• Journal of Science Education
• /
• v.45 no.1
• /
• pp.90-104
• /
• 2021

This study conducted an online survey to understand what elementary school teachers think about the learning contents of elementary science education subjects needed to train elementary science teachers suitable for the era of the 4th Industrial Revolution. The results are as follows: First, there were many elementary school teachers who thought that the current learning content of elementary science education was not suitable for the era of the 4th Industrial Revolution and that it needed to modify the learning content. Many of the teachers said that the learning content of the subject did not include the characteristics of the 4th Industrial Revolution, but also did not reflect the changes of the times and remained in the past. Second, the content that elementary school teachers thought was important in training elementary school teachers suitable for the era of the 4th Industrial Revolution was mainly related to the interests and curiosity of students, and scientific experiments or inquiry. On the contrary, the items that they thought should be deleted or reduced included science learning theory, science teaching/learning model, nature of science, and guidance for gifted children. Third, the contents that elementary school teachers thought needed to be added as learning content of elementary science education subjects were SSI education, science education-related social change and future prediction, advanced science technology, STEAM guidance, and integrated education within the science field. Fourth, in order to train elementary school teachers suitable for the era of the 4th Industrial Revolution, the contents that they thought should be introduced first as learning content of elementary science education subjects were SSI education, integrated education within the science field, STEAM guidance, and core competencies. Other contents that need to be introduced were software education, safety education, and project learning methods.

• The Journal of the Korea Contents Association
• /
• v.21 no.11
• /
• pp.135-144
• /
• 2021

Recently, data-driven decision-making technology has become a key technology leading the data industry, and machine learning technology for this requires high-quality training datasets. However, real-world data contains missing values for various reasons, which degrades the performance of prediction models learned from the poor training data. Therefore, in order to build a high-performance model from real-world datasets, many studies on automatically imputing missing values in initial training data have been actively conducted. Many of conventional machine learning-based imputation techniques for handling missing data involve very time-consuming and cumbersome work because they are applied only to numeric type of columns or create individual predictive models for each columns. Therefore, this paper proposes a new data imputation technique called 'Denoising Self-Attention Network (DSAN)', which can be applied to mixed-type dataset containing both numerical and categorical columns. DSAN can learn robust feature expression vectors by combining self-attention and denoising techniques, and can automatically interpolate multiple missing variables in parallel through multi-task learning. To verify the validity of the proposed technique, data imputation experiments has been performed after arbitrarily generating missing values for several mixed-type training data. Then we show the validity of the proposed technique by comparing the performance of the binary classification models trained on imputed data together with the errors between the original and imputed values.

• The Korean Journal of Emergency Medical Services
• /
• v.26 no.3
• /
• pp.161-184
• /
• 2022

Purpose: This study aimed to develop a cardiopulmonary resuscitation training program for firefighters (FD-CPR) to help improve the survival rate after cardiac arrest on the fireground. Methods: The FD-CPR was developed following 3 steps of the FD-CPR instructional design based on the behaviorism theory. The content of the program was validated by a group of 7 experts using the contents validity index (CVI) and through a pilot-test. Results: A scenario consisting of 7 procedures, and a skill performance evaluation tool consisting of 16 questions were developed. The evaluation tool average score for the difficulty test was 41.16% (even) and that for the discrimination test was 0.32 (high). Subsequently, an 80 min training program was developed. As verified by the 7 experts through the CVI, it was as high as 1.0. Conclusion: The FD-CPR developed domestically for the first time in this study was effective in enhancing the CPR performance skills of the firefighters. If FD-CPR is added to the curriculum at the Fire Service Academy educational course for the new firefighters, the CPR performance skills could be maintained. Furthermore, the program can facilitate a better survival rate for colleagues having cardiac arrest on the field.

• Journal of Korea Society of Industrial Information Systems
• /
• v.28 no.1
• /
• pp.57-69
• /
• 2023

In a situation where digital transformation using artificial intelligence is active around the world, the growth of domestic AI companies or AI industrial ecosystems is slow. Where a large amount of government funds related to AI are being invested to overcome the difficult economic situation, systematic research on the effect is insufficient. So, this study aimed to examine the policy effectiveness of the government artificial intelligence solution voucher support project for small and medium-sized enterprises (SMEs) using Propensity Score Matching (PSM) and Difference-in-Differences (DID) on the financial performance of beneficiary companies. For empirical analysis, PSM-DID analysis was performed using sales performance since 2019 for 461 companies with a history of voucher support among the AI SMEs data released by the National IT Industry Promotion Agency. As a result of the analysis, the beneficiary companies' asset growth, salary, and R&D expenses increased overall after government support, and no significant contribution could be confirmed in terms of profits. This study suggests that the voucher policy business directly contributed to the company's growth in the short term, but it requires a certain period of time to generate profits.

• Journal of the Korean Geotechnical Society
• /
• v.38 no.11
• /
• pp.149-161
• /
• 2022

This study selected the indexes for evaluating the damage of the railway embankments due to liquefaction from the earthquake damage cases of railway embankments. The study correlated the selected indexes and the settlement of the embankment crest from the dynamic numerical analysis. Further, the correlation was used to develop a method for evaluating the liquefaction damage to the railway embankment. The damage cases and damage types were analyzed, and referring to the liquefaction damage assessment method for other structures, the embankment height (H), the non-liquefiable layer thickness (H₁), and the liquefaction potential index were selected as indexes for evaluating the damage. The study performed dynamic effective stress analyses on the railway embankment, and the PM4-Sand model was applied as the constitutive liquefaction model for the embankment foundation ground. The model's validity was first verified by comparing it with the existing dynamic centrifugal model test results performed on the railway embankment. Nine sites where the foundation ground can be liquefied were selected from the data of 549 embankments of the Honam High-speed Railway in Korea. Further, dynamic numerical analyses using four seismic waves as input earthquake load were performed for the selected site sections. The numerical analysis results confirmed the correlation between the evaluation indexes and the embankment crest settlement. A method for efficiently evaluating the damage to the embankment due to liquefaction was proposed using the chart obtained from this correlation.

