• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.325-328
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• 2000

The control of the data retention time is a main issue for realizing future high density dynamic random access memory. In this paper, we propose the new implantation scheme by gate-related ion beam shadowing effect and buffer-enhanced $\Delta$ Rp increase using buffered N- implantation with tilt and 4X-rotation that is designed on the basis of the local-field-enhancement model of the tail component. We report an excellent tail improvement of the retention time distribution attributed to the reduction of electric field across the cell junction due to the redistribution of N- concentration which is intentionally caused by Ion Beam Shadowing and Buffering Effect using tilt implantation with 4X-rotation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.8-14
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• 2007

Recently, the variation of industry has been changed faster and faster than before. It is using Rapid Prototyping Method to cope with fast change. This technology used to make a prototype, master pattern of manufactured product by vacuum casting, and so on. But this method has errors by contraction as a necessity. this error has been caused because the shape of prototype is smaller than CAD data. So we must solve the problem about precision of product. Therefore in this study, we will reduce the errors like contraction of material by manufacturing of rapid prototype product. Through these courses, we will enhance a precision of product.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.38-41
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• 2003

Better understanding and sharing information are getting important to manage interdisciplinary product development team in a globally-distributed company. This study propose a solution to implement RPD(Rapid Product Development) system, focusing on rapid production process, for better understanding between development team members in different place and easy sharing of product information. The system developed by this research shows that SOAP(Simple Object Access Protocol) operates in distributed environment more efficiently than other RPC(Remote Procedure Call) techniques and it does not respond sensitively to firewall. And SOAP is an excellent RPC and messaging technique to exchange structured data. Procedures developed with use of SOAP are worked together with web, and users can use remote services as an application program in their computer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.883-886
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• 1997

In all Rapid Prototyping (RP) processes, a CAD solid model is sliced ito thin layers of uniform, but not necessarily constant, thickness in the building direction. Each cross-sectional layer is successively deposited and, at the same tim, bonded onto the previous layer; the stacked layers form a physical part of the model. The objective of this study is to develop a methode for calculating the rotational angle(θ/sub x/, θ/sub y/) of the linear hotwire cutting system in the three-dimensional space for the Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-S). In order to examine the applicability of the developed method to VLM-S, various three-dimensional shapes, such s a screw, an extruded cross, and a figure of Sonokong, were made using the data obtaiend from the method.

• Laser Solutions
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• v.5 no.1
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• pp.23-31
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• 2002

The uniform metal droplet generation using Nd-YAG laser was studied and experiment was carried out. The shape and volume of developed droplet was measured and the Young-Laplace equation and equilibrium condition of force were applied this model. The differential equation predicting shape of droplet using equilibrium condition of force instead of Navier-stokes equation was induced and numerical solution of differential equation compared with experimentation data. The differential equation was solved by Runge-Kutta method. Surface tension coefficient of droplet was determined with numerical solution relate to experimental result under the statical condition. In case of dynamic vibration, metal droplet shape and detaching critical volume are predicted by recalculating proposed model. The result revealed that this model could reasonably describe the behavior of molten metal droplet on vibration.

• Archives of Pharmacal Research
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• v.17 no.1
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• pp.48-50
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• 1994

Three p-coumaroylamino acids (p-CAAs) were isolated from the yeast-elicited Ephedra distachya cultures by consecutive purification using XAD_2, silicagel and RP-HPLC. Retention times on HPLC as well as their UV, IR, NMR and MS spectral data indicated that the yeast-induced p-CAAs wre p-coumaroyl--D-valine, p-coumaroyl-D-serine and p-coumarouyl-D-threonine, respectively. The structures of p-CAAs were confirmed by the comparison of their physico-chemical properties 3with those of synthetic ones. They were isolated and identified for the first time from natural products and supposed to be accumulated as phytoalexins of Ephedra.

• Ocean and Polar Research
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• v.39 no.2
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• pp.115-124
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• 2017

The objective of this study is to evaluate the antioxidant activity of the fruits of Ligustrum japonicum. The crude extract was successively fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions by means of solvent polarity. The crude extract and its solvent fractions were evaluated for their antioxidant effect by four different assay systems: scavenging power on peroxynitrite and intralcellular ROS produced in HT-1080 cells; DNA oxidation inhibition; ferric reducing antioxidant power (FRAP). The n-BuOH fraction exhibiting potent antioxidant activity was further purified by C18 silica gel column chromatography and RP-HPLC to give tyrosol (1) and salidroside (2). The structure of isolated compounds was determined by extensive 2 D NMR experiments such as $^1H$ COSY, NOESY, HSQC and HMBC as well as by comparison with the published spectral data.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.82-86
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• 2010

Quinine (QN) is a weak anion-exchange type chiral selector and QN-based silica stationary phases have been widely used for enantioseparation of acidic chiral analytes in HPLC and recently in CEC. In this work we report enantioseparation of non-acidic chiral analytes on a quinine carbamate-immobilized zirconia (QNZ) in reversed-phase (RP) CEC. Influences of pH, composition of the buffer, acetonitrile content and the applied voltage on enantioseparation were examined. Enantiomers of the analytes investigated are well separated in acetonitrile/phosphate buffer mobile phases. Separation data on QNZ were compared to those on QN-bonded silica (QNS). Retention was longer but better enantioselectivity and resolution were obtained on QNZ than QNS.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.1
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• pp.8-14
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• 2004

As the number of offshore structure is glowing in deep waters, there have been increased damages of it. These floating structures in offshore locations exposed to harsh environmental conditions. In recent years, there has been a slowing attention around damages on bow and deck on FPSO caused by waves in steep storm condition. This paper describes a study of the water on deck due to the dynamic behavior of a FPSO with turret mooring system. The nonlinear motions of the FPSO are simulated under external forces due to wave, current, wind, and mooring forces in the time domain. The direct integration method is employed to estimate low frequency drift wave forces. The current forces are calculated by using slow motion maneuvering equations in the horizontal plane. The coefficients of a model for wind forces are calculated from Isherwood's experimental data and the variation of wind speed is estimated by wind spectrum according to the guidelines of API-RP2A.

• Journal of the Korean Society of Costume
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• v.43
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• pp.31-40
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• 1999

This purpose of present study was to examine the figures and colors of hanbok textile. The data were collected from 489 pieces selling at hanbok shops in Taegu pusan and were analysed. Result of this study was as follows: 1) Figures As the hanbok figures tradition figures were used a great many among the figures. The next was natural geometric abstract figures. The reactionism trend was worthy of notice in figures and traditional design occupied most of them. 2) Color In the hue, YR, R, RP group were used concentratedly. Because 5,6,7 level were used a great many among the value value was represented lightly more than midium light. Because 2,3,4 level were used a great many among the chroma chroma was represented duller than midium chroma. Thus hanbok color was used mainly in a several party and korean were tendancy to like natural the sence of color.