• Title/Summary/Keyword: Variability analysis

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Study on the Radial Pulse Wave Variables and Heart Rate Variability after Acupuncture Stimulation (침자극이 좌관맥상과 심박수 미세변화에 미치는 영향)

  • Won, Jae-Kyun;Jung, Soon-Kwan;Kim, Dong-Eun;Lim, Jin-Young;Kwon, Young-Dal;Yeom, Seung-Ryong;Lee, Su-Kyung;Song, Yung-Sun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.1
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    • pp.237-244
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    • 2009
  • We investigated the effects of acupuncture stimulation on pulse wave variables and heart rate variability (HRV) in healthy adults. To evaluate twenty healthy volunteers (10 men, 10 women) had acupuncture into both Hapkok (Ll4) and Taechung (Liv3) for 15 minutes. Radial pulse, Heart Rate Variability, body temperature and blood pressure were checked before and after acupuncture to evaluate Pulse Wave Variability and Autonomous Function. The results were as follows; Heart rate was significantly increased while systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) were significantly increased after acupuncture treatment. Sixteen subjects didn't change representative pulse wave variables after acupuncture treatment. Energy, height of main peak (H1), height of pre-dicrotic valley (H2) and height of descending valley (H4) were decreased while height of dicrotic peak (H5) was significantly decreased after acupuncture treatment. Time to main peak (T1), time to pre-dicrotic valley (T2), time to dicrotic peak (T5), total time (T) and T-T4 were decreased while time to descending valley (T4) was increased after acupuncture treatment. Total area (At), area of main peak (Aw) and ratio of diastolic period area (Ad) were decreased while ratio of systolic period area (As) and angle of main peak (MPA) were increased after acupuncture treatment. The standard deviation of all normal RR intervals (SDNN) was increased while the root mean square of successive differences between the normal heart beats (RMSSD) was significantly increased after acupuncture treatment by time domain analysis. Low frequency power (LF) and LF/HF ratio were decreased while high frequency power (HF) was significantly increased after acupuncture treatment by frequency domain analysis. This study suggests that acupuncture treatment changes pulse wave variability and heart rate variability. Further study on various acupuncture treatment for pulse wave variability and heart rate variability is required.

The Effects of Intrapatient Variability in Tacrolimus Concentration on Clinical Outcomes Immediately After Liver Transplantation (Tacrolimus의 혈중농도 변동성이 간이식 예후에 미치는 영향)

  • Kim, Eunji;Kim, Boram;Cho, Jungwon;Lee, Jung Hwa;Lee, Eunsook;Yu, Yun Mi;Cho, Jai Young;Lee, Euni;Choi, YoungRok
    • Korean Journal of Clinical Pharmacy
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    • v.30 no.1
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    • pp.36-43
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    • 2020
  • Background: Tacrolimus, a calcineurin inhibitor, is an immunosuppressant used in post-transplantation maintenance therapy. The drug has a narrow therapeutic range and requires periodic therapeutic drug monitoring. Although many studies have reported the effects of intrapatient variability of tacrolimus on survival, rejection, and complications in renal transplant recipients, very few studies have reported these effects in liver transplant recipients. The purpose of this study was to evaluate the effect of intrapatient variability of tacrolimus on clinical outcomes after liver transplantation. Methods: Intrapatient variability was calculated using individual, averaged tacrolimus concentrations. Patients were divided into two groups according to their median variability value: high-variability and low-variability groups. The rate of deviation from the therapeutic range, incidence of acute rejection, post-transplant diabetes, incidence of infection, and estimated glomerular filtration rate (eGFR) after transplantation were compared between the groups. Results: Of the total patients (n=82), the high-variability group (n=41) exhibited significantly greater deviation from the therapeutic range (65.92% vs. 56.84%; p<0.001). There was no significant difference in acute rejection or post-transplantation diabetes incidence or eGFR; however, the number of infection in the first 6 months was significantly lower in the low-variability group (0.4 vs. 0.9 times; p=0.039). Multiple linear regression analysis showed that the number of infection significantly increased as intrapatient variability increased (p=0.015). Conclusion: High intrapatient variability in tacrolimus concentrations was strongly associated with an increased frequency of deviation from the suggested therapeutic range and an increased number of infection.

