• KIEAE Journal
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• 제17권5호
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• pp.77-86
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• 2017

Purpose: Because of the growing concern over fossil fuel use and increasing demand for greenhouse gas emission reduction since the 1990s, the building energy analysis field has produced various types of methods, which are being applied more often and broadly than ever. A lot of research products have been actively proposed in the area of the building energy simulation for over 50 years around the world. However, in the last 20 years, there have been only a few research cases where the trend of building energy analysis is examined, estimated or compared. This research aims to investigate a trend of the building energy analysis by focusing on methodology and characteristics of each method. Method: The research papers addressing the building energy analysis are classified into two types of method: engineering analysis and algorithm estimation. Especially, EPG(Energy Performance Gap), which is the limit both for the existing engineering method and the single algorithm-based estimation method, results from comparing data of two different levels- in other words, real time data and simulation data. Result: When one or more ensemble algorithms are used, more accurate estimations of energy consumption and performance are produced, and thereby improving the problem of energy performance gap.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.136.1-136.1
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• 2011

An energy modeling analysis method currently has been considered as a new approach for energy policy research, because the importance of renewable energy use has been emphasized more and more. This study used RETScreen model as a clean energy decision making methodology for adaptation to climate change and elimination of various pollutions. This modeling method includes five step standard analysis; energy model, cost analysis, GHG analysis, financial analysis, and sensitivity & risk analysis and it also assesses both conventional and modern energy sources and technologies. This methodology for the photovoltaic(PV) energy modeling is used to evaluate the energy production, financial performance and GHG emissions reduction of photovoltaic projects. In addition, the PV application systems are classified into three basic applications; On-grid system, Off-grid system and water pumping system. This study assesses the renewable energy techno-economic modeling method with the feasibility analysis result of 10 MW PV power plant in Abu Dhabi in United Arab Emirates. Furthermore this study stresses the importance of renewable energy model research by applying to domestic PV power plant which is now in preparation.

• 대한전기학회논문지
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• 제32권2호
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• pp.59-64
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• 1983

This paper deals with the transient energy method of transient stability analysis of multi-machine power system by improving the transfer conductance, the kinetic energy and the critical transient energy. The tranfer conductance is considered more correctly, the generators of system are seperated to two states (critical and the rest state)and the correction term of critical transient energy (to reference point) is added. This analysis is performed by digital computer simulation and the application of this method to two model systems has shown its superiority to other available methods.

• 한국공간구조학회논문집
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• 제6권2호
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• pp.131-136
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• 2006

It is important to evaluate energy absorption capacity of frames required during a design earthquake. An inelastic computer analysis based on mathematical modelling of energy absorbing frames and elements makes it possible to evaluate required energy absorption capacity. But such an analysis sometimes consumes much computation time particularly in case of complicated structural system. This paper presents a proposal to predict energy absorption of multi-bent steel frames by simple equivalent linear method.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1350-1364
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• 2023

2D/1D coupling method is an important neutron transport calculation method due to its high accuracy and relatively low computation cost. However, 2D/1D coupling method may diverge especially in small axial mesh size. To analyze the convergence behavior of 2D/1D coupling method, a Fourier analysis for k-eigenvalue neutron transport problems is implemented. The analysis results present the divergence problem of 2D/1D coupling method in small axial mesh size. Several common attempts are made to solve the divergence problem, which are to increase the number of inner iterations of the 2D or 1D calculation, and two times 1D calculations per outer iteration. However, these attempts only could improve the convergence rate but cannot deal with the divergence problem of 2D/1D coupling method thoroughly. Moreover, the choice of axial solvers, such as DGFEM SN and traditional SN, and its effect on the convergence behavior are also discussed. The results show that the choice of axial solver is a key point for the convergence of 2D/1D method. The DGFEM SN based 2D/1D method could converge within a wide range of optical thickness region, which is superior to that of traditional SN method.

• KIEAE Journal
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• 제16권2호
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• pp.17-22
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• 2016

Purpose: Sensitivity analysis offers a good guideline for designing energy conscious buildings, which is fitted to a specific building configuration. Sensitivity analysis is, however, still too expensive to be a part of regular design process. The One-at-a-time (OAT) is the most common and simplest sensitivity analysis method. This study aims to propose a reasonable ground that the OAT can be an alternative method for the variance-based method in some early design scenarios, while the variance-based method is known adequate for dealing with nonlinear response and the effect of interactions between input variables, which are most cases in building energy simulations. Method: A test model representing the early design phase is built in the DOE2 energy simulations. Then sensitivity ranks between the OAT and the Variance-based methods are compared at three U.S. sites. Result: Parameters in the upper rank by the OAT do not much differ from those by the Main effect index. Considering design practices that designers would chose the most energy saving design option first, this rank similarity between two methods seems to be acceptable in the early design phase.

