• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.9-19
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• 2020

An integrated finite element model composed of a boiler and its supporting steel structure for a 375-MW coal-fired power plant was developed. This study used the developed model for seismic analysis using SAP2000 software. For the complex superheaters, reheaters, economizers, and membrane walls of the boiler, which consisted of numerous tubes, a method of modeling them by the equivalent elements in the viewpoint of stiffness and/or inertia was proposed. In addition, a method of modeling for the connection between the boiler and steel structure was proposed. Many hangers that connect the boiler to the girders of a steel structure were transformed into equivalent hangers by decreasing the number. The displacements of the boiler stoppers on the buckstay and the posts of the steel structure were coupled by considering their interface condition. Static analysis under the self-loading condition for the developed integrated model was implemented, and the results of deformation indicated that the behavior of the steel members and the major components of the boiler were appropriate. In conclusion, the integrated model developed in this study can be used to evaluate the safety of the boiler and steel structure under seismic loads.

• Journal of The Korean Association of Information Education
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• v.23 no.6
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• pp.607-619
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• 2019

As software education was introduced through the 2015 revised curriculum, various research activities have been carried out to improve the computational thinking of learners beyond the existing ICT literacy and software utilization education. With this change, the purpose of this study is to examine the research trends of various research activities related to computational thinking which is emphasized in software education. To this end, we extracted the key words from 190 papers related to computational thinking subject published from January 2014 to September 2019, and conducted frequency analysis, word cloud, connection centrality, and topic modeling analysis on the words. As a result of the topical modeling analysis, we found that the main studies so far have included studies on 'computational thinking education program', 'computational thinking education for pre-service teacher education', 'robot utilization education for computational thinking', 'assessment of computational thinking', and 'computational thinking connected education'. Through this research method, it was possible to grasp the research trend related to computational thinking that has been conducted mainly up to now, and it is possible to know which part of computational thinking education is more important to researchers.

• The Journal of Society for e-Business Studies
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• v.26 no.1
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• pp.1-28
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• 2021

FinTech has been discussed as an important business area towards technology-driven financial innovation. The term fintech is a combination of finance and technology, which means ICT technology currently associated with all finance areas. The popularity of the fintech industry has significantly increased over time, with full investment and support for numerous startups. Therefore, both academia and practice tried to analyze the trend of the fintech area. Despite the fact, however, previous research has limitations in terms of collecting relevant databases for fintech and identifying proper application areas. In response, this study proposed a new method for analyzing the trend of Fintech fields by expanding Fintech's terminology and using network analysis and topic modeling. A new Fintech terminology list was created and a total of 18,341 patents were collected from USPTO for 10 years. The co-classification analysis and network analysis was conducted to identify the technological trends of patent classification. In addition, topic modeling was conducted to identify the trends of fintech in order to analyze the contents of fintech. This study is expected to help both managers and investors who want to be involved in technology-driven financial services seize new FinTech technology opportunities.

• Geophysics and Geophysical Exploration
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• v.26 no.4
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• pp.268-274
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• 2023

Finite source inversion is performed with a Green's function matrix and geodetic coseismic displacement. Conventionally, the Green's function matrix is constructed using the Okada model (Okada, 1985). However, for more realistic earthquake simulations, recent research has widely adopted the physics-based model, which can consider various material properties such as elasticity, viscoelasticity, and elastoplasticity. We used the physics-based software PyLith, which is suitable for earthquake modeling. However, the PyLith does not provide a mesh generator, which makes it difficult to perform finite source inversions that require numerous subfaults and observation points within the model. Therefore, in this study, we developed CPInterface (COMSOL-PyLith Interface) to improve the convenience of finite source inversion by combining the processes of creating a numerical model including sub-faults and observation points, simulating earthquake modeling, and constructing a Green's function matrix. CPInterface combines the grid generator of COMSOL with PyLith to generate the Green's function matrix automatically. CPInterface controls model and fault information with simple parameters. In addition, elastic subsurface anomalies and GPS observations can be placed flexibly in the model. CPInterface is expected to enhance the accessibility of physics-based finite source inversions by automatically generating the Green's function matrix.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.3 s.73
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• pp.295-302
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• 2006

