• Journal of the Korean Society for Precision Engineering
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• v.31 no.12
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• pp.1133-1139
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• 2014

This paper proposes a simple method to improve a sensitivity of a straightness measurement system for a linear stage, which is applied to a system based on a geometric optic method. An optical system for this method is composed of a corner-cube retro-reflector, a ball-lens and a twodimensional position sensitive detector (2D PSD). The effectiveness of the proposed method was examined theoretically, and verified experimentally using a prototype measurement system. The results show that the measuring sensitivity was dependent on the size of the ball-lens and the setup position of PSD from the ball-lens, and that the proposed method is efficient method to improve the measuring sensitivity.

• Mass Spectrometry Letters
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• v.4 no.4
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• pp.79-82
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• 2013

Various types of alkaloids observed in several herbal medicines were analyzed by electrospray ionization tandem mass spectrometry in positive ion mode. In the present study, MS/MS spectralpatterns were investigated for eight-types of alkaloids (aporpine, protoberberine, tetrahydroprotoberberine, benzylisoquinoline, protopine, phthalide, morpine, and bisbenzylisoquinoline). For aporpine- and protoberberine-type alkaloids, main fragmentations occurred at substituted groups on rigid ring structures, not showing ring fusion. Interesting fragmentations due to iminolization and retro-Diels-Alder (RDA) reaction were observed in MS/MS spectra of protopine- and tetrahydroprotobereberine-type alkaloids. Also, several types of fragmentations such as inductive cleavage and ${\alpha}$-cleavage, or bond cleavage between two ring structures were observed depending on their structural characteristics. These fragmentation patterns are expected to allow instant classification of the specific alkaloid type in various MS/MS spectra of alkaloids.

• Journal of the Korean Society of Safety
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• v.21 no.6 s.78
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• pp.82-87
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• 2006

The existing raised pavement marker, however, have some limitations. Most of them are square-shaped which makes only forward and backward retro-reflection, their orientation can be easily changed by impact of vehicle, and the surface reflector can be readily contaminated leading poor functioning. In addition, maintenance for broken raised pavement marker is not easy. The purpose of the study is to design and manufacture a new and improved type of raised pavement marker. The new raised pavement marker has round-shaped upper structure. Its body was separated from the holder and the reflector was surrounded by acrylic cover. We tested performances of the constituent parts, optimum load after installation, and reflection efficiency. The new raised pavement marker will be an initiation of studies on the improvement of the shape and performance of raised pavement markers.

• Fashion & Textile Research Journal
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• v.10 no.6
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• pp.811-821
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• 2008

This study examined on the most noticeable game industry in a digital era, and on the definition and feature of post-digital generation enjoying it, along with the relations with the game. Especially, this paper examined correlations between game characters' fashion and pop singers' fashion targeting post-digital generation enjoying games. As the result of this study, on-line game's popularity affected popular culture and game business and popular stars have close interrelation. In addition, through variosus objective surveys, the game characters' fashion was classified into five images before being analyzed; fighter's image, retro image, surreal image, sensual image, and unisexual image. The game characters' fashion wasn't only analyzed also studied correlation between on-line game character's fashion and pop singers' fashion by five images. Consequently in case of game characters' fashion, it influenced on pop singers' fashion targeting teens and twenties enjoying games, which meant fashion connections between game characters and pop singers.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.26-31
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• 2008

A precision four-degree-of-freedom measurement system has been developed for simultaneous measurement of four motion errors of a linear stage, which include straightness and angular errors, The system employs a retro-reflector to detect the straightness errors and a plane mirror to detect the angular errors. A common-path compensation method for laser beam drift is put forward, and the experimental results show that the influences of beam drift on four motion errors can be reduced simultaneously. In comparison with the API 5D laser measuring system, the accuracy for straightness measurement is about ${\pm}1.5{\mu}m$ within the measuring range of ${\pm}650{\mu}m$, and the accuracy for pitch and yaw measurements is about ${\pm}1.5$ arc-seconds within the range of ${\pm}600$ arc-seconds.

