• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.314-323
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• 2022

Vessel Traffic Services (VTS) operators perform traffic management tasks using VTS systems and sensor equipment designated as VTS facilities to promote the safety and efficiency of vessel traffic. The necessary VTS information for effective operations could be obtained through the additional access of various information channels other than the designated VTS facility. To unify these various information access windows, the development of the VTS cloud system is in progress. In this study, the operational information analysis for VTS was performed through VTS tasks-facility linkage analysis to identify the user required information according to the introduction of the VTS cloud system. The VTS task analysis was performed through research of the international and domestic literature, and expert interviews. The necessary information were identified and linked according to the VTS facilities. As a result of the analysis, 37 categories of necessary information were identified for internal and external information windows, and 8 information windows were selected other than the present VTS equipment. The identified user requirements would be applied to the structure design of the VTS cloud system. In the future, it is necessary to update user requirements through scenario-based user operation analysis and to conduct additional research on the system interface design.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1013-1022
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• 2022

Recently, with the worldwide development of the fourth industry, the development of technologies for smart and eco-friendly ships is accelerating. With the emergence of autonomous vessels with complete unmanned or minimum personnel on board and eco-friendly fuel (methane, ammonia, electricity, etc.), the role of existing seafarers on board is expected to change significantly. To improve the competitiveness of seafarers in the future, predicting future seafarer occupation groups, improving the educational curriculum, and creating an educational system are necessary. In this study, eight occupational groups that seafarers may have in the future were derived through a review of earlier studies and brainstorming of maritime university students, incumbent seafarers and expert groups. A survey was conducted on the eight occupational groups using the Likert scale, and based on the results, a leading occupational group related to future seafarer was derived. The most likely occupational groups with high scores were remote control centre operators and cargo remote manager. In addition, essential educational elements to be educated first for these occupational groups were derived and presented.

• Journal of agricultural medicine and community health
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• v.47 no.3
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• pp.154-165
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• 2022

Objectives: The purpose of this study was to examine the success factors for the development of health community organizing in regard to its perspective in: 148 village, Gangbuk-gu, Seoul. Methods: We conducted a qualitative study using in-depth interviews from February 2020 to December 2021. Seven operators who had worked for the project were enrolled in this study. Results: In this study, the success factors for the development of health community organizing were analyzed as follows; building community relationships across generations; starting from interests of the community; belief that working together can solve the issues; external support based on spontaneity of community; project based on publicness; discovering community-based leadership. Conclusions: This study suggested that health community organizing following the principle of community organizing can sustain and develop itself without external support. In order to develop into resident-oriented health community organizing, it is necessary to reflect the success factors derived from this study.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.903-911
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• 2022

Groundwater, one of the resources for supplying water, fluctuates in water level due to various natural factors. Recently, research has been conducted to predict fluctuations in groundwater levels using Artificial Neural Network (ANN). Previously, among operators in ANN, Gradient Descent (GD)-based Optimizers were used as Optimizer that affect learning. GD-based Optimizers have disadvantages of initial correlation dependence and absence of solution comparison and storage structure. This study developed Gradient Descent combined with Harmony Search (GDHS), a new Optimizer that combined GD and Harmony Search (HS) to improve the shortcomings of GD-based Optimizers. To evaluate the performance of GDHS, groundwater level at Icheon Yullhyeon observation station were learned and predicted using Multi Layer Perceptron (MLP). Mean Squared Error (MSE) and Mean Absolute Error (MAE) were used to compare the performance of MLP using GD and GDHS. Comparing the learning results, GDHS had lower maximum, minimum, average and Standard Deviation (SD) of MSE than GD. Comparing the prediction results, GDHS was evaluated to have a lower error in all of the evaluation index than GD.

• Journal of Practical Engineering Education
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• v.14 no.2
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• pp.405-411
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• 2022

In this study, K-Digital Training program, which is a representative government project of vocational training for new digital technologies in response to the 4th industrial revolution, is analyzed and an improvement model is suggested. The K-Digital training project is rapidly expanding, with the number of training operators increasing by 7.1 times and training course programs by 8.5 times within three years of implementation, but there is a severe problem in that education and training programs are concentrated in the metropolitan. To solve this problem, a shared training model is proposed. This model is a plan to maximize the use of local human and material resources, to respond to new digital technologies through systematic composition and operation, and to enhance the stability and reliability of education and training. In each region, a sharing and cooperation model in the form of a consortium is established that jointly utilizes resources scattered by various training institutions such as instructors, training contents, and training infrastructure related to digital new technology. In addition, a training certification evaluation system is introduced to increase the credibility of the rapidly developing digital new technology training.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1054-1062
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• 2022

