CART 방법론을 사용한 클라우드 컴퓨팅 도입 의사 결정 모델링

백승현,장병윤,Baek, Seung Hyun,Chang, Byeong-Yun 한국시뮬레이션학회 2014 한국시뮬레이션학회 논문지 Vol.23 No.4

In this paper, we conducted a study on place-free and time-free cloud computing (CC) adoption decision-making model. Panel survey data which is collected from 65 people and CART (classification and regression tree) which is one of data mining approaches are used to construct decision-making model. In this modeling, there are 2 steps: In the first step, significant questions (variables) are selected. After that, the CART decision-making model is constructed using the selected variables. In the variable selection stage, the 25 questions are reduced to 5 ones. The benefits of question reduction are quick response from respondent and reducing model-construction time. 본 논문에서는 장소와 시간의 제약을 받지 않는 클라우드 컴퓨팅 도입 의사 결정 모델링에 대한 연구를 진행하였다. 연구에서는 65명의 응답자에게 수집 된 패널데이터와 데이터마이닝 방법 중 하나인 CART(회귀분류나무)를 사용하여 의사결정 모델을 구축하였다. 모델링에는 2단계로 진행되는데 첫 번째 단계에서는 패널데이터를 사용하여 도입 의사를 결정하는데 영향을 미치는 문항들을 선택하고 2 번째 단계에서는 선택된 문항을 사용하여 도입 의사 결정 모델을 구축하였다. 문항 선택을 통하여 설문지 수집 문항수를 25개에서 5개로 줄일 수 있어 응답자에게 빠른 답변을 얻을 수 있고 데이터의 사이즈가 작기 때문에 모델 구축 시간을 줄일 수 있는 장점을 보여주었다.

L2 읽기능력의 요인들과 L2 읽기능력과의 구조적 관계

백승현 ( Seung Hyun Baek ),지문건 ( Moon Gun Ji ) 21세기영어영문학회 2016 영어영문학21 Vol.29 No.2

The empirical research was examined for a sample of 129 4th graders in an EFL environment in order to explore the fundamental elements impacting on second language (L2) reading comprehension and their structural relationship to L2 reading comprehension. The materials used for the current study were (1) a questionnaire on L2 reading comprehension, (2) L2 productive/receptive vocabulary test and (3) L2 reading comprehension test, adopted from Woodcock-Johnson Ⅲ Diagnostic Reading Battery (Woodcock, Mather, and Schrank 2004). First, four factors on L2 reading comprehension were unveiled: L2 reading comprehension learning strategy, first language (L1) proficiency, parents’ interest on their children``s English learning, and extra-curricular activities. Those factors are strongly associated with L2 vocabulary and L2 reading comprehension. Second, L2 productive/receptive vocabulary were significant indicators of successful L2 reading comprehension. Finally, L2 vocabulary knowledge contributed a significant amount of unique variance to L2 reading comprehension based on the structural equation modeling (SEM). These findings are steadily aligned with the Lexical Quality Hypothesis in which L2 vocabulary knowledge is assumed to be a critical determinant of L2 reading comprehension (LQH: Perfetti & Hart, 2001).

인권과 정치사상 : 헬레니즘 시대의 정치사상에 관한 연구

백승현 ( Seung Hyun Baek ) 慶熙大學校 社會科學硏究院 2009 社會科學硏究 Vol.35 No.3

본 논문은 고대가 저물어가고 중세가 시작되기 이전인 헬레니즘 시대의 정치사상에 대해 고찰하고 있다. 특히 알렉산더에 의해 그리스 도시국가들이 소멸되고, 그 후 다시 마케도니 아제국과 그 잔존세력이 로마에 의해 대체되고, 로마가 세계질서의 주도세력으로 존속하는 기간 동안 명멸했던 그 시대의 사상가들과 철학학파들의 사상과 이론의 특징에 대해 살피고 있다. 폴리비우스, 키닉학파, 에피큐로스학파, 스토아학파에 대해 고찰하고 있으며, 아울러 로마인들이 세계에 기여한 바로 인정받는 로마법에 대해서도 살피고 있다. This study analyzes the political thought of the Hellenistic Age. During the Age, the Greek city-states were collapsed by Alexander the Great; the Macedonian Empire and its Diadochus kingdoms were replaced by the Romans. It investigates especially the characteristics of thoughts and theories of the major figures of that period such as Polybius and schools of philosophy including the Cynics, Epicureans, and the Stoics. The Roman Law tradition which is referred to as a major contribution of the Romans to the western world is also reviewed.

