• The Korean Journal of Applied Statistics
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• v.22 no.5
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• pp.981-993
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• 2009

It would cause a serious problem in the panel data when panel attrition is concentrated on certain socioeconomic groups. Using the GOMS, this study investigates whether there exists non-random attrition bias in the data and seeks for feasible solutions to minimize the bias. The results of logit analyses show that panel attrition in the GOMS results mainly from surveying system but not from the surveyed. Therefore, the result suggests to develop well-organized management skill and systems as well as to construct weighting methods.

• The Journal of the Korean dental association
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• v.54 no.11
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• pp.840-849
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• 2016

The purpose of this study was to examine dental care utilization and expenditures among children aged 0 to 19 years using Korea Health Panel Survey (KHPS) data in 2008 - 2013. Weighted estimates were nationally representative and statistical significances were analysed by $x^2$ test or adjusted Wald test using STATA 13 software. While dental care utilization increased steadily among children from 2008 through 2013, less than one-third the children received dental care in 2013. Compared with 2008, the proportion of restorative care, oral surgery, preventive care decreased and the proportion of orthodontic care, prosthetic care increased. While the proportion of amalgam markedly decreased, the proportion of resin increased. This study highlight socioeconomic disparities in dental utilization and expenditures among children. Especially the findings provide a baseline assessment for examining trends on dental care for children in the future.

• Survey Research
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• v.11 no.1
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• pp.107-121
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• 2010

The purpose of this paper is to design and implement a Computer Assisted Personal Interviewing (CAPI) system for Panel Survey of Employment for the Disabled (PSED) using Blaise software developed by Statistics Netherlands which is a powerful and flexible system used for computer-assisted survey processing. CAPI system for PSED is consisted of three parts, which are survey management program, electronic questionnaire program, and postprocessing program. These programs are constructed with modular approach and are integrated into CAPI system. The developed software is highlighted in its reusability which results in the improved efficiency and reduced cost of software maintenance. CAPI system for PSED proved its effectiveness in carrying out the survey by guaranteeing correctness of survey data, improved timeliness of survey, easy reforming the questionnaires, easy control on the interviewers, and rapid data processing in spite of the complexity of PSED.

• Survey Research
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• v.9 no.3
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• pp.71-91
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• 2008

Workplace Panel Survey(WPS) is the representative panel survey of workplace in Korea. WPS was newly sampled in 2005 and is to be used for the subsequent biennial survey. The main survey is divided into a questionnaire for human resources(HR) manager, a questionnaire for labor relations manager and a questionnaire for representatives of unions. The population of WPS 2005 included workplaces across the country with 30 or more employees. The WPS 2005 was composed of 1,905 workplaces including 290 workplaces in the public sector. The sample was selected by the stratified random sampling. Weighting process for the survey data was introduced to compensate for differential sampling and non-response rates. Personal interviews were conducted using the Computer Assisted Personal Interviewing(CAPI) system during visits by interviewers, along with survey via mail and e-mail concerning employment and financial issues. The CPAI system introduced for the WPS 2005 can by used for automatical detection for errors and inconsistencies which may occur during the survey process. The CAPI system played an important part in enhancing the reliability of the survey data.

• The Korean Journal of Applied Statistics
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• v.32 no.3
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• pp.375-389
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• 2019

Sample attrition according to a long-term tracking reduces the representativeness of the sample data in a panel study. Most panel surveys in South Korea and other countries have prepared response adjustment weights in order to solve problems regarding representativeness due to sample attrition. In this paper, we divided the panel data into continuous response group and non-continuous response group according to response patterns and considered a weighting adjustment method to reduce the bias of the non-continuous response group. A simulation indicated that the proposed composite estimation type weighting method, which reflected the characteristics of non-continuous response groups, could be more efficient than other weighting methods in terms of reducing non-response bias. As a case study, the proposed methods are applied to the Korean Longitudinal Study of Ageing (KLoSA) data of the Korea Employment Information Service.

