• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.109-113
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• 2020

Against the backdrop of low-carbon, green growth, many attention is focused on a sustainable society where humans and nature coexist. Carbon emissions increase with energy consumption, which is 40 percent of the world's energy consumption by buildings. Korea has a plan to make zero-energy houses mandatory only for new buildings in 2025, but it is relying on private technology investment for its technology. The reality is that the current technology costs more than 1.5 times more than general buildings, and private companies do not have many zero-energy house complexes other than experimental houses. This study aims to study the new model of zero energy house by introducing IOT system that efficiently observes and controls energy in zero energy house, monitoring pleasant environment on the web and introducing resident proper temperature maintenance system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.185-195
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• 2021

The flapping-wing micro air vehicle (FW-MAV) in this study utilizes the cambered wings made of quite flexible material. Similar to the flying creatures, the present cambered wing uses three different materials at its leading edge, vein, and membrane. And it is constrained in various conditions. Since passive rotation uses the flexible nature of the wing, it is important to select an appropriate material for a wing. A three-dimensional fluid-structure interaction solver is developed for a realistic modeling of the cambered wing. Then a parametric study is conducted to evaluate the aerodynamic performance in terms of the elastic modulus of leading edge and vein. Consequently, the elastic modulus plays a key role in enhancing the aerodynamic performance of FW-MAVs.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.409-419
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• 2022

The purpose of this study was to investigate how the increased sedentary behavior due to COVID-19 on physical factors to maintain health. The subjects of the study were 33 office women who mainly lead a sedentary behavior. The group settings were divided into high sedentary behavior groups(n=11), middle sedentary behavior groups(n=11), and low sedentary behavior groups(n=11) according to the hours of sitting down living. There was no significant difference between the groups in the VO₂max and EPOC, the level of lactate in blood showed a significant difference immediately after exercise(p<.05) and at 15(p<.001) and 20(p<.001) minutes of recovery, and the degree of recovery was more smooth in the low sedentary behavior groups. These results suggest that the difference in time according to the degree of sedentary behavior will affect the factors for maintaining health. Therefore, it is considered necessary to minimize sedentary behavior time even in the COVID-19 situation where the time spent in a personal space increases.

• Journal of Creative Information Culture
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• v.7 no.1
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• pp.53-67
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• 2021

This study The purpose of this study is to analyze the structural relationship among social support, job satisfaction, happiness, teacher efficacy. Participants were 249 teachers from teachers' training programs. Descriptive statistics analysis and path analysis were conducted. SPSS 22.0 and AMOS 21.0 were used. As a result of the analysis, it was found that teachers' social support had a significant effect on job satisfaction and happiness, and job satisfaction had a significant effect on happiness and teacher efficacy, but social support and happiness did not directly affect teacher efficacy. However, it was found that social support has a partial mediating effect through a sense of happiness through job satisfaction, and social support has a complete mediation effect through a sense of teacher efficacy through job satisfaction. This study is considered to be the basic data for preparing a plan to improve the teacher's sense of efficacy, an important factor in determining the quality of public education.

• Medical Lasers
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• v.9 no.2
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• pp.150-158
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• 2020

Background and Objectives Low-level laser therapy (LLLT) is used widely to promote hair growth in androgenetic alopecia (AGA). This study examined the clinical efficacy and safety of a home-use LLLT device with a newly designed array of light sources and software optimized for individual types of AGA. Materials and Methods The study was a randomized, double-blind, sham device-controlled trial. Forty-eight subjects (39 men and nine women) were assigned randomly in a 2:1 ratio to use either the test device (LG Pra'L HGN1, LG electronics, Korea) or sham device. The subjects used the LLLT device three times a week for 16 weeks. Phototrichogram was used to measure the hair density and hair thickness at 0, 8, and 16-weeks. Adverse events were closely monitored. Results After 16 weeks of using the device, the test group showed a significant increase in hair density and hair thickness compared to the control. In the test group, the hair density increased 6.96 counts/cm² at eight weeks and 13.67 counts/cm² at 16 weeks from the baseline. The hair thickness increased 7.21 ㎛ at eight weeks and 11.80 ㎛ at 16 weeks compared to the baseline. Conclusion The home-use LLLT device with a novel array of light sources and an individualized program according to the types of hair loss appears to be an effective and safe treatment modality for both male and female AGA patients.