중세 유럽의 법 전통과 정치이론

백승현 ( Seung Hyun Baek ) 경희대학교 사회과학연구원 2014 社會科學硏究 Vol.40 No.3

중세 유럽이 1천여 년 간 안정적 질서를 유지할 수 있었던 데에는 기독교 외에 법 전통 에 힘입은 바 크다. 중세 유럽의 법 전통은 대부분 로마법의 토대 위에서 기원 발전하였다. 본 연구는 중세 법 전통의 변화과정을 로마법 전통의 유산, 기독교 교부철학의 법 전통, 게르만 종족과 신성로마제국의 법 전통 등으로 구분, 살피고 있다. 서양 정치이론에 로마법 전통이 끼친 영향은 우선 중세 초반 가톨릭교회의 교회법 체계에 로마법이 기여한 바를 지적할수 있다. 또한 권위의 상승이론에서 볼 수 있듯이, 중세 후반 관심대상으로 재등장한 로마법이 근대 국민국가의 발전에 지대한 역할을 한 것을 꼽을 수 있다. 그런 점에서, 중세 는 어둡고 단절된 시대라기보다 근대의 시작을 준비하고 형성한 시대라고 할 수 있다. This study looks into the change and development of the Medieval legal tradition by examining the legacy of the Roman law tradition, the legal tradition of the Church Fathers’ philosophy, and the legal traditions of many tribal groups and of the Holy Roman Empire respectively. The legal tradition of the Middle Ages was indebted to the Roman law. Roman law declined in importance with the collapse of the Roman Empire, but it survived through its influence upon Roman Catholic canon law. When the modern nation-state began to emerge, Roman law provided the foundation for almost all modern European legal systems. And throughout the Middle Ages there had been two competing theories of authority: the ascending theory of authority and the descending theory of authority.

음소단위의 파닉스와 라임단위의 파닉스 비교연구

백승현 ( Seung Hyun Baek ),정상희 ( Sang Hee Jeong ) 21세기영어영문학회 2012 영어영문학21 Vol.25 No.4

As a follow-up study (Baek, 2009), the purpose of this study was to explore the efficacy of phoneme-based phonics in L2 early literacy skills such as L2 phonological sensitivity and L2 word recognition in comparison with that of rime-based phonics. Furthermore, the relationship between L2 phonological unit and L2 word recognition was also examined. The phoneme-based phonics approach group performed better on L2 phonological sensitivity and L2 word recognition skills than the rime-based phonics approach. Moreover, L2 nucleus (medial vowel or vowel cluster) across the two groups was closely related to L2 word recognition and was a critical precursor of L2 word recognition skills. The current findings propose that L2 phonemic awareness be first introduced to L2 beginning readers rather than L2 rime awareness.

L2 능동적,수동적 어휘습득요인에 관한 구조방정식 모형

백승현 ( Seung Hyun Baek ),지문건 ( Moon Gun Ji ) 21세기영어영문학회 2013 영어영문학21 Vol.26 No.3

The purpose of the present study was to identify the potential components influencing second language (L2) vocabulary acquisition and their structural process to L2 vocabulary knowledge. For the current study, 129 4th-grade students in an EFL context were invited, and they were assessed in productive/receptive vocabulary tasks and responded to questionnaire survey on L2 vocabulary acquisition strategies. The vocabulary test consisted of synonyms, antonyms, and analogies adopted from Woodcock-Johnson Ⅲ Diagnostic Reading Battery (Woodcock, Mather, and Schrank 2004) and the questionnaire was composed of 24 items concerning L2 vocabulary learning strategies. According to factor analysis, four factors of L2 vocabulary acquisition were found: vocabulary learning strategy, extra-curricular activities, parents` interest on their children`s English learning, and first language (L1) proficiency. Regression analysis unveiled that L2 vocabulary learning strategy and extra-curricular activities were significant indicators of L2 vocabulary knowledge. In addition, based on structural equation modeling (SEM), L2 vocabulary learning strategy made a significant direct effect on L2 vocabulary performance. These findings suggest that L2 vocabulary learning strategy plays a critical role in progressing L2 vocabulary achievement, as proposed in Involvement Load Hypothesis (ILH: Laufer and Hulstijn 2001) as well as extra-curricular activities positively impact on L2 vocabulary improvement. Moreover not only L1 vocabulary knowledge but also parents` interest in their children`s English learning cannot be excluded for successful L2 vocabulary acquisition.

