• Journal of the Korean earth science society
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• v.39 no.3
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• pp.241-249
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• 2018

As the international trade increases, vessel traffics around the Korean Peninsula are also increasing. Maritime accidents hence take place more frequently in the southern coast of Korea where many big and small ports are located. Accidents involving ship collision and sinking result in a substantial human and material damage as well as the marine environmental pollution. Therefore, it is necessary to locate the ships quickly when such accidents occur. In this study, we suggest a new ship detection index by comparing and analyzing the reflectivity of each channel of the Korea MultiPurpose SATellite-2 (KOMPSAT-2) images of the area around the Gwangyang Bay. A threshold value of 0.1 is set based on a histogram analysis, and all vessels are detected when compared with RGB composite images. After selecting a relatively large ship as a representative sample, the distribution of spatial reflectivity around the ship is studied. Uniform shadows are detected on the northwest side of the vessel. This indicates that the sun is in the southeast, the azimuth of the actual satellite image is $144.80^{\circ}$, and the azimuth angle of the sun can be estimated using the shadow position. The reflectivity of the shadows is 0.005 lower than the surrounding sea and ship. The shadow height varies with the position of the bow and the stern, perhaps due to the relative heights of the ship deck and the structure. The results of this study can help search technology for missing vessels using optical satellite images in the event of a marine accident around the Korean Peninsula.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.97-112
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• 2021

This study introduces lessons learned from investigation and analysis of major domestic and overseas cases of marine chemical incidents involving hazardous and noxious substances (HNS) during maritime transportation by chemical tankers carrying petrochemical products in bulk. The study then suggests plans to improve domestic marine HNS training curricula based on these lessons. Lessons learned from six incident cases are classified into the following six categories: 1) incident-related information, 2) safety, 3) pollution, 4) response, 5) salvage and 6) others. Based on these six categories, it is suggested that the curriculum provided by the Marine Environment Research & Training Institute for marine pollution prevention managers aboard noxious liquid substance carriers should be changed from the existing two-day training of eight subjects (16 h) to a three-day training of sixteen subjects (24 h). In addition, it is proposed that the marine chemical incident response course of the Korea Coast Guard Academy should be changed from the existing five-day training of fifteen subjects (35 h) to a six-day training of thirty-two subjects (48 h). These results are expected to contribute to sharing experiences and lessons learned about response to marine chemical incidents and to be used as basic data for improving the education and training courses for response personnel in preparedness for marine HNS incidents.

• Journal of the Korean Institute of Navigation
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• v.16 no.2
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• pp.53-78
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• 1992

GMDSS-the Global Maritime Distress and Safety system which is utilizing the new technologies such as satellite communication system, DSC and NBCP-is effectuated not only by the amendment of SOLAS but also by the conference of RR and IMO's MSC, and will be the major factor of the variation of the demand and supply of Radio Operators. To cope with the GMDSS voluntarily, regulations relating to the radio installation, the posting of Radio Operators, the bounds of duty, etc. must be established and the demand and supply of Radio Operators which take charge of the system must be accomplished pertinently. In this study, the authors suggested some practical schemes to improve the effect of policy as follow. 1. The Ministry of Communication must supervise strictly the arrangement of Radio Operators, especially relating tot he legally qualified complement of Radio Station, and must review the official certification system to upgrade the quality of Radio Operators. 2. The Ministry of Communication must take overall charge of the qualitifications and technical standards of Radio Operators, the extent of their engagement, etc. which are provided by International Regulations. 3. Relating Administrations must cooperate with Shipping Companies in onboard-training to foster and ensure the manpower of Radio Operators. 4. Institutional devices to drive the resolute investment in education and training for mariners, especially for the ship's officers, must be prepared. 5. The Communication Administration and the Korea Maritime and Port Adminstration(KMPA) must cooperate mutually in the balance of the demand and supply of Radio Operators and use make their best to realize more harmonious policies on the demand and supply of manpower.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.430-436
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• 2017

The most frequent occurring and the serious marine casualties in fishing vessels are the collision in statistics from Korea Maritime Safety Tribunal (2008-2015). Collisions are is given a great deal of weight in all marine casualties, and the main cause of collisions is the negligence of watching. From this point of view, this study deals with the collision and its immediate cause, the negligence of watching which are main factors on the indirect causes. Basic analyzing data was gathered from the questionnaire made by experts of sea service part, and analyzed by using the fault tree analysis (FTA). From the result of the study, the occurrent probability of the negligence of watching in the collision due to the indirect causes occupied 64.9%, and its probability caused by the man factors was less than the other factors; i.e. the media factors and the management factors. For the reduction of the negligence of watching in the collision from this study, it needs an effort to remove not only the man factors, but also the media factors and management factors.

