• Journal of the Society of Naval Architects of Korea
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• v.56 no.1
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• pp.58-65
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• 2019

The stability, reliability and efficiency of a smart ship are important issues as the interest in an autonomous ship has recently been high. An automatic collision avoidance system is an essential function of an autonomous ship. This system detects the possibility of collision and automatically takes avoidance actions in consideration of economy and safety. In order to construct an automatic collision avoidance system using reinforcement learning, in this work, the sequential decision problem of ship collision is mathematically formulated through a Markov Decision Process (MDP). A reinforcement learning environment is constructed based on the ship maneuvering equations, and then the three key components (state, action, and reward) of MDP are defined. The state uses parameters of the relationship between own-ship and target-ship, the action is the vertical distance away from the target course, and the reward is defined as a function considering safety and economics. In order to solve the sequential decision problem, the Deep Deterministic Policy Gradient (DDPG) algorithm which can express continuous action space and search an optimal action policy is utilized. The collision avoidance system is then tested assuming the $90^{\circ}$intersection encounter situation and yields a satisfactory result.

• Ocean and Polar Research
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• v.27 no.4
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• pp.419-431
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• 2005

With the draining of land resources, and rising new economic and resources expansionism, finding a new and yet to be developed ${\ulcorner}treasure{\lrcorner}$ is often a fierce and competitive challenge among many nations. This is especially true for Korea confronted with its urgent needs to find new resources and strategy to maintain the current pace of societal demand and economic development in this often impatient and rapidly progressing world. The ocean world in the South Pacific provides potentials to quench both orders with promises of new ${\ulcorner}treasure{\lrcorner}$ of living and ecosystem resources such as new fisheries and new bioactive products as well as providing alternative aesthetic, recreational resources and critical informations on various societal problems such as extreme weather conditions and early wining of the consequences resulting from global environmental changes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.954-966
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• 2021

With regards to the marine spatial plannings of the world, the spaces are being managed through the integration of various uses and the establishment of systems and laws in the perspective of the utilization of spaces. In the perspective of policy establishment, the policy readiness level is applied to analyze the trends in the studies on South Korea's marine spatial plans. The scope of the study included analyzing marine spatial plan as a keyword in articles published over the period from 2010 to 2020. The methods of analysis included the analyses of the frequency of word appearance, word clouds, and appearance intensity, which were used to identify key issues. Five keywords that were related to the topics were identified, and were again used to identify the key themes. The core themes were changing in all phases, such as the principles development phase, institutionalization phase, policy verification phase. For future benefit, this requires more research in South Korean public organizations and universities.

• Ocean and Polar Research
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• v.24 no.1
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• pp.93-114
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• 2002

Legal regimes of major countries actively involved in wetland programs including USA, Japan, Germany, Netherlands, and Denmark, show that these leading nations have developed their own legal regimes and policies for the conservation and restoration of wetlands since early 1990s. The main feature of their position is to preserve, create and restore wetlands, including tidal flats. However, this approach, so called 'mitigation' policy, is thus far, not a fully established policy but an evolving one. For Korea, there are only a few laws and policies which hint at the importance of creating coastal wetlands as a conservation measure, however, most of those systems only exist as vague provisions which lack any tangible and compulsory implementing procedures and technical guidelines. It seems that it is necessary to strengthen the legal measures for conserving coastal wetlands in Korea including specifying economic assessment methods and funding sources for the creation, restoration and rehabilitation of tidal flats to firmly establish a national wetland mitigation policy.

• Ocean and Polar Research
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• v.25 no.4
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• pp.483-491
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• 2003

Since the red grouper was declared overfished, the Gulf of Mexico Fishery Management Council must prepare a rebuilding plan considering the following alternative management policies: a Total Allowable Catch (TAC), 5-month season closure, 1800-pound trip limit, and a 50-fathom longline boundary. This study was aimed at evaluating the effects of proposed policies for rebuilding the red grouper stock in a 10-year period by developing a bioeconomic model. Under the assumption that the recreation sector was held to its share of TAC (24% of the total quota), the target stock biomass goal was attained in all policies. The NPV was the largest in the 5-month season closure policy if the output price did not fall. There were distributional effects on the different components of the fleets in the 1800-pound trip limit and the 50-fathom longline boundary policy.

