• The Research Journal of the Costume Culture
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• v.14 no.5
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• pp.828-839
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• 2006

These days, by the accelerated developments of science and industries and the menaces of war and terror, humans have come to have instinct to recur and nostalgia to nature and thereby many art works and designs with natural objectives have begun to be produced. Also the design in 21st century requires creative products based on cultural speciality of the countries. As the examples, we may easily find the images of the countries from visual expressions or products when we get in touch with the products of so called advanced countries in design i. e. U.S.A. Japan, Germany, France, Italy, countries of Scandinavian peninsular. This study, in such stream of the times, was to express our culture's own originality on clothing design with butterfly that is one of natural thing as the material but limited the boundary to realistic butterflies in folk drawings of the times of Chosun. As for the technique of expression, used digital textile printing for best expression of the fine lines, realistic shapes and peculiar colors of the butterflies in Chosun folk drawings and used diverse materials as materials for printing for diversity of the designs. Thereby this thesis is purposed to grope the products with superior competitiveness in the world market by presenting the realistic butterflies in Chosun folk drawings as motives with cultural value native to Korea and applying them to clothing designs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1445-1449
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• 2007

This paper presents the DOD (Drop-On-Demand) characteristic using the electrostatic field induced inkjet printing system. In order to achieve the DOD characteristic of electrostatic field induced inkjet printing, applied the bias voltage of 1.4 kV and the pulse voltage of $2.0\;kV\;{\sim}\;2.7\;kV$ using high voltage pulse generator. Electrostatic field induced droplet ejection is directly observed using a high-speed camera and for investigated DOD characteristic, CNT ink used. The electrostatic field induced inkjet head system has DOD characteristic using pulse generator which can be applied pulse voltage. The bias voltage has a good condition which form meniscus and has micro dripping mode for small size micro droplet. Also, the droplet size decreases with increasing the applied pulse voltage. This paper shows DOD characteristic at electrostatic field induced inkjet head system, Therefore. electrostatic DOD inkjet head system will be applied industrial area comparing conventional electrostatic inkjet head system.

• Composites Research
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• v.34 no.2
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• pp.136-142
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• 2021

3D printing technology has the advantage of easy to make various shapes of products without a mold. However, it has a problem such as mechanical properties vary greatly depending on materials and manufacturing conditions. Thus, the need for research of 3D printing technology on ways to reduce manufacturing cost compared to physical properties is increasing. In this study, a 3D printing thermoplastic structure was fabricated using short fiber carbon fiber reinforced nylon filaments. And a method of improving mechanical properties was proposed by reinforcing the outer surface using pultruded continuous fiber-type carbon fiber or glass fiber-reinforced thermosetting composite material. It was confirmed that the bending properties were improved according to the reinforcing position of the stiffener and the type of fiber in the stiffener.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.965-966
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• 2008

• The Journal of Advanced Prosthodontics
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• v.16 no.2
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• pp.115-125
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• 2024

PURPOSE. The purpose of this in vitro study was to investigate the fracture resistance, surface hardness, and color stain of 3D printed, CAD-CAM milled, and conventional interim materials. MATERIALS AND METHODS. A total of 80 specimens were fabricated from auto polymerizing polymethyl methacrylate (PMMA), bis-acryl composite resin, CAD-CAM polymethyl methacrylate resin (milled), and 3D printed composite resin (printed) (n = 20). Forty of them were crown-shaped, on which fracture strength test was performed (n = 10). The others were disc-shaped specimens (10 mm × 2 mm) and divided into two groups for surface hardness and color stainability tests before and after thermal cycling in coffee solution (n = 10). Color parameters were measured with a spectrophotometer before and after each storage period, and color differences (CIEDE2000 [DE00]) were calculated. The distribution of variables was measured with the Kolmogorov Smirnov test, and one-way analysis of variance (ANOVA), Tukey HSD, Kruskal-Wallis, Mann-Whitney U tests were used in the analysis of quantitative independent data. Paired sample t-test was used in the analysis of dependent quantitative data (P < .05). RESULTS. The highest crown fracture resistance values were determined for the 3D printed composite resin (P < .05), and the lowest were observed in the bis-acryl composite resin (P < .05). Before and after thermal cycling, increase in mean hardness values were observed only in 3D printed composite resin (P < .05) and the highest ΔE₀₀ value were observed in PMMA resin for all materials (P < .05). CONCLUSION. 3D printing and CAD-CAM milled interim materials showed better fracture strength. After the coffee thermal cycle, the highest surface hardness value was again found in 3D printing and CAD-CAM milled interim samples and the color change of the bis-acryl resin-based samples and the additive production technique was higher than the PMMA resin and CAD-CAM milled resin samples.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.11 no.2
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• pp.109-114
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• 2005

