• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.3
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• pp.220-227
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• 2007

Heat transfer and momentum transfer under conditions of both oscillating flow and oscillating pressure within pulse tubes show very different behavior from those for steady state conditions. The analytic solutions of axial velocity and temperature of the gas within pulse tubes were obtained by assuming that the variations in pressure and temperature were purely sinusoidal and small. The shear stress and the heat flux at the tube wall obtained from the solutions are expressed in terms of the cross-sectional averaged velocity, the difference between mean temperature and instantaneous cross-sectional averaged temperature and the difference between mean pressure and instantaneous pressure. It is shown that the complex shear factor, which has been applied to momentum transfer of incompressible oscillating flow, and the complex Nusselt number, which has been applied to either heat transfer with oscillating pressure only or heat transfer of incompressible oscillating flow, could also be used for momentum transfer and heat transfer subjected to both oscillating flow and oscillating pressure, respectively.

• Journal of Sasang Constitutional Medicine
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• v.18 no.1
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• pp.118-131
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• 2006

1. Objective Pulse diagnosis is generally applied to Traditional Oriental Medicine but not to Sasang Constitution diagnosis. Recently new pulse analyzer using array piezoresistive sensor and multi-channel robot arm developed. It reflects Oriental Medical Doctors' diagnostic processes, and its reproducibility test was done at Korea Institute of Oriental Medicine. We performed this study to set parameters diagnosing Sasang Constitution. 2. Methods One hundred thirty three subjects participated in this study. They are healty and approved this study. Before being tested with pulse analyzer, they had interview with Sasang Constitution Specialist to diagnose their Sasang Constitution. We established some useful parameters from parameters of pulse analyzer according to the Original Texts of Oriental Medicine and clinical experiences to analyze with clinical data of this study. 3. Results (I) There is a significant difference in pre-dicrotic notch time among all parameters of pulse analyzer in Sasang Constitution groups(P=0.047). (2) There is a significant difference in maximum pulse pressure in 33 to 48 year Sasang Constitution groups(P=0.010). (3) There is a significant difference in frequency width in 17 to 32 year Sasang Constitution groups(P=0.002). (4) There is a significant difference in CFS value in groups which OMD diagnoses; Floating & Sinking pulse(P=0.020). (5) There is a significant difference in pulse rate in groups which OMD diagnoses; Rapid & Slow pulse(P=0.000). (6) There is a significant difference in maximum pulse pressure in groups which OMD diagnoses; Deficient & Solid pulse(P=0.000). 4. Conclusions Analyzing parameters in each Sasang Constitution group, we found it shows significant difference in maximum pulse pressure and corresponding tendency in coefficient of floating & sinking pulse with theories of Sasang Consti-tutional Medicine. As we accumulate more clinical data, we will establish algorithm to diagnose Sasang Constitution using a pulse analyzer.

• Journal of Convergence Korean Medicine
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• v.6 no.1
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• pp.5-20
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• 2024

Objectives: This study was aimed to evaluate the hemodynamic feasibility using pulse parameters as a way to establish safe dose guidelines for Chunwangbosim-dan, and to provide a foundation for developing evidence-based guidelines for clinical use. Methods: Forty-one volunteers were recruited to participate in a study examining the changes in pulse wave characteristics following the ingestion of Chunwangbosim-dan, over a period of 2 weeks, and pulse wave measurements were taken before and after the administration. Pulse wave parameters were measured in this study using a 3-dimensional radial pulse tonometry device(DMP-Lifeplus). In addition, questionnaire, blood pressure, temperature, and body composition were also measured as secondary measures. Results: Fifteen minutes after administration of Chunwangbosim-dan, the non-adverse event group(non-AE) exhibited a statistically significant increase in several power and pressure-related parameters, including h1, h3, h4, h5, SA, PA and PW, while the adverse event group(AE) showed a trend of decreasing stroke volume and increasing Systemic Vascular Resistance Index(SVRI) and applied pressure. After 2 weeks of administration, non-adverse event group(non-AE) exhibited significant changes in standard deviation of pulse rate and HRV_LH ratio. Notably, there are significant differences between AE group and non-AE group in h4/h1, w/t, applied pressure, SV and pulse rate. Conclusion: These findings suggest that pulse parameters may be a useful way to establish safe dosing guidelines for Chunwangbosim-dan. Further research is needed to confirm these results and to develop evidence-based guidelines for clinical use.

