• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.1-16
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• 1997

This paper improves the autonomy for supplier's schedule and the flexibility of the final assembly line. The final assembly line is a single work station and each product taking different assembly time is considered. In the assembly schedule, the heuristic method based on the goal chasing method is used. Consequently, suppliers can independently determine their output rates and thus, change their workload pattern according to their needs and priorities. Moreover, this flexibility can help to avoid expensive final-assembly-line stoppages in case of sudden part supply disruptions. The sequencing method can be easily implemented into an existing just-in-time system. In addition, the mathematical model was formulated and the algorithm was explained through the flow chart. The numerical example was given and the efficiency of this method is shown through the analysis of computational results of that example.

• Journal of the Korea Society for Simulation
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• v.11 no.4
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• pp.69-80
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• 2002

This study deals with the productivity improvement on a flow production system with the consideration of line-balancing. In a flow production system, similar product models are produced on a same assembly line, the predefined process order and the limitation of total worker number. The system can be increased the work-in -process(WIP) inventory and the worker's idle time. In this study, the worker assignment model is developed to assign evenly workload of process to each product model in such a manner that each process has the different number of worker. This worker assignment model is the mathematical model that determines worker number in each process such that the idle time of processes is reduced and the utilization of worker is improved. We use a simulation technique to simulate the production line proposed by the mathematical model and apply real production line. With the result of simulation, this study analyzes the propriety of production line and proposes the alternatives of new production line

• Smart Media Journal
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• v.11 no.6
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• pp.30-36
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• 2022

This paper explored the effect of using eye gaze pointer in addition to the hand gesture visual communication cue in remote collaboration. We recruited 24 participants and conducted a user study comparing two conditions: (1) only hand gesture visual communication cue, and (2) eye gaze pointer with hand gesture visual cue. The results showed that the added eye gaze pointer cue reduced the workload and increased the co-presence when using it together with hand gesture cue.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.565-576
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• 2022

The scope and functions of a conversational agent are gradually expanding. In particular, research and technology development is being conducted on a conversational agent that can speak first without user calls. However, still in its early stages, there is a lack of research on how a preceded utterance conversational agent will affect users. Accordingly, this study conducted a 2×3 mixed design using the user's task performance condition and the agent's self-exposure as independent variables and measured Intimacy, Functional Satisfaction, Psychological Reactance, and Workload as dependent variables to identify the effects of preceded utterance conversational agent on user experience.

• Journal of Korean Academy of Rural Health Nursing
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• v.18 no.1
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• pp.27-39
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• 2023

Purpose: This study is a mixed methods research that was conducted to verify factors affecting the working experience of community-based long-term care hospital workers during the COVID-19 pandemic. Methods: The study was carried out from July 19 to November 3, 2021 for 340 nurses who worked at 10 long-term care hospitals located in G city. Results: As the study results, factors that affected job stress of the workers working at community-based long-term care hospitals included job satisfaction (β=-.27, p<.001), work demand (β=-.25, p<.001), fatigue (β=.19, p=.001), and cooperation and leadership (β=-.12, p=.049). It was found that the participants were struggling with physical and mental stress caused by the increased workload due to the preventative measures taken to stop the infection and spread of COVID-19. Despite this, they accepted their situation as necessary to overcome the pandemic and shared the quarantine guidelines of the government and community health centers while actively responding to prevent the spread of COVID-19 under the leadership of their supervisors. However, they were experiencing psychological and emotional burnout in the prolonged pandemic situation. Conclusion: It is considered necessary to help relieve their stress and provide psychological and mental support by adopting a policy to develop and apply comprehensive programs.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.2
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• pp.37-48
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• 2014

Fighter squadron flight scheduling is the integrated air operation plan that is an important role for improving pilot's flight skill and maintaining combat readiness by efficient using available all air resources including pilot, aircrafts, air-weapons, fuel and supporting facilities etc. Korea airforce, however, has a limit as to an effective flight operation due to manual flight scheduling with scheduler's own experience and intuition. Therefore, in our study, we propose the optimization model of flight scheduling based on mixed integer programming. This model includes several constraints of realistic and essential quantified data related with flight schedule and can assign appropriate pilots optimally which are distinctive three type's solutions : flight, alert and duty crew schedules. Proposed solution method can be improved pilot's capability and allocated further air resources systematically and efficiently. In addition, it can be reduced a workload of flight scheduler and minimized obstructed factors of flight safety. Finally, we demonstrate the experiment's results for the check of efficiency and validity of this model.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.5
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• pp.265-272
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• 2022

