• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.371-383
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• 2012

Shaping the root canal system to maintain original canal curvature is essential to clinical success in endodontic treatment. Opposed to most root canals that are curved, endodontic instruments are made from straight metal blanks. They have a tendency of straightening the root canal during preparation and frequently result in procedural errors. A new treatment method to maintain original canal curvature during shaping has been introduced for preventing procedural errors. The aim of this study was to compare the ability of instruments to maintain original canal curvature of continuous rotary system and single file system. Thirty ISO 15, 0.02 taper, Endo Training Blocks(Dentsplay Maillefer) were used. Specimens were assigned to 1 of 3 groups for shaping: specimens in group 1 were shaped with ProFile #20/.06 at the WL. Specimens in group 2 were shaped with Mtwo #35/.04 at the WL. Specimens in group 3 were shaped with WaveOne Primary reciprocating files at the WL after the glide path was achieved with PathFile. Pre- and postinstrumentation digital images were superimposed and processed with Matlab r2010b(The MathWorks Inc, Natick, MA) software to analyze the curvature-radius ratio(CRr), representing canal curvature modification. Data for comparison on the ability of instruments to maintain original canal curvature depending on each Ni-Ti file were analyzed with 1-way ANOVA(P<.05). Data for comparison on the ability of instruments to maintain original canal curvature depending on each Ni-Ti file system were analyzed with independent t-test(P<.05). A statistically significant difference(P<0.05) was noted on each Ni-Ti file. ProFile and WaveOne instrumentations maintained the original canal curvature significantly better(P<0.05) than Mtwo file. There were no significant difference(P>0.05) between continuous rotary system and single file system. Under the conditions of this study, ProFile and WaveOne instruments maintained the original curvature significantly better than Mtwo file and were less modification of the canal curvature compared. There was no significant difference between continuous rotary system and single file system in shaping of simulated canals. As clinical practitioners, it may be advantages to use hybrid approach when root canal shapes depending on the design and usage of Ni-Ti files.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.205-214
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• 2020

Cyanobacteria are microorganisms which have important roles in the nitrogen cycle due to their ability to fix nitrogen in water and soil ecosystems. They also produce valuable materials that may be used in various industries. However, some species of cyanobacteria may limit the use of water resources by causing harmful algal blooms in water ecosystems. Many culture collection depositories provide cyanobacterial strains for research, but their systematic preservation is not well-developed in Korea. In this study, we developed a method for the cryopreservation of the cyanobacteria Trichormus variabilis (syn. Anabaena variabilis), using alginate microcapsules. Two approaches were used for the experiments and their outputs were compared. One of the methods involved the cryopreservation of cells using only a cryoprotectant and the other used the cryoprotectant within microcapsules. After cryopreservation for 35 days, cells preserved with both methods were successfully regenerated from the initial 1.0 × 10⁵ cells/ml to a final concentration of 6.7 × 10⁶ cells/ml and 1.1 × 10⁷ cells/ml. Irregular T. variabilis shapes were found after 14 days of regeneration. T. variabilis internal structures were observed by transmission electron microscopy (TEM), revealing that lipid droplets were reduced after cryopreservation. The expression of the mreB gene, known to be related to cell morphology, was downregulated (54.7%) after cryopreservation. Cryopreservation using cryoprotectant alone or with microcapsules is expected to be applicable to other filamentous cyanobacteria in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.1
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• pp.27-37
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• 2002

