• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.110-115
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• 1999

The surface gloss of an injection molded part is one of the most significant point for evaluating the quality of products appearance. The effects of process condition on the gloss of ABS(Acrylonitrile-Butadiene-Styrene) molded part were investigated in this work. The measurements of gloss and morphology on the surface of molded part were carried out with different melt temperature, mold temperature, mold surface roughness, injection pressure and holding pressure. Gloss had a maximum value with melt temperature in the range of 210 to 220 ${^\circ}C$ and with mold temperature 40 to 50${^\circ}C$ and with injection pressure 80~90 MPa, respectively. Melt temperature was shown to have the largest effect on gloss in our work. Gloss was not improved in the region of melt temperature 240${^\circ}C$ above and of mold temperature 60${^\circ}C$ above. It was concluded that the variation of gloss was mainly caused by rubber particles migration under shear stress not by their aggregation or necklace.

• Journal of the Korean GEO-environmental Society
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• v.6 no.4
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• pp.13-26
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• 2005

In this study, research results on organic and inorganic pollutant migration through single and composite liner were summarized. On the basis of these summarized research results, a design program for landfill liner, which can be used to optimize the liner thickness based on the allowable ground water criteria around the landfill subsurface, was developed. A reasonable liner thickness was obtained from the program output results, in the case of the migration of $Cl^-$ ion through a single clay liner. Therefore, the developed program could be used to carry out a preliminary design for landfill liners with respect to organic and inorganic pollutants.

• Journal of the Korean Dietetic Association
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• v.24 no.1
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• pp.75-91
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• 2018

The purpose of this study was to investigate changes in dietary life, lifestyle factors, and stress status of Chinese students who came to study abroad to South Korea. A total of 143 Chinese students were recruited from Seoul Women's University and Wonkwang University in 2013. We used SPSS 20 for statistical analyses in this study. The mean length of residence was 2.9 years for Chinese students. Most subjects aged 20~29 years immigrated to South Korea to obtain an academic degree (bachelor, master, or doctorate). We found a significant decrease in the frequency of eating fruits and vegetables among Chinese students in South Korea after migration. Further, there was a significant increase in fast food consumption and frequency of late-night snacking and eating out. In addition, their preferred beverage changed from soft drink or tea to coffee after migration. Stress level significantly (P<0.05) increased in male students compared to female students. The high stress group watched more TV when eating compared to the low stress group. In addition, there were more students who perceived their health status as bad in the high stress group. Overall results give us useful information for targeting the most vulnerable subjects and planning nutrition intervention programs.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.2
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• pp.88-94
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• 2011

In this paper, we design a 1-kb OTP (Onetime programmable) memory IP in consideration of BCD process based EM (Electro-migration) and resistance variations of eFuse. We propose a method of precharging BL to VSS before activation of RWL (Read word-line) and an optimized design of read NMOS transistor to reduce read current through a non-programmed cell. Also, we propose a sensing margin test circuit with a variable pull-up load out of consideration for resistance variations of programmed eFuse. Peak current through the non-programmed eFuse is reduced from 728 ${\mu}A$ to 61 ${\mu}A$ when a simulation is done in the read mode. Furthermore, BL (Bit-line) sensing is possible even if sensed resistance of eFuse has fallen by about 9 $k{\Omega}$ in a wafer read test through a variable pull-up load resistance of BL S/A (Sense amplifier).

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.4
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• pp.509-516
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• 2019

It is well known that nitroglycerin(NG) may evaporate and migrate from the triple base propellant grains in storage. This physical process makes it double base environment to the CCC(combustible cartridge case) which is based on nitrocellulose(NC) without NG. Meanwhile, it is not appropriate to use diphenylamine(DPA) as a stabilizer for CCC in this double base environment because of incompatibility between DPA and NG. So we estimated the shelf life to study the effect of NG migration from propellant to CCC by following the procedures in the STANAG 4257. And we found out that CCC with ethylcentralite(ECL) has 7.5 years longer shelf life than with DPA, when NG migrates to CCC from triple base propellant grains.

