• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2002.11a
• /
• pp.220-229
• /
• 2002

협력적 추천 기법은 유사한 이웃의 선호도를 이용하여 고객에게 개인화된 아이템을 추천해 주는 방법으로 비교적 높은 정확도를 보이며 추천 시스템의 중심으로 연구되어져 왔다. 그러나, 지금까지의 추천 시스템은 도메인의 특성을 제대로 고려하지 못한채 추천을 시행함으로써 특정 도메인에서 추천의 정확도가 떨어지는 문제점이 발생하였다. 이러한 문제점들을 보완하기 위하여 본 논문에서는 평균 고객 유사도, 평균 아이템 유사도, 밀집도 등의 추천 선행 평가 척도를 제안하고, 추천 선행평가 척도와 추천의 정확도와의 상관관계를 보이며, 이를 이용하여 짧은 수행시간 안에 추천 적용이 가능한 마케팅 도메인 및 고객군을 선정하는 방법을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.351-354
• /
• 2002

최근 생명공학 기술과 분석화학 기술의 발달로 생물 유전 데이터를 대량으로 얻는 것이 가능하게 되었다. 아울러 이렇게 얻어진 데이터를 적절하게 처리하고 분석하는 방법들도 여러 가지가 소개되어 왔다. 본 논문에서는 DNA 마이크로어레이 정보를 분류하기 위하여 세 가지 데이터에 대하여 여러 가지 특징 전혀 방법으로 선택된 유전자들을 사용하여 신경망 분류기에 적용시켜 보았다. 실험 결과 백혈병 데이터의 경우 피어슨 상관계수를 이용한 분류가 97.1%로 가장 높은 인식률을 보여주었다. 한편 여러 가지 특징 선택 방법에 의하여 공통적으로 선택된 유전자를 사용하여 분류하면 더 높은 인식률이 나올 것 같았지만 실제로는 기대에 못 미치는 성과를 보여주었다. 따라서 무조건 여러 번 선택된 특징을 선택하기 보다는 특징들끼리의 상관관계를 고려하여 선택하는 방법이 필요할 것이다.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.3
• /
• pp.83-92
• /
• 2004

Gene expression profile is numerical data of gene expression level from organism measured on the microarray. Generally, each specific tissue indicates different expression levels in related genes, so that we can classify cancer with gene expression profile. Because not all the genes are related to classification, it is needed to select related genes that is called feature selection. This paper proposes a new gene selection method using forward selection method in regression analysis. This method reduces redundant information in the selected genes to have more efficient classification. We used k-nearest neighbor as a classifier and tested with colon cancer dataset. The results are compared with Pearson's coefficient and Spearman's coefficient methods and the proposed method showed better performance. It showed 90.3% accuracy in classification. The method also successfully applied to lymphoma cancer dataset.

• Journal of the Korean Data and Information Science Society
• /
• v.26 no.4
• /
• pp.931-946
• /
• 2015

Many multiple life insurance products consider benefits that are contingent on the combined survival status of two lives. To value premiums of the insurance products accurately, we need to consider the impact of the survivorship of one life on another. To show a dependence relation between married couple, we calculate correlation coefficients by using married couples data from National Pension Service and the results show some positive dependence between them. Moreover, by analyzing the death after bereavement, we find a evidence that mortality rates increase after the death of a spouse and, in addition, that this phenomenon, the broken-heart syndrome, diminishes over time. The results of this study can support the method to calculate the premium of multiple life insurance reflecting more realistic joint mortality rates.

• The Korean Journal of Applied Statistics
• /
• v.16 no.1
• /
• pp.151-167
• /
• 2003

Although there exist numerous measures of association, most of them are lacking in generality in that they do not intend to measure the association between heterogeneous type of random variables. On the other hand, many statistical analyzes dealing with complex data sets require a very sophisticate measure of association. In this note, the p-value of independence tests is utilized to obtain a measure of association. The proposed measure of association have some consistency in measuring association between various types of random variables.

• The Korean Journal of Applied Statistics
• /
• v.34 no.4
• /
• pp.523-536
• /
• 2021

Although there exist numerous measures of association, most of them are lacking in generality in that they do not intend to measure the association between heterogeneous type of random variables. On the other hand, many statistical analyzes dealing with complex data sets require a very sophisticate measure of association. In this note, the p-value of independence tests is utilized to obtain a measure of association. The proposed measure of association have some consistency in measuring association between various types of random variables.

