• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.357-364
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• 2023

In this study, we propose a ripe tomato bunch localization method based on convolutional neural networks, to be applied in robotic harvesting systems. Tomato images were obtained from a smart greenhouse at the Rural Development Administration (RDA). The sample images for training were extracted based on tomato maturity and resized to 128 × 128 pixels for use in the classification model. The model was constructed based on four-layer convolutional neural networks, and the classes were determined based on stage of maturity, using a Softmax classifier. The localization of the ripe tomato bunch region was indicated on a class activation map. The class activation map could show the approximate location of the tomato bunch but tends to present a local part or a large part of the ripe tomato bunch region, which could lead to poor performance. Therefore, we suggest a recursive method to improve the performance of the model. The classification results indicated that the accuracy, precision, recall, and F1-score were 0.98, 0.87, 0.98, and 0.92, respectively. The localization performance was 0.52, estimated by the Intersection over Union (IoU), and through input recursion, the IoU was improved by 13%. Based on the results, the proposed localization of the ripe tomato bunch area can be incorporated in robotic harvesting systems to establish the optimal harvesting paths.

• Journal of The Korean Association of Information Education
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• v.17 no.2
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• pp.225-232
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• 2013

The smart education is performed in the education field, but the contents related to the subject class performed in the various smart devices are insufficient and it is necessary to continue training teacher and learner for the app development education. Therefore this study developed and applied the contents production education program of the game type web app around elementary science 6 grade 1 term utilizing Storyline authoring tools, similar to PowerPoint and be executable in the various devices. After educating students, we investigate the convenience of the use of Storyline, satisfaction level of learning contents work activity, and the continued availability, and etc,. They are interested in the activity of the smart educational contents development and they wished to participate in the continued app development education and activity in spite of it make difficulty for using English menu.

• Journal of the Korea Society of Computer and Information
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• v.20 no.4
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• pp.147-159
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• 2015

This paper is to design smart based collaborative learning model for programming education of fifth graders of elementary school and applies it to a class and analyze its result. Designed learning model is composed of understanding of concept, realization, learning and sharing and it includes step by step learning materials and smart based collaborative learning activities. Scratch traffic light learning materials at leaning stage classify content to be checked in programming by colors and write to support programming internalization of learners. Provision of smart based collaborative learning activities that considered learning conditions of learners makes it possible for beginners to participate in and keep study actively. This study showed that there was statistically significant difference in learners' programming interest and those who achieved over 8 out of 10 points were 60.7% at three stage evaluations for achievement level that applied learning model which suggests that satisfactory achievement level is achieved.

• Journal of The Korean Association For Science Education
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• v.35 no.2
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• pp.325-331
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• 2015

In this study, we investigated the effects of individualized learning adapted to students' conceptions using smart devices in science instruction upon students' conceptual understanding, the retention of conception, achievement, learning motivation, enjoyment of science lessons, and perception about individualized learning using smart devices. Four seventh-grade classes at a coed middle school in Seoul were assigned to a control group and a treatment group. Students were taught about molecular motions for seven class periods. Two-way ANCOVA results revealed that the scores of a conception test, the retention of the conception test, a learning motivation test, and an enjoyment of science lessons test for the treatment group were significantly higher than those for the control group. Although the score of the treatment group was higher than that of the control group in the achievement test, the difference was not statistically significant. Students' perceptions about individualized learning using smart devices were also found to be positive.

• Smart Structures and Systems
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• v.18 no.1
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• pp.139-154
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• 2016

This paper is concerned with the dynamics of hyperelastic solids and structures. We seek for a smart control actuation that produces a desired (prescribed) displacement field in the presence of transient imposed forces. In the literature, this problem is denoted as displacement tracking, or also as shape morphing problem. One talks about shape control, when the displacements to be tracked do vanish. In the present paper, it is assumed that the control actuation is provided by imposed eigenstrains, e.g., by the electric field in piezoelectric actuators, or by thermal actuators, or via analogous physical effects, such as magneto-striction or pre-stress. Structures with a controlled eigenstrain-type actuation belong to the class of smart structures. The action of the eigenstrains can be conveniently characterized by actuation stresses. Our theoretical derivations are performed in the framework of the theory of small incremental dynamic deformations superimposed upon a statically pre-deformed configuration of a hyperelastic solid or structure. We particularly ask for a distribution of incremental actuation stresses, such that the incremental displacements follow exactly a prescribed trajectory field, despite the imposed incremental forces are present. An exact solution of this problem is presented under the assumption that the actuation stresses can be tailored freely and applied everywhere within the body. Extending a Neumann-type solution strategy, it is shown that the actuation stresses due to the distributed control eigenstrains must satisfy certain quasi-static equilibrium conditions, where auxiliary body-forces and auxiliary surface tractions are to be taken into account. The latter auxiliary loading can be directly computed from the imposed forces and from the desired displacement field to be tracked. Hence, despite the problem is a dynamic one, a straightforward computation of proper actuator distributions can be obtained in the framework of quasi-static equilibrium conditions. Necessary conditions for the functioning of this concept are presented. Particularly, it must be required that the intermediate configuration is infinitesimally superstable. Previous results of our group for the case of shape control and displacement tracking in linear elastic structures are included as special cases. The high potential of the solution is demonstrated via Finite Element computations for an irregularly shaped four-corner plate in a state of plain strain.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.5
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• pp.410-420
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• 2015

