• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.2
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• pp.117-124
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• 2019

Parallel sparse solvers are essential for solving large-scale finite element models. This paper introduces the combination of iterative and direct solver that can be applied efficiently to problems that require continuous solution for a subtly changing sequence of systems of equations. The iterative-direct sparse solver combination technique, proposed and implemented in the parallel sparse solver package, PARDISO, means that iterative sparse solver is applied for the newly updated linear system, but it uses the direct sparse solver's factorization of previous system matrix as a preconditioner. If the solution does not converge until the preset iterations, the solution will be sought by the direct sparse solver, and the last factorization results will be used as a preconditioner for subsequent updated system of equations. In this study, an improved method that sets the maximum number of iterations dynamically at the first Krylov iteration step is proposed and verified thereby enhancing calculation efficiency by the frequency domain analysis.

• Journal of Korean Home Economics Education Association
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• v.33 no.3
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• pp.159-171
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• 2021

In order for young people to be interested in tradition, a specialized experience program that can be frequently encountered is needed. We have developed an after-school traditional gift-wrapping design program in relation to the subject of home economics for the purpose of enabling students to become interested in tradition and deepen their traditional knowledge. The research process was comprised of analysis, development, and evaluation. We analyzed the home economics curriculum, authentic designs from blogs and department stores along with books published by gift-wrapping associations, and interviews with three gift wrapping specialists. Contemporary traditional packaging design is not limited to the reproduction of the traditional design but also creates designs that strongly express unique Korean identity using traditional symbol patterns, colors, traditional decorations, and small items along with modern materials. A 16-week after-school program was developed based on the analysis results. After the implementation of the after-school program in a middle school, survey results showed students who were indifferent toward tradition showed interest and acquired a positive image towards tradition.

• Journal of the Korean Chemical Society
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• v.64 no.6
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• pp.429-437
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• 2020

This study investigated a total of 529 integrated science teachers' implementation and changes to apply the curriculum-instruction-assessment. Data was collected through online survey on scientific competencies and skills, teaching-learning and assessment methods, changes of teacher's preparation, topics/materials, teaching-learning, and assessment to apply the curriculum-instruction-assessment as teaching integrated science. The results of the study were as follows: first, in the integrated science class, teachers implemented more on scientific communication and scientific inquiry among scientific core competencies, and analysis and interpretation of data collection and communication among scientific skills. Teachers often taught in lectures and used multiple choice items and short essay for evaluation. Teacher groups with less than 10 years of teaching experience appeared to be less active in teaching scientific core competencies and skills than those with more than 10 years. Second, Teachers have increased more time and efforts to search and to organize various materials in addition to textbooks, and try to integrated concepts in various fields to prepare learning topics and textbooks. Third, even though teachers made little change in implementing the process-oriented assessment, they used instructional strategies to increase student engagement in the integrated science class, restructured the instruction to provide immediate feedback after conducting the assessment. It is necessary to build a system that ensures fairness and credibility of evaluation while respecting the autonomy and professionalism of teachers.

• Journal of the Korea Computer Graphics Society
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• v.27 no.2
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• pp.1-11
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• 2021

In a virtual environment, a 3D workspace and 3D interaction are possible, but most virtual reality applications use a 2D color picker. This paper implements a 3D color picker based on 3D color space in a virtual environment, and compares color selection performance with the existing 2D color picker. The 3D color picker is intuitive by using the 3D color space as it is, and it can position the 3D pointer at a specific point in the color space using a controller, which is a virtual reality device, so a user can select a color in one step. On the other hand, the 2D color picker has the advantage of being familiar with existing users who work with colors in a computer environment, but has a disadvantage that requires several steps of user interaction since it has to set color properties through 2D interfaces. Based on user experiments, we confirmed the usefulness of a 3D color picker in addition to a 2D color picker in a virtual environment, and it was possible to perform natural 3D work in a virtual environment using the 3D color picker.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.32 no.1
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• pp.223-246
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• 2021

Based on the Everyday Information Seeking Behavior Theory, this study investigates information activities and library experience of 66 elderly or people with disabilities in Autonomous District A. In addition, this study analyzes contextual circumstances of daily information activities through in-depth interviews with a subset of 11 people. Although community welfare centers provide basic welfare, the elderly and people with disabilities seek to learn and socialize in cultural welfare centers, particularly in libraries. This study shows that libraries can fulfill their top three of Maslow's hierarchy of needs: Self-Actualization, Esteem, and Love and Belonging. Specifically, digital literacy education has been identified to be highly demanded. They seek to distinguish correct online information and to socialize using digital technologies in this contactless society. This study proposes a detailed plan for public libraries to offer cultural and information welfare in order to reduce the information gap within the local communities.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.67-73
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• 2021

