• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.635-640
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• 2003

Due to the development of information technology and widespread use of telecommunications networks, the design of mesh-survivable net works has received considerable attention in recent years. This paper deals with spare capacity planning scheme in mesh-based fiber-optic networks. In this study, a new spare capacity planning scheme is proposed utilizing path restoration with maximal sharing of share capacity that is traced by the spare capacity incremental factor (after this, we called "SCIF"). We compare it with three other spare capacity planning scheme : link capacity of IP (Integer Programming), SLPA(Spare Link Placement Algorithm) and GA(Genetic Algorithm). The approach shows better performance with heuristics algorithm for determining the spare capacity assignment and the computational time is easily controlled allowing the approach to scale to large networks. The major advantages of the new approach are reduction of spare capacity and a polynomial time complexity.omplexity.

• Journal of Korean Society of Steel Construction
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• v.16 no.4 s.71
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• pp.443-452
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• 2004

Recently, the Artificial Neural Network(ANN) which can organize complex non-linear problems by effectively applying the parallel computational model that is similar to the human brain, was adopted in the wide department of technology and resulted in many successful applications. In this study, a more appropriate formal method is suggested for the preliminary structural design stage controlled merely by the designer's experience and intuition. To do so, this study proposes a multi-level ANN according to the general progressive structural design procedure, using Back-Propagation Algorithm (BP) and Genetic Algorithm (GA) for the ANN learning. The preliminary structural design of cable-stayed bridges was applied to illustrate the applicability of the study formulated as stated above, and the results of two different learning methods were compared.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.245-246
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• 2012

ITER 초전도자석 전원공급장치의 예비설계가 실제 크기 6펄스 R&D 컨버터의 제작 및 시험결과를 기반으로 수행되었다. ITER 컨버터는 자체적으로 지지되는 알루미늄 버스바 구조로 제작되며, 이 버스바에 양면 클램핑 방식으로 조립되는 Thyristor 스위치는 4인치 규격으로써 컨버터의 종류에 따라 한 개의 암 당 8 - 16 개의 소자가 병렬로 구성된다. ITER 컨버터 예비설계는 알루미늄 버스바 구조설계, 컨버터 냉각설계, 컨버터 전기회로 설계, 컨버터 고장해석 및 보호설계, 시험절차 및 요건 등을 포함하며, 본 논문에서 그 설계결과를 기술한다. ITER 컨버터는 예비설계 결과를 기반으로 상세설계 및 제작설계를 거친 후 제작된다.

• Journal of The Korean Association For Science Education
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• v.40 no.3
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• pp.307-320
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• 2020

This study explores how the positioning of two pre-service science teachers (PSTs) is reflected in their different epistemic understandings of inquiry-based lessons. We collected the PSTs' products during their design and enactment of an inquiry-based lesson and recorded their practices in the enacted lesson. Interviews were recorded and transcribed for analysis. The results indicate that one PST, Dohyung was positioned as a subject of evaluation throughout the course and the other, Jinwoo, was positioned as a preservice teacher and a subject of evaluation. Their positions were reflected in their epistemic understandings of inquiry-based lessons, which were developed when designing these lessons. During lesson design, both PSTs showed a shared understanding; they explained inquiry-based lessons as students setting and evaluating hypotheses under teachers' guidance. However, as they faced unexpected situations during lesson enactment, they developed different epistemic understandings. To receive a good grade, Dohyung showed a strong preference for anticipating situations that could occur in class and planning responses to them. He understood inquiry-based lessons as ones in which students conduct experiments to produce results expected by the teacher. On the other hand, Jinwoo emphasized the reasoning process based on students' prior knowledge and explained inquiry-based lessons as ones in which students construct new knowledge through a scientific reasoning process based on their knowledge. The findings of this study will contribute to developing strategies to support PSTs' development of their epistemic understandings of knowledge construction in inquiry-based lessons.

• Journal of The Korean Association For Science Education
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• v.41 no.4
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• pp.311-324
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• 2021

In this study, we analyzed the process of pre-service science teachers' designing and implementation of lessons in teaching practice from the perspective of CHAT. Five pre-service teachers attending the Department of Chemistry Education at the College of Education in Seoul participated in this study. We observed their teaching practice, collected documentary data, and conducted in-depth interviews. The data were analyzed using the constant comparative method based on grounded theory. The analyses of the results reveal that, due to the lack of authority to make decisions for lesson design, pre-service teachers faced difficulties and had direct conflict with teachers. In addition, it was difficult for them to obtain sufficient contextual information for lesson design even through subject orientation and classroom observation, which made it difficult for them to design lessons. When consecutive lessons were taken by several pre-service teachers, there were many problems such as poor continuity of lessons. Given limited authority to assess students, they conducted additional assessments. They showed a lack of professionalism when conducting assessments. The cause of this could be found in the curriculum of the College of Education. Some ways to provide better teaching practice based on the results are discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.6
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• pp.484-492
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• 2016

