• Proceedings of the Population Association of Korea Conference
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• 2006.12a
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• pp.59-87
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• 2006

This paper explores the effects of the 1997 economic crisis on the pattern of socioeconomic differentials in fertility. Based on analysis of data from the 2003 Korea National Fertility Survey, this study focuses on recent changes in the level of fertility according to socioeconomic status of the couple including educational level, occupation, working status, income, etc. Results reveal that the level of fertility of those with the highest education, most prestigious occupation, and employer status are higher than those of the next group in the socioeconomic hierarchy. These findings imply that the straight line inverse pattern of socioeconomic differentials in CEB yielded to a reversed J-shaped curve. However, recent differentials of fertility after the economic crisis were found to contrast with the pattern above. Decrease in fertility has been most drastic among those with a high level of fertility, and relatively slow for those with a low level of fertility. The level of recent fertility turns out to be highest among those with upper-middle socioeconomic status, followed by those with the highest socioeconomic status and those with the lowest status. Policy implications and some comments on current population policies of the Korean government are also presented in this paper.

• Plant Journal
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• v.10 no.1
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• pp.47-53
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• 2014

The national capacity of electricity of Korea was 81,737 MW and the peak demand was renewed by the record of 71,230 MW in 2012 which has been increasing since the first lighting ceremony had taken place in the Royal Palace(Kyung-Bok Goong) in 1887. Aa the counteract on the rapid increasing of the demand, Korean government is constructing and operating the high capacity nuclear and thermal power plants, however, the operating reserve on weekdays is small while those of weekends are more than 40% of capacity, so they are providing the pumped-storage power plants with the surplus electricity during weekends and operating the power plants which cost higher production price and located in the capital area with WSS (Weekly Start and Stop) mode including the Seoul Thermal Power Plant. Since the Seoul Thermal Power Plant is spending huge amount of expenses for more than 30 times of the WSS annually due to the high production cost even though it is in Seoul, the core of the demand, I chose the power plant unit #5 which was on the grid in 1969 for the case to confirm reducing 23% of the warm start-up time by applying the "Start-up time management program", and that reducing 35% of the water temperature increasing time by accelerate the increasing rate of the inlet temperature of the water circulating pump.

• Food Science and Preservation
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• v.22 no.6
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• pp.811-816
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• 2015

The purpose of this study was to determine the optimum amount of Artemisia annua L. powder for adding rice flour. The A. annua powder was added to the rice flour at ratios of 1% (30 g/3 kg), 2% (60 g/3 kg), 3% (90 g/3 kg, w/w). As the amount of A. annua powder in rice cake dough increased, carbohydrate, ash content, total amino acid, and dietary fiber contents increased whereas the moisture content decreased. Hunter's L value decreased as A. annua powder content increased. On the contrary, the a- and b values increased. The sensory score of the rice cakes containing 30 g of A. annua powder was the highest of all the rice cakes tested. Based on these results, adding A. annua powder could improve the quality and sensory characteristics of rice cake.

• Clean Technology
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• v.14 no.2
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• pp.123-128
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• 2008

The waste solution, which was discharged from the recovery process of LCD etching solution, consists of 15 wt% nitric acid and 20 wt% acetic acid. In this study, it was conducted to separate acid individually from the mixed acid by vacuum evaporation under -760 mmHg gauge and at $40^{\circ}C$. We have investigated evaporation behavior of acid as a function of temperature. There have been problems that tiny amount of nitric acid were evaporated simultaneously above $33^{\circ}C$. Thus, efforts were conducted to recover acetic acid by vacuum evaporation with adding $H_2O$, waste mixed acid and 20 g/L NaOH for a curb on evaporation of nitric acid. By adding $H_2O$, evaporation of nitric acid was reduced from 7% to 0.78%. However, it was reduced from 7% to 0.25% by adding mixed acid. In view of the results achieved so far, we may expect to separate the etching solution individually by controlling vacuum conditions.

• Journal of dental hygiene science
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• v.12 no.3
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• pp.271-277
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• 2012

This study aims to figure out the effects of dental hygienists' professionalism and self-efficacy on job satisfaction using structural equations. This research conducted a survey to 616 study subjects. According to the analysis using SPSSWIN 18.0 and AMOS 20, the results are as follows : 1. It was shown that the dental hygienists' professionalism gained 3.34 points, self-efficacy was 3.76 points, and job satisfaction received 3.36 points. 2. It was found that as their age was higher, educational degree was higher, they were married, and working experience was more, their professionalism, self-efficacy, and job satisfaction were higher, which showed statistically significant difference. 3. Regarding the study model, there was positive effect as the correlation coefficient of professionalism and self efficacy was .69, that of professionalism and job satisfaction was .33, that of self-efficacy and job satisfaction was .59. In other words, there was correlation between professionalism and self-efficacy. When self-efficacy was higher than professionalism, job satisfaction also increased. Job satisfaction is affected by various environments within an organization and each individual's internal factors. The reason why job satisfaction is important is that along with the medical service quality and productivity, it is also associated with dental hygienists' individual life quality. In order to cope with this changeful time, it is needed for an organization to make efforts for change to enhance dental hygienists' job satisfaction, and also it is necessary to make endeavors so that dental hygienists can have confidence in their job and their professionalism and self-efficacy can be improved.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.1-8
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• 2015

To identify the satisfaction level towards Gwangju regional TV broadcasting company's program, "I Like the Market" and the effect of market vitalization on the market merchants' public relationships, this study carried out survey targeting 256 merchants who are residing at the region. The research results demonstrated that the satisfaction level towards the program and market vitalization via the program exert significant effect on the public relationships. Specifically, satisfaction level towards the program for the vitalization of regional broadcast exert effect in the following order; devotion, relationship and reliability. Meanwhile, market vitalization exert positive effect on the relationship, reliability and devotion, in the order mentioned. This implies that the development of quality program for the regional residents plays an important role in the convergence of regional broadcast and in increasing broadcasting company's brand image. Accordingly, positive interaction via regional vitalization when it comes to the formation of regional broadcast program going forth may be needed for regional broadcast policies.

• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1075-1082
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• 1999

Composite air electrodes of 50/50 vol% LSM- YSZ where LSM =$\textrm{La}_{1-x}\textrm{Sr}_{x}\textrm{MnO}_{3}$(0$\leq$x$\leq$0.5) were prepared by colloidal deposition technique. The electrodes were then examined by scanning electron microscopy (SEM) and studied by ac impedance spectroscopy in order to improve the performance of a solid oxide fuel cell (SOFC). Reproducible impedance spectra were confirmed by using the improved cell, consisting of LSM- YSZ/YSZ/LSM-YSZ. These spectra were a strong function of operating temperature and the stable conditions for the cells were typically reached at $900^{\circ}C$. The typical spectra measured for an air//air cell at $900^{\circ}C$ were composed of two arcs. Addition of YSZ to the LSM electrode led to a pronounced decrease in cathodic resistivity of LSM-YSZ composite electrodes. Polishing the electrolyte surface to eliminate the influences of surface impurities could further reduce cathode resistivity. The cathodic resistivity of the LSM-YSZ electrodes with catalytic interlayer (Ni or Sr) was much smaller than that of LSM-YSZ electrodes without catalytic interlayer. In addition, the cathodic resistivity of the LSM-YSZ electrodes was a strong function of composition of electrode materials, the electrolyte geometry, and applied current.

• Korean Journal of Materials Research
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• v.10 no.12
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• pp.845-852
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• 2000

Mesoporous ${\gamma}-Al_2O_3$ has been prepared by selective leaching of silica from calcined domestic kaolinite. From XRD and TG-DTA data, it was found that the microstructure of a spinel phase, consisting of ${\gamma}-Al_2O_3$ containing a small mount of amorphous silica, was obtained by calcining kaolinite samples at around $1000^{\circ}C$ for 24h. Porous ${\gamma}-Al_2O_3$ was prepared by selectively dissolving the amorphous silica in KOH solutions of 1~4M at temperatures of $25~90^{\circ}C$ for leaching time of 0.5~4h. In the case of the ${\gamma}-Al_2O_3$ obtained upon KOH treatment of 4M at $90^{\circ}C$ for 1h, it showed a very narrow unimodal pore size distribution, and also formed much mesopore at a diameter of around $40~80{\AA}$. The specific surface area was $250\textrm{m}^2/g$ and the total pore volume was $0.654\textrm{cm}^3/g$.

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.39-42
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• 2017

E-glass (electrical glass) fiber is the widely used as a reinforced composite material of PCBs (printed circuit boards). However, E-glass fiber is not stable because it has a dielectric constant of 6~7. On the other hand, D-glass (dielectric glass) fiber has a low dielectric constant of 3~4.5. Thus, it is adaptable for use as a reinforcing material of PCBs. In this study, we fabricated D-glass compositions with low dielectric constant, and measured the electrical and optical properties. In the glass composition, the boron content was changed from 9 to 31 wt%. To confirm the dependence of the dielectric constant on melting properties, D-glass with 22 wt% boron was melted at $1550^{\circ}C$ and $1650^{\circ}C$ for 2hrs. The glass melted at $1650^{\circ}C$ had a lower dielectric constant than the glass melted at $1550^{\circ}C$. Therefore, the D-glass with boron of 9~31 wt% was fabricated by melting at $1650^{\circ}C$ for 2hrs, and transparent clear glass was obtained. We identified the non-crystalline nature of the glass using an XRD (x-ray diffractometer) graph. The visible light transmittance values depending on the boron contents were measured and found to be 88.6 % ~ 82.5 %. Finally, the dielectric constant of the D-glass with 31 wt% boron was found to have decreased from 4.18 to 3.93.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.184-205
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• 2019

Buddhism was introduced to Gyeonggi-Do early on and thus created various types of Buddhist culture there. Since the introduction of Buddhism into Gyeonggi-do, the there has been continuous construction of stone stupas. More stone stupas were built in southern Gyeonggi than in northern Gyeonggi-do. In particular, Anseong, Icheon, Yongin, and Yeoju were centers of construction. Looking at the characteristics of each period, stone stupas remain from the Unified Shilla Period to Joseon, indicating that stone stupas were steadily built during this period. The stone stupa corresponding to the Unified Shilla Period is meaningful in that it shows the northern limit of Shilla Buddhist culture. Since then, the stone stupas of the Goryeo Dynasty were actively constructed in the southern part of Gyeonggi-do in the early Goryeo Dynasty. By the late Goryeo Dynasty, the stupas were built throughout Gyeonggi-do, indicating that the construction of the stupa was active. In the Joseon Dynasty, stone stupas were built in temples near Hanyang and deeply related to the royal family. Stone pagodas were erected mainly on major traffic routes. Stone stupas built in Gyeonggi-do have a variety of artistic and historical significance.