• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1323-1324
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• 2007

전기방사법을 이용하여 PVK-CdTe 용액으로 하이브리드 나노파이버를 제조하였다. 하이브리드 나노파이버 형상은 광학현미경과 Scanning Electron Microscope으로 관찰되었으며, 직경은 $300nm\;{\sim}\;30{\mu}m$이고, 길이는 $500\;{\mu}m$이상 이였다. PVK-CdTe 하이브리드 나노파이버의 Photoluminescence 측정을 통하여 하이브리드 나노파이버내에 나노입자특성을 유지한 CdTe 나노입자의 존재를 확인하였으며, 대기와 진공 중에서의 I-V 측정을 통해 진공 상태에서보다 대기상태에서 약 2배 정도 전류가 증가한다는 것을 알았다.

• Journal of the Korean Society for information Management
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• v.19 no.4
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• pp.35-51
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• 2002

Inductive learning and classification techniques have been employed in various research and applications that organize textual data to solve the problem of information access. In this study, we develop hybrid model combination methods which incorporate the concepts and techniques for multiple modeling algorithms to improve the accuracy of text classification, and conduct experiments to evaluate the performances of proposed schemes. Boosted stacking, one of the extended stacking schemes proposed in this study yields higher accuracy relative to the conventional model combination methods and single classifiers.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.1
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• pp.15-22
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• 2007

A hybrid experimental-numerical method is presented for determining the stresses around a circular hole in a finite-width, tensile loaded plate. Measured fringe orders along straight lines provided the input information on the external boundary of the hybrid element. In order to see the effects of varying stress field, different numbers of terms in a power-series representation of the complex type conformal mapping stress function were tested. For qualitative comparison, actual isochromatic fringes were compared with reconstructed theoretical fringes using stress-optic law. For quantitative comparison, relative errors and standard deviations with respective to relative errors were analyzed for all measured points by changing the number of terms of stress function. The hybrid results are highly comparable with those predicted by FEA. The results show that this approach is effective and promising because isochromatic data along the straight lines in photoelasticity can be conveniently measured by use of phase shifting photoelasticity.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.202-205
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• 2010

Auto ignition of hybrid rocket using $N_2O$ catalytic decomposition was studied in the present study. The hybrid rocket consists of catalytic igniter, solid fuel, combustor, and nozzle. The Ru/$Al_2O_3$ catalyst for $N_2O$ decomposition was synthesized by an impregnation method, and $N_2O$ conversion as reaction temperatures was measured. The temperature change of the catalytic ignitor was measured at the operating condition, and the possibility for the auto ignition of hybrid rocket was validated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.5
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• pp.465-474
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• 2008

The real-time hybrid testing method(RT-HYTEM) is a structural testing technique in which the numerical integration of the equation of motion for a numerical substructure and the physical testing for an experimental substructure are performed simultaneously in real-time. This study presents the quantitative evaluation of the seismic performance of a building structure installed with an passive and semi-active MR damper by using RT-HYTEM. The building model that was identified from the force-vibration testing results of a real-scaled 5-story building is used as the numerical substructure, and an MR damper corresponding to an experimental substructure is physically tested by using the universal testing machine(UTM). The RT-HYTEM implemented in this study is validated because the real-time hybrid testing results obtained by application of sinusoidal and earthquake excitations and the corresponding analytical results obtained by using the Bouc-Wen model as the control force of the MR damper respect to input currents were in good agreement. Also for preliminary study, some semi-active control algorithms were applied to the MR damper in order to control the structural responses optimally. Comparing between the test results of semi-active control using RT-HYTEM and numerical analysis results show that the RT-HYTEM is more resonable than numerical analysis to evaluate the performance of semi-active control algorithms.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.8
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• pp.731-736
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• 2016

Three-dimensional (3D) high-aspect-ratio (HAR) microstructures for biomedical applications (e.g., microneedle, microadhesive, etc.) are microfabricated using the hybrid ultraviolet (UV) lithography in which inclined, rotational, and reverse-side UV exposure processes are combined together. The inclined and rotational UV exposure processes are intended to fabricate tapered axisymmetric HAR microstructures; the reverse-side UV exposure process is designed to sharpen the end tip of the microstructures by suppressing the UV reflection on a bottom substrate which is inevitable in conventional UV lithography. Hybrid UV lithography involves fabricating 3D HAR microstructures with an epoxy-based negative photoresist, SU-8, using our customized UV exposure system. The effects of hybrid UV lithography parameters on the geometry of the 3D HAR microstructures (aspect ratio, radius of curvature of the end tip, etc.) are measured. The dependence of the end-tip shape on SU-8 soft-baking condition is also discussed.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.5 s.51
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• pp.99-106
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• 2006

The Real-Time Hybrid Test system presented in this paper is based on the pseudodynamic test method, and it combines physical testing with model-based simulation. The system is designed to achieve a rate of loading that is significantly higher than that of a conventional pseudodynamic test approaching the real-time response of a structure subjected to earthquake loads. To provide robust computation environment for the analysis of many degree-of-freedom structures, the system adopts an implicit time integration scheme in the model-based simulation. This paper presents an overview of the developed system and numerical simulations that were conducted to evaluate the performance of the computation scheme adopted here. Results of these studies have demonstrated the good performance of the computation scheme for real-time multiple-degree-of-freedom tests.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.205-208
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• 2001

전류 동기 검출법은 3상이 불평형된 전원 시스템하에서도 전원전류를 평형된 정현파로 보상해 줄뿐 만 아니라 순시전력이론에 비해서 단상에도 적용 가능한 이론이다. 그러나 종전의 전류 동기 검출법은 능동전력필터가 고조파 성분과 기본파 무효성분을 독립 제어하는 하이브리드형 능동전력필터 시스템에는 적용할 수 없다. 따라서 본 연구에서는 불평형 전원 시스템하에서도 비선형 부하전류를 유효성분 기본파 무효성분 그리고 왜형성분으로 분해하여 제어 가능한 확장된 전류 동기 검출법을 제시하였다. 본 연구에서 제시한 방법의 타당성을 입증하기 위해, 불평형 교류 전원하에서 평균전력이론 동기 전류 검출법 그리고 제안된 방법을 실험에 의하여 비교 검토하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.63-66
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• 2011

하이브리드 시스템은 연속적인 행위와 이산적인 행위가 긴밀하게 통합되어 있는 시스템이다. 하이브리드 시스템을 모델링 하기 위해서 본 논문에서는 확장한 CHARON을 사용한다. 확장한 CHARON은 기존의 CHARON에서 변수의 도식적 표기법, 모드의 도식적 표기법, 통신 방식 변경(Renaming 방식 제거), 통신과 계층 간 연계의 분리, 긴급 전이 추가, 신호 변수를 추가하였다. 또한 확장한 CHARON을 사용하여 전장을 모델링 하였다.

• Membrane Journal
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• v.14 no.2
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• pp.132-141
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• 2004

NBR-Clay hybrid membranes were prepared by melt intercalation method with internal mixer and two roll mills. MMT was intercalated or ekfoliated by the NBR and it was confirmed by X-ray diffraction method. D-spacing of the characteristic peak from MMT plate in WAXD was moved and diminished. Gas permeability, mechanical properties and thermal properties of the NBR-Clay hybrid membranes were investigated. Gas permeability through the NBR-Clay hybrid membranes decreased due to increased tortuosity made by intercalation of clay in NBR.