The population of Korea's solar salt-producing regions is rapidly aging, resulting in a decrease in the number of productive workers. In solar salt production, salt collection is the most labor-intensive operation because existing salt collection vehicles require human operators. Therefore, we intend to develop an unmanned solar salt collection vehicle to reduce manpower requirements. The unmanned solar salt collection vehicle is designed to identify the salt collection status and location in the salt plate via color detection, the color detection performance is a crucial consideration. Therefore, an image processing algorithm was developed to improve color detection performance. The algorithm generates an around-view image by using resizing, rotation, and perspective transformation of the input image, set the RoI to transform only the corresponding area to the HSV color model, and detects the color area through an AND operation. The detected color area was expanded and noise removed using morphological operations, and the area of the detection region was calculated using contour and image moment. The calculated area is compared with the set area to determine the location case of the collection vehicle within the salt plate. The performance was evaluated by comparing the calculated area of the final detected color to which the algorithm was applied and the area of the detected color in each step of the algorithm. It was confirmed that the color detection performance is improved by at least 25-99% for salt detection, at least 44-68% for red color, and an average of 7% for blue and an average of 15% for green. The proposed approach is well-suited to the operation of unmanned solar salt collection vehicles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1627-1634
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• 2021

This paper introduces a low-power compact ADC circuit for analog Convolutional filter for low-power neural network accelerator SOC. While convolutional neural network accelerators can speed up the learning and inference process, they have drawback of consuming excessive power and occupying large chip area due to large number of multiply-and-accumulate operators when implemented in complex digital circuits. To overcome these drawbacks, we implemented an analog convolutional filter that consists of an analog multiply-and-accumulate arithmetic circuit along with an ADC. This paper is focused on the design optimization of a low-power 8bit SAR ADC for the analog convolutional filter accelerator We demonstrate how to minimize the capacitor-array DAC, an important component of SAR ADC, which is three times smaller than the conventional circuit. The proposed ADC has been fabricated in CMOS 65nm process. It achieves an overall size of 1355.7㎛², power consumption of 2.6㎼ at a frequency of 100MHz, SNDR of 44.19 dB, and ENOB of 7.04bit.

• Archives of Craniofacial Surgery
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• v.23 no.4
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• pp.171-177
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• 2022

Background: The treatment of zygoma complex fractures is of crucial importance in the field of plastic surgery. However, surgical methods to correct zygoma complex fractures, including the number of fixation sites, differ among operators. Although several studies have compared two-point and three-point fixation, no comparative research has yet been conducted on one-point versus two-point fixation using computed tomography scans of surgical results. Therefore, the present study aimed to address this gap in the literature by comparing surgical results between one-point and two-point fixation procedures. Methods: In this study, we randomly selected patients to undergo surgery using one of two surgical methods. We analyzed patients with unilateral zygoma complex fractures unaccompanied by other fractures according to whether they underwent one-point fixation of the zygomaticomaxillary buttress or two-point fixation of the zygomaticomaxillary buttress and the zygomaticofrontal suture. We then made measurements at three points-the zygomaticofrontal suture, inferior orbital wall, and malar height-using 3-month postoperative computed tomography images and performed statistical analyses to compare the results of the two methods. Results: All three measurements (zygomaticofrontal suture, inferior orbital wall, and malar height) showed significant differences (p< 0.05) between one-point and two-point fixation. Highly significant differences were found for the zygomaticofrontal suture and malar height parameters. The difference in the inferior wall measurements was less meaningful, even though it also reached statistical significance. Conclusion: Using three parameters in a statistical analysis of imaging findings, this study demonstrated significant differences in treatment outcomes according to the number of fixations. The results indicate that bone alignment and continuity can be achieved to a greater extent by two-point fixation instead of one-point fixation.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.369-375
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• 2022

Due to the so-called COVID-19 pandemic, railway service management has also faced an unprecedented situation over the past. This study conducted a survey of customers using high-speed railways during the COVID-19 pandemic to explore the impact of infectious diseases on the railway service customer experience. As a result, customer satisfaction and loyalty increase as customers are more aware of the quarantine-related services provided by railway operators. The moderating role of customer's COVID-19 risk perception was examined as well because there are individual differences in the level of thinking dangerously about Covid-19. As a result, the perceived level of the service's quarantine-related services has a significant impact on customer satisfaction when the customer's risk perception of Covid-19 is at an appropriate level, but its impact is relatively weak when the customer's risk perception is significantly high. Eventually, only the complete extinction of COVID-19 risk will bring a complete recovery to the service industry. Nevertheless, during the epidemic period, it was confirmed that the main service characteristics are that the service operator thoroughly conducts quarantine activities and faithfully communicates with customers.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.321-330
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• 2022

Busan New Port manages the largest volume of traffic among Korean ports, and accounts for 68.5% of the total volume of the Busan port. Due to this increase in volume, ultra large container ships call at Busan New Port. When the additional south container terminal as well as ongoing construction project of the west container terminal are completed, various encounters may occur at the Busan New Port entrance, which may cause collision risk.s Thus, the purpose of this study was to provide a plan to improve the safety of vessel traffic, in the in/out bound fairway of Busan New Port. For this purpose, the status of arrivals and departures of vessels in Busan New Port, was examined through maritime traffic flow analysis. Additionally, risk factors and safety measures were identified, by AHP analysis with ship operators of the study area. Also, based on the derived safety measures, scenarios were set using the Environmental Stress model (ES model), and the traffic risk level of each safety measure was identified through simulation. As a result, it is expected that setting the no entry area for one-way traffic would have a significant effect on mitigating risks at the Busan New Port entrance. This study can serve as a basis for preparing safety measures, to improve the navigation of vessels using Busan New Port. If safety measures are prepared in the future, it is necessary to verify the safety by using the traffic volume and flow changes according to the newly-opened berths.