• 한국태양에너지학회 논문집
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• 제33권2호
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• pp.42-49
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• 2013

Recently, the attention to renewable energy has increased globally because of the environmental issue and the global energy crisis. Accordingly, south korea is focused on increasing the renewable energy usage. And the government enforced a law to the public buildings to install the renewable energy facilities. In this study, the building to evaluate renewable energy consumption and supply ratio was selected. This building has 9.79% of renewable energy supply ratio by PV system. In this study, the method for improving renewable energy supply ratio was analyzed using additional PV system. And The 5 methods to increasing electricity were evaluated. The method of increase 4.24 times PV arrays area is most efficient way to increase the renewable supply ratio. The case 1, show that the increasing renewable energy supply ratio of 39.2% compared to exsiting PV system. The result of the above, consider the additional supply of renewable energy.

• Nutrition Research and Practice
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• 제8권6호
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• pp.695-704
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• 2014

BACKGROUND/OBJECTIVES: The type of sweet snack incorporated into an energy-restricted diet (ERD) may produce differential effects on metabolic improvements associated with body weight (BW) loss. This study compared effects of incorporating either twice daily energy-controlled dark chocolate snacks plus once daily sugar-free cocoa beverage (DC) to non-chocolate snacks plus sugar-free non-cocoa beverage (NC) into an ERD on BW loss and metabolic outcomes. MATERIALS/METHODS: In an 18-week randomized comparative trial, 60 overweight/obese premenopausal women were assigned to DC (n = 30) or NC group (n = 30). Dietary intake was measured at baseline and week 18, and BW, anthropometrics, blood pressure (BP) and serum glucose, insulin and lipid concentrations were measured at baseline, and weeks 6, 12 and 18. Data were analyzed using repeated measures ANOVA. RESULTS: Using intention-to-treat analysis, women in DC and NC groups reduced energy intake (both P < 0.001) and lost $4.4{\pm}0.6kg$ and $5.0{\pm}0.9kg$ (both P < 0.001), respectively. Both groups lowered systolic and diastolic BP [DC = 2.7 (P < 0.05), 2.7 (P < 0.01); NC = 3.4 (P < 0.01), 4.2 (P < 0.01) mmHg, respectively]. Glucose and insulin concentrations decreased by 0.72 mmol/L (P < 0.001) and 13.20 pmol/L (P < 0.01) in DC group and by 0.83 mmol/L (P < 0.001) and 13.20 pmol/L (P < 0.01), respectively, in NC group. Total cholesterol increased in NC group (P < 0.05), with no significant lipid changes in DC group. There were no significant differences in biomarker outcomes between groups. CONCLUSIONS: Overweight/obese premenopausal women following an 18-week ERD that included either DC or NC sweet snack and sugar-free beverage lost equivalent amounts of BW and improved BP measurements and glucose and insulin concentrations.

• 대한기계학회논문집B
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• 제37권12호
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• pp.1105-1112
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• 2013

본 연구에서는 난방설비 제어에 필요한 난방부하를 건물 특성계수를 사용하여 예측하는 방법을 제안하였고, 난방부하에 주된 영향을 미치는 시간별 온도와 일사량을 예측하는 방법을 제안하였다. 온도와 일사량은 기상청에서 예보되는 정보로부터 퍼지이론을 이용하여 예측하였고, 난방부하 예측을 위한 건물 특성계수는 EnergyPlus로부터 도출하였다. 본 연구에서 제안된 방법으로 얻어진 난방부하는 EnergyPlus의 결과와 잘 일치하였으며, 예측된 온도와 일사를 이용하여 예측한 난방부하의 변화 양상은 실측 기상데이터를 사용한 결과와 유사하였다.

• 비파괴검사학회지
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• 제21권5호
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• pp.501-509
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• 2001

증기발생기 전열관에서 1차측 응력부식균열의 발생빈도가 증가하고 있으므로 이의 정확한 탐지와 평가를 위해서는 균열 형상에 따른 와전류 신호특성을 규명하고 적합한 탐촉자를 선정하는 것이 매우 중요하다. 본 연구에서는 증기발생기 전열관의 내면 축방향 균열에 대한 와전류 검사의 검출능과 크기예측에 대한 신뢰도를 정량적으로 평가하고 pancake coil과 plus coil과의 신호특성 차이를 비교하였다. 이를 위하여 전열관 내면에 EDM으로 노치를 가공한 시편과 실제 증기발생기에서 1차측 응력부식균열이 발생하여 인출한 전열관을 시험편으로 사용하였다. 본 연구에서 얻어진 결과를 토대로 내면 축방향 균열에 대한 와전류 검사 신뢰도 향상을 위한 방안을 제시하였다.

