• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.304-309
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• 2015

To evaluate the degree of contamination caused by oil spill accident in the sea, the in-situ sensors which are based on the scientific method are needed in the real site. The sensors which are based on the fluorescence detection theory can provide the useful data, such as the concentration of oil. However these kinds of sensors commonly are composed of the ultraviolet (UV) light source such as UV mercury lamp, the multiple excitation/emission filters and the optical sensor which is mainly photomultiplier tube (PMT) type. Therefore, the size of the total sensing platform is large not suitable to be handled in the oil spill field and also the total price of it is extremely expensive. To overcome these drawbacks, we designed the fluorimeter for the oil spill detection which has compact size and cost effectiveness. Before the detail design process, we conducted the experiments to measure the excitation and emission spectrum of oils using five different kinds of crude oils and three different kinds of processed oils. And the fluorescence spectrometer were used to analyze the excitation and emission spectrum of oil samples. We have compared the spectrum results and drawn the each common spectrum regions of excitation and emission. In the experiments, we can see that the average gap between maximum excitation and emission peak wavelengths is near 50 nm for the every case. In the experiment which were fixed by the excitation wavelength of 365 nm and 405 nm, we can find out that the intensity of emission was weaker than that of 280 nm and 325 nm. So, if the light sources having the wavelength of 365 nm or 405 nm are used in the design process of fluorimeter, the optical sensor needs to have the sensitivity which can cover the weak light intensity. Through the results which were derived by the experiment, we can define the important factors which can be useful to select the effective wavelengths of light source, photo detector and filters.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.497-503
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• 2018

Passenger ships and training ships have a common feature in that they serve many passengers. Thus, safe navigation is very important. During normal sailing, a ship may turn using various types of steering, including maneuvers to avoid collisions with dangerous target. When a ship turns, a heeling angle occurs. If trouble arises during sailing, a dangerous heeling angle may result or a capsizing accident. In this study, the heeling angle during turning was measured through experimentation with two training ships similar to passenger ships. These findings were compared with theoretical formulas for heeling angle when turning. We confirmed that the limit of the maximum heeling angle estimation using heeling angle formula when turning presented in IMO stability criteria. In addition, it was confirmed that the maximum estimated heeling angle can be reached by applying the result calculated in the theoretical formula 1.4 times when turning right and 1.1 times when turning left to reflect sailing speed when of rudder hard over. It is expected that this study will provide basis data for establishing safe operation standards for the prevention of dangerous heeling angles when turning.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.698-707
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• 2019

The removal of oil spilled by the sinking of a foreign ship in Korea's Exclusive Economic Zone (EEZ) began in May 2019 four years after the ship sunk near Jeju Island. The cleanup was conducted by a foreign company that was contracted to the ship-owner's protection & indemnity (P&I) insurance company. In contrast to the time taken to begin the cleanup, the operation itself was completed in just 22days. Compared to similar cases, the decision to begin the removal was a delayed one. This study analyzes all 93 documents related to the ship's sinking and the eventual cleanup, confirming delays in administrative decision-making on the removal, and identifies factors that influenced this delay. These factors include a neglect of accident-related data verification, and other, legal, technical, environmental, and human aspects. Finally, this study suggests ways to improve decision-making efficiency. As the first study dealing with the cleanup in the EEZ, this research is expected to facilitate decision-making and influence the formulation of policies in the future.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.35-42
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• 2005

This study aims at analyzing the extent of seafarers' perception on their stress and ways to cope with the stress and providing fundamental data for establishing on the stress management of seafarers. In this paper 428 seafarers, who were in the fire-fighting and survival technique training course in Korea Institute of Maritime and fisheries Technology, were sampled and asked to fill out two kinds of questionnaire. One is a questionnaire on seafarers' stress perception and the other is that on the measure of their coping with stress. The collected data were analyzed by using descriptive statistics, t-test and ANOVA by SPSS 10.1 package. The results of this study are as follow. 1) There were significant differences of stress perception in navigation area, marital status, amount of smoking, frequency of drinking, exercise, sleep pattern, sleeping hours, leisure time, and job satisfaction 2) There were significant differences of method coping with stress in current position, navigation area, age, ship career, level of education, marital status, yearly income, frequency of drinking, amount of drinking, exercise, sleep pattern, and job satisfaction 3) The relation between stress perception and ways of coping with stress showed that the group with higher stress perception tended to use emotion-focused coping style and desirable thinking.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1353-1369
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• 2023

