• 한국해양학회지
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• 제30권1호
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• pp.64-68
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• 1995

수심이 얕고 조류가 강한 서해 연안역에 출현하는 자어의 적정 채집 방법을 검토 하기 위하여 아산만에서 채집된 자어를 대상으로 주야간 층별 출현량을 비교하였다. 자어는 층별 출현량이 다를 뿐만 아니라 일주기 수직 이동에 의하여 수직 분포 양상이 변한다. 주간의 상층 채집 자료만을 이용하면 출현종수와 출현량이 과소 평가될 위험 이 있다. 전수층에 대한 주간 채집량이 야간보다 유의하게 작지 않으므로, 주간의 경 사 채집도 유용한 자어 채집 방법으로 판단된다.

• 해양환경안전학회지
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• 제22권1호
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• pp.11-19
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• 2016

한국 주변 해역에서 수온과 살오징어 유생 분포와의 관계를 파악하기 위해 서해 중부(2013년 8월), 동중국해 북부(2013년 8월), 동해 남부연안(2013년 6월, 11월, 2014년 4월, 5월, 6월, 8월, 9월) 등 3개 해역에서 유생 채집과 CTD 조사를 하였다. 유생 채집은 망구 직경 60 cm, 망목 $333{\mu}m$의 Bongo net를 조사선 속도 2-3 knot에 맞춰 저층 부근에서 표층까지 경사채집(oblique tow) 하였다. 서해 중부에서는 오징어 유생이 발견되지 않았으며, 동중국해 북부에서는 외투장 1.0 mm의 1 개체가 발견되었다. 동해에서는 총 39 개체의 유생이 발견되었으며, 외투장 범위는 1.9-13.5 mm이다. 2013년 8월 서해 중부의 표층 수온은 약 $30^{\circ}C$인 반면 30 m 이하에서는 $10^{\circ}C$ 이하로 낮게 나타나 살오징어 유생의 생존에 적합한 수온($15-24^{\circ}C$)의 공간적 분포가 좁았다. 동중국해 북부의 표층 수온은 $31^{\circ}C$에 이르는 고온이며, 50 m 이하 수심에서도 $20^{\circ}C$ 이상의 수온이 분포하여 비교적 깊은 수심에 유생이 분포하는 것으로 추정되었다. 동해 남부 연안에서는 관측기간 동안 유생의 생존에 적합한 수온이 75 m보다 얕았다.

• 수산해양교육연구
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• 제25권4호
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• pp.991-997
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• 2013

Distribution and occurrence of swimming crab, Portunus trituberculatus larvae were investigated in the mid-western coast of Korea in the Yellow Sea. P. trituberculatus larvae were collected in July and August from 2010 to 2012. Bongo net with 303 mesh was deployed once with a double oblique tow. Zoea I (ZI) densities were highest in all sampling months. Then densities of later larval stages decreased dramatically. In general, larval densities at the stations in northern parts and coastal areas were higher than those at the southern and offshore area. Because egg bearing seasons of P. trituberculatus in the study area are between April and August, larval densities, particularly, of ZI may be underestimated. Considering higher densities of ZI and lower ones of later stages, larvae may be transported to growing area and returned to the parental populations. Larval densities and sea surface temperature were not correlated.

• 한국수산과학회지
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• 제45권6호
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• pp.716-722
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• 2012

The larval occurrence of the red snow crab Chionoecetes japonicus was investigated near Dokdo in the East Sea of Korea, and the larval timing of the genus Chionoecetes in world oceans was reviewed. C. japonicus larvae were collected seasonally at 12 stations in February, May, August, and November in 2011. A Bongo net with a 303 mesh was deployed with a double oblique tow. Larvae appeared from February to August, but no larvae were found in November. Zoea I occurred at nine stations with a few zoea II in February, and were found until August. The larval densities in February were high near the northern. In May, megalopa were found at eight stations with a few zoea II. No larvae were caught in November. The larval abundance in the research area peaked in February. Overall, the larval duration of the genus Chionoecetes in the world's oceans persisted for a long time, and Chionoecetes larvae occurred during the warm season in each area. The cold temperature at the sea bottom, where gravid females are found, may prolong larval production along the distribution range of the genus Chionoecetes.

