• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.121-122
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• 2019

This study analyzes the operating conditions of domestic marinas in response to changes in coastal and marine leisure trends and demand for recreational boats, and suggests ways to improve services according to the types and functions of marinas. In order to popularize marine leisure and to foster coastal and marine tourism industry, the 'Act on the Development, Management, etc. of Marinas' was enacted in 2009 and 'The 1st Marina Basic Plan' was established, and more than 34 marinas are operated nationwide. In order for domestic marinas to be used as an infrastructure for marine leisure activities, measures for enhancing service functions should be prepared in accordance with the size and characteristics of marinas.

• Fisheries and Aquatic Sciences
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• v.21 no.8
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• pp.22.1-22.7
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• 2018

Background: Apoptosis is a process of programmed cell death, and apoptosis defect results in serious diseases such as cancer. Apoptosis induction is one of the key mechanisms of anti-cancer agents. This study was aimed to find anti-prostate cancer compounds from marine-derived fungus Microsporum sp. Results: We found that physcion isolated from the fermentation broth extract of the marine fungus Microsporum sp. strain MFS-YL decreases the cell proliferation of PC3 human prostate cancer cells. Physcion induced cell apoptosis as determined by Annexin V/propidium iodide double staining. Physcion downregulated the anti-apopotoic proteins such as Ras, Bcl-xL, and Bcl-2, whereas upregulated the pro-apoptotic Bax. Physcion also activated caspase-3, caspase-8, and caspase-9. Conclusion: These results suggest that physcion from Microsporum sp. inhibits the proliferation of PC3 human prostate cancer cells via the pathway leading to apoptotic cell death. Physcion may be a potential candidate in the field of anticancer drug discovery against human prostate cancer.

• Journal of Power System Engineering
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• v.3 no.3
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• pp.83-90
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• 1999

제어이론분야에서의 발전은 그러한 이론을 다방면으로 응요할 수 있는 분야를 더더욱 폭넓게 제공해 주고 있다. 자동화와 관련된 분야뿐만 아니라, 건축 및 토목분야에서도 고도의 제어어이론을 응용한 예를 쉽게 접할 수 있게 되었으며, 지진동에 의한 구조물의 진동을 억제하려는 방책이 그 ??ㅣ다. 이에 관한 많은 연구에서도 알 수 있듯이, 일반적으로 구조물의 수학적 모델에만 의존하여, 즉 구조물의 설계파라미터는 이미 설계되어져 있다는 가정하에 제어계를 설계하고 있다. 그러나 이러한 설계법에 있어서는 설계자로 하여금 구조물의 설계파라미터를 조정할 수 있는 자유도는 전혀 주어지지 않게 되며 단지 제어계의 파라미터를 조정하는 자유도만 허용된다. 이러한 문제점을 극복하기 위해 구조계 및 제어기의 설계파라미터를 동시에 조절할 수 있는 자유도가 허용되는 '구조계/제어계의 동시 최적화' 기법이 있다. 따라서 본 논문에서는 교량의 주탑 및 해양구조물 등의 진동제어 문제에 이러한 설계기법을 이용하여 주어진 설계사양을 만족하도록 구조계 및 제어계의 파라미터를 최적화 한다. 특히 본 논문에서는 제어계 설계 문제에 있어서의 일반적인 경우를 고려하여 상태의 일부가 관측된다고 가정하고 출력피드백의 경우에 대해 고찰하고 있다. 이때의 설계사양은 선형행렬부등식(LMI)으로 주어지며, 실험을 통하여 본 논문에서 소개하는 설계기법의 유효성을 검증한다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.437-445
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• 2017

Distribution and composition of the seabed litters in the exclusive economic zone of the West Sea of South Korea including 18 sea-blocks were investigated using a bottom trawl gear of the R/V Tamgtu 20 (National Institute of Fisheries Science) from 24th April 2011 to 4th May 2012. Each trawl shot was conducted for an hour in each sea-block and the total trawl shots was 18. As a result, 325.6 kg of seabed litter in total has been collected. The quantity of the seabed litter was highest at No. 202 of the sea-block, close to the Heuksan-Do. The highest occupied sea material was plastic (83.1% of entire seabed litters), the second highest material was metal combined with plastic (10.6%), and glass (2.9%), metals (2.3%), vinyl (0.6%), cloth (0.4%) and wood (0.2%) in order. The origin of seabed litters was from fishing gear (89.0% of all seabed litters). Therefore, it could be assumed that most seabed litters were derived from the fishing activity for example fishing nets and ropes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.1055-1062
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• 2014

