• Journal of the Korean School Mathematics Society
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• v.24 no.1
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• pp.83-105
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• 2021

In this paper, we analyzed the misconceptions and errors incurred during factorization learning. We also examined whether online individualization classes had a positive effect on students' mathematical achievement. The experiment was conducted for 4 weeks (16 times in total) on middle school juniors in rural areas of Gyeonggi Province, where the influence of private extra education was small. In the class, the 'Google Classroom' was used as a LMS, the video lecture was uploaded to YouTube, and the teacher interacted with the students through "Zoom" and "Facetalk". In the online class situation, students' assignments and test answers were checked in real time through 'Google Classroom', and immediate feedback was provided to the experimental class group's students. However, for the control group students, feedback was provided only to those who desired. A total of 7 achievement evaluations were conducted in the order of pre-test, formative evaluation (5 times), and post-test to confirm the change in students' ability improvement and achievement. Through the formative evaluation analysis, it was possible to grasp the types of errors and misconceptions that occured during the factorization process. Students' errors were divided into four types: theorem or definition distortion error, functional errors such as calculation, operation, and manipulation, errors that do not verify the solution, and no response. As a result of ANCOVA, the two groups did not show any difference from the 1st to 4th formative assessment. However, the 5th formative assessment and post-test showed statistically significant differences, confirming that online individualization classes contributed to improvemed achievement.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.1-16
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• 2021

The act of design in landscape architecture consists of a concept within a designer's mind, technical representations, and finally, a process of construction. In the 4th Industrial Revolution, the design process is facing many changes due to the rapid development of computer technology and the IT ecosystem. Computer technology was initially developed for simple functions, such as mathematical calculation and graphic representation. However, after the spread of Personal Computers, starting with IBM and Macintosh, programming languages and hardware rapidly developed, algorithms and applications became specialized, and the purpose of using computers became very diverse. This study diagnoses issues concerning the functions and roles that new design methods, such as computational design, parametric design, and algorithmic design, can play in landscape architecture based on changes in the digital society. The study focused on the design methodology using parametric technology, which has recently received the most attention. First, the basis for discussion was developed by examining the main concepts and characteristics of parametric design in modern landscape architecture. Prior research on the use of parametric design in landscape architecture was analyzed, as were the case studies conducted by landscape design firms. As a result, it was confirmed that parametric design has not been sufficiently discussed in terms of the number and diversity of studies compared to other techniques investigated by landscape design firms. Finally, based on the discussion, the study examined specific cases and future possibilities of the parametric design in landscape architecture.

• Journal of vocational education research
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• v.37 no.4
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• pp.23-44
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• 2018

The purpose of the study was to examine the vocational competency of students enrolled in vocational high schools including specialized vocational high school and meister vocational high school, and vocation program of general high school. We analyzed their vocational competency, based upon the vocational competency data of KCCI (Korea Chamber of Commerce & Industry). The results were as follow. First, latent profiles of subjects were categorized into four folds: general cognition-low adaption, cognition adaption general, pursuit of job adaption, low cognition-job mal-adaption. Each percentage of four groups was 39%, 30%, 11%, and 20%. Second, mainly, specialized vocational high school pattern is matched with vocational high schools' pattern. However, the cognitive competency of students in meister vocational high school was higher than that of student in vocation program of general high school. Third, latent profile group was clarified in terms of non-cognition aspect. Fourth, The higher the job adaption is, the higher the career decision level. We suggested some policy implications for improve the vocational competency.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.253-260
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• 2019