In the event of a disaster accident at sea, the scale of damage will vary due to weather effects such as wind, currents, and tidal waves, and it is obligatory to minimize the scale of damage by establishing appropriate control plans through quick on-site identification. In particular, it is difficult to identify pollutants that exist in a thin film at sea surface due to their relatively low viscosity and surface tension among pollutants discharged into the sea. Therefore, this study aims to develop an algorithm to detect suspended pollutants on the sea surface in RGB images using imaging equipment that can be easily used in the field, and to evaluate the performance of the algorithm using input data obtained from actual waters. The developed algorithm uses image enhancement techniques to improve the contrast between the intensity values of pollutants and general sea surfaces, and through histogram analysis, the background threshold is found,suspended solids other than pollutants are removed, and finally pollutants are classified. In this study, a real sea test using substitute materials was performed to evaluate the performance of the developed algorithm, and most of the suspended marine pollutants were detected, but the false detection area occurred in places with strong waves. However, the detection results are about three times better than the detection method using a single threshold in the existing algorithm. Through the results of this R&D, it is expected to be useful for on-site control response activities by detecting suspended marine pollutants that were difficult to identify with the naked eye at existing sites.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.31-38
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• 2020

The characteristics of ship traffic routes and the long term fluctuation in marine traf ic volume of the incoming and outgoing routes of the Yeosu Gwangyang Port were analyzed using vessel traffic data from the past 22 years and a real-time vessel traffic volume survey performed for 72 hours per year, for three years, between 2015 and 2017. As of 2017, the number of vessels passing through Yeosu Gwangyang Port was about 66,000 and the total tonnage of these ships was about 804,564 thousand tons, which is a 400 % increase from the 189,906 thousand tons shipped in 1996. Specifically, the dangerous cargo volume was 140,000 thousand tons, which is a 250 % increase compared to 1996. According to the real-time vessel traffic volume survey, the average daily number of vessels was 357, and traf ic route utilization rates were 28.1 % in the Nakpo sea area, 43.8 % in the specified sea area, and the coastal area traf ic route, Dolsan coastal area, and Kumhodo sea area showed the same rate of 6.8 %. Many routes meet in the Nakpo sea area and, parallel and cross passing were frequent. Many small work vessels entered the specific sea area from the neighboring coastal area traffic route and frequently intersected the path of larger vessels. The anchorage waiting rate for cargo ships was about 24 %, and the nightly passing rate for dangerous cargo ships such as chemical vessels and tankers was about 20 %. Although the vessel traffic volume of Yeosu Gwangyang Port increases every year, the vessel traffic routes remain the same. Therefore, the risk of accidents is constantly increasing. The route conditions must be improved by dredging and expanding the available routes to reduce the high risk of ship accidents due to overlapping routes, by removing reefs, and by reinforcing navigational aids. In addition, the entry and exit time for dangerous cargo ships at high-risk ports must be strictly regulated. Advancements in the VTS system can help to actively manage the traffic of small vessels using the coastal area traffic route.