Hydroacoustic surveys were conducted for spatio-temporal distribution and size estimation of fish in the Yongdam reservoir, Korea, from April to July 2014. Acoustic data were collected along acoustic transects using a 120 kHz scientific echosounder. The received acoustic data were the in situ acoustic target strength (dB) and nautical area scattering coefficient ($m^2/mile^2$). Data on fish behavioral patterns and size were collected using a DIDSON acoustic camera at stationary stations. Fish were mainly distributed in the center channel and close to the outer Yongdam reservoir. Acoustic density of fish in the summer season were higher than in the spring season. The seasonal vertical distribution pattern of fish aggregations may be strongly related to the vertical temperature structure. The size distribution of fish obtained from an acoustic camera correlated well with the acoustic size of fish from an echosounder.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.2
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• pp.105-113
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• 2020

The fish influx and behavioral properties at a set-net off Goseong, South Korea were investigated using an imaging sonar. As a result, the average influx of fish was 33.9% at day time and 66.1% at night time, respectively, which indicated that a majority of fish entered into a playground in the set-net at night. The fish behavioral properties such as target (fish) length, range, orientation and major-axis angle were examined and compared among survey dates (4, 5, and 6 June 2019) using the statistical analysis tool (analysis of variance, ANOVA). The behavioral properties presented differently sometime of survey dates. This is preparatory study to support fish behavior properties in a set-net. It is expected that more elaborated behavioral information of fishes in the set-net is beneficial for designing and deploying a set-net fishing gear as well as general fish behavior research in the future.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.30-37
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• 2013

For vessels operating in the cold climate regions, the ballast water inside or hopper tanks above the waterline may be frozen, starting at the top of the tank and at the side walls. Therefore, countermeasures against freeze-up of the ballast tank such as air-bubbling system, hot steam injecting system, heating coil system and water circulating system are taken to prevent freeze-up phenomenon; however, there are no rigorous investigations of anti-freezing to examine the effectiveness and validity of systems against freeze-up of the ballast tank, in which the temperatures are about -$25^{\circ}C$ (ambient air temperature) and $0^{\circ}C$ (sea water), respectively. In this paper, to ensure reasonable specifications for cold regions if the measures from the above-mentioned systems against freeze-up are effective, the phenomenon of ballast tank freeze-up is simulated and discussed in low temperature conditions. With the results using the commercial CFD code, CFX 14, the most cost-effective solution is conducted to prevent being frozen along the outer surface.

• The Journal of Fisheries Business Administration
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• v.49 no.1
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• pp.37-50
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• 2018

The purpoose of this paper is to analyze the relative effciency of dreid laver processing companies in Korea and provide the development direction and improvement plan for the dried laver industry. Data on 76 dried laver processing companies were selected as the subjects for Dea. As a result of Dea, the average efficiency rate is shown that the technical efficiency is 84.90%, the pure technical efficiency is 93.83%, and the scale efficiency is 86.65%. and based on BCC results 38 companies are relatively efficient. comparing pure technical efficiency and scale efficiency, it showed that inefficiencies caused by scale of the company was greater than inefficiencies caused by the scale of technical matter. It implies that expanding the size is essential for achieving high-efficiency of dried laver processing company. In the inefficiency factor analysis, the result reveals that unstable supply of raw materials, quality management, capital flexibility and distribution ability influence the efficiency of laver processing company.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.76-82
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• 2006

The large-eddy simulation(LES) technique, based an a message passing interface method(MPI), was applied to investigate the turbulent flaw phenomena around a ship. The Smagorinski model was used in the present LES simulation to simulate the turbulent flaw around a ship. The SPMD(sidsngle program multiple data) technique was used for parallelization of the program using MPI. All computations were performed an a 24-node PC cluster parallel machine, composed of 2.6 GHz CPU, which had been installed in the Advanced Ship Engineering Research Center(ASERC). Numerical simulations were performed for the Wigley hull, and the Series 60 hull(CB=0.6) using 1/4-, 1/2-, 1- and 2-million grid systems and the computational results had been compared to the experimental ones.

• Journal of Ocean Engineering and Technology
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• v.26 no.6
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• pp.74-79
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• 2012

The present study aims at suggesting the systematic approach to analyze the local drag components as the resistance performance characterized by the flow of the ship. In order to identify the local areas, the hull surface is decomposed into SVM (Station-Vertical Section Map) which consists of 20 stations along the longitudinal direction and 20 sections along the vertical direction (from the bottom to the waterline). Successively, on the SVM, the friction and pressure drag coefficients as the components of total drag coefficient have been analyzed for two different hull forms of Wigley and KVLCC by using CFD.