혼합모형을 이용한 체지방 반복측정자료에 대한 통계적 분석

조진남,장은재,Jo, Jinnam,Chang, Un Jae 한국데이터정보과학회 2013 한국데이터정보과학회지 Vol.24 No.2

Forty two female students whose fat mass ratio was over 30% were participated in the experiment of fat mass loss of two treatments for 8 weeks. They kept diary for foods they ate every day, took a picture of the foods, transmitted the picture to the experimenter by the camera phone. Among those, 28 students took the picture by regular camera phone (Treatment A), and the other students used smart phone (Treatment B). Fat mass weight and its related variables had been measured repeatedly four times at an interval of two weeks during 8 weeks. It was shown from mixed model analysis of repeated measurements data that AR(1) covariance matrix was selected as the optimal covariance matrix pattern. The correlation between two successive times is highly correlated as 0.838. Based upon the AR(1) covariance matrix structure, the students using smart phones were somewhat more effective in losing fat mass weight than the students using regular camera phones. The time effect was highly significant, but the treatment-time interaction effect was insignificant. The baseline effect and total cholesterol were found to be significant, but the calories with taking foods were somewhat significant, but the waist to hip ratio was found to be insignificant.

품질보증 반환 데이터의 신뢰성 분석

백재욱,조진남,Baik, Jaiwook,Jo, Jinnam 한국데이터정보과학회 2014 한국데이터정보과학회지 Vol.25 No.4

A certain number of products are sold each month and some of them are returned for repair. In this study both return rate and cumulative return rate are shown on the graph to show the general trend of how many products are returned as time goes by. Next this type of summary data can be considered as a conglomeration of both left and right censored data. So reliability analysis is attempted for this type of summary data. Lastly, left censored data can be traced to find the exact time period during which the product has been claimed. In that case the left censored data can be taken as failure data. So similar type of reliability analysis is attempted for the resulting right censored data.

품질보증 반환 데이터의 여러 가지 분석방법

백재욱,조진남,Baik, Jaiwook,Jo, Jinnam 한국데이터정보과학회 2015 한국데이터정보과학회지 Vol.26 No.1

A certain number of products are transported to be sold each month and some of them are returned for repair. In this study we first assume that the transported products are the ones that have been sold, Then nonparametric approach is applied to the warranty returns data to see how the reliability decreases over time. Parametric approach such as Weibull distribution is applied to the same data and the results for both nonparametric and parametric approaches are compared. Next we assume that there is a time lag between shipment and sale. Then both nonparametric and parametric approaches are applied to the time-lag data and the results are compared.

PSR 모델을 적용한 근로환경조사 지표 개발

김영선,조진남,Kim, Youngsun,Jo, Jinnam 한국통계학회 2014 응용통계연구 Vol.27 No.7

본 연구에서는 업종에 따른 다양한 근로환경 요인들을 파악하고 관련 분야의 산업안전보건 정책을 판단할 수 있도록 근로환경조사 기초자료를 분석하여 사회요인을 고려한 지수 및 지표 개발을 목표로 하였다. 지표개발을 위해 OECD에서 제시하는 지표개발 가이드라인과 해외의 지표개발 사례들을 벤치마킹하여 수행되었다. OECD의 압력-상태-대응 모형을 벤치마킹하여 건강과 관련 있는 지표들을 제시하였다. 근로환경조사의 압력-상태 건강관련 지표는 압력은 물리적 위험환경, 노동시간, 업무환경, 사회 환경으로 구성되었고, 이에 따른 상태 항목은 건강관련 항목으로 정신건강, 신체건강, 건강문제로 인한 결근, 업무 만족으로 구성되었다. 그 결과 임금근로자, 상용근로자, 관리자, 사무종사자, 전문가 및 관련 종사자, 50세 미만 근로자의 압력-상태 지표가 상대적으로 양호하였다. 반대로, 50세 이상, 자영업자, 일용 직, 농림어업 숙련직, 단순노무, 장치 기계 조립 근로자의 압력-상태 지표가 상대적으로 취약한 것으로 나타났다.

키워드 네트워크의 클릭 분석을 이용한 특허 데이터 분석

김현,김동건,조진남,Kim, Hyon Hee,Kim, Donggeon,Jo, Jinnam 한국데이터정보과학회 2016 한국데이터정보과학회지 Vol.27 No.5

본 연구에서는 기계 학습 분야의 특허를 수집하여 키워드 네트워크를 구축하고 클릭 분석을 실시하였다. 먼저 텍스트 마이닝 기법을 적용하여 핵심 키워드들을 선정한 다음, 이 키워드를 기반으로 키워드 네트워크를 구축하였다. 다음으로 네트워크 구조 분석, 중요 키워드 분석 및 클릭 분석을 시행하여 2005년도와 2015년도에 출원된 기계 학습 특허의 동향을 파악하였을 뿐만 아니라 양해년도의 분석 결과를 통해 특허 경향을 파악하였다. 분석 결과 기계 학습 특허의 키워드 네트워크는 밀도와 군집 계수가 낮은 것으로 드러났으며 기계 학습 기법 자체에 대한 특허보다는 다양한 응용 영역에서 기계학습을 적용한 특허들이 다수이기 때문으로 판단된다. 클릭 분석 결과 2005년도 클릭 분석에 의해 발견된 주제는 뉴스메이커 검증, 상품 소비 예측, 바이러스 공격 예방, 바이오마커, 그리고 워크플로우 관리였으며, 2015년도 기계 학습 특허 주제는 디지털 이미지 편집, 직불카드, 수신자 인라이닝 시스템, 유방 촬영 시스템, 재고 관리 시스템, 이미지 편집 시스템, 비행기 티켓 가격 예측, 그리고 문제 예측 시스템으로 나타났다. 2005년도에 비하여 2015년도의 근접 중앙성은 낮아지고 매개 중심성은 높아진 것으로 보아 최근의 특허 경향은 보다 다양한 분야에서 출원되고 있으며 이들 간의 연결이 활발해지고 있음을 알 수 있다. 클릭 분석은 클릭을 형성하는 키워드 집합을 해석하여 주제를 파악하는데 활용될 수 있을 뿐만 아니라 추출된 공유 멤버쉽 키워드 집합은 특허 검색 시스템과 같이 키워드 검색 기반의 시스템에서 검색 키워드로 활용될 수 있을 것으로 기대된다.

