• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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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).

• 대한한의진단학회지
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• 제9권2호
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• pp.123-144
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• 2005

Objectives: Pulse-Respiration Ratio has been used for estimating subject's Han-Yeol [寒熱] status since it mentioned in suwen [素問]. In practicing Pulse-Respiration Ratio over 5 means the status of Yeol [熱], Pulse-Respiration Ratio below 3 means the status of Han [寒]. We performed this study to examine the Optimum Standard for Measuring Pulse-Respiration Ratio on the Basis of Repeatability and Reproducibility. Methods: After subject's 5 minutes rest we measured subject's ECG, respiration pattern, EEG, EMG simultaneously. In this research examiner's number is two, subject's number is four, and the number of repeat is two. We calculated Pulse-Respiration Ratio through dividing Respiration cycle average by Pulse cycle average according to each standard including time section, $EEG(relative-{\alpha}$ density, $relative-{\beta}$ density, ${\alpha}/{\beta}$ and EMG. We analyzed these data through Gage R&R study using MINITAB 13.20 program and considered the results of below 30 %R&R and over 4 Number of Distinct Categories to have a significance. Results: 1. In the applying of time standard, Pulse-Respiration Ratio from section 3, 4, 6, 8 had a significant meaning in the aspect of Repeatability and Reproducibility. 2. In the applying of $EEG({\alpha}$ I , ${\beta}$ I , ${\alpha}/{\beta})$, EMG(E I) standard, there was no significant results. 3. In the applying of time standard(section 5, 6, 7), $EEG({\alpha}$ I , ${\beta}$ I , ${\alpha}/{\beta})$ and EMG(E I) standard simultaneously, Pulse-Respiration Ratio from ${\alpha}/{\beta}$ in section 6, ${\beta}$ I in section 8 had a significant meaning in the aspect of Repeatability and Reproducibility. Conclusions: We can suggest the Optimum Standard for Measuring Pulse-Respiration Ratio on the basis of Repeatability and Reproducibility as followings; 1. Pulse-Respiration Ratio Measuring time should be at least 15 minutes. 2. Applying of time(section 6, 8) and $EEG({\beta}$ I, ${\alpha}/{\beta})$ standard simultaneously is recommended considering reliability and validity but more study is needed. 3. EMG(E I) may be helpful to detect the segment of physical rest and exclude artifacts but more study is needed.

• 한국컴퓨터산업학회논문지
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• 제2권7호
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• pp.975-982
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• 2001

펄스형 Nd：YAG레이저는 연속형에 비해 효율이 높고 높은 첨두출력이 가능하므로 가공에 있어서 여러 가지 장점이 있다. 더구나 레이저 펄스모양을 가변 시키는 기능은 펄스형 Nd：YAG레이저로 가공하기 힘든 특수분야에까지 가공을 가능하게 하였다. 본 연구에서는 3개의 플래쉬 램프를 순차 점등시키는 방식의 레이저시스템을 설계, 제작하여, 램프 점등시간의 변화에 따른 레이저빔의 펄스 폭과 펄스 세기를 조사하였다. 즉 PIC-Onechip microprocessor를 이용하여 실시간으로 3개의 플래쉬 램프를 순차적으로 점등시켜 보다 다양한 펄스모양을 만드는 기술을 개발하였다. 위 방식의 장점은 램프의 점등 지연시간을 0∼10ms까지 다양하게 변화시킬 수가 있고, 외부의 키보드로 실시간 제어가 가능하므로 보다 편리하게 펄스모양을 변화시킬 수가 있다. 또한, 긴 펄스를 만들 수가 있어 산업용 가공이나 의료용으로 널리 사용될 수가 있을 것이다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권7호
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• pp.329-333
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• 2001

The pulsed poser system has been widely used to many applications, such as E/P(Electrostatic Precipitator), DeNox/DeSOx power system, ozon generator, etc. A pulse energy efficiency for load depends on the rising time, peak value, pulse duration and impedance matching, etc. The pulse generator generally required for short pusle duration and high peak value was forced to consider its volume and economy. In this study, developing a compact pulse generator that applied for cascading method to be made of two pulse transformers, we compared cascading voltage with non cascading one by applying the pulse energy to load. Adopting cascading technique to pulse transformer, we found that average cascading voltage was about 60[%] of theoretical value. Maximum cascading ratio was calculated at 60 times compared with non cascading voltage.

• Journal of the Optical Society of Korea
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• 제17권5호
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• pp.441-446
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• 2013

A split-step time-domain model for the analysis of pulse delay characteristics through ring resonator all-pass filters (APF's) is developed and its accuracy is checked. The dependence of the delay time and pulse distortion on the coupling ratios is investigated using the model. It is observed that the bandwidth of the APF's needs to be wide enough to minimize the pulse distortion.

• Journal of information and communication convergence engineering
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• 제5권2호
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• pp.112-115
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• 2007

A CMOS TDC(time-to-digital converter) is proposed which has a simple cyclic structure. The proposed TDC consists of pulse-shrinking elements, D latches and D flip-flops. The operation is based on pulse-shrinking of the input pulse. The resolution of digital output can be easily improved by increasing the number of the pulse-shrinking elements, D latches and D flip flops. The TDC performance is improved in viewpoints of power consumption and chip area. Simulation results are shown to illustrate the performance of the proposed TDC circuit.

• 대한의용생체공학회:의공학회지
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• 제31권1호
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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.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권8호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1297-1300
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• 2008

A conventional linear accelerator system requires a flat-topped pulse with less than ${\pm}$ 0.5% ripple to meet the beam energy spread requirements and to improve pulse efficiency of RF systems. A pulse transformer is one of main determinants on the output pulse voltage shape. The pulse transformer was investigated and analyzed with the pulse response characteristics using a simplified equivalent circuit model. The damping factor ${\sigma}$ must be >0.86 to limit the overshoot to less than 0.5% during the flat-top phase. The low leakage inductance and distributed capacitance are often limiting factors to obtain a fast rise time. These parameters are largely controlled by the physical geometry and winding configuration of the transformer. A rise time can be improved by reducing the number of turns, but it produces larger pulse droop and requires a larger core size. By tradeoffs among these parameters, the high-voltage pulse transformer with a pulse width of 10 ${\mu}s$, a rise time of 0.84 ${\mu}s$, and a pulse droop of 2.9% has been designed and fabricated to drive a klystron which has an output voltage of 284 kV, 30-MW peak and 60-kW average RF output power. This paper describes design optimization of a high-voltage pulse transformer for high-power pulsed applications. The experimental results were analyzed and compared with the design. The design and optimal tuning parameter of the system was identified using the model simulation.

• 한국표면공학회지
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• 제36권2호
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• pp.161-167
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• 2003

In order to investigate the effects of pulse plating conditions on the electrodeposition of trivalent chromium, electroplating experiments from bath with low concentration of trivalent chromium were performed. The variation of current efficiency of chromium electroplating with the electroplating conditions was explained. The maximum current efficiency of pulse plating is 6.4 times as high as that of direct plating at the same mean current density The nodular size increased with pulse plating time and the pulse frequency.