• 전기학회논문지
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• 제64권2호
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• pp.222-227
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• 2015

This paper presents the optimal energy generation systems for economical EVs(Electric Vehicles) charging stations located in an island area. The system includes grid electricity, diesel generator and renewable energy sources of wind turbines and PV(Photovoltaic) panels. The independent generation system is designed with data resources such as annual average wind speed, solar radiation and the grid electricity price by calculating system cost under different structures. This sensitive analysis on the varying data resources allows for the configuration of the most economical generation system for charging stations by comparing initial capital, operating cost, NPC(Net Present Cost) and COE(Cost of Energy). Depending on the increase of the grid cost, the NPC variation of the most economical system which includes renewable energy generations and grid electricity can be smaller than those of other generation systems.

• 한국통신학회논문지
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• 제36권6B호
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• pp.738-743
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• 2011

본 고에서는 각 센서에 필요한 에너지를 공급하는 장치를 포함한 센서 네트워크 시스템을 고려하고, 에너지 공급 장치의 설치 및 운용 비용을 최소화하는 방법을 제안한다. 센서와 에너지 공급원이 정방형으로 배치되는 구조하에서 센서 노드의 밀도, 에너지 공급장치당 센서 노드 커버 범위 등에 따라 에너지 공급 장치의 설치 및 운용비용을 함수화한다. 또한 주어진 센서 노드밀도 환경에서 총 비용을 최소화하는 에너지 공급장치당 센서 노드 커버 범위를 결정하여 에너지 공급장치가 포함한 센서 네트워크의 배치를 최적화한다. 모의 실험을 통해 기존 방법에 비해 제안된 방법이 약 19%의 센서 네트워크 비용을 절감하는 효과를 가짐을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권6호
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• pp.1133-1151
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• 2010

Energy balanced consumption routing is based on assumption that the nodes consume energy both in transmitting and receiving. Lopsided energy consumption is an intrinsic problem in low-cost sensor networks characterized by multihop routing and in many traffic overhead pattern networks, and this irregular energy dissipation can significantly reduce network lifetime. In this paper, we study the problem of maximizing network lifetime through balancing energy consumption for uniformly deployed low-cost sensor networks. We formulate the energy consumption balancing problem as an optimal balancing data transmitting problem by combining the ideas of corona cluster based network division and optimized transmitting state routing strategy together with data transmission. We propose a localized cluster based routing scheme that guarantees balanced energy consumption among clusters within each corona. We develop a new energy cluster based routing protocol called "OECR". We design an offline centralized algorithm with time complexity O (log n) (n is the number of clusters) to solve the transmitting data distribution problem aimed at energy balancing consumption among nodes in different cluster. An approach for computing the optimal number of clusters to maximize the network lifetime is also presented. Based on the mathematical model, an optimized energy cluster routing (OECR) is designed and the solution for extending OEDR to low-cost sensor networks is also presented. Simulation results demonstrate that the proposed routing scheme significantly outperforms conventional energy routing schemes in terms of network lifetime.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 추계 학술대회 논문집
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• pp.25-31
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• 2005

원자력연구시설에 대한 해체비용 산정은 해체계획 수립하는 데 중요한 작업이다. 해체비용 산정은 해체활동 단계와 해체 시설의 구설요소에 맞게 해체작업을 분류하여 계산을 해야 한다. 본 논문에서는 원자력연구시렁 해체비용 산정을 위하여 해체작업 활동을 분류하고 비용자료의 기준이 되는 비용항목을 계층적으로 세분화하여 구성하는 방법과 작업지연을 유발하는 비용영향 요인인 작업 난이도 인자에 대한 산출방법을 마련하였다. 이렇게 함으로써 해체활동 단계 및 작업에 대한 비용 항목별 분류 및 산정이 가능할 뿐만 아니라 원자력연구시설 해체비용 산정 방법론 및 프로그램을 개발하는데 활용할 예정이다.

• 한국수소및신에너지학회논문집
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• 제31권4호
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• pp.337-344
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• 2020

Worldwide, there is a significant surge in the efforts for addressing the issue of global warming; the use of renewable energy is one of the solutions proposed to mitigate global warming. However, severe volatility is a critical disadvantage, and thus, power-to-gas technology is considered one of best solutions for energy storage. Hydrogen is a popular candidate from the perspective of both environment and economics. Accordingly, a hydrogen production system based on renewable energy sources is developed, and the economics of the system are assessed. The result of the base case shows that the unit cost of hydrogen production would be 6,415 won/kg H₂, with a hydrogen production plant based on a 100 MW akaline electrolyzer and 25% operation rate, considering renewable energy sources with no electricity cost payment. Sensitivity study results show that the range of hydrogen unit cost efficiency can be 2,293 to 6,984 Won/kg H₂, depending on the efficiency and unit cost of the electrolyzer. In case of electrolyzer operation rate and electricity unit cost, sensitivity study results show that hydrogen unit cost is in the range 934-26,180 won/kg H₂.

