• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.218-221
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• 2001

This paper presents a new control scheme for a Dynamic Voltage Restorer(DVR) system consisting of series voltage source PWM converters. The control system is designed using differential controllers and digital filters to transfer the faulted ac source voltage to a d-q model and to separate the positive and negative sequence component for individual compensation. The performance of the presented controller and scheme are confirmed through simulation and actual experiment.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.7 no.1
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• pp.91-99
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• 1999

On the basis of KTMPO visibility data measured for 17 years(Jan.1983 to Oct.1999), time-series data analysis is accomplished for regression trend, cyclical periodicity, dependency of these data in this paper. After that, to predict visibility in KIMPO international airport a probability model is presented using this statistic probability characteristics.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.45-52
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• 1993

Evaluation of structural stability of aged wharf structure of pier type is of great importance for both safety and rehabilitation, Series of field dynamic experiments were performed for berthing impact and the results were used to calibrate analysis model. Through dynamic analysis for design, berthing impact safety of old wharf structure were evaluated. In this paper the procedure and results of experiments and analysis are presented.

• Research in Mathematical Education
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• v.11 no.3
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• pp.177-184
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• 2007

The purpose of this paper is to introduce the development of a new Lesson Video-Case Lab (LVCL) program in Suzhou, China. This program involves the creation of several series of hypermedia video-cases on teaching and learning designed to facilitate mathematics teachers' professional development. Each of these video-cases consists of lesson clips, case questions, interviews with experts, comments by peers, responses by students and other related resources. The study has implications pertaining to the use of technology in teacher development, the production of hypermedia video-cases, as well as research on case-based pedagogy and pedagogy in general.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.167-168
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• 2016

수업시간에 강의 듣고, 집에서 숙제를 하는 방식은 더 이상 학습자의 학습동기를 이끌지 못하고, 효과적인 수업이 이루어 질 수 없다. 수업시간에는 학생들의 적극적 상호작용이, 집에서는 인터넷 환경을 통한 핵심 강의식 내용을 미리 듣고 수업 활동에 임하는 플립러닝에 대한 영어과 수업의 도입이 필요하나 이에 대한 연구가 충분하지 않은 실정이다. 이에, 본 연구를 통해 영어수업(독해중심)에서의 플립러닝 활용 수업 모형을 개발하고, 이를 현장에 적용 후 수정 보완하여 대학 영어수업에서의 플립러닝 정착 및 발전을 도모한다.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.167-170
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• 2005

This paper summarizes the results of a series of numerical evaluations (Lee et al., 2004, 2005) on the performance of pre-cracked reinforced concrete (RC) beams coated with polymeric composites. It was intended to numerically show the superior characteristics of the polymeric composites for enhancing the strength and ductility of existing concrete structures. Further, the predicted load-carrying and energy absorbing capacities of the beams were compared with previous experiments to verify the predictive capability of implemented computational model.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.215-218
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• 2005

Three series of 36 short square columns confined by wraps, full shells and partial shells were tested by varying the thickness of GFRP laminates. An assessment of the effectiveness of the existing model on confinement of concrete columns with FRP was made. Test results indicated moderate increases in strength, but significantly enhanced deformability compared with those in unconfined concrete, particularly the warp and full shell confinement.

• Journal of electromagnetic engineering and science
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• v.1 no.1
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• pp.60-62
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• 2001

A novel approach for modeling the thermic endfire interstitial applicator is presented. A hypothetical semi-infinite circular cylinder is added in the endfire direction in order to facilitate the theoretical modeling approach. The Fourier transform and mode-matching technique is utilized to obtain a solution in fast-convergent series Numerical computations for the input impedance are performed to check the Validity of the theoretical model.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1156-1158
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• 1998

This paper Presents two distribution-feeder models to simplify complicated distribution system calculations. These equivalent models are developed to simulate the total series voltage drop at the end of the given feeder and the total line loss of the given feeder accurately. In addition, the proposed models are bidirectional. This means that power infeed can be at either end and the model is accurate. Also, it is shown that the proposed models are suitable for network reconfiguration.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.139-143
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• 2002

The purpose of this paper is to develop the CFD code to consider the viscous flow features of the marine propeller. The flow of the marine propeller has been numerically analyzed by using three dimensional viscous incompressible Navier-Stokes equation. The model used in this study is Screw B with 4 blades whose pitch ratio is 1 in Ka-4-55 screw series. The result of the analysis was compared with panel method.