• 상하수도학회지
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• 제18권4호
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• pp.470-479
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• 2004

The experimental conditions and relationships between parameters such as organic matter, aeration volume, aeration time, and precipitation time for the effective treatment of domestic wastewater were investigated. With the batch systems, the adsorption amount of unit microbe was measured with the change of MLSS concentration, precipitation time, and aeration amount. Theoretical adsorption amount of microbes was then numerically formulated by use of a SPSS multiple analysis as follows: $$Y=-0.0106(X_1)+0.07310(X_2)+42.705(X_3)+62.700$$ In this study, the amount of organisms to be removed in the range of MLSS concentration 2,000~4,500 mg/l were examined. In order to investigate the optimal condition of nitrification, the upper water in the biosorption stage was used as the initial experiment water. The results showed that the C/N ratio was 1.5 and the reaction time for the optimal nitrification was 1.5 hr. When the adsorption efficiency for microbe biosorption was 66%, the optimum denitrification efficiency was 83.3%. When the optimum parameters obtained from the batch experiment were applied to the lab-scale operation, the total retention time from the flow-in to flow-out was 10 hours and the removal efficiency was 93.8% for $COD_{cr}$ and 80.9% for TN. For the full-scale operation, the total retention time was 9.0 hours and the removal efficiency was 94.4% for BOD, 89.6% for $COD_{cr}$, 88.0% for TN, and 86.2% for TP.

• 대한화학회지
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• 제67권1호
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• pp.28-32
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• 2023

The reaction conditions optimization, including the temperature of the reaction, amount of catalyst required, and reaction time for the linoleic acids (LAs) and conjugated linoleic acids (CLAs) production by catalytic dehydration of castor oil via saponification was investigated by response surface methodology (RSM). It was confirmed that all three parameters (temperature, time, and amount of catalyst) were influential factors in isolating LAs and CLAs. When the temperature was increased, the iodine value increased, and the reaction time and catalyst amount increased. The optimal reaction conditions were: 240 ℃, 2.2 h reaction time, and 7 wt% catalyst amount. The maximum iodine value reached 156.25 with 91.69% conversion to the essential fatty acids.

• 한국농촌생활과학회지
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• 제9권1호
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• pp.67-78
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• 1998

This study compared the pattern of couples' time-use in rural areas. Wives' and husbands' time spent in household work, leisure, and agricultural labor were compared. In addition, this study examined what factors determine the amount of time of couples spent in such activities. According to the results, in general, the pattern of couple's time-use in rural area was different. Regarding the pattern of time-use, three major results could be mentioned. First of all, husband in rural area spent most agricultural labour time in busy farming season. And then husband spent much time in leisure activities and wife spent in household work. Second, wife spent more time in inactive leisure and husband spent more time in active leisure. Third, husband in rural area spent less time in household work. In particular. they spent less time in female-typed work than male-typed work. To examine what factors determine the extent of time spent in such activities, three theories were employed and tested. According to the results, the models employed in this study were realistic in explaining the amount of time of couple in rural area, and more adjustable wife than husband. In conclusion, a combination of the multidimensional theoretical perspectives used in this study helpfully explains the variation in the amount of time-use of couple in rural area.

• 한국포장학회지
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• 제10권1호
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• pp.1-6
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• 2004

Amount of residual ink solvent on the packaging materials from Korea, Japan and Europe was measured and compared. The amount of packaging materials from Korea was much higher than that of Japan and Europe. To reduce the residual amounts of ink solvent, aging condition of printed packaging materials including aging time and temperature was modified and evaluated. Aging with high temperature and short time ($60^{\circ}C$ and 24 hours) was more effective for reduction of residual amount of ink solvent than that with low temperature and long time. To find out change of reduction pattern of residual amount of solvent according to plastic packaging material, several monolayer and multilayer packaging materials were selected. Among the monolayer packaging materials, the amount of EVOH and PET was lower than that of polyolefin plastic film including PE and PP. PP/EVOH/PET among the selected multilayer film showed the lowest amount of residual ink solvent on food packaging materials. Result of this research revealed that the residual amount of ink solvent can be reduced by proper selection of aging condition with and by appropriate application of mutilayer plastic film.

• 가족자원경영과 정책
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• 제24권3호
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• pp.19-33
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• 2020

The purpose of this study was to investigate whether paid work time desynchronization affected housework time desynchronization. Time slot data from the Korean Time Use Survey data from 2014 was analyzed. This study included 1,475 married couples aged 20 to 59. They were dual-earner couples, heterosexual couples, and both partners worked during the day, either durong the week or on the weekend. The data was analyzed by the following four groups: weekday-husband, weekday-wife, and weekend-husband, weekend-wife. The results demonstrated that as the desynchronization of paid work increased, the desynchronization of time spent on housework in the weekday-husband and weekend-husband groups also increased. Second, the amount of leisure time did not affect the desynchronization of time spent on housework. Lastly, the amount of time that one person spent on housework increased the housework time desynchronization level. In addition, if the family had children who attended primary, middle, or high school-mothers in the weekday-wife group completed more housework. These results demonstrated that paid work time desynchronization might be a way to decrease the amount of time that dual-earner wives' spent housework.

