• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.767-776
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• 2020

Due to the recent climate change caused by global warming, weather changes in a different pattern from the past have occurred, and the increase in seawater temperature has led to an increase in the size and intensity of typhoons. Accordingly, there is an increasing need for bitts that can be used to secure mooring safety of the ship when a sudden gust occurs. Based on 12 scenarios of a mooring safety evaluation program, this study analyzed the criteria for arranging bollard and bitt, and analyzed the sensitivity of mooring safety when using storm bitts. As a result of the evaluation, it was analyzed that the mooring factor value decreased compared to the general mooring line arrangement when the fore and stern breastline were added to the bitts for gusts. The results of this study can be used as basic data for proposing storm bitts arrangements for gusts in consideration of the characteristics of berth ships and ports. From the perspective of ship operators, storm bitts at the pier will be an effective method for securing the ship's mooring safety in case of a gust of wind.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.3
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• pp.159-165
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• 1997

This paper presents the optimum dimension of 89 ton class stow-net vessel with stern-fishing. The model of basic design is developed by using the optimization techniques referring to objective function and numerous constraints as follows; speed, fishing quantity, fishing days, catch per unit effort(CPUE), and weight/ratio of main dimensions, etc. Thus, the basic design of stow-net fishing vessel is built up by using the optimization of the design variables called the economic optimization criteria, and the objective function represents the criterion which is cost benefit ratio(CBR). The main conclusions are as follows. 1. S/W for decision of optimum hull size is developed in 89 ton class stow-net fishing vessel which is constructed with optimization of the design variables called the economic optimization criteria. 2. For optimum ship dimensions in 89 ton class stow-net fishing vessel, the hull dimensions can be obtained in the range of L= 27.3m, B = 6.6m, D = 2.80m, Cb = 0.695, T/D = 0.80, $\Delta$(displacement)=281.7ton with 10 knots.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.225-231
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• 2013

Liquefied gas carriers generally transport cargoes of flammable or toxic nature. Since these cargoes may cause an explosion, fire or human casualty, the accommodation spaces, service spaces and control stations of liquefied gas carriers should be so located as to avoid ingress of gas. For this reason, the paragraph 8.2.9 of IGC Code in IMO requires that the height of vent exits should be not less than B/3 or 6 m whichever is greater, above the weather deck and 6 m above the working area and the fore and aft gangway to prevent any concentration of cargo vapor or gas at such spaces. Besides as known, the LNG market has been growing continually, which has led to LNG carriers becoming larger in size. Under this trend, the height of a vent will have to be raised considerably since the height of a vent pipe is generally decided by a breadth of a corresponding vessel. Accordingly, we have initiated an examination to find an alternative method which can be used to determine the safe height of vent masts, instead of the current rule requirement. This paper describes the dispersion characteristics of boil-off gas spouted from a vent mast under cargo tank cool-down conditions in the membrane type LNG carriers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.417-422
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• 2016

Aids to Navigation (AtoN) are marine traffic facilities to improve the safety and efficiency of shipping. "New Dangers" should be appropriately marked using lateral, cardinal or isolated danger marks or by using an Emergency Wreck Marking Buoy. However, Emergency Wreck Marking Buoys are difficult to implement in terms of speed and accuracy of installation. In the case of sinking accidents, it is often difficult to immediately install an Emergency Wreck Marking Buoy because of weather conditions, the marine environment or accident positioning. This study concerns Auto-Releasing Emergency Wreck Marking Buoys, which should be installed in all vessel for safe marine navigation and efficient maritime transport with reference to the Maritime Buoyage System (MBS). Auto-Releasing Emergency Wreck Marking Buoys include an auto-release unit, auto reel chain and auto lighting lantern. These buoys can be automatically released from the deck of a vessel and will float in the water for quick installation at the scene of an accident, even in the case of sinking accidents. Auto-Releasing New Mark Buoys are expected to reduce to installation process, prevent secondary accidents by the risk of navigation and be search and rescue rapidly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1310-1316
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• 2014

The IMO has recommended on VHF digital communications operation for sailing ships from 2017. And ships more than 5 tons is obliged to digital communications by fishing Vessels Act and Vessel Safety Act in domestic. The owner of all vessel is equipped to the automatic position reporting device in accordance with the Notice of the Ministry of Oceans and Fisheries to regulations, It shall be ensure to navigations safety and in order to respond quickly in the event of maritime accidents on all vessels. The info-communications station of fishery is operating the automatic position reporting system using the VHF DSC in east sea from 2012, Continuously, which is underway the install plan in south sea and yellow sea. But this plan is very difficult, because of propagation environment is poor on account of complicated coastline and many islands. This paper has analyzed the propagation coverage for position setting of coast station in south sea and the traffic zone set up by compare with RSSI and methode of navigation tracking by VMS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2331-2338
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• 2014

The HEMP threat may have acquired new, and urgent, relevance as the proliferation of nuclear weapons and missile technology accelerates of the North Korea, for example, is assessed as already having developed few atomic weapons, and is on the verge of North Korea already has missiles capable of delivering a nuclear warhead against South Korea. ITU K.78, K81 and IEC recommended its counter-measuring for the industrial facilities with navigation and sailing facilities in order to obviate the all of processor equipped system malfunctions from the EMP/HEMP but its simulation must only be done by the computer simulation which had studied on the 1960-1990 years USA/AFWL papers. This result has a significant activities to the South Korea being under the North Korea threat because all of HEMP related products was strongly limited for export. The HEMP cord which was developed newly by the KTI including the HEMP generation & propagation analysis, optimal shelter design tool, essential EM energy attenuation in multi-layered various soils and rocks and HEMP filter design tool. Especially, the least square fitting method was adopted to analysis for the EM energy attenuation in the soils and rocks because it has a various characteristics based on the many times field test reports.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1577-1588
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• 2018

Recently, many researches are progressing to support the operation and maintenance works of vessels using analyzed result based on various information of equipment. The interfaces of communication equipment are standardized very well, but the interfaces of machinery and other parts are not standardized yet. For that reason, there has limitations for data exchange and management. To solve the problem, the ISO is establishing new standards which are ISO 19847 for shipboard data servers th share field data at sea and ISO 19848 for standard data for shipboard machinery and equipment. In this paper, we developed a data management platform for shipboard machinery equipment, and tested the field data exchanging using the developed platform based on the standards. To do this, we analyzed the requirements of the standards and related researches, and designed an architecture of shipboard data platform that satisfied the requirements. Also, we developed components of the designed platform architecture and verified the effectiveness for it.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1059-1066
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• 2021

In Korea, the importance of marine activities is great, and automatic weather observation facilities are operating on land to investigate abnormal weather phenomena caused by industrialization; however, the number of facilities at sea is insufficient. Marine survey ships are operated to establish marine safety information, but there are many places where marine survey ships are difficult to access and operating costs are high. Therefore, a small, unmanned vessel capable of marine surveys must be developed. The sail has a significant impact on the sailing performance, so much research has been conducted. In this study, the camber effect, which is a design variable of the twin curvy sail known to have higher aerodynamic performance than existing airfoil shapes, was investigated. Flow analysis results for five cases with different camber sizes show that the lift coefficient is highest when the camber size is 9%. Curvy twin sails had the highest lift coefficient at an angle of attack of 23° because of the interaction of the port and starboard sails. The port sail had the highest lift coef icient at an angle of attack of 20°, and the starboard sail had the lowest lift coef icient at an angle of attack of 15°. In addition, the curvy twin sail had a higher lift coefficient than NACA 0018 at all angles of attack.