• 한국자동차공학회논문집
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• 제4권4호
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• pp.179-189
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• 1996

An unstructured grid finite-volume method has been applied to predict the linear and nonlinear attenuation characteristics of the expansion chamber silencer system. In order to achieve a grid flexibility and a solution adaptation for geometrically silencer system. In order to achieve a grid flexibility and a solution adaptation for geometrically complex flow regions associated with the actual silencers, the unstructured mesh algorithm in context with the node-centered finite volume method has been employed. The present numerical model has been validated by comparison with the analytical solutions and the experimental data for the acoustic field of the concentric expansion chamber with and without pulsating flows, as well as the axisymmetric blast flowfield with open end. Effects of the chamber geometry on the nonlinear wave attenuation characteristics is discussed in detail.

• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1709-1718
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• 2017

This paper presents a hybrid stochastic deterministic multi-timescale scheduling (SDMS) approach for generation scheduling of a power grid. SDMS considers flexible resource options including conventional generation flexibility in a chance-constrained day-ahead scheduling optimization (DASO). The prime objective of the DASO is the minimization of the daily production cost in power systems with high penetration scenarios of variable generation. Furthermore, energy storage is scheduled in an hourly-ahead deterministic real-time scheduling optimization (RTSO). DASO simulation results are used as the base starting-point values in the hour-ahead online rolling RTSO with a 15-minute time interval. RTSO considers energy storage as another source of grid flexibility, to balance out the deviation between predicted and actual net load demand values. Numerical simulations, on the IEEE RTS test system with high wind penetration levels, indicate the effectiveness of the proposed SDMS framework for managing the grid flexibility to meet the net load demand, in both day-ahead and real-time timescales. Results also highlight the adequacy of the framework to adjust the scheduling, in real-time, to cope with large prediction errors of wind forecasting.

• 한국실내디자인학회논문집
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• 제17호
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• pp.181-186
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• 1998

Grid serves as an auxiliary instrument that explains design logically and objectively when you designing an interior. But grid is unacceptable to the space which is produced by designer who wants to express a design subjectively. Because grid makes usual and standardized space without flexibility. Changing and developing a fundamental unit with modern touch is going to be a way compensate for the weakpoint Also versatile grid unit can support the designer's subjective intention. This study focuses on the limits of Wright's house which show interior space aestheically through grid planing. In this paper Wright's uniqe interior space pattern will be examined through the selection of some of his works specifically the Prairies and Usonians whose transforming is noticable as Wright house and analysis about formation process of grid planning characteristics and spaces is continued. With all this analysis I'm, going to look over Wright's philosophy and pattern that is usually intended by his grid planning.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.376-378
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• 2002

Within LG.Philips Displays electron gun assembly different grid alignment methods are used. Besides the commonly used mandrel alignment of grids (Inner Reference System, IRS), also a unique Outer Reference System (ORS) is used as grid alignment method in high-end gun assembly. This alignment method combines alignment accuracy with maximum electron optical design freedom and maximum flexibility in electron gun production.

• 한국전산유체공학회지
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• 제2권1호
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• pp.84-92
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• 1997

In this paper a new structured grid generation technique is introduced. This new technique utilizes predictor-corrector approach, and is a marching scheme in the global sense as the hyperbolic scheme is. In the predictor step, one layer of grid cells is obtained by using Modified Advancing Front Method which generates a collection of quadrilateral cells simultaneously. In the corrector step, the layer of grid cells that is calculated in the predictor step is adjusted by solving Laplace equations to prevent grid lines from skewing and overlapping in highly curved configurations. It is shown that the resultant algorithm, named a MAP scheme, which combines the Modified Advancing Front Method as a Predictor with an elliptic scheme as a corrector can be used to generate globally smooth and locally near-orthogonal grids for external flow fields even for highly curved configurations. Examples of grid generations for external flow fields about several configurations by use of the present approach are given, and its applicability and flexibility have been demonstrated and discussed.

