• 응용통계연구
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• 제27권5호
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• pp.843-853
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• 2014

급증하고 있는 전력수요에 대한 신뢰성 있는 예측은 합리적인 전력수급계획 수립 및 운용에 있어서 매우 중대한 사안이다. 본 논문에서는 여러 시계열 모형의 비교를 통해 전력수요량과 밀접한 연관성이 있는 온도를 어떠한 형태로 고려할 것인지, 또한 4계절이 뚜렷하여 계절별 기온 차가 많이 나는 우리나라의 특성을 어떻게 고려할 것인지에 대하여 연구하였다. 모형 간 예측력을 비교하기 위하여 Mean Absolute Percentage Error(MAPE)를 사용하였다. 모형의 성능비교 결과는 냉 난방지수와 계절요인을 동시에 고려하면서 큰 변동성을 잘 고려해줄 수 있는 Reg-AR GARCH 모형이 가장 우수한 예측력을 나타냈다.

• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1310-1317
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• 2014

In our daily life, the need of energy increases day by day. However, the amount of natural resources on the earth is limited and thus gaining renewable energy as an energy resource is one of the important and urgent problems. Solar energy is one of the most popular available energy sources that can be converted into electricity by using solar panels. In order for solar panels to produce maximal output power, the incident angle of the sunlight needs to be persistently perpendicular to the solar panel. By the way, most of the solar panels are installed at fixed position and direction. Therefore, as the sun's position changes, it is impossible to produce maximal output power inevitably. To improve this problem, in this paper, a sun tracking system using two degree-of-freedom (DOF) active sensor array is proposed so that the solar panel may always direct sunlight perpendicularly. And also a series of software, such as a search mode and a holding mode, which can control the developed sun tracking system is developed. Several experiments using the implemented sun tracking system are executed and the effectiveness of the system is verified from the experimental results.

• 환경영향평가
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• 제19권6호
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• pp.591-605
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• 2010

Cool roofs are currently being emerged as one of important mechanism to save energy in relation to the building. This paper reviews worldwide experiences (USA, Japan and EU etc) for the potential benefits cool roofs offer in relation to building energy saving for comparison purposes. It is confirmed that there is a significant potential to the energy saving by introducing the cool roof in a Korean climate because of similarity in terms of HDD (Heating Degree Day) and CDD (Cooling Degree Day) as those countries reviewed. Such a comparative study highlights that the type of measurements performed and the quantitative parameters reported from the countries should be standardized in Korean context in order to implement further comparable experiments for scientifically sound investigations. It is anticipated that this research output could be used as a valuable reference in implementing a Nation-wide cool roofing strategy in the central and local governments since a suitable technical, more objective direction has been proposed based on the measured, fully quantitative performance of the involved components of a cool roof system in the global context. From this critical review, a very important step has been made concerning the practicality of cool roof in Korean context. Ultimately, the suggestion in this paper will greatly contribute to opening new possibilities for introducing cool roof in this country, proposed as an initial aim of this paper.

• 한국농공학회지
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• 제15권2호
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• pp.2968-2979
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• 1973

The aim of this study was to bring light on the effect of permeability to yield weight of paddy rice on the compressed soil. a) The percolation volume during the growth of paddy rice reduced, while the degree of compression on soil column increased and varied by the evaporation and absorption volumn. b) The percolation volume in the natural soil column was notably low compared with that of in the artificial and had little influence to the variation of permeabilty by compression. c) The results in growth of paddy rice were best on the section of low compression and the yield weight reduced, while the degree of compression on the soil column increased. d) The relationship between the yield weight and percolation volumn, under the condition when percolation volume is 1mm/day, had little difference in the yield weight but immediately reduced under $0.5{\sim}1.0mm/day$. The consequences of investigation are not so perfect, but have done my best to get some new data for effect on additional yield by inquiring into influences of permeability to the yield weight of paddy rice on compressed paddy field. I will have a great pleasure if treatise helps investigaters or the men of affairs in this field.

• 대한가정학회지
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• 제19권2호
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• pp.73-85
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• 1981

The present trend is to classify time as a human resource. Time is considered as a human resource and refers not only to "clock time" that man possesses in equal amounts, but also to person's characteristic methods of assimilating and perceiving the passage of time. People differ in their ability to gauge the passage of time or to estimate the amount of time that an activity will take. The time used for household work by homemaker was analysed in that viewpoint. Specially the aim of this study was to find and analyse any differences from the style of house, the kind of fuel for cooking, the system of the family, the age and educated degree of homemaker and income degree. For analysis useable responses of 247 returned were used. The conclusion is as follows. 1. Homemakers spent 11.8∼13.4 hours for household work for a day. 2. Husband contributed 1∼1.4 hours, daughters and sons 0.6∼2.4 hours for household work a day. 3. There were large differences of the time spent on all food activities and care of clothes by the style of house and kitchen and the kind of fuel for coking. 4. The homemaker who has many children and preschool children spent much time for preparing the meal and care of clothes than others. 5. High educated homemaker spent less time for household work than others. 6. There are not any differences between time spent and income. 7. There are not also differences between time spent and having household equipment. It is assumed that many household equipment in the house aren't used effectively.

