• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.11-19
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• 2018

With the development of smart grid technology, it has become a hotspot to increase benefits of both residential users and electric power companies through demand response technology and interactive technology. In this paper, the game theory is introduced to the interaction between residential users and an electric company, making a mutually beneficial situation for the two. This paper solves the problem of electricity pricing and load shifting in the interactive behavior by building the game-theoretic process, proposing the interaction strategy and doing the optimization. In the simulation results, the residential users decrease their cost by 11% mainly through shifting the thermal loads and the electric company improves its benefits by 5.6% though electricity pricing. Simulation analysis verifies the validity of the proposed method and shows great revenue for the economy of both sides.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.495-501
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• 2017

The introduction of smart grid, which is an innovative application of digital processing and communications to the power grid, might lead to more and more cyber threats originated from IT systems. In other words, The Energy Management System (EMS) and other communication networks interact with the power system on a real time basis, so it is important to understand the interaction between two layers to protect the power system from potential cyber threats. This paper aims to identify and clarify the cyber security risks and their interaction with the power system in Smart Grid. In this study, the optimal power flow (OPF) and Power Flow Tracing are used to assess the interaction between the EMS and the power system. Through OPF and Power Flow Tracing based analysis, the physical and economic impacts from potential cyber threats are assessed, and thereby the quantitative risks are measured in a monetary unit.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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• pp.163-169
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• 1999

The numerical procedure has been developed for simulating incompressible viscous flow around a turbine stage with rotor-stator interaction. This study solves 2-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system. The Marker-and-Cell concept is applied to efficiently solve continuity equation. To impose an accurate boundary condition, O-H multiblocked grid system is generated. O-type grid and H-type grid is generated near and outer rotor-stator The cubic-spline interpolation is applied to handle a relative motion of a rotor to the stator. Turbulent flows have been modeled by the Baldwin- Lomax turbulent model. To validate present procedure, the time averaged pressure coefficients around the rotor and stator are compared with experiment and a good agreement obtained.

• 디자인학연구
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• 제13권3호
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• pp.29-38
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• 2000

인간은 항상 단순한 도구에서 복잡한 시스템에 이르기까지 수많은 물건과 관계를 맺으면서 생활하고. 있다. 여기에서 관계란 인간과 물건 사이에 이루어지는 상호작용으로 이러한 상호작용은 곧 사용자의 어떤 목적 달성을 위해 이루어지는 사용자와 제품 사이의 입출력과정으로 볼 수 있다. 이런 쌍방향적인 교류관계에서 중요한 것은 사용자 측면에서의 입력과 출력 그리고 제품 측면에서의 입력과 출력을 아무 문제없이 이어주는 것으로 비시각적인 제품의 조작과 반응사이의 관계를 좀 더 시각화하고 그 대응관계를 명료화하는 것이다. 따라서 이런 유형의 제품에서 제품개선의 의미는 무엇보다도 사용자와 제품간의 상호작용을 이해하고 분석하여 그 사이에 존재하는 물리적, 인지적 부하를 제거함으로서 사용자와 제품이 서로 무리없이 접근할 수 있도록 하는 것이다. 본 연구에서는 인간의 행동모형에 대한 고찰을 바탕으로 제품과 사용자와 상호작용을 시각화할 수 있는 틀을 만들고 이러한 틀을 이용하여 그 관계를 모델링하고 분석함으로서 인간중심의 제품개선을 위한 아이디어를 얻을 수 있는 방법을 논하였다.

• 한국태양에너지학회 논문집
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• 제38권4호
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• pp.55-66
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• 2018

nZEH (net-Zero Energy House) is defined as a self-sufficient energy building where the sum of energy output generated from new & renewable energy system and annual energy consumption is zero. The electricity generated by new & renewable energy system with the form of distributed generation is preferentially supplied to electrical demand, and surplus electricity is transmitted back to grid. Due to the recent expansion of houses with photovoltaic system and the nZEH mandatory by 2025, the rapid increase of distributed generation is expected. Which means, we must prepare for an electricity-power accident and stable electricity supply. Also electricity charges have to be reduce and the grid-connected should be operated efficiently. The introduction of ESS is suggested as a solution, so the analysis of the load matching and grid interaction is required to optimize ESS design. This study analyzed the load matching and grid interaction by expected consumption behavior using actual data measured in one-minute intervals. The experiment was conducted in three nZEH with photovoltaic system, called all-electric houses. LCF (Load Cover Factor), SCF (Supply Cover Factor) and $f_{grid}$ (Grid Interaction Index) were evaluated as an analysis indicator. As a result, LCF, SCF and $f_{grid}$ of A house were 0.25, 0.23 and 0.27 respectively; That of B house were 0.23, 0.23, 0.19, and that of C were 0.20, 0.19, 0.27 respectively.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권3호
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• pp.277-300
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• 2016

