• Journal of the Korean Society of Mechanical Technology
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• v.13 no.1
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• pp.23-29
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• 2011

The measurement of ice properties such as thickness, strength are important to know the performance of the ice breaking vessel. The measuring equipment of ice properties and methods are summarized in this paper. The actual measured data are also described. The strength of ice at Svalbard area on April 2010 is much stronger than the Chukchi Sea on August 2010. The mean strength of Svalbard is about 500 kPa and one of Chukchi Sea is 250 kPa. The first sea trial in Arctic sea using Araon was carried out in the Chukchi Sea. The power and speed was also measured to check the ship performance in ice. The speed was measured from GPS(Global Positioning System) and engine power was recorded from DPS(Dynamic Positioning system) of Araon. The design target of Araon in level ice is 3 knots in 1m thickness and 630 kPa flexible strength but mean speed in Chuckchi sea is 3.98 knots when 6.6 MW engine power, 2.4m ice thickness and 250 kPa strength. This results comes from the difference of ice types and the weak flexible strength of ice but it will be a good information to know the performance of Araon in similar ice condition.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.6
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• pp.553-561
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• 2009

This paper presents the results of prediction of maneuverability of KCS by CPMC captive model test. The CPMC(Computerized Planar Motion Carriage) with captive model test equipment is installed at Ocean Engineering Tank of MOERI. KCS is the container ship which was open to the world by MOERI. And the test results for the prediction of maneuverability were presented by NMRI in Japan. The research results about the maneuverability of KCS were presented at SIMMAN 2008 Workshop in Denmark. The results of test and simulation of this paper are compared with the results of simulation by MOERI using test results of NMRI and simulation results by NMRI.

• Journal of Navigation and Port Research
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• v.43 no.5
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• pp.296-301
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• 2019

The Electronic Chart Display and Information System (ECDIS) is an integral component of ship navigation equipment, that enables mariners to view Electronic Navigational Charts (ENC). Recently, it has become possible to transport freight and energy resources via the Northern Sea Routes (NSR) as global warming has been accelerating. However, ice can impact all types of ships and the potential danger that ice poses is significant. Until now, ice, consistently proven to be one of the most dangerous threats impacting navigation in ice-covered regions, has its detailed standard in the specification of the International Hydrographic Organization (IHO) for ECDIS. The investigations described in this paper were conducted to assess the advantages and problems of the display of ice objects on ECDIS. The experiments were conducted by using the Geographic Information System (GIS) to perform ice objects with their corresponding colors and symbols. Implementation of the standardized appearance of ice objects can enable mariners to access the ice condition of seas in a short time before navigating a safe passage through potentially treacherous waters. However, remain issues that must be overcome for data on ice to be fully compatible with an ECDIS system.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.509-516
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• 2022

Recently, ships have begun using the Asterix CAT 240 format as a method for transmitting radar image data to other devices. However, the Asterix format has a flexible structure that can be defined by the user, and a format structure defined as unsuitable for ship radar operation may undesirably increase navigational equipment network traffic or reduce stability. Therefore, to reduce the traffic of the navigation network and enhance the stability, a method of defining the optimized Asterix CAT 240 format with an appropriate setting value according to the performance of the radar scanner and display device was studied.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.191-202
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• 1997

As the suitability of berth allocation will ultimately have a significant influence on the performance of a berth, a great deal of attention should be given to berth allocation. Generally, a berth allocation problem has conflicting factors between servers and users. In addition, there is uncertainty in great extent caused by various factors such as departure delay, inclement weather on route, poor handling equipment, a lack of storage space, and other factors contribute to the uncertainty of arrival and berthing time. Thus, it is necessary to establish berth allocation planning which reflects the positions of interested parties and the ambiguity of parameters. For this, a berth allocation problem is formulated by fuzzy 0-1 integer programming introducing the concept of maximum Position Shift(MPS). But, the above approach has limitations in terms of computational time and computer memory when the size of problem is increased. It also has limitations with respect to the integration of other sub-systems such as ship planning system and yard planning system. For solving such problem, this paper focuses particularly on developing an efficient heuristic algorithm as a new technique of getting an effective solution. And also the suggested algorithm is verified through the illustrative examples and empirical appalicaton to BCTOC.

