• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.8
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• pp.709-714
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• 2014

Reverse-offset printing is one of the technologies that can be used for patterning fine features of the order of a few micrometers for printed electronics. In reverse-offset printing, a coated ink film is transferred to a blanket made of elastomer-like poly-dimethylsiloxane. Then, the blanket is impressed onto a clich$\acute{e}$ that has intaglio patterns. The blanket is deformed by penetrating the intaglio of the clich$\acute{e}$ according to the printing pressure. Excessive deformation of the blanket can cause printing defects upon touching the bottom of the intaglio pattern, especially in large patterns. In this paper, we modelled the deformation of the blanket using the finite element method. Considering the actual printing parameters, a condition for fabricating a clich$\acute{e}$ is proposed to prevent defects by the deformation of the blanket.

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.2
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• pp.89-100
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• 2003

We have reviewed the method for surface tension of printing inks. Most of the methods fir for the low viscosity inks and solvents for inks. However, the inks for the offset lithography and intaglio should have high viscosity and high tack. The elongation of the ink filaments has more effect on the measuring surface tension than the energy of the surface molecules. In this paper, we propose the elongation method to estimate the surface tension of high viscosity printing inks. Even though we could measure the surface tension for low viscosity inks such as gravure and screen, elongation method could more useful to estimate the surface tension of lithography and intaglio inks than any other methods.

• Journal of Korean Dental Science
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• v.14 no.2
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• pp.79-89
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• 2021

Purpose: The technique introduced in this study describes a technique for surface treatment that applies a photocuring resin to the surface of an interim crown fabricated by three-dimensional (3D) printing without a conventional polishing method. The purpose of this study was to evaluate marginal and internal fit and the intaglio surface trueness of interim crowns after surface treatment of 3D-printed crowns for clinical application. Materials and Methods: An interim crown was fabricated using a 3D printer with digital light-processing technology, and the surface support was removed. After the posttreatment process, the resin was thinly applied to the surface of the interim crown and polymerized to solve the esthetic problem of the surface without the conventional polishing process. In addition, the marginal and internal fits were measured to verify the clinical use of this technique, and the trueness was evaluated to confirm the deformation of the inner surface according to the technical application of the outer surface of the interim crown. The difference before and after the evaluation by a statistical method was verified using an independent t-test (α=0.05). Result: There was no significant difference in the marginal and internal fit before and after the application of this technique (P>0.05). There was no significant difference in intaglio surface trueness before and after the application of this technique (P=0.963). Conclusion: There was no change in the marginal and internal fit or in intaglio surface trueness of the interim crowns to which this technology was applied. This surface treatment technique is a more convenient method for interim crowns fabricated using 3D-printing technology without the conventional polishing process.

• 연구논문집
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• s.32
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• pp.15-22
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• 2002

In offset or intaglio printing machine, it's operated with combination of blanket cylinder and impression cylinder. The blanket cylinder has some number of grooves to attach the blanket on surface. In case of operating the printing machine, it has generate mechanical impact noise when the two cylinders encounter with the grooves. So, in this study, we developed a printing pressure control algorithm with hydraulic servo control system. We also proposed simulation model of experimental device to analysis the throw on force response of hydraulic servo actuator. Finally, we have reduced the mechanical impact noise and improved printing quality with a groove detecting signal and PI control of hydraulic servo actuator.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.1
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• pp.15-22
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• 2008

For the improvement of letterpress printing paper quality, special fibers obtained from the sea were used by mixing with wood fibers. The sizes of the special fibers, which were from red algae in the sea, were 0.5-1 mm in length, and 3-7 ${\mu}m$ in width, respectively, and the fibers were supplied by Pegasus Research Inc. for the study. From the study, it was found that 10% addition of algae fibers greatly improved paper surface strength and internal bonding strength. The compressibility was estimated by utilizing 'Print-surf method' at high clamping pressure and with hard backing. Again, 10% addition of algae fibers greatly improved the compressibility of the paper. These results were expected that algae and wood fibers were distributed evenly through the sheet, and integrated one another to leave no empty space inside the paper.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.2
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• pp.23-36
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• 2004

The surface tension method has been possible only for the low viscosity materials. However, the inks for the off-set lithography and intaglio should have high viscosity and high tack. In this paper, we propose the elongation method to estimate the surface tension of high viscosity printing inks. The elongation method could be more useful to estimate the surface tension and shown in this research, it is possible to calculate the surface tension of high viscoxity ink without diluting the sample.

