• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.656-658
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• 2012

본 논문에서는 엔진의 엔진성능, 안전성 및 내구성에 직접적인 영향을 미칠 수 있는 LP 연료필터의 유동 특성을 분석하고자 하였다. LP 연료필터를 3차원 모델링하였으며, 유동해석을 위하여 계산격자를 구성하고 유동해석을 수행하였다. 유동장을 분석하여 입구부를 거쳐 연료필터를 지나 출구부까지 유동이 원활한 것을 확인하였고, LP 연료의 유동장은 필터내에서 양호한 것으로 판단된다. 또한, 연료필터 내부의 압력강하량을 분석하였으며, 질량유량이 증가함에 따라 압력강하량이 증가하였다.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.11
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• pp.82-87
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• 1999

To temperature-compensate the Bragg wavelength of fiber grating filters two materials with different thermal expansion coefficients were depolyed for packaging. After temperature-compensation packaging the maximum difference of the Bragg wavelength in the temperature range of $-10^{\circ}C$ to $70^{\circ}C$ was 0.03nm, which is only about one thirtiety of the Bragg wavelength shift of the temperature-uncompensated fiber grating filter.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.3
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• pp.308-316
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• 2013

This paper proposes an observation model for a particle filter-based localization using a sonar grid map. The proposed model estimates a predicted observation by considering the properties of a sonar sensor which has a large angular uncertainty. The proposed model searches a grid which has the highest probability to reflect a sonar beam using the following procedures; (1) the reliable area of a single sonar data is determined using the footprint association model; (2) the detection probability of each grid cell in a sonar beam coverage in estimated. The proposed model was applied to the particle filter based localization, and was verified by experiments in indoor environments.

• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.435-442
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• 2004

We obtained precise linear transverse displacements from the results of signal processing on moire fringes measured by the superposition of a fixed self-imaging elongated circular(EC) grating and a moved EC grating. The linear displacement less than one pitch of the moving EC grating was calculated from the position of a bright moire fringe generated on the linear grating part of the EC gratings. The moire signals were high-frequency-filtered, smoothed, curve-fitted, and first-differentiated moire signals in sequence. Also the linear displacement created by movement by the unit of integer times of a pitch was readily measured by the count of the even number of zero-crossing points corresponding to bright moire fringes obtained by the above same processing without curve fitting. Then we can measure linear transverse displacements with the accuracy of better than 3 %, which are more accurate values than those by the traditional visual method within the displacement of 80 ${\mu}{\textrm}{m}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.350-356
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• 2012

The tension effect on fiber Bragg gratings was analyzed and the linearity of 1.24 nm/10kpsi was obtained when Bragg wavelength was varied within 3 nm by applied tension. Using tension control method, different center wavelength fiber Bragg grating(FBG) were fabricated by only single period phase mask. These serially connected four FBGs showed the transmission spectrum of 1.5 nm linewidth as a 3 dB bandwidth which was twice that of a conventional FBG.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.54-60
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• 2007

We constructed a fiber-optic temperature sensor system using a sensor array with 15 fiber Bragg gratings for distributed temperature monitoring in electrical power systems. A polynomial fitting algorithm was used to compensate the nonlinear action of the MEMS tuneable wavelength filter used for Bragg wavelength demodulation Fixed passband wavelengths from a Fabry-Perot ITU filter were used as reference wavelengths for the fitting algorithm which obtained constant accuracy regardless of the wavelength scanning range and frequency. About 0.18[%] of linearity error compared to reference thermocouple thermometer has been obtained in the preliminary experimental results.

• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.409-414
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• 2004

A signal processing system of long period grating sensor that works in the optical wavelength domain is proposed. The system is based on a wavelength-swept semiconductor light source that includes an SLD and a F-P tunable filter. The hysteresis effects of PZT in the F-P filter is compensated by using an etalon filter and an athermal Fiber Bragg Grating. The detected signals from the photodiode are transmitted to a computer using an A/D converter and the result of the process is displayed in the monitor.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.214-215
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• 2003

평면광도파로 브래그격자는 광도파로 내부의 코어의 굴절률을 주기적으로 또는 비주기적으로 변화시켜 특정 파장의 빛을 반사시키거나 투과손실로 작용하게하는 광소자이다. 이러한 광소자는 광가감다중화기, 분산보상기, 파장선택형 반사거울, 파장제거필터, 증폭기의 이득평탄화, 광스위치등 여러분야의 소자 개발의 핵심적인 기능을 부여한다. UV 엑시머레이저의 출력을 게르마늄이 첨가된 실리카 유리에 조사하여 격자구조를 형성시키는 방법이 Hill 등에 의해 발표되었고 이후, 홀로그래피 방법, 위상마스크 방법등 여러 가지의 광섬유 격자 형성방법을 활용하여 여러종류의 광통신소자들이 연구되었다. (중략)

• Proceedings of the KIEE Conference
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• 1986.07a
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• pp.481-485
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• 1986

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.158-159
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• 2005