• 한국노년학
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• v.39 no.3
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• pp.467-484
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• 2019

The purpose of this study is to explore latent classes of longitudinal medical expenses of older people and to analyze its predictors and its effects on subjective health. Among participants of the Korean Health Panel, the sample of this study includes 1,119 people who is 65-year-old or older and reported their medical expenses for nine consecutive years. The analyses were conducted in three steps. First, Growth Mixture Model (GMM) was applied to find distinct subgroups showing similar patterns in medical expenses. The results showed four groups which were classified as high medical expenditure maintenance group, medical expenditure increase group, low medical expenditure maintenance group, and medical expenditure reduction group. Second, the multinominal logistic regression found that the presence of spouse, economic participation, the number of chronic diseases, and the type of health insurance were significant predictors of latent classes in medical expenses. In particular, the greater the number of chronic diseases, the higher the likelihood of belonging to the high medical expenditure maintenance group. In addition, medical benefit recipients are more likely to belong to the low medical cost maintenance and medical cost reduction groups. Third, multiple regression analysis revealed that the older people in the groups with low or reducing expenses reported better subjective health than people with higher expenses. This study has its meanings in exploring the heterogeneity in longitudinal medical expenses among older people and its predictors and its associations with health outcome. The results of this research provide background information in establishing public health policy for older people.

• International Commerce and Information Review
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• v.11 no.2
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• pp.173-201
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• 2009

As a result of overemphasizing the goods sector in trade structure, Korea does not meet properly the global trend which has the key role of 'trade in services' as the service economy have been expanded. Hereafter, it is easily forecasted that trade in services will be one of the main factors for Korea's competitiveness and engine of growth. Nevertheless, because Korea does not equip the concreteness of governance for trade in services, it is possible that the efficiency deterioration of trade volume, confusion of Korea's trade policy, conflict among trading countries, and discordance between the interested parties may be occurred. This paper analyzes the governance system of Korea for trade in services in order to enhance the competitiveness reflecting the importance of trade in services and to draw some strategies for remodeling the service governance system. It is expected to raise the efficiency of Korea's trade policy by constructing the systematic governance for trade in services, and to remove lots of latent risks during global transactions by improving the imbalance between manufacturing and service part for the development of trade in services in Korea. Analysis revealed itself the result that Korea is weak enough to can not identify the governance system about trade in services. Except 'Extent of Services' article of the Foreign Trade Act, Korea has not prepared the governance system for trade in services so that governance system have been scattered overly or decentralized. Problems about trade in services are not limited to enterprise's side, but extended to all the players including government agency whole, academic world and research institute. Therefore, the governance of trade in services should be strengthened and systematized by making the model law for trade in services(provisional name : Master Law for Trade in Services or Promotion Law for Trade in Services) by formatting type of fundamental law or separate legislation. If the bill legislation does not meet the conditions, the Foreign Trade Act should be totally reformed to Omnibus Trade Act concept including trade in services.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.100-106
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• 2022

A longitudinal study refers to a research method based on longitudinal data repeatedly measured on the same object. Most of the longitudinal analysis methods are suitable for prediction or inference, and are often not suitable for use in exploratory study. In this study, an exploratory method to analyze longitudinal data is presented, which is to find the longitudinal trajectory after determining the best number of clusters by clustering longitudinal data using self-organizing map technique. The proposed methodology was applied to the longitudinal data of the Employment Information Service, and a total of 2,610 samples were analyzed. As a result of applying the methodology to the actual data applied, time-series clustering results were obtained for each panel. This indicates that it is more effective to cluster longitudinal data in advance and perform multilevel longitudinal analysis.

