• Title/Summary/Keyword: Pearson's Correlation

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On the Study of Perfect Coverage for Recommender System

  • Lee, Hee-Choon;Lee, Seok-Jun
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1151-1160
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    • 2006
  • The similarity weight, the pearson's correlation coefficient, which is used in the recommender system has a weak point that it cannot predict all of the prediction value. The similarity weight, the vector similarity, has a weak point of the high MAE although the prediction coverage using the vector similarity is higher than that using the pearson's correlation coefficient. The purpose of this study is to suggest how to raise the prediction coverage. Also, the MAE using the suggested method in this study was compared both with the MAE using the pearson's correlation coefficient and with the MAE using the vector similarity, so was the prediction coverage. As a result, it was found that the low of the MAE in the case of using the suggested method was higher than that using the pearson's correlation coefficient. However, it was also shown that it was lower than that using the vector similarity. In terms of the prediction coverage, when the suggested method was compared with two similarity weights as I mentioned above, it was found that its prediction coverage was higher than that pearson's correlation coefficient as well as vector similarity.

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A Study on the Maximizing Coverage for Recommender System

  • Lee, Hee-Choon;Lee, Seok-Jun;Park, Ji-Won;Kim, Chul-Seoung
    • 한국데이터정보과학회:학술대회논문집
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    • 2006.11a
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    • pp.119-128
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    • 2006
  • The similarity weight, the pearson's correlation coefficient, which is used in the recommender system has a weak point that it cannot predict all of the prediction value. The similarity weight, the vector similarity, has a weak point of the high MAE although the prediction coverage using the vector similarity is higher than that using the pearson's correlation coefficient. The purpose of this study is to suggest how to raise the prediction coverage. Also, the MAE using the suggested method in this study was compared both with the MAE using the pearson's correlation coefficient and with the MAE using the vector similarity, so was the prediction coverage. As a result, it was found that the low of the MAE in the case of using the suggested method was higher than that using the pearson's correlation coefficient. However, it was also shown that it was lower than that using the vector similarity In terms of the prediction coverage, when the suggested method was compared with two similarity weights as I mentioned above, it was found that its prediction coverage was higher than that pearson's correlation coefficient as well as vector similarity.

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Identifying Spatial Distribution Pattern of Water Quality in Masan Bay Using Spatial Autocorrelation Index and Pearson's r (공간자기상관 지수와 Pearson 상관계수를 이용한 마산만 수질의 공간분포 패턴 규명)

  • Choi, Hyun-Woo;Park, Jae-Moon;Kim, Hyun-Wook;Kim, Young-Ok
    • Ocean and Polar Research
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    • v.29 no.4
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    • pp.391-400
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    • 2007
  • To identify the spatial distribution pattern of water quality in Masan Bay, Pearson's correlation as a common statistic method and Moran's I as a spatial autocorrelation statistics were applied to the hydrological data seasonally collected from Masan Bay for two years ($2004{\sim}2005$). Spatial distribution of salinity, DO and silicate among the hydrological parameters clustered strongly while chlorophyll a distribution displayed a weak clustering. When the similarity matrix of Moran's I was compared with correlation matrix of Pearson's r, only the relationships of temperature vs. salinity, temperature vs. silicate and silicate vs. total inorganic nitrogen showed significant correlation and similarity of spatial clustered pattern. Considering Pearson's correlation and the spatial autocorrelation results, water quality distribution patterns of Masan Bay were conceptually simplified into four types. Based on the simplified types, Moran's I and Pearson's r were compared respectively with spatial distribution maps on salinity and silicate with a strong clustered pattern, and with chlorophyll a having no clustered pattern. According to these test results, spatial distribution of the water quality in Masan Bay could be summed up in four patterns. This summation should be developed as spatial index to be linked with pollutant and ecological indicators for coastal health assessment.

On the Effect of Significance of Correlation Coefficient for Recommender System

  • Lee, Hee-Choon
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1129-1139
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    • 2006
  • Pearson's correlation coefficient and vector similarity are generally applied to The users' similarity weight of user based recommender system. This study is needed to find that the correlation coefficient of similarity weight is effected by the number of pair response and significance probability. From the classified correlation coefficient by the significance probability test on the correlation coefficient and pair of response, the change of MAE is studied by comparing the predicted precision of the two. The results are experimentally related with the change of MAE from the significant correlation coefficient and the number of pair response.

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Evaluation of Reliability and Validity of the Louisville Instrument for Transplantation (LIFT) in Korean Population (한글판 Louisville Instrument for Transplantation 설문지의 신뢰도 및 타당도 평가)