• Journal of the Korea Fashion and Costume Design Association
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• v.2 no.2
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• pp.41-54
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• 2000

History of fashion and clothing is needed to understand modern fashion and to predict Future mode. The period of Romanticism in fine arts was from the end 18th century up to the first half of 19th century. The characteristics of shilouttes were found in the emphasis owomen's body line. This feature of romantic fashion is founded in 1960, 1970, 1980, 1990'mode. Major characters of this times are retro of romantic costume. As time goes by, more romantic fashion was set up and new corncern of 2000 fashion trend. The Characteristics of romantic image in 2000 of fashion trend are the emphasis of romantic details and decorations. Such as ruffle, frill, shirring, beads, spangle, sequin, flower. Trend colors are pink, lilac, aqua blue, yellow, green, pastel color. Trend materials chiffon, organza, satin, velvet, gauze, georgette, lace and glittery material. And floral print and stripe print. Forward­looking fashion is ethnic­romantic image influenced India. Trend and fashion have very close relationship and if it is fully comprehended, it will be good opportunity to awkardness againnst new fashion line.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.2
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• pp.106-113
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• 2000

This study describes how a properly calibrated simulation method could be used to investigate the latchup immunity characteristics among the various high energy ion implanted CMOS twin well (retro-grade/BILLI/BL) structures. To obtain the accurate quantitative simulation analysis of retrograde well, a global tuning procedure and a set of grid specifications for simulation accuracy and computational efficiency are carried out. The latchup characteristics of BILLI and BL structures are well predicted by applying a calibrated simulation method for retrograde well. By exploring the potential contour, current flow lines, and electron/hole current densities at the holding condition, we have observed that the holding voltage of BL structure is more sensitive to the well design rule (p+to well edge space /n +to well edge space) than to the retrograde well itself.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.195-202
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• 2013

PURPOSES : This study analyzed the regional dew possibility in road sign using meteorological data. METHODS : Four years of meteorological data such as temperature, humidity, dew point, wind velocity were collected and analyzed. As a result of literature review, dew was frequent in large diurnal range, high humidity and weak wind. So, dew possibility was analyzed by (temperature-dew point ${\leq}1^{\circ}C$ and wind velocity ${\leq}$ 1.5m/s). RESULTS : The possibility was analyzed for each meteorological observation point and the point of Suncheon and Bonghwa were selected as the most likely points of dew in road sign. The area of East Coast, Kyungbuk and Kyungnam were relatively low potential. CONCLUSIONS : Alternative with high effect of preventing dew should be selected in high possibility dew area despite of low economics.

• Bulletin of the Korean Chemical Society
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• v.13 no.1
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• pp.32-36
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• 1992

The gas-phase pyrolysis reactions of 2-alkoxypyrimidines(II), 2-alkoxypyrazines(III), 4-ethoxypyrimidine(IV) and 3-ethoxypyridazine(V) are investigated theoretically using the AM1 MO method. These compounds pyrolyze in a concerted retro-ene process with a six-membered cyclic transition state (TS). The relative order of reactivity if (IV)>(II)>(III)>(V), which can be rationalized by the two effects arising from electron-withdrawing power of the aza-substituent: (ⅰ) Electron withdrawal from the C-O bond accelerates the rate and (ⅱ) electron withdrawal from the $N^1$-atom, that is participating in the six-membered TS, deactivates the reaction. We are unable to explain the experimental result of the greatest reactivity for pyridazine, (V), with our AM1 results. The reactivity increase accompanied by successive methylation of the ethoxy group, ethoxytert-butoxy, is due to a release of steric crowding in the activation process.

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.560-564
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• 1991

The gas-phase pyrolysis reactions of iminoethers (Ⅱ), 2-alkoxypyridines (Ⅲ), 2-N-alkylated pyridones (Ⅳ) and N-alkylated acetamides (Ⅴ) have been studied MO theoretically with the AM1 method. The decomposition of these compounds proceeds by a concerted retro-ene process through a six-membered cyclic transition state. The reactivity decreases in the order (Ⅱ) > (Ⅲ) > (Ⅳ) > (Ⅴ), with a greater reactivity for the imine series, (Ⅱ) and (Ⅲ), compared to the amide series, (Ⅳ) and (Ⅴ), and a difference in basicity between the N and O atoms. Within a given series, however, the reactivity is dictated mainly by the aromaticity in the transition state. The reactivity order with respect to side alkyl chain of a species was found to increase as the steric crowding effect increases. The AM1 reactivity in this work agree well with the experimental results.