• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.318-320
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• 2018

When a ship sails on sea, it may be influenced by the environmental disturbance such as wind, wave, sea surface temperature, etc. These affect on the ship's speed, fuel consumption, safety and operating performance. It is necessary to find the optimal weather route of a ship to avoid adverse weather conditions which can put the crews in serious danger or cause structural damage to the vessel, machinery, and equipment. This study introduced how to apply A* algorithm based on sea trial test data for determining the optimal ship routes. The path cost function was modelled as a function of minimum arrival time or minimum energy depending on the time of various environment conditions. The specially modelled path-cost function and the safety constraints were applied to the A* algorithm in order to find the optimal path of the ship. The comparison of ship performances estimated by real sea trial's path and estimated optimal route during the voyage of the ship was investigated. The result of this study can be used to create a schedule to ensure safe operation of the ship with short passage time or minimum energy. In addition, the result of this study can be integrated into an on-board decision supporting expert system and displayed in Electronic Chart Display and Information System (ECDIS) to provide all the useful information to ship master.

• 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.

• Korea Trade Review
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• v.44 no.4
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• pp.115-128
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• 2019

This article analyzes issues regarding the economic development of the arctic area with the aim of finding ways to help solve the problems and to support sustainable economic development of the arctic area. Some proposals are introduced for establishing a sound legal infrastructure of the Korea-Russia economic development of the arctic area. As Russia develops the Arctic area and the route through the Arctic area, Korea will gain the possibility of transportation efficiency, vitalization of international transaction, and finding new markets. Resource development in the North Pole is ongoing, with matching international transaction and economic benefits. To reflect the Korea-Russia interests and to sustain the effect, the legal infrastructure is inevitable. For example, it would be reinforced by pushing forward the Korea-Russia FTA. The legal infrastructure for economic cooperation of Korea and Russia has to reflect that 'the development of the Arctic area and making the route through the Arctic area' should increase the sustainability and vitality of international transaction. The legal infrastructure for economic benefits can also help mitigating non-economic arguments of international community such as the security risk in the Korean-peninsula and around the world.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.461-473
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• 2015

Jinhae Bay located in the southern of Korean Peninsular is an important spawning area in Korea. By some preliminary studies it was measured several times that adult Pacific codes (Gadus microcephalus) were passed (swimming layer: 15 to 18 m) over a submerged sea tunnel (sea bottom: about 30 m) rather than another immigration route when the Pacific codes were tagged surgically with an acoustic transmitters and released inside of the Bay. There is a possibility that the Pacific codes and the other fishes use the route on the sea tunnel as an immigration route are affected by a human-generated underwater noise around the sea tunnel due to the sea tunnel traffic. On this study the 25-hour measurements of the underwater noise level by water layer were conducted with a hydrophone attached on a portable CTD and an underwater noise level meter during four seasons, and the acoustical characteristics of the underwater noise was analyzed. The mean traffic volume for one hour at the sea tunnel on the spring was shown the largest value of 1,408 [standard deviation (SD): 855] vehicles among four seasons measurement. The next one was ordered on the autumn [1,145 (SD: 764)], winter [947 (SD: 598)] and summer [931 (SD: 558)] vehicles. Small size vehicle was formed 84.3% of the traffic volume, and ultra-small size, medium size, large size and extra-large size of the vehicle were taken possession of 8.7%, 3.2%, 2.0% and 1.8%, respectively. On the daily change of the noise level in vertical during four seasons the noise level of 5 m-layer was shown the highest value of 121.2 (SD: 3.6) dB (re $1{\mu}Pa$), the next one was 10 m-layer [120.7 (SD: 3.5)], 2 m- and 15 m-layer [120.3 (SD: 3.5 to 3.7)] and 1 m-layer [119.2 (SD: 3.6)] dB (re $1{\mu}Pa$). In relation with the seasonal change of the noise level the average noise level measured during autumn was shown the highest value of 123.9 (SD: 2.6) dB (re $1{\mu}Pa$), the next was during summer [121.4 (SD: 3.2)], spring [118.0 (SD: 3.4)] and winter [116.5 (SD: 5.1)] dB (re $1{\mu}Pa$). In results of eigenray computation when the real bathymetry data (complicate shape of sea bed) was applied the average number of eigenray was 2.68 times (eigenrays: 11.03 rays) higher than those of model bathymetry (flat and slightly sloped sea bottom). When the real bathymetric data toward inside (water depth becomes shallow according to a distance between the source of noise and hydrophone) of the Bay was applied on the eigenrays calculation the number of the eigenray was 1.31 times (eigenrays: 12.49 rays) larger than the real bathymetric data toward outside (water depth becomes deep with respect to the distance). But when the model bathymetric data toward inside of the Bay was applied the number of the eigenray was 1.05 times (eigenrays: 4.21 rays) larger than the model bathymetric data toward outside.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.47-53
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• 1987

