• Tuberculosis and Respiratory Diseases
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• v.80 no.1
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• pp.21-26
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• 2017

It is well established that health care workers (HCWs) have a considerably higher risk of occupationally acquired tuberculosis (TB). To reduce the transmission of TB to HCWs and patients, TB infection control programs should be implemented in health care settings. The first and most important level of all protection and control programs is administrative control. Its goals are to prevent HCWs, other staff, and patients from being exposed to TB, and to reduce the transmission of infection by ensuring rapid diagnosis and treatment of affected individuals. Administrative control measures recommended by the United States Centers for Disease Control and Prevention and the World Health Organization include prompt identification of people with TB symptoms, isolation of infectious patients, control of the spread of the pathogen, and minimization of time spent in health care facilities. Another key component of measures undertaken is the baseline and serial screening for latent TB infection in HCWs who are at risk of exposure to TB. Although the interferon-gamma release assay has some advantages over the tuberculin skin test, the former has serious limitations, mostly due to its high conversion rate.

• Journal of Engineering Education Research
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• v.18 no.4
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• pp.34-44
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• 2015

Mathematical, spatial, and verbal abilities are important for future engineers to succeed in the STEM disciplines. The purpose of the study is to assess engineering students' spatial abilities and analyse the relationship with mathematical achievement, verbal achievement, and gender. On the mental rotation tests, 65% of male students demonstrated a substantial level of spatial abilities. But only 30% of female students exhibited spatial skills at the same level as their male colleagues. The correlations between mathematical - spatial - verbal abilities are found to be negligible. When spatial visualization ability was plotted according to the mathematical achievement level, there was no difference in the mean spatial abilities score. But when mathematical achievement score was plotted according to the spatial abilities, there was a noticeable difference. Regression analysis confirmed that female students' mathematical achievement increased as spatial abilities improved. This phenomenon was not observed for male students. It's because male students' spatial ability already contributed to their mathematics achievement. So spatial ability can be regarded as one factor for the gender differences in mathematics achievement. The gender gap on spatial abilities and math achievement is large among high achieving students. For example, there was a 4.3 to 1 male - female ratio and 3.4 to 1 male - female ratio among students scoring 99th percentile in spatial visualization test and scholastic aptitude test-math.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.314-318
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• 2007

The feasibility of the employment of waste oyster shell as an adsorbent for fluoride ion has been tested by considering the effect ionic condition on the adsorption of fluoride ion on oyster shell. The adsorption capacity of oyster shell for fluoride ion was found not to be significantly influenced by the ionic strength of aqueous environment. The existence of complexing agent such as nitrilotriacetic acid in wastewater decreased the adsorbed amount of fluoride ion by forming a stable complex of $CaT^-$ and the adsorption reaction of fluoride ion on oyster shell was examined to be endothermic. The coexisting heavy metal ionic adsorbate in wastewater hindered the adsorption of fluoride ion, however, its adsorbed amount was increased as the particulate size of adsorbent was decreased. Finally, a serial adsorption column test has been conducted for a practical application of adsorption process and the breakthrough of the column adsorption was observed in 22 hours under the experimental condition.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.39-46
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• 2008

Background : Acupuncture has been used as a clinical treatment in Oriental medicine for various diseases including pain relief. The descending pain control system of periaqueductal gray (PAG) is a powerful pain control system in mammalians. Expression of c-Fos is used as a marker for stimuli-induced metabolic changes of neurons. Objective : In the present study, the effects of acupuncture on analgesic effect in visceral pain were investigated through the writhing reflex and c-Fos expression in ventrolateral PAG (vlPAG) area using immunohistochemistry in mice. Method : For the writhing test, mice were divided into five groups. Immediately after finishing the behavioral test, the animals were weighed and overdosed with Zoletil. After a complete lack of response was observed, the brains of the mice were dissected into serial coronal sections, and c-Fos immunohistochemistry was performed. Statistical analysis of all data was performed using one-way ANOVA. Result : The present results showed that acupuncture affected the writhing reflex and that Choksamni (zusnali) acupoint and aspirin significantlysuppressed acetic acid treatment-induced increased writhing reflex, and the expression of c-Fos in vlPAG was significantly increased in the acupunctured group. Conclusion : The present study suggests that acupuncture has an antinociceptive effect on acetic acid-induced visceral pain by increase of c-Fos expression in mice. Aspirin also showed analgesic effect, however the mechanism is different from the acupuncture.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.41-44
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• 2016