• Nuclear Engineering and Technology
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• 제41권4호
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• pp.493-520
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• 2009

During the last four decades, 16 Pressurized Water Reactors (PWR) and 4 Pressurized Heavy Water Reactors (PHWR) have been constructed and operated in Korea, and nuclear fuel technology has been developed to a self-reliant state. At first, the PWR fuel design and manufacturing technology was acquired through international cooperation with a foreign partner. Then, the PWR fuel R&D by Korea Atomic Energy Research Institute (KAERI) has improved fuel technology to a self-reliant state in terms of fuel elements, which includes a new cladding material, a large-grained $UO_2$ pellet, a high performance spacer grid, a fuel rod performance code, and fuel assembly test facility. The MOX fuel performance analysis code was developed and validated using the in-reactor test data. MOX fuel test rods were fabricated and their irradiation test was completed by an international program. At the same time, the PWR fuel development by Korea Nuclear Fuel (KNF) has produced new fuel assemblies such as PLUS7 and ACE7. During this process, the design and test technology of fuel assemblies was developed to a self-reliant state. The PHWR fuel manufacturing technology was developed and manufacturing facility was set up by KAERI, independently from the foreign technology. Then, the advanced PHWR fuel, CANFLEX(CANDU Flexible Fuelling), was developed, and an irradiation test was completed in a PHWR. The development of the CANFLEX fuel included a new design of fuel rods and bundles.. The nuclear fuel technology in Korea has been steadily developed in many national R&D programs, and this advanced fuel technology is expected to contribute to a worldwide nuclear renaissance that can create solutions to global warming.

• 설비공학논문집
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• 제26권5호
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• pp.231-239
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• 2014

This paper represents a method of existing building energy simulation using energy audit data. Energy audit must be carried out for reasonable analysis, because characteristics of existing buildings such as efficiency of fan, pump, flow rate, pressure, COP and operating schedule could be changed during the building operation. These building characteristics should be measured to estimate actual energy consumption of the existing building. In this study, we conducted energy audit and calculated energy savings for a 7-stories building as a case-study. The energy audit data were used to calibrate the building model of EnergyPlus simulation. Baseline model validated according to M&V guideline index. As a result, building characteristics are significant parameters making a big impact on energy savings in existing buildings.

• 대한건축학회논문집:계획계
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• 제35권1호
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• pp.37-46
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• 2019

The energy of the building is influenced by the user 's activity due to the population, society, and economic characteristics of the building user. In order to obtain accurate energy information, the difference in the amount of energy consumption by the activities and characteristics of building users should be identified. The purpose of the study is to identify the difference in the amount of energy consumption by the user's activities in the same building, and to analyse the relationship between user's activities and demographic, social and economic characteristics. For research, energy simulation is performed based on actual user activity schedule. The results of the simulation were clustered by using K-Means clustering, a machine learning technique. As a result, four types of users were derived based on the amount of energy consumption. The more energy used in a cluster, the lower the user's income level and older. The longer a user's indoor activity times, the higher the energy use, and these activities relate to the user's characteristics. There is more than twice the difference between the group that uses the least energy consumption and the group that uses the most energy consumption.

• 설비공학논문집
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• 제24권8호
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• pp.612-620
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• 2012

High economic growth causes increase of the building energy consumption. The energy consumption for HVAC system accounts for 40~50% of the whole building consumption. The trend for building is large-scale and high-rise. Because of the trend, the energy consumption is becoming bigger than before. Nowadays, HVAC system design are recognized as the solution for a energy-saving. This paper is focused on the energy performance evaluation of central air-conditioning system(water-based) and system air-conditioning that were applied to the office building. The systems are modeled and simulated by using EnergyPlus Software 6.0. After the Simulation, annual cooling and heating energy consumption were calculated. It was found that the system air-conditioning can reduce the energy consumption approximately 55.24% annually compared with the central air-conditioning system(water-cooled). In addition, about 46.13% of annual operating costs can be reduced by use of system air-conditioning.

• KIEAE Journal
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• 제15권5호
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• pp.67-74
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• 2015

This study aimed to develop a design manual to be used during the initial stage of the nearly Zero Energy Building (nZEB) design process. Recently, with the increased demand for nZEBs, there are many architects and architectural firms who are becoming interested in nZEB design. However, since the nZEB design process requires a different approach to the conventional building design process, architects have difficulties with application of the nZEB design process in their projects. Therefore, a design manual which can be used in the nZEB design process was developed in this study. Based on an intensive literature review, energy-saving strategies and their performance levels, which affect heating and cooling energy consumptions were established for a reference building. To analyze the sensitivity of each energy strategy to the overall performance, computer simulations using EnergyPlus were performed. At the same time, an Analysis of Variance assessment was conducted to estimate the relative importance of each energy factor. The energy sensitivity and priority of the energy factors was developed into a set of design guidelines.

• 한국CDE학회논문집
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• 제16권2호
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• pp.146-155
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• 2011

As the seriousness of environmental pollution being on a rise, a low carbon and environment-friendly design for energy efficiency has been issued. With respect to energy in the construction industry, an adoption of BIM which is possible for the various energy performance assessments in the early design phase has been actively working on. In the most cases of energy performance assessment, the data compatibility from the lack of standard software and format became a problem and the improvement for data compatibility system has been needed. This study is to develop the IFC based IDF converter as a middleware which connects between BIM software and energy analysis software. For the building energy performance assessment, Energy Plus and IFC are selected for the standard energy analysis software and its file format. Parameters are organized by steps and the integrated material library is built so it is trying to reduce the existing problem of energy software interface as much as possible. The development of IDF Converter will promote the spread of related fields with increasing the BIM standard and the utilization of energy performance assessment.