키워드 커뮤니티 네트워크의 소셜 네트워크 분석을 이용한 사물 인터넷 특허 분석

김도현,김현희,김동건,조진남,Kim, Do Hyun,Kim, Hyon Hee,Kim, Donggeon,Jo, Jinnam 한국통계학회 2016 응용통계연구 Vol.29 No.4

In this paper, we analyzed IoT patent data using the social network analysis of keyword community network in patents related to Internet of Things technology. To identify the difference of IoT patent trends between Korea and USA, 100 Korea patents and 100 USA patents were collected, respectively. First, we first extracted important keywords from IoT patent abstracts using the TF-IDF weight and their correlation and then constructed the keyword network based on the selected keywords. Second, we constructed a keyword community network based on the keyword community and performed social network analysis. Our experimental results showed while Korea patents focus on the core technologies of IoT (such as security, semiconductors and image process areas), USA patents focus on the applications of IoT (such as the smart home, interactive media and telecommunications).

산업재해 예방정책에 대한 평가모형

김영선(Youngsun Kim),조진남(Jinnam Jo),백재욱(Jaiwook Baik) 한국신뢰성학회 2017 신뢰성응용연구 Vol.17 No.1

Purpose: The purpose of this study is to introduce the assessment model for industrial accidents prevention policy. Methods: 10 years of industrial accidents data are explored through EDA approach. Case control study is tried in order to assess the effectiveness of the measures taken by Korea Safety and Health Agency, Civilian, and ‘Ministry of Employment and Labor’. Propensity score matching is used to match the characteristics of the two groups compared, and then case control study is again conducted. Next, logistic and Poisson regressions are used to assess the risk factors. Results: According to case control study involvement of ‘Korea Safety and Health Agency’ and ‘Ministry of Employment and Labor’ were not effective, but Civilian was. Propensity score matching leads to the same conclusion. Poisson regression reveals the impact of the risk factors on the industrial accidents. Industrial accidents occur more often as the number of employees grows. Mining, farming, fishing, ‘transportation·storage and telecommunication’ and forestry have a higher level of industrial accidents but service industry has a lower level. It is odd that more involvement of Korea Safety and Health Agency, Civilian, and Ministry of Employment and Labor means more industrial accidents. Conclusion: ‘Korea Safety and Health Agency’, Civilian, and ‘Ministry of Employment and Labor’ seem to visit those industries with more industrial accidents.

변기 및 세탁기 가정용수 사용량의 시계열모형 연구

명성민,김동건,이두진,김화수,조진남,Myoung, Sungmin,Kim, Donggeon,Lee, Doo-Jin,Kim, Hwa Soo,Jo, Jinnam 한국데이터정보과학회 2013 한국데이터정보과학회지 Vol.24 No.6

End-uses of household water have been influenced by a housing type, life style and housing area which are considered as internal factors. Also, there are external factors such as water rate, weather and water supply facilities. Analysis of influential factors on water consumption in households would give an explanation on the cause of changing trends and would help predicting the water demand of end-use in household. In this paper, we used real data to predict toilet and laundry water-uses and utilized the linear regression model with autoregressive errors. The results showed that the monthly autoregressive error models explained about 71% for describing the water demand of end-use in toilet and laundry water-uses.

음용수의 염소살균부산물(DBPs)인 염화지방족화합물의 QSAR 독성예측치에 대한 열역학적 분자표현자의 역할(Ⅱ)

김재현(Jae Hyoun Kim),조진남(Jinnam Jo) 한국환경성돌연변이발암원학회 2001 한국환경성돌연변이·발암원학회지 Vol.21 No.2

The predictive screening of various molecular descriptors for predicting carcinogenic, mutagenic, teratogenic and alkylation activity of chlorinated disinfection byproducts (DBPs) has been investigated for the application of quantitative structure-activity relationships (QSAR). The toxicity index for 29 compounds were<br/> computed by the PASS program and active values were employed in this study. Studies show that different descriptors account for the model equation of each genotoxic endpoint, and that thermodynamic descriptors significantly played a major role on prediction of endpoints of chlorinated aliphatic compounds.

국가별 관심도 측정을 위한 온톨로지 기반 위키피디아 사용 데이터 분석

김현희(Hyon Hee Kim),조진남(Jinnam Jo),김동건(Donggeon Kim) 한국컴퓨터정보학회 2014 한국컴퓨터정보학회논문지 Vol.19 No.4

In this paper, we propose an ontology-based approach to measuring degree-of-interest in country by analyzing wikipedia usage data. First, we developed the degree-of-interest ontology called DOI ontology by extracting concept hierarchies from wikipedia categories. Second, we map the title of frequently edited articles into DOI ontology, and we measure degree-of-interest based on DOI ontology by analyzing wikipedia page views. Finally, we perform chi-square test of independence to figure out if interesting fields are independent or not by country. This approach shows interesting fields are closely related to each country, and provides degree of interests by country timely and flexibly as compared with conventional questionnaire survey analysis.