• 한국태양에너지학회 논문집
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• 제40권1호
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• pp.15-24
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• 2020

Building energy consumption generally depends on living patterns of residents and outdoor air temperature changes. Although outdoor air temperature changes effect on building energy consumption, there is no calibration method for the comparison before and after Green Remodeling or BEMS installation etc., Big data of building energy consumption are collected and managed by 『National Integrated Management System of Building Energy』 in Korea, and they are utilized for the development of a calibration method for individual buildings as shown as the calibration method for small-area building stocks in the previous research. This study aims to develope a calibration method using big data of building energy consumption of individual buildings and outdoor air temperature changes, and to propose application of appropriate calibration methods for individual buildings or small-area building stocks according to the calibration purpose and conditions.

• 교육녹색환경연구
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• 제11권2호
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• pp.19-27
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• 2012

This study was carried out in order to establish the estimation equation for school power consumption using regression analysis based on collected power consumption for two years of weather data and schools are located in Central Changwon and Masan district in Changwon city. (1) The power consumption estimation equation for Heating and cooling is calculated using power consumption per unit volume, the difference between actual power consumption and results of estimation equations is 4.1%. (2) The power consumption estimation equation for heating load is showed 2.6% difference compared to actual power consumption in Central Changwon and is expressed 2.9% difference compared to that in Masan district. Therefore, the power consumption prediction for each school using the power consumption estimation equation is possible. (3) The power consumption estimation equation for cooling load is showed 8.0% difference compared to actual power consumption in Central Changwon and is expressed 2.9% compared to that in Masan district. As the power consumption estimation equation for cooling load is expressed difference compared to heating load, it needs to investigate influence for cooling load.

• 한국태양에너지학회 논문집
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• 제40권5호
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• pp.47-58
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• 2020

Ministry of Land, Infrastructure and Transport(MOLIT) has increased reduction rate from 18.1% to 32.7% in Building sector compared to BAU of the national greenhouse gas emission according to the 2030 Greenhouse Gas Reduction Road map Amendment. For this purpose, MOLIT has been activating the green remodeling projects for existing buildings. Considering that 15 year old buildings after completion are 74% (5.25 million buildings) among about 7 million existing building stocks in Korea, reduction of building energy consumption by green remodeling is urgently needed, However, it is a major difficulty of activation for green remodeling projects because there are few case studies on Before and After building energy consumption of actual green remodeling projects. Considering that building energy performance and value increase after green remodeling through previous researches, additional studies of the energy consumption assessment on actual green remodeling projects are essential. Therefore, this study aims to propose results on Before and After building energy consumption of actual green remodeling projects.

• 한국식품조리과학회지
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• 제19권2호
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• pp.136-143
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• 2003

This study was carried out to investigate the quality of bread made with different types of brown rice flours. 20% of the wheat flour from the bread recipe was substituted with the different types of brown rice flours, such as, raw brown rice flour (RBRF), soaked brown rice flour (SOBRF), and sprouted brown rice flour (SPBRF). The loaf volume of the bread: decreased by 3.2%∼7.4% with the addition of the brown rice flours. The "L" value of these breads decreased, while the "a" and "b" values increased. In terms of the texture, the SPBRF bread was the hardest on the 1st day of storage, but it was the least hard on the 5th day of storage. The RBRF bread was the least springy. The SPBRF bread was the most cohesive. The adhesiveness was not significantly different among the breads. In terms of the degree of retrogradation using the ${\alpha}$-amylase method, the SOBRF and SPBRF breads showed a little lesser degree of retrogradation than the control and the RBRF bread. In the sensory evaluation, the control bread obtained high score for crumb color and grain, while the brown rice flours breads obtained high scores for mouthfeel and taste. Overall acceptability, defined by a higher score, was higher for the SOBRF and SPBRF breads than the control bread, which was not significant. Thus, this study showed that processing rice flour was more effective than raw rice flour in substituting wheat flour.

• 한국태양에너지학회 논문집
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• 제38권6호
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• pp.15-26
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• 2018

It is difficult to check the exact building energy consumption reduction such as when green remodeling of buildings, because it is due to outdoor air temperature over the years. And in Korea although Big Data of building energy consumption is collected and managed through "The Information System of the Building Energy and Greenhouse Gases" it is underutilized because of non calibration of outdoor air temperature change. Therefore, this study aims to develope calibration method of building energy consumption by outdoor air temperature according to micro climates, and building use types. As a result of analysis, Regression equations of Building energy consumption and $HDD_m/CDD_m$ are derived and calibration method is developed by Regression coefficient.