• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.11a
• /
• pp.217-220
• /
• 2007

본 논문에서는 이중 구조의 공동에서 작은 공동 내부에 존재하는 전자파원으로부터 방사되는 전자파를 내부 공동의 개구를 지나 외부 공동의 개구를 통해 방사될 때, 외부 공동의 개구 크기 변화에 따른 방사 전자파의 크기를 FDTD법으로 검토하고 있다. 외부 공동 개구의 크기는 최대 방사 전자파의 주파수를 결정하므로 개구의 크기를 조절하면 방사되는 전자파의 크기를 제어할 수 있음을 이론해석을 통하여 확인하고 있다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.05a
• /
• pp.339-342
• /
• 2008

본 논문에서는 이중 구조의 공동에서 작은 공동 전원단 내부에 존재하는 전자파원으로부터 방사되는 전자파를 내부 전원단의 개구를 지나 외부 공동의 개구를 통해 방사될 때, 내부 전원단의 위치와 외부 공동의 개구 위치 변화에 따른 방사 전자파의 크기를 FDTD법으로 검토하고 있다. 외부 공동 개구의 크기는 최대 방사 전자파의 주파수를 결정하며 내부 전원단의 위치를 조절하면 방사되는 전자파의 크기를 제어할 수 있음을 이론해석으로 통하여 확인하고 있다.

• Explosives and Blasting
• /
• v.26 no.1
• /
• pp.7-14
• /
• 2008

In order to complete successfully the demolition of a silo structure by means of felling method, structural properties and the geometric design of blast mouth have to be considered. In this study, a commercial software, 3-dimensional applied element analysis (3D AEM), was used to investigate the effect of the geometrical parameters of blast mouth on the collapse behavior of the silo structure.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.29 no.3
• /
• pp.154-161
• /
• 2017

The purpose of this study was to investigate the change of length, opening width, and number of openings effecting on topography change around artificial reefs under erosive wave condition. Hydraulic model test was conducted to see sediment transport around the structures and the relation among the installation condition of the artificial reefs, generated velocity, wave deformation, and topographic change was reviewed. Experimental results show that the sediment transport rate was reduced; however, the scour around the structures was increased under the condition of having a single opening compared to the structures having a plurality of openings which shows inversely proportional to the size of Lr/W.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.6
• /
• pp.939-947
• /
• 2001

This paper presents the penetrated electric fields and resonant frequencies inside a metallic enclosure with aperture excited by an external dipole source. In the theoretical analysis, integral equations for the current distribution and electric field distributions on the aperture are solved by applying Galerkin\`s method of moments. The results show that the electric fields inside metallic enclosure is maximum at the near the aperture and resonant frequencies are the same as calculated of the enclosure without aperture. To verify the theoretical analysis the electric field inside enclosure and resonant frequencies are compared with the experimental results.

• Journal of Korean Society of Steel Construction
• /
• v.13 no.5
• /
• pp.513-524
• /
• 2001

A total of nine H-shaped beams with web openings under cyclic loading condition were investigated. The dimension criteria are based on the formulae proposed by Darwin. The suitability of existing design formulae the effects of plastic hinge on beams with web openings the fracture around the web openings and the influence of cracks neighboring web openings to the beam strength under cyclic loading were also investigated through the observation of the behavior of these beams with various opening dimensions. locations numbers and spacing between the two openings.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.10 s.101
• /
• pp.982-988
• /
• 2005

An analytic solution of circular aperture antenna with a feed transition is presented using a hybrid method of generalized scattering matrices and integral transform. The method can give an analytic solution to antennas with integrated filters or mode converters, etc. Scattering matrices and integral transform techniques are combined to accommodate discontinuities connected between an aperture and a feed waveguide, and radiated field from the aperture. The method gives radiation fields as well as return losses of the antenna.

• Korean Journal of Optics and Photonics
• /
• v.15 no.3
• /
• pp.258-262
• /
• 2004

The uncertainty of the detector-based candela scale is limited by the area measurement uncertainty of radiometric apertures. The apertures were fabricated with a diamond-turning machine which trimmed the edge of the apertures as sharply as a knife edge. The positions of the apertures were controlled by a digital feedback algorithm to scan the laser spot with the beam waist less than 5 ${\mu}{\textrm}{m}$. The knife edge scan yielded a set of coordinates on the edges of the aperture. The areas of the apertures were obtained by fitting the coordinates to the ellipses. The relative standard uncertainty of the measurement was estimated to be 8${\times}$10$^{-5}$.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.11 no.3
• /
• pp.77-86
• /
• 2007

The more demands on efficient utilization of resources, the more structural engineers prefer to select remodeling to improve old building's capacity. A series of four shear wall specimens were tested under constant axial stress and reversed cyclic lateral loading in order to evaluate the effect of the opening on the lower center of the wall induce by remodeling. Consequently, the existence of opening was verified to induce a different failure, which was caused by reduction of compression strut area formed on the wall to diagonal direction. Especially, the ultimate strength of the wall with an opening was revealed approximately 35% lower than that of the wall without an opening. And the similar results were appeared in characteristics of stiffness and energy dissipation capacity.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.2
• /
• pp.66-73
• /
• 2021

In the existing study of steel beams with openings, openings are located at a location where the distance to the support point is equal to or greater than the section height. Considering the facilities using the openings in the steel beam, the distance from the opening to the support point may be closer than the height of the beam section. Therefore, research on this is needed. This study is an experimental study to understand the structural performance of beams with openings close to the ends subjected to Cyclic Loading. In addition, in this study, we want to understand the structural performance through experiments on beams with openings reinforced with vertical or horizontal steel plates.