• KSBB Journal
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• v.17 no.2
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• pp.158-161
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• 2002

In this study, a prototype fiber-optic biosensor was fabricated using the inhibition of enzyme reaction by organophosphorus compounds to detect organophosphorus compounds, which is nervous toxic material an? is used as chemical weapon and pesticide. Enzyme, substrate, and inhibitor for enzyme reaction were acetylcholinesterase (key enzyme in nervous cell), acetylthiocholine iodide, and paraoxon (a kind of organophosphorus compounds), respectively. The detection principle of sensor is the detection of enzyme reaction inhibited by organophosphorus compounds by the quantitative measurement of acetic acid, which was achieved by absorbance measurement using litmus solution that maximum absorbance band is changed by pH. To fabricate prototype fiber-optic biosensor, high bright LED and photodiode was used as light source and light intensity detector, respectively. From the experimental results using a prototype biosensor, the linear change of sensor signal was obtained in a range of 0-2 ppm inhibitor concentrations. From these results, it was verified that the quantitative measurement of organophosphorus compounds could be achieved fast (within 2 minutes) and accurately by a prototype fiber-optic biosensor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1233-1239
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• 2011

The visible light convergence communication technology is suitable for indoor wireless communication and digital lighting fixtures, it could be used as lighting devices as well as a communication device. However, because that VLC is the technology of came to world a few years ago, there are many problems which had to solve. The signal sensing of VLC transmitter is one of the most challenging issue in VLC systems. Therefore in this paper, we analysis the performance of various sensing scheme for efficient detection of VLC systems. The signal of user is OFDM signal and the wirelss channel between a user and VLC system is modeled as indoor VLC channel. From the simulation results, it is confirmed that the proposed scheme is very effective to signal sensing for VLC systems.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.104-104
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• 2017

정상적인 부화 여부를 판별하기 위한 1차 검란은 일반적으로 5일~7일 이후에 시행된다. 미부화란을 이보다 더 빠른 시간 안에 검출할 경우 부화에 소요되는 에너지의 감소 효과 및 미부화란을 다른 용도로 활용하는 것을 기대할 수 있다. 시중에서 쉽게 구입할 수 있는 산란계인 하이라인 브라운 품종의 유정란 29개와 인위적인 미부화란을 만들기 위한 동일 품종의 무정란 11개를 사용하였으며 $38^{\circ}C$, 70% 조건의 항온항습기에서 96시간 동안 부화하였다. 스펙트럼 획득 장치의 광원은 녹색영역을 발광하는 LED램프와 일반 할로겐 광원을 별도로 사용하였으며 스펙트로미터는 VIS/NIR 영역인 520~1,180nm영역과 NIR영역인 900~1,700nm영역의 것을 사용하였다. 부화 시작 전과 부화 시작 후 1일 간격으로 각각 1개의 샘플에 대한 1개의 스펙트럼을 측정하였다. 측정 영역은 LED광원을 이용한 경우는 520~1,1800nm, 할로겐광원을 이용한 경우에는 520~1,180nm와 900~1,700nm이었다. 정상 부화여부는 4일차에서 할란하여 확인하였고, 측정 일자별로 PLS-DA분석법을 이용한 판별 모델을 개발하였다. 4일차에서 유정란 29개 중 11개가 정상 부화하였고, 18개는 미부화하였다. 3일차에서 판별 모델의 정확도는 LED광원의 VIS/NIR 영역 스펙트럼을 이용한 경우는 100%, 할로겐 광원의 VIS/NIR 영역 스펙트럼을 이용한 경우는 70%, 할로겐 광원의 NIR영역 스펙트럼을 이용한 경우는 70%였다. 4일차에서 판별 모델의 정확도는 LED광원의 VIS/NIR 영역 스펙트럼을 이용한 경우는 100%, 할로겐 광원의 VIS/NIR 영역 스펙트럼을 이용한 경우는 90%, 할로겐 광원의 NIR영역 스펙트럼을 이용한 경우는 100%였다. 부화 3일차는 정상 부화할 경우 피가 생성되는 시기이다. 피가 형성된 이후의 부화 여부를 판단하는 광원으로는 할로겐램프보다 LED램프를 사용하는 것이 더 적합한 것으로 나타났다.

• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.57-63
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• 2007

Our research was performed in order to implement a new pointing device for human-computer interactions in a collaborative environments based on Tiled Display system. We mainly focused on tracking the position of an infrared light source and applying our system to various areas. More than simple functionality of mouse clicking and pointing, we developed a device that could be used to help people communicate better with the computer. The strong point of our system is that it could be implemented in any place where a camera can be installed. Due to the fact that this system processes only infrared light, computational overhead for LED recognition was very low. Furthermore, by analyzing user's movement, various actions are expected to be performed with more convenience. This system was tested for presentation and game control.

