• Geomechanics and Engineering
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• v.18 no.3
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• pp.329-337
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• 2019

This paper presents an experimental investigation about visualization of bulging development of geosynthetic-encased stone column (GESC) based on the digital image correlation (DIC) technique and transparent soil. Visual model tests on GESC and ordinary stone column (OSC) were carried out. In order to delete the warping effect resulting from transparent soil and experiment setup, a modification for experiment results was performed. The bulging development process of the GESC and the displacement field of the surrounding soil were measured. By comparing with the existing experimental and theoretical results, it demonstrates that the model test system developed for studying the continuous bulging development of GESC is suitable. The current test results show that the bulging depth of GESC ranges from 1.05 to 1.40 times the diameter of GESC. The influence depth of GESC bulging on surrounding soil displacement is 0~3 the times diameter of GESC.

• Journal of Engineering Education Research
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• v.16 no.6
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• pp.3-10
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• 2013

The purpose of this study is to design the instructional model to develop logical thinking competency of engineering students and to investigate the effect of the model. The instructional model is composed of the virtual context (films were provided), problem solving, feedback, another problem solving with different perspectives, feedback. The process is looped. The results showed statistically significant improvements between pre- and post-test. The first standardized test of critical thinking showed the improvement from pre-test to post-test (d=0.646). The second test of logical thinking showed the improvement from pre-test to mid-term test (d=0.753) and improvement from mid-term to post-test (d=1.529).

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1702-1715
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• 2006

The increasing use of nano-positioners in a wide variety of laboratory and industrial applications has created a need for nano-mechatronics education in all engineering disciplines. The subject of nano-mechatronics is broad and interdisciplinary. This article focuses on the way nano-mechatronics is taught in department of mechanical engineering at Korea Advanced Institute of Science and Technology (KAIST). As one model of nano-positioning systems, design and experimental methodology is presented in this article. For design phase, the stiffness and resonant frequencies are found analytically and verified by using a commercial finite element analysis program. Next, for experimental phase, various tests are performed to access the performances of the designed nano-positioner, for example, sine-tracking, multi-step response and travel-range check etc. Finally, the definition of 'separation frequency' is described and some comments are discussed.

• Structural Engineering and Mechanics
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• v.70 no.4
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• pp.421-429
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• 2019

This paper presents an analytical model for the estimation of initial lateral stiffness of steel moment resisting frames with masonry infills. However, rather than focusing on the single bay-single storey substructure, the developed model attempts to estimate the global stiffness of multi-storey and multi-bay frames, using an assembly of equivalent springs and taking into account the shape of the lateral loading pattern. The contribution from each infilled frame panel is included as an individual spring, whose properties are determined on the basis of established diagonal strut macro-modeling approaches from the literature. The proposed model is evaluated parametrically against numerical results from frame analyses, with varying number of frame stories, infill openings, masonry thickness and modulus of elasticity. The performance of the model is evaluated and found quite satisfactory.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.130-136
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• 2019

Recently, the importance of creativity and problem-solving skills are being emphasized in engineering education. In particular, research is actively being conducted on learning models considering practicality or applicability in practice and education among many creative problem-solving methods. The objective of the present study is to develop a teaching and learning model and verify its effects in order to promote creative thinking and problem-solving skills using the TRIZ Contradiction Analysis. This study led the participants to obtain basic knowledge of creative engineering design through the creative engineering design course for freshmen at an engineering college, and come up with ideas and solutions using the TRIZ Contradiction Analysis. A survey was conducted and analyzed to verify the effectiveness of education using the proposed teaching and learning model, and as a result, the effectiveness of education has been proven by an average of 89 positive responses. Follow-up research is needed on improved application models so that the proposed learning model can be applied to various subjects.

• Earthquakes and Structures
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• v.13 no.6
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• pp.573-588
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• 2017

The earthquake input is required when the soil-structure interaction (SSI) analysis is performed by the direct finite element method. In this paper, the earthquake is considered as the obliquely incident plane body wave arising from the truncated linearly elastic layered half space. An earthquake input method is developed for the time-domain three-dimensional SSI analysis. It consists of a new site response analysis method for free field and the viscous-spring artificial boundary condition for scattered field. The proposed earthquake input method can be implemented in the process of building finite element model of commercial software. It can result in the highly accurate solution by using a relatively small SSI model. The initial condition is considered for the nonlinear SSI analysis. The Daikai subway station is analyzed as an example. The effectiveness of the proposed earthquake input method is verified. The effect of the obliquely incident earthquake is studied.

