• Journal of Astronomy and Space Sciences
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• v.29 no.3
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• pp.287-293
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• 2012

Satellite operating agencies are constantly monitoring conjunctions between satellites and space objects. Two line element (TLE) data, published by the Joint Space Operations Center of the United States Strategic Command, are available as raw data for a preliminary analysis of initial conjunction with a space object without any orbital information. However, there exist several sorts of uncertainties in the TLE data. In this paper, we suggest and analyze a method for estimating the uncertainties in the TLE data through mean, standard deviation of state vector residuals and covariance matrix. Also the estimation results are compared with actual results of orbit determination to validate the estimation method. Characteristics of the state vector residuals depending on the orbital elements are examined by applying the analysis to several satellites in various orbits. Main source of difference between the covariance matrices are also analyzed by comparing the matrices. Particularly, for the Korea Multi-Purpose Satellite-2, we examine the characteristics of the residual variation of state vector and covariance matrix depending on the orbital elements. It is confirmed that a realistic consideration on the space situation of space objects is possible using information from the analysis of mean, standard deviation of the state vector residuals of TLE and covariance matrix.

• Korean Institute of Interior Design Journal
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• no.18
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• pp.103-109
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• 1999

The purpose of this research is to suggest the ultimate solution to the interior elements and ways to express specific function within interior design of the new high-speed train station in Korea through careful studies based on the characteristics of each areas in the stations. During the research, it became very clear that the most important points in designing of the high speed train station's interior space can be found from close examination on whether each space allocation was thoughtfully organized to provide enough space to accommodate various activities of the users. Another point is to realize, within the space program, that there should be a clear understanding of the future expansion plan and reserving sufficient areas for the future growth. Also the problem of requiring larger floor areas to accommodate various functions divided by separate units must be recognized simultaneously during the programming. The new high-sped train must be able to function as a multi service facility of the future. In summary this research is to present datas and suggestion to various areas in the station and redefine its new meaning of train station space program with much borader concept which can be adopted to the process of better space programing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.7
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• pp.601-608
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• 2015

The static aeroelastic analysis and optimization of flexible wings are conducted for steady state conditions while both aerodynamic and structural parameters can be used as optimization variables. The system of multidisciplinary design optimization as a robust methodology to couple commercial codes for a static aeroelastic optimization purpose to yield a convenient adaptation to engineering applications is developed. Aspect ratio, taper ratio, sweepback angle are chosen as optimization variables and the skin thickness of the wing. The real-coded adaptive range multi-objective genetic algorithm code, which represents the global multi-objective optimization algorithm, was used to control the optimization process. The support vector regression(SVR) is applied for optimization, in order to reduce the time of computation. For this multi-objective design optimization problem, numerical results show that several useful Pareto optimal designs exist for the flexible wing.

• Korean Institute of Interior Design Journal
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• v.21 no.4
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• pp.12-20
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• 2012

The aim of this study is to review phenomenological characteristics in Steven Holl's architecture through his design of St. Ignatius Chapel at Seattle University. To obtain this purpose, an analytical frame based on Holl's theory of phenomenological architecture is suggested to have a systematic study for St. Ignatius chapel. This chapel can be a good example of phenomenological architecture in that it is based on the concept of 'A Gathering of Different Lights' related to phenomenology and considered perception including multi sensory (as well as vision) as primary factors from site and program interpretation to spatial configuration. Unprecedented exterior of St. Ignatius chapel reflected on characteristics and function of rooms to magnify user's spatial experiences through inducing natural light and spatial effect. Holl used various openings and screen for natural light with colors to invoke religious inspiration. He also try to give spatial depth and multi foci for experiencing space through various ceiling forms. These phenomenological features originated in client's strong will as well as appropriateness of the function of facility's religious experiences through building to the purpose of phenomenological architecture.

