• Transactions on Electrical and Electronic Materials
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• 제9권5호
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• pp.213-219
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• 2008

Pulse waves continuously change with respect to the characteristics and status of the cardiovascular system and in relation to the blood pressure (BP) and the pulse wave velocity (PWV). Monitoring the vascular condition by analyzing the variations in pulse waveforms has been used to diagnose vascular disorders and in drug treatment of arteriosclerosis and peripheral circulatory obstruction. In this paper, we investigated the vascular characteristic index with regard to the BP and classified by pulse wave signals. The pressure pulse wave and photoplethysmography (PPG) were measured simultaneously while subjects exercised, producing changes in the BP, to analyze the variation in the vascular characteristic index. We investigated the correlation between the BP and vascular characteristic index with regard to the classification methods of the pulse wave. The reflection index (RI) and vascular stiffness index were correlated with the diastolic BP, but no correlation was found between these parameters and the systolic BP. These results suggest the possibility of estimating BP through simple measurements of pulse waves.

• 대한한의진단학회지
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• 제16권1호
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• pp.19-26
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• 2012

Objectives The aim of this study is to develop a cardiovascular simulator that can reproduce blood pressure pulse and blood flow similar to those of the human body. Methods In order to design a system similar to the human cardiovascular system, the required performances were determined by investigating the hemodynamic characteristics of the heart and the arterial system. Main organ to be imitated is heart in simulator. The rest of the system was minimally designed. Also, a blood pressure and blood flow measurement system was developed for measuring the results. Results The developed system showed blood pressure pulse at similar range of the human aorta. The result waveform include primary wave caused by ventricular systole except reflected wave. Conclusions The blood pressure and blow flow patterns were replicated by the simulator. These patterns were similar to those of the human body. The system will play an important role in studying pulse diagnostics.

• Advances in Computational Design
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• 제8권3호
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• pp.219-236
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• 2023

In this paper, finite element modeling of the laser ultrasonics (LU) process in ablation regime is of interest. The momentum resulting from the removal of material from the specimen surface by the laser beam radiation in ablation regime is modeled as a pressure pulse. To model this pressure pulse, two equations are required: one for the spatial distribution and one for the temporal distribution of the pulse. Previous researchers have proposed various equations for the spatial and temporal distributions of the pressure pulse in different laser applications. All available equations are examined and the best combination of the temporal and spatial distributions of the pressure pulse that provides the most accurate results is identified. This combination of temporal and spatial distributions has never been used for modeling laser ultrasonics before. Then by using this new model, the effects of variations in pulse duration and laser spot radius on the shape, amplitude, and frequency spectrum of ultrasonic waves are studied. Furthermore, the LU in thermoelastic regime is simulated by this model and compared with LU in ablation regime. The interaction of ultrasonic waves with a defect is also investigated in the LU process in ablation regime. Good agreement of the results obtained from the new finite element model and available experimental data confirms the accuracy of the proposed model.

• 한국환경과학회지
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• 제13권3호
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• pp.223-232
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• 2004

The change of pressure drop according to the change in the inlet concentration, pulse interval, and injection distance of pulse air jet type bag filters, and the effect of venturi installation are as follows. The pressure drop with the range of 30 to $50mmH_2O$ varies according to the injection distance with 30, 50, 70, 90sec and the inlet concentration of venture built-in fabric filters. For the lower concentration of 0.5g/㎥ and 1g/㎥, the pressure $drop(\DeltaP)$ was stable 60 to 90minutes after operation. For the higher concentration of 3g/㎥, as $\DeltaP$ continues to go up, pulse interval should be set shorter than 30 seconds. The pressure drop with the injection distance of 1l0mm, when inlet dust concentration is 0.5g/㎥ or 1g/㎥, is 1.3 to 2 lower than with the injection distance of 50, 160, and 220mm, which means that the inflow amount of the secondary air by the instant acceleration is large. The injection distance of 2g/㎥ and 3g/㎥ has the similar pressure distribution. The higher inlet concentration is, the more important pulse interval is than injection distance. The pressure drop has proved to be larger when inlet concentration is lower and injection distance closer, on condition that the venturi is installed. The change in the pressure drop was smallest when injection distance was 50mm, followed by 220mm, 160mm, and 110mm.

• Journal of Yeungnam Medical Science
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• 제3권1호
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• pp.81-85
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• 1986

저자는 enflurane을 사용한 200예의 전신마취 시술하에서 혈압 및 맥박의 변화상을 이론식을 도입하여 시계열형(時系列型)으로 표현하여 실현된 형(型)의 유별(類別)과 분포상태를 분석하였던바 다음과 같은 결과를 얻었다. 1. 삽관시 혈압 및 맥박이 상승한다. 2. 삽관시 혈 압 및 맥박이 상승하였다가 하강하여 20분 이내에 대체로 안정상태로 되었다. 3. 구조상으로 상승하강동치이행 (ADEE) 형이 73~74%로 가장 많았고 다음은 상승동치이행(AEEE)형이 40~44%였다.