• Korean Journal of Computational Design and Engineering
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• v.4 no.1
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• pp.19-31
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• 1999

One of the non-photorealistic rendering method, a drawing technique which uses only fine curves and dashed line, is widely employed in an knots and post stamps printing. Engraving of the curves and lines are traditionally performed by human engravers which leads to low productivity in printing preparation. As an effort to improve productivity and quality, a drawing automation method which can easily produce a portrait composed of vector data for laser or chemical engraving is proposed. The method shows that it is possible to draw a portrait by controling the width and length of predefined fine lines according to the gray scales a the end points of each fine lines. A gradually controled weighting factor method is proposed in addition to the author previous works to prevent undesirable boundaries in an identical texture region. User interface functions of a commercial CAD system are heavily employed to exploit the presented method.

• Journal of Science of Art and Design
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• v.11
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• pp.79-108
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• 2007

"Printing is an Art of reproduction & a Technique of However printing has extended its limitation from a genre of reproduction itself and now it stands on the turning point as an art such as painting or sculpture which expresses artist's originality. Early Printing has had relations in depth with press printing in terms of information recording, preservation, and transmission. It was acknowledged value in a way of information satisfaction different from how it is valued as a pure art today. But, later printing has transferred its function from a mean of reproduction to pure art due to the development of printing skills and photography invention. It can be said that the concept of modern printing is taking over its genealogy as a creative work not as just printing. Also its expression capability is widen to dimensional printing and high-tech multimedia from original tradition techniques. As we discussed above, modern painting is very open to various changes. This modern painting aspect can be seen as an extended interpretation of 'board' concept. This dissertation raises a question why monotype and monoprint couldn't secure its position in printing history in spite of numerous artists' tryouts in its way. Monotype and monoprint fundamentally based on intaglio technique in its history. Yet, its systematic study hasn't been worked out. This is because of the lack of recognition of monotype and monoprint's originality as printing. Especially in monoprint, it has known as an early stage in copperplate printing process which is an attempt to solve the technique limitation or trial work for edition. Likewise the reason why monotype and monoprint remains at the edge of printing border ambiguously is because of conceptual, technical characteristics which are against traditional printing. In traditional printing, the concept of board is important as a method of reproduction. Different from the fact, monotype and monoprint accept the form of medium 'board' conceptually out of limited condition as mentioned. Thus monotype and monoprint hasn't stand out for several reasons until late 20th century when it started come out to public as people starts to have interests that works from famous artists are actually based on monotype and monoprint. This dissertation likes to step into the monotype and monoprint theoretically which is not well known in domestic and try to study the meaning of monotype and monoprint as a printing medium which is also hasn't been considered sincerely. For this study the process follow as below. First, look into how monotype and monoprint has a concept and history. Next, check differences through comparison with traditional printing and how printing can be understood in what aspects at the same time. After, verify how monotype and monoprint have influence on the acceptance of extended concept of 'board'. This study will show the expressional possibility of monotype and monoprint which has already known as 'tableau printing' in today's situation where adventurous experiments of printing medium are going on with the development of technology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.6
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• pp.849-852
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• 2021

This paper presents a vision based tire mold inspection system where mold defects are inspected and the sizes of specific parts of the mold are measured. There are a lot of challenging issues as letters and pictures of intaglio are engraved on a bright surface of the tire mold. To solve the issues, we carefully selected a line-scan camera and a line light. In addition, we used PLC to control the mechanical parts. The developed system provides inspection of misspelled and deformed letters as well as a variety of the functions such as size measurement of engraved regions and inspection report file creation.

• The Journal of Advanced Prosthodontics
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• v.11 no.1
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• pp.55-64
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• 2019

PURPOSE. The accuracy of denture bases was compared among injection molding, milling, and rapid prototyping (RP) fabricating method. MATERIALS AND METHODS. The maxillary edentulous master cast was fabricated and round shaped four notches were formed. The cast was duplicated to ten casts and scanned. In the injection molding method, designed denture bases were milled from a wax block and fabricated using SR Ivocap injection system. Denture bases were milled from a pre-polymerized block in the milling method. In the RP method, denture bases were printed and post-cured. The intaglio surface of the base was scanned and surface matching software was used to measure inaccuracy. Measurements were performed between four notches and two points in the mid-palatal suture to evaluate inaccuracy. The palatine rugae resolution was evaluated. One-way analysis of variance was used for statistical analysis at ${\alpha}=.05$. RESULTS. No statistically significant differences in distances among four notches (P>.05). The accuracy of the injection molding method was lower than those of the other methods in two points of the mid-palatal suture significantly (P<.05). The degree of palatine rugae resolution was significantly higher in the injection molding method than that in other methods (P<.05). CONCLUSION. The overall accuracy of the denture base is higher in milling and RP method than the injection molding method. The degree of fine reproducibility is higher in the injection molding method than the milling or RP method.