• 전자공학회논문지A
• /
• 제29A권11호
• /
• pp.19-24
• /
• 1992

In this paper, a high frequency method is developed which combines the uniform Geometrical Theory of Diffraction(GTD) and the Aperture Integration(AI) to analyze electromagnetic plane wave scattering by a perfectly-conducting, open-ended, semi-infinite parallel plate waveguide with a uniform layer of absorbing material on its inner wall, and with a slanted planar termination inside. In this method, first, the field of an arbitary point inside the paraller plate waveguide is computed by the GTD. Second, the field scattered into exterior region by the waveguide is found using the equivalent current, which can be obtaind from the aperture field of the waveguide and using the AI. Numerical results based on this GTD method are presented and compared with those based on the mode matching method.

• Progress in Superconductivity
• /
• 제11권2호
• /
• pp.141-146
• /
• 2010

Phase stability diagram and boundary of a- and c-axis orientation of $SmBa_2Cu_3O_{7-y}$ (SmBCO) thin films grown by pulsed laser deposition (PLD) were reported with studies based on x-ray diffraction [1]. Four different samples are systematically analyzed: normal c-axis oriented orthorhombic $SmBa_2Cu_3O_{7-y}$, a-axis oriented $SmBa_2Cu_3O_{7-y}$, c-axis oriented orthorhombic $SmBa_2Cu_3O_{7-y}$ with $Sm_2BaCuO_5$ phase, and a mixture with c-axis oriented orthorhombic $SmBa_2Cu_3O_{7-y}$ and anomalously long-c tetragonal $SmBa_2Cu_3O_x$. Raman scattering spectroscopy equipped with polarization analysis elucidates the crystal orientation and the origin of the growth of the materials. It indicates that the technique can be used for quality control of conductor manufacturing processes as well as for enhancement of the materials properties.

• 전자공학회논문지D
• /
• 제34D권10호
• /
• pp.45-52
• /
• 1997

An analysis method for the electromagnetic scattering of a gaussian beam wave by finite periodic conducting strip grating on a groudned dielectric slab is considered. The intergral equation for the unknown current induced on the conducting strip surface is derived and solbed numerically by use of the method of moment. From knowledge of the strip current, the quantities of interest such as radiation pattern, the space wave power radiated into the free space, and the coupled surface wave power propagating along the dielectric slab are computed for the appropriately chosen parametes Some similarity between scattering behaviours of the present geometry and the infinite geometry is examined by observing the Off-bragg as well as bragg blaxing penomena in both geometries.The validity of the numerical results are assured by a check of the power conservation relations.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
• /
• pp.366-369
• /
• 1999

Synthetic diamond films have been deposited on the silicon(100) surface and molybdenum substrates using an microwave plasma enhanced vapor deposition (MWPECVD) method. The effect of deposition time, surface morphology, X-ray diffraction pattrm, infrared transmittance and Raman Scattering have been studied, The diamond film deposited on Mo substrate for (100) hours at 40 torr H$_2$-CH$_4$O$_2$ gas system have been shown 1${\mu}{\textrm}{m}$/h of growth rate and good crystallization

• 한국인터넷방송통신학회논문지
• /
• 제17권1호
• /
• pp.231-236
• /
• 2017

다층 유전체 격자에 입사하는 평면파에 의해 생성 된 공간 고조파들은 GMR 특성으로 알려진 강한 공진 산란 변화를 겪는다. 이러한 효과를 명확히 분석하기 위하여 본 논문에서는 산란 문제의 정확한 등가전송선로 이론(RETT)을 사용하여 격자 영역 내부의 전파특성과 분산곡선을 조사하였다. 그 결과, 산란 공진의 최대 크기에서 산란된 모드와 격자 구조에 의하여 발생하는 누설 모드가 거의 동일하다는 것을 알 수 있었다. 따라서 누설파의 자유 공명 특성과 관련된 GMR 효과가 다층 유전체 격자구조에서 발생한다는 이전 연구를 확인하고 일반화하였다. 전형적인 격자의 공진특성을 보여주는 정량적인 수치해석 결과가 주어졌으며 TM 모드가 반사면에 수직 입사된 특수한 경우를 논의하였다.

