• Resources Recycling
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• v.25 no.1
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• pp.48-59
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• 2016

The earth has been warming due to $CO_2$ gas emissions from fossil fuel cars and a ship. So the hydrogen fuel cell vehicle(FCV) using hydrogen as a fossil fuel alternative energy is in the spotlight. Hyundai Motor Company of Korea and a car companies of the US, Japan, Germany is developing a FCV a competitive. Obtained hydrogen as a by-product of the coke plant, oil refineries, chemical plants of steel mill, coal is reacted with steam at high temperatures, methane gas, manufacture of high purity hydrogen Methane Steam Reforming and hydrogen detachable reforming method using the Pressure Swing Adsorption or Membrane Reforming technical or decomposition of water to produce electricity. Hydrogen is the electronic industry, metal and chemical industries, which are used as rocket fuel, etc. are used in factories, hospitals, home of the fuel Ene.Farm system or FCV. And a method of storing hydrogen is to store liquid hydrogen and a method for compressing normal hydrogen to the hydrogen container, by storing the latest hydride or Organic chemical hydride method is used to carry the hydrogen station. Korea is currently 13 hydrogen stations in place and in operation, plans to install a further 43 places.

• Journal of the Geological Society of Korea
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• v.54 no.6
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• pp.641-656
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• 2018

Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite derived potential field data can be alternatively used to image three-dimensional (3D) density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3D forward density modeling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and 3D forward modeling showed that there are two modeled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about $2,000kg/m^3$, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about $250km^3$ at a depth of about 3,000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about $300km^3$ at a depth of about 2,500 m. A comparison between the TRIDENT derived gravity field and the ship-based gravity field measured in 1980s shows us that our results are highly reliable and there is a very high probability to detect another low-density layer existings in the northwestern part of the central subbasin.

• Journal of Korea Port Economic Association
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• v.25 no.2
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• pp.57-72
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• 2009

The purpose of this paper is to show the empirical measurement way of operation risk evaluation in domestic seaports for overcoming the limitations which the traditional DEA method has by using 13 Korean ports in 2003 for 4 inputs(birthing capacity, cargo handling capacity, number of coastal guard vessel, number o f coastal special guard vessel ) and 5 outputs(Export and Import Quantity, Number of Ship Calls, number of coastal accident, number of coastal crime, number of coastal pollution). Because traditional DEA method has produced the limited set of information, negative DEA mixed with tier, stratification and layering methods should be adopted. The goal of negative DEA is to set up DEA models that will place the poor operating ports on or close to the empirical frontier. The core empirical results of this paper are as follows. First, Donghae ports should benchmark the operation way of Yeasu, Busan, Woolsan ports in terms of the middle and longterm base. Second, 5 ports(ports of Taean, Yeasu, Tongyoung, Busan, Sokcho) which were revealed as the poor operating ports in Negative DEA analysis should benchmark Incheon, Woolsan, Pohan, and Donhae ports. The policy implication to the Korean seaports and planners is that Korean seaports should introduce the new methods like Negative DEA of this paper for predicting the poor operating in the ports.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.446-452
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• 2018

A traffic route is an area associated with high risk for accidents due to the flow of heavy traffic. Despite this concern, most studies related to traffic focus solely on traffic distribution. Therefore, there is a need for studies investigating the characteristics of ships' routes and traffic patterns. In this study, an investigation was carried out to analyze the traffic distribution and pattern in 3 major traffic routes for 3 days. For the purpose of the study, based on the prevailing traffic conditions, the route was divided into 10 gate lines. The ships passing through the lines were also classified into either small, medium and large. ND-K-S (normal distribution, kurtosis, and skewness) test was carried out for the traffic distribution at each gate line based on the information analyzed on each traffic route. The analysis of the results obtained from the ND test showed that large vessels have normal distribution, medium sized vessels have satisfied normal distribution in one-way route only while small sized vessels do not have normal distribution. According to the result obtained from the K-S test, normal traffic pattern shows a significant difference between two-way route and one-way route. Results obtained from the K test result shows that in the case of one-way route, vessels have a traffic pattern using a wide range on traffic route. Further analysis shows that vessels concentrate on one side of route in case of two-way route. Results obtained from the S test show that, in case of one-way route, vessels have a normal traffic pattern according to center line. However, analysis pf the results shows that vessels are shifted to the right side of route in case of two-way route. Despite these findings, it should be noted that this study was carried out in only 3 ports, therefore there is need for investigation to be carried out in various routes and conditions in future studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.412-419
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• 2019

Negative space in the discipline of art defines the space around and between the subject of an image. The use of negative space is an element of artistic composition, since it is occasionally used to artistic effect as the "real" subject of an image. In painting, it is a technique that negatively touches the background of an object to be expressed, so that it gives a feeling of unique texture and silhouette by touching unnecessary parts while leaving necessary parts. As in art, negative space in a design can also be useful to identify an image of infeasible design ranges with a straightforward view. Similarity between two disciplines leads to the introduction of the negative space concept for design space exploration. A rough design space exploration using statistics and visual analytics may support more efficient decision-making, and can provide meaningful insights into the direction of early-phase system design. For this, the approach guarantees dynamic interactions between visualized information and human cognitive systems. Visual analytics is useful to summarize complex and large-scale data. It is useful for identifying feasible design spaces, as well as for avoiding infeasible spaces or highly risky spaces. This paper investigates the possible use of the negative space concept by using an application example.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.18-29
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• 2019

