• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1870-1872
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• 2003

High voltage pulse generator with fast rise time has been studied theoretically and experimentally. The complexity and stray inductance of a pulse generator components can be very difficult to reduce. As a result, a compact size and stable Pulse can be obtained by using a rotary air-hole. Parametric studies showed that the rise time of the output pulse was depended little on the change of the revolutions per minute(RPM) while the pulse width of the output pulse was depended greatly upon the change of the revolutions per minute (RPM).

• Korean Journal of Digital Imaging in Medicine
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• v.15 no.1
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• pp.21-26
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• 2013

To be investigated and measures to reduce the medical exposure of patients to change the Epidural Injection time Fluoroscopy Pulse Rate in this study. Was conducted in 50 patients who underwent surgery Epidural Injection performed by interventional care of Konkuk University Hospital from January to April 2013. The treatment time with the change of Pulse rate, is measured in minutes fluoroscopy time, and measured the area dose (${\mu}Gym^2$) and depth dose (mGy). Using the Image J program, to measure the PSNR and SNR. The fluoroscopy time as a result surgery, there was no significance in the statistical analysis, and depth dose is 34.3 to 34.9%, was reduced from 35.8 to 38.7% the area dose. It is possible to reduce the appropriate Pulse rate, to reduce the dose without statistical analysis significance fluoroscopy time.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.1
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• pp.35-41
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• 2003

In this paper statistics on the radiation field waveforms produced by stepped leaders just prior to lightning return strokes were described. As a parameter of stepped leader pulse characteristics, the time interval between the final leader pulse and return stroke peak, the pause time between stepped leaders, the ratio of the final leader peak to the return stroke peak and the stepped leader pulse width at half maximum were examined. The average time intervals between the final leader pulse and return stroke peak were about 16.2 and 14.8$mutextrm{s}$ for the positive and negative polarities, respectively. When the stepped leader approaches closely to ground, the time interval between leader steps was decreased and the mean value was about 17$mutextrm{s}$, and the present results were in reasonable agreement with the data observed in Florida and Japan. The large fraction of the ratios of the final stepped leader pulse to the lightning return stroke peak were distributed over the range from 5 to 35% and in average the ratio of the final leader pulse to the return stroke peak was 17.4$\pm$11.9% for the positive and 18.5$\pm$9.4% for the negative electric field waveforms. In addition, the mean pulse widths at half maximum of the stepped leaders are 1.4Us with a standard deviation of 0.9 for the positive Polarity and 2.2us with a standard deviation of 1.2 for the negative polarity, respectively.

• Journal of Biomedical Engineering Research
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• v.31 no.1
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• pp.14-19
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• 2010

Baroreflex sensitivity (BRS) is a parameter of the cardiovascular system that is reflected in changes in pulse interval (PD and systolic blood pressure (SBP). BRS contains information about how the autonomic nervous system regulates hemodynamic homeostasis. Normally the beat-to-beat SBP measurement and the pulse interval measured from the electrocardiogram (ECG) are required to estimate the BRS. We investigated the possibility of measuring BRS in the absence of a beat-to-beat SBP measurement device. Pulse arrival time (PAT), defined as the time between the R-peak of the ECG and a single characteristic point on the pulse wave recorded from any arterial location was measured by photoplethysmography. By comparing the BRS obtained from conventional measurements with our method during controlled breathing, we confirmed again that PAT and SBP are closely correlated, with a correlation coefficient of -0.82 to -0.95. The coherence between SBP and PI at a respiration frequency of 0.07-0.12 Hz was similar to the coherence between PAT and PI. Although the ranges and units of measurement are different (ms/mmHg vs. ms/ms) for BRS measured conventionally and by our method, the correlation is very strong. Following further investigation under various conditions, BRS can be reliably estimated without the inconvenient and expensive beat-to-beat SBP measurement.

