• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.35-41
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• 2022

UAM (Urban Air Mobility) is a new safe, secure, and more sustainable air transportation system for passengers and cargo in urban environments. Commercial operations of UAM are expected to start in 2025. Since production rates of UAM are expected to be closer to cars than conventional aircraft, the airworthiness methodology for UAM must be prepared for mass production. Composite materials are expected to be mainly used for UAM structures to reduce weight. In this paper, the composite material qualification method was derived and the materials were applied for small aircraft application. It is expected to reduce the airworthiness certification time by applying composite material qualification system and its database.

• Women's Health Nursing
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• v.28 no.3
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• pp.222-234
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• 2022

Purpose: This study investigated the changes in the health-related behaviors of adult women in Korea during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Data from the eighth Korea National Health and Nutrition Examination Survey (2019-2020) were analyzed. The participants were 4,848 women aged 19 to 64 years in 2019 and 2020. Data analysis using the complex sampling design was performed using SPSS 20.1. Results: Positive changes during the pandemic compared to before the pandemic in Korean adult women were found for improved subjective oral health perceptions (odds ratio [OR], 1.77; p<.001), increased moderate-intensity exercise in work and leisure activities (OR, 1.75; p<.001 and OR; 1.29, p=.004), and a decrease in secondhand smoke exposure at the workplace and in public places (OR, 0.64; p=.004 and OR, 0.60; p<.001). However, the following negative health behavior changes were found: decreased frequency of walking 5 days a week (OR, 0.81; p=.011) and an increase in unhealthy daytime sleep durations (OR, 1.40; p=006). Conclusion: Compared to before the COVID-19 pandemic, Korean adult women perceived their subjective dental health more positively during the COVID-19 pandemic, decreased their exposure to secondhand smoke at work and in public places, decreased walking, and increased sleep duration during the week. Since this study only compared data between 1 year before and after the start of the pandemic, it is necessary to investigate a longer period of time in the future. A future study should attempt to identify the factors related to changes in health behaviors caused by the pandemic.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.513-528
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• 2022

The purpose of this study is to analyze Korean game-related issues and policies to increase the effectiveness of related policies in the future and to increase the consistency of social norms of the policies. this study analyzes related issues by analyzing changes in Korean newspaper articles using spline function and text mining methods, and analyzes the contents of newspaper articles at the time of amplification of issues to present major issues and development directions. As a result of the analysis, game-related issues appeared in various topic, and there are not only support from the government and local governments but also coexisted with game-related regulations (taxation, gambling regulations, game addiction disease, and prevention of fee expansion). Despite regulations, the government presents preemptive responses to problems caused by the application of metabuses and NFTs to games, fostering game-related experts, start-up support, and supporting manpower departure as policy implications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1770-1776
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• 2021

For hand expression recognition, hand pose recognition based on the static shape of the hand and hand gesture recognition based on hand movement are used together. In this paper, we proposed a hand expression recognition method that recognizes symbols based on the trajectory of a hand movement on a virtual blackboard. In order to recognize a sign drawn by hand on a virtual blackboard, not only a method of recognizing a sign from a hand movement, but also hand pose recognition for finding the start and end of data input is also required. In this paper, MediaPipe was used to recognize hand pose, and LSTM(Long Short Term Memory), a type of recurrent neural network, was used to recognize hand gesture from time series data. To verify the effectiveness of the proposed method, it was applied to the recognition of numbers written on a virtual blackboard, and a recognition rate of about 94% was obtained.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.278-281
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• 2022

Purpose: This study sought to compare the muscle activity of the deltoid muscle according to the range of motion during the proprioceptive neuromuscular facilitation (PNF) upper extremity D2 pattern exercise performed with an isokinetic exercise device. The aim was to provide basic data for selecting an exercise for the relevant segment of the range of motion to enhance function in clinical practice. Methods: In this study, the relevant measurements of the anterior and middle trapezius of 25 healthy adults were taken using a surface electromyography system. The upper extremity pattern exercise was performed in three ranges (0% to 50%, 50% to 100%, and 25% to 75%) using the upper extremity isokinetic device. Results: There was a statistically significant difference in the muscle activity ratios of the anterior and middle deltoid muscles according to the measurement conditions (p<0.05). There was a statistically significant difference in the activity ratio of the middle deltoid muscle according to the measurement conditions in the ratio from the start range to the end range (p<0.05). There was no significant difference in the muscle onset time difference according to the measurement conditions (p>0.05). Conclusion: The muscle activity of the anterior and middle deltoid muscles was analyzed according to the range of motion during the PNF upper extremity pattern exercise performed with an isokinetic device. The results could be used as a basis for selecting exercises for the relevant segment of the range of motion according to the function to be emphasized.

• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.146-155
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• 2022

The purpose of this study is to investigate the recyclability of Shenlong in China using SWOT. The main analysis results are as follows. First, provided that the company's current capacity utilization rate is seriously insufficient, reducing staff is one among the effective ways. Second, Shenlong should open a web store to cater to young people's online shopping behavior, and further expand the brand visibility using national mainstream media and online shopping platforms like Taobao and JingDong to market Dongfeng Peugeot and Dongfeng Citroen on the whole network. Third, under the premise of maintaining the present best-selling models, Shenlong should appropriately reduce the amount of models, adjust the assembly capacity ratio of every model and every displacement in real time per the newest market trends, increase the agility of auto companies' production, and timely meet the wants of domestic consumers. Fourth, dual-brand coordination and channel integration are very necessary, and also the profitability and profitability of dealers are going to be further improved, thereby increasing sales. Fifth, target building new energy leading products of Shenlong, strive to attain the forefront of the industry within the sales of recent energy vehicles within 5 years, and gradually expand new energy vehicle products from passenger vehicles to passenger vehicles and commercial vehicles. Finally, the marketing field of Shenlong Automobile should achieve "three major changes", that is, change from a goal-driven type to a demand-driven type, cancel the bundling of outlet invoicing goals and delivery incentive tiers; start from basic capabilities, and set pragmatic and challenging goals; focus Channels, to realize following the activation of outlets, and single store sales increase.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.755-764
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• 2021

This study aimed to examine the effects of the character education program applying mindfulness diary in 'H' girls' middle school, which is implemented as a practical character education at the school level while supplementing the limitations of existing character education programs. To achieve this, the pre- and post-design of a single treatment group in which data were collected over three time periods over two years for all 182 enrolled students was conducted. As a result of repeated measures of ANOVA to examine the significant mean change in the data, this program significantly improved the level of self-control, prosocial behavior, and gratitude of students. This was not only showing a significant improvement one year after the start of the program, but also showing a continuous significant improvement even one year later. Based on the above results, the implications and suggestions of this study were discussed.

• Journal of Korea Trade
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• v.24 no.4
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• pp.34-48
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• 2020

Purpose - The rapid rise of e-commerce enterprises has led to the development of the logistics industry. At the same time, some enterprises are motivated by the interests to start reducing costs and inputs, which on the contrary leads to low quality of service, thus reducing customer satisfaction. In recent years, vicious competition, violent express delivery and lack of professionalism in the logistics market have led to high annual customer complaint rate, which has resulted in the company losing many loyal customers, but also unable to obtain new customers. Therefore, to pay attention to and understand the psychological needs of customers and improve the quality of logistics distribution service has become a pressing problem for Every express company. Design/methodology - By analyzing the problems existing in logistics distribution of express companies, this paper explores various factors affecting customer satisfaction and takes consumer sentiment as a mediating variable. Through questionnaires to collect relevant data, put forward hypotheses for empirical analysis, use two different software including SPSS 21.0 and AMOS 21.0 to analyze the information, draw conclusions and make recommendations. Findings - According to the above research results, the reliability, convenience, efficiency, professional can have a positive impact on customer satisfaction through the mediating effect of their sentiment, convenience and professional on consumer sentiment and satisfaction are more significant. Originality/value - This paper the establishment of distribution service indicators related to customer satisfaction and empirical analysis can not only enrich and supplement the distribution service quality indicator system studied by the former, but also provide a theoretical basis for future research.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.2
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• pp.119-143
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• 2021

Selecting liquid methane as fuel is a prevailing trend for recent rocket engine developments around the world, triggered by its affordability, reusability, storability for deep space exploration, and prospect for in-situ resource utilization. Given years of time required for acquiring a new rocket engine, a national-level R&D program to develop a methane engine is highly desirable at the earliest opportunity in order to catch up with this worldwide trend towards reusing launch vehicles for competitiveness and mission flexibility. In light of the monumental cost associated with development, fabrication, and testing of a booster stage engine, it is strategically a prudent choice to start with a low-thrust engine and build up space application cases.

• Geomechanics and Engineering
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• v.27 no.5
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• pp.527-535
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• 2021

The creep characteristics of rock is of great significance for the study of long-term stability of engineering, so it is necessary to carry out indoor creep test and creep model of rock. First of all, in different water-bearing state and different positive pressure conditions, the granite is graded loaded to conduct indoor shear creep test. Through the test, the shear creep characteristics of granite are obtained. According to the test results, the stress-strain isochronous curve is obtained, and then the long-term strength of granite under different conditions is determined. Then, the fractional-order calculus software element is introduced, and it is connected in series with the spring element and the nonlinear viscoplastic body considering the creep acceleration start time to form a nonlinear viscoplastic creep model with fewer elements and fewer parameters. Finally, based on the shear creep test data of granite, using the nonlinear curve fitting of Origin software and Levenberg-Marquardt optimization algorithm, the parameter fitting and comparative analysis of the nonlinear creep model are carried out. The results show that the test data and the model curve have a high degree of fitting, which further explains the rationality and applicability of the established nonlinear visco-elastoplastic creep model. The research in this paper can provide certain reference significance and reference value for the study of nonlinear creep model of rock in the future.