• Advances in Computational Design
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• v.1 no.3
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• pp.275-296
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• 2016

This article presents an adaptive directional differential evolution (ADDE) algorithm and its application in solving discrete sizing truss optimization problems. The algorithm is featured by a new self-adaptation approach and a simple directional strategy. In the adaptation approach, the mutation operator is adjusted in accordance with the change of population diversity, which can well balance between global exploration and local exploitation as well as locate the promising solutions. The directional strategy is based on the order relation between two difference solutions chosen for mutation and can bias the search direction for increasing the possibility of finding improved solutions. In addition, a new scaling factor is introduced as a vector of uniform random variables to maintain the diversity without crossover operation. Numerical results show that the optimal solutions of ADDE are as good as or better than those from some modern metaheuristics in the literature, while ADDE often uses fewer structural analyses.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.3
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• pp.283-292
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• 2006

The purpose of this study was to explore the component factors on images of good elementary teacher. 579 elementary teachers in Busan were sampled to be surveyed. The subjects answered open-ended questionnaire related to characteristics of good teacher. The number of items obtained from the questionnaire is 79. The exploratory factor analysis was applied to the data. As a result of exploratory factor analysis, the components of good teacher are classified into five factors : fairness, enthusiasm, commitment, warmth, self-management. All such factors might be related to the personality in common. It shows that teachers think the personality important as a characteristic of good teacher. On the basis of this result we offer a suggestion to the teacher education.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.570-573
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• 2008

In spite of many experimental studies of low-power applied-field magnetoplasmadynamic(AFMPD) thrusters, thrust efficiencies of the past thrusters are very low. Hence, drastic improvement in thrust performance is required for AF-MPD thrusters to compete against other types of electric propulsion in a moderate power regime around 10 kW. For the optimization of AF-MPD thrusters, a numerical code for the flowfield simulation is now under development. A preliminary result shows that the code can deal with a complicated mixture of the induced and applied magnetic fields, which will lead to a combination of the self-field, swirl, Hall, as well as electrothermal accelerations.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.312-319
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• 2023

This study aims to enhance the engineering education for non-majors by incorporating the concept of Global Citizenship Education and addressing the need for education that responds to climate and ecological changes. The study uses robot programming as a tool to foster the development of global citizens. Non-majors often struggle with producing more than just motionless forms or solid productions, due to a lack of understanding of mechanisms and coding. The study proposes the use of the Convergence D-SteamRobot (DSR) to address this issue by blending humanities and engineering. This is achieved by presenting problems through books to increase empathy, integrating simple machine mechanisms, and creating prototypes to solve self-defined problems. Through this process, learners determine the SDGs topic they want to solve and learn about the simple mechanical mechanism involved in producing the prototype. The educational model provides a constructivist learning environment that emphasizes empathy and exploration, encourages peer-learning, and improves divergent thinking and problem-solving skills.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.175-180
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• 2023

Fractal geometry, a relatively new branch of mathematics, was first introduced by Benoit Mandelbrot in 1975. Since then, its applications have expanded into various fields of natural science. In fact, it has been recognized as one of the three significant scientific discoveries of the mid-20th century, along with the Dissipative System and Chaos Theory. With the help of fractal geometry, designers can create intricate and expressive artistic patterns, using the concept of self-similarity found in nature. The impact of fractal geometry on the digital art world is significant and its exploration could lead to new avenues for creativity and expression. This paper aims to explore and analyze the development and applications of fractal geometry in digital art design. It also aims to showcase the benefits of applying fractal geometry in art creation and paves the way for future research on sacred geometry.

• Phonetics and Speech Sciences
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• v.15 no.2
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• pp.13-20
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• 2023

This study explores the potential of automated speech recognition (ASR) in assessing English learners' pronunciation. We employed ASR technology, acknowledged for its impartiality and consistent results, to analyze speech audio files, including synthesized speech, both native-like English and Korean-accented English, and speech recordings from a native English speaker. Through this analysis, we establish baseline values for the word error rate (WER). These were then compared with those obtained for human raters in perception experiments that assessed the speech productions of 30 first-year college students before and after taking a pronunciation course. Our sub-group analyses revealed positive training effects for Whisper, an ASR tool, and human raters, and identified distinct human rater strategies in different assessment aspects, such as proficiency, intelligibility, accuracy, and comprehensibility, that were not observed in ASR. Despite such challenges as recognizing accented speech traits, our findings suggest that digital tools such as ASR can streamline the pronunciation assessment process. With ongoing advancements in ASR technology, its potential as not only an assessment aid but also a self-directed learning tool for pronunciation feedback merits further exploration.

