• 대한공업교육학회지
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• v.38 no.1
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• pp.239-258
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• 2013

The purpose of this study is to define what circuit repairing ability is and to check improvement in learner's circuit repairing abilities by verifying conformity of learner's achievement of target goals that have been derived from headlight assignment based on circuit repairing ability that has been categorized into six sub-factors, which are preparing ability, attaching/detaching ability, circuit analyzing ability, inspecting and measuring ability, repairing (problem solving) ability and organizing ability. In order to achieve the purpose of study, degree of improvement in circuit repairing ability of learner's group was measured through experiment design and verification by group of experts. SPSS statistics program was used for statistical analysis in which average value for descriptive statistics, Cronbach ${\alpha}$ coefficient and t-test were conducted. Level of significance for t-test was p<.05. The conclusions from conducting this study are as follows. Firstly, the usage of terminology 'circuit repairing ability' pertaining to ability to repair failure of electrical devices in automobiles was confirmed to be appropriate. Secondly, the categorization of circuit repairing ability into sub-factors of preparing ability, attaching/detaching ability, circuit analyzing ability, inspecting and measuring ability, repairing (problem solving) ability and organizing ability was confirmed to be appropriate. Thirdly, field instruction on headlight assignment that has been revised according to achievement of learner's goals was confirmed to be effective in improving learner's circuit repairing abilities compared to regular training. Fourthly, field instruction on headlight assignment that has been revised according to achievement of learner's goals was confirmed to be effective in improving sub-factors of circuit repairing abilities, which are preparing ability, attaching/detaching ability, circuit analyzing ability, inspecting and measuring ability, repairing (problem solving) ability and organizing ability.

• Korean Security Journal
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• no.23
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• pp.87-107
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• 2010

The purpose of this study is to examine the effects of customer aggression on the job stress and emotional burnout of security guards in casino. Investigating tools used questionnaire, the sampling was drawn from security guards at 6 casinos which had more than 30 security guards. To this study, the partisans of the study were 269 people. Data for creation for questionnaire is completely computed processing and using SPSS 15.0 Windows that is social studies scholastic mantle command program after imputed encoding according to each purpose. Analyzing techniques to use for analysis of data enforced technology figure analysis, factor analysis, reliability analysis, t-test, one-way ANOVA, multiple regression analysis. Through data analysis by such method and procedure, conclusion that gets in this research is as following. First, exposure that is difference that keep in mind partially as result that verify difference of aggression according to demographical features, job stress and emotional burnout that is security guard's in casino. Second, exposure that is difference that keep in mind as statistical as result that verify effect that customer aggression gets in job stress of security guards in casino. Third, exposure that is difference that keep in mind as statistical as result that verify effect that customer aggression gets in emotional burnout of security guards in casino.

• Communications for Statistical Applications and Methods
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• v.16 no.2
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• pp.239-347
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• 2009

This paper presents Kolmogorov-Smirnov, mean difference, AUROC and AR, four well known statistics that have been widely used for evaluating the discriminatory power of credit rating models. Criteria for these statistics are determined by the value of mean difference under the assumption of normality and equal standard deviation. Alternative criteria are proposed through the simulations according to various sample sizes, type II error rates, and the ratio of bads, also we suggest the meaning of statistic on the basis of discriminatory power. Finally we make a comparative study of the currently used guidelines and simulated results.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.401-404
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• 2022

한국 문학이 세계로 뻗어나감에 따라 해외 시장에서 자리를 잡는 것이 중요해진 시점이다. 본 연구에서는 2016 년도부터 2020 년도까지 최근 5 년간 해외 출간된 도서들 중에서 굿셀러로 분류되는 누적 5 천부 이상 판매 여부를 예측하고자 했다. 굿셀러로 분류되는 도서는 전체 번역 도서 중 적은 비율을 차지하여 데이터 불균형이 발생하였으며, 본 연구에서는 SMOTE 기법과 앙상블 알고리즘을 적용하여 데이터 불균형 문제를 해결하였다. 그 결과, 데이터 클래스 비율이 1:1 에 가까울수록 성능 개선 효과가 나타났으며 LightGBM 모델이 99.83%의 AUC 값을 얻어 다른 앙상블 알고리즘에 비해 가장 좋은 예측 성능을 보임을 검증하였다. 또한 누적 5 천부 이상 판매 여부 예측에 있어 큰 영향을 미치는 변수로는 작가가 가장 중요한 요인으로 나타났으며 출간 국가, 그리고 평점 평균, 평점 참여자 수 같은 온라인 요인도 판매 예측에 유의미한 변수로 나타난 것을 확인할 수 있었다.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.261-270
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• 2009

