• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.666-669
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• 2011

이중펄스 로켓모타에 적용되는 격벽형 펄스분리장치의 파열판 형상을 변경하는 설계를 진행하였다. 펄스분리장치 설계 확정에 앞서 3가지 다른 형상의 파열판 평판시험을 진행하여 파열판 성능을 확인하였다. 평판시험후 시험결과를 분석하여 펄스분리장치 파열판의 8개의 원형 구멍형과 8개의 사다리꼴 구멍 형상을 적용하기로 결정하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.578-582
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• 2000

When the motion of vibrating structure is restrained due to the adjacent objects, the frequencies and the mode shapes of the structure change and its vibration characteristics becomes unpredictable, in general. Although the importance of the study on this type of vibration model increases in many engineering areas, most studies conducted so far are limited to the theoretical study on dynamic responses of the structure with the separation plate, including some experimental works. In the paper, both numerical analyses and experiments are conducted to study the chaotic vibration characteristics and the dynamic response of a fixed-free beam which has restrained motion at the free end by the separation plates. Results are presented for various magnetic forces and gaps between stops.

• 한국작물학회지
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• 제60권1호
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• pp.29-32
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• 2015

Two-dimensional electrophoresis (2-DE) was executed to separate the seed storage proteins from the buckwheat. The proteins extracted from the whole seed proteins were better separated and observed in the use of lysis buffer. Using this method, the highly reproducible isoelectric focusing (IEF) can be obtained from polyacrylamide gels, and IEF from the polyacrylamide gel at all the possible pH range (5.0-8.0) was more easily separated than IPG (immobilized pH gradient) gels. The polyacrylamide gels in the first dimension in 2-DE was used to separate and identify a number of whole seed proteins in the proteome analysis. In this new apparatus using 2-DE, 27cm in length of plate coated with polyacrylamide gel was used and the experiment was further investigated under the various conditions.

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.83-90
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• 1999

A cellulose acetate membrane containing silver nitrate was prepared by gelatinizing in water at $2^{\circ}C$ after evaporating solvent from the casting solution on a glass plate. Permeation experiments for oxygen and nitrogen were conducted in the ranges of temperature, $5-40^{\circ}C$ and pressure difference, $1-5kg/cm^2$ in order to investigate the effects of temperature and pressure difference on permeation characteristics of the membrane. When the evaporation time was increased, the permeability of oxygen decreased but the separation factor of oxygen against nitrogen increased since a more dense layer was formed on the membrane surface. When the silver nitrate was added, the permeation flux was doubled and the separation factor was improved from 3.0 to 3.3. This implies that silver nitrate acts as an oxygen carrier in the membrane.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권3호
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• pp.177-182
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• 2007

This paper presents the see-saw type RF MEMS switch based on a single crystalline silicon structure with narrow gap vertical comb. Low actuation voltage and high isolation are key features to be solved in electrostatic RF MEMS switch design. Since these parameters in conventional parallel plate RF MEMS switch designs are in trade-off relationship, both requirements cannot be met simultaneously. In the vertical comb design, however, the actuation voltage is independent of the vertical separation distance between the contact electrodes. Therefore, the large separation gap between contact electrodes is implemented to achieve high isolation. We have designed and fabricated RF MEMS switch which has 46dB isolation at 5GHz, 0.9dB insertion loss at 5GHz and 40V actuation voltage.

• 약학회지
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• 제21권2호
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• pp.110-114
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• 1977

The purified .omicron.-iodobenzoic acid-$^{131}$ I, sodium iodide-$^{131}$I and mixtures of those compounds were applied to radio paper or radio thin layer chromatography to select the developing solvents with useful separation efficiency. The separation efficiencies were checked by radiochromatogram sacnnings. It has been found that the two dimensional radio paper chromatogrphy using the solvent systems of 8% phenol and butanol-glacial acid-water (4:1:1 v/v) and the radio thin layer chromatography using alumina gel plate and butanol- glacial acetic acid- water (4:1:1 v/v) are both efficient. In this method, the Rf value of .omicron.-iodobenzoic acid-$^{131}$ I and the unbound $^{131}$ I is 0.48, 0.85 and 0.15, respectively.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1998년도 제10회 학술강연회논문집
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• pp.15-15
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• 1998

