• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4724-4747
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• 2016

To efficiently reduce on-grid energy consumption, the admission control algorithm in the hybrid energy powered cellular network (HybE-Net) with base stations (BSs) powered by on-grid energy and solar energy is studied. In HybE-Net, the fluctuation of solar energy harvesting and energy consumption may result in the imbalance of solar energy utilization among BSs, i.e., some BSs may be surplus in solar energy, while others may maintain operation with on-grid energy supply. Obviously, it makes solar energy not completely useable, and on-grid energy cannot be reduced at capacity. Thus, how to control user admission to improve solar energy utilization and to reduce on-grid energy consumption is a great challenge. Motivated by this, we first model the energy flow behavior by using stochastic queue model, and dynamic energy characteristics are analyzed mathematically. Then, fuzzy logic based admission control algorithm is proposed, which comprehensively considers admission judgment parameters, e.g., transmission rate, bandwidth, energy state of BSs. Moreover, the index of solar energy utilization balancing is proposed to improve the balance of energy utilization among different BSs in the proposed algorithm. Finally, simulation results demonstrate that the proposed algorithm performs excellently in improving solar energy utilization and reducing on-grid energy consumption of the HybE-Net.

• The Korean Journal of Applied Statistics
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• v.32 no.2
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• pp.319-330
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• 2019

Forecasting the electricity consumption through analyzing the past electricity consumption a advantageous for energy planing and policy. Machine learning is widely used as a method to predict electricity consumption. Among them, ensemble learning is a method to avoid the overfitting of models and reduce variance to improve prediction accuracy. However, ensemble learning applied to daily data shows the disadvantages of predicting a center value without showing a peak due to the characteristics of ensemble learning. In this study, we overcome the shortcomings of ensemble learning by considering the temperature trend. We compare nine models and propose a model using random forest with the linear trend of temperature.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.281-289
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• 2019

Desalination plants are generally studied with higher operating costs compared to water supply facilities. This study was conducted to reduce the cost of water production and to preserve existing water resources. Therefore, the purpose of this study was to utilize the control valves to increase maximum efficiency, thereby reducing the power of the pumps and operating costs. Specific energy consumption was shown to reduce the process operating power by up to 1.7 times from 6.17 to $3.55kWh/m^3$ based on seawater reverse osmosis 60 bar. In addition, the water intake process was divided into pre, inter, and post-according to the use method of blasting, and the water treatment process was divided into pre, inter, and post blending. In order to reduce power consumption, the blending process was combined to operate the facility, which resulted in the reduction of power consumption in the order post > pre-inter> inter blending.

• Korean Journal of Organic Agriculture
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• v.30 no.2
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• pp.191-206
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• 2022

Rice has prevailed as a staple food in South Korea. Rice consumption has sharply shrunk nowadays. In the wake of COVID-19 Shock and the "untact" era, the instant rice market has significantly grown, and there is a possibility of solving the shrinking consumption of domestic rice. This study contributes to the development of rice consumption promotion strategies by examining the factors of purchasing instant rice based on the Hedonic Price Methodology. In particular, given the increase in online market, this study compares attribute values of product characteristics between online and offline markets. The empirical results show that calorie, brand, organic and functional products have positive effects on instant rice prices. The rate of carbohydrate, the PB and bundle attributes have negative effects on instant rice prices. The results also show that the magnitude of brand, bundle and PB attribute values are bigger in offline market while that of the number of multigrain attribute value is relatively bigger in online market. The organic attribute value is important regardless of marketing channels.

• Journal of ILASS-Korea
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• v.27 no.4
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• pp.195-202
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• 2022

Recently, the global automobile market is rapidly changing from internal combustion engine vehicles to eco-friendly vehicles including electric vehicles. Among eco-friendly vehicles, LPG vehicles are low in fine dust and are suggested as a realistic way to replace diesel vehicles. In addition, it is more economical than gasoline in its class, showing a cost-saving effect. In Korea, the business of converting gasoline into LPG is active. Research is being conducted to apply this to hybrid vehicles. In this study, the difference in energy consumption efficiency was analyzed when LPG fuel was applied by selecting a 2-liter GDI hybrid electric vehicle. The operation of the hybrid system according to various driving characteristics was confirmed by selecting the WLTC mode. As a result, it was confirmed that the BSFC was about 5% lower than that of gasoline fuel when using LPG fuel. This is due to the active operation of the motor while driving. Optimization is required as battery consumption increases from an energy perspective.

