• Journal of Korean Elementary Science Education
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• v.42 no.4
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• pp.538-559
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• 2023

In this study, the interplay between models and theories was explored through a series of focus group discussions (FGDs) involving five experts in science education. The FGDs were held seven times, beginning with the question of what is modeling in relation to models, which is a current area of research in science education. Throughout the discussion, several key issues regarding models and modeling were addressed, with a particular emphasis on their relationship to theory. A notable finding from this study is that the participants' discussions did not converge into a single viewpoint regarding the relationship between theory and models; instead, multiple related issues emerged, leading to attempts to reframe existing concepts and seek new understanding. The study findings relate to three main areas of inquiry: What is the meaning of models or modeling? What is the nature of the relationship between models and theories?, and Is modeling possible without a foundation in theory? Particularly, the relationship between models and theories was discussed in reference to the following points: 1) Is a model to be understood as derived from theory, and is modeling the application of theory to phenomena? 2) Can a model be inferred from theory? 3) Does modeling originate from a specific, structured foundational theory (a framework of empirical knowledge), or is it to be understood through the integration of various resources without explicit reference to a foundational theory? Based on the study outcomes, implications are presented for philosophy of science and for researchers and educators working in the realm of science education.

• Journal of The Korean Association For Science Education
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• v.35 no.5
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• pp.919-929
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• 2015

This study aims to develop a modeling-based learning program about geologic structures and to reveal the relationship between the argumentation patterns and levels of students' mental models. Participants included 126 second grade high school students in four sessions of modeling-based learning regarding continental drift, oceanic ridges, transform faults, and characteristics of faults. A modeling-based learning program was implemented in two classes of the experimental group, and teacher-centered traditional classes were carried out for the other students in the comparison group. Science achievement scores and the distribution of students' mental models in experimental and comparison groups were quantitatively compared. The video-taped transcripts of five teams' argumentation were qualitatively analyzed based on the analytic framework developed in the study. The analytic framework for coding students' argumentation in the modeling-based learning was composed of five components of TAP and the corresponding components containing alternative concepts. The results suggest that the frequencies of causal two-dimensional model and cubic model were high in the experimental group, while the frequencies of simple two-dimensional model and simple cross sectional model were high in the comparison group. The higher the frequency of claims, an argumentation pattern was proven successful, and the level of mental model was higher. After the rebuttal was suggested, students observed the model again and claimed again according to new data. Therefore, the model could be confirmed as having a positive impact on students' argumentation process.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.310-312
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• 1994

A partial shunt regulator (PSR) which is the power regulator of KOREASAT is modeled. The modeling of the PSR consist of solar array, power circuit, controller. and load models. To realize simple structure. a voltage source of the PSR controller is used the output voltage of the PSR. The model of the PSR has very complex structure with two additional coupled feedback loops. The complex model is simplified to a simple meaningful model with only main feedback control loop. The proposed model is compared to a PSR model with DC voltage source at the PSR controller. The proposed PSR model is verified by comparing the model with SPICE simulation for small signal analysis.

• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.51-57
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• 2004

This paper describes the dynamic performance of a variable speed wind turbine system responding to a wide variety of wind variations. Modeling of the wind generation using power electronics interface is proposed for dynamic simulation analysis. Component models and equations are addressed and their incorporations into a transient analysis program, PSCAD/EMTDC are provided. A wind model of four components is described, which enables observing dynamic behaviors of the wind turbine resulting from wind variations. Controllable power inverter strategies are intended for capturing the maximum power under variable speed operation and maintaining reactive power generation at a pre-determined level for constant power factor control or voltage regulation control. The components and control schemes are modeled by user-defined functions. Simulation case studies provide variable speed wind generator dynamic performance for changes in wind speed

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1268-1275
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• 2005

The computerization works and environment have been changed from simple transaction and data process request to system connection request, from data computerization to application work automation and process computerization through IT development and Internet spread. Recently, BPM(Business Process Management) concept has been widely propagated. It is expanding interest of business subject. Korea Railroad is operating train operation management system through 5 regional headquarters and organizations under the influence of each regional headquarter. But integrated operation and management of communication each department, work flow management and resources of depot equipment and materials have to need a lot of effort and time in huge organization as Korea Railroad. Therefore, this article realized Web Based BPM Group Ware. This article will define Korea Railroad organization and business process in using this Group Ware. And it will introduce Korea Railroad computer manage system of this Group Ware and efficient Korea Railroad Business Process through modeling and operating department work and resources management in Korea Railroad.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1266-1271
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• 2009

