• 한국항해항만학회지
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• 제42권6호
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• pp.378-387
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• 2018

본 논문에서는 LNG 벙커링 바지에 대한 예인력을 계산하였다. 친환경 에너지원인 LNG(액화천연가스)의 전환을 위한 인프라로 LNG 벙커링 바지가 개발되고 있다. LNG 벙커링 바지의 경우, 부선의 형태로 개발되고 있으나 향후 운용관점에서 추진기 탑재 개조(Retrofit)를 통한 자항추진을 고려하고 있다. 따라서 LNG 벙커링 바지는 일반적인 예인바지와 비교하여 선박의 선형과 유사하기 때문에 선급의 부선 규칙을 통한 예인력은 과대 추정된다. 이를 극복하기 위해, 정수 중 저항은 Rankine source method를 이용한 조파저항을 고려하여 ITTC 1978 방법에 따라 계산하였고 파랑 중 부가저항은 NMRI의 단파장 보정이 고려된 수정된 방사에너지법을 이용하여 계산하였다. 계산된 정수 중 저항과 부가저항을 통해 예인저항 성능을 KR 선급의 부선 규칙과 비교 검토하였다.

• 생명과학회지
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• 제11권3호
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• pp.203-210
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• 2001

To produce the instant marsh calm(Corbicula elatior) soup with abundant taste and flavor. optimum conditions of heating temperature and time for extraction were investigated. Excretion rate in a pre-treatment for excretion of estuary was 82% at 15% salt concentration for 6 hr and 95% at pH 7.5 for 10 hr. The contents of glycogen and amino-nitrogen were the most high levels in the treatments extracted at 9$0^{\circ}C$ for 3 hr, at 10$0^{\circ}C$ for 1.5 hr and at 11$0^{\circ}C$for 1 hr. The contents of total free amino acids in the extracts treated at 9$0^{\circ}C$, 10$0^{\circ}C$ and 11$0^{\circ}C$ were 367.05mg/100g, 472.23 mg/100g and 463.54 mg/100g, respectively and optimal temperature was above 10$0^{\circ}C$. The mineral contents was the most high level for the extract treated at 10$0^{\circ}C$ for 1.5hr. The results of sensory evaluation showed that tastes for the marsh calm extracts had no significant discrimination, while external appearances and flavors for the extract done at 10$0^{\circ}C$ for 1.5 hr were excellent. The extracts at 10$0^{\circ}C$ showed a little dark color and those at 9$0^{\circ}C$ smell a little fish flavor.

• 대한조선학회지
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• 제21권3호
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• pp.11-18
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• 1984

In recent days, many manufacturing factories have been established and operated along riversides or on sea coasts. In consequence thereof, modern inland vessels with their small draught but large carrying capacity have been developed to operate as a single unit or in convoy with a barge. Knowledge in the behaviour of inland cargo vessels in shallow water exists presumably in U.S.A., U.S.S.R. and West Germany Literature available on this subject is quite limited. Model tests were carried out, both in calm water and in waves to obtain hull lines, which not only improve the seaworthiness of inland vessels but also permit to run in convey with other vessels on inland waterways. The results, which to some extent have also been tested in full scale, are entirely satisfactory. This paper discribes the resistance of some newly developed inland water cargo vessels.

• Journal of Ship and Ocean Technology
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• 제11권4호
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• pp.55-71
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• 2007

The primary objective of this work is to develop methodologies for virtual model basin and to demonstrate the capabilities for generic multi-hull ship geometry. A computational fluid dynamics approach is used to simulate various model basin tests for steady resistance, maneuvering and seakeeping. For a catamaran hull configuration, the methodologies are used for solving these problems and the results are discussed. Computational results are compared with the results of a benchmarked potential flow theory method for calm water resistance.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.644-644
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• 2020

• 한국조경학회지
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• 제25권4호
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• pp.107-122
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• 1998

