• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.67-76
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• 2012

This paper proposes the aggregated modeling and control of integated boost-flyback converter (IBFC) for understanding of dynamics characteristic and designing of relevant controller. The basic concept of the aggregated modeling is to substitute the boost or the flyback converter with an equivalent current source. Since each converter with equivalent current source corresponds to the basic boost and flyback converters, the overall mathematical process is significantly simplified for the modeling. Afterwards each result is combined to construct the complete model of the IBFC, and the relevant controller is designed through the achieved small-signal model. Simulation and experimental results show excellent agreement with the theoretical expectations.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.249-254
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• 2021

This study is about the class model that can demonstrate the modeling ability using the spatial perception capability on basic modeling required for jewelry design majors and the most important perspective method in jewelry design. The outputs were obtained by presenting the topics for creative activities to students after theoretical explaining how to present a spatial sense and presenting practical classes on basic shapes, stereoscopic shapes and perspective methods. While the existing basic molding classes were only practical classes, this study presented students with a class model that allows them to use creativity, basic perspective, and spatial sense together. And it was found out evaluation method that both students and professors can relate to each other through the intensive education effects and clear evaluation standards. I hope that this paper will continue to study more diverse materials and convergent class models.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1797-1799
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• 2008

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.3-8
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• 2001

Regarding current rapid innovations and applications of information and telecommunication technologies as well as economical requirements, modeling and simulation (M&S) plays an increasingly important role for the planning, development and operation of high-tech products and systems. M&S has to seen as a key technology for multi-facetted analysis of complex systems during their life-cycles. For reasons as accuracy, credibility and cost-effectiveness, the selection of adequate and effective M&S techniques and tools is of significant importance. Regarding these aspects, this paper summarizes the basic methodological modeling approach for effective product and system modeling. In addition, besides a classification of different basic architectures and taxonomies combining knowledge-processing and simulation techniques, the paper describes some practical implementations and experiences.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.349-350
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• 2023

In the field of domestic construction, 3D modeling mainly targets outdoor construction sites, and acquires outdoor spatial information by operating UAVs and UGVs equipped with cameras. 3D modeling of construction sites tends to expand its scope to indoors along with the increasing demand for site monitoring and management through indoor spatial information. In the case of indoors, it is impossible to shoot with a drone after the framework and outer walls of the building are completed, so it is necessary to collect indoor spatial information and 3D modeling using a 360 camera. The purpose of this study is limited to basic research to establish a process that can obtain simple and high-quality indoor 3D modeling results using indoor data collected from 360 cameras.

• Proceedings of the Korean Biophysical Society Conference
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• 1998.06a
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• pp.21-21
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• 1998

Since the repair efficiency of non-Watson-Crick base pairs in DNA is affected by the mismatched base-pairs and their neighbor sequences, the structural studies are necessary for the elucidation of the repair efficiency. NMR and molecular modeling studies on the DNA duplexes including AA mismatches were performed.(omitted)

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.404-405
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• 2011

In this paper, we present basic modeling of Juju power system using PSCAD/EMTDC. In detail, models of bipolar HVDC system, power transmission line, basic thermal power plant, load, and wind farm have been developed for Jeju power system. For evaluating basic dynamic behavior, we tested the system with a simple scenario and the test result showed acceptable response.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.3
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• pp.215-221
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• 2011

To improve the naval ship acquisition process, systems engineering, modeling and simulation, etc. have been introduced, and there has been ongoing research on acquisition systems for effective support of it. However, due to characteristics of the naval ship acquisition process, development process mainly carried out at a shipyard such as basic design, detailed design, construction and test is difficult to integrate with the acquisition systems of IPT(Integrated Project Team). In addition, research aimed to improve this is rather lacking. In this paper, the naval ship product structure concept proposed in previous research was applied to the basic design system at shipyard, and basic research for expanding the coverage of naval ship acquisition systems to the basic design phase is performed. A data structure of modeling system appropriate to the basic design phase was proposed through research findings and the prototype system based on it was implemented.

• Communications of Mathematical Education
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• v.37 no.4
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• pp.615-633
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• 2023

This study analyzed Korean studies up to August 2023 to suggest the direction of future research on basic academic abilities in mathematics. For this purpose, frequency analysis and LDA-based topic modeling were conducted on the Korean abstracts of 197 domestic studies. The results showed that, first, 'academic achievement', 'impact', 'effect', and 'factors' were all ranked at the top of the TFs and TF-IDFs. Second, as a result of LDA-based topic modeling, five topics were identified: causes of basic academic abilities deficiency, learning status of math underachievers, teacher expertise in teaching math underachievers, supporting programs for math underachievers, and results of National Assessment of Educational Achievement. As a direction for future research, this study suggests focusing on the growth of math underachievers, systematizing the programs provided to students who need learning support in mathematics, and developing teacher expertise in teaching math underachievers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.5
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• pp.2186-2203
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• 2020

Security administrators of companies and organizations need to come up with proper countermeasures against cyber-attacks considering infrastructures and security policies in their possession. In order to develop and verify such countermeasures, the administrators should be able to reenact both cyber-attacks and defenses. Simulations can be useful for the reenactment by overcoming its limitations including high risk and cost. If the administrators are able to design various scenarios of cyber-attacks and to develop simulation models from their viewpoints, they can simulate desired situations and observe the results more easily. It is challenging to simulate cyber-security issues, because there is lack of theoretical basis for modeling a wide range of the security field as well as pre-defined basic components used to model cyber-attacks. In this paper, we propose a modeling method for cyber-security simulations by developing a basic component and a composite model, called Abstracted Cyber-Security Unit Model (ACSUM) and Abstracted Cyber-security SIMulation model (ACSIM), respectively. The proposed models are based on DEVS(Discrete Event systems Specification) formalism, a modeling theory for discrete event simulations. We develop attack scenarios by sequencing attack behaviors using ACSUMs and then model ACSIMs by combining and abstracting the ACSUMs from a security perspective. The concepts of ACSUM and ACSIM enable the security administrators to simulate numerous cyber-security issues from their viewpoints. As a case study, we model a worm scenario using ACSUM and simulate three types of simulation models based on ACSIM from a different security perspective.