• Journal of vocational education research
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• v.37 no.1
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• pp.119-138
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• 2018

The purpose of this study was to analyze the factors influencing of separation and the time of separation for middle and old aged self-employed workers. The cox proportional hazards model was used in the first survey of KLoSA, 684 persons who were over 40 years old in 2006, using data up to the 5th period of 2014. The main findings of this study are as follows. First, the average duration of job for middle and old aged self-employed workers in 2005 was 15.5years. Of the total 684 workers, 214(31.3%) person was found to have lost their job during survey period. Second, gender, age at start up, and education level have significant effects on job separation of them. When women, when they were older at start up, when they were graduate the university or higher, increased their risk of leaving their businesses. Third, in the characteristic of their work, the type of job and job satisfaction were found to affect to job desertion. When people are engaged in accommodation and food business rather than agriculture and forestry fishery, when the satisfaction of the work is lower, the risk was high. Based on these conlusions, the following implications are suggested. First, it is necessary to establish a support strategy for female middle-aged and old self-employed and older workers who start their own business after their 60s. Second, it is necessary to support them to enter into various fields by utilizing their own aptitude and experience rather than establishing them in industries with low entry barriers. Third, it is necessary to develop policies to help improve job satisfaction in the working environment. In particular, it is necessary to ensure that high educated self-employed workers are satisfied with various compensations by self-employed.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.309-324
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• 2015

In this paper we introduce how to analyze survival data via a SRC-Stat statistical package. This provides classical survival analysis (e.g. Cox's proportional hazards models for univariate survival data) as well as advanced survival analysis such as shared and nested frailty models for multivariate survival data. We illustrate the use of our package with practical data sets.

• Journal of the Korean Data and Information Science Society
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• v.23 no.2
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• pp.257-269
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• 2012

Global crisis expedites the change in the environment of industry and puts small size enterprises in danger of mass bankruptcy. Because of this, domestic small size enterprises is an urgent need of restructuring. Based on the small business data registered in the Credit Guarantee Fund, we estimated the survival probability in the context of the survival analysis. We also analyzed the survival time which are distinguished depending on the types of business in the small business. Financial variables were also conducted using COX regression analysis of small businesses by types of business. In terms of types of business wholesale and retail trade industry and services were relatively high in the survival probability than light, heavy, and the construction industries. Especially the construction industry showed the lowest survival probability. In addition, we found that construction industry, the bigger BIS (bank of international settlements capital ratio) and current ratio are, the smaller default-rate is. But the bigger borrowing bond is, the bigger default-rate is. In the light industry, the bigger BIS and ROA (return on assets) are, the smaller a default-rate is. In the wholesale and retail trade industry, the bigger bis and current ratio are, the smaller a default-rate is. In the heavy industry, the bigger BIS, ROA, current ratio are, the smaller default-rate is. Finally, in the services industry, the bigger current ratio is, the smaller a default-rate is.

• 한국노년학
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• v.37 no.4
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• pp.871-891
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• 2017

The purpose of this paper is to reduce the reverse-causality and overestimate bias of analysis on how health affected middle-aged and elderly worker's early retirement. From the Korean Longitudinal Study of Ageing(KLoSA) panel data, I researched 1,049 people who were 45-52 years old in 2006. To eliminate the reverse-causality problem, I used the health data which is surveyed before retirement. To reduce bias, I controlled the health status when retirees worked. The main results are as follows. First, the worsened health still affects the hazard of early retirement, with reducing the endogeneity problem. Second, chronic illness is one of the strong predictors of early retirement to self-employed, and self-reported bad health is the main health predictor of wage workers. These results give two implications; first, the impact magnitude of the health indicator depends on employment type. Each employment type has different flexibility of working hours. It seems that the flexibility can reduce early retirement hazard with health problems. Self-employed, who has more flexibility of working hours can work until they have to stop working due to the serious health problem or doctor's advice. Second, to promote middle-aged and elderly workers to keep working, the long-term health policy which decreases chronic illness is needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2219-2231
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• 2012

This study conducted to investigate incidence rate and association of serum lipid profiles with incidence of ischemic heart disease. Study subjects consisted of 417,642 adults aged 30 years and over, who underwent physical examination and responded to questionnaire from health examination center of 19 university general hospitals. Hazard ratio of risk factor for ischemic heart disease (IHD) were calculated by Cox's proportional hazard regression model adjusted for ages, BMI and lifestyle (drinking, smoking and exercising). For TC/HDL ratio, hazard ratio of IHD in male increased from 1.21 times to 1.84 times increase with TC/HDL ratio, and that in female also increased from 1.26 times to 1.86 times. For TG/HDL ratio, hazard ratio of IHD in male increased from 1.17 times to 1.49 times increase with TG/HDL ratio, and that in female also increased from 1.42 times to 1.97 times. For LDL/HDL ratio, hazard ratio of IHD in male increased from 1.26 times to 1.82 times increase with LDL/HDL ratio, and that in female also increased from 1.26 times to 1.68 times. In conclusion serum lipid indexes are the significant risk factors for cardiovascular diseases. The higher the concentration of TC, LDL and TG is, the lower the concentration of HDL is, hazard ratio for IHD increased. Ratio of TC/HDL, TG/HDL and LDL/HDL were also verified to be significant risk factors for IHD.

