• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.525-533
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• 2017

Objective: The aim of this study is to investigate maritime officers' strategies to avoid the ship collision in crossing situations. Background: In a situation where there is a risk of collision between two ships, maritime officers can change the direction and speed of the own-ship to avoid the collision. They have four options to select; adjusting the speed only, the direction only, both the speed and direction at the same time and no action. Research questions were whether the strategy they are using differs according to the shipboard experience of maritime officers and the representation method of ARPA (automatic radar plotting aid) - radar graphic information. Method: Participants were 12. Six of them had more than 3 years of onboard experience, while the others were 4th grade students at Korea Maritime and Ocean University. For each participant, 32 ship encounter situations were provided with ARPA-radar information. 16 situations were presented by the north-up display and 16 situations were presented by the track-up display. Participants were asked to decide how to move the own-ship to avoid the ship collision for each case. Results: Most participants attempted to avoid the collision by adjusting the direction of the ship, representing an average of 22.4 times in 32 judgment trials (about 70%). Participants who did not have experience on board were more likely to control speed and direction at the same time than participants with onboard experience. Participants with onboard experience were more likely to control the direction of the ship only. On the other hand, although the same ARPA Information was provided to the participants, the participants in many cases made different judgments depending on the method of information representation; track-up display and north-up display. It was only 25% that the participants made the same judgment under the same collision situations. Participants with onboard experience did make the same judgment more than participants with no onboard experience. Conclusion: In marine collision situations, maritime officers tend to avoid collisions by adjusting only the direction of their ships, and this tendency is more pronounced among maritime officers with onboard experience. The effect of the method of information representation on their judgment was not significant. Application: The results of this research might help to train maritime officers for safe navigation and to design a collision avoidance support system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1822-1829
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• 2016

DGPS Reference station is established in Korea for improvement of GPS navigation accuracy and needs of integrity. Recently, DGPS stations provide user positioning information on land as well as ocean. However, this paper investigated visibility and interference environment for performance degradation of Chung-ju DGPS reference station. In case of Young-do reference station, visibility and interference environment were satisfied with reference standard. In case of Chung-ju reference station, visibility was satisfied with 7 degree elevation angle. However, interference environment was not satisfied with reference standard of -50dBm. This paper proposed time differential measurement analysis method excluding error of signal noise for analyzing measurement error. Chung-ju reference station measurement analysis result is three times the error than on Young-do in Dec, 2015. In addition, this paper has confirmed measurement performance degradations because of reference station equipment problem. Future study will be carried out performance analysis of 17 DGPS reference station.

• Strategy21
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• s.31
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• pp.142-163
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• 2013

Ieodo is a submerged rock within a Korea's Exclusive Economic Zone(EEZ) in the East China Sea with its most shallow part about 4.6m below the sea level which has no specific rights for the EEZ delimitation. The United Nations Convention on the Law of the Sea (UNCLOS) stipulates that any coastal state has the rights to claim an EEZ that stretches up to 200 nautical miles from its shore, except where there is an overlap with a neighboring country's claims. Korea claims that Ieodo is within its EEZ as it sits on the Korean side of the equidistant line and the reef is located on the Korea section of the continental shelf. China does not recognize Korea's application of the equidistance principle and insists that Ieodo lies on its continental shelf. According to UNCLOS, Ieodo is located in international waters, rather than one country's EEZ as the two countries have failed to reach a final agreement over the delimitation of the maritime border. This study seeks to understand the evolution of the People's Liberation Army Navy(PLAN) strategy as main obstacles for the EEZ delimitation between Korea and China. PLAN's Strategy evolves from "coastal defense" to "offshore defence", since the late 1980s from a "coastal defence" strategy to an "offshore defence" strategy which would extend the perimeter of defence to between 200 nm and 400 nm from the coast. China's economic power has increased It's dependence on open trade routes for energy supplies and for its own imports and exports. China want secure Sea Lane. PLAN's "offshore defence" strategy combines the concept of active defence with the deployment of its military forces beyond its borders. China's navy try to forward base its units and to achieve an ocean going capability. China's navy expects to have a 'Blue Water' capability by 2050. China insists that coastal states do have a right under UNCLOS to regulate the activities of foreign military forces in their EEZs. China protests several times against US military forces operating within It's EEZ. The U.S. position is that EEZs should be consistent with customary international law of the sea, as reflected in UNCLOS. U.S. has a national interest in the preservation of freedom of navigation as recognized in customary international law of the sea and reflected in UNCLOS. U.S. insists that coastal states under UNCLOS do not have the right to regulate foreign military activities in their EEZs. To be consistent with its demand that the U.S. cease performing military operations in china's EEZ, China would not be able to undertake any military operations in the waters of South Korea's EEZ. As such, to preserve its own security interests, China prefers a status quo policy and used strategic ambiguity on the Ieodo issue. PLAN's strategy of coastal defence has been transformed into offensive defence, Korea's EEZ can be a serious limitation to PLAN's operational plan of activities. Considering China'a view of EEZs, China do not want make EEZ delimitation agreement between Korea and China. China argues that the overlapping areas between EEZs should be handled through negotiations and neither side can take unilateral actions before an agreement is reached. China would prefer Ieodo sea zone as a international waters, rather than one country's EEZ.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.43-55
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• 2018