• 가정과삶의질연구
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• 제22권1호
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• pp.139-151
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• 2004

The purposes of this study were to examine the time use on weekdays and weekends by the time amount of each activities and compare time amounts of single parent with that of two parents family. So two methods were applied, one was secondary data analysis ,the other was deep-interview. The major findings of analysis of time use were as follows; 1) Mothers in single parent family used significantly less time amount of household labor and family care than them in two parent family 2) Fathers in single parent family used significantly more time amount of household labor but used significantly less time amounts of family care than them in two parent family And 3) Mothers in single parent family used significantly more time amounts of household labor and family care than fathers in single parent family. The results of deep-interview were as follows; roughly the amounts of household labor time, family care time, leisure time were of little quantity and absence of spouse, family size, family life cycle stage, economic condition, sex role identity, psychological factor maybe seemed important.

• 산경연구논집
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• 제9권8호
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• pp.35-40
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• 2018

Purpose - The purpose of this study is to conduct a monitoring study on the learning process of e-learning contents. This study has two research objectives. First, by conducting monitoring research on the learning process, we aim to explore the implications for content development that reflects future student needs. Second, we want to collect empirical basic data on the estimation of appropriate amount of learning. Research design, data, and methodology - This study is a case study of learner's learning process in e-learning. After completion of the study, an in-depth interview was made after conducting a test to measure the total amount of cognitive load and the level of engagement that occurred during the learning process. The tool used to measure cognitive load is NASA-TLX, a subjective cognitive load measurement method. In the monitoring process, we observe external phenomena such as page movement and mouse movement path, and identify cognitive activities such as Think-Aloud technique. Results - In the total of three research subjects, the two courses showed excess learning time compared to the learning time, and one course showed less learning time than the learning time. This gives the following implications for content development. First, it is necessary to consider the importance of selecting the target and contents level according to the level of the subject. Second, it is necessary to design the learner participation activity that meets the learning goal level and to calculate the appropriate time accordingly. Third, it is necessary to design appropriate learning support strategy according to the learning task. This should be considered in designing lessons. Fourth, it is necessary to revitalize contents design centered on learning activities such as simulation. Conclusions - The implications of the examination system are as follows. First, it can be confirmed that there is difficulty in calculating the amount of learning centered on learning time and securing objective objectivity. Second, it can be seen that there are various variables affecting the actual learning time in addition to the content amount. Third, there is a need for reviewing the system of examination of learning amount centered on 'learning time'.

• 한국수소및신에너지학회논문집
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• 제21권6호
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• pp.507-512
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• 2010

The effect of catholyte to anolyte amount ratio on the electrodialysis cell performance for HI concentration was investigated. For this purpose, the electrodialysis cell was assembled with Nafion 117 as PEM membrane and activated carbon fiber cloth as electrodes. The initial amount of catholyte was 310 g and that of anolyte varied from 1 to 3 of amount ratio. The calculated electro motive force (EMF) increased with time and the increment enhanced as the amount ratio of catholyte to anolyte decreased. The mole ratios of HI to $H_2O$ (HI molarity) in catholyte were almost the same and exceeded pseudo-azeotropic composition for all amount ratios after 2 h operation. The HI molarity continuously increased with time for 10 h operation. The mole ratio of $I_2$ to HI decreased in catholyte but increased in anolyte. The increment of mole ratio of $I_2$ to HI in anolyte rose as the amount ratio of catholyte to anolyte decreased. In case of 1:1 amount ratio, the cell operation was stopped for the safety at approximately 6 h operation, since the mole ratio of $I_2$ to HI reached solubility limit. The cell voltage of the electrodialysis cell increased with time and the rate of increase was high at low amount ratio. This suggests that the amount ratio of catholyte to anolyte not only crucially influences the cell voltage, but also cell operation condition.

• 한국염색가공학회지
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• 제31권1호
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• pp.25-32
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• 2019

The influence of the contact amount of carbon dioxide per unit mass of dyestuff(${\alpha}$) on dyeing uniformity in supercritical fluid dyeing is analyzed in this study. The experiments using a 5L class Pilot Scale dyeing machine is carried out for this study purpose. For a fixed temperature and pressure, the amount of sample and the dyeing leveling time were considered as process variables. The results show that the increase in the amount of the sample causes a higher color difference than the reference sample, and it also increases the amount of residual dye. On the other hand, the color difference tended to decrease with the increase in dyeing time. Based on these results, the correlation between ${\alpha}$ value and dyeing uniformity in supercritical fluid dyeing is obtained.

• 한국의류학회지
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• 제46권5호
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• pp.868-889
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• 2022

Fashion companies are using a big data approach as a key strategic analysis to predict and forecast sales. This study investigated the effectiveness of the past sales, web search volume, information amount, brand promotion, and the advertising endorser on the sales forecasting model. The study conducted the autoregressive distributed lag (ARDL) time series model using the internal and external social big data of a national fashion brand. Results indicated that the brand's past sales, search volume, promotion, and amount of advertising endorser information amount significantly affected the sales forecast, whereas the brand's advertising endorser search volume and information amount did not significantly influence the sales forecast. Moreover, the brand's promotion had the highest correlation with sales forecasting. This study adds to information-searching behavior theory by measuring consumers' brand involvement. Last, this study provides digital marketers with implications for developing profitable marketing strategies on the basis of consumers' interest in the brand and advertising endorser.