• 한국전자통신학회논문지
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• 제17권2호
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• pp.351-356
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• 2022

The parity function can be implemented with XOR (exclusive-OR) and XNOR (exclusive NOR) circuit. In this paper we propose a high performance XOR-XNOR circuit. The proposed circuitreduced the internal load capacitance on critical path and implemented with 8 transistors. The circuit produces a perfect output signals for all input combinations. Compared with the previous circuits, the proposed circuit presents the improved characteristics in average propagation delay time, power dissipation, power-delay product (PDP), and energy-delay-product (EDP). The proposed circuits are implemented with standard CMOS 0.18um technology. Computer simulations using SPICE show that the proposed circuit realizes the expected logic functions and achieves a reasonable performance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.126-129
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• 1999

This paper presents a new averaged model for controlled on time boost power factor correction (PFC) circuit. The proposed model accurately predicts the average behavior of the PFC circuit, and offers a good alternative in studying the large signal dynamics of the circuit. The accuracy of the model is verified through both computer simulation and experiments.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1562-1568
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• 2014

Based on the average method and the geometrical technique to calculate the average value, the average model of the open-loop step-up converter in CCM operation is established. The DC equilibrium point and corresponding small signal model is derived. The control-to-output transfer function is presented and analyzed. The theoretical analysis and PSIM simulations shows that the control-to-output transfer function includes not only the DC input voltage and the DC duty cycle, but also the two inductors, the two energy-transferring capacitors, the switching frequency and the load. Finally, the hardware circuit is designed, and the circuit experimental results are given to confirm the effectiveness of theoretical derivations and analysis.

• 대한전자공학회논문지TC
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• 제38권4호
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• pp.18-26
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• 2001

본 논문에서는 극성 판단(Polarity Decision) PD를 이용하여 모드 변환과 루프이득(Loop Gain)의 변환시점을 자동적으로 검출해 주는 ATC(Automatic Transfer mode Control)알고리즘을 설계하고 모드 전환시 안정적으로 주파수 오프셋을 추정하는 평균방식 Gear-shift PLL을 설계하였다. 제안하는 모드 전환 시점 검출 알고리즘인 ATC 알고리즘은 종전의 QPSK방식에 적용되던 Lock Detector 알고리즘보다 구현이 매우 간단하며 정확하게 모드 전환시점을 검출한다. 또한 Shift Register에 저장했던 주파수 추정 값들을 평균하는 평균전환방식은 모드 전환시 낮은 주파수 추정 에러값으로 다음 모드에서의 빠른 추적 성능을 가능하게 한다. 본 논문에서 제안하는 알고리즘은 적은 회로 면적과 고속 처리가 가능하도록 설계되어 ASIC 설계에 매우 유용하다. 아울러 본 논문에서는 극성판단 PD를 적용하여 위상 포착 및 추적 성능평가를 수행하고 성좌도(constellation)를 각 모드별로 분석하였다.

• 한국화재소방학회논문지
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• 제30권2호
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• pp.114-122
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• 2016

본 논문은 리튬배터리의 고온 및 단락전류에 따른 폭발 및 화재 위험성을 분석하기 위한 연구이다. 이에 대표적인 리튬배터리 종류인 리튬폴리머배터리 및 리튬이온배터리를 실험시료로 선정하였다. 고온에 따른 폭발위험성 측정결과 리튬폴리머배터리의 경우 평균 $170^{\circ}C$, 리튬이온배터리의 경우 평균 $187^{\circ}C$에서 폭발이 일어났다. 단락전류에 따른 온도상승측정결과 보호회로가 정상작동 할 경우 과전류를 제한하여 온도상승이 거의 없었지만, 보호회로가 고장 났을 경우 리튬폴리머배터리의 경우 평균 $115.7^{\circ}C$ 및 리튬이온배터리 경우 평균 $80.5^{\circ}C$까지 상승하여 화재 및 화상 위험성이 높게 나타나는 것으로 측정되었다.

• The Journal of Korean Physical Therapy
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• 제15권2호
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• pp.168-181
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• 2003