Radiation dose enhancement is a method of increasing the cross section of interaction, thus increasing the deposited dose. This can contribute to linear energy transfer, LET and relative biological effectiveness, RBE. Previous studies on dose enhancement have been mainly focused on X, ${\gamma}-rays$, but in this study, the dose enhancement was analyzed for proton using Monte Carlo simulation using MCNP6. Based on the mathematical modeling method, energy spectrum and relative intensity of spread out Bragg-peak were calculated, and evaluated dose enhancement factor and dose distribution of dose enhancement material, such as aurum and gadolinium. Dose enhancement factor of 1.085-1.120 folds in aurum, 1.047-1.091 folds in gadolinium was shown. In addition, it showed a decrease of 95% modulation range and practical range. This may lead to an uncertain dose in the tumor tissue as well as dose enhancement. Therefore, it is necessary to make appropriate corrections for spread out Bragg-peak and practical range from mass stopping power. It is expected that Monte Carlo simulation for dose enhancement will be used as basic data for in-vivo and in-vitro experiments.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.611-622
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• 2018

In this study, I was to investigate the trends in research on walking and positioning in Korea and to compare the results of researches on the Visually Impaired and the Non-disabled. I selected 113 papers in order to know the current status of the study for the visually impaired and to suggest future research directions. This study analyzed the general features (publication year, academic journals, number of authors, keywords, research methods, research types, implementation methods, research support, references) and research themes and contents of domestic research on walking and positioning. As a result, there was no an upward trend in number of publications by the Visually Impaired compared to the Non-disabled. In addition, in the case of the non-disabled, Research topics, types of research, implementation include various attempts of location-related technologies, and system development, improvement, stabilization, and accuracy, whereas in the case of the visually impaired, there were focused on development of systems, portable or attachable devices that reflect the characteristics of the visually impaired. There were not many studies on system improvement. Research support also showed that the non-disabled received various research support. Therefore, I suggested the need to continuously develop and improve the research, to diversify research topics and research types, to expand the research scope, to improvement feasibility for the visually impaired.

• (The) Research of the performance art and culture
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• no.36
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• pp.255-287
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• 2018

This article deals with one of the pansori master's life and activities. Bak Songhui(1927~2017), who was the holder of National Intangible Cultural Asset No. 5 for pansori Heungboga. She had played a significant role through the modern history of pansori genre including Yeoseong Gukkeuk(Korean classical opera by women) and Changgeuk(Korean traditional opera in pansori style) as well as original pansori itself. In the article, the early stage of her learnings and the way she got involved to pansori from Gwonbeon period are offered, and the activities by group, solo recitals, and educational activity lists are also provided. Bak Songhui began to learn pansori, Geommu(dance), Seungmu(dance), Gayageum, Yanggeum, and Gagok genres at her age of 13 in Gwangju. She fulfilled 5 years of study in Gwangju Gwonbeon, and entered to a Hyeomnyulsa-travelling theater company, led by Gim Yeonsu at her age around 19. Later, Bak used to be an actress in Yeoseong Gugak Donghohoe(Female Korean music fans' club) led by Gim sohui as well as in Haennim Gukkeukdan, and Saehan Gukkeukdan at around her age of 30. She took the main actress' role in several performances. And thanks to her effort, the Yeoseong Gukkeuk can be one of the representative genre in history. As she entered to the National Changgeuk company, her brilliant talents worked well by leading the company's big hit with her talents of taking many different characters, devotions, and know-hows from her experience. After her 70s, she kept the pansori go on its right way to pass down. She unfolded pansori performances as well as her own students' public presentations, recordings, TV and radio broadcasting activities as the holder of National Intangible Cultural Asset. The activities that Bak Songhui showed us can become another chance to make her a great master of pansori, especially in Dongpyeonje style.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.353-358
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• 2018

In this study, it is describe to an optimization analysis process for the weight reduction of the voltage converter in the electric vehicle charging systems. The optimization design is a technique that finds the optimal material distribution under a given material quantity constraint by combining the design sensitivity with the material properties and the mathematical optimization. Among the topology optimization, a lightweight design is performed by a solid isotropic material with penalization with simple formula and well-convergence. The lightweight design consists of three steps. As a first step, a finite element model for the basic design of the on-board voltage converter was constructed and static analysis was performed on the load. In the second step, the optimum shape is obtained for the lightweight by performing the topology optimization using the solid isotropic material with penalization applying the stiffness coefficient of the isotropic material to the static analysis result. As a final step, impact analysis was performed by applying a half-sinusoidal pulse shape impact load which satisfies the impact test standard of the vehicle-mounted part with respect to the optimum shape. In the topology optimization, the design domain was defined as the mounting bracket area, and the design technology was finally achieved by optimizing the mounting bracket to achieve a weight reduction of 20% over the basic design.

