• The Korean Journal of Applied Statistics
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• v.29 no.5
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• pp.873-885
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• 2016

Onions are grown in a few specific regions of Korea that depend on the climate and the regional characteristic of the production area. Therefore, when onion yields are to be estimated, it is reasonable to use a statistical model in which both the climate and the region are considered simultaneously. In this paper, using a spatial panel regression model, we predicted onion yields with the different weather conditions of the regions. We used the spatial auto regressive (SAR) model that reflects the spatial lag, and panel data of several climate variables for 13 main onion production areas from 2006 to 2015. The spatial weight matrix was considered for the model by the threshold value method and the nearest neighbor method, respectively. Autocorrelation was detected to be significant for the best fitted model using the nearest neighbor method. The random effects model was chosen by the Hausman test, and the significant climate variables of the model were the cumulative duration time of sunshine (January), the average relative humidity (April), the average minimum temperature (June), and the cumulative precipitation (November).

• Journal of the Korea Convergence Society
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• v.10 no.7
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• pp.391-397
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• 2019

In 2016, the number of suicides per 100,000 population in Korea was 24.6, which is the highest record of OECD countries. The number of suicide deaths increased with age. Elderly people have a higher risk of completed suicide than any other age group. The purpose of this study was to analyze the panel data of the Korean Welfare Panel Study to identify the factors affecting the suicide of Korean older people. This study analyzed the data of the 11th Korean Welfare Panel Study, which was constructed in 2016. The mean age of the participants was 75.55 years and 37% were man and 63% were women. The annual prevalence of suicidal ideation was 3.4%. The effects of depression(Exp(B)=1.113) and subjective health status((Exp(B)=.767) on suicidal ideation was statistically significant by stepwise logistic regression analysis(Nagelkerke $R^2=.248$). Therefore, for the effective application of suicide prevention program for the older people, assessment of subjective health status and depression screening should be preceded.

• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.429-440
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• 2015

This study was to investigate factors influencing the school adjustment according to gender and body mass index (BMI) of middle school students who participated in the 2nd-wave Korea Children and Youth Panel Study (KCYPS). This study used a crosssectional design with secondary analysis with KCYPS. The variables were parental interest, behavioral problem, aggression, attention problem, somatic symptom, social withdrawal, depression, and academic achievement. The data were analyzed with descriptive statistics, Pearson's correlation coefficients, and multiple regressions. School adjustment was significantly associated with academic achievement high, explaining 11.3~19.1% of the variance in boys. School adjustment was significantly associated with attention problem, explaining 14.9~42.4% of the variance in girls. Factors influencing school adjustment were significantly different according to gender and BMI. To improve the school adjustment, it is necessary to develop gender-specific school adjustment promotion programs according to BMI.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.297-309
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• 2020

This study focuses on the application of the data mining technique logistic regression analysis and decision tree analysis to the domestic public database called Korean Children Youth Panel Survey (KCYPS) to derive a series of important factors affecting the enhancement of life satisfaction of domestic youth. As a result, the general impact factors on life satisfaction for each grade were derived from logistic regression. Using decision tree analysis, we came to conclusions that those factors such as depression, overall grade satisfaction, household economic level, and school adaptation play crucial roles in affecting high school adolesscents' life satisfaction.

• Proceedings of the Technology Innovation Conference
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• 2005.08a
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• pp.168-188
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• 2005

본 연구는 R&D가 경영성과에 미치는 영향에 대해 전기$\cdot$전자산업에 속한 중소기업과 벤처기업을 대상으로, 패널 데이터 (2001$\~$2003년)를 이용하여 실증분석하고, 중소기업과 벤처기업을 비교분석하였다. 실증분석 모델은 기업의 총매출액을 종속변수로 하고, R&D 투자액, 연구원 수, 자본금 총액, 종업원 수, 연구원 수를 제외한 종업원 수를 독립변수로 한 1차 선형함수를 설정하였다. 실증분석모델로는 패널분석 (임의효과모델, Random Effect Model)을 이용하였다. 실증분석 결과 중소기업과 벤처기업의 공통점은 첫째, R&D 인력과 그것을 제외한 종업원수가 경영성과에 대한 영향이 긍정적이라는 점 둘째, R&D 투자액 및 자본금이 기업의 경영성과에 긍정적인 영향을 주고 있다는 점을 들 수 있다. 실증분석 곁과의 차이점은 첫째, 중소기업의 경우 연구소 설립 연수와 기업 설립 연수가 기업의 경영성과와 무상관으로 나타났으나, 벤처기업의 경우 추정결과 1을 제외하면 모두 긍정적이고 유효했으며 둘째, 중소기업의 경우 자산효과와 자본금 효과가 긍정적이고 유효한 것으로 나타났으나, 벤처기업은 자산효과가 유효한 부정으로 나타났다. 따라서 기업은 인적자원의 확보, 육성, 활용 등의 전락에 의해 기업 경영성과가 크게 달라질 수 있고, 중소기업이나 벤처기업의 경우 자산의 팽창보다는 시장 경쟁력 향상을 위한 R&D투자에 좀 더 힘써야 할 것이다.

• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.189-207
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• 2015

The purpose of this study is to examine the relationship between the network characteristics of ports and their performance that is represented by port competitiveness for the port operators. The study employs Social Network Analysis (SNA) to evaluate network characteristics comprising four centrality indices. For this research, data from Containerization International Yearbooks for 2006-2011 is used to analyze the service networks of 20 major liner shipping companies. In SNA, nodes (vertices) in the network are the ports and links (edges) in the network are connections realized by vessel movements, such that the liner shipping network determines the port network. In addition, panel regression analysis has been employed to investigate the relationship between port network characteristics and their performance. The results suggest that the four centrality indices identify the roles of the world's major ports from 2006 to 2011 and that port performance is determined not only by macroeconomic variables and service capabilities but also by the eigenvector centrality of ports in networks.

• Korea Trade Review
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• v.41 no.5
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• pp.373-389
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• 2016

This study mainly investigates the port SOC's impact on trade volume. In order to investigate the relationships between port SOC and trade volume, we did the empirical analysis using panel data regression and fixed effects model. The total period of 97 years and 1,082 ports' information were applied to panel data and regression model. According to the results, the coefficients of development of container berth, development of bulk berth, maintenance of port, the jetty facilities like breakwater have positive(+) impact on the dependent variable, the trade volume. Especially, the jetty facilities show a strongly positive impact on trade volume. On the other hand, the development of new port and navigation facilities like lighthouse have a negative(-) impact. In examining Hausman test and LR test, the fixed effect model is statistically more appropriate than the random effect model for this study.

• Journal of Korea Port Economic Association
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• v.31 no.1
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• pp.171-188
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• 2015

Logistics network has been increasingly acknowledged as one of the important driving force for economic development in China. With the scope of logistics effect broadening and the development of logistics infrastructure, both logistics network and economy in terms of GDP in China has experienced rapid development hand in hand. This paper investigates the relationship between logistics network and economic growth, using a dataset covering 31 provinces over the period from 2003 to 2012 in China. Factor analysis is applied to obtain a total evaluation of logistics function defining the impact of logistics network on the national economy growth. According to fixed effect panel data approach, a significant and positive impact of logistics network on economic growth in China is found, meanwhile, a comparative analysis regarding economic development between coastal provinces and interior provinces is also conducted. The results suggest that the impact of logistics network on economic growth is higher in eastern provinces than that in western provinces. The policy implication for other nations, in particular for developing nations, is logistics network should be regarded as an important driving force for economic development, and investment should be made in advance to achieve the best efficiency in economic development and planning.

• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.157-176
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• 2024

Integrative analysis for better understanding of complex biological systems gains more attention. Observing subjects from various perspectives and conducting integrative analysis of those multiple datasets enables a deeper understanding of the subject. In this paper, we compared two methods that simultaneously consider two datasets gathered from the same objects, canonical correlation analysis (CCA) and co-inertia analysis (CIA). Since CCA cannot handle the case when the data exhibit high-dimensionality, two strategies were considered instead: Utilization of a ridge constant (CCA-ridge) and substitution of covariance matrices of each data to identity matrix and then applying penalized singular value decomposition (CCA-PMD). To illustrate CIA and CCA, both extensions of CCA and CIA were applied to NCI60 cell line data. It is shown that both methods yield biologically meaningful and significant results by identifying important genes that enhance our comprehension of the data. Their results shows some dissimilarities arisen from the different criteria used to measure the relationship between two sets of data in each method. Additionally, CIA exhibits variations dependent on the weight matrices employed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.347-349
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• 2022

본 연구에서는 장애 임금근로자의 근로환경, 업무특성, 지속근무 의도, 직무만족도 간의 구조적 관계분석을 통해 장애 임금근로자의 직무만족도 향상 방안을 제시하고자 한다. 분석자료는 장애인고용패널 2차웨이브 6차년도 패널데이터 중 15세이상 임금 장애근로자 1,582명을 분석에 사용하였다. 분석결과, 첫째, 장애 임금근로자의 근로환경은 직무만족도에 정(+)적인 영향을 미쳤지만, 지속근무 의도에는 유의한 영향을 미치지 않았다. 둘째, 장애 임금근로자의 업무특성은 지속근무 의도와 직무만족도에 정(+)적인 영향을 미쳤다. 셋째, 장애 임금근로자의 지속근무 의도는 직무만족도에 정(+)적인 영향을 미치는 것으로 나타났다. 넷째, 장애 임금근로자의 근무환경과 직무만족도 사이에 지속근무 의도는 매개효과를 나타내지 않았다. 다섯째, 장애 임금근로자의 업무특성과 직무만족도 사이에 지속근무 의도는 매개효과를 미치는 것으로 분석되었다.