In this study, computational structural dynamic analyses of a gyrocopter have been conducted considering unsteady dynamic hub-loads due to rotating blades. 3D CATIA models with detailed mechanical parts we constructed and virtually assembled into the complete aircraft configuration. The dynamic loading generated by rotating blades in the forward flight condition are calculated by a commercial computational fluid dynamics (CFD) code such as FLUENT. Modal based transient and frequency response analyses are used to efficiently investigate vibration characteristics of the gyrocopter. Free vibration analysis results for different fuel and pilot conditions, frequency responses and transient responses for critical flight conditions are also presented in detail.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.444-453
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• 2017

This paper proposes an operational algorithm for a Photovoltaic Power-Hardware-In-Loop Simulator that is designed to improve the control algorithm and reliability of the PV Inverter. There was an instability problem in the PV PHILS with the conventional algorithm when it was connected tothe PV inverter. Initially, a real-time based computing unit with mathematical modeling of the PV array is implemented and a DC amplifier and an isolated device for DC power measurement are integrated. Several experiments were performed based on theabove concept undercertain conditions, which showed that the proposed algorithm is more effective for the PV characteristic test and grid evaluation test than the conventional method.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.189-194
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• 2005

현재 국가에서는 하천지도전산화사업 등의 성과물인 하천관련 DB의 활용 극대화를 위해 하천주제도구축사업을 시행중에 있다. 그 결과 요구도 높은 하천주제도의 항목이 결정되었으며, 이를 활용하기 위하여 GIS를 이용한 효율적인 하천주제도 관리 방법의 필요성이 증대되고 있다. 따라서 본 연구에서는 2002년 한국수자원공사의 '하천주제도사업계획수립'에서 정립한 하천주제도 데이터 모델을 활용하여 하천주제도의 효율적인 관리를 위하여 GIS를 활용한 시범 시스템을 개발하였다. 개발방법으로는 설계한 데이터모델을 적용하고, 하천관리지리정보시스템(RIMGIS) 및 향후 유통측면을 고려하였다. 이에 앞서 연구대상지역을 선정하였고, 모델을 기반으로 한 DB의 위하여 기 구축된 DB의 효과적 활용 방안을 제시하였다. 개발된 하천주제도 관리시스템은 하천주제도에 관련된 도형자료를 구축하고, 그에 대한 속성자료를 연계한 시스템 제작을 의미한다. 이를 위해 세부적으로 정의된 주제도를 기 구축된 RIMGIS 도형자료 및 속성자료, 하천정비기본계획, 수자원공사자료, 환경부자료, 건교부 자료, 문화관광부자료 등을 활용하여 하천주제도 관리시스템을 제작하였다. 아울러 하천주제도 구축에 앞서 설계한 하천주제도의 보델을 통하여 하천과 관련된 데이터와 수리 수문 입력변수를 산정하기 위한 전처리 및 후처리 과정이 동일 시스템 내에서 통합처리가 가능할 것이며, 하천에 대한 동적 모델링을 위한 기초 자료의 제공도 가능하리라 본다. 나아가 하천주제도 구축시 간단한 연산기능에서부터 다양한 응용정보를 요구하는 주제도에 대한 효율적인 구축 방안을 제공할 수 있을 것으로 사료된다. 또한 관리시스템을 활용하여 하천주제도의 관리 및 사용이 보다 효율적이며, 하천업무 담당자뿐만 아니라 일반인들의 이해를 돕고, 연구의 성과를 향상시킬 수 있다. 더욱이 이러한 하천주제도 관리시스템의 개발은 타 분야에 구축된 방대한양의 하천 관련 GIS데이터 등의 자료를 연계하여 기 구축데이터의 활용도를 제고할 수 있다.