CART를 이용한 주가결정요인분석과 주가예측

백승현(Seung Hyun Baek),황승준(Seung-June Hwang) 한국경영과학회 2018 經營 科學 Vol.35 No.1

Existing stock price analysis studies tended to focus only on stock price rather than stock price determinants, but in this study we develop a stock price forecasting system with a two-step method. In the first step, we find the factors that determine the stock price and predict the stock price based on the factors determined in the second step. The scope of the research is meaningful in reducing the cost of collecting data by developing predictive-based models that can be used in the stock market and selecting the variables needed for forecasting. The research methodology will use CART (Classification And Regression Tree). In this study, we applied to the stock price prediction in two directions of both prediction and classification. We use the KOSPI 200 data for empirical analysis and present a quantitative forecasting model that considers the direction of future share prices by using financial statement indices, past and present stock prices related to asset value and profitability value. Experiments were conducted in three experiments according to the input parameters of prediction and classification problem. Based on the experimental results, two determinants and two models are suggested for prediction and classification.

재무지표에 기초한 횡령 및 배임 위험평가

백승현 ( Seung Hyun Baek ),김유찬 ( Yoo Chan Kim ) 한국회계학회 2016 회계저널 Vol.25 No.6

본 연구의 목적은 (1) 회계정보의 횡단면상 혹은 시계열상 비기대 금액을 이용하여 횡령·배임 위험평가에 도움이 될 수 있는 재무지표를 식별하고, (2) 횡령·배임 부정의 예측과 관련하여 로지스틱회귀모형과 서포트벡터머신의 예측정확도를 비교ㆍ평가하는데 있다. 재무제표 상에서 손쉽게 획득 가능한 분석지표를 바탕으로 수행되는 횡령ㆍ배임 위험의 예단은 다양한 이해관계자들의 정보수요를 충족시키는데 도움을 줄 수 있을 것이다. 본 연구의 분석결과를 살펴보면 다음과 같다. 첫째, 네 가지 의사결정영역(즉, 영업관리, 투자관리, 재무전략, 배당정책)에 속한 주요 재무지표들의 전기 비기대 금액은 대부분 당기횡령ㆍ배임과 통계적으로 유의한 관련성을 갖는 것으로 나타났다. 둘째, 로지스틱회귀모형확률변화와 서포트벡터머신 분류초평면 가중치에 관한 분석은 영업관리에 속하는 수익성관련지표들(예; 매출총이익과 영업현금흐름)이 횡령ㆍ배임 위험평가에 보다 유용할 수 있음을 보여주었다. 셋째, 횡령ㆍ배임의 예측과 관련하여, 서포트벡터머신은 로지스틱회귀모형에 비해 유의하게 높은 예측성과를 갖는 것으로 확인되었다. 본 연구의 결과는 재무제표상의 회계정보에 대한 관찰만으로도 횡령ㆍ배임 위험의 예단이 가능할 수 있음을 시사하고 있다. 또한 본 연구의 결과는 회계이슈에 대한 서포트벡터머신의 적용가능성을 시사하고 있다. 서포트벡터머신은 경영 및 의료분야를 비롯하여 그 외의 여러 분야에서 높은 예측정확도를 보여주는 분류모형의 하나로 평가되고 있다. 하지만 지금껏 서포트벡터머신을 이용하여 회계실무에서의 분류 의사결정 문제를 다룬 연구는 많지 않았던 것으로 보인다. 회계실무에 대한 서포트벡터머신의 적용가능성은 향후 회계문헌에 방법론적 차원의 기여를 할 수 있을 것으로 기대된다. The purpose of this paper is (1) to identify financial indicators that can help assess the risk for misappropriation and the breach of trust using the unexpected values of accounting information either in a cross section or in a time series, and (2) to compare and evaluate the performance of logistic regression model and support vector machine in the fraud prediction. The fraud prediction using financial indicators that are readily obtained on the financial statements is expected to help satisfy the information demand of various interested parties. The results show that (1) the unexpected values of key financial indicators in four decision areas (i.e., operating management, investment management, financial strategy, and dividend policies) in the prior period are mostly statistically associated with the fraud detected in the current period, (2) the analysis based on both the probability change of logistic regression model and the hyper-plane weights of support vector machine shows that the profitability-related indicators (e.g., gross profit margins and operating cash flows) are found to be more useful for fraud prediction, and (3) support vector machine significantly outperforms logistic regression model in the prediction accuracy. The results of this paper imply that the risk for misappropriation and breach of trust can be assessed and predicted just simply by observing the accounting information on the financial statements. In addition, the results of this paper also imply the possibility of applying support vector machine to the accounting issues. Support vector machine is believed to be one of classification algorithms with superior prediction accuracy in such areas as business, medicine, and others. However, little research in accounting field applied support vector machine to accounting issues. From the methodological perspective, the discussion of applying support vector machine to accounting issues is able to contribute to accounting literature.