• Journal of Korean Society of Disaster and Security
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• v.11 no.2
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• pp.37-43
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• 2018

The storm surge is caused by an typhoons and it is not easy to predict the location, strength, route of the storm. Therefore, research using a scenario for storms occurrence has been conducted. In Korea, hazard maps for various scenarios were produced using the storm surge numerical simulation. Such a method has a disadvantage in that it is difficult to predict when other scenario occurs, and it is difficult to cope with in real time because the simulation time is long. In order to compensate for this, we developed a method to predict the storm surge damage by using research database. The risk grade prediction for the storm surge was performed predominantly in the study area of the East coast. In order to estimate the equation, COMSOL developed by COMSOL AB Corporation was utilized. Using some assumptions and limitations, the form of the basic equation was derived. the constants and coefficients in the equation were estimated by the trial and error method. Compared with the results, the spatial distribution of risk grade was similar except for the upper part of the map. In the case of the upper part of the map, it was shown that the resistance coefficient, k was calculated due to absence of elevation data. The SIND model is a method for real-time disaster prediction model and it is expected that it will be able to respond quickly to disasters caused by abnormal weather.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.4
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• pp.249-256
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• 2019

This paper presents an optimization framework of electrical impedance tomography for characterizing electrical conductivity profiles of concrete structures in two dimensions. The framework utilizes a partial-differential-equation(PDE)-constrained optimization approach that can obtain the spatial distribution of electrical conductivity using measured electrical potentials from several electrodes located on the boundary of the concrete domain. The forward problem is formulated based on a complete electrode model(CEM) for the electrical potential of a medium due to current input. The CEM consists of a Laplace equation for electrical potential and boundary conditions to represent the current inputs to the electrodes on the surface. To validate the forward solution, electrical potential calculated by the finite element method is compared with that obtained using TCAD software. The PDE-constrained optimization approach seeks the optimal values of electrical conductivity on the domain of investigation while minimizing the Lagrangian function. The Lagrangian consists of least-squares objective functional and regularization terms augmented by the weak imposition of the governing equation and boundary conditions via Lagrange multipliers. Enforcing the stationarity of the Lagrangian leads to the Karush-Kuhn-Tucker condition to obtain an optimal solution for electrical conductivity within the target medium. Numerical inversion results are reported showing the reconstruction of the electrical conductivity profile of a concrete specimen in two dimensions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.872-877
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• 2018

STEAM is an acronym for Science, Technology, Engineering, Arts, and Mathematics. It is considered important to equip students with a creative thinking ability and the core competences required in future society, helping them devise new ideas emerging from branches of study. This study is about the convergence of instructional design in private finance for the life sciences, which aims to foster talent through problem-based learning (PBL). Skills like collaboration, creativity, critical thinking, and problem solving are part of any STEAM PBL, and are needed for students to be effective. STEAM projects give students a chance to problem-solve in unique ways, because they are forced to use a variety of methods to solve problems that pop up during these types of activities. The results of this study are as follows. First is the structured process of convergence lessons. Second is the convergence lesson process. Third is the development of problems in the introduction of private finance and the life sciences for a convergence lesson at Dornod University. Learning motivation shows the following results: understanding of learning content (66.6%), effectiveness (63.3%), self-directed learning (59.9%), motivation (63.2%), and confidence (63.3%). To make an effective model, studies applying this instructional design are to be implemented.