• Journal of Korea Multimedia Society
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• v.25 no.3
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• pp.546-557
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• 2022

Recently, the demand to interpret image data with artificial intelligence in various fields is rapidly increasing. Object recognition and detection techniques using deep learning are mainly used, and video integration analysis to determine unstructured object recognition is a particularly important problem. In the case of natural disasters or social disasters, there is a limit to the object recognition structure alone because it has an unstructured shape. In this paper, we propose intelligent video integration analysis system that can recognize unstructured objects based on video turning point and object detection. We also introduce a method to apply and evaluate object recognition using virtual augmented images from 2D to 3D through GAN.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.121-129
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• 2022

In this paper, the virtual environment using rack server type HPC and 3U VPX server type HPC was applied and tested to the basic functions of the Jangbogo-III class submarine combat system developed for the first time in Korea. Based on this test results, the possibility of applying virtualization to the domestic submarine combat system to be developed in the future is confirmed. Existing studies have been limited to deriving applicable virtualization solutions through simple performance analysis of virtualization solutions or applying virtualization to some functions of the surface ship combat system, but in this paper, the application of virtualization is expanded to the submarine combat system through testing.

• Korean Journal of Childcare and Education
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• v.19 no.2
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• pp.119-141
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• 2023

Objective: This study aimed to investigate Pre-service early childhood teachers' perceptions and roles regarding young children's free play time. Methods: The study utilized the photovoice method and involved 21 pre-service early childhood teachers who expressed interest in participating. Participants were enrolled in an infants teaching methodology class in B city. The study involved four virtual meetings conducted via untact teams, and the automatic recordings of these meetings were transcribed for analysis. Results: The results revealed that pre-service early childhood teachers recognized young children's free play time as a period to enjoy full freedom, develop as the main agent of their lives, and express their imagination. Furthermore, pre-service early childhood teachers perceived their roles during young children's free play time as a specialist infant observer, a connector between play and learning, and a versatile supporter. Conclusion/Implications: The findings suggest the need for a systematic curriculum to provide pre-service early childhood teachers with a balanced perspective and awareness of the meaning of free play and teacher roles. The study highlights the importance of expanding pre-practice courses for observation of play and field-oriented curriculum for incumbent teachers.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.3
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• pp.146-154
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• 2023

Efforts have been made to reduce the greenhouse gas emissions from ships by limiting the energy efficiency index, and net zero CO₂ emission was proposed recently. The most ideal measure to achieve zero emission ship is electrification, and fuel cells are considered as a practical power source of the electrified propulsion system. The electric efficiency in the electrochemical reaction of fuel cells can be achieved up to 60% practically. The remaining energy is converted to heat energy but most of them are dissipated by cooling. In the author's previous research, a hybrid propulsion system utilizing not only electricity but also heat was introduced by combining electric motor and steam turbine. In this article, long term efficiency is evaluated for the introduced hybrid propulsion system by considering a virtual 24,000 TEU class container carrier model. To reflect a more practical operating condition, the actual navigation data of a similar real ship in the real world were collected from automatic identification system data and applied. From the result, the overall efficiency of the hybrid propulsion system is expected to be higher than a conventional electric propulsion fuel cell ship by 30%.

• The korean journal of orthodontics
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• v.42 no.6
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• pp.280-290
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• 2012

Objective: This study aimed to compare the effects of conventional and orthodontic mini-implant (OMI) anchorage on tooth movement and arch-dimension changes in the maxillary dentition in Class II division 1 (CII div.1) patients. Methods: CII div.1 patients treated with extraction of the maxillary first and mandibular second premolars and sliding mechanics were allotted to conventional anchorage group (CA, n = 12) or OMI anchorage group (OA, n = 12). Pre- and post-treatment three-dimensional virtual maxillary models were superimposed using the best-fit method. Linear, angular, and arch-dimension variables were measured with software program. Mann-Whitney U-test and Wilcoxon signed-rank test were performed for statistical analysis. Results: Compared to the CA group, the OMI group showed more backward movement of the maxillary central and lateral incisors and canine (MXCI, MXLI, MXC, respectively; 1.6 mm, p < 0.001; 0.9 mm, p < 0.05; 1.2 mm, p < 0.001); more intrusion of the MXCI and MXC (1.3 mm, 0.5 mm, all p < 0.01); less forward movement of the maxillary second premolar, first, and second molars (MXP2, MXM1, MXM2, respectively; all 1.0 mm, all p < 0.05); less contraction of the MXP2 and MXM1 (0.7 mm, p < 0.05; 0.9 mm, p < 0.001); less mesial-in rotation of the MXM1 and MXM2 ($2.6^{\circ}$, $2.5^{\circ}$, all p < 0.05); and less decrease of the inter-MXP2, MXM1, and MXM2 widths (1.8 mm, 1.5 mm, 2.0 mm, all p < 0.05). Conclusions: In treatment of CII div.1 malocclusion, OA provided better anchorage and less arch-dimension change in the maxillary posterior teeth than CA during en-masse retraction of the maxillary anterior teeth.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.71-80
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• 2017

The standards for achievement levels for building blocks in elementary geometry class is to enhance spatial cognitive ability through practices describing shape patterns of building blocks observed from different directions. However, most of building block in the textbook is described from only one perspective. Even worse, some examples in the textbook are almost impossible to observe in the real world. Contrary to this, simulated views by Wings3D has shown that each box may look quite differently from different angles let alone the size of each box. Using Wings3D, it is also very easy to build different types of building blocks with various levels of difficulty in the virtual space. Based on these results, in this study, 3D visualization SW is suggested as a potential pedagogical tool for the elementary geometry class to help kids perceive objects in space more precisely. We have shown that 3D visualization SW such as Wings3D could be a powerful, compact 3D SW for most of subjects which are covered in elementary geometry education. Wings3D has another advantage of economic open source SW fully compatible with school PCs.