• Steel and Composite Structures
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• v.39 no.2
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• pp.135-148
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• 2021

Hollow structural section (HSS) columns have been increasingly popular due to their structural and architectural merits. However, practical difficulty lies in developing proper connections. The through-diaphragm connections are considered as suitable connection type that is widely adopted in Asian countries. However, the stress concentration occurs at the location connecting through-diaphragm and steel beam. Furthermore, the actual load path from the beam flange is not uniformly transferred to the HSS column as conventionally assumed. In this paper, tensile tests were further conducted on three additional specimens with beam flange plate to evaluate the load versus displacement response. The load-displacement curves, yield and ultimate capacity, ductility ratio were obtained. Furthermore, the strain development at different loading levels was discussed comprehensively. It is shown that the studied connection configuration significantly reduces the stress concentration. Meanwhile, simplified trilinear load-displacement analytical model for specimen under tensile load was presented. Good agreement was found between the theoretical and experimental results.

• Journal of Engineering Education Research
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• v.26 no.6
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• pp.19-29
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• 2023

This study aims to develop and apply a metaverse-based instructional design model for the education in science and technology. It analyzed the concept and characteristics of metaverse, existing non-contact education models, and major teaching strategies systematically. Based on the prior researches, an instructional design model using metaverse is developed that presents metaverse-related teaching strategies and design principles for the before-, during-, and after-lesson phases. Then, this model was applied to a project-based learning program, conducted a perception survey on instructors and learners, and revised the metaverse instructional design model based on the results of the survey. In the Metaverse Instructional Design Model, before-lesson phase is a physical and psychological preparation stage for class participation, which includes familiarization with the Metaverse learning environment, formation of expectations for education, and self-directed pre-learning. During the lesson, to effectively deliver the lesson content, it is necessary to build confidence in the learning environment, promote learning participation, provide reference materials, perform team projects and provide feedback, digest learning content, and transfer learning content. The after-lesson phase provides strategies for ongoing interaction between learners and mentors. This study introduces a new instructional design model that utilizes metaverse and shows the potential of metaverse-based education in science and technology. It also has important implications in that it provides practical guidelines for the effective design and implementation of metaverse-based education.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.31-38
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• 2023

In this paper, a basic machine learning model learning and utilization education curriculum for non-majors is proposed, and an education method using Orange machine learning model learning and analysis tools is proposed. Orange is an open-source machine learning and data visualization tool that can create machine learning models by learning data using visual widgets without complex programming. Orange is a platform that is widely used by non-major undergraduates to expert groups. In this paper, a basic machine learning model learning and utilization education curriculum and weekly practice contents for one semester are proposed. In addition, in order to demonstrate the reality of practice contents for machine learning model learning and utilization, we used the Orange tool to learn machine learning models from categorical data samples and numerical data samples, and utilized the models. Thus, use cases for predicting the outcome of the population were proposed. Finally, the educational satisfaction of this curriculum is surveyed and analyzed for non-majors.

• Journal of Engineering Education Research
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• v.23 no.4
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• pp.37-51
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• 2020

This study examined the differential effects of High-Impact Practices(HIPs) on the career aspiration of STEM college students by gender. Through the theoretical lens of Social Cognitive Career Theory(SCCT), a two-level model analysis was conducted. A sample of 2,101 third- and fourth-year undergraduate students majoring in STEM at 38 universities, which had been collected from the National Survey on College Student Experiences and Learning Outcomes funded by the Korea Research Foundation, was used. This study found that the three HIP domains(learning with peers, faculty support, content relevancy) had different influences depending on gender. These findings suggest that HIPs can benefit the development of female students' career aspiration and have gender-differential effects on students in STEM majors. Based on those findings, this study also deduced implications about the roles of faculty members and higher-education institutions that might foster the retention of women in STEM.