• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1299-1306
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• 2014

Recently, there are many roundabouts installation works which are ordered to provide convenient transportation to road users as well as to eliminate traffic accidents and traffic delays. This study propose an approximate construction cost estimation model for early stages of roundabout construction. The model is designed considering the conditions of the early stage roundabout construction sites in Jeju. The regression equation of approximate construction cost was derived through regression analysis of 25 design data of roundabout construction in Jeju, and it was analyzed to have a high prediction accuracy. Finally, results verifies high prediction accuracy of the derived regression equation. Difference between the estimation cost and the design cost was only 2.3%, 3.7%, and 5.8% that verifies the high accuracy of the proposed approximate construction cost estimation model.

• Journal of Digital Convergence
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• v.15 no.9
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• pp.365-373
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• 2017

The purpose of this study was to examine relationships among positive psychological capital and social support on depression and identify the factors that influence on depression in the adolescents. The data were collected from 140 adolescents in the two middle school located J city using self-reported questionnaires and May 9 2017 to May 19 2017. The data were analyzed by descriptive statistics, T-test, ANOVA, Pearson's correlation coefficient, and stepwise multiple regression with SPSS 20.0 program. Depression was found to be in a significant negative correlation with positive psychological capital and social support. The result of the stepwise multiple regression indicates the positive psychological capital, social support and economic status predict 22.4% (F=14.38, p<.001) of depression. Therefore, it is necessary to develop convergence positive psychological capital and social support strategy program for decrease and prevents depression in adolescents.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.09a
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• pp.387-395
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• 1995

롤(Roll)의 주물 가공 시스템의 성능(Performance)분석의 문제는 일반적으로 관련된 많은 요인들 때문에 매우 복잡하다. 롤 제조 시스템의 성능과 관련된 주요 요인으로서 주형(Moulding) 제작, 원재료의 용해, 후처리 및 가공 공정 의 요인들을 들 수 있다. 본 연구에서는 이러한 복잡한 롤의 주물 및 가공공 정상의 요인들로부터 롤 제조 시스템의 불량률을 평가하기 위하여 발견적인 방법인 GMDH(Group Method Data Handling)-Type 모델링 방법을 이용하 였다. 롤 주물 가공 시스템의 성능을 불량률로 두고 이에 주요 영향 요인들 의 입력 Data를 위하여 현장 자료로부터 상하한 값을 구하여, Hyper-Cube 프로그램을 이용하여 필요한 수의 Data를 보완하여 사용하였다. 시스템 성능 과 관련된 인자들을 2개식 가능한 조합을 하고 이들 각각의 조합들에 대하 여 6개항으로 된 예측식으로 회귀분석하고 일정 수준 이상의 결과들만을 다 음 단계의 자료로 사용하였다. GMDH 방법은 매 단계마다 영향이 적은 변 수조합을 제외시키므로 최종 해는 그 정확성이 매우 높다. 본 연구를 위하여 GMDH 알고리즘에 따라 계산할수 있는 전산 프로그램을 개발하여 사용하였 으며, 적용예를 롤 주물제조공정에 응용하여 보였다.. 분석된 자료에 의하면 예측 오차가 매우 적음을 보였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.775-779
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• 2006

강우자료의 구축은 수문해석에 있어 가장 기본적이며 중요한 단계라 할 수 있다. 하지만 수문 관측 자료의 경우 결측치가 존재하여 그에 대한 보정이 필요한 경우가 종종 발생하게 된다. 따라서 수문자료의 분석을 수행하기에 앞서 우선 자료에 대한 검정을 실시하고, 결측치가 존재할 경우는 이를 보정하여 분석을 수행하여야 한다. 본 연구에서는 다변량통계기법의 하나인 다중회귀분석을 이용하여 강우 결측치를 보정하였다. 본 연구에서는 다중공선성과 자기상관에 대하여 고려한 다중회귀모형을 구성하였다. 모형의 구성시 모든 결측지점에 적용이 가능하지 않아 일반성이 떨어짐을 확인 할 수 있었지만, 모형이 구성될 경우 통계적 적합도와 유의수준을 확인 할 수 있는 장점이 있었으며, 다중회귀모형이 구성되는 경우 좋은 보정 결과를 주는 것을 확인 할 수 있었다.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.1
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• pp.233-261
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• 2023

Drawing on Bronfenbrenner's ecological system, the study explored the effect of the ecological variables affecting library satisfaction for mothers of early school-age children. The study used the eighth wave(2015) of Panel Study on Korean Children and conducted correlation analysis, multiple regression analysis, hierarchical regression analysis, and stepwise regression analysis. Researchers selected ecological variables for each ecological system based on previous studies. Results showed that mothers had moderate satisfaction with libraries, and their satisfaction with libraries was affected by library accessibility, satisfaction with public services, type of residence, children's reading time, and supportiveness of parenting policy. The study showed that external factors such as family, community, and policies could affect library satisfaction along with internal factors in the sociocultural context. The study suggested a possible practical implication for library policy.