• Journal of Contemporary Eastern Asia
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• v.19 no.2
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• pp.84-103
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• 2020

Spurred by the ongoing globalization, an increase in mobility has diversified migrant categories and strengthened intercultural rapport. Alongside the "traditional" migrants, "White" (Caucasian) individuals are coming into greater focus of migration studies as "lifestyle migrants". Although White migrations are not a new phenomenon, the deep-seated idea of White supremacy continues to play an important role in contemporary intercultural communication, awarding Whites across communities a "cosmopolitan" status of highly educated cultural elites. As such, the focus of this research is on highly skilled White European migrants, on their subjective experiences of integration in Japan, and whether they perceive Whiteness as an obstacle or an advantage in this process, if integration is desired at all. To discern the connection between race and integration, this research investigates the non-White majority society of Japan as it has established racial hierarchies according to the Western models, consequently influencing the status of its contemporary White immigrants. Privileged, yet singled out as racial and cultural role models, White Europeans' integration seemingly becomes nearly impossible. The data obtained in fifteen semi-structured interviews confirms that Whiteness grants advantages when entering the Japanese job market, but remains an obstacle in everyday community integration. European professionals do not feel accepted and abandon efforts to integrate, if such were made, retreating into "cosmopolitan islets" wherein they renegotiate their White European identities.

• Journal of the Korean association of regional geographers
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• v.6 no.2
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• pp.1-19
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• 2000

This study is to investigate and analyze regional patterns of aging in Taejeon Metropolitan city-the overpopulated area of Choong-Cheong Province-by cohort analysis method. According to the population structure transition caused by rapid social and economic changes, Korea has made a rapid progress in population aging since 1970. This trend is so rapid that we should prepare for and cope with aging society. It is not only slow to cope with it in our society, but also there are few studies on population aging of the geographical field in Korea. The data of this study are the reports of Population and Housing Censuses in 1975 and 1985 and General Population and Housing Censuses with 10% sample survey in 1995 taken by National Statistical Office. The research method is to sample as the aging district the area with high aged population rate where the populations over 60 reside among total population during the years of 1975, 1985, 1995 and to sample the special districts of decreasing population where the population decreases very much and the special districts of increasing population in which the population increases greatly, presuming that the reason why aged population rate increases is that non-elderly population high in mobility moves out. It is then verified and ascertained whether it is true or not with cohort analysis method by age. Finally regional patterns in the city are found through the classification and modeling by type based on the aging district, the special districts of decreasing population, and the special districts of increasing population. The characteristics of the regional patterns show that there is social population transition and that non-elderly population moves out. The aging district with the high aged population rate is divided into high-level keeping-up type, relative falling type below the average of Taejeon city in aging progress, and relative rising type above the average of the city. This district can be found at both the central area of the city and the suburbs because Taejeon city has the characteristic of over-bounded city. But it cannot be found at the new built-up area with the in-migration of large population. The special districts of decreasing population where the population continues to decrease can be said to be the population doughnuts found at the CBD and its neighboring inner area. On the other hand, the special districts of increasing population where the population continues to increase are located at the new built-up area of the northern part in Taejeon city. The special districts of decreasing population are overlapping with the aging district and higher in aged population rate by the out-migration of non-elderly population. The special districts of increasing population are not overlapping with the aging district and lower in aged population rate by the in-migration of non-elderly population. To clarify the distribution map of the aging district, the special districts of decreasing and increasing population and the aging district are divided into four groups such as the special districts of decreasing population group-the same one as the aging district, the special districts of decreasing population group, the special districts of increasing population group, and the other district. With the cohort analysis method by age used to investigate the definite increase and decrease of aging population through population transition of each group, it is found that the progress of population aging is closely related to the social population fluctuation, especially that aged population rate is higher with the out-migration of non-elderly population. This is to explain each model of CBD, inner area, and the suburbs after modeling the aging district, the special districts of decreasing population, and the special districts of increasing population in Taejeon city. On the assumption that the city area is a concentric circle, it is possible to divide it into three areas such as CBD(A), the inner area(B), and the suburbs(C). The special districts of increasing and decreasing population in the city are divided into three districts-the special districts of decreasing population(a), the special districts of increasing population(b), and the others(c). The aging district of this city is divided into the aging district($\alpha$) and the others($\beta$). And then modeling these districts, it is probable to find regional patterns in the city. $Aa{\alpha}$ and $Ac{\beta}$ patterns are found in the CBD, in which $Aa{\alpha}$ is the special district of decreasing population and is higher in aged population rate because of aged population low in mobility staying behind and out-migration of non-elderly population. $Ba{\alpha}$, $Ba{\beta}$, $Bb{\beta}$, and $Bc{\beta}$ patterns are found in the inner area, in which neighboring area $Ba{\alpha}$ pattern is located. $Bb{\beta}$ pattern is located at the new developing area of newly built apartment complex. $Cb{\beta}$, $Cc{\alpha}$, and $Cc{\beta}$ patterns are found in the suburbs, among which $Cc{\alpha}$ pattern is highest in population aging. It is likely that the $Cc{\beta}$ under housing land readjustment on a large scale will be the $Cb{\beta}$ pattern. As analyzed above, marriage and out-migration of new family, non-elderly population, with house purchase are main factors in accelerating population aging in the central area of the city. Population aging is responsible for the great increase of aged population with longer life expectancy by the low death rate, the out-migration of non-elderly population, and the age group of new aged population in the suburbs. It is necessary to investigate and analyze the regional patterns of population aging at the time when population problems caused by aging as well as longer life expectancy are now on the increase. I hope that this will help the future study on population aging of the geographical field in Korea. As in the future population aging will be a major problem in our society, local autonomy should make a plan for the problem to the extent that population aging progresses by regional groups and inevitably prepare for it.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.1
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• pp.115-120
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• 2008

