• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.457-466
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• 2015

In this paper, the academic research on the value chain and the supply chain of offshore business are conducted for the investigation of the offshore business comprehensive configuration. Then, the assembly and ergonomic simulation was conducted for the purpose of advanced validation of offshore project.. With respect to the simulation analysis, the assembly simulation model(w.r.t. drill ship) and the ergonomic simulation model(w.r.t. FPSO) are constructed. Through the assembly simulation of drillship, the production processes could be validated in terms of availability. Also, the problem of topside design of FPSO was found by ergonomic simulation.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.129.1-129.1
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• 2010

Since the commencement of the fuel cell business in 2007, POSCO POWER has been the major supplier of the MCFC (Molten Carbonate Fuel Cell), which is the most commercialized stationary fuel cell system in the world. With its quite, yet active movement, more than 20MW MCFC systems have been installed and are operating in Korea. While trying to localize the components and set up a firm supply chain in Korea to provide more reliable and cost-competitive products to its customers, POSCO POWER is also devoting itself to developing new MCFC application products. One such product is a back-up power system, in which a back-up algorithm is embedded to the present system so that the product can work as a back-up generator in case of grid failure. The technology to enhance load following capability of a stack module is also being developed with the back-up algorithm. Another example is a building application, the goal being to make the present Sub-MW product suitable for urban area. For this, downsizing and modularization are the main R&D scope. The project for developing ship service fuel cell for APU application will launch soon as well. In the project, a system which can operate in marine environment, and reforming technology for liquid logistic fuel will be developed.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.3
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• pp.204-214
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• 2017

Recently, ship owners have been requiring the assessment of the maneuverability of a twin-screw ship under machinery failures. In this paper, we are only focused on the propulsion failure among propulsion failure, power supply failure, steering system failure etc. First of all, the mathematical model for the twin-screw 174K LNGC is verified by comparing the simulated results for $35^{\circ}$ turning test, $10^{\circ}/10^{\circ}$ zigzag test and $20^{\circ}/20^{\circ}$ zigzag test under normal operating condition and those obtained from free running model tests. And, sea trial results of 216K LNGC under single propeller failure are compared with those of 174K LNGC under identical condition to verify the proposed method to predict maneuverability under single propeller failure. After the straight line maneuver is simulated under the single propeller failure, the speed and equilibrated heading and rudder deflection angles at steady state are predicted. After the IMO maneuvering tests are simulated under the single propeller failure, the results are reviewed to investigate the maneuvering characteristics due to the failure.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.5
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• pp.609-616
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• 2018

The cargo handling system, which is composed of a fuel gas supply unit and cargo tank pressure control unit, is the second largest power consumer in a Liquefied Natural Gas (LNG) carrier. Because of recent enhancements in ship efficiency, the surplus boil-off gas that remains after supplying fuel gas for ship propulsion must be reliquefied or burned to regulate the cargo tank pressure. A full or partial liquefaction process can be applied to return the surplus gas to the cargo tank. The purpose of this study is to review the current partial liquefaction process for LNG carriers and develop new processes for reducing power consumption using exergy analysis. The developed partial liquefaction process was also compared with the full liquefaction process applicable to a LNG carrier with a varying boil-off gas composition and varying liquefaction amounts. An exergy analysis showed that the Joule-Thomson valve is the key component needed for improvements to the system, and that the proposed system showed an 8% enhancement relative to the current prevailing system. A comparison of the study results with a partial/full liquefaction process showed that power consumption is strongly affected by the returned liquefied amount.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.49-60
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• 2019

Recently the concentration of fine dust and ultra fine dust becomes so bad, which seriously threatens the health and even the life of people. So, government started to investigate several ways to reduce the amount of fine dust and ultra fine dust. From a few years ago it has been known that ships anchored at port emit a lot of pollution and seriously affect air quality of neighboring cities. To reduce the pollution emitted by ship AMP (Alternative Maritime Power Supply) has been proposed, which uses the electricity instead of bunker C oil or diesel. Many developed countries already installed AMP to improve air quality in port area. Korea is in the stage of planning to install AMP at port. However, there are many complicated problems to be handled before AMP installation. Due to huge initial cost and long period of construction ship owner and habour operating company are reluctant to AMP installation. And there are serious technological difficulties in constructing AMP in existing harbour. Lack of AMP core technology and operational difficulties of AMP are also big challenges to be conquered. In this study SWOT/AHP method is used to find strategic and efficient ways to handle above complicated challenges and then to vitalize the AMP installation.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.1
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• pp.54-64
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• 1996

