• Speech Sciences
• /
• v.9 no.1
• /
• pp.193-206
• /
• 2002

The aim of this study is to find out how the labiovelar onglide /w/ in English kwV sequences that have minimal pairs with kV sequences is pronounced differently among Korean EFL learners based on acoustic evidence. This study tries to identify /w/ sound in English kwV sequences through spectrograms and to examine the duration ratios of each segment in kwV words to compare the patterns of an English native speaker with those of Korean speakers of English. In spectrographic analyses, the complete deletion of /w/ and partial pronunciation of /w/ dubbed [$k^{w}$] were identified as well as the targetappropriate production of /w/. The general production patterns with respect to the duration ratios in English [kw] sequence words showed that the subjects who produced /w/ had similar ratio patterns that the native speaker had in that the vowel duration ratio in kwV sequences was shorter than that in kV sequences. By contrast, the subjects who deleted [w] had a long ratio of the onset [$k^{h}$] while the speaker with a partial pronunciation of /w/ had a long ratio of the following vowel.

• Journal of the Mineralogical Society of Korea
• /
• v.21 no.2
• /
• pp.193-200
• /
• 2008

We tried to evaporate and dry the moisture contained Flue gas desulfurization gypsum and phosphogypsum by using the microwave directly. In the result of the heating to the Flue gas desulfurization gypsum and phosphogypsum using 2.45 GHz microwave which was created by magnetron 700 W, 1,000 W and 1,700 W, respectively. According to the increasing the microwave output intensity from 700 W to 1,700 W, the evaporate time of moisture was shortened from 10 to 3 minutes. Gypsum were changed to calcium sulfate hemihydrate. However, ${\beta}$-calcium sulfate hemi-hydrate were not changed to anhydrite.

• Korean Journal of Materials Research
• /
• v.10 no.3
• /
• pp.227-232
• /
• 2000

Cu-W composites containing 20wt.% W were fabricated by hot pressing. Hot pressing was carried out at temperatures ranging from 800 to $1000^{\circ}C$ under pressures of 15MPa for 30MPa for 30min and 60min. This process gave composites of higher density, higher hardness and higher wear resistance than the conventional sintering processes. However, the microstructure of Cu-W composites under pressure of 15MPa revealed there was an inhomogeneous distribution of W, segregation of W on some area. These undesirable results are attributed to the immiscibility of W in Cu and the pressure effect on sintering.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.14 no.1
• /
• pp.47-50
• /
• 1985

Changes in fatty acid composition of phospholipids from human milk during the course of lactation were determined in milk from Korean lactating mothers giving birth at term. The levels of 8 : 0 increased significantly from colostral to transitional stages with a further small decrease at mature stage. The proportions of 10 : 0, 12 : 0 and 14 : 0 increased markedly from colostrum to transitional to mature milk. The w6-derived long-chain polyunsaturated fatty acids, 20 : 2w5, 20 : 4w6 and 22 : 4w5, were decreased with time of lactation. The levels of 24 : 1w9 were significantly higher in transitional milk than in colostrum and then significantly decreased to lowers than the colostral levels at mature milk.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.456-459
• /
• 2007

Thermal conductivities (TC) of 57 Jurassic muscovitic granite samples (KIGAM) and 149 porphyritic granite samples (Yeonki: BE-2, BE-3) were measured with LFA-447. Ranges of TC values are $2.429{\sim}3.878$ W/mK (KIGAM), $2.220{\sim}3.767$ W/mK (Yeonki, BE-2) and $2.019{\sim}3.990$ W/mK (Yeonki, BE-3); arithmetic means are 2.924 W/mK (KIGAM), 2.907 W/mK (Yeonki, BE-2), and 2.881 W/mK (Yeonki, BE-3), respectively. In this study, harmonic mean values were calculated to estimate the average value of TC. Harmonic mean values are 2.883 W/mK (KIGAM), 2.886 W/mK (Yeonki, BE-2), and 2.866 W/mK (Yeonki, BE-3), respectively. Heat extraction rates of a borehole heat exchanger strongly depend on TC values. Heat-extraction rates from re values are expected to be a little lower than 84 W/m in all sites. However, considering ground water flow, it is expected that actual heat extraction rate would be higher than the expected value.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.8
• /
• pp.1092-1100
• /
• 2012

