• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.922-930
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• 2020

Marine accidents involving fishing boats, caused by a loss of stability, have been increasing over the last decade. One of the main reasons for these accidents is a sudden wind attacks. In this regard, the wind loads acting on the ship hull need to be estimated accurately for safety assessments of the motion and maneuverability of the ship. Therefore, this study aims to develop a computational model for the inlet boundary condition and to numerically estimate the wind load acting on a fishing boat. In particular, wind loads acting on a fishing boat at the wind speed profile boundary condition were compared with the numerical results obtained under uniform wind speed. The wind loads were estimated at intervals of 15° over the range of 0° to 180°, and i.e., a total of 13 cases. Furthermore, a numerical mesh model was developed based on the results of the mesh dependency test. The numerical analysis was performed using the RANS-based commercial solver STAR-CCM+ (ver. 13.06) with the k-ω turbulent model in the steady state. The wind loads for surge, sway, and heave motions were reduced by 39.5 %, 41.6 %, and 46.1 % and roll, pitch, and yaw motions were 48.2 %, 50.6 %, and 36.5 %, respectively, as compared with the values under uniform wind speed. It was confirmed that the developed inlet boundary condition describing the wind speed gradient with respect to height features higher accuracy than the boundary condition of uniform wind speed. The insights obtained in this study can be useful for the development of a numerical computation method for ships.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.1-6
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• 2011

The underlying principle of environmental conservation and restoration is to receive continuous services from nature. In this context, the basic objective of oil spill response and recovery activities is to allow affected residents to retain sustainability of their daily livelihood and productive environment. Hence, monitoring the status of socio-economic impact and the extent of restoration is an important parameter in the restoration effort to repair the damaged functions of environmental services with oil spill accident. However, assessment of socio-economic impact poses investigators with much difficulties in selecting the most appropriate approaches because the process often involves various stakeholders, directly and indirectly. Moreover, the analyses and interpretation of the results also pose a great challenge. The present study monitored fisheries and tourism numbers which were considered as major local socio-economic indicators of living and production environment affected by M/T Hebei Spirit oil-spill accident. This monitoring was conducted by examining the published papers and statistical reports. This was supplemented by surveying how the local residents actually felt about the damage and recovery for the first time in Korea. The results showed that the rate of the recovery was about 40~50 %, and the rate of the recovery seemed to be slowed or decreased. However, what the local residents actually felt was 2~10 points less than the literature surveys and statistical reports. These results suggested limits to using only the literature and statistical surveys for the traditional socio-economic impact assessment. The study also showed the need to include in the impact assessment process what and how the local residents actual feel about the oil spill damage and recovery process.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.542-548
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• 2022

In order to reduce marine accidents, each contracting Government needs to implement the instruments enacted and amended by the International Maritime Organization (IMO). The III Code requires each administration of the government to have a system for improvement through periodic review and evaluation and to include performance indicators in its evaluation methods. Thus, each IMO Member State needs to develop its own performance indicators. The purpose of this paper is to develop and present an evaluation model using the Balanced Scorecard (BSC) and Key Performance Indicators (KPI) in order to quantify and evaluate the level of implementation of the instruments by the administrations. From the perspective of 'III-BSC', which applies the BSC concept to the III code requirements, the Critical Success Factors (CSF) that must be secured to achieve the established vision were drawn up, and candidate KPIs for each evaluation area were developed to measure the derived key success factors and an initial study model was designed composed of four levels. The validity of the KPIs was verified and the study model was finalized using the survey design using the SMART technique. Furthermore, based on the developed study model, an evaluation model for the implementation of the BSC-based IMO instruments was developed by deriving the weights of elements for each level through AHP analysis. The developed evaluation model is expected to contribute toward improving the administrations' level of implementation of the IMO instruments as a tool for quantitatively grasping the level of performance of the implementation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.551-560
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• 2020

Recently, the offshore wind power generator market is expected to grow significantly because of increased energy demand, reduced dependence on fossil fuel-based power generation, and environmental regulations. Consequently, wind power generation is increasing worldwide, and several attempts have been made to utilize offshore wind power. Norway's Petroleum Safety Authority (PSA) requires a leg-structure design with a collision energy of 35 MJ owing to the event of a collision under operation conditions. In this study, the results of the numerical analysis of a wind turbine installation vessel subjected to ship collision were set such that the maximum collision energy that the leg could sustain was calculated and compared with the PSA requirements. The current leg design plan does not satisfy the required value of 35 MJ, and it is necessary to increase the section modulus by more than 200 % to satisfy the regulations, which is unfeasible in realistic leg design. Therefore, a collision energy standard based on a reasonable collision scenario should be established.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.395-402
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• 2019

The development and operation of the MASS (Maritime Autonomous Surface Ship) is being actively discussed for more efficient and safer maritime transportation solutions. The autonomous navigation technology has positive aspects such as the prevention of marine accidents, improvement of fuel efficiency of ships and cost reduction, and negative aspects such as job loss, task change, and security problems. It is expected that there will be new human element issues such as the situation awareness of remote operators, because the shore-based control will be conducted when fully autonomous ships are in operation. In this paper, we consider major human element issues that should be factored in the development and operation of MASS, and suggest a method of HRA (Human Reliability Analysis) for P IFs (Performance Influencing Factors) of the remote operators that are expected according to the shore-based control.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.161-162
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• 2020

