• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.379-382
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• 2009

As IT becomes leading part of futurity industry, issue about Green IT is being on the increase and resources recycling, toxicity water use resection, saveenergy etc. are emphasized. Fundamental purpose for Neteuwokeusiseutem's Green IT realization that is constructed on ship studied about network security system that can control access that use resources as efficient and safe and is enemy of evil which can give subordinate of system for this and resect unnecessary hardware waste by back more.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1603-1611
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• 2021

As IMO environmental regulations are tightened, the need to establish a system that can reduce emissions is increasing, and for this purpose, various power control management systems have been studied and implemented as a new energy management system for ships. In this study, we design a control process through modeling for Bi-Directional Converter (BDC) application with bi-directional power flow to link batteries, which are energy storage devices, to conventional generator power systems, and propose mechanisms for batteries optimized for varying loads. This work models MATLAB/Simulink as a BDC and simulates current control and state of charge (SOC) optimization at the time of charging and discharging batteries according to load scenarios. Through this, the battery, power, and load were interlocked so that the generator operated on board could be operated in the optimal operation range, and power control management was performed to enable the generator to operate in the high fuel efficiency range.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.576-582
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• 2016

To cope with international regulations, such as Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP) and so forth, and to enforce limitations on $CO_2$ emissions, green-ship technology to lower fuel consumption has been actively researched, and the development of an energy-saving device (ESD) is being pursued. In order to design an ESD for small and medium-sized domestic vessels, an analysis on flow characteristics has been performed in the present study. Through a model test and numerical analyses, the characteristics of flow around the stern bilge and bulb have been compared to improve wake quality and resistance performance. As a result of these comparisons and analyses, a vertical plate has been adopted,, as a new ESD. Design criteria for the proposed ESD are also suggested. By applying this new ESD, it is expected that the total resistance and average nominal wake can be reduced by 3.04 % and 18.8 %, respectively.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.361-370
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• 2015

Wind energy began to receive attention as a new alternative fuel since 20 years ago and is growing as a booming global business model. Global wind power generation in the world has been continuously increasing for the past 10 years, accounting for over 30% of cumulative rate compared to total power generation. Global demand for wind power generation is gradually expanding due to restriction on carbon emission and environmental problems caused by increased greenhouse effect. Accordingly in this study, current transportation routes are classified into three types including access-priority route, economics-priority route, and convenience- priority route depending on distribution characteristics of wind power equipment in order to suggest transportation methods other than ships. The three types of transportation route that this study declared can make the Wind power equipment manufacturing companies can judge not only the duration of transportation but also effectiveness and economic feasibility. It means that the manufacturers can analyze and compare the effectiveness and economic feasibility, which are proceed by the shipping company and freight forwarder until now days.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.590-599
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• 2011

The electrification of the waste heat of fuel cell is necessary to enhance the efficiency of fuel cell system. For this purpose, the SOFC/ST(Solid oxide fuel cell/Steam turbine) hybrid system is suitable. The purpose of this work is to predict the performance of methane fueled SOFC/ST hybrid power system and to analyze the influence of operating temperature of stack, current density of stack, combustor outlet gas temperature, and boiler outlet gas temperature. According to the analysis, it is proved that making the best use of the waste heat of stack and minimizing the fuel consumption of combustor are essential for the high-efficiency of SOFC/ST hybrid system.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.306-311
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• 2017

In the future ubiquitous network, information will collect data from various sensors in the field. Since the sensor nodes are equipped with small, often irreplaceable, batteries with limited power capacity, it is essential that the network be energy-efficient in order to maximize its lifetime. In this paper, we propose an effective network routing method that can operate with low power as well as the transmission of data and information obtained from sensor networks, and identified the number of sensors with the best connectivity to help with the proper placement of the sensor. These purposes of this research are the development of the sensor middle-ware to integrate the maritime information and the proposal of the routing algorithm for gathering the maritime information of various sensors. In addition, for more secure ship navigation, we proposed a method to construct a sensor network using various electronic equipments that are difficult to access in a ship, and then construct a communication system using NMEA(the national marine electronics association), a ship communication standard, in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.538-549
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• 2021

In this study, a trim tab on the stern hull of a small high-speed vessel of approximately 10 m length sailing at a Froude number of 1.0 was designed for energy efficiency. The running attitude and resistance performance of the bare hull and trim tab hull at several angles to the base line were analyzed for model and full scale ships using computational fluid dynamics, and compared to investigate the scale effect. The analysis results for the bare hull were quite similar, but a difference in the attitude control under same conditions of the trim tab was observed, resulting in the total resistance error. However, there was no significant difference in tendency of the variation in the resistance with the attitude. Thus, the optimum running attitude could be determined from the tendency despite the scale effect, but a full scale analysis is required to analyze the control of the attitude by the trim tab and flow characteristics near the full scale ship.

• Journal of IKEEE
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• v.26 no.4
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• pp.596-601
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• 2022

The application of the EGR system is increasing according to the recent trend of conversion to green-ships. EGR blower, one of the core parts of the EGR, consists of aerodynamic system and e-motor and inverter and etc. For the e-motor, a permanent magnet type synchronous motor with high energy density and excellent efficiency is applied recently. Small and medium-sized enterprises trying to develop the e-motors, however, for marine inverters mostly developed by global advanced companies due to the rigid classification certification and technical difficulties. One of disadvantage of universal inverters is that when optimal control fails, it is difficult to find the cause from user's point of view. Therefore, in this study, optimal controllers(Current vector contol and Tracking observer) for SPMSM for EGR blower was designed and verified to analyze the causes of failure of optimal control of universal inverter.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.201-202
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• 2021

Regulations on greenhouse gases emitted from ships in international shipping are being strengthened, and the greenhouse gas reduction target established by the International Maritime Organization is acting as a great challenge for shipping companies in terms of technical and operational aspects. The International Maritime Organization aims to reduce carbon intensity by 30% by 2030, 70% by 2050, and by 50% in terms of gross emissions compared to 2008. To realize this situation, the IMO adopted some short-term and mid-to-long-term measures and adopted technical measures such as the application of EEXI, an energy efficiency index, to existing ships from 2023, and the early application of EEDI phase 3 for some tpe of ships. In addition, reduction measures were introduced to reduce greenhouse gas in the operational aspect.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.876-880
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• 2015

In 2016, the IMO's new rules for an 80% reduction in NOx emissions in newly built ships will necessitate the use of LNG as a clean fuel. So far, the developed European countries have led the development of LNG bunkering ships and related facilities. An LNG bunkering system stores LNG in a horizontal or vertical IMO "C"-Type tank insulated with perlite powder, and a vacuum in the annular space between the double walls, like the cryogenic liquid nitrogen tank. Current storage tanks have high heat leakage, evaporating over 2.0% daily, and are difficult to build with the required vacuum. A more efficiently insulated storage tank could reduce the evaporation rate. This research carried out thermal analysis on a new effective insulation method that separates high vacuum in the annular space between two tanks with a solid insulation material, such as urethane foam, lining the outer vessel. This highly efficient insulation system obtained an evaporation rate of 0.03% per day under a $10^{-3}torr$ vacuum, and an evaporation rate of 0.11% at $10^{-45}torr$. Even if the space loses its vacuum, the new insulation system showed a lower evaporation rate of 4.12% than the present perlite system of 4.9%. This newly developed tank can increase the efficiency of LNG storage tank and may help keep LNG bunkering systems safe.