• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.97-115
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• 2022

Smart power grid is a user friendly system that transforms the traditional electric grid to the one that operates in a co-operative and reliable manner. Demand Response (DR) is one of the important components of the smart grid. The DR programs enable the end user participation by which they can communicate with the electricity service provider and shape their daily energy consumption patterns and reduce their consumption costs. The increasing demands of electricity owing to growing population stresses the need for optimal usage of electricity and also to look out alternative and cheap renewable sources of electricity. The solar and wind energy are the promising sources of alternative energy at present because of renewable nature and low cost implementation. The proposed work models a smart home with renewable energy units. The random nature of the renewable sources like wind and solar energy brings an uncertainty to the model developed. A stochastic dual descent optimization method is used to bring optimality to the developed model. The proposed work is validated using the simulation results. From the results it is concluded that proposed work brings a balanced usage of the grid power and the renewable energy units. The work also optimizes the daily consumption pattern thereby reducing the consumption cost for the end users of electricity.

• 한국태양에너지학회 논문집
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• 제36권6호
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• pp.61-69
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• 2016

In this study, we analyzed five-year(2011~2015) data for D high school in Seoul area to analyze energy consumption characteristics in high school. The results are summarized as follows. (1) In the result of comparison analysis about 2015 energy consumption by usage, based on primary energy, 18% of energy was consumed in cafeteria, and 82% was consumed in main building. In the case of main building, base and constant load excepting hot water supply in restroom took 40%, heating including freeze protection took 20%, hot water supply in restroom took 14%, and cooling took 8% in order. (2) In the 2015 total energy consumption in D high school based on primary energy, heating energy takes 28%. The range and limit of energy savings coming from the reinforcement of insulation and window performance could be estimated. (3) To introduce new & renewable energy system in high school, electricity-based system is suitable than heat-based system because usage of electric energy is larger than that of heat energy in high school. (4) Five-year energy consumption unit according to heating degree-day showed a linearly increasing trend, and the coefficient of determination(R2) was 0.9763, which means high correlation.

• Journal of the Korean Wood Science and Technology
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• 제42권2호
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• pp.89-100
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• 2014

Energy consumption statistics in 2005 from the Korea Energy Management Corporation show that building energy usage was about 24.2% of total domestic energy consumption, and 64% of total building energy usage was consumed by residential buildings. Thus, about 10% of total domestic energy consumption is due to the heating of residential buildings. Building energy can be calculated by the configuration of the building envelope and the rate of infiltration (the volume of the infiltration of outdoor air and the leakage of indoor air), and by doing so, the annual energy usage for heating and cooling. Therefore, air-tightness is an important factor in building energy conservation. This investigate air infiltration and various factors that decrease it in timber frame buildings and suggest ways to improve air-tightness for several structural types. Timber frame buildings can be classified into light frame, post and beam, and log house. Post and beam includes Han-ok (a Korean traditional building). Six light frame buildings, three post and beam buildings, one Korean traditional Han-ok and a log house were selected as specimens. Blower door tests were performed following ASTM E779-03. The light frame buildings showed the highest air-tightness, followed by post and beam structures, and last, log houses.

• 한국콘텐츠학회논문지
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• 제20권9호
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• pp.261-270
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• 2020

본 연구는 적소 이론(Niche Theory)을 기반으로 뷰티 콘텐츠 소비를 통한 이용 충족 측면에서 웹진, TV 및 인터넷 동영상 플랫폼이 어떤 경쟁 구도를 형성하는 지를 살펴보고자 하였다. 선행 연구들을 기반으로 정보성, 오락성, 매력적인 인물 등장, 이용 편리성 및 솔직함 등 5가지의 공통적인 이용 충족 요인들을 도출하였고, 이를 바탕으로 적소분석을 실시하였다. 연구 결과 인터넷 동영상 플랫폼이 매력적인 인물 등장 측면을 제외한 모든 이용 충족 차원에서 적소폭이 다른 미디어들에 비해 넓은 것으로 나타났으며, TV와 인터넷 동영상 플랫폼이 적소 중복이 가장 적은 것으로 나타났다. 또한, 인터넷 동영상 플랫폼은 다른 미디어들에 비해 이용 편리성과 솔직함에서 경쟁 우위에 있는 것으로 나타났다. 본 연구를 통해 나타난 결과들은 향후 뷰티 콘텐츠 소비가 어떤 방향으로 전개될 지를 예측하기 위한 기초 자료로 활용될 수 있다.

