• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.12
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• pp.1215-1218
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• 2013

A 90-deg phase shifter using corrugated square waveguide structure for 86 GHz band VLBI(Very Long Baseline Interferometry) dual-circular polarization observation has been developed. The 90-deg phase shifter was designed to have two corrugated walls inside the square waveguide so that the vertically and horizontally polarized waves at the output port have phase differences of $90{\pm}3.3$ deg across 85~115 GHz. Measurements show that the return and insertion losses for the both polarizations are better than 17 dB and 0.25 dB, respectively. The axial ratio is estimated to be less than 0.6 dB within the required frequency band.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.93-103
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• 2015

This study set out to figure out the tendencies of the staff members participating in the space design of Blade Runner and compare and analyze its set and location characteristics with its narrative based on Gilles Deleuze' Simulacrum, one of the basic theories of Post modernism, thus identifying the characteristics of postmodern space inherent in it. The findings were as follows: first, the spaces in a Late modernism tendency in Blade Runner seem to have been created by the cinematic imagination of Syd Mead and Douglas Trumbull rather than being influenced by the old Late modernism architecture. Second, the postmodern spaces of the movie were designed to depict a more realistic future by reinforcing the old ornamental elements or adding the mechanical aesthetics of Late modernism based on a prediction of future cities. Third, the characters representing Late modernism and Post modernism in the narrative of the movie embrace the tendencies of the parties objected by Model and Simulacrum in the scenes where they deny the tendencies of the spaces to which they belong, thus exhibiting a dual trend. Fourth, the dual narrative of Model and Simulacrum holds duality even in the space and architecture of the movie, which is the reason why the movie chose postmodern spaces reflecting historical contexts instead of inner spaces in the tendency of minimalism, which was in vogue when SF movies were made those days. Finally, the spaces of the movie can be categorized according to the Late modernism and Post modernism tendencies from the perspective of the 1980s and be understood to show the architecture and space of future Post modernism feasible through the layering of historicity, locality, and mechanical aesthetics from ancient Maya to a future city in Los Angeles, the background of the movie, from the perspective of 2019.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.40-48
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• 2016

Micro-vibration induced by on-board appendages that have mechanical moving parts has always been treated as an useless objective that has to be isolated, in order to comply with a high-resolution mission requirement of the observation satellite. In this study, we proposed a tuned mass damper energy harvester combined with a conventional passive vibration isolator for exhibiting dual functions of both electrical energy harvesting and micro-vibration isolation. The feasibility of the proposed dual-function complex system has been demonstrated through the comparison with numerical simulations, based on the results of basic characteristic tests, and experiments of the harvested power and micro-vibration.

• Korean Institute of Interior Design Journal
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• no.28
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• pp.44-50
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• 2001

This study propose the new concept of residence by analyzing the change of residence through the characteristic of popularity and degree of development of technology on home network information appliance for intelligent home. Accordingly, Cyber village represented as home automation and extend to information of society. it encourage need of information and multimedia of home. It expect home information infrastructure for accepting informations, which make smart home to linked home-working home-learning home-treatment. home-shopping and home-banking. The system of intelligent home is the intelligence of human-biology in the side of environmental friendly and multi-function. it distinguish the system of security, controlling system of inside environment, supporting system of house-working, automatic controlling, house working. Future house require to meet demand of young generation, such as small residental space, the multi-functional space, the flexible space, making mood for dual income couple and of single as intelligent home. Accordingly, basic purpose which are pleasantness, the safe and the convenience the mobile multi-function as well as networking with controlling of temperature, security, health-test, home-entertainment, home-office and consider environment together.

• Proceedings of the KSRS Conference
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• v.1
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• pp.135-137
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• 2006

HY-2, the China's satellite for oceanic dynamic environment measurement, is planed to be launched around 2010. The main payloads of HY-2 include a dual-frequency radar altimeter equipped with a three-band nadir-looking radiometer for atmospheric delay correction, a Ku-band radar scatterometer, and a five-band scanning radiometer. This presentation outlines the specifications, parameters, and design of the HY-2 radar altimeter and scatterometer.

