• Journal of dental hygiene science
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• v.1 no.1
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• pp.28-38
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• 2001

The aim of this study was to analyze the dental caries of chilren's deciduous teeth in relation to their mothers' socioeconomic factors and their oral health beliefs to increase the effect on children's oral health. One hundred seventy four children and their mothers were selected for the study. The children were 5 and 6 years old in children house in Kun-san, Korea. Research was conducted by oral examination, their mothers' socioeconomic factors and dental health belief model. The finding of analysis can be summaried as follows; In regard to the caries in deciduous teeth status, the five-year-old boy children's dft index was 3.39 and that of the girls of the same age was 2.76. The dft index of the boys of six was 3.86 and that of the girls of the same age was 3.27. The five-year-old boy children had the highest df rate(81.8%), and their dt rate was more than their ft rate. But for the six-year-old girl children, ft rate was higher than dt rate. For the five years old, the boy children's ft rate was significantly higher than that of the girls(p<0.05). Concerning the caries in deciduous teeth states by socioeconomic factors, their oral health status was significantly different according to mother employment and householder age. The df rate of the preschoolers with working mothers(84.7%) was significantly higher than that of those with nonworking mothers(66.7%)(p<0.05). The dft index of the group whose households were over forty was highest with 4.07, followed by the children of the households aged 35 to 39 with 3.83, those of the households aged 25 to 29 with 3.33, and those of the households aged 30 to 34 with 2.15. The difference between the groups was significant(p<0.05). As to the difference of maternal dental health beliefs by maternal socioeconomic factors, households educational background and whether to live with parents or parents-in-law under the same roof made a significant difference to maternal oral health beliefs. The mothers whose households were college graduates or better-educated were stronger in oral health susceptibility and seriousness(p<0.01, p<0.05). The salience was recognized more by those who lived with parents or parents-in-law than by the others who didn't(p<0.05). The dft index of the preschoolers was related to maternal dental health beliefs. That was lower when their mothers perceived dental health benefit better.

• Korean Journal of Poultry Science
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• v.26 no.2
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• pp.119-129
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• 1999

In recent years, numerous researches have been carried out in author's laboratory to develop several kinds of methods for producing transgened chicken, leaving a lot of new findings. Some of them are very useful to search for new approaches necessary to improve the efficiency of hatchability and the survival rate of developing trasgened embryos. The results obtained hitherto might be summarized as follows: (1) foreign gene(Lac Z/ Miw Z) introduced into blastodermal cells of developing embryos was successfully transferred to embryos, leading to the production of primordial germ cells(PGCs) carrying foreign DNA. However, hatched hickens failed to show the incorporation of introduced gene into the gonads. (2) When foreign gene was introduced into germinal crescent region (GCR), the gene was also efficiently incorporated into germ cells, resulting in the production of transgened chickens(offspring) which produced fruther offspring having foreign gene in the gonads. In this case, 2nd and 3rd generations of chickens were obtained through the reproduction of transgened birds. (3) In another way, the gene was injected into blood vessels of developing embryos at stage 13∼15, creating PGCs having foreign gene, and produced some transgened chickens. In this work, the PGCs were transfered between embryos, resulting in the production of transgenic chickens. (4) in these experiments, PGCs were effectively employed for producing transgenic birds, developing some kinds of chimeric chickens from homo- or hetero-sexual transfer of the PGCs from embryos. This means that the gonads from donor PGCs developed in some degree to the stage of hatching. However, these gonads showed slightly abnormal tissues similar to ovotestis like organs through histological examination. (5) Avian Leukosis Virus(ALV) induced B cell line(DT40) successfully carried foreign genes into chicken embryos, suggesting the possibility of the cells as a vector in this field of study in the future. (6) Inter-embryonic transfer of the PGCs also gave us some.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.156-156
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• 2011

VPH (Volume Phase Hologram) grating is one of the transmission gratings and is known as its remarkable efficiency (>90%). It has two different densities of gelatins causing interference patterns. The VPH grating is favored in many astronomical instruments these days and also IGRINS, which is up coming near infrared high-resolution spectroscope expected to see the first light next year, uses the VPH grating as its cross-disperser. The infrared astronomical instruments operate at cryogenic temperature (~100K) in order to cut down thermal noise and the optical components of IGIRNS will be operated at 130K. The VPH grating is sandwiched in between fused silica or glass and glued together using optical adhesive. IGRINS is expected to go through 50 times of thermal cycling in 10 years including the performance test and this research is to check whether the physical characteristic such as the adhesion or dichromatic gelatin does not break and change from the several cryogenic thermal cycling. The two identical test gratings provided from Kaiser Optical System, Inc. are used in this test. One VPH grating is cooled down to 100K for 2 hours with maximum dT/dt = 5 and warmed up to the room temperature and another grating is kept stored in the room temperature and used as a control sample. In order to check the change, we inspected the grating with eyes and checked its efficiency and transmission at the room temperature every 10 cycling. From the 40 times of cryogenic temperature cool down cycling, the VPH grating showed no signs of change within the error compared to the control sample. We concluded the VPH grating is durable through several cryogenic thermal cycling.

