• Journal of Ocean Engineering and Technology
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• v.23 no.4
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• pp.58-63
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• 2009

Two kinds of welding methods are used for austenitic 304 stainless steel: laser welding and TIG welding. The difference in the corrosion characteristics of the welded zone between these two welding methods was investigated using electrochemical methods, such as corrosion potential measurements, polarization curves, cyclic voltammograms, etc. The Vickers hardnesses of all the welded zones (WM: Weld Metal, HAZ: Heat Affected Zone, BM: Base Metal) showed relatively higher values in the case of laser welding than for TIG welding. Furthermore, the corrosion current densities of all the welding zones showed lower values compared to TIG welding. In particular, the corrosion current density of the HAZ with TIG welding had the highest value of all the welding zones, which suggests that chromium depletion due to the formation of chromium carbide appears in the HAZ, which is in the range of the sensitization temperature. Thus, it can easily be corroded with a more active anode. Consequently, we found that the corrosion resistance of all of the welding zones for austenitic 304 stainless steel could apparently be improved by using Laser welding.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.863-869
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• 2018

Due to recent changes in the maritime traffic environment, naval warship accidents are constantly occurring. Especially in 2017, serious loss of life was caused by a US navy destroyer accident. The purpose of this study is to analyze the characteristics of naval warship accident cases and construct an accident scenario by using naval training materials, adjudication of naval warship accidents and US navy destroyer accident reports. Based on the surveyed data, the status of accidents was identified and cases were analyzed. We reproduced 17 accident cases in accordance with accident reproduction procedure and constructed naval warship accident scenarios. As a result of analyzing the CPA, TCPA and PARK model for risk, reproducing 17 naval ship accident cases, collision risk increased on average 5-6 minutes before an accident. The result of this study represents basic data for naval and simulation education materials, contributing to the prevention of marine accidents.

• Journal of Navigation and Port Research
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• v.45 no.4
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• pp.224-230
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• 2021

It has been 16 years since the government announced its first Ocean Education Policy in 2005. Although the public consensus on the importance of ocean education has been formed, it is impossible to objectively analyze the impact of the policy on the society or the economy. The aim of this paper was to identify differences in perceptions and behaviors about the ocean between groups participating in ocean education and non-participating groups and to analyze the effectiveness of ocean education by developing measurement indicators for the value that individuals gave to ocean education services. To conduct this study, first, the value of ocean education was defined and value items that could be provided to individuals were classified. Second, to develop indicators that could measure classified value items, a Delphi survey was conducted to collect opinions of various experts. Third, by measuring the content validity ratio (CVR) for each item, final indicators and questionnaire were derived. As a result of Delphi analysis, 18 items with a CVR value of 0.6 or higher were finally adopted out of 32 indicator items. In the cognitive value category, indicators that could identify an individual's level of knowledge of the ocean, change in perception, and problem-solving ability were selected. In the behavioral value category, indicators were expanded to judge changes in attitudes and relationships toward the ocean and responsible behavior in more detail. This study is meaningful in that it provides the basis for directly judging the value of ocean education service provided by the government to the people. Results of such analysis are expected to contribute to securing a stable budget and the justification for expanding human resources in the government's continuous promotion of ocean education policies.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.3
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• pp.248-256
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• 2013

Part 2 of the Questionnaire Survey on Marine Safety and VTS in the Philippine Coastal Waters presents the alternatives to risk reduction, modifying the VTS, the qualification and competency of a VTS operator and effectiveness of the services and assistance rendered by VTS. This study finds that majority of respondents chose "Improved education and training of mariners" as the best alternative to risk reduction and the "Strict enforcement of ship safety regulations" as the best alternative based on the respondents' ranks last served onboard and areas of familiarity. In modifying the VTS, the areas with VTS chose to "Improve or upgrade" and for those without, is to "Implement" the system. The best VTS system is the "Port and Approaches" type and the PCG is selected to operate, maintain and supervise the system. As a VTS operator, the necessity of shipboard experience is considered "Essential" and the experiences include "Ship-handling and Communication", and "Management level" experiences. The effectiveness of the assistance and services rendered by VTS are considered "Very Important". Based on these findings, this study recommends improvement of education and training of mariners and users of the waterways including the training of VTS operators manning the VTS centers, strict enforcement of ship safety regulations along the busy and main ports of the country and installation of VTS system with the most appropriate type with the supervision of PCG.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.811-821
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• 2017

This paper intends to propose the direction for improving the welfare space in crew accommodation of fishing vessels engaged in coastal and inshore fishery business in order to solve the phenomenon which young fishers trend to avoid working on fishing vessels. Coastal and inshore fisheries are defined as permitted fisheries business under the Fisheries Act and classified into coastal fisheries and inshore fisheries based on a gross tonnage of 10 tons. Fisheries Act also stipulates the upper limit tonnage regulation and the restrictions on bottoms of fishing vessels permitted for coastal and inshore fisheries to protect fishery resources and to prevent overfishing. It is difficult to increase the welfare space in crew accommodation of fishers under such restrictions because the welfare space in crew accommodation could be secured by reducing the space for the strength of fishing. Therefore, this paper compares the revision trend of the international convention(The Work in Fishing Convention, 2007) and domestic laws on welfare space in crew accommodation of fishing vessels engaged in coastal and inshore fishery business to find out the problems and improvement points in securing the welfare space in crew accommodation of fishing vessels. As a result, it is proposed to revise the Enforcement Ordinance of the Fisheries Act so as to secure the welfare space in crew accommodation of coastal and inshore fishing vessels within the scope of maintaining the maximum allowable tonnage limit regulation by adding an exemption provisions of the restrictions on bottoms of fishing vessels in which case the gross tonnage is increased for securing the spaces for crew accommodation and sanitary facilities of fishers without increasing net tonnage where the bottoms of fishing vessels is increased by renovating or replacing the fishing vessels bigger than the bottoms of fishing vessels permitted within the scope of maintaining the maximum allowable tonnage limit regulation.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.231-237
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• 2013

