• 수산해양기술연구
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• 제46권4호
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• pp.368-375
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• 2010

Maturation and spawning of the Blackthroat seaperch, Doderleinia berycoides were investigated based on the samples captured in Korean waters from January 2008 to December 2009. Gonadosomatic index began to increase in June, and reached maximum between July to September. After spawning it began to decrease from October. Reproductive season was estimated to July-September, with peak in August. Fecundity was proportional to the size of the female, with the clutch size varying from 115,500 eggs in the smallest female (TL〓28.2cm) to 652,000 eggs in the largest (TL〓33.5cm). Size at 50% sexual maturity ($TL_{50}$), determined from mature females, was 29.6cm. Annual reproductive cycles of this species could be divided into six successive stages; immature stage (October-May), nucleolus stage (June-July), yolk vesicle stage (July-August), vitellogenic stage (June-September), ripe and spent stage (August-October).

• The Korean Journal of Ecology
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• 제25권6호
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• pp.383-389
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• 2002

Pb and Cd concentrations and reproductive progress of feral pigeons were investigated in urban (Seoul) and industrial complex (Ansan) areas from November 2000 to May 2001. Results of the Pb analysis for the feral pigeons from the Ansan industrial complex (egg contents: 1.13 $\mu$g/wet g, bones of adult: 10.5 $\mu$g/wet g) and Seoul (1.64 $\mu$g/wet g, 29.5 $\mu$g/wet g, respectively) indicated that the Pb level of eggs and bones of adults were significantly different between the two colonies (p<0.05). Cd concentrations in liver and kidney of adult pigeons were also significantly different between the Ansan (liver: 0.14 $\mu\textrm{g}$/wet g, kidney: 0.43 $\mu$g/wet g) and Seoul (liver. 0.24 $\mu$g/wet g, kidney: 1.05 $\mu$g/wet g) colonies. (p<0.05). However, egg size and thickness, incubation period and nestling growth rates did not differ between the study areas. Also, clutch size, number of young hatched per nest and number of young fledglings per nest did not significantly different in the noted areas. Considering the lead and cadmium concentrations of pigeons, these were not as high as those considered as results in toxic effects in other species, and the biological significance from these level differences is uncertain.

• 한국산림과학회지
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• 제94권5호통권162호
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• pp.338-341
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• 2005

This study was conducted to describe the differences in artificial nest boxes use of tits between deciduous and coniferous forests at 2nd campus of Chung-Ang University ($37^{\circ}00^{\prime}04^{{\prime}{\prime}}N$, $127^{\circ}13^{\prime}96^{{\prime}{\prime}}E$), Ansung, Korea from January to August 2005. Tree species richness, tree species diversity index (H') and total basal areas were higher in deciduous forest than in coniferous forest. High, middle, low and understory canopy layers were more developed in deciduous forest, except the coverage of bush-ground layer. Varied tit Parus varius, marsh tit P. palustris and great tit P. major used the artificial nest boxes in this study. Number of breeding pairs of tits used artificial nest boxes, clutch size, and weight and size of eggs were higher in deciduous forest than in coniferous forest. The differences in habitat structure between study sites are very likely to have influenced how breeding birds used the available habitat. Artificial nest boxes could be used as management and conservation tool for birds, particularly in areas, where the availability of natural cavities and coverage of higher layer are limited.

• 한국자동차공학회논문집
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• 제24권6호
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• pp.702-708
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• 2016

The torque converter is deformed according to the rotating speed and control pressure when engine power is transferred to the transmission. This deformation, which is called ballooning phenomenon, occurs mainly at the outer side by the centrifugal force of the automatic transmission fluid (ATF) and the control pressure from the valve body. Although the torque converter is slightly deformed when rotating, the ballooning phenomenon affects fluid performance, efficiency and durability. Thus, expansion characteristics analysis is important in determining torus size, control pressure and structure. In this paper, an analysis equation and FEM model was developed to investigate the expansion characteristics. Using this model, structural analysis was performed to investigate the relationships between deformation and the torus diameter. The results were confirmed by comparing with the test results.

• 한국환경생태학회지
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• 제21권1호
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• pp.93-100
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• 2007

2004년 2월부터 2005년 6월까지 제주특별자치도 애월읍 신엄리에서 흑로의 번식과정을 조사하였다. 한배 산란수는 $3.24{\pm}0.75$개(N=17, 범위 $2{\sim}4$개)였으며, 알은 새벽이나 밤에 $1{\sim}3$일 간격으로 산란하였다. 알(N=39)의 크기는 장경 $46.73{\pm}l.91mm$, 단경 $34.06{\pm}0.83mm$, 무게 $27.67{\pm}3.12g$, 두께 $0.26{\pm}0.03mm$였다. 흑로의 둥지 보수나 짓기는 매년 2월부터 시작해서 늦게는 4월말까지, 산란기는3월초부터 늦게는 5월 초순까지였고, 부화기는4월 초순에서 5월 중순까지, 이소기는 5월 중순부터 7월말까지였다. 보충 산란은 1차 번식과정 중 포란과 육추에 실패한 $5{\sim}6$월에 바로 시도하는 것으로 추정된다. 포란 기간은 $28.17{\pm}4.12$일(N=6)이었으며, 알은 비동시성으로 부화되었다. 육추 기간은 $40.00{\pm}6.84$일(N=5)이었으며, 새끼의 부리, 날개, 부척, 체중의 성장속도는 부화가 빠른 개체일수록 빠른 경향을 보였다. 우리나라에서 번식하는 백로과 조류의 산란시기를 비교해보면, 흑로는 왜가리보다는 느렸으나, 해오라기, 쇠백로, 중대백로는 보다는 빨랐다.