• Journal of the Korean earth science society
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• v.21 no.5
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• pp.635-646
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• 2000

Geological achievements of the 20th century revolutionized our views about geological understanding and concept. A good example is the concept of continental drift suggested early in the 20th century and later explained in terms of seafloor spreading and plate tectonics. Our understanding of the compositions of materials forming earth has also improved during the20th century. Radio and stable isotopes together with biostratigraphy and sequence stratigraphy allow us to interpret the evolution of sedimentary basins in terms of plate movement and sedimentation processes. The Deep Sea Drilling Project initiated in 1960s and continued as the Ocean Drilling Project in 1980s is one of the most successful international research observations, and new developments in computational techniques have provided a wholly new view about the interior of the earth. Most of the geological features and phenomena observed in deep sea and around continental margins are now explained in terms of global tectonic processes such as superplumes flowing up from the interior of our planet and interacting with such as Rodinia Pannotia and Nena back in the Precambrian time. The space explorations which began in the late 1950s opened up a new path to astrogeology, astrobiology, and astropaleontology. The impact theory rooted in the discovery of iridium and associated phenomena in 1980s revived Cuvier's catastrophism as a possible explanation for the extinctions of biotas found in the geological record of this planet. Due to the geological achievements made in the 20th century, we now have a better understanding of geologic times and processes that were too long to be grasped by human records.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.109-117
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• 2005

Based on the previous studies on alcohol effects on human behavior and performance in transportation system such as airplane and car driving, the alcohol exposure before and on watch of a ship has a great influence on subsequent behavior. In this paper, to examine the drinking status of officers on board multiple choice questionnaires are circularized under instruction and surveyed for 118 officers. According to the results of the questionnaire survey on alcohol dependance (Alcoholism) that was invested by WHO, over 27% of those surveyed represented alcohol abuse symptoms. In addition to that, the existing state and awareness for on-board-drinking was summarized to make a scenario of drunk-operation with a ship handling simulator to investigate the effect of alcohol (0.08 g% blood alcohol concentrations) on ship operational performance. A main effect for alcohol was found indicating that ship operational performance was comparatively impaired by this alcohol relative to performance in the non-alcohol condition. The results of this research can be applied to minimize marine acciedents as basic data.

• Journal of Navigation and Port Research
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• v.35 no.8
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• pp.631-636
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• 2011

Stable power supply to a light mounted on a navigational buoy is indispensable factor because unstable power can lead to fatal marine accident. Despite the difference lies between onshore and offshore environment, as well as the power output characteristics, the PV(Photovoltaic) power generation system is designed by the independent onshore power generation system standards. Furthermore, the capacity of PV power generation system does not take into account the structural characteristics of the buoy in the sea. Therefore, the faulty design makes battery over-discharge owing to lack of the power generation and the battery can not supply stable power to the light. This paper introduces a design method for a power system of the PV powered buoy. The data has been acquired for 3 months period, which includes PV-generated electricity, power consumption and battery voltage from experimental buoy. Further, a power management features of the buoy has been analyzed based on the acquired data. From the analysis of the acquired data, it was evident that PV power generation system produces different electric power output depend on its installed environment - land and sea. Based on the analytical result, a design criterion has been proposed for the power system in the navigational buoy.

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.213-220
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• 2010

Following the application of Formal Safety Assessment(FSA) to bulk carriers, crude oil tankers and large passenger ships, an urgent need to consider the safety of general cargo ships has recently been raised through the International Maritime Organization(IMO)(IMO, 2006a), and related FSA studies are being carried out by International Association of Classification Societies(IACS) as a preparatory work for the discussion on the issue of general cargo ship safety in the IMO committee. FSA is a structured and systematic methodology which is based on the techniques of risk analysis and cost benefit assessment to assist in the decision-making process, and aims at enhancing maritime safety, including protection of life, health, the marine environment and property. FSA can be used as a tool to facilitate the development of regulatory changes equitable to the various parties, with a view to aiding the achievement of consensus, and to help in the evaluation of new regulations and in making a comparison between existing and possibly improved regulations(IMO, 2007). This study aims at verifying the usefulness of FSA methods as a tool to conduct a safety assessment of general cargo ships flying the Korean flag, and providing useful information on 'the safety of general cargo ships' for IMO committee's discussion on the matter at a future session. FSA comprises five steps, however, steps 1(Hazard identification) and 2 (Risk analysis) from the FSA study for the Korean-flagged general cargo ships are discussed in this paper.