• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.514-522
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• 2020

To understand the ecotoxicological differences between representative Skeletonema sp. and Dunaliella tertiolecta, both producers as international standard test species for marine ecotoxicity testing, we compared each standard test method, and comparatively analyzed the suitability of the species for environmental assessment and their sensitivity to various test substances. Although most of the test conditions were the same in each method, there were differences in limitation of pH changing and the initial inoculation density in the validation criteria, which is supposed to originate from the low growth rate of D. tertiolecta. In terms of suitability, both species showed consistency in test performance by repeatedly meeting the validation criteria required by the standard test methods. The salinity ranges available for testing were 20 and 10 psu for Skeletonema sp. and D. tertioelecta, respectively. Finally, regarding sensitivity, the toxicity sensitivity of Skeletonema sp. was relatively higher than that of D. tertiolecta for the reference toxicant, actual polluted water discharged (ballast water), and other chemicals. This implies that using at least two species of microalgae from different classification groups could help increase the reliability and objectivity of test results in the performance of marine ecotoxicity tests using producers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.511-518
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• 2018

Research indicates, about 80% of maritime accidents are caused by human error. Further investigation of the human factors behind maritime casualties is essential in order to establish preventive measures. The main purpose of this study is to identify and analyze human factors behind maritime traffic-related accidents using the m-SHEL model. Since the m-SHEL model used in other fields is based on generic human factors, it has expanded in this study to accommodate ship operating systems and define human factors. In addition, the validity of the expanded model was verified by reliability analysis using SPSSWIN. A classified table for this extended m-SHEL model was then used to analyze human factors behind maritime traffic-related accidents extracted from a written verdict by the Korean Maritime Safety Tribunal. Human factors were arranged in the order L, L-E, L-H, L-m, L-L, and L-S. This paper contributes to the prevention of maritime traffic-related accidents caused by human factors by presenting useful analytical results that can be applied to build a maritime safety management system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.67-72
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• 2017

This study developed an electric power propulsion personal watercraft by combining a battery and an electric system from the domestic automobile industry with water motorcycle from marine leisure industry in a convergence of technology. It also developed a safety inspection plan and type approval standard for personal watercraft that use electric power propulsion. For the registration and production of the electric power PWC (Personal Watercraft), a safety inspection standard (draft) and type approval standard (draft) have been established. PWC that use this electric power propulsion certification standard have been divided into two categories according to the use of gasoline engines as related to the ship's electrical system. The contents of these safety inspections standards is divided into 7 categories, and their purpose is to confirm the facilities used for the safe operation of PWC. Type approval is divided into 7 categories and is intended to ensure the safe production of PWC. This is basic data can be used to establish criteria for safety inspection and type approval of electric power propulsion vessels and to guide the production of the environmentally friendly PWC in Korea.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.187-194
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• 2020

It is very important to forecast freight volume accurately to establish major port policies and future operation plans. Thus, related studies are being conducted because of this importance. In this paper, stepwise regression analysis and artificial neural network model were analyzed to compare the predictive power of each model on Gwangyang Port, the largest domestic port for coal and iron ore transportation. Data of a total of 121 months J anuary 2009-J anuary 2019 were used. Factors affecting coal and iron ore trade volume were selected and classified into supply-related factors and market/economy-related factors. In the stepwise regression analysis, the tonnage of ships entering the port, coal price, and dollar exchange rate were selected as the final variables in case of the Gwangyang Port coal volume forecasting model. In the iron ore volume forecasting model, the tonnage of ships entering the port and the price of iron ore were selected as the final variables. In the analysis using the artificial neural network model, trial-and-error method that various Hyper-parameters affecting the performance of the model were selected to identify the most optimal model used. The analysis results showed that the artificial neural network model had better predictive performance than the stepwise regression analysis. The model which showed the most excellent performance was the Gwangyang Port Coal Volume Forecasting Artificial Neural Network Model. In comparing forecasted values by various predictive models and actually measured values, the artificial neural network model showed closer values to the actual highest point and the lowest point than the stepwise regression analysis.

