• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.4
• /
• pp.555-562
• /
• 2022

This study measured and analyzed the propagation characteristics at frequencies 6, 10, and 17 GHz to discover the new propagation demands in a semi-basement indoor corridor environment for meeting the 4th industrial revolution requirements. The measured indoor environment is a straight corridor consisting of three lecture rooms and glass windows on the outside. The measurement scenario development and measurement system were constructed to match this environment. The transmitting antenna was fixed, and the frequency domain and time domain propagation characteristics were measured and analyzed in the line-of-sight environment based on the distance of the receiving antenna location. In the frequency domain, reliability was determined by the parameters of the floating intercept (FI) path loss model and an R-squared value of 0.5 or more. In the time domain, the root mean square (RMS) delay spread and the cumulative probability of K-factor were used to determine that 6 GHz had high propagation power and 17 GHz had low propagation power. These research results will be effective in providing ultra-connection and ultra-delay artificial intelligence services for WIFI 6, 5G, and future systems in a semi-basement indoor corridor environment.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.21 no.5
• /
• pp.15-27
• /
• 2022

An omnidirectional VR treadmill is a highly-immersive walking simulator that allows identical body movements, such as walking, running, and sitting. However, the operation difficulty of an omnidirectional VR treadmill may cause data reliability problems. Therefore, this study aims to verify the effectiveness of a VR treadmill by comparing the ability to orient in the real and virtual worlds spatially. For this purpose, a rotating and searching path experiment was conducted with participants. This experiment showed that there was no statistically significant difference in the ability of the participants to orient in the real and virtual worlds spatially. In addition, the omnidirectional VR treadmill requires an adaptation time for the users due to the difficulty in the treadmill operation. However, there was no significant difference in the difficulty felt by the participants according to the adaptation time. Hence, these findings supported the possibility of collecting realistic walking data without safety concerns through an omnidirectional VR treadmill. Furthermore, this treadmill could be used in future research to solve problems directly related to pedestrian safety, such as the interaction between vehicles and pedestrians.

• Journal of the Society of Disaster Information
• /
• v.19 no.3
• /
• pp.519-531
• /
• 2023

With the aim of preventing safety accidents at construction sites, the company aims to create safe behaviors intended through variables called smart safety and health activities to help reduce industrial accidents. Purpose: It analyzes how smart safety and health activities affect accidents caused by unsafe behavior and changes in worker behavior, which is the root cause, and verifies the hypothesis that it helps prevent safety accidents and protect workers' lives. Method: Smart safety and health activities were selected as independent variables (X), and intended safety and anxiety, which are workers' behavioral intentions, were set as dependent variables (Y), attitude and subjective norms, and planned behavioral control as parameters (M). Exploratory factor analysis, discriminant validity analysis, and intensive validity analysis of safety and health activities were used to analyze the scale's reliability and validity. To verify the hypothesis of behavior change, the study was verified through Bayesian model analysis and MC simulation's probability density distribution. Result: It was found that workers who experienced smart safety and health activities at construction sites had the highest analysis of reducing unstable behavior and performing intended safety behavior. The research hypothesis that this will affect changes in worker behavior has been proven, the correlation between variables has been verified in the structural equation and path analysis of the research analysis, and it has been confirmed that smart safety and health activities can control and reduce worker instability. Conclusion: Smart safety and health activities are a very important item to prevent accidents and change workers' behavior at construction sites.