It seems that blowing air bubble out of the bulb surface of a ship of flat bottom will reduce the frictional resistance, since wetted area of the hull surface is reduced owing to air bubble staying close to the surface. To as certain this concept, at first, the limiting streamlines around the bow was observed, and local distribution of pressure and shear stress, due to the change of air-blowing position, air supply pressure, and the model speed, was investigated. It was found that the local friction was reduced near the bulb and air-bubble formations also play an important role as a drag component. This paper can be considered as a preliminary study on the drag reduction of conventional ships by the micro-bubble injection.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.207-210
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• 2005

This paper describes a design of several ship's emergency lighting system(SELS) that power factor is improved and power is controlled extensively, and techniques to control and monitor this system in remote distance by PC serial communication. The remote monitoring control system is composed of emergency power supply system (EPSS), half bridge(HB)inverter, fluorescent lamp(FL), microprocessor, multi communication interface. EPSS checks the voltage of the emergency backup battery in real time. In case that the voltage of 13[V] or less has been detected for 5[msec] or longer for 3 times in a row, charger circuit is connected for battery charging. Experimental works using proposed system confirm that speedy and stable power to be supplied when main power source cut-off, compared with conventional analog type, and input power up to 35.0[%] by adjusting of pulse frequency of the HB inverter.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.370-376
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• 2007

The purpose of this study is to measure the thermal conditions of the various cabins in a long cruise passenger ship which is an integration of the high level technological know-how. We did an experiment and found out the following problems. (1) The temperature from the damper is stable but the humidity varies lower. (2) Comparing A deck-located cabins to B deck-located cabins, A-deck located cabins' temperatures are higher because of the 24% more air supply. (3) More influences from outdoor climate makes the temperature of the outside cabin lower than the inside cabin. (4) In some cabins, there are vertical temperature differences of $4{\sim}6^{\circ}C$. (5) And $2{\sim}4^{\circ}C$ temperature differences are occurred at between 2-story bed. (6) Repeatability of measurement results are confirmed by 2 times measurements.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.2
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• pp.143-151
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• 2019

This study describes a method for analyzing log data generated in a process using process mining techniques. A system for collecting and analyzing a large amount of log data generated in the process of manufacturing an offshore plant piping material was constructed. The analyzed data was visualized through various methods. Through the analysis of the process model, it was evaluated whether the process performance was correctly input. Through the pattern analysis of the log data, it is possible to check beforehand whether the problem process occurred. In addition, we analyzed the process performance data of partner companies and identified the load of their processes. These data can be used as reference data for pipe production allocation. Real-time decision-making is required to cope with the various variances that arise in offshore plant production. To do this, we have built a system that can analyze the log data of real - time system and make decisions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.7
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• pp.1-7
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• 2021

Restrictions on the emissions of nitrogen oxides, sulfur oxides, carbon dioxide, and particulate matter from marine engines are being tightened. Each of these emissions requires different reduction technologies, which are costly and require many pieces of equipment to meet the requirements. Liquefied natural gas (LNG) fuel has a great advantage in reducing harmful emissions emitted from ships. Therefore, the marine engine application of LNG fuel is significantly increasing in new ship buildings. Accordingly, this study analyzed the internal support structure, insulation type, and fuel supply piping system of a 35 m3 International Maritime Organization C type pressurized storage tank of an LNG-fueled ship. Analysis of the heat transfer characteristics revealed that A304L stainless steel has a lower heat flux than A553 nickel steel, but the effect is not significant. The heat flux of pearlite insulation is much lower than that of vacuum insulation. Moreover, the analysis results of the constraint method of the support ring showed no significant difference. A553 steel containing 9% nickel has a higher strength and lower coefficient of thermal expansion than A304L, making it a suitable material for cryogenic containers.