• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.442-449
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• 2003

This paper discusses how to generate the reference compensation voltages in Dynamic Voltage Restorers (DVR) by use of PQR instantaneous power theory. Sensed three-phase terminal voltages are transformed to PQR coordinates without time delay. Since the reference voltage in PQR coordinates is a single dc value, the voltage controller for DVRs is simple and easy to design. Proposed control method can be implemented by feedforward controllers or by feedback controllers. This paper verified the theory by a feedforward controller of a DVR with simulation and experiment.

• Proceedings of the KIEE Conference
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• summer
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• pp.956-958
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• 2004

이 논문에서, 우리는 PMLSM(permanent magnet linear synchronous motor) 시스템에서 발생하는 detent force의 ripple 저감을 위한 진동보상 모델과 제안한 구조에 대한 제어기 설계 방법을 제시한다. 본 논문에서 고려되어진 제어기는 feedforward 보상기, PID feedback 보상기, 그리고 adaptive feedforward 보상기의 세 부분으로 구성된 제어기를 사용한다. 특히, PMLSM의 위치 정밀성 향상에 관한 연구를 위한 정밀 위치 제어의 문제는 PM으로 인해 발생하는 detent force이며, 이를 해결하기 위해 출력신호를 웨이블릿 변환하여 추출 후 이를 보상하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1706-1715
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• 1996

The decision feedback equalizer(DFE) received recent attention since it can compensate for channels with severe intersymbol interference(ISI) without as much noise enhancement as the linear equalizer(LE). In this paper, we propose a new DFE which can icrease the performance of DFE further by using error feedback. The performance increase is achieved by reducing correlation of error signal, which cannot be reduced by the feedforward or feedback filter. Hardware complexity for the proposed approcach is minimal since it requires only additional few taps to the conventional DFE. Based on theoretical analysis and computer simulations, the proposed approach is shown to be much more effective than the conventional DFE, especially for channels with large ISI.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.404-409
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• 2003

This paper discusses how to generate the reference compensation voltages in Dynamic Voltage Restorers (DVR) by use of PQR power theory Sensed three-phase terminal voltages are transformed to PQR coordinates without time delay. Since the reference voltages in PQR coordinates are do values, the voltage controller for DVRs is simple and easy to design. Proposed control method can be implemented by feedforward controllers or by feedback controllers. This paper verified the theory in the feedforward controller of a DVR by experiments.

• ETRI Journal
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• v.30 no.5
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• pp.729-734
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• 2008

Wireless communication systems, such as WLAN or Bluetooth receivers, employ preamble data to estimate the channel characteristics, introducing stringent settling-time constraints. This makes the use of traditional closed-loop feedback automatic gain control (AGC) circuits impractical for these applications. In this paper, a compact feedforward AGC circuit is proposed to obtain a fast-settling response. The AGC has been implemented in a 0.35 ${\mu}m$ standard CMOS technology. Supplied at 1.8 V, it operates with a power consumption of 1.6 mW at frequencies as high as 100 MHz, while its gain ranges from 0 dB to 21 dB in 3 dB steps through a digital word. The settling time of the circuit is below 0.25 ${\mu}s$.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.837-843
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• 2016

This paper presents a position control strategy for a pump-controlled electro-hydrostatic actuator (EHA) using feedforward control with disturbance compensation. As the disturbance observer is used to estimate nonlinear dynamics of EHA, which has valve-opening conditionals, as well as external disturbances, an additional feedforward control is adopted to achieve rapid response. The effectiveness of the proposed control strategy is verified through experiment using an EHA test bench. The proposed controller shows better tracking performance compared with a conventional PID controller.

• Journal of Mechanical Science and Technology
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• v.16 no.3
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• pp.283-291
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• 2002

The paper demonstrates the tracking performance of a sliding horizon feedback/feedforward preview optimal control when applied to a hydraulic motion simulator which has been built to provide a means of replicating the actual ride dynamics of an automobile seat/human system. The design was developed by solving an ordinary differential equation problem instead of a Ricatti equation. Simulation results indicate that the proposed technique has good performance improvement in phase tracking when compared to the classical design methods. It is also found that the controller can be adjusted more easily for robustness due to more tuning parameters.

• Journal of Power System Engineering
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• v.19 no.4
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• pp.24-29
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• 2015

This paper designs a looper-tension controller for strip top-tail parts in hot strip finishing mills. A three-degree linear model of the looper-tension system is derived by a Taylor's linearization method, where the actuator's dynamics are ignored because of their fast responses. A feedforward shaping controller for the strip top part and a feedforward model reference controller for the strip tail part are respectively designed, they are combined with an ILQ(Inverse Linear Quadratic optimal control) feedback controller for the strip middle part. It is shown from by a computer simulation that the proposed controller is very effective to the strip top-tail parts including the middle part.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.349-356
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• 2000

EPC(Engineering process control) is usually applied to processes in which successive observations ate related over time and where the mean drifts dynamically. This paper aims to literature surrey concerned about EPC theory developments and their applications including macGregor model as Basic EPC model, feedback controllers, feedforward controllers, run-to-run controllers, MMSE controllers, PID model and PI adjustment model and so on. We suggest some perspective area for further study.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.11
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• pp.66-73
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• 1993

This paper presents an analog circuit implementation and experimental resuls of the Hopfield type neural network. The proposed architecture enables the reconfiguration betwewn feedback and feedforward networks and employs new circuit designs for the weight supply and storage, analog multilier, nd current-voltage converter, in order to achieve area efficiency as well as function al versatility. The layout design of the eight-neuron neural network is tested as an associative memory to verify its applicability to real world.