• Tribology and Lubricants
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• v.24 no.6
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• pp.326-331
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• 2008

The contact surfaces between mold and target should be in parallel for a proper imprinting process. However, large size of contacting area makes it difficult for both mating surfaces (mold and target planes) to be in all uniform contact with the expected precision level in terms of thickness and position. This is caused by the waviness of mold and target although it is very small relative to the area scale. The gripping force for both mold and target by the vacuum chuck is other major effect to interrupt the uniform contact, which must be avoided in imprinting mechanism. In this study, the cause of non-conformal contact mechanism between mold and target is investigated with the consideration of deformation due to the vacuum gripping for the size $470{\times}370\;mm^2$ LCD panel.

• Tribology and Lubricants
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• v.22 no.5
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• pp.243-251
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• 2006

Molecular dynamics simulations of nanoimprint lithography NIL) are performed in order to investigate effects of process parameters, such as stamp shape, imprinting temperature and adhesive energy, on nanoimprint lithography process and pattern transfer. The simulation model consists of an amorphous $SiO_{2}$ stamp with line pattern, an amorphous poly-(methylmethacrylate) (PMMA) film and an Si substrate under periodic boundary condition in horizontal direction to represent a real NIL process imprinting long line patterns. The pattern transfer behavior and its related phenomena are investigated by analyzing polymer deformation characteristics, stress distribution and imprinting force. In addition, their dependency on the process parameters are also discussed by varying stamp pattern shapes, adhesive energy between stamp and polymer film, and imprinting temperature. Simulation results indicate that triangular pattern has advantages of low imprinting force, small elastic recovery after separation, and low pattern failure. Adhesive energy between surface is found to be critical to successful pattern transfer without pattern failure. Finally, high imprinting temperature above glass transition temperature reduces the imprinting force.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.1
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• pp.21-24
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• 2020

We investigated a solution-driven Yttrium Tin Oxide (YSnO) film that was imprinted using a parallel nanostructure as a liquid crystal (LC) alignment layer. The imprinting process was conducted at the annealing temperature of 100℃. To evaluate the effect of this process, we conducted surface analyses including atomic force microscopy (AFM). During imprinting, the surface roughness was reduced, and anisotropic characteristics were observed. Planar LC alignment was observed at a pretilt angle of 0.22° on YSnO film. Surface anisotropy induced by imprinting method forces LC to align along the direction of the parallel nanostructure, which is an alternative to conventional polyimide treated using a rubbing process.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.844-849
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• 2008

A nano-imprinting stage has been widely used in various fields of nano-technology. In this study, A 4-axis nano-imprinting stage is modeled with using the 3D-CAD Tool. Structural components such as an upper-plate, bearings and cross-roller-guides are modeled with finite elements to analyze flexibility effect during the precision stage motion. In addition, Dynamic analysis is executed to reproduce actual motion of 4-axis nano imprinting stage.

• Reproductive and Developmental Biology
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• v.28 no.2
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• pp.107-112
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• 2004

Molecular genetic markers were genotyped used to detect chromosomal regions which contain economically important traits such as growth traits in pigs. Three generation resource population was constructed from a cross between the Korean native boars and Landrace sows. A total of 193 F2 animals from intercross of F1 were produced. Phenotypic data on 7 traits, birth weight, body weight at 3, 5, 12, 30 weeks of age, live empty weight were collected for F2 animals. Animals including grandparents (F0), parents (F1), offspring (F2) were genotyped for 194 microsatellite markers covering from chromosome 1 to 18. Quantitative trait locus analyses were performed using interval mapping by regression under line-cross model. To characterize presence of imprinting, genetic full model in which dominance, additive and imprinting effect were included was fitted in this analysis. Significance thresholds were determined by permutation test. Using imprinting full model, four QTL with expression of imprinted effect were detected at 5% chromosome-wide significance level for growth traits on chromosome 1, 5, 7, 13, 14, and 16.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1073-1077
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• 2003

This study aims to investigate the fabrication process of nano silicon mold using electron beam lithography (EBL) to generate the nanometer level patterns by nano-imprinting technology. the nano-patterned mold including 100mm pattern size has been fabricated by EBL with different doses ranged from 22 to 38 ${\mu}C/cm^2$ on silicon using the conventional polymethylmetharcylate(PMMA) resist. The silicon mold is fabricated with various patterns such as circles, rectangles, crosses, oblique lines and mixed forms, The effect of dosage on pattern density in EBL is discussed based on SEM (Scannning Electron Microscopy) analysis of fabricated molds. The mold surface is modified by hydrophobic fluorocarbon (FC) thin films to avoid the stiction during nano-imprinting process.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.269-272
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• 2006

Surface contacts between mold and target should be in parallel for the imprinting mechanism. However, the size of contacting area makes it difficult for both mating surfaces to be in all contact because of precision level of the imprinting machine and the waviness of mold and target. The gripping force for both mold and target with the vacuum chuck is also major effect to interrupt the full contact, which must be avoided in imprinting mechanism. In this study, the preliminary study for the causes of non-uniformity of contacting surfaces such as mold and target is performed with $470{\times}370mm^2$ LCD panel size.

• Korean Journal of Agricultural Science
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• v.43 no.1
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• pp.72-79
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• 2016

It has long been known that nutritional and environmental influences during the early developmental period affect the biological mechanisms which determine animal metabolism. This phenomenon, termed 'metabolic imprinting', can cause subtle but long-lasting responses to prenatal and postnatal nutrition and even be passed onto the next generation. A large amount of research data shows that nutrient availability, in terms of quantity as well as quality, during the early developing stages can decrease the number of newborn piglets and their body weight and increase their susceptibility to death before weaning. However, investigation of potential mechanisms of 'the metabolic imprinting' effect have been scant. Therefore, it remains unknown which factors are responsible for embryonic and early postnatal nutrition and which factors are major determinants of body weight and number of new born piglets. Intrauterine undernutrition, for example, was studied using a rat model providing dams 50% restricted nutrients during pregnancy and the results showed significant decreases in birth weight of newborns. This response may be a characteristic of a subset of modulations in embryonic development which is caused by the metabolic imprinting. Underlying mechanisms of intrauterine undernutrition and growth retardation can be explained in part by epigenetics. Epigenetics modulate animal phenotypes without changes in DNA sequences. Epigenetic modifications include DNA methylation, chromatin modification and small non-coding RNA-associated gene silencing. Precise mechanisms must be identified at the morphologic, cellular, and molecular levels by using interdisciplinary nutrigenomics approaches to increase pig production. Experimental approaches for explaining these potential mechanisms will be discussed in this review.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.51-57
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• 2014

Ultrasonic imprinting is a novel process for replicating micropatterns on thermoplastic polymer substrates with low energy consumption and short cycle time. The polymer substrate is softened by the frictional heat and repetitive deformation energy under ultrasonic excitation; thus, a number of micropatterns are replicated on the softened polymer substrate. In the present work, the effect of mold temperature on the replication characteristics of ultrasonic imprinting is investigated. The temperature change in the patterned region is measured by varying the mold temperature. Numerical simulation is then performed for investigating pattern replication characteristics under various mold temperatures. In addition, pattern replication ratio and uniformity are compared through various experimental measurements. Through the results of these comparisons, it is found that the mold temperature has a significant positive effect on the replication characteristics of ultrasonic imprinting.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.273-274
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• 2012