• Korea journal of population studies
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• v.26 no.2
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• pp.63-90
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• 2003

This study aims to discover patterns of Korean women's life course in terms of their life time sequence of family roles and economic activity. Primary factors for the change and diversity of family-work role sequence are also examined. Data used in this study is the Fourth Survey of Korean Women's Economic Activity which was conducted by Korean Institute of Women Development (KIWD) in 2002. According to the main results, five distinctive patterns of life course are to be disentangled for ever married women: First, doing simultaneously family and work roles with no maternal leave (13.7%); second, reentry into labor market after maternal leave (M type, 18.6%); third, no reentry into labor market after maternal leave (latent M type, 26.9%); fourth, first job entry after child rearing (23.5%); and finally, no work experience (17.3%). The relative composition of the respective life course has changed over marriage cohorts. M type including latent M type became a dominant life pattern among married women since marriage cohorts of 1980 and later. The share of married women who begin to work first after maternal role or have no work experience has declined with recent marriage cohorts. It is also noted that the share of women with simultaneous family and work roles has increased among marital cohorts of 1990 and later. Marriage cohort differences being controlled, life patterns significantly differ by women's educational level, existence of role model of working mother at growth, women's own and husbands' gender role attitude, and family economy. Finally, some policy concerns for gender role division of family and work are raised.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.123-132
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• 2016

The importance of energy saving technology for managing greenhouse was recently highlighted. For practical use of energy in greenhouse, it is necessary to simulate energy flow precisely and estimate heating/cooling loads of greenhouse. So the main purpose of this study was to develope and to validate greenhouse energy model and to estimate annual/maximum energy loads using Building Energy Simulation (BES). Field experiments were carried out in a multi-span plastic-film greenhouse in Jeju Island ($33.2^{\circ}N$, $126.3^{\circ}E$) for 2 months. To develop energy model of the greenhouse, a set of sensors was used to measure the greenhouse microclimate such as air temperature, humidity, leaf temperature, solar radiation, carbon dioxide concentration and so on. Moreover, characteristic length of plant leaf, leaf area index and diffuse non-interceptance were utilized to calculate sensible and latent heat exchange of plant. The internal temperature of greenhouse was compared to validate the greenhouse energy model. Developed model provided a good estimation for the internal temperature throughout the experiments period (coefficients of determination > 0.85, index of agreement > 0.92). After the model validation, we used last 10 years weather data to calculate energy loads of greenhouse according to growth stage of greenhouse crop. The tendency of heating/cooling loads change was depends on external weather condition and optimal temperature for growing crops at each stage. In addition, maximum heating/cooling loads of reference greenhouse were estimated to 644,014 and $756,456kJ{\cdot}hr^{-1}$, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.941-951
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• 2015

In the recent years, Korean construction companies have been awarded 680 billion USD in the oversea projects which lead to a successful quantitative growth. However, due to the lack of capability in the core technology and project management compared to the leading companies, in addition to low-price bidding, massive deficit projects have caused problems to the companies. In order to overcome the limitations of the lack of capabilities, the term constructability has been researched recently by developed countries to apply in the practical use. The concept of constructability must be applied for Korean companies to compete in the EPC construction projects. The term constructability is defined as the factor that affect the overall construction process of a project which is defined by the ease of construction and to secure the project quality. Therefore, this study aims to develop a constructability assessment model using the structural equation to assess the factors that affect the constructability in the design and construction stage. The purpose of using the structural equation is to analyze the direct and indirect correlation between each factor that affects the international construction projects. Total of 8 latent variables and 34 measured variables are derived through literature review, corporate reports, experts' interview and surveys. The result of the model suggests the constructability factors that are to be managed the most efficiently to reduce cost, time and improve the quality as well as a countermeasure strategy to successfully execute the target international construction projects.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2533-2539
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• 2012