• 서비스연구
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• 제13권2호
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• pp.181-203
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• 2023

유튜브는 OTT와 개인방송 플랫폼의 특성을 모두 갖춘 하이브리드적 성격을 띠고 있다. 그러나, 이러한 하이브리드적 특성을, 특히 유료 채널멤버십의 맥락에서 조사한 선행연구는 제한적이다. 따라서, 본 연구에서는 소비가치이론과 선행연구를 바탕으로 유튜브 유료 채널멤버십과 관련된 소비가치 요인이 이용만족도와 지속이용의도에 미치는 영향을 검증하고자 한다. 구체적으로, 본 연구는 유튜브 유료 채널멤버십 맥락에서 인지된 네 가지 소비가치 요인(기능적 가치, 사회적 가치, 감정적 가치, 진귀적 가치)을 도출하고, 각 요인이 이용만족과 지속이용의도에 미치는 영향을 검증한 후, 이러한 관계에서 상황적 가치(유료 유튜브 멤버십 채널에서의 실시간 방송 시청경험)의 조절효과를 추가적으로 살펴보고자 한다. 데이터는 여러 유료 유튜브 채널멤버십에 가입한 한국 성인을 대상으로 온라인 설문조사를 통해 총 274부가 수집되었다. 구조방정식모델링 기법을 활용하여 연구모형을 검증한 결과, 네 가지 소비가치 요인이 모두 이용만족에 유의미한 영향을 미치며, 이용만족은 지속이용의도에 긍정적인 영향을 미치는 것으로 나타났다. 상황적 가치 또한, 기능적/감성적 가치와 이용만족 간의 관계와 이용만족과 지속이용의도 간의 관계를 유의하게 조절하는 것으로 조사되었다. 본 연구는 OTT와 개인방송 플랫폼의 특성을 모두 포괄하는 유튜브 채널 유료 멤버십에 초점을 맞춘 최초의 연구로서, 본 연구의 결과를 통해 개인방송 진행자 및 이해관계자들에게 시청자의 이용만족에 영향을 미치고 채널멤버십 가입 및 지속유지를 유도하는 동기부여 요인에 대한 인사이트를 제공할 수 있을 것으로 기대한다.

• Human Ecology Research
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• 제55권2호
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• pp.105-124
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• 2017

The recent global economic crisis has resulted in increased discussion and attention on the sharing economy, a form of economic activity where individuals share currently available products. This study investigates consumer sharing economy usage attitudes and usage intentions by applying rational choice theory. For this study, an investigation that had 400 adult consumers from across Korea answer a structured questionnaire was conducted. A statistical approach using SPSS ver. 22.0 was used to analyze the data. The study found that the consumer's sharing economy value and participation levels were higher than usual. Higher than usual consumption patterns were seen for the construct of rational behavior theory. An analysis of the relative influence of variables regarding sharing economy usage intention also found that usage intention was higher for those who had experienced using a sharing economy services rather than those who did not have experience. In addition, the sharing economy usage intention also increased along with the values for subjective norms, sharing economy usage attitudes, sharing economy participation, sharing economy emotional benefits, and increased values. This study found that fundamental materials for consumer education should be made to eliminate difficulties that consumers have when they use sharing economy services. It is also expected that economic policy will develop to stimulate the sharing economy in a stable manner, that sharing economy-related information will be provided to consumers, and that consumer policies will be prepared to prevent consumer problems before they occur.

• 상하수도학회지
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• 제36권3호
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• pp.149-165
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• 2022

The water consumption data of individual consumers must be analyzed and forecast to establish an effective water demand management plan. A k-mean cluster model that can monitor water use characteristics based on hourly water consumption data measured using automated meter reading devices and demographic factors is developed in this study. In addition, the quantification model that can estimate the daily water consumption is developed. K-mean cluster analysis based on the four clusters shows that the average silhouette coefficient is 0.63, also the silhouette coefficients of each cluster exceed 0.60, thereby verifying the high reliability of the cluster analysis. Furthermore, the clusters are clearly classified based on water usage and water usage patterns. The correlation coefficients of four quantification models for estimating water consumption exceed 0.74, confirming that the models can accurately simulate the investigated demographic data. The statistical significance of the models is considered reasonable, hence, they are applicable to the actual field. Because the use of automated smart water meters has become increasingly popular in recent year, water consumption has been metered remotely in many areas. The proposed methodology and the results obtained in this study are expected to facilitate improvements in the usability of smart water meters in the future.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권5호
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• pp.13-22
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• 2017

