• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.7
• /
• pp.946-956
• /
• 2011

The main objectives of this study are to analyze the leaked gas dispersion and quantify the potential overpressures due to vapor cloud explosions in order to identify the most significant contributors to risk by using Computational Fluid Dynamics (CFX & FLACS) for gas fuelled ships. A series of CFD simulations and analyses have been performed for the various gas release scenarios in a closed module, covering different release rates and ventilating methods. This study is specially focused on the LNG FGS (Fuel Gas Supply) system recently developed for the propulsion of VLCC crude oil carriers by shipyards. Most of work presented is discussed on the gas dispersion from leaks in the FGS room, and shows some blast prediction validation examples.

• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.7
• /
• pp.863-871
• /
• 2007

This paper proposes a methodology to estimate the system coefficients for the infinite impulse response(IIR) digital filters using real code GA. In the traditional real coded GA, it adapts the general genetic operations, whereas in this paper the proposed real coded GA applies improved genetic operations in order to search the optimal solution in given problems. Each of unknown IIR digital coefficients collected as forms of a chromosome. Two illustrative examples including the band pass and band stop IIR digital filters are demonstrated to verify the proposed method.

• Journal of the Optical Society of Korea
• /
• v.20 no.1
• /
• pp.1-7
• /
• 2016

Using coherence theory, the partially coherent flat-topped vortex hollow beam is introduced. The analytical equation for propagation of a partially coherent flat-topped vortex hollow beam in turbulent atmosphere is derived, using the extended Huygens-Fresnel diffraction integral formula. The influence of coherence length, beam order N, topological charge M, and structure constant of the turbulent atmosphere on the average intensity of this beam propagating in turbulent atmosphere are analyzed using numerical examples.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2006.11a
• /
• pp.113-120
• /
• 2006

In this paper, generation mechanisms of ocean freak waves are briefly introduced in the context of wave-current interaction phenomena. As an accurate and efficient numerical tool, the spectral element method is presented with general features and specific treatment for the wave-current interaction problem. The present model of the fluid motion is based on the Navier-Stokes equations incorporating a velocity-pressure formulation. In order to deal with the free surface motion, an Arbitrary Lagrangian-Eulerian (ALE) description is adopted. As an intermediate stage of development, solution procedure and characteristic aspects of the present modeling and numerical method features are addressed in detail, and numerical results for wave-current interaction is left as further study.

• Asian review of World Histories
• /
• v.3 no.2
• /
• pp.201-218
• /
• 2015

World history today has been greatly influenced by the fact that it was the revolution in naval power during the past two centuries that made the world truly global. This has led to a new master narrative that re-framed five millennia of recorded history in order to explain the ultimate triumph of the maritime economies. The result of such revision is to underestimate and distort the role of continental Eurasia in the shaping of the three key civilizations that developed independently and remain distinct: the Mediterranean, the Indic and the Sinic. Only by a fuller reappraisal of the linkages of trade and war dominated by the Eurasian central forces for most of history can we understand the global pressures perennially at work. By setting the continental and the maritime in their total historical context and recognizing their importance today, we can better explain what is happening and what is likely to continue to influence the course of world history.

• Journal of Navigation and Port Research
• /
• v.34 no.9
• /
• pp.693-698
• /
• 2010

In port and its approach channel, traffic accidents such as collision, aground, minor collision have reached about 77% of total marine casualty in the area. In this paper, an attempt to enhance the safe navigation was proposed by offering marine traffic supporting system which helps VTS operator assist vessel effectively with the quantitative assessment on difficulty of each vessel. The system collects navigation data from onboard AIS, assesses the data in assessment mode to analyze the navigation difficulties of each vessel and displays the degree of danger of each vessel on the ECDIS in real-time to decide the intervention time or order of priority for VTS operator. The effectiveness of the system was verified by the VTS operators in Korea.

• Journal of the Korean Institute of Navigation
• /
• v.21 no.1
• /
• pp.89-102
• /
• 1997

Since 1979, the People's Republic of China has been opeining their marke tprogressively toward all over the world for developing its own domestic economy and international trade. China also has paid a great attention to the international maritime transport due to the fact that its volume of international trade has increased continuoulsy. Under such circumstance, the Chinese Maritime Code was issued in 1992 in which the regulation with regard to carrier's liability occupied an important position. The author, therefore, selected this issue for demonstration of the legal proinciples about carrier's liability which is provided in the Chinese Maritime Code. The study on the issue is under guidance of related international conventions. On the basis of the above, the differences between the Code and relevant conventions have been pointed out in order to make the people in the field of shipping understood for legal system with regard to carrier's liability in China which is a great potential partner of Korea in shipping and trade.

• Honam Mathematical Journal
• /
• v.35 no.2
• /
• pp.225-234
• /
• 2013

Many studies of experimental economics have produced outcomes which contradict the predictions of Nash equilibrium, which relies heavily upon the premise of selfishness of an individual. In the games involving contexts of social conflicts represented by the prisoners' dilemma game, the experiments yields outcomes quite different from what are predicted by the conventional wisdom. In order to fill this gap between the conventional Nash Equilibrium and experimental outcomes, non-selfish (or other-regarding) motives of human behavior are introduced and then a new equilibrium concept, RAE-equilibrium is developed. It is also proved that an RAE-equilibrium exists under quite general conditions. Then it is applied to the prisoners' dilemma game that some of the experimental outcomes can be explained.

• Journal of Navigation and Port Research
• /
• v.30 no.7
• /
• pp.611-615
• /
• 2006

This paper proposes a method for generating radar images used in a ship handling simulator, which includes mathematical logics based on radar equations and information from Openflight format files. In order to make radar image much similar to that of real radar in PPI type, the proposed mathematical logic derives radar video signals under the consideration of not only the data form flight format file of simulation scenes, but also geographical radar's position. The proposed method is considered useful to make radar images in ship handling simulator with accuracy and reality.

• Journal of Navigation and Port Research
• /
• v.42 no.2
• /
• pp.137-142
• /
• 2018

Vietnam is entering an important phase of urbanization that corresponds to the current economic development. Developing logistics of Vietnam in general, and Haiphong particularly, is urgent in order to meet the need for the economic development of Viet Nam in this period of international integration. Hai Phong's development record over the past 20 years is remarkable. In conjunction with the local government's efforts, external factors, such as increasing direct foreign investment, is turning Hai Phong into Vietnam's logistics hub. However, even though Hai Phong accounted for 98% of North Vietnam's throughput, its logistics services are low level, the ports are fragmented, and the port management scale is backward, with the legal system overlapping. This paper has systematically evaluated the development of Haiphong city during recent years, then offers some solutions to develop logistics for Hai Phong ports.