• Magazine of the Korean Society of Agricultural Engineers
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• v.19 no.3
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• pp.4483-4491
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• 1977

The results obtained are as follows; 1. The variation of the temperature in a vinyl house without heating system is similar to that of air temperature in a day. The difference of maximum temperature and minimum one in a day is 27$^{\circ}C$ which is two times greater than the daily difference of air temperature. 2. When the length of the duct is increased, the high temperature zone is built up in the direction of warm air discharge from the duct, and the low temperature zone is built up in the opposite direction of warm air discharge. But, in case of the duct length is short (0.05 L), the temperature distrubution in a vinyl house become uniform. It is concluded that the shorter length of the duct, the better the distribution of the temperature in a vinyl house is. 3. When the duct is installed at high position, the high temperature zone is built up in the upper zone of the vinyl house and the low temperature zone is built up in the lower zone. And when the position of the duct is low, the rate of temperature variation along the vertical direction become high, and the direct contact of warm air with the plant in the house is occured. It is concluded that the duct should be installed at the position of slightly higher than the plant height. 4. When the fuel consumption rate is fixed at the 101/hr, the lowest temperature warming rate in the vinyl house is 5$^{\circ}C$ without regard to the air temperature.

• Journal of Environmental Science International
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• v.23 no.11
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• pp.1863-1879
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• 2014

This study aims at classifying and interpreting on the shrine forest vegetation located in Jirisan national park affiliated to an ecotone in southern part of Korea, foreseeing a vegetation change based on composition species and dominant species on canopy, and proposing the direction of vegetation management. The shrine forests were classified into the 7 community units as Chamaecyparis obtusa-Cryptomeria japonica afforestation, Pinus densiflora community, Pinus rigida afforestation, Quercus variabilis-Quercus serrata community, Zelkova serrata-Kerria japonica for. japonica community, Phyllostachys bambusoides forest, Camellia japonica community. This research is also expatiated on the analogous results of ordination analysis with phytosociological analysis. The constituents of deciduous broad-leaved forest in the warm temperate zone were appeared in the most vegetations. It emerged less that the constituents of evergreen broad-leaved forest in the warm-temperate zone and deciduous broad-leaved forest in the cold-temperature zone. The life form analyses were made use with the two ways: appearance species in total communities and each community. The species diversity of shrine forests is declined because the high dominances of Sasa borealis and Pseudosasa japonica emerged in the shrub and herb layers. These shrine forests will be succession to Q. variabilis-Q. serrata community as the representative vegetation of deciduous broad-leaved forest in the warm-temperate zone, owing to the temperature rise by global warming, and an evergreen broad-leaved forest will be able to be also formed if a temperate rise will be continued. The one of the artificial management of shrine forests is to consider the introduction of the constituents of evergreen broad-leaved forest in the warm-temperate zone.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.860-865
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• 2006

The traditional Korean Ondol System that is a radiant floor heating system was made as warm floor and cool indoor temperature. Nowaday, Ondol is developed as the hydronic floor heating system. But unbalance of floor temperature and indoor temperature is occurred bocause strengthen thermal insulation and airtightness in building changes thermal performance. To solve these problems, we examine actual indoor environment of heating system methods in existing apartments and present the new method of floor heating system. The existing heating system made definite indoor temperatures but floor temperatures that is $22^{\circ}C-26^{\circ}C$ was maintained. To solve these problems, we adopted the differential heating system which made warm area and cool area. A differential heating system was made different pitches of heating pipe in single zone and ratio of warm area to cool area is 1 to 2. As a result of experiments, warm area temperature is $40.7^{\circ}C$, cool area temperature is $36.1^{\circ}C$. A difference of temperature between both area is 4K. A distribution of indoor vertical temperature is similar to both warm area and cool area.

