• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.63-66
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• 2008

2010년 5월에 발사 예정인 KOMPSAT-5(KOrea Multi-Purpose SATellite-5)는 KOMPSAT-1, 2호에 탑재된 광학센서와는 달리 기상상태와 태양고도에 제약을 받지 않고 자료 획득이 가능한 SAR 시스템이 탑재된다. 본 연구에서는 KOMPSAT-5의 SAR 시스템으로부터 radargrammetry 기법을 적용하기 위해 위성의 궤도와 영상 모드를 분석하였다. Radargrammetry 적용을 위한 SAR 영상 pair의 parallax의 height sensitivity를 이론상으로 계산하였다. 그리고 STK 소프트웨어를 사용하여 대전과 남극 세종기지에서의 최적 조건을 각각 예시하였다. 입사각이 20$^{\cric}$-45$^{\cric}$가 되는 nominal mode의 descending pass만을 사용하여 height sensitivity가 0.5-0.75 사이의 영상 조합을 찾았다. 그 결과 Pass Number 쌍으로서, 대전은 5-4, 7-5, 8-5의 영상 조합을 하였을 때 radargrammetry 적용이 용이하고, 남극 세종기지는 8-6, 9-7, 10-7, 11-8, 12-8, 13-9, 14-9, 15-9, 15-10, 15-11의 영상 조합을 하였을 때 radargrammetry 적용이 가능한 것으로 예측되었다.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.202-209
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• 2005

A new effective thick-layered RP process, Transfer-type Variable Lamination Manufacturing using expandable polystyrene foam (VLM-ST) has been developed with thick layers and sloped surfaces. VLM-ST has the innate advantages by virtue of its working principle: high building speed, low cost for introduction and maintenance of VLM-ST apparatus, little staircase surface irregularities of parts. Despite these advantages in VLM-ST, the surface roughness of VLM-ST parts is still inadequate to be used as RP master patterns for rapid tooling (RT). This paper describes the systematic and effective methodology to remove the laminated pattern and improve the surface roughness for VLM-ST parts. From the results of surface finishing of VLM-ST parts, it can be seen that the laminated pattern is completely removed and the surface characteristics such as surface roughness, surface hardness, and paintability are improved.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.81-87
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• 2008

In this paper, we propose a forensic watermarking scheme using temporal differences of video chrominance values. Proposed method has low complexity and good visual quality, which is suitable for traitor tracing of digital cinema. Experimental results show that our forensic watermarking method has good detection performance and is robust to several attacks, such as camcorder recording and video compression.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.284-293
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• 1999

The rigid-plastic finite element analysis requires a large amount of computation time due to its non-linearity. For economic computation, mismatching refinement, and efficient domain decomposition method with different mesh density for each sub domain, is developed. A modified velocity alternating scheme for the interface treatment is proposed in order to obtain good convergence and accuracy. As a numerical example, the axisymmetric extrusion process is analyzed. The results are discussed for the various velocity update schemes form the viewpoint of convergence and accuracy. The three-dimen-sional extrusion process with rectangular section is analyzed in order to verify the effectiveness of the proposed method. Comparing the results with those of the conventional method of full region analysis, the accuracy and the computational efficiency of the proposed method are then discussed.

• Fibers and Polymers
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• v.3 no.3
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• pp.109-112
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• 2002

Polybutadiene(PB) was epoxidized to various extents with m-chloroperbenzoic acid (MCPBA) in homogeneous solution. The thermal properties of the epoxidized PBs were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). As a result of epoxidation the glass transition temperature (Tg) of PB increased by approximately $0.8^{\circ}$ for each 1 mol% of epoxidation. The thermal decomposition of the epoxidised PBs occurred in two-step process, while that of PB exhibited apparent one-step degradation process.

• 기술발표회
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• s.2006
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• pp.248-260
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• 2006

광양항 3단계 1차 컨테이너터미널 부지 연약지반개량의 경우 광양지역의 특성상 재하용 토사확보 곤란, 시공기간 단축 및 환경훼손 최소화를 위해 진공압밀공법이 적용되었다. 본 사례연구에서는 진공압밀공법의 시공에 따른 문제점 및 개선사항을 제시하였고, 현장계측 및 진공 압밀완료 후에 실시된 지반조사 결과 등을 분석하여 준설매립지반에서의 진공압밀공법의 적용성을 평가하였다.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.515-517
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• 1987

The direct alleylation of 1,4-cyclohexanodione with 1-dodecene underwent in one stop and n-dodecyl-tetracyanoquinodimethano was synthesized. The total yield of n-dodecyl-tetracyunoquinodimethane was about 55.2% when the n-dodecyl-1,4-cyclohexanedione was a starting material.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.511-514
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• 1987

Langmuir-Blodgett (LB) films of TCNQ(tetracyanoquinodimethane) with alkyl radical($C_{12}TCNQ$) were prepared on the sample of Al/LB film/Al type where Al are electrode, and polarization in LB film and dipolar moment of molecules in the films were measured by TSC. $Al_2O_3$ layer was yielded on the electrode by natural oxidation in air. According to the cooperation of $Al_2O_3$ dielectric layer and the polarization of $C_{12}TCNQ$-LB film, the macroscopic electrical field was yielded in LB film and $Al_2O_3$ layer. The field strength in $C_{12}TCNQ$-LB films was evaluated at about $1{\times}10^6{\sim}5{\times}10^6\;V/cm$.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.796-798
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• 1988

Langmuir-Blodgett(LB) films of arachic acid and TCNQ(tetracyanoquinodimethane) were prepared in the sample of Al/LB film/Al type where Al are electrodes, and polarization in LB film and dipolar moment of molecules in the films were measured by themally stimulated current(TSC). It is ascertaind in our experiments that dipolar mament of $C_{12}$TCNQ molecule was about 13-15 debye and the moment was directed from the alkyle chain toward TCNQ. Generation of the open circuit voltage was investigated on the z-type and Hetero structure of LB films.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.915-916
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• 2006

This paper proposed the extraction method of reactor parameters in atmosphere plasma power supply. This methods is performed by detection of phase difference between inverter voltage and current, and extraction of impedance through active, reactive power. The validity of the proposed scheme is investigated through simulation results.