• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.1-7
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• 1993

This paper describes development of a knowledge-based system for main engine selection of ships using general purpose expert system development tool, Nexpert Object. Developed system consist of ship performance estimation module such as resistance and propulsion, data base for main engine, knowledge base for main engine selection in Nexpert Object and graphic user interface.

• Journal of Chest Surgery
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• v.33 no.12
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• pp.974-977
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• 2000

유아에서 흔치 않지만, 선천적 혹은 후천적 원인으로 혈관에 의해 기도가 눌릴 수 있다. 8개월 남자 환아가 승모판 성형술, 동맥관 개존증 결찰 후 좌측 폐의 무기폐가 발생하였다. 흉부 컴퓨터 단층 촬영상 동맥관 개존증 결찰 후 남은 비대해진 하행대동맥에 의해 좌측 폐의 무기폐가 발생하였다. 흉부 컴퓨터 단층 촬영상 동맥관 개존증 결찰 후 남은 비대해진 하행대동맥에 의해 좌측 주기관지가 눌리는 소견이 관찰되었다. 결찰 부위를 완전히 분리하고 하행대동맥을 봉합하여 크기를 줄여 기관지 압박을 해결할 수 있었다. 술 후 환자는 특별한 합병증 없이 퇴원하였으며 외래 추적 관찰 중이다.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.8-14
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• 2017

Due to the financial crisis in 2008, the world economy collapsed leading to an increase in oil prices and a decrease in freight by shipping. To overcome this crisis, major shipping companies ordered larger ships, changed their trading route and improved operating of ships to overcome deficits. In particular, low-speed navigation was much favored by many companies so that it can reduce fuel consumption. However, the long-term operation of high-speed optimized engines in low-speeds has affected the jacket cooling fresh water (J.C.F.W.) system as they fail to maintain the normal operational temperature. The temperature of J.C.F.W. system dropped leading to low temperature corrosion. As a result, when the engine is operating at minimal load the functioning of existing J.C.F.W cooler is decreased and the use of fresh water generator is substantially limited. Therefore, an improvement in the functioning of J.C.F.W. system is necessary. In this paper, in order to review the improvements required for the operation of J.C.F.W. of low-speed operating marine diesel, an experiment was conducted by comparing and analyzing the results of the main engine J.C.F.W. system of a Panamax class bulk carrier 82k and a Cape class bulk carrier 180k by installing and uninstalling the J.C.F.W. Cooler. Thus, this paper proposed an improved design of the J.C.F.W. system that is suitable for the present low-speed operation.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.722-728
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• 2015

The demand for shipboard energy management is expected to gradually increase based on ship energy efficiency management plans (SEEMPs), which have been in use since January 1, 2013. Therefore, the fuel consumption of the main engine, which occupies the greatest portion of the energy used, along with elements related to the engine power, should be strictly monitored. There are many different methods for indicating the engine power. However, this study performed an experiment to monitor the status of a ship's engine power in real time using an encoder and a proximate switch, which are economical to purchase and easy to install. In the experiment, the angular velocity during one cycle of a two-stroke low-speed engine was measured, and the measured data were converted to the torque fluctuation. The angular velocity during an abnormal firing condition in the cylinder was also measured, and the torque fluctuation as a result of a misfire was considered. The results were compared with sea trial data to determine the reliability. In this study, the status of the engine power was determined using the torque fluctuation of the main engine in an operating ship.

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.111-116
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• 2001

Factors influencing elongation of the ovipositor in the bitterling Rhodeus uyekii were examined under several conditions. The ovipositors of the females were periodically elongated under the presence of mussels or males, and in some cases without either. When females were reared without mussels and males, the ovipositor did not elongate in one fish in a large aquarium, but it did become elongated in another fish in a small aquarium and in many fishes in a large aquarium. Duration of the elongated state of the ovipositor was 1~3 days (mean 1.2~2.5 days) and the periodicity of elongation was 4~15 days (mean 6.4~11.9 days). Length of the elongated ovipositor was 68~100% (mean 78.5~98.8%). Length of ovipositor in the interpeak period was 20~51% (mean 27.3~33.1%); in the post-elongation period it did not elongated further 3~30% (mean 11.1~19.9%). The effect of aquarium size and number of individuals in the aquarium on the elongation of the ovipositor, and inter-specific or inter-generic differences based on previous reports are discussed.

• Journal of Korea Fishing Vessel Association
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• v.34
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• pp.78-82
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• 1988

• Journal of Korea Fishing Vessel Association
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• v.46
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• pp.27-34
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• 1991

• Journal of Korea Fishing Vessel Association
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• v.33
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• pp.78-80
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• 1987

• 기계와재료
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• v.13 no.3 s.49
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• pp.125-138
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• 2001

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.525-532
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• 2015

In order to determine the testicular cycle of the Asian toad, Bufo gargarizans, adult males of the species were captured around Jeongeup city (Jeollabuk-do, Korea) during March, 2012 to February, 2013 and the gonadosomatic index (GSI) and the changes of germ cells in their testes were investigated throughout the year. The study indicated that the spermatogenesis in the seminiferous tubule of testes began in April and became most active in July. The recorded GSI was the highest and the cross area of seminiferous tubule was the widest in this period. The seminiferous tubules at the post spawning stage appeared in February, the largest amounts occurred in March and primary spermatogonia also appeared in this period. The GSI and the cross area of seminiferous tubules were found to be the lowest in March, indicating a testicular cycle with potentially continuous spermatogenic process. According to the findings above, it is confirmed that testicular spermatogenesis takes place actively between April to July in male Asian toad and that their breeding season is February to March.