• Molecules and Cells
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• 제27권2호
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• pp.217-223
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• 2009

Development of symbiotic root nodules in legumes involves the induction and repression of numerous genes in conjunction with changes in the level of phytohormones. We have isolated several genes that exhibit differential expression patterns during the development of soybean nodules. One of such genes, which were repressed in mature nodules, was identified as a putative aldo/keto reductase and thus named Glycine max aldo/keto reductase 1 (GmAKR1). GmAKR1 appears to be a close relative of a yeast aldo/keto reductase YakC whose in vivo substrate has not been identified yet. The expression of GmAKR1 in soybean showed a root-specific expression pattern and inducibility by a synthetic auxin analogue 2,4-D, which appeared to be corroborated by presence of the root-specific element and the stress-response element in the promoter region. In addition, constitutive overexpression of GmAKR1 in transgenic soybean hairy roots inhibited nodule development, which suggests that it plays a negative role in the regulation of nodule development. One of the Arabidopsis orthologues of GmAKR1 is the ARF-GAP domain 2 protein, which is a potential negative regulator of vesicle trafficking; therefore GmAKR1 may have a similar function in the roots and nodules of legume plants.

• Restorative Dentistry and Endodontics
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• 제24권2호
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• pp.356-363
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• 1999

The purpose of this study was to compare the apical sealing effect of Microseal obturation technique with lateral condensation technique in 26 recently extracted single rooted teeth. The root canals were instrumented using step-back technique and obturated with laterally condensed gutta-percha or Microseal. Teeth were suspended in methylene blue dye for 2 days and then longitudinary splited. The apical microleakage and the adaptability of gutta-percha to the root canal wall were examined under a stereomicroscope at ${\times}20$ magnification. The results were as follows: 1. The mean leakage was 1.38${\pm}$1.18 mm for laterally condensed gutta-percha group, and 0.71${\pm}$0.57 mm for Microseal gutta-percha group. But there was no statistical difference between two groups. 2. In Microseal gutta-percha group, they showed no gap between the master cone and Microseal gutta-percha, and showed homogeneous mass. 3. In contrast, laterally condensed gutta-percha group showed some gaps not only between gutta-percha cones, but also between gutta-percha cones and the canal walls, and the gaps were filled with some sealer. And also this group showed some amout of sealer on the root canal walls, Within the limits of the results of this experiment, Microseal gutta-percha obturation technique demonstrated relatively favorable apical sealing effect and shorter obturation time. Thus, it is thought that this obturation technique is a acceptable method for clinical use but further studies on this matter should be conducted.

• 한국수자원학회논문집
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• 제53권11호
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• pp.929-938
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• 2020

본 연구에서는 청미천 유역에서의 플럭스타워에서 산출되는 증발산량의 결측값을 보완하기 위해 인공신경망(Artificial Neural Network, ANN)을 사용하였다. 비교 평가를 위해, Mean Diurnal Variation(MDV), Food and Agriculture Organization Penman-Monteith(FAO-PM) 방법들을 이용하여 증발산량을 산정하였고, ANN 방법을 이용한 결과와 비교하였다. 비교 평가 방법으로 시계열 방법 및 통계 분석(결정계수, IOA, RMSE, MAE)이 사용되었다. 각 gap-filling 모델의 검증을 위해 2015년의 30분 단위 데이터를 이용하였으며, 121개의 결측값 중 MDV, FAO-PM, ANN 방법 순으로 각각 70, 53, 54개의 결측값을 보완하여 모든 데이터가 관측되지 않은 36개의 데이터를 제외하면 각각 82.4%, 62.4%, 63.5%의 성능을 보였다. 결정계수(MDV, FAO-PM, ANN 방법 순으로 각각 0.673, 0.784, 0.841)와 IOA(MDV, FAO-PM, ANN 방법 순으로 각각 0.899, 0.890, 0.951)를 분석한 결과, 3가지 방법 모두 양질의 상관성을 보여 활용성이 충분하다고 판단되며, 이 중 ANN 모델이 가장 높은 적합도와 양질의 성능을 나타내었다. 본 연구를 기반으로 기계학습방법을 이용한 플럭스 타워 자료의 gap-filing 연구에 보다 적절하게 활용될 수 있을 것이다.

