• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.541-550
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• 2021

While open-air compost has value as a source of nutrients for crops in agricultural land, it acts as a pollution that adversely affects the environment during rainfall, and management is required. In this study, it was intended to analyze the accuracy of calculating open-air compost volume using fixed-wing UAV (unmanned aerial vehicle) capable of acquiring a wide range of images and automatic path flights and to identify the possibility of utilization. In order to evaluate the accuracy of calculating the three open-air compost volume, ground LiDAR surveys and precision surveys using a rotary UAV were performed. and compared with the open-air compost volume acquired through a fixed-wing UAV. As a result of comparing the calculation of open-air compost volume based on the ground LiDAR, the error rate of the rotary-wing was estimated to be ±5%, and the error rate of fixed-wing was -15 ~ -4%. one of three open-air compost volume calculated by fixed-wing was underestimated as about -15 %, but the deviation of the open-air compost volume was 2.9 m3, which was not significant. In addition, as a result of periodic monitoring of open-air compost using fixed-wing UAV, changes in the volume of open-air compost with time could be confirmed. These results suggested that efficient open-air compost monitoring and non-point pollutants in agricultural for a wide range using fixed-wing UAV is possible.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.6
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• pp.235-242
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• 2021

In this work, we develop a Korean dependency parser based on a stack-pointer network that consists of a pointer network and an internal stack. The parser has an encoder and decoder and builds a dependency tree for an input sentence in a depth-first manner. The encoder of the parser encodes an input sentence, and the decoder selects a child for the word at the top of the stack at each step. Since the parser has the internal stack where a search path is stored, the parser can utilize information of previously derived subtrees when selecting a child node. Previous studies used only a grandparent and the most recently visited sibling without considering a subtree structure. In this paper, we introduce graph attention networks that can represent a previously derived subtree. Then we modify our parser based on the stack-pointer network to utilize subtree information produced by the graph attention networks. After training the dependency parser using Sejong and Everyone's corpus, we evaluate the parser's performance. Experimental results show that the proposed parser achieves better performance than the previous approaches at sentence-level accuracies when adopting 2-depth graph attention networks.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.68-75
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• 2022

In this study, in order to directly evaluate the prestress of the PSC structure, a new sensor module based on the measurement of the deformation of concrete was proposed using hetero-core optical fibers and performance tests were performed. In a hetero-core optical fiber, optical loss occurs when a specific part of the transmission path is bent, and the amount of optical loss changes linearly according to the magnitude of the curvature. In order to confirm the measurement performance of the sensor module and the applicability of the optical fiber, the sensor module was deformed and the light passing through the optical fiber was converted into wattage and measured. It can be seen that the light passing through the optical fiber has a linearity of 0.9333 in relation to the deformation while generating the maximum deformation of 0.5 mm at a rate of 0.12 mm/min in a cylindrical concrete specimen with a diameter of 15 cm and a height of 35 cm in which the sensor module is embedded. Based on the results of this experiment, it is judged that it is possible to directly evaluate the prestress of a PSC structure by embedding a sensor module using a hetero-core optical fiber in the structure and measuring the compression deformation in concrete. It is judged that it can be used as useful data for the development of a sheath tube integrated sensor module to be applied to be applied to the girder model experiment.

• Journal of Creative Information Culture
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• v.7 no.4
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• pp.187-196
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• 2021

This study was conducted as a study on the SW career education of students from underprivileged areas, which is a necessary condition for SW education to become a universal education or where research has not been conducted. Therefore, this study conducted a SW career selection model using structural equations for 2,231 students in grades 3 to 6 in 6 schools located in the marginalized areas of eup/myeon. As a result of the study, it was analyzed that the intrinsic SW learning motive of students from underprivileged areas did not affect their SW career choice, whereas the external SW learning motive was analyzed to affect their SW career choice. This is inferred that the intrinsic SW learning motive does not affect the SW career choice due to the lack of SW experience of students in underprivileged areas. The correlation between internal and external SW learning motivation was analyzed to be significant. In the future, as students from the underprivileged class have more SW education experiences, research should be conducted on how internal SW learning motives affect SW career choice and how external SW learning motives support internal SW learning motives.

• Korean Journal of School Psychology
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• v.17 no.1
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• pp.109-123
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• 2020

The purpose of this study was to understand path of internal narcissism toward SNS addiction tendency of middle school students. The study intended to test the hypothesis that internal narcissism personality would lead to the SNS addiction tendency through interpersonal problems and that the internal narcissism effect on the interpersonal problems can depend on Gender difference The subjects of the study were 240 middle school students (95 male and 145 female students) in Gwangju area. The descriptive statistics, correlation analysis, and SPSS Macro PROCESS Model were used. The results of the study are as follows. First, there was a significant positive interpersonal problems mediation efffect between inner narcissism and SNS addiction tendency of middle school students. Second, as a result of examining Gender difference moderatiing effect between internal narcissism, and interpersonal problems relationship. according to gender difference statistically significant. Third, Moderated mediation effect of gender difference and interpersonal problems between internal narcissism personality and SNS addiction tendency relationship is statistically significant. Recently, social networking has become a serious problem in our society and it shows the highest rate of addiction in early middle school students. The purpose of this study was to investigate the effects of psychological factors of inner narcissism and interpersonal problems on the SNS addiction tendency, focusing on the gender differences in middle school students, and to provide basic data to prevent adolescent SNS addiction problems have.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.153-170
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• 2022

