• 수산해양기술연구
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• 제45권3호
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• pp.177-187
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• 2009

This paper describes a automatic video surveillance system(AVSS) with long range and 360$^{\circ}$ coverage that is automatically rotated in an elevation over azimuth mode in response to the TTM(tracked target message) signal of vessels tracked by ARPA(automatic radar plotting aids) radar. This AVSS that is a video security and tracking system supported by ARPA radar, CCTV(closed-circuit television) camera system and other sensors to automatically identify and track, detect the potential dangerous situations such as collision accidents at sea and berthing/deberthing accidents in harbor, can be used in monitoring the illegal fishing vessels in inshore and offshore fishing ground, and in more improving the security and safety of domestic fishing vessels in EEZ(exclusive economic zone) area. The movement of the target vessel chosen by the ARPA radar operator in the AVSS can be automatically tracked by a CCTV camera system interfaced to the ECDIS(electronic chart display and information system) with the special functions such as graphic presentation of CCTV image, camera position, camera azimuth and angle of view on the ENC, automatic and manual controls of pan and tilt angles for CCTV system, and the capability that can replay and record continuously all information of a selected target. The test results showed that the AVSS developed experimentally in this study can be used as an extra navigation aid for the operator on the bridge under the confusing traffic situations, to improve the detection efficiency of small targets in sea clutter, to enhance greatly an operator s ability to identify visually vessels tracked by ARPA radar and to provide a recorded history for reference or evidentiary purposes in EEZ area.

• 한국수산과학회지
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• 제37권2호
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• pp.129-136
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• 2004

Visual line-transect surveys for the finless porpoise (Neophocaena phocaenoides) were conducted in the offshore of the west coast of Korea (WCOK) from 18 April to 17 May 2001 $(34^{\circ}18'\;to\;37^{\circ}18'N,\;123^{\circ}00'\;to\;126^{\circ}00'E),$ and in the inshore of the west coast of Korea (WCIK) from 29 July to 2 August 2003 $(35^{\circ}17'\;to\;36^{\circ}17'N,\;126^{\circ}00'\;to\;126^{\circ}25'E).$ A total of transect survey efforts were 810.27 n.m. in 2001 and 216.09 n.m. in 2003, which cover a survey areas of $23,012\;n.m^2\;and\;1,550\;n.m^2,$ respectively. There were 76 and 24 sightings for the finless porpoise during the surveys in the WCOK (2001) and the WCIK (2003), respectively. More than $80\%$ of the finless porpoise occurred near the coast within 15 n.m. from the land. Porpoise were observed mainly in a depth range from 20 to 50 m $(78\%).$ Few porpoise were observed in a depth shallower than 10 m or deeper than 60 m. The hazard-rate model, truncated at the largest $5\%$ distance, showed the best fitting from the frequency distribution of perpendicular distance of the finless porpoise sighted from the trackline in the WCOK (2001), while the uniform model showed the best fitting from in the WCIK (2003). Abundance of finless porpoises were estimated to be 58,650 individuals ($95\%$ CI=34,961-98,389) in the WCOK (2001) and 1,571 individuals ($95\%$ CI=881-2,800) in the WCIK (2003), respectively.

• 한국수산과학회지
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• 제42권3호
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• pp.290-296
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• 2009

Acoustic technologies are commonly used to estimate biomass and distribution of fisheries resources in coastal areas and the open ocean. The pelagic species of Engraulis japonica, Scomber japonicus and Sardinops melanosticta spawn migrate to the southern part of the Sea of Korea and capture of these three species comprise 50% of the total abundance in Korean waters. Since 1970, anchovy landings have increased to 0.2 million tons in 1990, 0.27 million tons in 2001, and 0.25 million tons in 2003. Acoustic surveys were conducted on 24-26, May and 20-21, June 2005 around the Tongyeong, Geojae, and Namhae anchovy fishing ground using a dual beam echo sounder (DT-5000, 200 kHz Biosonics). Using this approach, information was obtained on the distribution (depth and position) of zooplankton, and adult and juvenile anchovy. We calculated and compared anchovy biomass using simple summation and geostatistic methods to assess the advantages and constraints of the two techniques.