Major advanced ports around the world are preparing for environmental regulations such as increased efficiency of ports and low emission of pollutants in ports by utilizing fourth industrial technologies and ICT technologies such as AI, big data, self-driving cars and connected cars. It is also investing in developing fully unmanned terminals to solve the problem of workforce reduction caused by avoidance of 3D industries. However, the introduction of advanced technology is being delayed in domestic ports, which has led to a drop in port efficiency. In addition, port safety accidents have also occurred frequently, seriously affecting port marketing. Thus, the characteristics and types of each container terminal in Korea were analyzed and the factors for introducing autonomous cooperative driving were classified into five section factors and 15 division factors. Hierarchically classified factors will be surveyed on workers working in shipping lines, port construction, container terminals and related ministries.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.1-17
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• 2018

Related incidents and accidents are frequent after 2000 years, such as the outbreak of the Taian peninsula crude oil spillage and Gumi hydrofluoric acid leakage accident. In the wake of such environmental pollution accidents, Consensus has been formed to enact legislation on liability for the compensation of environmental pollution in 2014 and the rescue, and has been in force since January 2016. Therefore, in the domestic insurance industry, the introduced environmental liability insurance system needs to be managed through the standardization formula of a new insurance model for managing the environmental risk. This study has been carried out by the emergence of a safe insurance model with a risky nature of the risk type, which is one of the services of the knowledge base. The verification of the six assurance media on the occurrence of environmental pollution such as chemical, waste, marine, soil, etc. is expressed through semantic interoperability through this possible ontology. The insurance model was designed and presented by deducing the relationship between the amount of money and the amount of money that was written in the area of existing expertise, In order to exclude the possible consequences, the concept of abstract is conceptualized in the form of a customer, and a plan for the future development of an ontology-based decision support system is proposed to reduce the cost and resources consumed every year. It is expected that standardization of the verification standard of the mass of mass will minimize errors and reduce the time and resources required for verification.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.423-434
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• 1995

It was used boundary element method(BEM) and analysed axisymmetric problem to solve hydraulic cylinder for large vessel acting uniform internal pressure(25N/m super(2)) within elastic limit. This paper was utilized the carbon steel tubes for machine structural purposed model, inner radius was 150mm and outer radius was 250mm, axial length was semi-infinite and the isoparametric element was used. The important results obtained in this study were summarized as follows. Radial, tangential and shearing stress occured the maximum stresses(48, -20 and 34MPa) at the inner radius and the minimum stresses(32, -4 and 18MPa) at the outer radius of the hydraulic cylinder for large vessel. But negative signs have meaning compressive stress and stress diminution ratio was about 0.15MPa/mm. The use of isoparametric element raised accuracy and the increment of input data lessened the error in internal point but computer run-time was increased. The double node was improved the internal solutions to settle discontinuity at corner and the double exponential formula lessened error of stress value at boundary neighborhood. And then coincidence between the analytical and exact results is found to be fairly good, showing that the proposed analytical by BEM is reliable.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.629-635
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• 2007

Reduced crew performance is frequently cited as a major causal factor in maritime accident causation. Although considerable research has been conducted on the hours of work undertaken by seafarers through interviews and the analysis of records, experimental studies to observe the effects of factors such as high workload, shift patterns, stress, sleep deprivation and disturbance on the cognitive performance of mariners have been limited. Other safety-critical transport industries, such as aviation and rail, have developed fatigue management tools to help manage the work patterns of their operators. Such a tool for mariners would assist shipboard crew, marine pilots and shore management in planning and improving work schedules. The overall aim of this paper is to determine a fatigue factor, which can be applied to human performance data, as part of a software program that calculates total cognitive performance. This program enables us to establish the levels of cognitive performance of a group of marine pilots to test a decision-making task based on radar information. This paper addresses one of the factors that may contribute to the determination of various fatigue factors: the effect of different work patterns on the cognitive performance of a marine pilot.

• Journal of Navigation and Port Research
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• v.37 no.4
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• pp.401-407
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• 2013

In parallel with the development of ship equipment, bridge systems have been improved, but marine accidents due to human error have not been reduced. Recently, research in nautical bridge equipment has focused on suitable ergonomic designs in order to reduce these errors due to human factors. In a bridge of a ship, there are numerous auditory signals that deliver important information clearly to the sailors. However, only a few studies have been conducted related to the human recognition of these auditory signals. There are three types of auditory signals: voice alarms, abstract sounds, and auditory icons. This study was conducted in order to design more appropriate auditory icons using a sensibility evaluation method. The auditory icons were rated to have five warning situations (engine failure, fire, steering failure, low power, and collision) using the Semantic Differential Method. It is expected that the results of this study will be used as basic data for auditory displays inside bridges and for integrated bridge alarm systems.