• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.96-101
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• 2004

When the wind blows hard, most waves are breaking in sea. Breaking waves occur, exceeding limitation of wave steepness(wave height/wave length=l/7). Because a wave of single angular frequency couldn't generate the breaking phenomena at two dimensional ocean engineering basin, the breaking wave can be generated by the superposition of waves with various angular frequencies. We research how are the particle kinematics in the breaking wave and the magnitude of the breaking wave exciting force. We compare the force in a regular wave which has same specifications(wave height, period and length) as the breaking wave. Also the experimental results of wave exciting force and particle velocity are investigated by comparison on the analytic results using the potential theory.

• Journal of Ocean Engineering and Technology
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• v.21 no.1 s.74
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• pp.18-24
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• 2007

When the wind blows strong, most waves are breaking at sea. Breaking waves occur by exceeding the limitation of wave steepness (wave height/wave length = 1/7). Because a wave of single angular frequency couldn't generate the breaking phenomena at a two-dimensional ocean engineering basin, the breaking wave can be generated by the superposition of waves with various angular frequencies based on dispersion relation. This study investigates the particle kinematics in the breaking wave and the magnitude of the breaking wave exciting force at the breaking point and breaking region. We compare the regular wave load in a regular wave, which has same specifications (wave height, period and length), with the breaking waveload. Also, the experimental results of wave exciting force and particle velocity are investigated, by comparison with the analytic results using the potential theory.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1948-1953
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• 2005

The Teakwondo is composed of the breaking, competition and poomsea. In the hand breaking, the breaking impact of human is affected by the breaking posture. In this paper, impact analysis of the human model for breaking posture is carried out. The LifeMOD is used in breaking modeling and simulation. The simulation model createsthe human model to hit and to grasp a pine board. For the breaking, the poomsea motion of the hand joint inputs the splines pass condition. As the results, the reaction of human joint is presented

• Ocean Systems Engineering
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• v.12 no.4
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• pp.439-459
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• 2022

This paper describes experimental studies of impact pressure generated by breaking regular waves in shallow water on a vertical cylinder. Experimental work was carried out in a shallow water flume using a 1:30 - scale model of a vertical rigid circular hollow cylinder with a diameter 0.2 m. This represents a monopile for shallow water offshore wind turbines, subjected to depth induced breaking regular waves of frequencies of 0.8 Hz. The experimental setup included a 1 in 10 sloping bed followed by horizontal bed with a constant 0.8 m water depth. To determine the breaking characteristics, plunging breaking waves were generated. Free surface elevations were recorded at different locations between the wave paddle to the cylinder. Wave impact pressures on the cylinder at a number of elevations along its height were measured under breaking regular waves. The depth-induced wave breaking characteristics, impact pressures, and wave run-up during impact for various cylinder locations are presented and discussed.

• Textile Coloration and Finishing
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• v.9 no.5
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• pp.1-9
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• 1997

In the single yarn spinning process by the ring spinning system, the finer the fineness of yarn and the lower the twist coefficient, the lower the breaking strength and breaking elongation. The change of yarn specific volume to yarn number agreed with Peirce's formula in the range of Ne 50 to 70, but above that range the values of the experiment are higher than that of the formula. The change of diameter of yarn to the reciprocal of the square root of yarn number agreed with Peirce's formula in the range of under 0.14, but above that value the values of the experiment are higher than that of the formula. In breaking strength variation according to twist constant of single yarn, as the twist coefficient increased, breaking strength increased. At 5.8∼6.0 of twist coefficient the maximum breaking strength was shown, but above that value breaking strength decreased. Breaking elongation also showed a similar tendency. But at 6.0∼6.5 of twist coefficient the maximum breaking elongation was shown. Also spinning tension increased as twist coefficient increased. Twist coefficient, breaking strength and breaking elongation according to the number of coils stayed almost the same. Yarn spinning tension according to the number of coils at the maximum of diameter was the lowest value. The speed of the traveller at the maximum of diameter was the highest value.

• Journal of Navigation and Port Research
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• v.39 no.5
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• pp.385-391
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• 2015

In offshore, various external forces such as wind force, tidal current and impulsive breaking wave force act on offshore wind tower. Among these forces, impulsive breaking wave force is especially more powerful than other forces. Therefore, various studies on impulsive breaking wave forces have been carried out, but the soil reaction are incomplete. In this study, the p-y curve is used to calculate the soil reaction acting on the offshore wind tower when an impulsive breaking wave force occurs by typhoon. The calculation of offshore wind tower against impulsive breaking wave force is applied for the multi-layered soil. The results obtained in this study show that although the same wave height is applied, the soil reaction generated by impulsive breaking wave force is greater than the soil reaction generated by wave force.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.3
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• pp.178-186
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• 1992

An experimental study of deep-water breaking waves are performed by superposition of different wave frequencies, faster waves overtaking slow waves at a certain location. Large spilling and plunging breaking waves are generated near the expected breaking location. Wave steepness in spilling and plunging breakers significantly increases as the breaking point is approached and then decreases after breaking. Larger growth rate of the wave steepness in vigorous plunging breaking is observed. The fundamental wave frequencies in a wave group are dominant through the wave evolution, even in an intense plunging breaking event.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.14-23
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• 2002

Wave breaking and breaking wave-induced hydrodynamics are very important subjects in the field of coastal and ocean hydrodynamics and engineering. In the coastal zone, a submerged breakwater has been increasingly popular, since it is one of nature-matching structures with multi- functions such as (1) wave energy dissipation by wave breaking and friction, (2) oxygen supply to sea by wave breaking and breaking wave, (3) water purification by entrained air bubbles, (4) keeping. good seascape. and (5) good habitat for sea livings. Recently, the breaking wave-induced high frequency pressure over a submerged breakwater is said to have a function of gathering sea livings around the structure, which has encouraged the construction of the submerged breakwater in coastal zone. (omitted)

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.1
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• pp.11-18
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• 2002

Directional breaking waves are generated by the component wave focusing both in direction and frequency based on constant wave steepness and constant wave amplitude spectrum models. The generated breaking waves are classified in the incipient, single and multi breaking waves. The characteristics of directional breaking waves are investigated in terms of surface profile parameters of wave crest steepness and asymmetry. The evolution of breaking wave characteristics is analyzed in a view of focusing efficiency. It shows that the front steepness and vertical asymmetry play an important role in breaking process, while the crest rear steepness and horizontal asymmetry are nearly constant during the process. The superposition of directional components greatly enhances the focusing efficiency and it suggests that characteristics of directional breaking waves may significantly different from uni-directional ones.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.4
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• pp.45-51
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• 1999

In this study to assess chip breaking characteristics of cold-drawn free machining steels a newly developed non-dimensional parameter chip breaking index CB has been adopted. And for comparison with free machining steels chip breaking characteristics of conventional carbon steels were investigated. Properly controlled chips were produced with the CB value of 0.05-0.2 regardless of steel types. In case of cold-drawn free machining steels however cycle times of chip breaking are relatively shorter than those of conventional steels. And properly controlled chips were obtained from wider range of feed rate.