• The Journal of Bigdata
• /
• v.2 no.1
• /
• pp.41-48
• /
• 2017

Recently, the popularity of the recommendation system and the evaluation of the performance of the algorithm of the recommendation system have become important. In this study, we used modeling and RMSE to verify the effectiveness of various algorithms in movie data. The data of this study is based on user-based collaborative filtering using Pearson correlation coefficient, item-based collaborative filtering using cosine correlation coefficient, and item-based collaborative filtering model using singular value decomposition. As a result of evaluating the scores with three recommendation models, we found that item-based collaborative filtering accuracy is much higher than user-based collaborative filtering, and it is found that matrix recommendation is better when using matrix decomposition.

• The Journal of Korean Academy of Sensory Integration
• /
• v.20 no.2
• /
• pp.11-21
• /
• 2022

Objective : This study examined the test-retest reliability and interrater reliability of the Sensory Processing Scale for Children (SPS-C). Method : Senventy primary caregivers of children with sensory processing difficulties and 3 years old participated in the study. The subjects were recruited through child development centers, welfare centers, and acquaintances located in Seoul, Gyeonggi-do, Busan, and Gyeongsang-do. The test-retest reliability verification targeted 20 main caregivers of children with difficulty in sensory processing. Re-evaluation was performed within 7 to 14 days after the initial evaluation, and Pearson's correlation coefficient was used to confirm the relevance between the two time points, and the Intraclass correlation coefficient was used to confirm the degree of agreement. The interrater reliability verification was conducted with 18 primary caregivers and 18 subsidiary caregivers of children with sensory processing difficulties. Each caregiver evaluated the same child, and the Intraclass correlation coefficient was used to confirm the agreement between the two sets of caregivers. Results : The test-retest reliability was Pearson's correlation coefficient r=.914 and intraclass correlation coefficient ICC=.939, indicating a high level of relevance and agreement. The interrater reliability was an Intraclass correlation coefficient ICC=.727, which showed a moderate level of agreement, but the tactile area (ICC=.455) and proprioceptive area (ICC=.439) were not statistically significant and showed a low degree of agreement. Conclusion : Through this study, it was confirmed that the children's Sensory Processing Scale for Children (SPS-C) is a stable evaluation tool with test-retest reliability and interrater reliability verified, and it will be able to provide help in standardization studies for future clinical use.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.28-28
• /
• 2022

본 연구는 용담댐유역을 포함한 금강 유역 상류 지역을 대상으로 Sentinel-1 SAR (Synthetic Aperture Radar) 위성영상을 기반으로 한 토양수분 산정을 목적으로 하였다. Sentinel-1 영상은 2019년에 대해 12일 간격으로 수집하였고, 영상의 전처리는 SNAP (SentiNel Application Platform)을 활용하여 기하 보정, 방사 보정 및 Speckle 보정을 수행하여 VH (Vertical transmit-Horizontal receive) 및 VV (Vertical transmit-Vertical receive) 편파 후방산란계수로 변환하였다. 토양수분 산정에는 Water Cloud Model (WCM)이 활용되었으며, 모형의 식생 서술자(Vegetation descriptor)는 RVI (Radar Vegetation Index)와 NDVI (Normalized Difference Vegetation Index)를 활용하였다. RVI는 Sentinel-1 영상의 VH 및 VV 편파자료를 이용해 산정하였으며, NDVI는 동기간에 대해 10일 간격으로 수집된 Sentinel-2 MSI (MultiSpectral Instrument) 위성영상을 활용하여 산정하였다. WCM의 검정 및 보정은 한국수자원공사에서 제공하는 10 cm 깊이의 TDR (Time Domain Reflectometry) 센서에서 실측된 6개 지점의 토양수분 자료를 수집하여 수행하였으며, 매개변수의 최적화는 비선형 최소제곱(Non-linear least square) 및 PSO (Particle Swarm Optimization) 알고리즘을 활용하였다. WCM을 통해 산정된 토양수분은 피어슨 상관계수(Pearson's correlation coefficient)와 평균제곱근오차(Root mean square error)를 활용하여 검증을 수행할 예정이다.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.27 no.1
• /
• pp.24-31
• /
• 2000

The purpose of study was to compare the laser fluorescence detection by Diagnodent(KaVo, Germany), visual inspection using dental explorers, and conventional dental radiography as diagnostic tests for dental caries. One hundred and three human premolars and molars which had no caries or fissure caries were tested by the three methods. Diagnodent scores increased as the scores of the other two tests increased(P<0.01) There were significant relationships between visual inspection scores and Diagnodent scores(Pearson 0.676, Spearman 0.694) and between radiography scores and Diagnodent scores(Pearson 0.623, Spearman 0.658) (P<0.01, all). Diagnodent test proved to have high sensitivity and low specificity and more studies are necessary to present the diagnostic criteria for progressive caries stages.