• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.657-660
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• 2009

Optically compensated bend (OCB) mode has intrinsic characteristics such as wide viewing angle and fast response time. However, in order to operate the OCB mode in bend state, this device needs quick transitions from the initial splay state to bend state. In this paper, we proposed OCB mode with initially bend state using reactive mesogen (RM) monomer for surface polymer stabilization. The device shows continuous reorientation of the LC with applied field and a very fast response time.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.33-37
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• 2004

To meet an increasing demand for high performance in gun dynamic plant, both a precise and a fast response positioning are strongly required for the gun servomechanism control. A mode switching control(MSC) system, which includes a fine stabilizing controller, fast positioning one and a switching function, is widely used to meet this requirement. Stabilization is performed through PID controller, while proximate time optimal servo(PTOS) is used for target designation. Because gun dynamic have large damping comparing to acceleration, PTOS algorithm with damping is newly derived. This paper adopts the initial value compensation method that improve the transient response after switching. Some simulation results are given to show the effectiveness of our scheme.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.889-897
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• 1999

This paper deals with a problem searching a target transfer function to meet the time-domain specifications for feedback system with given plant transfer function. For the Type I system, we first define three forms of transient response to unit step input, which are named by F, M, S-type. These are charaacterized as follows ; F-type has fast initial response and slow approach to the steady sate after reaching at 90% of the steady state value, S-type has slow initial response but fast approach to the steady state, and M-type is denoted by highly smooth response between F-type and S-type. Three prototypes corresponding to each form are proposed, time. For the order $n{\geq}4$, after determining admissible root structures of target characteristic polynomials empirically and expressing such polynomial coefficients by using special parameters ${\gamma}_i$ and $\epsilon$, the optimal prototypes that minimize the integral of the squared of the modified errors(ISME) have been obtained. Since the step responses of these prototypes have almost same wave forms irrespective to the order, the desired settling time or the rise time can be converted into the equibalent time constant $\tau$ and thus it is easy to obtain a target transfer function. It is shown through a design example that the present prototype is very useful for meeting the time-domain specifications and has been compared with different methods with a viewpoint of pertinence.

• Journal of Magnetics
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• v.17 no.1
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• pp.56-60
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• 2012

This paper presents an analysis and experiment of the flat coil actuator with shorted turn. The flat coil actuator is widely used in high precision products because it has no friction between the moving coil and the guide. A shorted turn and a center pole are placed into the flat coil actuator in order to reduce the inductance of the coil and improve the initial response when the actuator is voltage-driven. Enhanced dynamic performance of the flat coil actuator with shorted turn was demonstrated by simulation and experiment.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.91-96
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• 2005

In this paper, a general performance of the PSS-LCD or Polarization Shielded Smectic Liquid Crystal Display is discussed. This smectic base LCD does not use any spontaneous polarization, but uses induced polarization just same with current nematic base LCDs. Specific initial molecular alignment as well as specific cell design realizes extremely fast optical response speed with native wide viewing angle. Moreover, this performance is provided by full compatible electronics for current conventional LCDs. A general performance of the PSS-LCD is introduced here.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.83-94
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• 2017

Near-field source localization algorithms are very sensitive to sensor gain/phase response errors, and so it is important to calibrate the errors. We took into consideration the uniform linear array and are proposing a blind calibration algorithm that can estimate the directions-of-arrival and range parameters of incident signals and sensor gain/phase responses jointly, without the need for any reference source. They are estimated separately by using an iterative approach, but without the need for good initial guesses. The ambiguities in the estimations of 2-D electric angles and sensor gain/phase responses are also analyzed in this paper. We show that the ambiguities can be remedied by assuming that two sensor phase responses of the array have been previously calibrated. The behavior of the proposed method is illustrated through simulation experiments. The simulation results show that the convergent rate is fast and that the convergent precision is high.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.12
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• pp.35-44
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• 1994

In this paper, we propose a new modification method of the look-up table in self-organizing fuzzy control using look-up table. This method has the property that look-up table is modified to have fast response property. Its principle is that the controller forces the trajectory to go into the fast respose region which the error change amount is larger than the error at initial time whenever the reference or disturbance change. Also we introduce the variable learning speed coefficient which is proportional to distance from switching curve. And to demonstrate the applicability of the proposed method, we had simulation study for some examples and esecuted pole balance experiments with inverted pendulum.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.409-414
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• 2005

In the literatures, the FFT-based SAM has been well applied to the computation of the steady-state responses of discrete dynamic systems. In this paper, a fast fourier transforms (FFT)-based spectral analysis method (SAM) is proposed fur the dynamic analysis of spectral element models subjected to the non-zero initial conditions. However, the FFT-based SAM has not yet been developed for the continuous systems represented by the spectral element model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.146-153
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• 2010

When the production run is short and process parameters change frequently, it is difficult to monitor the process using traditional control charts. In such a case, the coefficient of variation (CV) is very useful for monitoring the process variability. The CV control chart is an effective tool to control the mean and variability of process simultaneously. The CV control chart, however, is not sensitive at small shifts in the magnitude of CV. The CV-EWMA(exponentially weighted moving average) control chart which was developed recently is effective in detecting a small shifts of CV. Since the CV-EWMA control chart scheme can be viewed as a weighted average of all past and current CV values, it is very sensitive to small change of mean and variability of the process. In this paper, we propose an FIR(Fast initial response) CV-EWMA control chart to improve the sensitivity of a CV-EWMA scheme at process start-up or out-of-control process. Moreover, we suggest the values of design parameters and show the results of the performance study of FIR CV-EWMA control chart by the use of average run length(ARL). Also, we compared the performance of FIR CV-EWMA control chart with that of the CV-EWMA control chart and we found that the CV-EWMA control chart gives longer in-control ARL and much shorter out-of-control ARL.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.5
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• pp.549-560
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• 1989

In this paper, the method of determining the initial weighting vlaues fuctioning as a filter under the Directional Constrained Minimization of Power(DCMP) algorithm is presented. By analyzing the sideband beamformer with the Finite Impulse Response (FIR) filter concepts, the constraints of any desired directions are obtained and the initial weighing values with fast adaptation time are formulated from those constraints. By applying this proposed initial weighting values to the DCMP and the spatial averaging processor, the interference of a desired direction and the coherent noises are eliminated at the same time. The improvement of this method compared with the existing algorithm is confirmed by computer simulation.