• Journal of Korean Society of Industrial and Systems Engineering
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• 제38권4호
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• pp.39-44
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• 2015

The VHTR (Very High Temperature gas-cooled nuclear Reactor) has been considered as a major heat source and the most safe generation IV type reactor for mass hydrogen production to prepare for the hydrogen economy era. The VHTR satisfies goals for the GIF (Generation IV International Forum) policy such as sustainablility, economics, reliability and proliferation resistance and physical protection, and safety. As a part of a VHTR economic analysis, we have studied the VHTR construction cost and operation and maintenance cost. However, it is somewhat difficult to expect the ripple effect on the whole industry due to the lack of information about Inter-industries relationship. In many case, the ripple effect are based on experts' knowledge or uncertain qualitative assumptions. As a result, we propose quantitative analysis techniques for ripple effects such as the production inducement effect, added value inducement effect, and employment inducement effect for VHTR 600MWt${\times}$4 modules construction and operation ripple effect based on NOAK (Nth Of A Kind). Because inducement effect values have been published annually, we predict inducement effect's relation function and estimated values including production inducement effect value, added value inducement effect value, and employment inducement effect value using time series and estimated values are verified with published inducement effects' value. This paper presents a new method for the ripple effect and preliminary ripple effect consequence using a time series analysis and inter-industry table. This ripple effect analysis techniques can be applied to effect expectation analysis as well as other type reactor's ripple effect analysis including VHTR for process heat.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제57권7호
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• pp.1218-1222
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• 2008

We investigate the effect of rise time of a pulse bias voltage on atmospheric plasma generation. With the faster rise time of the pulse bias, the glow discharge appears to be more uniformly generated along the electrodes. I-V measurement confirms that higher loading power can be obtained using the faster rise time. A new understanding for atmospheric plasma generation at a micro-gap electrode is suggested.

• Journal of the Korean Society of Tobacco Science
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• 제6권1호
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• pp.13-18
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• 1984

To find out the effect of transplanting time on the autonomic characters, yield of cured leaves and content of polyphenols in burley tobacco, three transplanting time were evaluated. The results obtained are as follows. Low temperature which was caused damage earliest stage of tobacco in early transplanting could escape by vinyl mulching and other treatment. 2. The major polyphenols in leaves were chlorogenic acid and rutin, small amount of scopolin and quercetin were also detected. 3. Chlorogenic acid decreased during curing. 4. Polyphenols content was not influenced by transplanting time.

• Proceedings of the KIEE Conference
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1236-1238
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• 1999

This paper presents an effect of cross magnetization to the generator simplified linear model which is used for multi-machine power systems. The formulae of reactances and time constant with saturation effect are presented. The simulation results show that cross magnetization has an effect which can not be ignored, to the reactances, time constant and eigenvalues in one machine infinite bus system of simplified linear model.

• YAKHAK HOEJI
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• 제27권2호
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• pp.163-168
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• 1983

The effect of ginseng butanol fraction (total sponin) on the absorption rate of ethanol in rat intestine was examined. Ginseng butanol fraction showed inhibitory effect on the intestinal absorption of ethanol in situ as well as in vitro test. Ginseng butanol fraction markedly decreased the ethanol blood level, delayed onset time of ethanol effect and shortened sleeping time when it was adminstered orally together with ethanol. These results suggest that ginseng may alter the ethanol blood level by decreasing the intestinal absorption of ethanol.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.28.1-28.12
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• 2023

Background: Owing to the coronavirus disease 2019 pandemic, being exposed to work from home and work during nonwork time simultaneously can lead to sleep disturbance; however, their combined effect is unclear. We aimed to investigate the combined effect of work from home and work during nonwork time on sleep disturbance. Methods: This study used data from the Sixth Korean Working Condition Survey and included 27,473 paid workers. Logistic regression analysis was conducted to investigate the relationship between work from home, work during nonwork time, and sleep disturbance according to sex. We re-classified participants into 4 groups based on their working from home (No/Yes) and working during nonwork time (No/Yes). The relative excess risk due to interaction was calculated to examine the effect of exposure to both telecommuting and non-regular work hours on sleep disturbance. Results: Workers exposed to work from home and work during nonwork time had significantly higher risks of sleep disturbance for all, men, and women workers (OR [95% CI]: 1.71 [1.46-2.02], 1.79 [1.43-2.23], and 1.64 [1.29-2.08] for work from home and 3.04 [2.70-3.42], 3.61 [3.09-4.22], and 2.41 [2.01-2.90] for work during nonwork time, respectively). Compared to those who were not exposed to both factors, when workers had both job factors, the ORs (95% CI) of sleep disturbance for all, men, and women were 3.93 (2.80-5.53), 5.08 (3.21-8.03), and 2.91 (1.74-4.87), respectively. The relative excess risk due to interaction of work from home and work during nonwork time was not significant for sleep disturbance. Conclusions: Work from home and work during nonwork time were each associated with sleep disturbance, but the interaction between the two factors on sleep disturbance was not observed in both men and women.

