• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.3
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• pp.225-232
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• 2018

This paper proposed the optimization method of the extremely low numerical-dispersion finite-difference time-domain (ELND-FDTD) method based on the H(2,4) scheme for wideband and extremely accurate electromagnetic properties of lossy material, which has a constant conductivity and relative permittivity. The optimized values of three variables are calculated for the minimum numerical dispersion errors of the proposed FDTD method. The excellent accuracy of the proposed method is verified by comparing the calculated results of three different FDTD methods and the analytical results of the two-dimensional dielectric cylinder scattering problem.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.97-104
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• 2016

In this paper, in order to relieve the area of terrestrial DTV broadcasting, we watch the same channel DTV Repeater output ICS using nano field test and analysis of effect was proven. Interspersed throughout the blanket area(natural) and buildings(artificially) 7 established the field selected as the test area, and each station(KBS1, KBS2, MBC, SBS, EBS) Extremely Low Power ICS Repeater the same channel of the receiving field strength and after install, SNR(Signal to Noise Ratios) verify the equipment to measure the efficacy and minimal output for future ICS type nav should you wish to provide a research-based for the spread.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2003-2008
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• 2013

In this paper, a design method for a ultra-wideband printed semi-circular-shaped dipole antenna operating in the band of 1-15 GHz is studied. The effects of the gap between the two arms of the semi-circular-shaped dipole and the radius of the semi-circle on the input reflection coefficient and gain characteristics are examined to obtain the optimal design parameters. The optimized printed semi-circular-shaped dipole antenna is fabricated on an FR4 substrate and the experimental results show that the antenna has a desired extremely wideband characteristic with a frequency band of 1-15 GHz (175%) for a VSWR < 2.

• Journal of Microbiology and Biotechnology
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• v.4 no.1
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• pp.36-40
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• 1994

A water sample was taken from a black smoker chimney of a deep-sea hydrothermal vent by using an unmanned submersible "Dolphin 3K". The temperature of the hydrothermal fluid from the black smoker was $276^{\circ}C$. After isolation by repeated serial dilutions, An extremely thermophilic bacterial strain was selected. The strain designated as DT1331, was an anaerobic, non-motile, coccoid shaped bacterium with about 0.5 to $1.0\;\mu\textrm{m}$ in diameter. The strain DT1331 could grow up to $93^{\circ}C$, but the optimum temperature of this strain was $80^{\circ}C$. The growth occurred in the pH range of 4.5 to 8.5 and the optimum pH was 6.0. The strain DT1331 required 1% to 5% NaCl for growth and cell lysis was observed below 1% NaCl concentration. The bacterium could grow on polypeptides such as tryptone, peptone, soytone and on proteins such as casein or gelatin. However, no growth was observed on single amino acids, sugar and organic acids. Hydrogen gas was detected slightly during growth. This bacterium obligately required elemental sulfur and hydrogen sulfide gas was produced during growth.

• Clinical and Experimental Pediatrics
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• v.51 no.3
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• pp.237-242
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• 2008

To investigate the trends in the survival rate (SR) for very low birth weight infants (VLBW) and extremely low birth weight infants (ELBWI) in Korea, a total of 43 articles pertaining to SR were analyzed, covering the years from 1967 to 2007. The changes in SR were compared using 5 year periods. The SR for VLBWI has increased remarkably, from 31.8% in early 1960 to 65.8% in early 1990 and 78.8% in early 2000. The SR for ELBWI has increased from 8.2% in early 1960 to 37.4% in early 1990 and 62.4% in early 2000. The SR has improved steeply since early 1990. When the SRs for VLBWI in Korea were compared with those in the U.S.A. and Japan, the figures were 40%, 72%, and 79% in 1985; 65.8%, 82%, and 86% in 1990; 71.3%, 86%, and 88% in 1995; 78.8%, 86%, and 89% in 2000, respectively. Although the recent SRs for VLBWI and ELBWI in Korea has improved rapidly, they have not yet reached the levels in these highly developed countries. To obtain accurate statistics that could be represented as an SR for premature infants in Korea, we have to develop a nationwide network database project.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.14-21
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• 2009

Neurodevelopmental outcomes of very low birth weight infants (VLBWI) and extremely low birth weight infants (ELBWI) in Korea on 14 reports from 1984 to 2008 were analyzed. Follow-up rates were varied from 42.9% to 90.2%. Duration of follow-up ranged from 4 months to 5 years. The prevalence of cerebral palsy (CP) of VLBWI was as follows: 4.3-5.3% in 1980s, 7.1-9.1 % in 1990s and 3.6-15.6% in 2000s. CP was noted in 8.2-30.8% of ELBWI on studies reported in 2000s. Delayed Mental development was diagnosed in 2.0-17.9% of VLBWI and in 20.4-30.8% of ELBWI. Sensory impairments such as hearing loss or visual deficit were reported in 3.1-3.6% of VLBWI and 0.0-10.0% of ELBWI. Seizure disorder was reported in 5.3% of VLBWI by one report. No reports for minor neurodevelopmental dysfunctions in VLBWI and ELBWI were found from 1984 to 2008. It is necessary to establish basic protocols and nationwide systems for long-term follow-up study to obtain valuable data.