Waterjet has been comprehensively used in urban areas owing to a suitable technique for cutting concrete and rock, and low noise and vibration. Recently, the abrasive waterjet technique has been adopted and applied by the Korea Atomic Energy Research Institute to demolish concrete plugging without disturbing and damaging In-situ Demonstration of Engineered Barrier System in the disposal research tunnel. In this study, the use of abrasive waterjet in the tunnel was evaluated for practical applicability and the existing cutting model was compared with the experimental results. As a variable for waterjet cutting, multi-cutting, water flow rate, abrasive flow rate, and standoff distance were selected for the diversity of analysis. As regarding the practical application, the waterjet facilitated path selection for cutting the concrete plugging and prevented additional disturbances in the periphery. The pump's noise at idling was 64.9 dB which is satisfied with the noise regulatory standard, but it exceeded the standard at ejection to air and target concrete because the experiment was performed in the tunnel space. The experimental result showed that the error between the predicted and measured cutting volume was 12~13% for the first cut and 16% for second cut. The standoff distance had a significant influence on the cutting depth and width, and the error tended to decrease with decrement of standoff distance.

• Education of Primary School Mathematics
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• v.24 no.3
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• pp.135-156
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• 2021

Achievement pressure and enthusiasm affecting mathematics academic achievement are constantly changing and affecting academic achievement. Therefore, a longitudinal study is needed to examine the influence of the change patterns of teachers' achievement pressure and enthusiasm on the change patterns of academic achievement. This study utilized student data from the 5th grade of elementary school (2013 year) to the third grade of middle school (2017 year) of the Korean Education Longitudinal Study 2013. The longitudinal change patterns of mathematics academic achievement were classified into similar subgroups and the influence of the longitudinal change patterns of the achievement pressure and enthusiasm of each group on the longitudinal change pattern of mathematics academic achievement and the path were compared and analyzed. As a result of the analysis, in all four subgroups with similar longitudinal changes in mathematics academic achievement, the teacher's achievement pressure showed little change from the fifth grade, while the teacher's enthusiasm continued to decline from the fifth grade. In addition, the influence of teachers' achievement pressure and enthusiasm perceived by students in each group on mathematics academic achievement was different. This suggests that in order to improve mathematics academic achievement, it is necessary to support teaching and learning reflecting the characteristics and dispositions of students.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.381-390
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• 2020

This purpose of study was to influence of fitness club leader's emotional labor on job involvement and occupation performance. This study aims at providing fundamental data and information on fitness club leader's emotional labor. The survey was done through 250 copies and excluding 23 copies ran an analysis on the remaining 227(90.8%) copies. After question investigating the data which is collected used IBM SPSS statistics 21 and IBM AMOS 21 program, frequency analysis, Exploratory factor analysis and confirmatory factor analysis, convergent validity, discriminant validity, Cronbach's α, correlation analysis, path analysis through Structural Equation Model(SEM). The result of this study were as follows. First, fitness club leader's emotional labor showed (-) effects on job involvement. Second, fitness club leader's emotional labor showed (-) effect on occupation performance. Third, job involvement showed (+) effects on occupation performance. Fitness instructors have severe emotional labor. Therefore fitness instructors manage their emotional labor. This can increase job commitment and job performance. For teeth manager need to increase support options from fitness instructors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1106-1115
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• 2021

In this study, a fin that controls ship stern flow was attached on stern hull of a 80k bulk carrier to improve resistance performance. The rectangular cross-sectional fin was attached at several locations on the hull, and angle to streamline was changed with constant length, breadth, and thickness. The resistance performance and wake on propeller plane of the hull with and without the fin were analyzed using model-scale computational fluid dynamics simulation. The analysis results were extrapolated to full-scale to compare the performance and wake of the full-scale ship. First, the fin changed path of bilge vortex that flowed into the propeller along the stern hull without the fin to transom stern. This change increased pressure of the stern hull and upper region of the propeller, so pressure resistance and total resistance of the hull were reduced - the nearer the fin location to after perpendicular (AP) and base line of the hull, the larger the reduction of the resistances. Second, nominal wake fraction of the hull with the fin was lower than that without the fin. This dif erence was in proportion to the angle of the fin, but the total resistance reduction was in proportion until a certain angle at which the reduction was maximum. The largest total resistance reduction was approximately 2.1% at 12.5% of length between perpendiculars from the AP, 10% of draft from the base line, and 14° with respect to the streamline.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.55-65
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• 2022

Recently, deep learning-based automated systems for identifying and detecting landmarks have been proposed. In order to train such a deep learning-based model without overfitting, a large amount of image and labeling data is required. Conventionally, an experienced reader manually identifies and labels landmarks in a patient's image. However, such measurement is not only expensive, but also has poor reproducibility, so the need for an automated labeling method has been raised. In addition, in the X-ray image, since various human tissues on the path through which the photons pass are displayed, it is difficult to identify the landmark compared to a general natural image or a 3D image modality image. In this study, we propose a geometric data augmentation technique that enables the generation of a large amount of labeling data in X-ray images. In addition, the optimal attention mechanism for landmark detection was presented through the implementation and application of various attention techniques to improve the detection performance of 16 major landmarks in the skull. Finally, among the major cranial landmarks, markers that ensure stable detection are derived, and these markers are expected to have high clinical application potential.