데이터마이닝을 이용한 학자금 대출 부실 고위험군 예측모형 개발

최재석,한준태,김면중,정진아,Choi, Jae-Seok,Han, Jun-Tae,Kim, Myeon-Jung,Jeong, Jina 한국데이터정보과학회 2015 한국데이터정보과학회지 Vol.26 No.6

We develop the high risk group predictive model for loan default by utilizing the direct loan data from 2012 to 2014 of the Korea Student Aid Foundation. We perform the decision tree analysis using the data mining methodology and use SAS Enterprise Miner 13.2. As a result of this model, subject types were classified into 25 types. This study shows that the major influencing factors for the loan default are household income, national grant, age, overdue record, level of schooling, field of study, monthly repayment. The high risk group predictive model in this study will be the basis for segmented management service for preventing loan default. 본 연구는 한국장학재단의 2012-2014년간 일반 학자금 대출 자료를 활용하여 부실채권 보유 및 신용유의자로 분류될 수 있는 위험요인들을 파악하고, 부실 고위험군 예측모형을 개발했다. 예측모형 개발은 데이터마이닝 방법 중 의사결정나무 분석을 적용하였으며, 분석 패키지는 SAS Enterprise Miner 13.2를 활용했다. 개발된 모형은 25가지의 그룹으로 세분화 했으며, 부실 위험군에 영향을 미치는 주요 요인은 소득분위, 국가장학금 수혜유무, 나이, 연체계좌 보유 이력, 대학구분 (학부/대학원), 전공 계열, 월평균 상환액이 주요 요인으로 나타났다. 본 연구에서 개발된 부실 고위험군 예측모형은 장기연체로 인한 부실채권 발생 및 신용유의자 발생 예방을 위한 세분화된 관리서비스 제공을 위한 기초자료가 될 수 있을 것이다.

길경(桔梗)의 추출조건에 따른 사포닌 함량의 변화

최재석,유대석,최연희,연규환,홍경식,이병회,김혜진,김현기,김은주,노성환,정영철,김영섭,유시용,Choi, Jae-Seok,Yoo, Dae-Seok,Choi, Yeon-Hee,Yon, Gyu-Hwan,Hong, Kyung-Sik,Lee, Byung-Hoe,Kim, Hye-Jin,Kim, Hyun-Ki,Kim, Eun-Ju,Roh, Seong-Hwan,Jeong 한국생약학회 2007 생약학회지 Vol.38 No.2

We investigated the contents of crude saponin in the decoctions of Platycodi Radix prepared by the different extraction processes. Each lyophilized decoctions prepared by the different protocol were suspended in water and partitioned with ethylacetate (EtOAc) and n-butanol (BuOH), which gave the EtOAc fraction, BuOH fraction and the remaining water fraction, respectively. The content of crude saponin, which was estimated as the amount of BuOH fraction, and the HPLC profiles of the BuOH fraction were analyzed, and compared each others. The crude saponin content in the decoctions were increased proportionally to the increment of the extraction time, amount of water, extraction temperature and the number of repetition for extraction. Consequently, the optimized conditions were deduced to be suitable and recommendable for the preparation of Platycodi Radix ; the water amount needed for the extraction be 15-20 volumes to crude material, temperature for extraction be optimal at $85{\sim}100^{\circ}C$, extraction time be more than 5 hours and the repetition of extraction was 2 times.

콘크리트 아치교 시공기술

최재석(Jae-Seok Choi),곽동주(Dong-Joo Kwak) 한국콘크리트학회 2007 콘크리트학회지 Vol.19 No.5

KCL 안산해양환경폭로시험장 기반구축 현황

최재석 ( Choi Jae Seok ),김영근 ( Kim Young Geun ),장필성 ( Jang Pil Sung ),최윤석 ( Choi Yoon Suk ) 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.19 No.1

볼 베어링을 사용하는 선형 운동 가이드의 동적 특성

최재석(Choi, Jae Seok),이용섭(Yi, Yong-sub),김윤영(Kim, Yoon Young),이동진(Lee, Dong Jin),이성진(Lee, Sung Jin),유정훈(Yoo, Jeonghoon) 한국소음진동공학회 2004 한국소음진동공학회 논문집 Vol.14 No.9

The linear motion(LM) guide using ball bearing has many advantages compared with conventional sliding guides. Therefore, LM guide using ball bearing has been widely used to increase the accuracy of the position of a system. This research investigates dynamic characteristics of LM guide through mainly linear analyses. Linear analysis is accomplished by Lagrange equation and the finite element method. And another trial that performs nonlinear analysis about one mode(bouncing mode) of LM guide from Hertzian contact theory is accomplished in the latter half of this research. Through nonlinear analysis we could observe the softening characteristic due to the Hertzian contact nonlinearity.

국내 극한 환경 장기폭로시험 현황과 건설재료 성능기반 설계기법

최재석(Choi, Jae Seok),장필성(Jang, Pil Sung) 한국콘크리트학회 2011 한국콘크리트학회 학술대회 논문집 Vol.2011 No.5

극한 환경(혹한, 혹서, 염해환경)하에서 건설되고 있는 구조물의 효율적인 유지관리를 위하여 장기폭 로시험관련 국내 현황을 파악하고, 건설재료의 성능기반에 기초한 성능설계의 필요성에 대하여 검토하고자 한다.

