• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.691-705
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• 2009

Phytolith analysis was made on a 660cm core from Lake Gyeongpo in the East Sea of Korean Peninsula to clarify the environmental change including climate and agricultural characteristics during the Holocene. From the results of phytolith analysis, six phytoliths assemblage zone(PAZ) were recognized from the base to the surface. PAZ I around 5,000 yr BP suggests the transition from the warm and dry to the cool and wet climatic conditions. The climate of PAZ II(ca. 4,000-2,000 BP) was kept on warm, but repeated between dry and wet conditions. PAZ III(2,000~1,000 yr BP) suggests the expansion of agricultural activities under the warm and humid climatic conditions due to the significant phytoliths production of Paniceae and Oryza sativa. While PAZ IV(1,000~500 yr BP) indicates very cool and dry conditions, PAZ V and IV suggest the warm-dry and cool-humid climatic conditions, respectively. Similar to the results of pollen analysis in the lake, the agricultural activities were recognized by PAZ III around 2,000 yr BP from the results of phytolith analysis, and the rice cultivations such as Oryza sativa have been expanded since 2,000 yr BP or later.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.261-265
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• 2003

In order to examine the difference in processing quality of potato tubers among localities, chemical properties of soils were analyzed and climatic conditions were investigated. Potatoes (Solanum tuberosum L.) were grown at seven localities of Korea during two years from 1994 to 1995. Soil samples and tubers were obtained from 2 to 3 commercial farms per locality with 10 days interval from 70 days before harvesting. As the result of that, higher correlation in processing quality was found with organic material content among soil conditions. On the climatic conditions, minimum temperature and sunshine hours during the period from 30 to 11 days before harvesting exhibited highly significant negative correlations with all quality parameters except reducing sugar content. Additionally, regression equations based on the observed level of these factors showed the relatively high coefficients of determination for dry matter content and chip color. To produce higher quality potatoes for processing, therefore, climatic conditions such as minimum temperature and sunshine hour and soil condition such as organic matter content have to be considered before the selection of areas or fields.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1450-1455
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• 2017

Objective: The objective of this experiment was to investigate the effect of dietary ${\beta}-mannanase$ on productive performance, egg quality, and utilization of dietary energy and nutrients in aged laying hens raised under hot climatic conditions. Methods: A total of 320 84-wk-old Hy-line Brown aged laying hens were allotted to one of four treatments with eight replicates in a completely randomized design. Two dietary treatments with high energy (HE; 2,800 kcal/kg nitrogen-corrected apparent metabolizable energy [$AME_n$]) and low energy (LE; 2,700 kcal/kg $AME_n$) were formulated. Two additional diets were prepared by adding 0.04% (MN4) or 0.08% ${\beta}-mannanase$ (MN8) to LE treatment diets. The feeding trial was conducted for 28 d, covering a period from July to August in South Korea. The average daily room temperature and relative humidity were $29.2^{\circ}C$ and 83%, respectively. Results: Productive performance, egg quality, and cloacal temperature were not influenced by dietary treatments. The measured $AME_n$ values for MN8 diets were similar to those for HE diets, which were greater (p<0.05) than those for LE and MN4 diets. However, the $AME_n$ values for MN8 diets did not differ from those for LE and MN4 diets. Conclusion: The addition of ${\beta}-mannanase$ to low energy diets increases energy values for diets fed to aged laying hens. However, this increase has little positive impacts on performance and egg quality. These results indicate that dietary ${\beta}-mannanase$ does not mitigate the heat stress of aged laying hens raised under hot climatic conditions.

• Journal of Korean Society on Water Environment
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• v.40 no.2
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• pp.89-100
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• 2024

Climate change has a broad impact on the entire water environment, and this impact is growing. Climate adaptation in water supply systems often involves quantity and quality control, but there has been a lack of research examining the impacts of climatic factors on water supply productivity and operation conditions. Therefore, the present study focused on, first, building a database of climatic factors and water purification operating conditions, and then identifying the correlations between factors to reveal their impacts. News big data was analyzed with keywords of climatic factors and water supply systems in either nationwide or region-wide analyses. Metropolitan area exhibited more issues with cold waves whereas there were more issues with drought in the Southern Chungcheong area. A survey was conducted to seek experts' opinions on the climatic impacts leading to these effects. Pre-chlorination due to drought, high-turbidity of intake water due to rainfall, an increase of toxins in intake water due to heat waves, and low water temperature due to cold waves were expected. Pearson correlation analysis was conducted based on meteorological data and the operating data of a water purification plant. Heavy rain resulted in 13 days of high turbidity, and the subsequent low turbidity conditions required 3 days of high coagulant dosage. This insight is expected to help inform the design of operation manuals for waterworks in response to climate change.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.2
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• pp.105-113
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• 2001

This study was conducted to reveal the effects of local climatic conditions on the vegetative growth in a mature stand of Korean white pine based on climatic estimates. For this, the annual increments of stand variables such as DBH, height, basal area and volume were measured and estimated for seven years from 1974 to 1980. The local climatic conditions in the study site were also estimated by both a topoclimatological method and a spatial statistical technique. The local climatic conditions were then correlated with and regressed on the growth factors to reveal the relationships between the climatic estimates and the growth. It is found that relatively high temperatures had positive effects on the diameter growth. The yearly diameter growth increased when each of mean, maximum, and minimum temperature during the growing season was high. Height growth showed positively significant correlation with three climatic variables. The most important variable influencing height growth was the average of maximum temperature for 10 months from January to October. It means that the higher the average of maximum temperature for 10 months from January to October is, the more height growth of Korean white pine increases. Other climatic variables related to height growth were average of minimum temperature for 3 months in the early growing season and mean relative humidity for the growing season. Six climatic variables related to temperature had effects on basal area increment and all of them were positively correlated with basal area increment. Especially, temperatures from January to March were important factors affecting the basal area increment. In volume increment, high correlation was also recognized with most of temperature variables. This tendency was the same as the results in diameter and hight increments. This means that the volume growth increases when temperatures during the growing season are relatively high.

