• Title/Summary/Keyword: correlation measure

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Reliability and validity of pelvic mobility measurement using a cushion sensor in healthy adults

  • Jung, Seung-Hwa;Kim, Su-Kyeong;Lee, Ji-Hyun;Choi, Soo-Ih;Park, Dae-Sung
    • Physical Therapy Rehabilitation Science
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    • v.9 no.2
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    • pp.74-81
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    • 2020
  • Objective: To prevent low back pain, an objective evaluation tool to evaluate pelvic mobility and exercise to improve the flexibility of the lumbar region is needed. The purpose of this study was to compare the results of pelvic mobility measurements using the Wii Balance Board (WBB) and Sensbalance Therapy Cushion (STC), evaluate the usefulness of the STC as a tool for measuring pelvic mobility. Design: Cross-sectional study. Methods: Fifty healthy subjects participated in this study. The subjects performed pelvic mobility range, proprioception, reaction time and reach of the arm using the STC. The pelvic movement parameter was measured two times to determine the intra-rater reliability. To measure the correlation between lumbar muscle tension and pelvic mobility, Myovision was used to measure tension of L4, L5 level erector spinae muscle. Correlations between measured variables were checked to determine the validity of the pelvic mobility assessment tool. Results: STC showed high test-retest reliability in pelvic tilt measurement and reaching task [intraclass correlation coefficients (3,1)=0.804-0.915]. The relationship between WBB and STC showed a significant positive correlation with the pelvic tilt and reaching task (p<0.05). Posterior tilt and erector spinae activation (Lt. L5) showed a significant negative correlation (p<0.05). Left, right tilt and erector spinae activation (L5) showed a significant negative correlation (p<0.05). Conclusions: This study confirmed the advantages of the STC and found efficiency as an objective measuring device of pelvic mobility.

Correlation Results of Pulse/Respiration Ratio and Body Composition Analysis (맥솔(脈率)과 체성분(體成分) 분석(分析)의 상관성(相關性) 연구(硏究))

  • Park, Jae-Sung;Park, Young-Bae;Kim, Min-Yong;Park, Young-Jae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.10 no.2
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    • pp.132-150
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    • 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.

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A Unified Measure of Association for Complex Data Obtained from Independence Tests (혼합자료에서 독립성 검정에 의한 연관성 측정)

  • 이승천;허문열
    • The Korean Journal of Applied Statistics
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    • v.16 no.1
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    • pp.151-167
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    • 2003
  • Although there exist numerous measures of association, most of them are lacking in generality in that they do not intend to measure the association between heterogeneous type of random variables. On the other hand, many statistical analyzes dealing with complex data sets require a very sophisticate measure of association. In this note, the p-value of independence tests is utilized to obtain a measure of association. The proposed measure of association have some consistency in measuring association between various types of random variables.

A unified measure of association for complex data obtained from independence tests (혼합자료에서 독립성검정에 의한 연관성 측정)

  • Lee, Seung-Chun;Huh, Moon Yul
    • The Korean Journal of Applied Statistics
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    • v.34 no.4
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    • pp.523-536
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    • 2021
  • Although there exist numerous measures of association, most of them are lacking in generality in that they do not intend to measure the association between heterogeneous type of random variables. On the other hand, many statistical analyzes dealing with complex data sets require a very sophisticate measure of association. In this note, the p-value of independence tests is utilized to obtain a measure of association. The proposed measure of association have some consistency in measuring association between various types of random variables.

MIMO Capacity, Level Crossing Rates and Fades: The Impact of Spatial/Temporal Channel Correlation

  • Giorgetti, Andrea;Smith, Peter J.;Shafi, Mansoor;Chiani, Marco
    • Journal of Communications and Networks
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    • v.5 no.2
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    • pp.104-115
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    • 2003
  • It is well known that Multiple Input Multiple Output (MIMO) systems offer the promise of achieving very high spectrum efficiencies (many tens of bit/s/Hz) in a mobile environment. The gains in MIMO capacity are sensitive to the presence of spatial and temporal correlation introduced by the radio environment. In this paper, we examine how MIMO capacity is influenced by a number of factors e.g., a) temporal correlation b) various combinations of low/high spatial correlations at either end, c) combined spatial and temporal correlations. In all cases, we compare the channel capacity that would be achievable under independent fading. We investigate the behaviour of "capacity fades," examine how often the capacity experiences the fades, develop a method to determine level crossing rates and average fade durations and relate these to antenna numbers. We also evaluate the influence of channel correlation on the capacity autocorrelation and assess the fit of a Gaussian random process to the temporal capacity sequence. Finally we note that the particular spatial correlation structure of the MIMO channel is influenced by a large number of factors. For simplicity, it is desirable to use a single overall correlation measure which parameterizes the effect of correlation on capacity. We verify this single parameter concept by simulating a large number of different spatially correlated channels.

