• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.3
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• pp.273-278
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• 2017

This paper is to study a technique to detect the real-time route aberrance on the passage route using bumper area of the ship domain theory. In order to evaluate the risk of route aberrance, a quarter line was created between the center line and the outer line, and a passage route with the image line outside the outer line was designed. It calculated the real-time route aberrance with the vessel bumper area to measure the risk level on the passage route. The route aberrance using overlap bumper area was simulated through three kinds of scenario vessel at the designed passage route. In this paper, we proposed Ratio to Aberrance Risk as one of the evaluation parameter to detect the route aberrance risk at each sector in the passage route and to give the evaluation criteria of 5 levels for seafarer's navigation safety. The purpose of this work is to provide the information of the route aberrance to seafarer automatically, to make it possible to prevent the human errors of seafarer on the high risk aberrance route. As the real-time risk of route aberrance on the passage route is automatically evaluated, it was well thought that seafarer can have only a little workload in order to know the risk of route aberrance at early-time. Following the further development of this work, the techniques for detecting the real-time route aberrance will be able to use the unmanned vessel.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.71-76
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• 2008

The main ports of Korean south sea are exposed to intensive danger as 58.1% of total vessel in Korea waters and 62.9% of total dangerous cargo ships. Therefore, it is required to establish fundamental database to solve numerous issues at the main ports cf the south sea as studying amount of the vessel traffic and their flows into the main ports, and evaluating degree of danger by traffics environmental stress model as analyzing relationships among degree of danger, maritime accident, and number of vessel arriving or departing in the main ports.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5B
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• pp.449-454
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• 2009

In this paper, we analyze the hardware and software platform for constructing the USN in the vessel environment. Specifically, we analyze the mote technology based on the CC2420 in the hardware platform and analyze the TinyOS platform in the software platform. We also analyze the physical layer of IEEE802.15.4 which is the standard of the USN communication. In the simulation, we evaluate the performance in the physical layer of ZigBee/IEEE 802.15.4 by using the MATLAB and verify the validity of constructing the USN in the vessel environment based on the simulation results.

• Journal of Korean Society on Water Environment
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• v.35 no.2
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• pp.115-122
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• 2019

The objective of this study was to investigate the sonophysical and sonochemical effects induced by acoustic cavitation in heterogeneous systemin a 28 kHz double-bath reactor using calorimetry, the aluminiumfoil erosion test, and the luminol test. With no glass beads, calorimetric power in the inner vessel increased as much as the outer sonoreactor lost and total calorimetric power was maintained for various liquid height conditions (0.5 ~ 7 cm) in the vessel. Higher calorimetric energy was obtained at higher liquid height conditions. Similar results were obtained when glass beads were placed with various beads heights (0.5 ~ 2.0 cm) and relatively high calorimetric energy was obtained in spite of large attenuation in the glass beads layer. An aluminium foil placed between the bottom of the inner vessel and the glass beads layer was damaged, indicating significant sonophysical effects. Much less damage was detected when the foil was placed above the beads layer due to large attenuation of ultrasound. Sonochemical effects, visualized by sonochemiluminescence (SCL), also decreased significantly when the beads were placed in the vessel. It was established that the optimization of the liquid height above the solid-material layer could enhance the sonophysical and sonochemical effects in the double-bath sonoreactors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.290-296
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• 2022

According to an investigation performed on shipping accidents, the number of domestic shipping accidents has been increasing despite the decrease in global shipping accidents. Therefore, to reduce domestic shipping accidents, the present study investigated the criteria for the stability of fishing vessels. The IMO, foreign, and domestic regulations regarding fishing vessel stability were investigated, and a comparative study was conducted. The results showed that domestic regulations were the most relaxed regarding vessel stability. Finally, we proposed five items for the KOREA FISHING VESSELS STABILITY CRITERIA AMENDMENTS on the basis of the comparative study.

• Progress in Superconductivity and Cryogenics
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• v.15 no.4
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• pp.53-58
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• 2013

KSTAR in-vessel cryo-pump has been installed in the vacuum vessel top and bottom side with up-down symmetry for the better plasma density control in the D-shape H-mode. The cryogenic helium lines of the in-vessel cryo-pump are located at the vertical positions from the vacuum vessel torus center 2,000 mm. The inductive electrical potential has been optimized to reduce risk of electrical breakdown during plasma disruption. In-vessel cryo-pump consists of three parts of coaxial circular shape components; cryo-panel, thermal shield and particle shield. The cryo-panel is cooled down to below 4.5 K. The cryo-panel and thermal shields were made by Inconel 625 tube for higher mechanical strength. The thermal shields and their cooling tubes were annealed in air environment to improve the thermal radiation emissivity on the surface. Surface of cryo-panel was electro-polished to minimize the thermal radiation heat load. The in-vessel cryo-pump was pre-assembled on a test bed in 180 degree segment base. The leak test was carried out after the thermal shock between room temperature to $LN_2$ one before installing them into vacuum vessel. Two segments were welded together in the vacuum vessel and final leak test was performed after the thermal shock. Commissioning of the in-vessel cryo-pump was carried out using a temporary liquid helium supply system.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.899-908
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• 2021

