• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.45-52
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• 1996

This study was conducted to know how cold tolerance of rice is inherited. Several crosses were made between cold tolerant and susceptible varieties, and their progenies were evaluated for days to heading, spikelet number per panicle and spikelet fertility under both cold water and natural conditions. In F$_1$ and F$_2$ generations, earlier heading, more number of spikelet per panicle and higher spikelet fertility under the cold condition were dominance, and less delay or reduction in heading days and spikelets per panicle by cold treatment were over dominance or partial dominance, while less reduction in spikelet fertility by cold-water irrigation was complete dominance. Heritability in most characters by cold treatment was high and there was less difference of heritabilities in heading days and spikelets per panicle between cold treatment and natural conditions, while there was much difference of heritability in spikelet fertility between two conditions. Heterosis in spikelet fertility was considerably high, while those in heading days and spikelets per panicle were relatively low. Heterosis in remote crosses was especially larger under the cold-water treatment condition compare with that under natural condition.

• Atmosphere
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• v.25 no.3
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• pp.435-447
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• 2015

This study explores the synoptic characteristics of cold days over South Korea and their relationship with large-scale climate variability. The cold day, which is different from cold surge, is defined when daily-mean surface air temperature, averaged over 11 KMA stations, is colder than 1-percentile temperature in each year by considering its long-term trend over 1960~2012. Such event is detected by quantile regression and the related synoptic patterns are identified in reanalysis data. Composite geopotential height anomalies at 500 hPa show that cold days are often preceded by positive anomalies in high latitudes and negative anomalies in midlatitudes on the west of Korea. While the formers are quasi-stationary and quasi-barotropic, and often qualified as blocking highs, the latters are associated with transient cyclones. At cold days, the north-south dipole in geopotential height anomalies becomes west-east dipole in the lower troposphere as high-latitude anticyclone expands equatorward to the Northern China and mid-latitude cyclone moves eastward and rapidly develops over the East Sea. The resulting northerlies cause cold days in Korea. By performing composite analyses of large-scale climate indices, it is further found that the occurrence of these cold days are preferable when the Arctic Oscillation is in its negative phase and/or East Asian monsoon circulation and Siberian high are anomalously strong.

• Journal of the Korean Institute of Oriental Medical Informatics
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• v.19 no.1
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• pp.1-34
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• 2013

Objectives : A common cold is a viral disease. There exists only allopathy for it depending on symptoms because of no cure. Korean medicine has taken a serious view of common cold patients with digestive problems as well as patients of the common cold. Accordingly, this study is aimed at finding out the traits of patients with digestive problems among common cold patients. Methods : A survey was conducted with 62 cold patients who got medical treatment in Korean medicine clinics located in small cities and towns including metropolitan cities. The SPSS for Windows( 19.0 Version) was used for statistical analysis. Results : Depending on which clinic common cold patients decided to go to, there was a significant difference in the number of sick days. The group of patients who decided to go straight to oriental medicine clinics had fewer sick days. Only 9.7% of the group of patients who got treatment in Koean medicine clinics had more than 6 sick days. The group of common cold patients with digestive problems had more sick days than the group with no digestive problems, which showed that there was a significant correlation between digestive problems and sick days. When it came to digestive problems depending which clinic common cold patients decided to go to, there was no significant value because of little data collection. However, while 41.9% of the group who went to hospital at first and then to Koean medicine clinic had digestive problems, 24.2% of the group who directly went to Koean medicine clinic had digestive problems. On the whole, 66.1% of the entire common cold patients were shown to have digestive problems. Conclusion : There are relatively many patients with digestive problems among common cold patients, and there is a significant correlation between digestive problems and sick days on common cold.

• Journal of Climate Change Research
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• v.6 no.2
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• pp.87-94
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• 2015

To compare changes in winter temperature over South Korea, 30-year average climate data and climate data of recent 10 years (2014~2014) such as mean temperature, daily maximum temperature and daily minimum temperature were analyzed. Also, we set analysis extreme cold waves frequency related to winter such as freezing days, snow days, days with temperature of below -5, and days with temperature of below -10. This process enabled the comparative analysis of winter temperature changes and extreme cold waves frequency related to winter. This study estimated that winter temperature has gradually increased throughout the last five decades, however, the frequency of extreme weather, such as cold waves has also increased.