The turbine is an important component and has a significant impact on the thermodynamic efficiency of the organic Rankine cycle. A precise preliminary design is essential to developing efficient turbines. In addition, performance analysis and structural analysis are needed to evaluate the performance and structural safety. However, there are only a few exclusive studies on the development process of the radial inflow turbines for the organic Rankine cycle (ORC). In this study, a preliminary design of the ORC radial inflow turbine was performed. Subsequently, the performance and structural analysis were also carried out. The RTDM, which was developed as an in-house code, was used in the preliminary design process. The results of the performance analysis were found to be in good agreement with target performances. Structural analysis of the designed turbine was also carried out in order to determine whether the material selection for this study is suitable for the flow conditions of the designed turbine, and it was found that the selected aluminum alloy is suitable for the designed turbine. However, the reliability of the preliminary design algorithms and numerical methods should be strictly verified by an actual experimental test.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.2
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• pp.123-135
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• 2021

In this study, we apply a lesson design process using an argumentation structure to preservice earth science teachers and analyzed argumentation levels displayed in the lesson plans written by preservice teachers in the process. As a result of the study, the preservice teachers designed a logically structured lesson by reflecting more argumentation components in the final lesson plan than the first one. In addition, in the case of lesson topics in which all argumentation elements were not explicitly presented in textbooks or curriculum, preservice teachers could not clearly reflect some argumentation components in the lesson plan. The conclusions and implications based on the results are as follows: First, it is necessary to use the argumentation structure as a tool to design logical science lessons, considering that argumentation levels of lesson plans written by preservice science teachers were improved by using argumentation structures in instructional design. Next, it is necessary to cultivate the preservice science teacher's ability to reconstruct the curriculum for science lesson design using the argumentation structure since argumentation levels of lesson plans written by preservice science teachers were limited to the argumentation components presented in the textbook and curriculum. Additionally, it is necessary to develop and apply a preservice teacher education program that uses the argumentation structure in the context of actual teaching activities so that preservice science teachers can not only understand argumentation but also improve their class expertise.

• Journal of the Korean School Mathematics Society
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• v.23 no.1
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• pp.159-177
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• 2020

Education researchers have been continuously interested in the teacher's ability to design lessons and conducted various studies in order to improve the teacher's professionalism in determining the quality of school instruction. So, this study explored the change of instructional design through the lesson reflection of pre-service mathematics teachers who participated in practicum settings. As a result, in the lesson plan prepared by pre-service mathematics teachers, the motivation to induce learning in the introduction stage, to present the learning contents in the development stage, and to reconstruct the formative evaluation of the closing stage was the highest rate. And the categories of the reconstructed contents appeared intensively in terms of curriculum contents and teaching and learning methods. This result can be attributed to the lack of experience in designing and performing lessons by pre-service mathematics teachers, so it suggests that the opportunity to design and conduct classes that take into account the practical aspects of education should be provided in the preparation process for pre-service mathematics teachers.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.11a
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• pp.26-26
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• 2000

본 연구에서는 풍력발전기용 복합재 회전날개의 설계단계에서 공력 설계 후 결정되어진 공력 형상을 기초로 하여 구조적 형상설계를 수행 할 때에 여러 가지 경우의 형상을 해석하여 이중 설계요구조건에 적합한 경우를 채택하는 시행착오 방법으로 인한 비효율적인 요소를 배재 하기 위해 고전 적층판 이론을 기초로 한 해석 프로그램을 사용하여 예비설계를 수행하는 수정된 설계절차를 제안하였으며 예비설계단계에서 신속하고 신뢰성 있는 해석결과를 얻을 수 있었다.(중략)

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.01a
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• pp.117-120
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• 2018

테크놀로지의 발달에 따라 Technological Pedagogical Content Knowledge(TPACK)의 중요성이 증가하고 있다. 이에 따라 김성원과 이영준(2017)은 TPACK에서 테크놀로지의 도구를 프로그래밍까지 확장한 TPACK-Programming(TPACK-P) 교육 모델을 제안하였다. 또한, TPACK-P 교육 모델을 기반으로 TPACK-P 교육 프로그램을 개발하였으며, 예비 교사에게 적용하여 효과를 검증하였다. 그 결과, 다른 영역의 지식 발달에는 효과적이지만, Technological Content Knowledge(TCK)와 Technological Knowledge(TK)에는 영향을 주지 못하였다. 본 연구는 TPACK-P 교육 프로그램이 모든 영역의 지식 발달에 효과적이도록 만들기 위해서 예비 교사를 대상으로 TPACK-P 교육 프로그램을 적용하고, TPACK-P 교육 프로그램에 대한 인식을 조사하였다. 그 결과, 예비 교사는 프로그래밍 학습, 교과와 교육과정에 맞는 프로그램 설계, 프로그램 제작 과정에서 어려움이 있는 것으로 나타났다. 또한, 이러한 어려움을 극복하기 위해서 프로그래밍 학습의 강화와 프로그래밍 수업 설계 예시의 탐색이 필요하다고 말하였다. 이러한 연구 결과를 통하여 TCK와 TK의 향상을 위하여 프로그래밍을 효과적으로 가르치기 위한 교육 방안과 예비 교사의 교과 내용과 프로그래밍의 연결을 촉진하기 위한 내용이 TPACK-P 교육 모델에 보완되어야 한다는 것을 확인할 수 있었다.