• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.2
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• pp.61-69
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• 1989

Mackerel purse seine fishery operating in the sea area of Cheju and Tsushima is one of the most important fishery in Korean off shore fishery, which a fishing fleet are generally composed with one purse seiner, two light ships and three or four fish carriers. In this study, purse seiners are classified in to four classes in term of their gross tonnage : A class(80-100tons), B class(100-120tons), C class(130-140tons), and D class(140-150tons). Operating sea area are divided into five sectors including east and west sea area of Tsushima Island, coastal sea area of Cheju Island and south and west sea area of Cheju Island. The performance of the purse seiner, the fishing efficiency, the dimension of fishing gear and variation of CPUE in each operating sea area are summarized as follows: 1. The relationship between a gross tonnage x and net area of purse seine y of a purse seiner can be expressed as : y=538.8x+99657.3 2. The index of seasonal variation of CPUE from May to October is lower than the standard value, whereas index from November to April is higher. 3. The power factor of fishing efficiency by classes of boat-size shows significant differences with 1% level in each operating sea area. 4. The net efficiency of purse seiner by classes of boat-sea shows that B and C classes are higher than A and D classes.

• Journal of the Korean Society for Railway
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• v.13 no.2
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• pp.201-207
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• 2010

The replacement criterion of rail by accumulated passing tonnage was estimated by the bending fatigue life of rail. In order to estimate the bending fatigue life, it is basically needed to analyze bending fatigue behavior on the rail. In this study, the bending fatigue test were performed for 50kg/m and 60kg/m rails, and test specimens were distinguished by new and used rails and by the types of welded rail such as base material, thermite weld, and gas pressure weld. Also, this study analyzed the fractured surface, the position of initial crack and the bending fatigue behavior (S-N curve). Therefore, it evaluated S-N curve for welded rails according to the fracture probability. The result from this study might be used essential data in order to estimate the bending fatigue life of rail by the accumulated passing tonnage.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.33-40
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• 2006

To promote the consistent and effective implementation of IMO instruments such as SOLAS, MARPOL, STCW, LL, TONNAGE, COLREG IMO has adopted voluntary IMO member state audit. This audit scheme is voluntary audit which will be carried out on a voluntary basis, at the request cf the member state to be audited. Nevertheless, the Korea government is preparing the implementation of the audit scheme to strengthen the competitiveness in shipping and shipbuilding industries. In this paper, we investigated the actual conditions of implementation of mandatory IMO instruments and carried out a feasibility study by assessing the cost to be audited and positive effects expected by introducing the audit scheme. As a result of cost benefit analysis we obtained high benefit-cost ratio.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.5
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• pp.1158-1164
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• 2014

The propensity analysis for oral exam candidates of sixth class deck officer's license was conducted to serve as a basic data for improving the ability of seamanship and a stable workforce supply using a questionnaire. A general information of them was identified as 64.4% of offshore fishing, 56.8% of over 50, 56.6% of less middle school education, 55.6% of under 100 gross tonnage, 81.2% of over 10 years experience, 85.6% of deck department, which means they are from mainly less than 100 gross tonnage of offshore fishing vessel, less educated, and long term experienced in the deck job. The reason why they took the test was mainly due to their will (71.1%). And 52.7% of them took the test for the first time, 52.7% of answers responded they are lack of knowledge about a written exam and text of KIMFT in preparation data for an oral exam 23.3%. Given the fact that 83.3% of respondents experienced marine accidents on board, the need for marine casualty reduction education was verified. Even after obtaining a license, they showed a higher preference of boarding that they embarked before the examination. Also, 61.7% of them have a plan for long-term boarding at least three years, thus leading to supply of workforce in coastal and offshore areas.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.5
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• pp.1151-1157
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• 2014

