• Smart Structures and Systems
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• v.13 no.4
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• pp.587-614
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• 2014

In recent years the interest in online monitoring of lightweight structures with ultrasonic guided waves is steadily growing. Especially the aircraft industry is a driving force in the development of structural health monitoring (SHM) systems. In order to optimally design SHM systems powerful and efficient numerical simulation tools to predict the behaviour of ultrasonic elastic waves in thin-walled structures are required. It has been shown that in real industrial applications, such as airplane wings or fuselages, conventional linear and quadratic pure displacement finite elements commonly used to model ultrasonic elastic waves quickly reach their limits. The required mesh density, to obtain good quality solutions, results in enormous computational costs when solving the wave propagation problem in the time domain. To resolve this problem different possibilities are available. Analytical methods and higher order finite element method approaches (HO-FEM), like p-FEM, spectral elements, spectral analysis and isogeometric analysis, are among them. Although analytical approaches offer fast and accurate results, they are limited to rather simple geometries. On the other hand, the application of higher order finite element schemes is a computationally demanding task. The drawbacks of both methods can be circumvented if regions of complex geometry are modelled using a HO-FEM approach while the response of the remaining structure is computed utilizing an analytical approach. The objective of the paper is to present an efficient method to couple different HO-FEM schemes with an analytical description of an undisturbed region. Using this hybrid formulation the numerical effort can be drastically reduced. The functionality of the proposed scheme is demonstrated by studying the propagation of ultrasonic guided waves in plates, excited by a piezoelectric patch actuator. The actuator is modelled utilizing higher order coupled field finite elements, whereas the homogenous, isotropic plate is described analytically. The results of this "semi-analytical" approach highlight the opportunities to reduce the numerical effort if closed-form solutions are partially available.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.77-83
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• 2020

The technologies of 3D spatial information, such as Smart City and Digital Twins, are developing rapidly for managing land and solving urban problems scientifically. In this construction of 3D spatial information, an object using aerial photo images is built as a digital DB. Realistically, the task of extracting a texturing image, which is an actual image of the object wall, and attaching an image to the object wall are important. On the other hand, occluded areas occur in the texturing image. In this study, the ResNet algorithm in deep learning technologies was tested to solve these problems. A dataset was constructed, and the street tree was detected using the ResNet algorithm. The ability of the ResNet algorithm to detect the street tree was dependent on the brightness of the image. The ResNet algorithm can detect the street tree in an image with side and inclination angles.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.395-401
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• 2020

With the popularization of smartphones and the development of digital technologies, new concepts that maximize interactive communication have begun to appear in marketing strategies. One of them is the gamification marketing strategy that combines games with marketing that induces customer interest and voluntary participation. Gamification is a compound word of 'game' and '-fication', and marketing cases using game formats are being implemented in various fields. Therefore, this study will identify the implications of the usage of gamification that has become a trend, and analyze the gamification techniques and factors shown in various cases to suggest the direction of gamification as an effective marketing strategy. Companies are actively using gamification in their marketing strategies in a variety of forms and apply gamification techniques such as challenge, competition, accomplishment, reward, and relationship. As a result of the case analysis, important factors commonly identified in the gamification techniques used in marketing are 'Accomplishment' and 'Rreward'. Using various products and benefits obtained through solving a given mission or task as game elements, it was found to be an effective strategy to induce consumers' interest and participation and to promote consumption by encouraging consumers' immersion.

• Journal of Korea Technology Innovation Society
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• v.19 no.2
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• pp.231-253
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• 2016

The purpose of this study is two fold. First, we will explore the meaning, spread effect and consideration factors of manufacturing innovation in terms of theoretical perspective. Second, we will verify the status of high performance computing (HPC) utilization policy, and analyze the situation of US and Korea. Manufacturing innovation policy in each country has the objective in common which aims epoch-making enhancing of productivity. Nevertheless it can be characterized as innovation oriented policy rather than simple trial of productivity improvement. For long term growth and employment, the need for reindustrialization instead of deindustrialization should be recognized. Employment may be decreased temporarily and partially due to manufacturing innovation. However net effect of employment increasing will be bigger because of indirect employment. HPC utilization policy has the importance as a separate movement other than as a subset of manufacturing innovation. US government is trying to eliminate the bottleneck elements in adoption of HPC based M&S activity, and to promote the way of problem solving through the mechanism of public-private partnership, in spite of low level of HPC based M&S. In Korea, ecosystem related with the activity of HPC based M&S is needed, and expansion of M&S utilization in manufacturing companies and fostering of M&S supporting institutions will be important for this task.