Current financial crisis triggered by shaky U.S. banking system adds to the emphasis on the importance of the volatility in controlling and understanding financial time series data. The ARCH and GARCH models have been useful in analyzing economic time series volatilities. In particular, multivariate GARCH(MGARCH, for short) provides both volatilities and conditional correlations between several time series and these are in turn applied to computations of hedge-ratio and VaR. In this short article, we try to assess various MGARCH models with respect to the back-testing performances in VaR study. To this end, 14 korean stock prices are analyzed and it is found that MGARCH outperforms rolling window, and BEKK and CCC are relatively conservative in back-testing performance.

• The Korean Journal of Applied Statistics
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• v.31 no.3
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• pp.409-416
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• 2018

Significant research has been conducted in the financial sector on the behavior of investors in the stock market. In this paper, we directly measure the degree of interest using the ranking of the frequency mentioned in the stock message board operated by Daum Communications Corp. and test the fact that the higher ranking of the frequency results in the higher stock returns in order to investigate the attention effect on the stock returns in the Korean stock market. We also propose and apply the likelihood ratio test procedure for order restricted hypotheses in order to test the attention effect. The test results shows that the higher rank in the frequency mentioned in the message board is related to stock returns (p-value < $10^{-6}$). Therefore, we conclude that an investors' attention effects exist in the Korean stock market.

• The Journal of Korean Association of Computer Education
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• v.3 no.2
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• pp.107-114
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• 2000

In this study, a program for statistics education is developed. This program deals with statistical hypothesis testing which is indispensible to demonstrate the research hypothesis. Statistical inference which is the process of using data obtained from a sample to make inference about the characteristics of a population is an essential concept to peoples to learn or use statistics. But in practice, there are many cases of wrong application and peoples think that statistics is hard to understand. Therefore, it is very important subject to teach easily and rightly statistics, specially elementary statistics. This program is developed especially for non-specialist. This program under multimedia environment which includes sound, video, animation etc. can interest students greatly. It doesn't show only the result but make it possible for students to execute the program by stages. By executing it, the students can understand the method and meaning of statistical hypothesis testing naturally.

• Journal of Industrial Convergence
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• v.21 no.3
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• pp.149-157
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• 2023

The purpose of this study was to verify the mediating effect of self-efficacy in the effect of social workers' ethical consciousness on job satisfaction. Based on the ratio of the statistical yearbook of Korean social workers in 2020, the subjects of the study conducted an online survey on 512 social workers working at social welfare facilities in Seoul. The study was conducted with IRB approval. The analysis and statistics of this study used SPSS & AMOS 25.0. Bootstrapping was used to verify the mediating effect of self-efficacy in the effect of social workers' ethical consciousness on job satisfaction. As a result of the study, the positive effect on self-efficacy and job satisfaction of social workers was verified. In addition, the positive mediating effect of self-efficacy was verified between the ethical consciousness of social workers on job satisfaction. The results of the study suggest the importance of systems and practices to support capacity building and promote self-efficacy for ethical awareness to improve job satisfaction of social workers.

