• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.308-315
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• 2015

The purpose of this study, using 3D printer, was tried to fabricate the short arm cast of mesh types that can be hygienic and adequate ventilation with a good radiography. We used the multi channel computed tomography (MDCT) with three dimension printer device of the fused deposition modeling (FDM) techniques. The material is used a degradable plastic (poly lactic acid, PLA). Three-dimensional images of the short arm were obtained in the MDCT and then make the three-dimensional volume rendering. Three dimension volume rendering of the short arm is implemented as a tomography obtained in MDCT. Virtual mesh type cast model was output as three-dimensional images is designed based on the three-dimensional images of the short arm. As a results, the cast output by 3D printers were able to obtain excellent radiograph images than the conventional cast, and then it can decreased itching with unsanitary, and can break down easily to the cast. In conclusion, the proposed virtual mesh type cast output by 3D printers could be used as a basis for future three-dimensional printing cast productions and offered help to patients in the real life.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.1
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• pp.1-8
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• 2006

Effective three dimensional modeling becomes essential in a wide range of drawings, such as construction, machinery and design. In particular, it has been developed as the tool enabling reverse design. Three dimensional modeling requires rapidity, accuracy and tangibility. Data acquisition methods for modeling including contact type coordinate measurement machine, LASER scanner, pattern scanner and digital photogrammetry. In this study, we try to analyze modeling techniques as well as introduce three dimensional modeling using pattern scanner. In addition, this study conducts three dimensional modeling using OPTO-Top pattern scanner with distinguished accuracy and rapidity, and then compare efficiency with digital photogrammetry. And, this study attempts to form environment that enables to turn around models on web in three dimensional ways.

• Structural Engineering and Mechanics
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• v.69 no.5
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• pp.499-509
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• 2019

While the wheel flat is an asymmetrical phenomenon in the railway, majority of researches have used two-dimensional models in the investigation of the effect of wheel flat on the wheel rail forces. This is due to the considerably low computational costs of two dimensional (2D) models although their reliability is questionable. This leaves us with the question of "what is the optimum modeling technique?". It is addressed in this research. For this purpose, two and three dimensional numerical models of railway vehicle/track interaction were developed. The three dimensional (3D) model was validated by comparisons of its results with those obtained from a comprehensive field tests carried out in this research and then, the results obtained from the 2D and 3D models were compared. The results obtained indicate that there are considerable differences between wheel/rail forces obtained from the 2D and 3D models in the conditions of medium to large wheel-flats. On the other hand, it was shown that the results of the 2D models are reliable for particular ranges of vehicle speed, railway track stiffness and wheel-fats lengths and depths. The results were used to draw a diagram, which presents the optimum modeling technique, compromising between the costs and accuracy of the obtained results.

• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.161-165
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• 2015

Three-dimensional (3D) reconstruction of cone-beam computed tomography (CBCT) scans appears to be a valuable method for assessing pulp canal configuration. The aim of this report is to describe endodontic treatment of a mandibular second premolar with aberrant pulp canal morphology detected by CBCT and confirmed by 3D modeling. An accessory canal was suspected during endodontic treatment of the mandibular left second premolar in a 21 year old woman with a chief complaint of pulsating pain. Axial cross-sectional CBCT scans revealed that the pulp canal divided into mesiobuccal, lingual, and buccal canals in the middle third and ended as four separate foramina. 3D modeling confirmed the anomalous configuration of the fused root with a deep lingual groove. Endodontic treatment of the tooth was completed in two appointments. The root canals were obturated using lateral compaction of gutta-percha and root canal sealer. The tooth remained asymptomatic and did not develop periapical pathology until 12 months postoperatively. CBCT and 3D modeling enable preoperative evaluation of aberrant root canal systems and facilitate endodontic treatment.

• Journal of Conservation Science
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• v.37 no.1
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• pp.25-33
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• 2021

To extend the application of digital technology to the replication of artifacts, meticulous details of the process and the diversity of three-dimensional (3D) printing output materials need to be supplemented. Thus, in this study, a bronze mirror with Hwangbichangcheon inscription was digitalized by 3D scanning, converted into a voxel model, and virtual conservation treatment was performed using a haptic device. Furthermore, the digital mold of the bronze mirror completed by Boolean modeling was printed using a 3D sand-printer. Such contactless replication based on digital technology reflects the stability, precision, expressivity, collectivity, durability, and economic feasibility of artifacts. Its application can be further extended to cultural products as well as such areas as education, exhibition, and research. It is expected to be in high demand for metal artifacts that require casting. If empirical studies through experimental research on casting are supplemented in the future, it could extend the application of digital technology-based contactless replication methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1151-1156
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• 2013

In this study, to clearly establish the concept of a geometric modeling I apply for the concept of Pushbroom, limited to two-dimensional radiation Locator to provide a three-dimensional information purposes. Respect to the radiation scanner Pushbroom modeling techniques, geometric modeling method was presented introduced to extract three-dimensional information as long as the rotational component of the Gamma-Ray Linear Pushbroom Stereo System, introduced the two-dimensional and three-dimensional spatial information in the matching relation that can be induced. In addition, the pseudo-inverse matrix by using the conventional least-squares method, GCP(Ground Control Point) to demonstrate compliance by calculating the key parameters. Projection transformation matrix is calculated for obtaining three-dimensional information from two-dimensional information can be used as the primary relationship, and through the application of a radiation image matching technology will make it possible to extract three-dimensional information from two-dimensional X-ray imaging.