Recently, there has been the gradual growth of the public in rural amenities, hobby farming works, much more urbanities, and especially near-retires. However, in spite of popular preference to ruralities, little has been known about their demand on retired rural life. Therefore, this study examined urbanites' attitude to preparatory works for out-migration, preferred residential site condition and life styles in the countryside. For the purpose, data were collected from the survey with the sample of 62 urban trainees who were studying farming technology in department of training on agricultural technology of Korea National Agricultural College, RDA. We carried out the experience farming to candidate with using the abandoned sericultural facilities which are the silkworm rearing house and mulberry fields. The 71% of urban trainees, who answered in this survey, hoped to move into countryside after retirement and to make a monthly income of $1,000 from agriculture. The age distribution of sericulural farmers is about 79% more than that of 60 years old. In the experience farming works. The two candidates made 1,977$ with net income through 32 days worked in spring season. In autumn season, the couple candidates made 1,317$ with net income through 23 days worked. Knowledge of these results will be important to policy-makers and to understand the role that retirement in-migration play in stimulating economic growth of rural agricultural farmers.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.139-145
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• 1986

An improved mothod of assessing fuel status by analyzsis of the fission product in the reactor coolant system is proposed. The release mechanism of specific fission products is established for determination of the coefficients in the equations which relate the radioactivities with the amount of defected fuel. Knock-out and migration models are employed in the formulation of the release mechanism. The influence of the tramp uranium is quantified. Sample calculations were made for KNU 1 reactor system using the I-131 and I-133 concentrations in the primary coolant. The estimated number of defected fuel pins in the third and sixth cycles appeared to be $9.34{\pm}1.13\;and\;0.294{\pm}0.092$, respectively.

• Journal of the Korean Geographical Society
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• v.51 no.6
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• pp.837-851
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• 2016

The growth and development of Gwangyang city was a result of the POSCO Gwangyang Works, and Gwangyang city is one of typical firm citys in Korea. The objective of this study is to identify and examine the change of migration and population structure in Gwangyang city from 2001 to 2010. Since 1981, total number of population of Gwangyang city increased from 78,478 in 1981 to 145,512 in 2010. The population structure by age was changed with population increase since 2001, and 30-40 aging group was 35% of total in 2010. During 2001-2010, the netmigraion showed -2,925 people, however, the number of inmigrants were overtaking the number of out-migrants since 2008. The most common reason of in-migrants was occupation(49.5%). Factors influencing Gwangyang City's population growth and oversupply are the location of POSCO Gwangyang Works and steel-related enterprises, opening and construction of Gwangyang container berth, the related development projects and establishment of Gwangyang Bay Area Free Economic Zone, and the local policies of Gwangyang City connected with these large-scale national projects. As a result, the number of manufacturing-related businesses increased due to various regional development projects conducted in Gwangyang City, and the growth of the business continued to increase due to the increase of younger people and births.