• Korean Journal of Oriental Medicine
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• v.13 no.3
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• pp.105-110
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• 2007

This work reports the pulse diagnosis system using FBG sensors which can display pulse signals detected while oriental medical doctors are conducting pulse diagnoses and simultaneously pressing the sensors by three fingers. Each optical fiber has five FBG sensing units fabricated in 2 mm width and 2 mm inter-sensor spacing. Three optical fibers with the FBG units in the parallel line configuration are then placed on each finger-pressing region and thus overall 9 fibers are used for the pulse measurements on the so-called "chon", "gwan", and "ch대k". A fixture holding the optical fiber arrays is able to adjust the height of the FBG sensing units while placing the fibers on the wrist. The pulse signals detected by the FBG sensors from chon, kwan, and chuk have been analyzed using 4 channel spectrum analyzer connected to the optical fibers. The measured pulse signals exhibit variations due to the nonuniform pressure distributions applied. resulting in the differences in the detected pulse signals between fiber lines. However. this work is the first step towards objective and quantitative analyses of the pulse diagnosis in oriental medicine which has traditionally been performed on subjective basis. Future works will be devoted to improving sensor stability, developing the way applying pressure and algorithms reporting the objective classification of the pulse status from systemic measurements using the sensors instead of relying on the clinicians' diagnoses subjectively performed. A successful pulse diagnosis system emerging in the future is expected to contribute to education as well as promoting pulse diagnosis in oriental medicine to the scientific research area.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.942-948
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• 2011

Solid propulsion systems have simple structures compared to other propulsion systems and are suitable for long-term storage. However the systems generally have limits on control of thrust levels. In this paper we introduce controllers for combustion chamber pressure using on-off control techniques which have been known for relatively easy implementation and energy efficiency. For this, we use a simple pressure change model by considering only mass conservation within the combustion chamber and we design a classical controllers and on-off controllers with are Pulse Width Modulation(PWM) and Pulse Width Pulse Frequency Modulation (PWPFM). Then we compare the performance results of the controllers through numerical simulations.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1100-1106
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• 2009

This study intends to develop a pulse discharge device to strengthen the pushing power by expanding the cavity of the anchor settlement to form a spheric root for the purpose of constructing the economical and stable anchor. and, a series of field test were carried out in order to check applicability of machines of pulse powered underreamed anchors. Through the experiments, the electrical characteristics of the pulse power equipment had been identified it and the dynamic pressure generated from the subsequent change had been measured. Here, the measured dynamic pressure is the cavity expansion pressure to impact on the ground around the anchor settlement. Since this pressure has effects of cavity expansion and bored surface hardening with dynamic hardening effects on the anchor settlement, it is expected that it will largely contribute the increase of pushing power with a strong frictional resistance.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.12 no.2
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• pp.8-17
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• 2008

Objectives: For the traditional pulse diagnosis in Oriental Medicine, not only the pulse shape in time domain, but the width, length and depth of arterial pulse also should be measured. However, conventional pulse diagnostic systems have failed to measure the spatial parameters of the arterial pulse e.g. effective length of arterial pulse in the wrist. In fact, there are many ways to measure that kind of spatial features in arterial pulsation, but among them, the method using image sensor provides relatively cheap and simple way, therefore I tested feasibility of measuring 2-dimensional pressure distribution by imaging devices. Methods: Using widely used PC cameras and dotted balloons, the subtle oscillation of skin over the radial artery was recorded continuously, and then the displacement of every dot was calculated. Consequently, the time course of that displacements shows arterial pulse wave. Results: By the proposed method I could get pressure distribution map with 30Hz sampling rate, 21steps quantization resolution, and approximately 1mm spatial resolution. With reduced quantization resolution, $3cm{\times}4cm$ view angle could be achieved. Conclusion: Although this method has some limitations, it would be useful method for detecting 2-dimensional features of arterial pulse, and accordingly, this method provides a novel way to detect 'narrow pulse', 'wide pulse', 'long pulse', 'short pulse', and their derivatives.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.203-208
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• 2018