Visitor Impact Management (VIM) framework was developed in the United States to help recreation resources management to be more systematic and effective. It consists of a series of steps from examining problems and their causes to planning and implementing management strategies in order to solve the problems. This study was conducted to find management problems in Moodeung-san Provincial Park and suggest some alternatives based on VIM framework. Data were collected by on-site survey and a mail-back questionnaire in August of 1996 in Moodeung-san Provincial Park. Out of 1173, 519 respondents (44.2%) were used for the study. According to the study results, there were differences between users' perceptions about the present use of the park and the users' personal norms about the use of the park. That is, while 46% of the respondents considered the park should be used as 'the place for calm and meditiation,' only 19% of the respondents considered the park had been used as 'the place for calm and meditation.' Three social indicators (the number of users, the number of seeing others' inconsiderate behaviors, and the crime) and four ecological indicators (littering, human waste, trail conditions, and water quality of Moodeung-san valleys) were selected for the major managerial indicators of the study area. Generally, five out of 7 selected indicators were in worse conditions than the evaluative standards, Five indicators which were evaluated as in worse conditions include two social indicators (the number of users and the number of seeing others' inconsiderate behaviors) and three ecological indicators (littering, human waste and trail conditions). Two other indicators such as water quality of Moodeung-san valley and the crime were identified to be important for users' recreational experience. More concerns and systematic investigations on these indicators are needed. This study discussed some management strategies to solve the identified problems, and introduced how mangers may make use of these information for recreation resource menagement in the park.

• 한국기계연구소 소보
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• 통권10호
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• pp.49-62
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• 1983

A series of model tests on a container ship in waves was executed at the Experimental Towing Tank of Ship Research Station, KIMM. This paper presents the results of resistance, self-propulsion, propeller open-water and ship motion tests in regular head waves. Firstly, the experimental results of ship motion measured on a towed model and a self-propelled model were compared with those of Japanese results showing fairly good agreements. Secondly, the results of resistance and propulsion tests were analyzed and the data of added resistance, thrust increase, torque increase, revolution increase and self-propulsion factors in waves were presented. Also the diffraction force measured on a fixed model in waves was analyzed. Finally, this report shows the propeller characteristics in calm water based on propeller immersion and in regular waves based on wave length.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2002년도 춘계학술대회논문집
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• pp.145-153
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• 2002

A coastwise chemical tanker sailing at full speed has capsized in calm water and whole turing. In the precious paper, we investigated reasons of the accident by demonstrating the proper correction for the free surface effect of the liquid cargo and the bow-sinkage effect. In this paper, we also carry out model experiments of a transverse pressure under the seawater and an outward heel moment according to the heel angle and rudder angle, on the basis of radius of turning circle, ship's speed and drift angle of model ship occurring in turning. It is also shown that the flooding of seawater onto the deck occurring in turning generated a significant outward heel moment and the vertical distance between the center of gravity of the ship and the renter of lateral water drag.

• 한국해양공학회지
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• 제33권5호
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• pp.421-426
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• 2019

The directivity of an underwater sound source should be measured in an acoustically open field such as a calm sea or lake, or an anechoic water tank facility. However, technical difficulties arise when practically implementing this in open fields. Signal processing-based techniques such as a sound intensity method and near-field acoustic holography have been adopted to overcome the problem, but these are inefficient in terms of acquisition and maintenance costs. This study established a simple directivity estimation technique with data acquisition, filtering, and analysis tools. A numerical simulation based on an acoustic radiosity method showed that the technique is practicable for sound source directivity estimation in a diffused reverberant acoustic field like a reverberant water tank.

• 한국환경과학회지
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• 제16권5호
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• pp.583-591
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• 2007

In this study, meteorological characteristics concerning the occurrence of fog are analyzed using 4-years (2000-2003) data at Chuncheon. From the analysis of meteorological characteristics, the fog at Chuncheon occurred before sunrise time and disappeared after that time and lasted for 2-4 hours. When fog occurred, on the whole, wind direction was blew the northerly and wind speed was below 2.1 m/s. Especially, about 42 % of foggy day fell on the calm($0{\sim}0.2m/s$) conditions. The difference between air temperature and dew point temperature near the surface were mainly less than $2^{\circ}C$. For the lack of water surface temperature, the water sur-face temperature was calculated by using Water Quality River Reservoir System (WQRRS). In Chuncheon, there is close correlation between the frequency of fog day and outflow from Soyang reservoir and high frequency of occurrence due to the difference between air and cold outlet water temperature.