• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.116-125
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• 2021

A three-dimensional (3D) intraoral scanner, which is one of the major developments in digital dentistry, is widely used in fixed prosthodontics. The application of intraoral scanner is now increasing in removable prosthodontics. Sclerotic change induced by scleroderma causes the limitation of mouth opening and multiple loss of the teeth. Conventional prosthodontic procedures are challenging for patients with this disease. This study showed a case of digital approach to the removable prosthodontic treatment of a patient who had the scleroderma and the consequent microstomia. At the provisional stage, the optical impression of patient's oral structures was digitally obtained. Using a 3D printer, the provisional dentures were fabricated. After extraction of hopeless tooth, the definitive digital impression was taken and the metal frameworks were fabricated, based on the data acquired from the impression. The definitive removable partial dentures were completed and delivered to the patient, who was satisfied with the prostheses.

• Archives of design research
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• v.14
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• pp.109-119
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• 1996

One of the most important factors in the work environment of the industrial design is the design process which can systematically synthesize the informations of related fields. Because the computer technology is being radically developed, industrial should not only positively be able to cope with new technologies, but also should positively be able to take part in the development of the integrated system for the process by the new technologies. Recently in the industrial design field, designers are often using the computer~applied-3D modeling techniques in the development process of industrial design products, especially in the visualization level of the design development. In this paper, we studied the workstation modeling process to understand the computer~applied-3D modeling and presented the methods of transfer of the 3D-modeling data of a workstation(SGI) to the AutoCAD data of a personal computer which is generally being used as a drawing tool in mechanism parts. Through the development process of an electronic taxi meter as a practical case study, we check the possibility whether the 3D-modeling data transferred from an industrial design part to a mechanism part can directly be used as the mechanism data. For this, we transferred the 3D-modeling data of an electronic taxi meter created with a workstation(SGI) to the AutoCAD data of a personal computer and checked the usefulness of data transferred from an industrial design part to a mechanism part. Through these processes of data transfer, we aimed to find out the basic principles which can be rationally applied to a mechanism part or a production part.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1111-1125
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• 2010

Study is a basic analysis of a future virtual clothing system based on a comparative analysis of all the shirring, using a 3-dimensional apparel cad system. Frilled skirts shirred at the lower hemline were the subject of this study for a comparison of expression and shape of shirring. It compared the silhouette and details expressed in virtual and real skirts made of woolen fabrics and polyester satin, with different widths (1.5, 2 and 2.5 widths). It was found that the virtual skirt could not express shirring as exquisitely as the real skirt due to fabric thickness and other fabric characteristics. In addition, the increase in widths caused the frill shape to deform badly. In the case of a virtual skirt made of polyester satin, the increased multiplication factor let the frill spread out sharply (unlike the real skirt). Simulated skirts of polyester satin and woolen spread out to the sides with the sidelines of their frills hanging down markedly (unlike the real cloths) when the frills changed from 1.5 widths to 2 widths. When it came to the virtual skirt, side-line from the hip down all the way short of frill contorted with the wrinkle multiplication factor of 2 and 2.5 widths. This phenomenon was more notable in polyester satin skirts than in woolen skirts.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1627-1635
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• 2001

Virtual manufacturing is a technology facilitating effective development and agile manufacturing of products via sophisticated computer models representing physical and logical schema and behavior of real manufacturing systems including manufacturing resources, environments, and products. For the successful application of this technology, a virtual plant as a well-designed and integrated environment is essential fur sharing information and engineering collaboration among diverse engineering activities. The systematic approaches and effective methods for construction and application of a virtual plant are proposed in this paper, such as a 3-D CAD modeling, cell and line simulations, databases and some information technologies. Measuring and 3-D CAD modeling technologies of many equipments, facilities and structures of the building are developed, and effective information management system managing CAD models, related files and data is implemented in WWW environments. Finally, precise simulations of unit cell lines and the whole plant are performed. For the beginning of implementing a Virtual Automotive Plant, the Virtual Plant fur the Body Shop of a Korean automotive company is constructed and implemented. We could obtain the benefit of savings in time and cost in many manufacturing preparation activities in the new car development processes.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.77-83
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• 2016

Pipe working is consist of design, making and installation. Pipe line is consist of spool pipes which are made in fabrication shop. And these spool pipes installation in shipyard. Spool pipes are designed based 2D Drawings(ISO Drawing), so spool pipes are not considered working area, that wake decreasing working efficiency and delay working time. In this paper, suggest make spool pipe design method using analysis working area about 3D CAD model and genetic algorithm.

