• 응용통계연구
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• 제29권7호
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• pp.1445-1458
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• 2016

본 논문에서는 1976년부터 2015년까지 40년 간, 59개 지역 기온 시계열을 대상으로 degrended cross-correlation analysis(DCCA) 방법을 이용한 상관 계수를 도출하였다. 4년 단위의 평균기온, 최고기온, 최저기온 시계열을 분석하여 상관계수 값이 0.9 이상이면 단위 기간 동안 두 지역의 온도 상관성이 존재하는 것으로 판단하고, 두 지역 간의 연결선을 만드는 방식으로 네트워크를 구축하였다. 이후 네트워크 이론을 바탕으로 평균 경로 길이, 결집 계수, 유사성, 모듈성 등의 값들을 도출하였다. 그 결과, 기온 네트워크는 좁은 세상 성질을 만족하고, 유사성과 모듈성이 높은 네트워크임을 알 수 있었다.

• 한국정보통신학회논문지
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• 제10권8호
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• pp.1471-1477
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• 2006

뇌파 기록은 난치성 간질 환자인 성인을 대상으로 하였다. 경막하 전극으로 부터 기록된 피질뇌파를 위상차해석에 의해서 간질 초점의 동정 및 발작파 전파의 가시화를 행하였다. 발작파의 세밀한 시간변화를 조사하기 위해서 자기 회귀모델, 웨이브렛해석을 이용하여 발작파 성분을 구하고, 상호상관법에 의해 각 전극 간의 위상차를 해석했다. 그 결과, 발작파의 초점은 적어도 2종류가 존재하였고, 각각의 전파방법도 달랐다. 이로 부터 발작파의 출현 기구는 동시에 적어도 2종류 존재하는 것을 확인할 수 있었다. 또한, 발작파 출현의 변화를 경시적으로 해석할 수 있기 때문에 발작파 전파의 가시화에 유효하다고 생각되어 진다.

• 한국운동역학회지
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• 제30권3호
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• pp.205-215
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• 2020

Objective: The purpose of this study was to investigate the relative angles and cross-correlation between body segments and ski among four alpine ski turning techniques. Method: 19 alpine ski instructors participated in this study. Each skier asked to perform 4- types of turning technique, classified by radius and level. 8 inertial measurement units were used to measure orientation angle of segment and ski on the anteroposterior and vertical axis. Results: Significant differences were found between types of turning in the segments-ski relative angle on the anteroposterior and vertical axis (p<.05). Although, cross-correlation showed a high correlation between angles of segment and ski, there were significant differences between types of turning. Conclusion: Based on our results, the relative movement and timing between each segment and ski is different according to the turning techniques, so the training methods should be applied differently.

• 한국정보통신학회논문지
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• 제17권12호
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• pp.2875-2882
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• 2013

여러 가지 디지털통신 시스템에서 많이 사용되고 있는 의사 난수열을 설계하는데 있어 가장 중요한 문제는 생성된 수열들 사이의 상호상관관계가 낮은 수열을 생성하는 것이다. 또한 설계된 이진수열의 상호상관관계의 빈도분석은 많은 연구자에 의해 연구되어왔다. 본 논문에서는 n=2m, $d=2^{n-1}(3{\cdot}2^m-1)$일 때 5-값 상호상관관계를 갖는 비선형 이진수열군 $S^r=\{Tr^m_1\{[Tr^n_m(a{\alpha}^t+{\alpha}^{dt}]^r\}{\mid}a{\in}GF(2^m),0{\leq}t &lt; 2^n-1\}$에 대한 상호상관관계에 대한 빈도 분석과 여러 가지 상호상관관계 성질을 분석한다. 여기서 $gcd(r,2^m-1)=1$이다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.781-784
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• 1994

Detecting partial discharge(PD) and locating its source are one of many diagnosis methods. Location the PD source is very important to reduce the time and cost of repairing power transformers. And to locate the PD source, the cross-correlation method is a well known one. But there many spurious peaks in cross-correlation, and occasionally, some peaks could be bigger than the true one. In order to analysis these spurious peaks and to reduce them, we have done many experiments and simulations. As the results we could reduce the spurious peaks, and get well defined cross-correlation from which it is easy to locate the PD source accurately.

• Smart Structures and Systems
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• 제16권1호
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• pp.213-222
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• 2015

Early detection and precise location of leakage is of great importance for life-cycle maintenance and management of municipal pipeline system. In the past few years, acoustic emission (AE) techniques have demonstrated to be an excellent tool for on-line leakage detection. Regarding the multi-mode and frequency dispersion characteristics of AE signals propagating along a pipeline, the direct cross-correlation technique that assumes the constant AE propagation velocity does not perform well in practice for acoustic leak location. This paper presents an improved cross-correlation method based on wavelet transform, with due consideration of the frequency dispersion characteristics of AE wave and the contribution of different mode. Laboratory experiments conducted to simulate pipeline gas leakage and investigate the frequency spectrum signatures of AE leak signals. By comparing with the other methods for leak location identification, the feasibility and superiority of the proposed method are verified.

• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.703-710
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• 2010

In this paper, an overload detecting algorithm for an excavator is presented. The proposed overload detecting algorithm is based on the time series analysis especially correlation function. The main purpose of this paper is to prevent damage or crack from the fatigue loaded on an excavator in advance. Generally, the larger data, the longer processing time, and the amount of the data used in this paper are also large, especially every sampling period, 1600 data are gathered and calculated. So this paper focuses on minimizing the number of required sensors by using the correlation function. From the cross correlation function, similar pattern sensors are eliminated and dissimilar pattern sensors are considered, and from the auto correlation function, the overload can be detected. To prove the efficiency of the proposed overload detecting algorithm, this paper shows the computer simulation results.

• 대한건축학회논문집:구조계
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• 제35권1호
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• pp.47-56
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• 2019

As the zero interest rate era was over with the end of quantitative easing, the economy of several global markets observed the fluctuations of the base interest rate. Interest rate, which is the change of money value with respect to time, is negatively correlated with construction investment. Considering the characteristics of interest rates and construction investment as economic variables, the necessity of cross-border analysis between base interest rate and construction investment was suggested in this paper. Cross-correlation analysis between base interest rates and construction investment crossing the border was performed. The effective correlations were confirmed with values varying by countries. Similar characteristics were also observed among countries with similar economy, which were then divided into three groups. Additionally, identifying the base interest rate that affects the construction investment of a particular country was made possible by reflecting a self-cycle of base interest rates. Lastly, from the result of examining the influence of each rise and fall of the interest rate, it was verified that the difference was more than twice as large in some countries. These results are expected to contribute to construction-related policy makers or investors to make decisions in response to the economic status of the construction market.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.810-831
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• 2019

Recently, continuous dimensional emotion recognition from audiovisual clues has attracted increasing attention in both theory and in practice. The large amount of data involved in the recognition processing decreases the efficiency of most bimodal information fusion algorithms. A novel algorithm, namely the incomplete Cholesky decomposition based kernel cross factor analysis (ICDKCFA), is presented and employed for continuous dimensional audiovisual emotion recognition, in this paper. After the ICDKCFA feature transformation, two basic fusion strategies, namely feature-level fusion and decision-level fusion, are explored to combine the transformed visual and audio features for emotion recognition. Finally, extensive experiments are conducted to evaluate the ICDKCFA approach on the AVEC 2016 Multimodal Affect Recognition Sub-Challenge dataset. The experimental results show that the ICDKCFA method has a higher speed than the original kernel cross factor analysis with the comparable performance. Moreover, the ICDKCFA method achieves a better performance than other common information fusion methods, such as the Canonical correlation analysis, kernel canonical correlation analysis and cross-modal factor analysis based fusion methods.

• 한국습지학회지
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• 제14권4호
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• pp.503-518
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• 2012

지면에서 탄소수지를 모의하는 모형들은 주로 수직적인 탄소 플럭스에 주된 관심을 두어왔다. 반면에 수평 적인 탄소 플럭스에 관한 연구는 부족한 실정이다. 따라서 수평적인 탄소 플럭스의 흐름에 대해 연구하고자 유역 내 식생에 의해 생산되는 총 일차생산량(Gross primary production, GPP)과 유역에서 배출되는 총 유기탄소(Total Organic Carbon, TOC)의 교차상관분석을 실시하였다. 분석결과, GPP와 유역에서 배출되는 TOC의 유량가중 평균 농도는 서로 지체시간이 없을 경우에 가장 큰 상관관계를 보여주고 있음을 확인하였다. 또한 주기성이 고려된 상관구조를 살펴본 결과, 여름철의 TOC와 GPP 사이의 상관관계가 주기성이 고려되지 않았을 경우의 상관관계와 유사하게 나타났다. 이로부터 GPP와 TOC의 상관관계는 여름철에 맺어지는 GPP와 TOC 상관관계에 의해서 대부분이 규정되고 있음을 살펴볼 수 있었다. 이에 따라 식생에 의해 생산된 탄소와 유역에서 배출되는 유기탄소의 관계가 계절적으로도 긴밀한 관계가 있을 것이라 추측된다. 따라서 향후 연구는 계절에 따른 식생변수와 GPP와 TOC의 관계를 분석함으로서 조금 더 정량적으로 수평적인 탄소 플럭스 흐름에 대해 이해 할 수 있을 것으로 기대된다.