• 말소리와 음성과학
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• 제14권1호
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• pp.29-36
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• 2022

The English word-final /rl/ cluster poses a particular problem for Korean learners of English because it is the sequence of two sounds, /r/ and /l/, which are not contrastive in Korean. This study compared the similarity distances between English and Korean speakers' /rl/ productions using the dynamic time warping (DTW) algorithm. The words with /rl/ (pearl, world) and without /rl/ (bird, word) were recorded by four English speakers and four Korean speakers, and compared pairwise. The F2-F1 trajectories, the acoustic correlate of velarized /l/, and F3 trajectories, the acoustic correlate of /r/, were examined. Formant analysis showed that English speakers lowered F2-F1 values toward the end of a word, unlike Korean speakers, suggesting the absence of /l/ in Korean speakers. In contrast, there was no significant difference in F3 values. Mixed-effects regression analyses of the DTW distances revealed that Korean speakers produced /r/ similarly to English speakers but failed to produce the velarized /l/ in /rl/ clusters.

• 품질경영학회지
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• 제45권4호
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• pp.995-1002
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• 2017

Purpose: The purpose of this study was to evaluate the color stability of composite resins used for splinting teeth by comparing a self-cure resin cement (Superbond C&B, SB), a flowable composite resin (G-aenial Universal Flo A2, GU), and a composite resin exclusively used for splinting teeth (G-Fix, GF) before and after aging in NaOCl. Methods: Resin samples were fabricated to a size of 2 mm thickness and 8.5 mm diameter and light-cured with an LED light curing unit (G-Light, n = 12). Immediately after fabrication, CIE L*a*b* values of the resin samples were measured with a spectrophotometer (CM-5) as baseline. Then, the resin samples were immersed in 5% NaOCl at $60^{\circ}C$ and the color was measured after 23 hours every day for 4 days. Data were analyzed with one-way ANOVA followed by Duncan post hoc test (p<0.05), and color differences (${\Delta}E$) of resin samples before and after NaOCl aging were also calculated. Results: For SB, there were no changes in L* and a* values but changes were observed in b* values. For GU, there were no changes in L* and b* values but in a* values. For GF, changes were observed in L*, a*, and b* values. All resin samples showed highest ${\Delta}E$ between baseline and the 1st day of NaOCl immersion. ${\Delta}E$ of SB, GU, and GF was 4.6 - 5.8, 4.9 - 7.9, and 9.9 - 16.9, respectively. GF showed highest color change during NaOCl aging. Conclusion: The results of this color quality evaluation showed that the composite resin exclusively used for splinting teeth might be more vulnerable to color change during intraoral service.

• Reproductive and Developmental Biology
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• 제39권1호
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• pp.13-21
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• 2015

