• 말소리와 음성과학
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• 제7권1호
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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.

• Geomechanics and Engineering
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• 제24권2호
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• pp.167-178
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• 2021

Spatial variability is an inherent uncertainty of soil properties. Current reliability analyses generally incorporate random field theory and Monte Carlo simulation (MCS) when dealing with spatial variability, in which the computational efficiency is a significant challenge. This paper proposes a KL-FORM algorithm to improve the computational efficiency. In the proposed KL-FORM, Karhunen-Loeve (KL) expansion is used for discretizing random fields, and first-order reliability method (FORM) is employed for reliability analysis. The KL expansion and FORM can be used in conjunction, through adopting independent standard normal variables in the discretization of KL expansion as the basic variables in the FORM. To illustrate the effectiveness of this KL-FORM, it is applied to a case study of a strip footing in spatially variable unsaturated soil under rainfall, in which the bearing capacity of the footing is computed by numerical simulation. This case study shows that the KL-FORM is accurate and efficient. The parametric analyses suggest that ignoring the spatial variability of the soil may lead to an underestimation of the reliability index of the footing.

• 대한약침학회지
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• 제11권1호
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• pp.55-69
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• 2008

Objective : We investigated the effects of distilled Wild Ginseng Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how distilled Wild Ginseng Herbal Acupuncture on the balance of the autonomic nervous system. Method : We investigated the effects of distilled Wild Ginseng Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how distilled Wild Ginseng Herbal Acupuncture on the balance of the autonomic nervous system. 1 healthy volunteers consisted of 31 subjects in experiment(distilled Wild Ginseng Herbal Acupuncture) group and 30 subjects in control(Normal Saline) group. Study form was a randomized, placebo-controlled, double-blind clinical trial. 31 subjects in experiment group were injected distilled Wild Ginseng Herbal Acupuncture at $GB_{21}$(Kyonjong) and 30 subjects in control group were injected Normal Saline at $GB_{21}$(Kyonjong). except of 2 subjects(in control group) who can't be measured and 11 subjects(7 in experiment group and 4 in control group) who move or make unforceable error during measuring. Finally 24 subject in experiment group and 24 subject in control group are studied. We measured HRV by PolyG-I on 7 times : before and after injection per 5 minutes during 30 minutes. The SPSS 10.0 for windows was used to analyze the data and the paired t-test(in group) and Student t-test(between two groups) were used to verify the result. Result : 1. After distilled Wild Ginseng Herbal Acupuncture injection, Mean HRV is significantly low only for first 5 minute, SDNN is significantly high after 5 minute, Complexity is significantly low after 5 minute, HRV index is significantly high after 10 minute and pNN50 is significantly low after 5 minute. 2. SDNN of distilled Wild Ginseng Herbal Acupuncture Group significantly increased from 20minute to 25minute, and pNN50 of distilled Wild Ginseng Herbal Acupuncture Group significantly decreased from 10minute to 15minute and 20 minute to 30 minute compared with those of Normal Saline group. 3. After distilled Wild Ginseng Herbal Acupuncture injection, Ln(TP), Ln(VLF) and Ln(LF) are significantly high after 5 minute, normalized LF is significantly high after 5 minute and normalized HF is significantly low after 5 minute. 4. Ln(TP) and Ln(VLF) of distilled Wild Ginseng Herbal Acupuncture Group significantly increased from 20minute to 25 minute compared with those of Normal Saline group. Conclusion : The results suggest that distilled Wild Ginseng Herbal Acupuncture in healthy adult man tend to activate the autonomic nervous system and sympathetic nervous system compared to Normal Saline within normal range.

• Journal of Acupuncture Research
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• 제22권6호
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• pp.51-60
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• 2005