The biggest change in the field of coastal ship safety control since the accident of passenger ship Sewol has been the introduction of the maritime safety supervisor system. With its introduction, the safety control system in coastal passenger ships was changed from consisting of operation managers and marine police to operation managers and a newly-introduced maritime safety supervisor. The safety control system for coastal cargo ships was also converted from relying on ship inspection officers to having a maritime safety supervisor and ship inspection officers. However some negative elements have surfaced due to confusion related to the scope of work in the coastal cargo shipping field. These have been caused by dividing the supervisory agency, a lack of work continuity given non-permanent public official status, low supervisor qualifications overlooking reality, and limitations of the order for improvement to secure seaworthiness. It is essential that the maritime safety supervisor system be solidified to reinforce coastal ship safety control. Therefore, systematic safety control in the coastal cargo shipping industry should be conducted by a single, integrated government agency, and the area covered by the order for improvement to secure seaworthiness should be extended. Also limitations of the supervisor recruitment system due to non-permanent public official status should be simultaneously improved. In addition, it is necessary to upgrade supervisor qualifications to require experience with surveyors of international class, ship captains, and chief engineers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.309-316
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• 2020

Waterway design should prioritize appropriate channel width to ensure preferential safe passage for the arrival and departure of vessels. To calculate the minimum channel width required for safe passage a comprehensive review of several factors is required. These factors include vessel maneuverability, determined by vessel size, type and speed; environmental factors such as wind, tide, and wave action; human factors, including personal experience and operator judgment as well as marine traffic and navigation support facilities for decision making. However, the Korean channel width design standard is based only on vessel length, and requires improvement when compared with the standards of PIANC, USA, and Japan. This study aims to estimate the appropriate channel width required for one-way traffic in a straight channel, considering various vessel and environmental factors, using Fast Time Simulation (FTS). When the wind speed is 25 knots, with a current speed of 2 knots and a normal vessel speed of 10 knots FTS shows that a 150K GT Cruise Ship requires a minimum channel width of 0.67-0.91 the vessel length (L), whereas a 120K TEU Container Ship and a 300K DWT VLCC require 0.79-1.17 and 1.02-1.59, respectively. Such results can be used to calculate the minimum channel width required for safe passage as an improved Korean design standard.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.169-174
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• 2007

A huge marine accident causes a loss of valuable lives, property and the serious environmental contamination. In the IMO, active discussions about a potential occurrence possibility of marine accidents and appropriate place(place of refuge) to minimize the damage are being developed as appropriate transferring vessels which has a worry of a secondary marine environmental pollution from a previous marine accident Our country has a great potential et marine accidents due to the foreign vessel in distress because there is a huge vessel traffic amounts of the passage since which locate with in the important navigation connects the Asian region. and North America centering around north Pacific Ocean Also, we need the minimize the secondary damage from accident which occurs in domestic ports as transferring safe쇼 place when it is needed In this paper, analyzed and investigated a designated the place of refuge that analyze foreign cases, and will make a efficient and reasonable investigating plan of interior place of refuge.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.818-824
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• 2018

