• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.301-309
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• 2021

Pulse count method is the classical reaction wheel speed detection method. In this study, we represent the pulse count method as mathematical equations. Instead of rotation speed, we model the reaction wheel rotation through rotation angle during sampling periods. We verified the effectiveness of the proposed model by comparing the pulse counts variation and averaging method effects from the model and previous research results. Then, we add tacho pulse non-uniformity to this verified model, and examine the errors of pulse count method. We express the measurement error increasement due to non-uniformity as mathematical equations, and also shows the requirement of moving average numbers to offset the measurement errors.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.41-46
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• 2005

In this paper, we proposed noninvasive and continous measurement of blood pressure using pulse transit time(PTT) and physical characteristic parameters and verified its clinical effectiveness. PTT can be obtained by electrocardiogram and phtoplethysmogram. There are many researches for estimating blood pressure using PTT which can be used for individual. However, it is not enough for extracting general regression equation which can estimate blood pressure for unspecified people. In this study, we suggested the regression equatin using PTT and physical characteristic parameters related to blood pressure and did measure blood pressure of many people. we compared the performance between two methods. As the results, we knew that the regressin model using PTT combined with physical characteristic parameters can estimate blood pressure more acurately and is closer to American National Standards Institute of the Association of the Advancement of Medical Instrument(ANSI/AAMI).

• Journal of the Microelectronics and Packaging Society
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• v.16 no.4
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• pp.49-53
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• 2009

In order to investigate the formation behavior of hollow Cu via for MEMS packaging, we observed the microstructure of the Cu vias and measured the average thickness and the thickness deviation with variations of pulse-reverse pulse current density and electrodeposition time. With electrodeposition for 3 hours at the pulse and reverse pulse current densities of $-5\;mA/cm^2$ and $15\;mA/cm^2$, the average thickness and the thickness deviation of the Cu vias were $5\;{\mu}m$ and $0.63\;{\mu}m$, respectively. With increasing the electrodeposition time to 6 hours, it was possible to form the Cu vias, of which the average thickness and thickness variation of the Cu vias were $10\;{\mu}m$ and $1\;{\mu}m$, respectively. With increasing the pulse and reverse pulse current densities to $-10\;mA/cm^2$ and $30\;mA/cm^2$, Cu vias of uniform thickness could not be formed due to the faster increase of the thickness deviation than that of the average thickness with increasing the electrodeposition time.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.7
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• pp.39-46
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• 2009

A fast-switching current-pulse driver for light emitting diode (LED) backlight is proposed. It uses a regulated drain current mirror (RD-CM) [1] and a high-voltage NMOS transistor (HV-NMOS). It achieves the fast-response current-pulse switching by using a dynamic gain-boosting amplifier (DGB-AMP). The DGB-AMP does not discharge the large HV-NMOS gate capacitance of the RD-CM when the output current switch turns off. Therefore, it does not need to charge the HV-NMOS gate capacitance when the switch turns on. The proposed current-pulse driver achieves the fast current switching by removing the repetitive gate discharging and charging. Simulation results were verified with measurements performed on a fabricated chip using a 5V/40V 0.5um BCD process. It reduces the switching delay to 360ns from 700ns of the conventional current-pulse driver.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.202-208
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• 2010

This study reports developmental changes in the vocal signals produced by infant or young Pipistrellus abramus. In contrast to adult bats, infant bats of the P. abramus emitted calls characterized by multi harmonics and variable signal patterns. Infants at two day of age emitted a irregular signal and showed gentle FM signals between 10 and 20 days. After about 40 days of age, the young bats emitted similar signals to the echolocation calls of adults. As the infant bats growing up, vocal signals trend showen a decrease in pulse duration(p<0.001), pulse interval(p<0.001) and number of harmonic(p<0.001). And the peak frequency(p<0.001), starting frequency(p<0.001) and ending frequency(p<0.001) in infant bats increased with the age. The largest change in pulse interval occurred in 5 days. And the pulse duration, peak frequency, starting frequency and ending frequency of the bat's sounds changed most dramatically in 25 days of age.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.7
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• pp.1218-1222
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• 2008

