• Land and Housing Review
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• v.3 no.4
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• pp.433-449
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• 2012

An experimental investigation was conducted to study the behavior of RC wide beam-column joints with slab subjected to reversed cyclic loads under constant axial load. Six half scale interior wide beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including three specimens without slab and three specimens with slab. The primary variables were the ratio of column-to-beam flexural capacity ($M_r={\Sigma}M_c/{\Sigma}M_b$ ; 0.77~2.26), ratio of the column-to-beam width (b/H ; 1.54, 1.67). Test results are shown that (1) the current design code and practice for interior joints(type 2) are apply to the wide beam-high strength concrete column. (2) the presence of a slab have an effect on the performance of the wide beam-high strength concrete column interior joints(type 2). therefore in the design of the wide beam-high strength concrete column interior joints(type 2), the width of slab effective as a T beam flange should be considered. It was show that the case of the ratio of column-to-beam flexural capacity is more than 2.0, the effective width of slab are 2 times of an effective depth of wide beam, however if the ratio of column-to-beam flexural capacity is 1.4~2.0, the effective width of slab are not able to be considered.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.135-141
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• 2014

In this paper, the device design guideline to reduce the threshold voltage variation with fin width in junctionless MuGFET has been suggested. It has been observed that the threshold voltage variation was increased with increase of fin width in junctionless MuGFETs. To reduce the threshold voltage variation with fin width in junctionless MuGFETs, 3-dimensional device simulation with different gate dielectric materials, silicon film thickness, and an optimized fin number has been performed. The simulation results showed that the threshold voltage variation can be reduced by the gate dielectric materials with a high dielectric constant such as $La_2O_3$ and the silicon film with ultra-thin thickness even though the fin width is increased. Particularly, the reduction of the threshold voltage variation and the subthreshold slope by reducing the fin width and increasing the fin numbers is known the optimized device design guideline in junctionless MuGFETs.

• Journal of the Korean GEO-environmental Society
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• v.10 no.4
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• pp.65-71
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• 2009

Hydraulic fracturing technology has been widely applied in the industry for the recovery of the natural resources such as gas, oil and geothermal heat from hot dry rock. During hydraulic fracturing stimulation, multiple cracks are created resulting in mechanical interaction between cracks. Such an interaction influences obtaining hydraulic fracturing key parameters (crack opening, length, and borehole net pressure). The boundary collocation method (BCM) has been proved to be very effective in considering mechanical interaction. However, for better confidence, it needs to be verified by comparison with analytical solutions such as stress intensity factors. In this paper, three cases, single fracture in remote uniaxial tension, single fracture in remote shear stress field and two arbitrary segments in an infinite plane loaded at infinity are considered. As a result, the BCM is proved to be valid technique to consider mechanical interaction between cracks and can be used to estimate the hydraulic fracturing parameters such as opening of the fracture, and so on.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.77-85
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• 2015

This paper describes the development of force limiting device(FLD). The FLD could induce compressive yield before occurring elastic buckling for slender member under compressive load. Therefore, it might prevent reduction of load carrying capacity by elastic buckling and the structures with the devices would behave stable. A new type of FLD reduced cross area is proposed in this study different to existing studies like as out of plane type, slit type and folded plate type. The parameters of specimens are depth, width and number of cutting. The structural capacity and characteristics of proposed types were verified by experiment and FEM analysis. The FLD of cutting type is efficient in compressive member.

• Korean Journal of Optics and Photonics
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• v.9 no.5
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• pp.307-314
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• 1998

We have studied the effects of interface on polarization dependence of waveguide and designed the polarization independent 2-dimensional waveguides on InP for arrayed waveguide grating. To figure out the effects of interface on polarization dependence, we have solved the 1-dimensional wave equation using a transfer matrix method. It is shown that the birefringence becomes stronger as the number of interfaces increases. In order to design polarization independent 2-dimensional waveguides, we have used effective index method. The structures considered are ridge type, raised strip type, and buried type waveguide. In the cases of ridge and raised strip type, conventional effective index method was used. In the case of buried type corrected effective index method was used. We have determined the height and width of waveguides such that the waveguides become polarization independent.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2224-2226
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• 1997

공간벡터 펄스폭변조법과 관련하여 과변조시의 전류제어성능을 향상시킬 수 있는 벡터 과변조의 새로운 연산 알고리즘으로 유효전압벡터를 반지름으로 하는 원을 이용하여 수정된 기준전압벡터가 위치할 섹터를 구하고, 전압제한 6각형을 나타내는 전압벡터식을 이용하여 동일한 수식으로 벡터과변조하는 간결한 새로운 알고리즘을 제시하고, 이를 전류제어 시뮬레이션에 적용하였다.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.84-86
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• 2005

본 논문에서는 역 방향 전하공핍(reverse bias depletion)을 적용한 새로운 구조의 다결정 실리콘 박막 트랜지스터(poly-Si TFT)를 제안한다. 제안된 소자는 kink 전류 억제를 목적으로 counter-doped(p+) 영역이 채널 내로 확장되어 유효채널 폭을 감소시키는 구조이다. 감소된 채널 폭에 의하여 포화 영역의 채널 내 저항이 증가하고, 훌 전류를 통하여 kink 효과가 억제된다. 제작된 새로운 poly-Si TFT는 기존의 소자에 비해 효과적으로 kink 전류를 억제할 수 있음을 실험을 통해 검증하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1968-1974
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• 1997

In this paper, the spectral domain approach is employed to investigate the characteristics of symmetrical and asymmetrical broadside-coupleed coplanar waveguides(BSC-CPW). These structures have large even(c)-odd(.pi.) mode-velocity ratio, suitable for wide-band and tight-coupling microwave circuit design. Efficient design parameters can be obtained from the effective dielectric constants and characteristic impedances calculated by varying the strip widths and slot widths in the BSC-CPW structure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.47-52
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• 2011

In this paper, to evaluate the design properties of 3D optical multimode interference (MMI) couplers with ultracompact width, modal transmission line theory and effective dielectric method are combined with together. A coupling efficiency based on the composed approach is defined, and the coupling length is numerically determined for the design of 3 dB coupler, cross coupler and bar coupler. The simulation result shows that the designed MMI coupler has a low insertion loss and a high splitting ratio.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2411-2425
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• 2013

In the design of pile foundation on the rock layer in the stratified structure with sedimentary and rock layers, the structural analysis of the stratified rock layer is required to determine the failure modes (flexural failure, punching shear failure or end bearing failure) and the bearing capacity of the rock layer. However, the existing usable Elastic Plate Analysis Method (EPAM) suggested by ACI committee 436 and Korean Code Requirements for Structural Foundation Design is very complex, and engineers have many difficulties in using it. Therefore, in this research, we proposed the relatively simple Circular Foundation Analysis Method (CFAM) with the concept and the equation of the equivalent effective width (radius) instead of the complex EPM, and the related equations of bending moment and shear force to be equal to the analysis results of EPAM. As a result, the proposed CFAM using the equivalent effective width (radius) is simple and convenient to use, and the analysis results of it are very good in their accuracies comparing those of EPAM and Finite Element Method.