This paper introduces the current status of total overseas packaging industries. The total market of the world packaging industry reached over 500 billion dollars in 2002. The top nations for the packaging industry were U.S. at about 27 percent, the countries of Western Europe at about 27%, Japan at about 14%. In terms of packaging materials, the overall market rate for paper, plastics, and metal parts in world packaging industry was 84%. Also, the market rate of glass, packaging machine, and others was only 5-6%. Among EU nations, Germany showed largest packaging consumption of 23 percent in 2000, and consumed about 17,125,814 ton of packaging materials yearly. For paper and paperboard cartons, the percentage used for the packaging consumption was about 39.4%. The consumption rate of plastic and glass packaging was approximately 14.6% and 23.7% respectively. For metal packaging the consumption rate was about 5.9%. In Japan, the production rate of packaging materials was decreased slowly at paper, metal, glass, and wood areas, but plastic packaging showed a constant rate of growth. In China, total production of packaging industry amounted to about 33.7 billion in 2003. The paper packaging in china was a remarkable production rate of 32%. The production rate of plastic and printing packaging was 28% and 20% respectively. The rate of packaging industry for printing in China was much higher than that in other countries.

• Journal of Korean Society of Archives and Records Management
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• v.9 no.2
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• pp.5-18
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• 2009

Congress established the Federal Depository Library Program (FDLP) to ensure that the public has free access to the Government's information. Operated by the U.S. Government Printing Office (GPO), the mission of the FDLP is to disseminate information products from all three branches of the Government to over 1,250 Depository libraries in the FDLP program nationwide. Depository libraries safeguard the American public's right to information by making Government information in all formats freely available. This paper discusses the role of the GPO and FDLP, the GPO's organizational structure, the Depository library's obligations and responsibilities, services and collections, referrals and networking, and the Depository's future and challenges.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.4
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• pp.29-37
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• 2007

The effects of latex particle size, basis weight of base paper and coating color concentration on the printing quality of coated paper were investigated. Coating colors were prepared with five types of latexes having different particle sizes. Coated papers were produced with high solid coating colors and with low solid coating colors in a industrial coater, respectively. In high solid coating colors, rheology modifier was used and GCC content was high. It was concluded that, in order to control binder migration and hence print mottle, latex particle sizes shall be controlled as well as formation, sizing degree and roughness of basis paper.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.40-43
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• 2004

Stamps for microcontact processing are fabricated by casting elastomer such as PDMS on a master with a negative of the desired pattern. After curing, the PDMS stamp is peeled away from the master and exposed to a solution of ink and then dried. Transfer of the ink from the PDMS stamp to the substrate occurs during a brief contact between stamp and substrate. Generally, negative-tone masters, which are used for making positive-tone PDMS stamps, are fabricated by using photolithographic technique. The shortcomings of photolithography are a relative high-cost process and require extensive processing time and heavy capital investment to build and maintain the fabrication facilities. The goal of this study is to fabricate a negative-tone master by using Nano-indenter based patterning technique. Various sizes of V-grooves and U-groove were fabricated by using the combination of nanoscratch and HF isotropic etching technique. An achieved negative-tone structure was used as a master in the PDMS replica molding process to fabricate a positive-tone PDMS stamp.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.8
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• pp.1021-1029
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• 2001

Rapid prototyping(RP) is a novel technology to create 3D products directly from CAD system. This study proposes a new RP method which uses the PZT ceramic plate to make a Drop-On-Demand liquid jet from the nozzle. The characteristic of drop formation in the new system is investigated both numerically and experimentally. The optimal drop for 3-D Printing can be obtained by the proper amplitude and frequency of the applied voltage. Also the process of the drop formation is analyzed using the pressure wave theory and verified by numerical simulation. First, the pressure wave generated by the deformation of the Piezo-plate at the nozzle is analyzed by solving the 2D axisymmetric wave equation via Finite Element Method. Finally, the drop formation process is simulated using a commercial software, FLOW 3D considering the pressure at the nozzle obtained by solving the wave equation as the boundary condition.