• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.12
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• pp.1011-1015
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• 2002

In this study, Au thin films were etched with a Cl$_2$/Ar gas combination in an inductively coupled plasma. The highest etch rate of the Au thin film was 3500 A/min at a Cl$_2$/(Cl$_2$+Ar) gas mixing ratio of 0.2. The surface reaction of the etched Au thin films was investigated using x-ray photoelectron spectroscopy (XPS) analysis. There is Au-Cl bonding by chemical reaction between Cl and Au. During the etching of Au thin films in Cl$_2$/Ar plasma, Au-Cl bond is formed, and these products can be removed by the physical bombardment of Ar ions[l].

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.3
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• pp.271-278
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• 2001

Oxidative stress and methylglyoxal (MG), a reactive dicarbonyl metabolites produced by enzymatic and non-enzymatic reaction of normal metabolism, induced aldose reductase (AR) expression in rat aortic smooth muscle cells (SMC). AR expression was induced in a time-dependent manner and reached at a maximum of 4.5-fold in 12 h of MG treatment. This effect of MG was completely abolished by cyclohemide and actinomycin D treatment suggesting AR was synthesized by de novo pathway. Pretreatment of the SMC with N-acetyl-L-cysteine significantly down-regulated the MG-induced AR mRNA. Furthermore, DL-Buthionine-(S,R)-sulfoximine, a reagent which depletes intracellular glutathione levels, increased the levels of MG-induced AR mRNA. These results indicated that MG induces AR mRNA by increasing the intracellular peroxide levels. Aminoguanidine, a scanvenger of dicarbonyl, significantly down-regulated the MG-induced AR mRNA. In addition, the inhibition of AR activities with statil, an AR inhibitor, enhanced the cytotoxic effect of MG on SMC under normal glucose, suggesting a protective role of AR against MG-induced cell damages. These results imply that the induction of AR by MG may contribute to an important cellular detoxification of reactive aldehyde compounds generated under oxidative stress in extrahepatic tissues.

• Journal of electromagnetic engineering and science
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• v.17 no.1
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• pp.1-8
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• 2017

This paper introduces a technique to obtain the broadband characteristics of circularly polarized antennas using an L-shaped probe. A waveguide antenna is suitable for obtaining high gain and handling convenience in some applications; however, the asymmetrical structure of the L-shaped probe results in cross-polarization and frequency dependence on the field distribution of higher-order modes (HOM). In addition to the basic characteristics of a waveguide antenna with an L-shaped probe, the author discusses some techniques to reduce the HOM and cross-polarization. As a result, the 3-dB axial ratio (AR) is obtained with the fundamental mode even when the frequency is expanded to the region for HOM of TM. This reduction is mainly due to the cutoff structure to the TM mode around the short wall of the waveguide. Furthermore, some aperture modification techniques can reduce the cross-polarization in a wide range of angles in the radiation pattern. Such techniques and their mechanisms are discussed in this paper. The obtained performance shows that the proposed antennas have a wide range of angles of 3-dB AR in the radiation pattern, broadband characteristics in impedance and AR, and low variation in group velocity.

• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.202-214
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• 2017

The augmented visualization of analysis results can play an import role as a post-processing tool for the modeling & simulation (M&S) technology. In particular, it is essential to develop such an M&S tool which can run on various multi-devices. This paper presents an augmented reality (AR) approach to visualizing and interacting with M&S post-processing results through mobile devices. The proposed approach imports M&S data, extracts analysis information, and converts the extracted information into the one used for AR-based visualization. Finally, the result can be displayed on the mobile device through an AR marker tracking and a shader-based realistic rendering. In particular, the proposed method can superimpose AR-based realistic scenes onto physical objects such as 3D printing-based physical prototypes in a seamless manner, which can provide more immersive visualization and natural interaction of M&S results than conventional VR or AR-based approaches. A user study has been performed to analyze the qualitative usability. Implementation results will also be given to show the advantage and effectiveness of the proposed approach.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.213-216
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• 2001

Etching behaviors of ferroelectric YMn $O_3$ thin films were studied by an inductively coupled plasma (ICP). Etch characteristic on ferroelectric YMn $O_3$ thin film have been investigated in terms of etch rate, selectivity and etch profile. The maximum etch rate of YMn $O_3$ thin film is 300 $\AA$/min at Ar/C $l_2$ of 2/8, RF power of 800W, dc bias voltage of 200V, chamber pressure of 15mTorr and substrate temperature of 3$0^{\circ}C$. Addition of C $F_4$ gas decrease the etch rate of YMn $O_3$ thin film. From the results of XPS analysis, Y $F_{X}$ compunds were found on the surface of YMn $O_3$ thin film which is etched in Ar/C1/C $F_4$ plasma. The etch profile of YMn $O_3$ film is improved by addition of C $F_4$ gas into the Ar/C $l_2$ plasma. These results suggest that fluoride yttrium acts as a sidewall passivants which reduce the sticking coefficient of chlorine on YMn $O_3$.>.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.71-78
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• 2004

