• 설비공학논문집
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• 제17권1호
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• pp.82-87
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• 2005

The purpose of this study is to suggest the characteristics and actual state of energy consumption by the analysis of energy consumption data in an office building. This study examines and analyzes daily and monthly energy consumption of an office building located in Seoul, Korea regarding type of load and business classification within a building. The results are as follows. 1) Energy consumption of office building for each type of load show similar consumption patterns, regardless of seasons such as cooling period and heating period. 2) Out of all annual energy consumption, consumption for lighting took about $43\;\%,$ general electric Power about $23\;\%,$ emergency power $25\;\%,$ computer center $5\;\%$ and cooling power $4\;\%,$ showing that the consumption for lighting was highest, and the percentage of energy consumption for cooling power for operation of cooling facilities took the lowest percentage. 3) Annual gas consumption used for heating and hot water supply were $38,\;36\;\%$ for officetel and office respectively, and $26\;\%$ for arcade. 4) Electricity consumptions used for cooling power for each use of building, office and officetel recorded in July and August of cooling seasons. Even though it shows different patterns for each month, energy consumption showed unique pattern throughout the cooling seasons.

• 전기학회논문지P
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• 제67권2호
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• pp.70-74
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• 2018

Social infrastructure such as production, transportation, gas, and electrical facilities would be degraded according to time and those facilities might need more maintenances, repairing, and management as time goes by. Especially, in the case of a power transformer, it is important to diagnose the transformer in order to avoid malfunction and failure because they could cause enormous damage. The economic as well as technical aspects of a transformer management must be considered while it is operated. Therefore, the concept of asset management should be applied as an advanced method of transformer management. Asset management refers to a series of processes to make a plan of maintenance and conservation of a power transformer considering the soundness, investment cost, and importance of equipment. It is important to apply the asset management considering calculation of a lifetime loss. In this paper, the lifetime loss calculation method of asset management for a power transformer is suggested.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.769-779
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• 2023

This paper describes an hp-angular adaptivity algorithm in the discrete ordinates method for Boltzmann transport applications with strong angular effects. This adaptivity uses discontinuous finite element quadrature sets with different degrees, which updates both angular mesh and the degree of the underlying discontinuous finite element basis functions, allowing different angular local refinement to be applied in space. The regular and goal-based error metrics are considered in this algorithm to locate some regions to be refined. A mapping algorithm derived by moment conservation is developed to pass the angular solution between spatial regions with different quadrature sets. The proposed method is applied to some test problems that demonstrate the ability of this hp-angular adaptivity to resolve complex fluxes with relatively few angular unknowns. Results illustrate that a reduction to approximately 1/50 in quadrature ordinates for a given accuracy compared with uniform angular discretization. This method therefore offers a highly efficient angular adaptivity for investigating difficult particle transport problems.

• 통상정보연구
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• 제14권1호
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• pp.301-314
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• 2012

FTA 체결에 따른 피해지원 및 경쟁력 향상을 위해 향후 농수산업 등의 직접적 피해에 대해서는 피해보전직불제도와 폐업지원제도를 통해 지원하며, 피해보전직불제도는 FTA로 인한 수입증가로 피해가 발생하였을 경우 발생된 피해의 일정부분을 피해보전직불금으로 보전하여 농수산업의 경영안정을 도모하는 제도이고, 폐업지원제도는 FTA로 인한 수입증가로 과수, 축산 등 해당 사업을 계속하는 것이 곤란하다고 인정하는 품목에 대하여, 농가가 폐업을 희망하는 경우에 폐업지원금을 지급함으로써 농가의 경영안정과 해당 산업의 구조조정을 도모한다. 산업경쟁력 강화 및 농어촌 소득기반 확충을 위한 지원방안 마련하여 해당 산업의 지원하며, 농공단지 확대 조성, 도농교류 확대 등을 통해 농어촌 지역 소득기반을 강화에 노력할 예정이다. 본 연구에서는 FTA 체결에 따른 국내지원대책을 직접적 피해보전, 산업별 경쟁력 강화, 소득기반확충으로 나누어 계층설계를 하였다. 직접적 피해보전대책에는 농업인, 어업인, 제조업, 서비스업 경영인, 근로자로, 산업별 경쟁력 강화는 농업, 수산업, 제조업, 제약산업, 서비스업, 소득기반확충에는 농업과 어업에 대하여 계층적으로 구조화된 평가틀을 구축하였으며, 27개의 하위기준의 측정항목을 선택하여 AHP분석을 위한 계층 설계를 하였다. 국내지원대책 중에서는 직접적 피해보전 대책보다는 산업경쟁력 강화와 소득기반확충을 위한 대책의 중요도가 높게 나타났다. 산업경쟁력강화에서는 농업과 제조업에 대한 지원을 소득기반확충에서는 어업보다는 농업에 대한 지원을 그리고 직접적 피해보전대책에서는 농업인과 근로자에 대한 지원대책이 중요도가 높은 것으로 분석되었다.

