• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.6
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• pp.1439-1449
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• 2015

This study, based on the sociological crime theory, is to examine the relation between urban characteristics and the incidence of crime, helping establish effective crime prevention measures. For doing so, the study employs crime data from the Supreme Prosecutors' Office and socio-demographic data including the regional Statistical Yearbooks -both from 2005 to 2012- to build the study's panel data, and analyzes the panel model on the 16 subordinate districts in the city of Busan. To reduce the incidence of crime and prevent crimes from occurring based on the analysis results, first, prevention measures specific to each region by its attributes are needed rather than general ones; second, new institutional frameworks or policies are required for utilizing accurate crime data; third, interdisciplinary research in which various fields including urban engineering are associated to that of social science is necessary to further the study.

• Korean Journal of Social Welfare
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• v.68 no.3
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• pp.105-125
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• 2016

School absenteeism is considered one of the early predictors of school drop-out and serious delinquency or criminal behavior. The primary goal of the current study was to explore the protective and risk factors related to changing school absenteeism over time based on the ecological-systemic perspective. The data was derived from the Korean Children and Youth Panel Survey (KCYPS) using the 2011 and 2012 survey waves collected from 2,378 elementary school students. Using this data, Panel Fixed Effects Analysis was conducted. Major findings indicated that daily computer usage, parental abuse, school activity attendance, and school grades had an effect on students missing school days over time. Specifically, high levels of computer usage and parental abuse were related to increased school absenteeism, while high levels of school activity attendance and school grades were associated with decreased school absenteeism. These findings emphasized the importance of predictive intervention for children and suggested the need to construct a school absenteeism monitoring system in South Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.1
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• pp.46-56
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• 2018

This paper aimed to identify main factors of community characters, which have an effect on the land surface temperature(LST) change and estimate the impacting coefficient(ratio) of factors in a significant level of statistics. Chungcheongbuk-do province was selected and then partitioned into city and county areas for the sake of convenience of modeling. LST time series data and the community character data were developed based on Terra Satellite MODIS data and collected from the National Statistical Office, respectively. By the cause and effect relationship between community characters and LST, regression coefficients were estimated using a penal model. In a panel modeling, LST and community characters were used as a dependent variable and explanatory variables, respectively. Panel modeling analysis was carried out using statistical package STATA14 and one-way fixed effect model was selected as the most suitable model to evaluate the regression coefficients in the study area. The impacting ratio of LST change by any explanatory variable derived from the regression coefficients of the panel model fixed. Impacting ratios for industrial areas, elevation ${\times}$ building, energy usage, average window speed, non-urban management area, agricultural, nature and environmental conservation, average precipitation were 3.746, 2.856, 2.742, 0.553, 0.102, 0.071 and 0.003, respectively.

• The Korean Journal of Applied Statistics
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• v.35 no.6
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• pp.703-724
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• 2022

Although longitudinal studies mainly produce multivariate longitudinal data, most of existing statistical models analyze univariate longitudinal data and there is a limitation to explain complex correlations properly. Therefore, this paper describes various methods of modeling the covariance matrix to explain the complex correlations. Among them, modified Cholesky decomposition, modified Cholesky block decomposition, and hypersphere decomposition are reviewed. In this paper, we review these methods and analyze Korean children and youth panel (KCYP) data are analyzed using the Bayesian method. The KCYP data are multivariate longitudinal data that have response variables: School adaptation, academic achievement, and dependence on mobile phones. Assuming that the correlation structure and the innovation standard deviation structure are different, several models are compared. For the most suitable model, all explanatory variables are significant for school adaptation, and academic achievement and only household income appears as insignificant variables when cell phone dependence is a response variable.

• KDI Journal of Economic Policy
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• v.27 no.2
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• pp.123-154
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• 2005

Using Korean household data, this paper examines how consumption of durable goods is determined. Previous studies report that the standard Permanent Income Hypothesis (PIH), while being broadly consistent with non-durable goods consumption, provides little explanation for durable goods consumption. In this paper, we consider the (S, s) model as an alternative to the standard PIH. The (S, s) model predicts that, because of fixed adjustment costs, consumers make no adjustment to the durable goods stock until deviation from the optimal level becomes large. When the adjustments are made, the durable goods stock attains the optimal level. In order to test this prediction, we examine the intra-temporal relationship between non-durable goods and durable goods consumption and intertemporal changes in durable goods consumption, using data from the Korean Household Panel Study. The results show that, while the standard PIH is rejected by the data, the (S, s) model is not.