Adrenergic receptors play a major role in thermogenesis and lipolysis in brown and visceral adipose tissues, and have been implicated in the pathogenesis of obesity and metabolic disorders. The purpose of this study was to estimate the effects of $\beta$2-adrenergic receptor ($\beta$2AR) and $\beta$3-adrenergic receptor ($\beta$3AR) genotypes on hyperglycemia and obesity in the Korean population. A representative sample consisting of 530 Korean men and women were measured for height, weight, BMI, WHR, obesity index and body composition. The genotypes of $\beta$2AR polymorphism in codon 27 and $\beta$3AR polymorphism in codon 64 were analyzed by the PCR RFLP method. Serum concentrations of fasting glucose, total cholesterol, HDL cholesterol and triglyceride were determined. The frequencies of $\beta$2AR and $\beta$3AR genotype were: both wild type, 62.5% ; only $\beta$2AR variant type, 12.8% ; only $\beta$3AR variant type, 18.8% ; and both variant type, 5.8% ; the frequency of E and R alleles were 0.098 and 0.137, respectively. Among the physiological parameters, fasting glucose level was significantly higher in subjects with both variant type compared with the three other types (p <0.05), Subjects with both variant type had 12%, 12% and 9.3% increases in serum glucose levels compared with wild type, only $\beta$2AR variant type, and only $\beta$3AR variant type, respectively. When logistic regression analysis was conducted to estimate the risk for hyperglycemia, the subjects were selected for fasting blood glucose concentrations of more than 6.105 m㏖/L (110 mg/dL), and the odds ratios were 1.215 (p=0.636) for only $\beta$2AR variant type,1.659 (p=0.089) for only $\beta$3AR variant type, and 3.078 (p=0.011) for both variant type. These results suggest that the interaction of $\beta$2AR and $\beta$3AR variant genotypes has a strong association with increased glucose levels, and might be a significant risk factor for hyperglycemia among Korean subjects.

• The Korean Journal of Applied Statistics
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• v.16 no.1
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• pp.141-150
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• 2003

This paper presents the multiple testing method of an autoregressive parameter in stationary AR(1) model using the usual Bayes factor. As prior distributions of parameters in each model, uniform prior and noninformative improper priors are assumed. Posterior probabilities through the usual Bayes factors are used for the model selection. Finally, to check whether these theoretical results are correct, simulated data and real data are analyzed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.938-941
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• 2000

SrBi$_2$Ta$_2$$O_{9}$(SBT) thin films were etched in Ar/SF$_{6}$ and Ar/CHF$_3$gas plasma using magnetically enhanced inductively coupled plasma(MEICP) system. The etch rates of SBT thin film were 1500$\AA$/min in SF$_{6}$/Ar and 1650 $\AA$/min in Ar/CHF$_3$at a rf power of 600W a dc-bias voltage of -l50V. a chamber pressure of 10 mTorr. In order to examine the chemical reactions on the etched SBT thin film surface , x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) were examined. In etching SBT thin film with F-base gas plasma, M(Sr. Bi. Ta)-O bonds are broken by Ar ion bombardment and form SrFand TaF$_2$ by chemical reaction with F. SrF and TaF$_2$are removed more easily by Ar ion bombardmentrdment

• Korean Journal of Acupuncture
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• v.36 no.1
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• pp.63-73
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• 2019

Objectives : This study was designed to investigate the effects of Alismatis Rhizoma (AR) pharmacopuncture at BL23 on acute renal failure induced by cisplatin. Methods : The Sprague-Dawley rats were divided into Normal group (no injection of cisplatin and no treatment), Control group (cisplatin injection without treatment), Acu group (needling at BL23 after cisplatin injection), AR-PA1 group (treated with $0.3571mg/kg/20{\mu}l$ of AR pharmacopuncture at BL23 after cisplatin injection), and AR-PA2 group (treated with $1.7855mg/kg/20{\mu}l$ of AR pharmacopuncture at BL23 after cisplatin injection). Each treatment was given once daily for 8 days. Changes in body weight, kidney weight, tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin-6 (IL-6), Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GPx), serum blood urea nitrogen (serum BUN), and serum creatinine were observed. Results : Body weight was significantly increased in AR-PA1 on $4^{th}$ and $6^{th}$ days and AR-PA2 on $2^{nd}$ day. $TNF-{\alpha}$ was significantly decreased in Acu, AR-PA1 and AR-PA2 groups. Cu-Zn SOD was significantly increased in AR-PA2 group. GPx was significantly increased in AR-PA1 and AR-PA2 groups. But kidney weight, IL-6, serum BUN and serum creatinine were not significantly changed in any groups compared to control group. Conclusions : In acute renal failure induced by cisplatin, AR pharmacopuncture has a mitigating effect on the inflammatory reaction related to the increase of $TNF-{\alpha}$ in the kidney tissue and a protective effect on the oxidative stress of the kidney tissue. However it is unlikely to restore the glomerular function or inhibit the renal swelling.

• Korean Journal of Metals and Materials
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• v.46 no.3
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• pp.125-130
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• 2008

Conventional plasma carburizing or nitriding for austenitic stainless steels results in a degradation of corrosion resistance. However, a low temperature plasma surface treatment can improve surface hardness without deteriorating the corrosion resistance. The 2-step low temperature plasma processes (the combined carburizing and post nitriding) offers the increase of both surface hardness and thickness of hardened layer and corrosion resistance than the individually processed low temperature nitriding and low temperature carburizing techniques. In the present paper, attempts have been made to investigate the influence of the introduction of Ar gas (0~20%) in nitriding atmosphere during low temperature plasma nitriding at $370^{\circ}C$ after low temperature plasma carburizing at $470^{\circ}C$. All treated specimens exhibited the increase of the surface hardness with increasing Ar level in the atmosphere and the surface hardness value reached up to 1050 HV0.1, greater than 750 $HV_{0.1}$ in the carburized state. The expanded austenite phase (${\gamma}_N$) was observed on the most of the treated surfaces. The thickness of the ${\gamma}_N$ layer reached about $7{\mu}m$ for the specimen treated in the nitriding atmosphere containing 20% Ar. In case of 10% Ar containing atmosphere, the corrosion resistance was significantly enhanced than untreated austenitic stainless steels, whilst 20% Ar level in the atmosphere caused to form CrN in the N-enriched layer (${\gamma}_N$), which led to the degradation of corrosion resistance compared with untreated austenitic stainless steels.