• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.5
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• pp.572-580
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• 2019

In view of the numerous discussions on global environmental issues, policies have been implemented to limit emissions in the field of marine transport, which accounts for a major part of international trade. In this study, a ship's emissions were calculated by applying the engine load factor to determine the total quantity of emissions based on the ship's speed reduction. For ships entering and leaving the Busan North Port from 1 January to 31 December 2017, emissions were calculated and analyzed based on the ship's type and its speed in the reduced speed zone (RSZ), which was set to 20 nautical miles. The comparison of the total amount of emissions under all situations, such as cruising, maneuvering, and hotelling modes revealed that the vessels that generated the most emissions were container ships at 76.1 %, general cargo ships at 7.2 %, and passenger ships at 6.8 %. In the cruising and maneuvering modes, general cargo ships discharged a lesser amount of emission in comparison with passenger ships; however, in the hotelling mode, the general cargo ships discharged a larger amount of emission than passenger ships. The total emissions of nitrogen oxides (NOx), sulphur oxides (SOx), particulate matter (PM), and volatile organic compounds (VOC), were 49.4 %, 45 %, 4 %, and 1.6 %, respectively. Furthermore, the amounts of emission were compared when ships navigated at their average service speed, 12, 10, and 8 knots in the RSZ, respectively. At 12 knots, the reduction in emissions was more than that of the ships navigating at their average service speed by 39 % in NOx, 40 % in VOC, 42 % in PM, and 38 % in Sox. At 10 knots, the emission reductions were 52 %, 54 %, 56 %, and 50 % in NOx, VOC, PM, and Sox, respectively. At 8 knots, the emission reductions were 62 %, 64 %, 67 %, and 59 % in NOx, VOC, PM, and Sox, respectively. As a result, the emissions were ef ectively reduced when there was a reduction in the ship's speed. Therefore, it is necessary to consider limiting the speed of ships entering and leaving the port to decrease the total quantity of emissions.

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.29-34
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• 2004

Ship is bring operated under a highly dynamic environments and many factors are related whit marine accident and those factors are interacting. An analysis on the marine accident is very important to prepare countermeasures which will ensure the safe navigation This paper aims to build a model of the rouses and improved policy for marine accident using SD(System Dynamics) approach and to measure a effect which is risk control countermeasures of marine accident The methodology of this paper is to perform the causes and improved policy for marine accident using Brainstorming method, and was to changed by quantitutive, qualitative factors and their feedback loops in casual map. This model was performed over 23 years($1997\~2020$) in a standard simulation model and 4 policy simulation models.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.876-883
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• 2016

In this study, we selected CFRP to construct a canoe hull. A ship design was made using a commercial ship design program, SOLIDWORKS, and a flow analysis of the canoe on a free surface was calculated using STAR-CCM+. A flow field and waveform were obtained in this way. These results were used to check the resistant performance of the canoe. Results showed that if the draft is 0.09 m, it is safe to run at less than 4 m/s, and if draft is 0.24 m, it is safe to run at less than 2 m/s. Moreover, it was confirmed that those speeds can be made by two adults. The developed canoe, which is 20 % lighter in comparison with conventional FRP models, was briefly introduced in this paper.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.3
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• pp.236-242
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• 2018

Damage due to ice collision is the most serious threat for the structural safety of ships operating in arctic region. Since such hull damages are usually caused by the collision of floating ice at excessive voyage speed of ships, the authorities responsible for the shipping at arctic sea are required to provide the speed limit for safe voyage, so-called safe speed. In countries near arctic ocean, such as Canada and Russia, empirical methods to determine the safe speed of ships based on their long experience of arctic voyage have been established and applied them in the real arctic navigation. However, in Korea, it is not easy to accumulate the arctic voyage experience and related technical database, so it seems to be a realistic approach to adopt a safe voyage speed estimating method in arctic sea based on the ice collision simulation technology using the nonlinear finite element analysis. The aim of this study is to develop a technique for estimating the safe voyage speed of vessels operating at arctic sea through the ice collision analysis, In order to achieve this goal, the standard procedure of the ice collision analysis is dealt with and example analysis was carried out and the results were considered. To investigate the validity of developed method, POLARIS system proposed by IMO was studied for comparison.

