• Journal of Korean Society of Water and Wastewater
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• v.31 no.2
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• pp.149-159
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• 2017

It is considered necessary to renewal a considerable number of water supply facilities in Korea because they began to be intensively buried in the period of rapid economic growth. Accordingly, local water providers are required to take measures against this situation, but they have currently been caught in a vicious circle of the lack of budget spent in renewing water supply facilities because county-based small-scale local water supply cannot afford to cover annual expenditures with their revenues from water rates. Therefore, this study developed an optimal renewal planning model capable of achieving a balance of financial revenue and expenditure in local water supply using nonlinear programming and furthermore of minimizing the total cost incurred during the analysis. To this end, this study selected the water supply area located in County Y as a research area to build the financial revenue and expenditure and used Solver function provided by Microsoft Excel to use nonlinear programming. As a result, this study developed an optimal renewal planning model minimizing incurred costs in consideration of 6 items in the financial revenue and expenditure. The optimal renewal plan was modeled according to the available annual budget. As a result, this study proposed SICD, a scenario to minimize total costs from the perspective of water suppliers, and SITS, a scenario to minimize the increase in water rates from the perspective of consumers. It can be said that the method proposed in this study is the core of the optimal financial and renewal plans as a final stage of asset management for water supply facilities. Therefore, it is considered possible for local water providers to use the method proposed in this study according to circumstances for the asset management of water supply facilities.

• Journal of Energy Engineering
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• v.9 no.2
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• pp.95-101
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• 2000

The purpose of this study is to find plant utilities capacity for economical operation of combined heat & power by reducing energy expenditure. Using a numerical simulation program CHPSIM, a comparative analysis of additional heat expenditure (AHE) of combined heat & power plant in relation to size of district heating has been performed within the comparison of the difference capacity of gas turbine and steam turbine . As a results, if a 105.2MW gas turbine (exhaust gas temp ; 540$^{\circ}C$) installed in CHP plant can reduced 17-18% yearly the AHE than 75MW gas turbine (520$^{\circ}C$) installed. If a 130-150MW gas turbine (560-580$^{\circ}C$) installed, can reduced 34.7-35.8% of the yearly AHE.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.16 no.2
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• pp.135-151
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• 2005

In accordance with changes in life style, people's desire to eat out is getting changed in their preferring factors from whether they can buy food they want to eat fast and easily to mood of the dining space, content and quality of service, hygiene condition of restaurant, quiet location and surrounding circumstance, and discount coupon and price destruction. In addition, consumers who begin to recognize the seriousness of environmental pollution prefer health-oriented food. On the other hand, excessive presence of competitors, growing personnel expense, increasing expenditure in accordance with swelling price of rent and material expenditure, increase of tax burden, decrease of income because of credit card service charge and high expected level by consumers make it difficult for restaurant's owners to manage restaurant business. Therefore, this study purposes to establish development of menu from the consumer's and the supplier's point of view and propose how to develop menu aiming at convenience, health and diversity.

• Environmental and Resource Economics Review
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• v.14 no.4
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• pp.839-866
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• 2005

This study addresses the effects on the economy of atomic sector's R&D by considering how much KAERI's R&D expenditures in 2000 affect on the production and value-added of each industry and the whole economy. This study answers to the question using competitive import input-output tables and both supply driven and demand driven IO models, which are frequently employed in evaluating economic impacts of R&D in both domestic and foreign academic areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.488-493
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• 2020

The demand for hydrogen, which is considered an environmentally friendly energy source, is increasing, and at the same time, the fuel cell market is increasing continuously. This study aimed to establish a strategy for securing intellectual property rights on fuel cell by-product utilization technology for operating expenditure reduction of hydrogen-powered residential buildings. In this patent analysis, this study investigated Korean, American, Japanese, and European patents filed/published/registered by October 2019 and established a technical classification system and classification criteria through expert discussion. To reduce the operating expenditure of hydrogen-powered residential buildings, intellectual property rights will be improved using systems and methodologies involving cathode-side purified air, product water, and oxygen-depleted air captured with the dead-end mode operation of polymer electrolyte fuel cells.

• ETRI Journal
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• v.43 no.2
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• pp.173-183
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• 2021

As low-power wide-area network (LPWAN) end devices (EDs) are deployed in massive scale, their economic and environmental costs of operation are becoming too significant to ignore and too difficult to estimate. While LPWAN architectures and protocols are designed to primarily save energy, this study shows that energy saving does not necessarily lead to lower cost or environmental footprint of the network. Accordingly, a theoretical framework is proposed to estimate the operational expenditure (OpEx) and environmental footprint of LPWAN EDs. An extended constrained optimization model is provided for the ED link assignment to gateways (GWs) based on heterogeneous ED configurations and hardware specifications. Based on the models, a simulation framework is developed which demonstrates that OpEx, energy consumption, and environmental footprint can be in conflict with each other as constrained optimization objectives. We demonstrate different ways to achieve compromises in each dimension for overall improved network performance.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1139-1144
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• 2015

The gross domestic product(GDP) measures the welfare of a nation's economy through the aggregation of products and services produced in a nation. Although GDP is a proficient measure of the magnitude of the economy, many economists, environmentalists, and citizens have recently criticized the gross domestic product. The criticism stems from the fact that this measurement of domestic product does not account for environmental degradation and resource depletion. We need to estimate the environmentally adjusted net domestic product. The gross domestic product was 913 trillion won while environmental protection expenditure was 32.9 trillion won by monetary accounts of Korea, 2010. Loss of natural assets was 76.6 trillion emwon by emergy analysis of Korea, 2010. The Green GDP was accounted for 88.0% of the GDP to 803.5 trillion won.