Many studies are conducted to evaluate the risk of maneuvering ships in the congested harbours and narrow channels. These studies are very important for the prevention of sea traffic accidents in those sea areas. In this paper, the author carried out a series of observations on sea traffic condition of the vessels entering and leaving the harbour of CHUNG MU, in order to evaluate the risk of grounding, the margin and burden of route keeping maneuver of vessels proceeding along the fairway of this harbour. The results obtained are as follows: 1. The grounding risk indices for the east bound and west bound vessels at the middle part and western part of the fairway were higher than those of them at the eastern part. 2. The margin of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for the east bound vessels, and the highest at the middle part for the west bound vessels, but the lowest at the western entrance for both of them. 3. The burden of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for both of the east bound and west bound vessels, but the lowest at the eastern part for both of them. 4. The influence of maneuvering indices T' on the grounding risk indices appeared to be larger than that of maneuvering indices K' on them.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.1-1
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• 1987

Many studies are conducted to evaluate the risk of maneuvering ships in the congested harbours and narrow channels. These studies are very important for the prevention of sea traffic accidents in those sea areas. In this paper, the author carried out a series of observations on sea traffic condition of the vessels entering and leaving the harbour of CHUNG MU, in order to evaluate the risk of grounding, the margin and burden of route keeping maneuver of vessels proceeding along the fairway of this harbour. The results obtained are as follows: 1. The grounding risk indices for the east bound and west bound vessels at the middle part and western part of the fairway were higher than those of them at the eastern part. 2. The margin of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for the east bound vessels, and the highest at the middle part for the west bound vessels, but the lowest at the western entrance for both of them. 3. The burden of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for both of the east bound and west bound vessels, but the lowest at the eastern part for both of them. 4. The influence of maneuvering indices T' on the grounding risk indices appeared to be larger than that of maneuvering indices K' on them.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.174-180
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• 2016

This study suggests a navigation route for maritime tourism cruise sail yacht that sails off from Yeosu, and passes by Baekdo and Geomundo with their live island culture, to Kimnyeonghang of the Jeju islands. Recently, there are increasing number of accidents in proportion to vitalizing marine leisure. That's why it should be examined by region and sea when developing safe sea route considering characteristics of the sailing yacht. Thus, it is needed to introduce marine culture, hold international sailing yacht race and develop multi-functional sea port according to the case of Geomundo. Also additional analysis for navigation ruote patterns and density of the fairway is required. This information will improve safe sailing level of sailing yacht that will help the local tourism industry.

• Journal of Digital Convergence
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• v.16 no.4
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• pp.49-54
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• 2018

Russia has access to unique port locations and routes, one of them is North Sea route, which have been a major debate topic for last several decades. In order to handle any shipments along the route, an adequate and capable port system must be present. This study aims to identify development and competition patterns from 2007 to 2016 of Russian ports in the Arctic basin, concentration trends in particular. The objectives achieved through utilizing the Herfindahl-Hirschman Index (HHI), concentration ratio (CR), the Gini coefficient and Lorenz curve, and shift-share analysis. Results demonstrate concentration trend, positive overall growth and lack of real competition. Originality of this study lies in the fact that certain analysis had not been done in previous studies, but importance of it may be found in several papers. Findings of this paper may assist policy-makers, port authorities and other researchers in understanding and further study on the region.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.670-678
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• 2018

In coastal waters where the traffic volume of the ship is high, there is a high possibility of a collision accident because complicated encounter situations frequently occurs between ships. To reduce the collision accidents at sea, a quantitative collision risk assessment is required in addition to the navigator's compliance with COLREG. In this study, a new collision risk assessment system was developed to evaluate the collision risk on ship's planned sailing routes. The appropriate collision risk assessment method was proposed on the basis of reviewing existing collision risk assessment models. The system was developed using MATLAB and it consists of three parts: Map, Bumper and Assessment. The developed system was applied to the test sea area with simple computational conditions for testing and to actual sea areas with real computational conditions for validation. The results show the length of own ship, ship's sailing time and sailing routes affect collision risks. The developed system is expected to be helpful for navigators to choose the optimum safe route before sailing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2073-2078
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• 2014

Based on the DGPS radio wave measurement in the coast of the yellow-sea, south-sea and east-sea, the DGPS service regions in the korean coastal ferry route are analyzed in this paper. The impact of obstacles on the propagation due to the archipelago and island regions are measured and analyzed in the point of service region. The ocean-based DGPS reference stations provide the wide DGPS ocean service regions with signal strength more than $40dB{\mu}V/m$ and signal-to-noise ratio more than 10 dB. Based on the overlapping of the service regions between the DGPS reference stations, the DGPS services with good quality are provided in the coastal ferry route segments. In case of regions where the propagation obstacles are scattered, the increasingly good service can be provided under conditions of output power reinforcement and antenna efficiency enhancement.