• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.160-160
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• 2003

Plasma melatonin in the seasonal light-period is circadian rhythmically secreted. Maximal secretion showed at 14 o'clock in summer- and winter-like period, but minimal secretion showed at 5 o'clock in summer-like period and at 8 in winter-like period. These times of minimal secretions were at the beginning of light period. Plasma melatonin in the light period is secreted 62.5% more than in the dark period in summer-like period and 45.9% more in winter-like period. Total plasma melatonin in winter-like period is secreted 56.5% more than in summer-like period. The weights of testis(-20.8%) and body(-7.1%) were reduced in the winter-like period. By the increase of plasma melatonin in mice, body- and testis-weights are decreased, on the contrary by the decrease of plasma melatonin in mice, body and testis weights are increased. In view of the results so far achieved melatonin changes on the body weight and reproductive organ in mice. It is presumed that melatonin effects on the metabolism and sex hormone.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.57-61
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• 2003

Plasma melatonin in the seasonal light-period is circadian rhythmically secreted. Maximal secretion showed at 14 o'clock in summer- and winter-like period, but minimal secretion showed at 5 o'clock in summer-like period and at 8 in winter-like period. These times of minimal secretions were at the beginning of light period. Plasma melatonin in the light period is secreted 62.5％ more than in the dark period in summer- like period and 45.9％ more in winter- like period. Total plasma melatonin in winter-like period is secreted 56.5％ more than in summer-like period. The weights of testis (-20.8％) and body (-7.1％) were reduced in the winter-like period. By the increase of plasma melatonin in mice, body - and testis -weights are decreased, on the contrary by the decrease of plasma melatonin in mice, body and testis weights are increased. In view of the results so far achieved melatonin changes on the body weight and reproductive organ in mice. It is presumed that melatonin effects on the metabolism and sex hormone.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.6
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• pp.73-82
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• 2005

This study was performed to evaluate the need for heating wastewater to enhance treatment efficiency of organic matter (BOD, SS) during cold winter in newly developed Absorbent Biofilter System (ABS) which was established in the Suwon Campus of the Seoul National University. Treatments consisted of non-heating (2000 year) and heating(2001, 2002 year), and sampled data were analyzed during cold winter period as well as post winter period to investigate the influence of heating after winter season. Even the average air temperature showed only $0.4^{\circ}C$ difference between two experimental years, the difference in the average effluent temperature during cold winter period between heating and non-heating experiment was approximately $11^{\circ}C$. The average effluent concentration of organic matter in non-heating treatment exceeded the Korean standards for water quality of discharged effluent in riparian area (BOD and SS 10 mg/L); however, the standards were met in case of heating treatment during both winter and post winter period. Therefore, the need fur heating wastewater during cold winter season in ABS was justified. On the other hand, there was no improvement of treatment efficiency in T-N and T-p, but we observed the more activated nitrification as increasing the wastewater temperature. Because the average underground temperature was $5^{\circ}C$ higher than the average air temperature during cold winter period, we recommend that the ABS can be established in the underground rather than on-ground for saving the heating cost.

• Journal of Climate Change Research
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• v.6 no.3
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• pp.203-208
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• 2015

This study was conducted to provide the agricultural climatological basic data for the reset of sowing period of the winter crop on the double cropping system with rice. During the past 30 years from 1981 to 2010, mean air temperature has risen by $0.45^{\circ}C$ per 10 years (with statistical significance), while precipitation has decreased by 6.74 mm per 10 years and the numbers of days for precipitation has reduced by 0.23 days per 10 years (with no statistical significance) in the sowing period ($1^{st}$ Oct. to $5^{th}$ Nov.) of winter crop. It was analyzed that double cropping system of rice and winter crops need to be reset in the way of delaying the sowing time of winter crops, because rising trend of temperature was clear while variability of precipitation was great and the trend was not clear in the sowing period of winter crops. We have also analyzed the meteorological features of the sowing period of winter crops in 2014, and found that mean air temperature in 2014 was higher than that in normal years (similar to recent temperature change feature) while precipitation in 2014 was much more frequent than that in normal years (unlike recent precipitation features). Such tendency in 2014 made the sowing of winter crops difficult because mechanical sowing could not be worked in flooded paddy fields. Heavy rain in October 2014 was also analyzed as a rare phenomenon.