• Advances in nano research
• /
• 제2권2호
• /
• pp.89-98
• /
• 2014

A novel and simple method for the synthesis of nano-magnetite particles is disclosed. In the novel procedure, $Fe^{2+}$ is the only source of metal cation. Carboxymethylcellulose (CMC) is used as the structure directing agent. The phase analysis of the nano-particles was performed using XRD and electron diffraction techniques. Size and morphology analysis was performed using light scattering and TEM techniques. The effect of $NH_4OH$ solution (32 wt. %) at different CMC concentrations on the size distribution of the final magnetite powders is studied. An optimal base concentration exists for each CMC concentration leading to minimal agglomeration. There exists a minimum CMC concentration (0.0016 wt. %), lower than that no magnetite forms. It is shown that using the new method, it is possible to immobilize a lipase enzyme (Candida Rugosa) with immobilization efficiency larger than 98 % with a loading more than 3 times the reported value in the literature. The latter phenomenon is explained based on the agglomerate state of the nano-particles in the liquid phase.

• Journal of the Optical Society of Korea
• /
• 제14권4호
• /
• pp.424-430
• /
• 2010

In coherent anti-Stokes Raman scattering (CARS) microscopy reported until now, conventional microscope objectives are used, so that they are limited for introduction into a living body. Gradient-index (GRIN) rod lenses might be a solution for miniaturized microscope objectives for in-vivo CARS microscopy. However, due to the inherent large amount of chromatic aberration, GRIN rod lenses cannot be utilized for this purpose. CARS imaging catheter, composed of miniaturized microscope objective and fiber bundle, can be introduced into a living body for minimally invasive diagnosis. In order to design the catheter, we have to first investigate design requirements. And then, the optical design is processed with design strategies and intensive computing power to achieve the design requirements. We report the miniaturized objective lens system with diffraction-limited performance and completely corrected chromatic aberrations for an in-vivo CARS imaging catheter.

• 한국전자파학회논문지
• /
• 제10권3호
• /
• pp.412-418
• /
• 1999

기하학적 균일 회절 이론 (Uniform Geometrical Theory of Diffraction)을 이용하여 옵\ulcorner 파라볼릭 안테나의 산란 특성을 분석하였다. 먼저 파추적법(Ray Tracing)에 의하여 음영경계를 나눈후, 각 영역에 존재하는 반사파와 회절파를 기하학적 균일 회절 이론을 이용해 구하였다. 또한, 옵\ulcorner 파라볼릭 안테나의 모서리(edge)의 형태가 전자파의 산란 특성에 미치는 영향을 알아보기 위해 knife 모서리인 경우와 원형 캡을 부착한 경우를 분석하여 비교하였다.

• 한국자기학회지
• /
• 제22권3호
• /
• pp.103-108
• /
• 2012

수 ${\AA}$의 파장과 수 meV에서 수백 meV의 에너지를 가지는 중성자는 물질의 구조와 동역학을 연구하는데 적절한 특징을 가지고 있다. 이런 중성자 산란은 지난 60여년 동안 발전되어 이제는 응집물질물리학을 비롯한 다양한 재료과학 분야에서 대표적이고 핵심적인 실험방법으로 자리잡았다. 본고에서는 이런 중성자 산란을 이용한 구조 및 동역학 연구의 기본 원리를 설명하고 간단한 예를 제시한다.

• Bulletin of the Korean Chemical Society
• /
• 제34권10호
• /
• pp.2942-2946
• /
• 2013

Nanostructured Ag thin films could be facilely prepared by soaking glass substrates in ethanolic solutions containing $Ag_2O$ powders at an elevated temperature. The formation of zero-valent Ag was corroborated using X-ray diffraction and X-ray photoelectron spectroscopy. The deposition of Ag onto a glass substrate was readily controlled simply by changing the reaction time. Due to the aggregated structures of Ag, the surface-enhanced Raman scattering spectra of benzenethiol could be clearly identified using the Ag-coated glass. The enhancement factor at 514.5 nm excitation estimated using benzenethiol reached $1.0{\times}10^5$ while the detection limit of rhodamine 6G was found to be as low as $1.0{\times}10^{-13}$ M. Since this one-pot fabrication method is eco-friendly and is suitable for the mass production of diverse Ag films, it is expected to play a significant role in the development of surface plasmon-based analytical devices.