• Journal of Navigation and Port Research
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• v.28 no.5
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• pp.339-345
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• 2004

The term ton is widely used as the unit of the ship's size. Before people used the term ton as the unit of the ship's size, the various terms had been used for indicating the ship's size. For examples, the term ton was used in Western Europe, last in Northern Europe, cantara in Geneva, milliaria in Venice, and carra in Naple respectively. In Asia the rice had been the most important cargo for many centuries. So the term SEOK in Korean or SHI in Chinese was used as the unit of the ship's size. Especially the Chinese used the term LIAO in Chinese or RYO in Korean for indicating the ship's size. As above seen, the different terms had been used for showing the ship's size from places to places. But with the introduction of Moorsom's Tonnage Measurement in the middle of the 19th century and its spread to all over the world, the term ton was become the only unit of ship's size.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.103-109
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• 2004

The term ton is widely used as the unit of the ship's size nowadays. Before people accepted the term ton as the unit of the ship's size, the various terms had been used for indicating the ship's size. For examples, the term ton was used in Western Europe, last in Northern Europe, cantara in Geneva, milliaria in Venice, and carra in Naple. In Asia the rice had been the most important cargo for many centuries. So the term SEOK in Korean or SHI in Chinese was used as the unit of the ship's size. Especially the Chinese used the term LIAO or RYO in Korean for indicating the ship's size. As above seen, the different terms had been used for showing the ship's size from places to places. But with the introduction of Moorsom's Tonnage Measurement in the 19th century and its spread to all over the world, the term ton was become the only unit of ship's size.

• Journal of the Korean Institute of Navigation
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• v.6 no.1
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• pp.19-39
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• 1982

There may be a lor of studies on the economic design of ship for the most favorable combination of design basis on the owner's request. However, there are few on the economical ship's size and speed for the ship owner's stand point. This paper describes on the optimal ship's size and speed to the given marine commercial environments for the owner's requirement to the shipyard. As the result of the paper, the criterion curve of bulk carrier will also be used to assess existing ships for their profitability.

• Journal of Ocean Engineering and Technology
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• v.28 no.1
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• pp.28-33
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• 2014

The Korean icebreaking research vessel "Araon" performed four sea trials in the Arctic and Antarctic Seas. The ice properties, such as the ice thickness, floe size, ice strength, and power of the vessel were quite different in these trials. To compare the speeds of ship with the same ice strength and power, the AARC (Arker Arctic Research Center) method is used with a vessel power of 10 MW and an ice strength of 630 Pa in this paper. Based on the analysis results, the speed of the ship was 1.62 knots (0.83 m/s) with a 1.02-m ice thickness and 2.5-km floe size, 5.3 knots (2.73 m/s) with a 1.2-m ice thickness and 1.0-km floe size, and 13.8 knots (7.10 m/s) with a 1.1-m ice thickness and 200-m floe size. The analysis results showed that the ship speed and floe size have an inversely proportional relationship. Two reasonable reasons are given in this paper for the final result. One is an ice breaking phenomenon, and the other is the effect of the ice floe mass. For the breaking phenomenon, the ice breaking force is very small because the ice floe is not breaking but tearing when a ship is passing through a small ice floe. Regarding the effect of the ice floe mass, it is impossible for a ship to push and tear an ice floe if the mass of the ice floe is too large compared to the mass of the ship. The velocity of the ship decreases when the ice floe has a large mass and a large size because the ship has to break the ice floe to move forward.

• Journal of Navigation and Port Research
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• v.48 no.2
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• pp.104-108
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• 2024

This study investigates the relationship between national controlling fleets and the managerial performance of ship management companies in Korea. As industries clearly show interrelations between upstream and downstream entities , it is likely that the managerial performance of ship management companies in Korea is affected by the size of national fleet. Therefore, the present study analyzes the impact of Korean fleet size on the growth and the profitability of ship management firms. To this end, the performances of 10 major ship management companies in the period from 2012-2022 are examined through panel data regressions. The results indicate that the size of the national fleet has a positive impact on growth in both the assets and the sales of ship management companies. Specifically, the size of the Korean-flagged fleet is the most crucial factor, while that of the foreign-flagged fleet has no significant effect. In stark contrast to the findings regarding growth, the size of national fleet is found to have no significant impact on the profitability of ship management companies. This study's findings are expected to provide valuable implications informing both the managerial decision-making of ship management companies as well as policy-making for shipping and its related industries.

