• Korean Journal of Materials Research
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• v.29 no.11
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• pp.720-726
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• 2019

Recently, research on cost reduction and efficiency improvement of crystalline silicon(c-Si) photovoltaic(PV) module has been conducted. In order to reduce costs, the thickness of solar cell wafers is becoming thinner. If the thickness of the wafer is reduced, cracking of wafer may occur in high temperature processes during the c-Si PV module manufacturing process. To solve this problem, a low temperature process has been proposed. Conductive paste(CP) is used for low temperature processing; it contains Sn57.6Bi0.4Ag component and can be electrically combined with solar cells and ribbons at a melting point of $150^{\circ}C$. Use of CP in the PV module manufacturing process can minimize cracks of solar cells. When CP is applied to solar cells, the output varies with the amount of CP, and so the optimum amount of CP must be found. In this paper, in order to find the optimal CP application amount, we manufactured several c-Si PV modules with different CP amounts. The amount control of CP is fixed at air pressure (500 kPa) and nozzle diameter 22G(outer diameter 0.72Ø, inner 0.42Ø) of dispenser; only speed is controlled. The c-Si PV module output is measured to analyze the difference according to the amount of CP and analyzed by optical microscope and Alpha-step. As the result, the optimum amount of CP is 0.452 ~ 0.544 g on solar cells.

• The Journal of Korean Philosophical History
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• no.36
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• pp.259-291
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• 2013

This article is to study the purpose and significance of Chongyoulun of Peiwei, and it is composed of the two parts of philosophy and critical mind. The critical mind on Chongyoulun is as follows: first, it is mis-interpretative to define the main thought of Laozi as Xuwu. Next, the old philosophers did not criticize Xuwuism properly; as a result, they failed to stop spreading Xuwuism. Last, Guiwulun brought about the disorder of the way of life and the collapse of the public order. Based on this critical mind, Peiwei built up the following philosophy based on You as the fundamental principle of the existence and the movement of universal nature. First, Tao is the combined Wanyou, not abstract substance which is outside of Wanyou. Second, Wu is the state of being without You, and You only comes from You. Third, You can survive depending on external You because You is not the independent substance. Therefore, understanding the external You is the main factor of its existence. Fourth, Wanyou do not harm each other as they get together since Wanyous are interdependent. People are the being who can live through the mutual dependent relationships; hence, social system and morals (ethics) are key factors of the world in the oncological point of view. Wanyou had tried to rebuild the corrupted way of life and public order by recovering the justification of moral orders based on the mutual dependence of Wanyou which is the substance character.

• The Journal of Bigdata
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• v.5 no.2
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• pp.201-213
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• 2020

Despite empirical research that the response to human risk is significantly influenced affective factors, the role of affective factors has been unexplored in information privacy research. This study aims to explore the privacy behaviors of location-based service (LBS) users from an affective point of view. Specifically, the study explored the relationship between three types of privacy threats (collection, hacking, secondary use), two affects (worry, anger), and a coping behavior (continuous use intentions). The structured survey was conducted with 552 users. In order to analyze the effect of the combination of perception of particular privacy threats and particular affects on the intention of continuous use, association rules, one of the data mining techniques, was employed. As a result, there was a difference in the intention to use according to the combination of the perception of risk and affect responses, and the most significant influence on the intention is when the second use of personal information was combined with anger. This study has significant theoretical contribution in that it includes affective factors in the research of information privacy users, complementing the biases of existing cognition-oriented approaches and providing a comprehensive understanding of privacy response behavior.

• Conservation Science in Museum
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• v.26
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• pp.119-142
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• 2021

The gilt-bronze-and-silver shoes, excavated from the Tomb of King Muryeong, revealed many defective parts, which constantly raised in-depth re-investigation and reporting. In that point, scientific treatment and analysis were conducted to investigate the manufacturing techniques applied. The conservation treatment was carried out with an emphasis on the restoration of the original form and joining parts. As a result, the upper part of the right shoe and some part of the back heel were joined, confirming the joining method and the number of rivet used for instep bonding. From the component analysis, it is presumed that the outer plate was gilded with mercury amalgam on pure copper, and pure silver was used for the inner plate. The main pattern of the gilt-bronze-and-silver shoes includes designs of phoenix, lotus, and six-petal flower, while the lotus pattern is high in terms of ratio. Thus, youngnaksa(twisted gilt-bronze thread), geumdongsa(gilt-bronze thread), wondujeong (rivet), and samyeonjeong(quadrangular cleats) were used for bonding each plate. Twisted gilt-bronze thread was used to join the inner and outer plates, while the center and rear of the inner plate were combined with only gilt-bronze threads. From the fact, it is presumed that the joining method was different whether the function was decoration or just bonding. Regarding the manufacturing process, traces of burnishing were confirmed on the outer surface of the gilt-bronze and silver shoes, but no burnishing traces were identified on the inner surface of the silver plate, which is likely to prove more importance put on the finishing of the outer plates rather than that of the inner.

