• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.27-28
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• 2023

Currently, the Off-Site Construction (OSC) construction method, which emphasizes the minimization of field work, is being emphasized at construction sites due to the lack of construction skilled manpower, extreme weather, and the Severe Disaster Punishment Act. In this study, we developed a stacked PC modular, which is a method of stacking PC modules, and solved the lifting problem by reducing the weight of the unit module, which is emerging as the biggest disadvantage of PC modules, to around 20 tons. For the connection between modules, structural safety was secured through repeated history tests of the wall and slab connection. Walls and slabs satisfied all statutory fire resistance times through fire resistance tests, and residential performance was evaluated to be satisfactory through mock-up demonstration. The developed PC modular has been applied to the construction of commercial houses, detached houses, shopping malls, churches, etc., and has design results for many buildings such as dormitories, detached houses with 4 floors or more, and resorts, so it is expected that an atmosphere of revitalization of construction methods will be created.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.4
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• pp.489-502
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• 2023

This article presents the crucial role played by the French underground research laboratory (URL) in initiating the deep geological repository project Cigéo. In January 2023, Andra finalized the license application for the initial construction of Cigéo. Depending on Government's decision, the construction of Cigéo may be authorized around 2027. Cigéo is the result of a National program, launched in 1991, aiming to safely manage high-level and intermediate level long-lived radioactive wastes. This National program is based on four principles: 1) excellent science and technical knowledge, 2) safety and security as primary goals for waste management, 3) high requirements for environment protection, 4) transparent and open-public exchanges preceding the democratic decisions and orientations by the Parliament. The research and development (R&D) activities carried out in the URL supported the design and the safety demonstration of the Cigéo project. Moreover, running the URL has provided an opportunity to gain practical experience with regard to the security of underground operations, assessment of environmental impacts, and involvement of the public in the preparation of decisions. The practices implemented have helped gradually build confidence in the Cigéo project.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.330-338
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• 2024

In this paper, a Ka-band high-output active phased array antenna device applicable to small radars and seekers was designed, and the improved performance was studied. The radiation device assembly consists of 1x8 arrangements, and the step flared notch antenna type. It shows low active reflection loss characteristics in broadband, and low loss characteristics by applying the air-strip feeding structure, and is designed to enable beam steering up to 45 degrees. The TRM(transmit receive module) output power is more than 2.0W per channel using GaN HPA in the transmitting path, and satisfies more than 25.0 dB gain and less than 6.0 dB noise figure in the receiving path. Accordingly, the Effective Isotropically Radiated Power(EIRP) of the antenna unit shows the performance of 0.00 dB or more and the receive gain-to-noise temperature ratio(G/T) of 0.00 dB/k or more. For demonstration, we have designed aforementioned planar array antenna which consists of 64 radiating elements having a size within 130 mm x 130 mm x 300 mm and weight of less than 4.9 kg..

• Wind and Structures
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• v.38 no.3
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• pp.161-170
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• 2024

In recent years, there have been an increasing number of experimental studies showing the need to include robustness criteria in the design process to develop complex active control designs for practical implementation. The paper investigates the crosswind aerodynamic parameters after the blocking phase of a two-dimensional square cross-section structure by measuring the response in wind tunnel tests under light wind flow conditions. To improve the accuracy of the results, the interpolation of the experimental curves in the time domain and the analytical responses were numerically optimized to finalize the results. Due to this combined effect, the three aerodynamic parameters decrease with increasing wind speed and asymptotically affect the upper branch constants. This means that the aerodynamic parameters along the density distribution are minimal. Taylor series are utilized to describe the fuzzy nonlinear plant and derive the stability analysis using polynomial function for analyzing the aerodynamic parameters and numerical simulations. Due to it will yield intricate terms to ensure stability criterion, therefore we aim to avoid kinds issues by proposing a polynomial homogeneous framework and utilizing Euler's functions for homogeneous systems. Finally, we solve the problem of stabilization under the consideration by SOS (sum of squares) and assign its fuzzy controller based on the feasibility of demonstration of a nonlinear system as an example.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.2
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• pp.157-178
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• 2013

This study gives a conceptual and basic direction to develop a URL (underground research laboratory) program for establishing the performance and safety of a deep geological disposal system in Korea. The concept of deep geological disposal is one of the preferred methodologies for the final disposal of spent nuclear fuel (SNF). Advanced countries with radioactive waste disposal have developed their own disposal concepts reasonable to their social and environmental conditions and applied to their commercial projects. Deep geological disposal system is a multi-barrier system generally consisting of an engineered barrier and natural barrier. A disposal facility and its host environment can be relied on a necessary containment and isolation over timescales envisaged as several to tens of thousands of years. A disposal system is not allowed in the commercial stage of the disposal program without a validation and demonstration of the performance and safety of the system. All issues confirming performance and safety of a disposal system include investigation, analysis, assessment, design, construction, operation and closure from planning to closure of the deep geological repository. Advanced countries perform RD&D (research, development & demonstration) programs to validate the performance and safety of a disposal system using a URL facility located at the preferred rock area within their own territories. The results and processes from the URL program contribute to construct technical criteria and guidelines for site selection as well as suitability and safety assessment of the final disposal site. Furthermore, the URL program also plays a decisive role in promoting scientific understanding of the deep geological disposal system for stakeholders, such as the public, regulator, and experts.

