• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.453-460
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• 2017

In the offshore industry, helicopters are mainly used for transportation of goods or operating personnel between offshore sites and onshore facilities. A helideck is a structure that is required for landing and take-off of helicopters on the offshore structure. There are several shapes of helidecks depending on the type of offshore structures or installation location. Among them, cantilever-type helidecks usually provide more space on the topside of offshore structures and it is safer against potential accidents like fire or explosion. In this paper, the cantilever-type helideck is selected for the research object and topology design optimization is applied for lightweight design of the helideck. A finite element model is then created from the optimal layout of truss structures of the helideck, and structural analysis is performed under various landing conditions and wind loads. Based on the analysis results, the detailed section dimensions of structural members are determined so that the maximum stress at each structure member does not exceed the allowable stress of the structural material. Also, the final optimal design shows significant decrease in the total weight of the helideck.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1589-1597
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• 2021

Submarine groundwater discharge (SGD) in coastal areas is gaining importance as a major transport route that bring nutrients and trace metals into the ocean. This paper describes the analysis of the seasonal changes and spatiotemporal characteristicsthrough the modeling monthly SGD for 35 years from 1986 to 2020 for the Nakdong river basin. In this study, we extracted 210 watersheds and SGD estimation points using the SRTM (Shuttle Radar Topography Mission) DEM (Digital Elevation Model). The average annual SGD of the Nakdong River basin was estimated to be 466.7 m²/yr from the FLDAS (Famine Early Warning Systems Network Land Data Assimilation System) recharge data of 10 km which is the highest resolution global model applicable to Korea. There was no significant time-series variation of SGD in the Nakdong river basin, but the concentrated period of SGD was expanded from summer to autumn. In addition, it was confirmed that there is a large amount of SGD regardless of the season in coastal area nearby large rivers, and the trend has slightly increased since the 1980s. The characteristics are considered to be related to the change in the major precipitation period in the study area, and spatially it is due to the high baseflow-groundwater in the vicinity of large rivers. This study is a precedentstudy that presents a modeling technique to explore the characteristics of SGD in Korea, and is expected to be useful as foundational information for coastal management and evaluating the impact of SGD to the ocean.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.121-122
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• 2023

As containerized maritime transport began in earnest, the size of container ships has steadily increased, and recently, the operation of 24,000 TEU-class vessels has become regular. However, concerns about the efficiency and productivity of such mega container ships from a port operational perspective have continued to be raised. The 10^th Busan International Port Conference requested an in-depth study on the trends of container ship enlargement by analyzing the order status of ultra-large container ships from major global liners. Generally, the factor that drives the upsizing of ships is the realization of economies of scale that lowers transportation costs per TEU, which leads to a higher level of cost reduction per unit transportation compared to the increase in fuel consumption due to transporting large amounts of cargo with a single ship. However, it is necessary to examine whether this trend of container vessel enlargement is feasible for port operations. To this end, this study compares and analyzes the productivity and efficeiency of different ship sizes to evaluate the effect of ship size on port operations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.72-73
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• 2023

As containerized maritime transport began in earnest, the size of container ships has steadily increased, and recently, the operation of 24,000 TEU-class vessels has become regular. However, concerns about the efficiency and productivity of such mega container ships from a port operational perspective have continued to be raised. The 10th Busan International Port Conference requested an in-depth study on the trends of container ship enlargement by analyzing the order status of ultra-large container ships from major global liners. Generally, the factor that drives the upsizing of ships is the realization of economies of scale that lowers transportation costs per TEU, which leads to a higher level of cost reduction per unit transportation compared to the increase in fuel consumption due to transporting large amounts of cargo with a single ship. However, it is necessary to examine whether this trend of container vessel enlargement is feasible for port operations. To this end, this study compares and analyzes the productivity and efficeiency of different ship sizes to evaluate the effect of ship size on port operations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.690-698
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• 2017