• New & Renewable Energy
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• v.1 no.3 s.3
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• pp.35-41
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• 2005

This paper analyses the economics of grid-connected photovoltaic systems. With the 2003 cost of photovoltaic systems, under prevailing capital market conditions, with a system lifetime of 30 years, and under the best climatic conditions, it appears that the cost of production of grid-connected electricity could be of 0.21 US $/kWh, and under medium climatic conditions, European locations, Switzerland, Japan and South Korean could be of 0.28$/kWh. If the lifetime if the system goes up, due to future technological improvements, to a very large value such as 50 years, these costs can be lowered by 10-20%. Competitiveness of grid-connected photovoltaic electricity, while it still cannot be taken for granted, is a possibility, especially if major technological advances further lowers the costs of photo cells and increases their lifetimes.

• Journal of the Korean Society of Systems Engineering
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• v.6 no.1
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• pp.41-46
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• 2010

The ground high/low temperature test objective is to check the normal ground operation of FA-50 aircraft in the extreme ground ambient conditions. The aircraft was exposed in climatic conditions of the basic climatic category according to the MIL-HDBK-310. For verified normal operation in the extreme high temperature, the high temperature test was performed in the hot regional type conditions and accentuated solar radiation heat. This test was performed at the test chamber in ADD where is in Haemi. This paper was described about the test procedure of FA-50 high/low temperature including preparation, testing and results.

• International Journal of High-Rise Buildings
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• v.5 no.4
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• pp.327-338
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• 2016

This technical paper presents a detailed review of the stack effect phenomenon and of the associated implications pertaining to the design and construction of high-rise buildings in regions of extreme climatic conditions. The present review is focused on both the classical 'chimney' effect as well as on the reverse stack effect, which are respectively related to cold and hot climates. For the purposed of the work here presented, the ASHRAE (2013) design conditions of Astana (Kazakhstan) and Riyadh (Kingdom of Saudi Arabia) were selected. A 230 m tall residential building of rectangular floor plan was numerically modelled in the context of the climatic conditions of the two abovementioned cities and a number of sensitivity analyses were performed, covering parametric changes of: temperature, façade air tightness, site wind speeds and wind directions.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.235-246
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• 2011

Sea level fluctuations during the Holocene reconstructed by the results of age dating, microfossils researches and sedimentary facies from coastal alluvial plains contain the valuable informations on climatic changes. The sea level during 'maximum phase of transgression' during 6,000~5,000 yr BP was slightly higher than the present by approximately 0.8~1.0 m and the summer temperature conditions seemed to be higher than those of the present by 2~3℃ in the Central Europe when the period of 'Climatic Optimum' might be dominant. The sea level in Korean Peninsula was assumed by 0.8~1.0 m higher at that time compared to the present and climate seemed to be warmer. At 2,000~1,800 yr BP in Korean Peninsula, the sea level reached the higher stand than the present by approximately 1.1~1.3 m and the climatic conditions might be warm similar to the period of 'Climatic Optimum'. Although the temperature in the Central Europe during the period of 'Subboreal' was about 2~3℃ cooler, it is supposed that the sea level in Korean Peninsula was relatively higher than the present. The sea level at 2,300 yr BP might be similar to that of the present, which was the lowest level since the mid-Holocene. From the fact, climatic environment during the cold period might not be reflected exactly in the sea level.

• Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.43-52
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• 2007

The relationships among long-term climatic change in the southern part of the Korean peninsula, oceanic conditions of the South Sea, Korea, and winter catches of major small pelagic fishes were analyzed using 33 years of time-series data from 1971-2003. In the early 1990s, winter climatic conditions in the southern part of the Korean peninsula shifted to a warmer regime with higher air temperature, weaker wind speed, and lower relative humidity. Also, winter sea surface temperature (SST) became consistently higher in the South Sea. The annual catch of major small pelagic fishes in the South Sea increased dramatically in the mid 1990s, whereas the catch of total fishes decreased in the late 1980s. In particular, the winter catch started to increase markedly in the late 1980s, and has remained over 120,000 M/T since the late 1990s. Correlation analysis of the winter catch of major small pelagic fishes and environmental factors showed that catch was correlated with air temperature (r=0.468, P< 0.01), wind speed (r=-0.732, P< 0.01), relative humidity (r=-0.73l, P< 0.01), and SST (r=0.672, P< 0.01). Multiple regression analysis between the winter catch of major small pelagic fishes (Y) and environmental factors (X) resulted in the equation: $Y=-0.017-0.217\;X_3-0.486\;X_4+0.325\;X_5(R^2=0.754,\;P<0.000)$.