• 동굴
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• 제4호
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• pp.51-58
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• 1996

Caves abd the life they contain face constant pressure from a worldw demand for cement. hydro-electric power and land for building a agriculture. The 8th International Congress of Speleology held in Kentu two years ago passed a resolution on behalf of the IUCN "Cave Speci Group" which called for "...biological surveys of threatened caves. mos in the tropics, and ecological studies to solve specific managem provlems on the causes of endangerment and how these can be remov or mitigated". This final article in the "Cave Life" series explains the n for an ecological approach to cavelife conservation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.917-919
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• 1997

Recently, electric industry confront a strategical change and high competiveness environment in the course of deregulation. Especially, rapid growth in electricity demand, financial need for new power plant construction, and environmental problems have led to search for more efficient energy production and energy conservation technologies in Korea. Due to the potential energy and cost savings, DSM(Demand-Side Management) plays and important role in the electric resource planning. In this paper, we suggest DSM potential evaluation procedures and algorithm. Also, we present screening analysis methods for DSM potential evaluation.

• Architectural research
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• 제18권2호
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• pp.59-64
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• 2016

Since the massive power outages that hit across the nation in September 2011, a growing imbalance between energy supply and demand has led to a severe backup power shortage. To overcome the energy crisis which is annually repeated, a policy change for deriving energy supply from renewable energy sources and a demand reduction strategy has become essential. Buildings account for 18% of total energy consumption and have great potential for energy efficiency improvements; it is an area considered to be a highly effective target for reducing energy demand by improving buildings' energy efficiency. In this regard, retrofitting buildings to promoting environmental conservation and energy reduction through the reuse of existing buildings can be very effective and essential for reducing maintenance costs and increasing economic output through energy savings. In this study, we compared the energy reduction efficiency of national power energy consumption by unit production volume based on thermal power generation, renewable energy power generation, and initial and operating costs for a building retrofit. The unit production was found to be 13,181GWh/trillion won for bituminous coal-fired power generation, and 5,395GWh/trillion won for LNG power generation, implying that LNG power generation seemed to be disadvantageous in terms of unit production compared to bituminous coal-fired power generation, which was attributable to a difference in unit production price. The unit production from green retrofitting increased to 38,121GWh/trillion won due to the reduced energy consumption and benefits of greenhouse gas reduction costs. Renewable energy producing no greenhouse gas emissions during power generation and showed the highest unit production of 75,638GWh/trillion won, about 5.74 times more effective than bituminous coal-fired power generation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권7호
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• pp.3351-3369
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• 2017

In recent years, datacenters, network devices and computers have proliferated. The power consumed by information and communication technology (ICT) devices has inflated in an extraordinary manner. Green communication has emerged as a new approach to reduce and optimize power consumption in ICT sector. Many methods and protocols have been proposed and implemented to achieve green communication. Nevertheless, the increase of power consumption remains a problem. In this work, we attempt to reduce and optimize power consumption of network devices in datacenters environment utilizing software defined network (SDN) paradigm. To gain more insight of the power consumption requirements of network switches, a power measurement system is constructed to measure power consumption levels of network devices. Subsequently, we propose a duplication resolver algorithm (DRA) to power off/on switches reactively. DRA algorithm reduces the required time by switches to construct their flow tables after rebooting. To this end, DRA-based external circuit has been constructed utilizing Ethernet module and an Arduino kit to control power supplies of network devices. To facilitate our work, a testbed has been constructed utilizing Ryu SDN controller, HP2920-24G switches and Arduino kits. Our results show that DRA algorithm can reduce both the power usage and start-up time delay of network switches after failures.

• 전력전자학회논문지
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• 제12권6호
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• pp.433-440
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• 2007

에너지 절약과 환경 문제가 이슈화되면서 대표적인 전원공급장치인 SMPS의 대기모드 효율이 중요시되고 있다. 특히 많은 SMPS들이 다출력 구조로 설계됨에 따라 대기모드에서 전력손실을 줄이기가 쉽지 않다. 본 논문에서는 SSPR(Secondary Side Post Regulator)을 개발하여 단일 컨버터에서 Cross Regulation과 대기전력을 함께 해결하였다. 그리고, 다중 컨버터의 대기전력 감소를 위하여 전류모드 제어와 Power Sequence 제어기술을 제안한다. 제안된 기술은 이론적 해석과 더불어 120[W], 270[W]급 SMPS에 적용하여 그 타당성 및 우수성을 검증하였다.

• 보존과학회지
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• 제27권2호
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• pp.127-134
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• 2011

본 논문은 목조문화재의 생물학적 제어를 위하여 몬테카를로(Monte Carlo) 방법을 이용한 감마선 조사선량의 예측과 실증에 관한 연구이다. 박물관 수장고에 보관되어 있는 목재 유물 돈궤의 미생물 오염을 조사한 결과 채집된 곰팡이들은 대부분 Aureobasidium pullulans로 동정되었으며 돈궤를 20 kGy의 감마선 조사한 결과 모두 불활성화 되었다. 몬테카를로 방법을 이용하여 돈궤의 방사선 조사선량 분포를 예측하였으며, alanin dosimeter를 이용하여 돈궤의 앞, 뒷면에 각각 7 지점에 대한 방사선 조사선량 분포를 실측하였다. 그 결과 몬테카를로 모사값과 실험값을 비교해 보았을 때 좋은 일치도를 보였다. 이러한 결과는 감마선의 높은 투과력과 모사 예측을 통하여 최적 방사선 조사선량으로 목조 유물의 미생물학적 제어를 제공할 수 있다는 사실을 보여준다.