• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.260-262
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• 2022

선박의 전통적인 운항 패턴은 국제적인 기준과 본선의 선장 및 승조원의 역할 수행이 중심이 되지만 자율 운항 선박(Autonomous Ship)에서는 컴퓨터 기반의 시스템과 소프트웨어가 선박의 항해, 기관 정보를 수집하여 상화 인식과 지능형 항로 의사 결정 시스템의 판단에 따라 본선 자체 또는 육상에서의 원격 관제를 통하여 자율운항 모드가 실행이 되어야 한다.. 이 연구에서는 이러한 자율운항 선박의 모든 데이터의 수집과 정보 교환,를 위한 "디지털 브릿지" 플랫폼을 개발하고 시나리오에 기반한 자율운항에 대한 알고리즘을 연구 개발하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.945-951
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• 2012

In this study, we analyze the static and dynamic characteristics of a bulk-cement trailer with a simpler structure that carries powders. The commercial software ANSYS is used to prepare a detailed three-dimensional model of the chassis frame and tank body that bear most of the load of a bulk-cement trailer for the finite element analysis. Modal analysis is conducted to examine the dynamic characteristics of the trailer body, and static analysis shows weak links in the structure. Finally, we propose a method to increase the strength of vulnerable areas and to reduce the weight of the trailer by applying the Taguchi method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.5
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• pp.572-580
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• 2019

In view of the numerous discussions on global environmental issues, policies have been implemented to limit emissions in the field of marine transport, which accounts for a major part of international trade. In this study, a ship's emissions were calculated by applying the engine load factor to determine the total quantity of emissions based on the ship's speed reduction. For ships entering and leaving the Busan North Port from 1 January to 31 December 2017, emissions were calculated and analyzed based on the ship's type and its speed in the reduced speed zone (RSZ), which was set to 20 nautical miles. The comparison of the total amount of emissions under all situations, such as cruising, maneuvering, and hotelling modes revealed that the vessels that generated the most emissions were container ships at 76.1 %, general cargo ships at 7.2 %, and passenger ships at 6.8 %. In the cruising and maneuvering modes, general cargo ships discharged a lesser amount of emission in comparison with passenger ships; however, in the hotelling mode, the general cargo ships discharged a larger amount of emission than passenger ships. The total emissions of nitrogen oxides (NOx), sulphur oxides (SOx), particulate matter (PM), and volatile organic compounds (VOC), were 49.4 %, 45 %, 4 %, and 1.6 %, respectively. Furthermore, the amounts of emission were compared when ships navigated at their average service speed, 12, 10, and 8 knots in the RSZ, respectively. At 12 knots, the reduction in emissions was more than that of the ships navigating at their average service speed by 39 % in NOx, 40 % in VOC, 42 % in PM, and 38 % in Sox. At 10 knots, the emission reductions were 52 %, 54 %, 56 %, and 50 % in NOx, VOC, PM, and Sox, respectively. At 8 knots, the emission reductions were 62 %, 64 %, 67 %, and 59 % in NOx, VOC, PM, and Sox, respectively. As a result, the emissions were ef ectively reduced when there was a reduction in the ship's speed. Therefore, it is necessary to consider limiting the speed of ships entering and leaving the port to decrease the total quantity of emissions.

• Journal of Digital Convergence
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• v.10 no.5
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• pp.79-87
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• 2012

On June 29th, 2010, a cross-straits "Economic and Cooperation Framework Agreement" (ECFA) is signed between China and Taiwan. This pact seems to be the greatest step forward on cooperation between the two sides, reflecting China-Taiwan thaw. As these countries are especially economically interdependent, great economic incomes and security benefits are expected for both sides after cooperation. this development of enlightened cooperation between China and Taiwan, gives many implications for Korea, the two divided countries. Recently, relation between north and south Korea is developing in an entirely different situation compared to the former Kim Dae-Jung or Roh Moo-hyun administrations. But exchange between north and south Korea has not been stopped, though reduced. This reflects the necessity of exchange of the north and the south, and this means that making preparation for the efficient conduct of exchange is needed. So in this study, we consider the China-Taiwan exchange and cooperation development carefully as a model for exchange and cooperation of the north and south Korea, and sought realizable ways to exchange and cooperate between the north and south Korea, which is also a win-win strategy for northeast Asia.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.10-21
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• 2022

The propellant tank, which is a space launch vehicle structure, must have structural integrity as various static and dynamic loads are applied during ground transportation, launch standby, take-off and flight processes. Because of these characteristics, the propellant tank cylinder, the structural object of this study, has a thin thickness, so buckling due to compressive load is considered important in the cylinder design. However, the existing buckling design standards such as NASA and Europe are fairly conservative and do not reflect the latest design and manufacturing technologies. In this study, nonlinear buckling analysis is performed using various analysis models that reflect initial defects, and a method for establishing new buckling design standards for cylinder structures is presented. In conclusion, it was confirmed that an effective lightweight design of the cylinder structure for common bulkhead propulsion tank could be realized.