• Journal of the Korea Safety Management & Science
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• v.25 no.1
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• pp.23-29
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• 2023

Among the Additive Manufacturing (AM) technologies, the Binder-Jetting printing technology is a method of spraying an adhesive on the surface of powder and laminate layer by layer. Recently, this technique has become a major issue in the production of large casting products such as ship-building, custom vehicles and so on. In this study, we performed research to make actual mold castings and increase mechanical property by using special sand and water-based binders. For use as a mold, it has a strength of more than 3MPa and permeability. Various experiments were carried out to obtain suitable them. The major process parameters were binder jetting volume, binder types, layer thickness and heat treatment condition. As a result of this study, the binder drop quantity was measured to be about 60 pico-liter, layer thickness was 100㎛ and the heat treatment condition was measured about 1,000℃ and compressive strength were measured to be more than 5MPa. The optimum condition of this experiment was established through actual casting of aluminum. The equipment used in this study was a Freeforms T400 model (SFS Co., Ltd.), and the printing area of 420 * 300 * 250mm and resolution of 600dpi can be realized.

• Journal of Navigation and Port Research
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• v.48 no.2
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• pp.125-136
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• 2024

This research presents an innovative integrated ethanol solid oxide fuel cell (SOFC) system designed for applications in marine vessels. The system incorporates an exhaust gas heat recovery mechanism. The high-temperature exhaust gas produced by the SOFC is efficiently recovered through a sequential process involving a gas turbine (GT), a regenerative system, steam Rankine cycles, and a waste heat boiler (WHB). A comprehensive thermodynamic analysis of this integrated SOFC-GT-SRC-WHB system was performed. A simulation of this proposed system was conducted using Aspen Hysys V12.1, and a genetic algorithm was employed to optimize the system parameters. Thermodynamic equations based on the first and second laws of thermodynamics were utilized to assess the system's performance. Additionally, the exergy destruction within the crucial system components was examined. The system is projected to achieve an energy efficiency of 58.44% and an exergy efficiency of 29.43%. Notably, the integrated high-temperature exhaust gas recovery systems contribute significantly, generating 1129.1 kW, which accounts for 22.9% of the total power generated. Furthermore, the waste heat boiler was designed to produce 900.8 kg/h of superheated vapor at 170 ℃ and 405 kP a, serving various onboard ship purposes, such as heating fuel oil and accommodations for seafarers and equipment.

• Journal of Navigation and Port Research
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• v.33 no.3
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• pp.199-206
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• 2009

Since Emma Maersk, which is a container vessel capable of holding a freight capacity of 11,000 TEU, was launched early last year, the appearance of the ULCS (Ultra Large Container Ship) will be expected in 5 years. That requires the high productivity, the high technology, the automation, and the high efficiency in port operations. GTO (Global Terminal Operator) and port equipment companies are striving for the prior occupation of the port market and the development of the port technology. Within the country, however, there has been few systematic, analytic, and detailed technology road map, and the effective execution of the development policy for the port technology and the activation of port industries has not been achieved. In this study, we deduces the development subject of the domestic port technology and analyzes the priority of them. In conclusion, we establishes the macro technology road map and the product-related road map for container ports in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.678-684
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• 2016

The detection of an underwater work space boundary is very important when an underwater construction is carried out using seabed type underwater equipment, such as underwater machines for rubble mound leveling, because it can induce industrial disasters. Therefore, divers are needed to mark the underwater work space boundary. A nylon rope is used to improve the convenience during an underwater diver's work. The results showed that the work space boundary can be detected using a sonar system. Using these results, an efficient method to detect the underwater work space boundary can be obtained when an underwater construction is carried out using seabed type underwater equipment.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.367-374
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• 2022

The purpose of this study was to propose a deep learning algorithm that applies to the fault diagnosis of fuel pumps and purifiers of autonomous ships. A deep learning algorithm reflecting the time dependence of the measured signal was configured, and the failure pattern was trained using the vibration signal, measured in the equipment's regular operation and failure state. Considering the sequential time-dependence of deterioration implied in the vibration signal, this study adopts Conv1D with sliding window computation for fault detection. The time dependence was also reflected, by transferring the measured signal from two-dimensional to three-dimensional. Additionally, the optimal values of the hyper-parameters of the Conv1D model were determined, using the grid search technique. Finally, the results show that the proposed data preprocessing method as well as the Conv1D model, can reflect the sequential dependency between the fault and its effect on the measured signal, and appropriately perform anomaly as well as failure detection, of the equipment chosen for application.