• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.153.2-153.2
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• 2011

The IGRINS (Immersion GRating INfrared Spectrometer) is a high resolution wide-band infrared spectrograph developed by Korea Astronomy and Space Science Institute (KASI) and the University of Texas at Austin (UT). Immersion grating is a key component of IGRINS, which disperses the input ray by using a Silicon material with a lithography technology. Opto-mechanical mount for the immersion grating is important to keep the high spectral resolution and the optical alignment in a cold temperature of $130{\pm}0.06K$. The optical performance of immersion grating can maintain within the de-center tolerance of ${\pm}0.05mm$ and the tip-tilt tolerance of ${\pm}1.5arcmin$. The mount mechanism utilizes the flexure and the kinematic support design to satisfy the requirement and the operation condition. When the IGRINS system is cooled down to a cold temperature, three flexures compensate the thermal contraction stress due to the different material between the immersion grating and the mounting part(Aluminum 6061). They also support the immersion grating by an appropriate preload. Thermal stability is controlled by a copper strap with proper dimensions and a heater. Generally structural and thermal analysis was performed to confirm the mount mechanism. This talk presents the opto-mechanical mount design of the immersion grating of IGRINS.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.2
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• pp.141-157
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• 2012

For the application TBM tunneling method, Both tunnel design standard and case study designed & constructed in domestic and foreign have been conducted. According to the study, the number of lane and inner shape (single or duplex) vary depending on the volume of traffic. Also extra space located in the top and bottom of tunnel is used for a multipurpose such as ventilation, disaster prevention, maintenance and administration. To find area ratio according to the components of road TBM tunnel, a standard section was considered as a two-lane road. Then, the analysis of area ratio of this section which consists of components for clearance, extra space in upper and lower tunnel was carried on two widths of shoulder. In addition, after a structural analysis, a thickness requirement of lower slab which is essential for road tunnel was derived on a few supporting types. Through correlation analysis, the ranges of available cross-sectional area between slab thickness and lower extra space of the tunnel was presented.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.71-80
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• 2006

The land area, which is on the inner side of the water line, is controlled to a certain degree due to the purposes of space utilities controllers' respective roles, but the sea area is not so much controlled as the land area. However, as interest in the security and utility of the marine space, as well as that in the consistent development of the land space, has increased, there has been increase of the requirement for information about marine data and environment. The object of this study, Busan, plays various roles such as a harbor and bay, a tourist resort, and a port unlike coastal seas of other areas, and thus needs systematic control because it has numerous environmental factors. However, there are limitations in the number of data about Busan coastal sea constantly provided while the acquisition of data from main points and many areas is important for the analysis of marine contamination in Busan coastal sea area. Thus, using nautical charts with numerical values in preparing increase of the demand of them according to the degree of information requirement for the analysis of the changes in coastal areas, this study constructs property data and space data by combining vertex data about Busan's 17 coastal sea areas provided by NFRDI, and tries to present the analytical techniques for grasping the environmental conditions and continuity of the coastal areas and methods of their utilities, using GIS Geostatistical Analysis Technique.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.97-101
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• 2011

Interplanetary space between Sun and Earth is area of flowing very fast solar wind which is contained X ray, flare, corona mass, etc. occurred Sun surface to Earth. This solar wind is affected directly to Earth magnetosphere and ionosphere so that this bring out broadcasting and communication interruptions, satellite operation obstacles and power gird defects and etc..Solar wind flow in interplanetary space is measured as solar wind speed, density and direction by measuring scintillation value to be produced during radio source is passed through solar wind. The wider effective collective areas and the more radio sources, accuracy of solar wind measuring is got higher. Function test was performed using 3 tiles which was manufactured as prototype. Restriction of quantity of tiles, test was performed to confirm whether measured beam pattern is complied with requirement or not. In this paper, it is shown design and their specification of ground interplanetary radio measurement system as well as technical issues and resolutions which were raised during design phase. Also result of function verification test using prototype is suggested. It is confirmed that measured beam pattern was met with requirement.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.49.1-49.1
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• 2014

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is the near-infrared instrument onboard NEXTSat-1 which is being developed by KASI. The imaging low-resolution spectroscopic observation in the near-infrared range for nearby galaxies, low background regions, star-forming regions and so on will be performed on orbit. After the System Requirement Review, the optical design is changed from on-axis to the off-axis telescope which has a wide field of view (2 deg. ${\times}$ 2 deg.) as well as the wide wavelength range from 0.95 to $3.8{\mu}m$. The mechanical structure is considered to endure the launching condition as well as the space environment. The design of relay optics is optimized to maintain the uniform optical performance in the required wavelength range. The stray light analysis is being made to evade a light outside a field of view. The dewar is designed to operate the infrared detector at 80K stage. From the thermal analysis, we confirmed that the telescope can be cooled down to around 200K in order to reduce the large amount of thermal noise. Here, we report the current status of the NISS development.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.11
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• pp.88-94
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• 2005

This paper is a study on the blade-type optical bench satisfying stiffness and thermal pointing error requirements for earth observation satellite. According to shape requirements, optical bench is designed. Because it does not satisfy the stiffness requirement, the stiffener is added on the outer/inner area of optical bench. But it does not meet the thermal pointing error requirement. So symmetrical structure is suggested with platform support structure attached on the upper/lower part of platform. Although it has better value than previous case, it still does not meet the thermal pointing error requirement. Based on the results of prior cases, optical bench finally designed, which satisfied both the stiffness and thermal pointing error requirements. Next conclusions follow from this design. It is efficient to increase thickness of platform facesheet, add stiffener and increase blade number to raise stiffness. It is effective to connect component consisting of same material and design optical bench having symmetrical structure to lower thermal pointing error.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.4
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• pp.131-141
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• 2014