Influence Analysis on a Test Statistic in Canonical Correlation Analysis

  • Jung, Kang-Mo
    • Communications for Statistical Applications and Methods
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    • v.8 no.2
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    • pp.347-355
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    • 2001
  • We propose a method for detecting influential observations that have a large influence on the likelihood ratio test statistic for the two sets of variables are uncorrelated with one another. For this purpose we derive a local influence measure for the likelihood ratio test statistic under certain perturbation scheme. An illustrative example is given to show the effectiveness of the proposed method on the identification of influential observations.

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Drop Size Measurement using Image Processing Method under High Ambient Pressure Condition (고압환경에서 이미지 프로세싱 기법을 이용한 액적크기 측정)

  • Lim Byoungjik;Khil Taeock;Jung Kihoon;Yoon Youngbin
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.111-114
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    • 2003
  • Drop size is one of the most important parameters which are control the performance of the engine using liquid fuel/oxidizer and drop formation is mainly controlled by aerodynamic force caused by ambient gas. Because of this, empirical data and correlation acquired under standard ambient condition are not valid. So experiments under high ambient pressure condition to measure the drop size using image processing method And find the empirical correlation between SMD and chamber pressure(density), injection velocity.

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Correlation Analysis between Job Stress and Job Satisfaction of Building Construction Field Managers

  • An, Sung-Hoon;Zhang, Zhen;Lee, Ung-Kyun
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.5
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    • pp.474-481
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    • 2013
  • The success of a construction project hinges on the effective and efficient management of human resources. The stress of human resources is directly related with work performance, and as such, should be managed to improve work performance. This study examined the correlation between job stress and job satisfaction among building construction project managers. A questionnaire to measure work performance was created by referring to the Korean Occupational Stress Questionnaire Short Form developed by the Korean Occupational Safety & Health Agency, as well as a previous study. The mean job satisfaction score of field managers was 3.6, which suggests that they are generally satisfied in their current job environment. A Pearson's correlation analysis showed that the field managers that were satisfied with their job had less job stress. These results could be used for the effective management of construction site managers and to improve their job performance in the field.

A Study on the Correlation between Lead in Airborne Suspended Particulates and Leaves of Roadside Trees in Urban Area (대기부유분진중 Pb와 가로수잎중 Pb와의 상관성에 관한 연구)

  • 고현규;김희강;현용범
    • Journal of Korean Society for Atmospheric Environment
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    • v.2 no.3
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    • pp.11-18
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    • 1986
  • In order to evaluate the state of the environmental pollution by vehicle exhaust in Seoul area the correlation between lead in air and leaves of roadside trees has been investigated during August in 1985. The dust in the atmosphere was collected by high volume air sampler to measure the concentration of lead. On the other hand, lead as a pollution indicator was extracted from the leaves of roadside trees (Ginkgo biloba, Salix pseudo/lasiogyne, platanus occidentalis) by conventional method and their concentrations were determined. The following results were obtained : 1. Lead concentrations in the leaves of roadside trees varied with trees, for example, the average concentrations of lead in each of the leaves of Ginkgo biloba, Salix pseudo/lasiogyne and Platanus occidentalis were 20.66 ppm, 9.37 ppm, and 10.58 ppm, respectively. 2. The dust sampled along heavily traveled highways showed that lead content tended to increase with traffic volume. 3. The correlation coefficients between lead correlation in air and leaves of Gingo biloba, Salix pseudo/lasiogyne, and Platanus orientalis were 0.80, 0.85, and 0.87, respectively.

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A Specific Character on the Urinary Hippuric Acid Excretions of Workers Exposed to Toluene in Specific Character of Manufacturing Industry (작업장 특성에 따른 톨루엔 노출 근로자의 마뇨산 배출 특성)

  • Park Heung-Jai;Kim Hyung-Joon;Jeong Seong-Wook;Lee Byung-Ho
    • Journal of Environmental Science International
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    • v.14 no.2
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    • pp.201-207
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    • 2005
  • This study was carried out to investigate the correlation between toluene in air and hippuric acid in human urine, which is based in the results of the health check-in and measure of working environment, was investigated for five years. Toluene in air and hippuric acid in urine were checked 116 workers who exposed to toluene in five type of industry. The Mean concentration of toluene in air by type of industry and every year and sex distinction, had positive correlation.(p<0.01) The Mean concentration of hippuric acid in urine by type of industry, every year, sex distinction, disparity of age and term of duty had positive correlation.(p<0.01).