• 한국물환경학회지
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• 제27권4호
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• pp.542-550
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• 2011

Changes of suspended sediment concentration in the Seomjin river estuary located in south sea of the Korea peninsula were investigated during the spring tide in autumn (i.e. 25 hours in October) 2000 and winter (i.e. 25 hours in February) 2001. The changes of temperature and salinity during the spring tide in October 2000 showed larger variations than the those in February 2001. During the spring tide in October 2000, currents at bottom layer were observed to be stronger than during the spring tide in February 2001, showing that both of the two periods had ebb currents-predominant tide asymmetries. The suspended sediment concentrations in October 2000 were larger than the those in February 2001. At the time of the maximum of tide currents or after about one hour of the maximum during the autumn months, the suspended sediment turbidity was observed to be maximum. Another observation station at Hadong upstream from the Seomjin river estuary showed about one hour delay in tide phase, Thereby, the suspended sediment concentration showed high turbidity after two hours at bottom and three hours at surface layer, in particular, in October 2000. This results can be explained by the facts that river discharge increased significantly after the summer rainy season, causing also increase of erosion processes by strong current velocity at bottom layer.

• 농업과학연구
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• 제12권2호
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• pp.341-348
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• 1985

This study aims at analysis hog cycles and seasonal price patterns, and at develop the procedure for price forecasting based on the relative price ratios by farmers. Seasonal price patterns have been a persistent feature of hog markets. Some month have historically high price and other months historically low price. Hog price tend to be high in Feb, May, June, Sept, winter (Nov. to Jan.) and tend to be low in the other months. There have been four price cycles for 12 years, 1972-1984, the length of the hog price cycle has varied from 24 month to 42 months, with the irregular frequency. The increasing period of the price cycle lasted 23 months and the decreasing period of the price cycle lasted 13 months. Tables 2, 3, 4 in this study show average hog price ratios and the number of times price fall, rose for one, two, and three months ahead of each calendar month.

• Pediatric Infection and Vaccine
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• 제15권1호
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• pp.5-11
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• 2008

Primary rotavirus gastroenteritis infection usually occurs in infants under 2 years of age worldwide regardless of level of hygiene, quality of water, food or sanitation or type of behavior. In Korea, the disease mostly occurred in infants under 2 year old, and usually in late fall to early winter with the highest incidence shown in November until early 1990s. However, since then, relatively the age incidence of this infection has increased in children over 2 years old, and it has mainly occurred in late winter to early spring with the highest incidence shown between February and March. And rotavirus gastroenteritis serotypes varied year to year as well as varied by year within the same region in our country. The comparison of severity scores between age groups in Korea showed that severity score was lowest in infants less than 3 months and highest in infants more than 6 months and less than 12 months, and hospitalization period between age groups was longest in infants older than 3 months and less than 3 months and highest in infants more than 6 months and less than 12 months and less than 6 months. In this aspect, rotavirus vaccines should be given to infants less than 2 years of age in whom the incidence of rotavirus gastroenteritis is the highest, and vaccination should be ideally started before 3 months considering hospitalization period and severity of rotavirus gastroenteritis. However, It should be careful for the introduction of new rotavirus vaccine, and the effectiveness of rotavirus vaccines should be assessed by long-term post marketing surveillance. And we guess an multivalent vaccine may be an ideal rotavirus vaccine to prevent primary infection caused by variable rotavirus strains in Korea. In addition, clinical epidemiology studies on rotavirus gastroenteritis which evaluate the age and serotypes related severity should be continuously conducted in various regions.

• 한국해양학회지
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• 제6권2호
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• pp.78-84
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• 1971

A year-long survey of bacteriological water quality for Lake Eui-am in Kang- won Province, Korea, was conducted from June 1970 to May 1971. the purpose of this investigation was: 1) to determinate the seasonal prevalence of fecal pllution bacteria, such as coliforms, fecal coliforms and enterococci, in Lake Eui-am; 2) to correlate these findings with associated microbiological parameters; and 3) to interpret these results with respect to water quality and environmental health. The membrane filter techniques were used, for the determination of these bacteria.Densities of total coliforms, fecal coliforms and enterococci exhibited seasonal variations, the numers of these fecal pollution bacteria being high in summer and fall months in close possitive relation to the amount of rainfall, and being low winter and spring months. On the whole, the level of fecal pollution bacteria in Lake Eui-am is yet quite low There were not any evident correlation among the density of these pollution bacteria. The ratio of fecal coliforms to enterococci of the lake water varied from 0.01 to 4.25 with average of 1.47.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.777-783
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• 2004

