• Journal of the Korean Society for Precision Engineering
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• v.33 no.11
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• pp.893-898
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• 2016

Plastic array lens are cheap to manufacture; however, plastic is not resistant to high temperatures and moisture. Optical glass represents a better solution but is a more-expensive alternative. Glass array lens can be produced using lithography or precision-molding techniques. The lithography process is commonly used, for instance, in the semiconductor industry; however, the manufacturing costs are high, the processing time is quite long, and spherical aberration is a problem. To obtain high-order aspherical shapes, mold-core manufacturing is conducted through ultra-precision grinding machining. In this paper, a $4{\times}1$ mold core was manufactured using an ultra-precision machine with a jig for the injection molding of an aspherical array lens. The machined mold core was measured using the Form TalySurf PGI 2+ contact-stylus profilometer. The measurement data of the mold core are suitable for the design criterion of below 0.5 um.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.587-590
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• 2000

The new core making method economized on core sand requested. The new method is heating core box until it reaches reasonable temperature and then spraying core sand with core binder into core box. Inner temperature distribution have to uniform in order to form core of uniform thickness. Therefore, in this study we treat of inner temperature distribution of core box in priority. First, determine proper torch number. Next, optimize the torch position to minimize the average of absolute deviation(AVEDEV) of inner temperature. The results are as followed : 1. The torch number that makes inner temperature distribution about $300^\circ{C}$ uniformly is 25. 2. When $S_H$ and $S_V$ is 0.7, the torch position is optimized and AVEDEV is 5.85.

• Fibers and Polymers
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• v.5 no.1
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• pp.25-30
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• 2004

The present paper reports the impact of thermal treatment on the characteristics of core-sheath type hybrid technical yarns. The core-sheath type hybrid yams are prepared using DREF-III technology. Polyester and glass multifilaments are used as core components whereas the cotton and polyester staple fibers are the sheath components wrapped around the core filament with different proportions to form a hybrid structure. The thermal treatment is carried out both in dry and in wet state under relaxed condition and the thermal shrinkage, sheath-slipping resistance and tensile and bending properties of hybrid yarns have been studied. Thermal treatment markedly increases the thermal shrinkage and sheath-slipping resistance of hybrid yarns with polyester multifilament in core, but insignificant effect for yarns with glass multifilament in core. Breaking elongation of hybrid yams with polyester multifilament in core increases with treatment temperature. The hybrid yarns with glass multifilament in core are least affected by thermal treatment.

• Journal of Oriental Neuropsychiatry
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• v.33 no.3
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• pp.241-257
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• 2022

Objectives: To investigate emotional characteristics of healthy adults using the Core Seven Emotions Inventory-Short Form (CSEI-s) and to investigate the correlation between the CSEI-s and Korean version of the Perceived Stress Scale (K-PSS). Methods: Overall, 2,178 healthy adults aged ≥19 years who completed the CSEI-s and K-PSS in a nationwide multicenter study were included in this study. One-way analysis of variance was performed to identify associations of seven emotions with sociodemographic characteristics. Bonferroni corrected post-hoc tests were performed for multiple comparisons. Pearson's correlation analyses were conducted to examine the correlation between each emotion and stress. Results: Scores of all emotions except for joy (喜) and stress were significantly greater in women than in men. However, the score of joy (喜) in women was significantly less than that in men. There were significant differences in joy (喜), thought (思), depression (憂), fear (恐), and fright (驚) according to age groups in both men and women. The score of depression (憂) was significantly lower in women attending or graduating from graduate school than in those attending or graduating from undergraduate school. Significantly lower scores in joy (喜), thought (思), depression (憂), sorrow (悲), fear (恐), and fright (驚) were observed in married men than in single men. There were significant positive correlations between depression (憂) and stress and between sorrow (悲) and stress in both men and women. Conclusions: There were significant associations of seven emotions with sociodemographic characteristics in healthy adults.

