• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.120.1-120.1
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• 2014

Fast-steering Secondary Mirror prototype (FSMP) of the Giant Magellan Telescope (GMT) has been developed by the consortium consisting of institutes in Korea and the US. In 2014 we are finalizing the FSMP project as combining two sub-systems, the mirror fabricated by Korea Research Institute of Standards and Science (KRISS) and the mirror cell with tip-tilt controlling system developed by Institute for Advanced Engineering (IAE), in the KRISS facility. In the assembly process we will identify potential difficulties or problems for the process, such that this process can be reflected to the further development of the FSM for GMT. In the presentation, we present how the assembly process can be carried out in safety.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.122-133
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• 2005

This study could begin with the improvement of computer graphic technology The graphic technology is the standards of computer technology level and up-to-date technology intensive. Above all, the technology of virtual reality has developed rapidly and the development of the program has changed from professional one only for the experts to easy of access ones for the space designers. Moreover, the program which major internet user's can experience the virtual model has been made, as the development of virtual reality technology that is based on the web. These graphic technology and the development of the web helped to extract human experiences on the space design step. However, to find the meeting point with real recognition is not easy though the virtual reality technology develops. Because the real space is made up of various senses that people feel in their surroundings. But, this study was possible because most of the space recognition is based on the visual organ, even though it can't satisfy all sensible factors that we feel in reality. Therefore, the significant of this study is the standards and criteria of evaluation, the technological proposal, expecting to make more advanced alternative design than before.

• Journal of Astronomy and Space Sciences
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• v.27 no.2
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• pp.153-160
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• 2010

We modified the optical system of 500 mm wide-field telescope of which point spread function showed an irregularity. The telescope has been operated for Near Earth Space Survey (NESS) located at Siding Spring Observatory (SSO) in Australia, and the optical system was brought back to Korea in January 2008. After performing a numerical simulation with the tested value of surface figure error of the primary mirror using optical design program, we found that the surface figure error of the mirror should be fabricated less than root mean square (RMS) $\lambda$/10 in order to obtain a stellar full width at half maximum (FWHM) below $28\;{\mu}m$. However, we started to figure the mirror for the target value of RMS $\lambda$/20, because system surface figure error would be increased by the error induced by the optical axis adjustment, mirror cell installation, and others. The radius of curvature of the primary mirror was 1,946 mm after the correction. Its measured surface figure error was less than RMS $\lambda$/20 on the table of polishing machine, and RMS $\lambda$/15 after installation in the primary mirror cell. A test observation performed at Daeduk Observatory at Korea Astronomy and Space Science Institute by utilizing the exiting mount, and resulted in $39.8\;{\mu}m$ of stellar FWHM. It was larger than the value from numerical simulation, and showed wing-shaped stellar image. It turned out that the measured-curvature of the secondary mirror, 1,820 mm, was not the same as the designed one, 1,795.977 mm. We fabricated the secondary mirror to the designed value, and finally obtained a stellar FWHM of $27\;{\mu}m$ after re-installation of the optical system into SSO NESS Observatory in Australia.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.119-127
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• 2009

There have been about 450 atomic frequency standards (or atomic clocks) launched into orbit for the use on communications and scientific payloads since 1970's. GPS satellites carry on-board Rubidium and Cesium atomic frequency standards which are utilized for the precise positioning and timing. The evolving technologies of space qualified atomic frequency standards have enhanced in the performance, reliability, and lifetime of satellites. In this paper we describe the fundamentals and performance of the atomic frequency standards, and introduce the atomic frequency standards which are presently on-board various satellites systems. We also present the GPS time scale and its applications.

• Journal of the Korean Institute of Educational Facilities
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• v.17 no.3
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• pp.3-11
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• 2010

This survey study aims to explore the school area standards for elementary, middle and high schools. Traditionally the school site has been recognized as a space of teaching and learning for students. Though its functions and needs have recently been changing from the areas for physical education and training to for various activities such as recreation, play, communication, informal and social areas etc. Moreover the school site is also a critical component of community life. Many communities have a significant shortfall in the amount of park and open space land available and accessible for use. In this viewpoint the standards of school facilities should develop a comprehensive approach to insure that students and residents are provided the opportunity to engage in appropriate types and amounts of everyday's activities during the school day and after school. In doing so, it surveys the school areas of the existing schools and the new schools built in Dongtan City. Finally, it points out the problems of government's regulation for school facilities and proposes the adequate directions for school area standards. This study would help to plan the optimum size of school area and ground and the reasonable expenditure for school facilities.