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.92-97
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• 2009

Two conventional speed detection methods (Elapsed-time method and Pulse-count method) are analyzed and compared for a high speed motor with digital tacho pulse with non-uniformity. In general, the elapsed-time method usually has better performance than a pulse-count method in case sufficiently high speed clock is used to measure the time difference. But if a tacho pulse non-uniformity exists in the reaction wheel - most of reaction wheel has a certain amount of non-uniformity - the accuracy of the elapsed-time method is degraded significantly. Thus the performance degradation is analyzed with respect to the level of non-uniformity of tacho pulse distribution and an allowable bound is suggested.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.8
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• pp.504-509
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• 2005

This paper presents a new method for obtaining the noninvasive and unrestrained blood pressure readings noninvasively and unrestrainedly using based on reflected wave arrival time(RAT) in the volume of pulse. Since this new method employs only volume pulse, is more rapider and simpler than the method using pulse transit time(PTT) because it only employs the volume of pulse. Blood pressure, PTT and RAT were acquired from 15 healthy subjects. Each subjects were performed forty trials of each measurement. As a result of those trials, the mean error between oscillometric and RAT measurements for systolic blood pressure was $4.55\pm5.64mmHg$. This result showed quite equal with the mean error between oscillometric and PPT measurf:ments, $4.22\pm5.30mmHg$, However, it was not obtained a satisfactory result in the relativity of oscillometric to both RAT and PPT measurements for diastolic blood pressure because of personal difference. To conclude, the method of systolic blood pressure estimation noninvasively and unrestrainedly using by RAT may be used as the method by PTT. Nevertheless, additional studies would be necessary for the RAT/PTT estimation of diastolic blood Pressure measurement.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1174-1180
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• 2015

We investigate in this paper the radiated electromagnetic waves together with the discharge characteristics of Trichel pulse of negative DC corona discharge in air in pin-to-plate and wire-to-plate configurations. The feature of the current pulse and the frequency spectrum of the electromagnetic radiations were measured under various pressures and gas gaps. The results show that the repetition frequency and the amplitude of Trichel pulse current depend on the discharge conditions, but the rising time of the pulse relates only to the radius of needle or wire and keeps constant even if the other conditions (including the discharge current, the gas gap and the gas pressure) change. There exists the characterized spectrum of electromagnetic waves from negative corona discharge in Trichel pulse regime. These characterized radiations do not change their frequency at a given cathode geometry even if the averaged current, the gas gap or the air pressure changes, but the amplitude of radiations changes accordingly. The characterized electromagnetic radiations from Trichel pulse corona relate to the formation or the rising edge of current pulse. It confirms that the characterized radiations from Trichel pulse supply information of discharge system and provide a potential method for detecting charged targets.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.1976-1980
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• 2008

This paper deals the characteristic analysis of Switched Reluctance Motor(SRM) driven by single-pulse mode considering dc link voltage ripple. Two dimensional time-stepped Finite Element Method(FEM) is used to analyze the characteristic of SRM driven by single-pulse mode with dc link voltage ripple. The analysis results is verified by experimental test.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.1
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• pp.67-75
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• 1992

A new method of driving the PDP(Plasma Display Panel) was proposed and its characteristics were investigated. Applying high frequency non-discharge pulses to an auxiliary anode resulted an increased region of stable operation, decreased delay time and increased light intensity. It is suggested that PDP with DPM (Double Pulse Memory) drive technique improves the delay time, luminance, region of stable operation and luminous efficacy compared to PDP with PPM(Planar Pulse Memory) drive technique developed by NHK Lab. in Japan.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.834-837
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• 2005

In this paper, we describe the method of non-invasive blood pressure measurement using pulse wave transit time(PWTT). PWTT is a new parameter involved with a vascular that can indicate the change of BP. PWTT is measured by continuous monitoring of ECG and pulse wave. No additional sensors or modules are required. In many cases, the change of PWTT correlates with the change of BP. We measure pulse wave using the photo plethysmograph(PPG) sensor in an earlobe and we measure ECG using the ECG monitoring device our made in the chest. The measurement device for detecting pulse wave consists of infrared LED for transmitted light illumination, pin photodiode as light detector, amplifier and filter. We composed 0.5Hz high pass, 60Hz notch and 10Hz low pass filter. ECG measurement device consists of multiplexer, amplifier, filter, micro-controller and RF module. After amplification and filtering, ECG signal and pulse wave is fed through micro-controller. We performed the initial work towards the development of ambulatory BP monitoring system using PWTT. An earlobe is suitable place to measure PPG signal without the restraint in daily work. From the results, we can know that the dependence of PWTT on BP is almost linear and it is possible to monitoring an individual BP continuously after the individual calibration.