Formwork layout is perceived as important due to its strong tie to site works. But, most formwork is done manually and influenced by worker's skill and thus, a lot of construction errors occur. The introduction of BIM (Building Information Modeling) enables acquiring more precise information on the building shape, dimension, structure, etc. than 2D-based drawings and thus, the increased productivity, such as reduction of workload and work times, and the economic efficiency, such as reduction of formwork types and form dimensions with the consideration of constructability, are expected. This study reviewed the previous studies and formwork layout systems to derive this study's differentiations and factors to be first considered for formwork planning were derived by analyzing priorities against consideration factors. Last, a flow chart and algorithm were developed to apply the derived factors to the formwork layout module.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.587-592
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• 2009

Construction companies in Korea have shown interest in BIM (Building Information Modeling) even if late, adopted it, and applied it to several projects. But, it is hard to figure out the status of BIM implementation. Thus, this study is to figure out the status of BIM implementation in Korea by surveying major construction companies in Korea and comparing with similar surveys abroad. The survey result shows that only 11 companies in Korean construction industry adopted BIM. The clash check (73%) was mostly used among various BIM functions and other functions were used less than 30%. As of 2008, only 8 construction companies have used BIM in 27 projects and thus, Korean companies are in the BIM introduction period. Therefore, successful introduction of BIM is required by benchmarking the BIM introduction process of overseas construction industries

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.139-144
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• 2005

A rigorous research is underway in our team, for the design and development of high figure of merits (ZT= 1.5${\sim}$2.0) micro-thermoelectric coolers. This paper discusses the fabrication process that we are using for developing the $Sb_2Te_3-Bi_2Te_3$ micro-thermoelectric cooling modules. It describes how to obtain the mechanical properties of the thin film TEC elements and reports the results of an equation-based multiphysics modeling of the micro-TEC modules. In this study the thermoelectric thin films were deposited on Si substrates using co-sputtering method. The physical mechanical properties of the prepared films were measured by nanoindentation testing method while the thermal and electrical properties required for modeling were obtained from existing literature. A finite element model was developed using an equation-based multiphysics modeling by the commercial finite element code FEMLAB. The model was solved for different operating conditions. The temperature and the stress distributions in the P and N elements of the TEC as well as in the metal connector were obtained. The temperature distributions of the system obtained from simulation results showed good agreement with the analytical results existing in literature. In addition, it was found that the maximum stress in the system occurs at the bonding part of the TEC i.e. between the metal connectors and TE elements of the module.

• Journal of Research and Publication Ethics
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• v.2 no.1
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• pp.19-24
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• 2021

Purpose: The purpose of this study is to check the direction of KODISA's pursuit of complex and convergence studies by confirming the research trends of KODISA's direct academic journals such as JDS, JIDB, JBEES and JAFEB. To this end, we tried to compare and confirm the research trends of the papers in four academic journals targeting keywords. Research Design, data and methodology: The analysis was conducted from 2014 to 2020 on 867 papers from JDS, 315 papers from JIDB, 120 papers from JBEES, and 867 papers based on the publication year of the most recently published journal from JAFEB. For the analysis, frequency analysis, word crowding, topic modeling, and frequency analysis by applying weights for each year group were performed on the keywords crawled using Python. Results: The results of frequency analysis showed that each journal is properly oriented toward its target direction. In addition, it was confirmed that the results of topic modeling significantly reflected the results of frequency analysis. Finally, it could be concluded that the results of frequency analysis using the weights of keywords by year group were also developing in the direction the target journals were analyzed. Specifically, in the case of JDS, 20 keywords such as Service Quality, Distribution were found to increase continuously according to the year group. Meanwhile, the keywords that continued to increase according to JIDB's year group were India, Social Capital, and Job Stress. The keywords that continued to increase according to the year group of JBEES were Micro Finance Institutions and Microfinance, and the keywords that of JAFEB were confirmed to be Vietnam and Service Quality. Conclusion: It was confirmed that KODISA's direct management journals responded appropriately to convergence issues. In particular, it was confirmed that researches in various fields of JDS are continuously increasing. However, it seems that JIDB needs to deal with various issues additionally in the service industry field and JBEES in the environment field. Finally, it was found that JAFEB needs to be wary of the relatively low level of interest in some countries such as Kazakhstan and India in recent years.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.799-807
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• 2019

The study was conducted to identify if the first-year program of science-focused school improved students' scientific core competency and science learning motivation. The first-year program of the science-focused school consisted of basic education in scientific inquiry, investigation, advanced experiment, and basic education in small research. There were a total of 262 participants in the program, and 169 students took three survey tests. Through the analysis of a group-based trajectory modeling, students were differentiated based on similarity of score changes. This study showed that the first-year program of the science-focused school significantly improved students' scientific core competency and science learning motivation. A group-based trajectory modeling found that about 40~60% of students saw the effects of the program. The students who chose the humanity track showed effects, while some students who chose the science-focused track did not show effects. A group-based trajectory modeling showed the methodological effects of identifying the change process of individual students. This study identified the positive effects of science-focused school policy statistically and is a meaningful example for analyzing the effectiveness of science-focused school programs.