• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.13-15
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• 2006

microRNA는 유전자의 전사 후 과정에서 negative regulation을 담당하는 small noncoding RNA의 한 증류이다. 최근까지 330여개의 인간 microRNA가 발견되었지만 그들의 기능이 밝혀진 것은 소수에 불과하다. microRNA의 기능은 3'UTR에 불완전 상보결합을 통해 negative regulation을 받게 되는 유전자의 기능으로부터 유추되는 것이 일반적이다. 특별히 유전체상에 군집화 된 microRNA들은 하나의 전사체로부터 발현되는 것으로 판단되며, 같은 또는 관련된 기능을 하거나 같은 목표 유전자를 조절하기 위한 functional family일 가능성이 높다. 또한 이러한 functional family는 하나의 전사체로부터 발현되기 때문에, 조직별로 조건별로 같은 발현 패턴을 보여야 한다. 본 연구에서는 발현데이터로부터 microRNA functional family를 탐색하기 위해, 5개의 연구 그룹에서 공개한 조직별 microRNA 발현데이터를 표준화 작업을 거친 후 통합하고 k-nearest neighbor 알고리즘을 이용해 결측치를 보정한 후 microRNA 발현사이의 correlation을 계산한다. 이때 데이터 통합에서 생기는 문제에 robust한 결과를 얻기 위해 실제 발현데이터가 아닌 rank 데이터부터 correlation을 측정한다. 계산된 spearman ranked correlation 결과와 microRNA의 genomic coordination 정보로부터 34개의 functional family를 정의할 수 있었다.

• Communications for Statistical Applications and Methods
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• v.19 no.3
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• pp.367-379
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• 2012

In baseball rankings, prediction has been a subject of interest for baseball fans. To predict these rankings, (based on 2011 data from Korea Professional Baseball records) the arithmetic mean method, the weighted average method, principal component analysis, and principal component regression analysis is presented. By standardizing the arithmetic average, the correlation coefficient using the weighted average method, using principal components analysis to predict rankings, the final model was selected as a principal component regression model. By practicing regression analysis with a reduced variable by principal component analysis, we propose a rank predictability model of a pitcher part, a batter part and a pitcher batter part. We can estimate a 2011 rank of pro-baseball by a predicted regression model. By principal component regression analysis, the pitcher part, the other part, the pitcher and the batter part of the ranking prediction model is proposed. The regression model predicts the rankings for 2012.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.129-137
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• 2014

In this study, the characteristics of exhaust gas as a function of the biodiesel mixing ratio were investigated. Diesel and waste oil were used for preparing mixed fuel, and the ratios of the mixed fuel were varied in the BD3~BD100 range. The injection pressures(${\Delta}p_{inj}$) was considered as an experimental variable and was set to 400 bar, 600 bar, 800 bar, 1000 bar, and 1200 bar. Furthermore, for quantitatively analyzing the characteristics of exhaust gas(NOx and Soot), the concepts of Pearson correlation coefficient and Spearman rank-order correlation coefficient based on statistics were introduced. Consequently, it was found that the correlation of the emission of NOx and Soot is linear, and the Pearson and Spearman coefficients are -0.732 and -0.724, respectively, under all analysis conditions. Especially, for the injection pressure of 800 bar, a simultaneous reduction in NOx and Soot emission is possible by controlling the biodiesel mixing ratio. This is because the correlation coefficients of NOx and Soot emissions were nearly 0, as the Pearson correlation coefficient was -0.089.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.558-568
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• 2023