• 한국환경생태학회지
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• 제31권1호
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• pp.24-29
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• 2017

본 연구는 2012년부터 2014년까지의 번식기 동안 광주광역시에서 제비의 영소지 선택과 번식생태를 파악하기 위하여 이루어졌다. 모든 둥지는 건물의 수직 벽과 지붕에 붙어 있었으며, 둥지의 외측 직경은 $18.2{\pm}3.2cm$, 깊이는 $9.8{\pm}3.1cm$, 둥지 내측 직경은 $11.2{\pm}1.5cm$, 내측 깊이는 $3.4{\pm}0.5cm$로 지면에서 평균 $2.9{\pm}0.3m$ 높이에 위치하였다. 번식 둥지는 시멘트 벽(44.9%), 목재(23.1%), 벽돌(21.8%), 전등(6.4%)에 부착되어 있었다. 한배 산란수는 2~5개 범위로 평균 4.5개이었다. 평균 알 장경은 $18.23{\pm}0.73mm$, 단경은 $13.11{\pm}0.25mm$, 알 부피는 $1.60{\pm}0.11cm^3$, 알 형태지수는 $1.39{\pm}0.05$, 알 무게는 $1.69{\pm}0.15g$이었다. 부화 및 이소 성공률은 각각 89.1%와 84.5%이었다. 번식 실패의 주요 원인은 미수정란과 포식, 둥지훼손, 번식포기로 나타났다. 이러한 결과들은 제비의 서식지 보존 및 종 관리에 필요한 자료로 널리 활용될 것이라 판단된다.

• 수산해양기술연구
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• 제48권3호
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• pp.217-226
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• 2012

Reproductive ecology of the sharp toothed eel, Muraenesox cinereus was investigated based on the samples captured in southern Korean waters from January 2010 to December 2011. Gonadosomatic index began to increase in April, and reached maximum between July to August. After spawning it began to decrease from October. Reproductive season was estimated to April-September, with peak in July. Fecundity was proportional to the size of the female, with the clutch size varying from 56,000 eggs in the smallest female (anal length, 27.0cm) to 1,400,000 eggs in the largest (anal length, 49.5cm). Size at 50% sexual maturity ($AL_{50}$), determined from mature females, were 21.9cm. Annual reproductive cycles of this species could be divided into four successive stages; immature stage (October-February), maturing stage (March-May), mature stage (June-August) and spent stage (August-October).

• 수산해양기술연구
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• 제45권4호
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• pp.243-250
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• 2009

Maturation and spawning of the jack mackerel, Trachurus japonicus was investigated based on the samples captured in the coastal waters around Jeju Island from January 2007 to December 2008. Gonadosomatic index began to increase in March, and reached a maximum between April to June. After spawning it began to decrease from August. Reproductive season was estimated to March-July, with peak in April. Fecundity was proportional to the size of the female, with the clutch size varying from 33,493 eggs in the smallest female(FL=27.0cm) to 627,061 eggs in the largest(FL=40.6cm). Size at 50% sexual maturity(FL50), determined from mature females, was 26.6cm FL. Annual reproductive cycles of this species could be divided into six successive stages; immature stage(September-December), nucleolus stage(January-February), yolk vesicle stage(February-March), vitellogenic stage(March-April), ripe stage(April-July) and spent stage(July-September).

• 수산해양기술연구
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• 제43권4호
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• pp.320-328
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• 2007

Maturation and spawning of the Pacific cod, Gadus macrocephalus was investigated based on the samples captured in East Sea of Korea from April 2006 to July 2007. Gonadosomatic index began to increase in November, and reached maximum between December and January. After spawning it began to decrease from March. Reproductive season was estimated to November-February, with peak in January. Fecundity was proportional to the size of the female, with the clutch size varying from 753,985 eggs in the smallest female(TL＝58.6cm) to 9,311,520 eggs in the largest(TL＝101.0cm). Size at 50% sexual maturity(TL50%) determined from mature females was 56.3cm of TL. Annual reproductive cycles of this species could be divided into six successive stages; immature stage(March-September), nucleolus stage(September-October), yolk vesicle stage(October-November), vitellogenic stage (November-December), ripe stage and spent stage(December-February).

• Journal of Forest and Environmental Science
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• 제28권4호
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• pp.220-226
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• 2012

An assessment of Marsh crocodile's (Crocodylus palustris LESSON, 1831) habitat, its feasibility in supporting the total population, feeding, hatching difficulty and variations in egg and clutch size of Marsh crocodile were carried out in Bangabandhu Sheikh Mujib Safari Park for one year (July 2010 to June 2011). Major problem identified was the breeding failure, i.e. till now no hatching were found. Mainly two local weather variables (average temperature and humidity) were identified as the most obstructing parameters. Higher temperature (average $37.03^{\circ}C$) and Lower Humidity (average 75.33%) in comparison with standard range of incubation temperature and humidity for Marsh crocodile were seems to be vital reason for the failure of hatching. Understanding of the identified problem of this paper can direct the wildlife conservationist and the policy maker to take proper action for conserving the Marsh Crocodile in Bangladesh.