• Aerospace Engineering and Technology
• /
• v.1 no.1
• /
• pp.177-187
• /
• 2002

Some kinds of precision optical systems for spaceborne high resolution cameras were designed at preliminary design level and an optical design for a hyperspectral imager was performed for its development model. A Cassegrain-based catadioptric system and an unobscured reflective triplet system are illustrated in detail for spaceborne high resolution electro optical cameras which have performance of 5m resolution at an altitude of 685km and the design are evaluated in its spot-diagram and MTF to prove they have good performance enough to implement the requirements for realistic satellite payload taking the fabrication conditions and the on-orbit operation into consideration. For the development of hyperspectral imager as a next-generation payload, an optical system has been designed and elaborated. It can be divided into two parts, a catoptric telescope forming an off-axis 2 mirror type and a dispersive spectrometer which comprises collimator, grating and reimaging lens cell. From its optical design to the system characteristics are shown with the MTF performance reaching 25% approximately.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2010.05a
• /
• pp.347-348
• /
• 2010

• Journal of the Korea Convergence Society
• /
• v.13 no.1
• /
• pp.357-364
• /
• 2022

This study aims to design a humanities model for preliminary universities using an online platform to develop and expand humanities thinking of preliminary university students. P University Expert Focus Group Interview and student surveys are conducted, and based on the analysis results, a preliminary university model suitable for the humanities field is proposed. Expert FGI suggested the necessity of human resources education to build an online platform-based preliminary university model and improve humanities capabilities. As a result of the student survey, it was found that a majority of the respondents had high interest in humanities and recognized the need for a humanities preliminary university. This study proposes a humanities-based preliminary university model that enables interactive communication in virtual space using the cross-platform Photo Server. The implication of this study is that it contributes to strengthening the humanities capabilities of preliminary university students by presenting an online platform preliminary university model that can respond to changes in the external environment. Since this study has a limitation in that it does not present examples of preliminary universities, it is necessary to verify the educational effect of platform-based ppreliminary university management in the future.

• Journal of the Korean School Mathematics Society
• /
• v.18 no.4
• /
• pp.449-470
• /
• 2015

The purpose of this study was to explore the feasibility of Flipped Learning teaching and learning methods in pre-math teachers' education through investigation of pre-math teachers' awareness about the method. To achieve the goal, we implemented Flipped Learning model that was composed of three steps in mathematics education class of 30 pre-math teachers and then we investigated their awareness about the model and process. Pre-math teachers' awareness were positive about the model and process of Flipped Learning, but some matters were suggested about learning environment. The results of this study showed the feasibility of Flipped Learning in pre-math teachers' education.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.12A
• /
• pp.1899-1909
• /
• 1999

Considering survivability in fiber-optic transmission networks using B-DCS(Broadband Digital Cross-connect System), a network design problem consists of WCAP(Working Channel Assignment Problem) and SCAP(Spare Channel Assignment Problem). WCAP has not been studied intensively as a part of a network design problem to minimize total network cost while SCAP has been studied in the several papers as an independent problem. In this study, we developed a WSCAP(Working and Spare Channel Assignment Problem) algorithm which is to minimize the total number of spare channels and working channels. After problem description, an IP(Integer Programming) model is formulated and several heuristic algorithms are presented. Finally, the result of a case study is described.

• Communications of Mathematical Education
• /
• v.37 no.3
• /
• pp.497-516
• /
• 2023

The purpose of this study is to explore the possibility of enhancing teachers' pedagogical design capacity using ChatGPT. For this purpose, a survey was conducted to investigate preservice teachers' perceptions of ChatGPT, and lesson plans created using ChatGPT were analyzed from the perspectives of design elements, conversations with ChatGPT, and information transforming. The results showed that pre-service teachers have a rather passive attitude toward the use of ChatGPT, and that teacher moderation and ChatGPT characteristics affect pre-service teachers' perceptions of the use of ChatGPT. In addition, pre-service teachers mainly used ChatGPT for motivational activities and play activities, and there were significant differences in the level of utilization of ChatGPT among individuals, i.e., how they interacted with ChatGPT and how they transformed information. Based on these findings, we explored the possibility of using ChatGPT for teacher professional development and teacher education.