The spatio-temporal distribution of the sand crab Ovalipes punctatus larvae was investigated in the Korean waters in 2019. Sea surface temperature (SST) was the lowest in February and highest in September. Sea surface salinity (SSS) was the lowest in September and highest in March. Further, sea surface chlorophyll a (SSC) was the highest in September. Larvae were distributed in the South Sea and coastal area of Jeju Island from April to June, and the abundance was the highest in May. The spatio-temporal distribution analysis suggested that larval groups showed a tendency to be dispersed over a wider area as the larvae developed, due to the increase in their swimming ability. The correlation analysis between environmental factors and larval density suggested that larvae appeared in the SST range 11.8-20.9℃ and SSS range 31.5-35.3 psu. The Megalopal stage appeared in a wider range of SST and SSS than other larval stages, possibly due to the increased environmental tolerance before settlement. Results of redundancy analysis (RDA) and Spearman's rank correlation analysis between the larval density by developmental stages and the environmental factors suggested that SST showed a positive correlation and SSC showed a negative correlation in the later stage.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.6
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• pp.913-927
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• 2010

This study investigates the influence of Likert scale formats such as the number of response categories and the inclusion of a mid-point from a methodological point of view using instruments that measure a fashionmarketing-related subject. Using a self-administered questionnaire, 201 respondents rated their economic clothing shopping orientation on three formats of scales that differed only in the number of response categories (ranging from 5 to 7) from February 8 to February 12, 2010. Descriptive statistics, Spearman's rank order correlation, t-test, exploratory factor analysis, confirmatory factor analysis, Pearson's correlation, and Cronbach's alpha were used in the analysis. The results are as follows. First, three scale formats were generally suitable for use due to validity and reliability. Second, the response results varied with the number of categories and the inclusion of a mid-point, although the differences were statistically insignificant (with only a few cases that differed). Third, construct validity was more secure in scales with fewer categories, whereas convergent and discriminant validity was generally good in all scale formats. Fourth, reliability coefficients were higher in scales with more categories. Fifth, the number of categories was of greater importance to instrument design than the inclusion of a mid-point. Implications for appropriate scale designs are suggested in this study.

• Geomechanics and Engineering
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• v.31 no.2
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• pp.129-147
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• 2022

The properties of soil are naturally highly variable and thus, to ensure proper safety and reliability, we need to test a large number of samples across the length and depth. In pile foundations, conducting field tests are highly expensive and the traditional empirical relations too have been proven to be poor in performance. The study proposes a state-of-art Particle Swarm Optimization (PSO) hybridized Artificial Neural Network (ANN), Extreme Learning Machine (ELM) and Adaptive Neuro Fuzzy Inference System (ANFIS); and comparative analysis of metaheuristic models (ANN-PSO, ELM-PSO, ANFIS-PSO) for prediction of bearing capacity of pile foundation trained and tested on dataset of nearly 300 dynamic pile tests from the literature. A novel ensemble model of three hybrid models is constructed to combine and enhance the predictions of the individual models effectively. The authenticity of the dataset is confirmed using descriptive statistics, correlation matrix and sensitivity analysis. Ram weight and diameter of pile are found to be most influential input parameter. The comparative analysis reveals that ANFIS-PSO is the best performing model in testing phase (R² = 0.85, RMSE = 0.01) while ELM-PSO performs best in training phase (R² = 0.88, RMSE = 0.08); while the ensemble provided overall best performance based on the rank score. The performance of ANN-PSO is least satisfactory compared to the other two models. The findings were confirmed using Taylor diagram, error matrix and uncertainty analysis. Based on the results ELM-PSO and ANFIS-PSO is proposed to be used for the prediction of bearing capacity of piles and ensemble learning method of joining the outputs of individual models should be encouraged. The study possesses the potential to assist geotechnical engineers in the design phase of civil engineering projects.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.456-456
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• 2017