• Journal of Embryo Transfer
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• 제11권3호
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• pp.225-231
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• 1996

This study was conducted to investigate the effects of preincubation time, concentration and exposure time of sperm on in vitro fertilization of porcine follicular oocytes rnatured in in vitro. The results obtained are as follows ; 1. Effect of preincuhation time for porcine sperm capacitation on in vitro fertilization in medium with heparin was investigated. Normal fertilization rate was highest in 15 min(26.4%). However, there were no significant differences among preincuhation times of 5~90 min, 2. Normal fertilization rates of sperm concentrations were 17.0~26.5%, and normal fertilization rate from l$\times$ l05cell /ml concentration was also higher than those of other sperm concentration. 3. Normal fertilization rates of sperm exposure time of 4, 8, 12, 16 and 20 hours were 6.1, 20.8, 27.8, 25.0 and 26.7%, respectively. Normal fertilization rate from sperm exposure time of 12 hours was also higher than that of other sperm exposure times.

• Journal of Information Technology Services
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• 제21권4호
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• pp.1-26
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• 2022

Recently, the number of cases of purchasing food online has been increased, especially in the open market. Therefore, we examined the characteristics of status quo bias and switching costs in the open market. Also, in this study, the causal relationship between the characteristics of status quo bias and switching costs, switching costs and switching intention in the open market was investigated. The analysis result consists of four parts as follows. First, in the open market, rational decision making, which belongs to the characteristics of status quo bias, was found to have a positive (+) effect on time switching cost among switching costs, but did not have a positive (+) effect on economic and psychological switching cost. Second, cognitive misperceptions was consistent with the assumption that it have a positive (+) effect on all of the economic, time, and psychological switching cost, which are switching costs in the open market. Third, psychological commitment was found to have a positive (+) effect on economic and time switching cost among switching costs, but did not have a positive (+) effect on psychological switching cost. Fourth, psychological switching cost, which belongs to switching costs in the open market, was found to have a negative (-) effect like the hypothesis set in switching intention. However, it was found that economic and time switching cost did not have a negative (-) effect on switching intention. This study subdivided the switching costs into three dimensions and compared the degree of influence on the switching intention, and the degree of influence was different for each dimension. Therefore, it was found that when switching from the existing open market to the new open market, it is not possible to simply judge that the switching costs directly has a negative (-) effect on the switching intention or does not.

• Transactions on Electrical and Electronic Materials
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• 제16권2호
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• pp.99-102
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• 2015

Thin film transistors (TFTs) with amorphous 2 wt% silicon-doped zinc tin oxide (a-2SZTO) channel layer were fabricated using an RF magnetron sputtering system, and the effect of post-annealing treatment time on the structural and electrical properties of a-2SZTO systems was investigated. It is well known that Si can effectively reduce the generation of oxygen vacancies. However, it is interesting to note that prolonged annealing could have a bad effect on the roughness of a-2SZTO systems, since the roughness of a-2SZTO thin films increases in proportion to the thermal annealing treatment time. Thermal annealing can control the electrical characteristics of amorphous oxide semiconductor (AOS) TFTs. It was observed herein that prolonged annealing treatment can cause bumpy roughness, which led to increase of the contact resistance between the electrode and channel. Thus, it was confirmed that deterioration of the electrical characteristics could occur due to prolonged annealing. The longer annealing time also decreased the field effect mobility. The a-2SZTO TFTs annealed at 500℃ for 2 hours displayed the mobility of 2.17 cm²/Vs. As the electrical characteristics of a-2SZTO annealed at a fixed temperature for long periods were deteriorated, careful optimization of the annealing conditions for a-2SZTO, in terms of time, should be carried out to achieve better performance.

• Journal of Korean Society on Water Environment
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• 제22권4호
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• pp.639-647
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• 2006

The temperature effect at $20^{\circ}$ and $10^{\circ}$ on the nutrient removal efficiency was evaluated in the combined biological nutrient removal system (CBNR) with anaerobic-intermittent aerobic-oxic reactors. The test was conducted under the conditions of various ratios of intermittent aeration time and distribution of influent raw water to CBNR. The removal efficiencies of organics, nitrogen and phosphorus were a little bit better at $20^{\circ}$ than at $10^{\circ}$. However the large difference of temperature effect on the nutrient removal efficiency between $20^{\circ}$ and $10^{\circ}$ was not appeared because of highly sustained MLSS concentrations in the reactors and controlled intermittent aeration time. In the removal of phosphorus, Mode III (50/70 min in aeration on/off time, 3 times of intermittent aeration) showed more effective compared with short aeration time of Mode IV. In case of N, P removal, the denitrification rate was lower in Mode A with splitted inflow into anaerobic and intermittent aeration basins than in Mode B with sole inflow into anaerobic basin.