Objectives : This study was designed to evaluate the effect of inbalance of autonomic nerve system on peripheral facial palsy patients in comparison of Heart Rate Variability results of healthy control group with that of peripheral facial palsy group. Methods : The peripheral facial palsy patiens who visited the Dongguk university Bundang oriental medicine hospital from April to June in 2005 were tested Heart Rate Variability items which are Mean Heart Rate(MHRT), Standard Deviation of all the Normal RR intervals (SDNN), Root Mean Square of Successive Differences Between The Normal Heart Beats(RMSSD), Total Power(TP), Low Frequency, High Frequency, ratio between the Low Frequency and High Frequency power(LF/HF ratio). The Heart Rate Variability test results of peripheral facial palsy group were compared with the HRV test results of healthy control group who didn't have nervous disease, musculoskeletal disease, heart problem and pain for the past 6 months. Results : 1. MHRT was not significantly different between peripheral facial palsy group and healthy control group(P=0.18). 2. SDNN was not significantly different between peripheral facial palsy group and healthy control group(P=0.41). 3. RMSSD was not significantly different between peripheral facial palsy group and healthy control group(P=0.93). 4. TP was not significantly different between peripheral facial palsy group and healthy control group(P=094). 5. LF and HF were not significantly different between peripheral facial palsy group and healthy control group((P=0.34, 0.30). 6. LF/HF ratio was significantly different between peripheral facial palsy group and healthy control group(P=0.04). Conclusion : LF/HF ratio is generally used as autonomic nerve system evaluation and there was significantly statistical difference between peripheral facial palsy group and healthy control group.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.451-454
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• 1997

It has been reported that sudden cardiac death and ventricular tachycardia occur after treatment of tetralogy of fallot(TOF). It is regarded that ventricular arrythmia is the main source or the sudden cardiac death, but it is not verified. It is likely that TOF has effect on the heart rate variability because of the ventricular arrythmia. We study how complex and periodic heart rate dynamics change in the normal children (n=13) and TOF children (n=13) throughout 24 hours. We recorded 24-hour holter ECG, and segmented each ECG data into 1 hour length. We analyze each HR time series, and quantify the overall complexity of each HR time series by its correlation dimension. We also calculate the power spectrum of HR, and obtain low-frequency component (0.03-0.15Hz) and high-frequency component (0.15-0.4Hz). We compare the results between normal and TOF groups throughout 24 hours. TOF group have lower correlation dimension ($4.055{\pm}0.4134$ vs. $4.9310{\pm}0.2054$, p<0.05) than the normal group, even though there are no significant differences in the low($0.9864{\pm}0.5598$ vs. $1.5560{\pm}0.8325$, p<0.05) and high($1.1168{\pm}0.1.1448$ vs. $0.9271{\pm}0.6528$, p<0.05) frequency components. It can be concluded that HR time series of TOF group are more regular than that of normal group, and that correlation dimension reveals a nonlinear characteristics of HR time series which is not determined in the frequency domain.

• 동의생리병리학회지
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• 제26권4호
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• pp.532-538
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• 2012

The aim of this study was to find correlation between EGG and HRV parameters in dyspeptic patients. 39 patients (male 8, female 31) were enrolled. EGG and HRV was measured in all patients. EGG parameters like % of gastric slow wave and power ratio were used to classify patients as normal or abnormal EGG groups. HRV parameters which were included TP (total power), LF(low frequency density), HF (high frequency density), and LF/HF ratio were compared between them. EGG parameters were compared among normal, sympathetic hyperactivity, and parasympathetic hyperactivity groups classified by LF/HF ratio. There was no difference in HRV parameters between normal and abnormal EGG groups. Comparing EGG parameters among normal, sympathetic hyperactivity, and parasympathetic hyperactivity groups, both sympathetic and parasympathetic hyperactivity groups had lower value of postprandial regularity of gastric slow wave than normal group. Abnormal value of LF/HF ratio(both sympathetic and parasympathetic hyperactivity) may be related with disturbance of electrical gastric activity in patients with dyspepsia.

• 정신신체의학
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• 제28권1호
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• pp.81-88
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• 2020

연구목적 이 연구는 심박변이도(Heart rate variability, HRV) 지표를 이용하여, 불안장애, 우울장애, 외상 및 스트레스 관련 장애의 차이를 비교하고 증상 심각도와의 연관성을 보고자 한다. 방 법 2017년부터 2018년까지 국립정신건강센터 스트레스 클리닉 내원 환자의 후향적 의무기록을 분석하였다. 총 473명 환자(불안장애 166명, 우울장애 184명, 외상 및 스트레스 관련 장애 123명)의 HRV 지표의 진단 군간 차이를 비교하였다. 또한 지표와 전반적 임상 인상 심각도(Clinical Global Impression-Severity Scale, CGI-S)의 연관성이 진단군에 따른 차이를 보이는지 분석하였다. 결 과 세 군에서 HRV 지표는 유의한 차이를 보이지 않았다. 그러나, 심박도 간격(normal-to-normal, NN)의 표준 편차(standard deviation of normal RR intervals, SDNN)와 연속된 NN 간격들의 변이의 제곱 평균값의 루트 값(the square root of the mean squared differences of successive NN intervals, RMSSD)의 CGI-S와의 관련성은 그룹 간 유의한 차이가 나타났다(SDNN, p=0.017 ; RMSSD, p=0.034). 불안장애와 우울장애에서는 CGI-S에 따른 SDNN, RMSSD가 음의 관련성을 보였지만, 외상 및 스트레스 관련 장애에서는 양의 관련성을 보였다. 결 론 본 연구에서 세 군의 HRV 지표는 차이를 보이지 않았지만, 각 군에서 지표와 임상적 심각도와의 연관성은 다른 양상을 보였다. 본 연구 결과는 외상 및 스트레스 관련 장애군은 HRV의 특징 및 임상적 활용이 불안 및 우울장애와 다를 수 있음을 시사한다.