• Journal of Mechanical Science and Technology
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• 제19권4호
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• pp.1006-1017
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• 2005

In this work, we developed an accurate and efficient radiative finite volume method applicable for the complex 2D planar and 3D geometries using an unstructured-grid finite volume method. The present numerical model has fully been validated by several benchmark cases including the radiative heat transfer in quadrilateral enclosure with isothermal medium, tetrahedral enclosure, a three-dimensional idealized furnace, as well as convection-coupled radiative heat transfer in a square enclosure. The numerical results for all cases are well agreed with the previous results. Special emphasis is given to the parallelization of the unstructured-grid radiative FVM using the domain decomposition approach. Numerical results indicate that the present parallel unstruc­tured-grid FVM has the good performance in terms of accuracy, geometric flexibility, and computational efficiency.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.441-441
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• 2014

The characteristics of hybrid conductive films based on multilayer graphene and silver grid have been investigated for the high-performance and flexible organic solar cells. The hybrid conductive films have been prepared on glass and polyethylene terephthalate (PET) substrates using conventional photolithography process and transfer process of graphene. The optical and electrical properties of prepared conductive films show transmittance of 87% at 550nm and sheet resistance of $28{\Omega}/square$. The electromechanical properties were also investigated in detail to confirm the flexibility of the hybrid films. OSCs have been fabricated on the hybrid conductive films based on graphene and silver grid on glass substrate. The power conversion efficiency of 2.38%, a fill factor of 51%, an open circuit voltage of 0.58V and a short circuit current of $8.05mA/cm^2$ were obtained from the device on glass substrate. The PCE was enhanced 11% compared with OSCs on the MLG films without silver grid.

• 한국전자통신학회논문지
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• 제19권1호
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• pp.93-104
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• 2024

수요 반응은 전력망의 신뢰성을 높이고 비용을 최소화하기 위해 수요가 가장 많은 시간대에 고객이 소비패턴을 조정하도록 유도한다. 재생 에너지원을 스마트 그리드에 통합하는 것은 간헐적이고 예측할 수 없는 특성으로 인해 상당한 도전 과제를 안고 있다. 강화 학습 기법과 결합된 수요 대응 전략은 이러한 문제를 해결하고 기존 방식에서는 이러한 종류의 복잡한 요구 사항을 충족하지 못하는 경우 그리드 운영을 최적화할 수 있는 접근 방식으로 부상하고 있다. 본 연구는 재생 에너지 통합을 위한 수요 반응에 강화 학습 알고리즘을 적용하는 방법을 찾아 적용하는데 중점을 둔다. 연구의 핵심 목표는 수요 측 유연성을 최적화하고 재생 에너지 활용도를 개선할 뿐 아니라 그리드 안정성을 강화하고자 한다. 연구 결과는 강화 학습을 기반으로 한 수요 반응 전략이 그리드 유연성을 향상시키고 재생 에너지 통합을 촉진하는 데 효과적이라것을 보여준다.

• 한국항공우주학회지
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• 제33권10호
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• pp.17-25
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• 2005

중첩격자계와 접합격자계를 이용한 적응격자 기법이 개발되었다. 유동장은 물체와 근접한 영역과 떨어진 영역으로 구분된다. 근접한 영역은 곡선 격자계로 채워지며 중첩격자기법으로 영역이 연결되고 떨어진 영역은 다양한 적응 단계를 가진 직교 격자계로 채워지며 접합격자기법으로 연결된다. 본 적응격자기법은 격자생성에 있어서의 유연성과 효과적인 격자적응 기능을 보여준다. 2차원 스토어 분리 해석을 포함하는 몇 가지 수치해석을 통해 본 적응격자기법의 성능을 검증하였다.

• 한국정보전자통신기술학회논문지
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• 제14권1호
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• pp.91-97
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• 2021

전기자동차를 이용하여 계통에 전력을 공급하는 Vehicle to Grid(V2G)의 구현을 위한 통신표준으로 ISO/IEC 15118이 적용되고 있다. 통신 프로토콜에 기반을 두는 전기자동차의 충방전 제어 시에 필연적으로 충방전 실행까지의 시간지연이 발생하게 되는데, 이러한 시간지연은 전력 유연성 공급 측면에서 제한의 요인이 된다. 본 연구에서는 ISO/IEC 15118 기반 V2G 에뮬레이터를 구현하고 전기 자동차 충방전 제어에 따른 반응성을 확인하였다. 실험결과 시간지연은 0.12ms로 나타났으며, 이를 기반으로 현 표준 하에서 참여 가능한 전력 유연성 시장에 대하여 검토하였다.