• Journal of Distribution Science
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• v.21 no.4
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• pp.113-119
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• 2023

Purpose: This study aims to investigate the effect of retailer's ESG performance on consumption value. The research analyzed the effect of consumption value that can be obtained through ESG management of retail companies on consumer attitude and repurchase intention. Research design, data, and methodology: A research model and hypothesis were established, and statistical analysis was performed on a total of 278 samples of all age groups. To secure the reliability and validity of the data, confirmatory factor analysis and discriminant validity analysis were performed, and the causal relationship of latent variables was verified through path analysis. Results: As a result of the analysis, it was found that among the characteristics of consumption value according to ESG management, social value, economic value, accessible value, and eco-friendly value had an effect on social contribution attitude. Also, the economic value was found to have an effect on the self-actualization attitude, and both the social contribution attitude and the self-actualization attitude have an effect on the purchase intention. Conclusions: This study empirically analyzed the value of ESG management in the retail industry that consumers are paying attention to recently. This will serve as a basis for revising and supplementing the retail companies' strategy in the near future.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.1
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• pp.333-343
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• 2022

Humans are facing many environmental challenges. Climate change, water pollution, global warming, and hazardous waste disposal are all issues that many countries throughout the world are dealing with. People's psychology and consumer behavior are significantly affected by these challenges, particularly generation Z, which is immediately affected by environmental changes. Young people have a strong sense of curiosity and have access to readily updated knowledge. Today's youth, in particular, live a civilized and responsible lifestyle. As a result, people recognize the significance of their own consumption behavior in affecting environmental change and are increasingly replacing them with green, ecologically friendly products as a fantastic method to mitigate their harmful consequences. In this research, there are four factors related to the young generation and environmental awareness that affect green consumption intention: perceived environmental responsibility, green knowledge, green attitude, and green product value. The goal of this study is to look into how detrimental environmental changes affect Generation Z's green consumption habits. This study used primary data from over 1000 people in the age group, which was processed using the AMOS 20 software. All the characteristics described above had an impact on Generation Z's green consumption intentions, according to the findings.

• The Journal of Economics, Marketing and Management
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• v.5 no.4
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• pp.19-28
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• 2017

This study is aiming to suggest baseline date for the establishment of policy alternative to make healthy consumption life of the elderly through investigating and analyzing actual condition of consumption related with the awareness of health functional food such as purchase behavior and consumer's problems about health functional food. Under the assumption that the vitalization of health functional food market will become an important market in the present and in the future, the fundamental marketing information about elder consumers is more important than any other information that is essential for successful marketing to domestic corporations and senior policy experts. In addition, there was a fundamental significance to provide necessary basic data for health promotion of the elderly by offering information about rights and interests of elder consumers who are members of vulnerable social group or right choice of purchasing or intake. The limitations of this study are as follows. First, the subjects were selected who live in Gangwon-do with the age of 60 and over due to the limitation of sampling, and that might be shown local characteristics. Therefore, the study result could not be generalized on behalf of all elderly in Korea and it is difficult to apply the result to more segmented market. To solve this problem, studies containing sampling by regional groups might be needed.

• Journal of Korean Society of Water and Wastewater
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• v.38 no.1
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• pp.29-38
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• 2024

Wastewater management is increasingly emphasizing economic and environmental sustainability. Traditional methods in sewage treatment plants have significant implications for the environment and the economy due to power and chemical consumption, and sludge generation. To address these challenges, a study was conducted to develop the Intermittent Cycle Extended Aeration System (ICEAS). This approach was implemented as the primary technique in a full-scale wastewater treatment facility, utilizing key operational factors within the standard Sequencing Batch Reactor (SBR) process. The optimal operational approach, identified in this study, was put into practice at the research facility from January 2020 to December 2022. By implementing management strategies within the biological reactor, it was shown that maintaining and reducing chemical quantities, sludge generation, power consumption, and related costs could yield economic benefits. Moreover, adapting operations to influent characteristics and seasonal conditions allowed for efficient blower operation, reducing unnecessary electricity consumption and ensuring proper dissolved oxygen levels. Despite annual increases in influent flow rate and concentration, this study demonstrated the ability to maintain and reduce sludge production, electricity consumption, and chemical usage. Additionally, systematic responses to emergencies and abnormal situations significantly contributed to economic, technical, and environmental benefits.

• Journal of Korean society of Dental Hygiene
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• v.16 no.3
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• pp.417-426
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• 2016

Objectives: The objective of the study was to investigate the related factors of preventive behavior experience toward dental caries and periodontal disease in Korean adolescents. Methods: The study subjects were 72,060 adolescents in 800 schools who completed 2014 Korean Youth Risk Behavior Web-based survey. Dependent variables included general characteristics of the subjects, oral health behavior, and oral disease experience. The experience rate of sealant and scaling showed the prevention behavior of dental caries and periodontal disease. Data were analyzed by IBM SPSS statistics 20.0. Results: The experience rate of sealant accounted for 26.9%. The experience of sealant was related with gender, school, maternal education level, economic status, vigorous physical activity, smoking, usual stress, fruit consumption, milk consumption, soda consumption, snack consumption, tooth brushing, oral health education experience, periodontal bleeding and pain, mucosal disorders, and bad breath. The experience rate of scaling was 22.6%. The experience of scaling was related with gender, school, city division, learning achievement, maternal education level, economic status, residential type, vigorous physical activity, usual stress, fruit consumption, milk consumption, tooth brushing, oral health education experience, periodontal bleeding and pain, mucosal disorders, and bad breath. Conclusions: To expand preventive oral health behavior in the adolescents, it is necessary to support the systematic policy making and monetary establishment in the future.