• Laser Solutions
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• v.3 no.3
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• pp.21-29
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• 2000

For the direct metal shape processing the powder feed device which is different from the widely used in rapid prototyping. is developed, The three dimensional object is shaped with the melting metal powder. The developed research has applied to rapid prototyping in ultraprecision for MEMS and medical science fields required of rapid manufacture of complex shape. The goal of this study make 3D model which has precision accuracy. Powder spreading apparatus has been more improved because that the control of powder spread is very important in layer manufacturing. It consists of the vibration motor, nozzle and tube which supplies various metal powder. This apparatus could control the spreading velocity that could control powder spreading thickness. Laser on/off switch was adapted because laser scanning velocity must be preserved constantly to prevent heat transformation of laser overheating. The error between sintered thickness md experimental one occurred by shrinkage in sintering melting process. The problem of heat transformation was solved by On/Off switching system.

• Journal of Magnetics
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• v.16 no.4
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• pp.413-416
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• 2011

An array of FeCo nanotubes has been successfully fabricated in the pores of porous anodic aluminum oxide (AAO) templates by wetting templates method. The morphology and structure of the nanotube array were characterized by scanning electron microscopy, transmission electron microscopy and x-ray diffraction. The average diameter of the nanotubes was about 200 nm, and the length was more than 10 ${\mu}m$. Vibrating sample magnetometer and superconducting quantum interference device were used to investigate the magnetic properties of the nanotube array. Interaction between the nanotubes has been found to be demagnetizing as expected and the switching field distribution is broad.

• Macromolecular Research
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• v.14 no.1
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• pp.59-65
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• 2006

We report a new approach to fabricate electrospun polymer nonwoven mats with porous surface morphology by varying the collector temperature during electrospinning. Polymers such as poly(L-lactide) (PLLA), polystyrene (PS), and poly(vinyl acetate) (PVAc) were dissolved in volatile solvents, namely methylene chloride (Me) and tetrahydrofuran (THF), and subjected to electrospinning. The temperature of the collector in the electrospinning device was varied by a heating system. The resulting nonwoven mats were characterized by using scanning electron microscopy (SEM), field emission SEM (FESEM), and atomic force microscopy (AFM). We observed that the surface morphology, porous structure, and the properties such as pore size, depth, shape, and distribution of the nonwoven mats were greatly influenced by the collector temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.634-634
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• 2013

Transfer molding methods have a problem that weak adhesion between nanostructures and substrates. It is important to make various nano scale applications, also the stability of nanostructure on substrate is related with device performance. We studied an effect of poly 4-vinylphenol (PVP) as the polymeric adhesion layer between organic nanowires and a Si substrate when the nanowires are transferred by liquid-bridge-mediated nanotransfer molding method (LB-nTM). Their structural stability was examined by optical microscopy, scanning electron microscopy as multiple transfer molding and washing process. Field-effect transistors were fabricated with organic semiconductor nanowires on a polymeric adhesion layer and their electrical properties showed no significant difference as the one without the adhesion layer. As a result, adhesion layer can be used in the washing process and making multi-layer nano-scale patterns.

• Journal of the Korean institute of surface engineering
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• v.39 no.5
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• pp.199-205
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• 2006

Titanium nitride (TiN) coatings were produced on AISI 420 stainless steel by DC magnetron sputtering of a Ti target changing the processing variables, such as the flow rate of $N_2/Ar$, substrate temperature and the existence of Ti interlayer between TiN coatings and substrates. The hardness and residual stress in the films were investigated using nanoindentation and a laser scanning device, respectively. The stoichiometry and surface morphology were investigated using X-Ray Diffraction and SEM. The corrosion property of the films was also studied using a polarization method in NaCl (0.9%) solution. Mechanical properties including hardness and residual stress were related to the ratio of $N_2/Ar$ flow rate. The corrosion resistance also was related to the processing variables.

• ETRI Journal
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• v.18 no.3
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• pp.195-206
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• 1996

Molecular conformations of stereoregular poly(methyl methacrylate) (PMMA) monolayers have been investigated by scanning probe microscopes. Isotactic and syndiotactic PMMAs were found to have right and left hand helical structures, respectively. On the contrary atactic PMMA showed rather random arrangement of the chains. It has been demonstrated that the PMMA Langmuir-Blodgett (LB) films can be utilized to form nanoscale patterns down to 50 nm and to forma geodesic lens. It has also been manifested that the quantum efficiency of a polymer electroluminescent device can be significantly enhanced by inserting the PMMA LB films between the emitting layer and the cathode. All the applications utilize the unique characteristics of the LB films to form thin and uniform films in the molecular level.

• Fashion & Textile Research Journal
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• v.3 no.4
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• pp.351-356
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• 2001

The purpose of these experiments is to improve the perm techniques which are fast growing and changing in our life style, for customer satisfaction and to use as basic data for academic purpose through comparing between two methods which are the new permanent wave treatment and the old one. I classified the hair samples to three kinds, which are healthy, normal, and damaged hair. This study is focused on the top part of hair sample which is damaged by strong and long-time sunshine. To get the best result, I use the scanning electron microscope (JSM-5200) as main device of these experiments. The followings are the results of these experiments. First, the new way of permanent wave technique has much more damage on hair than the old one. Second, There are big differences of damaging in this study. The harmed hair has worse result than the healthier hair.

• ETRI Journal
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• v.36 no.4
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• pp.617-624
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• 2014

Through-silicon via (TSV) technology provides much of the benefits seen in advanced packaging, such as three-dimensional integrated circuits and 3D packaging, with shorter interconnection paths for homo- and heterogeneous device integration. In TSV, a destructive cross-sectional analysis of an image from a scanning electron microscope is the most frequently used method for quality control purposes. We propose a quantitative evaluation method for TSV etch profiles whereby we consider sidewall angle, curvature profile, undercut, and scallop. A weighted sum of the four evaluated parameters, nominally total score (TS), is suggested for the numerical evaluation of an individual TSV profile. Uniformity, defined by the ratio of the standard deviation and average of the parameters that comprise TS, is suggested for the evaluation of wafer-to-wafer variation in volume manufacturing.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.757-760
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• 2006

This study aims to manufacture ultra fine cement(UFC) with a multi air-classifier of the dry-type. The classifier employed and devised for materials refining was a cyclone type fitted with an air suction device. This study also investigates the basic physical properties and quality of UFC and evaluates its utilizable possibility as a construction material. The basic properties of the UFC containing granulated blast furnace slag were analyzed and examined through recovery ratio, particle size distribution, scanning electron microscopy and compressive strength. Results obtained from the analysis of ultra fine cement have shown that there are possibilities for manufacturing UFC, which could compensate the weak properties of ordinary Portland cement.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.712-713
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• 2015

IoT (Internet of Things)가 차세대 기술로 각광을 받으면서 않은 IT 전문인들이 대표주자인 웨어러블 디바이스(wearable device) 의 활용도에 많은 관심을 기울이고 있다. 하지만 현재까지 헬스케어(healthcare)와 피트니스(fitness) 서비스 중심으로 구성되는 등 다양성을 갖지 못하고 있다. 본 논문에서는 스마트 위치를 이용하여 장보기에 다양한 편리성을 제공하는 라이프스타일 관련 웨어러블 어플리케이션을 제안한다. 바코드 스캐닝 기능을 통하여 구매한 제품에 대한 정보를 자동으로 검출하여 가계부를 작성한다. 또한 고객에게 현재까지의 구매 내역에 기반하여 최적의 추천상품 목록을 구성하는 서비스도 제공한다.