• Composites Research
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• v.34 no.4
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• pp.233-240
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• 2021

VaRI(Vacuum assisted Resin Infusion) process, which is cost effective and suitable for manufacturing large-sized composites, is an OoA(Out-of Autoclave) process. For rapid resin infusion in the VaRI process, a DM(distribution media) is placed on top of the fabric. The resin is rapidly supplied in plane direction of the fiber along the DM, and then the supplied resin is impregnated in the out-of-plane direction of fiber. It is difficult to predict the flow of resin because the flow of in-plane direction and the out-of-plane direction occur together, and a 3D numerical analysis program is used to simulate the resin infusion process. However, in order to analyze in 3D, many elements are required in the out-of-plane direction of fabric. And the product size is larger, the longer the analysis time needs. Therefore, in this study, a method was suggested to reduce the time required for flow analysis by simplifying the 3D flow analysis to 2D flow analysis. The usefulness was verified by comparing the 3D flow analysis with the simplified 2D flow analysis at the same conditions. The filling time error was about 7% and the reduction of flow analysis time was about 95%. In addition, by utilizing the constant difference in the flow front between the top, middle, and bottom of the fabric of the 3D analysis, the flow front of the top, middle, and bottom of the fabric can be also predicted in the 2D flow analysis.

• Conservation Science in Museum
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• v.24
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• pp.17-36
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• 2020

This paper describes the consevation treatment of eleven bigyeokjincheolloe bomb shells that were excavated from the Joseon-period local government office and fortress of Mujang-hyeon (present-day Mujang-myeon) in Gochang in 2018. It also provides information on the production method of the shells revealed through CT scanning, gamma-ray transmission imaging, and metallographic analysis. In preparation for the special exhibition "Bigyeokjincheolloe" at the Jinju National Museum in 2019 (July 16 to August 25), contaminants were removed from the shells and their surface was reinforced during the first phase of conservation treatment. Furthermore, the closures for the shells were identified for the first time. Regarding the production of the shells, the CT scanning and gamma-ray transmission imaging identified many blowholes in the interior of the body and the use of a chaplet on the side of one shell. The side of the body proved to be relatively thinner than the top and bottom. The traces of a hole for pouring molten metal into the center of the bottom indicates that molten metal was indeed emptied into the inverted body. In the metallographic analysis of two of the bodies and one lid, cementite and pearlite structures were identified on the body, indicating that it was made by casting. The presence of the ferrite structure with a partial distribution of the pearlite along with non-metallic inclusion in the lid suggested that the lid was made by forging.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.177-185
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• 2021

Clinical applications of translucent zirconia as well as traditional zirconia (3 mol% yttria stabilized tetragonal zirconia polycrystal, 3Y-TZP) are increasing. For this reason, studies on factors affecting the optical properties of dental zirconia have been continuously reported. The optical effect of dental zirconia may vary depending on the yttria content, the thickness of the prosthesis, the sintering process, polishing, glazing and cementation in laboratory and clinical procedures. Increasing the yttria concentration can reduce the masking effect. Translucency decreases as the thickness of the restoration increases, but the required thickness may vary depending on the properties of the zirconia block. The high-speed sintering method can shorten the manufacturing time, but in some cases, the translucency of the prosthesis may decrease. In addition, the optical properties can be affected by the surface roughness of zirconia and the polishing process. The use of an appropriate colored cement can help with the masking effect of zirconia and can be useful for color matching for more esthetic results.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.3
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• pp.141-148
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• 2022

Recently, reinforcement learning combined with deep neural network technology has achieved remarkable success in various fields such as board games such as Go and chess, computer games such as Atari and StartCraft, and robot object manipulation tasks. However, such deep reinforcement learning describes states, actions, and policies in vector representation. Therefore, the existing deep reinforcement learning has some limitations in generality and interpretability of the learned policy, and it is difficult to effectively incorporate domain knowledge into policy learning. On the other hand, dNL-RRL, a new relational reinforcement learning framework proposed to solve these problems, uses a kind of vector representation for sensor input data and lower-level motion control as in the existing deep reinforcement learning. However, for states, actions, and learned policies, It uses a relational representation with logic predicates and rules. In this paper, we present dNL-RRL-based policy learning for transportation mobile robots in a manufacturing environment. In particular, this study proposes a effective method to utilize the prior domain knowledge of human experts to improve the efficiency of relational reinforcement learning. Through various experiments, we demonstrate the performance improvement of the relational reinforcement learning by using domain knowledge as proposed in this paper.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.264-271
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• 2022

In this study, the nutritional properties of sterilized and non-heat-pressed raw perilla oil (SRPO) were studied and its potential as a functional food was evaluated. The copper, cobalt, and calcium levels were high in sterilized and SRPO. The total polyphenol content and ABTS radical scavenging activity were the highest in SRPO, whereas nitrite scavenging activity was the highest in 45℃ cold pressed perilla oil (CPPO). The above results confirmed that sterilized and non-heat-pressed perilla oil had high mineral and total polyphenol contents, as well as ABTS radical scavenging activity and nitrite scavenging ability. The peroxide value of SRPO decreased as the storage period increased, and the acid value of low-temperature pressed perilla oil over 65℃ (LPPO) significantly increased. This work also provided an opportunity to develop a new method for manufacturing perilla oil, and it is hoped that these experiments will form a basis for the commercialization of perilla oil.

