• Korean Medical Education Review
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• v.25 no.2
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• pp.84-101
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• 2023

Longitudinal data can provide important evidence with the potential to stimulate innovation and affect policies in medical education and can serve as a driving force for further developments in medical education through evidence-based decisions. Tracking and observing cohorts of students and graduates using longitudinal data can be a way to link the past, present, and future of medical education. This study reviewed practical methods and technical, administrative, and ethical considerations for the establishment and operation of a longitudinal database and presented examples of longitudinal databases. Cohort study design methods and previous examples of research using longitudinal databases to explore major topics in medical education were also reviewed. The implications of this study are as follows: (1) a systematic design process is required to establish longitudinal data, and each university should engage in ongoing deliberation about this issue; (2) efforts are needed to alleviate "survey fatigue" among respondents and reduce the administrative burden of those conducting data collection and analysis; (3) it is necessary to regularly review issues of personal information protection, data security, and ethics regarding the survey respondents; and (4) a system should be established that integrates and manages a longitudinal database of medical education at the national level. The hope is that establishing longitudinal data and cohorts at individual medical schools will not be a temporary phenomenon, but rather that they will be well utilized at the national level to innovate and implement ongoing changes in medical education.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.223-234
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• 2022

This study demonstrated the relationship between members' perception of meaning of work and turnover intention and analyzed the moderating effect of work-family promotion efforts. To this end, data were obtained through a survey of 143 SME workers in Busan, and the results were used for analysis. As a result of the study, first, it was possible to confirm a negative (-) relationship with turnover intention when members in the organization positively perceived the meaning and value of their work. In addition, it was confirmed that efforts to promote work-family within the organization showed a moderating effect in this process. Based on these results, the following implications were derived. First, SMEs operate somewhat insufficient treatment and welfare systems compared to large companies, so they should pay more attention to the design and operation of various personnel systems so that they can recognize the organization's growth potential and technical advantage and meaning of work. In particular, in the case of rapidly growing SMEs, institutional support for work-family promotion may be insufficient, and the importance of introducing and operating a system to further revitalize it was suggested.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.587-595
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• 2008

Many studies on bus scheduling optimization have been done from the 1960s to recent years for establishing rational bus schedule plan that can improve convenience of bus passengers and minimize unnecessary runs. After 2000, as part of the Intelligent Transport Systems (ITS), the importance of the schedule management and providing schedule information through bus schedule optimization has become a big issue, and much research is being done to develop optimization models that will increase bus passenger convenience and, on the side of bus management, minimize unnecessary bus operation. The purpose of this study is to calculate the optimal bus frequency and create a timetable for each bus stop by applying DTR or DTRC model that use data for each bus stop and route segment. Model verification process was implemented using data collected from bus management system (BMS) and integrated transit-fare card system for bus route of Seoul's No. 472 line. In order to evaluate the reliability and uncertainty of optimal solution, sensitivity analysis was implemented for the various parameters and assumptions used in the bus scheduling model.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.673-681
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• 2023

Hydrocarbon-based polymer membranes to replace perfluorinated polymer membranes are being continuously researched. However, hydrocarbon-based membranes have a problem in that they are less durable than fluorine-based membranes. In this study, we sought to compare the annealing effect to improve the durability of sulfonated poly(ether ether ketone) (SPEEK). After membranes formation, thermogravimetric analysis and tensile strength were measured to compare changes in membranes properties due to annealing. After manufacturing the membrane and electrode assembly (MEA), the initial performance and chemical durability was compared with unit cell operation. During the 24-hour annealing process, the strength increased due to the increase in-S-O-S-crosslinking, and the sulfonic acid group decreased, leading to a decrease in I-V performance. By annealing, the hydrogen permeability was reduced to less than 1/10 of that of the nafion membrane, and as a result, open circuit voltage (OCV) and durability was improved. The SPEEK membranes annealed for 24 hours showed higher durability than the nafion 211 membranes of the same thickness.

• Tribology and Lubricants
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• v.39 no.5
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• pp.197-202
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• 2023

Recently, research on experimental and analytical techniques utilizing microfluidic devices has been pursued. For example, lab-on-a-chip devices that integrate micro-devices onto a single chip for processing small sample quantities have gained significant attention. However, during sample preparation, unnecessary gases can be introduced into the internal channels, thus, impeding device flow and compromising specific function efficiency, including that of analysis and separation. Several methods have been proposed to mitigate this issue, however, many involve cumbersome procedures or suffer from complexities owing to intricate structures. Recently, some approaches have been introduced that utilize hydrophobic device structures to remove gases within channels. In such cases, the permeability of gases passing through the structure becomes a crucial performance factor. In this study, a method involving the deposition and sintering of diluted Ag-ink onto a silicon wafer surface is presented. This is followed by unstructured nano-pattern creation using a Metal Assisted Chemical Etching (MACE) process, which yields a nanostructured surface with unstructured pillar shapes. Subsequently, gas permeability in the spaces formed by these surface structures is investigated. This is achieved by experiments conducted to incorporate a pressure chamber and measure gas permeability. Trends are subsequently analyzed by comparing the results with existing theories. Finally, it can be confirmed that the significance of this study primarily lies in its capability to effectively evaluate gas permeability through unstructured pillar-like nanostructures, thus, providing quantitative values for the appropriate driving pressure and expected gas removal time in practical device operation.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.37-44
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• 2023