Samples of 13 species of forest tree leaves fed to livestock in the semi-hilly arid zone of Punjab State in India were collected at 30 d interval for 12 months, in order to assess their nutritional worth for livestock. The ground samples were pooled for 4 different seasons viz. dry hot, hot humid, fall and winter. The chemical composition irrespective of the season revealed that CP content varied between 8.9 (Carrisa) to 22.0% (Leucaena). Globulin was the major protein fraction in most of the leaves. The lowest concentration of cell wall constituents was observed in Morus alba and Grewea. The leaves in general became fiberous and lignified during winter and fall as compared to summer season. The leaves of Grewea, Morus alba, Leucaena, Carrisa and Acacia were rich in Ca, P and most of the trace elements. The total phenolics ranged between 1.88% (Azardirachta) to 15.82% (Acacia). The leaves of Acacia had the highest concentration of hydrolysable tannins (14.6%) whereas that of Carrisa had that of condensed tannins (5.9%). The condensed tannins (more than 3%) were negatively correlated to the digestibility of dry matter (DM), neutral detergent fiber (NDF) and crude protein (CP). The digestion kinetic parameters for DM, NDF and CP revealed that leaves of Morus alba, Zizyphus and Ehretia had highest insoluble but potentially degradable fraction. The minimum rumen fill values also revealed that leaves of Grewea, Azardirachta, Morus, Ehretia and Leucaena had great potential for voluntary DM intake. The leaves of Ougeinia, Malha, Dodenia and Carrisa had significantly higher rumen fill value indicating poor potential for voluntary DM intake. Season did not have any significant impact on digestion kinetic parameters except that most of the leaves had low potentially degradable fraction, which was degraded at slow rate during winter. It was concluded that the leaves of Morus, Ehretia, Grewea and Leucaena had great potential as livestock feed, while feeding of Ougeinia, Malha and Dodonea leaves should be avoided.

• 환경생물
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• 제30권1호
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• pp.47-53
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• 2012

이식된 포기거머리말의 현장 적응성을 알아보기 위해 철사고정법으로 포기거머리말을 이식후 이식된 개체(이식구)와 인근 자연군락 포기거머리말 (대조구)의 밀도, 형태적 특성과 생산성의 변화를 약 2년간 조사하였다. 대조구에서는 봄 여름에 증가하고 가을 겨울에 감소하는 밀도변화를 보였으나, 이식구에서는 조사기간 동안 지속적으로 증가하였으며, 초기 밀도감소가 나타나지 않았다. 엽초 길이, 잎 폭, 개체 길이와 엽초, 잎, 개체의 무게는 이식초기에는 대조구에 비해 이식구에서 감소하는 경향이 보였으나 약 5개월 후부터는 대조구와 이식구가 유사해졌다. 잎 생산성도 대조구와 이식구 모두 봄 여름에 증가하고 가을 겨울에 감소하는 뚜렷한 계절 경향을 보였으나, 이식초기 이식구의 개체 잎 생산은 생산성이 낮은 가을인데도 불구하고 증가하였다. 철사고정법으로 이식된 포기거머리말은 개체의 유실이 없었고, 형태적 특성으로 보아 약 5개월의 현장적응기간을 소요하는 것으로 판단된다.

