• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.221-228
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• 2021

The aim of this study was to evaluate the use of easily accessible machine learning application to identify mesiodens, and to compare the ability to identify mesiodens between trained model and human. A total of 1604 panoramic images (805 images with mesiodens, 799 images without mesiodens) of patients aged 5 - 7 years were used for this study. The model used for machine learning was Google's teachable machine. Data set 1 was used to train model and to verify the model. Data set 2 was used to compare the ability between the learning model and human group. As a result of data set 1, the average accuracy of the model was 0.82. After testing data set 2, the accuracy of the model was 0.78. From the resident group and the student group, the accuracy was 0.82, 0.69. This study developed a model for identifying mesiodens using panoramic radiographs of children in primary and early mixed dentition. The classification accuracy of the model was lower than that of the resident group. However, the classification accuracy (0.78) was higher than that of dental students (0.69), so it could be used to assist the diagnosis of mesiodens for non-expert students or general dentists.

• Korean Journal of Heritage: History & Science
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• v.48 no.3
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• pp.186-203
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• 2015

This article attempts to examine both the outcome and future task of the art history research on Central Eurasia, better known under the name of "Silk Road". The term Central Eurasia encompasses Xinjiang Uygur, Tibet, Mongolia, former Soviet Republics, the northwest region of India, Iran and Turkey. The article analyzes the 30-year history of the region's art history research and further presents a desirable direction that the study should move towards. Though short in its research period, the ROK's art history study on Central Eurasia has shown eye-catching achievement in several areas such as the northwest region of India and the Xinjiang Uygur, Dunhwang of China. Two factors allowed for this accomplishment. First was the actual improvement of the work environment, where the scholars were finally able to travel to Central Eurasia and explore the historic sites for themselves since 1990. More important was the 'arena of study' for the next-generation scholars made possible by institutions like The Korean Association for Central Asian Studies and the Center for Central Eurasian Studies. Slowly but consistently, the two academic societies induced scholars' attention towards the field and fostered new experts. Circumstances changed, marking 2012 as the starting point. International academic forums held by the government branches surged in number. The intention behind it was to link the ROK with the Silk Road and ultimately to obtain the "Eurasia initiative". As of now, the public has shown heightened interest in the issue. The academia is subsequently riding on this second "wave of interest" following the first wave in the 1980s. However, increased popularity comes with some negative consequences, and this art history research on Central Eurasia is no exception. There are criticisms regarding the objectivity of recent academic forums. Some argue that the aim of the forums are sternly set most of the times, prohibiting the presenters to voice their own perspectives. Still, this heated attention will definitely play its role as a stepping stone for further development. The academia should commit to fostering rising researchers who will systemically and professionally study the field. This is imperative in order for the Korean culture to successfully communicate with the world and take itself to a new level. Without completing this task, the ROK's art history research on Central Eurasia is likely to remain idle.

• Korean Journal of Heritage: History & Science
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• v.48 no.1
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• pp.62-79
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• 2015

The Stele for State Preceptor Doseon and Seon Master Sumi of Dogapsa Temple in Yeongam was erected in the fourth month of 1653. It was made with stone obtained from Yeosan(present-day Yeosan-myeon, Iksansi), and contains an inscription - engraved in the spring of 1651 - commemorating the two priests. The project to erect the monument was led by eminent monks, including Gakseong and Sucho, with the support of royal patrons and powerful statesmen including Prince Inpyeong(1622~1658). This monument is thought to be the first of its kind to have a capstone in the shape of a 'dragon loop' handle of the kind traditionally attached to the top of a temple bell. Stone stelae with a dragon-loop-shaped capstone continued to be used by the royalty and nobility of Joseon until the 18th century. The inscription engraved on the rear face of the monument reveals that it was made by Jo Mal-ryong, a renowned stonemason who worked on stone monuments and figures for royal tombs in the mid-Joseon period. He is known as the only stonemason to have been awarded the third highest rank(Jeong-sampum) of government, including the posts of Grand Master(Tongjeong Daebu) and General(Jeolchung Janggun), as recorded in the inscription. The monument corroborates the prevalent view that he was the creator of monumental capstones of the highest aesthetic merit in Joseon, and provides valuable insights about the leading artisans who produced monumental stones for royal tombs in the 17th century. This particular monument is highly regarded as a valuable historical relic because of the detailed information contained in the inscription, including the dates, work processes, patrons and artisans related with its creation, and because it features outstanding workmanship by some of the greatest artisans of the period. The monument also provides important clues about the transition from the Buddhist monuments created under the auspices of the royalty and nobility of mid-period Joseon to the symbolic stone structures and figures made for the tombs of royalty and nobility.