• Polymer(Korea)
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• v.35 no.1
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• pp.40-46
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• 2011

The synthesis of well-defined poly(styrene-b-isobutylene-b-styrene) (SIBS) triblock copolymers was accomplished by cationic sequential block copolymerization of isobutylene (IB) with styrene (St) using 1,4-di(2-chloro-2-propyl) benzene (DCC) /$TiCl_4$/2,6-di-tert-butylpyridine(DtBP) as an initiating system in methyl chloride ($CH_3Cl$)/methylcyclohexane(MeChx) (50/50 v/v) solvent mixture at $-80^{\circ}C$. The triblock copolymers exhibited excellent thermoplastic and elastomeric characteristics. Tensile strengths and Shore hardness increased with increasing polystyrene (PS) content, while elongation at break decreased. The blood-compatibility of SIBS was assessed by SEM observation of the platelet adhesion, blood clotting time and haemolysis ratio. The haemolysis ratios were below 5% which met the medical materials standard. The platelet adhesion test further indicated that SIBS block copolymers had a good blood compatibility.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.95-101
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• 1996

The in vitro antibacterial activities of LB10522, a new catechol-substituted cephalosporin, were compared with those of cefpirome, ceftazidime, ceftriaxone, and cefoperaz one against clinical isolates and laboratory standard anaerobes. LB10522 had broad spectrum antibacterial activities against both gram-positive and gram-negative microorganisms. It was most active against gram-positve bacteria among the reference cephalosporins tested. Against gram-negative strains such as the family Enterobacteriaceae, LB10522 showed an activity comparable to that of cefpirome. But LB10522 was more potent than ceftazidime, ceftriaxone and cefoperazone. In particular, Pseudomonas aeruginosa was highly susceptible to LB10522, which was 32-fold and 64-fold more active than ceftazidime and cefpirome, respectively. Against anaerobic strains, the activity of LB10522 was similar to those of reference compounds. LB10522 exhibited potent therapeutic activities against experimental local infections in mice. The therapeutic effect of LB10522 against urinary tract infection (UTI) caused by P. aeruginosa 1912E in mice was superior to that of cefpirome. Against experimental respiratory tract infection (RTI) caused by K. pneumoniae DT-S in mice, LB10522 was as effective as cefpirome. The in vivo efficacy of LB10522 was correlated well with its in vitro activity.

• Food Science and Preservation
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• v.20 no.2
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• pp.278-283
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• 2013

The purpose of this study was to evaluate the mortality rate, weight gain, and protein, lipid cholesterol, and total amino acid contents in processed-sulfur-diet chicken meat. Also investigated were the antioxidant activity and glutathione content of blood plasma. The mortality of the processed-sulfur-diet chickens was relatively reduced, and their weight increased compared to the normal-diet chickens. Although the glutathione content decreased in the processed-sulfur-diet chicken blood plasma, the antioxidant activity increased compared with the normal-diet chickens. Also, there was no difference in the total cholesterol contents of the blood, but the level of HDL cholesterol increased while that of LDL cholesterol decreased. Furthermore, there were no changes in the total amino acid and protein contents, but the fat content was significantly reduced. As no toxicity was found in the DT 40 cells in the MTT assay, it can be concluded that dietary sulfur in chicken feed can improve the quality of poultry products.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.623-623
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• 2003

I. Objectives The aim of this was to evaluate the use possibility of light curing flowable composite resins as a luting agent for translucent fiber posts. II. Materials and Methods 20 single-rooted maxillary central incisors were selected and crown was sectioned below the cemento-enamel junction to obtain a 13 mm ling root. Root canals were filed, cleaned, and shaped to ＃40 with K-file. Prepared canals were filled with gutta percha and AH26 root canal sealer by lateral condensation method. Teeth were than divided into 4 groups of 5 specimens each. In group 1 and 2, the canal space of each root was enlarged with ＃3 DT Light post preparation drill (Bisco, USA) to a depth of 9mm from the cervical.(omitted)

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.317-317
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• 2021