• 한국동물위생학회지
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• 제22권1호
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• pp.71-77
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• 1999

Research results on actual management situation of 16 goat farms and internal parasite infection of 155 goats from January to November in 1997 in southern Kyoungnam area were as follows ; 1. An average number of goats was 93. Among them, 81% were farming the goat as avocation with the income rate less then 50%, Eight-four percent of farms terminated the parasites more than twice a year, and the survey showed the black goats had a high digestive and respiratory disease infection rate. 2. The internal parasite infection rate of the black goat was 96.8% , the goats were infected with 13 types of parasites. Of them, Emeria sp was 87.1%, Ostertagia sp 55.5%, Paraphistanum sp 45.8%, and Moniezia expansa 20%, respectively. 3. On the survey of multiple infection rate, both double and triple infection were 19.4%, more than septuple-infection 15,5%, single infection 13.4%, quintuple infection 12.3 n, sextuple infection 9.0% and quadruple infection 7.7%, respectively. 4. Look over on seasonal infection rate, higher in fall and lower in winter. Especially, Paramishitom sp was higher in summer and winter, both Moniezia expansan and Bonaostom sp were higher in summer. 5. Research on the infection rate of parasites termination period revealed less-than-1-month period had 10-30 infection rate, the infection rate has increased sharply since 3 months passed after the goats were treated with parasite-cid.

• Ocean and Polar Research
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• 제33권spc3호
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• pp.325-336
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• 2011

Seasonal to inter-annual variations of water properties in the western channel of the Korea Strait are investigated using quasi-monthly hydrographic observations collected during 2006-2010. Weak vertical temperature and salinity gradients are observed during the winter months and these remain until May. At the upper layer, temperature increases from March and reaches a maximum in August, while salinity decreases during the same period. Near-bottom water shows low temperatures during late winter and fall with a minimum peak in September. Korea Strait Bottom Cold Water produces thick layers (>20 m) in 2006 and 2010, while it is observed very near the bottom with relatively high temperature in 2008 and 2009.

• 한국어류학회지
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• 제35권4호
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• pp.294-304
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• 2023

가덕도 인근해역에서 출현하는 자어 군집에 대한 계절변동을 파악하기 위해 2019년 5월, 8월, 11월 그리고 2020년 2월에 조사를 실시하였다. 조사기간 동안 자어는 총 45과 85개 분류군이 출현하였다. 우점종은 멸치(Engraulis japonicus), 망둑어류(Gobiidae spp.), 청어(Clupea pallasii), 가라지(Decapterus maruadsi), 돛양태류(Callionymidae sp.) 등으로 나타났으며, 이들 5종은 조사기간 중 출현한 자어 전체 출현개체수의 84.1%를 차지하였다. 멸치와 망둑어류, 가라지, 돛양태류는 여름철 우점종이었고, 청어는 겨울철 우점종이었다. 종다양도지수는 여름철에 가장 높고 가을, 겨울철로 갈수록 낮아졌으며, 봄철에 가장 낮은 값을 나타내었다. 조사기간 동안 출현한 자어의 출현개체수로 군집분석을 실시한 결과 계절에 따라 4개의 그룹으로 뚜렷이 구분되었다. 특히, 계절적 수온변화에 따라 여름철에는 자어의 적정한 성육환경이 형성되었고, 겨울철에는 겨울산란어종의 적정한 부화수온이 형성되어 자어군집의 계절적 특성을 반영하고 있었다.

• The Korean Journal of Ecology
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• 제16권4호
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• pp.397-408
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• 1993

대기의 오존농도에 대한 민감도가 다른 스트로브 잣나무의 가스교환과 아스코르브산, 글루타치온의 농도변화를 1988년 6월부터 시작하여 10개월간 측정하였다. 오존에 의해 가시적 피래를 입은 나무의 당년잎의 건중량과 길이는 저항성이 있는 나무에 의해 각각 60~75%와 45~60% 작았다. 순광합성량과 잎의 전도율은 전체적으로 가스교환이 감소하기 시작하는 늦은 9월까지 저항성이 있는 나무에서 높은 값을 보였다. 증산작용도 비슷한 양상을 보였다. 당년잎의 아스코르브산과 글루타치온 농도는 여름, 가을 동안 계속 증가하여 겨울에 최고치를 나타내다가 봄에 감소하기 시작했다. 아스코르브산 농도는 4월에 감소하기 시작할 때 까지 일년 내내 저항성이 있는 나무에서 높은 농도를 나타내었다. 예민한 나무와 저항성이 있는 나무사이의 아스코르브산 농도차이는 겨울동안보다 (8~19%) 여름에 (25~30%)) 훨씬 컸다. 글루타치온의 농도는 에민한 나무와 저항성이 있는 나무에서 비슷한 결과를 보였다.