• Food Engineering Progress
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• v.21 no.1
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• pp.57-63
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• 2017

This study investigated the effects of 27.12 MHz radio frequency (RF) heating on heat transfer phenomena during the thawing process of frozen food. To determine the velocity of the RF thawing machine, samples were frozen at $-80^{\circ}C$ and subjected to different power treatments. The phase change times (-5 to $0^{\circ}C$) of frozen radish were 30, 26, 13, and 8 min; those of pork sirloin were 38, 25, 11, and 5 min; those of rump were 23, 17, 11, and 6 min; those of chicken breast were 42, 29, 13, and 9 min; and those of tuna were 25, 23, 10, and 5 min at 50, 100, 200, and 400 W, respectively. The heating limit temperatures of the radish, pork sirloin, rump, chicken breast, and tuna samples were 19.5, 9.2, 21.8, 8.8, and $16.8^{\circ}C$ at 50 W; 23.5, 15.5, 27.3, 12.3, and $19^{\circ}C$ at 100 W; 42, 26.9, 45.7, 22.1, and $39.4^{\circ}C$ at 200 W; and 48.5, 54.7, 63.6, 57.3, and $44.9^{\circ}C$ at 400 W. These results suggest that high-power RF improves thawing velocity and heating limit temperatures, and that an improvement on the operation of the RF thawing machine, according to food temperatures, is needed.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.268-273
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• 2019

The intestinal microbiomes vary according to the factors such environment, age and diet. The purpose of this study was to compare the gut microbial diversity between Korean infants receiving breast-fed milk and formula-fed milk. We analyzed microbial communities in stool samples collected from 80 Korean infants using next generation sequencing. Phylum level analysis revealed that microbial communities in both breast-fed infants group (BIG) was dominated by Actinobacteria ($74.22{\pm}3.48%$). Interestingly, the phylum Actinobacteria was dominant in formula-fed infants group A (FIG-A) at $73.46{\pm}4.12%$, but the proportions of phylum Actinobacteria were lower in formulafed infants group B and C (FIG-B and FIG-C) at $66.52{\pm}5.80%$ and $68.88{\pm}4.33%$. The most abundant genus in the BIG, FIG-A, FIG-B, and FIG-C was Bifidobacterium, comprising $73.09{\pm}2.31%$, $72.25{\pm}4.93%$, $63.81{\pm}6.05%$, and $67.42{\pm}5.36%$ of the total bacteria. Furthermore, the dominant bifidobacterial species detected in BIG and FIG-A was Bifidobacterium longum at $68.77{\pm}6.07%$ and $66.85{\pm}4.99%$ of the total bacteria. In contrast, the proportions of B. longum of FIG-B and FIG-C were $58.94{\pm}6.20%$ and $61.86{\pm}5.31%$ of the total bacteria. FIG-A showed a community similar to BIG, which may be due to the inclusion of galactooligosaccharide, galactosyllactose, synergy-oligosaccharide, bifidooligo and improvement material of gut microbiota contained in formula-milk. We conclude that 5-Bifidus factor contained in milk powder promotes the growth of Bifidobacterium genus in the intestines.

