• Communications of Mathematical Education
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• v.21 no.4
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• pp.647-661
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• 2007

In this paper, we study the role of college mathematics education in summer and winter school. And we discuss the effectiveness that the college mathematics education can be promoted throughout the summer and winter school course.

• Journal of the Korean Home Economics Association
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• v.30 no.2
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• pp.81-86
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• 1992

The purpose of this study was to investigate the psychophysical correponding to temperature and to establish the comfort zone of thermal environment for Korean in winter. An experimental investigation was carried out in climate chamber maintaining the air temperature at 20, 22, 24, 26℃ and subjects were 128 college-age Korean(64 males and 64 females) in good health. Data were analyzed by SPSS PC＋ packages. 'Neutral' on the thermal sensation ratings was most frequently indicated at 24℃ by subjects was 23.1℃ (male 24.0℃, female 22.7℃), therefore the comfort zone of thermal environment in winter was considered as 23∼24℃.

• Journal of Environmental Science International
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• v.10 no.2
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• pp.129-133
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• 2001

The purpose of this study is to examine the property of climatological environment using the daily mean meteorological data measured at the serveral meteorological observatory for 30years(1961~1990). It was found that the distribution of discomfort index tended to mainly depend on the geographical situation in the same season. Major portions of Korea were subjected to continental except for some seaside districts. The discomfort index have a large(small) value in summer(winter) season. And there is a short interval(1 or 2 months) between summer and winter season in Korea.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.201-206
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• 2010

Two male reticulated giraffes (Giraffa camelopardalis reticulata), 21-year-old, died of nutritional deficiency that primarily caused by serious tooth wear at Seoul Zoo in winter. A 970 kg-weighed giraffe showed tooth wear of premolars, molars and incisors at necropsy. A foreign body in the rumen, congestion and ulcer of abomasum and duodenum were also observed. Mild appearance of serous fat atrophy in pericardial sac suggests that lack of nutritional intake caused by tooth wear can become harmful enough to threat life. At the necropsy of a 1,290 kg-weighed giraffe, a large quantity of sandy soil were found in the rumen which would stuck the pathway of well-fermented ruminal contents at esophageal groove. Nutritional deficiency could be suspected to urge this giraffe to graze grass on the ground along with sandy soil. Secondarily, the soil damaged teeth and become a culprit making irregular tooth wear and mild serous fat atrophy. Nutritionally good care of geriatric animals is needed especially for browsing animals like giraffes and critically in winter season.

• 한국해양학회지
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• v.22 no.4
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• pp.228-235
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• 1987

Based on the hydrographic data for 19 years (1968-1984) at 65 stations in the West Sea of Korea, we investigate the relationships between the sea surface temperature (SST) in winter and the bottom water temperature (BWT) in summer. The spatially-averaged anomalies of BBT are highly correlated with those of SST during the preceding winter. However, due to advection of heat by ocean currents, the spatial pattern of BWT anomaly in summer does not closely resemble that of SST anomaly in the preceding winter.

• The Korean Journal of Ecology
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• v.14 no.4
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• pp.469-479
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• 1991

The abundance and local distribution of birds around the three atomic power plants were studied during summer in 1998 and winter 1989. It was particularly pointed out how to determine species diversity indices, rarefaction model appeared and habitat use. During the study over 2,200 birds were censused; black-tailed gull, terek sandpipper, asian wandering tattler and australian curlew accountedfor over 76% of the observed birds in summer. Black-tailed gull, black-headed gull, mallard, ancient murrelet and tree sparrow accounted for 76% of the observed birds in winter. overall, 53 species were occurred ; 23 have been observed on yonggwang-gun, 16 used on ulchin-gun, 12 used on kyungju-gun in summer. 18 on yonggwang-gun,,14 on ulchin-gun,12 on kyungju-gun in winter respectively. These three habitats in terms of their of species richness were computed as follows; yonggwang-gun has the highest richness with an expected species number of 17.5 as the same as two season. Kyungju-gun has the lowest with an expected species number of 8.2 in summer and 11.5 in winter.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2001.11a
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• pp.76-81
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• 2001

Recently, the structure is higher and larger, so that the application of high-strength concrete is increased, And as the development of construction skills, it is possible to place during the winter. Concrete work during winter is indispensible to shorten time of completion and cut costs. When concrete work during winter is placed, it has anxiety that concrete freeze at low temperature. As repetition of concrete's freezing cause reduction of durability, it is necessary for mixing to pay attention to air content and W/C ratios. Accordingly, in this study, we estimate the frost resistance by air content and W/C ratios, and development of strength after early-frost damage in the high-strength concrete during the cold weather. In this study, it could be confirmed that factors which were air content, W/C ratios and early curing period, affected on the frost resistance.

• Journal of Industrial Technology
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• v.38 no.1
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• pp.1-7
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• 2018

This paper introduces the design, casting, and sound evaluation results of the Great Bell of 2018 Pyeongchang Winter Olympics. The Olympic Bell was manufactured to announce the opening of the successful Winter Olympics in the world with a grand sound. The bell was designed to the dynamic shape to give a grand and harmonious sound in consideration of the global sports festival. In this study, the performance of the beat making the sound magnificent and the harmony of the bell sound were quantitatively evaluated using acoustical factors. Beat maps were investigated to understand the directivity of the beating sound. The purpose of the research is to present the production technique of a traditional Korean bell that has a dynamic shape and a grand and harmonious sound.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.297-305
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• 2017

This study was analysed the species composition of demersal fishes caught by a bottom trawler, KAYA, in the winter season during 4 years and the study area was the eastern fishing ground in depth of about 110m, 40 miles eastward from Jeju Island, Korea. A total of 54 species were collected, including 40 species of Pises, 9 species of Mollusks, 5 species of Crustaces. The number of individuals and biomass of unit area was $7,978ind/km^2$ and $1,800kg/km^2$, respectively. The dominant species in winter season were Dentex tumifrons, Carangoides equula, Callanthias japonicus, Thamnaconus modestus and Pagrus major. And these also were caught every year. The ranges of the diversity index(H') were 1.97 to 2.40, the richness(R) 1.91~4.59, the evenness(E) 0.54~0.83 and the dominance(D) 0.42~0.61.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.279-283
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• 2011

The immature embryos during seed development were examined to predict the suitable embryos for an efficient regeneration system. Five spring wheat genotypes and five winter wheat genotypes were tested using immature embryos as explants. Spring wheat genotypes showed much higher levels of plant regeneration than those of winter wheat genotypes. The highest frequencies of embryogenesis and regeneration were obtained when embryos at 13-14 days after anthesis (DAA) were used as explant and decreased using embryos at 21-22 DAA during seed development. Significant differences were also found for callus induction and regeneration as affected by immature embryo size. The regeneration efficiency was drastically decreased in spring and winter wheat genotypes when embryos larger than 2.0 mm of length were used. The optimum developmental stage and embryo length for regeneration efficiency were at 13-14 DAA and 1.0-1.5 mm, respectively. The selection of suitable embryos for the high frequencies of embryogenesis and regeneration leads us to efficient genetic improvement of wheat.