• Clinical and Experimental Pediatrics
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• v.59 no.2
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• pp.96-99
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• 2016

Survival rates of preterm infants have improved in the past few decades, and central venous catheters play an important role in the intensive medical treatment of these neonates. Unfortunately, these indwelling catheters increase the risk of intracardiac thrombosis, and they provide a nidus for microorganisms during the course of septicemia. Herein, we report a case of persistent bacteremia due to methicillin-resistant Staphylococcus aureus in an extremely low birth weight (ELBW) infant, along with vegetation observed on an echocardiogram, the findings which are compatible with a diagnosis of endocarditis. The endocarditis was successfully treated with antibiotic therapy, and the patient recovered without major complications. We suggest a surveillance echocardiogram for ELBW infants within a few days of birth, with regular follow-up studies when clinical signs of sepsis are observed.

• Journal of Sensor Science and Technology
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• v.18 no.2
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• pp.139-146
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• 2009

A Multilayered microelectrode design is presented for large area travelling wave dielectrophoresis (TwDEP) separators. Most of typical TwDEP chip has been arrayed with 1000 electrodes in $20{\times}20\;mm^2$. However, there is a limitation of the device area that is critical in throughput, because when the area of TwDEP becomes larger, the resistance of microelectrodes for bus bar is also increased. In this paper, we successfully developed a novel TwDEP chip with extremely large area ($31{\times}25\;mm^2$) by a unique multilayered bus bar design. According to the resistance simulation of our microelectrodes, it is possible to realize a TwDEP chip with an infinite longitudinal length. We demonstrated the feasibility of our suggestion with latex microbeads and showed the potential of extremely high throughput separation with TwDEP technique.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.1
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• pp.1-10
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• 2016

Objectives: The aim of this study is to review the results of exposure to chemicals and to extremely low frequency(ELF) magnetic fields generated in wafer fabrication operations in the semiconductor industry. Methods: Exposure assessment studies of silicon wafer fab operations in the semiconductor industry were collected through an extensive literature review of articles reported until the end of 2015. The key words used in the literature search were "semiconductor industry", "wafer fab", "silicon wafer", and "clean room," both singly and in combination. Literature reporting on airborne chemicals and extremely low frequency(ELF) magnetic fields were collected and reviewed. Results and Conclusions: Major airborne hazardous agents assessed were several organic solvents and ethylene glycol ethers from Photolithography, arsenic from ion implantation and extremely low frequency magnetic fields from the overall fabrication processes. Most exposures to chemicals reported were found to be far below permissible exposure limits(PEL) (10% < PEL). Most of these results were from operators who handled processes in a well-controlled environment. In conclusion, we found a lack of results on exposure to hazardous agents, including chemicals and radiation, which are insufficient for use in the estimation of past exposure. The results we reviewed should be applied with great caution to associate chronic health effects.

• Child Health Nursing Research
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• v.17 no.2
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• pp.145-152
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• 2011

Purpose: To evaluate the efficacy of Optimal humidification during Nasal Continuous Positive Airway Pressure (nCPAP) for Extremely Low Birth Weight Infant (ELBWI). Methods: The study design was a pre-test-post-test nonequivalent nonsynchronized quasi-experimental design. The participants were 218 ELBWI on nCPAP (experimental group: 102 and control group: 116). Data collection was conducted from January 2005 to April 2010. In order to measure and analyze the nCPAP duration, reintubation and nasal condition, Chi-square test and t-test were used. Results: Hypothesis 1, that the duration with nCPAP in the experimental group is longer than that of the control group and hypothesis 2-3, that the rate of reintubation and nasal problems in the experimental group are lower than the control group, were all supported as there were statistically significant differences between two groups. Conclusion: The findings suggest that the Optimal humidification in this study is an efficient intervention because it helps increase the last time of nCPAP with ELBWI and minimize complications. It is expected that Optimal humidification is beneficial and helpful in preventing and caring for respiratory problems in these infants.