• Journal of Conservation Science
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• v.35 no.1
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• pp.71-80
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• 2019

This study examined the applicability of digital technologies based on three-dimensional(3D) scanning, modeling, and printing to the restoration of damaged artifacts. First, 3D close-range scanning was utilized to make a high-resolution polygon mesh model of a roof-end tile with a missing part, and a 3D virtual restoration of the missing part was conducted using a haptic interface. Furthermore, the virtual restoration model was printed out with a 3D printer using the material extrusion method and a PLA filament. Then, the additive structure of the printed output with a scanning electron microscope was observed and its shape accuracy was analyzed through 3D deviation analysis. It was discovered that the 3D printing output of the missing part has high dimensional accuracy and layer thickness, thus fitting extremely well with the fracture surface of the original roof-end tile. The convergence of digital virtual restoration based on 3D scanning and 3D printing technology has helped in minimizing contact with the artifact and broadening the choice of restoration materials significantly. In the future, if the efficiency of the virtual restoration modeling process is improved and the material stability of the printed output for the purpose of restoration is sufficiently verified, the usability of 3D digital technologies in cultural heritage restoration will increase.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.240-240
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• 2015

As Simpson et al. (1990) emphasized the importance of the straining process in the stratification and mixing in the estuarine circulation process, various researches have investigated on the relative contribution of each process to the overall potential energy anomaly dynamics. However, many numerical works have done only for two dimensional modeling along channel or the short distance cross sectional three dimensional simulations as Burchard et al. (2008) and the estuarine channel was not simulated so far. But, in the study on the physics of shallow coastal seas, spatial dimension in the three dimensional way affects significantly on results of a particular numerical model. Therefore, the comparison of two and three dimensional models is important to understand the real physics of mixing and stratification in an estuary. Also, as Geyer and MacCready (2013) pointed out that the lateral process seems to be important in determining the periodic stratifications, to study such process the three dimensional modeling must be required. The present study uses a numerical model to show the signification roles of each term of the time-dependent dynamic equation for the potential energy anomaly (PEA) in controlling along and lateral channel flows and different stratification structures. Moreover, we present the relationships between the ${\Phi}$-advection, the depth mean straining, vertical mixing and vertical advection can explain well how water level, salinity distribution and across velocity 2D model are slightly different from 3D.

• Journal of Conservation Science
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• v.38 no.1
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• pp.55-63
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• 2022

The Bigyeokjincheolloe (bomb shell), a scientific cultural heritage, has outstanding historical value for sustaining a gunpowder weapon of Joseon. In this study, the bomb shell was modeled through three-dimensional (3D) scanning centered on the external shape and 𝛾-ray radiography-based on the internal shape. In particular, to improve the contrast in the radiographic image, optimization and image processing were performed. After these processes, the thickness of the inner wall (2.5 cm on average) and the positions of the three mold chaplets were clearly revealed. For exhibition purposes, the 3D model of the bomb shell was output to a 3D printer and the output was rendered realistic by coloring. In addition, the internal functional elements, such as Mokgok, fuse, mud, gunpowder, and caltrops, were reproduced through handwork. The results will contribute to the study of digital heritages in two ways. First, the internal and external shapes of the bomb shell were modeled by fusing two different technologies, namely, 3D scanning and 𝛾-ray radiography. Second, the internal shape of the bomb shell was constructed from the original form data and the reproduction was utilized for museum exhibitions. The developed modeling approach will greatly expand the scope of museum exhibitions, from those centered on historical content to those centered on scientific content.

• Research in Mathematical Education
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• v.27 no.3
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• pp.401-408
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• 2024

New technological advancements that are available in price and usability for K-12 classrooms result in new content areas to be explored and advancement of previous content area struggles. Visualizations of two-dimensional (2D) representations of three-dimensional (3D) figures and the actual 3D figure is a struggle not only limited to mathematics teaching and learning. However, if this struggle can be rectified and potentially improved through mathematics teaching and learning, the broader impacts of this extends beyond classroom mathematics. New 3D modeling software and 3D printers allow users to easily create and share models or download 3D models from online resources and print them to manipulate in their hand. There is plenty of literature now on classroom use of 3D modeling and printing. This article serves to build onto Ball and Stacey's (2005) suggestions for judicious use of calculators and computer software to address the judicious use of 3D modeling and printing technology for teaching mathematics for student learning. We discuss the following teaching strategies: promote careful decision making about 3D modeling and/or printing use, integrate 3D modeling and or printing into the curriculum, tactically restrict use of 3D modeling and or printing, and promote habits of spatial visualization.