• Journal of Technology Innovation
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• v.28 no.1
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• pp.1-30
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• 2020

The government has implemented policies to increase university technology commercialization while supporting university research over time. This paper adopts the neo-institutional theory and examines the effect of change in the government research funds that universities have received overtime on the change in their technology commercialization performance. It also investigates a location (Seoul metro or others) effect on the relationships. Using latent growth curve modeling (LGM), which is widely used for time-varying analysis, this study longitudinally analyzes 138 universities in South Korea over the past nine years from 2009 to 2017. The results indicate that the growth in the annual government research funds that universities attain affects the growth in the economic value of technology transfers. In addition, the relationship is stronger for universities in Seoul metropolitan areas than those in other areas. The relationships are intact with one-year lagging effects. The findings help understand the effectiveness of government R&D policies for promoting technology commercialization.

• Journal of Convergence for Information Technology
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• v.9 no.4
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• pp.78-87
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• 2019

The study examined how job satisfaction and pay level can affect on old salary workers over time using longitudinal data and longitudinal data analysis. The KLoSA 6-period panel data was used which contains alternate year from 2006 to 2016. In addition, Gender and Age is also considered as moderating variables. As result, the initial value and the slope of pay level influenced the initial value and the slope of job satisfaction, vice versa. It implicates the two factors of pay level and job satisfaction are interrelated. Based on the results of this study, limitations and suggestions were discussed for further research.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3227-3238
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• 2018

This study attempts to investigate the trajectories of socio-economic deprivation on the depression trajectories among middle-aged individuals using a latent growth model over the last five years. Using the Korea welfare panel study data ranged from the year 2013 (8th wave) to the year 2017 (12th wave), a sample of 7,437 aged over 40 was selected. Three hypothesis was proposed as follows. Is the trajectory of depression changing over the years? Are the initial values of socio-economic deprivation causally related to the initial values of depression? Are the rates of change in socio-economic deprivation causally related to the rates of change in depression? Results showed that the growth curve of depression tended to decline negatively over the five-year period. As the intial values of socio-economic deprivation increased, so did the initial values of depression move upwards. Finally, as the changes of socio-economic deprivation tended to get larger, those changes of depression also accordingly increased as well. The public policy implications based on the current study were discussed to pay more attention to those middle-aged individuals suffering from socio-economic deprivations.

• The Mathematical Education
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• v.60 no.2
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• pp.191-207
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• 2021

Recently, the number of multicultural families has significantly increased in Korea, and this trend creates a need to understand how successfully students from multicultural families achieve their mathematics learning. To understand and predict the changes in mathematics learning achievement of these students over time, we conducted in this study a latent growth mixture model analysis. The study findings show that the majority (92%) of the students from multicultural families experience a decrease in their mathematics achievement over time as their grade level goes up. It was found, in particular, that female students are likely to have lower initial achievements and rapid decline over time more than male students and that the decline over time was more severe for female students than their male counterparts. The findings of this study convey several implications on the how to support the students from multicultural families. First, the result of this study was different from the outcomes of previous studies that presented the income of the household and the education level of the students' parents as major factors that determine the academic achievement of the students from multicultural families. Furthermore, the study indicates the need for more research to identify variables related to the mathematical achievements of the students from multicultural families and the need to use these research findings to develop public support plans for the students from multicultural families.

• (The)Korea Educational Review
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• v.23 no.1
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• pp.205-230
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• 2017

Drawing on third to fifth wave data from the Longitudinal Study of North Korean Migrant Youths' Education, we examined the longitudinal relationship between social capital of North Korean Migrant Youths and school adjustment using latent growth modeling(LGM). Specifically, we sought to answer the following research questions: Do social capital and school adjustment among North Korean Migrant Youths change over time? Is there a relationship between the changes in social capital and school adjustment among these students? Our LGM results showed that trends in social capital and school adjustment among these students were not fixed but changed over time. While the social capital developed by these students was found to influence school adjustment at the time of its development, it did not continue to influence changes in school adjustment over time. Changes in school adjustment of North Korean migrant youths were affected by changes in social capital. These results suggest that there is room for gradual improvement of school adjustment level by strengthening social capital of North Korean migrant youths.

• Journal of the Korean Regional Science Association
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• v.37 no.1
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• pp.15-27
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• 2021

This study investigates the difference in income trajectories of the working poor and the non-working poor and explains the effects of socio-demographic (marriage, education) and regional (living in large cities) factors on intergroup differences. We use Seoul Survey data collected between 2009-2018 and the latent growth modeling approach. It was found that the trajectory difference between groups was statistically significant. Since 2016, the income gap widened as the income of the working poor stagnated. The three variables included in this model better explained the income trajectory of the working poor compared to the working non-poor. In particular, the change in income growth rate was positively related to whether they live in large cities. This suggests the possibility that living in a large city would act as an economic premium for the working poor. It is necessary to conduct follow-up studies on urban premiums for the working poor.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.230-230
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• 2022

