• 대한기계학회논문집B
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• 제27권5호
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• pp.644-654
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• 2003

An analytical solution for a vertically stratified viscous flow in a microchannel with a rectangular cross-section is constructed, assuming fully developed laminar flow where the interfaces between the fluid layers are flat. Although the solution is for n-layer flow, restricted results to symmetrical three-layer flow are presented to investigate the effects of the viscosity and thickness ratios of the fluid layers and the aspect ratio of the microchannel on the flow field. Relations between the flow rate and thickness ratios of the fluid layers with varying viscosity distributions are found, considering the cross -sectional velocity profiles which vary noticeably with the three parameters and differ significantly from the velocity profiles of the flow between infinite parallel plates. Interfacial instability induced by the viscosity stratification in the microchannel is discussed referring to previous studies on the instability analysis for plane multilayer flow. Exact solution derived in the present study can be used for examining a diffusion process and three -dimensional stability analysis. More works are needed to formulate the equations including the effects of interfacial' tension between immiscible liquids and surface wettability which are important in microscale transport phenomena.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.846-851
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• 2003

The differential equations governing free, in-plane vibrations of non-circular arches with non-uniform cross-section, including the effects of rotatory inertia, shear deformation and axial deformation, are derived and solved numerically to obtain frequencies. The lowest four natural frequencies are calculated for the prime parabolic arches with hinged-hinged, hinged-clamped, and clamped-clamped end constraints. Three general taper types for rectangular section are considered. A wide range of arch rise to span length ratios, slenderness ratios, and section ratios are considered. The agreement with results determined by means of a finite element method is good from an engineering viewpoint.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1254-1259
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• 2001

This paper deals with the free vibrations of circular arches with variable cross-section. The differential equations governing free, in-plane vibrations of tapered circular arches, including the effects of rotatory inertia, shear deformation and axial deformation, are derived and solved numerically to obtain frequencies and mode shapes. Numerical results are calculated for the quadratic arches with hinged-hinged and clamped-clamped end constraints. Three general taper types for a rectangular section are considered. The lowest four natural frequencies and mode shapes are presented over a range of non-dimensional system parameters： the subtended angle, the slenderness ratio and the section ratio.

• Structural Engineering and Mechanics
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• 제10권2호
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• pp.125-138
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• 2000

The paper analyzes the problem of torsion in an adhesive non-tubular bonded single-lap joint. The joint considered consists of two thin rectangular section beams bonded together along a side surface. Assuming the materials involved to be governed by linear elastic laws, equilibrium and compatibility equations were used to arrive at an integro-differential relation whose solution makes it possible to determine torsional moment section by section in the bonded joint between the two beams. This is then used to determine the predominant stress and strain field at the beam-adhesive interface (stress field along the direction perpendicular to the interface plane, equivalent to the applied torsional moment and the corresponding strain field) and the joint's elastic strain (absolute and relative rotations of the bonded beam cross sections). All the relations presented were obtained in closed form. Results obtained theoretically are compared with those given by a three dimensional finite element numerical model. Theoretical and numerical analysis agree satisfactorily.

• 한국전통조경학회지
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• 제32권1호
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• pp.74-82
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• 2014

본 연구의 목적은 지형에 의한 입지, 평면 및 단면 형태 등 토성의 공간구조적 특성을 규명하는 것이다. 사적이나 시도기념물로 지정된 37개소의 토성을 대상으로 문헌연구, 현장조사, 지형자료조사, 지형과 공간구조와의 관계 분석이 이루어졌다. 토성의 공간구조 연구의 결과는 다음과 같다. 첫째, 평지형 토성은 강이나 천과 같은 수계와 인접하였으며, 토성의 평면 형태는 정형적이었으며, 토루의 단면 형태는 단일경사의 사다리꼴형이 가장 많이 나타났다. 둘째, 구릉지형 토성은 1.5km이하의 근거리에 수계가 존재하는 곳이 70%이상을 차지했다. 평면 형태는 부정형이 73%이상으로 가장 많았고, 토루의 단면 형태는 테두리형과 산탁형이 86%이상을 차지하였다. 셋째, 산지형 토성은 1.5km이하의 근거리에 수계가 존재하는 곳이 59%이하로 평지형이나 구릉지형에 비해 외부 수계의존도가 낮았다. 평면 형태는 부정형이 67%이상으로 주류를 이루었으며, 토루의 단면 형태는 단일경사방식의 테두리형과 산탁형이 94%이상으로 나타났다.

• 태양에너지
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• 제19권2호
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• pp.45-56
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• 1999

The performance of vertical and horizontal tubes with extended surface of rectangular and triangular cross section was investigated theoretically for boiling heat transfer. A simple method for numerical program assuming one-dimensional heat flow was used to predict the performance of these extended surface tubes. The object of this study was to predict the effects of the height, thickness, numbers and, clearance of the extended surface on boiling heat transfer. The results showed that extended surfaces are quite effective as compared to plane surfaces especially near the bum-out point and to promote heat flux in boiling heat transfer.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2000년도 KIASC Conference 2000 / 2000년도 학술대회 논문집
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• pp.177-179
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• 2000

In this paper, we analyzed quench characteristics of field windings using 2 dimensional analysis. The quench origin was assumed to take place at the inner most point in the mid-plane of the coil. The temperature distribution was numerically calculated on the coil cross section using FDM analysis, and was used to estimate the normal zone resistance of the coil. Finally, we obtained voltage current characteristics of the quenched winding coils.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 춘계학술발표회 논문집
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• pp.467-470
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• 2003

This study tries to introduce the precision measurement of 3-dimensional terrain of reservoir using Echo Sounder and RTK-GPS which is unprecedented in domestic. In this study, to introduce the way to produce the plane figure, the cross section and data of underside reservoir by constructing the 3-dimensional terrain models using 3-Dimensional data gained by measurement.

• Radiation Oncology Journal
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• 제3권1호
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• pp.59-64
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• 1985

Computation of three dimensional dose distribution using CT image and RT plan was applied to a case of pituitary adenoma. Algorithm was based on two dimensional Tissue Maximun Ratio model extended to the third dimension. The resulting isodose curve of transeverse, coronal and sagittal section was demonstrated. This RT plan allows computation of dose distribution in any arbitarily defined plane in addition to conventional cross sectional view.

• 한국전자파학회논문지
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• 제19권2호
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• pp.107-113
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• 2008

본 논문에서는 차단 영역 도파로로 구현된 협소한 형태의 H-plane slot을 이용하여 다수의 감쇄극을 가지는 반파장 partial H-plane filter를 제안하였다. 협소한 형태의 H-plane slot은 대역 통과 필터의 어드미턴스 인버터 역할을 하는 동시에 특정 주파수에서 공진을 발생시킨다. 따라서 제안된 필터는 어떠한 부가적인 coupling이나 추가적인 구조의 변형 없이 저지 대역에서 감쇄극을 가지는 간단한 구조로 구현되고, 감쇄극 수는 인가되는 slot의 수만큼 발생된다. 제안된 필터는 일반적인 도파로의 1/4의 단면적을 가지는 partial H-plane waveguide로 설계되므로 소형화에 유리하다 저지 대역에서 각각 4개와 5개의 감쇄극을 갖는 3단과 4단 반파장 대역 통과 필터를 H-band에서 설계하여, 이론적 주파수 응답 특성이 실험적 응답 특성과 잘 일치함을 확인하였다.