• Fisheries and Aquatic Sciences
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• 제12권2호
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• pp.152-161
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• 2009

The largehead hairtail (Trichiurus lepturus) is one of the most common fisheries stocks in the East China Sea and the Yellow Sea. The species is caught using a variety of fishing tools, such as a stow net or a long line, as well as jigging and trawling. Scientific investigations have been conducted throughout the world to enable evidence-based estimations for the management and protection of the main fisheries biomass. For example, inshore and offshore hydro acoustic surveys are performed annually using bottom- and mid-water trawls around the Korean Peninsula. However, to date, no acoustic survey has been conducted to estimate fish size distribution, which is necessary to construct a data bank of target strength (TS) relative to fish species, length (L), and frequency. This study describes the frequency and length dependence of TS among fishes in Korean waters for the purpose of constructing such a TS data bank. TS measurements of the largehead hairtail were carried out in a water tank (L 5 m$\times$width 6 m$\times$ height 5 m) at frequencies of 50, 75, 120, and 200 kHz, using a tethering method. The average TS patterns were measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down) to $+45^{\circ}$ (head up) every $0.2^{\circ}$. The length conversion constant ($b_{20}$) was estimated under the assumption that TS is proportional to the square of the length. In addition, in situ TS measurements on live largehead hairtails were performed using a split beam echo sounder.

• 해양환경안전학회지
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• 제9권2호
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• pp.65-72
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• 2003

1996년 6월에 실시된 CREAMS 항해 관측 자료를 이용하여 동해 남부 해역의 해황을 분석하였다. 1996년은 1990년∼1999년 사이의 다른 해에 비해 동해 남부 해역에 저수온 현상이 나타났으며, 이러한 현상은 일본 연안을 따라 이동하는 쓰시마난류의 지류가 더욱더 연안에 근접하여 이동하는 것과 관련이 있다. 쓰시마난류의 분포는 수심 200m 이천의 대륙붕 위에 존재하는 core 형태의 고염분수 분포와 지형류의 분포로부터 확인된다. 해수의 안정도 계산결과로부터 고온 고염분수인 쓰시마 난류의 유입은 연안역의 연직 밀도 구조에 영향을 주게 되며, 이로 인하여 수주의 불안정한 상태를 초래하는 요인 중 한가지로 작용하는 것으로 나타난다.

• 한국수산과학회지
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• 제47권1호
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• pp.59-61
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• 2014

We conducted eight surveys in the northern East China Sea (ECS) in winter (February - April), summer (July), and autumn (October) 2004-2009, to investigate the seasonal distribution of T. pacificus. A total of 482 paralarvae, ranging in mantle length (ML) from 1.0 - 17.0 mm, were collected at 73 out of 181 stations. There were higher numbers of paralarvae during the winter and summer months than in the autumn. There was significant seasonal variation in the paralarval mantle lengths; mantle lengths were longer in winter (April) than in summer (July). The position of oceanic fronts in the study area played an important role in restricting paralarval distribution along the inshore edge of the Tsushima Warm Current (TWC). When the TWC expanded to western Jeju Island in winter and autumn, the paralarval distribution range extended to include western Jeju Island. However, when the TWC was located southeast of Jeju Island in the summer, paralarvae were distributed along the frontal zone off southeast Jeju Island. Sites at which paralarval mantle length was <2.0 mm ML indicated that the spawning ground were likely to be within the northern ECS in winter and summer, but north of the study area in autumn.

• 한국항해항만학회지
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• 제41권3호
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• pp.103-108
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• 2017

이 연구에서는 최근 5년(2010~2014년) 동안의 데이터를 이용하여 우리나라의 풍랑특보 분포 특성에 대하여 분석하였다. 풍랑특보는 우리나라 주변 해역을 항해하는 선박 및 해양 구조물 등의 안전에 큰 영향을 미치므로 중요한 의미를 가진다. 풍랑특보는 한반도의 동측 즉, 동해남부 및 동해중부 해역, 남해동부 해역에서 많이 나타난다. 이 결과는 온대저기압의 이동과 발달, 계절풍의 세기 등과 밀접히 관련되어 있다. 그리고 풍랑특보는 12월에 가장 많고, 1월과 3~4월에도 높은 빈도수를 보인다. 계절로 구분해 보면, 겨울 > 봄 > 가을 > 여름의 관계를 확인할 수 있는데, 이들 결과는 온대저기압의 발생 및 발달, 계절풍의 세기 차이 등에 의한 것이다. 앞바다와 먼바다의 월별 풍랑특보 분포에 대하여 통계 분석한 결과, 양자는 강한 양의 상관관계가 있음을 확인하였다.