What to analyze cognitive works that are involved in ship navigation is a basic work to make alternatives for maritime safety such as development of bridge equipments, extraction of potential human errors and development of education/ training methods. In the domains in which much research on the human error has been performed such as aviation and nuclear plant, analysis methods for cognitive work analysis have been developed and applied to them. However, the research on the cognitive work analysis is not sufficient in the maritime domain. This paper proposes a method to analyze cognitive work of ship navigation. The method was developed so that some maritime characteristics and a variety of factors influencing cognitive works are reflected on cognitive work analysis processes. On the other hand, an ship collision accident was analyzed by the proposed method as a case study.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.12-18
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• 2017

Lots of fishery stocks are overexploited and the overcapacity exists in Korean fishing fleets. One of the reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the offshore large powered purse seine fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. Fishing gear material was changed to the knotless webbing to settle faster. Fishing equipments was modernized and supply rate was also increased. Therefore the relative fishing power index in the offshore large powered purse seine fishery increased from 0.4 in 1970 to 1.0 in 1980, to 1.5 in 2000 and to 1.6 in 2010, but the rate of increase slowed down gradually. The results are expected to contribute to reasonable fishery stock management.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.34-46
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• 2016

This study analyzes inspection results of ships by Port State Control. Particularly, this research focuses on a detention trend of vessels that registered to Korean Register of Shipping. In order to conduct this research, we have searched 170 ships that got a detention with a Code-30 within recent 46 months period. The deficiencies of the detentions are inspected by ship types, ship years, flags, ports inspected, and criteria. Moreover, we categorized the deficiencies for the detentions into 17 types for internal and external inspections. As the results of the comparison study, bulk and general cargo carriers dominate the portion of detentions by almost 66 percent. Self-induced detention due to a lack of preparation by crews and company support are the main reasons of repeated detentions from the same type ships. Ships between six and ten years old show the lowest detention rate by 4 percent whereas ships less than five years old generate the highest detention rate by 22 percent. The main categories of the detentions from ships less than 5 years old are a lack of documentation and certification, and the clues support our opinion that owners and crews may neglect to prepare the inspections because their strong confidence for the ship condition due to young ship age. As a result of a great effort of Korean government and shipping companies to reduce a detention rate, the detention rate has been recently reduced to 0.3 percent. The results also require companies with the flag of convenience ships to spend more effort to reduce the detention rate, too. We expect that using social networking service by Korea Register will lower the detention rate by sharing relevant information real-time to ships and owners.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.925-935
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• 2016

It is provided that seafarers qualified in accordance with STCW(International Convention on Standards of Training Certification and Watch-keeping for Seafarers) convention and code in safety training shall be required, every five years, to provide evidence of having maintained the required standard of competence, to undertake the tasks, duties and responsibilities listed in Chapter VI, section A-VI/1 of the STCW Code A. Every party to the STCW Convention has amended the relevant national regulations according to the above international convention and code. These amended Seaman's Act require the updating safety training which is only five years valid for existing seafarers serving onboard ship on international voyage. And above specified existing seafarers must, as of the 1st January 2017, have documentary evidence of either having completed the training course or updated their training within the last 5 years. In relation to the above international trend, the Korean Ministry of Oceans and Fisheries also has completed an amendment to its Seaman's Act. But, the Korean Seaman's Act has a supplementary provision to exempt the seafarers who have completed STCW advanced safety training from basic safety training. The purpose of this study is to define the problems of above mentioned exemption provisions and to make better policies for improvement. In order to complete the purpose, the research team has conducted an in-depth survey of various foreign cases on STCW safety training. Moreover, the team has suggested an improvement scheme in consonance with Korean shipping industry and society through out this report.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1358-1364
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• 2016

Maritime accidents caused by a ship include collisions, sinking, stranding and fire etc. This study is intending to consider fire accidents among such diverse marine accidents. It is much likely that various sorts of fires break out because crewmen are living in a narrow space for long periods of time consequent on the ship's characteristic of sailing on the sea. According to the ship fire survey, about 50% of the total fire accidents occurred at an engine room, and the main fire origin was analyzed to be oil. In addition, ship fire breaks out in the order of baggage racks and living quarter. In short, the survey indicates that all sorts of fires belonging to A, B, C and D-class have occurred. This study, targeting an actual passenger ship 'A', found the response time to evacuation, during which the people on board a ship recognize the outbreak of fire, and act, and the travel time for evacuation which is the actual travel time. In addition, this study carried out a simulation through the special program for fire analysis - FDS (Fire Dynamics Simulator) in order to find the effective evacuation time, i.e. life survival time. Particularly, this study did comparative analysis of the influence on the survival of passengers and crew based on the collected simulation data by fire size and sort. As a result of the analysis, it was found that when examining the only actual evacuation movement time excepting the response time to evacuation, people are safe by completing evacuation before the effective evacuation time only in case fire size is 100Kw among all sorts of fires. In other words, in case of the outbreak of fire more than 1 MW, it was found to fail to meet evacuation safety regardless of fire size.