• Title/Summary/Keyword: positive feedback bias control

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An OTA with Positive Feedback Bias Control for Power Adaptation Proportional to Analog Workloads

  • Kim, Byungsub;Sim, Jae-Yoon;Park, Hong-June
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.3
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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.

Design of output feedback variable structure control system with robust properties (출력궤한 가변구조제어게의 강인성 설계)

  • 이기상;임재형;이정동
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.1199-1205
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    • 1993
  • It has been well known that the assumption of full state availability is one of the most important restrictions to the practical realization of VSCS. And several attempts to alleviate the assumption had been made. However, it is not easy to find a positive scheme among them. Recently, an output feedback variable structure control system(OFVSCS) was proposed and the effectiveness of the scheme was validated for the disturbance free systems. The purpose of this study is to propose a robust OFVSCS that have the robust properties against process parameter variations and external distrubances by extending the basic OFVSCS and to evaluate its control performances through power system stabilizer design example. The ROFVSCS is composed of dynamic switching function and output feedback switching control inputs that are constructed by the use of the unknown vector modeling technique. With the proposed scheme, existence of sliding mode is guaranteed and any nonzero bias can be suppressed in the face of disturbances and process parameter variations as far as well-known matching condition is satisfied. Due to the fact that the ROFVSCS is driven by small number of measured informations, the practical application of VSCS for the systems with unmeasurable states and for high order systems that conventional schemes cannot be applied, is possible with the proposed scheme. It is noticeable that the implementation cost of VSCS can be considerably reduced without sacrifice of control performances by adopting ROFVSCS since there is no need measure the states with high measurement cost.

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Design of Robust Output Feedback Variable Structure Control System (강인한 출력궤환 가변구조제어계의 설계)

  • 이기상;임재형
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.3
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    • pp.458-467
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    • 1994
  • It has been well known that the assumption of full state availability is one of the most important restrictions to the practical realization of VSCS. And several attempts to alleviate the assumption had been made. however, it is not easy to find a positive scheme among them. Recently, an output feedback variable structure control system(OFVSCS) was proposed and the effectiveness of the scheme was validated for the disturbance free systems. The purpose of this study is to propose a robust OFVSCS that have the robust properties against process parameter variations and external disturbances by extending the basic OFVSCS and to evaluate its control performances. The ROFVSES is composed of dynamic switching function and output feedback switching control inputs that are constructed by the use of the unknown vector modeling technique. With the proposed schems, existence of sliding mode is guaranteed and any nonzero bias can be suppressed in the face of disturbances and process parameter variations as far as well-known matching condition is satisfied. Due to the fact that the ROFVSCS is driven by small number of measured informations, the practical application of VSCS for the systems with unmeasurable states and for high order systems, the conventional schemes cannot be applied, is possible with the proposed scheme. It is noticeable that the implementation cast of VSCS can be considerably reduced without sacrifice of control performances by adopting ROFVSCS since there is no need to measure the states with high measurement cost.

Sales Control Systems and Behavioral Responses: Mediating Role of Regulatory Focus and Moderating Role of P-O Fit

  • Yoo, Jaewon
    • Asia Marketing Journal
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    • v.17 no.1
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    • pp.123-148
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    • 2015
  • Built on regulatory focus theory, this article develops a research model proposing the relationship between management controls (outcome, activity and capability), sales employees' prevention and promotion focus and their behavioral responses (feedback seeking from different sources and relationship investment). The model also suggests that salesperson perceived organizational fit (P-O fit) contributes by influencing the situational self-regulatory mechanism based on regulatory fit theory. To analyze the data, a structural equation model procedure using LISREL 8.5 was employed. To access the potential common method bias, the MV" marker method was applied using a scale theoretically unrelated to at least one scale in the analysis as the MV marker. The results showed that the greater the salesperson's perceived activity control system, the greater the extent of employee prevention focus. The findings also showed that output control and capability control system are positively related to the promotion focus of salespeople. Salespeople's prevention focus relates negatively to the relational investment and positively to organization feedback seeking. The results indicate that salespeople who have promotion focus exhibit the predicted positive influence on their relationship investment. A significant contribution of this research framework is suggesting salesperson regulatory focus as a mediator and its' effects on different types of sales-related behaviors. The author suggests that the motivational orientations of salespeople play key roles in shaping feedback seeking behaviors from different sources; broadly, that employees with a promotion focus will be more sensitive to customers' feedback, and employees with a prevention focus will seek more feedback from the organization. Furthermore, salespeople with a promotion focus will invest more resources to build relationships with customers than salespeople with a prevention focus. This research also explains the moderating role of person-organization fit on the effect of salespeople's regulatory focus and behavioral responses based on regulatory fit theory

Interpretation bias modification for social anxiety disorder: Development of computer based cognitive modification program (사회불안장애의 해석편향 연구: 컴퓨터 기반 해석편향 프로그램 개발 및 효과검증)

  • Yoon, Hyae-Young
    • Journal of the Korea Convergence Society
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    • v.8 no.4
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    • pp.111-122
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    • 2017
  • The purpose of this study was to develop a computer-based cognitive bias modification program (CBM-I) and to test the efficacy of CBM-I for college students with social anxiety. Forty socially anxious individuals were randomly assigned to the CBM-I(n=21) or a waiting list condition(n=19). Both groups were assessed at the beginning and the end of the program with interpretation bias and social anxiety symptoms(e.g. B=FNE=Brief-Fear of Negative Evaluation Scale, LSAS=Liebowitz Social Anxiety Scale). The CBM-I modified interpretation by providing positive feedback when participants made benign interpretations and negative feedback in response to threat interpretations. Participants in CBM-I completed three computer sessions over three weeks. The CBM-I successfully decreased social anxiety symptoms compared to the control condition(t=2.35, p<.05; t=4.70, p<.001). This result suggests that interpretation modification may have clinical utility when applied as a multi-session intervention.

A Study of Iterative QC-BC Method for AMSU-A in the KIAPS Data Assimilation System (KIAPS 자료동화 시스템에서 AMSU-A의 품질검사 및 편향보정 반복기법에 관한 연구)

  • Jeong, Han-Byeol;Chun, Hyoung-Wook;Lee, Sihye
    • Atmosphere
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    • v.29 no.3
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    • pp.241-255
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    • 2019
  • Bias correction (BC) and quality control (QC) are essential steps for the proper use of satellite observations in data assimilation (DA) system. BC should be calculated over quality controlled observation. And also QC should be performed for bias corrected observation. In the Korea Institute of Atmospheric Prediction Systems (KIAPS) Package for Observation Processing (KPOP), we adopted an adaptive BC method that calculates the BC coefficients with background at the analysis time rather than using static BC coefficients. In this study, we have developed an iterative QC-BC method for Advanced Microwave Sounding Unit-A (AMSU-A) to reduce the negative feedback from the interaction between BC and QC. The new iterative QC-BC is evaluated in the KIAPS 3-dimensional variational (3DVAR) DA cycle for January 2016. The iterative QC-BC method for AMSU-A shows globally significant benefits for error reduction of the temperature. The positive impacts for the temperature were predominant at latitudes of $30^{\circ}{\sim}90^{\circ}$ of both hemispheres. Moreover, the background warm bias across the troposphere is decreased. Even though AMSU-A is mainly designed for atmospheric temperature sounding, the improvement of AMSU-A pre-processing module has a positive impact on the wind component over latitudes of $30^{\circ}S$ near upper-troposphere, respectively. Consequently, the 3-day-forecast-accuracy is improved about 1% for temperature and zonal wind in the troposphere.