• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.7
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• pp.83-89
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• 2019

In the conventional casting and forging method, there is a disadvantage that a mold is an essential addition, and a production cost is increased when a small quantity is produced. In order to overcome this disadvantage, a metal 3D printing production method capable of directly forming a shape without a mold frame is mainly used. In particular, overseas research has been conducted on various materials, one of which is a metal printer. Similarly, domestic companies are also concentrating on the metal printer market. However, In this case of the conventional metal 3D printing method, it is difficult to meet the needs of the industry because of the high cost of materials, equipment and maintenance for product strength and production. To compensate for these weaknesses, printers have been developed that can be manufactured using sand mold, but they are not accessible to the printer company and are expensive to machine. Therefore, it is necessary to supply three-dimensional casting printers capable of metal molding by producing molds instead of conventional metal 3D printing methods. In this study, we intend to reduce the unit price by replacing the printing method used in the sand casting printer with the FDM method. In addition, Ag paste is used to design the output conditions and enable ceramic printing.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.72-77
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• 2008

This paper investgated on fabrication process and tolerance of resistance body with a uniform thickness formed by the process of cavity type on organic substrate for application of embedded resistor. To improve the tolerance of resistance value according to a position of PCB cause by conventional screen printing, we introduced the process of cavity type from organic substrate. A resistor with a desired shape and volume was precisely formed by the process of cavity using a resistor paste and screen printing. This method can increase PCB's productivity by shortening its production time because process conditions of a screen prining device can be set quickly without any affection on its position accuracy.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.2
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• pp.33-38
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• 1998

In point of flexographic printing on generally corrugated fiberboard cartons, the precision of film master and the adequate compression rate are very important factor in bar-code printing. Also, the complete system including scanner is essential for the purpose of enhancing the reading rate. The film master had good precision when the film was prepared by means of printing/developing machine after transformation of input bar-code number through transceiver, and the BWR 100 showed better compression rate than BWR 200. Also considering the bar-code reading, the complete system targeting the reading rate above 99.8% could be configured by Omni-Directional Scanner type accomplishing the reading rate above 99.5%.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.30.2-30.2
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• 2010

Nano-scale p-n junction can generate various nano-scale functional devices such as nanowire light emitting diode, nanowire solar cell, and nanowire sensor. The core shell type nanowire p-n junction has been considered for the high efficient devices in many previous reports. On the other hand, although device efficiency is relatively lower, the cross bar type p-n junction has simple topological structure, suggested by C.M. Lieber group, to integrate easily many p-n junction devices in one board. In this study, for the integration of the cross bar nanowire p-n junction device, a simple fabrication route, employed dielectrophoretic array and direct printing techniques, was demonstrated by the successful fabrication and programmable integration of the nanowire cross bar p-n junction solar cell. This direct printing process will give the single nanowire solar cell the opportunity of the integration on the circuit board with other nanowire functional devices.

• Journal of the HCI Society of Korea
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• v.12 no.2
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• pp.21-29
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• 2017

While the second and the third industrial revolutions made it possible a few standardized designs to be extracted and produced in large quantities, the recent development of the 3D printing technology allowed many individuals to reflect their unique personal characteristics on their creative works and produce them in large quantities-i.e., personally customized designs and mass production of various designs. However, for the customized designs and the mass production of various designs through the 3D printing technology, the individuals should use a 3D modeling software and the supporting features of the software can significantly affect the type and shape of a creative work. In this study, we surveyed the individuals who design the creative works using 3D printers about the type of software that they use and the type of creative works that they design using the software, to propose a possible direction of new software that supports their activities. To do this, we first surveyed sixty members of the OpenCreators, which is the largest 3D printing creator community in South Korea, about the 3D modelling Software that they use for their 3D printing creations, the best 3D modelling software for the 3D printing, and the type of frequently printing creation using the best 3D modelling software. We then analysed the response results. As a result, we found that most of 3D printing creators in South Korea use Rhino and 123D Design. More specifically, the Rhino was being widely used by the people in the 3D printing industry to print prototypes, samples, and mock-ups, while the 123D Design was being mainly used for general purposes such as educational tools, accessories, and home interior accessories. Therefore, we believe it is necessary to develop the software in two separated categories, i.e. for the business, like the Rhino, and for the beginners, and educational and personal purposes, like the 123D Design. Finally, we stressed and proposed the necessity to support individual creators by developing an industry-specific 3D modeling software.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.715-716
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• 2008

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1463-1465
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• 2008

We report all-ink-jet printed inorganic/organic hybrid TFTs on plastic substrates. We have investigated the optimal printing conditions to make uniform patterned layers of gate electrode, dielectrics, source/drain electrodes, and semiconductor as a coplanar type TFT in a successive manner. All ink-jet printed devices have good mechanical flexibility and current modulation characteristic even when bent.

• Journal of the Korean Graphic Arts Communication Society
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• v.10 no.1
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• pp.23-33
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• 1992

The negative pressure distribution curves of the exit of printing nip were obtained by the transducer type tackometer. As the results, found that the elasticity of rubber rollers and pastic viscosity affect to the maximum negative and positive pressure but, the gap of the printing nip didn`t affects to the tack values of ink and ink film thickness. Ink spritting is accured by negative pressure and inks viscoelasticity. And the tack value is affect by properties of the vehicle component in the inks.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.76-83
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• 2022

Since the 3D printing mortar is exposed to the atmosphere immediately after printing, moisture is largely evaporated from the surface of the layer. The evaporation of moisture on the surface of the layer greatly causes drying shrinkage and increases the risk of cracking and damage to the structure due to drying shrinkage. This study experimentally evaluated the shrinkage behavior of the initial age using the mortar used for 3D printing. The change in shrinkage was evaluated by comparing the shrinkage of the specimen cured by the sealing method and the atmospheric exposure method. In addition, compared with the case where type 1 cement was used 100%, the shrinkage amount was evaluated when 20% of fly ash was replaced and 10% of silica fume was used. In particular, the effect of three chemical admixtures applied using 3D printing on shrinkage was evaluated experimentally. When fly ash and silica fume were used, the shrinkage amount increased by 60 - 110% compared to the case when type 1 cement was used. The application of viscosity modifiers and shrinkage reducers reduced the shrinkage by at least 18% and at most 70% depending on the curing conditions. The temperature of the specimen temporarily decreased to 15 ℃ at the beginning of curing, and the correlation between the internal temperature of the specimen and the shrinkage behavior was observed.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.5
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• pp.939-949
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• 2017

This study uses 3D printing technology to design and fabricate a fall impact protection pad with a spacer fabric structure. The design of the pads consists of hexagonal three-dimensional units connected in a honey-comb shape; in addition, the unit consists of a surface layer and a spacer layer. Protect pads were designed as either a hexagonal type or diamond type according to the surface layer structure; subsequently, a spacer filament was also designed as the most basic I-shape type. Designed pads were printed using four types of flexible filaments to select suitable material for a fall impact protection pad. Impact protection performance and bending stiffness were evaluated for the eight type of pad outputs. As a result of the impact protection performance evaluation, when the force of 6,500N was applied, the force passed through the pad was in the range of 1,370-2,132N. FlexSolid$^{(R)}$ and Skinflex$^{TM}$ showed good protection performance and cubicon flexible filament showed the lowest protection. NinjaFlex$^{(R)}$ was found to be the most flexible in the bending stiffness evaluation.