• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.167-167
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• 2010

Ge-Sb-Se계 칼코게나이드 유리의 Melting 조건변화에 따른 특성변화를 연구하였다. Glass melting 조건(homogenization-temperature, homogenization-time, annealing) 에 따라 제작된 칼코게나이드 유리 bulk를 FT-IR, XRD, SEM 등의 분석장비를 이용하여 특성을 분석하였다. Homogenization temperature가 높을수록 석영관 급냉 시 발생되는 mechanical stress와 내부응력차로 인해 칼코게나이드 유리 깨짐현상이 증가하였으며 조성비와 melting 조건에 따라 XRD분석에서 확인되지 않는 미소결정이 SEM 분석결과 관찰되었다. 본 연구를 통해 칼코게나이드 유리의 melting 조건에 따른 경향성을 확인할 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.457-458
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• 2008

We have developed new process to product Al clad steel wire. New machine was modified to be able to apply an four step of "foiling-sizing-cladding-drawing" considering low clad temperature and high clad pressure. The foiling part for continuous foiling of Al sheet was designed and machine. Cladding properties at Al and steel interface were investigated for the processes of new work.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.979-982
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• 2003

In this study, because of change in electromagnetic force, deformation of the free surface motion of a magnetic fluid is changed. Deformation of the free surface motion of a magnetic fluid for the change in electromagnetic force is discussed and carried out theoretically and experimentally on the basis of Rosensweig Ferrohydrodynamic Bernoulli Equation. Objective of this study explicates free surface motion by electromagnetic force and planes to designed controller. To control free surface of magnetic fluid, it embody designed two-dimensional free surface form of magnetic fluid. By using this characteristics, they applied to oscillator for surface control, flow control, boundary layer control. Strength of magnetic field and height of free surface of magnetic fluid measure as a hall-effect sensor. As performing height control of magnetic fluid, the result will be presented possibility of free surface deformation control.

• Journal of IKEEE
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• v.6 no.1 s.10
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• pp.102-110
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• 2002

An effective scheme to detect and diagnose multiple failures in a dynamic system is described for the case where the measurement noise is correlated sequentially in time. It is based on the modified interacting multiple model (MIMM) estimation algorithm in which a generalized decorrelation process is developed by employing the autoregressive (AR) model for the colored noise and applying measurement difference method.

• Journal of the Microelectronics and Packaging Society
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• v.5 no.1
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• pp.31-38
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• 1998

저온소결기판용 Glass-ceramics를 제조하기 위해 LiO2-MgO-MgF2-SiO2계 조성에 서 B2O3첨가가 결정화 특성 및 물성에 미치는 영향을 고찰하였다. 145$0^{\circ}C$에서용융하여 제조 한 모유리의 핵형성 온도와 결정화 온도를 결정하기 위해 TMA와 DTA분석을 실시하였다. 결정화시킨 유리의 결정상과 미세구조를 관찰하기 위하여 XRD와 SEM관찰을 실시하였다. Water swelling을 통해 Glass-ceramics powder를 제조하였으며 제조한 powder의 평균입자 크기는 8.32$\mu$m였다.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1087-1090
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• 1999

중수로(CANDU) 형 월성 원자력발전소의 칼란드리아 압력관 전면부를 감시점검하기 위한 열영상 관측프로그램을 개발하였다. 국내의 사용자들의 요구에 부응할 수 있는 다양한 기능을 부가 하였다. 부가된 기능에는 임의의 포인트, 영역, 라인, 경계선을 마우스로 지정하여, 선택된 지점, 영역, 라인 및 경계선의 특징을 추출할 수 있는 기능을 갖추고 있다. 또한 KAERI Thermo Inspector 의 기능을 살린 일반영상/열영상의 매핑기능을 부가하였다. 일반영상에 비해 상대적으로 해상도가 떨어지는 열영상대신에 CCD 영상의 관측포인트를 지정하면 열영상카메라좌표계의 매핑된 지점의 이상상태를 판정할 수 있는 특성을 갖는다.

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.157-160
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• 2000

Nowadays, internet or web is popularized in society. So, intranet or inside computation environment of business has been changed a web based open system. Client and Server system that has been used core technique for enterprise information system several years is developing e-business system that perform a business in web based. Because, internet is extension of a whole field like business or information technology Therefore we understand a meaning of e-business and ERP system that a form of e-business system. Then we realize problem of existing system and study a technology for complement of system. Finally, we propose a proper model for e-business system and develop an example.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.9
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• pp.15-20
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• 1997

Waveguide bandpass filters using E-plane or H-plane discontinuities have been used in many satellite communication systems. Since the transmitter and receiver of such systems tend to be getting smaller, components such as bandpass filters must also be reduced in size. In this paper, in order to reduce the waveguide, itself, of which bandpass filters consist, double plane step waveguide discontinuities are considered. They are analyzed using the mode matching method and the genralized scattering parameter of the cascaded structure is calculated. The characteristics of the bandpass filter which is designed using the reduced size waveguide is optimized by OSA90$^{TM}$. The bandpass filter has a good characteristics and smaller size than those made of the E-plane or H-plane step discontinuities.s.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.5
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• pp.90-102
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• 1993

In this paper, we propose a prgressive image transmission technique using hierarchical pyramid data structure which is constructed based on the projection data of an image. To construct hierarchical Gaussian pyramids, we first divide an image into 4$\times$4 subblocks and generate the projection data of each block along the horizontal, vertical, diagonal, and antidiagonal directions. Among images reconstructed by backprojecting the projection data along a single direction, the one giving the minimum distortion is selected. The Gaussian pyramid is recursively generated by the proposed algorithm and the proposed Gaussian images are shown to preserve edge information well. Also, based on the projection concept a new transmission scheme of the lowest Laplacian plane is presented. Computer simulation shows that the quantitative performance of the proposed pyramid coding technique using projection concept is similar to those of the conventional methods with transmission rate reduced by 0.1 ~ 0.2 bpp and its subjective performance is shown to be better due to the edge preserving property of a projection operation.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.4
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• pp.12-24
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• 1997

An intelligent steering control system is designed for the steering control of a 4 wheel drive (4WD) electric vehicles without steering mechanism, where the vehicle is assumed to have 3 degree of freedom and input-output feedback linearization is employed. Especially, a fuzzy-rule-based side force estimator is suggested to avoid uncertain highlynonlinearexpression sof relations between side forces and their factors. Also, aneural-network-based predictive compensator is additionally utilized for the vehicle model to be correctly controlled with unstructured uncertainties. The proposed overall control system is numerically shown to be robust against drastic change of the external environments.