• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.167-168
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• 2018

In this research, the feasibility of wireless senor for compressive strength evaluation was checked by applying on the actual apartment construction site with insulation formwork during winder period. As a result, there was no significant problem on monitoring the compressive strength of the concrete with the sensor. Thus it is considered that the suggested method can be an efficient method for the quality control at the construction site.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.455-459
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• 2003

The Reconstructive techniques of palatal defect are palatal island flap, palatal mucoperiosteal expansion, buccal flap, tongue flap, pushback palatoplasty, free flap and so on. We report a reconstruction of palatal defect using palatal flap. Excellent results were obtained by palatal connective tissue island flap and split thickness pedicle flap. Healing of defect occured rapidly. There were no postoperative complications except dull pain.

• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.525-528
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• 1999

Mutagenic activities of extracts from the filtrate of the cultured broth (PI-I), mycelia (pI-II), and the fruiting bodies (PI-III) of Phellinus igniarius were examined by Ames/Salmonella tests. No mutagenic activity was found in Salmonella typhimurium strains TA98 and TA100, either with or without S9 activation. In contrast, PI-I, PI-II, and PI-III showed inhibitory effects on the mutagenic activities by the directly-acting mutagens, 4-nitro-ο-phenylenediamine(NPD) and sodium azide ($NaN_3$), and also by the indirectly-acting mutagens, 2-aminofluorene (2-AF) and benzo[a]pyrene (B[a]P). These results suggest that P. igniarius possesses some antimutagenic activity and may contain some chemopreventive agents.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2809-2812
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• 2010

The Chemical Doping of epitaxial graphene (EG) due to p-tert-butylcalix[4]arene was investigated using high resolution photoemission spectroscopy (HRPES). The measured work function changes verified that increased adsorption of the p-tert-butylcalix[4]arene on EG showed p-type doping characteristics due to charge transfer from the graphene to the p-tert-butylcalix[4]arene through the hydroxyl group. A single oxygen bonding feature associated with the O 1s peak was clearly observed in the core-level spectra, indicating the presence of one equivalent adsorption state.

• Journal of Power Electronics
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• v.1 no.2
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• pp.71-77
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• 2001

This paper proposes a new zero-current switching (ZCS) pulse-width modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero current condition. The diodes commutate softly and the reverse recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of DC to DC PWM converters is derived. The new family of ZCS PWM converters is suitable for the high power applications employing IGBTs. Among the new family of DC to DB PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5 kW prototype converter operating at 40 kHz.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.937-939
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• 2007

Carbon nanotubes (CNTs) have used as an electron field emitter of the field emission display (FED) due to their characteristics of high-electron emission, rapid response and low power consumption. However, to commercialize the FED with CNT emitter, some fundamental problems regarding life time and emission efficiency have to be solved. In this study, we investigated the $TiO_2$ coated CNT as a field emitter. $TiO_2$ nanoparticles can coated on CNT surface by chemical solution method. $TiO_2$ nanoparticles had uniform size with the average size of about 2.4 nm to 3.1 nm. Field emission performance of CNT coated with $TiO_2$ nanoparticles was evaluated and discussed.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.115.2-115
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• 2003

No Abstract, See Full Text

• Journal of the Korean earth science society
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• v.41 no.4
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• pp.381-390
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• 2020

When a radial collector well is installed and operated for agricultural purposes, negative impacts may be observed over time due to the clogging of horizontal arms, such as reduced groundwater discharge and water quality deterioration. When radial collector well No. 2 was rehabilitated using the high-pressure impulse generation technique, the specific capacity and transmissivity were increased by 43.1 and 100.6%, respectively. In contrast, according to air surging, the specific capacity and transmissivity increased by 33.8 and 85.8%, respectively, compared to the initial rate before rehabilitation. During the operation of radial collector wells since construction, the time of well rehabilitation can be effectively determined by continuously monitoring the groundwater level and pumping rate of the radial collector wells, thereby preventing a decrease in productivity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1044-1047
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• 2004

This aim of this study is is an experimental study to introduce the Reduction method of Floor Impact Sound in Apartment Houses by using Model Test, We are measured the floor impact sound in Rahamen and Apartment with Shear Wall and Post-tensioning. There is comparison between Rahmen Structure and Apartment with Shear Wall. The main results from this study are effective in reduction of heavt-weight The slab was constructed by rahamen structure. Heavy-weight can reduced by upgrading naturial frequency of floor impact sound in rahmen structure.

• Journal of the Korean Mathematical Society
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• v.44 no.2
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• pp.307-326
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• 2007

We know that there are no real hypersurfaces with parallel Ricci tensor or parallel structure Jacobi operator in a nonflat complex space form (See [4], [6], [10] and [11]). In this paper we investigate real hypersurfaces M in a nonflat complex space form $M_n(c)$ under the condition that ${\nabla}_{\varepsilon}S=0\;and\;{\nabla}_{\varepsilon}R_{\varepsilon}=0,\;where\;S\;and\;R_{\varepsilon}$ respectively denote the Ricci tensor and the structure Jacobi operator of M in $M_n(c)$.