• Ocean and Polar Research
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• v.35 no.4
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• pp.351-353
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• 2013

Until recently, Pacific equatorial tropical island states were subject of only very limited interest by scientists, government officials, industry and policy makers of Korea. And, comprehensive information and data on these island regions is not very detailed to help better understand their social backgrounds as well as their natural environment. However, these island regions are now in the middle of diplomatic tug-of-war among super powers as well as becoming nucleus of various science-based ocean issues including marine biodiversity, shifting ecosystem, global environmental change including sea level rise and ocean acidification, fisheries, etc. Therefore, rising political and scientific importance of these areas call for better understanding of these regions, in social aspects as well as natural scientific knowledge of the region. To be provocatively prepared to more actively role in these regions, "A study on Establishing Research Infrastructures in the Tropical Pacific" has been supported during 2012-2013 as a mission-oriented in-house project of the KIOST. This project aims to provide various research infrastructure for Pacific island states, to reinforce cooperation with these nations, and to enhance Korea's national prestige. This special issue contains 10 research articles based on the studies conducted in 2012~2013.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.75-84
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• 2022

Since South Korea did not adopt the recreation fishing using right (coupon) system, there were no recreation fishing statistics. This study selected 480 fishing vessels (10.4%) of a total of 4,611 fishing vessels (as of December 2019) as a survey sample using stratified sampling. Unlike other research institutes that conducted surveys related to the amount of tide on a one-time, this survey was conducted for five months (from May to October 2020, except the month of August). The captain investigated about types of fish, size, weight, etc. to anglers. A difference from previous studies was that about 7.0 million angler population (fishing more than three times a week) had 19.4 kg of catch per person for a year while other studies showed about 25.5-52.0 kg, respectively. The total fisheries resource catch amount was analyzed to be about 95,000 tons in this study and 116,000-166,000 tons in other studies. So there was a difference of about 1.2 to 1.8 times. This study aims to lay the foundation for the development of the fishing industry by preparing accurate statistical data and securing reliable basic statistics related to the fishing industry. Also, it could be usefully used as basic policy data such as introduction of a fishing using right (coupon) system.

• Ocean and Polar Research
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• v.36 no.4
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• pp.505-514
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• 2014

The development of deep seabed manganese nodules has been carried out with the aim of commercial development in 2023. It is important to forecast the price of the four metals (copper, nickel, cobalt, and manganese) extracted from manganese nodules because price change is a criterion for investment decision. The main purpose of the study is to forecast the price of four metals using the ARIMA model and VAR model, and calculate the MAPE to compare a goodness-of-fit between the two models. The estimated results of the two models reveal statistical significance and are in keeping with economic theory. The results of MAPE for goodness-of-fit show that the VAR model is between 0.1 and 0.2, and the ARIMA model is between 0.4 and 0.6. That is, the VAR model is better than the ARIMA model in forecasting changes in the price of metals.

• Ocean and Polar Research
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• v.28 no.3
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• pp.273-285
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• 2006

As the political arguments on international power concept has gradually been deepened, the role of international regimes, defined as principles, norms, rules, and decision-making procedures around which nation-actors' expectations converge in a given issue-area, has also been reinforced. There are many ways of understanding about international regimes. In terms of realistic theories, international regimes are one of methods of maintaining hegemonic power order of hegemonic nation and in terms of liberalistic theories, international regimes are understood as the products of mutual inter-dependence of nations in changing international society. As a matter of fact, if we take structural causes and regime consequences into severe consideration, we can find not a few characteristics of international regimes, such as security regime, world trade and fiance regime, ocean regime, environmental regime, human right regime, etc. This paper will examine the changing concept of power after World War II in three categories of hard power (military power), meta power (regime creating power), and soft power (advanced in cultural, diplomatical, and technological power). This paper will provide the evidence of why the changing power concepts will be strongly related with the emergence of international regimes. The UN convention on the law of the sea will chosen as a standard case of the ocean regime and it's regime structure and role will also be analysed in both realistic :md liberalistic theories. Futhermore, the nations' interests involved in the UN convention on the law of the sea will be analytically classified and finally a future prospectus of the UN convention on the law of the sea as an ocean regime will be tested.

• Ocean and Polar Research
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• v.45 no.3
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• pp.173-183
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• 2023

The barren ground phenomenon in Korea began to occur and spread in the southern coast region and in Jeju Island in the 1980s, and since the 1990s, the damage has become serious in the east coast region as well. Korea has enacted the fisheries resource management act to manage such barren ground through the installation of sea forests among projects for the creation of fishery resources. Until now, projects related to the identification of the cause of barren ground have focused on the density of crustose coralline algae, sea urchins and seaweed, so the original cause of barren ground has not yet been identified. In order to manage barren ground, it is necessary to identify the cause of barren ground. To identify these causes, it is necessary to comprehensively consider i) studies on spatial characteristics such as rock mass distribution, slope and water depth, ii) studies on ecological and oceanographic characteristics such as water temperature, salinity, El Niño, and typhoons etc, iii) studies on organisms such as crustose coralline algae, macroalgae, and sea urchins, and iv) studies on coastal use such as living and industrial sewage inflow. Next, as with regard to legislative policy proposals , it is necessary to prepare self-management measures by the government, local governments, and fishermen as well as address management problems related to the use of sea forests by fishermen after their creation . In addition, when creating a sea forest, a management model for each resource management plan is required, and evaluation indicators and indexes that can diagnose the cause of barren ground and guidelines for barren ground measures should be developed.