• Journal of Periodontal and Implant Science
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• v.51 no.6
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• pp.422-432
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• 2021

Purpose: The aim of this study was to compare straight and tapered implant designs in terms of marginal bone loss, the modified plaque index (mPI), and the modified bleeding index (mBI) for 5 years after functional loading. Methods: Twelve patients were recruited. Two types of implants were placed adjacent to each other: 1 straight implant and 1 tapered implant. Marginal bone loss, mPI, and mBI were measured every year for 5 years after loading. Results: The straight implants showed 0.2±0.4 mm of marginal bone loss at 5 years after loading, while the tapered implants showed 0.2±0.3 mm of marginal bone loss; this difference was not statistically significant (P=0.833). Our analysis also showed no statistically significant differences in mPI (straight implants: 0.3±0.3 vs. tapered implants: 0.2±0.3; P=0.414) or in mBI (straight implants: 0.3±0.4 vs. tapered implants: 0.2±0.3; P=0.317) at 5 years after prosthesis delivery. Conclusions: Straight and tapered implants showed no significant differences with respect to marginal bone loss, mPI, and mBI for 5 years after loading.

• Journal of Dairy Science and Biotechnology
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• v.39 no.4
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• pp.157-165
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• 2021

This study aimed to determine the effect of extraction temperature and time on the antioxidant activity of hot water extract from Panax ginseng sprout powder and to evaluate the suitability of this extract for use in dairy products. Water-soluble fractions of commercial Panax ginseng sprout powder were obtained by hot water extraction at 25, 60, or 80℃ for 0.5, 2, 12, or 24 h. The antioxidant activity of each extract was evaluated by measuring its free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS). DPPH and ABTS free radical scavenging activity increased with extraction temperature from 25 to 80℃. At 80℃, increasing the extraction time from 0.5 to 2 h led to increases in DPPH and ABTS free radical scavenging activity. Thus, the extract obtained under 2 h at 80℃ was selected for addition to milk and yogurt. After 16 days of storage, there were no significant changes in the pH of the milk or the antioxidant activity of the extract. With regard to yogurt fermentation, adding the extract did not affect the pH or the number of viable lactic acid bacteria. In conclusion, hot water extract from Panax ginseng sprout powder can be added to dairy products to enhance antioxidant activity.

• Conservation Science in Museum
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• v.28
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• pp.89-108
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• 2022

Among about 500,000 characters in metal types in National Museum of Korea, this study conducts a statistical analysis of 62 metal types from the early Joseon Dynasty, including 33 gabinja (甲寅字) types and 29 eulhaeja (乙亥字) Hangeul types by examining the shape, measuring the specific gravity, and identifying the components based on previously-studied Joseon metal types. Among them, 33 gabinja types and 24 eulhaeja types were made of two-component bronze (copper and tin) (Group A), and four eulhaeja types were produced with three-component bronze (copper, tin and lead). (Group B), and one eulhaeja type was created with two-component bronze (copper and tin) with a high tin content (Group C). By comparing with imjinja (壬辰字) types of the late Joseon Dynasty based on multiple statistical analyses of type components, this study confirms that late-Joseon types have low copper content and high zinc and lead content, and therefore it may be possible to distinguish between the types of early and late Joseon Dynasty.

• Imaging Science in Dentistry
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• v.52 no.4
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• pp.351-357
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• 2022

Purpose: Convolutional neural networks (CNNs) have rapidly emerged as one of the most promising artificial intelligence methods in the field of medical and dental research. CNNs can provide an effective diagnostic methodology allowing for the detection of early-staged diseases. Therefore, this study aimed to evaluate the performance of a deep CNN algorithm for apical lesion segmentation from panoramic radiographs. Materials and Methods: A total of 1000 panoramic images showing apical lesions were separated into training (n=800, 80%), validation (n=100, 10%), and test (n=100, 10%) datasets. The performance of identifying apical lesions was evaluated by calculating the precision, recall, and F1-score. Results: In the test group of 180 apical lesions, 147 lesions were segmented from panoramic radiographs with an intersection over union (IoU) threshold of 0.3. The F1-score values, as a measure of performance, were 0.828, 0.815, and 0.742, respectively, with IoU thresholds of 0.3, 0.4, and 0.5. Conclusion: This study showed the potential utility of a deep learning-guided approach for the segmentation of apical lesions. The deep CNN algorithm using U-Net demonstrated considerably high performance in detecting apical lesions.

• Journal of the Korean Geotechnical Society
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• v.24 no.10
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• pp.71-81
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• 2008

Wall displacements caused by earth pressure, rainfalls, rise in ground water level, inappropriate deep excavation and structural defects of the wall may produce differential settlements to existing buildings, which often result in damages and/or collapses of the building structures. In this case, measures to protect the walls and nearby structures would be required. One of the recent measures to reduce differential settlements and protecting walls is to reinforce the ground using micro-piles. In this study physical model tests were carried out to evaluate the performance of the micro-pile method. It is revealed that reduction of the settlement was maximized when the length of micro-pile is twice of the foundation width, distance between piles is twice of the pile diameter and the distance to wall is one tenth of the foundation width. Based on the test results some design recommendations were made.