• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.111-116
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• 2018

Recently, shape manufacturing method has been changed to a 3D printer. Since lamination type manufacturing method is the basis for forming a three-dimensional shape by repeated lamination, the horizontal accuracy of the lamination layer is very important. In the current paper, we have proposed a new leveling system to be installed in a large 3D printer. The light source was reflected from the water surface contained in the measuring device, and the inclination of the measuring device was measured from the light that entered into four regions of a quarter photodetector. The electrical signals generated differently according to the position of the beam spot incident on the quarter photodetector was acquired and compensated to be horizontal by using a motor mounted at the corner. Compared to a digital leveler, the newly developed leveling system gave errors of only 2 to 3%. This new device can be applied to various fields including the 3D printer in future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.105-108
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• 1997

To reduce design period, demands for rapid prototyping system is increasing. Among the rapid prototyping system, as a concept modeler, 3D Printer appears before the footlights. In spite of short production time and convenience, 3D Printer causes post processing problem. And that is too slow to adapt to the demand of workshop. In this research, we developed a system for reducing build time and roughness using splitting operation. Also, propose BFS(B-rep For STL) data structure to maintain model data, split STL model and implement Euler Operation for input and output.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.107-113
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• 2018

In this study, the 3D printer filaments were manufactured by using the representative eco-friendly material, bio-composite. Bio-composites were made by incorporating biodegradable polymer of poly lactic acid (PLA) as the matrix and bamboo flour as the filler. The bamboos which were used in this experiment are Phyllostachys bambusoides, Phyllostachys nigra var. henonis, and Phyllostachys pubescen grown in Damyang district in Korea, and the mixture ratio between bamboo flour and PLA were set 10/90, 20/80, 30/70 by weight standard. Also, tensile strength of bamboo/PLA bio-composites manufactured with three kinds of bamboo were estimated and compared. In this result, the highest estimated bio-composites was Phyllostachys bambusoides flour/PLA which mixture ratio was 10/90, that is, it was the most suitable bamboo/PLA bio-composites for manufacturing 3D printer filament.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.11
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• pp.35-41
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• 2020

The structure of the femur bone was analyzed. Moreover, the mechanical strength of the bone was determined by considering two parameters, namely, the outer wall thickness and inner filling density to realize the 3D printing of a cortical bone and spongy bone by using a fused deposition modeling type 3D printer and ABS material. A basic experiment was conducted to evaluate the variation trend in the mechanical strength of the test specimens with the change in the parameters. Based on the results, the parameters corresponding to the highest mechanical strength were selected and applied to the artificial bone, and the mechanical strength of the artificial bones was examined under a load. Moreover, we proposed an approximation method for the 3D printing parameters to enable the comparison of the actual bones and artificial bones in terms of the strength and weight.

• Journal of Yeungnam Medical Science
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• v.40 no.3
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• pp.302-307
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• 2023

With recent developments in digital dentistry, research on techniques and materials for three-dimensional (3D) printing is actively underway. We report the clinical applications and outcomes of 3D printing of temporary crowns fabricated with polylactic acid (PLA) using a fused deposition modeling (FDM) printer. Five participants were recruited from among patients scheduled to be treated with a single full-coverage crown at a dental clinic in a university medical center from June to August 2022. We used 3D-printed crowns fabricated with PLA using an FDM printer as temporary crowns and were assessed for discomfort, fracture, and dislodging. The 3D-printed temporary crowns were maintained without fracture, dislodging, or discomfort until the permanent prosthesis was ready. The average time required for printing the temporary crowns was approximately 7 minutes. The 3D printing of temporary crowns with PLA using an FDM printer is a convenient process for dentists. However, these crowns have some limitations, such as rough surface texture and translucency; therefore, the 3D printing process should be improved to produce better prostheses.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.627-634
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• 2020