• Atmosphere
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• v.29 no.5
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• pp.599-607
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• 2019

The change and periodicity of Korean winter temperature in the period 1979-2018 are investigated. It is shown that the winter temperature is on a long-term rise, with two regime shifts of winter temperature during 40 years. In addition, the decrease in cold days is confirmed along with the rise in temperature. Analysis of the periodicity of daily temperature in winter is carried out by means of power spectral analysis. Of the spectral peaks that are statistically significant, the most frequent detection exists on the time scale between 7 and 8 days. It is found that the number of significant periods have decreased since 2014, particularly no longer existent around the period of 7 day. The longer periods than 7 days gradually increase during 40 years, while the shorter periods show the tendency of decrease but recently rebound. Spectral analysis calculated from high/low-pass filtered daily temperature data also shows similar results.

• Atmosphere
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• v.22 no.2
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• pp.187-197
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• 2012

This study investigates the relationship between the Korean temperature and the atmospheric circulation such as Arctic Oscillation, Siberian High and Aleutian Low during the winter (December-January) for the period of 1970-2011. It is found that all indices to represent aforementioned circulations are significantly correlated with Korean winter temperature for the period of 1970 - 2011. There are marked contrasts in such relationship, however, before and after the mid-1980s when a significant regime shift of Korean winter temperature occurred. While Korean winter temperature has a close relationship with Arctic Oscillation after the mid-1980s, its relationship with Siberian High and Aleutian Low is weakened. The composite analysis between a positive and negative phase of Arctic Oscillation before and after the mid-1980s is conducted to examine a recent strengthening of Arctic Oscillation-Korean winter temperature relationship. It is found that the structural changes of low-level wind and the geopotential height at 500 hPa between the two phases of Arctic Oscillation are more effective to influence Korean winter temperature after the mid-1980s. This may induce a close relationship between the Korean winter temperature variability and Arctic Oscillation after the mid-1980s compared to before the mid-1980s.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1015-1025
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• 2021

Our research work aimed to evaluate cover crop effects of winter rye on soil characteristics, soil conservation, and yield productivities on potato fields with 15% slope during a fallowed period. There were two controls of bared field without any cultivation and conventional potato cultivation without winter rye. Potato cultivation increased soil pH, organic matter, available phosphate, and exchangeable cation regardless of cover crop cultivation. Sub-soil, particularly, all components of soil chemical properties showed higher value in winter rye cultivation than conventional cultivation. Higher soil density was observed on cover crop cultivation than conventional cultivation resulting from root residues of the cover crop both topsoil and subsoil. Cover crop residues positively affected plant growth and reduced the amount of soil erosion by holding the soil. Although severe soil erosion was seen in conventional cultivation, winter rye cultivation declined soil erosion by 47% during the fallow period on potato slope fields. Distinct soil bacterial communities were detected among treatments and some OTU(Operational Taxonomic Unit)s showed significantly higher abundance in winter rye treatment. Total yield and commercial rate demonstrated no significant differences while higher tuber phosphate, K⁺, and Mg²⁺ contents were observed in winter rye cultivation.

• Journal of the Korean Society of Costume
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• v.58 no.7
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• pp.133-150
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• 2008

