• The Korea Journal of Herbology
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• v.38 no.4
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• pp.45-52
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• 2023

Objectives : Fine dust caused by environmental pollution cause oxidative damage and skin aging. In this study, The possibility of using the Codium fragile extract (CFE) as an anti-aging product for skin improvement was evaluated by confirming the protective effect of skin cells from PM10 (particulate matter 10) through inhibition of ROS and MMPs. Methods : In this study, elastase and collagenase inhibitory activities were evaluated. Cell viability was evaluated by treating keratinocytes (HaCaT cell line) with CFE at various concentrations. The cytoprotective effect from PM10 in keratinocyteswas evaluated using the 3-[4,5-dimethylthiazol]-2-yl]-2,5-diphenyl-tetrazoliumbromide (MTT) assay. ROS (reactive oxygen species) was measured in keratinocytes damaged by PM10 using DCF-DA (2′,7′-dichlorofluorescin diacetate) fluorescence staining. As an anti-aging effect of CFE, MMP-1 (matrix metalloproteinase-1) and MMP-1 (matrix metalloproteinase-9) inhibitory activities were evaluated. Results : As a result, CFE decreased the activity of elastase and collagenase. As a result of evaluating the toxicity of CFE, it is non-toxic at a concentration of 10 to 80 ㎍/㎖. Although cell viability of HaCaT cells treated with PM10 decreased, cell viability increased by 38% when treated with CFE 80 ㎍/㎖. Also, ROS decreased by 8.4%, and MMP-1 and MMP-9 decreased at CFE 80 ㎍/㎖. Conclusions : CFE showed excellent cell protection effect, and it is considered that it can be used in anti-aging products for skin improvement by effectively inhibiting ROS and MMPs from keratinocyte damage caused by fine dust.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.283-296
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• 2023

Purpose: The purpose of this study is to actually implement and verify whether welding defects can be detected in real time by utilizing deep learning AI solutions in the welding process of electric vehicle hairpin winding motors. Methods: AI's function and technological elements using synthetic neural network were applied to existing electric vehicle hairpin winding motor laser welding process by making special hardware for detecting electric vehicle hairpin motor laser welding defect. Results: As a result of the test applied to the welding process of the electric vehicle hairpin winding motor, it was confirmed that defects in the welding part were detected in real time. The accuracy of detection of welds was achieved at 0.99 based on mAP@95, and the accuracy of detection of defective parts was 1.18 based on FB-Score 1.5, which fell short of the target, so it will be supplemented by introducing additional lighting and camera settings and enhancement techniques in the future. Conclusion: This study is significant in that it improves the welding quality of hairpin winding motors of electric vehicles by applying domestic artificial intelligence solutions to laser welding operations of hairpin winding motors of electric vehicles. Defects of a manufacturing line can be corrected immediately through automatic welding inspection after laser welding of an electric vehicle hairpin winding motor, thus reducing waste throughput caused by welding failure in the final stage, reducing input costs and increasing product production.

• International Area Studies Review
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• v.13 no.1
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• pp.309-340
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• 2009

Multinational Corporations (MNCs) are increasingly establishing globally-distributed R&D (Research and Development) centers in which sites around the world work collaboratively to develop new manufacturing and product technologies. Following new globalization strategies, these projects more often include sites in Emerging/Newly Industrializing Economies (E/NIEs). The success of these ventures promises to be increasingly important both for the bottom line of MNCs and for the development ambitions of E/NIEs. This study attempts to identify these trends and to compare R&D transfer between Korea and China. The study identifies specific factors on MNC's R&D transfer and compares those operating factors between the R&D centers in Korea and China, which attract many MNCs in the world. Among those eight dimensions relating to MNCs' operation, there are significant differences in site selection, market characteristics, government support, and R&D networking between Korea and China. The analysis show more positive factors on China than Korea regarding R&D operations. The result will be helpful for both MNC's managers and governments' decision makers with respect to R&D transfer.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.23-31
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• 2023

In this study, a smart bench was developed and researched smart benches that can contribute to user convenience and satisfaction by installing them in parks, bus stops, and tourist attractions in line with the rapidly changing construction of smart cities. The smart bench is automatically operated by the control system according to the external temperature and provides additional functions such as charging, lighting, and advertising to improve general bench functions as well as heating in winter and cooling in summer, making it suitable for smart urbanization. The developed smart bench is designed to be strong enough to withstand loads of about 2,500 N. It minimizes the visible parts such as assembled bolts and 220V power supply wires, It can also give aesthetic effects. The development was carried out with the aim of waterproofing and dustproofing of IP44 grade in accordance with the climate of Republic of Korea, which has four seasons, and it is advantageous for long-term use because the paint was selected for the weather ability (discoloration) grade 3 or higher. If smart bench is commercialized, it is believed that various options can be provided to the smart bench market, where buyers had few product options, as the parts were developed in an assembled type so that all functions can be responded in an optional form according to the installation environment and the buyer's budget.