• Architectural research
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• 제16권3호
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• pp.93-100
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• 2014

Existing BIM(Building Information Modeling) based energy evaluation tools cannot be utilized enough for the potential performance of BIM because most of them have not provided the integrated model for energy evaluation, assessment of the material, cost of the construction, and so on. This research aims to propose and develop a new application, EcoBIM, to support an integrated evaluation of the energy and cost efficiencies of the design alternatives within the design process. The proposed application functions as a BIM-based evaluation system that calculates energy-savings performance as well as the construction cost of the alternatives at the design stage. This study mainly focuses on the possibilities of developing the proposed technology. We also suggest an advanced design process using the proposed system, corresponding to changes of national regulations in Korea. This study deduce that EcoBIM can allow architects to make suitable decisions regarding energy- and cost-efficient designs. The proposed design process will allow architects not only to check the eco-friendly performance of design alternatives but also predict the operation cost in a certain period in the future. EcoBIM can prevent large-scale design changes required to obtain environmental certification and enable the owner to make an informed decision about the initial investment of construction according to the result of the analysis of the energy requirement at the design stage.

• KIEAE Journal
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• 제12권1호
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• pp.105-112
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• 2012

When a building is planned and designed, the design should be able to minimize the cost during the whole life cycle of the building. This study has begun to analyze LCC about the alternative design which is applicable to renewable energy facility construction. It is reviewed domestic and foreign papers about the trend of LCC technology and it is determined the analytical method to analyze the LCC of renewable energy. Regarding the review of alternatives, it is chosen the three alternatives which are able to designed combing the renewable energy facilities and it is performed the LCC analysis about each alternative. Alternative 1 is Photovoltaic + Solar Thermal + Photovoltaic /Wind Power, Alternative 2 is Geothermal + Photovoltaic, and Alternative 3 is Photovoltaic + Solar Thermal. The LCC analysis is present value method, its analytical period is 40 years and it is applied 3.2% of real discount rate. As a result, it is proved that Alternative 1 and Alternative 3 are not able to collectible the early investment cost during the analytical period and Alternative 2 is analyzed that its pay-back period of early investment cost is about 31 years. As the final outcome of this study on case analysis, it is more advantageous to use the combination of Geothermal and Photovoltaic energy than to use the other combination in LCC aspect.

• 방사성폐기물학회지
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• 제4권2호
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• pp.171-178
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• 2006

해체비용 산정은 원자력시설에 대한 해체 설계 및 계획 수립하는 데 중요한 기술이다. 해체비용 산정은 해체활동 단계와 해체시설의 구성요소에 맞게 해체작업을 분류하여 계산을 해야 한다. 본 논문에서는 원자력연구시설 해체비용 산정 기술로 이용하기 위하여 해체비용항목 및 그룹의 구성요소와 해체대상물에 대한 작업시간 계산의 기준이 되는 단위비용 인자 구성요소를 도출함으로써 해체비용 산정에 필요한 기본 구조를 완성하였다. 또한 주요 해체활동 및 작업에 대한 비용 산정 시 구성요소에 대한 고려사항을 살펴보았다. 향후, 이러한 기법을 이용하여 원자력연구시설에 대한 해체비용 산정 및 평가 방법론을 확립하는데 기본 기술로 활용할 예정이다.

• 설비공학논문집
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• 제20권10호
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• pp.654-661
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• 2008

Our government will make a plan regulating the cooling limit temperature of the summer season to 26 degree and the heating limit temperature of the winter season to 20 degree for energy saving. Where, the key point of this politic pursuit can be the charge system on heating and cooling cost. Currently, the heating and cooling cost are charged as much as the volume or heat flow rate regardless of the high and low room temperature. However, we have suggested new cost estimating methodology as a worth method in the precedent study, and preformed the worth evaluation and cost allocation of electricity and heat on various cogenerations. In this study, we applied the suggested worth method to four kind of warm air, and preformed the worth evaluation and cost allocation of each warm air. As a result, the more energy a customer saved, the more heating unit cost decreased, and the more energy a customer consumed, the more heating unit cost increased. From this analysis, we hope that the suggested worth methodology can offer a theoretical basis to the politic pursuit of government, and induce the spontaneous energy saving of consumers.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.1-13
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• 2015

Feed is single most expensive input in commercial pork production representing more than 50% of the total cost of production. The greatest proportion of this cost is associated with the energy component, thus making energy the most important dietary in terms of cost. For efficient pork production, it is imperative that diets are formulated to accurately match dietary energy supply to requirements for maintenance and productive functions. To achieve this goal, it is critical that the energy value of feeds is precisely determined and that the energy system that best meets the energy needs of a pig is used. Therefore, the present review focuses on dietary supply and needs for pigs and the available energy systems for formulating swine diets with particular emphasis on the net energy system. In addition to providing a more accurate estimate of the energy available to the animal in an ingredient and the subsequent diet, diets formulated using the this system are typically lower in crude protein, which leads to additional benefits in terms of reduced nitrogen excretion and consequent environmental pollution. Furthermore, using the net energy system may reduce diet cost as it allows for increased use of feedstuffs containing fibre in place of feedstuffs containing starch. A brief review of the use of distiller dried grains with solubles in swine diets as an energy source is included.