• 설비공학논문집
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• 제27권7호
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• pp.354-361
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• 2015

The building energy audit is an important process when collecting basic information for improving the energy performance of existing buildings. Audit parameters should be associated with the energy performance of the building. Such audit parameters will vary according to an individual building's characteristics and energy consumption patterns, but most building energy audits are performed in the same way. The sensitivity analysis (SA) is a statistical method to quantify the correlation between inputs and outputs that can determine which input is influential to which output. Therefore, an SA can identify influential parameters when applied to building energy analysis. In this paper, we adopted the Morris method to identify building energy audit parameters and performed a Monte Carlo simulation for uncertainty analysis. As a result, this method was able to identify an influential parameter for building energy audits and reduce uncertainty in energy consumption in buildings.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.187-194
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• 2003

This paper presents an energy method for the analysis of the in-plane ultimate load capacity of cable-stayed bridges considering deck and pylon connection. The potential energy of the whole bridge, including bridge deck, stayed cables, and pylons, and the work done by external loads are considered in the development of the bridge energy equation. Both geometric and material nonlinearities are taken into account in the analysis. The method is simple to use and has a high convergence rate.

• 자원ㆍ환경경제연구
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• 제17권2호
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• pp.255-286
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• 2008

에너지 요인분석의 한계와 확장을 위하여 요인분석과 계량모형의 결합을 시도하였다. 에너지 원단위 효과의 변화 결정 요인을 계량적 방법으로 추정하고, 에너지 원단위 효과와 계량모형의 에너지 효율 변화를 비교하였다. 에너지 원단위 효과를 이용한 확장모형에서 에너지 가격이 오르면 에너지 원단위 효과가 개선되는 것으로 나타나고 있다. 그리고 계량모형에서 에너지 효율 변수의 대변수인 시간추세의 준탄력성을 살펴보면, 단기에서는 -0.02로 장기에서는 -0.04로 서서히 완만한 에너지 효율 개선을 보이고 있다. 마지막으로 요인분해 결과와 계량모형의 결과를 비교하면, 전체 제조업과 8개 제조업 업종 중 4개 업종의 경우 에너지 효율의 개선 방향이 일치하는 결과를 보이고 있다. 요인분해의 결과와 계량모형의 결과 비교에서 나타나듯이, 두 방법이 서로 교류할 수 없는 방법이 아니라는 점을 확인하였다. 향후 학문적 정책적 노력에 따라 최소한 서로 보완할 수 있는 여지가 충분히 있음을 보였다. 따라서 이러한 연구가 지속될 수 있는 학문적 정책적 노력이 필요하다고 할 수 있다.

• 태양에너지
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• 제10권1호
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• pp.63-79
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• 1990

태양열 주택 및 급탕의 보급 정책은 민수용 에너지의 절감 또는 대체의 의미에서 그 필요성 및 당위성을 인정받고 있으나, 다른 대체에너지와 마찬가지로 태양열 이용시스템의 경제성이 가상 문제가 되고 있는 실정이다. 본 연구에서는 태양열 주택 및 급탕의 경제성을 상세히 분석함으로써 실질적인 보급정책 자료를 제공하며, 실수요자를 위한 계몽근거를 마련하고자 한다. 본 연구에서는 태양열 이용시스템의 경제성을 정확히 수행하기 위한 의사결정지원 시스템(decision support system)을 확립시켰으며, 이에 따른 태양열 이용시스템의 열적성능 해석과 동시에 경제성 분석은 시행오차(trial & error)하에 수행할 수 있도록 각종전산 프로그램을 개발하였다. 태양열 주택 및 급탕의 열적성능 해석은 모의실험을 통하여 기상 조건과의 상관관계를 도출하고 태양열 이용시스템의 추가비용 및 연료가 이용을 현재가 (present worth) 개념으로 적응하여 산출하고, 순익분기 해석법 (break-even point analysis method) 및 수명가 산정법(life-cycle cost analysis method)으로 경제성 분식을 중점적으로 수행하였다.