• Korean Chemical Engineering Research
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• v.57 no.3
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• pp.425-431
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• 2019

As rechargeable metal-air batteries will be ideal energy storage devices in the future, an active cathode electrocatalyst is required with bi-functionality on both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) during discharge and charge, respectively. Here, a class of perovskite cathode catalyst with a micro-tubular structure has been developed by controlling bi-functionality from different Ru and Ni dopant ratios. A micro-tubular structure is achieved by the activated carbon fiber (ACF) templating method, which provides uniform size and shape. At the perovskite formula of $LaCrO_3$, the dual dopant system is successfully synthesized with a perfect incorporation into the single perovskite structure. The chemical oxidation states for each Ni and Ru also confirm the partial substitution to B-site of Cr without any changes in the major perovskite structure. From the electrochemical measurements, the micro-tubular feature reveals much more efficient catalytic activity on ORR and OER, comparing to the grain catalyst with same perovskite composition. By changing the Ru and Ni ratio, the $LaCr_{0.8}Ru_{0.1}Ni_{0.1}O_3$ micro-tubular catalyst exhibits great bi-functionality, especially on ORR, with low metal loading, which is comparable to the commercial catalyst of Pt and Ir. This advanced catalytic property on the micro-tubular structure and Ru/Ni synergy effect at the perovskite material may provide a new direction for the next-generation cathode catalyst in metal-air battery system.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.334-339
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• 2019

In this study, the vibration test method to nondestructively evaluate the possibility of vehicle BSR (Buzz, Squeak, Rattle) noise generation in spot-welded structures was proposed. The weld quality was predicted by analyzing the local vibration transmission characteristics for the beam-shaped structure attached to testing spots. The bending stiffness was evaluated from the identified vibration properties. From the change in the stiffness, the weld quality was evaluated. For verification of the proposed method, the welded specimens were fabricated with partial changes in welding parameters. The local vibration transfers were measured. The frequency bands affected by the weld quality was identified. The capability of evaluating the welding parameters including defect position and quality variations was investigated. The proposed method enables fast quality evaluation to minimize the possibility of BSR noise generation in the manufactured vehicle.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.35-45
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• 2021

The e-commerce industry using mobile or web is growing rapidly, and the emergence of various platform services is causing innovative changes in the e-commerce industry. This study aims to identify the attachment types of e-commerce users and to demonstrate the relationship between the PPerceived Usefulness, and Perceived Ease of Use by TAM. In order to empirically verify the research model of this study, a survey was conducted on ordinary people with experience using e-commerce and path analysis was conducted by using PLS to analyze its Internal consistency, Confirmatory factor analysis, Discriminant validity and Goodness-of-fit verification. As a result, a significant relationship between Perceived Stability, Perceived Usefulness, and Perceived Ease of Use was identified, could verify the association with the TAM and Acceptance Intention.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.3
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• pp.341-348
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• 2020

The ability to extract useful information from an image, such as the human eye, is an interface technology essential for AI computer implementation. The building recognition technology has a lower recognition rate than other image recognition technologies due to the various building shapes, the ambient noise images according to the season, and the distortion by angle and distance. The computer vision based building recognition algorithms presented so far has limitations in discernment and expandability due to manual definition of building characteristics. This paper introduces the deep learning CNN (Convolutional Neural Network) model, and proposes new method to improve the recognition rate even by changes of building images caused by season, illumination, angle and perspective. This paper introduces the partial images that characterize the building, such as windows or wall images, and executes the training with whole building images. Experimental results show that the building recognition rate is improved by about 14% compared to the general CNN model.

