• Bulletin of the Korean Chemical Society
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• 제23권11호
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• pp.1509-1510
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• 2002

• 한국물환경학회지
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• 제33권2호
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• pp.130-139
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• 2017

With the need to evaluate accuracy of real-time measurement of cyanobacterial fluorescence to determine cyanobacterial blooms, this research examined 357 paired data (2013-2016) comprising both microscopic toxic cyanobacterial cell counts and concurrent real-time cyanobacterial concentrations at 2 sites (YS1 and YS2) in Yeongsan river. The increase in real-time cyanobacterial concentration was closely associated with the exceedance of 5,000 cyanobacterial cells/ml (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.03-1.12) and 10,000 cells/ml (OR 1.08, 95% CI 1.04-1.12) at YS2 site. The area under the receiver operating characteristic (ROC) curve for the real-time cyanobacterial measurement at the YS2 site was 0.93, which indicates the measurement provides a high accurate detection of cyanobacterial blooms. On the ROC curve, the early alert levels of real-time cyanobacteria ranging $16-23{\mu}g$ chl-a/L would produce acceptable sensitivity of 79% and specificities greater than 90%. The real-time fluorescence measurement was found to be an accurate indicator of cyanobacteria and can serve as a tool for detecting toxic cyanobacterial bloom events in Youngsan river.

• 센서학회지
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• 제33권1호
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• pp.30-33
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• 2024

The occurrence of harmful algae on the coast of Korea has been a cause of damage to the aquaculture industry and deterioration of the coastal ecosystem environment. A method is required to predict their outbreak in real-time at the site. Therefore, this study attempted to develop a small hybrid optical sensor and real-time monitoring system based on LiDAR that can be used in the field and laboratory and can be applied to various platforms. FMS-L specifically suggested the amount of Chlorophyll a (Chl a) in the sample by measuring and analyzing the fluorescence emitted by the irradiating light. The accuracy of FMS-L was verified by measuring the concentrations of standard Chlorophyll a substances and Margalfidinium polykirkoids. In addition, the precision was verified by comparing the measurement results of FMS-L using commercial equipment Phyto-PAM-II. This equipment is compact and easy to move. Therefore, it can be easily applied to field surveys, allows short time measurements (10 s), and can be applied at a distance of 10 m from the measurement site.

• Applied Microscopy
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• 제46권1호
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• pp.6-13
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• 2016

Fluorescence lifetime imaging microscopy (FLIM) has been considered an effective technique to investigate chemical properties of the specimens, especially of biological samples. Despite of this advantageous trait, researchers in this field have had difficulties applying FLIM to their systems because acquiring an image using FLIM consumes too much time. Although analog mean-delay (AMD) method was introduced to enhance the imaging speed of commonly used FLIM based on time-correlated single photon counting (TCSPC), a real-time image reconstruction using AMD method has not been implemented due to its data processing obstacles. In this paper, we introduce a real-time image restoration of AMD-FLIM through fast parallel data processing by using Threading Building Blocks (TBB; Intel) and octa-core processor (i7-5960x; Intel). Frame rate of 3.8 frames per second was achieved in $1,024{\times}1,024$ resolution with over 4 million lifetime determinations per second and measurement error within 10%. This image acquisition speed is 184 times faster than that of single-channel TCSPC and 9.2 times faster than that of 8-channel TCSPC (state-of-art photon counting rate of 80 million counts per second) with the same lifetime accuracy of 10% and the same pixel resolution.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1297-1303
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• 2021

Most thickness measurement techniques using X-ray radiation are unsuitable in field processes involving fast-moving organic films. Herein, we propose a Compton scattering X-ray radiation method, which probes the light elements in organic materials, and a new simple, non-destructive, and non-contact calibration-free real-time film thickness measurement technique by setting up a bench-top X-ray thickness measurement system simulating a field process dealing with thin flexible organic films. The use of X-ray fluorescence and Compton scattering X-ray radiation reflectance signals from films in close contact with a roller produced accurate thickness measurements. In a high-thickness range, the contribution of X-ray fluorescence is negligible, whereas that of Compton scattering is negligible in a low-thickness range. X-ray fluorescence and Compton scattering show good correlations with the organic film thickness (R² = 0.997 and 0.999 for X-ray fluorescence and Compton scattering, respectively, in the thickness range 0-0.5 mm). Although the sensitivity of X-ray fluorescence is approximately 4.6 times higher than that of Compton scattering, Compton scattering signals are useful for thick films (e.g., thicker than ca. 1-5 mm under our present experiment conditions). Thus, successful calibration-free thickness monitoring is possible for fast-moving films, as demonstrated in our experiments.

