• 제목/요약/키워드: cross correlation analysis

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다중채널 뇌파를 이용한 감정상태 분류에 관한 연구 (A Study on the Emotion State Classification using Multi-channel EEG)

  • 강동기;김흥환;김동준;이병채;고한우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 D
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    • pp.2815-2817
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    • 2001
  • This study describes the emotion classification using two different feature extraction methods for four-channel EEG signals. One of the methods is linear prediction analysis based on AR model. Another method is cross-correlation coefficients on frequencies of ${\theta}$, ${\alpha}$, ${\beta}$ bands. Using the linear predictor coefficients and the cross-correlation coefficients of frequencies, the emotion classification test for four emotions, such as anger, sad, joy, and relaxation is performed with a neural network. Comparing the results of two methods, it seems that the linear predictor coefficients produce the better results than the cross-correlation coefficients of frequencies for-emotion classification.

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시계열 분석을 이용한 하천수위에 따른 다심도 관정의 지하수위 변동해석 (Time Series Analysis of the Responses of the Groundwater Levels at Multi-depth Wells According to the River Stage Fluctuations)

  • 하규철;고경석;고동찬;염병우;이강근
    • 자원환경지질
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    • 제39권3호
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    • pp.269-284
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    • 2006
  • 지하수위와 하천수위와의 상호반응과 수리적으로 다른 특성을 가지는 각 층별(실트질 모래층, 자갈모래층, 풍화대층) 반응관계를 알아보기 위하여 시계열 분석에서 많이 사용되어 온 방법인 자기상관분석과 교차상관분석방법을 이용하였다. 만경강 하천부지에 각 층을 대표하는 깊이에서 지하수위를 관측한 결과, 지하수위가 강수량보다는 하천수위변동에 민감하게 반응하고 있었다. 연구지역의 하천수위변동은 만경강 제수문의 조절과 조석의 영향을 받아 주기적인 수위변동이 우세하기 때문에 강수량과의 상관성은 낮다. 다심도 관정에서 각층별 하천수위에 대한 지하수위 반응은 시간지연 없이 서로 같이 변동하는 것으로 나타났으며, 반응시간은 하천과 가까운 관정에서 30-60분 이내로 빠르며 하천에서 거리가 멀어지면서 반응시간은 대체로 늦게 나타났다. 그러나 하천과 멀리 떨어져 있는 관정이더라도 하천수위에 대하여 빠른 반응을 보이는 관정이 있으며, 이는 하천과 대수층과의 높은 수리적 연결성을 나타낸다. 지하수위의 하천에 대한 반응양상이 다르게 나타나는 것은 대수층의 수리적 불균질성에 의한 것으로 사료된다. 연구지역의 하천은 대체로 지하수위가 하천수위보다 높게 관측되고 있기 때문에 지하수가 하천으로 유출되는 이득하천의 성격을 가지고 있다고 판단되나, 하천의 급격한 수위상승에 따라 역으로 하천의 물이 지하수로 공급되는 손실하천의 성격도 보여주었다. 하천수위와 대수층이 연결된 시스템에서 시계열분석으로서의 자기 및 교차상관분석은 수리적 상호관계를 파악하기 위한 유용한 도구로 활용될 수 있다.

4대강 주요지점에서의 조류 발생인자의 배타적 상관성분석에 대한 연구 (Exclusive correlation analysis for algae and environmental factors in weirs of four major rivers in South Korea)

  • 이은형;김연화;김경현;김상현
    • 한국수자원학회논문집
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    • 제49권2호
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    • pp.155-164
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    • 2016
  • 남조류의 대번성은 특정 생물종의 감소와 물고기의 서식처를 감소하게 하는 결과를 가져와서 생태계에 상당한 교란을 가져오고 4대강의 수질을 위협하고 있다. 조류의 대번성에 영향을 미치는 인자를 해석하기 위해서 전통적으로 클로르필 a의 농도와 환경인자간의 교차상관함수를 계산하는 방식이 수행되어왔다. 교차상관함수에 사용되는 원 시계열 자료는 추계구조에 의해 영향을 받기 때문에 시계열 데이터의 추계학적인 구조를 파악하고 외부의 영향을 제거하는 선백색화 기법을 도입하였다. 이와 같은 모의과정은 모형구조의 파악, 매개변수추정, 선택된 모형의 자가진단수행등의 일련의 과정으로 진행된다. 선백색화 처리된 데이터를 이용하여 배타적 상관분석을 실시하였고 원데이터의 결과와 비교하였다. 이와 같은 과정은 조류농도 발생의 영향 인자를 구분하기 위해서도 유용한 과정이고 다른 환경인자들 사이에서의 인과성을 규명하는데도 유용하다.