Water Mass Formation Variability in the Intermediate Layer of the East Sea

  • Min, Hong-Sik;Kim, Cheol-Ho
    • Ocean Science Journal
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    • v.41 no.4
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    • pp.255-260
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    • 2006
  • Long-term variability in the intermediate layer of the eastern Japan Basin has been investigated to understand the variability of water mass formation in the East Sea. The simultaneous decrease of temperature at shallower depths and oxygen increasing at deeper depths in the intermediate layer took place in the late 1960's sand the mid-1980's. Records of winter sea surface temperatures and air temperatures showed that there were cold winters that persisted for several years during those periods. Therefore, it was assumed that a large amount of newly-formed water was supplied to the intermediate layer during those cold winters. Close analysis suggests that the formation of the Upper Portion of Proper Water occurred in the late 1960's and the Central Water in the mid-1980's.

A Study of Development Method for Component Reuse & Extension (컴포넌트의 재사용과 확장성을 위한 개발 방법)

  • Lee, Eun-Seo;Lee, Kyung-Whan
    • The KIPS Transactions:PartD
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    • v.9D no.5
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    • pp.837-846
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    • 2002
  • When you develop component, you can offer reusability and extension by analyzing commonality and variability about attribute and behavior. Therefore Component that analyzing commonality and variability are use for the purpose of reducing discord of function and adaptedness. I wish to research reusability and extension of component by analysis commonality and variability of component that exist by domain in this paper, extractfunctionofcomponentbybehavioranalysis.

Comparison of Shape Variability in Principal Component Biplot with Missing Values

  • Shin, Sang-Min;Choi, Yong-Seok;Lee, Nae-Young
    • The Korean Journal of Applied Statistics
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    • v.21 no.6
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    • pp.1109-1116
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    • 2008
  • Biplots are the multivariate analogue of scatter plots. They are useful for giving a graphical description of the data matrix, for detecting patterns and for displaying results found by more formal methods of analysis. Nevertheless, when some values are missing in data matrix, most biplots are not directly applicable. In particular, we are interested in the shape variability of principal component biplot which is the most popular in biplots with missing values. For this, we estimate the missing data using the EM algorithm and mean imputation according to missing rates. Even though we estimate missing values of biplot of incomplete data, we have different shapes of biplots according to the imputation methods and missing rates. Therefore we propose a RMS(root mean square) for measuring and comparing the shape variability between the original biplots and the estimated biplots.

A Stochastic Analysis of Crack Propagation Life under Constant Amplitude Loading (균일진폭 하중하에서의 확률론적 균열진전 수명해석)

  • 윤한용;양영순;윤장호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.9
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    • pp.1691-1699
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    • 1992
  • The experimental results of fatigue crack propagation under constant amplitude loading show that intra-and inter-specimen variability exist. In this paper, a stochastic model for the estimation of mean and variance of crack propagation life is presented To take into account the intra-specimen variability, the material resistance against crack propagation is treated as an 1-dimensional spatial stochastic process, i. e. random field, varying along the propagation path. For the inter-specimen variability, C in paris equation is assumed to be a random variable. Compared with experimental results reported, the present method well estimate the variation in fatigue crack propagation life. And it is confirmed that the thicker the specimen thickness is, the less the variation of propagation life is.

Assessing Methods of Heart Rate Variability (심박변이에 대한 평가방법)

  • Park, Ki-Jong;Jeong, Heejeong
    • Annals of Clinical Neurophysiology
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    • v.16 no.2
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    • pp.49-54
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    • 2014
  • Heart rate variability is significantly associated with cardiovascular complications in various neurological disorders with cardiac impairment. Measures of spontaneous heart rate variability might be different from provocating tests of heart rate variability such as deep breathing and Valsava maneuver. Methods for analysis are divided into time domain methods and frequency domain methods. There are standard deviation of NN interval, standard deviation of average NN interval, root mean square of the successive differences, NN50, and pNN50 in time domain methods. Frequency domain bands can be divided into very low, low, and high frequency. Each variables are influenced by sympathetic and/or parasympathetic activity.