• Journal of Labour Economics
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• v.43 no.2
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• pp.41-74
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• 2020

In this study, using the job history data of the Youth Panel(1-12th year: 2007 ~ 2018) of the Korea Employment Information Service, it is found that characteristics and duration distribution of first jobs of wage and salary worker, and estimated the factors of first job exit by utilizing survival analysis. As a result of the analysis, regular workers are less likely to leave their first jobs than temporary/daily workers. In addition, the group with a high degree of major congruence was found to have a lower chance of leaving the first job than the group with a major mismatch. And the higher the income level, the lower the probability of departure, which shows that the possibility of leaving low-income workers is very high.

• Journal of Korea Planning Association
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• v.54 no.2
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• pp.5-16
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• 2019

The purpose of this study is to analyze the spatial characteristics of business-type-changed parcel in the Hongik-University commercial area, from the view point of commercial gentrification. A commercial gentrification occurs through a business-type-change in a spatial basic unit (microscopic spatial unit such as parcel) of an area which has not been considered in relavent policies and research. So, this study analyzed the spatial characteristics of business-type-changed parcels using the Cox's proportional hazard regression model. The main results of this study are as follows. First, as new developments in the adjacent area occur, the business-type-change probability increases. Second, by the commercial area division, the business-type-change probability is different. Finally, the accessibility is better, the probability is higher. These results could suggest that a consideration of the spatial characteristics form microscopic viewpoint is necessary to understand the commercial gentrification. And these could be used as basic data for a gentrification diagnostic and management system, which can predict gentrification from the view point of business-type-change on the basis of a parcel.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.692-700
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• 2022

This study was conducted to analyze firms' death rate and impact factors on the death of Foreign-invested Companies in Korea which is between 20013 and 2017. Cox Proportional Hazard Model took to conduct on the death impact factors, such as 2 characteristics factors of the firm, and 4 financial characteristics variables, variables, and 4 profitability factors. As a result of the impact factors of Foreign-invested Companies' death the Labour(NE) variables of characteristics firm had negative effects. And the Debt(LB), Operating Profit (OP), and Sales Profit (SP) of the financial characteristics had a negative effect. Other factors did not produce significant results. As a result of an empirically comparative analysis of the mortality rate of foreign-invested companies by the Kaplan-Meier method, it was analyzed that fully owned companies and large enterprises had lower extinction risk and greater sustainable management potential than joint ventures or SMEs.

• Korea Real Estate Review
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• v.27 no.3
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• pp.103-118
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• 2017

Under the ownership pre-sale system in the South Korean apartment market, developers can sell apartment ownerships as soon as they start to construct an apartment complex. In the South Korean apartment market, people call this kind of ownership "Bun-yang right." There is a time difference between ownership sale and apartment completion under the ownership pre-sale system. The pre-completion apartment ownerships can be resold to third parties until the apartment complexes are completed, which is called "Geon-mae" of the Bun-yang right. Using survival analysis, this research analyzed the elapsed time between ownership purchase and resale to a third party using 48,316 apartment units nationwide in the 192 complexes supplied from 2000 to 2016. Specifically, this study analyzed the influence of the real estate policy, contract term, location, apartment complex, and unit characteristics on the elapsed time between ownership purchase and resale to a third party. The empirical analysis revealed that the real estate policy and contract term characteristics have a significant effect on the elapsed time between ownership purchase and resale to a third party. Also, this study confirmed that the product characteristics, such as the location and apartment complex and unit characteristics, have an influence on the elapsed time between ownership purchase and resale to a third party.

• The Korean Journal of Applied Statistics
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• v.28 no.5
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• pp.965-976
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• 2015

Determining relevant variables for a regression model is important in regression analysis. Recently, a variable selection methods using a penalized likelihood with various penalty functions (e.g. LASSO and SCAD) have been widely studied in simple statistical models such as linear models and generalized linear models. The advantage of these methods is that they select important variables and estimate regression coefficients, simultaneously; therefore, they delete insignificant variables by estimating their coefficients as zero. We study how to select proper variables based on penalized hierarchical likelihood (HL) in semi-parametric frailty models that allow three penalty functions, LASSO, SCAD and HL. For the variable selection we develop a new function in the "frailtyHL" R package. Our methods are illustrated with breast cancer survival data from the Medical Center at Chonnam National University in Korea. We compare the results from three variable-selection methods and discuss advantages and disadvantages.