• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.5
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• pp.349-359
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• 2022

The aim of this study is to analyze the dynamic characteristics of proportional control valves according to various working conditions as a basic study for developing proportional control valves for auto-steering tractors. The dynamic characteristics of proportional valves were measured using hydraulic characteristics measurement system, and the power was analyzed using measured flow rate and pressure data. As the experimental conditions, the tractor engine speed and steering angle was selected as the main variables, and the experiment was performed on urethane road conditions. As a result, it was found that the flow rate, pressure, and power of the proportional control valve increased as the tractor engine speed and steering angle increased. In particular, as the steering angle increased at the same engine speed, the flow rate, pressure, and power tended to increase by up to 190%, 172%, and 273%, respectively. Similarly, as the engine speed increased at the same steering angle, the flow rate, pressure, and power tended to increase up to 161%, 122%, and 168%, respectively. Therefore, it can be seen that the steering angle has a higher influence on the dynamic characteristics of the proportional control valve than the engine speed.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.544-560
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• 2022

In order to verify the effect of job-esteem attitude on the empowerment of social service workers on service orientation, this study conducted a questionnaire survey on manpower providing local autonomous social service investment projects in Chungcheongbuk-do through analyzing 329 copies of data. The main research results show that, work performance relationship and personal work orientation have a significant effect on job esteem among the sub-factors of empowerment, it was found that the work environment control had a significant effect on all of the service-oriented sub-factors (trust-oriented, sincerity-oriented, and type-oriented). In addition, personal work-oriented empowerment was found to have a significant effect on sincerity-oriented and type-oriented among the service-oriented sub-factors, and it was confirmed that the empowerment of social service workers had a positive effect on service orientation through employee appreciation as a medium. It was confirmed that job-esteem, which is a mediator, affects sincerity and type orientation, which are sub-variables of service orientation. In order to improve the service orientation of social service workers, it is necessary to develop a manual for a clear understanding of their work and to provide continuous and practical maintenance education so workers can develop their own abilities.

• Korean Association of Arts Management
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• no.58
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• pp.89-119
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• 2021

This study empirically analyzes the factors that affect the people's enjoyment of pure culture and arts, especially art exhibitions. We use 56,588 sample data from the "The Survey of Cultural Enjoyment" collected by the Ministry of Cultrure, Sports and Tourism over the last 10 years and perform multiple regression and Multi-Way ANOVA to analyze the effect of individual's cultural experience on art exhibit visits. The results of the analysis show that the experience of participating in culture and arts events, culture and arts education, and participation in culture and arts clubs have a positive effect on the art exhibition visits. We also identify the positive interaction effects between the three independent variables. In other words, it was found that the average number of visits to art exhibitions was higher for groups who had experience of participating in culture and arts events, culture and arts education, and culture and arts clubs. This study provides a first empirical analysis on personal factors influencing art exhibition visits in Korea and lays the groundwork for future studies in developing a comprehensive predictive model for cultural art visits. In addition, we give policy implications and suggestions specifically, mid-term policies related to promoting art exhibition visits as an extension of individual's engagement with pure culture and arts through big data analysis.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.428-434
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• 2022

This study intends to develop an eco-friendly concrete panel mixed with biochars. Experiments about mechanical and thermal properties were conducted on porous biochar concrete, which has insulation and carbon-capture performance. The concrete has a mixing ratio of 0, 5, 10, and 15 % for biochar and a water-binder ratio of 0.35. The unit weight, porosity, and permeability were measured to evaluate the mechanical characteristics. From the results, as the biochar mixing rate increased, the porosity and the permeability increased, but the unit weight decreased. Even though a decreased trend was observed in the compressive strength results, they satisfied the design standard. Since the thermal conductivity was decreased during the increase of contents, biochar could be considered an excellent material for insulation performance. In addition, regression analyses were conducted regarding the relationship of unit weight with porosity, compressive strength with thermal conductivity, and porous with thermal conductivity. From the regression, significant variables for expanding the scope of the application of biochar were presented.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.25-40
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• 2022

This study is about how the quality of M2M big data that provides real-time information affects users. Recently, there are many difficulties in acquiring and managing data because data types such as variety, data volume, and data velocity are changing rapidly and diversified. This not only leads to a decrease in data quality but also it can give a negative impact when making decisions using data. Generally, the quality of data is defined as 'suitability for use', which means that data quality must meet the expectations of user needs. Therefore, data providers need activities to improve data quality for this purpose, and the key is to identify data quality dimensions in each field where data is used and provide data suitable for the level of user needs. In this study, the relationship between the quality area of real-time M2M data used in the traffic information system and user satisfaction was analyzed. Research models and hypotheses were established to analyze the effects between variables related to M2M big data. In order to test the hypothesis, a causal relationship between the major factors was identified by conducting a survey and analyzing the data users.

