• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.36-42
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• 2018

This paper considers the Marine Traffic Risk Assessment for fixed and moving targets, which threaten officers during a voyage. The Collision Risk Assessment Formula was calculated based on a dynamic ship domain considering the length, speed and maneuvering capability of a vessel. In particular, the Navigation Risk Assessment Model that is used to quantitatively index the effect of a ship's size, speed, etc. has been reviewed and improved using a hybrid combination of a vessel's dynamic area and the Collision Risk Assessment Formula. Accordingly, a new type of Marine Traffic Risk Assessment Model has been suggested giving consideration to the Speed Length Ratio, which was not sufficiently reflected in the existing Risk Assessment Model. The larger the Speed Length Ratio (dimensionless speed), the higher the CJ value. That is, the CJ value is presented well by the Speed Length Ratio. When the Speed Length Ratio is large, states ranging from [Caution], [Warning], [Dangerous] or [Very Dangerous] are presented from a greater distance than when the Speed Length Ratio is small. The results of this study, can be used for route and port development, including dangerous route avoidance, optimum route planning, breakwater width, bridge span, etc. as well as the development of costal navigation safety charts. This research is also applicable for the selection of optimum ship routing and the prevention of collisions for smart ships such as autonomous vessels.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.403-412
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• 2019

The characteristics of the manoeuvring motion of a ship are dependent on the ship type, as well as draft or speed in the same ship. In recent years, the number of extra-large vessels has increased significantly, which can cause enormous material and environmental damage in the event of a marine accident. Thus, the importance of ship maneuvering is increasing. The IMO has forced the officers to be trained in simulators through the STCW 95 amendment. However, FMSS is costly and difficult to access and the PC-based simulator has the disadvantage that only one person can engage in simulation. The purpose of this study was to solve the shortcomings of the FMSS and PC-based simulators by enabling multiple people to use their PCs to simulate based on a network. The simulator is implemented through the analysis and numerical calculation of the Nomoto model, Radar function mounting, data transfer protocol design, and GUI building. To verify the simulator, the simulation results were compared and analyzed with the test results of T.S. HANBADA according to the criteria of the Korean Register of Shipping(KR) and IMO standards for ship maneuverability. As a result, It showed a relative error of 0%~ 32.1% with an average of 13.7%, and it satisfied the IMO criteria for ship maneuverability.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.27-34
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• 2011

Purpose: Anterolateral thigh (ALT) perforator free flap is commonly used because of its various benefits. The author reports important factors of preoperative and perioperative ALT perforator free flap and causes of failure. Methods: 84 patients who were treated with ALT perforator free flap from December 2004 to 2008, and February 2010 to April 2010 were studied. 61 patients were male and 23 were female. The mean age of patients was 51.1. The main cause was neoplasm and the main reconstructive areas were head and neck area. The size of flap was various from $3{\times}4$ to $12{\times}18$ cm. 6 patients received split thickness skin graft at donor site. Preoperative angiography was checked to all patients. Results: Among the 84 patients, partial necrosis of flaps occurred in 4 patients because of atherosclerosis, varicose vein, or inattention of patient, etc. And total flap necrosis in 5 patients because of abnormal vessels of recipient area or delay of operation, etc. One case of serous cyst was found as the complication of donor area. Two cases of skin graft on donor site were done because of suspected muscle compartment syndrome, 4 cases of that because of large flap. Septocutaneous perforators were found in 7 cases. The author couldn't find reliable perforator in 3 cases, ipsilateral anteromedial thigh perforator and contralateral ALT perforator and latissimus dorsi musculocutaneous free flap were done instead of ALT. There was no case which needed reoperation because of the impairment of blood supply, and 3 cases were revised by leech because of the burn injury by a lamp or venous congestion. Conclusion: Although ALT perforator free flap is widely used with its various merits, many factors such as preoperative condition of donor or recipient area, morphology of defect and operating time need to consider to prevent flap necrosis. And operators should need careful technique because septocutaneous perforator is uncommon, and musculocutaneous perforator is common but difficult to dissect.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.423-430
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• 2012