지구온난화에 의한 태풍강도 증가로 한반도지역은 잠재적 위험성에 항상 노출되어있다. 따라서 본 연구는 한강의 대표적 다목적댐인 소양강댐을 대상으로 한반도 태풍영향을 정량화하고 그에 따른 수문변화특성을 피어슨 상관분석(Pearson Correlation)과 순위 분석(Rank Analysis)을 이용하여 조사하였다. 지오포텐셜 고도자료와 GPCP 강우자료를 분석한 결과 소양강댐의 여름철 유출량 중 태풍에 의한 유출이 크지 않았지만 엘리뇨에서 라니냐로 전환되는 시기의 태풍에 의한 유출량은 반 이상을 차지할 정도로 크게 나타났다. Rank분석결과 태풍발생비율(n/N)에 대한 첨두유량의 변화는 크지만 첨두유량의 발생빈도와 지속시간의 변화는 뚜렷하지 않은 것으로 나타났고 첨두발생시간은 더 지연되는 특성을 보였다. 그러나 High Flow 분석결과에서는 첨두유량과 첨두유량의 발생시기 변화의 통계적 유의성은 나타나지 않았으나 첨두유량 이상의 유출발생빈도와 지속기간은 증가하는 것으로 나타났다. 본 연구는 해수면 온도 변화에 따른 대규모 대기 순환패턴과 소양강댐 유역의 수문변화특성의 관계를 파악하기 위한 기초자료를 제공할 것으로 기대된다.

• Journal of Hospice and Palliative Care
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• v.18 no.1
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• pp.51-59
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• 2015

Purpose: Predicting life expectancy of terminally ill cancer patients is very important. In many studies, ferritin is detected at higher levels in the sera of cancer patients, and higher ferritin level correlates with aggressiveness of disease and poor outcomes of patients. This study evaluated a prognostic role of serum ferritin levels in terminally ill cancer patients. Methods: This study enrolled 65 terminally ill cancer patients from March through June 2012. We assessed routine laboratory findings including serum ferritin levels as well as demographic and clinical characteristics of the patients. To examine the association between serum ferritin levels and patient's characteristics, we used Spearman's correlation analysis, Wilcoxon's rank sum test or Kruskal-Wallis test, as appropriately. For multivariate analysis, Cox's proportional hazard regression model was used to evaluate significance of serum ferritin levels as a prognostic factor. Results: A negative correlation between serum ferritin levels and survival time was found. After adjusting for sex, age, performance status, creatinine levels and white blood cell counts, serum ferritin levels were significantly associated with survival time. Conclusion: Even at the very end of life of terminal cancer patients, serum ferritin levels were an independent prognostic factor for survival.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.2
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• pp.234-243
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• 1994

This research has studied situational effects on the perceived risk and store choice behavior. Data were obtained from 388 females with full-time jobs living in Pusan. The results analyzed by Spearman's rank correlation analysis, analysis of variance(ANOVA), 1-test and discriminant analysis. The results of this study were as follows; 1. There were significant differences in percieved risk according to the clothing purchasing situations. Performance risk was perceived high in gift-shopping situation and time-pressured situation, and financial risk was perceived high in self-shoving situation. 2. There were particularly significant differences in store attributes evaluation according to the clothing purchasing situations. In self-shopping situation, price, quality and reliability, store loyalty were evaluated as important store attributes. In gift-shopping situation, quality and reliability, product iuomation and in time-pressured situation, store loyalty and product information were evaluated as important store attributes. 3. Consumers preferred national brand franchise stores in self-shopping situation. They preferred department stores in gift-shopping situation and time-pressured situation. The types of selected store were mainly affetted by shopping convenience and location convenience.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.177-186
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• 2019

The purpose of this study was to investigate the influences of the smartphone overuse on health and academic impairment in adolescents. This study used data from Korea youth risk behavior web-based survey of 2017. This survey was conducted on 64,991 adolescents(middle and high school students), and 62,276 (95.8%) responded. The researchers used frequency analysis, independent t test, chi-square test and Pearson correlation analysis using SPSS 22. As a result, the usage rate of adolescents's smartphone was 54,603 out of 62,276, which was 87.7%. The purpose of smartphone usage was messenger(1st rank, 27.3%), SNS(2nd rank, 18.7%) and game(3rd rank, 13.3%). The average daily use time of the smartphone was 206.68±194.73 minutes. Girl students showed significantly more use time of smartphones than boy students(p<.001). Students with more than 206 minutes of smartphone use had worse health and academic performance than students with less than 206 minutes(p<.001). Time of smart phone usage and academic ability showed a weak correlation(p<.001, r=.245). The present findings showed that the higher the smartphone usage, the lower the health level and academic ability, and the author discussed these results.