As a primary technology of Industry 4.0, human-robot collaboration (HRC) requires additional measures to ensure worker safety. Previous studies on avoiding collisions between collaborative robots and workers mainly detect collisions based on sensors and cameras attached to the robot. This method requires complex algorithms to continuously track robots, people, and objects and has the disadvantage of not being able to respond quickly to changes in the work environment. The present study was conducted to implement a web-based platform that manages collaborative robots by recognizing the emotions of workers - specifically their perception of danger - in the collaborative process. To this end, we developed a web-based application that collects and stores emotion-related brain waves via a wearable device; a deep-learning model that extracts and classifies the characteristics of neutral, positive, and negative emotions; and an Internet-of-things (IoT) interface program that controls motor operation according to classified emotions. We conducted a comparative analysis of our system's performance using a public open dataset and a dataset collected through actual measurement, achieving validation accuracies of 96.8% and 70.7%, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.763-774
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• 2023

The water availability in a river is related to the return flow of residential water. However it is still difficult to determine the exact return flow. In this study, the residential water-cycle system is defined as a process consisting of water inflow, water transfer and water outflow. The study area is Hampyeong-gun, Jeollanam-do, and is set as a single inflow to a single outflow through the water-cycle system after classification of complete and incomplete measurement points. The time-series prediction models(ARIMA model and TFM) are established with daily inflow and outflow data for 6 years. Inflow and outflow are predicted by dividing into training and test periods. As a result, both models show the feasibility of short-term prediction by deriving stable residuals and securing statistical significance, implementing the preliminary form of the water-cycle system. As a further study, it is suggested to predict the actual return flow of the target basin and efficient water operation by adding input factors and selecting the optimal model.

• Journal of Auto-vehicle Safety Association
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• v.15 no.4
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• pp.79-87
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• 2023

In recent years, the population of children has been declining in Korea. Moreover, the phenomenon of elementary school closures is on the rise, particularly in non-urban and some new city areas, highlighting the need for school buses for children. Despite the mandatory safety features in place, accidents involving school buses for children are on the rise, underscoring the need for improvement in the safety of these vehicles. While various studies have been conducted to enhance the safety of children during their school commute, there has been a notable gap in research analyzing the school commuting environment concerning the vehicle safety of these buses. Hence, this study aims to develop a set of service evaluation criteria for school bus routes, considering vehicle safety through the Analytic Hierarchy Process (AHP). By conducting a survey to gather information on the current status of school buses for children and through questionnaires targeting stakeholders in the school bus sector, the study analyzed requirements and operating conditions. These results were used to select evaluation criteria and structure the hierarchy based on the external and internal aspects of school bus services. Through AHP surveys conducted based on the designed criteria, experts identified safety as the most crucial aspect, with a specific emphasis on Vehicle Safety. Using these developed service evaluation criteria, the study plans to identify service-vulnerable routes through a real route analysis and recommend improvements, with the ultimate goal of creating a safe and convenient school commuting environment for children.

• The Korean Journal of Emergency Medical Services
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• v.28 no.1
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• pp.97-112
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• 2024

Purpose: This study compared the relative importance of educational content, teaching methods, and evaluation methods in the patient assessment curricula of 119 emergency medical technicians (EMTs). Methods: First, we identified the educational content, training hours, and teaching and evaluation methods of the existing patient assessment curriculum based on the National Competency Standard learning module. Second, we surveyed 30 EMTs affiliated with 119 services using the Analytic Hierarchy Process (AHP) method. Subsequently, we compared the differences between the current curriculum and the AHP analysis results. Results: Currently in operation, the "Advanced EMT Course" comprises three learning modules: assessment of patient status, scene size-up and triage, and assessment using monitoring devices. Among these, content related to the assessment of patient status received the most allocated time and was deemed the most important according to the AHP survey results. Conversely, while less time was allocated to scene size and triage compared with assessment using monitoring devices, the former was assessed as more important than the latter in the AHP results. Furthermore, scenario-based team training and procedure-focused individual practice were evaluated as relatively important teaching methods, while practical examination using a checklist was deemed the most appropriate evaluation method for all learning content. Conclusion: To improve the patient assessment curriculum, we propose adjusting teaching hours and introducing new teaching and evaluation methods based on the results of relative importance. The proposed improvement plan will contribute to enhancing the competency of 119 EMTs.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.2
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• pp.69-80
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• 2024

In this paper, we studied a discrete-time queuing system that operates under a mixed situation of D-policy and T-policy, one of the representative server control policies in queuing theory. A single server serves customers arriving by Bernoulli arrival process on a first-in, first-out basis(FIFO). If there are no customers to serve in the system, the server goes on vacation and returns, until the total service time (i.e., total amount of workload) of waiting customers exceeds predetermined workload threshold D. The operation of the system covered in this study can be used to model the efficient resource utilization of mobile devices using secondary batteries. In addition, it is significant in that the steady state waiting time and system sojourn time of the queuing system under a flexible mixed control policy were derived within a unified framework.