• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.262-262
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• 2006

Biodegradable and amphiphilic di-block and tri-block copolymers, prepared with monomethoxy poly ethylene glycol (MPEG) and ${\varepsilon}-caprolactone\;({\varepsilon}-CL)$, were used for the application of W1/O/W2 multi- emulsion capsules. The effects of topology and the ratio of hydrophilic moiety of PCL-based polymers on the encapsulation efficiency of the $W_{1}/O/W_{2}$ multi-emulsion capsules containing Ascorbic Acid-2-Glucoside (AA-2-G) were investigated. The ratio of PEG and PCL was 1:0.5, 1:0.75, 1:1, and 1:1.25. PEG-PCL block copolymers were added to the first step of the preparation of $W_{1}/O$ emulsions. The dispersion stability, the particle size, the morphology of the $W_{1}/O/W_{2}$ multi-emulsion capsules were observed using an on-line turbidity meter, dynamic light scattering (DLS), a confocal microscopy (with FITC) and an optical microscopy. Biodegradable behavior of the PEG-PCL block copolymers and release behavior of AA-2-G were also observed by Gel Permeation Chromatography (GPC) and High Performance Liquid Chromatography (HPLC).

• 한국항공우주학회지
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• 제50권12호
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• pp.889-898
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• 2022

본 논문에서는 3차원 전자기장의 병렬 해석 기법을 제안하였다. 시간 조화 벡터 파동 방정식 및 유한요소 기법에 기반한 전자기장 산란 해석이 수행되었으며, 모서리 기반 요소 및 2차 흡수 경계 조건이 도입되었다. 개발한 알고리즘은 유한요소망을 분할한 뒤 각 프로세서에 할당함으로써 요소별 수치적분 및 행렬 조립 과정의 병렬화를 달성하였다. 이때 부영역 생성을 위해 그래프 분할 라이브러리인 METIS가 도입되었다. 대형 희박행렬 방정식의 계산은 다중 프론탈 기법 기반 병렬 연산 라이브러리인 MUMPS를 통해 수행되었다. 개발된 프로그램의 정확도는 Mie 이론해 및 ANSYS HFSS 결과와의 비교를 통해 검증되었다. 또한 사용된 프로세서 수에 따른 가속 지표를 측정하여 확장성을 확인하였다. 완전 전기 도체 구, 등·이방성 유전체 구 및 유도탄 예제 형상에 대한 전자기장 산란 해석이 수행되었다. 개발된 프로그램의 알고리즘은 추후 유한요소 분할 및 합성법에 활용될 예정이며, 더욱 확장된 병렬 연산 성능을 목표하고자 한다.

• 전자공학회논문지A
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• 제33A권5호
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• pp.65-74
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• 1996

in this paper, the propagation characteristics of the dominant modes in multiple coupled microstrip lines on a magnetized ferrite substrate are analyzed. The propagation constants and characteristic impedances are calculated by using the spectral domain method. With the numerical results, multi-port impedance parameters as well as scattering parameters are derived from nonreciprocal transmission line equations which are consistent with conventional transmission line theory. In additon, the numerical resutls of nonreciprocal characteristics for various values of structural, material parameters, and external magnetic fields are also presented.

• 대한수학회지
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• 제57권2호
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• pp.429-450
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• 2020

We prove that wave operators for Schrödinger operators with multi-center local point interactions are scaling limits of the ones for Schrödinger operators with regular potentials. We simultaneously present a proof of the corresponding well known result for the resolvent which substantially simplifies the one by Albeverio et al.

• 한국광학회:학술대회논문집
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• 한국광학회 1995년도 광학 및 양자전자학 워크샵 논문집
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• pp.210-215
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• 1995

Technology development toward the use of LiNbO3-based acoustic tunable filters as WDM 2$\times$2 cross-connect switches is reviewed. Recenly, it was found that a fundamental behavior of multi-wavelength Bragg scattering critically affects the crosstalk performance of the acousto-optic tunable filter. We revuew serveral reported methods of overcoming the performance degradation. We will eventually ask whether the device is up to task of WDM optical switching.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 하계학술발표회
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• pp.1-1
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• 2000

This paper presents a holography through high scatter mediums. Femtosecond light pulses are used as object light and reference light. When light passes through a high scatter medium, there are ballistic light, snake light and difussive light in transmitting light. However, ballistic and snake light are very weak, difussive light is very stronge so that they can not be imaged directly, By using femtosecond laser electronic holographic gating method to gate ballistic light and snake light and multi-holograms processing technology, high quality images can be obtained. (omitted)

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.487-488
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• 2011

• 대한원격탐사학회지
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• 제27권3호
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• pp.225-234
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• 2011

This study proposes an inversion algorithm to extract the surface parameters, such as surface roughness and soil moisture contents, using multi-frequency SAR data. The study areas include the tidal flats of Jebu Island and the reclaimed lands of Hwaong district on the western coasts of the Korean peninsula. SAR data of three frequencies were accordingly calibrated to provide precise backscattering coefficients through absolute radiometric calibration. The root mean square (RMS) height and the correlation length, which can describe the surface roughness, were extracted from the backscattering coefficients using the inversion of the Integral Equation Method (IEM). The IEM model was appropriately modified to accommodate the environmental conditions of tidal flats. Volumetric soil moisture was also simultaneously extracted from the dielectric constant using the empirical model, which define the relations between volumetric soil moistures and dielectric constants. The results obtained from the proposed algorithm were verified with the in-situ measurements, and we confirmed that multi-frequency SAR observations combined with the surface scattering model for tidal flats can be used to quantitatively retrieve the geophysical surface parameters in tidal flats.

• 대한조선학회논문집
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• 제44권4호
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• pp.445-450
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• 2007

An optimum design process of the broad-band multi-layered radar absorbing material, using genetic algorithm, is established for the radar cross section reduction of a complex target, which consists of multiple reflection structures, such as surface warships. It follows the successive process of radar cross section analysis, scattering center analysis, radar absorbing material design, and reanalysis of radar cross section after applying the radar absorbing material. It is demonstrated that it is very effective even in the optimum design of the multi-layer radar absorbing material. This results from the fact that the three factors, i.e.. the incident angle range, broad-band frequencies, and maximum thickness can be simultaneously taken into account by adopting the genetic algorithm.

• 한국전기전자재료학회논문지
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• 제15권1호
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• pp.79-84
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• 2002

An accurate cross sections set is necessary for the quantitatively understanding and modeling of plasma phenomena. By using the electron swarm method, we determine an accurate electron cross sections set for objective atoms or molecule at low electron energy range. It is general calculation that used in this method to an two-term approximation of Boltzmann equation. But it may give erroneous transport coefficients for CF$_4$ molecule treated in this paper having \`C2v symmetry\`, therefore, multi-term approximation of the Boltzmann equation analysis which can consider anisotropic scattering exactly is carried out. It is necessary to require understanding of the fundamental principle of analysis method. Therefore, in this paper, we compared the electron transport coefficients(W and ND$\_$L/) in pure Ar, O$_2$, and CF$_4$ gas calculated by using two-term approximation of the Boltzmann equation analysis code uses the algorithm proposed by Tagashira et al. with those by multi-term approximation by Rubson and Ness which was developed at James-Cook university, and discussed an application and/or validity of the calculation method by comparing these calculated results.