Vietnam is a marine nation with more than 3,444 km of shorelines, thousands of islands, and 2,360 rivers and canals of over 42,000 km long. As the frequency and the volume of oil transportation by ships increase, the possibility of oil spill incidents becomes higher than ever. Fuel oil and cargo oil spills at sea have widespread impact and long-term consequences on marine ecosystems, coastal resources and human health as well as socio-economy. This study is to show not only the present state of marine oil spills in Vietnam such as the number and the volume of oil spills for two decades, and an overall about Vietnamese national response system like national framework for Oil Spill Response (OSR), etc. but also to present the recommendations for enhancing national capability in response to oil spill incidents in Vietnam, especially, with a comparison of national OSR systems between Vietnam and South Korea. As the result, the number and the volume of marine oil spills in Vietnam showed an upward trend as opposed to a downward trend in South Korea. This means that Vietnam has the possibility of oil spills in coastal waters. Therefore, three main recommendations for the enhancement of national OSR capability in Vietnam are proposed as follows: (1) the development of alternative plan for reenforcing national OSR system involving legal system for preparedness and response to oil spill pollution such as the acceptance and implementation of OPRC Convention as well as the establishment of national fund compensating for the damage and loss caused by oil pollution; (2) the enhancement of a consistent reporting, alerting and monitoring system; and (3) the development of training and exercise programs with standard contents of educational courses.

• Journal of Navigation and Port Research
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• v.40 no.4
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• pp.197-205
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• 2016

Our country, which relies on maritime transport a majority of import and export trade volume and faced with unexpected accidents, it is difficult to operate the normal function of container terminal. It also caused by reliability issue raised is likely to be given a blow to the new volumes to attract and maintain existing volumes. Under this views, the container terminal is a situation that highlights the role of the harbor workers and cope with aggressive work to provide the best quality services to customers 365 days. On these grounds, the heavy work burden is passed on to the harbor workers and caused accidents every year. The study was analyzed the safety status of the container terminal under the real following the conditions as disaster status analysis, insufficient safety training circumstances and safety training from 2012 year to 2015 in the target current K.Y terminal. As a result of equipments safety training analysis, it shows that 2012 year happened 45 cases and 31 cases in 2013 year until not practicing the training over the Gantry Crane equipment. One hand 23 cases took place in 2014 while preparation training and the other intensive training period of 2015, 8 cases occurred. it shows that 2012 year happened 13 cases and 19 cases in 2013 year until not practicing the training over the Transfer Crane equipment. One hand 12 cases took place in 2014 while preparation training and the other intensive training period of 2015, 8 cases occurred. it shows that 2012 year happened 9 cases and 9 cases in 2013 year until not practicing the training over the Yard Tractor equipment. One hand 9 cases took place in 2014 while preparation training and the other intensive training period of 2015, 4 cases occurred. Because safety training of the container terminal was given to greatly impact on the mandatory safety training, self-educational enforcement and specified equipments safety training, hence the container terminal is to strengthen the safety education to prevent accidents in advance.

• Korean Business Review
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• v.21 no.2
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• pp.137-170
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• 2008