• Journal of Korean Home Economics Education Association
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• v.33 no.3
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• pp.143-157
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• 2021

This study analyzed and verified the effects of a dietary education program for Korean young adults in single-person households. The dietary education program was conducted for five weeks (from November 10 to December 8, 2020) for Korean young adults in single-person households living in Seongbuk-gu, via four face-to-face education sessions and one online education session, including both theoretical lectures and practice. The effect of the dietary education program was analyzed through the Nutrition Quotient (NQ) questionnaire for adults provided by the Korean Nutrition Society, a dietary evaluation checklist questionnaire developed by the researchers, and photovoices. The average of 'Nutrition' score increased from 51.81 to 53.20, but there was no statistically significant difference. However, there was a significant change in the 'Moderation' category (p<0.05). As for the researcher-developed dietary evaluation, the average of the 'Importance' area rose from 3.77 to 3.99, but there was no statistically significant difference. The average of the 'Practice' area rose from 3.03 to 3.57, significant results were found (p<0.05). When the pre-/post-tests were compared by the sub-categories, four elements of 'Importance', i.e., balanced meals and avoided foods, and all five elements of 'Practice' were significantly improved (p<0.05). A total of 200 photovoices were analyzed according to Social Cognitive Theory. As a result of the analysis, the deterrents that help people eat healthy homemade food were 48% environmental factors, 30% behavioral factors, and 22% individual cognitive factors. The deterrents found to hinder participants from eating healthy homemade food were 72% environmental factors and 14% individual cognitive and behavioral factors. The results suggest that the dietary education program for Korean young adults in single-person households can be an effective tool that promotes self-motivation, behavioral changes, and improvements of the surrounding environment.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.207-216
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• 2021

This study was conducted to determine the nutritional quality of two newly-developed native chicken strains, compared to the commercial Korean native chicken. A total of 600 chickens (CON: Hanhyup No. 3, CL1: candidate line C, CL2: candidate line D) raised under the same conditions were slaughtered at either 5 or 12 weeks. Leg meat was then obtained and analyzed for its physicochemical properties. The results showed that regardless of the growing period, there was no variation in proximate composition (P>0.05), except for crude protein, between strains. Water holding capacity did not differ between strains at either slaughter age; however, it was significantly lower in the 12-week group than in the 5-week group (P≤0.05). For both skin and muscle color, a^* and b^* values were lower at 12 weeks than at 5 weeks (P≤0.05). DPPH radical-scavenging activity tended to be lower at 12 weeks than at 5 weeks (P≤0.05). Furthermore, all chickens slaughtered at 5 weeks were found to have greater contents of linoleic acid (18:2) and polyunsaturated fatty acids (PUFA) and lower atherogenicity and thrombogenicity indices than those slaughtered at 12 weeks (P≤0.05). However, anserine, betaine, and glucose were more concentrated among the lines at 12 weeks than at 5 weeks (P≤0.05). In conclusion, the quality traits of native chickens were distinct by different production stages rather than chicken lines.

• Journal of the Korean Wood Science and Technology
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• v.32 no.4
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• pp.8-17
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• 2004

Antifungal, antibacterial, and antioxidative activities of ethanol extracts from 65 families 263 species were investigated to select tree species for the utilization of natural fungicide or preservative resources. The antifungal activities of extracts from wood, leaf and bark were measured as hyphal growth inhibition rate using four plant pathogenic and five wood rotting fungi. High inhibitory effect on the fungi growth was found in five species of Pinaceae (Pinus koraiensis, P. rigida, P. densiflora, P. banksiana. Cedrus deodara), three species of Cupressaceae (Juniperus rigida, J. chinensis, Chamaecyparis obtusa) and three species of Leguminosae (Albizzia julibrisssin, Sophora japonica, Maackia amurensis), respectively. Antibacterial activities of ethanol extracts were determined by means of disc-agar plate diffusion method using three gram-positive and five gram-negative bacteria. The ethanol extracts, which showed prominent effect on the suppression of bacteria growth, were six species of Betulaceae (Carpinus tschonoskii, C. coreana, C. laxiflora, Alnus hirsuta, A. firma, Betula schmidtii), five species of Fagaceae (Castanopsis cuspidata var. sieboldii, Quercus serrata, Q. mongolica, Q aliena, C crenata), four species of Euphorbiaceae (Aleurites fordii, Sapium sebiferum, S japonicum Mallotus japonicus) and three species of Elaeagnaceae (Elaeagnus umbellata, Elaeagnus glanbra, Elaeagnus macrophylla). According to these results, the extracts from Zelkova serrata, Pinus densiflora, Maackia amurensis, Chamaecyparis obtusa and Juniperus chinensis could be available for natural fungicide or food preservatives, because ethanol extracts from these species indicated excellent antifungal and antibacterial activities. In order to test antioxidative activities of ethanol extracts, free radical scavenging method was adopted with 1,1-diphenyl-2-picrylhydrohydrazyl (DPPH). Free radical scavenging activity was proved very high in the extracts of eight species of Rosaceae (Eriobotrya japonica, Prunus takesimensis, P yedoensis, P padus, P armeniaca var. ansu, Chaenomeles sinensis, Stephanandra incisa, Rosa multiflora) and five species of Ericaceae (Rhododenron mucronulatum, R. scblippenbacbii, R. yedoense var. poukhanense, Vaccinium bracteatum, V oldbami), resvectively. It turned out from this study that only six species among 48 species of Rosaceae showed less than 80% free radical scavenging activity. As a consequences, it could be deduced that the components effective on antioxidative activity commonly exist in Rosaceae plant family.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.287-298
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• 2022