• Journal of Science Education
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• v.40 no.1
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• pp.52-71
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• 2016

The purpose of this study is to analyze the learning activities which use asexual reproduction learning application(app) of students with special needs through the Cultural Historical Activity(CHAT). The asexual reproduction learning app was developed for students with special needs, and analyzed the learning activities of students with special needs in perspective of CHAT. The app was developed as subsidiary study material for asexual reproduction inquiry learning. Main functions of the app were composed of concept learning, problem solving, video playing, and report writing. According the CHAT analysis, findings indicated that students with special needs as the subject were able to organize division of labor demonstrated in cooperative learning with the object to actively participate in the class by using the tool of an app. This study also showed effective teaching strategy for improvement of learning achievement and task behavior level of student with special needs.

• School Mathematics
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• v.16 no.1
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• pp.1-17
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• 2014

Mathematical creativity in school mathematics is connected with problem solving. The purpose of this study was to analyse elementary students' the mathematical creativity using multiple solution tasks which required to solve a mathematical problem in different ways. For this research, I examined and analyzed the response to four multiple solution tasks according to the evaluation system of mathematical creativity which consisted of the factors of creativity(fluency, flexibility, originality). The finding showed that mathematical creativity was different between students with greater clarity. And mathematical creativity in tasks was different. So I questioned the possibility of analysis of students' the mathematical creativity in mathematical areas. According to the evaluation system of mathematical creativity of this research, mathematical creativity was proportional to the fluency. But the high fluency and flexibility was decreasing originality because it was easy for students to solve multiple solution tasks in the same ways. So, finding of this research can be considered to make the criterion in both originality in rare and mathematical aspects.

• Journal of Educational Research in Mathematics
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• v.14 no.1
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• pp.39-69
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• 2004

This paper investigates the teaching and learning of Linear function relating functional contexts and suggests the improved methods of representation-shift through this analysis. The methods emphasize the link between students' preacquired knowledge of mathematical representations and the way of using those. This methods are explanatory teaching, teaching and teaming based on modelling perspectives or tasks (interpretation, prediction, translation and scaling). We categorize the 8th grade middle school students' errors on the linear function relating real contexts and make a comparative study of the error-remedial effects and the teaching and teaming methods. We present the results of a study in which representation-shift methods based on modelling perspectives and tasks are more effective in terms of flexible connection of representations and error remediation. Also, We describe how students used modelling perspective-taking to explain and justify their conceptual models, to assess the quality of their models and to make connection to other mathematical representation during the problem solving focusing on the students' self-diagnosis.

• Journal of Educational Research in Mathematics
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• v.23 no.4
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• pp.505-516
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• 2013

The purpose of this paper is to analyse the essence of proportional reasoning and to analyse the contents of the textbooks according to the mathematics curriculum revised in 2007, and to seek the direction for developing the proportional reasoning in the elementary school mathematics focused the task variables. As a result of analysis, it is found out that proportional reasoning is one form of qualitative and quantitative reasoning which is related to ratio, rate, proportion and involves a sense of covariation, multiple comparison. Mathematics textbooks according to the mathematics curriculum revised in 2007 are mainly examined by the characteristics of the proportional reasoning. It is found out that some tasks related the proportional reasoning were decreased and deleted and were numerically and algorithmically approached. It should be recognized that mechanical methods, such as the cross-product algorithm, for solving proportions do not develop proportional reasoning and should be required to provide tasks in a wide range of context including visual models.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.9-18
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• 2016

ICT is still lacking relevant studies and efforts even though it needs to be accompanied by character education. Against this backdrop, this study has developed and operated an education program that combines ICT with character education and conducted surveys on its accomplishments. The research findings are as follows. The analysis of theme-based correlations has revealed that individual's character has not significantly affected character for others and global character and that building character for others have made a significant impact on establishing global character with a high level of correlations. Therefore, I have found that a program involving a group of people together such as team-based task has a positive effect on fostering problem-solving talents with global leadership. It is hard to obtain tangible results in character education in a short period of time but I would like to contribute to laying the foundation for cultivating and fostering talents equipped with global leadership while respecting oneself and caring for others in everyday life through these classes. There is a study on convergence of character education and different subjects, left behind of this study.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.501-510
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• 2013

In the creative problem solving processes, the core was to generate unique and various ideas. Thus, an assumption reversal thinking skill needed to be considered as a concrete method that could help students who have difficulties with generating ideas. In this study, we applied the assumption reversal thinking skill to university students and explored the characteristics of the idea generation process. On the basis of the results, we found that the assumption reversal thinking skill helped students generate new ideas, inducing their perspective changes. Therefore, we could ascertain the possibilities of the assumption reversal thinking skill as a thinking frame supporting students' idea generation. However, there is a need to develop methods for students to exclude prejudice by theoretical judgment, intervention of the value, and experience for fostering more effective assumption reversal thinking. Also, ways should be considered so that students would be able to cultivate task commitment and courage of implementing new ideas, bearing criticism from others.