최근 기후변화로 인해 예측이 어려운 국지성 호우가 빈번하게 발생하고 있다. 국지성 호우는 대량의 홍수를 일으켜 유송잡물을 동반한 흐름을 야기할 수 있다. 대량의 유송잡물이 하상에 퇴적되면 통수능을 저하시키기도 하며 식생효과와 마찬가지로 유목주변으로 유속이 증가하면서 세굴현상이 발생하게 되는데, 이는 하상저하를 일으키며 수공구조물의 안정성에 지속적으로 피해를 줄 수 있다. 기후변화는 또한 강우패턴을 변화시켜 식생의 성장과 활착에도 영향을 미치게 된다. 본 연구지역인 내성천 회룡포의 경우, 2015년 대가뭄 발생 이후 식생활착으로 인해 식생대 면적이 증가하고 잇는 상황이다. 이는 연구지역의 흐름과 사주교란 및 하상변동에도 큰 영향을 미칠 것으로 판단되며, 특히 식생의 증가는 유송잡물의 증가를 야기 할 수 있기 때문에 식생과 유송잡물의 영향이 하천에 미치는 영향을 예측하는 연구가 필요할 것으로 판단된다. 따라서 본 연구에서는 2차원 흐름모형인 Nays2D와 입자법기반의 유목동역학 모형을 활용하여 식생과 유송잡물이 하상변동에 미치는영향에 대한 수치실험을 수행하고 결과를 분석하였다. 여기서, 식생의 경우, 식생성장모형을 적용하여 시간에 따라 식생이 성장하여 항력이 증가하는 것으로 가정하였으며 유송잡물의 경우, 하상에 퇴적되는 유송잡물의 개수와 면적만큼 항력이 증가하는 것으로 가정하였다. 흐름의 경계 조건은 일반화된 부정류 수문곡선을 입력하였으며 초기 하도의 형상은 일정한 경사를 가지는 평지로 가정하여 부정류에 따라 하상변동이 발생하는 것으로 모의하였다. 시뮬레이션 결과, 유송잡물보다 식생대 번성이 하상변동에 상대적으로 큰 영향을 주는 것으로 나타났으며, 유송잡물의 경우 국부적으로 퇴적 분포되어 그 주변으로 침식을 일으키는 것으로 나타났다. 또한 유송잡물은 하안의 얕은수역에서 주로 퇴적되었다. 본 연구는 만곡부 하상변동에 대해 식생과 유송잡물을 고려하여 예측모의를 수행한 사례로서, 식생과 유송잡물이 흐름과 하상변동에 미치는 영향을 이해하는데 도움이 될 것으로 판단된다. 또한 이는 추후에 식생을 고려하는 하천관리방안을 수립 시, 식생과 유송잡물의 영향을 물리적으로 설명할 수 있는 근거자료로 제시할 수 있을 것으로 보인다.

• Korean System Dynamics Review
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• v.10 no.1
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• pp.5-32
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• 2009

This paper revisited the key advances on System Dynamics modeling about traditional macro-economic models and economic growth structures, and then tries to elaborate a new model based on the endogenous growth theory that incorporates new growth factors, relevant to knowledge/technology as well as the Environment, into traditional growth models. Accordingly, the new model augments the acceleration and multiplier loops and the balancing ones representing market clearing mechanism with a simple numerical example. The authors thus provides macroeconomic System Dynamics analysts with a milestone to model macro-economic structures reflecting on traditional and cutting-edge theories on sustainable economic growth and general equilibrium modeling.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.56-56
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• 2020

하도식생은 흐름과 유사의 이송에 영향을 주고, 하도의 지형변화를 일으키는데 중요한 역할을 하다. 하도 식생의 밀도가 증가하면, 하안의 안정성이 증가하고 하안침식이 감소하며, 사주의 형상과 거동에 영향을 준다. 또한 하천의 사행발달 및 하천의 지형변화에 영향을 준다. 식생의 성장과 밀도는 홍수 및 하상변동에 의하여 영향을 받으며, 이는 흐름 및 하천의 지형에 영향을 준다. 따라서 본 연구에서는 하도식생에 의한 사행하천의 발달과정을 2차원 수치모형을 적용하여 분석하였다. 하도식생의 생의 성장과 소멸과정을 고려하여 식생밀도를 고려하여 사행하천의 변화 과정을 분석하였다. 초기에 하안침식이 발생하고, 하폭이 증가하였다. 특히, 흐름이 집중되는 만곡부에서 하안침식이 증가하며, 하도의 사행도가 증가하였다(Fig.1(b)). 시간이 증가하면서 만곡부 내측에서 고정사주 내측에서 scroll bar가 발달하며, 만곡부 외측에서는 하안침식이 발생하고, 사행도가 증가하였다. 또한 식생의 침수시간이 감소하고 식생의 성장률은 증가하였다(Fig.1(c)). 식생의 밀도가 증가함에 따라 사행도는 증가하였다. 식생의 밀도가 증가함에 따라,

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.365-369
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• 1998

Theory of the adsorption by a monolayer is extended to the multiple adsorption layers. Though the model used is extremely simple, the adsorption isotherm thus obtained describes well qualitatively the nature of unsaturation adsorptions such as $Br_2$adsorption by the silica gel.