• Entomological Research
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• v.48 no.6
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• pp.550-558
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• 2018

To develop a system for the mass production of Protaetia brevitarsislarvae (Pbl), this study analyzed the oviposition characteristics of third instar Pbl through successive rearing and cold treatments. In the first generation, females laid 50 eggs each on average, and spawned higher numbers of eggs for the first 5 days but then fewer after this. However, all of the $2^{nd}$-generation females that were produced through the successive rearing of eggs from the $1^{st}$ generation did not spawn. When test insects (TI) were raised at $32^{\circ}C$, their $mean{\pm}SE$ pupal period and emergence rate were $28.4{\pm}1.9$ days and 87%, respectively. However, most individuals raised in cold treatments ($5^{\circ}C$ and $-5^{\circ}C$) without a pre-cooling period did not survive. Individuals exposed to a pre-cooling period, however, had a 7-10 days longer pupal period than those raised at $32^{\circ}C$, and their emergence rate (90%) was slightly higher. Different cold treatment temperatures ($0^{\circ}C$, $3^{\circ}C$, or $5^{\circ}C$) and periods (30 or 60 days) were tested in further experiments. The experimental group kept for 30 days at $0^{\circ}C$ and $3^{\circ}C$ had the shortest pupal period of all, and emergence rates exceeded 90% in most groups. With respect to the number of eggs spawned by the second generation females after cold treatments, the experimental groups held in cold treatments at $5^{\circ}C$ for 30 and 60 days were found to spawn the most eggs. Consequently, the experimental group kept at $5^{\circ}C$ for 30 days was the most effective set of conditions tested during the entire breeding period.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.1
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• pp.1-10
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• 2022

This study was conducted to investigate the germination characteristics through the temperature change treatment compared to the general room temperature immersion treatment of the native species, the Larix kaempferi, and the Berula platyphyllavar. japonica seeds, and to obtain basic data for the production of healthy seedlings with high productivity and efficiency. As a result, the germination rate of the larch seeds showed a significant difference according to room temperature and temperature immersion treatment, and the average germination days of the birch seeds showed a significant difference according to room temperature immersion and temperature immersion treatment. On the other hand, there was no significant difference in germinal uniformity. The results of the study are as follows. First, the results of the analysis of the fallen leaves were the highest germination rate in the treatment of 1.5 days of hot water and 1.5 days of cold water, the fastest germination rate, the lowest average germination day, and the highest germination uniformity. This is the best result in most items, and the change temperature immersion treatment of hot and cold baths was superior to the conventional room temperature immersion treatment. Second, the results of birch tree showed that the germination rate was the highest in 1.5 days of hot water and 1.5 days of cold water. The average germination day is 1.5 days of cold water 1.5 days of hot water 1.5 days, but the difference between 1.5 days of hot water and 1.5 days of cold water is 0.01 days. The highest germinated uniformity was found in 1.5 days of cold water and 1.5 days of hot water. As a result, in the case of larch and birch, the seed temperature immersion (1.5 days of hot water, 1.5 days of cold water) treatment is superior to the existing three-day immersion treatment in various analysis methods, and it is expected that productivity and efficiency can be improved at a low cost in a short period of time at the seedling production site through seeds.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.830-839
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• 2016

Germination of Hemerocallis seeds as influenced by cold stratification at $5^{\circ}C$ (CS) and maturity of seeds evaluated using X-ray imaging has not been well investigated. Seeds of H. lilioasphodelus, H. citrina, H. citrina 'April Flower', and H. minor collected from China and H. thunbergii collected from Korea were germinated at $20^{\circ}C$ without pre-temperature treatment, while H. hongdoensis, H. dumortieri, H. minor, and H. vespertina seeds were treated with CS. Harvesting 'Stella de Oro' capsules at 35-40 days after anthesis yielded mature seeds with well-developed embryo and cotyledons analyzed by X-ray images with a 92% germination in 17 days after sowing. Seeds of H. thunbergii and H. citrina germinated in less than 13 days without CS; two weeks of CS did not accelerate seed germination. Seeds of H. hongdoensis germinated in 24 days when seeds were stored at $25^{\circ}C$ without CS and in less than 27 days when cold stratified. Therefore, 'Stella de Oro' capsules should be harvested at 35-40 days after anthesis to harvest mature seeds. Cold stratification is not required to accelerate seed germination in the Hemerocallis taxa evaluated in this study.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.106-112
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• 2017