• Journal of Korea Port Economic Association
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• v.25 no.3
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• pp.183-206
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• 2009

The purpose of this study is to suggest the new strategies for strengthening the competi tiveness of Incheon port. To measure the calling factors and satisfaction of ports, this study developed a list of 24 items using a seven-point Likert scale through the previous literature reviews, pilot test and emerging factors. Factor analysis, regression analysis, one sample T-test, IPA and SPSS were conducted to verify the determinants choosing ports and customer satisfaction. The result of an empirical study revealed that the cargo volume and information system, etc. in Incheon port was evaluated as satisfied factors and berth availability and port charge, etc. as dissatisfied factors. Based on the outcomes of this study, to strengthen the competitiveness of Incheon port, several strategies were advised such as the inducement of North American and European cargo, port infrastructure, dedicated terminal and GTO inducement, hinterland construction, logistics companies inducement and cooperation with neighboring ports.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.189-200
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• 2019

Korean seafarers have played a key role throughout the country's history and economic development. They have been a major source of foreign remittance into the nation as well as a pivotal sector in emergency logistics during war times. However, the current number of Korean seafarers in decreasing due to low job attractiveness and retention rate onboard. This is a major problem for the national and international shipping industry as youth seem not to be interested in working onboard for long periods of time. The purpose of this study is to 1) determine what the public opinion about seafarers in Korea is and 2) find out what factors mostly stand out in the public opinion about seafarers profession. The paper suggests that three main types of opinion groups emerged. The first type is labeled as 'high risk, high workload and high stress' as respondents recognized a high possibility of accident onboard and, at the same time, acknowledged that seafarers can be fatigued and stressed. The second type was named as 'Dangerous, Dirty, Difficult', as seafarers' image was mainly associated to fishing vessels and not to merchant and passenger ships. The third type recognized that the social position of the seafarers was low due to 'low social recognition'. The study suggests that all three types have a negative image of seafarers' job. Based on the results of this study, it is necessary to establish various policies and marketing tools to improve the negative job image linked to seafarers by the public opinion. If the public image of seafarers can be improved and attractiveness rose, it is expected a higher number of seafarers will pursue and keep a career at sea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.858-863
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• 2020

We experimented with the particle-settling velocity and CHCl3 absorption efficiency of seven activated-carbon and analyzed seven heavy metal contents by elution for application to the field treatment of sunken HNS on the marine seabed. The mean particle-settling velocity was in the range 0.5-8 cm/s, except when the 8-20 mesh was used. The larger the HNS particle, the faster the particle-settling velocity was, and the CHCl3 absorption efficiency increased considerably owing to the larger surface area. In addition, the elution test results showed that the total Zn and As contents in >100-meshed activated carbon was higher than the contents criteria for the standard for water-treatment agents, and Cr, Zn, and As were released at higher concentrations than those released by other activated-carbon groups. Taken together, the CHCl3 absorption efficiency, settling velocity, and elution test results suggested that the 20-60, 20-40, and 2mm&down mesh activated-carbon adsorbents could be applied to the field treatment of HNSs and that the minimum required amount for field treatment were 0.82, 0.90, and 1.28 ton/㎘, respectively, as calculated based on the HNS-adsorption-capacity priority.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.1-10
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• 2022

As the volume of marine hazardous and noxious substances (HNSs) transported in domestic and overseas seas increases, the risk of HNS spill accidents is gradually increasing. HNS leaked into the sea causes destruction of marine ecosystems, pollution of the marine environment, and human casualties. Secondary accidents accompanied by fire and explosion are possible. Therefore, various types of HNSs must be rapidly detected, and a control strategy suitable for the characteristics of each substance must be established. In this study, the ground HNS spill experiment process and application result of detection algorithms were presented based on hyperspectral remote sensing. For this, styrene was spilled in an outdoor pool in Brest, France, and simultaneous observation was performed through a hyperspectral sensor. Pure styrene and seawater spectra were extracted by applying principal component analysis (PCA) and the N-Findr method. In addition, pixels in hyperspectral image were classified with styrene and seawater by applying spectral matching techniques such as spectral distance similarity (SDS), spectral correlation similarity (SCS), spectral similarity value (SSV), and spectral angle mapper (SAM). As a result, the SDS and SSV techniques showed good styrene detection results, and the total extent of styrene was estimated to be approximately 1.03 m². The study is expected to play a major role in marine HNS monitoring.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.160-167
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• 2023