• Journal of Welding and Joining
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• 제33권1호
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• pp.54-60
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• 2015

Laser-arc hybrid welding has been considered as an effective pipe girth welding process since early 2000's. Tolerance for fit-up offsets such as gap and edge misalignment is one of most important requirements in pipe girth laser-arc hybrid welding, and several approaches using parameter optimization, a laser beam scanning and an arc oscillation have been tried. However the required offset tolerance has not been fully accomplished up to now and laser-arc hybrid welding has not been widely applied in pipeline construction than expected, despite of its high welding speed and deep penetration. In this study, internal welding was adopted to ensure the offset tolerance and sound back bead. The effect of welding parameters on bead shape was investigated at the flat position. Also tolerances for gap and edge misalignment were verified as 0.5 mm and 2.0 mm, respectively. The position welding trials were conducted at several welding positions from the flat to the overhead position in a downward direction. With the fixed welding speed, arc current for gas metal arc welding current and laser output power, adequate welding voltages for gas metal arc welding were suggested for each position.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.35-44
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• 2009

The purpose of this paper is to describe experimental results about the T-joint welding of the high power continuous wave (CW) fiber laser for SAPH steel plate for seat frame of car. The seat rail is a part of seat frame of cars. The assembling method is mostly fix up using a bolt and nut. But this assembling method has many demerits in productivity such as increasing work process and material cost. This paper presents an experimental study about Laser T-Joint weldability of seat rail. Laser welding has many advantages in lightness and saving material costs of seat frame. The laser beam was moved along the work pieces by six axis robot with process optical fiber. The laser beam is focused with a welding head within incident angle $15{\sim}45^{\circ}$ for the purpose of the T-joint welding through two side full penetration. The range of the root gap size is less than ${\leq}0.4mm$. Optical microscopy SEM were performed to observe the micro structures and determine the structures of welded zone.

• 대한소아치과학회지
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• 제8권1호
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• pp.65-75
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• 1981

The author have studied on the pulp responses to the electric pulp stimulator (Pyo-Cure)(R) in the primary molar age from 4 to 11 of the 186 children (male 100, female 86). The total numbers of teeth used in this study were 1096. The results were as follows ; 1. The difference in responses between the teeth of the male and female was not statistically significant. 2. The difference in responses between the teeth of the right and left sides was not statistically significant. 3. The difference in responses between the teeth of the upper and lower jaws was not statistically significant. 4. The responses of the teeth in the older age is higher than its of the early age. 5. Inspite of advanced root resorption of the primary molars, except severe root resorption, the responses of the teeth was higher according to increasing the age. 6. The responses of the teeth were decreased severely in the primary molars as it becomes exfoliation time.

• 한국실내디자인학회논문집
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• 제19권3호
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• pp.57-66
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• 2010

Currently, the nature and ecosystem's destruction by human beings and science is appearing as a serious problem. The possibility of ecological aesthetics is being sought as one of operations for new society in the contemporary society that the nature and ecosystem are getting attention, The present research aims to examine the characteristics and its expression method by setting the ecological aesthetics as an alternative of the future design. The history, meaning, mental image and image of Korean traditional Space forming the balance and harmony with the Nature, etc., which are important design concepts, were deduced as the beauty of emptiness, the beauty of a gap, the beauty of harmony and the beauty of changing and the beauty of simplicity as characteristics of experiencing space. If the deduced expression is examined through a case analysis of traditional housing, the characteristics trying to unite with the Nature while seeing ecology and aesthetics as one root, which the ecological aesthetics regarding as a root. The ecological arts based on the ecological aesthetics enters inside the universal life of human beings by examining the ecological and aesthetic characteristics appearing in Korean traditional Space, and the arts will move forward in a direction that its function and role link with maintenance of total ecosystem. The space application possibility and expression characteristics of ecological aesthetics should be continuously researched.