• Journal of the Korean Geotechnical Society
• /
• v.38 no.12
• /
• pp.45-65
• /
• 2022

In this paper, a diaphragm wall that supports soils and rock was modeled using FLAC, a finite difference analysis program, to evaluate the seismic behavior of temporary retaining structures in a deep excavation. The appropriateness of the numerical model was verified by comparing its results with those of the centrifuge test performed in a similar condition. The bending moment distribution along the diaphragm wall shows a very similar tendency, and the maximum acceleration obtained at the backfill and top of the wall shows a difference within 5%. Based on the developed model, a parametric study was conducted in various input earthquake, ground, and excavation conditions. The maximum structural forces and bending moment under earthquake loading were compared with the maximum values during excavation, from which the critical condition that requires a seismic design was roughly sorted out. The maximum bending moment of a wall that retains soil layers increased 17%. Particularly, the axial force of struts located in loose soils increased 32% under 100 years return period of an earthquake event, which strongly is estimated to require seismic design for structural safety.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.34 no.4
• /
• pp.100-108
• /
• 2022

Three-dimensional FEM numerical analysis was performed to understand the behaviors of blocks and piles according to the horizontal load for the block breakwater combined with piles. The Modified Mohr-Coulomb model, the improved version of the Mohr-Coulomb model, was applied for the ground modeling. The cases when the pile is embedded only into the block, embedded to the riprap layer (H = 4.29 cm), and embedded to the ground down to 2H, 3H, and 4H were examined. The results of the laboratory model experiment and the numerical analysis showed similar horizontal resistance force-displacement behaviors. The pile showed rotational behavior up to the embedment depth of 1H~2H and bending behavior in the case of 3H~4H depth embedment. When the embedment depth of the pile is 3H or more, the pile shows a bending behavior, so it can be considered that the pile contributes significantly to the horizontal resistance of the block breakwater. The results of this study will be used for various numerical analyses for real-size structure design.

• The Korean Journal of Applied Statistics
• /
• v.35 no.3
• /
• pp.407-419
• /
• 2022

The semiconductor fabrication process is complex and time-consuming. There are sometimes errors in the process, which results in defective die on the wafer bin map (WBM). We can detect the faulty WBM by finding some patterns caused by dies. When one manually seeks the failure on WBM, it takes a long time due to the enormous number of WBMs. We suggest a two-step approach to discover the probable pattern on the WBMs in this paper. The first step is to separate the normal WBMs from the defective WBMs. We adapt a hierarchical clustering for de-noising, which nicely performs this work by wisely tuning the number of minimum points and the cutting height. Once declared as a faulty WBM, then it moves to the next step. In the second step, we classify the patterns among the defective WBMs. For this purpose, we extract features from the WBM. Then machine learning algorithm classifies the pattern. We use a real WBM data set (WM-811K) released by Taiwan semiconductor manufacturing company.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.26 no.3
• /
• pp.55-63
• /
• 2022

A modular underground arch structure using steel and concrete has been proposed as a structure that has a simple construction process and can effectively resist cross-sectional forces generated during construction and use. Structural behavior of modular underground arch was evaluated about span length less than 15m through 3D structural analysis and test. In general, 2D and 3D structural analysis methods may be applied for structural analysis such as underground arch and tunnels. However, if a 2D or 3D structural analysis method is applied to evaluate the structural safety of a modular underground arch structure, it is difficult to model for structural analysis and it may take an excessively long time to interpret. Therefore, it may not be reasonable as a structural analysis method for considering the structural safety and earth pressure in the design process of a modular underground arch structure. In addition, when a modular underground arch structure is configured for span lengths to which the predetermined cross-section is applicable, it may be reasonable to evaluate only the safety of the structure and cross-section according to the cross-section and load conditions. Therefore, in this study, a structural analysis model using frame elements was proposed for efficient structural safety evaluation. In addition, structural analysis results of the 2D structural analysis model and the simplified analysis model using frame elements were compared, and the structural safety of the modular underground arch structure for a span length of 20m was evaluated with a simplified analysis method.

• Science of Emotion and Sensibility
• /
• v.25 no.1
• /
• pp.103-114
• /
• 2022

Global virtual reality (VR) and augmented reality (AR) markets are growing as VR and AR become a new source of revenue for industries around the world. In the edutech sector, an industry that combines traditional education, research on new innovative educational models and business models are scarce, and improvements are needed in the technology group and business environment to realize edutech in detail. Therefore, this study aims to define the elements strategically required for VR Toon development by comparing and analyzing the characteristics of existing touch panel-based display Toon and VR Toon content experiences. Tablet PC Toon and VR Toon were selected to conduct the research. Thirty people (19 men and 11 women) from their teens through their forties were surveyed using questionnaires. The questionnaires were formulated through a quantitative method by using AttrakDiff with a 7-point scale (-3: negative words to 3: positive words). Qualitative evaluations were also performed addressing nine concepts (satisfaction, novelty, operability, creativity, understanding, education, interest, participation, expressiveness). As a result, the usability test results of educational content using tablet personal computers and VR equipment were analyzed from the viewpoint of user experience to define elements expected to be strategically required for VR Toon development.