• 제목/요약/키워드: frequency and correlation analysis

검색결과 2,821건 처리시간 0.032초

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

  • 오태석;김성실;문영일
    • 한국방재학회 논문집
    • /
    • 제10권3호
    • /
    • pp.119-131
    • /
    • 2010
  • 가뭄은 인간이 극복하기 힘든 자연재해로서 가뭄지역의 경제를 어렵게 할 뿐 아니라 생태계까지 파괴하기 때문에 전 세계적으로 가장 두려워하는 관심 재해 중 하나이다. 따라서 본 연구에서는 대표적인 가뭄지수인 팔머가뭄지수와 범지구적 해수면 온도의 상관관계를 분석하였다. 먼저 팔머가뭄지수를 산정하여 과거 가뭄발생연도와 비교분석을 실시하였다. 비교분석을 결과 대부분의 과거 가뭄사상과 지수가 일치하는 것으로 분석되었다. 상관성 분석을 위해 팔머가뭄지수 산정을 위한 지수인 강수자료와 온도자료를 월평균강수량과 월평균온도 자료로 산정하여 군집분석을 실시하였다. 우리나라 기상청관할에 있는 61개 지점을 선정하여 월평균강우량과 월평균온도 자료로 군집분석결과 총 6개의 군집을 형성하는 것으로 분석되었다. 또한, 군집분석결과와 팔머가뭄지수의 주성분 분석을 실시하였다. 주성분 분석을 통해 전체 자료의 분산을 80% 이상 설명할 수 있는 14개의 시계열 자료를 추출하였다. 추출된 팔머가뭄지수의 주요 성분과 범지구적 해수면 온도와의 상관성 분석결과 팔머가뭄지수는 양의 상관관계가 음의 상관관계보다 큰 것으로 분석되었으며, 태평양에서 관측되는 해수면 온도와 통계적으로 유의한 상관관계를 갖는 해수면 온도 구역을 확인할 수 있었다. 이를 통해 해수면 온도를 이용하여 우리나라에 발생할 수 있는 가뭄의 예측 가능성을 제시하였다.

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

  • 구기영;박승희;이종재;윤정방
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
    • /
    • pp.21-26
    • /
    • 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.

  • PDF

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

  • Park, Seung Tai
    • The Korean Journal of Ecology
    • /
    • 제9권3호
    • /
    • pp.135-147
    • /
    • 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.

  • PDF

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

  • CHOI, Eun-Mee
    • 웰빙융합연구
    • /
    • 제4권4호
    • /
    • pp.1-14
    • /
    • 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.

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

  • 김봉현
    • 한국정보통신학회논문지
    • /
    • 제17권8호
    • /
    • pp.1955-1961
    • /
    • 2013
  • 부비동은 얼굴에서 뼈 속에 존재하는 공기로 가득 찬 빈 공간이다. 그러나 부비동에 지속적으로 염증이 생기고 고름이 차면 축농증으로 발병하여 두통과 무기력증을 호소하고 음성의 변화를 가져온다. 따라서 본 논문에서는 외부 자극을 통해 부비동의 변화를 음성분석 요소로 측정하여 부비동 관련 질환을 예측하는 연구와 전두동, 사골동, 상악동, 접형동으로 구성된 부비동의 영역별 기능을 분석하는 연구를 수행하였다. 이를 위해 부비동 영역에 냉찜질 자극을 시행하고 자극 전과 후의 음성에 대한 포먼트주파수를 측정하여 상호간의 상관성 분석을 통해 외부 자극이 부비동에 미치는 영향을 분석하였다.

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

  • 홍민희
    • 한국치위생학회지
    • /
    • 제12권3호
    • /
    • pp.471-483
    • /
    • 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.

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

  • 우선걸;최호선;양훈기
    • 한국ITS학회 논문지
    • /
    • 제5권1호
    • /
    • pp.45-54
    • /
    • 2006
  • 주파수 선택적 채널에서의 신호왜곡은 수신기에서의 채널추정을 어렵게 하여 펄스 타입의 UWB 시스템의 경우 동기 회로의 구현이 어렵다는 단점이 있다. 본 논문에서는 구현상 난점인 채널추정과 동기회로 설계를 간단히 기준 펄스를 함께 전송함으로써 해결하는 TR(Transmitted Reference), DTR(Differential TR) UWB을 분석하고 FSK 변조방법을 이용한 새로운 형태의 PRM(Pulse Repetition Modulation) UWB 방식을 제안한다. 기준 펄스를 이용한 통신의 수신기 구조인 Auto-correlation(AcR) 수신기가 잡음이 섞인 기준펄스를 이용하는 경우 성능저하 정도를 확률적으로 분석한다. 또한 SNR에 영향을 미치는 AcR 적분기의 적분구간에 대한 분석을 시뮬레이션을 통하여 분석한다.

  • PDF

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

  • 원유권
    • 말소리와 음성과학
    • /
    • 제14권2호
    • /
    • pp.29-38
    • /
    • 2022
  • 이 연구는 국립국어원 일상 대화 음성 코퍼스(2020)에서 나타나는 발화를 분석하여 발화 속도 및 말차례 교체 빈도가 운율 단위 변화에 어떤 영향을 끼치는지 밝히는 것을 목적으로 하였다. 분석 결과, 발화 속도가 증가할수록 억양구, 어절 빈도, 발화 길이가 증가하는 양의 상관관계를 보였으나 상관관계가 낮았고, 회귀모형의 적합도는 3%-11%로 설명력이 약했다. 말차례 교체 빈도에 따른 평균 발화 속도는 유의미한 차이가 있었고, 말차례 교체 빈도가 증가할수록 발화 속도는 감소하였다. 또한 말차례 교체 빈도가 증가할수록 억양구 및 어절 빈도와 발화 길이는 감소하였으며 높은 음의 상관관계가 있는 것으로 나타났다. 회귀 모형의 적합도는 27%-32%로 계산되었다. 말차례 교체 빈도가 발화 속도와 운율 단위를 변화시키는 요인으로 작용했을 수 있다. 이는 대화체에서 나타나는 비유창성, 말차례 교체 특성, 화자 간 활발한 상호작용 등이 영향을 미쳤을 것이라 추측된다.

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

  • 김민수;이상권;장상엽;고재필
    • 한국소음진동공학회논문집
    • /
    • 제18권8호
    • /
    • pp.797-804
    • /
    • 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.

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

  • 곽혜원;김나현
    • 한국보건간호학회지
    • /
    • 제26권1호
    • /
    • pp.126-136
    • /
    • 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.