• 대한한의학회지
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• 제17권1호
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• pp.329-335
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• 1996

Rehmannia Radix is a thick tuberous root about 3-6 cm diameter. The tuberous root is repared for medicine. The material in the fresh state is shengdihuang (生地黃). The material in the dried state is gandihuang (乾地黃). Shudihuang (熱地黃) is made by taking juicy roots, washing them in millet wine, steaming on a willow frame in a percelain vessel, drying, and resteaming and redrying nine times. The aim of this experiments was to investigate the effect of Rehmannia Radix Water extracts on the plasma renin activity and plasma levels of aldosterone and atrial natriuretic peptide (ANP) in rats. The results of study were as follows: Plasma renin activity was not changed after administration of Rehmannia Radix water extracts. Plasma levels of aldosterone was decreased significantly after administration of Shudihuang (熱地黃) water extracts. Plasma levels of atrial natriuretic peptide was increased significantly after administration of Shudihuang (熱地黃) water extracts.

• 대한소아치과학회지
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• 제6권1호
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• pp.43-52
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• 1979

The purpose of this study was to finding out the relationship between the tooth calcification and eruption of the mandibular permanent teeth in Korean. This study was undertaken in 592 children at ages from 3 to 13 years who had good oral condition by means of panoramic roentgenographic analysis. The following results were obtained. 1. The mean ages of crown completion were as follows; Canine 1st. Premolar 2nd. Premolar 1st. Molar Male 6yrs. 4mos. 6yrs. 8mos. 7yrs. 6mos. 7yrs. 6mos. Female 5yrs. 11mos. 6yrs. 5mos. 7yrs. 2mos. 3yrs. 3mos. 2. Each tooth started to move toward occlusion at approximately stage 6 or after crown completion. 3. The highest increment in eruption rate was at about 1/3~1/2 completion of root and ages at 10-11 years in male, 9-10 years in female. 4. Eruption period of both sexes were as follows; Canine: 6-12years 1st. Premolar: 7-12 years 2nd. Premolar: 7-13 years 1st. Molar: 3-7 years 5. The eruption was completed before the root completion. 6. The sequence of eruption and calcification was 1st. Molar-Canine-1st. Premolar-2nd. Premolar in both sexes.

• 대한치과의사협회지
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• 제54권11호
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• pp.865-873
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• 2016

Background/Purpose: The purpose of this study was to evaluate the effect of Nd:YAG irradiation on adherence of retrograde filling materials (mineral trioxide aggregate [MTA] and Super-EBA) by micro-computed tomography (CT) measurement and to observe the dentinal surface after irradiation by scanning electron microscopy (SEM). Materials and methods: Forty retrofilling models using extracted human teeth were divided into four groups according to the material and method used: ProRoot MTA (MTA group), Super-EBA (EBA group), MTA with Nd:YAG laser irradiation (LMTA group), and Super-EBA with Nd:YAG laser irradiation (LEBA group). All specimens were stored in 100% humidity for 24 hours until micro-CT was performed. The gap volume of the tooth/material interface was measured using the CTAn program. In six samples, the laser-irradiated dentin surface was observed using SEM. Results: The mean percent difference in gap volume was not statistically significant between the Nd:YAG laser-irradiated groups and non-irradiated in both materials(P > 0.05). The gap volume in the MTA group was significantly lower than that in the EBA group (P < 0.05). Examination of the non-irradiated specimens by SEM showed patent dentinal tubules. In contrast, alterations in the texture of the dentin surface and obliteration of the dentinal tubules were evident in the Nd:YAG laser-irradiated specimens. Conclusion: In this study, changes in the dentinal surface after Nd:YAG irradiation did not affect adherence between the apical filling material and the dentin wall.