• 한국정보통신학회논문지
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• 제17권5호
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• pp.1239-1244
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• 2013

임상 의료 분야에서 질병 진단 및 치료를 위해서는 분자 수준(프로틴, DNA 등)의 크기 뿐만 아니라, 세포 수준에 대한 분석이 필요하다. 많은 경우 실험 샘플이 시간에 따라 변질되기 때문에 정확한 분석을 위해서는 빠른 분석과 실시간 데이터가 필요하다. 본 연구에서는 나노 마이크로 크기의 세포내 단백질이나 DNA의 변화 과정 등을 촬영할 수 있는 3차원 형광 관측 장치를 제작하고 이로부터 얻은 형광 이미지를 실시간 통합 관리 및 분석하기 위한 서버 클라이언트 기반의 형광 이미지 분석 시스템을 구축하였다. 시스템은 형광 관측 장치와 소프트웨어 그리고 형광 이미지를 실시간으로 분석할 수 있는 모바일 프로그램으로 구성된다. 개발된 시스템은 의료인이 시공간의 제약 없이 응급환자의 샘플에서 획득한 형광이미지를 실시간으로 전송받아 분석 및 진단을 내릴 수 있도록 해 주므로 유비쿼터스 헬스 구현에 활용할 수 있다.

• Fisheries and Aquatic Sciences
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• 제5권4호
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• pp.311-313
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• 2002

Proteolytic activity of live Uronema manum was analyzed by fluorescence polarization (FP) technique. Protease activity was measured by a decrease in FP value using fluorescein isothiocynate (FITC)-casein as a protein substrate. The results demonstrated an inverse linear relationship between fluorescence polarization (FP) values and live ciliate concentration over the range $1\times10^4\;to\;2\times10^5$ cells/well. However, the FP values of $10-10^3$ live parasites were not different significantly from that of control. Time-dependent decrease in FP value was shown in the wells containing live U. marinum. In the present study, FP assay had the benefit to provide measurements of substrate hydrolysis by live parasites in real-time, and did not require separations, precipitations, or transfers of reaction mixture.

• 한국진공학회지
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• 제18권6호
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• pp.418-425
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• 2009

권역별 싸이클로트론연구소에 설치되어 있는 KIRAMS-13 싸이클로트론에서 안정적이고 최적화된 양성자빔을 인출하기 위해서는 양성자빔의 횡단면 측정이 필수적이다. 빔의 횡단면 측정장치 중 비파괴적인 방법인 BIF(Beam Induced Fluorescence) 모니터는 그 구조가 상대적으로 간단하고 빔의 에너지 손실을 최소화하며 실시간 측정이 가능하다는 장점이 있다. 이 연구에서는 KIRAMS-13 싸이클로트론에서 양성자빔의 횡단면 측정을 위한 BIF 모니터를 설계하고 제작한 후 13 MeV 양성자빔 조사실험을 통하여 양성자 빔의 중심 및 반경을 측정하였다.

• Tribology and Lubricants
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• 제26권3호
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• pp.167-174
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• 2010

An apparatus for measuring oil oxidation was developed, which is capable of being mounted to mechanical devices for detecting power of fluorescent light reflected from oil in real time as an indication of the oil oxidation. This device has an advantage over conventional fluorescence spectrometers where the thin film is required for the measurement. Clean and used oil samples (mineral and synthetic oils) were tested by the developed apparatus that calculates a fluorescence quantum yield and a light absorption coefficient of the oil based upon the signals from the two light-receiving members and evaluates the degree of oil oxidation of test oils based on the fluorescence quantum yield. Results generally show that the developed device is able to effectively evaluate oil oxidation characteristics on-site in the field.

• 센서학회지
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• 제6권5호
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• pp.362-368
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• 1997

질소레이저, optode 및 광증배관을 사용하여 우라늄 농도를 원격 실시간으로 측정할 수 있는 방법을 연구하였다. 원격 측정에서 보다 효과적으로 우라늄 형광을 집광할 수 있는 optode를 설계하였으며, optode를 이용하여 우라늄 이온으로부터 나온 형광을 광섬유로 전송하여 광증배관으로 검출하였다. 신호처리에서는 온도 변화와 quencher들의 방해효과가 거의 없는 형광의 초기치를 유도하여 사용하므로 보다 정확한 우라늄 농도를 측정할 수 있었다. 측정 결과 우라늄 농도 변화에 따른 형광 강도의 변화를 쉽게 감지할 수 있었으며, 검출한계는 0.06ppm을 얻었고, $0.1{\sim}2ppm$ 범위에서 직선성이 우수하였다.