• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.260-262
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• 2006

This paper presents Hybrid-PI controller of induction motor drive using fuzzy control. In general, PI controller in computer numerically controlled machine process fixed gain. They may perform well under some operating conditions, but not all. To increase the robustness, fixed gain PI controller, Hybrid-PI controller proposes a new method based self tuning PI controller. Hybrid-PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of induction motor are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.215-215
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• 2006

The cyclic butylene terephthalte oligomer was synthesized and the composition of butylenes terephthalate cyclic oligomers was 51.2 % of dimer, 28.1 % of trimer, 7.9 % of tetramer, 8 % of pentamer and 4.8% of hexamer. Polybuthylene terephthalate was polymerized using this cyclic oligomer in the condition of melt process and supercritical process. And PBT/clay nanocomposite were manu- factured from melt process and supercritical process. Chlorodifluoro- methane(HCFC-22) was used as a solvent which has critical point ($Tc=96.2^{\circ}C$, Pc=49.7bar). Also polymer nanocomposite were manufactured using rapid expansion of supercritical solution process.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.20-24
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• 2003

The feasibility of hybrid motor as a first stage of the air launch vehicle is investigated, and the result shows the hybrid motor can replace the solid motor. Optimal design study has been performed for the hybrid motor as a first stage of nanosat air launch vehicle. The first stage hybrid motor of the nanosat air launch vehicle, which uses the F-4E Phantom as a mother plane is designed for given mission requirements. Selected design variables are the number of ports, the initial oxidizer flux, the combustion chamber pressure, and the nozzle expansion ratio. The design results show that a hybrid motor can be successfully applicable to very small air launch vehicles which have severe physical constraints of length and diameter imposed by the mother plane.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2006년도 춘계학술대회 학술발표 논문집 제16권 제1호
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• pp.381-384
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• 2006

Self Organizing Map(SOM) is a powerful neural network model for unsupervised loaming. In many clustering works with exploratory data analysis, it has been popularly used. But it has a weakness which is the poorly theoretical base. A lot more researches for settling the problem have been published. Also, our paper proposes a method to overcome the drawback of SOM. As compared with the presented researches, our method has a different approach to solve the problem. So, a hybrid SOM is proposed in this paper. Using Monte Carlo computing, a hybrid SOM improves the performance of clustering. We verify the improved performance of a hybrid SOM according to the experimental results using UCI machine loaming repository. In addition to, the number of clusters is determined by our hybrid SOM.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.29-32
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• 2002

The mechanical and thermal properties of spun carbon fabric/continuous carbon fabric interplay hybrid composite materials have been studied. The properties of the hybrid composites are compared with those of the continuous carbon fabric/phenolic composites and spun carbon fabric /phenolic composites. Through hybridization, tensile strength and flexural strength of hybrid composites were increased by about 17%, and 10%, respectively compared with spun carbon composites. The thermal conductivity of the hybrid composite is lower approximately 4~6% along the direction parallel to the laminar plane than that of the continuous carbon/phenolic composite.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.236-241
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• 2000

In this paper, transparent dynamic photoelastic experimental hybrid method for propagating cracks in orthotropic material is developed. Using transparent dynamic photoelastic experimental hybrid method, we can obtain stress intensity factor and separate the stress components from only isochromatic fringe patterns without using isoclinics. It is certified that the dynamic photoelastic experimental hybrid method is very useful for the problems of the dynamic tincture mechanics.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.418-418
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• 2012

We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.213-213
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• 2011

DC arc plasmatron is powerful plasma source to apply etching and texturing processing. Even though DC arc plasmatron has many advantages, it is difficult to apply an industry due to the small applied area. To increase an effective processing area, we suggest a DC-RF hybrid plasma system. The DC-RF hybrid plasma system was designed and made. This system consists of a DC arc plasmatron, RF parts, reaction chamber, power feeder, gas control system and vacuum system. To investigate a DC-RF hybrid plasma, we used a Langmuir probe, OES (Optical emission spectroscopy), infrared (IR) light camera. For RF matching, PSIM software was used to simulate a current of an impedance coil. The results of Langmuir probe measurements, we obtain a homogeneous plasma density and electron temperature those are about $1{\times}1010$ #/cm3 and 1~4 eV. The DC-RF hybrid plasma source is applied for plasma etching experimental, and we obtain an etching rate of 10 ${\mu}m$/min. through a 90 mm of reaction chamber diameter.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2001년도 제17회 학술발표회 논문초록집
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• pp.61-67
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• 2001

Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. The recent research efforts are focused on the improvement of volume limitation and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the eddy breakup model and Hiroyasu and Nagle and Strickland-Constable model are used for soot formation and soot oxidation. Radiative heat transfer is modeled by finite volume method. To reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect, the Low Reynolds number k-$\varepsilon$ turbulent model is employed. Based on numerical results, the detailed discussion has been made for the turbulent combustion processes in the vortex hybrid rocket engine.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.527-534
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• 2003

This paper presents the LRB-based hybrid base isolation systems employing additional active/semiactive control devices for seismic protection of cable-stayed bridges by examining the ASCE first generation benchmark problem for a cable-stayed bridge. In this study, ideal hydraulic actuators (HAs) and ideal magnetorheological dampers (MRDs) are considered as additional active and semiactive control devices, respectively. Numerical simulation results show that all the hybrid base isolation systems are effective in reducing the structural responses of the benchmark cable-stayed bridge under the historical earthquakes considered. The simulation results also demonstrate that the hybrid base isolation system employing semiactive MRBs is robust to the stiffness uncertainty of the structure, while the hybrid system with active HAs is not. Therefore, the LRB-based hybrid base isolation system employing MRDs could be more appropriate in real applications for full-scale civil infrastructures.