• Conservation Science in Museum
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• v.26
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• pp.143-160
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• 2021

The Seoul Baekje Museum has been conducting excavations at the Ancient Tomb Complex in Seokchon-dong, Seoul (Historic Site No. 243), known to be tombs of the royal family and the ruling class during the Hanseong period of the Baekje Kingdom. In this study, gold earrings that were revealed during the excavation underwent scientific analysis and conservation treatment. Stereo microscopy, SEM, X-ray imaging, CT, and XRF were applied in the analysis, and the characteristics, internal structure, and composition of the earrings as well as their production method were investigated. The results confirmed that the main hoops of the gilt-bronze earrings were made of copper cores gilt using mercury amalgamation. The findings also revealed that the hexahedron in the middle pendant was made by connecting small rings using molten gold powder, and the pendant sphere at the end was formed by soldering two hemispheres. As for the two thin-hoop earrings, they showed similar surface compositions but were made using different methods, with one made from a copper core wrapped with a gold plate and the other made by bending a gold rod. The gold content varied depending on the item and the place of measurement, but overall the earrings showed a relatively high gold content of approximately 19 to 21K. The purity of the golden earrings and the sophisticated manufacturing techniques applied indicate the high status of the buried person and of the tomb complex in Seokchong-dong.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.211-216
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• 2022

In radiation therapy, accurate Quality Assurance (QA) is required to irradiate tumor tissue while minimizing damage to normal tissue. Therefore, a dosimeter that can accurately measure radiation is needed. The purpose of this study is to develop a highly efficient radiation dosimeter with high sensitivity by applying a particle in binder method that can reduce manufacturing costs and simplify processes to perovskite materials that are cheaper and simpler to manufacture. By evaluating the response characteristics to high-energy photon, the applicability of QA dosimeter to radiation therapy was evaluated. As a result of reproducibility evaluation, RSD at 6 MV energy was presented as 1.178% and 15 MV energy was presented as 1.141%. As a result of linearity evaluation according to linear regression analysis, R² values of 0.9999 were presented under each condition of 6 MV and 15 MV energy. It was found that the CsPbBr₃ dosimeter manufactured based on the results of reproducibility and linearity evaluation is highly applicable as a QA dosimeter in the field of therapeutic radiation. The CsPbBr₃ dosimeter manufactured in this study presented more than the standard performance in the evaluation of reproducibility and linearity, and it can be used as a radiotherapy QA dosimeter through improvement.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.3
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• pp.111-125
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• 2022

Recently, the MZ generation has been leading overall fashion trends, and fashion companies focus on design, marketing, and new products targeting the MZ generation. However, it is expected that a fit problem may occur if the M and Z generations are combined when producing clothing. Therefore, this study aims to analyze the differences between the two groups by comparing the body size according to the classification of the M and Z generations. In addition, this study analyzes whether the body shape of the MZ generation is different from the past generations and analyzes major changes in body size for clothing manufacturing through graphical visualization. As for the research method, a t-test was conducted to verify the significant difference between the measurements for each age group. Generation M was defined as those who are 27-39 years old, and Generation Z was defined as those who are 20-26 years old. In order to examine the changes in body measurements according to the measurement year, the 7th Size Korea and 8th Size Korea data were analyzed. In order to examine the visual changes according to the measurement year and age group, major measurements of clothing construction were analyzed. As a result, it was found that Generation M had a significantly higher height item than Generation Z. Also, in terms of circumference, width, and thickness, Generation M was larger than Generation Z. But the size of the bra cup was larger in Generation Z than Generation M. As a result of analyzing the body size changes, in the height item, the 8th Size Korea measurements were found to be significantly higher in shoulder height and navel level waist height. In the length and circumference items, the 8th Size Korea measurements were larger than the 7th. In the width, thickness, and other items, the 8th measurements were larger than the 7th.

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.241-251
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• 2022

Diagnosis and management of customer's skin condition is an important essential function in the cosmetics and beauty industry. As the social media environment spreads and generalizes to all fields of society, the interaction of questions and answers to various and delicate concerns and requirements regarding the diagnosis and management of skin conditions is being actively dealt with in the social media community. However, since social media information is very diverse and atypical big data, an intelligent skin condition diagnosis system that combines appropriate skin condition information analysis and artificial intelligence technology is necessary. In this paper, we developed the skin condition diagnosis system SCDIS to intelligently diagnose and manage the skin condition of customers by processing the text analysis information of social media into learning data. In SCDIS, an artificial neural network model, AnnTFIDF, that automatically diagnoses skin condition types using artificial neural network technology, a deep learning machine learning method, was built up and used. The performance of the artificial neural network model AnnTFIDF was analyzed using test sample data, and the accuracy of the skin condition type diagnosis prediction value showed a high performance of about 95%. Through the experimental and performance analysis results of this paper, SCDIS can be evaluated as an intelligent tool that can be used efficiently in the skin condition analysis and diagnosis management process in the cosmetic and beauty industry. And this study can be used as a basic research to solve the new technology trend, customized cosmetics manufacturing and consumer-oriented beauty industry technology demand.

• Journal of the Korean Applied Science and Technology
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• v.39 no.3
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• pp.471-478
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• 2022

This study attempted to find out the improvement effect the improvement effect of Babassu oil on damaged hair by damaged hair by applying a hair-improving formulation with Babassu oil to damaged hair after manufacturing. As the experimental raw material, the contents of babassu oil were changed to 0 g, 3 g 6 g, and 9 g and added to the perm base agent. The prepared formulation was applied to 8 levels of bleached sample hair. Each sample and damaged hair were measured and compared and analyzed. As for the measurement method, tensile strength, absorbance using methylene blue, and gloss were measured to know the effect of improving damage hair Statistical analysis was conducted for the reliability of the research results. As a result of the research, it was found that the tensile strength was higher than that of the damaged hair in all samples applied by adding babassu oil. As a result of absorbance analysis using methylene blue, it was found that absorbance was decreased in all samples compared to damaged hair. As a result of the gloss measurement, it was found that the gloss was increased in all samples compared to the damaged hair. In conclusion, it was found that babassu oil had an improvement effect on damaged hair.