• 한국심리학회지:학교
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• 제16권2호
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• pp.207-230
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• 2019

본 연구는 범불안 성향의 대학생을 대상으로 주의편향 및 범불안 증상에 대한 주의 피드백 인식 및 조절 훈련의 효과를 확인하였다. 범불안장애 척도(GAD-7) 10점 이상 또는 펜실베니아 걱정 질문지 척도(K-PSWQ) 56점 이상이며, 주의편향을 나타내는 범불안 성향의 대학생 31명을 선발하여 주의 피드백 인식 및 조절 훈련(Attention Feedback Awareness and Control Training, A-FACT) 집단(n = 11), 주의편향수정(Attention Bias Modification, ABM) 집단(n = 10) 및 활성 위약 통제(Active Placebo Control, APC) 집단(n = 10)에 무선할당하였다. A-FACT 집단은 탐침탐사과제를 이용한 주의편향수정 훈련 시, 개인의 기저반응시간(Baseline Neutral Response time, BNR)을 기준으로 편향 여부에 대한 피드백을 실시간으로 제공받았다. ABM 집단은 기존 ABM 절차와 동일하며, APC 집단은 주의편향을 감소시키기 위한 프로그램이라는 안내는 주어지지만 피드백이 주어지지 않는 탐침탐사과제를 실시하였다. 총 8회기로 구성되어, 주 2회로 4주간 진행되었다. 주의편향수정 훈련의 효과는 주의편향점수(Attention Bias Score, ABS)와 GAD-7, K-PSWQ 및 상태 및 특성 불안 검사(K-STAI) 점수 변화로 평가하였다. 반복측정 변량분석 결과, A-FACT 집단은 ABM 집단과 APC 집단에 비해 ABS가 유의하게 감소하였으며, GAD-7, K-PSWQ 및 K-STAI 점수도 유의하게 감소하였다. 이는 주의편향수정 훈련 시 편향에 대한 피드백을 통해 편향의 여부를 인식시키고 이를 통한 주의의 자기 조절적 통제가 주의편향 및 범불안장애 증상 경감에 효과적일 가능성을 시사한다.

• 전기학회논문지
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• 제64권7호
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• pp.978-983
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• 2015

This paper presents Frequency Bias setting for the adequate AGC(Automatic Generator Control) operation based on the frequency response of power system in Korea. AGC frequency control recovers the frequency up to 60Hz following a primary control when the frequency suddenly drops due to a fault in power system. AGC can compensate an appropriate amount of generation by calculating ACE(Are Control Error) from the frequency deviation with the AGC frequency bias set from the actual frequency response in power systems. An appropriateness of the proposed AGC bias setting is verified through case studies employing the simulation model.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.317-320
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• 2000

In this paper, a 0.5W, 2GHz high-efficiency class A power amplifier using the dynamic bias control is proposed. First of all, the drain bias control amplifier is analyzed theoretically and designed with commercial devices. Simulation results show that the proposed amplifier has a significant improved efficiency, compared to fixed bias power amplifier.

• 제어로봇시스템학회논문지
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• 제6권4호
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• pp.254-260
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• 2000

This paper deals with the development of fault tolerant control for a nonlinear boiler system with noise and disturbance. The MCMBPC(Multivariable Constrained Model Based Predictive Control) is adopted for the control of the specific boiler turbin model. The fault detection and diagnosis are accomplished with the Kalman filter and two bias estimators. Once a fault is detected, two Bias estimators are driven to estimate the fault and to discriminate Process fault and sensor fault. In this paper, a fault tolerant control scheme combining MCMBPC with a fault compensation method based on the bias estimator is proposed. The proposed scheme has been applied to the nonlinear boiler system and shown a satisfactory performance through some simulations.

• 한국결정성장학회지
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• 제15권5호
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• pp.198-201
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• 2005

Carbon nanofibers were formed on silicon substrate which was applied by negative direct current (DC) bias voltage using microwave plasma-enhanced chemical vapor deposition method. Formation of carbon nanofibers were varied according to the variation of the applied bias voltage. At -250 V, we found that the growth direction of carbon nanofibers followed the applied direction of the bias voltage. Based on these results, we suggest one of the possible techniques to control the growth direction of the carbon nanofibers.