With increasing the concerns of health improving foods. the demands of C. boreale M., which is a perennial flower and has been historically used for a natural medicine, become higher, recently, However, wild C. boreale M. collected in a mountatinous area is limited and not enough to cover all demands. The cultivation system and fertilization strategy are required to produce much amount of C. boreale M. with a good quality. We investigated the effects of soil amendment application on plant growth and effective components of C. boreale M. to develop efficient cultivation system. C. boreale M. was cultivated in a pot scale, and lime, fly ash, poultry manure compost and swine manure compost as an amendment applied with rate of 2, 20, 150 and $150Mg\;ha^{-1}$, respectively. Here, chemical fertilizers were applied with the same level ($N-P_2O_5-K_2O=150-80-80kg\;ha^{-1}$) in all treatments. Flower yields of C. boreale M., edible part as a natural medicine, were increased to 37 and 27% by swine and poultry manure compost application, respectively. Poultry manure compost amending (NPK+PMC) increased 3.6 times of proline content and 58% of total amino acids in the flower part more than chemical fertilization (NPK). But the contents of amino acids did not increase with amending liming materials like lime and fly ash. Cumambrin A, which is a sesquiterpene compound and has the effect of blood-pressure reduction, increased to 34 and 19% by lime and fly ash applications, respectively. Cumambrin A was significantly correlated with calcium content in the flower part of C. boreale M. Conclusively, soil amendments like compost and liming materials might contribute to increase the yields and quality of C. boreale M.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.296-307
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• 2016

Ecological restoration is an eco-technology, which heals the nature damaged by human activity by imitating organization and function of the integrate nature and thereby provide an inhabitable space for diverse organisms. Such an ecological restoration has to be carried out by applying restoration plan prepared based on the results of diagnostic evaluation discussed in the diversified respects. This study aims to prepare an ecological restoration plan of the damaged forest ecosystem in Mt. Moodeung National Park. To arrive at the goal, first of all, we diagnosed quality of forest landscape established in Mt. Moodeung National Park based on natural (topography, climate, and distribution of vegetation) and artificial (land use, linear landscape element) factors. In addition, we evaluated the integrity of each zone divided by linear landscape element quantitatively based on geometric property and land use intensity. As the result of analysis, topography of Mt. Moodeung National Park tended to be depended on weathering property of parent rock and vegetation zones were divided to three vegetation zones. Based on land use pattern, deciduous broad-leaved forest, evergreen needle-leaved forest, and mixed forest occupied about 90% of Mt. Moodeung National Park. Mean score of forest landscape quality was shown in $69.86{\pm}11.41$. As a result, forest landscape elements in Mt. Moodeung National Park were influenced greatly by human activity and the degree was depended on topographic condition. This study suggested the synthetic restoration plan to improve ecological quality of Mt. Moodeung National Park based on the results of diagnostic evaluation.

• Current Research on Agriculture and Life Sciences
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• v.26
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• pp.63-69
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• 2008

The varietal difference, effect of root amounts and cultivation duration on the asparagine content of soybean sprouts, which is known to have the excellent detoxifying effect of ethanol, were investigated for developed varieties and indigenous sprout lines to establish cultivation methods of increasing the asparagine content and to develop soybean varieties having high asparagine content. Some of the research results obtained are summarized as follows; 1. Range and mean of asparagine content of 174 germplasm were 0.38~1.67% and 0.99%, respectively, on fresh weight basis. 2. Developed sprout-soybean varieties showed somewhat higher asparagine content of 1.29% than that of indigenous sprout lines of 0.96% on fresh weight basis. 3. No significant difference in asparagine content among the seed size groups was recognized though the highest asparagine content, 1.02% on fresh weight basis was observed in the seed size of 8.1~10.0g/100 seeds. 4. Among the seed coat color groups, soybean of brown seed coat color showed the highest asparagine content (1.15%) on fresh weight basis. No difference was observed among other groups of seed coat color. 5. Range of asparagine content of 174 varieties was 4.08~6.24% on dry weight basis. Soybean varieties that showed high asparagine content were Dawonkong, Sobacknamulkong, Sowonkong, and Somyungkong, with the contents of 6.24%, 6.21%, 5.95%, and 5.85%, respectively. 6. Amount of roots which have the highest asparagine content out of sprout parts was greatly increased up to 10 days of sprout cultivation. 7. Highly significant difference in asparagne content of sprout was recognized between those grown for five and ten days, with the asparagine content of 0.68% and 1.21%, respectively, on fresh weight basis. 8. Asparagine content of hypocotyle part was also highly proportional to days to cultivation; it increased from 2.91% at 2 days of cultivation to 15.68% on fresh weight basis at 14 days of cultivation.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.178-186
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• 2009