• Journal of Distribution Science
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• v.11 no.5
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• pp.55-62
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• 2013

Purpose - This study aims to determine the problems and limitations of the Commercial Area Activation System, which was created by a special law for promoting traditional markets and shopping districts to revitalize and efficiently manage the central commercial area in different regions. We also suggest different options for its improvement. Research design, data, and methodology - We also look into the problems of which is being promoted as a demonstration project, from the aspects of legal text and guidelines. Results - The current commercial area activation system has several problems. First, the establishment of a comprehensive basic plan on the commercial area activation is not a requirement. Second, the benefit principle should be established to prevent the moral laxity of merchants who serve important roles in the main components of the commercial area activation business when they conduct their business. Third, the current special law constrains the commercial management organization, as under the civil law yields a limitation on finding a profitable business model. Fourth, to efficiently, constructing a system that links the other central government businesses and is needed. into a regional development budget or a budget for funding small businesses that the central government can control, which is effective. Further, we offer some suggestions for medium- and long-term policies. First, an integrated coordination mechanism at the central office level should be installed while setting the basic policy to revitalize the Based on this policy, local governments need a system that exclusively based on the after establishing a comprehensive plan for urban regeneration and getting approval from the integration organization. Second, a system that enables an understanding of the problems with business promotion by monitoring the procedure of supporting projects and regularly assessing business achievements is needed. Third, a plan is needed for resolving conflicts between various interested parties that adopts the commercial area activation system for carrying out a total redevelopment of the commercial area where small shops are densely located. A market maintenance project has been conducted as a means to recover our traditional market, which was economically depressed, and to revive the local economy, but it is mostly conducted in the form of reconstruction or redevelopment and represents the interests of landowners and merchants. Thus, it is most likely to lead to a gradual disappearance of traditional markets. Conclusions - This study looks primarily into the problems that appeared in the legal text or the guidelines regarding the direction of improvement of the commercial area activation business that has been going on as a demonstration project since 2011 and suggests some solutions.

• Journal of the Korean Society of Earth Science Education
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• v.9 no.3
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• pp.341-351
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• 2016

The purpose of this study is to investigate the effects of pre-service teachers of elementary school who take courses in 'Science and Textbook Research' on science teaching efficacy and science knowledge after experimental treatment. For this purpose, this study was aimed at intensive course four classes (118 students) enrolled in the 'Science and Textbook Research' course and experimented from the beginning of September to the end of November. The experiment was about teaching textbooks and teaching methods for one semester, and the pre- service teachers of elementary school made the demonstration of science cooperation classes by group. The results and analysis of the study were analyzed by the corresponding sample test in before and after the group test. The conclusion of the study is as follows. First, after taking this class the pre - service teachers of elementary school were effective in science teaching efficacy. Second, after taking this course, pre-service teachers of elementary school were effective in acquiring science knowledge. Third, it was seemed to positive effect on Perception of pre-service teachers of elementary school in Demonstration classes. Pre-service teachers of elementary school have created science course plan by analyzing the tasks according to the principles of instructional design, and they found that they had the right mind and confidence in the lesson.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.10-18
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• 2021

CO₂ storage technology in an aquifer is one of the most effective way to decrease global warming due to a high storage capacity and economics. A demonstration-scale offshore CO₂ storage project was performed in a geological deep aquifer in the Pohang Basin, Korea for a technological development of large-scale CO₂ storage. A challenging issue in the early design stage of the project was to establish the proper injectivity during CO₂ injection. To solve this issue, injection conditions were calculated by calculating injection rate, pressure, temperature, CO₂ phase change, and thermodynamic properties. For this study, we simulated and numerically analyzed CO₂ phase change from gas to supercritical phase and flow behavior in transport piping and injection tubing using OLGA program. Our results provide the injectivity conditions of CO₂ injection system combined with a bottomhole pressure of an aquifer.

• Journal of the Korean Institute of Gas
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• v.26 no.4
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• pp.9-17
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• 2022

This paper is the continuation of our previous paper, which we refer to as numerical analysis of phase behavior and flow properties in an injection tubing during gas phase CO₂ injection. Our study in this paper show the results during supercritcal CO₂ injection under the same project. Geological CO₂ storage technology is one of the most effective method to decrease climate change due to high injectivity and storage capacity and economics. A demonstration-scale CO₂ storage project was performed in a deep aquifer in the Pohang basin, Korea for a technological development in a large-scale CO₂ storage project. A problem to consider in the early stage design of the project was to analyze CO₂ phase change and flow characteristics during CO₂ injection. To solve this problem, injection conditions were decided by calculating injection rate, pressure, temperature, and thermodynamic properties. For this research, we simulated and numerically analyzed CO₂ phase change from liquid to supercritical phase and flow characteristics in injection tubing using OLGA program. Our results provide discharge pressure and temperature conditions of CO₂ injection combined with a pressure of an aquifer.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.1
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• pp.40-51
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• 2008

To realize advanced collaboration environments for knowledge workers distributed geographically, there are extensive researches in ubiquitous computing environments. Especially, to cope with several known problems in traditional collaboration tools such as limited display resolution, uncomfortable shared documentation, difficult operation of collaboration environments, various approaches are attempted in the aspect of framework design. In this paper, we design a framework for collaboration environments covering hardware/software/networking architecture to flexibly coordinate a set of collaboration services and devices considering users' expectation and node capabilities. Based on the proposed framework, we develop the collaboration environment supporting the interactive networked tiled display enabling media/data sharing via networking, display interaction using pointing/tracking, and high-resolution tiled display. Finally the demonstration of the developed prototype is introduced to prove the possibility of its realization.