Ten Bacillus strains with antimicrobial activities were isolated from Cheonggukjang produced at different parts in Korea. They all inhibited Listeria monocytogenes ATCC 19111 and nine inhibited Bacillus cereus ATCC 14579. Four isolates (W42, H27, SKE 12, and K21) showing strong inhibiting activities were identified as B. subtilis. B. subtilis W42 was the most inhibiting strain. The antimicrobial activity of culture supernatant from B. subtilis W42 was destroyed completely by proteinase K treatment, indicating that a bacteriocin was the responsible agent. The bacteriocin, Bac W42, was most stable at pH 7 and stable between pH 3-6 and 8-9. Bac W42 was stable up to $80^{\circ}C$. BHI (brain heart infusion) and TSB (tryptic soy broth) were the best media for the activity (320 AU/ml) followed by LB (160 AU/ml). Bac W42 was partially purified by column chromatographies. The specific activity was increased from 1,151.2 AU/ml to 9,043.5 AU/ml and the final yield was 26.3%. Bac W42 was 5.4 kDa in size as determined by SDS-PAGE. Bac W42 showed bactericidal activity against L. monocytogenes ATCC 19111.

• Journal of the Korean Society for information Management
• /
• v.12 no.1
• /
• pp.45-66
• /
• 1995

The information users of the middle of 1990s. who know the Internet as well as its useful information services, are now expecting the virtual library services. Especially the increasing demands on hypertext and hypermedia information in the internet settings have been centered on the W3 with the man-page information. In this manner, the paper describes the access methods with brief concepts of the W3 and explains URLs and HTML. It also gives the retrieval layouts of unformatted data including images and sounds and then provides the information sources and software of W3 Clients and Servers in order to catch up the most recently post version of W3.

• Journal of Powder Materials
• /
• v.5 no.2
• /
• pp.145-153
• /
• 1998

W-Cu alloy is attractive to thermal managing materials in microelectronic devices because of its good thermal properties. The metal injection molding (MIM) of W-Cu systems can satisfy the need for mass production of the complex shaped W-Cu parts in semiconductor devices. In this study, the application of MIM process of the mechanically alloyed (MA) W-Cu composite powders, which had higher sinterability were investigated. The MA W-Cu powders and reduction treated (RT) powders were injected by using of the multicomponent binder system. The multi-stage debinding cycles were adopted in $N_2$ and $H_2$ atmosphere. The isostatic repressing treatment was carried out in order to improve the relative density of brown parts. The brown part of RT W-Cu composite powder sintered at 110$0^{\circ}C$ had shown the higher sinterability compared to that of MA powder. The relative sintered density of all specimens increased to 96% by sintering at 120$0^{\circ}C$ for 1 hour. The relationship between green density and the sintering behavior of MA W-Cu composite powder was analyzed and discussed on the basis of the nanostructured characteristics of the MA W-Cu composite powder.

• Solar Energy
• /
• v.10 no.1
• /
• pp.22-30
• /
• 1990

Steady laminar natural convection heat transfer from a square beam with a horizontal adiabatic plate has been studied numerically for various Grashof numbers and beam shapes. The heat transfer from a square beam increases as the dimensionless beam width W / L decreases. The mean Nusselt number of the upper surface is minimum at W / L = 1.0, maximum at W / L = 0.25 and that of the side surface is minimum at W / L = 0.25, maximum at W / L = 1.0. The increases of the total mean Nusselt number with increasing Grashof number is dominated by the beam width.

• Journal of the Korean Data and Information Science Society
• /
• v.21 no.4
• /
• pp.629-639
• /
• 2010

This paper shows that mathematics and statistics are not only a necessity but a strategic element in contributing for the competitiveness of field of S/W and H/W. First, a survey was conducted to investigate the perceived importance of mathematics and statistics to the specialists of the field. Second, computer programming was implemented in university mathematics courses to understand the educational effect related to problem solving ability. Third, a educational case in which mathematics and statistics in S/W and H/W subject were combined was analyzed. Lastly, an effective plan for mathematics and statistics education in the field of S/W and H/W will be presented.