• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.3
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• pp.305-316
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• 2021

Construction accidents occur due to a number of reasons-worker carelessness, non-adoption of safety equipment, and failure to comply with safety rules are some examples. Because much construction work is done outdoors, weather conditions can also be a factor in accidents. Past construction accident data are useful for accident prevention, but since construction accident data are often in a text format consisting of natural language, extracting construction hazards from construction accident data can take a lot of time and that entails extra cost. Therefore, in this study, we extracted construction hazards from 2,026 domestic construction accident reports using text mining and performed a seasonal analysis of construction hazards through frequency analysis and centrality analysis. Of the 254 construction hazards defined by Korea's Ministry of Land, Infrastructure, and Transport, we extracted 51 risk factors from the construction accident data. The results showed that a significant hazard was "Formwork" in spring and autumn, "Scaffold" in summer, and "Crane" in winter. The proposed method would enable construction safety managers to prepare better safety measures against outdoor construction accidents according to weather, season, and climate.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.161-171
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• 2021

This paper presents the findings of a comparative study on minimum weight design and sensitivity evaluation using different experimental design methods for the structural design of an active-type deck support frame (DSF) developed for the float-over installation of an of shore plant topside. The thickness sizing variables of the structural members of a passive-type DSF were considered the design factors, and the output responses were defined using the weight and strength performances. The design of the experimental methods applied in the comparative study of the minimum weight design and the sensitivity evaluation were the orthogonal array design, Box- Behnken design, and Latin hypercube design. A response surface method was generated for each design of the experiment to evaluate the approximation performance of the design space exploration according to the experimental design, and the accuracy characteristics of the approximation were reviewed. Regarding the minimum weight design, the design results, such as numerical costs and weight minimization, of the experimental design for the best design case, were evaluated. The Box- Behnken design method showed the optimum design results for the structural design of the passive-type DSF.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.416-423
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• 2021

Drawing upon research in affect and social identity theory, this study examines when and how an individual's trait positive affect (TPA) exerts a significant effect on the person's organizational citizenship behavior directed toward individuals (OCBI). A moderated mediation model was tested by using the data of 293 employees nested in 66 work groups. Results demonstrate that the indirect effect of TPA on OCBI mediated by group identification (GI) is significantly positive only when perceived group positive affect (PGPA) is low, highlighting the substituting role of PGPA in the relationship between TPA and GI. The significant conditional indirect effects at the low level of PGPA suggest that TPA functions as significant, affective resources for enhancing GI and consequently increasing OCBI of the focal member when PGPA is low. By contrast, TPA's role in enhancing GI becomes redundant when PGPA is high. The current analysis reveals potential complementary functions of TPA and PGPA in explaining subsequent identity cognition and individual behavior.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.95-101
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• 2021

The purpose of this study was to investigate the convergence effect of focal vibration stimulation and bilateral upper limb training on the recovery of upper limb function when applied to stroke patients. For 20 stroke patients, divided into an experimental group that performed convergence intervention with focal vibration stimulation and bilateral upper limb training, and a control group who performed only bilateral upper limb training. It was conducted 20 times for 4 weeks, 30 minutes per session. Vibration stimulation was applied to the affected side of the experimental group for 30 minutes during training. Results were measured for the degree of recovery of the affected upper limb function, amount of use on the affected and unaffected sides, the quality and satisfaction in performance on use of both upper limbs. Comparisons were made within groups using a paired-sample t-test and between groups using covariance analysis. As a result of the study, the experimental group showed a significant difference in dexterity and the amount of use on the affected than the control group. The effect size was more than the small effect size in all evaluation items. Through this study, it is thought that the convergence intervention of focal vibration stimulation and bilateral upper limb trainingcan be used clinically as an effective intervention for the recovery of arm function in stroke patients.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.1-9
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• 2021

In the winter forage study, Italian ryegrass(IRG) and barley were selected. In 2018, the dry matter yield of IRG was 16,915kg per ha under the Agrivoltaic System; this was a little more than 16,750kg per ha of outdoors. On the contrary, the dry matter yield of barley was slightly less under the Agrivoltaic System than that of outdoors. In 2019, the dry matter yield under the Agrivoltaic System was 12,062kg per ha for IRG and 12,195kg per ha for the barley; this was 5.4% and 11.5% less than that of outdoors, respectively. In the summer forage study, corn and sorghum×sudangrass were selected. In 2019, the dry matter yield of corn under the Agrivoltaic System was 13,133kg per ha which was 17% less than that of outdoors. The dry matter yield of sorghum×sudangrass was 12,450kg per ha, which was 82.5% of that of outdoors. In 2020, the dry matter yield of corn under the Agrivoltaic System was 8,033kg per ha which was 7.9% less than that of outdoors. The dry matter yield of sorghum×sudangrass was 5,651kg per ha, which was 11.4% less than that of outdoors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.798-809
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• 2020

