• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.112-118
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• 2013

This paper reports the results of a comparative study on rudder performance between the steel rudders that have been used in coastal angling fishing boats in the 20-GT class and the newly developed FRP composite material rudders. In order to compare the rudder performances of these two types, a sea trial test was carried out to investigate the speed performance, fuel consumption, and ship's turning ability. The results showed that the sea trial performance of the FRP composite rudder was better than that of the steel rudder type in terms of the sea speed, fuel consumption rate, and turning ability.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.506-515
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• 2005

Novel ships are commonly required iterative hull form modifications until she get reputation for new marine environment. Small FRP boats are manufactured in a identical shape with a mould. It implies that every modification step requires great time and expense which makes it difficult to improve the hull form promptly. Domestic hull form of small fishing boat of force has been evolved from the traditional hull form of developable shape. Utilizing this typical developable characteristics of small boats, ,New mouldless production method for FRP boat has been suggested and it is confirmed that the method is recommendable for a petty order of hull in evolving period of hull form development.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.495-503
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• 2019

Approximately 90,000 ships are registered in South Korea, and about 80,000 of these ships are used in domestic shipping. Among these, 84% are small ships, such as a fishing vessels that weigh less than 20 tons and are made mostly of an FRP (Fiber Reinforced Plastics). When this fact is taken into account, the greenhouse gas emissions that are released per ton of a composite vessel are sizeable. In this study, the laminated structures of an FRP fishing vessel, many of which currently are being built in Korea, were analyzed by ISO (International Organization for Standardization) and international design rules, and the structures of the hulls are lightweight with optimum glass fiber mass content as determined by the laminate weight minimization algorithm. As a result, it was confirmed that the laminations of the vessels in accordance with the Korean rule could have 6.4% to approximately 11% more design margin compared to the requirements of ISO and other international rules. And the case study of the application of the laminate weight minimization algorithm showed the possibility of reducing the weight of the hull bottom plating by as much as about 19.32% and by as much as about 18.06% in the overall structure.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.1-8
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• 2013

This study focuses on a ship detection and tracking method using Frequency Modulated Continuous Wave (FMCW) radar used for horizontal surveillance. In general, FMCW radar can play an important role in maritime surveillance, because it has many advantages such as low warm-up time, low power consumption, and its all weather performance. In this paper, we introduce an effective method for data and signal processing of ship's detecting and tracking using the X-band radar. Ships information was extracted using an image-based processing method such as the land masking and morphological filtering with a threshold for a cycle data merged from raw data (spoke data). After that, ships was tracked using search-window that is ship's expected rectangle area in the next frame considering expected maximum speed (19 kts) and interval time (5 sec). By using this method, the tracking results for most of the moving object tracking was successful and those results were compared with AIS (Automatic Identification System) for ships position. Therefore, it can be said that the practical application of this detection and tracking method using FMCW radar improve the maritime safety as well as expand the surveillance coverage cost-effectively. Algorithm improvements are required for an enhancement of small ship detection and tracking technique in the future.