• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.59-64
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• 1989

Raman vibrational Q0branch spectra of pure CO are measured by using the technique of quasicw inverse Raman spectroscopy utilizing a pulsed single-frequency laser source. This approach gives enhanced sensitivity compared to earlier work which employed CW lasers, allowing extension of that work to higher accuracy, higher J states, and higher pressure. Fitting laws with pertubation theory and modified energy gap(MEG) theory are described, and the line broadening and shifting coefficients of J=0 to 24 are determined with both fitting laws.

• Clinical Endoscopy
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• 제57권1호
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• pp.18-23
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• 2024

Computer-assisted polyp characterization (computer-aided diagnosis, CADx) facilitates optical diagnosis during colonoscopy. Several studies have demonstrated high sensitivity and specificity of CADx tools in identifying neoplastic changes in colorectal polyps. To implement CADx tools in colonoscopy, there is a need to confirm whether these tools satisfy the threshold levels that are required to introduce optical diagnosis strategies such as "diagnose-and-leave," "resect-and-discard" or "DISCARD-lite." In this article, we review the available data from prospective trials regarding the effect of multiple CADx tools and discuss whether they meet these thresholds.

• Agricultural and Biosystems Engineering
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• 제7권1호
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• pp.27-41
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• 2006

Assessment of nitrogen and chlorophyll content from crop leaves can help growers adjust N fertilizer rates to meet the demands of the crop. Numerous researchers have presented their studies about spectral signature of plant leaves to characterize the plant features. However, interrelational review and summary were limited and a communication gap exists between the plant science and optical engineering. Understanding the mechanism of leaf interaction to electromagnetic radiation and factors affecting spectrophotometric measurements can enhance the foundation of optical remote sensing technologies. This paper provides extensive review of previous works in optical sensing and explains the basics of plant optics, spectral measurements for plant stress, factors that affect sensitivity to spectral analysis, and applications that deploy optical remote sensing technologies.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.232-232
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• 2009

In this paper, we investigated the sensitivity characteristics of $Bi_{12}BiO_{20}$ (BSO) voltage transformer (VT) by utilizing optical output measured according to the variation of ambient temperature and applied voltage. Fabricated BSO VT slightly showed the decrease of the accuracy in range of from $-20^{\circ}C$ to $50^{\circ}C$, on the other hand, the variation of the optical output result was not observed at the variation of applied voltage. We could finally confirm the temperature stability, applied voltage range, and the possibility that BSO could be applied for optical sensors in GIS system.

• ETRI Journal
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• 제21권3호
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• pp.1-5
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• 1999

A clock and data recovery circuit with a phase-locked loop for 10 Gb/s optical transmission system was realized in a hybrid IC form. The quadri-correlation architecture is used for frequency-and phase-locked loop. A NRZ-to-PRZ converter and a 360 degree analogue phase shifter are included in the circuit. The jitter characteristics satisfy the recommendations of ITU-T. The capture range of 150 MHz and input voltage sensitivity of 100 mVp-p were showed. The temperature compensation characteristics were tested for the operating temperature from -10 to $60^{\circ}C$ and showed no increase of error. This circuit was adopted for the 10 Gb/s transmission system through a normal single-mode fiber with the length of 400 km and operated successfully.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.631-634
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• 2005

This paper has been studied a optical fiber sensor offer important advantages such as electrically passive operation, EMI immunity, high sensitivity, and multi-plexing capabilities of this technology has been the characteristic. The shift in optical fiber Bragg wavelength with mass can be expressed. Using the shift in the optical fiber Bragg grating(FBG) center wavelength due to mass change.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.507-508
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• 2009

We have proposed and demonstrated noncontact refractometer incorporating a fiber bundle. The fiber bundle is composed of a TEC(thermally expended core) fiber and hundreds multimode fibers. The fiber is designed in such a way that the detected reflected optical power from a liquid is constant against the distance between fiber bundle and liquid surface. Low differactive characteristic of TEC fiber make it possible to increase the available distance between the fiber bundle and liquid surface, The obtained sensitivity, optical intensity variation by change of refractive index of liquid is 0.4.

• 전기학회논문지
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• 제59권4호
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• pp.793-796
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• 2010

The equalizer compensates a signal distorted by transmission lines and amplifying stages, so the signal can have uniform characteristics over all frequency range. The equalizer in ODD(Optical Disc Drive) improves the stability of the extracted clock from a received signal and the readability of an inserted disc by suppressing noise and ISI(Inter-Symbol Inference). The length of marks-spaces and track pitch on discs becomes shorter as the recording density of an optical media is higher, which causes noise and ISI. And, the sensitivity about the fluctuation of physical systems is higher as the optical devices become more complicate. This paper proposes a method to select the coefficient of built-in equalizer of ODD in order to maintain the quality of signals against noise and ISI caused by system fluctuation.

• 조명전기설비학회논문지
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• 제17권6호
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• pp.60-65
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• 2003

본 논문에서는 Faraday 효과를 이용한 클램프형 구조의 광-전류 변류기 헤드 설계시에 고려해야할 조건을 이론적으로 해석하고, 이를 토대로 한 클램프형 광-전류 변류기 헤드를 제작하여, 도선에 흐르는 전류, 광의 입사각에 따른 광출력의 변화 및 감도를 측정하고 분석함으로써 전류계로서의 가능성을 입증하였다.

• 소음진동
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• 제8권2호
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• pp.346-352
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• 1998

This paper presents actuating characteristics of an asymmetric high-speed optical pick-up fine actuator that can be installed in a small area such as a notebook personal computer. In the asymmetric actuator four points (mass center, actuation center, supporting point of wire suspension on a bobbin, and optical axis) are not coincident so that the proposed actuator suspension reveals undesirable suspension resonance in the pitch and yaw direction. Lumped parameter dynamic model in each direction is used to investigate the driving characteristics with respect to relative location of the four points. Some of desired design directions toward reducing resonance peaks are suggested by using sensitivity information. In order to avoid undesirable resonance, at least supporting point on the obbin must be located in the middle of the mass and actuation center of the asymmetric pick-up actuator.