담배 약에서 유기된 반수체 배가계통의 변이, 상관 및 경로분석 (Correlation Coefficients and Path - Analysis of Various Characteristics of Dihaploids derived from Tobacco (Nicotiana tabacco L.)Anther Culture in vitro)

  • 금완수;제상율
    • 한국연초학회지
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    • 제3권1호
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    • pp.41-48
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    • 1981
  • Dihaploid lines were derived from the anthers of the F, of single cross, "Va 115" x"SC 72" (Nicotiana tabacum L.). The path-analysis, correlation coefficient, and variation of characteristics among dihaploid families were evaluated. Dihaploid lines displayed much greater variation than their parents. The genetic correlation coefficient between yield and total alkaloids of dihaploids was significantly lower than that of conventional varieties and lines. In path-analysis which relates yield components to yield, number of leaves harvested and leaf width had a direct effect on yield. a direct effect on yield.

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Effect of Cross-legged Sitting Posture on Joint Range of Motion: Correlation with Musculoskeletal Symptoms and Facial Asymmetry

  • Shin, Yeong hui
    • The Journal of Korean Physical Therapy
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    • 제34권5호
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    • pp.255-266
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    • 2022
  • Purpose: This study sought to study the effects of cross-legged sitting posture on joint motion. It also examined the correlation between the changes in the joint range of motion, musculoskeletal symptoms, and facial asymmetry. Methods: The Acumar Digital Inclinometer (Lafayette Instrument Company, USA) was used to measure the range of motion (ROM). We measured the flexion and extension of the cervical, thoracic, and lumbar spine using a dual inclinometer, and measured the ROM of the shoulder and hip joint with a single inclinometer. The Likert scale questionnaire was used to investigate musculoskeletal symptoms and facial asymmetry. Results: The data analysis was performed using the Jamovi version 1.6.23 statistical software. After confirming the normality of the ROM with descriptive statistics, it was compared with the normal ROM through a one-sample t-test. Correlation matrix analysis was performed to confirm the association between facial asymmetry and musculoskeletal symptoms. The result of the one-sample t-test showed a significant increase in the thoracic spine extension and right and left hip external rotation (p<0.001***), while most other joints were restricted. As per the frequency analysis, facial asymmetry was found to be 81.70%. Conclusion: The independent variable, namely cross-legged sitting posture led to an increase in ROM. The study also suggests that facial asymmetry and musculoskeletal symptoms could occur. Therefore, to prevent the increase and limitation of ROM and to prevent the occurrence of facial asymmetry and musculoskeletal symptoms, it is suggested that the usual cross-legged sitting posture should be avoided.

General Purpose Cross-section Analysis Program for Composite Rotor Blades

  • Park, Il-Ju;Jung, Sung-Nam;Kim, Do-Hyung;Yun, Chul-Yong
    • International Journal of Aeronautical and Space Sciences
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    • 제10권2호
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    • pp.77-85
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    • 2009
  • A two-dimensional cross-section analysis program based on the finite element method has been developed for composite blades with arbitrary cross-section profiles and material distributions. The modulus weighted approach is used to take into account the non-homogeneous material characteristics of advanced blades. The CLPT (Classical Lamination Plate Theory) is applied to obtain the effective moduli of the composite laminate. The location of shear center for any given cross-sections are determined according to the Trefftz' definition while the torsion constants are obtained using the St. Venant torsion theory. A series of benchmark examples for beams with various cross-sections are illustrated to show the accuracy of the developed cross-section analysis program. The cross section cases include thin-walled C-channel, I-beam, single-cell box, NACA0012 airfoil, and KARI small-scale blades. Overall, a reasonable correlation is obtained in comparison with experiments or finite element analysis results.

A Comparative Content Analysis on the Journal of International Marketing: A Study of Ten Years (2004-2013)

  • Shin, Dong-Jin
    • 유통과학연구
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    • 제12권5호
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    • pp.81-92
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    • 2014
  • Purpose - This paper aims to investigate topics and trends in international marketing and cross-cultural management by conducting a content analysis of the Journal of International Marketing. Research Design, Data, and Methodology - In this study, one of the leading journals in the field of international marketing, the Journal of International Marketing, was chosen for research. A total of 199 articles were identified from a time span of ten years (2004-2013). SPSS software was used for codification and analysis of the data. Results - This study revealed some of the factors on which cross-cultural management had a strong correlation with international marketing. Of the 199 articles in the Journal of International Marketing, 64 articles related to cross-cultural management. Conclusions - A content analysis of the Journal of International Marketing comparing general articles with articles related to cross-cultural management is unprecedented. This study offers insight into the impact of cross culture on the discipline of international marketing. The findings of this research could be employed as a reference for gaining insight into the trends and influence of cross-cultural management in international marketing.