  • Kim, Hong-Min;Kim, Ji-Hoon;Hwang, Jae-Ha;Kim, Kwang-Seog;Lee, Sam-Yong
    • Archives of Plastic Surgery
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    • v.38 no.3
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    • pp.245-250
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    • 2011
  • Purpose: Composite tissue allotransplantation has emerged as a new therapeutic modality to reconstruct major tissue defects of the head, neck and extremities. A questionnaire-based instrument, the Louisville Instrument for Transplantation (LIFT), has been developed to objectively assess the risk-versus-benefit ratio for composite tissue allotransplantation procedures. The objective of this study is to assess if the LIFT is a useful, reliable and valid tool to apply to the Korean population. Methods: Seventy-three medical students and 60 lay public completed the LIFT questionnaire (translated to Korean) over the period from February 2010 to April 2010. Internal consistency was assessed using Cronbach's alpha. Test-retest reliability was analyzed using Pearson's correlation coefficient. Construct validity was assessed by comparing Pearson's correlation coefficients between perceived improvements in quality of life and responses to risk tolerance questions concerning organ transplants. Results: Measurements of the test-retest reliability showed that Pearson's correlation coefficients ranged from 0.241 to 0.902, and Cronbach's alphas ranged from 0.52 to 0.80 for medical students and from 0.63 to 0.83 for the lay public. Pearson's correlation coefficients showed significant correlations between perceived improvements in quality of life and responses to risk tolerance questions concerning organ transplants. Hand transplant showed a significant correlation in medical students. Foot, hand, two hands, larynx, partial face transplants showed significant correlations for the lay public. Conclusion: The applicability of the LIFT to the Korean population was found to be reliable and valid. The LIFT may serve as a useful tool for clinical application in the Korean population.

Secure Multi-Party Computation of Correlation Coefficients (상관계수의 안전한 다자간 계산)

  • Hong, Sun-Kyong;Kim, Sang-Pil;Lim, Hyo-Sang;Moon, Yang-Sae
    • Journal of KIISE
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    • v.41 no.10
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    • pp.799-809
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    • 2014
  • In this paper, we address the problem of computing Pearson correlation coefficients and Spearman's rank correlation coefficients in a secure manner while data providers preserve privacy of their own data in distributed environment. For a data mining or data analysis in the distributed environment, data providers(data owners) need to share their original data with each other. However, the original data may often contain very sensitive information, and thus, data providers do not prefer to disclose their original data for preserving privacy. In this paper, we formally define the secure correlation computation, SCC in short, as the problem of computing correlation coefficients in the distributed computing environment while preserving the data privacy (i.e., not disclosing the sensitive data) of multiple data providers. We then present SCC solutions for Pearson and Spearman's correlation coefficients using secure scalar product. We show the correctness and secure property of the proposed solutions by presenting theorems and proving them formally. We also empirically show that the proposed solutions can be used for practical applications in the performance aspect.

Relations of School Organizational Climate and Teachers' Job Stresses (학교조직풍토와 교사의 직무스트레스의 관계)

  • LEE, Kyeong-Hwa;JUNG, Hye-Young
    • Journal of Fisheries and Marine Sciences Education
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    • v.21 no.1
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    • pp.121-133
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    • 2009
  • This study tested the relations of schools organizational climate and teachers' job stresses, perceived by 913 teachers from 45 elementary, junior- and senior-high schools. Pearson's correlation analysis for the relations between the sub-factors of both organizational climate and job stresses and cannonical correlation analysis for the relative contribution of individual variable of organizational climate upon job stress were applied for the test. The results of Pearson's correlation analysis showed that while 'intimacy', 'esprit', 'considerations', and 'production emphasis' climate had negative correlations with job stress sub-factors, 'disengagement' and 'aloofness' climate had positive correlation. 'Student guidance', a sub-factor of job stresses, did not have statistically significant correlation with any sub-factors of organizational climate. Findings from cannonical correlation analysis showed 2 significant cannonical functions to explain the relations between the sets of variables. 'Disengagement' from organizational climate positively contributed with 'authority forfeiture' and 'dissention and conflict' of the job stresses variables.

A Study on the Effect of Co-Ratings and Correlation Coefficient for Recommender System

  • Lee, Hee-Choon;Lee, Seok-Jun;Park, Ji-Won;Kim, Chul-Seung
    • 한국데이터정보과학회:학술대회논문집
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    • 2006.11a
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    • pp.59-69
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    • 2006
  • Pearson's correlation coefficient and Vector similarity are generally applied to The users' similarity weight of user based recommender system. This study is needed to find that the correlation coefficient of similarity weight is effected by the number of pair response and significance probability. From the classified correlation coefficient by the significance probability test on the correlation coefficient and pair of response, the change of MAE is studied by comparing the predicted precision of the two. The results are experimentally related with the change of MAE from the significant correlation coefficient and the number of pair response.

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Reliability and validity of free software for the analysis of locomotor activity in mice

  • Hong, Yoo Rha;Moon, Eunsoo
    • Journal of Yeungnam Medical Science
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    • v.35 no.1
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    • pp.63-69
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    • 2018
  • Background: Kinovea software that tracking semi-automatically the motion in video screen has been used to study motion-related tasks in several studies. However, the validation of this software in open field test to assess locomotor activity have not been studied yet. Therefore, this study aimed to examine the reliability and validity of this software in analyzing locomotor activities. Methods: Thirty male Institute Cancer Research mice were subjected in this study. The results examined by this software and the classical method were compared. Test-retest reliability and inter-rater reliability were analyzed with Pearson's correlation coefficient and intraclass correlation coefficient (ICC). The validity of this software was analyzed with Pearson's correlation coefficient. Results: This software showed good test-retest reliability (ICC=0.997, 95% confidence interval [CI]=0.975-0.994, p<0.001). This software also showed good inter-rater reliability (ICC=0.987, 95% CI=0.973-0.994, p<0.001). Furthermore, in three analyses for the validity of this software, there were significant correlations between two methods (Pearson's correlation coefficient=0.928-0.972, p<0.001). In addition, this software showed good reliability and validity in the analysis locomotor activity according to time interval. Conclusion: This study showed that this software in analyzing drug-induced locomotor activity has good reliability and validity. This software can be effectively used in animal study using the analysis of locomotor activity.