• Journal of the Korea Convergence Society
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• v.6 no.3
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• pp.127-134
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• 2015

In this paper, we design a semantic-based syllabus template including learning ontologies. A syllabus has been considered as a important blueprint of teaching in universities. However, the current syllabus has no importance in real world because most of all syllabus management systems provide simple functionalities such as, creation, modification, and retrieval. In this paper, our approach consists of definition of hierarchical structure of syllabus and semantic relationships of syllabuses, formalization of learning goals, learning activity, and learning evaluation using Bloom's taxonomy and design of learning subject ontologies for improving the usability of syllabus. We prove the correctness of our proposed methods according to implementing a real syllabus for JAVA programing course and experiments for retrieving syllabuses.

• Journal of the Society of Disaster Information
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• v.12 no.1
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• pp.47-53
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• 2016

Techniques to be developed in this study is intended to apply to an existing integrated control system to "A Study on the multiple Texture Rendering system for three-dimensional Image Signal Recognition" technology or become a center of the building control system in real time video. so, If the study plan multi-image mapping system developed, CCTV camera technology and network technology alone that is, will be a number of security do not have to build a linked system personnel provide services that control while the actual patrol, the other if necessary systems and linked to will develop a system that can reflect the intention Ranger.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.879-883
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• 2006

본 연구는 현장에서 측정되는 수질데이터를 실시간 수집하여 데이터의 적절성을 모니터링하고 모형입력자료로써 신뢰성을 유지하도록 구성되는 시스템과 이를 2차원 수질 해석 모형인 CE-QUAL W2모형의 입력자료로 연계 활용함으로써 그 결과를 그래프 및 하천 변화 모의 동영상으로 표출하는 시스템을 개발하는데 그 목적이 있다. 수질 모형은 물 관련 모형가운데 특히 다량의 자료와 정확한 자료를 입력자료로 사용하며 그 결과 표출에 있어서도 전체적인 결과부터 세밀한 요소자료까지 결과자료가 필요하다. 본 연구에서 개발한 RTMMS(Real-time Turbidity Monitoring & Modeling System)는 현장 계측기로부터 수집되는 실시간 자료를 이용하여 데이터를 모니터링하고 CE-QUAL W2 모형을 이용하여 모델링을 수행한 후 결과를 그래프로 도출 할 수 있도록 하는 시스템이다. 특히 일반적인 어플리케이션의 GUI 환경에서 벗어나 일반 사용자들이 쉽게 프로그램을 사용할 수 있고 공간 활용도를 높이기 위하여 웹 형식의 GUI로 구성하였다. RTMMS는 기본 크기가 가로 800 픽셀, 세로 600 픽셀로 고정 사이즈이며, 주요 화면 구성으로는 좌측에 네 개의 항목이 있고 우측에는 실시간 모니터링 지점에 대한 유역도가 표시되어 사용자 편의환경을 제공하였다. 사용자는 해당 지점을 선택하여 주요 지점에 대한 정보를 분석할 수 있다. 또한 우측에는 선택된 지점에 대한 정보와 실시간 감시 내용을 조회할 수 있는 탭이 존재한다. 각각의 메뉴 항목은 주요지점의 모니터링 현황을 파악할 수 있는 기능, 수질모형의 입력자료로 변환하도록 하는 자료 동화 기능, CE-QUAL W2 모형을 수행하는 기능 및 결과자료를 분석하는 기능으로 구성되어 있으며, 각 기능을 선택하면 해당 화면으로 GUI가 전환된다. 따라서 다량의 측정자료의 신뢰성을 유지하고 이를 모형의 입력자료로 활용하는 일련의 과정을 시스템화하기 때문에 자료의 이상적 유지 관리가 이루어지며 복잡한 2차원 수질해석 모형을 수월하게 운영할 수 있는 시스템으로 개발하였다.