• Ocean and Polar Research
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• v.42 no.2
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• pp.97-113
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• 2020

In-situ observations were carried out in April 2015 to investigate the occurrence of water temperature inversion in a region west of Jeju Island. Analysis of in-situ in the western part of Jeju island showed that cold water moved to the southeast from the surface to the middle layer and warm water moved from the middle to the lower layer of the northwest direction. The water temperature inversion occurred at 84 stations (63.1%) out of 133 stations. At the boundary of the water temperature inversion layer, it was formed in the middle layer and disappeared. In the strongly appearing, it started from the middle layer to the lower layer. The shape of the water temperature inversion layer was different. As a result of horizontal water temperature slope analysis of the water temperature inversion zone, maximum 0.23℃/km was obtained and the mean was 0.06℃/km. The role of water temperature inversion as an indicator to determine the formation of water front. As a result of the water mass analysis, Jeju Warm Current Water and Tsushima Warm Current Water of high temperature and high salt intruded from the middle to the bottom. In the middle layer occurred as the Yellow Sea Cold Water of low water temperature and low salinity expanded.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.749-759
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• 1998

Distribution of zooplankton abundance was studied in the front zone in the East Sea in November, 1996, Averaged total abundance in the front zone was less than that in the nearby cold surface water areas but more than that in the nearby warm surface water areas. The number of taxa was the greatest in the upper layer of mixing. Abundance and the number of tun in the front zone were contributed by the cold water and the warm water, respectively. Inspite of the differences in sampling time (day vs night), the species composition and abundance distribution were similar at two sites within cold or warm water area, However, they were quite different at two sites in the front zone although the sampling time of the day was the same. from this, the history of mixing was believed to be the most important factor for the species composition and abundance distribution in the front zone. Zooplankton distribution in the study area was mainly controlled by the dominant cold water Copepod Species Metridia paoifica, the only taxon that showed significant diet vertical migration. Most other taxa showed no significant diel vortical migration, Seawater temperature also affected zooplankton distribution. Positive correlations in the warm area, weak negative correlations in the cold water area, and no significant correlation in the front zone were obtained in general between the seawater temperature and the abundances of the major taxa.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.195-207
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• 2020

In Korea, specific thermal elements such as annual mean temperature (AMT) 13℃, 14℃, and Kira's coldness index (CI) -10℃, have been suggested about the northernmost distribution of the warm-temperate evergreen broad-leaved forest zone. We reviewed the relationship between three thermal elements and the actual distribution of evergreen broad-leaved woody plants or its communities. Thiessen and Kriging method using point-data calibrated by seasonal lapse rate according to altitude were utilized for the spatial distribution pattern analysis. Several phytoclimatic maps were also produced in order to compare different thermal values. We identified that the AMT 13℃ was the best thermal element to demarcate the northern limit of the warm-temperate forest zone. Its area was estimated ca. 20,334 ㎢ and larger than those of other thermal elements. We concluded that an indirectly fabricated index i.e. CI -10℃ is useless and it was enough for a direct value of AMT 13℃ to represent the northern-limit distribution of warm-temperate forest zone, at least in Korea. Further researches on the reciprocity between floristic regions and phytoclimate zones are raised.

• Ecology and Resilient Infrastructure
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• v.9 no.4
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• pp.269-281
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• 2022

The prediction of changes regarding the distribution of vegetation and plant species according to climate changes is important for ecosystem management. In this study, we attempted to develop an assessment method to evaluate the possibility of the potential distribution of warm-temperate woody plant species of East Asia in Korea. To begin with, a list of warm-temperate woody plants distributed in China and Japan, but not in Korea, was prepared, and a database consisting their global distribution and bioclimatic variables was constructed. In addition, the warm-temperate vegetation zone in Korea was delineated using the coldness index and relevant bioclimatic data were collected. After the exclusion of multicollinearity among bioclimatic variables using correlation analysis, mean temperature of the coldest quarter, mean temperature diurnal range, and annual precipitation were selected as the major variables that influence the distribution of warm-temperate plants. A multivariate environment similarity surfaces (MESS) analysis was conducted to calculate the similarity scores between the distribution of these three bioclimatic variables in the global distribution sites of the East Asian warm-temperate woody plants and the Korean warm-temperate vegetation zone. Finally, using stepwise variable-selection regression, the mean temperature of the coldest quarter and annual precipitation were selected as the main bioclimatic variables that affect the MESS similarity index. The mean temperature of the coldest quarter accounted for 88% of the total variance. For a total of 319 East Asian warm-temperate woody plant species, the possibility of their potential distribution in Korea was evaluated by applying the constructed multivariate regression model that calculates the MESS similarity index.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.247-253
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• 2004

