• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.189-191
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• 2018

This paper introduces a novel ZVS interleaved totem-pole PFC with the reduced circulating current and the reverse recovery current of the diodes. With the help of a simple auxiliary inductor, both ZVS turn-on of the main switches and soft turn-off of the body diodes can be achieved. In the proposed totem-pole PFC topology since the switching losses and the reverse recovery losses can be significantly reduced, the typical Si MOSFETs can be employed. In addition the circulating current is reduced by adjusting the switching frequency. The proposed PFC topology can be a low cost solution to achieve high efficiency in high power PFC applications. The validity and the feasibility of the proposed topology is verified by the experimental results with a 3.3kW interleaved totem-pole PFC converter.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.4
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• pp.23-32
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• 2009

• Journal of Korean Academy of Nursing
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• v.45 no.3
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• pp.347-356
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• 2015

Purpose: In this study, the effectiveness of a motivational interviewing smoking cessation YOU-TURN program for adolescents was examined. The program was based on the self-determination theory. Methods: The study was carried out with a nonequivalent control group pretest-posttest design. Participants in the present study were 136 high school students living in D city. The students were assigned to the experimental group (n=52) who participated in the motivational interviewing smoking cessation YOU-TURN program based on self-determination theory, or to the control group (n=84) who participated in a general smoking cessation program. Data were collected from September 1, 2013 through April 30, 2014. Collected data were analyzed using SPSS PC+ 21.0 with Chi-square test, Fisher's exact test, t-test, Mann-Whitney U test, Repeated Measures ANOVA, and MANOVA-Wilk's Lambda. Results: The experimental group had a significant increase in basic psychological needs, and duration of quitting-smoking in comparison with the control group. The experimental group had a significant decrease in cigarettes smoked per day and cotinine in urine in comparison with the control group. Conclusion: The motivational interviewing YOU-TURN program, when delivered to adolescents who smoked, was effective in discouraging smoking, and can be utilized as an effective nursing intervention for adolescents who smoke.

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.135-146
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• 2013

PURPOSES : This study aimed to analyze the impact the operation of pre-signals at 4-leg signalized intersections and present primary environmental factors of roads that need to be considered in the installation of pre-signals. METHODS : Shift of proportions safety effectiveness evaluation method which assesses shifts in proportions of target collision types to determine safety effectiveness was applied to analyze traffic crash by types. Also, Empirical Bayes before/after safety effectiveness evaluation method was adapted to analyze the impact pre-signal installation. Negative binomial regression was conducted to determine SPF(safety performance function). RESULTS : Pre-signals are effective in reducing the number of head on, right angle and sideswipe collisions and both the total number of personal injury crashes and severe crashes. Also, it is deemed that each factor used as an independent variable for the SPF model has strong correlation with the total number of personal injury crashes and severe crashes, and impacts general traffic crashes as a whole. CONCLUSIONS: This study suggests the following should be considered in pre-signal installation on intersections. 1) U-turns allowed in the front and rear 2) A high number of roads that connect to the intersection 3) Many right-turn traffic flows 4) Crosswalks installed in the front and rear 5) Insufficient left-turn lanes compared to left-turn traffic flows or no left-turn-only lane.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.179-182
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• 2008

It needs to consider of turns during a path-finding on real road network. Because a car is delayed by waiting a traffic signal and decreasing speed when drived in a turn road such as cross road and slip road. If a straightness of a path is increased, a real cost of traveling should be able to decrease. An older method, the algorithm with Turn Heuristic, considered of this case. The algorithm, that differently gave weights to left, right and U-turns, improved a straightness of a path, but increased a cost of exploring. In this paper, we propose a improved Turn Heuristic Algorithm. Proposed algorithm uses Dynamic Turn Heuristic. It is able to more decrease a cost of exploring than older method by using the Turn Heuristic in a part of path-finding.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.03a
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• pp.75-84
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• 1998

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1121-1122
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• 2013

• 한국ITS학회:학술대회논문집
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• 2004.11a
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• pp.18-23
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• 2004

• Journal of the Korean Statistical Society
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• v.18 no.2
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• pp.97-106
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• 1989

We consider two semiparametric regression lines where the density of the error terms are unknown. We give simultaneous estimatros of the differences of intercepts and slopes which turn out to be asymptotically minimax as well as efficient in semiparametric sense.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2211-2220
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• 2017

Chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) formulations are frequently used as antiseptics in healthcare and consumer products. Burkholderia cepacia complex (BCC) contamination of pharmaceutical products could be due to the use of contaminated water in the manufacturing process, over-diluted antiseptic solutions in the product, and the use of outdated products, which in turn reduces the antimicrobial activity of CHX and BZK. To establish a "afe use" period following opening containers of CHX and BZK, we measured the antimicrobial effects of CHX ($2-10{\mu}g/ml$) and BZK ($10-50{\mu}g/ml$) at sublethal concentrations on six strains of Burkholderia cenocepacia using chemical and microbiological assays. CHX (2, 4, and $10{\mu}g/ml$) and BZK (10, 20, and $50{\mu}g/ml$) stored for 42 days at $23^{\circ}C$ showed almost the same concentration and toxicity compared with freshly prepared CHX and BZK on B. cenocepacia strains. When $5{\mu}g/ml$ CHX and $20{\mu}g/ml$ BZK were spiked to six B. cenocepacia strains with different inoculum sizes ($10^0-10^5CFU/ml$), their toxic effects were not changed for 28 days. B. cenocepacia strains in diluted CHX and BZK were detectable at concentrations up to $10^2CFU/ml$ after incubation for 28 days at $23^{\circ}C$. Although abiotic and biotic changes in the toxicity of both antiseptics were not observed, our results indicate that B. cenocepacia strains could remain viable in CHX and BZK for 28 days, which in turn, indicates the importance of control measures to monitor BCC contamination in pharmaceutical products.