• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.90-94
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• 2022

Metal 3D-printing technology enables the manufacture of complex features or internal structures, which is not possible in fabrication by conventional cutting methods. The most successful types of metal 3D printing have been powder bed diffusion and directed energy deposition, which use laser heads exploiting high-power laser sintering metal powder. In this study, a cost-effective optical design was proposed for a 2-kW-level fiber laser head. Only two commercial lenses, a beamsplitter and a window, are used in the laser head, satisfying the technological requirements. According to the optical design, the spot size was 2.54 mm, and the stand-off distance from the laser head was 295 mm. The intensity distribution was Gaussian. Thus, smooth power sintering was possible without any laser spot marks. Monte Carlo analysis was employed to verify the consistency of the optical performance under conventional assembly tolerance.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.16-19
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• 2001

Rapid Prototyping (RP) and Rapid Tooling (RT) were introduced to reduce time-to-market and cost by shortening not only the development phase but also the production phase of the manufacturing process. RP generally builds up a prototype layer by layer, rapidly generating a fully three-dimensional free form shape. RT enables the manufacture of production tools. The integration of RP and RT has the potential for rapid net shaping of thee-dimensional parts, which have geometrical complexity. In this study, net shaping techniques for making three-dimensional parts using RP and RT are described and a sample part are shown. A three-dimensional metal part is manufactured by a new RP process, Variable Lamination Manufacturing by using Expandable Polystyrene Foam (VLM-S), and its application to RT for making a clover punch. In addition, we discussed the technology fusion between metal forming md RP/RT.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.45-52
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• 2020

Recently, design for additive manufacturing (DfAM) technology has become a prominent design methodology for exploiting 3D printing, which leads the Fourth Industrial Revolution. When manufactured by the 3D printing method, it is possible to produce several shapes compared to the conventional casting or cutting process. DfAM-as a newly-proposed design methodology-can be used to specially design products with various shapes to apply functional requirements. Topology optimization verifies load paths to determine the draft design, and a shape-optimized design with objective functions for weight reduction enables efficient lightweight product design. In this study, by using these two DfAM technologies, a lightweight and optimal design is constructed for a node part of a vehicle body with a space frame designed for a lightweight vehicle. DfAM methodologies for concept design and detailed design, and the associated results, are presented. Finally, the product was additively manufactured, a fatigue performance test was performed, and the design reliability was verified.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.442-450
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• 2021

The CAD-CAM technique is a rapidly developing field in the dental field and is applied to various fields of prosthetic treatment. Among them, the manufacturing of dentures using the milling technique classified as subtractive manufacturing is one of the commercialized digital full denture manufacturing methods. At the same time, it is possible to more efficiently manufacture a metal framework for implant overdenture by selective laser sintering or melting technique classified as an additive manufacturing method. The purpose of this article is to describe the fabrication of CAD-CAM maxillary complete denture and mandibular implant overdenture as well as its features.

• Korean Journal of Computational Design and Engineering
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• v.11 no.4
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• pp.303-314
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• 2006

The exchange of CAD (Computer Aided Design) models between different CAD systems and to downstream applications such as manufacturing has become very important to modem industry. One serious current issue is that the process cannot automatically import existing 3-D solid models in a variety of commercial CAD formats into the process without manually re-mastering the model in current standard including "SIEP AP(Application Protocol) 203 Edition 1" To fully integrate technical data from the design agency to the shop floor, design intent and validated 3D geometry of feature based parametric CAD model should be brought into the standardized processes. To overcome this limitation, AP203 Edition 2 (Ed.2) and its related STEP parts such as Part55, Part108, Part109, Part111 and Part112 are starting to be available to handle this problem. The features in Part111 are harmonized with the machining features available in AP224. This paper is focused on two mapping technologies: CAD to Part111 mapping and Pat111 to AP224 mapping including case studios and it will provide the guideline about what should be done next in the AP203 Ed.2 to AP224 mapping. The final goal of this project is to integrate technical data from CAD to AP224 based manufacturing information through AP203 Ed.2.