BACKGROUND: Kale (Brassica oleracea) biosynthesizes various phytochemicals including glucosinolates, flavonoids, and carotenoids. Phytochemicals of plants are influenced by light, temperature, carbon dioxide, and growing conditions. Specifically, carotenoids are affected by temperature, light, and oxygen. The aim of this study was to investigate the effect of cold stress (day/night: $25^{\circ}C/20^{\circ}C$, $20^{\circ}C/15^{\circ}C$, $15^{\circ}C/10^{\circ}C$) on carotenoids in kale leaves. METHODS AND RESULTS: Kale was grown in pots for up to 50 days after sowing (DAS) in a greenhouse. For cold acclimation experiments, kale grown in growth chambers for 3 days and was subjected to low temperature for 4 days. The conditions maintained in the growth chambers were as follows: photoperiod, 12/12 h (day/night); light, fluorescent; and relative humidity, 60%. Carotenoid (lutein, ${\alpha}-carotene$, zeaxanthin, ${\beta}-carotene$) contents were analyzed by high-performance liquid chromatography (HPLC). The total carotenoid content gradually increased during cold acclimation for 3 days. When kale was subjected to cold stress, the total carotenoid content was high at $25^{\circ}C/20^{\circ}C$ treatment, but low at $15^{\circ}C/10^{\circ}C$ treatment. The total carotenoid content of kale leaves continuously grown in greenhouse decreased from 50 to 57 DAS (1,418 and 1,160 mgkg-1 dry wt., respectively). The lutein, ${\alpha}-carotene$, and ${\beta}-carotene$ contents were very low and the zeaxanthin contents were very high at $15^{\circ}C/10^{\circ}C$ treatment. When kale was subjected to cold stress, the ratio of individual to the total carotenoid contents of kale leaves was 4553% for -carotene and 210% for zeaxanthin. CONCLUSION: The ${\beta}-carotene$ and zeaxanthin contents in kale leaves indicate their sensitiveness toward cold stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.214-219
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• 1998

This study was carried out to investigate the changes of physicochemical and sensory characteristics according to cold storage period of the vacuum-time beef loin. The pH was decreased for 10 days, and then was increased gradually during storage time. The lactic acid content during the initial storage was 483mg/100g, after storage for 10 days it was increased significantly (p<0.05) to 625mg/100g, and then was decreased with storage time. Regarding of color difference, the L values were 41.0~42.5, but after storage for 40 days they were increased significantly(p<0.05) to 46.2, the a and b values wee 17.3~14.3 and 7.2~5.8, respectively, they were no significant differences depending n storage time. The shear force values showed 584 and 560g for 0 and 10 days, respectively but after storage for 20 days it was decreased significntly(p<0.05) to 299g. The myofibrillar protein extractability was no significant difference for 20 days, howener, it was increased remarkably at 30 days(p<0.05). The myofibrillar fragmentation index was increased significantly (p<0.05) on 20 and 40 days, and the Mg-ATPase activity of myofibrils was increasd to 30 days. The free amino acid was increased during storage periods. The composition of amino acid was composed of glutamic acid, alanine, valine and lysine, which were predominant amino acids as 45%. The total free amino acid was increased 182.18mg/100g to 40 days. The raw meat aroma showed no significant changes during storage time, but the tenderness was increased until 30 days(p<0.05). The color was superior from 20 to 30 days. The taste of cooked meat indicated significant changer to 30 days, but was significantly inferior(p<0.05) at 40 days, the aroma was superior until 30 days(p<0.05). The palatability was superior between 20 and 30 days.

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.237-245
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• 2005

In this paper, the changes of the period of cold weather concrete in Korea with the elapse of age are discussed to investigate the influence of elapse of age on period of cold weather concrete. The climate data of Korean Meteorological Administration(KMA) ranging from 1971 to 2000 was used. The period of cold weather concrete was calculated by following the specification of Korea Concrete Institute(KCI), American Concrete Institute(ACI) and Architectural Institute of Japan(AIJ), respectively. Previous research by the authors used the climate dada of KMA from 1961 to 1990 and research conducted by Kim M.H. used the climate data from 1931 to 1980 were also compared with the period of present paper. According to the results, in present paper, the period of cold weather concreting by KCI was calculated about 95days on average and the period by ACI was 101 days on average and the period by AIJI was 92days on average. For the variation of the period with the elapse of time, the period of cold weather concrete by KCI and ACI in present paper was shortened by as much as 5${\~}$6days compared with that of previous paper 10years ago. However, the period of cold weather concreting by AIJ did not exhibit a marked reduction in the period compared with that of previous paper by the author. But the period by Kim following AIJ exhibited a decrease in the period compared to the period by present paper by as much as 3days. For regional influence, the period of cold weather concreting in southern part of Korea was found to be much shorter than those at northern part. This may be due to the rising of mean temperature caused by global warming effect.