• Journal of Broadcast Engineering
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• v.14 no.4
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• pp.475-487
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• 2009

We propose a visible light road-to-vehicle communication system at intersection as one of ITS technique. In this system, the communication between vehicle and a LED traffic light is approached using LED traffic light as a transmitter, and on-vehicle high-speed camera as a receiver. The LEDs in the transmitter are emitted in 500Hz and those emitting LEDs are captured by a high-speed camera for making communication. Here, the luminance value of each LED in the transmitter should be found for consecutive frames to achieve effective communication. For this purpose, first the transmitter should be identified, then it should be tracked for consecutive frames while the vehicle is moving, by processing the images from the high-speed camera. In our previous work, the transmitter was identified by getting the subtraction of two consecutive frames. In this paper, we mainly introduce an algorithm to track the identified transmitter in consecutive frames. Experimental results using appropriate images showed the effectiveness of the proposal.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.577-582
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• 2012

Quinine quantitative analysis, photo-bleaching, fluorescence quenching, and urine analysis have been performed by means of a UV-LED fluorometer, which can be easily built and used in a high-school laboratory. The quinine detection range is estimated to be 0.05-80 ppm, enough for many classroom luminescence experiments. The quinine content in commercial tonic water is determined from the calibration curve, and UV photo-bleaching of this anti-malarial drug is demonstrated with clear wavelength dependence. Halide quenching of quinine fluorescence is also observed and the increase in quenching efficiency in the order of $Cl^-$, $Br^-$, and $I^-$ is evident. Urine analyses for the student volunteers have been carried out and the results clearly reveal excretion of the ingested quinine. The student participants are exuberant throughout the course of this study and sense the practices resourceful.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.6
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• pp.1224-1239
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• 2020

This study develops a wearable solar energy harvesting device that absorbs solar energy to generate and store power which can be used during outdoor activities by users even after dark. For this study, a prototype hat for outdoor activities at night was developed after the design of a solar energy harvesting generation, storage, and delivery system was designed that could store energy to light up LEDs. First, the main control board of the system was designed to integrate the charging function, the darkness detection circuit, the battery voltage sensing circuit, and the LED driving circuit in order to reduce bulkiness and minimize the connection structure. It was designed to increase convenience. Second, the system was designed as a wearable fashion product that connected each part with fiber bands and manufacturing it so as to be detachable from the hat. Third, charging and LED operation tests show that the battery is fully charged after 5 hours even in winter when the illuminance value is low. In addition, the LED operation experiment verified the effectiveness of a buffered system that could operate the LEDs for about 3 hours at night.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.73-75
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• 2009

본 논문은 영상 처리에 의해 광학렌즈의 먼지 및 이물질의 유무를 검출하기 위한 방법을 제안한다. 현재 사용되고 있는 비접촉 검사용 비젼 시스템은 마스크 기법을 활용하여 기준 영상에 비해 어느 정도의 잡음이 있는지를 검사한다. 그러나 조명의 정도, 반사 및 이물질의 유형에 따라 검출하기가 어렵다. 이를 해결하기 위해 파란색 LED 광원을 수평축에 설치하여 양각 부분의 에지들을 더욱 강조하는 시스템을 구현하였다. 이물질 검출은 간단한 소벨 에지 마스크를 사용하고 이물질의 크기에 따라 먼지 및 이물질에 대한 판단을 결정하였다. 크기 및 색상이 틀린 렌즈를 사용하여 실험한 결과 일반 영상에서 검출한 것보다 파란색 LED 광원과 영상처리에 의해 잡음 및 이물질을 강건하게 검출하여 렌즈의 자동 검사용 로봇 비젼 시스템에 적용이 가능하다.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1650-1655
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• 2007

A lights-out detector, which helps the person in charge of maintenance make a quick judgment in the event of a failure of LED-type traffic lights, was explored/developed and installed/ tested, at Seoul Metro, after they developed a patented pilot product in 2005; and, a product improvement test was conducted to ensure reasonable maintenance of signaling facilities. Having better compatibility with existing circuit in use and displaying stable load current, the device makes the maintenance of lights-out detection and alert easier.

• Journal of Korean Society on Water Environment
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• v.40 no.1
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• pp.19-35
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• 2024

The global pandemic, coronavirus disease caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to the implementation of wastewater surveillance as a means to monitor the spread of SARS-CoV-2 prevalence in the community. The challenging aspect of establishing wastewater surveillance requires a well-equipped laboratory for wastewater sample analysis. According to previous studies, RT-PCR-based molecular tests are the most widely used and popular detection method worldwide. However, this approach for the detection or quantification of SARS-CoV-2 from wastewater demands a specialized laboratory, skilled personnel, expensive instruments, and a workflow that typically takes 6 to 8 hours to provide results for a few samples. Rapid and reliable alternative detection methods are needed to enable less-well-qualified practitioners to set up and provide sensitive detection of SARS-CoV-2 within wastewater at regional laboratories. In some cases, the structural and molecular characteristics of SARS-CoV-2 are unknown, and various strategies for the correct diagnosis of COVID-19 have been proposed by research laboratories. The ongoing research and development of alternative and rapid technologies, namely RT-LAMP, ELISA, Biosensors, and GeneXpert, offer a wide range of potential options not only for SARS-CoV-2 detection but also for other viruses. This study aims to discuss the effective regional rapid detection and quantification methods in community wastewater.