• Bulletin of the Korean Space Science Society
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• 2008.04a
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• pp.26.1-26.1
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• 2008

• Korean Journal of Optics and Photonics
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• v.21 no.5
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• pp.214-223
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• 2010

Optimization of a 30 cm lightweight mirror was proposed with the best optical performance under various loads of gravity and thermal loads with proper boundary conditions. A pattern for a lightweight mirror was generated based on the best optical performance combined with ease of manufacturing for proper design parameters of physical properties of face sheet, back sheet, rib, and web. Evaluation of the optical performances of a telescope mirror was obtained by using the finite element analysis program, NX I-DEAS. Surface errors, individual aberration terms, such as piston, tilts, focus and other aberrations were calculated by using Zernike polynomials. The proposed telescope mirror meets well the opto-mechanical design consideration of RMS surface error less than 16 nm.

• Korean Journal of Optics and Photonics
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• v.18 no.1
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• pp.37-43
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• 2007

We developed the equipment to measure the MTF(modulation transfer function) of an optical system for automatically inspecting the surface condition of an LCD substrate. We have made an object generator with USAF(United States Air Force) targets of three bar patterns and an integrating sphere, and an image analyzer with a 2 dimensional CCD(charge coupled device) and a relay lens. The MTF of the lens under test was obtained by correcting the measured CTF(contrast transfer function) which is the ratio of the contrast in the image of the USAF target to the contrast in the object. We have measured an optical system of F/13.65 (2.6x), the MTF are 30.6 % tangential plane and 26.1 % sagittal plane at 62.5 1p/mm.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.310-314
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• 2008

The light from the exterior considerably deteriorates the performance of displays including PDP (plasma display panel). Thus semi-conductor industries have developed a special optical film that can block or absorb the exterior light. In this paper, we propose a new inspection system for tracing the defects of the film. Our system is able to inspect a $1.5\;m\;{\times}\;1\;m$ area for 10 sec with $127\;{\mu}m\;{\times}\;50{\mu}m$ spatial resolution.

• Journal of the Korean Dietetic Association
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• v.9 no.3
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• pp.219-232
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• 2003

The purposes of this study were to assess the child care centers' foodservice facility, and to develop the kitchen facility model based on the general sanitation standards and guidelines in order to provide basic information for a plan review to build or renovate child care centers' foodservice facility. The scopes of the study include : 1) field assessment of the foodservice management practices and facilities in 8 public child care centers, and 2 private child care centers which they are subsidized from the government as public child care centers, 2) development of child care centers' kitchen facility model based on the General Sanitation Standards and Guidelines. The results of this study can be summarized as follows : 1. Field Assessment of the Child Care Centers' Foodservice Facility Average number of children in child care centers was 78.0$\pm$24.20, the average space of kitchen was 15.13$\pm$4.25($m^2$). Especially, the average space of kitchen was 18.49$\pm$4.35($m^2$) with enrollment capacity of 90～120 children in child care centers. The inventory level of most foods was relatively low except rice and kimchi. Kitchen facilities and equipments were similar to those of home kitchen and did not meet the standards of institutional practice. Therefore, the director in child care centers should recognize the importance of the sanitation management and pay more attention to the renovation of foodservice facilities as well as sanitation management practices. 2. Development of the Kitchen Facility Model based on the General Sanitation Standards and Guidelines The kitchen facility plan model with enrollment capacity of 100 children was developed based on the results of field assessment and literature review. Suggested kitchen space was 34.16$m^2$(6,100mm×5,600mm). This space was bigger than the results of field survey or precedent study, considered appropriate to implement the general sanitation standards. The main feature of the developed kitchen facility plan and model was product flow in one direction from the arrival of the raw material to the finished product in order to prevent cross contamination and to improve working efficiency.