• 응용통계연구
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• 제30권1호
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• pp.69-82
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• 2017

R-지수(representativeness indicator)는 무응답이 발생했을 때 표본의 대표성을 나타내주는 지표이다. 표본의 대표성은 모수 추정의 정확성(accuracy)과 관계가 있으며 정확성은 편향(bias)와 관계가 있다. 따라서 표본의 대표성을 나타내는 R-지수가 높으면 대표성이 높아 편향이 없고 정확성이 높은 결과를 얻을 수 있다. R-지수는 일반화선형모형의 로짓 또는 프로빗 모형을 적합한 후 얻어진 경향 점수(propensity score)에 의해 계산된다. 본 논문에서는 R-지수와 이질적인 층별 응답률과의 관련성을 연구하였으며 편향, 제곱근 RMSE 등과 같은 비교통계량이 무응답에 얼마나 민감한지 등을 모의실험을 통하여 살펴보았다. 또한 변형된 2010년 경제총조사 자료를 이용하여 실제 자료분석도 실시하였다.

• KDI Journal of Economic Policy
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• 제38권3호
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• pp.79-106
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• 2016

This paper investigates the effectiveness of public credit guarantee programs and interest-support programs for SMEs (small and medium enterprises). First, assuming that there is an imperfect information structure in the SME loan market, we analyze how SME support financial programs affect the corporate decisions made by SMEs with regard to default or loan sizes. In addition, this paper theoretically computes the optimal levels of credit guarantee amounts and the interest-support spread under equilibrium with imperfect information in a competitive loan market. Second, the paper empirically analyzes the continuous policy-treatment effect with the GPS (generalized propensity score) method. In particular, we consider the ratio of guaranteed debt to the total debt as a continuous policy treatment. The empirical results show that marginal effects of a credit guarantee on SMEs' productivity, profitability, and growth potential decrease with the ratio of guaranteed debt to the total debt. In addition, the average effect of a credit guarantee is maximized when this ratio is at 50% to 60%.

• 수산경영론집
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• 제48권4호
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• pp.11-25
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• 2017

The purpose of the study is to analyze the status and trend of less favored condition of fishing village in Korean island regions using the census of agriculture, forestry and fisheries. The less favored condition was measured as the difference in accessibility to major services and in fishery sales and resident infrastructure, applying the difference-in-difference method and propensity score matching method respectively. The result shows that access to major services has improved in island area between 2010 and 2015, implying that related policies such as the island comprehensive development project have been successful to some extent. However, some educational facilities, cultural facilities, and health facilities still have low inaccessibility and fishery sales are also significantly lower than in general area. This suggests that it is necessary to maintain related policies like the direct payment of fisheries.

• 한국경영공학회지
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• 제23권4호
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• pp.105-123
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• 2018

The purpose of this study is to verify whether the technology grade, which is the result of technology appraisal by Technology Credit Bureau, can be extended and applied to the venture certification system. We confirmed that there was a significant difference in the average financial performance for three years after the certification and appraisal of the two groups after matching the venture certification enterprise group and the technology appraisal enterprise group in 2015 through the propensity score matching method. As a result, there was no significant difference in the financial performance of venture certified firms and technology appraisal firms, so we confirmed that the technology grade can be expanded and applied to the venture certification system. As a result of estimating the technology grade conforming to the venture certification system, it was concluded that technology outstanding firm(T1-T4) is a technology grade suitable for the venture certification system.

• Communications for Statistical Applications and Methods
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• 제27권6호
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• pp.675-688
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• 2020

In survival analysis of observational data, the inverse probability weighting method and the Cox proportional hazards model are widely used when estimating the causal effects of multiple-valued treatment. In this paper, the two kinds of weights have been examined in the inverse probability weighting method. We explain the reason why the stabilized weight is more appropriate when an inverse probability weighting method using the generalized propensity score is applied. We also emphasize that a marginal hazard ratio and the conditional hazard ratio should be distinguished when defining the hazard ratio as a treatment effect under the Cox proportional hazards model. A simulation study based on real data is conducted to provide concrete numerical evidence.

• Communications for Statistical Applications and Methods
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• 제29권2호
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• pp.263-275
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• 2022

Use of appropriate technique for non-response occurring in sample survey improves the accuracy of the estimation. Many studies have been conducted for handling non-ignorable non-response and commonly the response probability is estimated using the propensity score method. Recently, post-stratification method to obtain the response probability proposed by Chung and Shin (2017) reduces the effect of bias and gives a good performance in terms of the MSE. In this study, we propose a new response probability estimation method by combining the propensity score adjustment method using the logistic regression model with post-stratification method used in Chung and Shin (2017). The superiority of the proposed method is confirmed through simulation.