• Journal of Life Science
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• v.18 no.4
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• pp.585-589
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• 2008

Chronophin is a phosphatase responsible for the dephosphorylation of cofilin, which regulates the rearrangement of actin cytoskeleton. It is also known as a phosphatase for pyrodoxal 5'-phosphate (PLP), an active form of vitamin $B_6$, and maintains the level of PLP in the cytoplasm. Since this phosphatase belongs to a HAD subfamily containing a cap domain, it is expected to undergo a conformational change for the binding of a substrate. However, the crystal structure of chronophin has a disulfide bridge between the cap and core domains preventing a movement of the cap domain against the core domain. It is possible that the disulfide bond between C91 and C221 was formed by an oxidation during the crystallization. Here, we obtained chronophin crystals under a reduced condition and determined the crystal structure. This reduced chronophin does not contain a disulfide bridge and shows a closed conformation like the oxidized form. It implies that an active chronophin binds its substrate under the closed conformation without the disulfide bond and shows a high substrate specificity in the cell.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.452-452
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• 2008

Abstract Head-mounted displays(HMD) are being developed and marketed in growing numbers for a variety of applications. Though most commonly associated with entertainment applications other applications are also being developed. The field vision on the display screens is expanded by the optical system producing an imaginary screen that appears to be positioned several meters in front of the viewer. In this study, the mold core for the prism lens of HMD was processed by fly-cutting method, and the form accuracy of the mold core was measured.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.178-185
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• 2023

The Chinese calligraphy art, which still adheres to tradition, has fallen into the formalism deeper and deeper. The majority of studies on calligraphy still focus on the formal beauty and neglect the core spirit hidden behind the calligraphy art. The calligraphy art is an art defined by words. This definition is not only reflected in the form of the characters but also, and more importantly, in the meaning of the characters. It is not a form of writing, but a writing of lives, wills and feelings, a writing of the experience of daily life, and an improvised poetic writing. With the advent of the age of artificial intelligence, the Chinese traditional calligraphy art, which still adheres to the "supremacy of the brush and ink", has shown a sense of dystopia, and its end is inevitable. Only by truly understanding the core of the calligraphy art, by integrating it with contemporary daily life, and by focusing on the communication of ideas in calligraphy, will it be possible to obtain a new life.

• Journal of the Korea Institute of Building Construction
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• v.7 no.4
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• pp.153-159
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• 2007

Recently, as a result of the economic growth, the concentration of population towards the cities and the rise in land prices, the demand for high rise buildings has increased significantly, the trend to build high rise buildings such as the mixed-use development buildings by the domestic construction companies continues. It's very important what kind of form work system is applied on the Core Wall of the high rise buildings to determine the economic efficiency for the whole project. That's because the appropriate selection of the Formwork system enables the construction cost lower, makes the good quality of the finished concrete, reduces the construction period, assurance of safety, and further more, it enables to achieve the successful performance of the projects. Therefore, this research, after comparing the strength and the weakness between the construction methods, focus the point to provide a builder the basic data to choose the right Formwork method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.19-20
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• 2010

• Nuclear Engineering and Technology
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• v.47 no.4
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• pp.416-423
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• 2015

It had been disputed how to apply wall drag to the dispersed phase in the framework of the conventional two-fluid model for two-phase flows. Recently, Kim et al. [1] introduced the volume-averaged momentum equation based on the equation of a solid/fluid particle motion. They showed theoretically that for dispersed two-phase flows, the overall two-phase pressure drop by wall friction must be apportioned to each phase, in proportion to each phase fraction. In this study, the validity of the proposed wall drag model is demonstrated though one-dimensional (1D) simulations. In addition, it is shown that the existing form loss model incorrectly predicts the motion of the dispersed phase. A new form loss model is proposed to overcome that problem. The newly proposed form loss model is tested in the region covering the lower plenum and the core in a nuclear power plant. As a result, it is shown that the new models can correctly predict the relative velocity of the dispersed phase to the surrounding fluid velocity in the core with spacer grids.