CFRP is often used as lightweight hull material for luxury yachts or special-service ships. An electric propulsion system is also eco-friendly, and has been trialled to equip a small vessel as its main propulsion. In this study, replacing the hull materials and propulsion system with CFRP and electric motors, we made an estimate of the effect of weight reduction and compared it to the original design, for this purpose a case study was conducted on a 45-ft yacht. When redesigning structures with CFRP, we applied the reinforcement content of the carbon fiber in the same way as the original (GC = 0.4), and when changing to the electric propulsion system, we designed motors and battery packs to achieve the same performance as the original. The result showed that CFRP and the electric propulsion system could make the structural and machinery weights 45 % and 58 % lighter, respectively. However, in terms of efficiency, it was confirmed that the electric propulsion system is practically inefficient because it requires a huge amount of battery packs for the same navigation range with diesel engines.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.637-645
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• 2018

This study analyzes the problem of lack of anchorage caused by some anchorage closed and suggests ways to improve Masan anchorage. For this, we established the evaluation criteria, and analysed the anchorage operating rate during 5 years after estimating the capacity of barge, and suggested improvement plan after appropriateness assessment of anchorage capacity, finally verified the anchorage improvement plan. As a result of study, it is analyzed that the Masan A-2, A-4, A-6 anchorage needs to expand the anchorage due to excess the anchorage assessment criteria of 60 %. So, in order to improve the Masan anchorage, we suggested the improvement plan that extended 1.8 times by the group designated anchorage, according to integrating the A-2, A-4, A-6 anchorage and anchorage dwell time and ship type. And, the result of verification improvement plan, it is analyzed that meet the assessment criteria since decreasing the anchorage operating rate by 1/2 compared to the existing one, does not act as a risk factor in terms of maritime traffic.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.393-406
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• 2018

Every year in the ocean, various accidents occur frequently and illegal fishing is rampant. Moreover, their size and frequency are also increasing. In order to reduce losses of life or property caused by these, it is necessary to have a means to perform remote monitoring quickly. As an effective platform of such monitoring means, an Unmanned Aerial Vehicle (UAV) is receiving the spotlight. In these situations where marine accidents or illegal fishing occur, main targets of monitoring are ships. In this study, we propose a UAV based ship monitoring system and suggest a method of determining ship positions using UAV multi-sensory data. In the proposed method, firstly, the position and attitude of individual images are determined by using the pre-performed system calibration results and GPS/INS data obtained at the time when images were acquired. In addition, after the ship being detected automatically or semi-automatically from the individual images, the absolute coordinates of the detected ships are determined. The proposed method was applied to actual data measured at 200 m, 350 m, and 500 m altitude, the ship position can be determined with accuracy of 4.068 m, 8.916 m, and 13.734 m, respectively. According to the minimum standard of a hydrographical survey, the ship positioning results of 200 m and 350 m data satisfy grade S and the results of 500 m data do grade 1a, where the accuracy is required for positioning the coastline and topography less significant to navigation order. Therefore, it is expected that the proposed method can be effectively used for various purposes of marine monitoring or surveying.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.42-48
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• 2014

Seasickness not only makes persons on board vessels to vomit but also causes vertigo, headache, sleepiness, fatigue, lethargy and other discomforts. This ailment leads to disturbance of biorhythm and decline of perception which would eventually cause reduction of situational awareness among ship's operators that leads to marine accident. This study is about the sensitivity of people onboard ships to seasickness and focused on deck or navigation officer cadets(apprentice officers) and engine officer cadets(apprentice engineers) who have no previous experiences on board. It is conducted by using motion sensor that can measure ship's X, Y, Z-axis motions and through the questionnaire survey, and evaluated each students' degree of seasickness symptoms. Through this study, in same circumstance, we have known that there are different degrees of motion sickness for wheel house worker and engine room worker, It also confirmed that seasickness have high relationship with degree of hull motion and also, with cycle of hull motion. In addition, we have confirmed that Z-axis hull movement has higher relationship with seasickness than X-axis and Y-axis hull movements. This study aims to initiate additional researches about X-axis and Y-axis of the ship's motion which it expects to greatly enhance safety of wheelhouse and engine room personnel, ship's livability and comfortable sailing.