• Journal of Advanced Marine Engineering and Technology
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• v.27 no.4
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• pp.479-486
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• 2003

This paper presents the Performance of PV(Photovoltaic) system. the design of MPPT and the battery characteristic. The output power of PV depends on the environmental factors such as insolation and cell temperature. It is proposed that the MPPT is based on an simple power control algorithm. Furthermore the converter has to maintain the optimum duty ratio. A switching strategy of converter for battery may Protect against excessive discharge and overcharge. This paper includes discussion on system reliability power quality and effects of the randomness of the wind and the solar radiation on system design.

• Strategy21
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• s.45
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• pp.91-115
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• 2019

When compared to land territorial claims, maritime claims have not attracted as much attention from the public as well as the academia. However, after the ICOW (Issue Correlates of War) data was published and was expanded to include maritime and river claims, there have been many quantitative studies that analyze maritime claims or separate different types of territorial claims to explain various mechanisms over different types of territorial claims. These quantitative studies have provided valuable explanations about the onset and the management of maritime claims. This research tries to review these quantitative research. Most studies about maritime claims, especially regarding the management of claims, analyze maritime claims based on two different levels of factors. First, from the perspective of systemic level, several studies focus on the role of international institutions and systemic level of democracy to explain the management of maritime claims. Second, at the dyadic level, many studies explain how the issue salience, past experience, the presence of resources, joint democracy, and relative power influence the occurrence of peaceful settlement attempts or conflictual behaviors over maritime claims. Based on the review of these literature, this research tries to identify several factors to explain the Dokdo issue and to encourage peaceful settlement attempts over the Dokdo issue.

• Strategy21
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• s.40
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• pp.144-161
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• 2016

A unanimous Award has been issued on 12 July 2016 by the Arbitral Tribunal constituted under Annex VII to the United Nations Convention on the Law of the Sea in the arbitration instituted by the Republic of the Philippines against the People's Republic of China. The current security issues in the regional sea shall be carefully reflected to anticipate whether the Award could resolve the existing political conflict or rather will grow military tension in the region. The Award clearly directs the scope of delimiting maritime jurisdiction to coastal States in the Southern China sea, so it seems to help facilitating finding resolutions of regional disputes on maritime boundaries. On the other hand, there are several limitations in reality to implementation of the decisions included in the Award. USA could use the decisions to restrict military activities and exercise of unilateral maritime jurisdiction by China in the region, while China shall encounter guilt to illegitimacy of its activities as well as shaking the legal foundation of its policy in the region. Then the resolution of this dispute through application of international law would rather cause more political confusion. The intension of bringing the case to an international court were to resolve political difficulties. If, however, the political difficulties are not properly reflected in the legal decisions, such decision would possibly raise more political risks.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.60-66
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• 2021

The importance of maintenance is leading the application of the maintenance strategy in various industries. The maritime industry is also a part of them, with changes in selecting and applying the maintenance strategy, but rather slowly, by retaining the old strategy. In particular, the ship is maintaining a previously used strategy. In the circumstance of the sea, ship requires a new suggestion for maintenance strategy. A ship predictive maintenance model predicts the breakdown or malfunction of machineries to secure maintenance time with preventive actions and treatments, thereby avoiding maintenance-related dangerous factors. This study focused on applying text analysis to an Liquefied Natural Gas Carriers dock indent document, and the analysis results were interpreted from the original document. The inter-relational patterns observed from the frequency of common maintenance combinations among different parts and equipment in ships will be applied to the development of ship predictive maintenance.

• Strategy21
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• s.38
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• pp.5-12
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• 2015

• Journal of the Korean Institute of Navigation
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• v.25 no.2
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• pp.183-193
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• 2001

Since its establishment in 1961, COSCO has developed to be one of the top ten shipping conglomerates in the world with its container fleet having grown to be number seven in terms of slot deployed. The purpose of this study is to examine COSCOs development strategy in the period of Chinese economic reform, and analyse its effects on COSCOs development.

• Strategy21
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• s.37
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• pp.65-103
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• 2015

