• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.91-100
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• 2005

Grid computing is widely applicable to various fields of industry including process control and manufacturing, military command and control, transportation management, and so on. In a viewpoint of application area, grid computing can be classified to three aspects that are computational grid, data grid and access grid. This paper focuses on computational grid which handles complex and large-scale computing problems. Computational grid is characterized by system dynamics which handles a variety of processors and jobs on continuous time. To solve problems of system complexity and reliability due to complex system dynamics, computational grid needs scheduling policies that allocate various jobs to proper processors and decide processing orders of allocated jobs. This paper proposes a service prediction-based job scheduling model and present its scheduling algorithm that is applicable for computational grid. The service prediction-based job scheduling model can minimize overall system execution time since the model predicts the next processing time of each processing component and distributes a job to a processing component with minimum processing time. This paper implements the job scheduling model on the DEVS modeling and simulation environment and evaluates its efficiency and reliability. Empirical results, which are compared to conventional scheduling policies, show the usefulness of service prediction-based job scheduling.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.29-33
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• 2005

Grid computing is widely applicable to various fields of industry including process control and manufacturing, military command and control, transportation management, and so on. In a viewpoint of application area, grid computing can be classified to three aspects that are computational grid, data grid and access grid. This paper focuses on computational grid which handles complex and large-scale computing problems. Computational grid is characterized by system dynamics which handles a variety of processors and jobs on continuous time. To solve problems of system complexity and reliability due to complex system dynamics, computational grid needs scheduling policies that allocate various jobs to proper processors and decide processing orders of allocated jobs. This paper proposes the service prediction-based job scheduling model and present its algorithm that is applicable for computational grid. The service prediction-based job scheduling model can minimize overall system execution time since the model predicts a processing time of each processing component and distributes a job to processing component with minimum processing time. This paper implements the job scheduling model on the DEVSJAVA modeling and simulation environment and simulates with a case study to evaluate its efficiency and reliability Empirical results, which are compared to the conventional scheduling policies such as the random scheduling and the round-robin scheduling, show the usefulness of service prediction-based job scheduling.

• Annual Conference of KIPS
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• 2018.05a
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• pp.202-204
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• 2018

2018년 현재 한국과학기술정보연구원(KISTI)은 계산과학공학 플랫폼 기반으로 온라인 시뮬레이션이 가능한 EDISON(EDucation-research Integration through Simulation On the Net) 서비스를 제공하고 있다. 해당 플랫폼 서비스는 7개 전문분야(전산의학, 전산설계, 전산열유체, 구조동역학, 계산화학, 나노물리, 도시환경)의 학생 및 연구자들이 학습 및 시뮬레이션을 실행하고 결과를 활용할 수 있도록 지원하고 있다. 하지만 EDISON 플랫폼은 시뮬레이션 서비스에 초점을 맞춰 개발과 서비스를 제공했기 때문에 국내외 MOOC(Massive Open Online Course) 서비스들에 비해 아직 교육 콘텐츠가 부족하다. 그리하여 본 논문에서는 계산과학공학 플랫폼에 교육 콘텐츠를 체계적으로 제공하기 위한 커리큘럼 서비스를 설계 및 제안하였다.

• Journal of Practical Engineering Education
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• v.10 no.1
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• pp.35-39
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• 2018

More and more universities are enforcing SW education for non-major undergraduates. However, they are experiencing difficulties in educating non-major students to understand computational thinking processes. In this paper, we did not use the mathematical operation problem to solve this problem. And we proposed a basic problem-solving process teaching method based on computational thinking using simple physical devices. In the proposed educational method, we teach a LED circuit using an Arduino board as an example. And it explains the problem-solving process with computational thinking. Through this, students learn core computational thinking processes such as abstraction, problem decomposition, pattern recognition and algorithms. By applying the proposed methodology, students can gain the concept and necessity of computational thinking processes without difficulty in understanding and analyzing the given problem.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.305-326
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• 2019

