• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.161-168
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• 2009

We demonstrated $\check{S}$olc-type wavelength filters in periodically poled Ti-diffused lithium-niobate channel optical waveguide (Ti:PPLN). A $\check{S}$olc-type transmission spectrum based on the polarization-mode conversion was observed experimentally in PPLN with period 16.6${\mu}m$. A reasonable explanation of such a phenomenon was presented. A polarization-mode converted transmission peak was observed at wavelength 1272.49nm. The FWHM and sidelobe of spectrum are about 0.23nm and 7 dB, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.1
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• pp.47-57
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• 2002

In this paper, a wavelength converter for RZ data which can controls XPM in SOA by using polarization controller within optical fiber loop mirror is proposed and demonstrated. The proposed structure needs only one polarization dependent SOA for implementation compared to previous XPM ones and makes the cost down. And it provides wavelength converted signals with non-inverted and inverted pattern into outputs respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1646-1652
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• 2015

In this paper, we propose a depth conversion method for orthoscopic real image reconstruction in integral imaging. Pseudoscopic image has been regarded a problem in conventional integral imaging. the depth of reconstructed image is depending on a coordinate of an elemental image. The conversion from pseudoscopic to orthoscopic may be possible by analysing the geometrical relation between pickup and reconstruction system of elemental image. The feasibility of the proposed method has been confirmed through preliminary experiments as well as ray optical analysis.

• Journal of the Korean Magnetics Society
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• v.7 no.6
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• pp.334-339
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• 1997

센서는 어떤 물리 .center dot. 화학적량을 다른 물리 .center dot. 화학적량으로 변환시키는 기능의 소자를 통칭하는 용어로써 그 범위가 매우 넓으며, 현대 산업사회에서 전기 .center dot. 전자공학의 반전과 더불어 센서가 더욱 중요시되고 있다. 특히 대부분의 센서가 피측정 물리 .center dot. 화학적량을 전기적 신호로 변화 시키는 기능으로 정밀측정, 생산자동화 및 자동제어등에 다양하게 사용되고 있다. 센서는 원리적 측면에서의 분류와 센서의 기능적 측면으로 분류방법이 있다. 센서 관련 학문적 연구면에서 보면 센서의 원리적 측면에서의 접근이 용이하며 센서를 사용하는 산업체나 사용자의 입장에서는 센서의 기능적 측면 즉 피측정 물리 .center dot. 화학적량의 종류에 따른 분류가 편리하다.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.256-257
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2006.02a
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• pp.321-322
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 2006.02a
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• pp.147-148
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• 2006

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.523-526
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• 2009

시계열 데이터에서 패턴을 분석하는 기법은 많은 발전이 이루어져 오고 있으나 주식시장의 경우 패턴 분석 및 예측에 관련되어 많은 연구가 이루어져 있지 않고 있다. 이는 주가의 등락 자체가 본질적으로 무작위하다고 생각되어지고 있기 때문이다. 본 연구에서는 주가의 등락이 보여주는 무작위성의 정도를 Kolmogorov Complexity로 측정, 그 무작위성의 정도와 본 논문에서 제시한 반전역정렬로 예측하는 주가의 예측 간의 상관관계를 보인다. 이를 위하여 KOSPI 주식 데이터 28년 690개의 데이터를 수집하여 이들 주식 데이터의 등락을 양자화된 문자열로 변환하여 본 논문에서 제시한 방법의 의미를 평가하였다. 그 결과 Kolmogorov Complexity가 높은 경우에는 주가 변동 예측이 어려우며, Kolmogorov Complexity가 낮은 경우에는 주식 변동 예측은 가능하나 등락 예측 율은 단기 예측은 12%이상의 예측율을 보일 수 없으며, 장기 예측의 경우 54%의 예측율로 수렴함을 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2304-2310
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• 2009

This paper presents WSK(wavelet shift keying) that can be improved to bit transmission rate in the digital communication. An algorithm of the conventional modulation is carried out that the scaling function and wavelet are encoded to 1(mark) and 0(space) for the input binary data, respectively. A new modulation technique that uses four carrier frequencies is proposed. Four carrier frequencies are defined as scaling function, inversed scaling function, wavelet, and inversed wavelet, which are encoded to 10, 11, 00 and 01 respectively. An algorithm of the proposed demodulation is decode to the original data using four correlation. As a results of simulation, we confirmed that the proposed method was improved to the performance at twice for the bit transmission rate.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.408-415
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• 2008

The characteristics of a ferroelectric-domain inverted grating fabricated by applying a high-voltage pulse at room temperature in Ti-diffused channel waveguides in z-cut $LiNbO_3$ (Ti:PPLN) were examined for channel waveguide quasi phase-matched secondharmonic generation devices. The fabrication conditions of uniform periodic domain-inversion were examined. Ti:PPLN with period ${\Lambda}=16.6{\mu}m$ for SHG were fabricated and the performances were measured. A normalized SHG efficiency as high as 473 (%/W) was obtained with 49 mm interaction length.