• Journal of Welding and Joining
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• v.31 no.6
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• pp.77-83
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• 2013

3D packaging technology using TSV (Through Silicon Via)has been studied in the recent years to achieve higher performance, lower power consumption and smaller package size because electrical line is shorter electrical resistivity than any other packaging technology. To stack TSV chips vertically, reliable and robust bonding technology is required because mechanical stress and thermal stress cause fracture during the bonding process. Cu pillar/solder ${\mu}$-bump bonding process is usually to interconnect TSV chips vertically although it has weak shape to mechanical stress and thermal stress. In this study, we suggest Insert-Bump (ISB) bonding process newly to stack TSV chips. Through experiments, we tried to find optimal bonding conditions such as bonding temperature and bonding pressure. After ISB bonding, we observed microstructure of bump joint by SEM and then evaluated properties of bump joint by die shear test.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.118-125
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• 2015

The roll-forming process is a highly productive incremental forming process and is suitable for manufacturing thin, high-strength steel products. Recently, this process has been considered one of the most productive processes in manufacturing high-strength steel automotive structural parts. However, it is very difficult to develop the roll-forming process when the cross-sectional shape of the product changes in the longitudinal direction. In this study, a roll-forming process for manufacturing high-strength steel automotive parts with a linearly variable symmetric hat-type cross-section was developed. The forming rolls were designed by the 3D CAD system, CATIA. Additionally, the designed forming rolls were modified by the simulation through the 3D elastic-plastic finite element analysis software, MARC. The results of the finite element analysis show that the final roll-forming roll can successfully produce the desired high-strength steel automotive part with a variable cross-section.

• Journal of Computational Design and Engineering
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• v.1 no.2
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• pp.140-151
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• 2014

Storing, and the loading and unloading of materials at production sites in the manufacturing sector for mass production is a critical problem that affects various aspects: the layout of the factory, line-side space, logistics, workers' work paths and ease of work, automatic procurement of components, and transfer and supply. Traditionally, the nesting problem has been an issue to improve the efficiency of raw materials; further, research into mainly 2D optimization has progressed. Also, recently, research into the expanded usage of 3D models to implement packing optimization has been actively carried out. Nevertheless, packing algorithms using 3D models are not widely used in practice, due to the large decrease in efficiency, owing to the complexity and excessive computational time. In this paper, the problem of efficiently loading and unloading freeform 3D objects into a given container has been solved, by considering the 3D form, ease of loading and unloading, and packing density. For this reason, a Group Packing Approach for workers has been developed, by using analyzed truck packing work patterns and Group Technology, which is to enhance the efficiency of storage in the manufacturing sector. Also, an algorithm for 3D packing has been developed, and implemented in a commercial 3D CAD modeling system. The 3D packing method consists of a grouping algorithm, a sequencing algorithm, an orientating algorithm, and a loading algorithm. These algorithms concern the respective aspects: the packing order, orientation decisions of parts, collision checking among parts and processing, position decisions of parts, efficiency verification, and loading and unloading simulation. Storage optimization and examination of the ease of loading and unloading are possible, and various kinds of engineering analysis, such as work performance analysis, are facilitated through the intelligent 3D packing method developed in this paper, by using the results of the 3D model.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.3
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• pp.277-285
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• 2019

In this study, effective cosmetic raw material weighing and bulk manufacturing management system were constructed by using bar code or quick response code (QR code) and database. Raw material labels and weighing labels for bulk manufacturing were published in web environment using the information entered in the database using ScriptX, a print component of Medi&Co. By checking the weighing and manufacturing process by using scanner, tablet and PC, it was possible to remarkably improve the product error caused by erroneous amount or misapplication which is the most cause of error in the production of cosmetic bulk. In conclusion, applying a database that utilizes bar code and QR code to cosmetics manufacturing can reduce the various problems in the process, thereby improving quality control and productivity of cosmetics.

• Fashion & Textile Research Journal
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• v.24 no.5
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• pp.505-518
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• 2022

3D printing technology, also known as additive manufacturing(AM), has not been actively used in the clothing industry despite its potential for economic, environmental, and labor efficiency. Therefore, this study aims to propose a new 3D printing method for the clothing industry, which will be more readily accessible. This roll-type printing method can print wide-sized patterns at once using a 3D modeling program and a FDM 3D printer and help overcome the limitations imposed by the size of the printer. Then, to demonstrate the practical application cases of this printing method, bags of three designs were developed. Prior to product development, a thickness test was performed for stable printing using TPU(Thermoplastic Poly Urethane) filament, and a thickness of 0.45 mm was found to be most suitable for it. Next, the time efficiency test showed that the roll-type printing method takes less time compared to the general printing method in printing wide-sized patterns. Based on these tests, three bags, , and , were developed to confirm the suitability of the roll-type printing method for product development. The advantages of 3D roll-type printing can lie in overcoming of the spatial limitation, and the environmental sustainability as it can reduce waste from the production process. This study is significant in that it presents a new 3D printing method to improve the space limitations and time inefficiency of 3D printers.