This study investigated the changes in the physiochemical property, phytochemical content, nutritional content and antioxidant activity of Polygoni multiflori Radix by steam, aging, and fermentation. After processing Polygoni multiflori Radix (PMR), pH slightly decreased, while acidity increased (pH 5.70→4.78, acidity 0.23→0.29%). The reducing sugar content increased after aging and fermentation from 1.19 mg/g (PMR) to 1.40 (fermented PMR, FPMR), 1.30 (red PMR, RPMR), 1.53 (fermented red PMR, FRPMR), 1.99 (black PMR, BPMR), and 2.33 mg/g (fermented black PMR, FBPMR). Total phenolic content was highest in PMR (6.05 mg/g) and total flavonoids and maillard product were increased after aging and fermentation of PMR, and were the highest in BPMR (1.60 mg/g) and FBPMR (2.76 O.D.), respectively. The major phytochemical was 2,3,5,4'-tetrahydroxystilbene-2-0-α-glucoside, which were highest in PMR (64.9 mg/g) with 46.47 mg/g at FPMR, 33.94 mg/g at RPMR, 48.76 mg/g at FRPMR, 36.68 mg/g at BPMR and 34.35 mg/g at FBPMR. The main fatty acids and free amino acids were detected as palmitic acid (C16:0) and proline, respectively. Generally, 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activities and FRAP reducing powers were shown high in PMR (39.06%, 98.32%, and 2.61 O.D. in extracts concentration 1.0 mg/mL), then were decreased after aging and fermentation.

• The Journal of Engineering Geology
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• v.33 no.3
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• pp.371-388
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• 2023

A stratum with a complex composition and a distributed low-permeability soil layer is difficult to remediate quickly because the soil remediation does not proceed easily. For efficient purification, the permeability should be improved and the soil remediation agent (H₂O₂) should be injected into the contaminated section to make sufficient contact with the TPH (Total petroleum hydrocarbons). This study analyzed a method for crack formation and effective delivery of the soil remediation agent based on pneumatic fracturing, plasma blasting, and vacuum suction (the PPV method) and compared its improvement effect relative to chemical oxidation. A demonstration test confirmed the effective delivery of the soil remediation agent to a site contaminated with TPH. The injection amount and injection time were monitored to calculate the delivery characteristics and the range of influence, and electrical resistivity surveying qualitatively confirmed changes in the underground environment. Permeability tests also evaluated and compared the permeability changes for each method. The amount of soil remediation agent injected was increased by about 4.74 to 7.48 times in the experimental group (PPV method) compared with the control group (chemical oxidation); the PPV method allowed injection rates per unit time (L/min) about 5.00 to 7.54 times quicker than the control method. Electrical resistivity measurements assessed that in the PPV method, the diffusion of H₂O₂2 and other fluids to the surface soil layer reduced the low resistivity change ratio: the horizontal change ratio between the injection well and the extraction well decreased the resistivity by about 1.12 to 2.38 times. Quantitative evaluation of hydraulic conductivity at the end of the test found that the control group had 21.1% of the original hydraulic conductivity and the experimental group retained 81.3% of the initial value, close to the initial permeability coefficient. Calculated radii of influence based on the survey results showed that the results of the PPV method were improved by 220% on average compared with those of the control group.