The propensity analysis for oral exam candidates of sixth class engineer officer's license was conducted to serve as a basic data for improving the ability of seamanship and a stable workforce supply using a questionnaire. A general information of them was identified as 62.1% of offshore fishing, 59.3% of over 50, 59.4% of less middle school education, 52.4% of under 100 gross tonnage, 75.2% of under 1,500kW engine output, 72.5% of over 10 years experience, 72.4% of engine department, which means they are from mainly less than 100 gross tonnage of offshore fishing vessel, less educated, and long term experienced in the engine job. The reason why they took the test was mainly due to their will (51.7%). And 45.5% of them took the test for the first time, 45.5% of answers responded they are lack of knowledge about a written exam and text of KIMFT in preparation data for an oral exam 35.9%. Given the fact that 74.5% of respondents experienced marine accidents with engine damage on board, the need for marine casualty reduction education was verified. Even after obtaining a license, they showed a higher preference of boarding that they embarked before the examination. Also, 61.4% of them have a plan for long-term boarding at least three years, thus leading to supply of workforce in coastal and offshore areas.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.55-65
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• 2002

The eighteenth century in Great Britain was the period of transformation, Great Britain externally experienced several wars intermittently mid internally transformed into the industrial country in the course of the 18th century. British shipowners were faced with short of seamen mainly due to several wars and expansion of shipping tonnage British shipowners tried to solve the mooing problem by decreasing the number of seamen from 22-23 sailors per ship of 100 tonnage in 1710's to 5 in 1810 and increasing seamen's wage from shillings per common seaman per month in the 17th century to 25 shillings in the middle of the 18th century and equation omitted during the French Revolutionary and Napoleonic Wars. What caused and resulted by specialized shipowners to cope with changeable market situation with flexibility was decrease of the number of seamen per ship and increase of wage.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.317-325
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• 2008

As a result of recent research, it is reported that the periodic replacements criterion of rails is able to extend as grinding rail surface and using the continuous welded rail (CWR). This study evaluated correlation between conditions of track and load capacity of rail by analysing the dynamic response of track while the metro train is running. Also, it was converted the measured stress waveform into stress frequency histogram by the rain-flow counting methods, and then accumulated fatigue damage ratio and remaining service life of laid rail were calculated so as the apply the equivalence of stress to S-N curve of a new welded rail. Finally, this study suggests a revision of the periodic replacements criterion of CWR, which was based on accumulated passing tonnage, classified by the types and conditions of track system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.3 s.26
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• pp.201-209
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• 2006

To promote the consistent and effective implementation of IMO instruments such as SOLAS, MARPOL, STCW, LL, TONNAGE, COLREG IMO has adopted voluntary IMO member state audit. This audit scheme is voluntary audit which will be curried out on a voluntary basis, at the request of the member state to be audited Nevertheless, the Korea government is preparing the implementation of the audit scheme to strengthen the competitiveness in shipping and shipbuilding industries. In this paper, we investigated the actual conditions of implementation qf mandatory IMO instruments and curried out a feasibility study by assessing the cost to be audited and positive effects expected by introducing the audit scheme. As a result of cost benefit analysis we obtained high benefit-cost ratio.

• Environmental and Resource Economics Review
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• v.28 no.3
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• pp.415-435
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• 2019

The purpose of this study is to analyze the returns to scale by estimating the bigeye tuna production function of Korean distant longline fisheries in WCFPC waters. In the analysis, number of crews, vessel tonnage, number of hooks, and bigeye tuna biomass are used as input variables and the catch amount of bigeye tuna is used as an output variable in the Cobb-Douglas production function. Prior to the function estimation, the biomass of bigeye tuna was estimated by the Bayesian state-space model. Results showed that the fixed effect model was selected based on the hausman test, and vessel tonnage, hooks, and biomass would have direct effects on the catch amount. In addition, it was shown that the bigeye tuna distant longline fisheries in WCFPC water would have increasing returns to scale.

• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.16-22
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• 2019

This study proposed estimation methods for weight and center of gravity of small fishing vessels. Weights loaded on small fishing vessels were divided into fixed weights such as crew, fishing gear, and variable weights such as fuel, fresh water, provision, bait, and fish. Based on statistical analyses with weight data of several small fishing vessels, weight, longitudinal center of gravity (LCG), vertical center of gravity (KG) of each item were represented as linear functions of vessel gross tonnage. In addition, weighting factors of variable weights were added on estimation formulas in accordance with vessel loading conditions, e.g. full load departure condition. Estimation methods were verified using actual small fishing vessel data.