• The Korean Journal of Financial Management
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• v.12 no.2
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• pp.43-71
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• 1995

본(本) 연구(硏究)는 한국증권시장(韓國證券市場)에서 무위험자산이 존재하지 않을 경우에 대용시장(代用市場)포트폴리오의 효율성(效率性) 검증(檢證)을 다변량(多變量)의 검증방법(檢證方法)에 의해 실시하고자 하였다. 검증을 위하여는 첫째로 제로베타수익률을 구하고자 하였으며 이는 Kandel(1984)과 Shanken(1985)의 연구에 기초하여 추정하는 방법을 제시하였다. 둘째로 Jobson-Korkie(1982,1989), Handel(1984,1986)과 Shanken(1985,1986)의 논문(論文)에 의거 대용시장포트폴리오의 효율성을 검증하는 과정을 유도하고 이의 검증(檢證) 통계량(統計量)을 유도하였다. 효율성 검증에 사용된 대용시장포트폴리오들은 한국종합주가지수(韓國綜合株價指數), 한경(韓經)다우지수(指數)와 2개의 동일가중지수(同一加重指數)이었다. 실증적 연구결과, 전기간(全期間)의 경우에 한국종합주가지수(韓國綜合株價指數)와 한경(韓經)다우지수(指數)의 평균수익률은 GMVP의 수익률보다 낮을 뿐만아니라 평균-분산(平均-分散)프론티어의 외부(外部)에 위치하여 이 대용시장지수(代用市場指數)들이 효율적(效率的)프론터어상에 있는가에 대한 검증(檢證)은 불가능하였다. 그리고 하위기간별분석(下位期間別分析)에서도 이 대용시장지수(代用市場指數)(후반기(後半期)의 한경(韓經)다우지수(指數) 제외)들은 평균-분산프론티어의 내부(內部)에 있어 효율성 검증은 가능하였다. 그러나 이는 대용시장지수(代用市場指數)가 효율적 프론티어상에 있는가에 대한 효율성 검증이 아니라 단순히 평균-분산프론티어상에 있는가에 대한 검증에 불과하였으며 이러한 검증 결과는 효율적(效率的)인 것으로 나타났다. 한편 한국증권거래소(韓國證券去來所)에 상장(上場)된 전 종목(種目)을 대상으로한 동일가중지수(同一加重指數)와 본 연구의 기준시점인 1980년도에 한국증권거래소에 상장된 종목을 대상으로 구성한 동일가중지수(同一加重指數)는 이들의 평균수익(平均收益)이 GMVP의 수익률보다 높을 뿐만 아니라 대용시장지수(代用市場指數)가 효율적(效率的) 프론티어 상에 있는가에 대한 효율성 검증에서 모두효율적(效率的)인 것으로 나타났다. 이러한 사실은 한국종합주가지수(韓國綜合株價指數)를 근거로 기관투자자들이 투자수익율(投資收益率)의 관점에서 포트폴리오를 구성하거나 CAPM의 실증적(實證的) 연구시에 대용시장지수(代用市場指數)로 사용하는 것은 문제점이 있는 것으로 판단되며 따라서 동일가중지수(同一加重指數)를 선택함이 바람직할 것으로 사료된다.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.94-96
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• 2012

본 연구는 물리치료학과 학생들을 대상으로 젊은 여성 신발의 높이 차이가 신체의 정렬과 균형에 미치는 영향을 알아보고자 연구를 실시하였다. 평균 나이 20.5세인 여대생을 대상으로 걷기 운동을 통한 높이를 같게 한 신발의 종류에서의 실험 전과 후의 신체 정렬과 균형에 관해 비교분석하였다. 통계처리 방법으로 실험 전 후 차이를 검증하였고, 모든 통계적 유의수준은 0.05로 하였다. 본 연구의 결과 신발의 종류에 따른 신체정렬의 변화에서 7cm의 높은 힐과 편평힐은 몸통 경사, 불안정성에서 통계적으로 유의하지 않았다. 안정된 지면 및 불안정 지면에서 신발 종류에 따른 체중분포도와 정적 안정감에서 통계적으로 유희한 증가를 보였다. 향후 신발 굽의 지지면 면적의 비교뿐 아니라 좀 더 다양한 여성의 신발 굽을 비교분석하고 굽 높이와 신체 정렬간의 상관성 분석을 밝힐 필요성이 있다고 본다.