• 수산해양교육연구
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• 제26권5호
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• pp.1158-1164
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• 2014

The propensity analysis for oral exam candidates of sixth class deck officer's license was conducted to serve as a basic data for improving the ability of seamanship and a stable workforce supply using a questionnaire. A general information of them was identified as 64.4% of offshore fishing, 56.8% of over 50, 56.6% of less middle school education, 55.6% of under 100 gross tonnage, 81.2% of over 10 years experience, 85.6% of deck department, which means they are from mainly less than 100 gross tonnage of offshore fishing vessel, less educated, and long term experienced in the deck job. The reason why they took the test was mainly due to their will (71.1%). And 52.7% of them took the test for the first time, 52.7% of answers responded they are lack of knowledge about a written exam and text of KIMFT in preparation data for an oral exam 23.3%. Given the fact that 83.3% of respondents experienced marine accidents on board, the need for marine casualty reduction education was verified. Even after obtaining a license, they showed a higher preference of boarding that they embarked before the examination. Also, 61.7% of them have a plan for long-term boarding at least three years, thus leading to supply of workforce in coastal and offshore areas.

• 한국수산과학회지
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• 제21권3호
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• pp.139-144
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• 1988

1985년 $6\~8$월 1986년 $6\~9$월에 동해남부해역 냉수조사의 일환으로서 실시된 수온관측자료 및 개폐형채집망을 사용하여 층별로 채집된 멸치난과 자${\cdot}$치어를 분석하였다. 수온약층은 1985년의 경우 연안측에서는 표층가까이에서, 외해측에서는 $20\~50m$층에서 형성되었으나 1986년에는 외해측까지 계절수온약층의 경사가 완만하게 형성되었다. 또한 멸치날${\cdot}$치어의 분포역은 1985연에는 울산 부근의 외해측에서, 1986년에는 감포부근의 연안측에서 주로 분포하였다. 특히 멸치 난은 일출시에는 대부분 발생초기에 해당되며 $10\~30m$층에 주로 분포하였으나 자정무렵에는 발생후기로 이행되고 $50\~100m$층에서의 분포비율이 높아지므로서 멸치 난은 발생이 진행됨에 따라 침하하는 경향을 보였다. 또한 자${\cdot}$치어의 경우에는 야간에는$0\~30m$층에서 주간에는 30m이심에서의 분포비율이 높았다.

• 한국재난정보학회 논문집
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• 제18권1호
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• pp.194-201
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• 2022

연구목적: 본 연구는 지난 30년(1981~2010년) 동안 우리나라 기후 요인과 근해 어업에서 어획량의 관계를 조사 분석하였다. 연구방법: 본 연구에서 어획량은 한국인 식탁에서 선호되는 7가지 어종을 대상으로 하였다. 본 연구에서는 장기적 추세를 쉽게 파악할 수 있도록 10년 이동평균을 사용하였다. 연구결과: 동 기간 동안 우리나라 연안의 기온과 표층수온(SST)은 모두 상승하였다(p < 0.05). SST의 상승은 기온의 상승과 유의한 상관관계가 있었지만(p < 0.05), 강수량과는 상관관계가 없었다. 2010년에는 1981년에 비해 멸치와 오징어 어획량이 크게 증가한 반면(p < 0.05), 명태는 거의 멸종되어 어획량이 거의 없었다. 이처럼 냉수 어종은 감소하거나 사라지고 어장은 온수 어종으로 대체되었다. 결론: 이러한 결과는 우리나라 근해 어업에서 어획되는 어종이 기후변화, 특히 온난화로 인해 변화했음을 나타낸다. 이는 한반도의 온난화가 가까운 장래에 한국인의 수산물 공급과 식량 안보에 중대한 영향을 미칠 수 있음을 시사한다.

• 수산해양기술연구
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• 제59권2호
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• pp.125-134
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• 2023

The swimming behavior of pacific bluefin tuna (Thunnus orientalis) in the offshore sea cage of the brass fishing net was observed and analyzed by imaging sonar techniques. The cultured fish spent most of the time swimming a circular path along the circular cage wall and continued to swim only clockwise direction without completely changing the swimming direction during the 23-hour observation time. In addition, changed swimming behaviors were divided into four categories: (a) the behavior of a large group temporarily swimming in the opposite (counter clockwise) direction, (b) the behavior of a small group temporarily swimming in a small circular path, (c) the behavior swimming small circular path in the center of the cage, and (d) the behavior of a large group swimming across the center of the cage. The maximum swimming speed of the cultured fish was from 3.5 to 3.8 TL/s, the mode was from 1.2 to 1.4 TL/s and the swimming speed during the day time was faster than at night time. It was confirmed the cultured fish swam not only on the surface but also near the bottom net of the cage during the day, but swam mainly at the upper part of the cage at night.