• Journal of Preventive Medicine and Public Health
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• 제17권1호
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• pp.239-243
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• 1984

The vascular reaction such as the indirect blood pressure and the pulse rate of the tail to the noise were examined in 8 naive Sprague-Dawley rats of both sexes. The sounds used in the experiment were 1KHz and 4 KHz, 95dB pure tone generated by Nagashima Audiometry. The indirect blood pressure and the pulse rate were checked at the rat tail by Polygraph at 5 minutes interval. The results were as follows: 1. The blood pressure and the pulse rate increased maximally 5 minutes after the exposure to both sounds. 2. The blood pressure and the pulse rate returned normal range within 20 minutes after the exposure of both sounds. 3. The increment of the blood pressure and the pulse rate was greater after the sound of 4KHz than after that of 1KHz, but it wasn't statistically significant.

• International Journal of Aerospace System Engineering
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• 제2권1호
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• pp.58-61
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• 2015

Under the background of combustion instability in solid rocket motor, to study the relationship between pressure oscillations and dynamic process of propellant flames, it is necessary to simulate an oscillation environment with certain frequency, amplitude and duration. This paper presents an experimental installation of pressure oscillation based on pulse-driving technique, with which pressure oscillations features under different pulse-driving conditions were compared and analyzed. For the pulse-driver applied in this paper, a pressure oscillation with 0.15s-0.5s duration, 179Hz-210Hz first order frequency, 0.04MPa-0.35MPa amplitude is simulated. The test results show that an oscillation with higher frequency and lager amplitude can be obtained when pulse-driver is installed on the top of the installation cavity, while on the side, an oscillation with a longer duration and approximate cavity natural frequency can be simulated.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.61-64
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• 2008

The present study of these experiments are close examination of spray characteristics that are continuous liquid jet and modulated pressure pulse liquid jet. The experiments were conducted using water, over a range of cross-flow velocities from 42${\sim}$136 m/s, with injection frequencies of 35.7${\sim}$166.2 Hz. Between continuous cross-flow jet and pressure pulsed cross-flow jet for characteristics of penetration, breakup point, spray angle and macro spray shape are investigated experimentally. In cross-flow field, main parameter of liquid jet for breakup was cross-flow stream rather than pressure pulse frequency. As oscillation of the periodic pressure that could make liquid jet moved up and down, the mixing efficiency was increased. Also, a bulk of liquid jet puff was detected at upper field of liquid surface. So, this phenomenon has a good advantage of mixing spray from concentration of center area to outer area. Because of pressure pulsation frequency, an inclination of SMD for the structured layer was evanescent. Cross-sectional characteristics of SMD at downstream area were non-structured distributions. Then cross-sectional characteristics of SMD size were about same tendency over a range that is effect of spray mixing. The tendency of volume flux value for various frequency of pressure pulse was same distribution. And volume flux was decreased when the frequency of pressure pulse increase.

• 한국응급구조학회지
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• 제21권2호
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• pp.89-102
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• 2017

Purpose: The purpose of the study was to investigate the effects of subtraction meditation on perceived stress, self-efficacy, blood pressure, and pulse rate in paramedic students. Methods: A quasi-experimental study with non-equivalent comparison groups using pre and post-test design was performed. The experimental group consisted of 27 participants who attended the meditation program, and the control group consisted of 26 non-participants of the program. The data were analyzed using SPSS/WIN 24.0. Results: There were a statistically significant differences between the experimental group and the control group in perceived stress(t=2.301, p=.026), systolic pressure(F=18.531, p=.000), diastolic pressure(F=9.745, p=.003), and pulse rate(F=33.869, p=.000) between pretest and posttest results. Conclusion: The subtraction meditation program can help reduce perceived stress, systolic pressure, diastolic pressure, and pulse rate.

• Korean Journal of Acupuncture
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• 제27권4호
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• pp.59-72
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• 2010

Objectives : In the study on the waveform analysis of radial artery pulse diagnosis, we need to establish fundaments of contemporary pulse diagnosis research, and to find the change of pulse waveform parameter with applied variation pf pressure. Methods : As we will to do experimental research on the difference of pulse waveform on the radial artery with applied variations of pressure(5 stage-pressure) and measuring position(left KWAN). In this research, we analyzed the change of the waveform according to five stage pressure. Results : The results were as follows; When we analyzed the change of the waveform according to pressure in the left KWAN, E, hl, h2 and A were the difference between 8ths pressure grades in 95% trust section. And t2, t4 were the difference between 8ths pressure grades in 95% trust section. W was the difference between 8ths pressure grades in 95% trust section. And h2/h1 was the difference between 6ths pressure grades in 95% trust section. There is the difference between 1st and 2nd grade & between 2nd and 5th grade in the case of t4/t2 in 95% trust section. And there is the difference between 1st and 5th grade, between 3rd and 4th grade, between 3rd and 5th grade & between 4th and 5th grade in the case of W/A in 95% trust section. And there is the difference between 1st and 2nd grade, between 2nd and 3rd grade, between 2nd and 4th grade, between 3rd and 4th grade, between 3rd and 5th grade & between 4th and 5th grade in the case of A/E in 95% trust section. Conclusions : We found the statistically resonable differences between each pulse depending on the applied pressure. And Analysing the radial pulse(left KWAN) at 5 applied pressure levels may be useful to study on the pulse waveform diagnosis.