• Phonetics and Speech Sciences
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• v.11 no.4
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• pp.63-70
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• 2019

This study investigated individual variability of L2 learners' categorical judgments of L2 stops by exploring English learners' perceptual processing of two acoustic cues (voice onset time [VOT] and f0) and working memory capacity as sources of variation. As prior research has reported that English speakers' greater use of the redundant cue f0 was responsible for gradient processing of native stops, we examined whether the same processing characteristics would be observed in L2 learners' perception of Korean stops (/t/-/t^h/). 22 English learners of L2 Korean with a range of L2 proficiency participated in a visual analogue scaling task and demonstrated variable manners of judging the L2 Korean stops: Some were more gradient than others in performing the task. Correlation analysis revealed that L2 learners' categorical responses were modestly related to individuals' utilizations of a primary cue for the stop contrast (VOT for L1 English stops and f0 for L2 Korean stops), and were also related to better working memory capacity. Together, the current experimental evidence demonstrates adult L2 learners' top-down processing of stop consonants where linguistic and cognitive resources are devoted to a process of determining abstract phonemic identity.

• Korean Journal of Materials Research
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• v.17 no.8
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• pp.425-432
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• 2007

The microstructural evolution of ferritic 9Cr-1Mo-V-Nb steel, subjected to creep-fatigue at $550^{\circ}C$, was evaluated nondestructively by measuring the ultrasonic velocity. The variation of the ultrasonic velocity with the fatigue life fraction exhibited three regions. In the first region ($N/N_f$<0.2), a significant increase in the velocity was observed, followed by a slight increase between the fatigue life fractions of $0.2N_f$ and $0.8N_f$, and then a decrease in the final region. The change of the ultrasonic velocity during creep-fatigue was interpreted in relation to the microstructural properties. This study proposes an ultrasonic nondestructive evaluation method of quantifying the level of damage and microstructural change during the creep-fatigue of ferritic 9Cr-1Mo-V-Nb steel.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.1
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• pp.120-139
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• 1996

Experiment was performed to study the heat transfer characteristics in 27 kinds of 15 : 1 scale models of multi-louverred fin heat exchangers with a wide range of variables(R $e_{Lp}$ =100~1, 800, $L_p$/F$p$=0.3~0.9, $\theta$=20$^{\circ}$~40$^{\circ}$). Thermofoil heaters were used to heat the louver fins and the local average Nusselt number for each louver in the louver array was obtained at constant wall temperature conditions. Correlations are developed to predict the heat transfer characteristics and drag coefficients. Generally, the heat transfer characteristics in the multi-louvered fins is shown to be similar to those of the laminar heat transfer on a flat plate. As the Reynolds number, the louver pitch to fin pitch ratio$L_p$/F$p$and the louver angle($\theta$) increase respectively, the average Nusselt number increases, but the variation of average Nusselt number as a function of the louver angle is smaller than that as a function of the louver pitch to fin pitch ratio. In case of$L_p$/F$p$ <0.5, the average Nusselt number of the 3rd louver is especially lower than the others, it is expected that it is due to the flow structure such as a recirculation flow and a flow separation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.4
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• pp.384-389
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• 2004

Crystal structure and microwave dielectric properties of Ba(Mg1/3Nb2/3) $O_3$ (BMN) ceramics were investigated. Ba(Mg1/3Nb2/3) $O_3$ has the 1:2 ordered hexagonal structure. The 1:2 ordering and relative density of specimens increased with small Mg deficiency(x). The variation of Q${\times}$ $f_{0}$ with Mg deficiency is very similar to that of 1:2 ordering and relative density. The highest Q${\times}$ $f_{0}$ achieved in this investigation is about 96,000 for Ba(Mg1/3Nb2/3) $O_3$. The improvement of Q${\times}$ $f_{0}$ with Mg-deficiency is related to the increase of degree of ordering and relative density of the specimen.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.463-467
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• 2009

Interspecific hybrid plants between Allium cepa L. (2n=2X=16) and A. fistulosum L. (2n=2X=16)and their backcross lines were developed by artificial pollination in order to introduce new desirable characters of A, cepa to A. fistulosum. The 2C nuclear DNA content has been estimated by flow cytometry in 5 Allium fistulosum inbreed lines, 2 interspecific hybrid lines of A. cepa${\times}$A. fistulosum and 34 their backcross lines $BC_1F_1$ to $BC_2F_2$, using propidium iodide (PI) as a fluorescence dye. Estimated 2C DNA values ranged from 22.2 pg to 23.7 pg in 5 A. fistulosum inbreed lines, 37.9 pg in F1 hybrid between A. cepa and A. fistulosum, 24.3 pg to 27.3 pg in 7 backcross lines in $BC_1F_1$, 21.9 pg to 24.4 pg in 9 $BC_1F_2$, 22.9 pg to 25.1 pg in 14 $BC_2F_1$, 22.6 pg to 23.4 pg in 4 $BC_2F_2$. This study showed mean 2C nuclear DNA content of $F_1$ hybrid was higher than their backcross progeny lines, while it was lower than female parental line, A. cepa (2C DNA=33.2 pg). Mean 2C DNA content of backcross lines, $BC_1F_1$ to $BC_2F_2$ was not significantly different but their 2C DNA contents in the more progress generation from $BC_1F_1$ to $BC_2F_2$ were reduced.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1378-1386
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• 2020