• 환경영향평가
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• 제18권3호
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• pp.185-193
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• 2009

This study documented and diagnosed the status and problems of coastal dredging and offshore disposal of dredged sediments in South Korea to improve assessment procedures for marine environmental impacts and develop effective management systems. A total of $729({\times}10^6)m^3$ of coastal sediment was dredged in the harbors during the period of 2001-2008. Most of dredged sediment was disposed to the land dumping sites whereas ocean disposal accounted for less than 5%. Ocean disposal areas were especially concentrated to the exclusive economic zone (EEZ) in the southeast of Busan, which is not only an important fishing area for fishermen, but also considered to be spawning and nursery ground for some commercial fish species. To minimize negative impacts of dredging and ocean disposal of coastal sediment on marine ecosystem and potential strife among coastal users, we suggest 1) in development projects involving ocean disposal, it should be mandatory to propose careful reuse plans in the land, and 2) guidelines of environmental assessment and consequence management programs should be developed and implemented.

• 한국수산과학회지
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• 제25권6호
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• pp.495-500
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• 1992

1985년 한국 동해에서 격월로 수직채집된 어류 난$\cdot$자어와 동물부유생물, 그리고 동시에 관측된 수온과 염분자료를 이용하여 멸치난$\cdot$자어분포와 그 분포에 영향을 미치는 환경요인과의 관계를 연구하였다. 멸치난과 자어는 6월과 8월에 채집되었는데, 6월에는 고수온과 고염분역인 난수역에 분포하였다. 8월에는 난과 자어분포역이 외해역으로 이동하였다. 멸치난과 자어분포 및 수온, 염분, 동물부유생물 밀도의 관계를 분석한 결과 6월의 멸치 난과 자어의 분포밀도는 수온 및 염분의 분포와 정상관 관계에 있다고 분석되었다.

• 한국수산과학회지
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• 제40권1호
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• pp.24-30
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• 2007

We developed an ecosystem indicator (EI) for the coastal and offshore areas of Korean waters. One of the major scientific challenges of this undertaking was to translate broad policy statements for ecosystem-based fisheries management (EBFM) into practical terms. Fish reproduction potential (FRP) was defined as an EI to describe the reproductive probability of adult fisheries resources in Korean waters. The FRP was estimated as the ratio of adult fish composition to total catch, catches (in metric tons) by species and by ecosystem, and fishery effort (in horse power per metric ton). The FRP indices of the East/japan Sea Ecosystem (EJSE), Yellow Sea Ecosystem (YSE), and East China Sea Ecosystem (ECSE) began to decrease after the mid-1980s, and the current indices have decreased further, at 0.63 (EJSE), 1.22 (YSE), and 0.68 (ECSE) index points compared to the indices of 1975, when similar catch amounts were recorded. Lower FRPs in the Korean marine ecosystems were the result of higher proportion of immature fisheries resources in the total catch. Because this kind of ecosystem-level indicator is thought to reflect scientific approaches to EBFM and to provide an important tool for assessing the current status of marine ecosystems with respect to both quantity and quality, more EIs should be developed for Korean waters.

• 수산해양기술연구
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• 제56권1호
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• pp.61-70
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• 2020

In this study, system modeling and dynamic analysis of crane are conducted. Especially, among many different kinds of a crane system, the issues on crane operating problems installed on the vessel are considered. As well known, marine systems including cranes are exposed to various disturbances such as vessel motions, hydrodynamic forces, wave and wind attack, etc. In order to analysis the system dynamic with environmental conditions, the authors derived the nonlinear dynamic model of offshore crane and derived a linear model which is used for designing the control system. Using the obtained nonlinear and linear models, simulations were conducted to evaluate the usefulness of the obtained models. By simulation and result evaluation, the usefulness of the linear model, which presents the dynamics, is effectively verified.

• 수산해양교육연구
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• 제25권1호
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• pp.167-180
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• 2013

A capstone design is regarded as one of cap courses in undergraduate engineering education because it requires most prerequisites and makes students experience real engineering design processes. There have been case studies to show how this subject should be organized, practiced, and optimized. This study shows one of the case studies by focusing offshore wind power, one of newly recognized renewable energy resources, especially targeting for the design of wind turbine foundation and submarine power cable protectors mainly because of current energy and global warming crisis. To pinpoint engineering design, the students'activities during the project and design procedures are monitored, evaluated, and recommended; hence, core factors are addressed to develop successful aim, theory, practice, and other necessities. These factors include creative problem solving abilities; recognition of engineering curriculum; selection of project theme based on significance, ripple effect, and education purpose; team organization by the full brain model; systematization of project process; realization of engineering design; and synthesis of evaluation. In the end, the aftermath and future works are discussed.

• 수산해양교육연구
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• 제28권5호
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• pp.1470-1477
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• 2016

This study has designed and evaluated the safety of watertight damper for Offshore Rigs. The watertight damper is an improved design for conventional DN 350 butterfly valve. Numerical analysis has been performed to investigate the safety factor and seat leakage of the designed 3-type disk dampers. The structure analysis results present the deformations, the equivalent stresses and the safety factor. It was confirmed that the designed disk, rib-disk and streamlined disk of watertight damper are safe enough in maximum operating pressure of 0.98MPa. The results show that the disk damper had the smallest maximum deformations and stress among 3-type disk dampers and the safety factor was 4.3. Therefore it is confirmed that the disk damper has the most excellent strength. Also linear static structural analysis was individually conducted for disk and body. The results show that the maximum disk deformation was larger than the body deformation, Therefore the disk damper is causes no seat leakage.