This study is an attempt to look into the future role of the ROKN and to provide a strategic way forward with a special focus on naval strategic concept and force planning. To accomplish this goal, this research takes four sequential steps for analysis: 1) assessing the role and utility of naval power of ROKN since its foundation back in 1945; 2) forecasting features of various maritime threats to influence the security of Korea in the future directly or indirectly; 3) identifying the roles to be undertaken by future ROKN; and 4) recommending Korean way of naval force planning and the operational concept of naval power. This study seeks to show that ROKN needs comprehensive role to better serve the nation with respect to national security, national prosperity and development, and future battle-space management. To safeguard the national security of Korea, it suggests three roles: 1) national guard for the peaceful unification; 2) protector of the maritime sovereignty; and 3) suppressor to maritime threats. Three more roles are highlighted for national prosperity: 1) escort of the national economy; 2) guardian for national maritime activities; and 3) contributor to the world peace. These roles need to be closely connected with the role for the battle-space management. This paper addresses the need for a dramatic shift of the central operational domain from land to maritime in the future. This will eventually offer future ROKN a leading role for developing strategic concept and force planning rather than merely a supporting one. This study finally suggests 'balanced' strategy both in concept development and force planning. A balanced force planning is a 'must' rather than an 'option' when considering a division of function between Task Fleets and Area Fleets, constructing cutting-edge conventional forces such as Aegis destroyer, CVs, or submarines, and the mix of high-profile platform and low-profile when composing future fleets. A 'balance' is also needed in operational concept. The fleet should be prepared to fulfill its missions based on two different types of force operation i.e., coercive or cooperative application of the utility of naval force. The findings and recommendations of the study are relevant today, and will be increasingly important in the future to achieve various political goals required by enhancing the utility of naval power.

• Strategy21
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• s.42
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• pp.196-223
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• 2017

The aim of this paper is to analyze China's naval strengthening and threat reflected in submarines, aircraft, destroyers and missile capabilities and US Navy's counter-forces. China is strengthening its naval forces in accordance with its three-step naval force build-up plan, and the introduction of Russian destroyers and submarines is a foothold for China's naval enforcement. The Chinese Navy also converted the concept of the First-Second Island Chain Defense, which it had already maintained, to the concept of maritime layer defense. Currently, the Chinese Navy maintains the concept of a Three-Maritime Layer Defense which includes the South China Sea, where artificial islands are being built by China, in the First Layer Defense and the East China Sea in the Third Layer Defense. Along with the advancement of Chinese Navy's submarines, surface vessels and aircraft's operational capabilities, ballistic and cruise missile capabilities become a major threat to the US Navy. If a crisis occurs in the East China Sea or in the Taiwan Waters, the US Navy will face more difficulties in employing the Carrier Strike Group to manage the crisis. Meanwhile, if a crisis occurs on the Korean Peninsula, it will be a burden to dispatch Carrier Strike GroupS to the East and West Seas of the Korean Peninsula. For the stable future, the US Navy should develop a strategy to respond more effectively to the Chinese Navy, which is challenging new maritime supremacy in East Asia.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.397-405
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• 2023

As interest in greenhouse gas reduction has increased in all sectors, the discussion of the International Maritime Organization (IMO) to regulate pollution by ships is attracting attention in international shipping. At the 80th IMO MEPC held in July 2023, the 「2023 IMO Strategy for the Reduction of Green House Gases from Ships (MEPC. 377(80))」 was adopted, which included the net-zero target around 2050, and a firm intention to the decarbonization of the international shipping sector showed. In particular, energy, fuel and technology targets for zero or near-zero greenhouse gas emissions by 2030 were added as new targets, and total greenhouse gas emission checkpoints for 2030 and 2040 were added as an indicator for achieving the 2050 target. The IMO's goal setting for 2030, which is about seven years away, will impose a lot of technical, economic, and political burden despite the decarbonization technology of international shipping, which has grown to a significant level in a short period of time. Accordingly, this paper presents the comprehensive impact of the 2023 IMO GHG Strategy on international shipping.

• Maritime Security
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• v.1 no.1
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• pp.241-271
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• 2020

The military technology currently receiving the most attention is the hypersonic missile. hypersonic is faster than the speed of sound or Mach 5+. The vast majority of the ballistic missiles that it inspired achieved hypersonic speeds as they fell from the sky. Rather than speed, today's renewed attention to hypersonic weapons owes to developments that enable controlled flight. These new systems have two sub-varieties: hypersonic glide vehicles and hypersonic cruise missiles. Hypersonic weapons could challenge detection and defense due to their speed, maneuverability, and low altitude of flight. The fundamental question of this study is: 'What effect will the hypersonic missile have on the maritime strategy?' It is quite prudent to analyze and predict the impact of technology in the development stage on strategy in advance. However, strategy is essential because it affect future force construction. hypersonic missiles act as a limiting factor in securing sea control. The high speed and powerful destructive power of the hypersonic missile are not only difficult to intercept, but it also causes massive ship damage at a single shot. As a result, it is analyzed that the Securing sea control will be as difficult as the capacity of sea denial will be improved geographically and qualitatively. In addition, the concept of Fortress Fleet, which was criticized for its passive strategy in the past, could be reborn in a modern era. There are maritime power projection/defence, SLOC attack/defence in exploiting sea control. The effects of hypersonic missiles on exploiting sea control could be seen as both limiting and opportunity factors.