본 연구에 사용된 공시축은 2013년 1월부터 2014년 12월까지 국립축산과학원 가축유전자원시험장 장내에서 사육 중인 모색을 기준으로 일반한우(황우), 백한우, 흑우 및 미니한우 등 총 75여 두(황우, 백우, 흑우 그리고 미니 한우)를 대상으로 연령별, 종별 그리고 성별로 각각 분류하고, 이들에 대한 혈액학적 수치를 확인하였다. 백한우와 흑우의 혈액학적 검사 결과에서 1년 이하에서 3년 이상으로 연령이 증가됨에 따라 RBC($11.6{\sim}9.4{\times}10^6/{\mu}L$, $12.3{\sim}9.9{\times}10^6/{\mu}L$로)와 PL치($645{\sim}510{\times}10^3$/, $673{\sim}425{\times}10^3/{\mu}L$로)에서 각각 유의성 있는 감소(p<0.05)가 인정되었다. 동일 연령(2~3년)의 대조군으로서 일반한우군과 희소한우군(백우, 흑우, 미니소) 간의 비교에서는 각각 RBC 수치가($10.0{\times}10^6/{\mu}L$, $9.6{\times}10^6/{\mu}L$, $10.5{\times}10^6/{\mu}L$, $10.1{\times}10^6/{\mu}L$)와 HCT (44.8%, 43.2%, 45.8%, 43.9%), MCV(53.5 fL, 52.1 fL, 54.9 fL, 53.7 fL) 및 MCHC(28.9 g/dL, 28.3 g/dL, 29.8 g/ dL, 29.0 g/dL)에서 일반한우와 희소한우 품종들 간의 차이점이 인정되었으며, MCV와 MCHC에서도 통계적 유의성이 인정되었다(p<0.05). 또한, 백한우와 흑우의 백혈구계 검사 결과에서도 1년 이하에서 3년 이상으로 연령이 증가함에 따라 WBC 수치($12.7{\sim}9.1{\times}10^3/{\mu}L$, $13.9{\sim}11.7{\times}10^3/{\mu}L$)가 감소하는 경향이 각각 인정되었으며, 동일 연령(2~3 년)의 희소한우의 백혈구 분포의 백분율에서는 전반적으로 림프구가 40.2~52.2%를, 분엽형 호중구가 27.2~33.9%로 나타났다. 일반한우군과 백한우군 간의 백혈구계의 림프구 수치의 비교에서는 백한우군(40.2%)로 일반한우(49.8%)에 비하여 유의적으로 낮음(p<0.05)을 확인하였다.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1545-1555
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• 2020

In the present study, we investigated the antioxidant activity of Aucklandia lappa Decne (AL). Cell viability was measured in an MTT assay. Antioxidant effects were evaluated based on total polyphenol/flavonoid contents, ABTS radical scavenging activity, DPPH radical scavenging activity, SOD activity, and ROS content. AL was found not to be toxic at concentrations of 1 ㎍/mL, 10 ㎍/mL, and 100 ㎍/mL, respectively. The phenolic content was higher in AL-D than in AL-E, while the flavonoid content was higher in AL-E than in AL-D. AL-E exhibited higher ABTS radical scavenging activity than AL-D, and the EC50 values for BHA were 217.1 ㎍/mL in AL-D and 180.5 ㎍/mL in AL-E. AL-E also showed the highest DPPH radical scavenging activity. EC50 values for BHA were 114.2 ㎍/mL in AL-D and 95.8 ㎍/mL in AL-E. The SOD-like activity of AL-E was higher than that of AL-D. The EC50 values for ascorbic acid were 48.5 ㎍/mL in AL-D and 72.9 ㎍/mL in AL-E, indicating that both AL extracts have a SOD activity higher than that of ascorbic acid. AL-E reduced relatively more ROS than AL-D. With 100 ㎍/mL AL-E, the reduction level was almost similar to that of dexamethasone. Our results demonstrate that AL have antioxidant effects, and we believe that they could be very valuable as raw materials for anti-aging products, based on their antioxidant activity.

• 한국지역사회생활과학회지
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• 제17권4호
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• pp.39-48
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• 2006