As the impermeable area increases due to urbanization and industrialization, the influence of non-point pollutants caused by rainfall runoff on the water system is increasing. In the past, the best management practices(BMP) were used a lot to manage non-point pollutants, but recently, technology that naturally treats them through LID (Low Impact Development) technology is widely used. In this study, various rainfall events were simulated through the SWMM model based on the data of rainfall monitoring in bioretention among natural facilities. The characteristic of LID modeling research is that it is difficult to build accurate modeling data with short-term data because real data is the result obtained through natural facilities, and it is difficult to implement an accurate model. In this study, the data monitored for 3 years It is significant in that it has built a precise model. The actual data monitored a total of 18 times was simulated, and the inflow and outflow and the removal efficiency of five pollutants were simulated. As a result of performing the performance evaluation, most of the 7 items showed excellent indicators, and the TN and TP showed relatively low simulation performance. In the future, it is expected that Korea will introduce an integrated water management system in which the water supply system and the sewage system are substantially integrated and operated. Therefore, the results of this study are considered to play an important role in the initial stage of rainfall management in the future integrated water management system, and the extent of rainfall runoff reduction and pollutant reduction in the expected installation area can be predicted in advance. This is expected to prevent overdesign of bioretention.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1103-1109
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• 2021

ECS is a control device so that the warship can perform the mission stably by controlling and monitoring the entire propulsion system. As the recent provisions of the warship, it's propelling system is complicated than past, as the demand performance and mission of the warships are diverse. In accordance with the complicated propulsion system configuration, the demand for automatic control function of the ECS is increasing for convenient and stable propulsion system control for convenient and stable. As a result, verification of ECS stability and reliability is required. In this paper, we develop an interlocking signal simulator for verifying ECS control logic and communication protocol for warship with CODLOG propulsion systems. The simulator developed was implemented to simulate a signal of gas turbine, propulsion motors, diesel generator and 11 kinds of auxiliary equipment. The reliability of ECS was verified through the ECS communication program and the I/O signal static test with the simulator.

• 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 Digital Convergence
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• v.20 no.4
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• pp.575-584
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• 2022

The purpose of this study is to derive interaction types that appear variously in immersive contents through John Dewey's empirical theory, and to explore how the derived types are delivered in real cases. For this reason, two cases of the National Museum of Korea 'Immersive Digital Gallery' and 'Arte Museum Jeju' were analyzed through interaction types derived from the empirical theory. The interaction types derived based on the experience theory are the elements of 'multi-sensory', 'simultaneous experience' and 'sensory expansion'. In both cases, these types appear connected rather than grafted one by one in common. In one direction, 'multi-sensory' leads to 'sensory expansion', and in two directions, 'simultaneous experience' leads to 'sensory expansion'. As such, the core types of communication between technology and humans are not delivered one by one, but a cycle of interaction is formed in multiple ways. Therefore, it can be seen that the interaction type of immersive contents is expanded step by step by fusion of various senses and experiences in various fields, rather than a 1:1 partial delivery method. Based on this, it will be necessary to study how types are expanded and how viewers are affected when interaction is implemented in immersive contents in the future.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.209-216
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• 2022

In this paper, we propose an effective software education program to promote employment of the disabled and verify the effectiveness of SW education through pilot operation. In this SW education program, we develop a SW curriculum consisting of the basic course, Unity programming course, and the advanced course, AR/VR digital content development course. The SW education achievement standard develops the basic and advanced course achievement standards in consideration of the level of the virtual reality content production job of the National Competency Standards(NCS) and the SW education achievement standards of youth with visual, hearing, and physical disabilities. SW education materials are developed on a project basis so that one AR/VR digital content can be implemented step by step according to the intellectual level of the disabled based on Unity. SW education pilot training is conducted as online education based on Blended Learning due to COVID-19. In order to derive the SW education effect and each learner's individual SW education academic achievement for the SW education pilot training, a survey is conducted on learners, and the results are analyzed. In the basic course, 77.3% of learners achieved academic achievement above excellent(80-90), and in the advanced course, 48.8% of learners achieved academic achievement above excellent(80-90). These results verify that the SW education program for the disabled developed in this paper is effective in activating employment for the disabled.