• Journal of the Korean Society for Precision Engineering
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• v.25 no.5
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• pp.89-95
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• 2008

The Acousto-Optic Tunable Filter (AOTF) is a high-speed full-field monochromator which generates two spectrally filtered light beams with ordinary and extraordinary polarization state. Thus, AOTF is widely used to build full-field spectral imaging system or spectral domain interferometer. However, AOTF has a big problem that the angle of diffracted light changes according to the scanning of wavelength, which makes image shift on CCD plane In this paper, we propose an analytic design of prism system to compensate the image shift. The detailed analysis of light paths in a prism and basic experimental results are presented to verify our proposed compensation method. The experimental results agree with simulation results based on suggested prism model and image shift is minimized at optimal condition. Also, it can be extended to compensate the image shift for ordinary and extraordinary polarized light simultaneously.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.1-6
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• 2019

The purpose of this paper is to design a curtain control system for centralized management of large curtains, which includes curtain structure, electric curtain controller, communication system, user interface and remote control. Curtain structure is designed to avoid using limit switch. The system is based on microprocessor, determined the stop position and complete running time of electric curtain through time control, and achieved remote control of curtain opening and closing through wired and wireless communication modes. By establishment of a mathematical model to calculate the inertia compensation time of the electric curtain, the electric curtain can be stopped ahead of time, and the curtain can be completely closed by the inertia. The result of test experiment of 32 electric curtain controllers shows the communication success rate reached 100%.

• Current Optics and Photonics
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• v.8 no.1
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• pp.56-64
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• 2024

In response to the current situation where general methods cannot effectively compensate for the phase delay of ordinary optical mixers, a multi-layer spatial beam-splitting optical mixer is designed using total reflection triangular prisms and polarization beam splittings. The phase delay is generated by the wave plate, and the mixer can use the existing parallel plates in the structure to individually compensate for the phase of the four output beams. A mixer model is established based on the structure, and the influence of the position and orientation of the optical components on the phase delay is analyzed. The feasibility of the phase compensation method is simulated and analyzed. The results show that the mixer can effectively compensate for the four outputs of the optical mixer over a wide range. The mixer has a compact structure, good performance, and significant advantages in phase error control, production, and tuning, making it suitable for free-space coherent optical communication systems.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.3
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• pp.232-239
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• 2013

This paper proposes an improved stator flux estimator through ensuring conventional PLPF to act as a pure integrator for sensorless control of induction motors. Conventional PLPF uses the estimated synchronous speed as a cut-off frequency and has the gain and phase compensators. The gain and phase compensators are determined on the assumption that the estimated synchronous angular speed is coincident with the real speed. Therefore, if the synchronous angular speed is not same as the real speed, the gain and phase compensation will not be appropriate. To overcome the problem of conventional PLPF, this paper analyzes the relationship between the synchronous speed error and the phase lag error of the stator flux. Based on the analysis, this paper proposes the synchronous speed error compensation scheme. To achieve a start-up without speed sensor, the current model is used as the stator flux estimator at the standstill. When the motor starts up, the current model should be switched into the voltage model. So a stable transition between the voltage model and the current model is required. This paper proposes the simple transition method which determines the initial values of the voltage model and the current model at the transition moment. The validity of the proposed schemes is proved through the simulation results and the experimental results.

• International Journal of Control, Automation, and Systems
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• v.4 no.2
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• pp.139-145
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• 2006

A multi-variable Golden-Section adaptive controller is proposed for the tracking control of robotic manipulators with unknown dynamics. With a small sample time, the unknown dynamics of the robotic manipulator are denoted equivalently by a characteristic model of a 2-order multivariable time-varying difference equation. The coefficients of the characteristic model change slowly with time and some of their valuable characteristic relationships emerge. Based on the characteristic model, an adaptive algorithm with a simple form for the control of robotic manipulators is presented, which combines the multi-variable Golden-Section adaptive control law with the weighted least squares estimation method. Moreover, a compensation neural network law is incorporated into the designed controller to reduce the influence of the coefficients estimation error on the control performance. The results of the simulations indicate that the developed control scheme is effective in robotic manipulator control.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.2
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• pp.163-172
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• 2010

A robust positioning control system has been studied using a friction parameter observer and a recurrent fuzzy neural network based on the sliding model. To estimate a nonlinear friction parameters of the LuGre friction model, a dual friction model-based observer is introduced. In addition, an approximating method for a system uncertainty has been developed using a recurrent fuzzy neural network technique to improve positioning performance. Experimental results have been presented to validate the performance of a proposed intelligent compensation scheme.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.520-521
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• 2008

This paper deals with simulation model of the micro-grid system based on the real power system and applying PV generation system to micro-grid system. PSCAD/EMTDC simulation model is developed for use in studying the effect of the dynamics of PV generation to the micro-grid system. Simulation results show that the addition of the PV system improves the voltage profile of the area. Case studies also show that power quality at the load side is improved via voltage compensation at the load bus.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.11
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• pp.916-921
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• 2002

We presents a new method of constructing an equivalent T-S fuzzy model by using the sum of products of linearly independent scalar functions from nonlinear dynamics. This method exactly expresses nonlinear systems and automatically determines the number of rules. We design a stabilizing controller f3r ul inverted pendulum system by using the concep of parallel distributed compensation (PDC) and linear matrix inequalities (LMIs) based on the proposed T-S fuzzy modeling method. We show effectiveness of a systematically designed fuzzy controller based on the proposed T-S fuzzy modeling method through the simulation and experiment of an inverted pendulum system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.2
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• pp.109-117
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• 2018

In order to form focused inverse synthetic aperture radar(ISAR) images of a non-uniformly rotating target, rotational motion compensation(RMC) should be performed. Prominent point processing(PPP), one of the most representative RMC methods, is used to compensate nonlinear rotation motion by exploiting the phase signals of scatterers. In this paper, we propose a new RMC method based on the integrated cubic phase function(ICPF). The ICPF requires only one-dimensional(1-D) maximization to estimate the phases of multi-component signals. Simulation results using a point scatterers model in the absence of dominant scatterers validate that PPP based on ICPF can achieve well-focused ISAR images in real time.

• 한국노년학
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• v.31 no.2
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• pp.381-400
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• 2011

The purpose of this study is to develop the scale on Selection, Optimization, Compensation(SOC) model as successful aging strategies of Korean Elderly. In first phase of the study, 64 pilot items were collected from researcher's indepth interviews with a purposive sample group of 24 elderly people(16 items) and original SOC scale(48 items). To analyze the factor structure and to verify the validity of the scale, 592 questionnaires collected from survey were divided randomly into 300 developmental samples and 292 validity samples. The items were examined exploratory with developmental samples and confirmatory factor analysis with developmental samples. Two factor analysis supported four factor structure of the SOC consisted of 20 items. Four factors are as follows: 'Elective Selection', 'Loss-Based Selection', 'Opimization', 'Compensation'. The cronbach's alpha estimate of the scale was .930. This scale of four factor model exhibited good fit, assessed by overall fit measure criteria(TLI=.939, CFI=.947, RMSEA=.058). The result of analysis by item response theory for SOC scale is satisfatory. Also, SOC scale was significantly related to the two successful aging scales for Korean elderly and life satisfation scale(SWLS). These results proved the validity of the scale.