This study was carried out to make a search for the usefulness of marigold plants (Tagetes erecta) as a natural dye. And we have also examined into the dyeability and antifungal activity of silk and cotton fabrics dyed with 2% powdered colorant and 1% liquid colorant. Almost surface colors of silk and cotton fabrics dyed with 2% powdered colorant and that dyed with 1% liquid colorant except for that treated Cu and Fe with mordants were shown by Y-level. $L^*$ values of silk fabrics dyed with 2% powdered colorant were 66.2 to 86.39, those $a^*$ values were -1.97 to 6.09, and those $b^*$ values were 13.69 to 35.97. And $L^*$ values of cotton fabrics dyed with 2% powdered colorant were 78.97 to 89.62, those a values were -3.39 to 0.38, and those $b^*$ values were 5.63 to 15.61 $L^*$ values of silk fabrics dyed with 1% liquid colorant were 34.37 to 85.57, those a values were -7.79 to 12.33, and those $b^*$ values were 15.13 to 82.91, And $L^*$ values of cotton fabrics dyed with 1% liquid colorant were 44.12 to 87.90, those $a^*$ values were -8.37 to 6.18, and those $b^*$ values were 11.65 to 78.87. Colorfastness of silk fabrics against light treated nothing with mordants and that dyed with 1% liquid colorant decreased for a little by second grade, however, that against washing, rubbing, perspiration and dry cleaning were increased over fourth grade. Colorfastness of cotton fabrics in terms of rubbing, light, and dry cleaning, except for washing and perspiration, were shown by over third grade, when that was treated nothing with mordants. Antifungal activities of silk fabrics treated nothing with mordants and dyed with 1% liquid colorant of marigold extracts were shown by 28.9% against Staphylococcus aureus. However, those of Al, Ca, Cu and tartaric acid mordanting were more than 25.5% against Staphylococcus aureus and Klebsiella pneumoniae.

• 대한수학회지
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• 제44권6호
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• pp.1243-1254
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• 2007

In this paper, we study the mean values of the homogeneous Dedekind sums and Cochrane sums in short intervals $[1,\;\frac{p}{3}]\;and\;[1,\;\frac{p}{4}]$, and give some asymptotic formulae by using the mean values of the Dirichlet L-functions.

• 대한수학회보
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• 제59권2호
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• pp.431-452
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• 2022

For any positive integer 𝜇, we compute the mean value of the 𝜇-th derivative of quadratic Dirichlet L-functions over the rational function field 𝔽_q(t), where q is a power of 2.

• Natural Product Sciences
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• 제16권4호
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• pp.239-244
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• 2010

Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling, has served as a potential drug target for the treatment of type 2 diabetes. The MeOH extracts of twenty-nine medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for PTP1B inhibitory activity in vitro. The results indicated that, most materials showed moderate to strong inhibitory activity with $IC_{50}$ values ranging from $3.4\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$; meanwhile, eleven extracts (37.9%) could demonstrate PTP1B activity with $IC_{50}$ values less than $15.5\;{\mu}g/mL$; sixteen extracts (55.2%) could demonstrate PTP1B activity with $IC_{50}$ values ranging from $15.5\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.

• 동아시아식생활학회지
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• 제21권4호
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• pp.535-544
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• 2011

The purpose of this study was to investigate the quality characteristics and antioxidative effect of cookies prepared with Curcuma longa L. powder (0, 1, 2, 3, 4%) substituted for flour. The pH of cookie dough decreased significantly in response to the addition of all levels of Curcuma longa L. powder (CLP). However, there were no significant differences in dough values among the test groups. Furthermore, when the spread factor values were compared among the groups, they were found to be inversely proportional to the CLP concentration. In addition, Hunter's color L value significantly decreased with increasing CLP content, whereas the a and b values increased. According to textural measurements, substitution of 1~4% for CLP resulted in increased hardness, cohesiveness, springiness, and brittleness when the samples were compared to the control. The results of sensory evaluation showed that the cookies containing 2% CLP had the highest scores. The acid value, peroxide value, and thiobarbituric acid value were all lower in cookies with 2% and 3% CLP than in cookies made with 4% CLP and control cookies.

• Journal of Ginseng Research
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• 제17권3호
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• pp.228-231
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• 1993

Physicochemival properties of ginseng roasted at 170 to $250^{\circ}C$ were investigated. Soluble solid contents in roast ginseng increased until $200^{\circ}C$, but decreased at higher temperature than $200^{\circ}C$. Contents of reducing sugar and protein were decreased and pH values were dropped, while optical density, acidic polysaccharide contents, precursor of brown pigments and hydrogen donating activities by DPPH were increased according to increasing in roast temperatures. The color distribution of roast ginseng expressed as Hunter L, a and b values demonstrated that lower L values and higher a values were observed according to higher temperature, but b values were almost not changed.