Accurate assessment of agricultural groundwater usage is an essential task to cope with drought that occurs irregularly in time and location. In this study, the agricultural groundwater usage was calculated in nationwide public wells (1,386 bedrock wells) during 5-year period (2010-2014) by using electric power consumption and well specification data. National average of agricultural groundwater usage per each well was estimated as $66.2m^3/day$, corresponding to 21.6% of total permitted volume of groundwater in each well. Chungcheong Nam-do had the highest usage with 38-55.6%. The value increased to 58.1% when the total permitted volume was based upon the supply standard against drought, and the value reached 100% in Chungcheong Nam-do. In Ganghwa distirct that suffered from severe drought in recent years, the average groundwater usage was 61.4%. In 2014, when the drought was the most severe with 45% precipitation of the average annual rainfall, the nationwide usage was turned out to be 25.6%, indicating about 4% higher than average agricultural groundwater usage 21.6%. Therefore, the quantitative assessment of groundwater usage in this study signifies that adequate use of groundwater is crucial to cope with agricultural drought.

• 대한지역사회영양학회지
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• 제28권4호
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• pp.269-281
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• 2023

Objectives: This study aimed to examine the frequency of convenience food consumption at convenience stores (CVS) and the CVS usage patterns of middle and high school students as well as to understand students' attitude toward sodium and sugar reduction. Methods: We used an online questionnaire for data collection. The questionnaire comprised five distinct categories: general characteristics, CVS usage, frequency of consumption according to convenience food menus at CVS, attitude toward sodium and sugar reduction, and adherence to dietary guidelines. Results: A total of 75 students from Seoul (14 middle school students and 61 high school students) participated in the study. Most respondents visit CVS 3-5 times a week. CVS are predominantly used during weekdays, mostly during lunch, and dinner. The students mostly checked the caloric content and expiration date as food labeling information. The participants were aware of the need to reduce their sugar and sodium intake. Among frequent CVS convenience food consumers, there was an increased consideration of the need to reduce their sugar and sodium consumption, despite their actual selection of foods with high sugar and sodium content. Additionally, they did not check the sugar and sodium levels indicated in food labeling. Further, the dietary action guide from the Ministry of Health and Welfare were poorly followed by most students. Conclusions: There is a need for nutrition education specifically addressing the sugar and sodium content of the convenience foods predominantly consumed by students. Additionally, educating students with frequent convenience food consumption to actively check the sugar and sodium information on food labels could help promote healthier food choices.

• 한국물환경학회지
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• 제36권6호
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• pp.535-545
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• 2020

This study aims to conserve and monitor energy use in public sewage treatment plants by utilizing data from the SCADA system and by controlling the aeration rate required for maintaining effluent water quality. Power consumption in the sewage treatment process was predicted using the equipment's uptime, efficiency, and inherent power consumption. The predicted energy consumption was calibrated by measured data. Additionally, energy efficiency indicators were proposed based on statistical data for energy use, capacity, and effluent quality. In one case study, a sewage treatment plant operated via the SBR process used ~30% of energy consumed in maintaining the bioreactors and treated water tanks (included decanting pump and cleaning systems). Energy consumption analysis with the K-ECO Tool-kit was conducted for unit processing. The results showed that about 58.7% of total energy consumed was used in the preliminary and biological treatment rotating equipment such as the blower and pump. In addition, the energy consumption rate was higher to the order of 19.2% in the phosphorus removal process, 16.0% during sludge treatment, and 6.1% during disinfection and discharge. In terms of equipment energy usage, feeding and decanting pumps accounted for 40% of total energy consumed following 27% for blowers. By controlling the aeration rate based on the proposed feedback control system, the DO concentration was reduced by 56% compared pre-controls and the aeration amount decreased by 28%. The overall power consumption of the plant was reduced by 6% via aeration control.