• 한국수산과학회지
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• 제44권2호
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• pp.162-166
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• 2011

The distribution and occurrence of Charybdis japonica larvae were investigated off Yeonpyong-do, Korea, in the Yellow Sea. C. japonica larvae were collected monthly at 15 stations from early June to late October in 2006 and 2007. At each station, a Bongo net with 303 and $505{\mu}m$ mesh was deployed once with a double oblique tow. No larvae were caught in June, in both years. Zoea I was predominant in late July in 2006 and early August in 2007, whereas Zoea I accounted for 84% of all larvae collected and no larval stages later than Zoea III were sampled. Megalopa were the most abundant larval stage at all stations in late August in both years. The timing of larval hatching of C. japonica may be related to that of phytoplankton blooms in the study area. The finding that Zoea I and Megalopa were predominant in the study are may indicate that C. charybdis larvae are carried by advection.

• 한국항해항만학회지
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• 제33권5호
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• pp.309-314
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• 2009

Manta형 무인잠수정(MUUTV)을 대상으로 회류수조에서의 모형실험을 통해 동일한 동체 모형에 대해 형상이 서로 다른 부가물을 부착했을 때의 동유체력 특성을 실험적으로 검토하였으며, 동유체력 측정 결과를 이론계산치와 비교하였다. 아울러 이를 바탕으로 운동안정성을 검토하여 최적의 부가물 형상 결정의 이론적 근거를 확립하였다.

• 한국어류학회지
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• 제26권2호
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• pp.133-138
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• 2014

진해만에서 동계기간 동안 자어의 분포 및 종조성에 관하여 조사하였다. 조사기간 동안 8과 12종이 출현하였고, 우점종으로는 Pholis crassispina, Clupea pallasii, Liparis tanakae, Hexagrammos otakii였다. 이들 4종은 출현한 총 개체수의 93%를 차지하였다. 잠도와 칠천도 동쪽에서 높은 밀도와 종 다양성을 보여, 이 지역이 진해만에서 자어의 주요 산란장인 것을 의미한다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.5-6
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• 2009

Manta형 무인잠수정(MUUTV)을 대상으로 회류수조에서의 모형실험을 통해 동일한 동체 모형에 대해 형상이 서로 다른 부가물을 부착했을 때의 동유체력 특성을 실험적으로 검토하였으며, 동유체력 측정 결과를 이론계산치와 비교하였다. 아울러 이를 바탕으로 운동안정성을 검토하여 최적의 부가물 형상 결정의 이론적 근거를 확립하였다.

• 수산해양교육연구
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• 제23권4호
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• pp.763-771
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• 2011

Development and distribution of Japanese mantis shrimp, Oratosquilla oratoria (De Haan) larvae were investigated in the northwestern water off Incheon. O. oratoria larvae were monthly collected at 15 stations from early June to early October in 2007. Bongo net with 330 and 505 um mesh was deployed in a double once with an oblique tow way. Larval densities were relatively higher in southerner stations in July and in northerner stations in August and September. No larvae were discovered in June. Zoea I and II were not captured during the entire sampling period. Zoea III occurred in July for the first time and were found until September. Thereafter, the proportion of later stages increased. The number of zoeal stages decreased during the summer months and no larvae were found in October. Of zoeal stages, zoea IV was the most abundant in number. Zoeal densities were highest in July and August, particularly at the stations near the coast. O. oratoria larvae may be retained and grow within our study sites without advection to growing areas. Non-occurrence of zoea I and II indicate that they were retained near spawning grounds or near parental burrows. Pattern of larval occurrence was coincided with previous researches conducted in conspecific distribution ranges.

• 대한기계학회논문집A
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• 제21권3호
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• pp.511-518
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• 1997

The technique of fretting fatigue test was developed and fretting fatigue tests of A12024-T4 were conducted under several conditions. The newly developed calibration methods for measuring surface contact tractions showed good linearity and repeatability. The plate type specimen to which tow bridge type pads were attached and vision system was used to observe the crack behaviour. The oblieque cracks appeared in the early stage of crack growth and they became mode I cracks as they grow about 1 mm. The mode I transition points were found to be longer when surface tractions are higher or bulk stress is lower. Before the crack becomes mode I crack, 'well point' where crack grow about rate is minimum, was detected under every experimental condition. The crack behaviour was found to be affected by surface tractions, contact area, bulk stress. It was also found that partial slip and stick condition is most detrimental and the crack starts from the boundary of stick and slip. For gross slip crack started at the outside edge of pad. After crack mode transition, fretting fatigue cracks showed almost same behaviour of plain mode I fatigue cracks. Equivalent stress intensity factor was used to analyze the behaviour of fretting fatigue cracks and it was found that stress intensity factors can be applied to fretting fatigue cracks.