• Korean Journal of Culture and Social Issue
• /
• v.21 no.3
• /
• pp.419-455
• /
• 2015

In study I, Domain-Specific Risk Taking Scale(DOSPERT) was translated into Korean and was validated that it had 6 factors structure and showed adequate reliability and validity, using the data had been collected from 438 participants. In study 2, two research problems were examined using the data had been collected from 497 participants who were different from study I. First, the mediation effect of sensation seeking and perceived benefit on the relationship between narcissism and risk-taking were examined. Using path analysis, it found that sensation seeking and perceived benefit mediated the relationship between NPI narcissism and risk-taking fully, and between PNI narcissism and risk-taking partially. Seceond, the moderate effect of contingencies of self-worth(CSW) on the relationship between perceived benefit-risk and risk-taking was examined. Using multi-group analysis, it found that virtue CSW moderated the relationship between perceived benefit-risk and total risk-taking, various CSWs moderated the relationships between perceived benefit-risk and 6 sub domains of risk-taking. These results were compared with previous studies of risk-taking and discussed the relevance of the narcissistic type.

• Industry Promotion Research
• /
• v.8 no.2
• /
• pp.81-91
• /
• 2023

This study aims to present basic data for preventing drop-out intention by identifying the mechanisms in which academic stress affects drop-out intention through self-esteem, peer relationships, and grit in high school students. The subjects of the study were 283 high school students purposively selected from three cities and counties in Chungcheongnam-do. The data were analysed using SPSS PC+ Win. ver. 25.0 and SPSS PROCESS macro ver. 4.2. The applied statistical techniques were descriptive statistics, reliability analysis, correlation analysis, and moderated mediation effect analysis. As a result of the study, first, academic stress showed a positive correlation with the drop-out intention, but a negative correlation with self-esteem, grit, and peer relationship. Second, grit not only played a moderating role in enhancing the relationship between self-esteem and peer relationship, but also played a moderated mediating role in the path of academic stress → self-esteem → peer relationship → drop-out intention. It was confirmed that the academic stress of high school students has a direct effect on the drop-out intention, and that self-esteem, peer relationships, and grit can be used as important factors to prevent the school drop-out.

• Industry Promotion Research
• /
• v.8 no.3
• /
• pp.51-60
• /
• 2023

The purpose of this study was to verify the double mediating effects of job stress and psychological commitment in the relationship between organizational incivility and job satisfaction of child-care teachers in South Korea. 234 Korean child-care teachers were purposively selected from S city of C Province. SPSS Win.25.0 and PROCESS Macro 4.2 were used for analyzing the data, and reliability analysis, frequency analysis, correlation analysis, and multiple mediation model analysis were conducted. Results are as follows. First, correlation analysis showed significant correlations between organizational incivility, job stress, psychological commitment, and job satisfaction. Second, path analysis showed that organizational incivility had a positive effect on job stress and a negative effect on psychological commitment and job satisfaction. Job stress had a negative and significant effect on psychological commitment and job satisfaction, and psychological commitment had a positive and significant effect on job satisfaction. Third, job stress and psychological commitment had consecutive double mediation in the link between organizational incivility and job satisfaction. This study suggests a way to utilize job stress and psychological commitment when childcare teachers' organizational incivility has a negative effect on job satisfaction.

• Analytical Science and Technology
• /
• v.19 no.5
• /
• pp.400-406
• /
• 2006

Hydrogen analysis by elastic recoil detection has been performed utilizing polyimide film as a reference sample of known hydrogen content assuming the soundness of ion beam current integration. However beam current integration at higher incidence angle is not reliable. Scattering yield per unit fluence by current integration which is normalized per unit path length decreases as the sample tilt angle is getting higher. Moreover because beam current integration at high tilt angle is incomplete, hydrogen evaluation is very risky by direct comparison of sequentially collected recoil spectra between reference and target sample. In this study, primary ion beam dose is determined by backscattering spectrum that is collected simultaneously with recoil spectrum instead of ion beam current integration in order to reduce uncertainty arising in the process of current integration and to enhance the reliability of quantitative analysis. Three test samples are selected $-7.6{\mu}m$ polyimide film, hydrogen implanted silicondioxide and Au deposited carbon wafer- and analyzed by two methods and compared.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2023.05a
• /
• pp.100-103
• /
• 2023

