• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 하계학술발표회
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• pp.64-67
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• 2004

The optics and opto-mechanics are disigned for imaging the sun at Lyman-${\alpha}$ line for scientific satellite. The optics are composed of conic mirrors. In order to block stary light. the new baffle design method is suggested. And we will present the opto-mechanics for this scientific satellite.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.383-387
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• 2010

The stereoscopic three-dimensional (3D) display provides a 3D image by inducing binocular disparity for the observers who wear special glasses. With the rapid progress in flat panel display technologies, the stereoscopic 3D display is becoming a new benefit-model of the current display industry, and several kinds of commercial stereoscopic 3D products have been released and are attracting people. Nowadays, the motion picture quality of the 3D image becomes as important as resolution or luminance since most of the commercial 3D products are 3D televisions or 3D monitors which are required to display a clear motion 3D image. In this paper, an analysis and simulation of the motion picture quality of stereoscopic 3D image is proposed, and a comparison of the motion picture performance among the current stereoscopic 3D technologies is also provided.

• Applied Microscopy
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• 제35권4호
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• pp.64-73
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• 2005

이 논문에서 한 결정체의 전위 결함에 형태를 결정짓는 인자들 (Burgers-벡터, Slip plane, 전위선 벡터)을, LACBED 방법과 전통적인 회절 빔 상 관찰에 의해, 어떻게 얻을 수 있는가에 대해 세세히 논의하였다. 이 방법은 기본적으로 Cherns과 Prestons의 규칙과 동역학적 회절이론에 입각한 공식에 의거한 LACBED 패턴 시뮬레이션이 따른다. 이 시뮬레이션 계산에서 필요에 따라 설정된 여러 근사들에 관해서도 역시 세세히 논의 하였다. 본 실험에 사용된 시료는 적적한 밀도로 분포된 전위 결함들을 많이 갖고 있는 순순 알루미늄이며, LACBED 실험에 적합한 것이다.

• 천문학회보
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• 제43권1호
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• pp.47.3-48
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• 2018

SPHEREx is a proposed MIDEX mission, planned to conduct spectral imaging survey to cover 0.75-5 um with a spectral resolution of R~40-135. We will briefly overview the uniqueness of SPHEREx data, and how Korean community can take advantage of it. We will present extragalactic science cases that can be addressed with SPHEREx dataset. In particular, SPHEREx survey will uniquely provide the variability information of bright QSOs, both in continuum and fluxes of emission lines, which enables us to investigate the central structures of QSOs through the reverberation mapping method. SPHEREx will also allow us to understand how supermassive black holes and host galaxies co-evolve, by discovering new high-z QSOs, and investigating star formation properties in nearby QSOs.

• 대한기계학회논문집B
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• 제27권7호
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• pp.829-836
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• 2003

Understanding of heat generation in semiconductor devices is important in the thermal management of integrated circuits and in the analysis of the device physics. Scanning thermal microscope was used to measure the temperature and the electric potential distribution on the cross-section of an operating metal-oxide-semiconductor field-effect transistor (MOSFET). The temperature distributions were measured both in DC and AC modes in order to take account of the leakage current. The measurement results showed that as the drain bias was increased the hot spot moved to the drain. The density of the iso-potential lines near the drain increased with the increase in the drain bias.

• 한국정밀공학회지
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• 제25권11호
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• pp.52-57
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• 2008

We demonstrate the operation of an apparatus that we call the laser scanning confocal microscopy. It is valuable tool of the investigations for imaging process. We measured the thin metal structure through the SCM manufacture. Confocal microscopy offers several advantages including shallow depth of field, elimination of out-of-focus glare, and the ability to collect serial optical sections from thick specimens than conventional optical microscope. This research is manufactured of scanning confocal microscopy and after measured of metal materials structure.

• 천문학회보
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• 제36권2호
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• pp.63.1-63.1
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• 2011

In understanding AGN physics, it is fundamental to determine black hole masses. Based on the gas kinematics of the broad-line region, black hole masses can be derived from the product of the width of the broad emission lines and the continuum/line luminosities. For a sample of 37 intermediate-luminosity AGN at z~0.4, we obtained high quality spectra (S/N~100) using the Low Resolution Imaging Spectrometer(LRIS) at the KECK telescope, in order to calibrate various black hole mass estimators based on the Mg II (2798A), the $H{\beta}$ (4861A), and the $H{\alpha}$ (6563$\bar{A}$) emission lines. Based on our multicomponent fitting analysis, we subtract continuum, FeII emission, and host galaxy starlight, reducing systematic errors in measuring emission line widths. Combining low S/N SDSS spectra with our high S/N keck spectra, we determine a set of ~30 black hole masses of the sample for each emission line. Then by comparing various sets of black hole masses, we internally calibrate each mass estimators and investigate uncertainties and limitations of each mass estimator.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.638-642
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• 2015

We present a simple method to determine the focal distances of lenses with the Talbot self-images. This method uses only one grating, and a priori knowledge of the period of the grating is replaced with a linear relation between the (de)magnified periods of the Talbot images and the lens-to-grating distance. A thick lens whose effective focal length is 500 mm was used to validate the method, and the focal distance of the converging beam was determined with the difference of 0.15% for the nominal focal distance of 521.9 mm. The determined period of the grating with the difference of 0.2% also supports the validation.

• Journal of Radiation Protection and Research
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• 제42권3호
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• pp.154-157
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• 2017

Background: Shielding properties of compound or mixture is presented in terms of mass attenuation coefficients using Monte Carlo simulation. Mass attenuation coefficients of cement, gypsum and the mixture of gypsum and $PbCO_3$ has been investigated using monte carlo MCNPX. Materials and Methods: The mass attenuation coefficients of cement, gypsum and the mixture of gypsum and $PbCO_3$ were calculated for photon energies 365.5, 661.6, 1,173.2, and 1,332.5 keV energies. Results and Discussion: The simulated values of mass attenuation coefficients were compared avaialable experimental results, theoretical values by XCOM and found good comparability of the results. Conclusion: Standard simulation geometry used in the present investigation would be very useful for various types of sample for shielding and dosimetry applications.

• 천문학회보
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• 제39권1호
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• pp.71.2-71.2
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• 2014

For better understanding of the physics of pores, we have investigated horizontal and vertical motions of plasma in a pore obtained on 2013 August 24 by using high time and spatial resolution data from the Fast Imaging Solar Spectrograph (FISS) of the 1.6 meter New Solar Telescope (NST). We infer the LOS velocity by applying the bisector method to the wings of Ca II 8542 ${\AA}$ profile, and inspect oscillations of the intensity and the LOS velocity in the pore. In this presentation, we discuss the physical implications of our results in view of a connection between LOS and horizontal plasma flows in a concentrated magnetic flux.