The quality control is needed to ensure the accuracy of medical information and achieved by evaluating the performance of and maintaining the system and practicing various measurements and evaluations. The Korean Institute for Accreditation of Medical Image, therefore, have held educational program for quality control of special medical equipments. The major of programs participants, however, are radiology specialists with only small number of radiological technologists from some hospitals, furthermore, the follow-up education and the share of information between participants and non-participants are insufficient in general, thus, the knowledge level of radiological technologists, regardless of their participation, is relatively low. This study carried out the questionnaire research for the 500 radiological technologists registered in Korean Society of MRI Technology, on the basis of 2008, and performed analysis for five months from May to Oct., 2008. The questionnaires were delivered by post to each radiological technologists and the response rate was 36%(n=180). The results of this revealed that the 86.7% of respondents felt the necessity of inspection on quality management, while only the 27.8% completed the educational program for manager of special medical equipment. and only the half(53.9%) had the knowledge about inspection on quality management. The completion of educational program had no correlations with sex, age, size of occupying hospital, the number of radiological technologists in occupying site and MRI laboratory, career year of general radiologist and in MRI laboratory, and the presence of biomedical engineering department in occupying hospital. The 78.0% of participants at the educational program for quality management held by the Korean Institute for Accreditation of Medical Image had the knowledge about inspection on quality management(p<.05) whereas the 43.9% of the hospitals held such program and the 54.4% of radiological technologists from those hospitals had related knowledge, which indicated that such programs held by hospitals had not effects on the knowledge level of radiological technologists. This indicates also that the contents, methods, and other conditional factors of educational programs are important for the outcome of them.

• Trans-
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• v.9
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• pp.17-36
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• 2020

This study is aimed at discussing the possibility of content production, utilization and expansion, focusing on the exhibition case of Danwon Art Museum run by Ansan Cultural Foundation. In 1991, the Ministry of Culture, Sports and Tourism named Ansan as the City of Danwon since it is believed to be the hometown of Danwon Kim Hong-do (1745~?), a painter of the late Joseon Dynasty and a well-known master of genre painting. As a result, Ansan is making various efforts to utilize Danwon Kim Hong-do for its unique resource through internal and external business such as the creation of Danwon Sculpture Park, the operation of Danwon Art Museum, and the planning of Danwon Kim Hong-do Festival. However, the biggest problem with Ansan is that there are not many collections of Kim Hong-do. Ansan has owned a total of six works as of May this year: a deer and a boy, flowers and a bird, A view of clouds on the water, Daegwallyeong, Yeodongbin, A way to Singwangsa. Accordingly, Danwon Contents Center has set up a vision to systematically collect, preserve, and display various visual and artistic materials related to Kim Hong-do, offering high-quality information based on digital data. In other words, it is a complex cultural information agency of One-Source Multi-Use, which combines the functions of libraries, archives and art galleries so that visitors' desire is satisfied. It reflects the contemporary trend of overcoming the limitations of the ancient paintings and satisfying the role and function of the art museum. From the opening of the Danwon Contents Hall, the original work of Kim Hong-do has been interpreted and produced as media contents or recreated as a new form of art by modern artists. Exhibition using technologies such as touch screen and 'deep zoom' helps visitors to heighten their experience of the archives and get inside the world of the genius painter.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.617-628
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• 2022

A ground support pattern should be designed by properly integrating various support materials in accordance with the rock mass grade when constructing a tunnel, and a technical decision must be made in this process by professionals with vast construction experiences. However, designing supports at the early stage of tunnel design, such as feasibility study or basic design, may be very challenging due to the short timeline, insufficient budget, and deficiency of field data. Meanwhile, the design of the support pattern can be performed more quickly and reliably by utilizing the machine learning technique and the accumulated design data with the rapid increase in tunnel construction in South Korea. Therefore, in this study, the design data and ground exploration data of 48 road tunnels in South Korea were inspected, and data about 19 items, including eight input items (rock type, resistivity, depth, tunnel length, safety index by tunnel length, safety index by rick index, tunnel type, tunnel area) and 11 output items (rock mass grade, two items for shotcrete, three items for rock bolt, three items for steel support, two items for concrete lining), were collected to automatically determine the rock mass class and the support pattern. Three machine learning models (S1, A1, A2) were developed using two machine learning algorithms (SVR, ANN) and organized data. As a result, the A2 model, which applied different loss functions according to the output data format, showed the best performance. This study confirms the potential of support pattern design using machine learning, and it is expected that it will be able to improve the design model by continuously using the model in the actual design, compensating for its shortcomings, and improving its usability.

