• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.4
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• pp.308-318
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• 2002

The requirements to the numerical model of wind-generated waves in shallow water are discussed in the framework of the Korteweg-de Vries equation. The weakness of nonlinearity and dispersion required for the Korteweg-de Vries equation applicability is considered for fully developed sea, non-stationary wind waves and swell, including some experimental data. We note for sufficient evaluation of the freak wave statistics it is necessary to consider more than about 10,000 waves in the wave record, and this leads to the limitation of the numerical domain and number of realizations. The numerical modelling of irregular water waves is made to demonstrate the possibility of effective evaluation of the statistical properties of freak waves with heights equal to 2-2.3 significant wave height.

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.342-347
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• 2023

The purpose of this study was to determine the comparison of upper arm, trunk and core muscle activities according to different performance in high Plank exercise using weightless exercise equipment. Six males(age, 23.00±0.73 years; height, 172.95±2.05 cm; body mass, 66.83±2.75 kg; and BMI, 22.33±0.72 kg/m²) completed this study as the subjects. Four type's high Plank exercises using weightless exercise equipment were performed(high plank, HP; high plank with air walker, HPAW; high plank with surf board, HPSB; high plank with waist trainer, HPWT). For the EMG analysis, we measured the body muscle activities of right side on the deltoid(DT), triceps brachii(TB), latissimus dorsi(LD), and external oblique(EO). This research's results were as follows. DT, TB, LD, & EO muscle activities were greatest during HPSB(p=.000). Therefore, these results are expected to serve as basic data for high Plank exercise using weightless exercise equipment performance applications in effective exercise programs.