• 제목/요약/키워드: correlation methods

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영상신호를 이용한 상관방식 추적기에 대한 간단한 수학적인 해석 (A Simple Mathematical Analysis of Correlation Target Tracker in Image Sequences)

  • Cho, Jae-Soo;Park, Dong-Jo
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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    • pp.485-488
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    • 2003
  • A conventional correlation target tracker is analysed with a simple mathematical approach. And, we will propose a correlation measure with selective attentional property in order to overcome the false-peak problem of the conventional methods. Various experimental results show that the proposed correlation measure is able to reduce considerably the probability of false-peaks degraded by the correlation between background images of a reference block and a distorted and noisy sensor input image.

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ppcor: An R Package for a Fast Calculation to Semi-partial Correlation Coefficients

  • Kim, Seongho
    • Communications for Statistical Applications and Methods
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    • 제22권6호
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    • pp.665-674
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    • 2015
  • Lack of a general matrix formula hampers implementation of the semi-partial correlation, also known as part correlation, to the higher-order coefficient. This is because the higher-order semi-partial correlation calculation using a recursive formula requires an enormous number of recursive calculations to obtain the correlation coefficients. To resolve this difficulty, we derive a general matrix formula of the semi-partial correlation for fast computation. The semi-partial correlations are then implemented on an R package ppcor along with the partial correlation. Owing to the general matrix formulas, users can readily calculate the coefficients of both partial and semi-partial correlations without computational burden. The package ppcor further provides users with the level of the statistical significance with its test statistic.

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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통계적 기법을 이용한 국지성집중호우의 이동경로 분석 (Rainstorm Tracking Using Statistical Analysis Method)

  • 김수영;남우성;허준행
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회 논문집
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    • pp.194-198
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    • 2005
  • Although the rainstorm causes local damage on large scale, it is difficult to predict the movement of the rainstorm exactly. In order to reduce the rainstorm damage of the rainstorm, it is necessary to analyze the path of the rainstorm using various statistical methods. In addition, efficient time interval of rainfall observation for the analysis of the rainstorm movement can be derived by applying various statistical methods to rainfall data. In this study, the rainstorm tracking using statistical method is performed for various types of rainfall data. For the tracking of the rainstorm, the methods of temporal distribution, inclined Plane equations, and cross correlation were applied for various types of data including electromagnetic rainfall gauge data and AWS data. The speed and direction of each method were compared with those of real rainfall movement. In addition, the effective time interval of rainfall observation for the analysis of the rainstorm movement was also investigated for the selected time intervals 10, 20, 30, 40, 50, and 60 minutes. As a result, the absolute relative errors of the method of inclined plane equations are smaller than those of other methods in case of electromagnetic rainfall gauges data. The absolute relative errors of the method of cross correlation are smaller than those of other methods in case of AWS data. The absolute relative errors of 30 minutes or less than 30 minutes are smaller than those of other time intervals.

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Spatio-Temporal Correlation을 이용한 동영상 오류 은닉 알고리즘 (Error Concealment Algorithm using Spatio-Temporal Correlation)

  • 이우찬;서동철;김용철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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    • pp.2113-2115
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    • 2006
  • This paper proposes a spatio-temporal correlation algorithm that takes advantage of the spatial and temporal correlations in video streams for error concealment. The spatio-temporal correlation algorithm sets the neighborhood area of the damaged part as a reference window, then finds the area that best matches the reference window in the previous frame. The best-matched area in the previous frame replaces the damaged part in the current frame. The results of ten variations of the proposed algorithm are compared with conventional error concealment methods. These methods include the ones applicable to P-frames as well as I-frames. The comparison results show that the proposed algorithm is very efficient for l-frame error concealment with a large motion between frames.

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SSTDR에서 시간-주파수 상관을 활용한 저압 케이블의 고장 검출 (Fault Detection of Low Voltage Cable using Time-Frequency Correlation in SSTDR)

  • 전정채;김택희;유재근
    • 전기학회논문지
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    • 제64권3호
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    • pp.498-504
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    • 2015
  • This paper proposed an Spread Spectrum Time Domain Reflectometry (SSTDR) using time-frequency correlation analysis in order to have more accurate fault determination and location detection than classical SSTDR despite increased signal attenuation due to the long distance to cable fault location. The proposed method was validated through comparison with classical SSTDR methods in open- and short-circuit fault detection experiments of low-voltage power cables. The experimental results showed that the proposed method can detect correlation coefficients at fault locations accurately despite reflected signal attenuation so that cable faults can be detected more accurately and clearly in comparison to existing methods.