• Journal of Acupuncture Research
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• 제26권5호
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• pp.57-63
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• 2009

Objectives : Since the Front Points are treated as response zone, it can be used for the diagnosis and treatment of disease in viscera and bowels. Jeonjung($CV_{17}$) is the Front Point of SIMPO, it is related with cardiovascular, neuro-psychiatrical disease in aspect of Oriental Medicine. This research is for clarifying relations with palpation of the Jeonjung($CV_{17}$) and autonomic nerve system by comparing HRV and SRI(Stress Reaction Index). Methods : This study was proceeded for three months, from June 2009 to September 2009. Among 31 healthy volunteers, 13 subjects who complained the pressure pain around Jeonjung($CV_{17}$) are classified pressure pain group and 18 subjects who had no pain around Jeonjung($CV_{17}$) as normal group. All subjects had their HRV(SA-2000E: Medicore Co..Ltd. Korea) and SRI measured at visit. We studied the difference of HRV between two groups.(Statistics by Student t-test, p<0.05) Results : LF normalization of the pressure pain group were significantly higher than those of the normal group. HF normalization of the pressure pain group were significantly lower than those of the normal group. Compared with those of the normal group, total SRI of the pressure pain group were low but it's not significant. Conclusions : The results of HRV of the pressure pain group show that pressure pain around Jeonjung($CV_{17}$) is related to mental stress and autonomic disturbance.

• 대한의용생체공학회:의공학회지
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• 제35권3호
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• pp.55-61
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• 2014

In sleep monitoring system, polysomnography (PSG) is the gold-standard but previous studies revealed that attaching numerous amount of sensors disturb sleep during the test which is the fundamental disadvantage of PSG. We suggest an unconstrained rapid-eye-movement (REM) sleep monitoring method measured with polyvinylidene (PVDF) film-based sensor for the normal and the obstructive sleep apnea (OSA) patients. Nine normal subjects and seventeen OSA patients have participated in the study. During REM sleep, rate and variability of respiration are known to be greater than in other sleep stages. Based on this phenomena, respiratory signals of participants were unconstrainedly measured using the PVDF-based sensor with the PSG and REM sleep were extracted from the average rate and variability of respiration. In epoch-by-epoch REM sleep detection, proposed method classified REM sleep with an average sensitivity of 72.3%, specificity of 92.5%, accuracy of 88.9%, and kappa statistic of 0.60 compared to the results of PSG. Student's t-test showed no significant difference between the results of normal and OSA group. This method is potentially applicable to REM sleep detection in homing environment or ambulatory monitoring.

• International Journal of Vascular Biomedical Engineering
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• 제3권2호
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• pp.10-16
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• 2005

Because patients with coronary artery disease (CAD) have depressed vagal modulation and the mortality risk from acute myocardial infarction is lower in patients with higher vagal modulation, methods that can increase vagal modulation are desirable in patients with CAD. We intended to inspect the effect of recumbent posture on vagal modulation. By using angiography, 33 patients with abnormal (CAD group) and 33 patients with normal coronary arteries (control group) were studied. The nonlinear as well as the linear characteristics of heart rate variability (HRV) were analyzed on these patients in three recumbent postures: namely, the supine, right lateral decubitus, and left lateral decubitus postures. The lower the normalized high-frequency power (nHF) in the supine or left lateral decubitus posture, the higher the increase in the nHF when the posture was changed from supine or left lateral decubitus to right lateral decubitus in both groups of patients. Right lateral decubitus posture can lead to the highest vagal modulation and the lowest sympathetic modulation among the three recumbent postures in both normal and patients with CAD. Therefore, the right lateral decubitus posture can be used as an effective physiologic vagal enhancer in patients with CAD.