• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.777-781
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• 2002

Recently, an optical disc system has been proposed using blue laser diode, high NA objective lens and groove only disc structure. A new method is needed to readout CD and DVD in this blue system. In order to readout CD and DVD in HD-DVD system, we adopted dual-lenses actuator in consideration of optical utilization efficiency, optical performance and insurance of sufficient W.D (working distance). This dual-lenses actuator has two objectives in radial direction, one is for CD/DVD and the other is for HD-DVD. We had to solve the induced problems of DC tilt increase, $2^{nd}$ resonance deterioration and AC sensitivity drop caused by disposing two lenses in an actuator. Especially, to solve AC sensitivity drop, we introduced two 2-pole magnets and separated focus and track magnetic circuits. Consequently we presented that dual-lenses actuator has been possessed good performance. And we measured eye patterns of CD, DVD and HD-DVD by using HD-DVD optical pick-up with dual-lenses actuator.

• 한국전기전자재료학회논문지
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• 제30권2호
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• pp.91-95
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• 2017

We were designed the hole transport layer of the new composite skeleton structure having a high charge mobility and thermal stability. In this paper, a hole transport layer material based on thiophene molecular structure capable of hole mobility characteristics and high triplet energy was designed and synthesized. The structures and properties of the synthesized compounds were characterized by NMR, fluorescence spectroscopy and energy band gap. As a result of NMR measurement, it was confirmed that when analyzing the integrated type with the position where the measured peak is displayed, it agrees with the structure of hole transport materials. The emission characteristics of the hole transport layer material showed absorption characteristics at 412 nm and 426 nm, respectively, and exhibited emission characteristics in the range of 469 nm and 516 nm.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.656-661
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• 2002

라이다 광원용 다중통과 Ti-sapphire 증폭기를 각도다중 방식으로 설계하여 출력에너지 및 스펙트럼 특성을 개선하였다. 2-단의 다중통과 증폭기에서 파장이 790nm 일 때, 42mJ의 출력에너지와 21dB의 증폭이득 및 26%의 출력효율을 얻었으며, 715~930nm이 파장가변 영역에서 스펙트럼 선폭은 0.05$cm^{-1}$ / 이하였다. 780nm의 파장에서 35%의 SHG 변환효율과 390nm의 파장에서 13%의 THG 변환효율을 각각 얻었다. 결과적으로 240~306nm의 자외영역과 360~460nm의 deep-blue 영역에서 연속적으로 파장을 가변시킬 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.539-541
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• 2022

광역학 치료는 빛을 이용해 암을 치료하는 방법 중 하나로, 레이저 조사시 광감각제가 반응하여 산소와 결합해 암세포를 파괴한다. 이 치료법은 암 환자들에게 부작용을 최소화하는 치료로 각광 받고 있다. 그 중 광감각제는 종류에 따라 치료 부위, 치료 효과, 흡수되는 정도가 다르게 나타난다. 따라서 본 연구에서는 광감각제 중 5-ALA를 주입한 HELA 세포주에 Blue LED를 조사하여 암세포 증식 억제 효과의 정량적 평가 연구를 진행하였다.

• Clinical Endoscopy
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• 제56권5호
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• pp.553-562
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• 2023

Colonoscopy plays an important role in reducing the incidence and mortality of colorectal cancer by detecting adenomas and other precancerous lesions. Image-enhanced endoscopy (IEE) increases lesion visibility by enhancing the microstructure, blood vessels, and mucosal surface color, resulting in the detection of colorectal lesions. In recent years, various IEE techniques have been used in clinical practice, each with its unique characteristics. Numerous studies have reported the effectiveness of IEE in the detection of colorectal lesions. IEEs can be divided into two broad categories according to the nature of the image: images constructed using narrow-band wavelength light, such as narrow-band imaging and blue laser imaging/blue light imaging, or color images based on white light, such as linked color imaging, texture and color enhancement imaging, and i-scan. Conversely, artificial intelligence (AI) systems, such as computer-aided diagnosis systems, have recently been developed to assist endoscopists in detecting colorectal lesions during colonoscopy. To gain a better understanding of the features of each IEE, this review presents the effectiveness of each type of IEE and their combination with AI for colorectal lesion detection by referencing the latest research data.

