• 한국발생생물학회지:발생과생식
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• 제18권4호
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• pp.259-266
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• 2014

The egg development and early life history of Korean spotted sleeper, Odontobutis interrupta which is Korean endemic species from Sora-choen was investigated. The Korean spotted sleeper were caught at Sora-myeon, Yeosu-si, Jeollanamdo, from Korea at May in 2014. The fertilized eggs were $4.23{\pm}0.05mm$ in long diameter and had oil globules. Hatching time of the embryo began about 442 hr 14 min after fertilization under water temperature of $19.5^{\circ}C$. The newly hatched larvae were $4.27{\pm}0.35mm$ in total length and their anus were not yet opened. 3 days after hatching postlarvae was measured $6.20{\pm}0.11mm$ in total length. 10 days after hatching postlarvae was measured $6.69{\pm}0.14mm$ in total length.

• 한국수산과학회지
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• 제52권4호
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• pp.408-417
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• 2019

This study was conducted to identify taxonomic differences in the characteristics of Rhodeus uyekii and Rhodeus ocellatus during their initial life history via an interspecific hybridization experiment. Hybrids were compared to their parent species, and the findings were used to inform developmental research in commercially useful aquarium fish. The hatching rates of the cross-bred eggs were 75.9% for cross UO (R. uyekii ♀${\times}$R. ocellatus♂) and 71.9% for cross OU (R. ocellatus♀${\times}$R. uyekii♂), which did not differ greatly from the hatching rates of the normal cross-bred group. Backcross experiments resulted in 100% egg mortality during development. Newly hatched larvae of the original hybrid crosses were similar to those of the maternal line, and the color of the egg yolk was similar to that of the paternal line; therefore, the respective traits of the interspecific parents were identifiable within the cross-bred offspring.

• 한국발생생물학회지:발생과생식
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• 제24권4호
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• pp.307-316
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• 2020

The purpose of this study is to observe the early life history of Korean Lefua costata and use the result as basic taxonomic research data for balitorid fish. The fertilized eggs were light green color with completely circle shape and mean size was 1.21±0.06 mm (n=30). Immediately after hatching, the size of the larvae was 2.81±0.11 mm (n=5) in mean length, with egg yolk. On the 3rd day after hatching, the preflexion larvae had a mean length of 4.64±0.09 mm (n=5), and their mouth was opened to start feeding. On the 8th day after hatching, a mean length of the postflexion larvae was 9.43±0.46 mm (n=5), the distal part of the notochord was bent to 45°, and 16 fin rays were developed on the caudal fin. On the 31st day after hatching, a mean length of juveniles was 22.3±0.85 mm (n=5), and the number of fin rays was the same as that of adult fish with (iv8) dorsal fins and (iii8) anal fins.

• 한국수학교육학회지시리즈A:수학교육
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• 제45권4호
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• pp.439-457
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• 2006

This research was to understand the features of mathematization and didactical phenomenology, in a way that was not a routine calculation of equation, rather a complete comprehension by the reinventing historical principles of the equation. To achieve the purpose of this study, one-mate middle school student participated in the study. Interview and observation were used for collecting data during the student's performance. The results of research were: First, the student understood the mathematical concepts from a real life and developed the abstract concepts from it, which were very intimately related with his life. Second, the skill and formula definition were accomplished with the accompanying predicted and consequently derived mathematical concepts. Third, through the approach of using the history of mathematics, he became more interested in what he was doing and took lessons with confidence. Forth, the student performed his learning based on the historical reinventing principle under the proper guidance of a teacher.

• 대한토목학회논문집
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• 제9권1호
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• pp.1-10
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• 1989

교량에 발생하는 응력이력은 교통류(traffic flow)의 성질에 따라 변하며, 교통류는 차종규성율, 차량중량, 차두시간간격(headway time)등에 따라 다르기 때문에 교량과 같은 휨부재에서 교통류에 의한 응력이력을 추정하기 위해서는 통계적 해석이 필요하며, 이것을 파괴역학에 적용함으로서 구조물의 잔존수명을 추정할 수 있을 것이다. 본 연구에서는 1)교통류의 불규칙성을 해석하기 위하여 차종구성율, 차량중량, 차두시간간격등을 통계적으로 분석 2)실제 교량에서의 응력이력의 측정과 분석 3)차종구성율, 차량중량, 차두시간간격을 확률변수로한 Monte Carlo 시뮬레이션에 의한 응력이력의 재현 4)실측 응력이력과 시뮬레이션한 응력이력의 비교 5)대상교량의 감소계수(reduction factor)의 계산 6)지간길이 변화에 따른 응력범위발생빈도의 비교등을 행하였다. 그 결과 시뮬레이션에 의한 응력이력 추정방법과 구조물의 잔존피로수명 예측에 필요한 기본적인 모형화된 응력이력을 제시하였다.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권4호
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• pp.279-284
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• 2021

The dung beetle, Gymnopleurus mopsus (Coleoptera: Scarabaeidae), is one of endangered species in South Korea. It was last recorded in 1971. To restore this species, we introduced G. mopsus populations from eastern and southern regions of Mongolia in July 2019 and August 2019, respectively. One of the main tasks for the restoration of endangered insects is to develop breeding techniques to eventually incorporate these insects into the restoration system. In a series of laboratory experiments, we investigated effects of short-term hibernation periods on life-history traits of G. mopsus. Adult G. mopsus that had hibernated for 30, 60, and 90 days had lower survival rates than adults that had hibernated for 120 days. We also compared developmental time of these four experimental groups and found a significant difference in the egg - phase. However, the duration of hibernation did not affect the fecundity, brood-ball size, or body size of F1 adults. Follow-up studies are currently being conducted to further investigate the effect of a short-term hibernation period on population growth of G. mopsus under laboratory conditions.