As the risk of lung cancer has increased, early-stage detection and treatment of cancers have received a lot of attention. Among various medical imaging approaches, computer tomography (CT) has been widely utilized to examine the size and growth rate of lung nodules. However, the process of manual examination is a time-consuming task, and it causes physical and mental fatigue for medical professionals. Recently, many computer-aided diagnostic methods have been proposed to reduce the workload of medical professionals. In recent studies, encoder-decoder architectures have shown reliable performances in medical image segmentation, and it is adopted to predict lesion candidates. However, localizing nodules in lung CT images is a challenging problem due to the extremely small sizes and unstructured shapes of nodules. To solve these problems, we utilize atrous spatial pyramid pooling (ASPP) to minimize the loss of information for a general U-Net baseline model to extract rich representations from various receptive fields. Moreover, we propose mixed-up attention mechanism of reverse, boundary and convolutional block attention module (CBAM) to improve the accuracy of segmentation small scale of various shapes. The performance of the proposed model is compared with several previous attention mechanisms on the LIDC-IDRI dataset, and experimental results demonstrate that reverse, boundary, and CBAM (RB-CBAM) are effective in the segmentation of small nodules.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.3-13
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• 1993

This study was conducted at seven degreasing processes in plating plants located in Seoul, Incheon, Ansan, and Taejeon areas from July 21 to august 27, 1992. This study was performed to assess the TWA exposures to trichloroethylene (TCE) and evaluate factors affecting TCE concentrations in degreasing process. Two-Point Eddy Diffusional Model suggested by Wadden et al. was employed to calculalte emission factors according to degreaser type. Results are summarized as follows. 1. The TWA exposures of the degreasing operators ranged from 1.4 ppm to 123 ppm, and those of three plants out of seven were exceeding 50 ppm of both the Korean and U.S. OSHA standards. Degreasing assistant of Plant B, was exposed to 59 ppm. 2. The average concentrations at the distance 0, 1.5, 3.0 m from the degreasers were 1.014, 24, and 18 ppm, respectively, and showed a signifficant difference by distance (p<0.01). 3. The emission of TCE was reduced by installing local exhaust systems, condensers, and refrigeration lines at the degreasers (p<0.01). 4. The major factors related to exposure of operators were workload (r=.9621. p<0.01) and dimensions of degreansing room(r=-.8667, p<0.05). 5. If the air in degreasing room is mixed violently by other factors in addition to diffusion, the emission factors can not be evaluated because the important hypothesis of the Two-Point Eddy Diffusional Model can not be accepted. 6. The ultrasonic degreaser without the local exhaust ststem, condenser, and refrigeration lines emitted TCE three times greater than the ultrasonic degreaser with condenser and refrigeration 1ines only.

• Women's Health Nursing
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• v.22 no.4
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• pp.221-232
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• 2016

Purpose: The purpose of this study was to examine the applicability of a flipped learning course in Women's Health Nursing for nursing students. Methods: A total of 200 senior nursing students participated in flipped learning class of pregnancy, delivery and postpartum area, which included team-based learning and self-reflection for 8 weeks. One group pre-post test design was adopted and the changes in learning motivation and satisfaction were examined. In addition, reflective journals of the students were analyzed by making a qualitative content analysis. Results: Students showed a significant increase in score of learning motivation in the posttest (t=-4.47, p<.001). They had a mean of 3.90 in learning satisfaction out of possible five points. As a result of content analysis, three themes were selected: 'Improved attitude toward active learning', 'Burden caused by excessive workload', and 'Valuing to the team-based activity' To be specific, six sub-themes were selected, with three positive and three negative categories: 'improved class attention and understanding', 'positive class participation by preparing lessons in advance', 'peer interactions through discussion', 'A lot of time and effort consuming', 'stress caused by the burden of preparing lessons', and 'difficulties in cooperative activities'. Conclusion: This study supports and confirms that the flipped learning can be a creative instructional model of positive teaching-learning strategy in clinical nursing courses to enhance students' learning motivation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.4
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• pp.107-121
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• 2017

This study conducted a 3-stage survey and simulation experiment to identify the impact of vehicle platoons on car-following behavior of manually-driven vehicles. Vehicle maneuvering data obtained from driving simulations was statistically analyzed based on three measures including average speed, acceleration noise, and offset to represent the deviation of lateral movements. Results indicate that MV drivers tended to have psychological burden while driving in automated vehicle platooning environments, which resulted in different vehicle maneuvers. It is expected that the outcome of this study would be useful fundamentals in developing various traffic operations strategies for managing mixed traffic stream consisting of MVs and autonomous vehicles.