As a large scale port development in coastal waters proceeds step by step and populations in the vicinity of port are getting increased, the issue on "how to dispose the treated municipal water and wastewater in harbor" brings peoples′ concern. The submarine outfall system discharges the primary or secondary treated effluent at the coastline or in deep water, or between these two. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding sea water and becomes very dilute. We intended in this paper to investigate the impact on dilution of effluent and the behavior of flume under the conditions of the seasonal and spatial temperature variations, which have not been noticeable in designing effective marine outfall system. To predict and analyze the behaviour and dilution characteristics of plume not just with the effluent temperature, but also with the seasonal variation of temperature of surround water and tidal changes, CORMIX(Cornell Mixing Zone Expert System)-GI have been applied. The results should be used with caution in evaluation the mixing zone characteristics of discharged water. We hope to help for the effective operation of outfall system, probable outfall design, protection of water quality, and warm water discharges from a power plant, etc.

• Journal of Ecology and Environment
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• v.41 no.6
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• pp.165-172
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• 2017

Background: This study investigated the temporal variation in soil $CO_2$ efflux and its relationship with soil temperature and precipitation in the Quercus glauca and Abies koreana forests in Jeju Island, South Korea, from August 2010 to December 2012. Q. glauca and A. koreana forests are typical vegetation of warm-temperate evergreen forest zone and sub-alpine coniferous forest zone, respectively, in Jeju island. Results: The mean soil $CO_2$ efflux of Q. glauca forest was $0.7g\;CO_2\;m^{-2}\;h^{-1}$ at $14.3^{\circ}C$ and that of A. koreana forest was $0.4g\;CO_2\;m^{-2}\;h^{-1}$ at $6.8^{\circ}C$. The cumulative annual soil $CO_2$ efflux of Q. glauca and A. koreana forests was 54.2 and $34.2t\;CO_2\;ha^{-1}$, respectively. Total accumulated soil carbon efflux in Q. glauca and A. koreana forests was 29.5 and $18.7t\;C\;ha^{-1}$ for 2 years, respectively. The relationship between soil $CO_2$ efflux and soil temperate at 10 cm depth was highly significant in the Q. glauca ($r^2=0.853$) and A. koreana forests ($r^2=0.842$). Soil temperature was the main controlling factor over $CO_2$ efflux during most of the study period. Also, precipitation may affect soil $CO_2$ efflux that appeared to be an important factor controlling the efflux rate. Conclusions: Soil $CO_2$ efflux was affected by soil temperature as the dominant control and moisture as the limiting factor. The difference of soil $CO_2$ efflux between of Q. glauca and A. koreana forests was induced by soil temperature to altitude and regional precipitation.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.73-80
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• 2005

Both theoretical and experimental investigations were conducted to analyze defrosting behavior of a window heater operating in the low outdoor temperature($-20^{\circ}C$). To achieve this purpose, first a warm-chamber experiment($23^{\circ}C$) was performed to measure inner and outer surface temperature of the rear window(heated by the electric heater supplying 195 W) as functions of both time and position. Secondly, a cold chamber experiment was made to continuously record defrosting process of the frosted window. From the comparisons of the two experimental results, it was found that there was a similarity between the spatial distributions of both temperature and remaining frost. Thus, the temperature data from the warm-chamber experiments can be utilized to predict an expected zone covered with remaining frosts, and this approach can also be adopted in the inspection process in order to economically guarantee optimized performance of the window heater. Finally, an analytical model based on one-dimensional, steady-state heat transfer theories was proposed and successfully predicted the outer surface temperature of the rear window surrounded by cold air($-20^{\circ}C$) for the given operating conditions(heater power, inside and outside heat transfer coefficients, and surrounding air temperature, etc.).