• 한국어류학회지
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• 제26권1호
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• pp.17-24
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• 2014

한국 고유종인 큰줄납자루 Acheilognathus majusculus의 종 보존을 위한 기초 자료를 확보하기 위해 난 발생과 자어의 성장을 관찰하고 초기생활사 특성을 논의하였다. 수정란은 둥근 타원형으로 평균 장경이 2.12mm(2.08~2.18 mm), 단경이 1.86mm(1.80~1.98 mm)이며 담황색 난황을 가진 분리침성란이다. 개체 당 산란 수는 40~112개(평균 72개)였고 수정란은 수온 $18.0{\pm}1.0^{\circ}C$에서 수정 후 43시간 만에 부화하였다. 부화 직후 자어의 크기는 4.23mm이고 형태적으로 납자루속의 자어 특성을 공유하고 있으며 자어 시기의 S자 운동은 없었다. 부화 후 25일 경에 소화기관이 완성되고 외부 먹이를 먹을 수 있어 자연에서 조개로부터 부출하는 시기로 추정된다. 만 1년 후에는 재생산이 가능한 크기로 성장한다.

• 한국어류학회지
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• 제24권2호
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• pp.101-109
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• 2012

중국으로부터 유입되어 일본의 이바라키현에서 정착한 큰납지리 Acheilognathus macropterus의 난발생과 자치어의 특성에 대해 관찰하였다. 담황색 수정란의 장타원형으로 난경은 장경이 2.68~2.86 mm (평균 $2.78{\pm}0.12mm$, n=40), 단경이 1.42~1.49mm(평균 $1.44{\pm}0.04mm$, n=40)였다. 암컷의 개체 당 채란된 알의 수는 124~180개 (평균 151개)였다. 수정란은 수온 $20{\pm}1.0^{\circ}C$에서 수정 후 78시간 만에 부화하였다. 부화 직후 자어의 크기는 3.8mm이고, 3일째부터는 S자 모양의 빠른 움직임을 보였다. 부화 후 25일 경에 소화기관이 완성되어 먹이를 먹기 시작하고 부출기에 이르렀다. 한국산 큰납지리와 외부형태나 미토콘드리아 cytochrome oxidase I (COI) 유전자의 차이는 크지 않았으나 수정란의 형태가 두 집단 간 뚜렷이 구별되어 분류학적인 논의가 필요하다.

• 한국어류학회지
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• 제21권1호
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• pp.15-22
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• 2009

성숙한 왕종개 Iksookimia longicorpa를 2007년 6월에 전라북도 남원시 운봉읍에서 채집하여 난발생과 초기생활사를 연구하였다. 채집된 성숙한 개체는 LHRH를 주사하였으며 건식법으로 수정시켰다. 성숙란은 분리침성란으로 밝은 노란색이었으며 난경은 평균 $1.53{\pm}0.07mm$였다. 수온 $23{\sim}25^{\circ}C$에서 수정 후 50~72시간 사이에 부화하였으며 크기는 전장 $5.1{\pm}0.23mm$였다. 부화 후 4일경에 난황이 거의 흡수 되었고 전장 $7.1{\pm}0.47mm$로 성장하였다. 부화 후 25일 경에 지느러미 기조가 모두 정수로 되어 치어기에 달하였으며 전장 $12.8{\pm}0.49mm$로 성장하였다. 부화 후 100일 후에 반문모양과 외부형태가 성어와 유사하였으며 전장 $38.5{\pm}2.95mm$로 성장하였다.

• 한국주거학회논문집
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• 제20권4호
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• pp.103-112
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• 2009

The purpose of this research was to find out the housing history of Sakhalin returnees in Ansan Gohyangmaeul since leaving hometown under the Japanese ruling period, who experienced two international migration for one's life. Face to face interview had been done with 20 returnees in the community center of Ansan Gohyangmaeul during October to December, 2008. The semi-structured questionnaire about housing the respondents lived in major life changes used to guide the individual interview. The results showed that personal life as well as housing histories were differed by the reason to move into Sakhalin, which still influenced the returnee' life up to now. The housing they had lived changed from barracks like a training camp, to Japanese small wooden cottage/row house, and then Russian brick house/ apartment. Housing alteration and addition and rebuilding were common to renew the old existing house. The boundary of residing area was mostly limited to the first residing location under soviet governing system throughout one's life without a long distance move. Housing satisfaction was very high in Gohyangmaeul because of the improvement of housing facilities and residence itself as well as the convenience of housing management, compared to former residence in Sakhalin. Economic and emotional aspects of life satisfaction were also high during about 8 years of living in the apartment. Forced movers still require the compensation on hand to either Korean or Japanese government no matter the amount. Social integration to the Korean community would be one of the main issues to new returnees as well as the already returned. In-depth interviews of case study need to reveal the unique housing experience of the forced mover according to the type of leaving hometown by oneself or by parents, and to returned region and time to motherland.