• Communications of the Korean Mathematical Society
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• v.23 no.1
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• pp.125-131
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• 2008

We introduce and study the concepts of strong generalized neighborhood systems, SGNS and sg-open sets. We also introduce and investigate the concept of (${\psi},\;{\psi}^'$)-continuity and sg-continuity on SGNS's.

• Macromolecular Research
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• v.17 no.5
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• pp.307-312
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• 2009

Core-shell hydrogel nanocomposite was fabricated by encapsulating a silica-gold nanoshell (SGNS) with poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-co-AAc) copolymer. The oleylamine-functionalized SONS was used as a nanotemplate for the shell-layer growth of hydrogel copolymer. APS (ammonium persulfate) was used as a polymerization initiator to produce a hydrogel-encapsulated SGNS (H-SGNS). The amounts of NIPAM (N-isopropylacrylamide) monomers were optimized to reproduce the hydrogel-encapsulated SGNS. The shell-layer thickness was increased with the increase of polymerization time and no further increase in the shell-layer thickness was clearly observed over 16 h. H-SGNS exhibited the systematic changes of particle size corresponding to the variation of pH and temperature, which was originated from hydrogen-bonding interaction between PNIPAM amide groups and water, as well as electrostatic forces attributed by the ionization of carboxylic groups in acrylic acid.

• Honam Mathematical Journal
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• v.33 no.1
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• pp.11-17
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• 2011

We study some properties of quasi-topological spaces. Also we introduce the concept of Q-continuity and investigate several types of quasi-topology on an SGNS.

• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.224-232
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• 2018

Objectives. Spiral ganglion neurons (SGNs) include potential endogenous progenitor populations for the regeneration of the peripheral auditory system. However, whether these populations are present in adult mice is largely unknown. We examined the presence and characteristics of SGN-neural stem cells (NSCs) in mice as a function of age. Methods. The expression of Nestin and Ki67 was examined in sequentially dissected cochlear modiolar tissues from mice of different ages (from postnatal day to 24 weeks) and the sphere-forming populations from the SGNs were isolated and differentiated into different cell types. Results. There were significant decreases in Nestin and Ki67 double-positive mitotic progenitor cells in vivo with increasing mouse age. The SGNs formed spheres exhibiting self-renewing activity and multipotent capacity, which were seen in NSCs and were capable of differentiating into neuron and glial cell types. The SGN spheres derived from mice at an early age (postnatal day or 2 weeks) contained more mitotic stem cells than those from mice at a late age. Conclusion. Our findings showed the presence of self-renewing and proliferative subtypes of SGN-NSCs which might serve as a promising source for the regeneration of auditory neurons even in adult mice.

• The Pure and Applied Mathematics
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• v.15 no.3
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• pp.221-227
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• 2008

We introduce and study the new concepts of interior and closure operators on strong generalized neighborhood spaces. Also we introduce and investigate the concept of sgn-continuity on SGNS.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.145-146
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• 2023

본 논문에서는 최대 규모의 게임 플랫폼인 Steam에서 수집한 유저 정보 데이터 셋에 Item2vec과 LSTM을 사용하여 추천 시스템을 구현한다. 수집한 유저 정보 데이터 셋에 Item2vec을 적용하여 각각의 유저들이 보유하고 있는 고유한 Appid들을 200차원의 벡터로 변환한다. 그 후 데이터 셋을 기간에 따라 4단계의 시퀀스로 나눈 후 LSTM을 사용하여 유저별로 최대 5가지의 추천 리스트를 생성한다. 유저 정보 데이터 셋은 액티브한 유저 정보를 얻기 위해 Steam 게임 리뷰 항목에서 리뷰를 남긴 유저들의 데이터를 api를 사용해 수집했으며 LSTM을 사용한 실험의 성능 평가 지표는 RMSE를 사용했고 이때의 성능은 0.1357을 얻을 수 있었다.

• Journal of Advanced Navigation Technology
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• v.24 no.2
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• pp.92-100
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• 2020

Satellite-based argumentation systems (SBAS) is a system that enhances the accuracy, integrity, availability and continuity of GNSS navigation users by using geostationary orbit (GEO) satellites to send correction information and the failures of global navigation satellite system (GNSS) satellites in the form of messages. The correction information provided by SBAS is pseudorange error, satellite orbit error, clock error, and ionospheric delay error at 250 bps. Therefore, A lot of message processing are required for the SBAS navigation. There is a need to reduce SBAS time to first fix (TTFF) for using SBAS navigation in systems with short operating time. In this paper, A-SGNSS operation method was proposed for reducing SBAS TTFF. Also, A-SGNSS TTFF and availability were analyzed.