• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.279-283
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• 2009

Approximately 12,547 kL of oil from the tanker 'Hebei Spirit' released into the western sea of Korea, which subsequently reached and covered extensive areas of the western coastlines of Korea. In the following days great numbers of tar balls hit the southwestern coast. Three different cleanup methods were used to mediate the southwestern coastline tar ball pollution by Korea Coast Guard (KCG) net setting, manual pick up, and sweeping them up. Net setting was useful in protecting coastlines from being hit by tar balls. The cold weather in winter conditions helped the tar ball response efforts because it caused them to harden, allowing them to be swept up from beaches and to be gathered up by hand.

• Journal of Navigation and Port Research
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• v.38 no.1
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• pp.81-87
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• 2014

Today, it is a trend that the demand of offshore plants is constantly growing, along with the advances in technology which are thoroughly needed to the rise of international oil price as well as offshore energy development. In addition, The main sectors of ship building, sale & purchase and chartering market regarding various kind of offshore supporting vessels that supports the business of offshore energy development is now maintaining its steady growth. However, in domestic case, the contract of time charter occasions regarding the offshore support vessel are almost non-existing situation. Thus, the relevant practical study regarding to implementation of various kinds of legal disputes and applicable laws that can be properly applied in time charter and the field of sale & purchase needs to be conducted actively. Therefore, the concept of this study has included the wide comparisons of other special provisions with the existing time-charter by making its base on "Supply Time 2005" which is the worldwide standard form of time charter in offshore support vessel market and its investigation, aiming to provide practical guidance and procedure for implementation of arbitration and applicable law issues which can be applied in legal disputes between parties.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.3
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• pp.162-168
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• 2017

Shallow-water bathymetry survey has been conducted using high definition color images obtained at the altitude of 100 m above sea level using a drone. Shallow-water bathymetry data are one of the most important input data for the research of beach erosion problems. Especially, accurate bathymetry data within closure depth are critically important, because most of the interesting phenomena occur in the surf zone. However, it is extremely difficult to obtain accurate bathymetry data due to wave-induced currents and breaking waves in this region. Therefore, optical remote sensing technique using a small drone is considered to be attractive alternative. This paper presents the potential utilization of image processing algorithms using multi-variable linear regression applied to red, green, blue and grey band images for estimating shallow water depth using a drone with HD camera. Optical remote sensing analysis conducted at Wolpo beach showed promising results. Estimated water depths within 5 m showed correlation coefficient of 0.99 and maximum error of 0.2 m compared with water depth surveyed through manual as well as ship-board echo-sounder measurements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.480-485
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• 2017

The main reason for the heat induced accidents occurring at the after stern tube journal bearing is the excessive local pressure caused by the deflection of the propulsion shaft due to the propeller loads. It is expected that the contact area could beenlarged and the local pressure reduced accordingly by using a lining material having alow Young's modulus instead of the existing white metal. The purpose of this work is to investigate the characteristics of the pressure distribution and determine the allowable pressure value in the case where bearing products made of materials having a low Young's modulus are used. In this study, the propeller loads, heat effect, and hull deflection are considered in the evaluation of the local pressure of the ship propulsion shaft. Also, the Hertzian contact condition was applied. From the analysis results in the case where a lining material with a low Young's modulus was used, it was found that a robust design could be achieved and the local pressure could be reduced effectively independent of the load conditions. It will be possible to producenew products made of materials having a low Young's modulus if the manufacturer confirms the performance specifications drawn by this study.

• Fire Science and Engineering
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• v.27 no.6
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• pp.104-114
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• 2013

This study is intended to figure out the effects of supervisors' transformational leadership on organizational culture and innovation in the fire fighting organization. To achieve this, a survey was carried out to fire officers from the National Emergency Management Agency and Seoul Metropolitan Fire & Disaster Headquarters. The results are as follows. First, the effect of supervisors' transformational leadership on organizational culture showed that supervisors' transformational leadership had an effect on group culture, norm culture and rational culture by sub-factors of organizational culture in the fire fighting organization. Second, the effect of organizational culture on organizational innovation showed that group culture and rational culture had an effect on organizational innovation. Third, the effect of supervisors' transformational leadership on organizational innovation showed that supervisors' transformational leadership had an effect on organizational innovation. As for findings stated above, supervisors' transformational leadership had positive effects on organizational culture and innovation in the fire fighting organization. Consequently, supervisors' energetic and change-seeking leader-ship for junior staffs with existing organization-and new generation-oriented new thinking system can contribute to rational culture and development-oriented innovation based on norms in the group.