An INS is a composite navigation system providing "added value" so defined if work stations provide Multi-Function Displays(MFDs) integrating information and functions for navigational tasks. Even though the minimum requirements for an INS are defined by IMO performance standards, a generic list of the devices and functions that constitute an INS does not exist, so the configuration of the INS is different for each manufacturer, and guidelines based on users' perspectives are also insufficient. This study was conducted to enhance the usability of the INS by analyzing the information required by users according to the ship's operating status and tasks and effectively structuring it in the MFD of the INS. By analyzing INS-related international standards and manufacturers' component equipment lists, mandatory navigation information was selected and card sorting tests were conducted on ship operators with experience in using MFDs to group the information required for each INS task. The results of the study can serve as a basic guideline for manufacturers to structure information based on users' experience when designing products.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.138-138
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• 2003

우리나라 전남 동부 연안에서 확인된 해마 서식지를 대상으로 해마 이외의 혼재 유영 어류에 대한 생태 조사를 실시하였다. 조사는 전남 동부 연안의 해마의 서식이 확인된 수역에서 임의의 3 정점 (A, B, C)을 지정하여 채집하였다. 해마 채집 및 혼재 어류상 조사에는 소형 선박을 이용하였으며, 길이 45m, 폭 5m, 망목 크기 6~8mm의 어구를 사용하여 서식 생물을 채포하였다. 그리고 1회에 어획된 전 어종을 한 조사군으로 설정하였고 채집된 해마와 혼재 어종에 대해서는 각 어종별 분류키를 이용하여 분류하였다. 그리고 해마와 혼재 어류에 대해서는 0.1mm 범위에서 전장과 체장을 측정하였으며, 1mg 범위에서 체중을 측정하였다. 임의로 선정한 각 조사 정점별 채집된 해마와 혼재 어류상은 다음과 같다. 확인된 서식지는 전남 동부의 여수와 고흥 연안으로 각 지역별로 서식하고 있는 해마의 종류는 다소 차이가 있었는데 조사 정점 A와 B에서는 산호 해마 hippocampus sp. of. japonicus만이 관찰된 반면, 정점 c에서는 산호해마, 가시해마 Hippocampus sp. of. histrix, (참)해마 Hippocampus sp. cf. coronatus의 3종이 모두 관찰되었고 채집된 개체수도 정점 A와 B에서 1개체씩만이 관찰된 반면 정점 C에서는 5개체가 채집되어 다른 조사 정점에 비교하여 종의 수 및 개체수에서 매우 높은 결과를 나타내었다. 각 조사 정점별 관찰된 유영 어류상은 정점 A에서는 7종, 정점 B에서는 6종 그리고 정점 C에서는 12종의 어류가 관찰되었고, 이들 중 해마를 제외한 혼재 어종 수는 정점 A, B 및 C에서 각각 6종, 5종, 9종이 관찰되었다. 혼재 어종 중 감성돔, 복섬, 두줄 망둑, 실비늘치, 주둥치는 조사정점 A, B, C 모두에서 관찰되었다. 이 결과는 해마의 서식장 또는 산란장이 되는 조사 정점 C (36개체)가 다른 조사 정점 A (53개체)와 B (67개체)에 비교하여 해마의 어린 치어 또는 해마 성체를 포식할 수 있는 포식자의 개체수가 현격하게 낮기 때문인 것으로 판단된다. 그러나, 임의의 3 조사 정점에서 혼재 어종의 출현 종 수를 비교한 결과에서는 오히려 정점 A에서 6종, 정점 5에서 5종 그리고 정점 C에서 8종으로 나타나 정점 C에서 다소 높은 혼재 어종 수가 관찰되었다. 결국 해마의 서식지 주변 혼재 어종 특히, 혼재 어종의 개체수가 많을수록 해마의 서식 밀도를 감소시킬 가능성이 있는 것을 알 수 있었다. 한편, 다른 조사 정점에 비교하여 정점 C에서 출현 종 수가 높음에도 불구하고 출현 개체수가 매우 낮은 이유로 혼재 어종도 자어 또는 치어 시기에 해마 성체의 먹이로서 이용되었을 가능성도 배제할 수 없을 것으로 판단된다. 2003년 9월 (2일간)에 우리나라 전라남도 동부 연안에서 채집된 해마는 하루 오전과 오후 조석에 맞추어 4회에 걸쳐서 총 30여회 투망 작업한 결과 3종 62개체가 채집되었다.