Over the last decade, the Global Navigation Satellite System (GNSS) has been increasingly utilized as a meteorological research tool. The Korea Astronomy and Space Science Institute (KASI) has also been developing a near real-time GNSS precipitable water vapor (PWV) information management system that can produce a precise PWV for the Korean Peninsula region using GNSS data processing and meteorological measurements. The goal of this paper is to evaluate whether the precise point positioning (PPP) strategy will be used as the new data processing strategy of the GNSS-PWV information management system. For this purpose, quality assessment has been performed by means of a comparative analysis of the troposphere zenith total delay (ZTD) estimates from KASI PPP solutions (KPS), KASI network solutions (KNS), and International GNSS Service (IGS) final troposphere products (IFTP) for ten permanent GNSS stations in the Korean Peninsula. The assessment consists largely of two steps: First, the troposphere ZTD of the KNS are compared to those of the IFTP for only DAEJ and SUWN, in which the IFTP are used as the reference. Second, the KPS are compared to the KNS for all ten GNSS stations. In this step, the KNS are used as a new reference rather than the IFTP, because it was proved in the previous step that the KNS can be a suitable reference. As a result, it was found that the ZTD values from both the KPS and the KNS followed the same overall pattern, with an RMS of 5.36 mm. When the average RMS was converted into an error of GNSS-PWV by considering the typical ratio of zenith wet delay and PWV, the GNSS-PWV error met the requirement for PWV accuracy in this application. Therefore, the PPP strategy can be used as a new data processing strategy in the near real-time GNSS-PWV information management system.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.169-185
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• 2023

The GMT-Consortium Large Earth Finder (G-CLEF) is the first instrument for the Giant Magellan Telescope (GMT). G-CLEF is a fiber feed, optical band echelle spectrograph that is capable of extremely precise radial velocity measurement. G-CLEF Flexure Control Camera (FCC) is included as a part in G-CLEF Front End Assembly (GCFEA), which monitors the field images focused on a fiber mirror to control the flexure and the focus errors within GCFEA. FCC consists of an optical bench on which five optical components are installed. The order of the optical train is: a collimator, neutral density filters, a focus analyzer, a reimager and a detector (Andor iKon-L 936 CCD camera). The collimator consists of a triplet lens and receives the beam reflected by a fiber mirror. The neutral density filters make it possible a broad range star brightness as a target or a guide. The focus analyzer is used to measure a focus offset. The reimager focuses the beam from the collimator onto the CCD detector focal plane. The detector module includes a linear translator and a field de-rotator. We performed thermoelastic stress analysis for lenses and their mounts to confirm the physical safety of the lens materials. We also conducted the global structure analysis for various gravitational orientations to verify the image stability requirement during the operation of the telescope and the instrument. In this article, we present the opto-mechanical detailed design of G-CLEF FCC and describe the consequence of the numerical finite element analyses for the design.

• Korea Science and Art Forum
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• v.19
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• pp.405-415
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• 2015

Recently the development of China has attracted all over the world, many scholars of different areas are interested in Chinese Culture and Chinese Market. After sixties of last century development of the economic of the South Korea closer to modernization, but there are many problems, one of them is the urban living style boasts of the features of concentration. Because of this phenomenon the lack of housing space become more serious. It also come to be a social problems. Therefore narrow residential area become inevitability. At the same time, effective utilization of housing space become a demand. Especially for those families with limited living space, it's meaningful for them. Between the China and the South Korea. Chinese have the same situation too, the different is kitchen space of chinese is closed. It means they have to cook in limited space. With increased supplies and more small appliances, an inevitable requirement is opening out the kitchen space, but unreasonable furnishings and living space reduces the efficiency of the kitchen, which has led to the discontent of users. From this, base on the investigation and analysis of diet&living space of most chinese apartment, and through differences kinds and places of storage items. With them I would combine the food culture and feature of storage space of China to solve problems of the efficiency of the kitchen.

• Korean Security Journal
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• no.30
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• pp.117-138
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• 2012

To cope with rapidly increasing crimes, the Smart-home system has become common to minimize and prevent crimes in the residential space. Accordingly, the interest on the security-related Smart-home system is also increasing. First is the establishment of Smart-home security standard. At present, the Smart-home security systems are implemented by individual policies of construction companies or by the requirement of residents. Each construction company has their own characteristics in the Smart-home security system; while there is no standardized system. Second is the introduction of Smart-home security certificate system. Like people have certificates, now the residential spaces may also need certificates. A certificate system that represents the performance of residential spaces cannot be an absolute criterion in the evaluation of apartment quality, however, it can be a basic requirement for the convenient residential environment and policies being implemented by the government. If a certificate system would be introduced, construction companies will compete with each other to provide with better security system and apartment operation companies will hire more specialized security personnel in order to get higher certificates. Consequently, better security of residential space will be secured. It is also required to develop and establish response measures by studying the key changes and trends of Smart-home security system. The advance in mechanical security devices will bring about more changes in the future. Therefore, more various in-depth studies are required on the basic specifications of security system in the residential spaces.