• Korean Journal of Community Nutrition
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• v.19 no.3
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• pp.231-240
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• 2014

Objectives: This study was intended to examine the seasonal differences in outdoor activity times and dietary vitamin D intakes, and explicates their relative impact on improving serum 25-(OH) vitamin D status among Korean young women. Methods: A cross-sectional study was conducted with 135 free-living women aged 19-39 years in Daegu-Kyungbook, Korea. We compared the results from 52 women for the summer and 83 women for the winter. Dietary intake of vitamin D was assessed by 24 hour recall method for non-consecutive three days as well as by food frequency method. Daily outdoor activity times were derived from 24 hour physical activity diary. Results: The average dietary intake of vitamin D of the participants by 24 hour recall method was 3.1 ${\mu}g$ during the summer, 3.3 ${\mu}g$ during the winter, showing no significant difference between the two seasons. Times spent on outdoor activities (p < 0.01) in the summer (= $23.8{\pm}23.6$ min) were much longer than that in the winter (= $10.8{\pm}13.4$ min). The serum 25-(OH) vitamin D levels of participants were $17.5{\pm}7.5$ ng/mL in the summer and $13.4{\pm}4.3$ ng/mL in the winter, showing that the latter was significantly lower than that of the former (p<0.001). The serum 25-(OH) vitamin D levels of subjects were positively related to outdoor activities (r=0.315, p<0.05) during the summer, while related to dietary intake (r=0.252, p<0.05) during the winter. Conclusions: In order to improve the current vitamin D status of Korean young women, nutrition education programs should focus on increasing more dietary intake especially during the winter, and performing more outdoor activities in other seasons.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.8
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• pp.77-86
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• 2018

The purpose of this study is to examine the condition of the architectural location and the history of Yeongbojeong and investigate the motivation which formed the YuSik space and the poetical circles of it. And another purpose of the study is to discover how Yeongbojeong, located in a military camp in Western coast, displayed the poetic scenery so to be the poetic summer house among so many Nujeongs in Joseon. Yeongbojeong is currently located in Soseong-ri, Ocheon-myeon, Boryeong City, Chungnam. Yeongbojeong has the biggest size among all the summer houses in the country with 24 architectural rooms. And Yeongbojeong is not only the summer house in which people could simply see its scenery, but beyond the poetic space of Joseon, it was the unique poetic summer house which enables poets and calligraphers to enjoy imaginary freedom. The time range of the study was from the building of Yeongbojeong in 1504 to its demolish in 1901, and its space range was taken focused on the particular scenery which was seen from around Yeongbojeong. To investigate the architectural aspect of Yeongbojeong, the existing records about the summer houses, "OcheonGoonJi" and the landscape paintings etc. were referred. The travel records and poems in the work collection of the famous poets who explored Yeongbojeong were referred to examine the formation of the Yeongbojeong poetical circles. The result of the study shows the process that Yeongbojeong had become the famous national place with scenery and how it became the most visited YuSik space. And this study figured out the full account of Yeongbojeong poetical circles which had been formed by so many poets of the country for 4 hundred years.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.3 no.2
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• pp.39-51
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• 2007

Unconsolidated and permeable alluvial deposit composed of sand and gravel is distributed along the fluvial plain at the Iryong study area. Previous studies on the area show that a single alluvial well can produce at least 1,650m3d-1 of bank infilterated shallow groundwater(BIGW) from the deposit. This study is aimed to evaluate and simulate the influence that seasonal variation of water levels and temperatures of the river have an effect on those of BIGW under the pumping condition and also to compare seasonal variation of COPs when indirectly pumped BIGW or directly pumped surface water are used for a water to water heat pump system as an heat source and sink using 3 D flow and heat transport model of Feflow. The result shows that the magnitude influenced to water level of BIGW by fluctuation of river water level in summer and winter is about 48% and 75% of Nakdong river water level separately. Seasonal change of river water temperature is about $23.7^{\circ}C$, on other hand that of BIGW is only $3.8^{\circ}C$. The seasonal temperatures of BIGW are ranged from minimum $14.5^{\circ}C$ in cold winter(January) and maximum $18.3^{\circ}C$ in hot summer(July). It stands for that BIGW is a good source of heat energy for heating and cooling system owing to maintaining quite similar temperature($16^{\circ}C$) of background shallow groundwater. Average COPh in winter time and COPc in summer time of BIGW and surface water are estimated about 3.95, 3.5, and about 6.16 and 4.81 respectively. It clearly indicates that coefficient of performance of heat pump system using BIGW are higher than 12.9% in winter time and 28.1% in summer time in comparision with those of surface water.