Surface Wind Regionalization Based on Similarity of Time-series Wind Vectors

  • Kim, Jinsol;Kim, Hyun-Goo;Park, Hyeong-Dong
    • Asian Journal of Atmospheric Environment
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    • v.10 no.2
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    • pp.80-89
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    • 2016
  • In the complex terrain where local wind systems are formed, accurate understanding of regional wind variability is required for wind resource assessment. In this paper, cluster analysis based on the similarity of time-series wind vector was applied to classify wind regions with similar wind characteristics and the meteorological validity of regionalization method was evaluated. Wind regions in Jeju Island and Busan were classified using the wind resource map of Korea created by a mesoscale numerical weather prediction modeling. The evaluation was performed by comparing wind speed, wind direction, and wind variability of each wind region. Wind characteristics, such as mean wind speed and prevailing wind direction, in the same wind region were similar and wind characteristics in different wind regions were meteor-statistically distinct. It was able to identify a singular wind region at the top area of Mt. Halla using the inconsistency of wind direction variability. Furthermore, it was found that the regionalization results correspond with the topographic features of Jeju Island and Busan, showing the validity.

The Power Spectral Estimation of Heart Rate Variability using Lomb-Scargle's algorithm (Lomb-Scargle알고리즘에 의한 심박변동의 파워스펙트럼 추정)

  • Shin, K.S.;Jeong, K.S.;Choi, S.J.;Lee, J.W.;Lee, M.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.275-278
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    • 1997
  • Standard methods estimating the power spectral density(PSD) from an irregularly sampled cardiac event series require deriving a new evenly-spaced signal applicable to those methods. To avoid that requirement, in this study, the power spectrum of heart rate variability was estimated by Lomb-Scargle's algorithm, which is a means of obtaining PSD estimates directly from irregularly sampled timeseries observed in astronomy. To assess the performance of Lomb-Scargle algorithm in the power spectral analysis of heart rate variability, it was applied to various cardiac event series derived through integral pulse frequency modulation model(IPFM) simulation and from real ECG signals, and the resultant power spectra was compared with those obtained by a conventional method based on the FFT. In result, it is concluded that Lomb-Scargle's periodogram is very effective in the power spectral analysis of heart rate variability, especially in the presence of arrhythmia and/or dropouts of cardiac events.

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The Stability and Variability based on Vowels in Voice Quality Analysis (음질 분석에 있어서 모음에 따른 안정성과 변이성)

  • Choi, Seong Hee;Choi, Chul-Hee
    • Phonetics and Speech Sciences
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    • v.7 no.1
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    • pp.79-86
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    • 2015
  • This study explored the vowel effect on acoustic perturbation measures in voice quality analysis. For this study, the perturbation parameters (%jitter, %shimmer) and noise parameter (SNR) were measured with 7 Korean vowels (/a/, /ɛ/, /i/, /o/, /u/, /ɯ/, /ʌ/) using CSpeech with 50 Korean normal young adults (24 males and 26 females). A significant vowel effect was found only in %shimmer and in particular, low-back /a/vowel was significantly different from other vowels in %shimmer. The least perturbation and noise were exhibited on high-back /ɯ/ and /o/ vowel, respectively. Based on tongue height, a significant higher %shimmer was demonstrated on low vowels than high vowels. In addition, back vowels in tongue advancement and rounded vowels in lip rounding showed significantly less perturbation and noise. The least variability of perturbation and noise within individuals was demonstrated on the vowel /i/ in three repeated measures. However, there was no significant difference among 3 token measures in single session among vowels tested except the vowel /o/. Consequently, the vowel /a/ commonly used in acoustic perturbation measures exhibited higher perturbation and noise whereas higher stability and less variability were demonstrated on the high-back vowel /u/. These results suggested that the Korean high-back vowel /u/ can be more appropriate and reliable for perturbation acoustic measures.