• Korea Journal of Hospital Management
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• v.25 no.4
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• pp.60-75
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• 2020

Purpose: This study aims to develop a cost model for NRP (Nursing Residency Program) operation and ultimately provide evidence for financial factors for NRP operation in the future by simulating a cost model. Methodology: This study developed a model for the NRP education cost calculation model based on the review of Hansen's model, which has systematically reported on the development and operation of NRP, and discussions with nursing education experts at a university-affiliated hospital. With the simulation, it was intended to predict nurses' supply and demand in the long term and to calculate changes in long-term education costs. Findings: Firstly, turnover model, term model, cost model necessary for calculating a model for the NRP education cost calculation model was set up. Secondly, the simulation showed the following results; 1) the proportion of newly graduated nurses less than 5 years of working decreases gradually over time, which will make the composition of nurses more balanced. 2) In the first year of the partial introduction of NRP, the cost of training new nurses was about 2.1 times higher than before. After the introduction, the training cost in the 13th year began to be lesser than before the introduction, and in the 25th year, it decreased by 28.1% compared to before the introduction. Practical Implications: Firstly, NRP would be an effective way to solve the higher turnover and frequent departure of new nurses and the imbalance of nurses' composition. Secondly, although the costs of NRP are incurred in the early stages, in the end, NRP training costs are reduced compared to before the introduction of NRP. It is necessary to systematically understand the contribution effect of NRP by analyzing the economic value of NRP considering financial and non-monetary returns in the future and providing a basis for decision-making related to NRP implementation.

• Journal of Periodontal and Implant Science
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• v.51 no.3
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• pp.179-188
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• 2021

Purpose: Due to the difficulty of the hygienic care and sanitary management of abutment teeth and subpontic areas associated with fixed dental prostheses (FDPs), intrabony defects occur and accelerate due to the accumulation of plaque and calculus. This study aimed to evaluate the efficacy of regenerative periodontal surgery for intrabony defects associated with FDPs. Methods: The study inclusion criteria were met by 60 patients who underwent regenerative treatment between 2016 and 2018, involving a total of 82 intrabony defects associated with FDPs. Periodontal osseous lesions were classified as 1-, 2-, and 3-wall intrabony defects and were treated with an enamel matrix derivative in combination with bone graft material. The changes in clinical (pocket probing depth [PPD] and clinical attachment level [CAL]) and radiographic (defect depth and width) outcomes were measured at baseline and at 6, 12, and 24 months. Results: Six months after regenerative treatment, a significant reduction was observed in the PPD of 1-wall (P<0.001), 2-wall (P<0.001), and 3-wall (P<0.001) defects, as well as a significant reduction in the CAL of 2-wall (P<0.001) and 3-wall (P<0.001) intrabony defects. However, there was a significant increase in the CAL of 1-wall intrabony defects (P=0.003). Radiographically, a significant reduction in the depth of the 3-wall (P<0.001) defects and a significant reduction in the width of 2-wall (P=0.008) and 3-wall (P<0.001) defects were observed. The depth decreased in 1-wall defects; however, this change was not statistically significant (P=0.066). Conclusions: Within the limitations of the current study, regenerative treatment of 2- and 3-wall intrabony defects associated with FDPs improved clinical and radiological outcomes. Additional prospective studies are necessary to confirm our findings and to assess long-term outcomes.

• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.4
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• pp.95-110
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• 2020

The purpose of this study is to empirically examine organizational change for a technological application of the fourth industrial revolution. The theoretical background of this study utilized organizational change management, the fourth industrial revolution, technological innovation, and voluntary acceptance. This research method used structural equations, cluster analysis, and analysis of variance. According to the results of the study, the organizational implement system, organizational leadership, and organizational operating system provided a positive effect on the voluntary technology acceptance of organization members. The voluntary technology acceptance provided a positive effect on the effectiveness of individual task innovation. However, organizational institutionalization among the independent variables did not affect voluntary acceptance. All independent variables except the organizational institutionalization had a partial mediating effect in the mediating effect verification. Meanwhile, The three groups by the cluster analysis were classified as new technology apathy, preference, and anxiety groups, and differences appeared among groups in the importance of organizational change variables. The organizational implement system in the technology apathy group and the organizational operating system in the technology anxiety group have a positive effect on voluntary technology acceptance. The technology preference group shows that a positive effect on organizational leadership and a negative effect on organizational institutionalization for voluntary technology acceptance. This study analyzed the technology application of the fourth industrial revolution in the organization based on the theory of organizational change. There has been reexamined the organizational change theory based on the new technology acceptance by the change of external environment in the fourth industrial revolution and the importance of technology innovation. As a practical implication, firms that are interested in a new technology of the fourth industrial revolution should prioritize preparing an implementation system when designing organizational changes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.301-307
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• 2021