거시경제변수를 고려한 기술평가모형의 개선 : 기술보증기금의 사례 (An Improved Technology Appraisal Model Considering Macroeconomic Variable : A Case of KOTEC)

  • 김대철;김재범;조근태
    • 경영과학
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    • 제30권2호
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    • pp.117-132
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    • 2013
  • The objective of this paper is to provide an improved technology appraisal model, which considers a variety of macroeconomic variables such as consumer price index and producer price index. The improved model was built using cross correlation analysis and logistic regression analysis. The AUROC analysis showed that goodness-of-fit of the proposed model turned out to be improved than that of the existing model. The model proposed in the paper would be helpful for making a reasonable investments and financing decision, lessening the default rates by systematic risk management, and enhancing the technology commercialization capabilities.

혈액학적 인자가 심혈관 질환 위험지수에 미치는 영향 (Effect of Hematological Factors on the Risk Index of Cardiovascular Disease)

  • 안현;윤현서;박충무
    • 대한방사선기술학회지:방사선기술과학
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    • 제46권4호
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    • pp.303-313
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    • 2023
  • This study aimed to investigate the relevance of cardiovascular disease risk factors AI and AIP, divided into three groups, among 300 individuals who underwent health checkups at the hospital. Various variables such as Age, Sex, BMI, WC, TC, TG, HDL-C, LDL-C, FBS, HbA1C, SBP, DBP, HR, AI (TC/HDL-C), and AIP (log(TG/HDL-C)) were analyzed using statistical methods including frequency analysis, cross-tabulation, one-way ANOVA, Pearson's correlation analysis, and multiple linear regression analysis. The cross-analysis based on cardiovascular disease risk criteria revealed that men and individuals in their 50s had higher cardiovascular disease risk based on AI and AIP. Significant differences were observed in TG, TC, HDL-C, LDL-C, SBP, DBP, AI (TC/HDL-C), and AIP (log(TG/HDL-C)) according to AI criteria. For the AIP criteria, TG, TC, HDL-C, FBS, HbA1C, HR, AI (TC/HDL-C), and AIP (log(TG/HDL-C)) were identified as cardiovascular disease risk factors. FBS and HbA1c showed the highest positive correlation In the correlation analysis, followed by TC and LDL-C. The lowest positive correlation was observed between LDL-C and DBP. In terms of negative correlation, HDL-C and AI had the highest negative correlation, while LDL-C and TG showed the lowest negative correlation. Multiple regression analysis indicated that the AI and AIP risk criteria had explanatory powers of 73.6% and 72.5%, respectively. HDL-C had the greatest negative effect on the AI risk criterion, while TG had the most significant influence on the AIP risk criterion. In conclusion, while other serological variables are important, managing HDL-C and TG levels may help reduce the risk of cardiovascular disease.

Revisiting the measurement of keratinized gingiva: a cross-sectional study comparing an intraoral scanner with clinical parameters

  • Ahmet Mert Nalbantoglu;Deniz Yanik
    • Journal of Periodontal and Implant Science
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    • 제53권5호
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    • pp.362-375
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    • 2023
  • Purpose: The aim of this study was to investigate the relationships between gingival thickness (GT) and keratinized gingiva width (KGW), papilla height (PH), and crown ratio (CR) by employing transgingival probing and an intraoral scanner (IOS). Methods: This cross-sectional study examined 360 maxillary anterior teeth from 60 patients. GT was assessed using transgingival probing with an endodontic spreader. KGW, CR, and PH were measured using an IOS. One-way analysis of variance, the Student's t-test, and Spearman correlation coefficients were employed for statistical analysis. Results: Higher GT was significantly associated with thinner KGW in the central region (P=0.019). There was no statistically significant difference in GT between teeth (P=0.06). PH was lower in lateral teeth than in canines (P=0.047), with a PH of 2.99 mm in lateral teeth. The KGW was narrower in canines than in central teeth (P=0.007). A moderate correlation was observed between KGW and PH in the central region (P=0.01), while a weak negative correlation was found between KGW and CR (P=0.043). Conclusions: A moderate negative correlation was found between GT and KGW, as well as between PH and KGW in central teeth. In contrast, a weak negative correlation existed between CR and KGW. The PH (2.99 mm) was lower in lateral teeth than in canines. The traditional paradigm, which suggests a positive correlation between KGW and GT, was reevaluated by measuring KGW using an IOS.