• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.262-271
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• 2024

In this paper, by applying deep learning, one of the A.I. techniques, through angle information, which is optical observation data generated when observing satellites at observatories, distance information from observatories is learned to predict range data, thereby increasing the precision of satellite's orbit determination. To this end, we generated observational data from GMAT, reduced the learning data error of deep learning through preprocessing of the generated observational data, and conducted deep learning through MATLAB. Based on the predicted distance information from learning, trajectory determination was performed using an extended Kalman filter, one of the filtering techniques for trajectory determination, through GMAT. The reliability of the model was verified by comparing and analyzing the orbital determination with angular information without distance information and the orbital determination result with predicted distance information from the model.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.56.1-56.1
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• 2015

We are at the initial performance-verification phase of our KMTNet Supernova Project (KSP) using the three wide-field telescopes of the KMTNet in the southern hemisphere. The primary science objectives of KSP, which take advantage of its unique 24-hour continuous sky coverage, are to study early (i.e., within a few hours from explosion) and rare/peculiar (e.g. fast decay) supernovae (SNe), SN progenitors, explosion mechanisms, as well as other exotic optical transients. We present the initial status/results of the program, along with the program strategy, science objectives, target fields, and future plan. While the target field selection will be made based on the performance of the system and consideration of various scientific merits, the initial target fields are focused on nearby galaxies with increased cadence and filter coverage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.500-503
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• 2012

스마트폰은 폭발적인 성장세와 더불어 어플리케이션의 시장규모가 크게 증대될 것으로 예상된다. 본 논문에서는 직접 사진을 캡처 시킨 문자들을 텍스트로 변환시켜주고 데이터베이스를 이용해서 그 문자들의 의미를 표현하는 어플리케이션을 구현한다. 어플리케이션의 기능으로는 텍스트로 변환하고자 하는 사진을 찍거나 혹은 앨범에 있는 사진을 불러내어 텍스트로 변환을 시켜서 상대방에게 메시지나 블루투스 등을 이용하여 전송을 가능하게 해줄 수 있으며, 글꼴을 바꾼다거나 크기 등 편집 기능까지 추가적으로 가능하도록 할 수 있다. 이 어플리케이션으로 인한 효과로 인터넷이나 거리를 돌아다니다가 원하는 문구가 있으면 바로 원하는 상대방에게 쉽고 간편하고 빠르게 전달할 수 있는 편리함 등이 있다.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1103-1107
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• 2004

Last year, we introduced a TFT-LCD with RGBW color system. The primary advantage of the RGBW system is that its optical efficiency is at least 50% higher than the RGB system. However, it is not a simple task to incorporate the new color system into the infrastructure of the RGB system: the driving circuitry, fabrication of color filter, and color conversion. In this report, the practical hurdles are discussed and the solutions are presented.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.315-319
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• 2007

This paper presents a algorithm, what is able to recognize 4 different continuous human motion using a single stationary camera as input. For the first step, we acquire images from a camera. To enhance the image, we perform preprocessing which deals with removing noise using median filter, thresholding. And then morphological operations are performed to remove which small blobs and eliminates small holes. At the forth step, blobs are analysed to extracts for foreground region. Then, motions are predicted from these images by using optical flow technique, and the predicted motion data are refined by comparing our cardboard models so as to judge behavior pattern.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.71-72
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• 2003

The aim of our study is to prepare nanocomposites consisting polymer/inorganic nanoparticles and investigate their physical properties as a functional material. In this study, a nanocomposite of copper sulfide (CuS) nanoparticles introduced into a poly(acrylic acid) matrix was prepared and the optical absorption property was measured. The composite exhibited strong absorption of both ultraviolet and near-infrared rays, indicating that the composite is applicable to a solar radiation shielding filter. The wavelength of the near infrared absorption was controlled from ca.1000 nm to 1700 nm by heat and acidic solution treatments.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.811-816
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• 2004

The tactile force sensor was studied using Fiber Bragg Grating (FBG). The FBG is able to multiplex easily and is immune to electromagnetic environment. A sensor frame was designed to a cantilever beam type. Strain of a beam is related with the peak shift of a bragg wavelength. Finite Element Method (FEM) was used for getting an appropriate thickness from 0.2 mm to 0.3 mm thick. FEM results showed that 0.3 mm thick was suitable for the force range 10 N. The force resolutions of 0.039 N and 0.113 N were obtained with optical spectrum analyser and tunable Fabry-Perot filter, respectively.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.995-998
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• 2017

본 논문에서는 객체 추적이 가능한 쿼드콥터의 구현에 대하여 연구하였다. 드론의 안정적인 호버링 및 영상촬영을 위하여 쿼드로터의 비행원리와 PID 제어에 대한 이론을 연구하고 보다 안전한 실험환경 구성을 위한 Solution을 제시하였다. 또한 색 정보와 광흐름(Optical Flow) 기법을 공간 주파수 영역의 영상처리 방법(Nonlinear Matched Filter)과 융합하여 객체추적 하는 방법을 연구하였다.

• Journal of Biomedical Engineering Research
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• v.30 no.2
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• pp.113-121
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• 2009

This study aims at designing and evaluating light source devices that can stably generate light with various wavelengths in order to make possible PDD using a photosensitizer and diagnosis using auto-fluorescence. The light source was a Xenon lamp and filter wheel, composed of an optical output control through Iris and filters with several wavelength bands. It also makes the inducement of auto-fluorescence possible because it is designed to generate a wavelength band of 380-420nm, 430-480nm, and 480-560nm. The transmission part of the light source was developed to enhance the efficiency of light transmission. To evaluate this light source, the characteristics of light output and wavelength band were verified. To validate the capability of this device as PDD, the detection of auto-fluorescence using mouse models was performed.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.29.2-29.2
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• 2008

The CCD photometric observations of the W UMa type contact binary GX Aur were performed for 33 nights from 2004 to 2008 using a 2K CCD camera and Johnson BVRI filter system attached to the 61cm reflector at Sobaeksan Optical Astronomy Observatory (SOAO). From our observations, the first BVRI light curves of GX Aur were completed and eight new times of minima (primary: 4, secondary: 4) were obtained. All the times of minima including our timings were collected and analyzed to see the dynamical behavior of GX Aur system. Intensive analysis of our BVRI lightcurves with the recent Wilson-Devinney binary model shows that GX Aur is an over-contact binary whose component stars have equal mass and time-variable spots.