This study is presenting the logistics strategy in the international logistics markets which makes competition and corporation among north-east Asian countries to establishing the multi-pass Eurasian railroads. The countries located in north-east area of Eurasia like China, Japan, Russia and Korea are paying higher costs and disutility to the transportations and communications due to repeated conflicts and confrontations causes from the politic problems. They are being used surface transportation for most of all logistics between Europe and Asia except special merchandises because of characteristic of cargo to be air, the Silk Road remains vestige only which was main logistic passage to this area since BC. So far the Trans-Siberian Railway is being used by Russia mostly as north of Eurasian transport because of difficulties of service. The Trans-China Railway built in 1992 is not accomplishing as a international logistic passages. It is expected to take a long lead time because of characteristic of resource development and poor logistic infrastructure to the countries like Uzbekistan, double landlocked country, Mongolia and Azerbaijan, the countries do not be adjacent to the sea, even they have great economic jump-up plans through the development of their own resources. The Shanghai Cooperation Organization(SCO) start to sail officially in 2001 is constructed with China, Russia, Tadzhikistan, Kyrgyzstan, Kazakhstan and Uzbekistan as regular members of 6 countries and Mongolia, India, Pakistan, Afghanistan and Iran as observers 5 countries. It is started as a military alliance to protect terror, but now, it is expended to cooperate with the traffic, transportation, trade and share of energies. The Russia is doing their best to activate TSR as a government target to developnorth area equivalently, and economic develop of far-east Siberia. And also it is agreed provisionally to improve and repair of rail road between Nahjin and Hassan to connect TSR and TKR( Trans-Korea Railroad) by Russia, North Korea and South Korea with Russian's aggressive efforts. The development plan of this area is over lapped with GTI(Greater Tumen Initiative) promoted by UNDP, and is a cooperated project by 5 countries of South Korea, Mongolia, China, Russia and North Korea, subject to review the appropriation of energy, tour, environment, rail road connection between Mongolia and China and establishing a ferry route to north-east Asia. It is Japanese situation to pay attention to Russia and China even they have been supplying large-scope of infrastructure in Mongol area without any charges, target to get East Asia Main Rail Road to connect Mongolia and Zalubino of Russia. In case of the program for the Denuclearization of North Korea is not creeping, it will be accelerated to connect the TKR and TSR, TKR and TCR by somehow attending United States, including developing program promoted by UN ESCAP. As the result, Korean peninsular will continue the central role of competition and cooperation as in the past, now and future of north-east Asia, as of geographical-economics and geographical-politics whether it is requested or not wanted by neighbor countries.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.307-319
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• 2009

Carbon dioxide capture and storage (CCS) technology has been regarded as one of the most possible and practical option to reduce the emission of carbon dioxide ($CO_2$) and consequently to mitigate the climate change. Korean government also have started a 10-year R&D project on $CO_2$ storage in sea-bed geological structure including gas field and deep saline aquifer since 2005. Various relevant researches are carried out to cover the initial survey of suitable geological structure storage site, monitoring of the stored $CO_2$ behavior, basic design of $CO_2$ transport and storage process and the risk assessment and management related to $CO_2$ leakage from engineered and geological processes. Leakage of $CO_2$ to the marine environment can change the chemistry of seawater including the pH and carbonate composition and also influence adversely on the diverse living organisms in ecosystems. Recently, IMO (International Maritime Organization) have developed the risk assessment and management framework for the $CO_2$ sequestration in sub-seabed geological structures (CS-SSGS) and considered the sequestration as a waste management option to mitigate greenhouse gas emissions. This framework for CS-SSGS aims to provide generic guidance to the Contracting Parties to the London Convention and Protocol, in order to characterize the risks to the marine environment from CS-SSGS on a site-specific basis and also to collect the necessary information to develop a management strategy to address uncertainties and any residual risks. The environmental risk assessment (ERA) plan for $CO_2$ storage work should include site selection and characterization, exposure assessment with probable leak scenario, risk assessment from direct and in-direct impact to the living organisms and risk management strategy. Domestic trial of the $CO_2$ capture and sequestration in to the marine geologic formation also should be accomplished through risk management with specified ERA approaches based on the IMO framework. The risk assessment procedure for $CO_2$ marine storage should contain the following components; 1) prediction of leakage probabilities with the reliable leakage scenarios from both engineered and geological part, 2) understanding on physio-chemical fate of $CO_2$ in marine environment especially for the candidate sites, 3) exposure assessment methods for various receptors in marine environments, 4) database production on the toxic effect of $CO_2$ to the ecologically and economically important species, and finally 5) development of surveillance procedures on the environmental changes with adequate monitoring techniques.