• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.443-452
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• 2001

Fatigue behavior of reinforced concrete(RC) and steel fiber reinforced concrete(SFRC) beams has been experimentally investigated. Fatigue behavior influenced by longitudinal reinforcement ratio, volume and type of steel fiber, strength of concrete and load ratio $P_{u}/P_{o}$. It can be observed from experimental results that addition of steel fiber to reinforced concrete beam reduces crack widths and increases stiffness, and thus enhances the behavior in serviceability limit states also for high cyclic fatigue loading.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.431-438
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• 2001

Fatigue behavior of reinforced concrete(RC) and steel fiber reinforced concrete(SFRC) elements has been experimentally investigated. Fatigue behavior influenced by longitudinal reinforcement ratio, volume and type of steel fiber, strength of concrete and load ratio $P_{u}$ $P_{o}$. It can be observed from experimental results that addition of steel fiber to reinforced concrete beam reduces crack widths and increases stiffness, and thus enhances the behavior in serviceability limit states also for high cyclic fatigue loadingngng

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.749-754
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• 2007

In this paper, the vibration of a rotating shaft with a thin rigid disk is considered. It is assumed that the shaft has uniform, circular cross-section. Based on the Timoshenko-beam theory, the transverse displacements and slops in two lateral directions, the axial displacement, and the torsional deformation are considered. The spectral element method is used for the vibration analysis of the rotating shaft with a thin rigid disk, which is modeled by two shaft elements and a thin rigid disk element.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.91-94
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• 2002

SFFS(Solid Freeform Fabrication System) is commercializing to rapid prototyping concept in foreign some corporations including the U.S.A, have much technological problems yet and need new mode for agile prototyping. In this paper, we design algorithm that the cutting path of laser beam, on the SFFS(Solid Freeform Fabrication System), is controlled with constant speed. The designed algorithm for constant-speed path control is implemented and experimented in the CAFL$\^$VM/ (Computer Aided Fabrication of Lamination for Various Material) system, the new SFFS which was developed in this paper.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.55.1-55
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• 2003

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.233-234
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• 2008

• Korean Journal of Materials Research
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• v.6 no.6
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• pp.605-609
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• 1996

MOS 소자의 얇은산화막(thin oxide)불량을 화학적으로 식각하지 않고 불량부위를 광전자방사(photon emission)반응을 이용하여 위치를 확인하고, 이곳을 FIB로 절단하여 불량부위의 단면을 관찰했다. 20nm 두께의 SiO2불량은 셀(cell)영역의 위치에 따른 의존성은 없고, 불량은 저전계의 입자(particle)성 불량과 중간전계의 Si 기판 핏(pit)과 관련된 불량이 주였다. 고전계에서는 전형적인 SiO2 산화막의 절연파괴가 일어난 것이 관찰된다.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.706-709
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• 1987

In this paper, the circuit analysis during the retrace period of E.H.T. generator is performed by means of the simplified equivalent circuit. The E.H.T. voltage and the beam current are computed by using Newton-Raphson method and the computed results are compared with those of experiment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.2
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• pp.101-116
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• 2017

The interaction of U(VI) (hexavalent uranium) species with natural organic matter (NOM) in KURT (KAERI Underground Research Tunnel) groundwater is investigated using a laser spectroscopic technique. The luminescence spectra of the NOM are observed in the ultraviolet and blue wavelength regions by irradiating a laser beam at 266 nm in groundwater. The luminescence spectra of U(VI) species in groundwater containing uranium concentrations of $0.034-0.788mg{\cdot}L^{-1}$ are measured in the green-colored wavelength region. The luminescence characteristics (peak wavelengths and lifetime) of U(VI) in the groundwater agree well with those of $Ca_2UO_2(CO_3)_3(aq)$ in a standard solution prepared in a laboratory. The luminescence intensities of U(VI) in the groundwater are weaker than those of $Ca_2UO_2(CO_3)_3(aq)$ in the standard solution at the same uranium concentrations. The luminescence intensities of $Ca_2UO_2(CO_3)_3(aq)$ in the standard solution mixed with the groundwater are also weaker than those of $Ca_2UO_2(CO_3)_3(aq)$ in the standard solution at the same uranium concentrations. These results can be ascribed to calcium-U(VI)-carbonate species interacting with NOM and forming non-radiative U(VI) complexes in groundwater.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.219-222
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• 2006

In this paper, we have designed 800MHz band broadband antenna which is improves of microstrip antenna narrow bandwidth problem including the CDMA band and be able to integrated the GSM and TRS band will design. It used the duplex resonance effect it had the L-Shaped feeding structure which adds the u-slot. It was measured that the frequency bandwidth of the designed antenna which is planed $897MHz\sim1013MHz$ with 215MHz(23.8%). And the antenna gain is 9.3dBi, 3dB beam width $60^{\circ}$ in both the E-plane and H-plane.