• Journal of Korean Home Economics Education Association
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• v.33 no.2
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• pp.95-113
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• 2021

This study examined the food group and dietary nutrient intakes by sugar-sweetened beverage(SSB) intake level in high school students aged 15~18 years(n=2,377) using the 2007~2015 Korea National Health and Nutrition Examination Survey. Subjects were classified into three groups by SSB(included carbonated drinks, sports drinks, and caffeinated drinks that contained added sugars) intake level obtained from 24-hour recall method: SSB 1(SSB intake 0 g/d), SSB 2(0 g/d < SSB intake < 50th percentile) and SSB 3(SSB intake ≥ 50th percentile). Result of daily intakes of SSB were 160.6±10.5 g/d for boys and 98.6±7.1 g/d for girls and it increased for boys(p<0.0001) and girls(p=0.0280) by year. The highest intakes were carbonated drinks followed by fruit juices for boys and girls. Intakes of carbonated drinks increased as 2.7 times for boys(p<0.0001) and 1.6 times for girls between 2007 and 2015 year. Daily intakes of vegetables were the lowest in SSB 3 of three groups for boys and girls(p<0.0001), and those of fruits were lower in SSB 2 and SSB 3 than SSB 1 for boys(p=0.0013). Daily intakes of milk & milk products decreased toward SSB 3 group for boys(p<0.0001) while those were the lowest in SSB 3 of three groups for girls. Daily intakes of dietary fiber(21.3~25.3%) and calcium(49.6~59.8%) were very low compared to the dietary reference intakes. Percentage of daily intakes compared to the dietary reference intakes increased for energy for boys and girls(p<0.0001) while decreased for vitamin C toward SSB 3 group for boys(p<0.0001) and girls(p=0.0382). Those of calcium were the lowest in SSB 3 of three groups for boys(p<0.0001) and girls(p=0.0008). Ratio of excess intakes of energy/fat increased toward SSB 3 group for boys and girls(p=0.0002). Ratio of calcium deficiency was not different among groups but that was very high(85.9~92.5%). Therefore, it should be emphasized to reduce SSB intakes in order to improve diversity in food group and dietary nutrient intakes among high school students through dietary education and government support.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.965-973
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• 2021

Since radiation therapy is irradiated with high-energy X-rays in a variety of at least 20 Gy to 80 Gy, a high dose is administered to the local area where the tumor is located, and various side effects of some normal tissues are expected. Currently, in clinical practice, lead, a representative material, is used as an effort to shield normal tissues, but lead is classified as a heavy metal harmful to the human body, and a large amount of skin contact can cause poisoning. Therefore, this study intends to manufacture a measurement sheet that can compensate for the limitations of lead using the materials Tungsten, Brass, and Copper of the 3D printer of the FDM (Fused Deposition Modeling) method and to investigate the penetration performance. Tungsten mixed filament transmission measurement sheet size was 70 × 70 mm and thickness 1, 2, 4 mm using a 3D printer, and a linear accelerator (TrueBeam STx, S/N: 1187) was measured by irradiating 100 MU at SSD 100 cm and 5 cm in water using a water phantom, an ion chamber (FC-65G), and an elcetrometer (PTW UNIDOSE), and the permeability was evaluated. As a result of increasing the measurement sheet of each material by 1 mm, in the case of Tungsten sheet at 3.8 to 3.9 cm in 6 MV, the thickness of the lead shielding body was thinner than 6.5 cm, and in case of Tungsten sheet at 4.5 to 4.6 cm in 15 MV. The sheet was thinner than the existing lead shielding body thickness of 7 cm, and equivalent performance was confirmed. Through this study, the transmittance measurement sheet produced using Tungsten alloy filaments confirmed the possibility of transmission shielding in the high energy region. It has been confirmed that the usability as a substitute is also excellent. It is thought that it can be provided as basic data for the production of shielding agents with 3D printing technology in the future.