• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.115-122
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• 2012

In this paper, we demonstrate that indoor wireless optical communication is possible with lighting LEDs without a photo diode or a solar cell. A LED is used for both light emitting and light signal detection. This scheme is very useful because transmission is possible without any additional communication systems. In experiments, wireless optical communication will be carried out at a higher signal frequency of 5MHz using a lighting LEDs with both light emitting and light detection characteristics in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.571-574
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• 2012

optical wavelength analyzer design and implementation of this study is about. For experiments, the input light in the infrared, ultraviolet, visible as a light source was used. I-V Converting circuit configured as a photodiode. I-V Converting circuit voltage is measured. Measured voltage can be determined for a wavelength in size.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.3
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• pp.239-243
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• 2003

In this paper, an angle diversity wireless optical detector is realized that can receive the optical signal at an angle from 0 to 360 degrees. Eight photodiodes constitute an angle diversity receiver, and in order to reduce the voltage variation with the incident angle, the optical detector is stabilized with a digital potentiometer. In a stabilized state, the voltage variation is kept within 1/10 of maximum voltage. This configuration is very useful in constructing an omni-directional receiver in a wireless optical interconnection.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.29-30
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• 2012

The objectives of this study are to examine the variation of flame chemiluminescence on flame condition and to evaluate the possibility to apply the optical sensor for air/fuel ratio control. Flame chemiluminescence is one of the most important factor to judge the real time flame condition like a air/fuel ratio. In this paper, it is experimentally found that a strong relationship between the air/fuel ratio and optical element output (i.e., photo diode) should be existed. This is verified through the flame spectral analysis for various PD output signal.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.754-756
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• 1999

In this paper, we have developed a high-sensitivity SNRD(Semiconductor Nuclear Radiation Detector) using silicon PIN photodiode. The SNRD is constructed with silicon PIN photodiode(S3590-05), preamplifier and shaping amplifier. To show the effectiveness of SNRD, nuclear radiation experiments are conducted with $\gamma$-ray Ba-133, Cs-137 and Co-60. The SNRD is different in characteristics of the energy spectrum to scintillation detectors. However, the SNRD have a good linearity on $\gamma$-ray energy and activity. The results of this paper can be applied to electronic personal dosimeter.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.3-4
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• 2014

무선전력전송 회로는 부하의 변동에 따라 출력값을 알맞게 제어해 줄 필요가 있는데 송신부와 수신부 회로는 분리되어 있으므로 제어루프 또한 분리되어야 한다. 기존에는 주로 통신방식이나 부하측 변조를 이용한 1차측 제어를 사용하였다. 하지만 통신을 이용하는 경우 가격이 비싸고 시스템이 복잡하며, 부하측 변조 방식은 제어회로의 반응이 느리다는 단점이 있다. 본 논문은 2.5W급 전계결합형 무선전력회로에 대하여 LED 광학링크를 이용해 송신부의 스위칭 주파수를 제어하는 회로를 제안한다. 이 회로는 수신부에 포토다이오드와 연산증폭기를 내장하여 부하에 추가적인 배터리전원 없이 저가로 우수한 성능의 제어기를 구성할 수 있으며, 그 성능을 하드웨어로 검증하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.206-209
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• 2002

With the progress of semiconductor processing technology, avalanohe photodiodes (APDs) based on InP/InGaAs are used for high-speed optical receiver modules. Planar-type APDs give higher reliability than mesa-type APDs. However, Planar-type APDs are struggled with a problem of intensed electric field at the junction curvature, which causes edge breakdown phenomena at the junction periphery. In this paper, we focused on studying the effects of junction curvature for APDs performances by different etching processes followed by single diffusion to from p-n junction. The performance of each process is characterized by observing electric field profiles and carrier generation rates. From the results, it can be understood to predict the optimum structure, which can minimize edge breakdown and improve the manufacturability.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2353-2355
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• 2004

본 논문에서는 고정도의 방사선 측정이 가능한 능동형 전자선량계를 제작하기 위해 필수적으로 요구되는 반도체 방사선 검출기를 ASIC으로 구현하였다. 이는 전자선량계의 소형화와 저소비전력을 실현할 수 있도록 전치증폭기와 성형증폭기를 일체화한 것으로 방사선과 방사선 검출 소자인 상용 핀 포토다이오드의 상호작용으로 생성된 수 [nA]의 전류펄스를 측정할 수 있다. MOSIS 공정을 통하여 ASIC으로 구현된 방사선검출기는 $10{\mu}Ci$의 ${\gamma}$-선 Ba-133, Cs-137 및 Co-60의 세 핵종에 대하여 방사선 조사시험을 수행하여 구현된 방사선 검출기의 유용성을 입증하였다.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.791-796
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• 2001

Welding using lasers can be mass-produced in high speed. In the laser welding, performing real-time evaluation of the welding quality is very important in enhancing the efficiency of welding. In this study, the plasma and molten metal which are generated during laser welding were measured using the UV sensor and IR sensor. The results of laser welding were classified into five categories such as optimal heat input, little low heat input, low heat input, focus off, and nozzle change. Also, a system was formulated which uses the measured signals with a fuzzy pattern recognition method which is used to perform real-time evaluation of the welding quality and the defects which can occur in laser welding. Weld quality prediction program was developed using previous weld results and statistical program which could show the trend of weld quality and signal was developed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.4
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• pp.53-58
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• 2010

In this paper, the output characteristics of PSD(Position Sensetive Detector) used in measurement system are described. Most of the precision measurment systems are accomplished by a laser diode(LD), a photo diode(PD) and PSD(Position Sensetive Detector), which are used in reflection of mirror or projection of infrared spectrometer. But it is especially restricted by resolution of PD and PSD in nano-measurement. A new inclined light methods into the PSD are employed in the surface measurement system for increasing the resolution. As the results, we can know that the output characteristics of detective senser (PSD) become more than 2 or 3 times by changing inclined angle(range: 5 degree) compared with common angle. In addition, the experiment results are confirmed that the change of inclined angle is not affecting to the linearity and repeating.