It is expected that the global market for vessel repair and remodeling will grow up to the scale of about 25 billion dollars by 2023. Korea's shipbuilding industry is leading the world with its international competitiveness in design and production technology. The actual status of vessel repair industry, however, is poor as there are only two or three companies for vessel repair that can deal with large vessels in the area of Gyeongnam. The reason is that civil complaints are filed severely about environmental problems and environment-related regulations are so strict that it is fairly hard to get governmental approval for the operation of a vessel repair workplace. Domestic vessel repair companies mainly target small- and medium-sized vessels. There are only few workplaces that can carry out regular examination or repair work on large vessels such as LNG vessels, and due to the high price of vessel repair, most of the domestic repair work on large vessels including LNG vessels tends to be snatched by markets in Southeast Asia or China. Despite the tremendous domestic demand of Korea that has established the world's first shipbuilding industry and world's sixth biggest harbor infrastructure, its vessel repair industry can be said to be in very poor condition. In order to vitalize vessel repair industry, this study is aimed to analyze the environmental influence of vessel repair workplaces in Gyeongnam where vessel repair companies are concentrated and suggest standard processes by analyzing vessel repair processes precisely.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.219-224
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• 2013

In the case of occurring marine oil pollution, it is the most effective way that to prepare all the necessary response resources in advance and to respond to incidents, but there are limits in reality. Therefore, may be an important alternative ways to use a fishing vessel registered in the affected area by massive marine oil pollution efficiently. In the United States and other developed countries, it is can be found that temporary response program by local fishing vessels(VOO program) has been developed and operated. This study was examined for sweeping arm system suitable for domestic small fishing vessels. The selected small vessel was as the model of Coastal gill-net and compound fishing vessel with classes of 2.5~3.5tons, length 8~9m, breath 2.5~2.8m, horsepower 200~250 HP and FRP materials. The developed equipment was designed that can be easily mounted on the model ship and portable structure. For increasing the field practicality, the weight of each part was composed less than 10kg for easy assembly and disassembly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6B
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• pp.859-866
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• 2010

Digital vessels can occur large a disaster at sea because vessels in fire and collision in case of certain unforeseen circumstances. In this paper, We propose digital vessel context monitoring system through risk analysis. We propose environment information analysis system using wireless sensor that have to acquire marine environment and context of marine digital vessel. For conducting simulation, we chose 300 data sets to train the neural network. As a result, we obtained about 96% accuracy for fire risk context and we obtained 88.7% accuracy for body of vessel risk context. To improve the accuracy of the system, we implement a FEC (Forward Error Correction) block. We implemented digital vessel context monitoring system that transmitted to diagnosis result in CDMA.

• Journal of Navigation and Port Research
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• v.31 no.2
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• pp.127-132
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• 2007

The primary purpose of this study is to examine empirically the effect of the organizational characteristics in the vessel with foreign crews on their self-efficacy and organization commitment. Currently, the restrictions on the employment of the foreign crews are being eased in the Korean shipping industry and many problems are occurring consequently. However, specific and empirical studies on the relevancy of organizational characteristics to the crew's self-efficacy and organizational commitment on board the vessels with combined crews have not yet been carried out. To solve these problems, we examined how the organizational characteristics such as communication and leadership trust of different language and culture related to vessels with combined crews influence on the self-efficacy, job satisfaction and organizational commitment of the foreign crews through SEM analysis. According to the results, hypothesis 1, 2 and 3 were all supported with statistical significance. That means that communication and leadership trust of the vessel with foreign crew had positive effects on their self-efficacy and that such self-efficacy also had a positive effect on the organizational commitment and job satisfaction. To conclude, this study suggests that foreign crew's self-efficacy should be firstly enhanced in order to improve organizational commitment on the vessel with combined crews. Furthermore, studies on self-efficacy of foreign crew's organization are urgently needed to enhance the effectiveness of an organization in a vessel with combined crews that has special environment - working environment with depression and uneasiness due to the exposure to the different language and culture, and excessive stress from the social and psychological adaptation. Therefore, an attempt of this study is considered to be timely since there has not been a study on this subject so far and result of this study will contribute a lot to the organization management of a vessel with combined crews.