The motion of a floating body and the free surface flow are the most important design considerations for ships and offshore platforms. In the present research, a numerical method is developed to simulate the motion of a floating body and the free surface using a fixed rectilinear grid system. The governing equations are the continuity equation and Naviere-Stokes equations. The boundary of a moving body is defined by the interaction points of the body surface and the centerline of a grid. To simulate the free surface the Modified Marker-Density method is implemented. Ships advancing in regular waves, the interaction of waves by a fixed circular cylinder array and the response amplitude operators of an offshore platform are simulated and the results are compared with published research data to check the applicability. The numerical method developed in this research gives results good enough for application to the initial design stage.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.172-174
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• 2003

Nnumerical investigations of the tip vortical characteristics were conducted with lateral tip blowing to reduce Blade-Vortex Interaction (BVI) noise. The predictions of BVI noise were performed using a combined method of an unsteady Euler code with an aeroacoustic code based on Ffowcs- Williams and Hawkings formulation. A moving overlapped grid system with three types of grids (blade grid, inner and outer background grid) was used to simulate BVI of helicopter with two OLS-airfoil blades in forward/ descending flight condition. The calculated waveform of BVI noise, which is characterized by the distinct peaks caused during blade vortex interaction, clearly shows the effect of lateral blowing at tip to reduce BVI noise

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.217-218
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• 2006

• 한국콘텐츠학회논문지
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• 제8권6호
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• pp.74-81
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• 2008

단백질 상호작용 네트워크는 허브(hub)라 할 수 있는 상호작용 수가 많은 소수의 단백질과 상호작용수가 적은 다수의 단백질들로 구성된다. 최근 들어 여러 연구들에서 허브 단백질이 비 허브(non-hub) 단백질보다 상호작용 네트워크에 필수적인 단백질일 가능성이 높다고 보고되고 있다. 이러한 현상을 중심-치명 룰(centrality-lethality rule)이라 하는데, 이는 복잡계 네트워크에서 허브단백질의 중요성 및 네트워크 구조의 중요성을 설명하기 위한 방법으로 폭넓게 신뢰받고 있다. 이에 본 논문에서는 중심-치명 룰이 항상 옳게 적용되는지를 확인하기 위해 Uetz, Ito, MIPS, DIP, SGD, BioGRID와 같은 효모에 관한 공개된 모든 단백질 상호작용 데이터베이스들을 분석하였다. 흥미롭게도, 상호작용 데이터가 적은 데이터베이스들(Uetz, Ito, DIP)에서는 중심-치명 룰을 잘 나타냈지만 상호작용 데이터가 대용량인 데이터 베이스들(SGD, BioGRID)에서는 중심-치명 룰이 잘 맞지 않음을 확인하였다. 이에 따라 SGD와 BioGRID 데이터베이스로 부터 얻은 상호작용 네트워크의 특징을 분석하고 DIP 데이터베이스의 상호작용 네트워크와 비교하였다.

• Water Engineering Research
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• 제1권3호
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• pp.187-197
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• 2000

This paper describes an adaptive quadtree-based 2DH wave-current interaction model which is able to predict wave breaking, shoaling, refraction, diffraction, wave-current interaction, set-up and set-down, mixing processes (turbulent diffusion), bottom frictional effects, and movement of the land-water interface at the shoreline. The wave period-and depth-averaged governing equations are discretised explictly by means of an Adams-Bashforth second-order finite difference technaique on adaptive hierarchical staggered quadtree grids. Grid adaptation is achieved through seeding points distributed according to flow criteria(e.g. local current gradients). Results are presented for nearshore circulation at a sinusoidal beach. Enrichment permits refined modelling of important localised flow features.