• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.1047-1049
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• 2003

Stibenequinone(SQ) derivative which was electronic transportation materials in Poly(N-vinylcarbazole) (PVK)-based on organic EL and an optical characteristic of organic EL which is mentioned previously was investigated. The Photoluminescence highest pick with blending TBSQ with PVK was shifted from 439nm to 517nm. This result indicates that an energy gap of a PVK/TBSQ blended sample is less than an energy gap of PVK. According to the electrochemistry characteristic, the ionization energy(Ip) and the electro affinity(Ea) decreased from 5.79eV to 5.63eV and 2.23eV to 2.63eV, respectively.

• Journal of the Optical Society of Korea
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• 제19권5호
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• pp.456-466
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• 2015

We investigated an anti-aliasing (AA) filter for digital camera photography by which the excessively high-frequency components of the image signal are suppressed to avoid the aliasing effect. Our optomechanical AA filter was implemented by applying rapid relative motions to the imaging sensor. By the engineered motion blur of the mechanical dithers, the effective point-spread function (PSF) of the imaging system could be tailored to reject the unwanted high-frequency components of the image. For optimal operations, we developed a spiral filter motion protocol that could produce a Gaussian-like PSF. We experimentally demonstrated that our AA filter provides an improved filtering characteristic with a better compromise of the rejection performance and the signal loss. We also found that the pass band characteristic can be enhanced further by a color-differential acquisition mode. Our filter scheme provides a useful method of digital photography for low-error image measurements as well as for ordinary photographic applications where annoying $moir{\acute{e}}$ patterns must be suppressed efficiently.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.503-505
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• 2009

본 논문에서는 Blu-ray 디스크의 기록을 위한 Laser Diode의 온도특성을 고려한 기록품질의 개선방법에 대해 연구했다. 주변 온도변화에 따라 Blu-ray Laser Diode는 전류-전압 관계로부터 미분저항이 변화하게 되는데 이러한 미분저항이 기록품질에 미치는 영향에 대해 분석하고 개선하는 방법을 제안한다.

• Journal of the Optical Society of Korea
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• 제14권3호
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• pp.209-214
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• 2010

The Raman shift of water vapor is 3657 $cm^{-1}$, and this Raman signal can be easily separated from other Raman signals or elastic signals. However, it is difficult to make simultaneous Raman measurements on the three phases of water, namely, ice water, liquid water, and water vapor. This is because we must consider the overlap between their Raman spectra. Therefore, very few groups have attempted to make Raman simultaneous measurements even on two elements (water vapor and liquid water, or water vapor and ice water). We have made an effort to find three characteristic Raman wavelengths that correspond to the three phases of water after measuring full Raman spectra of water on particular days that are rainy, snowy or clear. Finally, we have found that the 401-nm, 404-nm, and 408-nm wavelengths are the most characteristic Raman wavelengths that are representative of the water phases when we are using the 355-nm laser wavelength for making measurements.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1354-1363
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• 1993

Optical methods were developed to examine their feasibility for quality evaluation of peanut with pod. Surface color and internal quality of peanut were measured without contact. The surface color of peanut was measured by light reflectance at a region of visible wavelengths. Its characteristic was high correlated with a visual grading of peanut. A trial machine for the color grading of peanut was developed using an optical sensor and it was considered to compare with the visual grading. The spectral reflectance at a region of near infrared wavelengths from 1,200 to 2,500nm was measured , and the chemical components of peanut were related to spectral reflectance at special wavelengths. The protein, fat and moisture contents of peanut were estimated by the near infrared methods. An infrared imaging method was developed to evaluate the internal quality of peanut with pod. As thermal characteristic of peanut with pod was deeply related to internal quality , the quality of peanut can be evaluated by temperature changes on the surface of peanut. Measurement of surface color, near infrared reflectance and thermal imaging were shown to be very effective in grading of peanut with pod.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.320-323
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• 2008

In this paper, electro-optical characteristic of Nematic Liquid crystal (LC) with varying temperature in different LCD modes, namely Fringe Field Switching (FFS), In-plane switching (IPS), and Patterned Vertical Alignment (PVA) modes are investigated and compared. Electro optic me asurements suggest that rate of change of transmission with temperature in FFS mode was lowest and much more thermally stable as compared to IPS and PVA m odes. However the electro-optical characteristic of patterned vertical alignment (PVA) mode was most affected by changing temperature. The measured threshold voltage was found to be much more thermally stable in FFS and IPS modes than that of PVA mode.

• 한국인터넷방송통신학회논문지
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• 제14권2호
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• pp.135-140
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• 2014

본 논문은 광마우스의 패턴 잡음에 대한 움직임 벡터 값에 대해서 디지털 필터링을 통하여 특성 개선 내용을 기술한다. 설계된 회로는 PS2나 USB로 출력되기 전에 x축과 y축 움직임 벡터에 대해 필터링과 평균값을 취하여, 광마우스의 이동을 부드럽게 하고 떨림 현상을 개선하였다. FPGA를 이용해서 각각의 기능을 검증하고 $0.35{\mu}m$ 표준 CMOS 공정을 이용하여 칩으로 제작해서 성능을 측정하였다. 시스템 클럭 주파수는 6MHz를 사용하여 1/1700sec 마다 +6에서 -6사이의 움직임 벡터 값을 출력한다. 테스트는 카테시안 로봇을 이용하여 특성에 대한 측정을 실시하였다.

• 한국기계가공학회지
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• 제15권6호
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• pp.95-100
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• 2016

We suggest and simulate an optical filter that a red wavelength range cannot transmit to protect the psychological stress that originates from the cognition of red color in emergency medical technicians. When a nanohole hexagonal array is fabricated on gold film using Anodic Aluminum Oxide (AAO), the blocked wavelength can be tuned by the hole diameter and film thickness. The characteristic of the transmittance for normal incident white light is simulated with Finite Element Method (FEM) in the MATLAB platform. Although the transmittance of the overall wavelength is reduced by 50% by the gold film, the transmittance of the red wavelength range is decreased by over 87%.

• 한국정밀공학회지
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• 제27권5호
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• pp.69-74
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• 2010

An increasing interest towards the investigations of chalcogenide glasses has been observed in the past years. This interest is due to their specific properties, as well as to the possibilities for their application in different fields of science. The optical devices, working on the basis of photoinduced phase transition between amorphous and crystalline state in the chalcogenide glasses, are a perspective for the micro- and nano-electronics. Here we were analysis basic physical properties for Ge-As-Se and As-Se chalcogenide glasses samples for characteristic for a planning of chalcogenide aspheric lens. From differential DTA/TG results, activation energies of the crystallizations of $Ge_{10}As_{40}Se_{50}$ and $As_{40}Se_{60}$ were approximately 3.6 eV and 3.3 eV, respectively.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.683-686
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• 2002

It is fundamental to count and pack the pills in the medicine manufacture field but those tasks are time and labor consuming. Thus, the need fur automation of those tasks is necessarily getting increased in order to get effective mass production. It Is significant to perceive pills quickly and precisely. There were many trials for this processing but the performance of the existing counting machines varies about size, shape and dispersion tendency of pills. In this paper, the authors try to improve the counting performance of a pill counting machine that has optical sensors with the neural network. The passing signal of pill is acquired with optical sensor and the passage signal of the pill is extracted as input patterns. The gradient and integration of signal during passing time and the time keeping the pill interrupt the light from the LED are used as characteristic feature. The back propagation and perception algorithm are used for training. Experimental results with several pills show that the designed algorithm is a little bit effective to reduce the noise effect which is generated from interference among the machine components and unreliable environment.