• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.276-279
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• 2002

A problem formulation and solution for design optimization of laminated composite channel section beam is presented in this study. The objective of this study is the determination of optimum section dimensions of composite laminated channel section beam which has equivalent flexural rigidities to flexural rigidities of steel channel section beam. The analytical model is based on the laminate theory and accounts for the material coupling for arbitrary laminate stacking sequence configuration. The model is used to determine the optimal section dimensions of composite channel section beam. The web height, flange width and thickness of the beam are treated as design variables. The solutions described are found using a global search algorithm, Genetic Algorithms (GA).

• 환경영향평가
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• 제18권3호
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• pp.171-183
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• 2009

This study aims to analyze the sedimentary environment change in mid-channel bar of the lower Geum river basin after the construction of the estuary barrage using multi-temporal satellite data and GIS. The sedimentary environment changes were observed in mid-channel bar areas. The mid-channel bar F was found to have been newly formed for 10 years(1996-2006), whereas the mid-channel bar B located between mid-channel bar A and C has disappeared by erosion during the same periods. When examined by section, the areas of the mid-channel bar in the upper stream section from the Yipo's reference point generally increased due to the prevailing sedimentary environments, and those of the downstream section decreased where corrosive environments are dominant. In ternms of the centroid movement, the mid-channel bars grew up toward the downstream by switching erosion and accumulation, as sedimentation was prevailing in the downstream area of mid-channel bars and corrosion was dominant in the upper stream. Through grain size analysis, the study areas are divided into three sections according to the average grain size. In Section I, the mid-channel bars were formed as a result of sedimentary process of tides in the past. In Section II, the mid-channel bars were formed partly through the sedimentary process of rivers although the sedimentary process of tides is prevailing. In Section III, the mid-channel bars were formed mainly through the sedimentary process of rivers, even if it showed the sedimentary process of tides in the past.

• 물과 미래
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• 제25권3호
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• pp.87-96
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• 1992

측류취소로와 만곡부가 있는 원형수로를 1:20으로 축척한 모형수로에 대해 수리모형실험을 수행하여 만곡부에서의 유속, 수위와 유황과 같은 수리학적 특성을 살펴보고, 측류취소로가 만곡부에 미치는 영향을 살펴보고자 한다. 또한 모형수로에 대해 ADI방법으로 천수방정식을 수치해석하여 얻은 만곡부에서의 수리학적 특성을 실험에 의한 것과 비교하여 사용된 수치기법을 검증하였다. 대상이 된 전영역에 대하여 수리모형실험에서 얻어진 유속, 수위와 유황은 수치해석한 결과와 잘 일치한다. 그러나 직각좌표계를 사용함으로서 상대적으로 만곡부에서 단면축소 효과가 발생하므로 수치해석으로 얻어진 유속은 만곡부에서 실험치보다 약간 크게 나타나는데, 이것은 격자간격을 줄이면 개선되리라 판단된다. 수리모형실험과 수치해석 모두 만곡부 외측의 수위가 상승하고 내측의 유속이 빨라지는 만곡부의 특성을 잘 모사하고 있다. 만곡부 직전에 측류취수로가 있을 경우 측류취수로의 영향이 만곡수로내까지 미침을 알 수 있었다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 추계학술발표대회 논문집
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• pp.91-94
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• 2001

This paper presents the analytical investigation pertaining to the local buckling behavior of orthotropic channel section compression members stiffened with unsymmetric stiffeners at its free edges. In the analysis, tile edge stiffener is modeled as a beam element or a plate element. The result of both cases is presented in graphical form so that the effects of edge stiffeners on the local buckling strength of edge stiffened channel section member can be found.

• 한국구조물진단유지관리공학회 논문집
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• 제8권2호
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• pp.169-175
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• 2004

본 연구에서는 채널단면을 갖는 캔틸레버 복합적층 구조물의 안정성에 다루었다. 보다 합리적이고 효율적인 설계의 기초자료를 제시하고자 채널단면의 길이비와 곡절각도 등과 같은 기하학적 형상변화와 화이버의 보강각도에 따른 좌굴거동을 분석하고, 그에 따른 상호작용에 의한 안정성을 파악하였다. 이를 근거로 캔틸레버 복합적층 구조물의 적절한 채널단면 및 복합재료의 적층구조형식 등을 공학적 측면에서 고찰하고 제시하였다.

