• Title/Summary/Keyword: frequency and correlation analysis

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Low Frequency Relationship Analysis between PDSI and Global Sea Surface Temperature (PDSI와 범지구적 해수면온도와의 저빈도 상관성 분석)

  • Oh, Tae-Suk;Kim, Seong-Sil;Moon, Young-Il
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.3
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    • pp.119-131
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    • 2010
  • Drought is one of disaster causing factors to produce severe damage in the World because drought is destroyed to the ecosystem as well as to make difficult the economy of the drought area. This study, using Palmer Drought Severity Index carries out correlation analysis with sea surface temperatures. Comparative analysis carries out by calculated Palmer Drought Severity Index and past drought occurrence year. Result of comparative analysis, PDSI indexes were in accord with the past drought. Cluster analysis for correlation analysis carries out using precipitation and temperature that is input datas palmer drought severity index, and the result of cluster analysis was classified as 6. Also, principal component carries out using result of cluster analysis. 14 principal component analyze out through principal component analysis. Using analyzed 14 principal component carries out correlation analysis with sea surface temperature that is delay time from 0month until 11month. Correlation analysis carries out sea surface temperatures and calculated cycle component of the low frequency through Wavelet Transform analysis form principal component. Result of correlation analysis, yang(+) correlation is bigger than yin(-) correlation. It is possible to check similar correlation statistically the area of sea surface temperature with sea surface temperature in the Pacific. Forecasting possibility of the future drought make propose using sea surface temperature.

Temperature Effect-free Impedance-based Local Damage Detection (온도변화에 자유로운 임피던스 기반 국부 손상검색)

  • Koo, Ki-Young;Park, Seung-Hee;Lee, Jong-Jae;Yun, Chung-Bang
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.21-26
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    • 2007
  • This paper presents an impedance-based structural health monitoring (SHM) technique considering temperature effects. The temperature variation results in a significant impedance variation, particularly both horizontal and vertical shifts in the frequency domain, which may lead to erroneous diagnostic results of real structures. A new damage detection strategy has been proposed based on the correlation coefficient (CC) between the reference impedance data and a concurrent impedance data with an effective frequency shift which is defined as the shift causing the maximum correlation. The proposed technique was applied to a lab-sized steel truss bridge member under the temperature varying environment. From an experimental study, it has been demonstrated that a narrow cut inflicted artificially to the steel structure was successfully detected using the proposed SHM strategy.

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An Application of Canonical Analysis on the Distribution of Lichens in Mt. Duckyuoo (덕유산 지의식물 분포에 대한 정준분석법의 적용연구)

  • Park, Seung Tai
    • The Korean Journal of Ecology
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    • v.9 no.3
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    • pp.135-147
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    • 1986
  • The simplification and the searching trends of complex data which assumed relationship between predictor variables and object variables are one of primary objective of ecological research. This study was aimed to apply cononical analysis consisting of canonical correlation analysis and canonical variate analysis related to lichen vegetation and several environmental variables which are elevation, height on grond, exposure side and cover values. Data collected from the Duckyoo National Park in August 1985. Lichen species was ranked by eqivocation information theory with cover values. Canonical correlation analysis was applied to one data set both set both environmental variables and lichem family. In order to make two sets of data matrix the scale of position vector ordination was calculated from the vector scalar product for lichen species. Canonical variate analysis was applied to rearranged data which was made by interval class code for environmental variables. The sharpness values was calculated in frequency of cotingency tables and the dispersion profiles of each species in classes of environmental variables was designed to extract component values based on the decomposition of expected frequencies in contingency table. The results of canonical correlation analysis revealed canonical first correlation value 0.815(89%), and second correlation value 0.083(11%). Significance test showed that the hypothesis of joint mutuallity of canonical correlation is accepted (P>0.05). The relation between canonical score of vegetation variables and that of environmental variable indicated linear tendency.