Discriminative correlation filter (DCF) based tracking algorithms have recently shown impressive performance on benchmark datasets. However, amount of recent researches are vulnerable to heavy occlusions, irregular deformations and so on. In this paper, we intend to solve these problems and handle the contradiction between accuracy and real-time in the framework of tracking-by-detection. Firstly, we propose an innovative strategy to combine the template and color-based models instead of a simple linear superposition and rely on the strengths of both to promote the accuracy. Secondly, to enhance the discriminative power of the learned template model, the spatial regularization is introduced in the learning stage to penalize the objective boundary information corresponding to features in the background. Thirdly, we utilize a discriminative multi-scale estimate method to solve the problem of scale variations. Finally, we research strategies to limit the computational complexity of our tracker. Abundant experiments demonstrate that our tracker performs superiorly against several advanced algorithms on both the OTB2013 and OTB2015 datasets while maintaining the high frame rates.

• Journal of The Korean Association of Information Education
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• v.23 no.3
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• pp.207-217
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• 2019

In order to improve computational thinking, elementary schools have been using 'Scratch' to provide basic programming education. However, the study on evaluation of computational thinking is at an early stage. Therefore, this study evaluated the conceptual level of computational thinking using the scratch code analyzing. For this, Dr. Scratch was used to analyze 179 scratch projects. The results showed that the conceptual level of computational thinking of most elementary students was at the developing level, and that it varied according to gender and production style, showed the lowest level of logic and abstraction, and improved computational thinking during programming. This study is meaningful in that it provides implications for the improvement of teaching methods and self-directed evaluation in learning.

• The Journal of Korean Association of Computer Education
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• v.22 no.5
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• pp.67-77
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• 2019

The purpose of this study is to develop and validate a general-purpose evaluation tool and to analyze their applicability in problem solving programming education for college students of teacher training college. For this purpose, we have redefined the area of computational thinking and detail elements from the viewpoint of problem solving programming, and developed general-purpose computational thinking scale to evaluate them. The reliability and validity were analyzed by applying the evaluation tool developed for the actual college students of teacher training college. Through this study, it was confirmed that the a general-purpose evaluation tool developed in this study can be used as a tool to computational thinking assessment and can be generalized.

• 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.

• Journal of Internet Computing and Services
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• v.21 no.6
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• pp.123-132
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• 2020

The EDucation-research Integration through Simulation On the Net (EDISON) platform, which is a web-based platform that provides computational science and engineering simulation execution environments, can offer various analysis environments to students, general users, as well as computational science and engineering researchers. To expand the user base of the simulation environment services, the EDISON platform holds a challenge every year and attempts to increase the competitiveness and excellence of the platform by analyzing the user requirements of the various simulation environment offered. The challenge platform system in the field of computational science and engineering is provided to users in relation to the simulation service used in the existing EDISON platform. Previously, EDISON challenge servicesoperated independently from simulation services, and hence, services such as end-user review and intermediate simulation results could not be linked. To meet these user requirements, the currently in-service challenge platform for computational science and engineering is linked to the existing computational science and engineering service. In addition, it was possible to increase the efficiency of service resources by providing limited services through various analyses of all users participating in the challenge. In this study, by analyzing the simulation and usage environments of users, we provide an improved challenge platform; we also analyze ways to improve the simulation execution environment.

• 한국전산유체공학회:학술대회논문집
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• 2001.05a
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• pp.144-148
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• 2001

Characteristics of high temperature rocket nozzle flow is discussed along with the aspects of computational analysis. Three methods of nozzle flow analysis, frozen-equilibrium, shifting-equilibrium and non-equilibrium approaches, were discussed those were coupled with the methods of computational fluid dynamics. A chemical equilibrium code developed for the analysis of general hydrocarbon fuel was coupled with three approaches of nozzle flow analysis, and a test was made for a bell nozzle at typical operation condition. As a results, the characteristics of the approaches were discussed in aspects of rocket performance, thermal analysis and computational efficiency.