• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.6
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• pp.946-954
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• 1995

The purpose of this study is to modify the hydrophobic property and dyeability of polyethylene terephthalate fiber. Methacrylic acid (2nA) was graftpolymerized with benzoyl peroxide (BPO) as initiator onto polyethylene terephthalate fabrics. The results were as follow; 1. Graft-polymerization exhibited maximum graft ratio at a temperature of 100"C. 2. The polymer was gradually grafted in great amount to the surface of MA-g-PET as graft ration increase; with the cross-section examination of MA-g-PET, it was discovered that graft-polymeriation had also taken place inside the textile core. 3. Dyes absorption of basic dyes and disperse dyes was improved as craft ratio increase; with resistance to laundering, the former showed grade 3-4 and the latter showed grade 5.de 5.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1523-1525
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• 1994

This paper describes a proposed very fast transient overvoltages(VFTO) measurement system suited for established gas insulated switchgear(GIS). The detecting system consists of a shield electrode connected to a buffer amplifier, and the transmission of the detected signal to an oscilloscope is made through an optical fiber. The bandwidth of the measurement system is 5 Hz to 30MHz. When determining the voltage dividing ratio by use of the commercial frequency voltage, the error is less than 0.5 %. Also, the data were obtained by the electric field probe and the high voltage probe, and their deviation for voltage dividing ratio were less than 1 %.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.85-90
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• 2002

$RuO_2$/GaN and related contacts were investigated for Schottky contacts in GaN-Based optical and electronic devices. We demonstrated that an $RuO_2$ film forms a stable Schottky contact on a GaN layer with a barrier height (${\Phi}_B$) of 1.46 eV and transmittance of 70% in the visible and near UV region. $RuO_2$/GaN Schottky diode showed a breakdown at over -50V and leakage current of only 0.3 nA at -5V. The $RuO_2$/GaN Schottky type photodetector had the UV/Visible rejection ratio of over $10^5$ and the responsivity of 0.23 A/W at 330 nm. The $RuO_2$ gate AlGaN/GaN EFET exhibited high drain current ($I_d$) of 689.3 mA/mm and high transconductance ($g_m$) of 197.4 mS/mm. Cut-Off frequency ($f_t$) and maximum operating frequency ($f_{max}$) were measured as 27.0 GHz and 45.5 GHz, respectively.

• Korean Journal of Optics and Photonics
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• v.11 no.1
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• pp.13-18
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• 2000

The SiOxNy thin films were prepared on Si(lOO) by reactive RF sputtering method. The reactive gas ratio and the power were used as parameters for depositing SiOxNy thin fims. The properties of ${SiO_x}{N_y}$ thin tilms were investigated by XRD, XPS, refractive index and extinction coefficient analyzer (n'||'&'||'k analyzer), and FfIR. It was found by the results of the x-ray diffraction measurement that SiOxNy thin films were grown to an amorphous structure. From the results of the XPS, and the n'||'&'||'k analyzer, it was found that refractive index was intended to increase with the increasement of the relative nitrogen contents of the ${SiO_x}{N_y}$ thin films.

• Journal of the Korean Magnetics Society
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• v.13 no.1
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• pp.15-20
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• 2003

Diffusion speed of Cu metal fine particle is fast better than CuO, so it will promote grain growth in sintering. In this paper, the influence on substituting Cu fine particle for CuO of NiCuZn ferrite with basic composition (N $i_{0.204}$C $u_{0.204}$Z $n_{0.612}$ $O_{1.02}$)F $e_{1.98}$ $O_{2.98}$ has been investigated with varying Cu/CuO ratio. The perfect spinel structure of sintered specimen at 90$0^{\circ}C$ was confirmed by the analysis of XRD patterns. The best condition was obtained when the ratio of Cu/CuO was 60%, and the permeability was 1100 and Ms was 87 emu/g in this condition. Cu has influenced on grain growth in sintering, substituting Cu fine particle for CuO could lower sintering temperature over the 3$0^{\circ}C$. After sintering, substituting Cu performed as good as CuO.s CuO.s CuO.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.690-695
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• 1994

Simultaneous removal of phosphorus and nitrogen from wastewater was studied by the anaerobic-aerobic system of activated sludge. In the anaerobic stage, most of the influent glucose was removed and orthophosphate was released, when the nitrate and/or nitrite concentration in the wastewater was almost zero. The amount of the released phosphorus was found to be directly proportional to the amount of the removed glucose. When the ratio of phosphorus to glucose in the influent was less than 0.04, the phosphorus in the wastewater was almost completely removed during the aerobic state. Under the anaerobic condition, activated sludge released phosphate and excess removal of phosphate occurred during the aerobic condition. Namely, the stress received in anaerobic period stimulated the uptake of phosphorus in aerobic period. The amounts of phosphorus release in the anaerobic and uptake in the aerobic stage were less in proportional to the concentration of $NO_x-N$. Further, if the initial ratio of $NO_2-N$/glucose was less than 0.37, the inorganic nitrogen in the influent could be completely removed.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.29-35
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• 2005

