• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.1-8
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• 2004

In this study, the change of the current in the coastal zone before and after the construction of Jeju new harbor was predicted by using the numerical model, which uses Hardy-Cross method. The numerical model was carried out for the present state, before the construction, and the state after the construction, and for the wave direction the NNW direction for winter and NE direction for summer were tested so that the seasonal change may be considered. The computation result shows that a large amount of the wave induced current was occurred when there were high waves coming in from NNW direction before and after the construction. Also, before the construction a longshore current occurred moving from the west to the east at the new harbor construction site so that it formed a rip current in the Hwabuk-dong front sea. And also, after the construction, the tip current produced changed into nearshore circulating current and a small circulating current appeared at the harbor entrance. On the other hand, at Samyang 4each, which is 3.0km away from the new harbor in the NE direction, shows that there was a longshore current occurred from the west to the east, which is in the opposite direction the new harbor, and the effect on the new harbor by sediment transport at Samyang beach is thought to be very small.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2006.09a
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• pp.149-152
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• 2006

• Korean Journal of Environmental Biology
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• v.37 no.1
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• pp.68-71
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• 2019

An asteroid specimen that belongs to the genus Henricia was collected from the waters near Ongpo harbor, Jeju Island using fishing net on 24 January 2017. The specimen was identified as Henricia anomala Hayashi, 1973, which belongs to the family Echinasteridae and order Spinulosida. Henricia anomala was first described by Hayashi, 1973, who captured it from Sagami Bay at a depth of 110-116 m. This species can be distinguished from other Henricia species by short arms (R/r=4), abactinal spines lining the abactinal plates and bearing about two to five spinelets, closely meshed abactinal skeleton, composed of small rod-like and subtriangular plates, a narrow papular area containing one or two papulae, and adambulacral armature composed of five to seven bluntly pointed spinelets. This is the first report of Henricia anomala in Korea.

• Animal Systematics, Evolution and Diversity
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• v.22 no.1
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• pp.105-108
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• 2006

Some sea urchins were collected from the subtidal rocky bottom along the coastal line in Jeju Island by SCUBA diving in April 2005 and identified on the basis of their morphological characteristics. Among them, Asthenosoma ijimai Yochiwara, 1897 was newly recorded from Korea and redescribed based on the specimen collected at 20m deep in southern breakwater of Seogwipo harbor. The order Echinothurioida including family Echinothuriidae and genus Asthenosoma was firstly recorded in Korea. Seventeen species of echinoids are reported to be distributed in Jeju Island of Korea.

• Strategy21
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• s.39
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• pp.140-162
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• 2016

The construction of Jeju Naval Base was finally completed and donated to the Republic of Korea Navy on February 26th this year. There is no doubt that the new base will contribute to the substantial augmentation of Korea's naval power and maritime security. However, we should note that the new naval base took a long and hard twenty-three years to be completed. In the 21st century, Korea should adopt a new strategy that can fulfill the security requirements of Korea for the new age of international relations. The 21st century is characterized by globalization, and in the world of globalization, a national boarder has become meaningless. In the late 20th century, after the Cold War, trade between countries have greatly increased and so did the importance of the seas. Having transformed from an agricultural country into a commercial country, Korea went from a continental state to a maritime state. Korea has become the 9th largest trading state, and obviously, the importance of the sea has become significant. Korea's national strategic focus needs to be on the sea for national survival. Thus, since the 1990s, the Korean Navy has planned to build the Jeju Naval Base. Jeju, due to its geopolitical characteristics, is extremely important to the 21st century Korea's economy and national security. Jeju is the starting point of the sea route that reaches out to the world, and at the same time, the ending point of the sea route that heads towards Korea. Jeju is located in the center of Northeast Asia and thus, Jeju Naval Base is extremely important for the area's security and order. Jeju Naval Base will be very useful not only for the maritime security of Korea, but also for keeping peace and order in Northeast Asia. Jeju Naval Base was the minimal effort against the six sea route security threats towards Korea. The six sea route threats are: 1) Threat from North Korea; 2) China's Threat towards Korea's sovereignty; 3) China's treat towards Korea's fishery; 4) Threat from Japan; 5) Threat towards Korea's sea routes; 6) Threat from recent phenomena of isolationism of the United States. Jeju Naval Base is built for both warships and civilian ships--such as cruise ships--to use. Just like the United States' Pearl Harbor, Jeju Naval Base will become not only the largest military base, but a beautiful tourist site.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.243-253
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• 2017