• Herbal Formula Science
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• v.31 no.4
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• pp.253-264
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• 2023

Objectives : Bambusae Caulis in Liquamen (BCL), a traditional herbal medicine, is a distilled product of condensation from the burning of fresh bamboo stems. We previously identified the anti-oxidant capacity of BCL in hepatocytes and suggested that BCL is a promising therapeutic candidate for treating oxidative stress-induced hepatocellular damage. Despite the importance of the role played by Kupffer cells in liver disease, the efficacy of BCL on Kupffer cells is unclear. Therefore, this study aimed to determine whether BCL could suppress LPS-induced inflammation and LPS+ATP-induced inflammasomes in Kupffer cells. Methods : We used ImKCs, a murine immortalized Kupffer cell line to examined whether BCL inhibited LPS-induced inflammation response and oxidave stress. And, we prepared a total of 18 L of BCL, purchased from Bamboo Forest Foods Co., Ltd. (648 Samdari, Damyang-eup, Damyang-gun, Jeollanam-do, Republic of Korea), was concentrated using a decompression concentrator. Result : The LPS-induced release of inflammatory cytokines was abolished by BCL treatment. Also, BCL treatment suppressed the LPS+ATP-induced expression of inflammasome proteins (NLRP3, IL-1, and IL-18), and inhib β ited the release of IL-1 . BCL decreased LPS-or LPS+ATP-induc β ed reactive oxygen species production. In addition, BCL increased nuclear translocation of Nrf2 and the expression of HO-1 in a time-dependent manner. Conclusion : These results suggest the efficacy of BCL with respect to its anti-inflammatory and anti-inflammasome effects mediated by Nrf2 in Kupffer cells.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.3
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• pp.507-514
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• 2024

In the semiconductor manufacturing line, continuous efforts are being made to reduce the cost of products produced, and the demand for this is accelerating in the chemical mechanical polishing(CMP) process, and a representative example of these cost reduction items is the 5-Zone Ring. After about 150 hours of use in the CMP process, the thickness of the ring decreases to less than 1 mm and must be replaced with a new product. Therefore, in this study, bonding dispensers and press machines with a dispensing amount error of 10g±0.8% or less and a pressure uniformity of ±1.8% or less were developed to reduce semiconductor manufacturing costs by repeatedly regenerating worn parts of the retainer ring, and to minimize environmental pollution caused by industrial waste treatment.

• Journal of Practical Engineering Education
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• v.16 no.2
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• pp.179-184
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• 2024

Printed circuit boards (PCBs) are a key component widely used in the production of electronic products, and not only quantitative growth but also qualitative developments such as integration cannot be ignored. Wave soldering equipment is commonly used equipment at manufacturing sites, but it is impossible to configure a dedicated equipment environment suitable for each PCB specification during the preliminary research and prototype development stage. It is neither suitable for development within limited time line nor manufacturing various product groups because only equipment setting conditions can be changed within a given time. In this study, we introduce a case of introducing a PCB pallet to enable selection of optimal process conditions within the limited environment described above. In addition, by presenting a discriminant that can determine in advance whether production is possible with current general-purpose equipment, it is expected that problems that may arise due to limitations in the general-purpose wave soldering equipment environment can be identified and resolved in advance. Ultimately, this palette makes it possible to shorten the development period and improve productivity.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3
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• pp.121-128
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• 2006

Korean pyeongyeong, a set of sixteen L-shape chime stones covering one and one third octaves, is a standard instrument in the Korean traditional court music. We analyze the vibrational mode frequencies in a pyeongyeong replica which is played at the National Center for Korean Traditional Performance Arts and pyeongyeong remains which are exhibited at King Sejong Memorial Museum. The modal shapes on the Whangjong, the 1st stone and Cheonghyurjong, the 16th stone mapped by scanning accelerometer, TV holography and STAR system. The nominal frequencies in pyeongyeong replica at the National Center for Korean Traditional Performance Arts increase linearly with the thickness of the stones and the tones are tuned in line with the musical scale of Sambunsonik. The sexagenary cycles on the pyeongyeong remains at King Sejong Memorial. which show the Year of product indirectly, are different each other and the tones are not tuned in scale. The relative frequency ratios of each modes on stones differ more than just-noticeable differences from those on the pyeongyeong replica. Modal shapes are same for the two stones regardless of the thickness.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.92-96
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• 2024

The application of the technology for forming Al₂O₃ thin films using ALD(atomic layer deposition) method is rapidly increasing in the semiconductor and display fields. In order to increase the efficiency of the ALD process in a mass production line, metallic by-products generated from the ALD process chamber must be effectively collected. By collecting by-products flowing out of the chamber with a cold trap device before they go to the vacuum pump, damage to the vacuum pump can be prevented and the work room can be maintained stably, resulting in increased process flow rate. In this study, a cold trap was installed between the ALD process chamber and the dry pump to measure and analyze by-products generated during the Al₂O₃ thin film deposition process. As a result, it was confirmed that Al and O elements were discharged, and the collection forms were two types: bulk and powder. And the binding energy peaked at 73.7 ~ 74.3 eV, the binding energy of Al 2p, and 530.7 eV, the binding energy of O 1s, indicating that the binding structure was Al-O.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.268-276
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• 2021

As wireless communication devices become more common, interests in how to control the electromagnetic waves generated from the devices are increasing. One of the most commonly used electromagnetic wave control materials is magnetic one, but due to the features that make the product heavy and thick when applied to the product, it is difficult to use them in curved electronic devices. Therefore, a polymer flexible meta electronic device has been presented to sort out the problem, which is thin and can have various curvatures. However, it requires an additional evaluation of curvature reliability. In this study, we developed a method to predict electromagnetic wave control characteristics through the resistance/length of the conductive ink line patterns of polymer flexible meta electronic devices, which is inversely proportional to the electromagnetic wave control characteristics. As the radius of curvature decreased, the resistance/length increased, and there was little variations with the duration times of curvature. We also found that both permanent and recoverable changes along with the removal of curvature were occurred when the curvature was applied, and that the cause of these changes was newly created vertical cracks in the conductive ink line pattern due to the tensile stress applied by applying curvature.