• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.206-215
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• 2007

Ad-Hoc network technology is a mobile internet technology of the future that will be used widely not only in Mobile Network but also in Wireless Personal Area Network (WPAN) and Ubiquitous Network For this to occur, distributed routing protocol design, loop prevention for link information reduction in overhead for control messages and route restoration algorithm must be improved or complemented. Security techniques that can guarantee safe com-munication between Ad-Hot nodes net also be provided. This study proposes and evaluates a new authentication mechanism for MANET. The mechanism segregates the roles of certification authority to keep with the dynamic mobility of nodes and handle rapid and random topological changes with minimal over-head. That is, this model is characterized by its high expandability that allows the network to perform authentication service without the influence of joining and leaving nodes. The efficiency and security of this concept was evaluated through simulation.

• Journal of the Korean Society for Railway
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• v.11 no.5
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• pp.513-518
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• 2008

Currently, urban areas face congestion problems that diminish personal mobility and freight-transport productivity. An increasing number of experts suggest that separating freight traffic from passenger traffic makes sense in terms of economics, the environment, and safety. Some experts suggest that tube transportation is the solution. The objective of this paper is to evaluate the potential benefits and limitations of tube transportation system as a viable mode of transport that can alleviate congestion on roadways. Specifically, this research employs theoretical and practical method identifying, evaluating, and selecting appropriate freight pipeline systems; evaluating the technical and economic feasibility of tube transportation; and estimating environmental, energy, and safety benefits.

• Journal of muscle and joint health
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• v.28 no.2
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• pp.152-160
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• 2021

Purpose: This study, using the International Classification for Nursing Practice, aimed to identify the phenomenon of family nursing care, and the factors affecting it, for high-risk and frail older persons who have a significant need for home healthcare services. Methods: This study was conducted using secondary data collected by students who interviewed 93 healthcare subjects in a health center. The data was used to analyze the general characteristics, health-related characteristics, and confirmed problems of family nursing phenomena of the subjects. Independant t-test, Pearson correlation coefficient, and multiple linear regression were used for the data analysis. Results: The mean age of the subjects was 82.4±6.3 years. The most common problem of the family nursing phenomenon were unhealthy lifestyle, disturbance in family communication, and lack of family interaction in the community. People with greater family nursing phenomenon problems reported a higher degree of frailty and depression, lower quality of life and self-rated health. The factors that influence the family nursing phenomenon of frail older persons are the problems of mobility and hearing. Conclusion: Physical and psychological problems associated with aging can cause not only personal, but family functional problems as well. Therefore, a comprehensive family-oriented support program is required.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.4
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• pp.57-70
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• 2021

This study aims to investigate the security demand about the traffic policing by analyzing civil complaints. Latent Dirichlet Allocation(LDA) was applied to extract key topics for 2,062 civil complaints data related to traffic policing from e-People. And additional analysis was made of reports of violations, which accounted for a high proportion. In this process, the consistency and convergence of keywords and representative documents were considered together. As a result of the analysis, complaints related to traffic police could be classified into 41 topics, including traffic safety facilities, passing through intersections(signals), provisional impoundment of vehicle plate, and personal mobility. It is necessary to strengthen crackdowns on violations at intersections and violations of motorcycles and take preemptive measures for the installation and operation of unmanned traffic control equipments, crosswalks, and traffic lights. In addition, it is necessary to publicize the recently amended laws a implemented policies, e-fine, procedure after crackdown.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.54-69
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• 2021

Policy improvement such as the revision of the Road Traffic Act are proposed for personal mobility(especially e-scooter) usage. However, there is not enough discussion to solve the problem of using shared e-scooter. In this study, we analyze the influencing factors that amount of pick-up and drop-off of shared e-scooter by dividing the Seoul into a 200m grid. we develop spatial auotcorrelation model such as spatial lag model, spatial error model, spatial durbin model, and spatial durbin error model in order to consider the characteristics of the aggregated data based on a specific space, and the spatial durbin error model is selected as the final model. As a result, demographic factor, land use factor, and transport facility factors have statistically significant impacts on usage of shared e-scooter. The result of this study will be used as basic data for suggesting efficient operation strategies considering the characteristics of weekday and weekend.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.22-39
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• 2021

This study estimated mode choice models for access travel and neighborhood travel from an SP survey in metropolitan areas where shared e-scooter services are offered. Model results show that travel time and travel cost have negative effects on mode utility. It is also revealed that people are more sensitive to travel time in access travel, whereas they are more influenced by travel cost in neighborhood travel. Looking at individual and household attributes, it has a positive effect when under 40 yerars of age, owning bikes, being a public transportation user, while it has been shown a negative effect in less than 3 million won in monthly household income and owning individual cars.