• 전자공학회논문지
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• 제49권10호
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• pp.43-46
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• 2012

본 논문에서는 구동 증폭기와 Class-E 전력증폭기를 결합하여 높은 효율의 고이득 이단 전력증폭기를 구현하였다. 고효율 이단 Class-E 전력증폭기의 입력 단에 적응형 바이어스 조절 회로를 적용하여 낮은 입력 전력의 전력효율을 개선하였다. 최대출력인 40 dBm에서 고정 바이어스 전력증폭기와 적응형 바이어스 증폭기 둘 다 약 76 %의 효율을 갖는다. 하지만 적응형 바이어스 조절 회로가 적용된 전력증폭기의 입력전력 6dBm 인가했을 때 효율은 약 70 %이고 고정된 바이어스 입력시에 효율은 약 50 %이다. 바이어스 조절을 통해 낮은 입력에서 높은 효율을 갖는 회로를 설계하였다.

• Journal of the Korean Data and Information Science Society
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• 제25권5호
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• pp.1127-1135
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• 2014

Genome-wide association studies (GWAS) are designed to discover genetic variants such as single nucleotide polymorphisms (SNPs) that are associated with human complex traits. Although there is an increasing interest in the application of GWAS methodologies to population-based cohorts, many published GWAS have adopted a case-control design, which raise an issue related to a sampling bias of both case and control samples. Because of unequal selection probabilities between cases and controls, the samples are not representative of the population that they are purported to represent. Therefore, non-random sampling in case-control study can potentially lead to inconsistent and biased estimates of SNP-trait associations. In this paper, we proposed inverse-probability of sampling weights based on disease prevalence to eliminate a case-control sampling bias in estimation and testing for association between SNPs and quantitative traits. We apply the proposed method to a data from the Korea Association Resource project and show that the standard estimators applied to the weighted data yield unbiased estimates.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.963-966
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• 1999

This Paper describes the design of high speed and low power comparator based on the feed forward bias control. Major building blocks of this comparator are composed of input offset canceling circuit and feed forward bias control circuit. The usual offset canceling circuit cancels the offset voltages by storing them in capacitors using MOS switches, The comparator of this paper employs the bias control circuit which generates bias signal from the input signal. The bias signal is applied to the capacitors and keeps the transfer of chares in the capacitors in the minimal amount, therefore making the comparator operate in stable condition and reduce decision time. The comparator in this form has very samll area and power dissipation. Maximum sampling rate is 200 Ms/sec. The comparator is designed in 0.65${\mu}{\textrm}{m}$ technology and the offset is less than 0.5㎷.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권3호
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• pp.326-333
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• 2015

This paper reports an adaptive positive feedback bias control technique for operational transconductance amplifiers to adjust the bias current based on the output current monitored by a current replica circuit. This technique enables operational transconductance amplifiers to quickly adapt their power consumption to various analog workloads when they are configured with negative feedback. To prove the concept, a test voltage follower is fabricated in $0.5-{\mu}m$ CMOS technology. Measurement result shows that the power consumption of the test voltage follower is approximately linearly proportional to the load capacitance, the signal frequency, and the signal amplitude for sinusoidal inputs as well as square pulses.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.1053-1059
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• 2013

Heading bias effects in PNS using IMUs attached to shoes are analyzed in this paper. The navigation algorithms of a single foot PNS where one IMU is attached to a foot and dual foot PNSs where two IMUs are attached to each foot are derived. Two navigation algorithms are proposed for the dual foot PNS: 1) the positions from the independent right and left foot PNSs are averaged to provide the final position, 2) the right and left foot PNSs are correlated and it provides positions of each foot. Furthermore, it is proven that two methods are equal. Using the derived navigation algorithms the effect of heading bias caused by a misalignment of the moving direction and IMU is analyzed. The analysis explains the position error of a single foot PNS is diverged while the heading bias is effectively compensated in dual foot PNSs because of the symmetry of heading biases. The experimental results confirm the analysis.