• Therapeutic Science for Rehabilitation
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• v.11 no.4
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• pp.23-39
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• 2022

Objective : To summarize clinical and demographic variables and machine learning uses for predicting functional outcomes of patients with stroke. Methods : We searched PubMed, CINAHL and Web of Science to identify published articles from 2010 to 2021. The search terms were "machine learning OR data mining AND stroke AND function OR prediction OR/AND rehabilitation". Articles exclusively using brain imaging techniques, deep learning method and articles without available full text were excluded in this study. Results : Nine articles were selected for this study. Support vector machines (19.05%) and random forests (19.05%) were two most frequently used machine learning models. Five articles (55.56%) demonstrated that the impact of patient initial and/or discharge assessment scores such as modified ranking scale (mRS) or functional independence measure (FIM) on stroke patients' functional outcomes was higher than their clinical characteristics. Conclusions : This study showed that patient initial and/or discharge assessment scores such as mRS or FIM could influence their functional outcomes more than their clinical characteristics. Evaluating and reviewing initial and or discharge functional outcomes of patients with stroke might be required to develop the optimal therapeutic interventions to enhance functional outcomes of patients with stroke.

• Journal of the Korean Applied Science and Technology
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• v.39 no.3
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• pp.407-416
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• 2022

This study was attempted to determine how knowledge and fear of COVID-19 affects job-seeking anxiety of nursing students in the COVID-19 pandemic situation. The subjects of this study were 157 students from the 1st to 4th graders attending nursing universities. Data collection was collected from December 9, 2021, to February 21, 2022. Data were analyzed with the SPSS/WIN 24.0 program. As a result of this study, the job-seeking anxiety of the subjects was significantly correlated with the fear of COVID-19(r=.386, p<.001). And, influencing factors the job-seeking anxiety of nursing students identified in the order of fear of COVID-19, satisfaction with college. Therefore, it is necessary to develop a program that can reduce the fear of COVID-19 in order to lower the job-seeking anxiety of nursing students.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.85-89
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• 2021

AlGaN-based UV-C light-emitting diodes (LEDs) were applied for p-type activation by electrochemical potentiostatic activation (EPA). The p-type activation efficiency was increased by removing hydrogen atoms through EPA treatment using a neutral Mg-H complex that causes high resistance and low conductivity. A neutral Mg-H complex is decomposed into Mg^- and H⁺ depending on the key parameters of solution, voltage, and time. The improved hole carrier concentration was confirmed by secondary ion mass spectroscopy (SIMS) analysis. This mechanism eventually improved the internal quantum efficiency (IQE), the light extraction efficiency, the leakage current value in the reverse current region, and junction temperature, resulting in better UV-C LED lifetime. For systematic analysis, SIMS, Etamax IQE system, integrating sphere, and current-voltage measurement system were used, and the results were compared with the existing N₂-annealing method.

• Journal of Korea Entertainment Industry Association
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• v.15 no.6
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• pp.55-70
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• 2021

This study investigates the following important financial questions using entertainment enterprises: 1) how does cash reserve affect a firm's financial value? 2) what factors influence the level of cash retention of a firm? For empirical tests, we use accounting and financial data of entertainment companies listed in the KOSPI and KOSDAQ markets for a long-term time period covering from 2000 to 2018. The main findings of this paper are as follows: First, entertainment companies maintain higher level of cash holdings compared to non-entertainment companies. Second, the cash holdings of entertainment enterprises have positive influence on firms' financial value. Third, among various firm characteristics known for affecting the cash holdings level, leverage and profitability exhibit strong relationships in entertainment enterprises. Entertainment firms with lower leverage and higher profitability tend to reserve more cash inside them. These findings suggest that entertainment companies are highly valued by stock market participants as having prospective opportunities, thus, firms with sufficient cash holdings tend to have higher firm value. In addition, these findings imply that cash in entertainment enterprises functions as a substitute for debts and the cash holdings are less likely driven by agency problems.

• 한국노년학
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• v.40 no.2
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• pp.291-309
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• 2020

In this study, the behavioral model of Andersen and Newman(1973) was applied to identify the factors influencing the use of senior centers by the elderly in the community, and the mediating effect of user satisfaction was improved to improve the satisfaction of seniors using the Senior Center and operate the Senior Center. This study attempted to suggest policy and practical alternatives for activation. The subjects were 578 elderly people using 2,283 senior centers in Busan. As a result, the factors influencing the total usage period of the Senior Center were analyzed by age and type of potential factors among the leading factors, and the factors affecting the total number of days of senior center usage during the week were gender, age, and education level among the preceding factors. Appeared. Factors affecting user satisfaction as a parameter were analyzed as subjective health status among gender, age, and desire factors among preceding factors. As a result of verification of mediating effect of user satisfaction, there was a partial mediating effect between age and total use of Senior Center, full mediating effect between gender and days of Senior Center use, and partial mediating effect between age and Senior Center use days. Analyzed. According to the purpose and main findings of the study, the policy and practical suggestions for activating the satisfaction and use of Senior Center are as follows. First, program development and support according to the characteristics of senior center users are required. Second, there is a need to characterize per-path according to senior center type and regional environment. Third, there is a need to improve and raise the support standards for senior center operating expenses.