• Proceedings of the Korea Water Resources Association Conference
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• 1991.07a
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• pp.221-230
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• 1991

Various Models of the moisture content-capillary pressure hysteresie based on the approach of domain concept in porous media are compared with each other, Model III-1(Mualem, 1984) is superio to others as expected. A new model based on Model III-1 is proposed of which asuumption is the linearization of P$$($\theta$) accounting for the pore blockage effect against air-entry. The feature of this model is that only one branch of boundary curve is needed to calibrate it, which is the advantage to Model III-1. The prediction of boundary drying curve from boundary wetting curve using this model is better than that using Model I-1, II-1 compared with the experimental data. This model is to simulate scanning curves, while Model I-1, II-1 is not.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.66-68
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• 2012

본 논문에서는 자체 개발한 Java Platform 기반의 뇌파 분석 도구와 Android 기반의 Mobile 기기를 연계하여 중증 장애인의 상태 및 상황 등을 모니터링 할 수 있는 시스템을 제시한다. 제안된 시스템은 뇌파 측정기, 뇌파 분석 툴(PC Client) 그리고 Mobile 기기(Android)로 크게 3부분으로 구성된다. 뇌파 측정기로부터 수집된 원 주파수에서 저주파 대역의 잡음을 제거하기 위해 고주파 필터를 적용한 후, 적용된 데이터를 주파수 영역에서 분석하기 위해 FFT를 적용한다. FFT를 적용한 데이터를 Power Spectrum 분석 기법을 이용하여 Theta, Delta, Alpha, SMR, Beta 파형의 값을 추출하고, 14 채널의 뇌파 측정 위치에 따른 상관관계 분석기법을 통해 중증 장애인의 상태를 표현한다. 본 논문에서 제안한 방법으로 실험한 결과, 중증 장애인 모니터링 시스템에 효율적으로 적용되는 것을 확인하였다.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.310-315
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• 1998

In this paper a new analytical model for the non-linear flux-linkage/current characteristics of the switched reluctance motors at different rotor positions is proposed. The model has been successfully verified by the simulation and the experimental results of the instantaneous current waveforms and the average torque values in both single pulse and multiple pulse operation of the motor. The uniqueness of the model lies in its defining a simple algorithm for determining the rotor position ($\theta$). Hence, sensorless operation of the motor can be easily implemented with the aid of this model.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.414-417
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• 2011

Indium tin oxide (In:$SnO_2$) nanoparticles were synthesized employing a sol-gel combustion method followed by annealing. The TG, XRD, XPS and SEM results of the precursor powders and calcinated In:$SnO_2$ nanoparticles were investigated. Crystal structures were examined by powder XRD, and those results show shaper intensity peak at $25.6^{\circ}$ ($2{\theta}$) of $SnO_2$ by increased annealing temperature. A particle morphology and size was examined by SEM, and the size of the nanoparticles was found to be in the range of 20~30nm. In:$SnO_2$ films could controlled by nanoparticle material at various annealing temperature. The sol-gel combustion method was offered simple and effective route for the synthesis of In:$SnO_2$ nanoparticles.

• Journal of Information Processing Systems
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• v.11 no.1
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• pp.95-103
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• 2015

This paper presents a memory efficient tree based anti-collision protocol to identify memoryless RFID (Radio Frequency Identification) tags that may be attached to products. The proposed deterministic scheme utilizes two bit arrays instead of stack or queue and requires only ${\Theta}(n)$ space, which is better than the earlier schemes that use at least $O(n^2)$ space, where n is the length of a tag ID in a bit. Also, the size n of each bit array is independent of the number of tags to identify. Our simulation results show that our bit array scheme consumes much less memory space than the earlier schemes utilizing queue or stack.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.2
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• pp.82-89
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• 2006

The electroencephalogram generated by light stimulation in human body of dark adaption state was measured and analyzed in the cases that electromagnetic wave was put in and not put in, respectively. Shieldroom being able to interrupt the light and the electromagnetic wave of outer was constructed, and the experimental system being able to apply any light and any electromagnetic wave was designed. When the electromagnetic wave was applied to body or not, the variation characteristics of each component in the electroencephalogram were i3s follows. The 6 wave was increased and the $\alpha$ wave and the $\beta$ wave were decreased in the case that the electromagnetic wave was applied, and the variation range of the $\Theta$ wave was small. And the influence of electromagnetic wave on human body was that the appearance time of the $\beta$ wave was late, and it moaned that the time of visual recognition was delayed.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1593-1595
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• 2002

Single crystal 3C-SiC(cubic silicon carbide) thin-films were deposited on Si(100) wafers up to a thickness of 4.3 ${\mu}m$ by APCVD method using HMDS(hexamethyildisilane) at $1350^{\circ}C$. The HMDS flow rate was 0.5 sccm and the carrier gas flow rate was 2.5 slm. The HMDS flow rate was important to get a mirror-like crystal surface. The growth rate of the 3C-SiC films was 4.3 ${\mu}m/hr$. The 3C-SiC epitaxial films grown on Si(100) were characterized by XRD, AFM, RHEED, XPS and raman scattering, respectively. The 3C-SiC distinct phonons of TO(transverse optical) near 796 $cm^{-1}$ and LO(longitudinal optical) near $974{\pm}1cm^{-1}$ were recorded by raman scattering measurement. The hetero-epitaxially grown films were identified as the single crystal 3C-SiC phase by XRD spectra($2{\theta}=41.5^{\circ}$).

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.183-185
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• 2002

This paper proposes the test method for the testing of a RLC parallel circuit on the electronic circuit board. This method utilizes a guarding circuit and a phase detection circuit. The guarding circuit separates electrically the tested device or circuit from printed circuit board. Phase detector estimates the phase difference from two signals, voltage and current. This method computes R. L and C value from phase difference($\theta$) and impedance value(Z) obtained by enforcing two other frequence stimulus under the guarding state.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.770-775
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• 2000

A new photo-polymer material of the copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy)chalcone-cholesteryl methacrylate) for homeotropic alignment was synthesized and the electro-optical (EO) performance for the photo-aligned vertical-aligned (VA)-LC display (LCD) was studied. Good thermal stabilities of synthesized copolymer were obtained by TGA(Thermogravimetric Analysis) measurement. Good voltage-transmittance (V-T) and response time characteristics for the photo-aligned VA-LCD with polarized UV exposure in oblique direction($\theta$$_{i}$=30$^{\circ}$) on a copolymer-1 (2%) surfaces for 1 min were observed. but, light leakage in the off-state was observed. Therefore, we achieved excellent V-T and response time characteristics for the photo-aligned VA-LCD with UV exposure on a copolymer-3 (30%) surfaces for 3 min.n.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.37-38
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• 2014

최근 SNS의 발전으로 인해 데이터의 양이 급격히 증가하였으며, 이에 따라 빅데이터 처리를 위한 분산 DBMS 기반 질의 처리 연구가 활발히 진행되고 있다. 이를 위해 CUBRID는 CUBRID Shard 서비스를 통해 데이터베이스를 shard 단위로 수평 분할하여 각기 다른 물리 노드에 데이터를 분산 저장하도록 지원한다. 그러나 CUBRID Shard는 shard간 데이터가 독립적으로 관리되기 때문에 세타 조인 및 중첩 질의와 같이 다수 서버에서의 테이블 참조가 필요한 질의는 처리가 불가능하다. 따라서 본 논문에서는 분산 CUBRID 상에서 세타 조인 및 중첩 SQL를 지원하는 질의 재구성 기법을 제안한다.