• Journal of Astronomy and Space Sciences
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• v.26 no.3
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• pp.329-344
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• 2009

Daylight saving time aims at spending effective daylight in summer season. Korea had enforced daylight saving time twelve times from 1948 to 1988. Since 1988, it is not executed, but it is recently discussed the resumption of DST. In this paper, we investigate the trend of DST in other countries, review the history of DST in Korea, and suggest the optimal DST duration in terms of astronomical aspects (times of sunrise and sunset). We find that the starting day of DST in Korea is apt for the second Sunday in Mayor the second Sunday in April according to the time of sunrise or to the difference between Korean standard meridian and observer's, respectively. We also discuss time friction that might be caused by time difference between DST and Korea Standard Time (KST).

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.127-131
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• 1995

A crude crystal of phytoecdysone was obtained 355 mg per Kg dry radix of A. japonica, and it was identified to $\beta$-ecdysone by TLC. Feeding silkworms on mulberry leaves sprayed with the extract, mounting time shortened and pupation ratio improved. The feeding effects of the extract was differed according to the rearing seasons, spring and summer. In spring season, only mounting time shortened without any difference in pupation ratio from the control. In summer season, not only mounting time shortened, but also pupation ratio remarkably advanced.

• The Korean Journal of Applied Statistics
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• v.27 no.4
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• pp.655-665
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• 2014

An adequate understanding and response to natural hazards such as heat wave, heavy rainfall and severe drought is required. We apply extreme value theory to analyze these abnormal weather phenomena. It is common for extremes in climatic data to be nonstationary in space and time. In this paper, we analyze summer rainfall data in South Korea using exceedance values over thresholds estimated by quantile regression with location information and time as covariates. We group weather stations in South Korea into 5 clusters and t extreme value models to threshold exceedances for each cluster under the assumption of independence in space and time as well as estimates of uncertainty for spatial dependence as proposed in Northrop and Jonathan (2011).

• Journal of Ecology and Environment
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• v.32 no.4
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• pp.221-227
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• 2009

This study describes time lag responses between hydrological variables and phytoplankton biomass in a regulated river system, the lower Nakdong River in South Korea. The lower Nakdong is a typical flow-controlled lotic system, and its limnological characteristics are influenced by climatic variation such as monsoons and summer typhoons. Mean rainfall in the area during summer is about 1,200 mm, which comprises >60% of annual rainfall. Our results show that the regulation of flow in the Nakdong by multi-purpose dams from 1995 to 2004 affected phytoplankton dynamics. Diatom blooms occurred in winter, when the limited discharge allowed for proliferation of the phytoplankton community. Using multiple regression analysis, we detected significant time-delayed relationships between hydrological variables and phytoplankton biomass. These results may be useful for water resource managers, and suggest that 'smart flow' control would improve water quality in large regulated river systems of the Republic of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.472-482
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• 1991

Seasonal distributions of zooplankton were investigated in Asan Bay, Korea. Labidocera euchaeta, Sagitta crassa, Calanus sinicus, Acartia omorii were dominant taxa throughout the year with seasonally varying percent compositions. Bivalve veliger larva (fall), Decapoda larva (spring and summer), and Paracalanus Parvus, Evadne tergestina (summer) were also dominated during contain period. The patterns of time dependent vertical distributions of one major taxon, A. omorii, showed seasonal differences, i.e., it showed the trends of normal vertical migration in winter and reversed vertical migration in spring. At surface layer day time abundances were equal or less than night time abundances in general.

• Journal of the Korean Wood Science and Technology
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• v.25 no.1
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• pp.28-36
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• 1997

Several thick board and dimension lumbers of Japanese larch(Larix leptolepis), Dahurian larch(Larix gmelini) and radiata pine(Pinus radiata) air-dried in four different seasons to compare air-drying process. Patterns of air-drying curves were influenced by climatological conditions and limber thickness. The initial drying rates of summer were the highest, followed those of fall, spring and winter. The drying times to equilibrium moisture contents for four seasons were nearly the same except for winter. However, the drying time for winter required twice more time than the other seasons. The drying time of dimension lumbers required 1.3 times more than boards. The final moisture contents were lowest during spring, highest during winter and similar between summer and fall.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.44-53
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• 2008

To recognize the spatial and temporal variability of water temperature and dissolved oxygen in the Youngsan reservoir formed after dike construction, water temperature and dissolved oxygen data have been observed and analyzed from April, 2002 until March, 2003. As the results, certain stratifications were not distinctly observed in the Youngsan reservoir during summer, which was estimated due to the drainage characteristic from the Youngsan water gates. The yearly variation of water temperature in the Youngsan reservoir is shown seasonally ups and downs by the heat exchange between the atmosphere and the reservoir. On the other hand, dissolved oxygen and water temperature in the Youngsan reservoir have been shown inversed proportional correlation. As the calculation results of residence time and water exchange rate, it is considered that the feature of oxygen distribution is determined by the drainage characteristics caused the shortest residence time during summer, which also disturbed the formation of stratification in the Youngsan reservoir.