• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.60-62
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• 2001

This paper shows the optimal bidding strategy determination method using Nash equilibrium concept by defining bidding strategy vector. This vector is 2-dimension vector whose components are generation amount and generation cost. Thereby we are able to make all possible strategies and their's payoff table. And then we erase dominated strategies one by one so that we obtain Nash equilibrium, the optimal bidding strategy of generation bidding game.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.267-278
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• 2020

ESS is an essential requirement for resolving power shortages and power demand management and promoting renewable energy at a time when the energy paradigm changes. In this paper, we propose a cost-effective ESS Peak-Shaving operation plan through load and solar power generation forecast. For the ESS operation plan, electric load and solar power generation were predicted through RMS, which is a statistical measure, and a target load reduction guideline for one hour was set through the predicted electric load and solar power generation amount. The load and solar power generation amount from May 6th to 10th, 2019 was predicted by simulation of load and photovoltaic power generation using real data of the target customer for one year, and an hourly guideline was set. The average error rate for predicting load was 7.12%, and the average error rate for predicting solar power generation amount was 10.57%. Through the ESS operation plan, it was confirmed that the hourly guide-line suggested in this paper contributed to the peak-shaving maximization of customers.Through the results of this paper, it is expected that future energy problems can be reduced by minimizing environmental problems caused by fossil energy in connection with solar power and utilizing new and renewable energy to the maximum.

• Journal of Information Technology Services
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• v.23 no.2
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• pp.1-12
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• 2024

This study aims to find ways to increase the declining donation intention by using machine learning techniques. To this end, in order to predict factors that affect donations between the MZ generation and the senior generation, various machine learning algorithms, including logistic regression analysis, are applied to build a model to determine variables that affect donation intention, and provide statistical verification and evaluation indicators. In this study, differences in donation intention by generation were expected as a variable affecting donation intention, and the senior generation was expected to show a higher donation intention tendency than the younger generation. However, although the research results were not statistically significant, the younger generation showed a higher intention to donate, and these results are interpreted to mean that value consumption and ethical consumption, which are important to today's MZ generation, also influenced donations. However, there were differences between generations in the amount of donations, and higher donation amounts were confirmed among the senior generation (those in their 50s or older) than the younger generation. In addition, the results of the logistic regression analysis showed that previous donation experience had a positive effect on future donation intention, and the more motivation and importance of donation and various social participation activities online and offline, the more active one became in donating.

• Journal of the Korean Ceramic Society
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• v.53 no.4
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• pp.435-443
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• 2016

Coal ash, a material generated from coal-fired power plants, can be classified as fly ash and bottom ash. The amount of domestic fly ash generation is almost 6.84 million tons per year, while the amount of bottom ash generation is 1.51 million tons. The fly ash is commonly used as a concrete admixture and a subsidiary raw material in cement fabrication process. And some amount of bottom ash is used as a material for embankment and block. However, the recyclable amount of the ash is limited since it could cause deterioration of physical properties. In Korea, the ashes are simply mixed and used as a replacement material for cement. In this study, an attempt was made to mechanically activate the ash by grinding process in order to increase recycling rates of the fly ash. Activated fly ash was prepared by controlling the mill types and the milling times and characteristics of the mortar containing the activated fly ash was analyzed. When the ash was ground by using a vibratory mill, physical properties of the mortar mixed with such fly ash were higher than the mortar mixed with fly ash ground by a planetary mill.

• Journal of Environmental Science International
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• v.11 no.6
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• pp.537-541
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• 2002

This study aimed to obtain the relative formula with the unit treatment cost according to the treatment of a sewage plant in the service area under highway. The following results were obtained. The correlative formula connected to amount of sewage(Q)generation was as follows ; between an annual amount of sale(C) showed Q=19.113$.$C$\^$0.9294/, and between the number of users(P) showed Q=2${\times}$10$\^$-8/ $.$P$^2$- 0.0298$.$P + 75,666. The correlative formula connected to the treatment cost was as follows , according to the amount of sewage generation showed S= 3${\times}$10$\^$-6/$.$Q 0-0.2266$.$Q+29,895, according to the elimination of BOD(E) showed S=6${\times}$10$\^$-5/$.$E$^2$-0.6717$.$E + 27,744, according to the annual amount of sale showed S=0.0005 C$^2$-4.8013$.$C + 35,118, with the number, of persons(P) using the service area showed S= 2${\times}$10$\^$-8/ $.$P$^2$- 0.046$.$P + 48,803.