• Journal of Astronomy and Space Sciences
• /
• v.25 no.2
• /
• pp.227-238
• /
• 2008

GNSS (Global Navigation Satellite System) Ground Station monitors navigation satellite signal, analyzes navigation result, and uploads correction information to satellite. GNSS Ground Station is considered as a main object for constructing GNSS infra-structure and applied in various fields. ETRI (Electronics and Telecommunications Research Institute) is developing Monitoring and Control subsystem, which is subsystem of GNSS Ground Station. Monitoring and Control subsystem acquires GPS and Galileo satellite signal and provides signal monitoring data to GNSS control center. In this paper, the configurations of GNSS Ground Station and Monitoring and Control subsystem are introduced and the preliminary design of Monitoring and Control subsystem is performed. Monitoring and Control subsystem consists of data acquisition module, data formatting and archiving module, data error correction module, navigation solution determination module, independent quality monitoring module, and system operation and maintenance module. The design process uses UML (Unified Modeling Language) method which is a standard for developing software and consists of use-case modeling, domain design, software structure design, and user interface structure design. The preliminary design of Monitoring and Control subsystem enhances operation capability of GNSS Ground Station and is used as basic material for detail design of Monitoring and Control subsystem.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.3
• /
• pp.29-36
• /
• 2009

In this paper, a case of a high-rise building supported by a large-diameter drilled shaft socketed in a weathered ground has been studied. The design case of pile foundation presented in this paper could be a representative example of execution of pile design through three(3) design stages of "preliminary design-proof test-supplementary design". As proof test, two(2) BDH PLT (Bi-directional High Pressure Pile Load Test) were performed at the early construction stage. By following the design process of this way, the economic pile design could be carried out and a large amount of construction cost saving could be realized.

• Journal of the Korean Society of Earth Science Education
• /
• v.13 no.3
• /
• pp.238-252
• /
• 2020

In this study, we analyzed the types of rebuttals in the argument structure of learning contents in lesson plans constructed by Earth science preservice teachers, and then we explored examples of how they responded to resolving the rebuttal. As a result of analyzing preservice teachers' assignments, discussions, and interviews collected during a total of 20 hours of classes and group discussions for 5 weeks, all 5 types of rebuttals suggested by Verheij (2005) were identified. Through the data analysis, a total of 18 rebuttal cases derived, and these cases were classified into 3 types according to how preservice teachers solve the rebuttals in class. The conclusions and implications based on the results are as follows: First, this study provided empirical data that the thinking process of validating core elements of argumentation and processes of argumentation is actively taking place in preservice teachers' lesson planning using the argument structure, and expanded the scope of application of argumentation in science education research. Second, the argument structure of learning contents should be used to help teachers to come up with strategies to induce students' curiosity and devotion to learn science contents. Third, preservice teachers should have the opportunity to think about the nature of science, including the variability and uncertainty of scientific knowledge when they discover rebuttals and develop solutions to them. Based on these conclusions, implications and suggestions for science education and further research were suggested.

• Journal of The Korean Association For Science Education
• /
• v.43 no.6
• /
• pp.563-572
• /
• 2023

This study aimed to analyze cases of online class design by pre-service science teachers to identify the teaching strategies employed for online classes. For this purpose, the real-time online class lesson plans of 12 pre-service science teachers, who had experienced education utilizing online teaching tools for a semester, were collected and analyzed. The pre-service science teachers considered all the elements that were essential in traditional face-to-face class designs, including prerequisites, statements of learning objectives, stimulating motivation, teaching and learning methods, wrapping up, teacher-student interaction, and assessment. They devised teaching strategies that could overcome the limitations of online teaching and were not feasible in face-to-face classes for each element. Additionally, they were considering new instructional strategies tailored to the online teaching environment, such as creating a conducive environment for using online teaching tools and strategies related to checking the online teaching environment. However, for statements of learning objectives, stimulating motivation, and wrapping up, most of the pre-service science teachers predominantly utilized teaching strategies from traditional face-to-face classes, especially those involving the presentation of visual materials through online tools. Student-centered approaches were rarely implemented in stimulating motivation or wrapping up. These findings imply that one semester of exposure to the utilization of online teaching tools may be insufficient in teacher education. Thus, there is a need for a continuous and expanded educational program on the utilization of online teaching tools as part of pre-service teacher education.