• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.278-281
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• 2004

To realize magnetic sails, momentum of the solar wind should be efficiently transferred to a spacecraft via magnetic field, which is produced around a spacecraft. In this paper, two important physical processes are addressed: 1) diffusive processes caused by plasma turbulence at the magnetospheric boundary around the spacecraft; and 2) field aligned current loops that will electrically connect the magnetospheric boundary and the spacecraft. The idea of the magnetic sails will be demonstrated by an experimental simulator, in which a fast plasma beam will penetrate into a dipole magnetic field. For that purpose, the two important physical processes should be scaled down to a small laboratory experiment in a space chamber. From the scaling considerations, the interaction can be scaled down if high-speed and high-density $(10^{19}m^{-3})$ plasma jet is used with 1-T-class magnetic field.

• Korean Journal of Mathematics
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• v.9 no.2
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• pp.83-98
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• 2001

We characterize ($r,w$)-nuclear operators acting from a Banach space whose dual has weak type $q$ into a Banach space of weak type $p$ by the asymptotic behaviour of their entropy numbers.

• Bulletin of the Korean Space Science Society
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• 2002.10a
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• pp.42.2-42
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• 2002

• Bulletin of the Korean Mathematical Society
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• v.42 no.2
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• pp.307-313
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• 2005

The Lefschetz fixed point theorem is extended to compact continuous maps defined on an admissible subset of a Hausdorff topological space.

• Journal of Astronomy and Space Sciences
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• v.29 no.2
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• pp.123-129
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• 2012

The BINSYN program package, recently expanded to calculate synthetic spectra of cataclysmic variables, is being further extended to include synthetic photometry of ordinary binary stars in addition to binary stars with optically thick accretion disks. The package includes a capability for differentials correction optimization of eclipsing binary systems using synthetic photometry.

• Korean Journal of Mathematics
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• v.30 no.1
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• pp.155-160
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• 2022

Let X be a partial metric space generated by a partial metric p. In this paper, we introduce the notions of statistical convergence and strongly Cesàro summability in partial metric spaces. Also, we investigate the relations between the statistical convergence and strongly Cesàro summability.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.255-260
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• 1992

It is reported on the methodology of signal detection in noise which is based on a comparison of statistical parameters of observation sample from region of frequency-time noise space where a signal may be present and observation sample from region of this noise space and it is known a priori about the latter that the signal is absent in this region.

• Bulletin of the Korean Space Science Society
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• 1995.04a
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• pp.22-22
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• 1995

No Abstract. See Full-text

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.8
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• pp.763-771
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• 2013

In this paper, the propagation characteristics for ISM(Industrial Scientific and Medical) and TVWS(TV White Space) in indoor building environment are analyzed in comparison with theoretical and experimental results, the excellent propagation characteristics of the TVWS is confirmed. To this end, signals which have center frequencies of 503 MHz and 2.4 GHz are generated in building propagation environment. Through that, received power strength is measured according to the location and measured path loss is analyzed. Theoretical path loss is calculated using Hata, Extended Hata, Extended Hata SRD, ITU-R P.1238 and reliability for channel model in indoor environment is analyzed.

• Journal of the Korean Mathematical Society
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• v.43 no.2
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• pp.399-411
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• 2006

Let L be a subspace lattice on a Hilbert space H and X and Y be operators acting on a Hilbert space H. Let P be the projection onto $\frac\;{R(X)}$, where RX is the range of X. If PE = EP for each $E\;\in\;L$, then there exists an operator A in AlgL such that AX = Y if and only if $$sup\{{\parallel}E^{\bot}Yf{\parallel}/{\parallel}E^{\bot}Xf{\parallel}\;:\;f{\in}H,\; E{\in}L}=K\;<\;\infty$$ Moreover, if the necessary condition holds, then we may choose an operator A such that AX = Y and ${\parallel}A{\parallel} = K.$ Let x and y be vectors in H and let $P_x$ be the projection onto the singlely generated space by x. If $P_xE = EP_x$ for each $E\inL$, then the assertion that there exists an operator A in AlgL such that Ax = y is equivalent to the condition $$K_0\;:\;=\;sup\{{\parallel}E^{\bot}y{\parallel}/{\parallel}E^{\bot}x\;:\;E{\in}L}=<\;\infty$$ Moreover, we may choose an operator A such that ${\parallel}A{\parallel} = K_0$ whose norm is $K_0$ under this case.