• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1624-1626
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• 1997

In this paper, a new PD measurement technique of pulse superposition method was proposed in order to investigate both PD mechanism and phase related PD patterns. From the experimental results, we could find that the polarity and the phase angle of the superposed pulse take great effects on PD characteristics and these method make it possible to get the physical information which statistical approach can not give. We could conclude that the changes of PD characteristics in the void surrounded by polymers may be attributed to the injection of charge carriers thereby formation of space charge in the surface and/or the bulk of the polymer.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.1-4
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• 1999

The attenuation coefficients of SiC particle reinforced low-density polyethylene (LDPE) matrix composites were measured by pulse echo method and dynamic elastic measure method with varying the volume fraction of SiC particle ranged from 0% to 40% and the size of SiC particles ranged from 0.8$\mu$m to 48$\mu$m. The SiCp/LDPE composites were fabricated with the melt injection process and the fabricated composites showed almost full density above 99% up to 40vo1% SiCp reinforcements. The attenuation constant of LDPE measured by dynamic elastic constant had same result with that measured by pulse echo method, but the attenuation constant of SiCp/LDPE measured by dynamic elastic constant did not have same result with that measured by pulse echo method.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1910-1912
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• 1996

This paper presents the results of laboratory experimentals to remove $SO_2$ and $NO_x$ by a pulsed corona discharge in the wire-plate reactor. A rotating spark gap switch was used to generate the pulse by chewing the dc high voltage. Repetition frequency of the pulse was 60Hz and rising time of 50ns. The photo pictures of positive streamer corona taken by ICCD camera, pulse voltage and current were measured using a digital oscilloscope. Simultaneous effects of $C_{2}H_{4}$ injection and heterogeneous chemical reactions on nonthermal plasma process to remove $SO_2$ and $NO_x$ from flue gas were investigated in the present study

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.2
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• pp.131-134
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• 2008

Purpose: The objective of this study was to evaluate the clinical parameters in terms of the midazolam sedation in patients undergoing dental practice. Patients and Methods: Total 28 patients were included in this study. They received the dental practice in the daycare center and sedation was done with midazolam. The recorded variables were blood pressure, pulse rate, $SpO_2$, and patient's response. The differences between observations were analyzed with paired samples t-test. Results: The blood pressure was significantly decreased after the administration of midazolam and the systolic pressure was significantly increased at the start of operation (P<0.05). The pulse rate was significantly increased after lidocaine injection (P<0.001). The amnesic effect was shown 21 cases out of 28 cases (75%). Conclusions: The effect of midazolam on pulse rate was not significant. However, midazolam could decrease the blood pressure significantly. Therefore, the sedation with midazolam could be successfully used in the dental practice, particularly for the patients having the hypertension.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.2
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• pp.204-210
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• 1988

The residue number system offers the possibility of high-speed operation and error detection/correction because of the separability of arithmetic operations on each digit. A compact residue arithmetic module named the self-checking pulse-train residue arithmetic circuit is effectively employed as the basic module, and an efficient error detection/correction algorithm in which error detection is performed in each basic module and error correction is performed based on the parallelism of residue arithmetic is also employed. In this case, the error correcting circuit is imposed in series to non-redundant system. This design method has an advantage of compact hardware. Following the proposed method, a 2nd-order recursive fault-tolerant digital filter is practically implemented, and its fault-tolerant ability is proved by noise injection testing.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.173-174
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.26-27
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• 2005

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3179-3186
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• 1993

The study on the spray characteristics of TBI(Throttle Body Injection) injector has been carried out in this paper. The objective of this study is to improve the performance of TBI injector. The increase in the injection pressure and the utilization of assisted air are considered. The spray patten of TBI injector take the hollow-cone shape with $60^{\circ}~70^{\circ}$ spray angle regardless of injection pressure and injection pulse width. SAMD(Sauter Mean Diameter) of water in TBI injector are 510-$550{\mu}m$ and 310-$370{\mu}m$ respectively when injection pressures are $0.75 kgf/cm^{2}$ and $2.8 kgf/cm^{2}$. Then SMD of gasoline is estimated 380~$410{\mu}m$ and 230~$280{\mu}m$ respectively. The improvement of spray characteristics in TBI injector can be obtained with assisted air. If $W_{A}/W_{L}$ was over 0.2, SMD of water can be made under $50{\mu}m$.

• Child Health Nursing Research
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• v.12 no.2
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• pp.215-222
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• 2006

Purpose: This study was done to identify the effects of the distraction generated by character stamp and stickers on reduction of intravenous injection pain. Method: This study was conducted using a quasi experimental non-equivalent control group non-synchronized design. 60 preschool children who admitted to a Pediatric Department in a C University Hospital were selected as subjects. Convenience assignment was used. The two groups were homogeneous on characteristics. Results: In the experimental group, objective pain(t=3.666, p=.001), subjective pain (t=3.415, p=.001) and perceived pain by the mother(t=2.528, p=0.014) decreased after intravenous injections than the control group. There were no statistical significant differences in pulse rate or fear between the experimental and the control group.　Conclusion: These findings indicate that using character stamp and stickers could be considered as an independent nursing intervention for intravenous injection pain reduction in preschooler.

• Journal of ILASS-Korea
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• v.12 no.3
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• pp.154-159
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• 2007

Spray tip penetration and spray angle for one main injection were measured at the atmospheric condition with the fuel injection pressure of 270 bar and 540 bar. It investigates an effect of different nozzle hole geometry of conventional cylindrical one and those of elliptical ones. Injection period represented by injector pulse drive was fixed at 1ms. From the result of this study, it is shown that spray tip penetration becomes shorter and spray angle becomes wider with the elliptical nozzle hole geometry due to fast break-up of a fuel liquid column.