마스크 생산 라인에서 영상 기반 마스크 필터 검사를 위한 계층적 상관관계 기반 이상 현상 탐지 (Hierarchical Correlation-based Anomaly Detection for Vision-based Mask Filter Inspection in Mask Production Lines)

  • 오건희;이효진;이헌철
    • 대한임베디드공학회논문지
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    • 제16권6호
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    • pp.277-283
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    • 2021
  • This paper addresses the problem of vision-based mask filter inspection for mask production systems. Machine learning-based approaches can be considered to solve the problem, but they may not be applicable to mask filter inspection if normal and anomaly mask filter data are not sufficient. In such cases, handcrafted image processing methods have to be considered to solve the problem. In this paper, we propose a hierarchical correlation-based approach that combines handcrafted image processing methods to detect anomaly mask filters. The proposed approach combines image rotation, cropping and resizing, edge detection of mask filter parts, average blurring, and correlation-based decision. The proposed approach was tested and analyzed with real mask filters. The results showed that the proposed approach was able to successfully detect anomalies in mask filters.

A Study on the Health and Non Health Related Major University Students on Smartphone Addiction and the Correlation with Oral Health Behavior

  • Jang, Jung Yoo
    • International Journal of Clinical Preventive Dentistry
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    • 제14권4호
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    • pp.222-227
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    • 2018
  • Objective: The university students of the four universities located in the Gyeongbuk province district were studied to confirm the correlation between smartphone addiction and oral health behavior. Methods: The target audience was a total of 587 people, and from April 18, 2017 until June 10, 2017, collected data using individual questionnaire methods and analyzed using the IBM SPSS WIN 24.0 program. Results: Smartphone addiction was high in health related major, and oral health behaviors were high in non health related major. And the first grade students who smoke and drinking showed a high correlation between smartphone addiction and oral health behavior. Conclusion: It is possible to confirm the correlation between smartphone addiction of university students and oral health behaviors, and the smartphone guideline and appropriate oral health education program are required.

빅데이터에서의 상관성 측도 (Correlation Measure for Big Data)

  • 정해성
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제18권3호
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    • pp.208-212
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    • 2018
  • Purpose: The three Vs of volume, velocity and variety are commonly used to characterize different aspects of Big Data. Volume refers to the amount of data, variety refers to the number of types of data and velocity refers to the speed of data processing. According to these characteristics, the size of Big Data varies rapidly, some data buckets will contain outliers, and buckets might have different sizes. Correlation plays a big role in Big Data. We need something better than usual correlation measures. Methods: The correlation measures offered by traditional statistics are compared. And conditions to meet the characteristics of Big Data are suggested. Finally the correlation measure that satisfies the suggested conditions is recommended. Results: Mutual Information satisfies the suggested conditions. Conclusion: This article builds on traditional correlation measures to analyze the co-relation between two variables. The conditions for correlation measures to meet the characteristics of Big Data are suggested. The correlation measure that satisfies these conditions is recommended. It is Mutual Information.

An elaboration on sample size determination for correlations based on effect sizes and confidence interval width: a guide for researchers

  • Mohamad Adam Bujang
    • Restorative Dentistry and Endodontics
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    • 제49권2호
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    • pp.21.1-21.8
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    • 2024
  • Objectives: This paper aims to serve as a useful guide for sample size determination for various correlation analyses that are based on effect sizes and confidence interval width. Materials and Methods: Sample size determinations are calculated for Pearson's correlation, Spearman's rank correlation, and Kendall's Tau-b correlation. Examples of sample size statements and their justification are also included. Results: Using the same effect sizes, there are differences between the sample size determination of the 3 statistical tests. Based on an empirical calculation, a minimum sample size of 149 is usually adequate for performing both parametric and non-parametric correlation analysis to determine at least a moderate to an excellent degree of correlation with acceptable confidence interval width. Conclusions: Determining data assumption(s) is one of the challenges to offering a valid technique to estimate the required sample size for correlation analyses. Sample size tables are provided and these will help researchers to estimate a minimum sample size requirement based on correlation analyses.