• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.188-193
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• 1999

Transport of pollutants in aquifer largely depends on groundwater flow which is governed by aquifer hydraulic parameters. Determination of these parameters and associated groundwater modeling become essential for adequate remediation of contaminate groundwater. The objective of this paper is to analyze groundwater flow and determine the optimum hydraulic parameters by performing groundwater modeling based on sensitivity analysis for unconfined sandy gavel aquifer constructed in a laboratory scale under various boundary condition. Results revealed that the simulated drawdown was lower than the observed drawdown irrespective of boundary conditions. and specific yield (S$_{y}$) had less effect on the grondwater flow than permeability (K) in the aquifer. Water balance analysis showed that the measured drawdown in neighboring observation wells during pumping was higher than either simulated or recovered water table. The indicated that a difference might exist in the water tables between aquifer and wells. The difference was investigated by time domain reflectometry (TDR) measurements on water contents in the region of water table and capillary fringe, and explained by a delayed response of water table during gravitational drainage as the water table was lowered as a result of pumping.g.

• Cartoon and Animation Studies
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• s.14
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• pp.83-99
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• 2008

In general, the cut or dissolve or etc., collective changeover represents the change of scene in the film. Animation film makes scene's various parts to allow intended sensibility and narrative factors by special manufacturing skill generating frame image one by one and transfer it to the different symbolic dimensional expression. Nowadays sequential scene composition is not any more the unique special treatment for 2D animation according to image handling skill like morphing, metamorphosis, etc. becomes diverse and elaborate. But 2D manual animation makes spectator to be absorbed into different visual dimensions continuously and strongly beyond character and background, namely object and space. that is 2D manual animation's strong attractiveness. Finally these characteristics enable literary function which makes it possible to do delicate metaphorical through full scene composition basis and to communicate a implicative meaning system The analysis about scene broke boundary between symbolic perspective world and plane formative world and it became more diverse and complicated. Hereupon the analyzing the composition basis of formative element in the animation film scene and it's application effect make it helpful to analysis and application in the modern image scene having new absorbing methods

• Journal of Biosystems Engineering
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• v.18 no.2
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• pp.144-157
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• 1993

환기중인 실험축사내에서 가축의 현열과 환기공기의 온도차에 의한 열부력(熱浮力)(thermal buoyancy)이 공기유동 및 온도분포에 미치는 영향을 구명(究明)하기 위하여 TEACH 컴퓨터프로그램($k-{\varepsilon}$ 난류모형 및 SIMPLE계열 Algorithm)을 Curvilinear Coordinates에 맞게 변형하였다. 계산한 축사내 공기유통 및 온도분포의 유의성(有意性) 검증은 Boon(1978)의 실험결과를 이용하였다. 열부력의 크기에 따른 유동의 변화를 관찰하기 위하여 유입공기의 온도를 $17^{\circ}C$와 $10^{\circ}C$ 두 수준으로 입력하였으며, 가축의 현열플릭스(flux)는 실내온도에 따라 변화하므로 유압공기의 온도가 $17^{\circ}C$일 때는 130W/$m^2$, $10^{\circ}C$일 때는 170W/$m^2$을 경계조건으로 입력하였다. 예측한 공기유동의 형태는 실험값(Boon, 1978)과 비교하여 대체로 만족할만한 결과를 얻었다. 그러나 유입공기의 온도가 $10^{\circ}C$인 경우, 예측 공기유동은 실험 유동형태와 차이가 있었다. 즉, 실험에서는 수평슬롯으로 유입된 공기가 바로 아래로 굴절되어 유동(流動)하였으나, 계산의 결과는 일정 거리로 수평방향으로 유동하다가 아래로 굴절하였다. 이런 유동의 차이는 경험적으로 열부력(熱浮力)에 민감하게 반응하지 않는 k-${\varepsilon}$ 난류(亂流)모형의 적용이 원인이 되거나 실험의 부적절한 수행이 원인이 될 수도 있다. 이 유동(流動)의 Reynolds 수(數) (Re)는 약 3,300, 수정Ar수(修正Ar數)(Corrected Archimedes Number : $Ar_c$)64로써, $Ar_c$ <30 이거나 $Ar_c$ >75이면 유입공기의 제트는 수평유동한다는 Randall & Battams(1979)의 연구결과와는 일치하였다. 그러나 공기제트의 굴절은 유동의 특성이 같다하더라도 유체의 성질, 축사의 기하학적 형태에 따라서 매우 민감하게 반응하므로 실제 실험을 통한 재검정과정을 거쳐야 할 것으로 판단된다. Fig. 9와 Fig. 10의 기하학적 형태의 지점별 예측온도와 측정온도(Boon, 1978)와의 편차는 대부분의 지점에서는 $1^{\circ}C$ 미만으로 상당히 정확하였으며, 최대의 온도차는 Fig. 10의 지점 13에서 $1.7^{\circ}C$이었다.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.417-427
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• 2017

This study aims to present cases of rock slope failures caused by geological structures. Status of slope failures, results of cause analysis and stabilizing methods are introduced, focusing primarily on rock slope failures caused by specific geologic structures, such as intersection of faults infilled with clay, foliation and fault shear zone by dike intrusion and deep-seated clayey layer along lithologic boundary. Detailed geological survey, geophysical exploration and boring survey were conducted for cause analysis. Stabilizing method to prevent further slope failures and to ensure long-term stability of slopes were established, considering characteristics of geological structures, types of failure and geological conditions.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.93-93
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• 2011