• Journal of Navigation and Port Research
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• v.37 no.4
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• pp.419-427
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• 2013

The purpose of this study was to analyze the perceptions to improvement directions of related regulations for water leisure activation. In order to accomplish such study purpose, the study utilized a survey methodology with 205 water leisure participants and 117 water leisure business employees. In addition, this study attempted to review the license and education system, registration and inspection system and business organizations from the advanced countries such as US, British, Australia and Japan. Accordingly, following findings were derived from current study. First, the problems of current license system included difficulty of operating the system and deficiency of operating organizations, and the improvement directions included expansion of education organizations and differentiation of education based on levels. Second, the improvement directions of registration and inspection included simplification of registration procedures and expansion of registration and inspection organizations. Third, difficulties perceived by business employees included complexity of entry and departure, complexity of registrating water leisure business and insufficiency of supporting business policies. In conclusion, water leisure related regulations including Water Leisure Safety Act need to be reformed continuously to reflect changing demands and needs from participants and business sectors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.477-487
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• 2022

This study suggests a plan for revitalizing return-to-farming / fishing villages through the marine leisure industry by analyzing the practical problems faced by young and older adults who have returned to the marine leisure field. A case study was conducted to identify the problems faced by those returning to marine leisure, and to determine the measures for revitalizing return-to-farming / fishing villages. Interview participants were those returning to marine leisure and experts in related fields. The problems identified include the exclusive culture of fishing villages, difficulty in raising initial investment funds, and lack of marine leisure education programs for return-to-farming / fishing villages. The proposals to solve these problems and revitalize return-to-farming / fishing villages through the marine leisure industry include the introduction of an incentive system to mitigate barriers to entry; establishment of a matching system; use of idle land in fishing villages to promote return-to-farming / fishing villages; introduction of a consignment management system after the pre-investment of the fishing villages; and establishment of an education program, including in the fisheries field, and infrastructure for return-to-farming / fishing villages for marine leisure.

• The Journal of Fisheries Business Administration
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• v.50 no.3
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• pp.17-29
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• 2019

This paper aims to find out the problems and improvement direction of quality control and hygiene management of fishery products in Korea. For this reason, we conducted a comparative analysis of quality control and hygiene management of fishing, landing and selling between Japan and Korea, taking mackerel as an example. Japan has established a systematic freshness management system from fishing to landing (production) areas and consumption areas. On the other hand, Korea is not fully lead-managed in the production area after fishing, and is distributed in a state where the quality of the product is deteriorated due to exposure to room temperature. Accordingly, a certain quality can not be secured at the final consumption stage, and sanitary problems occur. In order to improve the quality control and hygiene management of the fishery products, the following needs to be improved. First, we will improve the fishing level freshness management system. Second, we will improve the quality control and hygiene management of fish in the production area and wholesale stage. Third, we will promote the introduction of innovative sales and consignment sales systems at the production stage. Fourth, we will establish a consistent low temperature distribution system from the production area to the wholesale stage from a long-term perspective. Fifth, we will promote the development and education of manuals on fish quality and hygiene management.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.802-808
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• 2019

DC motors are used extensively on shipboard, including as the ship's winch operating motor, owing to their simple speed control and excellent output torque characteristics. Moreover, they were used as propulsion motors in the early days of electric propulsion ships. However, mechanical rectifiers, such as brushes, used in DC motors have certain disadvantages. Hence, brushless DC (BLDC) motors are increasingly being used instead. While the electrical characteristics of both types of motors are similar, BLDC motors employ electronic rectifying devices, which use semiconductor elements, instead of mechanical rectifying devices. The inverter system for driving conventional BLDC motors uses a two-phase excitation method so that the waveform of the back electromotive force becomes trapezoidal. This causes harmonics and torque ripple in the phase current switching period in which the winding wire through which the current flows is changed. Researchers have studied and presented various methods to reduce the harmonics and torque ripple. This study applies a cascaded H-bridge multilevel inverter, which implements a proportional-integral speed current controller algorithm in the driving circuit of the BLDC motor for electric propulsion ships using a power analysis program. The simulation results of the modeled BLDC motor show that the driving method of the proposed BLDC motor improves the voltage waveform of the input side of the motor and remarkably reduces the harmonics and torque ripple compared with the conventional driving method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.939-944
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• 2018

Clean fire extinguishing agents refer to chemical that can replace Halon 1211 and Halon 1310 according to the Montreal Protocol fermented to protect the Earth's ozone layer. In Korea and abroad, system standardization and performance evaluation of clean fire extinguishing agents are being carried out. This paper proposes an optimal nozzle shape by modeling and numerical analysis of various nozzle shapes based on general clean fire extinguishing system. The ejection speed of the nozzle can be improved by studying three - dimensional modeling of the nozzle for two shapes, Type A and B. Flow analysis was performed on the two types of nozzles and the gas velocity and pressure distribution were measured with different nozzle diameters. It was confirmed that the jetting speed was changed at the nozzle outlet according to the number and diameter of the nozzle holes. The flow rate increased with increasing the pressure regardless of the nozzle hole diameter. Based on the results obtained from the experiment, the K-factor value was deduced. Finally, a nozzle with a 12-hole structure with a 5-mm nozzle hole was proposed.

• Journal of Navigation and Port Research
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• v.36 no.10
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• pp.819-824
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• 2012

In this paper, mandatory minimum requirements for certification of officers in charge of a navigational watch on ship by international convention on STCW (standards of training certification and watchkeeping for seafarers) were investigated. The training education and evaluation systems for navigational competence of Korean navy were compared and analyzed. As a result, we have confirmed that junior naval officers from Korean midshipmen had the navigational competence based on the STCW convention by analyzing the courses of Korea naval academy, midshipmen life, training exercise systems, and so on. OCS and NROTC provided a curriculum that did not quite meet the standard of the STCW convention. However, it was sufficient for nurturing basic abilities for navigation safety.