• Survey Research
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• v.11 no.1
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• pp.1-18
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• 2010

We compare various imputation methods for compensating wave nonresponse that are commonly adopted in many panel surveys. Unlike the cross-sectional survey, the panel survey is involved a time-effect in nonresponse in a sense that nonresponse may happen for some but not all waves. Thus, responses in neighboring waves can be used as powerful predictors for imputing wave nonresponse such as in longitudinal regression imputation, carry-over imputation, nearest neighborhood regression imputation and row-column imputation method. For comparison, we carry out a simulation study on a few income data from the Korean Welfare Panel Study based on two performance criteria: predictive accuracy and estimation accuracy. Our simulation shows that the ratio and row-column imputation methods are much more effective in terms of both criteria. Regression, longitudinal regression and carry-over imputation methods performed better in predictive accuracy, but less in estimation accuracy. On the other hand, nearest neighborhood, nearest neighbor regression and hot-deck imputation show higher performance in estimation accuracy but lower predictive accuracy. Finally, the mean imputation shows much lower performance in both criteria.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.345-348
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• 2008

In this paper, we investigated a dust pollution and spot survey of electrical installation in vulnerable area. From the survey results, we know that the dust was easily accumulated in cabinet panel because the cabinet panel cover was opened and the management of installation was not good. Although the dust pollution was not difference, the possibility of accident become increased by dust in salt area. Thus, it is necessary to variation of cabinet panel shape to prevention of electrical disaster in dust occurrence and another protection devices.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.729-742
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• 2016

The purpose of this study is to investigate the influence of parenting and peers on youth engagement to pornography media, the fourth year data of the fourth-grade panel (first year at middle school) and the fourth-year data of the eighth-grade panel (first year at high school) were analyzed. The number of cases investigated for this panel study were 2,378 subjects among the fourth-year panel of the fourth grade and 2,361 subjects among the fourth-year panel of middle schoolers. But this study, the total of 720 subjects that the response were made in the pornography items are analyzed. The result of this study reveals that male students were more likely to be addicted to pornography than female students. Also, inconsistency and excessive intervention among the parenting attitudes and peer attachment and numbers of delinquent friens among the peer factors were shown to have influence on youth addiction to pornography. Based on such results, a proposal that a plan to increase the parental education and strengthen peer relationships is important ahead of the Controlled intervention in the meantime was made.

• The Korean Journal of Health Service Management
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• v.10 no.1
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• pp.131-142
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• 2016

Objectives : Using several waves of the Panel Study of Worker's Compensation Insurance(PSWCI), this study analyzed the effect of work hours on health and lifestyle of Korean workers in a sample from the 2013~2014 year (The first survey was completed in August-October 2013; the second survey was completed in August-October 2014). Methods : The research subjects were 1,312 men from among employees who responded to a 2013 PSWCI panel report. Statistical analyses were done with SAS version 9.3 (SAS Institute Inc., Cary, NC, USA). Results : According to the results of the analysis, the male subjects had differences in economic activity and health conditions based on the length of working hours. There was a significant relationship among working hours and life satisfaction, and the correlation coefficients were statistically significant. The results show that workplace conditions has a direct positive effect on life satisfaction as we anticipated in the hypothesis. Conclusions : Management should focus on the factors identified in this study when developing employment interventions programs to improve the the promotion of healthy lifestyles for adults over the age of 40.

• The Journal of the Korean dental association
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• v.52 no.5
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• pp.291-301
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• 2014

Korea Health Panel Survey (KHPS) has been conducted to provide nationally representative estimates of health care use and expenditures for non-institutionalized population in Korea since 2008. The aim of this study was to present estimates from KHPS on dental utilization and expenditures from 2008 to 2011. While weighted estimates were presented for each year from 2008 to 2011, the focus of this study was on the 2011 estimates and changes in dental utilization and expenditures between 2008 and 2011. Weighted estimates were obtained using population weights and statistical significances were analysed by independent t-test or ANOVA test using SPSS version 20 for Windows. In 2011, 21.1% of Korean population obtained outpatient dental services from dentists. From 2008 to 2011, the percent of people with a dental visit in each year increased slightly. In 2011, the mean number of dental visits was 4.46. While the mean number of dental visits remained stable by 2010, it increased slightly in 2011. The total annual dental expense in 2011 for people with a visit was about 460,000 Korean Won and 10% higher in 2008. In summary, this study results highlight low rates of dental utilization and high dental expenses in Korean population.