This paper provides a comparison of power converter loss and thermal description for voltage source and current source type 5 MW-class medium-voltage topologies of wind turbines. Neutral-point clamped three-level converter is adopted for a voltage source type topology, whereas a two-level converter is employed for current source type topology, considering the popularity in the industry. To match the required voltage level of 4160 V with the same switching device of IGCT as in the voltage source converter, two active switches are connected in series for the case of current source converter. Transient thermal modeling of a four-layer Foster network for heat transfer is done to better estimate the transient junction and case temperature of power semiconductors during various operating conditions in wind turbines. The loss analysis is confirmed through PLECS simulations. Comparison result shows that the VSC-based wind turbine system has higher efficiency than the CSC under the rated operating conditions.

• The Journal of Korean Association of Computer Education
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• v.20 no.2
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• pp.57-65
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• 2017

The world's senior population is on the rise. In particular, unlike the past seniors who were in the digital insensitivity class, the smart seniors who want to continue to use smart devices and the Internet are emerging. Although the definition of senior is merely defined as a senior group, research on the characteristics of seniors has been done in psychology studies, but research using data based senior cognitive response is only at an early stage. In order to provide contents according to the cognitive characteristics of Smart Senior, there is a need to classify the cognitive characteristics of Smart Senior well. Therefore, this paper suggests a data - driven senior cognitive response modeling method that helps the enjoyment of culture for seniors through classification of cognitive responses to smart seniors.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.163-173
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• 2021

In the era of digital transformation, the transportation underprivileged remains as an underprivileged class without the benefits of technological advances. Electric assist devices for the People with disability are inadequate to provide services suitable for the current traffic environment, although the mobility of the People with disability is improved. In this paper, we develop IoT smart mobility by deriving essential elements through user satisfaction surveys to efficiently move physical distances based on the experience of users using existing electric assistive devices. Based on the data collected through user satisfaction survey, quantitative analysis using TF-IFD and qualitative analysis based on QFD are performed to determine the importance of user requirements. For the evaluation of IoT smart mobility design results reflecting essential functions, usability verification is conducted by forming an expert evaluation team in various fields. In the future, we plan to conduct a service design study that can improve mobility convenience and provide mobility service solutions by designing to provide efficient public services by utilizing IoT smart mobility to the People with disability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.5
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• pp.779-785
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• 2022

Study analyzes whether the 3D CAD class using the flipped learning-based PBL is effective in acquiring professional knowledge and nurturing talent. A Flipped Learning-based PBL class was implemented for 3rd grade students of Robot and Automation Engineering Major, Dong-Eui University, and a survey was conducted on satisfaction and effectiveness. The students seemed to be generally satisfied with the class, and the flipped learning-based PBL appeared to be effective in improving the competency required by companies. In particular, it is hoped that it will contribute to the use of video education in practical subjects in the future by proving that practical classes can be operated effectively even in non-face-to-face learning. Moreover, this study is an important indicator for future research and will be used as a quantitative indicator for class improvement.

• 한국정보교육학회:학술대회논문집
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• 2021.08a
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• pp.303-308
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• 2021

In this study, we intended to present a class design plan that combines safety education and software education, which are very important in the school field, but are considered necessary for change. In order to realize safety education centered on indirect experience, the 12th class plan was devised as a "Smart Safety Commuter Road Production Project" using a physical computing tool called Bitbrick. Based on the 12th city's class plan, qualitative research was conducted with interviews with a total of five teachers, showing both the effectiveness and problems of applying them to the class. The effectiveness is that unlike conventional delivery-type safety education, indirect experience-oriented safety education centered on real-life situations is possible, and it can be expected that procedural thinking skills can be developed along with stimulating interest. However, the problem has been shown that the process of implementing the direct situation can be challenging and that even activities can be more efficient than group activities.