Annona muricata L (Annonaceae), commonly known as soursop has a long, rich history in herbal medicine with a lengthy recorded indigenous use. It had also been found to be a promising new anti-tumor agent in numerous in vitro studies. The present investigation concerns chemopreventive effects in a two-stage model of skin papillomagenesis. Chemopreventive effects of an ethanolic extract of A. muricata leaves (AMLE) was evaluated in 6-7 week old ICR mice given a single topical application of 7,12-dimethylbenza(${\alpha}$)anthracene (DMBA 100ug/100ul acetone) and promotion by repeated application of croton oil (1% in acetone/twice a week) for 10 weeks. Morphological tumor incidence, burden and volume were measured, with histological evaluation of skin tissue. Topical application of AMLE at 30, 100 and 300mg/kg significantly reduced DMBA/croton oil induced mice skin papillomagenesis in (i) peri-initiation protocol (AMLE from 7 days prior to 7 days after DMBA), (ii) promotion protocol (AMLE 30 minutes after croton oil), or (iii) both peri-initiation and promotion protocol (AMLE 7 days prior to 7 day after DMBA and AMLE 30 minutes after croton oil throughout the experimental period), in a dose dependent manner (p<0.05) as compared to carcinogen-treated control. Furthermore, the average latent period was significantly increased in theAMLE-treated group. Interestingly, At 100 and 300 mg/kg, AMLE completely inhibited the tumor development in all stages. Histopathological study revealed that tumor growth from the AMLE-treated groups showed only slight hyperplasia and absence of keratin pearls and rete ridges. The results, thus suggest that the A.muricata leaves extract was able to suppress tumor initiation as well as tumor promotion even at lower dosage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2537-2547
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• 2015

The aim of this study was to examine the longitudinal effect of Pre-service Teacher Education Program for Children's Creativity. The participants of this study were 67 pre-service teachers in Seoul, Kyungggi-do, and Chungcheong-do, Korea. Thirty-six pre-service teachers were assigned to the control group and pre-service teachers were assigned to the experimental group. Pre-service teacher's creativity was measured in three times. TTCT was applied to measure pre-service teacher's creativity and their children's creativity. Multivariate Latent Growth Model was applied to verify the effect of the program on pre-service teacher's creativity. Also, Multiple Regression was used to examine the effect of the program on their children's creativity. As a result, the participation of the program was longitudinally effective on not only pre-service teacher's creativity development but also their children's creativity. The results of current study suggested that it is necessary to help the pre-service teachers foster their creativity in early childhood teacher preparation program.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.405-409
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• 2017

The purpose of this study is to obtain basic data to be used in social welfare intervention for relieving psychological burdens caused by job stress in the eco-boomer generation that will be the center of Korean society in future, by estimating job stress change trajectories of the eco-boomer generation in the convergence era, figuring out predicting factors and examining job stress factors that individuals experience, in accordance with the degree of job stress and the changes. This is a longitudinal study using secondary data and for analysis, the Latent Growth Model(LGM) was applied to the 1st year to the 7th year Korean Welfare Panel Data. Self-esteem was one of job stress predicting factors of the eco-boomer generation. Since most of eco-boomers were students in the early measurement period, the level of job stress was low, but over time, the burden of job increased by gradation. This study has significance by providing an empirical basis for predicting factors of job stress changes of the eco-boomer generation to understand job stress in the eco-boomer generation.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.433-442
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• 2016

In this study, we examine future changes in surface radiation associated with cloud amount and aerosol emission over East Asia. Data in this study is HadGEM2-CC (Hadley Centre Global Environmental Model version 2, Carbon Cycle) simulations of the Representative Concentration Pathways (RCPs) 2.6/4.5/8.5. Results show that temperature and precipitation increase with rising of the atmosphere $CO_2$. At the end of $21^{st}$ century (2070~2099) relative to the end of $20^{st}$ century (1981~2005), changes in temperature and precipitation rate are expected to increase by $+1.85^{\circ}C/+6.6%$ for RCP2.6, $+3.09^{\circ}C/+8.5%$ for RCP4.5, $+5.49^{\circ}C/10%$ for RCP8.5. The warming results from increasing Net Down Surface Long Wave Radiation Flux (LW) and Net Down Surface Short Wave Radiation Flux (SW) as well. SW change increases mainly from reduced total Aerosol Optical Depth (AOD) and low-level cloud amount. LW change is associated with increasing of atmospheric $CO_2$ and total cloud amount, since increasing cloud amounts are related to absorb LW radiation and remit the energy toward the surface. The enhancement of precipitation is attributed by increasing of high-level cloud amount. Such climate conditions are favorable for vegetation growth and extension. Expansion of C3 grass and shrub is distinct over East Asia, inducing large latent heat flux increment.