• Journal of Navigation and Port Research
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• v.46 no.5
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• pp.441-448
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• 2022

The aim of this study was to examine determinants of secondhand Bulk carrier and Oil tanker prices. This study compiled S& P transaction data taken from the Clarksons Research during J anuary 2018 to April 2022 to see how independent variables influenced secondhand ship prices. In the secondhand ship pricing model of entire segments, size, age, and LIBOR showed significant effects on prices. A vessel built in J apan and Korea was traded at a higher price than a vessel built in other countries. In the bulk segment, size, age, Clarksea index, LIBOR, and inflation were meaningful variables. In the Tanker segment, unlike Bulk carrier, only size and age were useful variables. This study performed regression analyses for various sizes of Bulk carriers and Oil tankers. It verified that impacts of variables other than ship size and age were significantly associated with ship type and size while macroeconomic variables had no influence except for bulk carriers. By applying diverse variables affecting secondhand ship price estimation according to various sizes of Bulk carriers and Oil tankers, this study will expand the scope of practical application for investors. It also reaffirms prior research findings that the secondhand ship market is primarily market-driven.

• Journal of the Korean Institute of Navigation
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• v.7 no.2
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• pp.65-113
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• 1983

A lot of studies of ship's economy are on the traditional fields such asreducing propulsion resistance, raising cargo handling rates and lessening building consts, but there are few researches on the merchant ship's economy concerning their deadweights and speeds according to shipping companies managerial cercumstances. Contrary to the contemporary trend that "the bigger, the better, if the cargo handling rate could increased sufficiently to hold down port time to that rate of smmaler vessels", this paper demonstrates the existence of certain limits in ship's size and speed according to the coditions of the freight rates, voyage distances, cargo handing rates, prices of fuel oil, interst rates etc. Fom the curves of criteria contour for various ship's deadweights and speeds which are depicted from the gird search method, one can get the costs and the yearly profit rates under the conditiions of large volume with long term contracts for the transportation of bulk cargoes. In estimating ship's transportation economy, the auther takes the position that the profit rate method is properer than the cost method, and introduces the calculation table of the voyage profit rate index. The use of the criteria contours will be of help to ship owners in determining the size and speed of the ship which will be built or purchased and serve in a certain trade route.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.132-137
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• 2003

This performance is motivated to develop a tracking antenna system for receive the satellite broadcasting signal in the coast sailing ship. Therefore, this system is made to small size, light weight and simple operation which is must to low cost system for popularization of small size ship and adaptive possibilities with useful on a ship in the coast using 1 axis Az-mount. The antenna mount structure is a compact size and easy operation to the Az-axis type which is operated by step motor. The antenna unit is a domestic made plate type of patch array and ship's moving detection is using the gyro sensor for ship's moving control. We are designed to algorithm, which walking is abreast for step track and ship's moving compensation. Ship's moving compensation is adapted to the closed loop control method by detection from gyro sensor. This system is consisted of micro processor, ADC, comparative amplifier, step motor driver, mount mechanism and algorithm. We have analysised the tracking performance of prototype on sailing ship board.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1130-1137
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• 2003

This performance is motivated to develop a tracking antenna system for receive the satellite broadcasting signal in the coast sailing ship. Therefore, this system is made to small size, light weight and simple operation which is must to low cost system for popularization of small size ship and adaptive possibilities with useful on a ship in the coast using 1 axis Az-mount. The antenna mount structure is a compact size and easy operation to the Az-axis type which is operated by step motor. The antenna unit is a domestic made plate type of patch array and ship's moving detection is using the gyro sensor for ship's moving control. We are designed to algorithm, which walking is abreast for step track and ship's moving compensation. Ship's moving compensation is adapted to the closed loop control method by detection from gyro sensor. This system is consisted of micro processor, ADC, comparative amplifier, step motor driver, mount mechanism and algorithm. We have analysised the tracking performance of prototype on sailing ship board.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.872-883
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• 2012

Generally the determination of turning basin for vessels of entering & sailing in the berth has been considered in the design standard of harbor construction rules of the port. In this regard, the turning basin has been determined by the max size of entering vessel of the berth/port. But the size of turning basin may considered the ship's maneuvering ability, operator's skillful power, mooring equipments of the berth, arrangement of the fairway and the environment condition of weather & seas around the designated port area. So this paper suggested the optimum size of turning basin after studying the harbour design rules of the advanced marine countries and using by maneuvering simulator for turning basin size and also evaluated the design standard of harbor construction rules and minimum size of turning basin against ship's length at the Gangjung civil/naval port of Jeju Island.