• Korean Journal of Remote Sensing
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• v.38 no.6_4
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• pp.1901-1910
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• 2022

Arriving in the new space age, securing technology for fusion application of KOMPSAT-3·3A and global satellite images is becoming more important. In general, multi-sensor satellite images have relative geometric errors due to various external factors at the time of acquisition, degrading the quality of the satellite image outputs. Therefore, we propose a fine-image registration methodology to minimize the relative geometric error between KOMPSAT-3·3A and global satellite images. After selecting the overlapping area between the KOMPSAT-3·3A and foreign satellite images, the spatial resolution between the two images is unified. Subsequently, tie-points are extracted using a hybrid matching method in which feature- and area-based matching methods are combined. Then, fine-image registration is performed through iterative registration based on pyramid images. To evaluate the performance and accuracy of the proposed method, we used KOMPSAT-3·3A, Sentinel-2A, and PlanetScope satellite images acquired over Daejeon city, South Korea. As a result, the average RMSE of the accuracy of the proposed method was derived as 1.2 and 3.59 pixels in Sentinel-2A and PlanetScope images, respectively. Consequently, it is considered that fine-image registration between multi-sensor satellite images can be effectively performed using the proposed method.

• The Journal of Internal Korean Medicine
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• v.43 no.4
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• pp.582-595
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• 2022

Objectives: To investigate the effects of acupuncture at GV20 and EX-HN1 on cerebral blood flow (CBF) velocity and cerebrovascular reactivity (CVR) in the middle cerebral arteries (MCA) and anterior cerebral arteries (ACA) and to compare the effects to acupuncture at GV20. Methods: The study was a randomized, crossover trial that included 10 healthy men aged 20 to 29 years who underwent acupuncture treatment four times with a washout period of one week. The CBF velocity and CVR were measured by transcranial Doppler sonography (TCD) on both MCAs at the first and second visits, and both ACAs at the third and fourth visits. Participants were randomly assigned to one of two groups (A and B) before the first and third visits. Group A received two phases of acupuncture intervention at a single GV20 point and a combination of GV20 and EX-HN1 acupoints. Group B received the same interventions, but in the reverse order. Results: The increase in CO₂ reactivity was significantly higher for the combination acupoints of GV20 and EX-HN1 than for the GV20 single acupoint in both MCAs (Right: 136 to 178, p=0.017; Left: 127 to 191, p=0.017) and ACAs (Right: 133 to 158, p=0.013; Left: 122 to 168, p=0.025). No significant change was noted in the corrected velocity at PETCO₂ 40 mmHg, blood pressure, or heart rate. Conclusions: The findings suggest that improvement of the CBF in the MCA and ACA after GV20 acupuncture increases when acupuncture is also performed at EX-HN1. These results clinically support the combined use of EX-HN1 and GV20 to treat disorders of MCA and ACA circulation.

• The Journal of Advanced Prosthodontics
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• v.13 no.4
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• pp.226-236
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• 2021