The purpose of this study was to investigate the effects of circuit weight training(CWT) on isokinetic muscle strength and body composition in elderly. The subjects who engaged in this experiment exercised at 40$\%$ of 1-RM, 12 repetitions, followed by 15 sec as the subject moved to the each break training program which was consist of the circuit of 10 stations performed on 3 set a day, circuits 3 days a week during 10 weeks. The assessment of isokinetic factor was in concentric flexors and extensors of right and left knee joint. Tests were performed on the Cybex 770 Isokinetic Dynamometer and body composition were estimated the three parts of chest, abdomen and anterior thigh by using skinfold caliper, calculated the average and followed by Seri and Brozek way. Statistical analysis were performed using analysis of variance paired t-test, accepting level for all significant was above $\alpha$=.05 and $\alpha$=.01. Following is as a result of 10 weeks circuit weight training. 1. At the $60_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly (p < .01). 2. At the $180_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly (p < .01). 3. At the $60_{\circ}$ /sec, the right and left knee isokenetic concentric flexors and extensors average power increased significantly(p < 0.5, p < .01) and at the $180_{\circ}$ /sec, the right extensors didn't show any statistical significant. 4. At the $60_{\circ}$ /sec, the right and left knee Isokinetic concentric flexors and extensors total work increased significantly(p < .05, p < .01) but at the $180_{\circ}$ /su right concentric flexors didn't show any statistical significant. 5. The body composition changed significantly(p < .01). These results suggest that 10 weeks circuit weight training increases the peak torque, average power, total work significantly and decreases the $\%$body fat significantly.

• The Journal of Korean Physical Therapy
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• 제15권4호
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• pp.398-411
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• 2003

The purpose of this study was to investigate the effects of circuit weight training(CWT) on isokinetic muscle strength and body composition in elderly. The subjects who engaged in this experiment exercised at $40\%$ of 1-RM, 12 repetitions, followed by 15 sec as the subject moved to the each break training program which was consist of the circuit of 10 stations performed on 3 set a day, circuits 3 days a week during 10 weeks. The assessment of isokinetic factor was in concentric flexors and extensors of right and left knee joint. Tests were performed on the Cybex 770 Isokinetic Dynamometer and body composition were estimated the three parts of chest, abdomen and anterior thigh by using skinfold caliper, calculated the average and followed by Seri and Brozek way. Statistical analysis were performed using analysis of variance paired t-test, accepting level for all significant was above ${\alpha}=.05$ and ${\alpha}=.01$. Following is as a result of 10 weeks circuit weight training. 1. At the $60_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly(p<.01). 2. At the $180_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly(p<.01). 3. At the $60_{\circ}$ /sec, the right and left knee isokenetic concentric flexors and extensors average power increased significantly(p<.05, p<.01) and at the $180_{\circ}$ /sec, the right extensors didn't show any statistical significant. 4. At the $60_{\circ}$ /sec, the right and left knee Isokinetic concentric flexors and extensors total work increased significantly(p<.05, p<.01) but at the $180_{\circ}$ /sec right concentric flexors didn't show any statistical significant. 5. The body composition changed significantly(p<.01). These results suggest that 10 weeks circuit weight training increases the peak torque, average power, total work significantly and decreases the $\%$body fat significantly.

• 전기학회논문지P
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• 제61권3호
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• pp.111-115
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• 2012

Generally, brushless DC motor(BLDCM) driving system uses hall sensors or encoders as the mechanical position or speed sensor. It is necessary to achieve the informations of rotor position for driving trapezoidal type brushless DC motor without any position sensor. In this paper, the commutation signals are obtained without the motor neutral voltage, multistage analog filters, A/D converters, or the complex digital phase shift circuits which are indispensable in the conventional sensorless control algorithms. In the proposed method, in stead of detecting the zero crossing point of the nonexcited motor back electromagnetic force for the average motor terminal to neutral voltage, the commutation signal are extracted directly from the specific average line to line voltage with low-pass filter, adder and comparators circuit. In contrast to conventional methods, the neutral voltage is not need; therefore, the commutation signals are insensitive to the common mode noise. Moreover, the complex phase shift circuit can be eliminated. The effectiveness of the proposed method is verified through simulation results.

• Journal of Power Electronics
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• 제16권3호
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• pp.905-914
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• 2016

A high-performance rectifier is introduced in this study. The proposed rectifier combines the conventional pulse width modulation, soft commutation, and instantaneously average line current control techniques to promote circuit performance. The voltage stresses of the main switches in the rectifier are lower than those in conventional rectifier topologies. Moreover, conduction losses of switches in the rectifier are certainly lower than those in conventional rectifier topologies because the power current flow path when the main switches are turned on includes two main power semiconductors and the power current flow path when the main switches are turned off includes one main power semiconductor. The rectifier also adopts a ZCS-PWM auxiliary circuit to derive the ZCS function for power semiconductors. Thus, the problem of switching losses and EMI can be improved. In the control strategy, the controller uses the average current control mode to achieve fixed-frequency current control with stability and low distortion. A prototype has been implemented in the laboratory to verify circuit theory.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권5호
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• pp.364-370
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• 2000

A large-signal average model for the controlled on-time boost power factor correction(PFC) circuit is developed and subsequently linearized resulting in a small-signal model for the PFC circuit. Ac analyses are performed using the small-signal model, revealing new results new on small-signal dynamics of the PFC circuit. The analysis results and model predictions are confirmed with experimental measurements on 200W prototype PFC circuit.