• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1844-1847
• /
• 1997

Assuming that EEG(electroencephalogram), which is generated by a nonlinear electrical of billions of neurons in the brain, has chaotic characteristics, it is confirmend by frequency spectrum analysis, log frequency spectrum analysis, correlation dimension analysis and Lyapunov exponents analysis. Some chaotic characteristics are related to the degree of brain activity. The slope of log frequency spectrum increases and the correlation dimension decreasess with respect to the activities, while the largest Lyapunov exponent has only a rough correlation.

• 대한전기학회논문지:전력기술부문A
• /
• 제48권4호
• /
• pp.478-485
• /
• 1999

The purpose of this paper was the determination of the relationship between the chaotic charateristics and various levels of brain activities. Assuming that EEG(eletroencephalogram), which is generated by a nonlinear electiecal behavior of billions of neurons in the brain, has chaotic characteristics, it was confirmed by frequency spectrum analysis, log frequency spectrum analysis, correlation dimension analysis and Lyapunov exponents analysis. Chaotic characteristics are related to the degree of brain activity. The slope of log frequency spectrum increased and the correlation dimension decreased with respect to the brain activities, while the lagrest Lyapunov exponent has some rough correlation.

• 화약ㆍ발파
• /
• 제39권4호
• /
• pp.1-11
• /
• 2021

본 연구에서는 기계식 해체공법을 적용한 슬래브 해체 시 발생하는 진동을 분석하기 위해 진동 자료를 획득하였다. 획득한 진동 자료는 부착장치에 따라 구별하여 파형 및 우세주파수 분석을 수행하였고, 작업위치와 계측위치 사이의 거리를 측정하는 방법을 달리하여 상관관계를 분석하였다. 부착 장치 별 파형분석 결과 장비 작업에 의한 진동 파형의 위상 변화는 거의 없고 진동속도의 크기인 진폭의 변화만 일어났으며, 주파수 분석 결과 압쇄기를 사용한 경우 브레이커를 사용한 경우에 비해 주파수 대역이 낮으며, 해체 대상 건축물의 고유 진동수와 주파수 대역이 근접하였다. 상관관계 분석결과 작업 위치와 계측위치의 이격거리는 상호 간의 직선거리가 아닌 실제 건축물을 따라 진동이 전파하는 경로로 평가해야 높은 상관성을 보임을 확인하였다.

• 한국치위생학회지
• /
• 제18권6호
• /
• pp.1025-1035
• /
• 2018

Objectives: This study examined dental hygiene students' frequency of participation in community volunteer activities, job consciousness, depression, and self-esteem, and then identified the correlation among them. We also analyzed the moderating effect of depression and self-esteem on the correlation between participation in community volunteer activities and job consciousness. Methods: We surveyed 312 dental hygiene students attending four universities in South Chungcheong Province, Korea, from May 2 to June 15, 2016, through direct visits. They were given structured questionnaires containing four items on community volunteer activities, three on job consciousness, ten on self-esteem, and 13 on depression. To examine the moderating effect of depression and self-esteem, we performed analysis of variance, correlation analysis, and structural equation modeling analysis (based on the path analysis model and by inserting interaction terms) using SPSS and AMOS. Results: We observed a negative correlation between self-esteem and depression (r=-0.062) but a positive correlation between self-esteem and job consciousness (r=0.125). Depression and job consciousness had a negative correlation (r=-0.176). Depression had a statistically significant impact on job consciousness (r=-0.519, p<0.01). The interaction term between depression and frequency of community volunteer activities also had a statistically significant influence on job consciousness (r=0.090, p<0.05). These findings indicate that depression moderates the correlation between frequency of community volunteer activities and job consciousness at a statistically significant level. Conclusions: More frequent participation in volunteer activities enhances dental hygiene students' self-esteem, reduces depression, and raises job consciousness. The positive impact of volunteering on self-esteem, depression, and job consciousness warrants encouraging students' participation in community volunteer activities, creating supportive structures, and developing various volunteer programs relevant to the students' area of study.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권2호
• /
• pp.495-513
• /
• 2020

The correlation identification of the subsurface is a novel electrical prospecting method which could suppress stochastic noise. This method is increasingly being utilized by geophysicists. It achieves the frequency response of the underground media through division of the cross spectrum of the input & output signal and the auto spectrum of the input signal. This is subject to the spectral leakage when the cross spectrum and the auto spectrum are computed from cross correlation and autocorrelation function by Discrete Fourier Transformation (DFT, "To obtain an accurate frequency response of the earth system, we propose an improved correlation identification method which uses all phase Fast Fourier Transform (APFFT) to acquire the cross spectrum and the auto spectrum. Simulation and engineering application results show that compared to existing correlation identification algorithm the new approach demonstrates more precise frequency response, especially the phase response of the system under identification.