Instead of lead, we intend to develop shielding materials for morphological implementation by mixing barium sulfate, an eco-friendly substance, and PLA filament, a 3D printer material. The environmental substance, barium sulfate powder and PLA filament, a 3D printer material, were used, and the shielding was made with a 3D printer after being fused into an extruder to mix the powder powder of barium sulfate with PLA. To check the mixing ratio of barium sulfate powder and PLA filament, the mixing input was analyzed, and the absorption dose by thickness according to barium sulfate content was obtained to check the shielding function of the mixed shielding. In the evaluation of the mixture of sulfate barium powder particles and PLA filaments, it was mixed in the most appropriate proportion when the content was 30% in the apparent and electron microscopic observation photographs. In the absorption dose results by thickness according to barium sulfate content, the difference between the content of 0% and the content of each % was greatest at 0.5 cm in thickness and the lowest dose value at 3 cm in thickness when the barium content was 30%. In addition, as the barium content began to increase at 30%, the absorbed dose value increased again. Instead of conventional lead, barium sulfate, an eco-friendly substance, could be mixed with PLA, a filament material, to create morphological shielding. Based on this study, it is expected that the mixing ratio of barium to the mixture is the most appropriate 30%, and will be used as the basis for the implementation of morphological shielding using 3D printers in the diagnosis and treatment section.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.113-119
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• 2018

The purpose of this study is to verify the effect of participating in teaching material development program using 3D printer on the recognition of universal design for learning of early childhood special education pre-service teachers. This study was conducted on 30 early childhood special education pre-service teachers who participated in teaching material development program using 3D printer. The results of this study showed that the early childhood special education pre-service teachers use of the 3D printer-based teaching material development program resulted in statistically significant differences in the 4 low rank factors of the universal design for learning. This research shows that direct experience in developing teaching material using 3D printers is very effective to improve universal design for learning awareness. In addition, the experience of developing teaching material for pre-service early childhood teachers is important for improving the instructional design ability, and they need the practice of the development of the teaching material using the latest technology for teaching students with various needs.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.119-127
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• 2020

The purpose of this study is to verify the effect on the creativity and Usability of young Children by applying design education pro young Children gramfor using 3D printer to the kindergarten field and, through the results, to prepare a realistic way to increase the utilization of 3D printer media in infant classrooms. In order to achieve this research purpose, 38 infants aged 5 from G kindergarten located in metropolitan A are divided into each experimental group and comparative group, and from August 2017 to January 2018, data were collected through 15 experiments over a period of about 6 months. As a research tool, in the Korean version of Torrance's Creativity Test, an infant shape test and a usability test scale were used, and the data processing and analysis were conducted through technical statistical methods and covariance analysis. As a result of the study, the program using 3D printer had a statistically significant effect on promoting creativity and Usability of young Children, and in particular, it had a remarkable effect on the elaboration of creativity composition. Based on these results, discussions on the existing Nuri process, which mainly aims to cultivate creative talents, the possibility of connecting 3D printers more widely and the role of teachers were made.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.615-621
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• 2021

In the medical field, radiation provides information for the diagnosis and treatment of diseases. As the use of radiation increases and the risk of exposure increases, interest in radiation protection is also rapidly increasing. Lead shielding material is mainly used, which has a risk of lead poisoning and absorption into the body. Tungsten mixed filament shielding sheets were fabricated with a size of 70 × 70 mm and a thickness of 1, 2, and 4 mm by using a 3D printer. In the general shooting experiment, the thickness of the shielding sheet is 1 ~ 5mm, the tube voltage is 60, 80, 100, 120 kVp and the tube current is 20, 40 mAs. In general photography, Tungsten showed better shielding rate compared to Brass, Copper, and Lead protective tools under all irradiation conditions, and in particular, Tungsten 5 mm showed 100% shielding rate. The 3D-printed tungsten mixed filament shielding is expected to be used as a new shield that can replace the existing lead protection tools as it shows a better shielding rate than the existing lead protection tools in Radiography.

• International journal of advanced smart convergence
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• v.6 no.4
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• pp.60-66
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• 2017

The advent of the 4th industrial revolution made the importance of software education to be emphasized, and thus, the Maker Education is attracting attention. This paper analyzes the curriculum to find contents suitable for Maker Education and proposes a workbook design using the results. The curriculum analysis data and workbook examples are expected to contribute to design elementary school curriculum for Maker Education using 3D printer. The workbook-based creative Making activities are, in addition, also expected to improve the computational thinking ability and to provide the insufficient instruction hours of SW education with an expandability.