This study aims to compare Jeju Island, Shanghai, and Yokohama cruise ports and to investigate the relative strengths and weaknesses of Jeju Island. This study conducted comparative evaluation of 8 factors [airport, berth, expenses, distance, access to town, shopping facilities, source market (background market), and tourism] through a cruise network analysis. Comparative evaluation results find that Jeju Island, which secured 2 berths (berthing capacity) by completion of the civil-military complex port, has ascendancy over Shanghai cruise port and will have ascendancy over Yokohama cruise port once construction of the new airport is completed. Therefore, it will qualify as the best cruise port in Northeast Asia in the future. Results obtained from the cruise network analysis provide insights for administrative policy. Study limitations include only eight factors are used for evaluating the cruise-ship harbor area and surrounding hinterlands, and thus cannot sufficiently evaluate the complex conditions of the sites. In the future, it is necessary to reexamine the evaluation factors of the cruise ship harbor in detail. Furthermore, future research will need to consider the economic effects of the cruise ship industry, and its relevance to related industries as a possible fusion or hybrid industry.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.112-119
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• 2002

In accordance with the development plans of Jeju for international free city, Jeju new harbor will be constructed cosidering supporting Jeju city as an international tour city, safe arrival and departure at the terminal of 80.000G/T cruise ship. In this study, we used a full-mission ship handling simulator adopting 80.000G/T cruise ship manoeuvered at the planned Juju international cruise terminal. Five masters who have had a long experience of shop maneuvering ware called to carry out the simulations of which No. 1 , Np. 2, and No.4 scenario of simulation were tried twice, completed the total of 10 times and No.3 scenario of simulation once, reached at the total of 5 time. The marine traffic safety was assessed in terms of 1) the closest point of approach(CPA) to breakwater and quay in the vicinty and the probability of crossing fairway limit, 2)subjective evaluation such as the mental burden and the maneuvering disfficulty of shiphanders and 3) the opinions of shiphandlers. From th result of this simulation, we have a conclusion that the 80.000G/T cruise ship can be maneuvered safely at the planned terminal.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.43-49
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• 2011

For the improvement of water quality in a harbor, several studies have been carried out on SEB (Seawater Exchange Breakwater) in recent years, but a problem has been shown whereby the water on the inside area far from the SEB cannot be easily exchanged. In order to solve the problem of the SEB, the Manifold channel, a new concept of the SEB, is introduced in this paper. By using the manifold channel, it is possible to exchange the water of the inside area for seawater from the outside. Here, to assess the outflow gates of the manifold channel governing flow behavior, a virtual manifold channel controlled the location, width and direction of outflow gates applied to the Jumunjin fishery port, where the SEB has been established. In addition, the desirable flow pattern of the port by utilizing the two layer current model is identified, and five general cases of the manifold channel are described in this paper. The model is verified by comparing with observation of the SEB model, and the results are in general agreement. From the results of the manifold channel, in the case of the Jumunjin fishery port, the small circulation of counter clockwise is necessary for the water exchange on the inside area, but it should be controlled by the outflow gates for other areas. Using the two layer current model, the desirable flow pattern of the port can be predicted, and the water exchange for the upper and lower layer can be examined. For the practical use of the manifold channel, further studies on the manifold channel will be necessary, and it may then be used broadly for the design of breakwater in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.372-382
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• 2006

Most of the conventional breakwaters impermeable breakwaters which block seawater exchange between the outside and inside of the harbors. The blocking of seawater exchange may cause pollution of water in harbors. To solve the water pollution problem, various kinds of seawater exchange breakwaters have been proposed. Their types can be classified into the current type which uses tidal current, and the overtopping type which uses the wave energy. The overtopping type breakwaters require a discharge coefficient to calculate the rate of overtopping into the harbor. The present study is to compute the rate of overtopping with introduction of a correct discharge coefficient and to evaluate the effect of the overtopping type breakwater on the water qualify inside a harbor. The rate of overtopping was computed by using Forchheimer formula with time dependent mild-slope equation for various wave conditions. The formula has been generally used to calculate the overflow discharge in steady state river flows. The discharge coefficient, which is the key parameter of the calculation, was determined by a series of hydraulic model tests. The present scheme was applied to the seawater exchange section of the western breakwater of Jeju New Harbor's and the efficiency of that section was examined. The calculated results showed that the rate of overtopping into the harbor reached about $27.5m^3/s$ in the wave condition (wave height 3.7 m, wave period 8.5s, and wave direction NNW).