• Journal of Positioning, Navigation, and Timing
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• v.6 no.1
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• pp.35-41
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• 2017

Precise Point Positioning (PPP) method is based on dual-frequency data of Global Navigation Satellite Systems (GNSS). The recent multi-constellations GNSS (multi-GNSS) enable us to bring great opportunities for enhanced precise positioning, navigation, and timing. In the paper, the multi-GNSS PPP with a combination of four systems (GPS, GLONASS, Galileo, and BeiDou) is analyzed to evaluate the improvement on positioning accuracy and convergence time. GNSS observations obtained from DAEJ reference station in South Korea are processed with both the multi-GNSS PPP and the GPS-only PPP. The performance of multi-GNSS PPP is not dramatically improved when compared to that of GPS only PPP. Its performance could be affected by the orbit errors of BeiDou geostationary satellites. However, multi-GNSS PPP can significantly improve the convergence speed of GPS-only PPP in terms of position accuracy.

• Korean Journal of Mathematics
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• v.15 no.1
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• pp.13-26
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• 2007

We prove that every strong null sequence in a Banach space X lies inside the range of a vector measure of bounded variation if and only if the condition $\mathcal{N}_1(X,{\ell}_1)={\Pi}_1(X,{\ell}_1)$ holds. We also prove that for $1{\leq}p<{\infty}$ every strong ${\ell}_p$ sequence in a Banach space X lies inside the range of an X-valued measure of bounded variation if and only if the identity operator of the dual Banach space $X^*$ is ($p^{\prime}$,1)-summing, where $p^{\prime}$ is the conjugate exponent of $p$. Finally we prove that a Banach space X has the property that any sequence lying in the range of an X-valued measure actually lies in the range of a vector measure of bounded variation if and only if the condition ${\Pi}_1(X,{\ell}_1)={\Pi}_2(X,{\ell}_1)$ holds.

• The Pure and Applied Mathematics
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• v.2 no.1
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• pp.43-51
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• 1995

In this paper, we introduce the almost linear spaces, a generalization of linear spaces. We prove that if the almost linear space X has a finite basis then, as in the case of a linear space, the cardinality of bases for the almost linear space X is unique. In the case X = Wx ＋ Vx, we prove that B'= {$\chi$'$_1,...,x'_n} is a basis for the algebraic dual X$^#$ of X if B = {$\chi$'$_1,...,x'_n} is a basis for the almost linear space X. And we have an example X($\neq$Wx ＋ Vx) which has no such a basis.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.60.1-60.1
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• 2011

We present the preliminary results of the pilot observations for the fringe survey at 43 GHz with the VLBI Exploration of Radio Astrometry (VERA). The main goals of the fringe survey are to establish a full list of phase calibrators for the VERA dual-beam astrometric observations, and for the KVN multi-frequency phase referencing observations. We performed two 24 hours experiments as a pilot observation to test the feasibility of the fringe survey. Each source from a list of 220 sources has been observed in one scan for 2 minutes. 67 sources were detected with the SNR threshold of 3.5. The correlated flux densities of the detected sources are presented in four ranges of projected baseline lengths.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.2
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• pp.87-94
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• 2019

The Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) positioning has been widely used in geodesy, surveying, and navigation fields. RTK can benefit enormously from the integration of multi-GNSS. In this study, we develop a GPS/BeiDou Navigation Satellite System (BDS) RTK integration algorithm for long baselines ranging from 128 km to 335 km in South Korea. The positioning performance with GPS/BDS RTK, GPS-only RTK, and BDS-only RTK is compared in terms of the positioning accuracy. An improvement of positioning accuracy over long baselines can be found with GPS/BDS RTK compared with that of GPS-only RTK and that of BDS-only RTK. The positioning accuracy of GPS/BDS RTK is better than 2 cm in the horizontal direction and better than 5 cm in the vertical direction. A lower Relative Dilution of Precision (RDOP) value with GPS/BDS integration can obtain a better positional precision for long baseline RTK positioning.