The purpose of this study was to investigate whether there is a relationship between pulmonary function, serum lipid and pulse pressure, which is a risk factor of cardiovascular disease, in subjects with 109 office workers(51 males and 58 females) be at Seoul, Korea. The mean age of the subjects was $43.44{\pm}7.23$ years old (male $43.44{\pm}7.27$, fenale $49.1{\pm}11.5$). The subjects' height, weight, BMI, systolic and diastolic blood pressures were measured and there was statistical difference between men and women.The mean pulse pressure of the subjects was $47.82{\pm}9.02mmHg$, and the mean of FVC was $84.26{\pm}9.91%$. There was no difference between men and women in both. There was a positive correlation between pulse pressure and systolic blood pressure in males (p<0.01) and females (p<0.01), and FVC and HDL in males were positively correlated (p<0.05). Pulse pressure and %FVC were negatively correlated (r =-0.267, P<0.01). Pulse pressure and %FVC were negatively correlated (r =-0.267, P<0.01). Regression analysis showed that PP was the independent affected %FVC. Therefore, pulse pressure and %FVC may be useful as a predictor of cardiovascular disease in middle-aged subjects with normal, suggest a long-term convergence follow-up is warranted to elucidate the incidence of cardiovascular disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.886-891
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• 2008

This experimental investigation is concerned with the relationship between the electrical-on time of a solenoid which is located on the top of a pulse valve and air consumption of a dust collector. For the air consumption per pulse would be one of major factors affecting the operating cost of a dust collector, more attention is needed on the behaviour of a pulse valve. A pulse jet is blasted into a bag filter as the diaphragm valve opens and inflates a bag filter. This air-blast breaks up the dust layer and cleans the filter by dislodging dust cake. It is interpreted in this research that the cleaning filter is done by the impulse of a pulse jet. Hence, the magnitude and fluctuation of the dynamic pressure is measured using by a dynamic pressure sensor and the impulse is obtained by integrating dynamic pressure variation against time. Through this experimental work, conclusions are drawn implementing magnitude of averaged impulsive pressure per pulse or pressure impulse per unit volume of consumed air.

• The Journal of Internal Korean Medicine
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• v.27 no.2
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• pp.416-428
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• 2006

Objectives : Arterial stiffness and pulse pressure are related to cardiovascular and cerebrovascular survival and longevity. This study is aimed at examining the effects of Chungpyesagan-tang on arterial stiffness and Pulse pressure in acute stroke Patients. Methods: The subject of this study was acute strike Patients within 1 week after ictus, with Cardio-ankle vascular index(CAVI) higher than 9.0. They were divided into two groups: A treatment group (n=44) and a control group(n=46). For two weeks, Chungpyesagan-tang was given to the former, other herbal medicines to the latter. used for stroke patients for the control group for 2 weeks. At the end of first and second week, CAVI, pulse Pressure, National Institute of Health stroke scale(NIHSS), Modified Barthel Index(MBI) were measured. Serum lipid Profile, aspartate transaminase(AST), alanine transaminase(ALT). blood urea nitrogen(BUN), creatinine were also measured at the end of the study. Results : After 2 weeks, CAVI and Pulse Pressure in Chungpyesagan-tane group were significantly tower than those in the control group(P<0.05). NIHSS and MBI were improved in both groups. But there was no significant difference between the treatment group and the control group in terms of the NIHSS and MBI. Conclusions : We suggest Chungpyesagan-tanghas desirable effects on arterial stiffness and Pulse Pressure of acute stroke patients. It can improve morbidity and mortality of patients on the basis of influencing vascular stiffness and increased pulse pressure.