• Journal of Technology Innovation
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• v.24 no.2
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• pp.21-56
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• 2016

Despite many previous studies on catch-up, understanding on the effect of product architecture developed by latecomers on the catch-up performance remains limited. On the other hands, in contrast to the semiconductor, ship building, and automotive industry, even if Korean industry and government have invested the development of numerical controllers for machine tools in the past four decades, the industry and government have failed to achieve catch-up. Therefore, we newly examine the effect of product architecture on the catch-up performance of the Korea by implementing comparative research with periods on the evolution of product architecture of Fanuc's numerical controllers, which have achieved the largest market share in the world. We found that Fanuc developed open modular architecture based numerical controllers and provided product with customization of user requirements as well as cost effectiveness. Consequently, Fanuc has sustained market leader position since the mid-1980s. However, despite all the efforts of the industry and government, we found that the Korea failed to develop open modular architecture based numerical controllers and could not achieve significant catch-up performance. Our findings provide important theoretical backgrounds for examining the catch-up performance as well as investigating the reason why latecomers failed to achieve market catch-up even if they accomplished technological catch-up.

• Journal of the Korean earth science society
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• v.22 no.5
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• pp.415-422
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• 2001

Studies of atmospheric general circulation in the troposphere and stratosphere are very important to understand the influence of human activities on the global climate and its change. Recently, the existence of an annual cycle in the circulation has been reported by a number of studies. In this study, the residual mean meridional circulation is calculated by the TEM momentum and continuity equations for the period from December 1985 to November 1995 (10 years), and the long-term variations of the circulation and mass fluxes across the 100hPa surface are examined. The multiple regression statistical model is used to obtain quantitatively the long-term variations. This study is focused especially on mean meridional circulation in the troposphere and stratosphere associated with ENSO (El Ni${\tilde{n}}$o-Southern Oscillation) which is known as a cause of the unusual weather, global climate, and its change. The results show that the global scale troposphere-stratosphere mean meridional circulation is intensified during El Ni${\tilde{n}}$o event and QBO (quasi-biennal oscillation) easterly phase and weakened during La Ni${\tilde{n}}$o event and QBO westerly phase. The signal of Mount Pinatubo volcanic eruption in June 1991 is obtained. Due to the volcanic eruption the global scale troposphere-stratosphere mean meridional circulation is abruptly intensified.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.257-262
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• 2013

A ship operating in rough sea may suffer from an undesirable motion which may severely degrade the performance of equipment onboard and give a person an uncomfortable feeling. Hence, roll stabilization received a considerable attention and various devices including bilge keels, stabilizing fins, gyroscopic, anti-rolling tanks, rudders and flaps have been conceived and utilized for the purpose. The Coanda effect is evident when a jet stream is applied tangential to a curved surface of a hydrofoil since then the jet increases the circulation around the foil and consequently the lift. Model tests and numerical simulation have been conducted to examine the practicality of a fixed type fin stabilizer augmented by the Coanda jet. The results show that the lift coefficient of the modified Coanda fin at the zero angle of attack identically coincides with that of the original fin at ${\alpha}=\26^{\circ}$ when Coanda jet is supplied at the rate of $C_j$ = 0.25. It is also shown that fixed type fin stabilizers for active control of the motions of ships and the other mobile units without rotation can be put to practical use if the Coanda effect is applied.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.421-430
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• 2016

In this study, a gate simulation model was developed to reduce the truck waiting time for trucking companies servicing container terminals. To verify the developed model, 4 weeks of truck gate-in/gate-out data was collected in December 2014 at the Port of Busan New Port. Also, the existing gate system was compared to the proposed gate system using the developed simulation model. The result showed that based on East gate-in, a maximum number of 50 waiting trucks with a maximum waiting time of 120 minutes. With the proposed system the maximum number of waiting trucks was 10 with a maximum waiting time of 5.3 minutes. Based on West gate-in, the maximum number of waiting trucks was 17 and the maximum waiting time was 34 minutes in the existing gate system. With the proposed system the maximum number of waiting trucks was 10 with a maximum waiting time of 5.3 minutes. Based on West gate-out, the maximum number of waiting trucks was 11 with a maximum waiting time of 5.5 minutes. With the proposed system the maximum number of waiting trucks was 9 with a maximum waiting time of 4.4 minutes. This developed model shows how many waiting trucks there are, depending on the gate-in/gate-out time of each truck. This system can be used to find optimal gate system operating standards by assuming and adjusting the gate-in/gate-out time of each truck in different situations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.582-588
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• 2014

IMO and IALA have undertaken projects that GMDSS Modernization and E-navigation, which refer to "Future digital communications systems" for a more efficient transmission of voice and data communications in the VHF maritime mobile service. ITU has also resolved in WRC-07 Resolution 357 to study the use of spectrum-efficient technologies in order to provide for the operation of ship and port security and maritime safety systems. IALA and ITU WP5B have coordinated for the technical developments and the spectrum issues. Recommendation ITU-R M.1842-1 has approved by WP5B meeting. This revision provides a wideband data service both 50kHz and 100kHz in the VHF maritime mobile service. This paper has studied E-navigation, its needs for data exchange that includes explanations of the current methods for transmitting data by VHF that based in land mobile radio service. A further technologies trend is estimated for Recommendation ITU-R M.1842-1, that is based on the land mobile radio standards with some tailored to fit the needs of the maritime mobile service.