To prove the buffering contribution of mitochondria to the increase of intracellular $Ca^{2+}$ level ($[Ca^{2+}]_i$) via background nonselective cation channel (background NSCC), we examined whether inhibition of mitochondria by protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP) affects endothelial $Ca^{2+}$ entry and $Ca^{2+}$ buffering in freshly isolated rabbit aortic endothelial cells (RAECs). The ratio of fluorescence by fura-2 AM ($R_{340/380}$) was measured in RAECs. Biological state was checked by application of acetylcholine (ACh) and ACh ($10{\mu}M$) increased $R_{340/380}$ by $1.1{\pm}0.15$ ($mean{\pm}S.E.$, n=6). When the external $Na^+$ was totally replaced by $NMDG^+$, $R_{340/380}$ was increased by $1.19{\pm}0.17$ in a reversible manner (n=27). $NMDG^+$-induced $[Ca^{2+}]_i$ increase was followed by oscillatory decay after $[Ca^{2+}]_i$ reached the peak level. The increase of $[Ca^{2+}]_i$ by $NMDG^+$ was completely suppressed by replacement with $Cs^+$. When $1{\mu}M$ CCCP was applied to bath solution, the ratio of $[Ca^{2+}]_i$ was increased by $0.4{\pm}0.06$ (n=31). When $1{\mu}M$ CCCP was used for pretreatment before application of $NMDG^+$, oscillatory decay of $[Ca^{2+}]_i$ by $NMDG^+$ was significantly inhibited compared to the control (p＜0.05). In addition, $NMDG^+-induced$ increase of $[Ca^{2+}]_i$ was highly enhanced by pretreatment with $2{\mu}M$ CCCP by $320{\pm}93.7$%, compared to the control ($mean{\pm}S.E.$, n=12). From these results, it is concluded that mitochondria might have buffering contribution to the $[Ca^{2+}]_i$ increase through regulation of the background NSCC in RAECs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.290-293
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• 2003

Ohmic contact characteristics of Al ion implanted n-type SiC wafer were investigated. Al ions implanted with high dose to obtain the final concentration of $5{\times}10^{19}/cm^3$, then annealed at high temperature. Firstly, B ion ion implanted p-well region were formed which is needed for fabrication of SiC devices such as DIMOSFET and un diode. Secondly, Al implanted high dose region for ohmic contact were formed. After ion implantation, the samples were annealed at high temperature up to $1600^{\circ}C\;and\;1700^{\circ}C$ for 30 min in order to activate the implanted ions electrically. Both the inear TLM and circular TLM method were used for characterization. Ni/Ti metal layer was used for contact metal which is widely used in fabrication of ohmic contacts for n-type SiC. The metal layer was deposited by using RF sputtering and rapid thermal annealed at $950^{\circ}C$ for 90sec. Good ohmic contact characteristics could be obtained regardless of measuring methods. The measured specific contact resistivity for the samples annealed at $1600^{\circ}C\;and\;1700^{\circ}C$ were $1.8{\times}10^{-3}{\Omega}cm^2$, $5.6{\times}10^{-5}{\Omega}cm^2$, respectively. Using the same metal and same process of the ohmic contacts in n-type SiC, it is found possible to make a good ohmic contacts to p-type SiC. It is very helpful for fabricating a integrated SiC devices. In addition, we obtained that the ratio of the electrically activated ions to the implanted Al ions were 10% and 60% for the samples annealed at $1600^{\circ}C\;and\;1700^{\circ}C$, respectively.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.4
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• pp.169-176
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• 2013

Objectives To investigate correlation between anthropometric data (neck circumference (NC), waist circumference (WC), body mass index (BMI), and body shape indexes) and radiological parameters of lumbosacrum. Methods The data of college students living in Seoul (n=24) were analyzed retrospectively. Anthropometric data of NC, WC, and BMI were measured. Lumbar spine X-ray film was taken to measure lumbar lordotic angle, Ferguson's angle. To evaluate body shape of participants, three indexes of neck-to-waist ratio (NWR), neck-to-height ratio (NHR), and waist-to-height ratio (WHR) were used. Anthropometric data's correlations with radiological parameters of lumbosacrum were investigated. Results Anthropometric data of NC, WC, and BMI had no significant correlation with radiological parameters of lumbosacrum. NWR had significant positive correlation with lumbar lordotic angle and Ferguson's angle. NHR and WHR had no significant correlation with radiological parameters of lumbosacrum. Conclusions The results suggest that NWR-related fat distribution in neck has significant correlation with radiological parameters of lumbosacrum regardless of obesity.

• Physical Therapy Rehabilitation Science
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• v.9 no.3
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• pp.191-196
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• 2020

Objective: Congenital muscular torticollis (CMT) is a disease with abnormal head and neck posture in infants. It affects the child's movement and development and can lead to complications. Therefore, this study aims to find out what factors influence the rehabilitation treatment duration of infants with CMT. Design: Cross-sectional study. Methods: The subjects were 63 infants under 90 days of age who were diagnosed with CMT. Age, thickness of the sternocleidomastoid muscle (SCM) on the affected and non-affected side, head tilt angle, and head rotation angle of the affected head in infants were collected. The ratio of muscle thickness was calculated from the thickness of the affected SCM and the thickness of the non-affected SCM (A/N ratio). All subjects underwent conservative physical therapy twice a week for 30 minutes, and the end of the treatment was when the angle of head tilt was normal or less than 5 degrees, and the treatment duration was calculated. Results: Age, thickness of affected SCM, and head tilt were significantly correlated with treatment duration (p<0.05). The thickness of the non-affected SCM, A/N ratio, and head rotation angle did not show any correlation with treatment duration. The factors affecting the treatment duration were head tilt and age, showing 21% explanatory power of adjusted R². Conclusions: The main factors affecting the treatment duration of infants with CMT are head tilt and age. Therefore, more attention should be directed to the infant's head tilt and age for effective physical therapy of infants with CMT.