• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.14-19
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• 2015

Since CAD is advertised 1980s, all across industries have been changed through engineering, manufacturing and inspection. Also marine industry has adopted not only CAD but also various IT systems to make productivity higher. This paper includes research and development to improve traditional draft reading by using IT system, it has focused to build draft database for new vessels, to improve robustness measuring weather condition and to reduce accident possibility.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.2
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• pp.86-92
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• 2021

Usually, the die-cast components used in small mobile devices require finishing processes, such as computer numerically controlled coating. In such cases, porosity is the most important defect. The shape of the molten aluminum that passes through the runner and gate in a mold is the one of the factors that influences gas porosity. To define the spurt index, which numerically indicates the shape of molten aluminum after the gate, Reynolds number and Ohnesorge number are used. Before die fabrication, computer-aided engineering analysis is performed to optimize the filling pattern. Finally, X-ray and surface inspection are performed after casting and machining to evaluate how the spurt index affects porosity and other product parameters. Based on the results obtained herein, a new gating system design process is suggested.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.338-343
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• 2009

Tomography is the imaging method of cross sectional area using multi beam signals and is mainly applied to the medical diagnosis to acquire the image of the inside human body. This method is pretty meaningful in nondestructive evaluation field since the imaging of the inspection region can enhance the comprehension of the inspector. Recently, much attention has been paid to the guided wave for the diagnosis of platelike structures. So, in this work, a study on the imaging of the damage location in a plate was carried out on the basis of computer aided analysis of guided waves and tomographic imaging. To this end, boundary element method was employed to analyze the effect of the damage in plate on the propagation of the guided waves and the analytic results were applied to the tomographic imaging method to identify the damage location. Consequently, it was shown that the number of sensors heavily affect the inspection performance of the damage location.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.115-122
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• 2003

This paper presents the development of a virtual forging factory framework. The technologies of virtual reality and relational database had been integrated in the developed framework using Microsoft $Windows^{(R)}$ programming as the main technique so as to emulate a physical forging factory. The developed virtual forging factory consists of forging cells and a forging cell is comprised of forging machine, forging die, and forging operations forming a forging production line. The technology of virtual reality had been successfully adopted in the production simulation of manufacturing such as CNC and robotics. However, the application in virtual forging factory seems to have not been studied yet. Potential application of a virtual forging factory can be beneficial to (1) computer aided instruction, (2) shorten the learning curve of a novice, (3) remote diagnosis and monitoring when remote monitoring and control technology and signal inspection is considered, (4) improve adverse forging environment when remote forging technology is applied, and (5) virtual reality application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.10
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• pp.887-895
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• 2013

Metastatic bone cancer, the cancer which occurred in the various organs and progressively spread to bone, is one of the complications in cancer patients. This cancer is divided into the osteoblast and osteolytic metastasis. Although Computer Tomography(CT) could be an useful tool in diagnosis of bone metastasis, lesions are often missed by the visual inspection and it makes clinicians difficult to detect metastasis earlier. Therefore, in this study, we construct a three-dimensional(3D) volume rendering data from tomography images of the chest CT, and apply a 3D based image processing algorithm to them for detection bone metastasis lesions. Then we perform a three-dimensional visualization of the detected lesions.From our test using 10 clinical cases, we confirmed 94.1% of average sensitivity for osteoblast, and 90.0% of average sensitivity, respectively. Consequently, our findings showed a promising possibility and potential usefulness in diagnosis of metastastic bone cancer.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.51-56
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• 2008

High quality power supplying of high voltage distribution lines electric railway system is the important function, high voltage distribution system is complicated witch is compose with distribution line, circuit break, protection facilities and so on. Among this components, role of substation is most important for elevation of reliability in electric power system. Therefore, the enhanced reliability considering the preventive inspection, repair work replacement is necessary. This paper proposes protection method in railway high voltage distribution lines. we model distribution system using PSCAD/EMTDC(Power System Computer Aided Design/Electro Magnetic Transients DC Analysis Program) and extract various fault data. In conclusion this methods can protection of ground fault.

• The Journal of Advanced Prosthodontics
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• v.12 no.6
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• pp.361-368
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• 2020

PURPOSE. The present study aimed to evaluate the accuracy of a desktop scanner and intraoral scanners based on the volumetric dimensions of a complete arch. MATERIALS AND METHODS. Seven reference models were fabricated based on the volumetric dimensions of complete arch (70%, 80%, 90%, 100%, 110%, 120%, and 130%). The reference models were digitized using an industrial scanner (Solutionix C500; MEDIT) for the fabrication of a computer-aided design (CAD) reference model (CRM). The reference models were digitized using three intraoral scanners (CS3600, Trios3, and i500) and one desktop scanner (E1) to fabricate a CAD test model (CTM). CRM and CTM were then superimposed using inspection software, and 3D analysis was conducted. For statistical analysis, one-way analysis of variance was used to verify the difference in accuracy based on the volumetric dimensions of the complete arch and the accuracy based on the scanners, and the differences among the groups were analyzed using the Tukey HSD test as a post-hoc test (α=.05). RESULTS. The three different scanners showed a significant difference in accuracy based on the volumetric dimensions of the complete arch (P<.05), but the desktop scanner did not show a significant difference in accuracy based on the volumetric dimensions of the complete arch (P=.808). CONCLUSION. The accuracy of the intraoral scanners was dependent on the volumetric dimensions of the complete arch, but the volumetric dimensions of the complete arch had no effect on the accuracy of the desktop scanner. Additionally, depending on the type of intraoral scanners, the accuracy differed according to the volumetric dimensions of the complete arch.

• Journal of Technologic Dentistry
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• v.45 no.3
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• pp.67-73
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• 2023

Purpose: This in vitro study aimed to evaluate the clinical acceptability of precision of fit of the support thickness of Co-Cr alloy copings fabricated using selective laser melting (SLM). Methods: Thirty dental stone models of maxillary left molar abutments were manufactured, images were taken using a scanner, and a computer-aided design program was used to design the form of a conventional metal ceramic crown coping. Overall, 30 single copings were made from Co-Cr alloy using SLM and divided into three support radius groups (0.1, 0.25, and 0.35 mm) of 10 for each. Digitized data were superimposed with three-dimensional inspection software to quantitatively obtain the machinability of a ceramic crown coping, and visual differences were confirmed using a color map. The root mean square values of the ceramic crown coping group were statistically analyzed using one-way analysis of variance (α=0.05). Results: The precision of fit was superior with 0.25 mm compared with 0.1 mm and 0.35 mm, and the results exhibited significant differences (p<0.05). All specimens showed that various support thicknesses did not exceed the clinically permitted value of 120 ㎛, which mean that more than 0.1 mm and 0.35 mm of support radius for SLM was adequate. Conclusion: The support thickness of Co-Cr alloy restoration fabricated using SLM is shown to affect the adaptation.