• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.30 no.6
• /
• pp.337-342
• /
• 2018

Wave flume that enables generating water waves is a core research facility for physical experiment related to coastal engineering works. Recently, a new wave flume of 50 m length was constructed in Korea. The wave flume has a sloped section on its bottom. A novel wave generating system incorporating most-updated wave maker theory was introduced to the flume. In addition, water circulating system for adjusting water level was installed beneath the flume. These technical features and detailed specifications of the wave flume are described in this paper.

• Journal of the Korean Mathematical Society
• /
• v.40 no.6
• /
• pp.1051-1060
• /
• 2003

We study the surface waves of an incompressible fluid passing over a small bump. A forced KdV equation for surface wave is derived without assuming that flow is uniform at far upstream. New types of steady solutions are discovered numerically. Two new cut off values of Froude number are found, above the larger of which two symmetric solutions exist and under the smaller of which two different symmetric solutions exist.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.135-136
• /
• 2008

By applying sonic wave technology in Vibration Exercise Equipment, we introduced an completely new concept of device into the fitness and medical industry creating a new trend. Sonic Vibration Exercise Equipment which got over the limit of technology will be easily accessible not only by professional athletes but also by ordinary users and even minority groups such as disabled, elderly, children.

• Proceedings of the Korean Society of Embryo Transfer Conference
• /
• 2003.10a
• /
• pp.125-125
• /
• 2003

• Journal of the Korean Society of Safety
• /
• v.24 no.5
• /
• pp.43-47
• /
• 2009

Armor block is used to reduce wave energy. To do this, the stability of coastal structure is enhanced. It is very expensive to develop a new type armor block. So, the research of new type armor block is very short. We develope truncated tetrahedron type armor block(new type block) which have a hole in center part. In this study, the stability of new type armor block is investigated by hydraulic model test. In the result, the stability coefficient($K_D$) of new type armor block is 11.8. this value is more superior than value of tetrapod.

• Structural Engineering and Mechanics
• /
• v.24 no.4
• /
• pp.395-410
• /
• 2006

This paper reports the result of an investigation into wave propagation in orthotropic laminated piezoelectric cylindrical shells in hydrothermal environment. A dynamic model of laminated piezoelectric cylindrical shell is derived based on Cooper-Naghdi shell theory considering the effects of transverse shear and rotary inertia. The wave characteristics curves are obtained by solving an eigenvalue problem. The effects of layer numbers, thickness of piezoelectric layers, thermal loads and humid loads on the wave characteristics curves are discussed through numerical results. The solving method presented in the paper is validated by the solution of a classical elastic shell non-containing the effects of transverse shear and rotary inertia. The new features of the wave propagation in laminated piezoelectric cylindrical shells with various laminated material, layer numbers and thickness in hydrothermal environment and some meaningful and interesting results in this paper are helpful for the application and the design of the ultrasonic inspection techniques and structural health monitoring.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.12
• /
• pp.2260-2264
• /
• 2011

This paper describes the development of an wave energy convertor. We devise a new type of the wave energy convertor which generates electricity by means of under-water pressure oscillation. This wave energy convertor is installed on the seabed floor. That is, there is no exposed body on the surface of the sea. The wave energy convertor comprises an activated assembly which is adapted to be displaced in response to water pressure oscillation to vary the volume of bellows cavity and a power take off assembly which generates electricity in response to movement of the activated assembly.

• Electronics and Telecommunications Trends
• /
• v.32 no.5
• /
• pp.85-96
• /
• 2017

The research, design, and development of wireless access technologies using the new 6 to 100GHz band mmWave are actively underway in order to address the frequency shortage problem in the sub-6GHz band and accommodate the 5G technical requirements, such as the increased transmission capacity. Technical elements to efficiently overcome the problems caused by mmWave signal characteristics, support an effective interworking with a conventional communication service, and ensure smooth mobility between mmWave base stations and existing base stations are also being investigated. This paper discusses the technical solutions for an mmWave-based 5G RAN configuration and their considerations under various operational scenarios.

• Ocean Systems Engineering
• /
• v.5 no.4
• /
• pp.245-259
• /
• 2015

The numerical simulation of wave slamming on a 3D platform deck was investigated using a coupled Level-Set and Volume-of-Fluid (CLSVOF) method for overset grid system incorporated into the Finite-Analytic Navier-Stokes (FANS) method. The predicted slamming impact forces were compared with the corresponding experimental data. The comparisons showed that the CLSVOF method is capable of accurately predicting the slamming impact and capturing the violent free surface flow including wave slamming, wave inundation and wave recession. Moreover, the capability of the present CLSVOF method for overset grid system is a prominent feature to handle the prediction of wave slamming on offshore structure.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2014.06a
• /
• pp.258-259
• /
• 2014

It is needed the introduction of a new wave dispersion relationship considering the condition of seabed to examine closely the interaction between wave and seabed. In this study, a wave dispersion relationship is newly developed considering the condition of seabed such as permeability and displacement. Wave damping rates are compared and analysed according to the various soil parameters such as seabed soil thickness, elastic modulus, saturation, permeability, and porosity.