• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.3
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• pp.189-202
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• 2012

An Oscillating Water Column (OWC) wave generation system uses the air flow induced by the vertical motion of water column in the air chamber as a driving force of turbine. It is well known that OWC is one of the most efficient devices to harness wave power. This study estimated the air flow velocity from the time variation of the water level fluctuation in the air chamber under regular wave conditions using 3-dimensional numerical irregular wave tank (3D-NIT) model that can simulate the 3-dimensional irregular wave field. The applicability of the 3D-NIT model was validated by comparing numerically predicted air flow velocities with hydraulic experimental results. In addition, the characteristics of air flow frequency spectrum variation due to the incident frequency spectrum change, and the variations of frequency spectrum and wave reflection due to the existence of converter inside the air chamber were discussed. It is found that the phase difference exists in between the air flow velocity and the water level fluctuation inside the air chamber, and the peak frequency of the spectrum in water level fluctuation is amplified by the resonance in the air chamber.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.5
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• pp.408-417
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• 2007

Recently, an artificial beach has been constructed compensating for loss of the natural one caused by the development of coastal area, as well as serving as a location for recreational activities such as sea bathing. It is well known that some structure should be constructed to protect an artificial beach from the outflow due to wave action of the reclaimed sand. In general, dike is utilized as the structure to protect an artificial beach. And, one of the factors which may need to be taken into consideration for stability of dike on seabed foundation is the ground water behavior behind dike. However, the interrelated phenomena of nonlinear wave and ground water response have relatively little attention although these interactions are important for stability of structure and sand suction to the artificial beach. In this paper, the numerical wave tank was developed to clarify nonlinear wave, dike and ground water dynamic interaction, which can simulate the difference of ground water and mean water level. Using the developed numerical wave tank, the present study investigates how variation of ground water level influences hydrodynamic characteristics in seabed around dike and numerically simulates the wave fields, pore flow patterns, pore water pressures and vorticities according to variation of ground water level. Numerical results explain well how hydrodynamic characteristics in seabed around dike is affected by the variation of ground water level.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.1
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• pp.51-64
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• 2011

Carbon dioxide Capture and Storage (CCS) is one of the key players in greenhouse gas (GHG) reduction portfolio for mitigating climate change. CCS makes simultaneously it possible not only to reduce a huge amount of carbon dioxide directly from the emission sources (e.g., coal power plant) but also to maintain the carbon concentrated-energy and/or industry infrastructure. Internationally, the United Nations Framework Convention on Climate Change (UNFCCC) is dealing the agenda for considering the possibility of including CCS project as one of Clean Development Mechanism (CDM) projects. Despite its usefulness, however, there are the controversies in including CCS as the CDM project, whose issues include i) non-permanence, including long-term permanence, ii) measuring, reporting and verification (MRV), iii) environmental impacts, iv) project activity boundaries, v) international law, vi) liability, vii) the potential for perverse outcomes, viii) safety, and ix) insurance coverage and compensation for damages caused due to seepage or leakage. In this paper, those issues in considering CCS as CDM are summarized and analyzed in order to suggest some considerations to policy makers in realizing the CCS project in Korea in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.4
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• pp.294-306
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• 2005

Most immersed tunnels investigated have been investigated based on the engineer's experience with design and construction. From engineering point of view, it is very important to understand the wave interaction with the seabed and immersed tunnel, since the stability of an immersed tunnel depends largely on the behavior of the seabed foundation. In this study, for the first stage research to find out the mechanism of the wave interaction with the seabed and immersed tunnel, the benchmarking method called as direct numerical simulation (DNS) was employed to analyze comprehensively the wave-induced pore water pressures, vorticity and flows in seabed or inside rubble stone around the immersed tunnel. The immersed tunnel is modeled based on Busan-Geoje fixed link project in Korea, which is now on the stage of planning. Moreover, the nonlinear water wave interaction with an immersed tunnel/its seabed foundation was thoroughly examined with regard to the stabilities of the immersed tunnel subjected to various water wave conditions, median grain size and so forth.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.4
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• pp.295-304
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• 2012

This study proposed a two-dimensional horizontal numerical model based on the nonlinear shallow water wave equations to simulate tsunami propagation and coastal inundation. We numerically investigated the possible impacts of tsunami caused by the triple interlocked Tokai, Tonankai and Nankai Earthquakes on the Jeju coastal areas, using the proposed model. The simultaneous Tokai, Tonankai and Nankai Earthquakes were created a virtual tsunami model of an M9.0 earthquake. In numerical analysis, a grid nesting method for the local grid refinement in shallow coastal regions was employed to sufficiently reproduce the shoaling effects. The numerical model was carefully validated through comparisons with the data collected during the tsunami events by 2011 East Japan Earthquake and 1983 central East Sea Earthquake (Nihonkai Chubu Earthquake). Tsunami propagation triggered by the combined Tokai, Tonanakai and Nankai, Earthquakes was simulated for 10 hours to sufficiently consider the effects of tsunami in the coastal areas of Jeju Island. The numerical results revealed that water level fluctuation in tsunami propagation is greatly influenced by water-depth change, refraction, diffraction and reflection. In addition, the maximum tsunami height numerically estimated in the coastal areas of Jeju Island was about 1.6 m at Sagye port.

• Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.7.1-7.8
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• 2020

Background: To minimize the use of antibiotics and to obtain a more sustainable fish culture and aquaculture industry, development of alternative natural source of immunostimulant to replace antibiotic in aquafeed is highly needed. Objective: Dietary inclusion effect of yacon (YC), ginger (GG), and blueberry (BB) on growth, body composition, and disease resistance of black rockfish against Vibrio anguillarum was compared to ethoxyquin (EQ). Methods: Four hundred eighty juvenile (an initial weight of 4.2 g) fish were randomly distributed into 12 of 50 L flowthrough tanks (forty fish per tank). Four experimental diets were prepared; the control (Con) diet with 0.01% EQ inclusion, and YC, GG, and BB diets at 1% each additive inclusion. Each additive was included into the experimental diets at the expense of wheat flour. Each diet was assigned to triplicate tanks of fish and hand-fed to satiation twice daily for 8 weeks. At the end of 8-week feeding trial, 20 fish from each tank fish were artificially infected by intraperitoneal injection with 0.1 mL of culture suspension of pathogenic V. anguillarum containing 3.3 × 10⁶ cfu/mL respectively. Fish were monitored for the following 8 days after V. anguillarum infection and dead fish were removed every 6 h for the first 4 days and 12 h for the rest of the study. Results: Weight gain, specific growth rate (SGR), and feed efficiency ratio (FER) of fish fed the YC diet was higher than those of fish fed all other diets. However, feed consumption, protein efficiency ratio, and protein retention was not affected by dietary additive. Moisture, crude protein, and crude lipid content of the whole body of fish were affected by dietary additive. Analysis of the Kaplan-Meier survival curves showed that survival of fish fed the YC, BB, and GG diets was higher than the Con diet. Conclusion: Oral administration of YC can improve not only weight gain, SGR, and FER of black rockfish, but lower mortality of rockfish at occurrence of V. anguillarum.

• Journal of Korea Port Economic Association
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• v.25 no.1
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• pp.107-124
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• 2009

In order to create value for maritime tourism industry, new port infrastructures have been planned, improvements in passenger terminal services have been designed, and new maritime transport technologies have been applied, so that ports improve their efficiency and the quality of their service more than their national and international competitors. Thus, the purpose of this study is to verify the dimensions of the service quality of ocean passenger terminal. Based on a survey of 260 customers in port of Busan and Inchon, terminal service quality's five main dimensions have been checked regarding their fit with the use of Confirmatory Factor Analysis. Empirical results support that this is a valid instrument for measuring service quality of a ocean passenger terminal. The interactive sequence of computing Cronbach's alpha, corrected item-to-total correlation, and factor analysis was repeated a few times and resulted in a final set of 19 items representing five distinct dimensions-tangibles, responsiveness, knowledge, reliability, and accessibility. This finding provides the more appropriate instrument to evaluate the customers perception as well as to measure the service quality of ocean passenger terminal.

• Journal of Navigation and Port Research
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• v.33 no.3
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• pp.167-174
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• 2009

Recently, design technology of has been required such as catamaran yacht with high-speed according to expand a marine leisure industry. The domestic technical development for design and production of yacht is not actively than Canada, USA, Japan etc. However, with further development of yacht design & technology, it is need to develop a key technology related to increase the value of catamaran yacht. In the present paper, new guideline is suggest for catamaran yacht as like kinds of marine leisure ship in order for fundamental structure design and structural analysis for twin-hulled ship yacht and techniques for structural analysis as sea leisure ship in this research. The class of society has not been proposed formally about regulation and methodology for estimation of strength of small hight-speed craft with satisfying two conditions as noted; length less than 50meters, ratio of length to breadth less than 12. In the present study, we were adopted DNV (Yachts, Design Principles, Design Loads, Hull Structural Design) Rule and KR (FRP rule application guide) for scantling of structural members. Furthermore, ABS rule is used for structural calculation about application of loading conditions for catamaran yacht. This study can be available feedback role to manufacture of 38ft diffusion style for catamaran yacht. It is expected that this study will be a good reference in order to design of catamaran yacht with high-speed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.214-215
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• 2013

Current competition among companies than regional, the time constraints, it is globalization, Tilt the efforts of many to be operated by building the efficient distribution system to reduce logistics costs and improve customer service it is reality's there. Therefore, the need for industrial complexes environmentally friendly can be cost competitive companies perform cavitation region's increased. To build the distribution center these logistics system through a joint of freight and appropriate policy is required. In particular, efficient operation through the system construction of industrial complexes in the logistics system is very important in terms of friendly low-cost urban logistics, the environment. Since the traffic volume which is Jipufa and utilization of network is transported by a more appropriate technicians and means suitable operating model can efficiency is improved. However, despite these advantages, research network design has not been actively conducted due to the complexity of the problem. Therefore, in this study, by analyzing the logistics system, and presents the operating model through a simulation and basic settings for the model of the logistics complex based on the analysis result, the construction of infrastructure of logistics industry complex it is intended to present the article.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.205-209
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• 2009

Recently, the increase of the size of GNP and the expansion of the foreign tour opportunities by the common 5 days work system in a week, reaction of the burden for visiting foreign countries, and expansion of airlines caused the rapid increase of overseas tour but slow increase in the number of foreign tourists, due to the price rise which might impact on the competitive power, and lack of tour infrastructure and attractiveness. As the wide area along the east coast of GyeongBuk Province has great amount of cultural, ocean and natural resources, it helps to get focused the tour industries and maximize the synergy effect through the mutual development coupling the resources and regions. On the basis of the potentials for the growth of east coast area to the international level and the development of local resources, a ocean tour and resort complex for four seasons, which has s strong connection to the local areas resulting the wide tour bond, could help to improve the local economy and balance the development of local province, and furthermore, jump to the level of the center in the East Coast area in the international society. Through the investigation and analysis of the ocean space development status and usage at the advanced foreign countries, the new meaning of the ocean space at the tour and resort complex would be proposed to the relevant local government in fit.