In addition to the revival of the Internet of Things, embedded systems, which are at the core of the Internet of Things, require intelligent control as things change. Embedded systems, however, are heavily constrained by resources such as hardware, memory, time and power. When changes are needed to firmware in an embedded system, flash Memory must be initialized and the entire firmware must be uploaded again. Therefore, it is time- and energy-efficient in that areas that do not need to be modified must also be initialized and rewritten. In this paper, we propose how to upload firmware in installments to each sector of flash memory so that only firmware can be replace the firmware in the parts that need to be modified when the firmware needs to be modified. In this paper, the proposed method was evaluated using real target board, and as a result, the time was reduced by about half.

• 대한상한금궤의학회지
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• v.13 no.1
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• pp.21-44
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• 2021

Objective : This study aimed to assess the preventive effect of Bupleuri Radix aqueous extracts (BR) and red koji-fermented BR (fBR) in lipopolysaccharide (LPS)-induced acute lung injury in a rat model. Methods : Rats were administered 30, 60, or 120 mg/kg/day of fBR for 28 days before LPS treatments. All rats were sacrificed 5 h after LPS treatment (500 ㎍/head, intratracheal instillation). Body weights, lung weights, pulmonary transcapillary albumin transit, arterial gas parameters (pH, partial pressure [Pa] of O2, PaCO2), bronchoalveolar lavage fluid (BALF) protein, lactate dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), total cell numbers, neutrophil/alveolar macrophage ratios, lung malondialdehyde (MDA), and myeloperoxidase (MPO) were measured. In addition, histopathological changes including the luminal surface of alveoli (LSA), thickness of alveolar septum, and number of polymorphonuclear neutrophils (PMNs) were checked. Results : LPS injection led to increases in lung weights, pulmonary transcapillary albumin transit, BALF protein, LDH, TNF-α and IL-1β contents, total cells, neutrophil and alveolar macrophage ratios, lung MDA, MPO, alveolar septum thickness, and PMNs, and decreases in PaCO2 and pH of arterial blood and LSA. However, these LPS-induced acute lung injuries were inhibited by pretreatment of 30, 60, and 120 mg/kg of fBR. The most favorable effects were seen with 30 mg/kg fBR as compared with 60 mg/kg of α-lipoic acid and BR. Conclusions : fBR showed preventive effects on LPS-induced acute lung injury, which resembles acute respiratory distress syndrome. The mechanisms of action were likely via antioxidant and anti-inflammatory means.

• Fashion & Textile Research Journal
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• v.24 no.3
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• pp.279-288
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• 2022

This study aims to derive the need for middle-aged women to consider using fashion product applications, styling, and personalized styling services. To analyze the fashion styling considerations of middle-aged women, 200 women in their 40s and 50s were surveyed. Middle-aged women usually tend to shop through home shopping, department stores, fashion soho (Small office home office) malls, and open market-type applications, and purchase fashion products more than two or three times a month, spending an average of less than 50,000 won per month. Middle-aged women consider choosing appropriate clothing based on the occasion and place, complementing the flaws of the changed body type as well as taking into account the weather in the styling process, and seek to showcase a sophisticated, luxurious, and youthful image through styling. However, they are confused and face difficulties in fashion styling, with regard to not only overall body shape but also partial body changes, such as increasing waistline, flabby thighs and arms, and decreasing hip volume. In addition, middle-aged women were looking for expert advice on styling to help them look the best. They also wanted to solve the difficulties of making a right choice amid the overflowing information related to fashion. The results of the study contribute to identifying products that meet the needs of middle-aged women and help develop detailed consumer-tailored marketing strategies, thereby improving sales of fashion products.