ROV surveys were conducted using 500 meter mini class ROV with HD video camera, 2 LED lights, a simple manipulator and 8 thrusters near the Dokdo and Simheungtaek seamount. Total six dives have been conducted using the ROV "V8 SII" from Sweden and ROV's support ship, "KOSAL V" at 4 stations between 45 and 370 meters with diving time ranged from 30 to 120 minutes. Dense communities of sea anemone (Actinostolidae sp.) and ophiuroids (Ophiuridae sp.) on the surface of rocky bottom and snow crab on the soft bottom with muddy-sand were observed at northwestern part of Simheungtaek seamount. We obtained the following results 1) habitats information for snow crab, one of the major fisheries resources, and deep-sea fauna, 2) observation on the specific topography and sediment conditions, 3) observation of the seabed surface covered with the discarded fishing gears. This study represents the first report of in situ visual observation of deep-sea organisms and their habitats near the Dokdo slopes and flat top of the Simheungtaek seamount in the East Sea. These results indicated that immediate oceanographic survey using the mini class ROV is available in the East Sea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1098-1105
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• 2021

The International Maritime Organization has steadily strengthened environmental regulations on nitrogen oxides and carbon dioxide emitted from marine vessels. Consequently, the demand for electric propulsion vessels based on eco-friendly elements has increased. To this end, research and development has been steadily conducted for various vessels. In electric propulsion systems, a redundancy configuration is typically adopted to increase reliability and facilitate the onboard arrangement. Furthermore, studies have been actively conducted to ensure the safety of electric propulsion systems through the combination with digital twin technology. A digital twin can be used to predict outcomes in advance by implementing real-world equipment or space in a virtual world like twins, integrating real-world information and data with the virtual world, and performing computer simulations of situations that can occur in a real environment. In this study, we perform failure modes and effects analysis (FMEA) to validate the electric power management system (PMS) redundancy scheme for the digital twin technology development of electric propulsion vessels. Then, we propose the role and algorithm of PMS as a compensation function for preventing primary and secondary damages caused by a single equipment failure of the PMS and preventing additional damages by analyzing the impact on the entire system under real vessel operating conditions based on the redundancy FMEA suggested for the ship classification and certification. We verified the improvement in propulsion conservation through tests.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.127-138
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• 2023

A variety of decarbonized energy sources are being developed globally to realize carbon neutrality (Net Zero) by 2050 as a measure to address the global climate crisis. As the Korean government has also established a Renewable Energy 3020 policy and promoted energy development plans using solar or wind power, large-scale offshore development projects not present before in coastal waters, such as offshore wind farms, are being promoted. From ships' point of view, offshore facilities present obstacles to safe navigation, and with the installation of marine facilities, ship collisions or contact accidents between ships and marine facilities may occur in the narrowed water areas. In addition, there are concerns about environmental pollution and human casualties caused by marine accidents. Accordingly, we review overseas and domestic offshore wind farm development plans, analyze whether institutional devices are in place to ensure the safe passage of ships in wind farm areas, and study the safe operation of large-scale offshore wind farms and safe passage of ships along the Korean coast by comparing overseas legislative cases with domestic laws and presenting a proposal to illuminate the legal blind sectors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.78-80
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• 2021

This study is based on Degree of Recognition and AHP surveys for experts, this study investigates changes in the demand of seafarers in response to changes in the shipping industry environment in which Maritime Autonomous Surface Ships(MASS) emerge according to the application of the fourth industrial revolution technology to ships, and it looks into changes in seafarers' skills. It also analyzes and proposes a plan for cultivating seafarers accordingly. As a result of Degree of Recognition and AHP analysis, it is analyzed that a new training system is required because the current training and education system may cover the job competencies of emergency response, caution and danger navigation, general sailing, cargo handling, seaworthiness maintenance, emergency response, and ship maintenance and management, but jobs such as remote control, monitoring diagnosis, device management capability, and big data analysis require competency for unmanned and shore based control.By evaluating the importance of change factors in the duties of seafarers in Maritime Autonomous Surface Ships, this study provides information on seafarers educational institutions response strategies for nurturing seafarers and prioritization of resource allocation, etc. The importance of factors was compared and evaluated to suggest changes in the duties of seafarers and methods of nurturing seafarers according to the introduction of Maritime Autonomous Surface Ships.It is expected that this study is meaningful as it systematically derived the duties and competency factors of seafarers of Maritime Autonomous Surface Ships from a practical point of view and analyzed the perception level of each relevant expert to diagnose expert-level responses to the introduction of Maritime Autonomous Surface Ships.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.910-914
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• 2023

With the technological innovation owing to the 4th industrial revolution, the maritime transportation is rapidly being developed with autonomous ships and systems. Particularly, autonomous ships will partially replace the manned ships and navigation among them remotely upon the degree of autonomy suggested by IMO. Accordingly, the remote operator and related research have increased as well. However, the data on the minimum required manpower for remote operators are lacking such as considering engage required situations and their co-occurrence probability. Therefore, this study proposes a simulation model that calculates the number of remote engage required situations by defining restricted water area and remote engage required situation as close-quarter situations based on accumulated trajectory data of actual ships. The findings are expected to be used as background materials to establish the appropriate manpower distribution of remote operators in remote operation centers.