• 한국결정성장학회지
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• 제30권1호
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• pp.21-26
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• 2020

이 논문은 라이트박스의 주력 상품인 세 가지 색의 합성 다이아몬드의 분광학적 특성에 대해 분석한 결과이다. 드비어스의 브랜드인 라이트박스 주얼리는 2018년 9월부터 CVD 합성 다이아몬드를 판매하기 시작했다. 본 연구에서 검사된 샘플은 0.25 ct, 0.25 ct, 0.26 ct의 무색(H grade), 핑크, 청색의 합성 다이아몬드이며, 각 샘플의 테이블 중앙에는 라이트박스 로고가 레이저 각인되어 있었다. 분광학적 기법에 기초한 분석 결과, 무색 샘플은 결정성장 후 색 향상을 위한 고온고압 처리과정을 거치지 않았다. 핑크 샘플은 H3, 3H, 594 nm, NV, GR1의 광학 결함이 발견되었고, 이로 인해 결정성장 후 색 향상을 위해 조사와 열처리 과정을 거친 것으로 판단했다. 또한 블루 샘플은 열처리 과정 없이 조사만 되었음을 알 수 있었다.

• 동의생리병리학회지
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• 제17권2호
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• pp.416-422
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• 2003

Jaeumgenby-tang(JGT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo caused by deficiency of qi(氣) and blood(血). Effect of Aurantii Fructus(AF) take off the phlegm by promoting the circulation of qi, Gastrodae Rhizoma(GR) has effects treating for headache, vertigo by calming the liver and suppressing hyperactivity of the liver-yang(陽). And, We reported that JGT adding AFㆍGR extract(JGTAG) was significantly increased regional cerebral blood f1ow(rCBF) by dilating pial arterial diameter(PAD). Therefor we designed to investigate whether JGTAG is mediated by adrenergic β-receptor, cyclooxygenase or guanylate cyclase in normal rats. The changes of rCBF and mean arterial blood pressure(MABP) were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video microscope and width analyzer. The results were as follows in normal rats; Pretreatment with propranolol(1mg/kg, i.v.) was significantly inhibited JGTAG induced increase of rCBF, PAD and MABP, and pretreatment with indomethacin(1 mg/kg, i.v.) was significantly inhibited too. But pretreatment with methylene blue(10μg/kg, i.v.) were accelerated JGTAG induced increase of rCBF and MABP, but pretreatment with methylene blue was inhibited JGTAG induced increase of PAD. This results suggest that the mechanism of JGTAG is mediated by adrenergic β-receptor and cyclooxygenase.

• 한국융합학회논문지
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• 제8권5호
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• pp.161-167
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• 2017

상온에서 단일소자의 경우 $0.98{\mu}A$ 문턱전류를 나타내는 $32{\times}32$ 광양자테 레이저 어레이를 제작하였다. 제작된 어레이의 전체 소자들의 문턱전류 및 밀도, 전압은 20 mA, $0.068A/cm^2$, 1.38 V의 값을 나타내었다. 발광 광양자테 어레이는 GaAs 물질이 다중-양자 우물 활성 영역을 구성하고, 칩이 차지하는 면적은 $1.65{\times}1.65mm^2$였으며, 소자들의 피크파워 파장은 $858.8{\pm}0.35nm$, 상대적인 레이저 세기는 $0.3{\pm}0.2$, 선폭은 $0.2{\pm}0.07nm$로 비교적 균일한 특성을 보였다. 또한, 레이저 어레이의 각도 의존적 청색 이동 특성을 이용한 파장 분할 멀티플렉싱 시스템 실험을 진행하였고, 각도에 따라 10 nm 정도 파장이 변하는 현상을 발견하였으며, 거리에 따른 레이저 세기를 측정한 결과 6 m에서도 감지할 수 있음을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1959-1961
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• 1999

We prepared the $Ag[100\AA])/Sb_2S_3[3000\AA]$ films using the thermal evaporator. The films were exposed by the blue-pass filtered mercury lamp and the polarized He-Ne laser. We have investigated the dependence of the induced optical energy with Ag-doping and have observed the transmittance variation near the optical absorption edge with the light source. It was shown that the energy gap of this thin film was largely changed by exposing He-Ne laser, the light source of the near energy gap of this thin film. It is because of the structural change from Ag-doping. It is investigated that the dissolution, the diffusion, and the field effect of the Ag thin film generate the Ag spatial distribution.

• 대한기계학회논문집B
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• 제26권10호
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• pp.1348-1354
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• 2002

We investigate the flame behavior and spatial distribution of OH, PAHs and soot in a confined buoyant diffusion flame with decrease of the coflowing air flow rate. Direct photographs and Schlieren images represent that flame is Ally occupied by blue flame and becomes unstable, which is partially detached to the fuel nozzle tip in a near extinction flame under extremely reduced oxidizer condition. Laser induced fluorescence profiles clearly shows that OH is still generated in near-extinction flame, although intensity becomes weak with decreasing air flow rate. But soot scattering image cannot be seen any more in an oxidizer deficient ambience and simultaneously the PAHs are widely distributed downstream. These results are due to that a decrease of oxygen concentration in the combustion chamber leads to a temperature drop of flame, as a consequence, to a delay in soot growth and to a expanding of the PAHs, as soot precursors.