• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.190-197
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• 2018

Background and Objectives : Positional OSAS is characterized by an apnea-hypopnea index (AHI) score >5, which, while sleeping in the supine position, is double that in non-supine position. This study was performed to compare the clinical characteristics of positional OSAS and non-positional OSAS patients, and the effects of the modified jaw thrust maneuver during drug-induced sleep endoscopy (DISE) between positional OSAS and non-positional OSAS patients. Materials and Methods : 68 positional OSAS patients and 19 non-positional OSAS patients were included. They all underwent full-night polysomnography and DISE. The modified jaw thrust maneuver was introduced during DISE. Airway structural changes induced by the modified jaw thrust maneuver were evaluated and documented. Results : There were no statistically significant differences in Friedman stage or tonsil grade, body mass index, Epworth sleepiness scale (ESS) score, blood pressure, AHI, or obstructive pattern between the positional and non-positional OSAS patients. However, mean arterial oxygen saturation (SaO2), lowest SaO2, and total arousal index values were more severe in the non-positional OSAS patients. After introduction of the modified jaw thrust maneuver, retrolingual level obstruction showed a tendency toward a higher rate of airway opening in positional OSAS patients than in non-positional OSAS patients. Conclusions : The effects of a mandibular advancement device (MAD) can be estimated by carrying out a modified jaw thrust maneuver during DISE. The tendency toward a higher rate of airway opening in positional OSAS patients than non-positional OSAS patients in retrolingual level obstruction after jaw thrust maneuver introduced during DISE may be clinically important for MAD.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.721-723
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• 1992

The electrical resistivity and piezoelectric properties have been studied for Lead Zirconate-Titanate(PZT) with $Nb_2O_5$ dopant, fabricated from conventional mixed-oxide powders and molten salt synthesis. The resistivity and electromechanical coupling factor(Kp) were increased with increasing Nb contents. The reason for increasing of the electrical resistivity below the Curie Temperature(Tc), It is believed that the p-type electrical conduction in PZT is caused by the lead vacancies. The electromechanical coupling factor(Kr) and piezoelectric constant $d_{33}$ were improved by Nb additives. This behavior can be explained as a compensation effect and $Nb^{5+}$ can serve as a donar and contribute electrons to the conduction process. As a result, the optimized $Nb_2O_5$ dopants on the PZT specimens were 0.75 wt%.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1250_1251
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• 2009

The SBN thin films are deposited on Pt-coated electrode(Pt/Ti/$SiO_2$/Si) using RF sputtering method at various deposition conditions. The capacitance of SBN thin films were increased with the increase of Ar/$O_2$ ratio and RF power, respectively. Also, The capacitance of SBN thin films were increased with the increase of deposition temperature.

• Natural Product Sciences
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• v.10 no.6
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• pp.341-343
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• 2004

A monoacyldigalactosyl glycerol was isolated from the $CH_2Cl_2$ soluble fraction of the MeOH extract from the green alga Enteromorpha prolifera. The structure was established as $1-O-palmitoyl-3-O-[{\alpha}-D-galactopyranosyl(1{\rightarrow}6)-{\beta}-D-galactopyranosyl]-sn-glycerol$ (1) by chemical and spectroscopic methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.10
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• pp.1786-1790
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• 2007

The $(SrCa)TiO_3(SCT)$ thin films are deposited on Pt-coated electrode ($Pt/TiN/SiO_2/Si$) using RF sputtering method at various deposition temperature. The dielectric constant of SCT thin films were increased with the increase of deposition temperature, and changed almost linearly in temperature ranges of $-80{\sim}+90[^{\circ}C]$. Also, SCT thin films was observed the phenomena of dielectric relaxation with the increase of frequency, and the relaxation frequency was observed above 200[kHz]. V-I characteristics of SCT thin films show the increasing leakage current with the increases of deposition temperature. The conduction mechanism of the SCT thin films observed in the temperature range of $25{\sim}100[^{\circ}C]$ can be divided into three characteristic regions with different mechanism by the increasing current. The region 1 below 0.8[MV/cm] shows the ohmic conduction. The region 2 can be explained by the Child's law, and the region 3 is dominated by the tunneling effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.149-154
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• 2000

In this paper, we studied the relation between addition of carbon and electromagnetic wave absorbing properties of ferrite-rubber composite. The ratio of carbon was 7 wt%. As s result, it has been shown that the electromagnetic wave absorbing properties of ferrite-rubber composite are changed by the addition of carbon in composite. And, we can control electromagnetic wave absorbing properties of ferrite-rubber composite by the using of carbon.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.162-166
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• 2000

In this paper, we studied the relation between using amount of Ferrite and electromagnetic wave absorbing properties of ferrite-rubber composite. The variation of using amount of Ferrite have been 52 wt.% ~ 62 wt.%. As s result, it has been shown that the electromagnetic wave absorbing properties of ferrite-rubber composite are related to the using amount of Ferrite in composite. And, we can control electromagnetic wave absorbing properties of ferrite-rubber composite by the control of using amount of Ferrite.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.265-268
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• 1990

In this study, PZT powder prepared by the wet direct process was synthesized. As starting materials, $TiCl_4$. $ZrOCl_2{\cdot}8H_2O$ and PbO were used. Uniformly shape and fine-grained PZT powder was obtained by the wet-direct process and PZT powder was characterized by XRD, DTA analysis. The X-ray diffraotion peaks from the PZT powder were observed at 700($^{\circ}C$) or over.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.45-49
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• 2002

In this paper, we have studied about electromagnetic wave absorbing properties of ferrite-rubber composite with a variation of ferrite. Amounts of ferrite in a composite absorber were changed from 52 wt.% to 62 wt.%. As a result, it has been shown that the electromagnetic wave absorbing properties of ferrite-rubber composite are related to the amount of ferrite in composite absorber. As a summary, it could be controled the electromagnetic wave absorbing property of ferrite-rubber composite by changing some kinds of annex A and amount of ferrite.

• Journal of the Korean Ceramic Society
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• v.48 no.6
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• pp.559-564
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• 2011

In order to investigate the behavior of $SiO_2$ in the molybdenum silicide powders, crystal structure of these powders was measured by XRD, in addition, surface composition and surface phase (or chemical states) and microstructure were analysed by XPS and TEM, respectively. Mo-silicide powders containing $SiO_2$ were synthesized by SHS (Self-Propagating High-Temperature Synthesis) technique. In XRD result, according to increase of $SiO_2$ contents, the crystal structure for synthesized $MoSi_2$ powders was still typical $MoSi_2$ bct without any other phases. By XPS analysis, the surface of Mo and Si source powders was covered with $MoO_3$ and $SiO_2$, respectively, and the surface of synthesized $MoSi_2$ powder was also covered with $MoO_3$ and $SiO_2$, which were stable oxides at room temperature. However, according to increase of $SiO_2$ addition, $MoSi_2$ phase in XPS spectra decreased and $SiO_2$ phase increased relatively in synthesized $MoSi_2$ powders. From the results by XPS and XRD, we found that the existent $SiO_2$ has amorphous structure. In the microstructure, the small particulates of the synthesized products added $SiO_2$ agglomerated together to form larger clusters (from ~10 nm to ~1 ${\mu}m$). From TEM, XPS, and XRD results, we found that the out layer of agglomeration of synthesized $MoSi_2$ powder is surrounded by amorphous $SiO_2$.