A Study on the Reliability Evaluation for Interconnecting Power Systems in Northeast Asia

崔在錫(Jae-Seok Choi),車濬敏(Jun-Min Cha) 대한전기학회 2008 전기학회논문지 Vol.57 No.7

This paper proposes a reliability evaluation for interconnection planning using a tie line equivalent assisting generator model (TEAG) that considers the uncertainties of the interconnected transmission systems and the tie lines. Development of this model was triggered by the need to perform probabilistic reliability evaluations on the NEAREST (North East Asia Region Electric Systems Tied) interconnection. The TEAG is the basis for the newly developed interconnection systems reliability evaluation computer program, NEAREL. The model is capable of considering uncertainties associated with generators, tie lines, and the tied grids. Reliability evaluations for six interconnection scenarios involving the power systems of six countries in the Asian north eastern region were performed using NEAREL. Sensitivity analysis was used to determine reasonable tie line capacities for three interconnected country scenarios of the six countries. Test results and summarized comments of the scenarios are included in the paper.

와전류 브레이크의 영구자석배열 최적설계

최재석(Jae Seok Choi),유정훈(Jeonghoon Yoo) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.7

Eddy current is usually generated in the material with high conductivity by time-varying source such as AC current and also is induced by the moving source with relative velocity. The contactless magnetic brake makes use of the braking force from the eddy current generated by the moving source and currently used for the secondary brakes of heavy trucks, buses and rail vehicles. This study aims to design the magnetization pattern of the eddy current brake system of a permanent magnet type where the design aim is to maximize the braking force. The analysis of brake systems is based on the two-dimensional finite element analysis. We use the sequential linear programming as the optimizer and the adjoint variable method is applied for the sensitivity analysis.

2007년 현재 일본 고교 일본사 교과서의 내용분석

최재석(Choi Jae-Seok) 고려대학교 아세아문제연구소 2007 亞細亞硏究 Vol.50 No.2

Throughout the sixth century Yamato-Wa (Japan) was virtually governed by the Yamato-Wa administering teams by turns dispatched by Paekche or Paekche kings, and the notoriously poor shipbuilding and navigation skills or the Japanese kept them from having free contact with neighboring peoples on their own, so that only with the help of Silla who had the command of the sea in the Far East could the Japanese go to Korea or China. These two indisputable facts are indirectly or directly mentioned in the Nihon shoki (Chronicles of Japan). In addition, it is now common knowledge that relocation of Japan's capitals (Fujiwarakyo and Heijokyo) and construction of Buddhist temples (the Horyuji temple and the reconstructed Horyuji temple) were carried out either by Korean experts themselves or with the technical cooperation of Korean professionals versed in expertise. Moreover, the origins of all cultures of ancient Japan, that is, in the sixth century through the early seventh century, were Korea, not China, so astutely observed a senior Japanese (mind you, not Korean) Buddhist historian, and another Japanese tumulus researcher points out, presenting indisputable evidence, that so many tumuli existing in Japan are related to Korea. Even so, the current highschool textbooks on the history of Japan reflect without exception only the biased assertions of those who grossly distorted actual history, in total disregard of conscientious scholars who spoke up on the true history of ancient Japan. In brief, current Japanese history textbooks allege that ancient Korea was Japan's colony and that Japanese culture resulted from sucking up Chinese culture, not Korean. Such historical falsification seems to take over the tradition of history distortion which was started by the General Staff Office of Imperial Japanese Army in the nineteenth century. I remember reading a long time ago in an American history textbook that the United States of America started from being a British colony. Now, textbooks published by private persons are also under the jurisdiction of the government. But, I believe, only when Japanese history textbooks?whether they are published by private individuals or by the government?record with a good conscience historical facts as they were and are will Japan be justly called a democratic country with good-neighbor policy that has entirely outgrown pre-1945 polity, ever having a high regard for factual historical facts.

연세 공공거버넌스와 법 포럼 : 군사법절차에 있어서의 장병의 기본권 향상 방안 연구

최재석 ( Jae Seok Choi ) 연세대학교 법학연구원 공공거버넌스와 법센터 2012 연세 공공거버넌스와 법 Vol.3 No.2

본 논문은 군사법의 절차법적 주제와 관련하여 가장 중요한 주제인 ‘재판권``과 현행 군사법원법 절차규정의 개선점. 그리고 군형사실체법에서 현재 논란이 있는 주제인 군형법 상 ‘상관’과 ‘추행’ 죄에 대하여 검토한다. 특히 군사법제도는 그 제도운영의 특성상 일반의 관심대상에서 벗어나기 쉬운데, 군사법제도에 관한 모든 논의는 결국 그 제도의 적용대상인 장병 의 입장에서 출발하여야 하며, 장병의 입장에서 수용가능한 제도가 마련 되어야 한다. 이 글은 바로 이러한 측면에서, 장병들의 눈높이에서 헌법 적 기준과 원칙에 따라 기존 군사법제도와 절차에 잔존하는 미비점이나 문제점을 추출하고 그 개선방안을 제시하고자 한다. 이러한 논의는 궁극 석으로 우리의 군사재판제도의 공정성과 전문성을 제고시키고 수사 및 재판과정에서의 적법절차준수를 강화시킴으로써 군내 법질서 확립이라는 사법기능적 역할과 조화롭게 모든 장병들의 인권이 존중, 보호되는 토양을 형성하기 위한 시도가 될 것이다. This article deals with the issues of military procedure law, including ``Jurisdiction`` and suggestion about the current Military Court Act. Also, it argues about the meaning of ``Superior`` and ``Assault``, which are the current hot issues in Military Criminal Act. The contents and operation of military legal system are prone to be in the blind spot. It is because the subjects and the objects of the military law are very few, and they are in a relatively closed society. However, the starting point of every argument about military legal system must be the individual soldiers who are the objects of the system, and the system must be accepted and respected by them. This article was wrote in that aspect, spotting some problems which exist in the current military legal system and suggesting resolutions in the eye level of ordinary citizens and individual soldiers.