The problem of the impingement of a sonic or a supersonic jet on a flat surface has not only wide applications but has also interesting and very complex flow phenomena. The main applications of this impinging jet include prediction of solid surface erosion, design of launcher systems, stage separation of multi-stage rocket system, V/STOL operations, thermal spray system, and manufacturing technologies of materials. Much have been learned about the supersonic impinging jet flow field but many fundamental questions have not been answered satisfactorily. The problem encompasses many facets of fluid dynamics which, in combination, present the compressibility effect and the viscous-inviscid interaction, coupled with flow separation and reattachment. What is more, there are many flow parameters that have on the impinging jet flow field, for example, Mach number, Reynolds number, pressure ratio, distance between the nozzle exit and flat plate, jet shock structure, nozzle diameter and etc. Thus the existing data on the supersonic impinging jet flow present considerable disagreement in which quantitative comparison between one result and another is often impossible.

• 콘크리트학회지
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• 제9권6호
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• pp.243-254
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• 1997

최근들어 구조물의 노후화와 차량하중 등의 증가로 구조물의 손상이 커지고 있으며 보강의 필요성이 절실히 대두되고 있다. 강판보강공법은 강성의 확실한 증가와 내구성 등으로 인하여 그 동안 폭넓게 사용되어 오고 있으나 효율적 보강을 위한 공법과 이론이 아직까지도 정립되지 않은 상태이다. 따라서 본 연구의 목적은 그 동안의 실험결과를 중심으로 보강도니 철근콘크리트보의 파괴기구와 박리거동을 분석하고 이로부터 합리적인 박리하중 산정이론을 제한하는데 그 목적을 두고 있다. 보강된 강판의 길이와 두께 등의 영향을 고찰하고,기존의 이론을 분석하여 기존이론의 불합리한 점을 밝혔으며, 이들을 보완한 수정이론을 제시하엿다. Roberts의 이론은 강판의 두께가 증가함에 따라 오히려 박리하중이 약간 증가하고 있어 실제적인 실험거동과 차이가 나고 있다. 본 연구의 제안식은 실제 거동을 합리적으로 표현하고 있으며, 앞으로 보강설계에 유용한 자료가 될 것으로 기대되고 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.105-108
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• 2004

In general, the nonlinear behavior of composite structures composing of steel and concrete is analyzed on the basis of the assumption of the perfect bond actions in steel-concrete interface in which the interface slip or separation is not allowed. The assumption is based on the fact that the full interface bond behavior is provided with the mechanical connectors of studs. However, since the number and spacing of the studs are determined by the stress resultants calculated in the interface area, the interface analysis is required to evaluate the stress resultants. This paper describes the nonlinear steel-concrete interface behavior considering the two interface failure mechanisms of slip and separation. Elastoplastic constitutive relation is developed. thru the formulation framework using the two energy dissipation mechanisms. As the result, the steel plate push-out tests sandwitched between concrete blocks are analyzed and compared with the test results with which the good agreements are observed.

• 전자공학회논문지C
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• 제36C권1호
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• pp.73-81
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• 1999

본 논문에서는 1-D DCT를 이용한 차량 영상의 번호판 영역 및 번호판의 문자 영역을 효과적으로 분할하는 방법을 제안한다. 차량 영상에서 번호판 영역과 번호판의 문자영역은 일정 크기의 고주파 성분에 의하여 구별될 수 있다. 본 방법은 이러한 고주파 성분을 DCT로써 추출하고, 추출된 고주파 성분에 의하여 번호판 영역과 문자영역을 분리하는 방법을 보인다. 또한 제안된 방법에 대한 타당성을 보이기 위하여, 다양한 영상에 대해 실험하였다. 그 결과, 간단한 전처리 만으로 비교적 정확한 번호판 영역 추출이 가능하였으며, 보다 효과적으로 문자영역을 분리할 수 있음을 확인할 수 있었다.