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Consumer Satisfaction Survey on Health Care Convergence College Students at a University

  • CHOI, Eun-Mee
    • Journal of Wellbeing Management and Applied Psychology
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    • v.4 no.4
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    • pp.1-14
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    • 2021
  • Purpose: This study aims to measure the level of satisfaction with the overall education of current students, who are major consumers of education by department at the Health Care Convergence University, and to establish development strategies such as improving education quality and satisfaction by deriving problems and improvements. Research design, data and methodology: This study drew conclusions through secondary data analysis based on data surveyed by the Educational Performance Management Center of a university in the academic year of 2020. The target of the education consumer satisfaction survey was 470 students of the College in the academic year 2020. Frequency analysis and correlation analysis were applied to the data using the statistical package program SPSS 25 version. Results: In the major curriculum satisfaction survey, the department with the highest score was optics and optics, 4.11, and the department with the lowest score was medical IT, 3.29. Conclusions: The department with the highest correlation in the correlation analysis result of the demand survey by department was the Department of Medical Management and the Department of Medical IT, with a correlation coefficient r=0.984, and the lowest correlation in the correlation analysis result of the demand survey by department was the Department of Medical IT and Dental Hygiene, with a correlation coefficient r= -0.085.

Correlation Analysis of Between Paranasal Sinuses and Formant Frequency According to External Stimulation (외부 자극에 따른 부비동과 포먼트주파수와의 상관성 분석)

  • Kim, Bong-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.8
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    • pp.1955-1961
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    • 2013
  • Paranasal sinuses of the empty space is filled with air that exists in the bones in the face. However, the pus becomes inflamed paranasal sinuses sinusitis onset brings the voice of change, and complained of headaches and lethargy. Therefore, in this paper, paranasal sinuses related diseases to predict voice analysis parameter as measured by changes in paranasal sinuses through external stimuli is investigated and carried out a study to analysis the function consisting of the frontal sinus, ethmoid sinus, maxillary sinus, sphenoid sinus. From this, cold pack stimulation in the paranasal sinus area for stimulation before and after voice was performed by measuring formant frequency and external stimuli through correlation analysis of the mutual impact on paranasal sinuses were analyzed.

The effects of occupational stress on oral health impact profile (OHIP) in local government workers (지방공무원의 직무스트레스가 구강건강 삶의 질에 미치는 영향)

  • Hong, Min-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.12 no.3
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    • pp.471-483
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    • 2012
  • Objectives : This study looked at the relationship between occupational stress and the Oral Health Impact Profile (OHIP), to evaluate the effect of occupational stress-related factors. Methods : Data was obtained from a cross-sectional survey of 260 local officials in Gangwondo. The research comprised three questions relating to subjective oral symptoms, an occupational stress measurement tool and an oral health impact factor which was composed of questions. The data was analysed using t-test, one-way ANOVA, Pearson correlation and path analysis in Amos. Results : Occupational stress had a positive correlation to drinking frequency, Oral symptoms had a negative correlation. And drinking frequency, smoking amount and occupational stress had a positive correlation to oral symptoms. It denoted that drinking frequency, occupational stress and oral symptoms had a negative correlation to OHIP. The path model had an excellent goodness of fit (p=0.07, namely p>0.05). Five 'goodness-of-fit indices' of the model were all above 0.9: GFI=0.987, AGFI=0.952, NFI=0.902, IFI=0.939, CFI=0.934), and its RMSEA was 0.045. Occupational stress and oral symptoms had a firsthand impact on OHIP. In addition, it affected OHIP through the parameters of oral symptoms. Occupational stress exercised a firsthand influence on drinking frequency, drinking frequency exercised a firsthand influence on smoking amount. Smoking amount had a firsthand impact on oral symptoms. Conclusions: Oral health education programs for the development of an improved oral hygiene environment through reduction in drinking and smoking also need to focus on relieving stress by improving workplace culture. In addition, due to good communication is required to reduce occupational stress caused by interpersonal conflict.

