• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.81-82
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• 2008

The projection-type integral imaging system using mirror array is studied at the viewpoint of the aperture ratio of system. The aperture ratio which is determined by the relation of the specifications of the projection lens and the elemental mirrors affects the viewing quality of integral imaging system. This factors play an important role in the system design.

• Journal of the Optical Society of Korea
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• v.5 no.3
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• pp.90-92
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• 2001

Direct and inverse mathematical operators of stereo transformation (stereo operators) are studied in this paper. The stereo operators install a one-to-one correspondence between three dimensional coordinates of any point in space and the stereo coordinates which can be displayed on the screen under the given conditions, i.e. stereo vision base and the position of viewer. The stereo operators can be applied to the analyses of stereoscopic image distortions when the stereo vision base and the position of viewer are changed.

• International Journal of Stem Cells
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• v.16 no.4
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• pp.363-375
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• 2023

Stem cells are the foundational cells for every organ and tissue in our body. Cell-based therapeutics using stem cells in regenerative medicine have received attracting attention as a possible treatment for various diseases caused by congenital defects. Stem cells such as induced pluripotent stem cells (iPSCs) as well as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), and neuroprogenitors stem cells (NSCs) have recently been studied in various ways as a cell-based therapeutic agent. When various stem cells are transplanted into a living body, they can differentiate and perform complex functions. For stem cell transplantation, it is essential to determine the suitability of the stem cell-based treatment by evaluating the origin of stem, the route of administration, in vivo bio-distribution, transplanted cell survival, function, and mobility. Currently, these various stem cells are being imaged in vivo through various molecular imaging methods. Various imaging modalities such as optical imaging, magnetic resonance imaging (MRI), ultrasound (US), positron emission tomography (PET), and single-photon emission computed tomography (SPECT) have been introduced for the application of various stem cell imaging. In this review, we discuss the principles and recent advances of in vivo molecular imaging for application of stem cell research.

• Journal of the Optical Society of Korea
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• v.17 no.2
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• pp.142-147
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• 2013

In order to deduce the difficulty of fixing the Ritchey-Chretien (R-C) dual reflective optical system and enhance the stability of the secondary mirror, a compact integral structure is presented here composed of two transmitting and two reflective aspheric surfaces. The four surfaces were manufactured from a single germanium lens and integrated together. The two reflective surfaces formed by coating the inner reflecting films were assembled in one lens. It makes the installation of the two mirrors easier and the structure of the secondary mirror more stable. A design of mid-wave infrared (MWIR) compact imaging system is presented with a spectral range chosen as $3.7-4.8{\mu}m$. The effective focal length is f=90 mm. The field of view (FOV) for the lens is $4.88^{\circ}$. It has good imaging capability with Modulation Transfer Function (MTF) of all field of view more than 0.55 close to the diffraction limitation. Outdoor experiments were carried out and it is shown that the integral catadioptric optical system performs well on imaging.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.145-146
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• 2012

We present the results from B-, R-, I-, J- and H-band observations of the NEP-Wide survey field. The NEP-Wide survey is an AKARI survey of the North Ecliptic Pole covering ~ 5 square degrees area. Our optical/NIR imaging supports the AKARI IR imaging data by providing a crucial coverage in the optical/NIR. The optical data were obtained in 2007 using the 1.5 m telescope and SNUCAM at Maidanak Observatory, Uzbekistan. The NIR data were obtained in 2008 with FLAMINGOS on the KPNO 2.1 m telescope. We used IRAF, SExtractor, SCAMP, and SWarp for reducing the raw data, I-band fringe pattern removal, astrometry, standard photometry calibration, and source detection. Our optical-NIR data reach the depths of B ~ 23.4, R ~ 23.1, I ~ 22.3, J ~ 21.05, and H ~ 20.64 AB mag at 5-sigma. Here, we present the astrometric accuracy, galaxy number counts, completeness, and reliability, as well as redshift tracks of some normal galaxies and quasars on the B - R vs. R - I color-color diagram. The photometric data are being used for identifying optical counterparts of the IR data provided by AKARI, studying their SEDs, and selecting interesting objects for spectroscopic follow-up studies.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.691-697
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• 2014

Optical measurements of the morphological and biochemical imaging of phytoplankton are presented. Employing quantitative phase imaging techniques, 3-D refractive index maps and high-resolution 2-D quantitative phase images of individual live phytoplankton are simultaneously obtained without exogenous labeling agents. In addition, biochemical information of individual phytoplankton including volume, mass, and density of individual phytoplankton are also quantitatively obtained from the measured refractive index distributions. We expect the present method to become a powerful tool for the study of phytoplankton.

• The Optical Journal
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• s.97
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• pp.48-52
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• 2005

한국광학기기협회는 한·일 광학산업기술협력사업중 대일 시장개척단 사업의 일환으로 지난 3월 17일부터 20일까지 일본 동경에서 열린‘Photo Imaging Expo 2005’에 국내업체 11개사와 한국공동관으로 참가한데 이어, 지난 4월 13일부터 16일까지 러시아 모스크바 국제컨벤션센터(SOKOLNIKI)에서 개최된 모스크바 사진영상기자재전(Photo Forum 2005)에 올해 처음으로 국내 업체 8개사와 한국공동관으로 참가, 우리 제품의 우수성을 세계 시장에 널리 알리고 수출활성화의 교두보를 마련했다.

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.259-260
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• 2007

In this paper, we propose a novel computational integral imaging reconstruction (CIIR) method using round-type mapping model. Proposed CIIP method can overcome problems of non-uniformly reconstructed images caused from the conventional method and improve the resoulution of 3-D images. To show the usefulness of the proposed method, both computational experiment and optical experiment are carried out and their results are presented.

• Journal of Astronomy and Space Sciences
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• v.29 no.1
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• pp.85-91
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• 2012

Optical interferometry and polarimetry have separately provided new insights into stellar astronomy, especially in the fields of fundamental parameters and atmospheric models. We present: scientific justifications for "full-Stokes" optical interferometric polarimetry (OIP); updated instrument requirements; preliminary beam combiner designs; polarimeter design; end-to-end OIP data reduction; and realistic reimaged full-Stokes models of Be stars with a suitable number of telescopes plus noise sources. All of this work represents preliminary research to construct an OIP beam combiner.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12S
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• pp.1261-1267
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• 2003

Since the grating optical low-pass fillet degrades the resolution of images, we developed a hologram optical low-pass filter that show low degradation of the image and studied its characteristics. We designed the hologram that divides input beam into circular shaped 21 beams with a Monte-Carlo based hologram generation program and calculated its MTE characteristics to compare it with that of a grating filter. The hologram was manufactured through the optical lithography process and attached to a digital imaging device (Zoran 732212) for measurement. The moirfiltering is compared with zone plate images and the resolution loss is measured with USAF resolution chart. The hologram optical low-pass filter showed better characteristics in both moly filtering and resolution.