• Journal of the Korean Ceramic Society
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• v.44 no.6 s.301
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• pp.331-337
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• 2007

High temperature reaction behaviors of various oxide materials (such as bauxite, pyrophyllite, mullite and fused silica powders) used in the refractory materials for tap-hole plugging of blast furnace were investigated with varying temperature in the carbon surrounding. Kinetics of carbothermal reduction of $SiO_2$ for forming SiC with high corrosion resistance were strongly dependent on it's crystalline phase. SiC generation yield increased with increasing catalyst amount in oxide regardless of generated SiO gas amount at temperature of $<1500^{\circ}C$. However, in case of fused silica over $1500^{\circ}C$, SiC generation yield was dominantly influenced by SiO amount without catalyst effect. Bauxite showed the most effective carbothermal reduction reaction, since bauxite have a large amount of catalyst and well-dispersed $SiO_2$ phase in oxide matrix.

• 연구논문집
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• s.32
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• pp.5-13
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• 2002

This paper deals with the result of an analysis on the effect of the power generation by municipal solid waste(MSW)-refuse derived fuel(RDF) and the introduction of tipping fee sharing between RDF manufacturing and power generation project. As a model case for the MSW generated at small and medium cities in our country, an analysis of the RDF power generation and Tipping fee sharing shows that 1) MSW amount of 7,800* $10^3 $t/y could produce 1,950*$10^3$t/y of RDF 2) Electric power generated by MSW-RDF could supply 290,000 households/year and 98,548 C-t/y of $CO_2$ could be reduced. 3) Tipping Fee should be shared by the considering of the contents of project of both side between RDF Production and power generation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2237-2248
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• 1995

In incompressible flow which has multi-length scale, it has a very important effect which dependent variables are used for adaptive grid generation. Among many length scales in incompressible flow, the dependent variables used for the adaptive grid generation should be able to represent the feature of the concerned system. In this paper, by using vorticity and stream function, in addition to velocity components, the smoother and more stable grid generation is possible and these four flow properties represent each scale. The adaptive grid generation for a lid-driven cavity flow with $N_{re}$ =3200 using four flow properties such as velocity components, vorticity, stream function is performed, and the usefulness of using vorticity and stream function as the indicator for adaptive grid generation is shown.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1907-1910
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• 2004

Generation of hydroxyl radical, one of their major active species in ozonation of water was directly observed with spin-trapping/electron spin resonance (ESR) technique using 5,5-dimethyl-pyrrolidine-1-oxyl (DMPO) as a spin-trapping reagent. Hydroxyl radical was trapped with DMPO as a stable radical, DMPO-OH. 80 mM of ozone produced $1.08{\times}10^{-6}$M of DMPO-OH, indicating that 1.4% of ${\cdot}$OH is trapped with DMPO if ${\cdot}$OH is produced stoichiometrically from ozone. Humic acid suppressed DMPO-OH generation in a dose-dependent manner. Generation rate of DMPO-OH was determined with ESR/stopped-flow measurement. Phenol derivatives increased the amount and generation rate of DMPO-OH, indicating that phenol derivatives enhance·OH generation during ozonation of water.

• Nuclear Engineering and Technology
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• v.32 no.6
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• pp.549-558
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• 2000

A transient model for hydrogen generation in molten metal-water interactions was developed with separate models for two stages of coarse mixing and stratification. The model selves the mechanistic equations (heat and mass transfer correlation, heat conduction equation and the concentration diffusion equation) of each stage with non-zero boundary conditions. Using this model, numerical simulations were performed for single droplet experiments in the Argonne National Laboratory tests and for FITS tests that simulated dynamic fragmentation and stratification. The calculation results of hydrogen generation showed better agreement to the experiment data than those of previous works. It was found from the analyses that the steam concentration to be reached at the reaction front might be the main constraint to the extent of the metal droplet oxidized. Also, the hydrogen generation rate in the coarse mixing stage was the higher than that in the stratification stage. The particle size was the most important factor in the coarse mixing stage to predict the amount of hydrogen generation.