• 한국수산과학회지
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• 제28권5호
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• pp.667-676
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• 1995

군산 연안 조간대에 있어서 1993년 6월에서 1994년 5원까지 조사한 동죽(M. veneriformis)의 침강과 가입 및 성장, 생산량에 대하여 조사하였다. 동죽의 부유유생의 높은 밀도는 1993년 6월 19일에서 7월 3일에 관찰되었으며, 침강된 치패의 크기는 250um에서 350um였고, 평균밀도는 약 $601\;inds\cdot\;m^{-3}$이었다. 유생의 침강에 의한 가입은 주로 1993년 6월 중순에서 7월 중순에 이루어 졌으며, 유생의 침강시 저질에 따른 선택성은 없었다 그러나 침강한 치패는 환경(저질, 노출시간, 성패의 밀도)에 의하여 사망율이 결정되었다. 평균 각장에 의하여 추정한 동죽의 성장은 가입 초기에 있어서 과소평가 되었으며, 성장기는 11월 중순까지이고, 겨울철에는 정지하였다. 0세군의 연간생산은 2,900 g\cdot\;m^{-2}\;\cdot\;yr^{-1}$으로 나타났으며, 회전율은 약 4.94 (Crisp, 1984)와 4.91 (Ricker, 1978)로 추정 되었다.

• 수산경영론집
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• 제16권2호
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• pp.1-18
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• 1985

The dispute on the object of study in the business management have been carried out since 1912 in Germany, and then it is the situation of "business management" academic world there is no the confirmed object. But P. F. Drucker has prescribed the large enterprise as the object of his study of management, because the large enterprise it the decisive, the representative, and constitutive in modern industrial country. And it is usual that we would consider the large manufacturing enterprise as the object of study. But, in fisheries management, because large fisheries enterprises are almost attached too much to the pelagic fisheries, it is judged that they are not "decisive". And it is judged that they are not "representative", because the large fisheries enterprises can not sufficiently symbolize the managerial characteristic of fisheries industry. The coastal and inshore fisheries which constitute th real part of fishing industry have been operating by private enterprises which are small business in scale, so the large fisheries enterprises could not be considered "constitutive " Therefore, the private fisheries enterprises is "decisive" because it is distributed in all most fisheries management, "representative" because it is exceedingly symbolize the managerial characteristic of fishing industry, and constitutive because it constitute the real part of fisheries industry. From the above-mentioned, it could be concluded that the object of study is regarded the private fisheries enterprise as appropriate as long as it is engaging in producing fisheries product as good and conducts the pursuit of principle of profit maximization. Because the object of study can not include all the thing which has to be observed in order to study, the materialization of the object is actually necessary. And then as aforesaid we intend to realize the materialization through taking the private fisheries enterprise as the object in fisheries management theory. And the materialization does mean a necessary process in choosing the object of analysis, but not the entity itself.choosing the object of analysis, but not the entity itself.

• 한국수산과학회지
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• 제44권3호
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• pp.267-275
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• 2011

The common squid Todarodes pacificus is an ecologically and commercially important species in Korea and Japan. However, the distribution pattern of its eggs and larvae in Korean waters has not yet been clarified. To determine the horizontal and temporal distribution of common squid larvae in the northern East China Sea, samples collected using paired, 60 cm diameter Bongo nets from the three surveys conducted in August 2003, May 2004 and November 2005 were examined. In addition, the vertical distribution was examined from the samples collected using a $1\;m^2$ MOCNESS in April 1999 (20 m interval down to 100 m). A total of 218 larvae ranging in mantle length (ML) from 1.2 to 17.0 mm were counted at 27 stations. Larval abundance was highest in May 2004. The larvae mainly occurred in the southeastern area of Jeju Island, where the water temperature and salinity at 50 m deep ranged from $15-23^{\circ}C$ and 34-34.6 psu, respectively. Most larvae were collected in the frontal zone, where the Tsushima Warm Current and inshore waters meet. The results from the MOCNESS samples showed that the larvae occurred mostly in 20-80 m depth ranges (about 90%), although collections were only conducted above 100 m. No significant differences in larval mantle lengths (ANOVA, P>0.05) were found among each depth interval. Given the occurrence sites of the larvae <2.0 mm ML, the spawning ground of this species appears to be within the northern East China Sea, mainly to the southeast and northeast of Jeju Island, in early spring.