We report here a case of maternal 3-methylcrotonyl-coenzyme A carboxylase (3-MCC) deficiency in a Korean woman. Her 2 infants had elevated 3-hydroxyisovalerylcarnitine (C5-OH) on a neonatal screening test by liquid chromatography-tandem mass spectrometry (LC-MS/MS), but normal results were found on urine organic acid analysis. The patient was subjected to serial testing and we confirmed a maternal 3-MCC deficiency by blood spot and breast milk spot test by LC-MS/MS, serum amino acid analysis, urine organic acid and molecular genetic analysis that found c.838G>T (p.Asp280Tyr) homozygous mutation within exon 9 of the MCCB gene. Especially, we confirmed marked higher levels of C5-OH on breast milk spot by LC-MS/MS, in the case of maternal 3-MCC deficiency vs. controls.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.43-51
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• 1998

In this paper, the performance about the CDMA inital synchronization under the Rician fading channel, which is actively studied as a CAI for IMT2000(FPLMTS) is analyzed. Through the performance analysis with the double dwell serial search code acquisition, the minimum mean initial synchronization acquisition time vs signal detection threshold value and first dwell duration time respectively with parameters of false alarm probability, detection probability and test PN chips is presented and the results show the mean initial synchronization acquisition time is increased with lower slope than Rayleigh fading as the threshold value of the initial synchronization acquisition decision is increased.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.193-193
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• 2017

Trend analysis can enhance our knowledge of the dominant processes in the area and contribute to the analysis of future climate projections. The results of previous studies in South Korea showed that southeast regions of Korea had the highest value of evapotranspiration. Thereby, it is of interest to determine the trend analysis in hydrological variables in this area. In this study, the recent 35 year trends of precipitation, reference evapotranspiration, and aridity index in monthly and annual time scale will be analyzed over three stations (Pohang, Daegu, and Pusan) of southeast Korea. After removing the significant Lag-1 serial correlation effect by pre-whitening, non-parametric statistical Mann-Kendall test was used to detect the trends. Also, the slope of trend of the Mann-Kendall test was determined by using Theil-Sen's estimator. The results of the trend analysis of reference evapotranspiration on the annual scale showed the increasing trend for the three mentioned stations, with significant increasing trend for Pusan station. The results obtained from this research can guide development if water management practices and cropping systems in the area that rely on this weather stations. The approaches use and the models fitted in this study can serve as a demonstration of how a time series trend can be analyzed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.5
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• pp.633-641
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• 1999

Experiments were carried out to investigate the condensation heat transfer characteristics for R22 and its alternatives, R407C (R32/125/134a, 23/25/52wt%) and R410A (R32/125, 50/50wt%). A concentric tube heat exchanger was made to conduct condensation heat transfer tests. Mass flux and saturation temperature of refrigerants at the test section inlet were varied to get the corresponding heat transfer coefficients. Serial and parallel input of secondary fluid (water) were applied to the test subsections. Compared with existing correlations of condensation heat transfer, experimental heat transfer coefficients obtained in this study were generally higher than the predicted values, and mean absolute deviations from several correlations were shown. Wall subcooling was introduced to get a new correlation for condensation heat transfer coefficients by modifying Shah's equation. The RMS deviation of the measured heat transfer coefficients from the new correlation in this study for R22 is 9.9% and that for R407C and R410A are 10.2% and 14.6%, respectively.

• Journal of Industrial Technology
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• v.17
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• pp.95-101
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• 1997

A smart pressure measurement system is described, which provides a precise A/D conversion and is highly suitable for communication with microprocessors. In order to avoid unstable problems of remote pressure sensing we have developed a new interface board which performs the A/D conversion and smart signal processing of the measured pressure data. Serial communication software which is based on ASCII code commands is also developed to process initial setup and calibration functions as well as multi-drop communication with PC. The test and evaluation of the proposed system has been shown as having the better performance compared to the other types of existing pressure measuring systems and will give good applications to the industrial use where a highly precision remote sensing is needed.

• Journal of IKEEE
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• v.15 no.2
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• pp.129-133
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• 2011

A spread spectrum clock generation is an efficient way to reduce electro-magnetic interference (EMI) radiation in modern mixed signal chip systems. The proposed circuit generates the spread spectrum clock by directly injecting the modulation voltage into the voltage-controlled oscillator (VCO) current source for SATA II. The resulting 33KHz modulation profile has a Hersey-Kiss shape with a rounded peak. The chip has been fabricated using $0.18{\mu}m$ CMOS process and test results show that the proposed circuit achieves 0.509% (5090ppm) down spreading at 1.5GHz and peak power reduction of 10dB. The active chip area is 0.36mm ${\times}$ 0.49mm and the chip consumes 30mW power at 1.5GHz.