• Journal of Korean Elementary Science Education
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• v.43 no.3
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• pp.415-432
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• 2024

This study developed and applied the teacher education model and its principles for science classes using Virtual and Augmented Reality (VR/AR) content and analyzed preservice elementary teachers' feedback on the teacher education model and the changes in their perceptions as to the use of VR/AR content. First, existing Technological Pedagogical Content Knowledge (TPACK) teacher education models and prior studies on the use of the VR/AR contents were reviewed to derive the teacher education model to cultivate the VR/AR-TPACK and set the key principles for each of its stages. The developed teacher education model has five stages: exploration, mapping, collaborative design, practice, and reflection. Second, to examine the appropriateness of the model's five stages and principles, we applied it within the regular course of instruction at the university of education, which was attended by 25 preservice elementary teachers. This study collected data from surveys on the perception of the usage of VR/AR contents before and after the course, as well as the group lesson plans prepared by the preservice teachers, and their feedback on the teacher education model. The feedback on the teacher education model and the survey conducted by the preservice teachers before and after the course were analyzed through open coding and categorization. As a result, most preservice teachers expressed positive opinions about the activities and experiences at each stage of the implementation of the teacher education model. Perceptions related to the usage of the VR/AR content changed in three aspects: first, the vague positive perception of the VR/AR content has changed to a positive perception based on specific educational affordance. Second, they recognized the need for preparedness by anticipating potential problems associated with the use of the VR/AR content. Third, they came to view the VR/AR contents as a useful instructional resource that the teachers could use. Based on these results, we discussed the implications for the VR/AR-TPACK teacher education model and assessed the limitations of the research.

• Journal of Korean Elementary Science Education
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• v.42 no.3
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• pp.399-408
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• 2023

This study developed and applied a maker education program for an elementary school's science unit on 'Animal Life'. It examined the program's impact on students' academic achievement and creative problem-solving ability. The theme of the maker education program was 'creating a robot virtual reality (VR) exhibition hall mimicking animal characteristics'. It explored scientific concepts and creatively created a robot VR exhibition hall in accordance with the TMI maker education model. Findings revealed that the program significantly improved students' academic achievement and creative problem-solving ability (p<.05). This study provides evidence for the effectiveness of maker education in elementary school science classes and suggests that using maker education can increase students' interest in and engagement with science learning. To implement maker education more actively in elementary school science classes, stakeholders should develop various topics and programs. Additional research investigating the effectiveness of maker education in different age groups and various other areas of elementary science education is required to generalize the results of this study. Moreover, educational and teacher capacity building is required for educators to utilize maker education effectively.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.59-72
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• 2023

This study analyzed a group interview with six earth science teachers and eight middle school students to find out the evaluations and criteria they use to evaluate VR/AR contents (two virtual reality content and two augmented reality contents) in middle school science digital textbook. The study found the VR/AR contents were evaluated on four criteria as follows: VR/AR media characteristics; technical operation; user interface; and teaching-learning design. The evaluations can be summarized by each criterion. First, regarding VR/AR media characteristics, interesting features of VR/AR contents were considered relatively advantageous compared to other media like videos. However, its shortage of visual presence and inconvenience of using markers were mentioned as shortcomings. Second, in the technical operation criteria, teachers and students found the following conditions as technically challenging: failing to properly operate on a particular OS; huge volumes of contents in the application; and frequent freezing when using the application. Third, poor intuitiveness and lack of flexibility were found as negative aspects in user interface. Fourth, regarding teaching-learning design, the teachers evaluated whether the VR/AR contents delivered scientifically accurate information; whether they incorporated class goals set by teachers; and whether they can help students' inquiry. It turned out teachers gave negative feedbacks on VR/AR contents. The students evaluated VR/AR contents by assessing whether they help them with learning science but concluded they did not regard them necessary in science learning at school. Based on the findings, this study discusses which development direction VR/AR contents should take to be useful in teaching and learning science.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.273-275
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• 2022

The use of drugs by pregnant women poses a potential risk to the fetus. Therefore, it is essential to classify drugs that pregnant women should prohibit. However, the fetal toxicity of most drugs has not been identified. This takes a lot of time and cost. In silico approaches, such as virtual screening, can identify compounds that may present a high risk to the fetus for a wide range of compounds at the low cost and time. We collected class information of each drug from the hazard classification lists for prescribing drugs in pregnancy by the government of Korea and Australia. Using the structural and chemical features of each drug, various machine learning models were constructed to predict fetal toxicity of drugs. For all models, the quantitative performance evaluation was performed. Based on the attention algorithm, important molecular substructures of compounds were identified in the process of predicting the fetal toxicity of the drug by the proposed model. From the results, we confirmed that drugs with a high risk of fetal toxicity can be predicted for a wide range of compounds by machine learning. This study can be used as a pre-screening tool for fetal toxicity predictions, as it provides key molecular substructures associated with the fetal toxicity of compounds.