We investigate the effect of rise time of a pulse bias voltage on atmospheric plasma generation. With the faster rise time of the pulse bias, the glow discharge appears to be more uniformly generated along the electrodes. I-V measurement confirms that higher loading power can be obtained using the faster rise time. A new understanding for atmospheric plasma generation at a micro-gap electrode is suggested.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.1
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• pp.1-7
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• 1999

In this paper, we use the FDTD method to analyze crosstalk characteristics for high speed pulse signal on MTL(Multi-Transmission Line) in time domain. The FDTD results are compared to the results of SPICE modeling method and the experimental result. The FDTD method has higher accuracy of results than other methods, and it can analyze transmission characteristics of MTL regard to loss of conductor. We analyze crosstalk characteristics for pulse on MTL for lossless and loss case.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.8
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• pp.45-51
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• 2000

The distortion of an electrical pulse, which has a rise/fall time due to the dispersion and the reflection, on tapered microstrip lines has investigated In time domain. The voltage and current transfer functions are shown for the tapered line. The dispersion distortion obtained by using these trans(or functions are represented for the nonideal square pulse along the triangular, Tchebycheff and exponential tapered lines, and analyzed the influence of the reflection and the frequency dispersion on the distorted voltage wave in the tapered lines. The observed overshoot in front of the distorted wane is caused due to the frequency dispersion and the sustained tail of that comes from the reflection in the tapered line.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.94-94
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• 2002

목적： 자기공명영상시스템의 스펙트로미터는 transmitter, receiver, gradient 등의 파형과 동작시간을 제어함으로써 원하는 pulse sequence를 구현한다. 이를 위하여 보통 여러개의 독립적인 DSP 보드를 사용하는 경우가 많은데, 이 경우 하나의 pulse sequence에 대하여 transmitter, receiver, gradient 에 대한 프로그램을 따로 작성해야 하므로 프로그램을 개발하는데 시간과 노력이 많이 소요되고, 프로그램의 변경이나 유지, 보수에 어려움이 많았다. 또한 프로그램간에 version이 다르거나, 또는 부분적으로 프로그램이 바뀌었을 경우 종종 error의 원인이 되기도 하였다. 본 연구에서는 개발하고자하는 pulse sequence에 대하여 하나의 프로그램으로 각 DSP 보드에 필요한 프로그램을 만들어주는 pre-compiler를 개발하였다. 개발된 pre-compiler는 통합된 개발 환경에 integration 되어, compile 과 downloading, debugging 등의 기능을 포함하고 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.344-344
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• 2012

추계학적 강우모의발생기법은 수문학적 분석에 널리 이용되는 방법으로서 장기간의 강우입력 자료를 이용할 수 없는 경우 과거의 관측 자료를 반복하여 이용하기 보다는 과거 관측치의 통계학적 특성을 지니고 있는 합성강우량 시계열자료를 모의하여 설계 강우량 산정 및 강우-유출모형을 이용한 장기해석 등과 같은 수문학적 해석을 위한 입력 자료를 확충하기 위해 이용된다. 그러나 최근 기후변화로 인해 수문학적 설계 강우량 산정 시 가장 중요한 강우발생 특성과 극한치의 특성이 변화하고 있기 때문에 전통적인 추계학적 강우발생기법을 이용하여 강우 시계열자료를 확충하는 것은 한계가 있을 것으로 추정되고 있다. 이에 본 논문에서는 최근 유럽 등에서 도시배수체계의 설계를 위해 널리 이용되고 있는 Bartlett-Lewis rectangular pulse 모형을 이용하여 시간단위 강수량자료를 확충하고 모의된 강우량시계열자료와 실측 강우량자료를 통계학적으로 비교하였다. 또한, 극한치 분석을 통해 변화하는 기후상황에서 적합한지를 평가하였다.