• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.96-98
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• 2000

Room-temperature continuous operation of two-dimensional photonic crystal lasers is achieved at 1.6 ${\mu}{\textrm}{m}$ by using InGaAsP slab-waveguide triangular photonic crystal on top of wet-oxidized aluminum oxide. The main difficulty in the realization of photonic bandgap (OBG) structures has been the nontrivial difficulties in nanofabrication, especially for 3-dimensional PBG structures. Recently, 2-D PBG structures have attracted a great deal of attention due to their simplicity in fabrication and theoretical study as compared to the three-dimensional counterparts [1]. Recently, air-gulfed 2-D slab PBG lasers were reported by Caltech group [2]. However, this air-slab structure is mechanically fragile and thermally unforgiving. Therefore, a new structure that can remove this thermal limitation is dearly sought after for 2-D PBG laser to have practical meaning. In this talk, we report room-temperature continuous operation of 2-D photonic bandgap lasers that are thermally and mechanically stable.

• Communications of the Korean Mathematical Society
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• v.20 no.4
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• pp.685-693
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• 2005

An aperiodic perfect map(APM) is an array with the property that every array of certain size, called a window, arises exactly once as a contiguous subarray in the array. In this article, we deal with the generalization of APM in higher dimensional arrays. First, we reframe all known definitions onto the generalized n-dimensional arrays. Next, some elementary known results on arrays are generalized to propositions on n-dimensional arrays. Finally, with some devised integer representations, two constructions of infinite family of n-dimensional APMs are generalized from known 2-dimensional constructions in [7].

• The Journal of Information Systems
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• v.6 no.2
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• pp.165-188
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• 1997

This paper describes about the development of the 3 Dimensional interactive physics experiment system using virtual reality technologies. Until now, most of the computer aided education systems have adopted one-sided learning way which only shows or tells. It excludes students during learning processes. To solve the problems of the one-sided learning way and to improve the educational productivity, the 3 Dimensional interactive physics experiment system is developed. The 3 Dimensional interactive physics experiment system introduced in this paper provides a new learning motivation for students and improves their educational effects through the 3 Dimensional graphics, realtime action, and realistic interactive experiment.

• Journal of the Korea Furniture Society
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• v.11 no.2
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• pp.79-84
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• 2000

It is well-known fact that dimensional stability of wood is greatly enhanced by acetylation of wood. This dimensional stability results from bulking of the reacted acetate within the cell wall, which reduces further swelling when the modified woods come into contact with water or water vapor. The purpose of this research was to determine the water absorption and dimensional stability of the acetylated solid wood in liquid water and in humidity tests. Beech and red oak were acetylated. Moisture and water absorption of acetylated wood were quite dependent on weight percent gain(WPG). Antiswelling efficiency(ASE) was quite dependent on WPG, but was not dependent on species.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.99-100
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• 2000

We measured 3-dimensional images of the light emitted from plasma display panel by using newly proposed scanned point detecting method (SPDM). From the 3-dimensional emission images, we know that as the sustain voltage increases, intensity of light detected without phosphor increases and the position of the maximum intensity moves to the outside from the electrode gap. Also, we know that 2-dimensional simulations under the assumption that neglects the Y axis variation do not agree with 3-dimensional experiment results.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.192-194
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• 2003

In this paper, we present a 2-Dimensional simulation model of the discharge in an ac plasma display panel cell. Therefore, we study a ramp reset waveform in an ac plasma display panel discharge cell using 2-Dimensional simulation. Finally We research a connection between priming particles' density and stability.

• Bulletin of the Korean Mathematical Society
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• v.46 no.2
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• pp.289-294
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• 2009

We show that on a Hermitian surface M, if M is weakly *-Einstein and has J-invariant Ricci tensor then M is Einstein, and vice versa. As a consequence, we obtain that a compact *-Einstein Hermitian surface with J-invariant Ricci tensor is $K{\ddot{a}}hler$. In contrast with the 4- dimensional case, we show that there exists a compact Einstein Hermitian (4n + 2)-dimensional manifold which is not weakly *-Einstein.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.175-178
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• 2003

This paper describes a active audition system for robot-human interface in real environment. We propose a strategy for a robust sound localization and for -talking speech recognition(60-300cm) based on 2-dimensional microphone array. We consider spatial features, the relation of position and interaural time differences, and realize speaker tracking system using fuzzy inference profess based on inference rules generated by its spatial features.

• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.214-216
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• 2013

The atomic and electronic properties of molybdenum disurfide ($MoS_2$) nanostructures are investigated through density functional theory (DFT) calculations. We find that the band gap is indirect (about 1.79 eV) and direct (about 1.84 eV) in GGA for 2-dimensional $MoS_2$ in our calculations. On the other hand, 1-dimensional armchair nanoribbons have semiconductor properties (band gap is about 0.11~0.28 eV), while 1-dimensional zigzag nanoribbons are metallic.

• Kyungpook Mathematical Journal
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• v.48 no.1
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• pp.109-121
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• 2008

We determine maximal space-like hypersurfaces which are the images of subbundles of the normal bundle of m-dimensional totally geodesic space-like submanifolds of an (m + 2)-dimensional Lorentzian space form $\tilde{M}_1^{m+2}$(c) under the normal exponential map. Then we construct examples of maximal space-like hypersurfaces of $\tilde{M}_1^{m+2}$(c).