L2 어휘 습득의 요인들과 L2 어휘 능력과의 구조적 관계

백승현 ( Seung Hyun Baek ),지문건 ( Moon Gun Ji ) 글로벌영어교육학회(구 호남영어교육학회) 2011 Studies in English education Vol.16 No.2

The purpose of the current study was to investigate the potential factors which impact on second language (L2) vocabulary acquisition and its relationship to L2 vocabulary ability. This study invited 171 elementary students in Grades 3 to 6 and they were assessed by vocabulary matching task and questionnaire survey on L2 vocabulary learning. The vocabulary test was composed of nouns, verbs, and adjectives adapted from elementary English textbooks based on 7th education curriculum and the questionnaire comprises 28 items. The results indicated that there were the five factors of L2 vocabulary learning: vocabulary learning attitude, vocabulary learning strategy, vocabulary exposure, first language (L1) proficiency, and parents` interest on their children`s assignments. Secondly, according to regression analysis, L2 vocabulary learning attitude and L1 proficiency were strong predictors of L2 vocabulary acquisition. Furthermore, as a result of structural equation modeling, L2 vocabulary learning attitude significantly contributed to L2 vocabulary proficiency. The present findings suggest that L2 leaners` perception on the importance of L2 vocabulary as well as L1 vocabulary plays a crucial role in facilitating L2 vocabulary competence. Furthermore diverse L2 vocabulary learning strategies/exposure and parents` concerns on their children`s L2 learning are necessary conditions for successful L2 vocabulary achievement.

수업언어가 제2언어 음운인식과 읽기능력에 미치는 효과

백승현 ( Seung Hyun Baek ) 글로벌영어교육학회(구 호남영어교육학회) 2010 Studies in English education Vol.15 No.2

The present study explored the effects of language of instruction on the L2 phonological awareness and word reading. Ninety Korean-speaking EFL children in third grade were randomly assigned to Korean-English instruction group or English-only instruction group. Twelve 40-minute teaching sessions in each language were implemented to each group. After treatments, the results unveiled that overall the phonological awareness gradually improved across the two experimental groups. More importantly, within each group, the achievement of sensitivity to phonemes and rimes children with English-only instruction showed was much larger than the performance of sensitivity to phonological units those with Korean-English instruction showed, Additionally, an Analysis of Covariance found that children taught to read out words in Korean and English performed better on L2 phoneme awareness, especially L2 nucleus (medial vowel) and L2 pseudo word reading than those in English only. The results suggest that an instructional language, Korean-English made a greater impact on the achievement of phonological recoding to read out unknown/unfamiliar words and phonological sensitivity to nucleus rather than another instructional language, English-only. Consequently, there will be an ongoing need for dynamically selecting the language(s) of L2 early literacy instruction, raising a precise caution in employing an English-only instruction.