• Korean small business review
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• v.39 no.2
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• pp.89-107
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• 2017

This study investigates the effect of risk avoiding activities and characteristic of venture capital on the financial performance of invested companies. Based on the review on the literature, we present staged financing, syndicated investment and preferred stock investment as the measurements for risk avoiding activities. Types and age of venture capital were chosen as the variables for characteristic. The financial performance data of the invested companies was derived from their publicly announced yearly financial report. Data were analysed using logistic regression technique. The result show that syndicated investment and independent venture capital have positive influence on the growth of sales revenue and asset of the invested companies. Age of venture capital appears to be positively associated with growth of sales revenue. Staged financing and preferred stock investment, however, have no impact on any financial growth and profitability. Activities and characteristic of venture capital show no influence on the profitability.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.495-506
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• 2021

A Conceptual cost estimate, which is computed in the preliminary step of a project, is important for decision-making by a contractor in terms of the project budget, economic feasibility and validity analysis, and alternative comparisons. Therefore, a high error rate of a prediction model for a conceptual cost estimate can lead to various problems including excessive project expenditures and a delayed break-even point. this study proposed optimal impact factors by configuring quantitative impact factors computable in a preliminary step in various cases(combinations of impact factors). subsequently, the accuracy of different cases was comparatively analyzed by using the cases as input values of a prediction model using regression analysis. when the optimal combination of impact factors proposed in this study and other combination of impact factors were applied to the prediction model, the regression analysis-based prediction model exhibited 0.2-4.7% improvements in accuracy, respectively. the optimal combination of impact factors proposed in this study improved the accuracy of the prediction model of a conceptual cost estimate by removing unnecessary impact factor.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1133-1146
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• 2015

The Horse race industry has the largest proportion of the domestic legal gambling industry. However, there is limited statistical analysis on horse races versus other sports. We propose prediction models for winning horses in horse races using data mining techniques such as logistic regression, linear regression, and random forest. Horse races data are from the Korea Racing Authority and we use horse racing reports, information of racehorses, jockeys, and horse trainers. We consider two models based on ranks and time records. The analysis results show that prediction of ranks is affected by information on racehorses, number of wins of racehorses and jockeys. We place wagers for the last month of races based on our prediction models that produce serious profits.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.355-363
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• 2018

Found pesticide-contaminated eggs in 2017, the situation became a hot issue in many countries in the world as well as Korea. In the context of the pesticide-contaminated egg, this study explored that preventive behavioral intention would be predicted by perceived susceptibility and severity from health belief model, trust in the government and evaluation of information from the government, and subjective knowledge. We found that preventive behavioral intention was explained by perceived severity (${\beta}=.262$, t=3.531, p<0.001), trust in the government (${\beta}=.25$, t=3.281, p<0.001), and evaluation of the information from the government (${\beta}=.226$, t=2.936, p<0.01) through stepwise multiple linear regression analysis. The findings imply the government would administer policy in terms of credibility, accuracy, and consistency for decreasing the public's sense of unease and panic when a similar incident occurs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.595-601
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• 2011

There is currently applied to the unit cost per a distance (KRW/km) for estimating the conceptual cost of civil work on basic planning stage of high speed railroad. This unit cost is an arithmetic average value based on historical data, which could be in big error. It also is difficult to explain the deficiency comparing the estimated cost derived from next basic design stage. This study provides the conceptual estimation model using by the parametric method and regression analysis. Independent variables are the distance and the geological materials (earth, weathered rock, soft-rock, hard-rock), extracting from the actual data to 36 contracts. The deviation between the unit costs estimated using the developed model and the actual cost data is presented in the range from -0.4% to +31%. This range is acceptable compared the typical range "-30% to + 50%". This model will improve the accuracy of existing method and be expected to contribute to effective total cost management and the economic aspects, reduce the financial expenditure.