The study aimed to classify and analyze about the winter cap in the literature of the Joseon Period, as the period of using, synonyms, user, shape and materials. The following are the result of the study. 1. The winter caps can be classified into two kinds of group by times. The first ones have been used continuously during the whole Joseon Dynasty, for example, Nanmo(煖帽, 暖帽), Ieom(耳掩) and Pigyeon(披肩). These names are winter caps for the bureaucracy. The second ones have been used a part of the Joseon Period. Some of the names used in the first half of the Joseon Period, for example, Mogwan(毛冠), Chopigwan(貂皮冠), Chogwan(貂冠) and Seobokpigwan(鼠腹皮冠). The other names used in the latter half of the Joseon Period, for example, Noepo(腦包), Nanja(暖子), Jeomgyeon, Chageompi(遮?皮), Pimaho(皮馬虎), Wibo, Chipo, pungryeong(風領), Nani(煖耳), Hohang(護項), Hwihang(揮項), Manseonduri, Pungcha(風遮), Samsangeon(三山巾), Iwi(耳衣), Aekeom(額掩), Yangjeongeon(凉轉巾), Bolkki, Ayam and Guile. 2. Synonyms with connoting relationship in which one name perfectly connotes meaning of another name are Nanmo, Nani and Pigyen, Nanmo connotes Ieom, Chomo, Homo, Iwi and Hwihang. Nani connotes Hwihang, Hoieom and Pungcha. Pigyen connotes Hwihang and Ieom. In these cases, the range of the meaning of clothing terms can be confirmed since names with broad meaning connote names with narrow meaning. 3. Some names related with the other names, as the user, shape and materials, for example, Ieom, Hwihang and Pungcha.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.231-237
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• 1995

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survival or regrowth yield. Forage rape (Brassica napus L.) was sown by three seeding densities of 5, 15 and 25cm interval among plants on Sep. 1, 1994. Field-grown plants were sampled on the before wintering (Dec. 4) and on the wintering period (Jan. 16) to analyze the nitrogen and non-structural cahohydrate reserves. The rate of winter survival and regrowth yield were also measured in the spring of next year. The dry matter yields from the plots of 5, 15 and 25cm seeding interval were 1,270, 1.01 9 and 1,062 kg/lOa respectively, on the before wintering. The similar pattern wa5 observed in the crude protein yields affected by seeding density. On the before wintering, both of nitrogen and starch contents per plant significantly increased as the seeding density was lowered. Starch content was relatively higher than that of nitrogen in all plots. On the wintering period, the contents of nitrogen reserves were 6.5, 41.2 and 121.7 mglplant, those of starch reserves were 1.0, 5.4 and 185.1 mg/plant, respectively, in the plots of 5, 15 and 25cm seeding interval. Nitrogen reserves on the wintering period increased while starch reserves highly decreased in all plots comparing to the before wintering. 'lhe rates of winter survival were 10.2, 20.6 and 37.1%, and regrowth yields were 76, 96 and 178 kgD.M/ IOa, respectively, in the plots of 5, 15 and 25cm seeding interval. These results cleariy showed that seeding density have a close influence on the level of nitrogen and non-structurd cahohydrate reserves, and that the rate of winter survival and regrowth yield were controlled by reserves level on the wintering period.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.6-11
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• 2015

This study was undertaken to characterize feed value and silage quality according to storage period and film layers for whole-crop barley silage. The crude protein (CP) content increased in all silage during the storage periods compared to those before silage, this content slightly increased over the prolonged storage period but it was not significant (p>0.05). Depending on the film layers of silage, 6 layers were higher than 4 layers. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents also increased in all silage during storage periods compared to those before silage (P<0.05), but they were maintained at similar levels during the storage period. Depending on the film layers of silage, 6 layers were higher than 4 layers. The total digestible nutrients (TDN) content decreased in all silage during the storage periods. However, it was maintained at a similar level for the duration of each storage period. Depending on the film layers of silage, 6 layers were lower than 4 layers. The pH value was decreased during the prolonged storage period and depending on the film layers, 6 layers were lower than 4 layers. In the organic acid contents during the prolonged storage period, lactic acid increased, acetic acid was lower, and butyric acid was significantly higher (p<0.05). Depending on the film layers, 6 layers showed higher levels of lactic acid and lower levels of butyric acid (p<0.05). Therefore, these results showed that 6 layer wrapping was advantageous for long term storage of whole crop barley silage, while also indicating that it is desirable to use 4 layer wrapping within a six month period.