• Transactions on Electrical and Electronic Materials
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• v.6 no.6
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• pp.272-275
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• 2005

We studied the control of pretilt angles for homeotropic aligned nematic liquid crystal (NLC) on SiOx thin film surface by $45^{\circ}$ evaporation method with electron beam system. The uniform vertical LC alignment on. the SiOx thin film surfaces with electron beam evaporation was achieved. It is considered that the LC alignment on SiOx thin film by $45^{\circ}$ electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the SiOx thin film surface created by evaporation. The pretilt angles of about $3.5^{\circ}$ in aligned NLC on SiOx thin film surfaces by electron beam evaporation of $45^{\circ}$ were measured. Consequently, the high pretilt angles of the NLC on the SiOx thin film by $45^{\circ}$ oblique electron beam evaporation method can be achieved.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1137-1146
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• 2016

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1795-1796
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• 2006

The accurate measurement of soil resistivity and earthing system resistance is fundamental to electrical safety. However, geological and meterological factors can have a considerable effect on the accuracy of conventional measurements and the validity of the measurement methods. This paper presents optimization method of dc resistivity data acquisition system using multi-electrode arrays.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.345-346
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• 2006

This study proposes a development of blades for the 6W class small wind turbine system, which is applicable to relatively low speed region like Korea, and very easy to pitch control. The materials of the blades was used for the still. Electrical properties of blades improved by increasing with wind speed. The maximum output showed at $10^{\circ}$ of pitch angle and about 3.8[W] at 5.5[m/s] of wind speed.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.791-793
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• 2000

The fuzzy inference system is a popular computing framework based on the concepts of fuzzy set theory, fuzzy if-then rules, and fuzzy reasoning. The advantage of fuzzy approach over traditional ones lies on the fact that fuzzy system does not require a detail mathematical description of the system while modeling. As modeling method. the Group Method of Data Handling(GMDH) is introduced by A.G. Ivakhnenko GMDH is an analysis technique for identifying nonlinear relationships between system's inputs and output. We study a Novel Neuro-Fuzzy Network (NNFN) in this paper. NNFN is a network resulting from the combination of a fuzzy inference system and polynomial neural network(PNN) (7) which is advanced structure of GMDH. Simulation involve a series of synthetic as well as experimental data used across various neurofuzzy systems.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.3
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• pp.231-236
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• 2002

In this paper, we present an analysis and design method fur the control of input-saturated nonlinear systems with the time-delay. The target system is represented by Takagi-Sugeno (T-S) fuzzy model and the parallel distributed compensation (PDC) controller is designed to guarantee the local stability of the equilibrium point. We derive the sufficient condition for the local stability by applying Lyapunov-krasovskii theorem and this condition is converted into the LMI problem.

• Transactions on Electrical and Electronic Materials
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• v.15 no.2
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• pp.77-80
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• 2014

The effect of reactive diluents on the ac electrical treeing in epoxy/nanosilicate systems was studied, in a needle-plate electrode geometry. Diglycidyl ether of bisphenol A (DGEBA) type epoxy was used as a base resin, and layered silicate was used as a nano-sized filler. Polyglycol (PG) or 1,4-butanediol diglycidyl ether (BDGE) was introduced as a reactive diluent to the DGEBA/nanosilicate system, in order to decrease the viscosity of the nanocomposite system. PG acted as a flexibilizer, and BDGE acted as a chain extender, after the curing reaction. To measure the treeing propagation rate, a constant alternating current (ac) of 10 kV/4.2 mm (60 Hz) was applied to the specimen, in a needle-plate electrode arrangement, at $30^{\circ}C$ of insulating oil bath. When 10 kV/4.2 mm (60 Hz) was applied, the treeing propagate rate in the DGEBA system was $1.10{\times}10^{-3}$ mm/min, and that in the DGEBA/PG system was $1.05{\times}10^{-3}$ mm/min. As 1.5 wt% of nanosilicate was added to the DGEGA/PG system, the propagation rate was $0.33{\times}10^{-3}$ mm/min. This meant that the nano-sized layered silicates would act as good barriers to treeing propagation. The effect of chlorine content was also studied, and it was found that chlorine had a bad effect on the electrical insulation property of the epoxy system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.589-592
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• 2001

In this paper, Electronic ballast for multiple fluorescent lamps based on the use of ferrite beads are presented. The use of this system in place of the conventional electromagnetic ballast results in lower power consumption and reduced maintenance cost, because the electronic system has higher efficiency and longer lamp lifetime than the electromagnetic ballast. In comparison with the conventional electronic ballast. The proposed system presents a significant reduction of cost. This reduction becomes were meaningful with the growing of the lamp number. The description of the lighting system, We show that the proposed model can be applied to multiple lamps electronic ballast by simulation processes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.589-592
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• 2001

In this paper, Electronic ballast for multiple fluorescent lamps based on the use of ferrite beads are presented. The use of this system in place of the conventional electromagnetic ballast results in lower power consumption and reduced maintenance cost, because the electronic system has higher efficiency and longer lamp lifetime than the electromagnetic ballast. In comparison with the conventional electronic ballast. The proposed system presents a significant reduction of cost. This reduction becomes were meaningful with the growing of the lamp number. The description of the lighting system, We show that the proposed model can be applied to multiple lamps electronic ballast by simulation processes.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.282-285
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• 2005

This paper discusses the interactive system for smart home environments. In order to realize this, the main emphasis of the paper lies on the description of the multiple signal processing on the basis of the technologies such as fingerprint recognition, video signal processing, speech recognition and synthesis. For essential modules of the interactive system, we adopted the motion detector based on the changes of brightness in pixels as well as the fingerprint identification for adapting home environments to the inhabitants. In addition, the real-time speech recognizer based on the HM-Net(Hidden Markov Network) and the speech synthesis were incorporated into the overall system for interaction between user and system. In experimental evaluation, the results showed that the proposed system was easy to use because the system was able to give special services for specific users in smart home environments, even though the performance of the speech recognizer was not better than the simulation results owing to the noisy environments.