• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.45-50
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• 2009

In this study, a simple gradient RRLC method for rapid determination of carbonyl compounds of cigarette smoke was developed. Within 10 min, 8 carbonyl compounds have been separated and identified on ZORBAX Eclipse XDB-C18 column ($4.6{\times}50\;mm$, $1.8\;{\mu}m$) with gradient elution using water and acetonitrile as a mobile phase. RRLC was used for the quantification of carbonyl compounds in mainstream smoke of 3R4F reference cigarette, and evaluated those efficiencies in the recovery, repeatability and reproducibility. The correlation coefficients ($r^2$) for calibration curves of carbonyl compounds were over 0.9998. The developed RRLC method was successfully applied to the analysis of smoke samples and the recoveries of carbonyl compounds were in the range of 97.5~102.1% with RSD<3.1%.

• The Journal of Korean Academic Society of Nursing Education
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• v.7 no.2
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• pp.323-332
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• 2001

This study was to investigate the level of nursing needs of parents who have hospitalized child. The subjects for this study were 70 parents who have hospitalized child at pediatric ward in S University Hospital, and the period of data collection was from June 5, 2000 to July 15, 2000. The research instruments used in this study was the Nursing Needs Scale and the cronbach's $\alpha$ of this scale was .92. This instrument had four dimensions : physical nursing needs, therapeutic nursing needs, emotional nursing needs and educational nursing needs. In data analysis, SPSSWIN 10.0 program was used for descriptive statistics. The results were as follows. 1) The range of nursing needs scores was from 104 to 156 and the mean score of the nursing needs was 132.64. 2) The mean score of the therapeutic nursing needs dimension was the most with 3.56 compared to emotional nursing needs(3.25), educational nursing needs(3.25), physical nursing needs(3.14). 3) There was a significant difference in nursing needs of parents according to the level of child's physical function(F=3.39, p<.05). 4) There was a significant correlation between nursing needs and child's physical function(r=-.262, p<.05).

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.47-52
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• 2001

This paper presents a high-performance control system for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consist of stator flux observer, rotor position/speed estimator, torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter, and F240/C31DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor position is estimated by the observed stator flux-linkage space vector. The estimated rotor speed can be determinated by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. To prove the suggested control algorithm, we have a simulation and testing at actual experimental system. The developed digitally high-performance position sensorless control system are shown a good motion control response characteristic results and high performance features using 1.0Kw RSM.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.4
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• pp.367-378
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• 2016

Recently, it was reported that the role of mitochondria-reactive oxygen species (ROS) generating pathway in cisplatin-induced apoptosis is remarkable. Since a variety of molecules are involved in the pathway, a comprehensive approach to delineate the biological interactions of the molecules is required. However, quantitative modeling of the mitochondria-ROS generating pathway based on experiment and systemic analysis using the model have not been attempted so far. Thus, we conducted experiments to measure the concentration changes of critical molecules associated with mitochondrial apoptosis in both human mesothelioma H2052 and their ${\rho}^0$ cells lacking mitochondrial DNA (mtDNA). Based on the experiments, a novel mathematical model that can represent the essential dynamics of the mitochondrial apoptotic pathway induced by cisplatin was developed. The kinetic parameter values of the mathematical model were estimated from the experimental data. Then, we have investigated the dynamical properties of this model and predicted the apoptosis levels for various concentrations of cisplatin beyond the range of experiments. From parametric perturbation analysis, we further found that apoptosis will reach its saturation level beyond a certain critical cisplatin concentration.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.11 no.3
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• pp.265-274
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• 2004

Purpose: This study was to identify the level of spirituality in student nurses and to provide baseline data to develop a spirituality development education program. Method: The participants were 499 students in departments of nursing in 5 universities in Busan. The data were collected between June 7 and July 18, 2002. The instrument was used Howden's spirituality assessment scale. Collected data were analyzed with frequencies, percentages, $Means{\pm}SD$, t-test F-test, Scheffe test, and Pearson's correlation coefficient. The SPSS program was used. Results: 1) The mean score for spirituality was $101.14{\pm}8.70$ (range 26-130). 2) The mean score for perceived health state was $3.42{\pm}0.80$. 3) Spirituality according to general characteristics showed significant differences for sex, religion, practice experience, smoking, drinking, and climate of home. 4) Spirituality according to religious characteristics showed significant differences for influence of religion, necessity of religion, help from religion, subjectivity of God in life, reading religious books, participation in religion ceremonies. 5) There was a significant positive correlation between perceived health state and spirituality. Conclusion: The spirituality of the student nurses was high and differed according to sex, religion, practice experience, smoking, drinking, and climate of home, religious characteristics, spirituality, and perceived health status.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.395-404
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• 2016

