• Journal of the Korean Chemical Society
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• v.40 no.1
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• pp.20-27
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• 1996

A stable and accurate inverse method for extracting potential from spectroscopic data studied. The method is based on the Tikhonov regularization method to overcome the possible instability of nonlinear inverse problems using a priori smooth properties of the potential energy surface. The merit of this method is to treat the potential as continuous functions of the intermolecular coordinates instead of the conventional parameter fitting of restricted potential forms. Numerical study for the Ar-Ar show that from spectroscopic data the exact potential has been recovered whole region and the discrepancies by the dispersion force observed at the large distance between the exact and Morse potential or from RKR method can be eliminated by this method.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1744-1746
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• 2001

In this paper, we investigated the breakdown characteristics of Ar, Kr and $N_2$ gas in pure states with pressure range of 58.8-137.3[kPa] under uniform and non-uniform fields, and the measured values are compared with those in Ar/$N_2$ gas mixtures. From these results, the breakdown voltages of $N_2$ gas in uniform field were increased about 4.8 and 4.4 times than those of Ar and Kr gas, respectively. Breakdown voltages of Ar/$N_2$ gas mixtures were decreased with decreasing the mixture ratio of $N_2$ gas. Breakdown voltages of Ar(70%)/$N_2$(30%) gas mixtures in the pressure of 101.3[kPa] (gap length : 3[mm]) were increased 1.9 times than those of pure Ar gas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.7
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• pp.570-575
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• 2002

$SrBi_2Ta_2O_9$ thin films were etched in $Cl_2/CF_4/Ar$ inductively coupled plasma (ICP). The maximum etch rate was 1300 ${\AA}/min$ at 900 W ICP power in Cl$_2$(20%)/$CF_4$(20%)/Ar(60%). As RF source power increased, radicals (F, Cl) and ion ($Ar^+$) increased. The influence of plasma induced damage during etching process was investigated in terms of P-E hysteresis loops, chemical states on the surface, surface morphology and phase of X-ray diffraction. The chemical states on the etched surface were investigated with X-ray spectroscopy and secondary ion mass spectrometry. After annealing $700^{\circ}C$ for 1 h in $O_2$ atmosphere, the decreased P-E hysteresises of the etched SBT thin films in Ar and $Cl_2/CF_4/Ar$ plasma were recovered.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.403-409
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• 1999

The surface state of Ar plasma-exposed Fe doped SI-InP have been investigated by photoreflectance (PR). From Ar plasma-exposed InP with 30 W for 10sec, the PR signals include a peak $(E_{Ar})$ that is located at 1.336 eV. We think that this peak was originated shallow level related to $V_In-V_P$. And we compared this level with the level obtained by surface photovoltage spectroscopy (SPV) measurement. The result of the PR agrees well with that from SPV. Additionally, Ar plasma induced phosphorus vacancy is related to shallow level. Therefore, the change of surface electric field are attributed to the shallow level. This level is caused by the existence of phsophorus vacancy on InP surface.

• Journal of Welding and Joining
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• v.12 no.1
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• pp.51-58
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• 1994

Amount of spatter, welding conditions and welding costs were investigated for MAG welding. $CO_2$, Ar+18%;$CO_2$ and Ar+8%$O_2$ were used for shielding gases. As results, arc characteristics and appropriate range for welding were obtained. Amount of spatter in Ar+18%$CO_2$ gas welding was 20% of that of $CO_2$ welding, and Ar+8%$O_2$ was 10% of that of $CO_2$ welding. Therefore by using Ar+18%$CO_2$and Ar+8%$O_2$ gases, welding costs could be reduced compared with $CO_2$ welding due to avoiding spatter.

• Electronics and Telecommunications Trends
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• v.31 no.1
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• pp.146-156
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• 2016

게임은 IT 기술의 발전에 따라 그 형태, 종류, 방식이 다양해져 왔다. 즉, 새로운 IT 기술에 대한 이해는 차세대 게임 동향 예측을 가능하게 한다. 최근, 소프트웨어 및 하드웨어 기술의 진보로 가상현실(Virtual Reality: VR) 및 증강현실(Augmented Reality: AR) 기술이 적용된 다양한 애플리케이션들이 등장하고 있다. 큰 규모의 시장을 형성하고 있는 게임 업계에서도 그 VR/AR 기술을 게임 개발에 이용하고자 하며, 일부 업체들을 중심으로 몇 가지 상용 게임이 이미 출시되었다. 본고에서는 차세대 게임을 위한 VR/AR 기술 및 게임 서비스 현황을 살펴보고, 향후 VR/AR 게임의 발전 방향에 대해 전망한다.