• 무역학회지
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• 제46권2호
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• pp.323-335
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• 2021

With the advent of the 4th Industrial Revolution, there is a rising interest in the impact of these changes on Korea's trade. While the previous studies related to the 4th Industrial Revolution are very limited in the field of trade research, this study attempts an empirical analysis regarding the effect of the use of the 4th Industrial Revolution technology on the performance of exporters, based on the data of the Survey of Business Activities during 2017-2019 by the Korean government statistical office. Through the empirical analysis in combination with the propensity score matching (PSM) and the difference-in-difference (DID) analysis, this research confirms that the use of the 4th Industrial Revolution technology has a positive effect on the export performance of Korean exporters.

• 한국벤처창업학회:학술대회논문집
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• 한국벤처창업학회 2021년도 추계학술대회
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• pp.113-117
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• 2021

Due to the recent COVID-19 pandemic, SMEs are forced to converge themselves into online business to cope with the rapidly changing business environment. However, due to various difficulties of becoming an online business, most SMEs choose to use services provided by the online sales platform. These platforms offer valuable support such as DSS in return for the high amount of commission fee. We analyze a novel data set from Naver Corporation's 'Smart Store' platform with the quasi-experimental method (propensity score matching technique combined with the difference in differences analysis) to analyze DSS usage and SME's performance empirically. Our results suggest that DSS usage leads to an increase in SME's sales performance in means of sales frequency and sales amount. Additionally, we have found weak support that DSS usage enables SMEs to attract customers better than those not using DSS.

• 한국과학교육학회지
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• 제37권4호
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• pp.719-730
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• 2017

본 연구는 공학 설계에 기반을 둔 연구 프로그램, 팀 프로젝트 활동 등의 통합적 STEM 연구 활동이 영재 학생들의 창의적 공학문제해결 성향과 공학에 대한 태도에 미치는 효과를 알아본 것이다. 이를 위해 Kang & Nam (2016)이 개발한 창의적 공학문제해결 성향 검사 도구와 Moon (2009)이 사용한 공학에 대한 태도 검사 도구를 본 연구 상황에 맞게 수정하여 통합적 STEM 활동의 사전과 사후에 측정 하였고, 연구 결과는 다음과 같다. 첫째, 영재 학생들의 공학 설계에 기반한 통합적 STEM 연구 활동은 창의적 공학문제해결 성향 변화과 공학에 대한 태도 변화에 긍정적 효과를 나타냈다. 창의적 공학문제해결 성향 검사지는 동기, 공학 설계, 공학적 사고 습관, 공학과 공학자, 소통 및 협업 능력 5요인으로 구성되어 있는데 모든 요인에서 유의미한 결과가 나타났다(p<.05). 창의적 공학문제해결 성향은 대부분의 요인에서 진로 희망 직업 계열과 성별 차이에 따른 유의미한 차이가 없었다. 하지만 '공학 설계' 요인에서는 남학생보다 여학생에게 효과가 있음을 알 수 있었다. 공학에 대한 태도 검사지는 공학에 대한 흥미, 공학의 난이도, 공학의 영향, 공학과 관련된 학교 교육과정, 공학과 직업에 대한 인식을 알아보는 문항으로 구성되어 있는데 모든 요인에서 유의미한 결과가 나타났지만(p<.05), 진로 희망 직업 계열과 성별 차이에 따른 유의미한 차이는 없었다.

• 한국융합학회논문지
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• 제9권6호
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• pp.261-269
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• 2018

본 연구는 치위생과 학생들의 윤리성향, 자아존중감 및 임상실습 만족도가 전공만족도에 미치는 영향을 분석하였다. 경남과 울산 소재 3개 대학의 치위생과 3학년 학생 381명을 대상으로 조사연구하였다. 자아존중감은 학과 선택시기가 '고등학교 3학년 이전', 구강건강이 '건강하다', 성격은 '외향적', 가정 분위기는 '화목하다'에서 높았다. 임상실습 만족도는 '치과 아르바이트 경험'이 있다에서 높았고, 전공만족도는 학과 선택시기와 구강건강상태에서 유의한 차이가 있었다(p<0.05). 전공만족도에 영향을 미치는 요인은 자아존중감(${\beta}=.165$, p=.000)과 임상실습만족도(${\beta}=.630$, p=.000)이었다. 따라서 본 연구를 통해 치위생과 학생의 윤리의식 수준과 자아존중감, 임상실습만족도를 향상시킬 수 있는 교육과정 개발의 필요성을 확인하였다.