• Journal of the Korean Institute of Navigation
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• v.25 no.3
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• pp.257-268
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• 2001

Marine traffic engineering is the technical field that observe flows of vessel traffic in accurate and describe the features of ships' movement statistically or analytically, then contribute to the improvement of the traffic flow and safety of traffic. Recently, marine traffic engineering has been developed until that possible to estimate a changes in traffic flow caused from some transformations of the traffic condition, and to assess the feasibility and validity of the changes by computer simulation. This paper aims to assess the present traffic safety at the sea area adjacent to Pusan harbour, and the validity of the suggested roundabouts traffic separation scheme at the Pusan approaching water(by Park in 1998) using environmental stress aggregation model There are couple of steps to describe the marine traffic situation and to assess it's safety by computer simulation. The first step is observe the movement of vessel traffic concerned waters and to obtain the relevant data for computer simulation. Second step is to carry out computer simulation to assess the simulated traffic flows by using suitable indexes of assessment model - environmental stress aggregation model. Eventually, this paper conclude that the environmental stress aggregation model is a useful technique to assess the traffic safety and the suggested roundabouts traffic separation scheme could make the concerned area safer than present traffic situation.

• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.599-605
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• 2012

As vessels are faster and bigger, higher safety navigation techniques have been required. In marine traffic area, buoy is to be one of the most important equipment, so that it should be built stable and robust. Verification in design level is good to accomplish it. This paper tries to implement visual program to confirm the external stability, which shows the movement on water by external factors such as wind, tide and current. Considering further requirements for additional influences or functions, design architecture for program introduces the concept of software component. Using Quest3D as the graphic tool, visual programming with software component concept can be implemented.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.3 s.26
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• pp.185-192
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• 2006

Distribution of wind direction and wind speed is very important from the viewpoint of ship's safety because it is closely related to the formation and development of sea wave. In this study, the climatological characteristics of monthly wind distribution in a greater coasting area of Korea are analyzed by the ECMWF objective analysis data for the period from 1985 to 1995{11 years). Distributions of wind direction from October to March are very similar and wind speed is strongest in January. The NW'ly and WNW'ly winds at a latitude of 30 degrees N and northward and the NE'ly wind in the Straits of Taiwan and the South China Sea are sustaining and very strong. Distributions of wind direction from June to August are similar and the SW'ly and SSW'ly winds in the South China Sea are strong. The strong Southeast trades exists in the winter hemisphere{Southern Hemisphere). Wind speeds in April, May and September are generally weak.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.6
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• pp.584-590
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• 2012

In this study, we have conducted a work on homogenizer development which is operated by high shearing force generated by stator and rotor inside it. To investigate the performance for homogenization and atomization of homogenizer, Bunker-C (IFO 380 cSt) was used as a fuel for experiment. Pre-treatment of bunker-C was carried out with homogenizer developed in this study. Oil purifier was used to investigate effect of oil sludge reduction after pre-treatment. Experimental result showed that the amount of sludge of fuel oil after pre-treatment with homogenizer has decreased by 13 %. To confirm combustion efficiency, Bunker-C which have pre-treatment with homogenizer and purified after are burned in boiler system. The result showed that CO concentration in exhaust gas was decreased. These results mean that if the homogenizer which is developed in this study for marine fuel oil is applied on real vessels, oil costs and operating costs can be reduced.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.554-563
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• 2016

Ships are capable of operating on residual fuel oil. Recently, various attempts have been made to meet environmental regulations and with ships operating on residual fuel oil. One way of fulfilling these requirements is by using fuel additives. Dispersants and fuel combustion improvers will have a positive effect on improving the combustion characteristics of the residual fuel oil. As such, this study examines fuel oils blended with additives by using fuel combustion analysis (FIA/FCA) and thermogravimetric analysis (TGA). The results of FIA/FCA focuse only on the amount of work done by the fuel oil. Therefore, it is recommended in this study that a new method to evaluate the combustion efficiency via FIA/FCA processes be developed. The analysis with ROHR curve gained by FIA/FCA brought similar results with pressure trace curve therefore it can be said that new analysis method can be reliable. The TGA, analysis process is very sensitive to the evaporation of fuel, for example, which could be addressed. In the performance-related findings of this study, blended samples with additives containing iron compounds showed a greater improvement in early combustion characteristics than samples without additives.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.708-715
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• 2014

In this paper, we suggest a method of realtime confidence interval estimation to detect abnormal states of sensor data. For realtime confidence interval estimation, the mean square errors of the exponential smoothing method and moving average method, two of the time series analysis method, where compared, and the moving average method with less errors was applied. When the sensor data passes the bounds of the confidence interval estimation, the administrator is notified through alarming. As the suggested method is for realtime anomaly detection in a ship, an Android terminal was adopted for better communication between the wireless sensor network and users. For safe navigation, an administrator can make decisions promptly and accurately upon emergency situation in a ship by referring to the anomaly detection information through realtime confidence interval estimation.