• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.609-611
• /
• 1996

Zero-Cross Detector makes pilot signal to control the power to CEDM(Control Element Drive Mechanism). Existing Zero-Cross Detectors has had a problem which can cause unexpected reactor trip resulted from fluctuating frequency of input signal coming from M/G Set. The existing Zero-Cross Detector can't work properly when power frequency is varying because it was designed to work under stable M/G Set operation, and produces wrong pilot signal and output voltage. In this report the Zero-Cross Detector is improved to resolve voltage fluctuating problem by using new devices such as digital noise filtering circuit, variable cycle compensator and alarm circuit. And through the performance verification it shows that new circuit is better than old one. If suggested detector is applied to plant, it is possible to use it under House Load Operation because stable voltage can be generated by new Zero-Cross Detector.

• 전기학회논문지
• /
• 제57권6호
• /
• pp.1032-1035
• /
• 2008

In this paper, a DC power management scheme is proposed for efficient battery operation of 60-GHz receivers. It consists of a rectenna and a zero-cross detector. The harmonic rejection capability of a circular sector antenna is used to simplify the rectenna. The zero-cross detector is introduced to increase sensitivity. When the received power density is larger than 0.013 $mW/cm^2$, it can generate enough DC power to activate an RF receiver. Experimental data is used to verify the proposed idea.

• 한국산학기술학회논문지
• /
• 제13권11호
• /
• pp.5403-5408
• /
• 2012

본 논문에서는 신체 성분 분석을 위한 다주파수 생체전기 임피던스 분석법에 대하여 소개하고 이를 기반으로 다주파수 생체전기 임피던스 분석 시스템을 구현하고 그 과정 및 결과를 제시하였다. 시스템의 구성요소들을 다주파수 교류 신호 발생부, 위상 신호 검출부, 전압 신호 검출부, 제어부, 입 출력부, 전극부, 전원부로 구분하여 설명하고, 구체적으로 구현 기법을 소개하였다. 체성분 데이터의 임상적 의의를 검토하고자 세계 최고 수준의 기술을 적용하여 높은 재현도와 고정밀도의 데이터를 제공하는 전문가용 체성분 분석기로 측정한 데이터와 비교 검토하고 두 측정치간의 상관관계를 구한 결과 시스템에 의한 체성분 분석은 상당히 높은 재현성을 나타낸다고 할 수 있다.

• Journal of Magnetics
• /
• 제19권2호
• /
• pp.197-204
• /
• 2014

A transcranial magnetic stimulation device is a complicated appliance that employs a switching power device designed for discharging and charging a capacitor to more than 1 kV. For a simple transcranial magnetic stimulation device, this study used commercial power and controlled the firing angle using a Triac power device. AC 220V 60 Hz, the power device was used directly on the tanscranial magnetic stimulation device. The power supply device does not require a current limiting resistance in the rectifying device, energy storage capacitor or discharge circuit. To control the output power of the tanscranial magnetic stimulation device, the pulse repetition rate was regulated at 60 Hz. The change trigger of the Triac gate could be varied from $45^{\circ}$ to $135^{\circ}$. The AVR 182 (Zero Cross Detector) Chip and AVR one chip microprocessor could control the gate signal of the Triac precisely. The stimulation frequency of 50 Hz could be implemented when the initial charging voltage Vi was 1,000 V. The amplitude, pulse duration, frequency stimulation, train duration and power consumption was 0.1-2.2T, $250{\sim}300{\mu}s$, 0.1-60 Hz, 1-100 Sec and < 1 kW, respectively. Based on the results of this study, TMS can be an effective method of treating dysfunction and improving function of brain cells in brain damage caused by ischemia.

• Journal of Pharmaceutical Investigation
• /
• 제35권2호
• /
• pp.117-122
• /
• 2005

After establishing improved HPLC analytical method of cefaclor in human plasma samples, a bioavailability study of cefaclor capsules was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). The standard calibration curve using an HPLC with UV detector was constructed in a range of $0.0324{\sim}16\;{\mu}g/ml$. The 6% perchloric acid instead of 6% trichloroacetic acid was used to precipitate plasma protein. The HPLC chromatograms were precisely and accurately resolved when spiked with human plasma spiked with cefaclor and cephalexin (internal standard). Twenty healthy male Korean volunteers received two commercial cefaclor capsules, $Neocef^{\circledR}$ capsule (Jinyang Pharm. Co., Ltd) or $Ceclor^{\circledR}$ capsule (Lilly Korea. Co., Ltd.) at the 250 mg cefaclor in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of cefaclor were monitored for 8 hours after oral drug administration. $AUC_t$ the area under the plasma concentration-time curve from time zero to 8 hr (13 points), was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the cross-over design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Neocef^{\circledR}/Ceclor^{\circledR}$ were $0.9049{\leq}{\delta}{\leq}1.226$, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the bioequivalence of $Neocef^{\circledR}/Ceclor^{\circledR}$ with respect to the extent of absorption.