• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.172-178
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• 2021

In the ship repair market, interest in maintenance and repair is steadily increasing due to the reinforcement of prevention of environmental pollution caused by ships and the reinforcement of safety standards for ship structures. By reflecting this effect, the number of requests for repairs by foreign shipping companies increases to repair shipbuilders in the Southwest Sea. However, because most of the repair shipbuilders in the southwestern area are small and medium-sized companies, it is difficult to lead to the integrated synergy effect of the repair shipbuilding companies. Moreover, the infrastructure is not integrated; hence, using the infrastructure jointly is a challenge, which acts as an obstacle to the activation of the repair shipbuilding industry. Floating docks are indispensable to operating the repair shipbuilding business; in addition, most of them are operated through renovation/repair after importing aging caisson docks from overseas. However, their service life is more than 30 years; additionally, there is no structure inspection standard. Therefore, it is vulnerable to the safety field. In this study, the finite element analysis program of ANSYS was used to evaluate the structural safety of the modified caisson dock and obtain additional structural reinforcement schemes to solve the derived problems. For the floating docks, there are classification regulations; however, concerning structural strength, the regulations are insufficient, and the applicability is inferior. These insufficient evaluation areas were supplemented through a detailed structural FE-analysis. The reinforcement plan was decided by reinforcing the pontoon deck and reinforcement of the side tank, considering the characteristics of the repair shipyard condition. The final plan was selected to reinforce the side wing tank through the structural analysis of the decision; in addition, the actual structure was fabricated to reflect the reinforcement plan. Our results can be used as reference data for improving the structural strength of similar facilities; we believe that the optimal solution can be found quickly if this method is used during renovation/repair.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.89-97
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• 2020

This experiment was conducted at Sancheong from 2013 to 2015. The objective of this study was to establish the seeding rate, and to clarify the optimum nitrogen fertilizer level for rye seed production in the southern area of Korea. We employed Korean rye cultivar 'Gogu' in this test. The experimental design was a split-plot design with three replications. A split-plot design was used with three seeding levels (3, 5, and 7 kg 10 a^-1) on the main plots and other treatments fully randomized in sub-plots. A factorial arrangement of treatments included three different nitrogen fertilizer levels (0, 3, 6, and 9 kg 10 a^-1). The grain yields of rye affected by increasing the seeding rate. The number of spike per m² and immature grain weight was increasing, while the fertility rate and the number of grain per spike were decreased as seeding rate were increased from 3 kg 10 a^-1 to 7 kg 10 a^-1. The percentage of a productive tiller, 1-liter weight, and 1000-grain weight also decrease by increasing seeding but the grain yields of rye had less effect. There was an increase in the number of spike per m², the number of grain per spike, and grain yields as nitrogen fertilizer level was increased from 0 kg 10 a^-1 to 9 kg 10 a^-1 and followed a delaying heading and an increasing lodging of the plant. But grain yields did not affected by the interaction of seeding rate × nitrogen fertilizer levels. The best seeding rate and nitrogen fertilizer level for rye seed production were 5 kg and 3 kg 10 a^-1, respectively, considering seed and fertilizer reduction and the prevention of pollution by excess fertilization.