A 6-bit 3.4 GS/s flash ADC in a 65 nm CMOS process is reported along with the proposed 4x time-domain interpolation technique which allows the reduction of the number of comparators from the conventional $2^N-1$ to $2^{N-2}$ in a N-bit flash ADC. The proposed scheme effectively achieves a 4x interpolation factor with simple SR-latches without extra clocking and calibration hardware overhead in the interpolated stage where only offset between the $2^{N-2}$ comparators needs to be calibrated. The offset in SR-latches is within ${\pm}0.5$ LSB in the reported ADC under a wide range of process, voltage supply, and temperature (PVT). The design considerations of the proposed technique are detailed in this paper. The prototype achieves 3.4 GS/s with 5.4-bit ENOB at Nyquist and consumes 12.6 mW power at 1 V supply, yielding a Walden FoM of 89 fJ/conversion-step.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.328-328
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• 2008

As a low K material for high frequency high integration modules, glass/ceramic composites were investigated. Glass composition were selected from $SiO_2-B_2O_3-Al_2O_3-R_2O$-RO system which having very low dielectric constant and cordierite was used as a ceramic filler. These composites were sintered at temperature range from $850^{\circ}$ to $950^{\circ}$ and XRD, SEM microstructure analysis of sintered bodies were performed for understanding sintering behavior. Any crystallization was not occurred and dense sintered bodies were attained. Dielectric and mechanical properties of these sintered glass/cordierite composites were analysed by network analyzer and UTM. Glass/ceramic composite with 50 wt% cordierite showing a dielectric constant (${\varepsilon}_r$) of 5.4, Q${\times}f_0$ (Q) of 1600 at 1 GHz and maximum bending strength of 163 MPa was attained.

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.81-85
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• 2012

This paper presents a wideband and low-noise direct conversion front-end receiver supporting VHF and UHFbands simultaneously. The receiver iscomposed of a low-noise amplifier (LNA), a down conversion quadrature mixer, and a frequency divider by 2. The cascode configuration with the resistor feedback is exploited in the LNA to achieve a wide operating bandwidth. Four gainstep modesare employed using a switched resistor bank and a capacitor bank in the signal path to cope with wide dynamic input power range. The verticalbipolar junction transistors are used as the switching elements in the mixer to reduce 1/f noise corner frequency. The proposed front-end receiver fabricated in 0.18 ${\mu}m$ CMOS technology shows very low minimum noise figureof 1.8 dB and third order input intercept pointof -12dBm inthe high-gain mode of 26.5 dBmeasured at 500 MHz.The proposed receiverconsumeslow current of 20 mA from a 1.8 V power supply.

• Advances in nano research
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• v.8 no.2
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• pp.95-102
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• 2020

In this work the properties of iron oxide magnetic nanoparticles (MNPs) synthesized by electrochemical method using different water-alcohol proportions and alcohols have been investigated. The syntheses were carried out using 99% iron foils acting electrodes in a 0.04 M NaCl solutions at room temperature applying 22 mAcm^-2 on the working electrode, mostly obtaining magnetite nanoparticles. The impact of the electrolyte in the size of the synthesized MNPs has been evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), chronopotentiometric studies, and magnetic characterization. The results have shown that nanoparticles can be obtained in the range of 6 to 26 nm depending on the type of alcohol and the proportions in the mixture of water-alcohol. The same trend has been observed for all alcohols. As the proportion of these in the medium increases, the nanoparticles obtained are smaller in size. This trend is maintained until a certain proportion of alcohol: 50% for methanol, and 60% for the rest of alcohols, proportions where obtaining a single phase of magnetite is not favored.

• YAKHAK HOEJI
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• v.40 no.5
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• pp.558-562
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• 1996

Betulinic acid and alphitolic acid, the triterpenoids of Zyziphi Fructus, were isolated with silica gel column chromatography and used as the standard substances for the analysis. The compounds were determined with HPLC and HPTLC. They were separated on reversed phase column (Nova-Pak C18) with 0.05M Na2HPO4-methanol (19:81) in HPLC and detected at 210nm. Separation on HPTLC precoated silica gel F254 plates was carried out with chloroform-methanol (6:1) and the separated compounds were reacted with p-anisaldehyde and detected at 540nm. The contents of betulinic acid and alphitolic acid in Zyziphi Fructus from four different regions in Korea were in the range of 2.9~3.8% and 3.2~3.9%, respectively.