연육 연도교에 주로 건설되는 초장대교량은 시설물 특성상 이용객들의 대피공간이 제약받고 태풍, 해일 등 자연재해에 노출이 많기 때문에 다른 공공시설물보다 재난에 취약한 구조물이다. 최근 공공시설물의 건설동향이 구조물의 장대화로 되어감에 따라 재난 발생시 예상 위험이 점점 더 커져가고 있다. 본 연구는 이전 연구를 통해서 구축된 재난관리 시나리오를 토대로 재난관리 알고리즘을 개발하였다. 초장대교량의 재난은 자연재해와 인적재해로 구분할 수 있다. 여러 가지 재해 중 본 연구에서 제시한 재난관리 알고리즘은 자연재해의 경우 안개, 강설, 결빙, 강풍, 지진, 해일 및 풍수해이며 인적재해의 경우 화재, 교통사고, 구조물파괴 및 테러이다. 이 재난관리 알고리즘은 재난관리 전산 프로그램 구축의 기초로 사용될 것이다. 본 연구는 국내외 재난관리 관련 사례조사를 토대로 재난 수준별 평가방법을 수립하였다. 안개, 강설, 결빙, 강풍, 지진, 해일 및 풍수해와 같은 자연재난은 심각한 재난 발생전에 교통통제가 가능한 형태로 분류될 수 있으며 사례조사를 통해 교통통제 관리기준을 설정하였다. 화재, 교통사고, 구조물 파괴 및 테러와 같은 인적재난은 상황 발생시부터 비상대응을 취해야할 재난의 형태로 분류될 수 있으며 사고발생 시나리오를 통해 대응 단계별 평가방법을 설정하였다. 또한 재난 수준별 평가방법을 토대로 재난관리 알고리즘을 개발하였다. 자연재해와 같이 사고 발생 전에 교통통제가 가능한 재해는 교통통제 모듈로 구분하여 재난관리 알고리즘을 설정하였다. 인적재해와 같이 사고 발생 즉시 비상대응을 실시해야할 재해는 비상대응 모듈로 구분하여 재난관리 알고리즘을 설정하였다. 교통통제 모듈과 비상대응 모듈은 원칙적으로 국가재난관리등급에 따라 관심, 주의, 경계, 심각의 4단계로 구분하였다. 교통통제 모듈과 비상대응 모듈은 AAD에 의해 관리자, 외부기관 및 이용자 각각의 세부 행동지침 및 요령을 제시하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.36-44
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• 2003

In this paper, an analytic solution method is proposed to overcome the numerical problems when the slewing dynamics of hybrid coordinate systems is investigated via time finite element analysis. It is shown that the dynamics of the hybrid coordinate systems is governed by the coupled dual differential equations for both slewing and structural modes. Structural modes are transformed into the time-based modal coordinates and analytic spatial propagation equations are derived for each space-dependent time mode. Slew angle history is obtained analytically by appropriate applications of the boundary conditions and structural propagation is re-calculated using the slew angle. Numerical examples are demonstrated to validate the proposed analytic method in comparison to the existing state transition matrix method.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.4
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• pp.46-51
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• 2007

The irregular fuel surface was observed by the visualization of hybrid rocket combustion. Even though the test condition maintained oxidizer rich environment, the irregular dark fuel surface was formed as the result of incomplete combustion. In order to investigate the correlation of the characteristics of oxidizer flow and the irregular fuel surface, various flow conditions were imposed such as swirl flow, induced swirl flow by helical fuel configuration and straight flow. Test results revealed no correlation was found between oxidizer flow condition and irregular fuel surface. And this can be a commonly observed phenomena in the tests with different fuel/oxidizer combination. Thus, the irregular fuel surface can be a result of the interaction of blowing flow of vaporized fuel and the boundary layer of oxidizer flow. A further study will be required to confirm the assumption for the formation of irregular fuel surface.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.359-363
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• 2011

In this paper, the characteristic of pressures had been analyzed with a series of shapes that are pressure probes used in supersonic wind tunnel. When a performance of supersonic wind tunnel is evaluated, the Mach number is calculated by using the ratio of static pressure in test section wall to total pressure in settling chamber. Also the flow condition can be visualized by schlieren system. However a number of limitations exist to measure pressure of test section due to high speed and boundary layer effect. Therefore a specific pressure probe is needed for evaluating flow condition in test section at a various of positions. In the paper, experiments were conducted in terms of some pitot probes and the results were compared and analyzed.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.159-163
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• 2005

This experimental study was performed to investigate internal flow and unsteady flow characteristics using a model for actual shape of a plate heat exchanger and visualization of flow through the particle image velocimetry. Seven Reynolds numbers were selected by calculation with the height of grooved channel and sectional mean velocity of inlet flow in the experiment, and instantaneous velocity distributions and flow characteristics were experimently investigated. The triangular grooved channel had a compound flow consisting of the flow in lower channel and the groove flow receiving shear stress by the channel flow in the experiment. The sheared mixing layer, in the boundary between the triangular groove and the channel, affected main flow to raise turbulent in the channel.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.153-158
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• 2005

The turbulent shear flaw around a surface-mounted vertical wall was investigated using the two-frame PIV(CACTUS 3.1) system. From this study, it is revealed that at least 500 instantaneous velocity field data are required for ensemble average to get reliable turbulence statistics, but only 200 field data are sufficient for the time-averaged mean velocity information The flow has an unsteady recirculation region post vertical wall with bottom gap, followed by a slow relaxation to the fiat-plate boundary layer flow. The time-averaged reattachment length estimated from the streamline distribution is about x/H=3H. The large eddy structure in the separated shear layer seems to have signification influence on the development of the separated shear layer and the reattachment process.