• Journal of the Korean Home Economics Association
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• v.35 no.2
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• pp.401-413
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• 1997

The objectives of this study were to measure the characteristics of environmentally conscious behavior in the private household focused on energy consumption, money expenditure and time usage, and to determine the socioeconomic variables, environmental consciousness and environmental education which are associated with the environmentally conscious behavior of private households. The data for this study were collected in a personal interview and the final sample consisted of 178 respondents and the statistics employed to analyze the data are discriminant analysis $\chi$2-test. As a result of the discriminant analysis, it was shown that environmentally conscious private households consumed less energy, had lower transportation costs, but spent more time in purchasing behavior in the market compared with those who did not exhibit environmentally conscious behavior. Environmentally conscious behavior of private households differed significantly according to the education of housewives, and also to the level of environmental consciousness and environmental education of the respondents.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.123-128
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• 2014

This study investigated the exercise intensity and energy expenditure involved in two gardening activities (planting transplants and sowing seeds in a garden plot) and four common physical activities (running, skipping rope, walking, and throwing a ball) in children. Eighteen children aged 11 to 13 years (mean age, $12.3{\pm}0.7$ years) participated in this study. The children made two visits to a high tunnel in Cheongju, Chungbuk, South Korea and performed randomly selected activities. Each activity was performed for 10 min, with a 5-min rest period between activities. The children wore a Cosmed $K4b^2$ (Cosmed $K4b^2$; Cosmed, Rome, Italy), which is a portable calorimetric monitoring system, to measure indicators of metabolic cost such as oxygen uptake and energy expenditure. The children's heart rates during the activities were measured by radiotelemetry (Polar T 31; FitMed, Kempele, Finland). We found that the two gardening and four physical activities performed by the 11-13 years old children in this study were moderate-to high-intensity physical activities [i.e.,$5.4{\pm}0.7$ to $9.1{\pm}1.4$ metabolic equivalents (METs)]. Running ($9.1{\pm}1.4$ METs) and skipping rope ($8.8{\pm}1.1$ METs) were high-intensity physical activities, whereas walking ($6.1{\pm}0.9$ METs), planting transplants ($5.8{\pm}1.1$ METs), throwing a ball ($5.6{\pm}1.1$ METs), and sowing seeds ($5.4{\pm}0.7$ METs) were moderate intensity physical activities. Running and skipping rope were significantly more intense than the other activities (P < 0.0001). The gardening tasks such as planting transplants and sowing seeds in a garden plot showed similar exercise intensities and energy costs as walking and throwing a ball. This study indicates that gardening can be used as a physical activity intervention to provide health benefits similar to more common physical activities such as walking and running.

• Journal of the Korean Home Economics Association
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• v.37 no.2
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• pp.127-144
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• 1999

The purposes of this study were to identify the housing maintenance cost, imputed rent fee and total housing cost of households living in rental house, to analyze the factors related to their housing maintenance cost, imputed rent fee and total housing cost and to investigate the factors contributing to total housing cost to total household income ratio. The data used for these purposes, was 97 KHPS of Daewoo Economic Research Institute. Sample size of households living in rental house, was 663. Statistics performed for the analysis were frequencies, percentiles, t-test, Lorenz cutie and Gini coefficient, Tobit analysis, OLS and Logistic analysis. The results of this study were as fellows: First, monthly cost of monthly rent & maintenance and repairs of households living in rental house with a deposit was lower than rental house, while the imputed rent fee of households living rental house with a deposit was higher than monthly rent households'And, total housing cost of households living in rental house with a deposit was higher than monthly rent households'. Second, Gini coefficient of the housing maintenance cost was 0.440, Gini coefficient of imputed rent fee was 0.362, and Gini coefficient of total housing cost was 0.291. Third, the variables related to their housing maintenance cost were family type, total household expenditure of socio-demographic characteristics and residence, type of rent, housing type of housing environmental factor. Also, the variables contributing to imputed rent fee were job type and educational attainment of household hearts, the number of family members, total household expenditure, residence, type of rent, housing type and tole number of rooms. In addition, the variables associated with total housing cost were job type and educational attainment of household head, total household income and residence, type of rent, housing type and the number of room. Finally, age, job type, educational attainment of household head, wife's employment status, the number of family members, family type, total household expenditure, residence, rent type of rent, housing type, the size of living space, and the number of room were significant variables contributing to total household cost to total household income ratio.