• Journal of Engineering Education Research
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• v.24 no.1
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• pp.15-23
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• 2021

The first job of university graduates is the beginning of career development, and it has a great influence on a personal life in the transition process of a labor market later. The study has compared and analyzed the effects of major variables (whether or not one participates in the career and employment programs, the satisfaction in the education infrastructure and curriculum) related to university education that determine the satisfaction in the first job of graduates from the entire university of 4-year general courses and the engineering college with experiences of having the first job. Through this, it is meaningful to make it possible for the design of university education related to career and employment tailored to the engineering college. The results of 2017 Graduate Occupational Mobility Survey were used as the data for analysis, which was analyzed by the decision tree analysis. As it was found that the most important factor determining the satisfaction in the first job was student welfare facilities for the entire graduates among education infrastructure and was major curriculum and its content among education curriculum for the graduates from the engineering college, it was analyzed that factors related to majors were more important compared to other majors in the engineering college. The customized major curriculum and content should be considered as a priority, taking into account of the demand of the industry for the successful settlement of graduates from the engineering college in a labor market.

• Journal of Korean Clinical Nursing Research
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• v.27 no.2
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• pp.199-209
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• 2021

Purpose: This study was conducted to investigate the nursing needs and workload of nurses according to nursing dependency for effective placement of nursing staff in the emergency department (ED). Methods: In June 2020, 256 adult patients who visited the ED were classified as two groups, suspected COVID-19 patients and general patients. The participants'electronic medical records were analyzed using descriptive statistics, t-test, 𝑥²-test, and Fisher's exact test using the SPSS. Results: The patient dependence score showed a significant difference between the two groups, with an average of 13.99±1.85 for the suspected COVID-19 patient group and 10.58±2.10 for the general patient group (t=12.42, p<.001). There were statistically significant differences in communication (t=3.28, p=.001), mobility (t=3.29, p=.001), nutrition, elimination, and personal care (t=7.34, p<.001) among the six domains of nursing dependency. In the domains of environment, safety, health, and social needs, the dependency score was 3 for all suspected COVID-19 patients and 1 for all general patients. Conclusion: The results of this study confirmed that infection control activities of emergency patients who need isolation affect the patients' nursing dependency on nursing care.

• Journal of Aerospace System Engineering
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• v.15 no.3
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• pp.30-44
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• 2021

Experimental investigation of counter-rotating propellers is subject to multiple time and cost constraint because of additional design parameters unlike single propeller. Also, a lot of computing time and resources are required for numerical analysis due to consideration of the interference between the upper and lower propellers. In the present study, numerical simulations were conducted to investigate the hover performance of counter-rotating propellers by using actuator method which is considered to be time-efficient. The accuracy of the present numerical methods was validated by comparing the ANSYS Fluent which is commercial CFD code. The axial spacing and rotational speed were selected as the analysis variables, and the aerodynamic performance was obtained under various conditions. Based on the obtained results, the Figure of Merit (FM) of single propeller and counter-rotating propellers and a prediction factor which enables prediction of counter-rotating propeller performance using a single propeller were derived to evaluate availability of the actuator method.

• Journal of the Korea Society of Computer and Information
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• v.28 no.3
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• pp.35-43
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• 2023

Emotion recognition while driving is an essential task to prevent accidents. Furthermore, in the era of autonomous driving, automobiles are the subject of mobility, requiring more emotional communication with drivers, and the emotion recognition market is gradually spreading. Accordingly, in this research plan, the driver's emotions are classified into seven categories using psychological and behavioral data, which are relatively easy to collect. The latent vectors extracted through the auto-encoder model were also used as features in this classification model, confirming that this affected performance improvement. Furthermore, it also confirmed that the performance was improved when using the framework presented in this paper compared to when the existing EEG data were included. Finally, 81% of the driver's emotion classification accuracy and 80% of F1-Score were achieved only through psychological, personal information, and behavioral data.