• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.171-182
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• 2015

The economic effects of sewage and wastewater treatment service (SWTS) sector on other sectors have been rarely investigated in the literature. This paper attempts to apply an inter-industry analysis to looking into the economic effects of the SWTS sector. To this end, the most recently published 2012 input-output table is used here. In particular, the SWTS sector is specified as exogeneous to identify the economic effects of the SWTS sector on other sectors. Production-inducing effect, value-added creation effect, and employment-inducing effect are quantified based on demand-driven model. Supply shortage effect and price pervasive effect are also analyzed employing supply-driven model and Leontief price model, respectively. The results show that production-inducing effect and value-added creation effect of a unit of investment or production in SWTS sector are estimated to be 1.7076 and 0.7392, respectively. The employment-inducing effect of one billion of investment or production in the SWTS sector is computed to be 11.0498 persons. The shortage effect of the SWTS sector amounts to 0.8417 won. The overall price effect of the 10% increase in the price of SWTS sector is calculated to be 0.0115%. This quantitative information can be utilized in predicting the economic effects of the SWTS sector-related activities or policy-making.

• KIEAE Journal
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• v.12 no.3
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• pp.41-46
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• 2012

The building envelope is important specially for saving energy consumption of residential buildings. but Apartment houses in Korea commonly have inside insulation system which have constantly arisen thermal bridges, the risk of heat loss, as a necessity. This study aims to evaluate integrated insulation performance according to the different shapes of external walls, adjacent to windows. The thermal performance analysis was carried out by Equivalent U-value and using the three-dimensional heat transfer computer simulation (TRISCO-RADCON), under nine different cases of comparing among three each of different bases(current standard model, 30percent energy saving model and 60percent energy saving model). The heating and the cooling load were also compared between two cases (standard U-value and Equivalent U-value) of three each of different bases, using the Building energy simulation which is based on DOE-2.1 analysis. As results, it turns out that if the Equivalent U-value is considered on the envelope analysis, the heat flow loss will be increasing more than the standard U-value, and if heat insulation property of the residential building reinforced rather than current, the rate of influences on the thermal bridges would be extremely expanded. In addition, it is shown that annual heating loads of the apartment house with applied Equivalent U-value substantially increased by more than 15 percent compared to those with the existing U-value, but annual cooling loads were negligibly affected.

• KIEAE Journal
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• v.15 no.2
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• pp.45-52
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• 2015

Purpose: Currently, since the energy consumption of apartment buildings is on the rise, it is necessary to reduce the total amount of the energy through the survey and analysis of energy consumption data. Although various studies for energy efficiency have been conducted, studies are more focused on the measurement of energy by using analysis tools. In addition, the studies are sufficient to analyze real data of the city gas in apartment buildings. Therefore, the objective of this study is to identify the property of annual and $1m^2$ city gas amount according to the exclusive dwelling area. Method: To achieve the objective, this study used the statistics such as descriptive, correlation, and analysis of variance (ANOVA) analysis. Result: As a result, there is positive relationship between the annual average of city gas and the exclusive dwelling area. However, in the case of $1m^2$ city gas amount, a negative relationship is mored. In the future, the findings of this study can be applied to develop the prediction model of the city gas consumption and implement it as basic data for energy efficiency of apartment buildings of future.

• Journal of Korea Port Economic Association
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• v.38 no.4
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• pp.87-106
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• 2022

Uncertainties in the energy market are increasing due to technology developments (shale revolution), trade wars, COVID-19, and the Russia-Ukraine war. Especially, since 2020, the risk of international trade in the energy market has increased significantly due to changes in the supply chain of transportation and due to prolonged demand reduction because of COVID-19 and the Russian-Ukraine war. Considering these points, this study analyzed connectedness between energy price, tanker index, and uncertainty to understand the connectedness between international trade in the energy market. Main results are summarized as follows. First, as a result of analyzing stable period and unstable period of the energy price model using the MS-VAR model, it was confirmed that both the crude oil market model and the natural gas market model had a higher probability of maintaining stable period than unstable period, increasing volatility by specific events. Second, looking at the results of the analysis of the connectedness between stable period and unstable period of the energy market, it was confirmed that in the case of total connectedness, connectedness between variables was increased in the unstable period compared to the stable period. In the case of the energy market stable period, considering the degree of connectedness, it was confirmed that the effect of the tanker freight index, which represents the demand-side factor, was significant. Third, unstable period of the natural gas market model increases rapidly compared to the crude oil market model, indicating that the volatility spillover effect of the natural gas market is greater when uncertainties affecting energy prices increase compared to the crude oil market.