효율적인 물관리를 위한 댐 유입량 대한 연구는 필수적이다. 본 연구에서는 다양한 머신러닝 알고리즘을 통해 40년동안의 기상 및 댐 유입량 데이터를 이용하여 소양강댐 유입량을 예측하였으며, 그 중 고유량과 저유량예측에 적합한 알고리즘을 각각 선정하여 머신러닝 알고리즘을 결합한 CombML을 개발하였다. 의사 결정 트리 (DT), 멀티 레이어 퍼셉트론 (MLP), 랜덤 포레스트(RF), 그래디언트 부스팅 (GB), RNN-LSTM 및 CNN-LSTM 알고리즘이 사용되었으며, 그 중 가장 정확도가 높은 모형과 고유량이 아닌 경우에서 특별히 예측 정확도가 높은 모형을 결합하여 결합 머신러닝 알고리즘 (CombML)을 개발 및 평가하였다. 사용된 알고리즘 중 MLP가 NSE 0.812, RMSE 77.218 m3/s, MAE 29.034 m3/s, R 0.924, R2 0.817로 댐 유입량 예측에서 최상의 결과를 보여주었으며, 댐 유입량이 100 m3/s 이하인 경우 앙상블 모델 (RF, GB) 이 댐 유입 예측에서 MLP보다 더 나은 성능을 보였다. 따라서, 유입량이 100 m3/s 이상 시의 평균 일일 강수량인 16 mm를 기준으로 강수가 16mm 이하인 경우 앙상블 방법 (RF 및 GB)을 사용하고 강수가 16 mm 이상인 경우 MLP를 사용하여 댐 유입을 예측하기 위해 두 가지 복합 머신러닝(CombML) 모델 (RF_MLP 및 GB_MLP)을 개발하였다. 그 결과 RF_MLP에서 NSE 0.857, RMSE 68.417 m3/s, MAE 18.063 m3/s, R 0.927, R2 0.859, GB_MLP의 경우 NSE 0.829, RMSE 73.918 m3/s, MAE 18.093 m3/s, R 0.912, R2 0.831로 CombML이 댐 유입을 가장 정확하게 예측하는 것으로 평가되었다. 본 연구를 통해 하천 유황을 고려한 여러 머신러닝 알고리즘의 결합을 통한 유입량 예측 결과, 알고리즘 결합 시 예측 모형의 정확도가 개선되는 것이 확인되었으며, 이는 추후 효율적인 물관리에 이용될 수 있을 것으로 판단된다.

• Korean journal of applied entomology
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• v.47 no.3
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• pp.217-226
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• 2008

Development of T. urticae was studied on the leaves of eggplant grown in hydroponics with potash contents of 0 mM, 2 mM, 6 mM, and 12 mM. As the levels of potash increased, that of nitrogen decreased and that of P, K, Mg increased in the plant. While contents of crude protein and fiber decreased, those of ash and sugar increased. Carbohydrate content was the highest at 2 mM. Water contents increased as those of potash increased with the exception at 0 mM. Biomass was the heaviest as 552.7 g at 6 mM and the lightest at 0 mM. Leaf thickness and the content of chlorophyll increased as the content of potash increased. Laboratory leaf disc tests provided with various potash levels revealed that feeding and oviposition preferences of T. urticae were high at 6 mM and 12 mM, respectively. Ratio of damaged leaf by naturally occurring T. urticae on eggplants of 99 days post-transplant in the greenhouse was the highest at 6 mM. Development of immature stages of T. urticae shortened as the levels of potash increased with a less tendancy in male than in female. No differences were detected in adult longevity and oviposition period but the number of eggs laid was the most as 84.7 at 6 mM and the least as 40.6 at 0 mM. There were no differences in the rate of egg hatch and the ratio of sex. $R_o,\;r_m,\;and\;{\lambda}$ were the highest at 6 mM and the lowest at 0 mM. T and Dt were the lowest at 6 mM and the highest at 0 mM. There was a descending trand of T. urticae developmet when levels of potash either gets high or low in the hydroponics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.187-194
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• 2020

The T&E (Test and Evaluation) results were applied for a judgment basis to decide the developmental process of system engineering for efficient weapon system R&D (Research and Development). During the OT&E (Operational Test and Evaluation) and DT&E (Development Test and Evaluation), an environmental test is essential for weapon system development owing to their highly exposed operational conditions. Based on the MIL-STD-810, MIL-HDBK-310, and AECTP 200, the ROK armed forces recommended operating temperatures for the ROK weapon system and applied this to the DT&E and OT&E. This study examined the compatibility of Korean temperature guidelines for stockpile material considering recent climate change. Moreover, this study analyzed the data from hourly measured temperatures on 101 observatories during 60 years, from 1960 to 2020, and percentage (0.5%, 1%, 5%, and 10%) and the 𝜎 (3𝜎, 2𝜎, and 1𝜎) frequency of occurrence on rigorous hot (August) and cold (January) periods, respectively. The results indicate that the highest temperature was 41℃, and the 0.5% frequency of occurrence was 37.0℃. In the case of the cold period, the lowest temperature was -32.6℃ and the 0.5% frequency of occurrence was -21.1℃. By considering the previously recommended operating temperature range for a general ground system, -30 ~ 40℃, regional operation probability is recognized 99.999%. Despite the recent abnormal climate change from global warming, the Korean temperature guidelines are compatible with the stockpile material environmental test.