• Journal of Astronomy and Space Sciences
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• v.29 no.3
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• pp.305-313
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• 2012

We conducted thermal analyses and cooling tests of the space observation camera (SOC) of the multi-purpose infrared imaging system (MIRIS) to verify passive cooling. The thermal analyses were conducted with NX 7.0 TMG for two cases of attitude of the MIRIS: for the worst hot case and normal case. Through the thermal analyses of the flight model, it was found that even in the worst case the telescope could be cooled to less than $206^{\circ}K$. This is similar to the results of the passive cooling test (${\sim}200.2^{\circ}K$). For the normal attitude case of the analysis, on the other hand, the SOC telescope was cooled to about $160^{\circ}K$ in 10 days. Based on the results of these analyses and the test, it was determined that the telescope of the MIRIS SOC could be successfully cooled to below $200^{\circ}K$ with passive cooling. The SOC is, therefore, expected to have optimal performance under cooled conditions in orbit.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.51-68
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• 2020

Purpose: The primary objective of this research is to develop the optimal operating conditions as well as their associated design spaces for a Cryogenic Submerged Arc Welding(SAW) process by improving its quality and productivity simultaneously. Methods: In order to investigate functional relationships among quality characteristics and their associated control factors of an SAW process, a stepwise design of experiment(DoE) method is proposed in this paper. Based on the DoE results, not only a multi-dimensional design space but also a safe operating space and normal acceptable range(NAR) by integrating statistical confidence intervals were demonstrated. In addition, the optimal operating conditions within the proposed NAR can be obtained by a robust optimal design method. Results: This study provides a customized stepwise DoE method (i.e., a sequential set of DoE such as a factorial design and a central composite design) for Cryogenic SAW process and its statistical analysis results. DoE results can then provide both the main and interaction effects of input control factors and the functional relationships between the input factors and their associated output responses. Maximizing both the product quality with high impact strength and the productivity with minimum processing times simultaneously in a case study, we proposed a design space which can provide both acceptable productivity and quality levels and NARs of input control factors. In order to confirm the optimal factor settings and the proposed NARs, validation experiments were performed. Conclusion: This research may provide significant contributions and applications to many SAW problems by preparing a standardization of the functional relationship between the input factors and their associated output response. Moreover, the proposed design space based on DoE and NAR methods can simultaneously consider a number of quality characteristics including tradeoff between productivity and quality levels.

• Korean Institute of Interior Design Journal
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• no.25
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• pp.176-183
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• 2000

The purpose of this study is to show the implications of the term "digital architecture," which are realized in the current architecture. To do this, I first observe its theoretical background and then analyze the works of Marcos Novak, Kas Oosterhuis, and Lars Spuybroek, all of whom are called the typical digital architects. In particular, this study tries to show that the digital architects are introducing the non-Euclidean multi-dimensions and the cyberspace and applying the notions of liquid architecture, transarchitecture, body-building, and body-building, and body-motorized system into their works. Finally, I conclude that the digital architecture anticipates the direction of the future architecture, in which the virtual world is merged with the real world, the digital space is realized in the real space, and the human is completely harmonized with nature.th nature.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.250-253
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• 2007

Korean Multi-Purpose SATellite 5 (KOMPSAT-5) will be the first high resolution X-band SAR satellite of Korea. A critical parameter necessary for interpreting SAR images over the ocean is surface wind field. SAR is the only system that can provide a synoptic view of wind fields over the ocean covering large areas. However, there has been no X-band wind retrieval model. In this study, we evaluate the development of an X-band wind retrieval model and show the possibility of KOMPSAT-5 SAR on wind estimations using a combination of theoretical models.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.344-346
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• 2004

KOMPSAT-2 (Korea Multi Purpose Satellite 2) which is scheduled to launch in 2005 year will communicate with KARI TTC (Tracking, Telemetry, and Command) station flying along sun synchronous orbits (685 km). The command from KARI TTC passes S-band omni-antenna, RF assembly, and transponder and finally reachs OBC (On Board Computer). The telemetry from KOMPSAT-2 arrives at KARI TTC through inverse procedure. In this paper, RF compatibility test between KOMPSAT-2 and KARI TTC station is demonstrated. RF interface for this test was established through real space and uplink signal test and downlink signal test and uplink & downlink signal test were performed.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.10a
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• pp.39-43
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• 2005

Here this Study is purposed importance of Public area and attend to planning of Admission Space so foster the growth of public area in super high - rise building apartment at present that, for contribution so Consider about Admission Space planning purpose of a Major building in super high - rise building apartment. The process of this Study 1) Consider Indispensable action and Choice action in theory of 'Jan Gehl'. 2) Express one's condolence about two housing development of super high - rise Apartment in Busan City. 3) Analysis by theory of 'Jan Gehl'. about two housing development of super high - rise Apartment in Busan City. 4) I have a result as being Comparison two housing development