• Journal of the Korean Solar Energy Society
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• v.39 no.5
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• pp.11-28
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• 2019

Governments are increasing energy efficiency in buildings through various policies to reduce building energy consumption. In 2002, the European Union adopted a building energy performance guideline to set minimum efficiency standards for residential and commercial buildings. Starting in 2020, all EU member states should ensure that all buildings are Near-Zero Energy Buildings (NZEB). In Korea, the government issued a zero-energy certification system. Since 2020, public buildings are required to cover energy consumption with the energy produced in buildings. As the demand for building energy simulation has increased to increase the energy efficiency of these buildings, the International Standard Organization (ISO) has created a standard for calculating building energy requirements called ISO 13790. This standard was revised to ISO 52016 in 2017. In this research, ISO 13790, which calculates the energy needs of existing buildings, and ISO 52016, which replaces them, are compared and analyzed, and applied to the calculation of heating energy needs of buildings. For models without thermal zoning(Case A), the difference in annual heating energy needs calculated from each criterion is $1.08kWh/m^2$, which is about 2% higher in ISO 52016. In the case of the thermal zoning model(Case B), the difference in annual heating energy needs calculated by each standard was $0.97kWh/m^2$, which was about 2% higher than ISO 52016. The heating energy needs model without thermal zoning has a higher energy needs than the heating energy needs model with thermal zoning. It is about 16% energy at $8.58kWh/m^2$ for ISO 13790 and $8.69kWh/m^2$ for ISO 52016.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.743-752
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• 1998

Numerical analysis for the flow and heat transfer in solid particle moving beds of heat exchangers is presented. The solid particle flow through the bundle of heat source tubes by the gravitational force. The heat energy is transferred through the direct contact of particles with the heat source tubes. The viscous-plastic fluid model and the convective heat transfer model are employed in the analysis. The flow field dominantly influences the total heat transfer in a heat exchanger. As the velocities of solid particles around the heat source tubes increase, the amount of heat transfer from the tubes increases. Some examples are presented to show the performance of the numerical model. The flow effect on the heat transfer is also studied through the examples.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.193-196
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• 1987

We reported that hot electron phenomena in submicron nMOSFET by Monte Carlo method. In order to predict the influence of the hot electron effects on the device reliability, either simple analytical model or a complete two dimensional numerical simulation has been adopted. Results of numerical simulation, based on the static mobility model, may be inaccurate when gate length of MOSFET is scaled down to less than 1um. Most of device simulation packages utilize the static nobility model. Monte Carlo method based on stochastic analysis of carrier movement may be a powerful tool to characterize hot electrons. In this work, energy and velocity distribution of carriers were obtained to predict the relative degree of short channel effects for different device parameters. Our analysis shows a few interesting results when $V_{ds}$ is 5 volt, average electron energy does not increase with gate bias as evidenced by substrate current.

• Journal of Korean Academy of Nursing
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• v.35 no.4
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• pp.709-720
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• 2005

Purpose. The purpose of this study was to obtain a clearer understanding of spirituality and examine the process of spirituality through defining the meaning and attributes of spirituality. Method. Concept analysis was done in the three phases, theoretical phase, fieldwork phase, and analytical phase suggested in the Hybrid Model. Five people participated in the fieldwork phase. Results. Spirituality is activated through self-awareness which occurs as spirit being activated through self-introspection, and through restoration of the relationship with Supreme Being. This interconnectedness with Supreme Being has an absolute impact on one's harmonious interconnectedness with self and neighbors, thus leads all the critical attributes of spirituality to be revealed. The core energy of this harmonious inter-connectedness is love. When activated, it has a great impact on an individual as integrative energy, leads one to go beyond everyday experience as well as to have new perspectives, and to live a satisfactory life in every aspect. Conclusion. The results of this study suggest that promotion of connectedness is the most important element in spiritual nursing interventions. The results can also be used effectively in developing spirituality assessment scales and theory.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.269-272
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• 2006

Numerical analysis of wind turbine scale effect was performed by using computational fluid dynamics. For the numerical analysis of wind turbine. Three dimensional Navier-Stokes solver with various turbulence models was tested and realizable k-e turbulence model was selected for the simulation of wind turbines. To validate the present method, performance of NREL (National Renewable Energy Laboratory) Phase VI wind turbine model was analyzed and compared with experiment and blind test data. Using the present method, numerical simulations for various size of wind tunnel model were carried out and characteristics were observed in detail. The power loss due to the interference between wind turbine and nacelle was also computed for relatively larger nacelle installation in wind tunnel test. The present results showed good correlations with experimental data and reasonable trends of scale effect of wind turbine.

• Journal of Korean Association for Spatial Structures
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• v.21 no.2
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• pp.81-88
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• 2021

In this paper, nonlinear finite element analysis was conducted based on the experimental results on buckling restrained brace. The reliability of the analytical model was verified by comparing the results of experimental studies with hysteresis loop, bi-linear curve, cumulative energy dissipation capacity, and equivalent viscous damping. A valid finite element model has been secured and will be used as basic data for finite element analysis of buckling restrained braces in the future.