Objective: Chinese indigenous sheep breeds can be classified into the following three categories by their tail morphology: fat-tailed, fat-rumped and thin-tailed sheep. The typical sheep breeds corresponding to fat-tailed, fat-rumped, and thin-tailed sheep are large-tailed Han, Altay, and Tibetan sheep, respectively. Detection of copy number variation (CNV) and selection signatures provides information on the genetic mechanisms underlying the phenotypic differences of the different sheep types. Methods: In this study, PennCNV software and F-statistics (F_ST) were implemented to detect CNV and selection signatures, respectively, on the X chromosome in three Chinese indigenous sheep breeds using ovine high-density 600K single nucleotide polymorphism arrays. Results: In large-tailed Han, Altay, and Tibetan sheep, respectively, a total of six, four and 22 CNV regions (CNVRs) with lengths of 1.23, 0.93, and 7.02 Mb were identified on the X chromosome. In addition, 49, 34, and 55 candidate selection regions with respective lengths of 27.49, 16.47, and 25.42 Mb were identified in large-tailed Han, Altay, and Tibetan sheep, respectively. The bioinformatics analysis results indicated several genes in these regions were associated with fat, including dehydrogenase/reductase X-linked, calcium voltage-gated channel subunit alpha1 F, and patatin like phospholipase domain containing 4. In addition, three other genes were identified from this analysis: the family with sequence similarity 58 member A gene was associated with energy metabolism, the serine/arginine-rich protein specific kinase 3 gene was associated with skeletal muscle development, and the interleukin 2 receptor subunit gamma gene was associated with the immune system. Conclusion: The results of this study indicated CNVRs and selection regions on the X chromosome of Chinese indigenous sheep contained several genes associated with various heritable traits.

• Environmental Engineering Research
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• v.19 no.3
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• pp.229-240
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• 2014

Rain events are extremely important for phosphorus (P) dynamics in rivers since large portions of annual river P loads can be transported in particulate forms during only a few major events. Despite their importance, a precise estimation of P contribution in river sediments after rainy seasons has rarely been reported. This study estimated the longitudinal variation in the concentrations of different inorganic P fractions in bed sediments of the South Han River over a rainy season, through using the sequential extraction method. Non-apatite P was the dominant form, representing more than 60% of total inorganic P (TIP) content in sediments. Although no significant variation of TIP contents was observed, the proportion of bioavailable P in TIP pools decreased after the rainy season. The concentrations of individual inorganic P fractions ($NH_4Cl-P$, $NH_4F-P$, NaOH-P, and $H_2SO_4-P$) were significantly different across sites and after the rainy season (p < 0.05, two-way ANOVA). $NH_4F-P$ and NaOH-P concentrations in sediments increased in a downstream direction. After the rainy season, $NH_4Cl-P$ concentrations in sediments decreased whereas $NH_4F-P$ and $H_2SO_4-P$ concentrations increased. The redistribution of individual P fractions in sediments observed after rainy seasons were possibly due to the changing contribution of various sources of runoff and the variation in flow related particle size. Current estimation of P in bed sediments of the South Han River suggests a lower potential of internal P loading from sediments after the rainy season.

• Advances in nano research
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• v.12 no.4
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• pp.345-352
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• 2022

In this paper, natural frequency curves are presented for three specific end supports considering distinct values of nonlocal parameter. The vibrational behavior of zigzag double walled carbon nanotubes is investigated using wave propagation with nonlocal effect. Frequency spectra of zigzag (12, 0) double walled carbon nanotubes have been analyzed with proposed model. Effects of nonlocal parameters have been fully investigated on the natural frequency against against variation of Poisson's ratio. A slow increase in frequencies against variation of Poisson's ratio also indicates insensitivity of it for suggested nonlocal model. Moreover, decrease in frequencies with increase in nonlocal parameter authenticates the applicability of nonlocal Love shell model. Also the frequency curves for C-F are lower throughout the computation than that of C-C curves.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.13-24
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• 2016

This research was conducted over four weeks from February 1, 2016 until Februay 29. Results were as follows. First, the effects of dietary lifestyle on the purchase intention of consumers was significant and postive, while food flavors (B=0.019 (p<.001)) and convenience (B=0.055 (p<.001)) had a significant and negative effect. To determine the coefficient to measure the adequacy of the model was explained 64.9% of variation in 0.649 premise, the model with F=187.244 (p<.001) to verify the significance level. Second, the moderating effects of consumer culture on the proposed realtionship was examined in 3 stages. The Stage 1 model found a significant effect (0.649, F=18.244 (p<0.01)). The Stage 2 model increased predictive power with the addition of "consumer culture" and was also significant(65.1% and F=142.119 (p<0.01)). The Stage 3 model increased the explanatory power due to the addition of 'lifestyle and found a significant moderating effect of 'Eating consumer culture' (65.9%, so for F=84.469 (p<0.01)).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.59-62
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• 1996

The effect of NiO addition on the microstructure and microwave dielectric properties of (Zr$_{0.8}$Sn$_{0.2}$)TiO$_4$(ZST) was investigated. With the NiO addition, a dense ZST body of density higher than 95% has been achieved in the sintering temperature range of 1400 to 150$0^{\circ}C$. Energy dispersive X-ray spectrometry (EDS) analysis of sintered specimen shows the presence of second phase at grain boundaries, which is considered to be NiTiO$_3$. Dielectric constant of the specimen is found to increase linearly with density. Q-values and TC$_{f}$decrease with increasing NiO content. The variation of dielectric properties with NiO content is discussed in term of the second phase. The ZST ceramics with small amount of additive gave $\varepsilon$$_{r}$=38, Q=7000 at 7 GHz and TC$_{f}$=-0.5 ppm/$^{\circ}C$, comparable with the values obtained by previous investigation.stigation.