Performance analysis of TR, DTR and PRM UWB systems in frequency selective channel (주파수 선택적 채널에서의 TR, DTR과 PRM UWB 통신 시스템 성능분석)

  • Woo Seon-Keol;Choi Ho-Seon;Yang Hoon-Gee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.5 no.1 s.9
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    • pp.45-54
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    • 2006
  • The UWB signal distortion in frequency selective channel has made it difficult to implement the channel estimator and the synchronizer of the UWB receiver. In this paper, we examine the performances of TR(Transmitted Reference) and DTR(Differential TR) UWB which use either reference pulse or differential method to estimate the channels. we also propose a FSK-based PRM(Pulse Repetition Modulation) UWB system as an another form of UWB system which is advantageous in frequency selective channel. Finally, resorting to statistical analysis, we examine the noise effect due to noisy reference at an auto-correlation(AcR) receiver. moreover, SNR dependance of the integration length in the AcR receiver is also investigated.

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A study on the change of prosodic units by speech rate and frequency of turn-taking (발화 속도와 말차례 교체 빈도에 따른 운율 단위 변화에 관한 연구)

  • Won, Yugwon
    • Phonetics and Speech Sciences
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    • v.14 no.2
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    • pp.29-38
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    • 2022
  • This study aimed to analyze the speech appearing in the National Institute of Korean Language's Daily Conversation Speech Corpus (2020) and reveal how the speech rate and the frequency of turn-taking affect the change in prosody units. The analysis results showed a positive correlation between intonation phrase, word phrase frequency, and speaking duration as the speech speed increased; however, the correlation was low, and the suitability of the regression model of the speech rate was 3%-11%, which was weak in explanatory power. There was a significant difference in the mean speech rate according to the frequency of the turn-taking, and the speech rate decreased as the frequency of the turn-taking increased. In addition, as the frequency of turn-taking increased, the frequency of intonation phrases, the frequency of word phrases, and the speaking duration decreased; there was a high negative correlation. The suitability of the regression model of the turn-taking frequency was calculated as 27%-32%. The frequency of turn-taking functions as a factor in changing the speech rate and prosodic units. It is presumed that this can be influenced by the disfluency of the dialogue, the characteristics of turn-taking, and the active interaction between the speakers.

Identification on Principle of Acoustic Wave Propagation Characteristics in a Gas Pipe (가스 배관 내부의 음파 전달 특성에 관한 연구)

  • Kim, Min-Soo;Lee, Sang-Kwon;Jang, Sang-Yup;Koh, Jae-Pil
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.8
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    • pp.797-804
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    • 2008
  • In the gas supply pipe, the gas leakage caused by the impact of the construct equipment is serious problem. The identification of the impact position is an important issue and an engineering work. For the basic research of this problem, the principle studies for the acoustic wave propagation in a gas pipe are proceeded in this paper. This principal work is based on the identification of the cut-off frequency associated with major modes of the gas pipe theoretically and experimentally The cut-off frequency is confirmed by STFT and cross-correlation function is used to identify the leakage position.

Study on Relations among Use of Earphones, Stress, and Hearing Threshold in University Students (대학생의 이어폰 사용, 스트레스 및 청력의 관계)

  • Kwak, Hye-Weon;Kim, Na-Hyun
    • Journal of Korean Public Health Nursing
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    • v.26 no.1
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    • pp.126-136
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    • 2012
  • Purpose: The purpose of this study was to investigate the relationship among use of earphones, stress level, and hearing threshold in university students. Methods: Study subjects included 210 university students (76 men, 134 women). Data were collected by questionnaire and audiometer from December 17 to 20, 2011. The SPSS win 19.0 program was used for data analysis by descriptive statistics, t-test, one-way ANOVA, and Pearson's correlation coefficient. Results: 1) 4KHz, 6KHz hearing threshold of subjects who used earphones was higher than average hearing threshold of same age group. 2) Not significant differences in hearing threshold were observed according to frequency of use, and stress level. 3) Significant differences in 4KHz hearing threshold were observed according to earphone volume. 4) A significant positive correlation was observed between frequency of use and stress level (r=0.15, p<.05), earphone volume, and 4KHz hearing threshold (left) (r=0.15, p<.05); however, a negative correlation was observed between stress level and 4KHz hearing threshold (right) (r=-0.14, p<.05). Conclusion: A significant positive correlation was observed between frequency of use and stress level and earphone volume and 4KHz hearing threshold (left). Development of a program for hearing conservation is needed.