• East Asian Economic Review
• /
• 제19권2호
• /
• pp.189-220
• /
• 2015

Multi-scale representations are effective in characterising the time-frequency characteristics of financial return series. They have the capability to reveal the properties not evident with typical time domain analysis. Given the aforesaid, this study derives crucial insights from multi scale analysis to investigate the co-movements between Indian and emerging Asian equity markets using wavelet correlation and wavelet coherence measures. It is reported that the Indian equity market is strongly integrated with Asian equity markets at lower frequency scales and relatively less blended at higher frequencies. On the other hand the results from cross correlations suggest that the lead-lag relationship becomes substantial as we turn to lower frequency scales and finally, wavelet coherence demonstrates that this correlation eventually grows strong in the interim of the crises period at lower frequency scales. Overall the findings are relevant and have strong policy and practical implications.

• 대한한의진단학회지
• /
• 제10권2호
• /
• pp.132-150
• /
• 2006

Objectives : The objective is that we measure and analyze Pulse-Respiration Ratio and Body Composition Analysis to study the correlation between both. Methods : First, after subjects take a rest over 10 minutes, we measure their electrocardiogram and respiration pattern through which we take average peak interval to calculate an average pulse cycle and a respiration cycle. An average respiration cycle divided by an average Pulse Rate gives Pulse-Respiration Ratio. Next, we draw out 22 Body Composition Analysis indicators by using In-Body 720 model. Last, we analyze and take statistics on them by using SPSS 13.0 program. Results : Negative is the correlation between P/R Ratio and Body Composition Analysis indicator like fatness degree, body fat volume, body fat rate, abdominal fatness, BMI. Conclusions : 1. The higher P/R Ratio the more likely to be thin, the lower P/R Ratio the more likely to be fat. 2. We separately analyze P/R Ratio depending on each breathing frequency and pulse frequency to find out that breathing frequency has great influence and that breathing frequency decides the fatness degree. 3. In study on the correlation between P/R Ratio and Body Composition Analysis, fatness degree, in-body fat volume, in-body fat rate, BMI are the related indicators, which shows the connection with the fatness indicators. 4. In study on the correlation between Han-Yeol [寒熱] grade and Body Composition Analysis indicators, the result is that Han[寒] has no connection and that only Yeol[熱] grade has something to do with it, which means the higher heat symptom subjects have, the more basic metabolism volume and muscular build they have.

• 대한물리치료과학회지
• /
• 제28권1호
• /
• pp.54-61
• /
• 2021

Background: The present study was performed to examine the factors required for active engagement of participants in exercise therapy by surveying the frequency of participation, fidelity of performance, and supporting materials and rewards provided to encourage participation in the study. Design: Cross-sectional study. Methods: The survey was conducted in a population of 103 participants in at least one exercise treatment study. A 12-item questionnaire was designed to determine the frequency of exercise participation and fidelity of participant performance. Results: The results were subjected to frequency analysis and Pearson's correlation analysis. The subjects were less likely to exercise with the therapist and less likely to exercise at home. In addition, the provision of supplementary materials, to be considered when exercising at home, was insufficient. A strong positive correlation was found between the frequency of exercise in the presence of a therapist and the fidelity of participant performance (r=0.812, p=0.001), whereas a weak negative correlation was found between the frequency of unperformed exercises and the fidelity of participant performance (r=-0.523, p=0.023). Conclusion: The results of the present study suggested that it is necessary to increase the number of times that exercises are performed with the therapist to motivate increased frequency of exercise participation and fidelity of participant performance. In addition, appropriate rewards and periodic management are required.

• 한국조리학회지
• /
• 제15권3호
• /
• pp.225-235
• /
• 2009

본 연구는 대학생들의 올바른 식생활 습관을 유도하기 위하여 부산 지역 남녀 대학생 282명을 대상으로 외식 행동, 식생활 습관, 패스트푸드 섭취 빈도가 비만도와의 상관관계를 조사하였다. 이를 확인하기 위하여 SPSS 통계프로그램 14.0을 활용하여 빈도분석, 요인 및 신뢰도분석, $\x^2$-test, t-test, 상관관계분석을 실시하였다. 분석결과, 비만도와 건강에 좋지 않은 음식을 자주 섭취하는 식생활 습관과는 상관관계 p<0.01에서 유의하였고, 비만도와 패스트푸드 섭취 빈도는 유의수준 p<0.01에서 상관관계가 있었다. 한편, 비만도와는 규칙적인 식생활 습관과는 음의 상관관계 유의수준 p<0.05에서 유의하였다. 따라서 대학생들의 비만도와는 식생활 습관과 패스트푸드 섭취 빈도와는 상관관계가 있는 것으로 확인되었다.

• Journal of Nutrition and Health
• /
• 제46권1호
• /
• pp.26-33
• /
• 2013

The purpose of this study was to investigate the sodium intake of office workers using 24-hour urine analysis and to analyze the correlation matrix between variables. The sodium intake of the subjects (n = 137), based on a 24-hr sodium excretion period, was male (n = 56) 6072.4 mg and female (n = 81) 5,168.2 mg. Urinary sodium excretion showed significant positive correlation with BMI, frequency of eating out, expenditure of eating out, salty taste assessment and high-salt dietary behavior. Analysis of urinary sodium excretion showed significant positive correlation with intake frequencies of cabbage kimchi, broiled fish, feast noodle and rice with leaf wraps. Based on the results of multiple regression, urinary sodium excretion was found to be related to intake frequencies of cabbage kimchi, broiled fish, rice with leaf wraps and high score of high-salt dietary behavior.