• Geophysics and Geophysical Exploration
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• v.25 no.1
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• pp.26-37
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• 2022

Recently, multiple methods using small aircraft for geophysical exploration have been suggested as a result of the development of information and communication technology. In this study, we introduce the hybrid unmanned aircraft electromagnetic system of the Korea Institute of Geosciences and Mineral resources, which is under development. Additionally, data processing and interpretation methods are suggested via the analysis of datasets obtained using the system under development to verify the system. Because the system uses a three-component receiver hanging from a drone, the effects of rotation on the obtained data are significant and were therefore corrected using a rotation matrix. During the survey, the heights of the source and the receiver and their offsets vary in real time and the measured data are contaminated with noise. The noise makes it difficult to interpret the data using the conventional method. Therefore, we developed a recurrent neural network (RNN) model to enable rapid predictions of the apparent resistivity using magnetic field data. Field data noise is included in the training datasets of the RNN model to improve its performance on noise-contaminated field data. Compared with the results of the electrical resistivity survey, the trained RNN model predicted similar apparent resistivities for the test field dataset.

• Geophysics and Geophysical Exploration
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• v.26 no.4
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• pp.211-228
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• 2023

Ground-penetrating radar (GPR) surveys are commonly used to monitor embankments, which is a nondestructive geophysical method. The results of GPR surveys can be complex, depending on the situation, and data processing and interpretation are subject to expert experiences, potentially resulting in false detection. Additionally, this process is time-intensive. Consequently, various studies have been undertaken to detect cavities in GPR survey data using deep learning methods. Deep-learning-based approaches require abundant data for training, but GPR field survey data are often scarce due to cost and other factors constaining field studies. Therefore, in this study, a deep- learning-based model was developed for embankment GPR survey cavity detection using data augmentation strategies. A dataset was constructed by collecting survey data over several years from the same embankment. A you look only once (YOLO) model, commonly used in computer vision for object detection, was employed for this purpose. By comparing and analyzing various strategies, the optimal data augmentation approach was determined. After initial model development, a stepwise process was employed, including box clustering, transfer learning, self-ensemble, and model ensemble techniques, to enhance the final model performance. The model performance was evaluated, with the results demonstrating its effectiveness in detecting cavities in embankment GPR survey data.

• Journal of The Korean Association For Science Education
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• v.26 no.2
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• pp.246-257
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• 2006

TIMSS (Trends in International Mathematics and Science Study) aims to produce reliable and internationally comparable indicators of student achievement. The TIMSS science achievement scale summarizes student performance on test items designed to measure a wide range of student knowledge and proficiency. This study analyzed Korean middle school students' science achievement at the advanced and high international benchmarks of the four benchmark levels of the benchmarks classified in TIMSS 2003 in light of science content areas (physics, chemistry, biology, earth science, and environmental science) and item characteristics. The average percent correct on items at the advanced benchmark by Korean students was highest in physics followed by earth science, biology, chemistry, and environmental science, whereas internationally the order was earth science, chemistry, biology, physics and lastly environmental science. Korean students performed relatively better in physics yet somewhat worse in chemistry than other top-performing countries. According to item analysis, Korean students reaching the advanced international benchmark understood some fundamentals of scientific investigation, but demonstrated weakness in written explanations of scientific principles, abstract science concept comprehension, and application of scientific concepts to solve quantitative problems. In addition, Korean students reaching the high international benchmark demonstrated relative weak conceptual understanding of ecology compared with other countries.

• Journal of Digital Contents Society
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• v.13 no.3
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• pp.359-371
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• 2012

The coffee market has been rapidly growing up recently as well as the coffee industry which makes the number of educational institutions increasing in Korea. On the other hand, the classes lean too much on the practical exercise so the coffee education is urgently needed to define precisely and systematize academically. This study is accomplished on the basis of the teachers and students requirement analysis. The features that sets this study apart from the existing educational digital media is that the definite teaching-learning methods and teaching strategies were developed first. Furthermore, the physical and chemical phenomenon of coffee brewing were simulated by 3D animation software based on the visual languages. The general process of this media production was composed by the mutual relationship of the teacher's needs, educationist's strategies and media producer. After applying the digital media to students in the lesson of coffee science theory it was effective to increase their concentrativeness, interesting and learning motive. This media is also receiving the positive evaluation by the teachers to help the students in understanding the coffee science.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.154-160
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• 2007