• Journal of the Korean Society of Visualization
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• v.21 no.3
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• pp.15-22
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• 2023

This research introduces an innovative approach for fabricating microstructure surfaces using spray-coating deposition. The resulting surface, referred to as Magnetically Responsive Microstructures (MRM), exhibits hierarchically structured micro-pillar arrays with remarkably high aspect ratios. The fabrication process involves precisely mixing PDMS and hexane with Carbonyl iron powders, followed by ultrasonication and spray-coating on the top of a PDMS substrate placed on the neodymium magnet. The MRM surface shows hydrophobic properties, characterized by a contact angle surpassing 150° and an aspect ratio exceeding 10. Through a comprehensive exploration of critical parameters, including spray amount, magnet-substrate distance, and solution ratio enhanced dynamic tunability and exceptional hydrophobic characteristics are attained. This novel approach holds significant potential for diverse applications in the realm of dynamically tunable microstructures and magnetically responsive surfaces.

• Management & Information Systems Review
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• v.39 no.1
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• pp.75-91
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• 2020

The purpose of this study is to examine the application of in-depth interviews in terms of exploration on the basis of the theoretical basis of various aspects of consumer empathy, and the question of whether the consumer can expand to the process of self empathy. Most studies related to consumer empathy divide the responsive dimension of consumer empathy into rational and emotional dimension based on empathy theory, and look at the empathic response perceived by consumers to the stimulus presented from the current point of view. In this study, however, we want to go one step further and confirm that the consumers themselves can ultimately go to the self-empathy stage by forming a creative street of reproduction and redevelopment. As a result of exploratory research through in-depth interviews, it was indirectly confirmed that consumer's empathetic response to specific marketing stimulus exists at the level of creative and self-empathetic as well as the emphasis of previous studies. Based on these findings, this study confirmed that consumer empathetic responses could go beyond a single dimension to form a multidimensional structure and move toward an expanded structure of empathic self-creation. This suggests that consumers' empathic responses should be grasped in terms of continuity of empathic responses rather than explained in a specific dimension. Although this study is meaningful as an early research of exploratory nature, it is necessary to supplement various content validity and refine the research method through subsequent studies. This study is expected to expand the understanding that consumer's empathy can be extended to other people's empathy and to be self-empathy.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.424-432
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• 2014

The purpose of study is to understand the relation with factors which affect the mental health and to investigate self-esteem, department satisfaction and career stress among dental hygiene students. The study performs self-administered questionnaires survey from March to May, 2013, among dental hygiene students of college in Busan and Ulsan with the convenience sampling and finally analyzes 376 questionnaires. The study performs the path analysis to analyze the impact of the mental health on self-esteem, department satisfaction and career stress and the correlation among these variables. The analysis result shows that the self-esteem most affects and the direct effect on the mental health. The factor which affects the self-esteem is the department satisfaction show direct effect, also career stress has direct and indirect effect. Self-esteem is important factors in the department satisfaction, career stress and mental health. Thus, a stable mental health for students and groups of individuals who need to take advantage of professional counseling and career exploration program structured should be configured.

• Journal of The Korean Association For Science Education
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• v.39 no.3
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• pp.321-335
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• 2019

This study aims to explore the influencing factors and the process of enhancing science self-efficacy (SSE) and to lay the foundation in understanding science self-efficacy of students. The ten categories related to the science self-efficacy were derived through the coding of the interview data based on the grounded theory and paradigm analysis to develop a process model of science self-efficacy improvement. Through the process analysis, four cyclical phases were found in the process of enhancing SSE: 'Entering into learning science' phase, 'enhancing SSE' phase, 'adjustment' phase, and 'result' phase. More specifically, the phase of 'entering into learning science' is where students choose science track and stimulated to construct SSE. The phase of 'enhancing SSE' is where students taking a science track actively learn science and perform science activities. In the phase of 'adjustment', students come to have successful performance about learning science and performing science activities by using diverse strategies. Finally, 'result' phase indicates different appearances of students depending on SSE levels. The phases were non-linear and periodically repeat depending on situation. The core category in the selective coding was indicated to be 'enhancing science self-efficacy.' Students' SSE form by learning science and performing science activities. These finding may help better understand the behavior of students who are taking a science track by facilitating effective science learning through the increase of their SSE levels.