Evidence-based policymaking and assessments for scientific administration have increased the importance of statistics (data) utilization. Statistics can explain specific phenomena by providing numerical values and are a public resource for national decision making. Due to these inherent attributes, statistics are utilized as baseline and base data for government policy determinations and the analysis of various phenomena. However, compared to the importance, the role of statistics is limited, and statistics are often used as simple abstracts, produced mainly for suppliers, not for consumers' perspectives to create value. This study explores the statistical data and other attributes that can be utilized for policies or research to address the problems mentioned above. The baseline statistical data used in this study is from the Maritime Distress Accident Statistical Yearbook published by the South Korean Coast Guard, and other additional attributes are from text analyses of vessel casualty situation reports from the South Korean Maritime Police. Collecting 56 attributes drawn from the text analysis and executing an EDA resulted in 88 attribute unions: 18 attribute unions had a satisfactory significance probability (p-value < .05) and a strong correlation coefficient above 0.7, and 70 attribute unions had a middle correlation. (over 0.4 and under 0.7). Additionally, to utilize the extra attributes discovered from the EDA politically, a keyword analysis for each detailed strategy of the disaster Preparation basic plan was executed, the utilization availability of the attributes was obtained using a matching process of keywords, and the EDA deducted attributes were examined.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.193-201
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• 2021

The welding has a high proportion of the production and drying of ships or offshore plants. Non-destructive testing is carried out to verify the quality of welds in Korea, radiography test (RT) is mainly used. Currently, most shipyards adopt analog-type techniques to print the films through the shoot of welding parts. Therefore, the time required from radiography test to pass or fail judgment is long and complex, and is being manually carried out by qualified inspectors. To improve this problem, this paper covers a platform for scanning and digitalizing RT films occurring in shipyards with high resolution, accumulating them in management servers, and applying artificial intelligence (AI) technology to detect welding defects. To do this, we describe the process of designing and developing RT film scanning equipment, welding inspection information integrated management platform, fault reading algorithms, visualization software, and testing and verification of each developed element in conjunction.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.200-220
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• 2021

The purpose of this study was to analyze the scope and content of high school textbooks based on the NCS competency unit criteria. The job competency level of hair beauty is included in the range of Level 1 to Level 5 according to the NCS standard. Among all the 40 units of NCS competency units, the number of them which can be acquired at the high school is 30 units. Among them, high school beauty textbooks were published around 19 competency units, 75% of which corresponded. Only about 85% of all the contents were contained in the text book. Based on the analysis contents, the improvement plan of the textbook is as follows. First, textbooks on 11 competency units that can be acquired at the high school level should be published and the professional curriculum with lessons related to this will be expanded at the same time. Second, there is a need for discussion to establish terminology in the field of Cosmetology. Third, it is necessary to improve the quality of the photographic and illustration materials. Fourth, it should be needed to correct typing errors and maintain a consistent editorial format. The results of this study can be used as basic data need to make curriculum and publish textbooks for high school graduates to perform their jobs at the same time as they get a job.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.3
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• pp.141-148
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• 2022

Recently, reinforcement learning combined with deep neural network technology has achieved remarkable success in various fields such as board games such as Go and chess, computer games such as Atari and StartCraft, and robot object manipulation tasks. However, such deep reinforcement learning describes states, actions, and policies in vector representation. Therefore, the existing deep reinforcement learning has some limitations in generality and interpretability of the learned policy, and it is difficult to effectively incorporate domain knowledge into policy learning. On the other hand, dNL-RRL, a new relational reinforcement learning framework proposed to solve these problems, uses a kind of vector representation for sensor input data and lower-level motion control as in the existing deep reinforcement learning. However, for states, actions, and learned policies, It uses a relational representation with logic predicates and rules. In this paper, we present dNL-RRL-based policy learning for transportation mobile robots in a manufacturing environment. In particular, this study proposes a effective method to utilize the prior domain knowledge of human experts to improve the efficiency of relational reinforcement learning. Through various experiments, we demonstrate the performance improvement of the relational reinforcement learning by using domain knowledge as proposed in this paper.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.141-152
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• 2022

As interest increases related to the development of eco-friendly energy, the offshore wind turbine market is growing at an increasing rate every year. In line with this, the demand for an installation vessel with large scaled capacity is also increasing rapidly. The wind turbine installation vessel (WTIV) is a fixed penetration of the spudcan in the sea-bed to install the wind turbine. At this time, a review of the spudcan is an important issue regarding structural safety in the entire structure system. In the study, we analyzed the current procedure suggested by classification of societies and new procedures reflect the new loading scenarios based on reasonable operating conditions; which is also verified through FE-analysis. The current procedure shows that the maximum stress is less than the allowable criteria because it does not consider the effect of the sea-bed slope, the leg bending moment, and the spudcan shape. However, results of some load conditions as defined by the new procedure confirm that it is necessary to reinforce the structure to required levels under actual pre-load conditions. Therefore, the new procedure considers additional actual operating conditions and the possible problems were verified through detailed FE-analysis.