• Journal of Fashion Business
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• v.19 no.5
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• pp.1-16
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• 2015

The appearances and geometry structures of knitted fabrics have important effects on their functions as textile fabrics. Structural design of the woven fabric, prior to the manufacturing processes in the weaving mill, often leads to a similar predictable appearance in the final outcome with the corresponding weave design. The increase of the employment of elastic textile yarns in knitting fabrics for comfort stretch or outdoor sports wear knit products has, however, resulted in difficulties in predicting the final appearance of the knit structure design. Due to the stretchability and exceptional recovery behavior of the elastic yarns such as polyurethane elastomeric yarns, the appearance of the final product often differs from the initial knit design. At textile CAD program for preparing tricot knit designs has been employed in this study to predict the two dimensional appearance of the design. The similarities between the designs and corresponding knit products seem to be acceptable for the two-dimensional textile CAD program in this study. However, when elastomeric yarns are partially employed in the polyester filament tricot product, a considerable amount of departure from the design is apparent due to the constriction and/or deformation of property differences in the elastomeric yarns and polyester filament yarns. Therefore, another purpose of this study is to measure the departure of the final tricot product from the initial tricot design, especially in the case employing elastomeric yarns in the knit structure together with regular polyester filament yarns. For measuring the three-dimensional departure, a 3D scanning system has been used for the mesh reconstruction of the fabric specimen. Hopefully, the result from this study will be used as a guide to modify and improve the current textile CAD program proposed for the two-dimensional simulation of the tricot.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.5 s.122
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• pp.415-426
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• 2007

In a link motion punch press, numerous links are interconnected and each link executes a constrained motion at high speed. As a consequence, dynamic unbalance force and moment are transmitted to the main frame of the press, which results in unwanted vibration. This degrades productivity and precise stamping work of the press. This paper presents an effective method for reducing dynamic unbalance in a link motion punch press based upon kinematic and dynamic analyses. Firstly, the kinematic analysis is carried out in order to understand the fundamental characteristics of the link motion mechanism. Then design variable approach is presented in order to automate the model setup for the mechanism whenever design changes are necessary. To obtain the inertia properties of the links such as mass, mass moment of inertia, and the center of mass, 3-dimensional CAD software was utilized. Dynamic simulations were carried out for various combinations of design changes on some links having significant influences on kinematic and dynamic behavior of the mechanism.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.74-83
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• 2013

Most current BIM systems are focused on the visual information of work status in the design and construction stages. In a passive BIM system, 3D CAD tool can visualize the interference elements of design drawings, however, it cannot suggest a solution to solve the interference status. And 4D CAD tool in the construction stage can simulate the appearance of each activity by construction schedule, however, it cannot suggest an optimized schedule plan considering specified schedule condition of the project. Recently, many organizations need BIM solutions that can improve the work status beyond the level of simple visual information from BIM system. Active BIM system can provide the solutions to the project manager. This study suggests active BIM functions for the solutions and attempts to develop a 4D CAD engine to validate the usability of the functions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.2
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• pp.135-146
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• 2020

To define an interface in a conventional level-set method, an analytical function must be revealed for an interfacial geometry. However, it is not always possible to define a functional form of level sets when interfaces become complex in a Cartesian coordinate system. To overcome this difficulty, we have developed a new level-set formalism that discriminates the interior from the exterior of a CAD modeled interface by parameterizing the stereolithography (STL) file format. The work outlined here confirms the accuracy and scalability of the hydrodynamic reactive solver that utilizes the new level set concept through a series of tests. In particular, the complex interaction between shock and geometrical confinements towards deflagration-to-detonation transition is numerically investigated. Also, a process of flame spreading and damages caused by point source detonation in a real-sized plant facility have been simulated to confirm the validity of the new method built for reactive hydrodynamic simulation in any complex three-dimensional geometries.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.4
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• pp.220-227
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• 2019

Purpose: The purpose of this study was to compare the degree of tooth preparation abilities of students according to three self-assessment methods. Materials and Methods: forty-eight sophomores in Kyungpook National University College of Dentistry were divided into three experimental groups. Students performed tooth preparation of the left mandibular first molar for full gold crown. They performed self-assessment using the three methods (visual, digital, and putty index self-assessment group), and reperformed tooth preparation. An intraoral scanner was used to scan each tooth model (prepared tooth and unprepared tooth), and data were acquired in standard tessellation language (STL) file format. The STL files of prepared tooth and unprepared tooth were superimposed using the 3-dimensional analysis software (Geomagic control X). And the reduction amount was measured. In the statistical analysis, all values of reduction amount were analyzed with the Wilcoxon signed rank test and Kruskal-Wallis test (α = 0.05). Results: The three self-assessment methods showed statistically significant differences (P < 0.001). The putty index self-assessment group showed the highest reduction in error than the digital self-assessment method. Conclusion: Within limitations of this study, students showed significant differences in improvement of tooth preparation ability according to the three self-evaluation methods.