• Development and Reproduction
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• v.5 no.1
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• pp.53-57
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• 2001

Sperm capacitation and acrosome reaction (AR) have been known to be Ca$^{2+}$-dependent events. Sperm capacitation accompanies with cholesterol efflux fiom plasma membrane, that eventually stimulates AR. However, whether the AR mediated by cholesterol efflux is Ca$^{2+}$ dependent has not been verified yet. Recently, methyl beta cyclodextrin (MBCD) was found to evoke AR by stimulating the cholesterol efflux fiom sperm membrane. In the present study, we examined the requirement of Ca$^{2+}$ in the MBCD-induced AR. During incubation of sperm in the bicarbonate buffered media MBCD increased AR in a dose-dependent manner regardless of the Ca$^{2+}$ presence. In the presence of low molar concentration of Ca$^{2+}$ (100 ${\mu}$M), MBCD-induced AR was slightly increased compared to Ca$^{2+}$-free condition. In the absence of Ca$^{2+}$ supplement, spontaneous AR was slightly increased during the incubation but inhibited by 100 ${\mu}$M EGTA. MBCD potentiated AR even the presence of EGTA. However, EGTA attenuated MBCD-induced AR, suagesting the functional involvement of intracellular Ca$^{2+}$ in the MBCD-induced AR. Taken together, it was suggested that cholesterol efflux from the sperm plasma membrane was sufficient for induction of AR even in the absence of extracellular Ca$^{2+}$and that a condition permissive for mobilization of intracellular Ca$^{2+}$ is important for MBCD-induced AR.

• Journal of the Korean earth science society
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• v.33 no.4
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• pp.329-336
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• 2012

In September 2009, a perfectly preserved fossil of a dinosaur egg nest was discovered in the Cretaceous formations of the Aphaedo area in Shinan, Jeollanam-do, South Korea. In order to estimate the age of dinosaur eggshells and the depositional age of the Cretaceous sediments in Aphaedo area, a whole-rock K-Ar dating was carried out on volcanic pebbles showing a sedimentary structure contemporaneous with the Aphaedo strata, acidic tuffs overlaying the strata conformably, and acidic dike rocks intrude to both of them. Volcanic rocks observed in the strata are 3-20 cm in diameter as pebbles found in lenticular conglomerate and pebble bearing mudstone strata. K-Ar whole-rock dating was performed on six different volcanic pebbles which show a sedimentary structure contemporaneous with the dinosaur egg nest contained in the strata, and all samples show Late Cretaceous ages: Cenomanian ($97.6{\pm}1.9$Ma), Coniacian ($87.6{\pm}1.7$ Ma), Santonian ($84.5{\pm}1.7$Ma) or Campanian ($82.5{\pm}1.6$, $77.3{\pm}1.5$, $75.7{\pm}1.5$ Ma). The K-Ar whole-rock age of acidic tuffs overlaying the Cretaceous formation conformably was estimated to be Campanian ($79.2{\pm}1.6$ or $77.3{\pm}1.5$Ma), when the dating was carried out under the same conditions. The acidic dike intruding both Cretaceous formation and acidic tuff showed a K-Ar whole-rock age of $70.9{\pm}1.4$Ma (Campanian). Therefore, the depositional age of the Cretaceous formation in the Aphaedo area and the time when dinosaurs lived in the study area are considered to be 77-83 Ma. Such results indicate that the ages of dinosaur eggshells from Aphaedo area can be correlated with the ages of the Seonso Formation (81Ma) with dinosaur egg nest fossils and the Uhangri Formation (79-81Ma) with dinosaur, pterosaur and web-footed bird tracks.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.914-919
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• 1998

A Capacitor Commutated Converter (CCC) has less difficulty of commutation failure in comparison to the conventional line commutated converter. This paper proposes the Ar1R control of the CCC in the inverter operation, which deserves as the Ar1R of the conventional converter. The CCC can be operated in high power factor area by using the proposing Ar1R control. The voltage stability at an AC bus connected the CCC inverter is investigated and estimated its ability of preventing the AC voltage collapse. To estimate the voltage stability, this paper developed the simplified converter mathematical model and led the VSF index. The results shows that the AC voltage stability is guaranteed and enables the interconnection to an weak AC system, when compensation factor of the compensation capacitor is higher than 200%.

• Journal of Information Science Theory and Practice
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• v.6 no.4
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• pp.6-16
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• 2018

This article shows an approach to the study of two fundamental aspects of the prepublication of scientific manuscripts in specialized repositories (arXiv). The first refers to the size of the interaction of "standard papers" in journals appearing in the Web of Science (WoS)-now Clarivate Analytics-and "non-standard papers" (manuscripts appearing in arXiv). Specifically, we analyze the citations found in the WoS to articles in arXiv. The second aspect is how publication in arXiv affects the citation count of authors. The question is whether or not prepublishing in arXiv benefits authors from the point of view of increasing their citations, or rather produces a dispersion, which would diminish the relevance of their publications in evaluation processes. Data have been collected from arXiv, the websites of the journals, Google Scholar, and WoS following a specific ad hoc procedure. The number of citations in journal articles published in WoS to preprints in arXiv is not large. We show that citation counts from regular papers and preprints using different sources (arXiv, the journal's website, WoS) give completely different results. This suggests a rather scattered picture of citations that could distort the citation count of a given article against the author's interest. However, the number of WoS references to arXiv preprints is small, minimizing this potential negative effect.