• The Optical Journal
• /
• s.177
• /
• pp.41-45
• /
• 2020

• The Optical Journal
• /
• s.176
• /
• pp.44-48
• /
• 2020

• The Optical Journal
• /
• s.176
• /
• pp.34-36
• /
• 2020

• The Optical Journal
• /
• s.174
• /
• pp.31-32
• /
• 2019

뇌를 비롯한 인체 장기 내부에 존재하는 소량의 생체물질을 영상으로 확인할 수 있는 길이 열렸다. 이 기술이 미래에 상용화한다면 질병을 진단하는 데 전례 없는 새로운 관점을 제공할 수 있을 것으로 기대된다.

• The Optical Journal
• /
• s.174
• /
• pp.29-30
• /
• 2019

과학자들은 때론 이전까지 아무도 시도해보지 않은 어떤 것을 시험해볼 필요가 있다. 스위스 취리히연방공과대(ETH) 지구물리학연구소 안드레아스 피흐너 교수는 어둠 속에서 한 줄기 빛을 찾아냈다.

• Korean Journal of Optics and Photonics
• /
• v.20 no.2
• /
• pp.71-75
• /
• 2009

A compact electric field probe sensor incorporating two different electro-optic materials of $LiNbO_3$ and GaAs was proposed and fabricated, and it was used to measure the strength of the horizontal and vertical fields generated by a microstrip ring-resonator filter. The sensitivities of the sensors in $LiNbO_3$ and GaAs were $9.315{\mu}V/\sqrt{Hz}$ and ${\sim}49.346{\mu}V/\sqrt{Hz}$ respectively, and their signal to noise ratios were approximately ${\sim}50\;dB$ and ${\sim}40\;dB$ respectively. And the operating frequency range was up to ${\sim}1.2\;GHz$. The electric field profile for the test circuit was scanned and found to be in good agreement with that obtained by using the HFSS simulation.

• Journal of the Korea Computer Graphics Society
• /
• v.6 no.3
• /
• pp.9-15
• /
• 2000

We Propose a sensor fusion technique for motion capture system. In our system, two kinds of sensors are used for mutual assistance. Four magnetic sensors(markers) are attached on the upper arms and the back of the hands for assisting twelve optical sensors which are attached on the arms of a performer. The optical sensor information is not always complete because the optical markers can be hidden due to obstacles. In this case, magnetic sensor information is used to link discontinuous optical sensor information. We use a system identification techniques for modeling the relation between the sensors' signals. Dynamic systems are constructed from input-output data. We determine the best model from the set of candidate models using the canonical system identification techniques. Our approach is using a simple signal processing technique currently. In the future work, we will propose a new method using other signal processing techniques such as Wiener or Kalman filter.

• Korean Journal of Optics and Photonics
• /
• v.16 no.5
• /
• pp.433-439
• /
• 2005

We have developed a biosensor reading system using a white light source and a color-sensor. To reduce the environmental effect, we used the ratio of specific color intensity to the entire white light intensity. Also we could improve the responsibility of the system by controlling the amplification of the color sensor output.

• Proceedings of the KSRS Conference
• /
• 2007.03a
• /
• pp.20-24
• /
• 2007

센서의 광학 해상력에 따라 센서에 도달하는 에너지의 앙은 영상의 화소값으로 변환되므로，이 관계는 위성 영상의 정량적인 광학적 특성을 이해하기 위한 바탕이 되며，영상의 질을 유지하기 위한 척도가 되기도 한다. 위성영상의 광학적 특성은 ON 값 을 실제 지표물의 반사에너지 값인 Radiance와 Reflectance로 의 변환을 통하여 추정할 수 있으며，이러한 과정을 절대복사보정(Absolute Radiometric Calibration) 이라고 한다. 절대복사보정 과정에서 센서에 도달하는 태양 에너지의 양을 추정하기 위하여 복사전달모델이 사용된다. 태양 에너지가 대기를 통과함에 따라 여러 가지 상호 작용이 일어나게 되므로 복사 전달모델을 사용하기 위해서는 다양한 입력 변수가 필요하게 된다. 이러한 입력 변수로는 지표물의 반사율， 대기자료，그리고 센서의 특성 등이 포함되며， 이 연구에서는 KOMPSAT-2 위성의 MSC 영상의 절대복사보정 과정에서 복사전달모델의 결과에 영향을 미치는 입력 변수의 특성을 살펴보고자 한다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.40 no.2
• /
• pp.135-144
• /
• 2022

Since vegetation provides humans with various ecological spaces and is also very important in terms of water resources and climatic environment, many vegetation monitoring studies using vegetation indexes based on near infrared sensors have been conducted. Therefore, if the near infrared sensor is not provided, the vegetation monitoring study has a practical problem. In this study, to improve this problem, the NDVI (Normalized Difference Vegetation Index) was used as a reference to evaluate the accuracy of the vegetation index based on the optical sensor. First, the Kappa coefficient was calculated by overlapping the vegetation survey point surveyed in the field with the NDVI. As a result, the vegetation area with a threshold value of 0.6 or higher, which has the highest Kappa coefficient of 0.930, was evaluated based on optical sensor based vegetation index accuracy. It could be selected as standard data. As a result of selecting NDVI as reference data and comparing with vegetation index based on optical sensor, the Kappa coefficients at the threshold values of 0.04, 0.08, and 0.30 or higher were the highest, 0.713, 0.713, and 0.828, respectively. In particular, in the case of the RGBVI (Red Green Red Vegetation Index), the Kappa coefficient was high at 0.828. Therefore, it was found that the vegetation monitoring study using the optical sensor is possible even in environments where the near infrared sensor is not available.