• Journal of Korea Port Economic Association
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• v.35 no.1
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• pp.57-76
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• 2019

This study deals with the determinants of employment productivity of transportation labor, who are the main agents of the transportation industry that has made significant contributions to our country's industrial development. The study selected the determinants of employment productivity using the Korea Labor and Income Panel Study data, and analyzed the effects of various factors using panel logistic regression, panel OLS model, and panel robust regression. The results were as follows. First, a more positive effect was shown when employees held a regular job, had a "high level of education", "joining the labor union" and "experiencing vocational training". Second, in the case of job security, having a "high level of education" and "joining the labor union" showed a more positive effect; further, job security was higher for employees who worked in a "big company" or were "married". Third, in the case of higher income productivity, higher values of "age", "academic ability" and "company size" had a more positive effect, whereas larger values of "education" and "health condition except job training" had a negative one. Fourth, in the case of job satisfaction, "female", "joining the labor union" and having a higher "income" or "job security" led to higher satisfaction and a better "health condition compared to an average person". Further, a higher "overall life satisfaction" and "economic level" led to lower job satisfaction. The analysis of the determinants of employment productivity of transportation business and seeking for improvement plan is expected to improve the employment productivity in the transportation business.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.377-390
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• 2017

When conducting a survey, item nonresponse occurs if the respondent does not respond to some items. Since analysis based only on completely observed data may cause biased results, imputation is often conducted to analyze data in its complete form. The panel study is a survey method that examines changes of responses over time. In panel studies, there has been a preference for using information from response values of previous waves when the imputation of item nonresponses is performed; however, limited research has been conducted to support this preference. Therefore, this study compares the performance of imputation methods according to whether or not information from previous waves is utilized in the panel study. Among imputation methods that utilize information from previous responses, we consider ratio imputation, imputation based on the linear mixed model, and imputation based on the Bayesian linear mixed model approach. We compare the results from these methods against the results of methods that do not use information from previous responses, such as mean imputation and hot deck imputation. Simulation results show that imputation based on the Bayesian linear mixed model performs best and yields small biases and high coverage rates of the 95% confidence interval even at higher nonresponse rates.

• Journal of Digital Convergence
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• v.12 no.7
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• pp.261-266
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• 2014

When the number of parameters in the time series model are diverse, it is hard to forecast because of the increasing error by a parameter estimation. If the homogeneity hypothesis which was obtained from the same model about severeal data for the time series is selected, it is easy to get the predictive value better. Nonlinear time-series panel data for each parameter for each time series, since there are so many parameters that are present, and the large number of parameters according to the parameter estimation error increases the accuracy of the forecast deteriorated. Panel present in the time series of multiple independent homogeneity is satisfied by a comprehensive time series to estimate and to test of the parameters. For studying about the homogeneity test for the m independent non-linear of the time series panel data, it needs to set the model and to make the normal conditions for the model, and to derive the homogeneity test statistic. Finally, it shows to obtain the limit distribution according to ${\chi}^2$ distribution. In actual analysis,, we can examine the result for the homogeneity test about nonlinear time series panel data which are 2 groups of stock price data.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.21-24
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• 2011

본 연구는 기업규모, 장부가치/시장가치 비율, 순이익/주가 비율, 현금흐름/주가 비율, 레버리지 등 기본적 변수를 사용하여 주식수익률에 유의적인 변수를 확인하고자 하였다. 이를 위해 본 연구에서는 횡단면 자료와 시계열 자료를 결합한 패널자료(panel data)를 이용하여 패널자료분석방법으로 연구모형을 실증적으로 분석하였다. 일반적으로 패널자료를 사용하면 Hsiao(2003)가 지적한 바와 같이 표본의 크기를 확대시켜 자유도를 증가시키고 이론적으로 설명변수간 다중공선성(muti-collinearity) 문제를 완화할 수 있다. 실증분석결과에 의하면 기업규모(SIZ), 장부가치/시장가치 비율(B/M), 순이익/주가 비율(E/P), 현금흐름/주가 비율(C/P) 등이 주식수익률의 횡단면적 차이를 설명할 수 있는 유의적인 변수라 할 수 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.181-182
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• 2020

본 연구는 다문화청소년 패널데이터 3차년(2013년)부터 7차년(2017년)까지 패널조사 데이터를 활용하여 다문화청소년의 이중문화수용성이 성취동기에 미치는 영향에 있어 시간의 흐름에 따른 변화를 분석하고자 한다. 이를 위해 잠재성장모형을 이용한 이중문화수용성과 성취동기 간의 상관관계 및 인과적 관계를 규명하는 방법을 적용하였다.