• International Journal of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.222-227
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• 2022

The purpose of this study was to investigate changes in heart rate according to recovery methods after circuit weight training exercise. Fourteen men in their twenties were selected as subjects, and three sets of circuit weight training were performed by cycling six sports, and two recovery conditions (dynamic and static) were performed immediately after exercise. Changes in heart rate did not have an interactive effect according to recovery method and time, and both conditions showed significant changes between sets 1 and 2, and between sets 3 and after recovery. In this study, the high heart rate of 2 sets and 3 sets was seen as a result of exercise stimulation, and the low heart rate of 1 set was thought to be due to the decrease in vagus nerve activity rather than the role of catecholamines. On the other hand, the heart rate after 20 minutes of exercise did not show any difference according to the recovery method, which could mean that the recovery process due to the aquatic environment can act more strongly than the process of dynamic recovery and static recovery. It is thought that the characteristics affected the sensory and circulation of the body, and thus the change of the afferent signal and the level of metabolic products generated in the active muscle.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1646-1658
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• 2020

In order to investigate the changes in growth hormone, testosterone, blood lactate, double product, and pain, this study conducted intensive weight training and circuit weight training with 60% intensity of 1RM for 7 men who had more than 6 months of resistance exercise and then performed Underwater Walking and Underwater Sitting with underwater recovery. Growth hormone was high in all exercise forms and recovery methods in order of after exercise, after recovery, and after stability, and testosterone was high in order of after exercise, after recovery, and stability. Blood lactate was higher in all exercise forms and recovery methods in order of after exercise, after recovery, and after stabilization, and dynamic recovery after concentration resistance exercise was lower than static recovery. Double product was higher in all types of exercise and recovery methods in order of after-exercise, after-recovery, and stability. Muscle pain decreased in the order of exercise, recovery, 24 hours, 48 hours, and 72 hours in all exercise forms and recovery methods. In the water environment, dynamic recovery is considered to be more effective in improving muscle fatigue than static recovery.

• Journal of Ocean Engineering and Technology
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• v.34 no.5
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• pp.361-370
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• 2020

We developed a heavy-duty work class ROV trencher named URI-T (Underwater robot it's trencher) that can conduct burial and maintenance tasks for underwater cables and small diameter pipelines. It requires various supporting systems, including a dynamic positioning (DP) vessel, launch and recovery system (LARS), A-frame, and winch in order to perform burial tasks because of its dimensions (6.5 m × 5.0 m × 4.5 m, 20 t) and the tough working environment. However, operating a DP vessel has disadvantages as it is expensive to rent and operate and it is difficult to adjust the working schedule for some domestic coast construction cases. In this paper, we propose a method using a barge instead of a DP vessel to avoid the above disadvantages. Although burying the cable and pipeline using a barge has lower working efficiency than a DP vessel, it can save construction expenses and does not require a large crew. The proposed method was applied over two months at the construction of the water supply in Yokji-do, and the results were verified.