• 한국산업융합학회 논문집
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• 제3권4호
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• pp.319-327
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• 2000

In this study, the hydraulic characteristics variation of flood level caused by tree-planting condition in channel section is evaluated through the examination and analysis of back water characteristics in a natural channel within urban area where the improvement is completed. The study channel is Sinchun runs through the center of Taegu metropolitan city. For the analysis, the comparative examination of runoff characteristics depend on tree- planting condition performed for the flood level of the most upstream point, and velocity of study channel when the project flood flows according to three cases that existing channel is improved to the pro-natural channel, the roughness condition of both riverside highlands is changed, and the composition rate of trees in the riverside highlands is changed. It is known that the variation ranges of the flood level increase remarkably in general, and of the velocity decrease from the result of the examination for the hydraulic characteristics parameters at the most upstream point depend on the tree-planting condition of the channel section when the project flood flows. From the results of the above study on the variation of the hydraulic characteristics according to the tree-planting condition in channel section, it is known that the hydraulic characteristics when the project flood flows in channel have close relationship with the section properties and the slope of channel.

• ETRI Journal
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• 제44권6호
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• pp.915-924
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• 2022

In this paper, we present a two-stage scalable channel estimator (TSCE), a deep learning (DL)-based scalable, and robust channel estimator for wireless cellular networks, which is made up of two DL networks to efficiently support different resource allocation sizes and reference signal configurations. Both networks use the transformer, one of cutting-edge neural network architecture, as a backbone for accurate estimation. For computation-efficient global feature extractions, we propose using window and window averaging-based self-attentions. Our results show that TSCE learns wireless propagation channels correctly and outperforms both traditional estimators and baseline DL-based estimators. Additionally, scalability and robustness evaluations are performed, revealing that TSCE is more robust in various environments than the baseline DL-based estimators.

• 한국환경과학회지
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• 제21권4호
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• pp.471-478
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• 2012

In this study, the flow characteristic analysis at the curved-channel of the actual channel section is compared and reviewed using the 2D RMA-2 model and the 3D FLOW-3D model. the curve section with curve rate 1.044 in the research section is analyzed applying the frequency of he project flood of 100 years. According to the result, the issue for the application of the FLOW-3D Model's three-dimensional numeric analysis result to the actual river is found to be reviewed with caution. Also, application of the 3D model to the wide basin's flood characteristic is determined to be somewhat risky. But, the applicability to the hydraulic property analysis of a partial channel section and the impact analysis and forecast of hydraulic structure is presumed to be high. In addition, if the parameters to reflect the vegetation of basin and the actual channel, more accurate topological measurement data and the topological data with high closeness to the current status are provided, the result with higher reliability is considered to be drawn.

• 한국수자원학회논문집
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• 제41권8호
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• pp.773-784
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• 2008

본 연구는 노면배수시설에 이용될 수로 양단에 유출구를 가지며 유량이 연속적으로 증가하는 선형 배수로의 부등류 흐름의 해석 방법을 정립하기 위하여 수행되었다. 지배 방정식으로서 유한 차분 형태의 대수방정식을 사용하여 지배단면에서의 수심 값을 경계조건으로 Newton-Raphson 방법에 의하여 수면곡선을 계산하였다. 하류단에 유출구를 갖는 수로와 수로 양단에 유출구를 갖는 수로를 고려하고, 다양한 종단경사에 대하여 흐름 해석을 수행하였다. 단, 양단에 유출구를 갖는 수로의 경우 양단을 지배단면으로 만드는 임계 종단경사를 조사하여 이보다 작은 종단경사에 대한 흐름 해석을 수행하였으며, 임계경사는 지배단면의 위치와 종단경사의 관계로부터 결정하였다. 하류단에 하나의 유출구를 갖는 수로의 경우 수로 상에 존재하는 지배단면의 위치를 조사하여 그 지점을 기준으로 상류 및 하류 방향으로 수심을 계산한다. 반면 양단에 유출구를 갖는 수로의 경우 지배단면이 수로 양단이라면 분수계를 가정하여 분수계를 기점으로 구분되어지는 상류측 및 하류측 수로에 대한 흐름 해석을 수행하고, 상류단에서 분수계 방향으로 그리고 하류단에서 분수계 방향으로 계산된 분수계 지점의 두 수심이 동일할 때까지 흐름 계산을 반복한다. 흐름 계산 결과 양단에 유출구를 갖는 수로가 임계경사보다 큰 경사로 설치된 경우에는 하류단에 유출구를 갖는 수로의 흐름 거동과 유사지는 것으로 판단되었다. 노면배수시설 설계의 중요한 요소인 최대수심은 종단경사가 작을 때 등류 해석으로 계산된 값이 부등류 해석보다 크게 산정되었으며, 이는 종단경사가 작을 때 등류 해석을 기반으로 한설계가 과대설계가 되기 쉽다는 것을 의미한다.

• 한국안전학회지
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• 제19권3호
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• pp.78-83
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• 2004

The channel-type lining board that partial welded on many partition frames is used to normal servicing lining board type. On this study is to investigate existing channel-type lining board's capacity by using the static loading test. From this study, to develop new-type lining board which reflect well cross section area and sectional modulus of existing channel-type lining board. Six types FEM model are adopted. The accumulated test results of stress conditions and deflections by section shapes will be used to analyzed the relation between the capacity and the section shape. With the comparing the results of static loading test and FEM analysis.