The purpose of Speed limit at sea is to keep harbor calmness, to maintain efficient traffic flow and to prevent maritime accidents. The Korean Regional Maritime Affairs and Port Office(KRMAPO) specified and enforced the ship's speed limits at the 19 harbors around the Korean coasts. However, problems have been raised to the adequacy of speed limits. This paper made a research on the speed limit set standards, analyzed vessel traffic survey and the dilemma on the specified speed limits imposed by KRMAPO. The result of this study has shown an overall average of 48 % violation rate on speed limit with passenger ships and large vessels of more than 5,000 tons having higher violation rate. Average speed was higher than the limit speed in some harbors and deviation of 4.2 to 5.2 knots was investigated. Further, harbors having higher average speed also have higher deviation accident incidence. Therefore, this paper had confirmed that there is a need for institutional review and improvement of Korea's port and fairways speed traffic management.

• Journal of architectural history
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• v.16 no.3
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• pp.75-94
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• 2007

There were many researches on marine transportation and granaries, most of which focused on the historical establishment and organization of the marine transportation. However, a few researches were conducted on the architectural aspects. Hence the purposes of this study are to investigate the following matters: first, documents and relics concerning the tribute granary castle at Cape Gongse in Asan, a typical granary during the Joseon Dynasty, were investigated to academically understand the castle's establishment and historical background; second, the dispositional characteristics of the granary and the castle, including its adjacent facilities, were investigated to review its archaeological value; finally, basic materials were provided for systematical preservation and management these relics. As for the research method, the author referred to and analyzed sundry records and old maps, and ascertained in detail historical evidence through residential testimonies and the on-the-spot surveys. In addition, the author investigated the dispositional characteristics of the tribute granary castle at Cape Gongse by analyzing its exact size and shape, based on the old documents and an actual survey of the castle remains. The characteristics of the tribute granary castle at Cape Gongse may be summarized as follows. First, tribute granary at cape Gongse is a only tribute granary which has a granary and castle. second, the tribute granary castle at Cape Gongse has a curvilinear shape, like a gourd dipper; a large circle surrounding the village and a small circle surrounding the area of Mt. Shinpoong both meet up with it. Third, the construction type of the tribute granary castle at Cape Gongse is in a style similar to a town castle or a battle camp castle located in the coastal regions. As for its locational conditions, however, the east gate, presumably an incoming and outgoing route to the granary for vessels, was a feature unique to the marine granary castle. Fourth, the tribute granary at Cape Gongse had a granary of eighty kan in 1523 and, in addition, there were also Bongsang-cheong, Sa-chang, Joseon-sobakcheo, Chimhae-dang, and more, not to mention many privates houses in the castle. The granary is located in the center of the tribute granary castle, where Gongse Nonghyub is currently located. The location of the government offices seemed to be on the northern ridge. Fifth, the tribute granary castle at Cape Gongse is a valuable relic that offers insight into marine transportation, tribute granaries, and tribute granary castles during the Joseon Dynasty. It has special archaeological value because it was one of only a few tribute granary castles that served to protect the tribute granaries.

• Korean journal of applied entomology
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• v.17 no.3 s.36
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• pp.131-138
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• 1978

A virus named Cymbidium mild mosaic virus(Cy MMV), was mechanically transmitted to Chenopodium amaranticolor from the leaves of Cymbidium with mild mosaic symptoms. The virus was cultured in C. amaranticolor, in which it produced local chlorotic and ring spots, followed by systemic vein clearing with distortion. CyMMV infected 7 out of 35 species of plants. In C. amaranticolor juice infectivity was lost by heating at $90^{\circ}C$ for 10 miuntes, and by aging at$20^{\circ}C$ for 60 days, and by diluting at $10^{-6}$ when bioassayed on C. amaranticolor. CyMMV was not transmitted by Myzus persicae. The virus was purified after clarification of homogenized C. amaranticolor leaf tissues with chloroform, by differential centrifugation followed by sucrose density gradient centrifugation. Electron microscopic examination of purified preparation showed spherical particles of 28nm in diameter. The UV absorption spectrum of purified preparation was typical of u nucleoprotein (max. at 261nm. min. at 243nm), and showed 260/280=1.72 and max/min=1.26. The value of the sedimentation coefficient of the virus was S20.w=126. In gel-diffusion tests, CyMMV antiserum reacted with CarMV, but not with any of four other viruses (BBWV, CRSV, CMV, TBRV) having similar particles and properties in vitro. In ultra-thin sections of CyMMV infected tissues, a large number of virus particles were found in the cytoplasm of mesophyll cells and in xylem vessels.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.61-66
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• 2019