Recently, development of maritime autonomoust surface ships and eco-friendly ships, production and evaluation research considering various marine environments is needed in the field of optimal routes as the demand for accurate and detailed real-time marine environment prediction information expands. An algorithm that can calculate the optimal route while reducing the risk of the marine environment and uncertainty in energy consumption in smart ships was developed in 2 stages. In the first stage, a profile was created by combining marine environmental information with ship location and status information within the Automatic Ship Identification System(AIS). In the second stage, a model was developed that could define the marine environment energy map using the configured profile results, A regression equation was generated by applying Random Forest among machine learning techniques to reflect about 600,000 data. The Random Forest coefficient of determination (R²) was 0.89, showing very high reliability. The Dijikstra shortest path algorithm was applied to the marine environment prediction at June 1 to 3, 2021, and to calculate the optimal safety route and express it on the map. The route calculated by the random forest regression model was streamlined, and the route was derived considering the state of the marine environment prediction information. The concept of route calculation based on real-time marine environment prediction information in this study is expected to be able to calculate a realistic and safe route that reflects the movement tendency of ships, and to be expanded to a range of economic, safety, and eco-friendliness evaluation models in the future.

• Journal of Venture Innovation
• /
• v.6 no.3
• /
• pp.73-93
• /
• 2023

This study provides a prospect for the fast growing the smartwatch market by investigating the relationship between the satisfaction and the continuous use intention of Apple watch users, as well as the factors influencing their satisfaction. Based on the TAM, this study uses system quality, information quality, and self-efficacy as independent variables, perceived usefulness, perceived ease of use, and satisfaction as mediators, and continuous use intention as the dependent variable. We analyze the data of 256 individuals who completed an online survey with SPSS 26.0 and AMOS 26.0 software. This study conducts several tests and analyses to empirically evaluate the data including reliability analysis, factor analysis, feasibility analysis, path analysis, hypothesis verification, and mediation analysis. Our results investigate which factors may influence consumers' intention to continuously using Apple Watch devices in the future. In summary, satisfaction has a positive effect on the intention to continuously use smartwatchs. Perceived usefulness and perceived ease of use have a positive effect on satisfaction. Among the three factors (system quality, information quality, and self-efficacy), only self-efficacy has no significant impact on perceived usefulness but had a positive effect on perceived ease of use. In addition, system quality and information quality positively affect perceived usefulness, perceived ease of use, satisfaction, and continuous intention to use an Apple Watch. Taking the Apple Watch as the subject of our research topic, this study provides theoretical value by exploring the impact of user's satisfaction with their smartwatch on their continuous usage intention. This study further explains the influence of system quality, information quality, and self-efficacy on user satisfaction. Additionally, this research offers valuable insight to practitioners by confirming that information quality, system quality, and self-efficacy are important features for enhancing satisfactory user experiences which in turn may increase users' intention to continued using smartwatches.

• Industry Promotion Research
• /
• v.8 no.4
• /
• pp.69-79
• /
• 2023

This study sought to propose ways to improve the happiness of Chinese product designers by verifying whether grit moderates the effect of job stress on happiness through professional values. A purposively sampled participants of 335 Chinese product designers living in Guangdong Province, southern China, were selected. Data analysis was performed using SPSS PC+ Win. Ver. 26.0 and PROCESS Macro ver. 4.2. The statistical techniques applied were frequency analysis, reliability analysis, correlation analysis, and moderated mediation effect analysis. The research results are as follows. First, job stress showed a negative correlation with professional value and grit, but did not show a significant correlation with happiness. Except for job stress, there was a positive significant correlation between other variables. Second, the conditional indirect effect was significant when grit was M-SD, M, or M+SD. M+SD. Therefore, the moderated mediating role of grit was verified. However, as professional value increased, grit played a role in increasing happiness. Still, in the path of job stress -> professional value -> happiness, grit did not buffer the negative effect of job stress on happiness through professional stress. Suggestions were made to improve the happiness of product designers using professional values and grit.