The 'spatial sense' means an intuitive feel for one's surroundings and the objects in them. The early childhood is an important period to develop the 'spatial sense'. For young children, motion is a major way of extending their spatial awareness. Consequently, an important step in spatial sense instruction involves getting the children moving. This paper proposes four motion based-contents for improving the spatial sense of young children: a bubble game, a cyber goalkeeper game, a mud-huddle game, and a shape recognition game, The proposed four games are implemented to the virtual learning environments. Also, the virtual learning environments utilize the realistic interfaces which can recognize motions of young children and then interact with the games as they do the movement at the virtual environments provided. Using the realistic interfaces not only develops young children's spatial sense but also offers them the pleasure and interest of self-study.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.260-267
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• 2008

The portfolio provides a method which can properly evaluate the student's long term period of learning and growth, and this allows students to have practical learning through self-reflection. However, following the realities of portfolio's operation, the portfolio is being operated formally just once only for the evaluation due to the difficulty of long custody and its time-consuming process. In this paper, after grasping the overall process of learning and the result of growth, we design the 'e-portfolio' which combines both learning and evaluation in order to minimize the physical constraint factors along with operating portfolio. After operating our newly designed 'e-portfolio' based on blog in order to verify it's effect, we found the meaningful changes in student's academic achievement and the positive possibility of its application to teachers. Therefore, with the operation of our suggested 'e-portfolio', we are expecting progressed and integrated portfolio education which combines the function of the learning and the evaluation.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.2
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• pp.49-72
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• 2018

The purpose of this study is to analyze the structure, and contents of the US national school library standards presented in the document National School Library Standards for Learner, Librarian and School Libraries made by AASL, and to provide basic information to refer to the direction and contents of Korean school library standards. AASL's National School Library Standards provide Learner Standards, School Librarian Standards, School Library Standards and Standards Integrated Frameworks that incorporate three previous standards, and emphasize the growth of learners and school librarians' competency by focusing on the educational activities of learners and school librarians. With the physical environment of the school library being somewhat established, it is necessary to establish standards for the educational content and competency of learners and teachers. And it is necessary to pay more attention to the materials including the contents of education.

• Journal of the Korea Computer Graphics Society
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• v.27 no.3
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• pp.13-23
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• 2021

In this paper, we proposed a framework that generates the trajectory of a single rigid body based on its COM configuration and contact pose. Because we use a smaller input dimension than when we use a full body state, we can improve the learning time for reinforcement learning. Even with a 68% reduction in learning time (approximately two hours), the character trained by our network is more robust to external perturbations tolerating an external force of 1500 N which is about 7.5 times larger than the maximum magnitude from a previous approach. For this framework, we use centroidal dynamics to calculate the next configuration of the COM, and use reinforcement learning for obtaining a policy that gives us parameters for controlling the contact positions and forces.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.4
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• pp.277-286
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• 2002

Most of the problems in dealing with the tunnel construction are the uncertainties and complexities of the stress conditions and rock strengths in ahead of the tunnel excavation. The limitations on the investigation technology, inaccessibility of borehole test in mountain area and public hatred also restrict our knowledge on the geologic conditions on the mountainous tunneling area. Nevertheless an extensive and superior geophysical exploration data is possibly acquired deep within the mountain area, with up to the tunnel locations in the case of alternative design or turn-key base projects. An appealing claim in the use of artificial neural networks (ANN) is that they give a more trustworthy results on our data based on identifying relevant input variables such as a little geotechnical information and biological learning principles. In this study, error back-propagation algorithm that is one of the teaching techniques of ANN is applied to presupposition on Rock Mass Ratings (RMR) for unknown tunnel area. In order to verify the applicability of this model, a 4km railway tunnel's field data are verified and used as input parameters for the prediction of RMR, with the learned pattern by error back propagation logics. ANN is one of basic methods in solving the geotechnical uncertainties and helpful in solving the problems with data consistency, but needs some modification on the technical problems and we hope our study to be developed in the future design work.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1883-1892
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• 2015

TRIZ is a theory of inventive problem solving. Recently the importance of creative capabilities is being emphasized and many successful cases using TRIZ are being introduced, therefore interest in TRIZ has been increasing. But TRIZ is not easy to learn alone compared to other creative thinking tools. Although it is effective to learn TRIZ through various cases, it is not easy for beginners to experience those many cases. Therefore, we developed a software called Do-TRIZ for TRIZ learning. Do-TRIZ provides descriptions and various examples of key concepts to make it easier for beginners to learn TRIZ. Also, the learners can add new cases continuously on Do-TRIZ. Especially, process-based problem solving modules have been implemented on Do-TRIZ, in order to make it possible to solve problems based on technical contradiction, physical contradiction, and IFR(Ideal Final Result). The learners can use the modules to solve their problems and to share the results. Also, we implemented Do-TRIZ Memo app that works with Do-TRIZ.