PURPOSE. This study aimed to evaluate the effect of incorporating zirconium oxide nanoparticles (nano-ZrO₂) in polymethylmethacrylate (PMMA) denture base resin on flexural properties at different material thicknesses. MATERIALS AND METHODS. Heat polymerized acrylic resin specimens (N = 120) were fabricated and divided into 4 groups according to denture base thickness (2.5 mm, 2.0 mm, 1.5 mm, 1.0 mm). Each group was subdivided into 3 subgroups (n = 10) according to nano-ZrO₂ concentration (0%, 2.5%, and 5%). Flexural strength and elastic modulus were evaluated using a three-point bending test. One-way ANOVA, Tukey's post hoc, and two-way ANOVA were used for data analysis (α = .05). Scanning electron microscopy (SEM) was used for fracture surface analysis and nanoparticles distributions. RESULTS. Groups with 0% nano-ZrO₂ showed no significant difference in the flexural strength as thickness decreased (P = .153). The addition of nano-zirconia significantly increased the flexural strength (P < .001). The highest value was with 5% nano-ZrO₂ and 2 mm-thickness (125.4 ± 18.3 MPa), followed by 5% nano-ZrO₂ and 1.5 mm-thickness (110.3 ± 8.5 MPa). Moreover, the effect of various concentration levels on elastic modulus was statistically significant for 2 mm thickness (P = .001), but the combined effect of thickness and concentration on elastic modulus was insignificant (P = .10). CONCLUSION. Reinforcement of denture base material with nano-ZrO₂ significantly increased flexural strength and modulus of elasticity. Reducing material thickness did not decrease flexural strength when nano-ZrO₂ was incorporated. In clinical practice, when low thickness of denture base material is indicated, PMMA/nano-ZrO₂ could be used with minimum acceptable thickness of 1.5 mm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.108-117
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• 2021

The educational approach using Capstone Design is gradually expanding with the change in social and educational paradigms. Course development utilizing the Capstone Design in models in the department of fashion can create a positive effect in that it enhances the practical capabilities of the fashion model and expands the perspective of various fields related to fashion shows. This study proved the educational efficacy by applying the Capstone Design to the model work presentation course and investigating the implications of the design from the instructor's perspective. The research methods used to guide this course utilizing the Capstone Design were theatrical research and model development research. This study showed that learners' satisfaction for this course combined with Capstone Design was very high, and students were very satisfied with the progress of the class. The instructor's point of view in progressing this course showed the need for education from an in-depth and convergence perspective related to fashion, improvement of temporal and spatial utilization of space, concerns about establishing connections with experts and various industries, and expanding the scope of education through continuous exchanges and cooperation with industry.

• Journal of Cadastre & Land InformatiX
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• v.52 no.1
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• pp.69-80
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• 2022

Drone photogrammetry generally acquires images vertically or obliquely from above, so when photographing for the purpose of three-dimensional modeling, image matching for the ground of a building and spatial accuracy of point cloud data are poor, resulting in poor 3D mesh completeness. Therefore, to overcome this, this study analyzed the spatial accuracy of each drone image by acquiring smartphone images from the ground, and evaluated the accuracy improvement and completeness of 3D mesh when the smartphone image is not combined with the drone image. As a result of the study, the horizontal (x,y) accuracy of drone photogrammetry was about 1/200,000, similar to that of traditional photogrammetry. In addition, it was analyzed that the accuracy according to the photographing method was more affected by the photographing angle of the object than the increase in the number of photos. In the case of the smartphone image combination, the accuracy was not significantly affected, but the completeness of the 3D mesh was able to obtain a 3D mesh of about LoD3 that satisfies the digital twin city standard. Therefore, it is judged that it can be sufficiently used to build a 3D model for digital twin city by combining drone images and smartphones or DSLR images taken on the ground.

• Korean Journal of Optics and Photonics
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• v.34 no.1
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• pp.22-30
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• 2023

The use of segmented mirrors is one of the ways to make the primary mirror of a spaceborne satellite larger, where several small mirrors are combined into a large monolithic mirror. To align multiple segmented mirrors as one large mirror, there must be no discontinuity in the x, y-axis (tilt) and axial alignment error (piston) between adjacent mirrors. When the tilt and piston are removed, we can collect the light in one direction and get an expected clear image. Therefore, we need a precise wavefront sensor that can measure the alignment error of the segmented mirrors in nm scale. The tilt error can be easily detected by the point spread image of the segmented mirrors, while the piston error is hard to detect because of the absence of apparent features, but makes a downgraded image. In this paper we used an optical testing interferometer such as a Fizeau interferometer, which has various advantages when aligning the segmented mirror on the ground, and focused on measuring the axial displacement error of a segmented mirror as the basic research of measuring the piston errors between adjacent mirrors. First, we calculated the relationship between the axial displacement error of the segmented mirror and the surface defocus error of the interferometer and verified the calculated formula through experiments. Using the experimental results, we analyzed the measurement uncertainty and obtained the limitation of the Fizeau interferometer in detecting axial displacement errors.