Unlike NG supplied through pipes, LPG is mainly used for independent storage of cylinders or small storage tanks. As LPG is widely used in islands and underdeveloped areas, accidents due to neglect of safety management are high. Houses and businesses that have LPG accidents are likely to be damaged due to relatively high population density. Therefore, the necessity of strengthening the safety management of LPG is constantly raised. Accordingly, in 1996, Korea Gas Safety Corporation conducted an LPG leak test. In this study, based on the 96-year experiment, the gas leakage measurement of LPG vessels was conducted by adding several conditions such as outside temperature and pipe condition. Through this, the trend of leakage for various scenarios of LPG leakage was examined. In the case of a gas leak, when the article which may affect the pressure such as a regulator is not connected, the leakage amount is greatly changed by the outside air temperature, and when the regulator is fastened, the influence of the outlet pressure is large. It is expected that the experiment can be used as basic data for determining gas accidents and leakages that may occur later.

• Journal of Navigation and Port Research
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• v.33 no.8
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• pp.525-530
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• 2009

VTS(Vessel Traffic Service) has been established in navigational waters to improve the safety and efficiency of navigation and to prevent marine accidents which could cause a large amount of damages to the marine environment and shipping industries. There have been several reports on analyzing the causes of marine accidents happened around Korean waters of jurisdiction, and those reports contributed not only to the enlargement of waters where VTS operation was needed and but also the construction of VTS system which was necessary to provide vessels navigating in the service waters with safety-related information. However, the researches for the role of VTS in marine transportation were not still enough to increase the safety of navigation and to decrease the number of accidents. In this paper, in view of the fact that VTS operation is closely connected with the accidents, we analyzed that what parts of VTS operation are involved deeply with the causes of marine accidents in Busan Port, and then proposed a method to improve its performance most effectively.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.83-90
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• 2020

Plate heat exchangers(PHE) have been commercialized since the 1920s. Since then, although the basic concept of PHEs has changed little, its design and construction have progressed significantly to accommodate higher temperatures, higher pressures, and large heat exchanging capacities. The development trend of PHEs is consistent with heat plate developments with better thermal efficiency, lower pressure drop, and good flow distribution. The purpose of this paper is to introduce the main development processes of a plate cooler for medium-speed engine lubricant oil cooling in vessels which is in line with the development trend of PHEs and to provide its thermal performance data that were found out during experimental tests. The plate cooler in this study cannot measure the wall temperatures directly due to its structural characteristics, so the heat transfer coefficients were calculated using the modified Wilson Plot method. The water-to-water tests were first conducted experimentally to figure out the characteristics of heat transfer coefficients and pressure drops on the water side and then the water-to-oil tests followed to obtain the heat transfer coefficients on the oil side. The test results showed that heat transfer coefficients and pressure drops on both water and oil side increased with flow rates, and it was also found that all the development targets of the plate cooler in this study were achieved successfully.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.1
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• pp.83-95
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• 2018

With recent technological advances in the shipbuilding industry, vessels have been improved in size and performance. As a result, an accident such as grounding, caused by a single ship-to-ship collision, could lead to a large-scale maritime disaster. Considering the seriousness of the situation, the international community has been consistently updating the standards for Electronic Navigational Chart(ENC) to improve the maritime safety. S-57, the existing ENC standard governed by the International Hydrographic Organization(IHO), includes standards for generating conventional binary-type ENC data sets. The S-57 standard, however, has not been updated since the release of Version 3.1 in December 2000. Since then, the standard has failed to reflect technological development regarding maritime spacial information, which has been consistently improving. In an effort to address this concern, the IHO designated S-100, i.e., the next-generation ENC production standard. S-100 differs from S-57 in data exchange type. Contrary to the conventional ENC standards, which use binary-type data, S-10X, based on the next-generation ENC standards, uses ENC data composed of Feature Catalogue, Portrayal Catalogue, and GML. Considering this fact, it is necessary to update S-58, the ENC validation check standard, or designate a new standard for ENC validation checks. This study is developed own software to implement validation checks for new types of data, and identified improvement points based on the test results.