• The Journal of the Korean dental association
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• v.24 no.7 s.206
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• pp.633-642
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• 1986

In order to evaluate the effects of various finishing devices (Sof-Lex disc, diamond point, rubber point, fussure bur) on the surface roughness or two composite resins (Restodent, Enamelite 500), 15 specimens for each composite resin were made in the mold. Composite resin was prepared on the mixing pad by manufacturer's direction and filled in the mold cavity. A sheet of matrix is immediately placed on it and hold for 5 minutes to polymerize the resin. Surface finish was done after 10 minutes from the start of mixing. Scanning electron microscopy and surface profilometer were used to evaluate the surface roughness, porositites and striations of dental composite resins. The following results were observed; 1. The best finished surface was formed by celluloid matrix band. 2. Rubber point was excellent polishing device for Restodent. 3. Sof-Lex disc was the device of choice for polishing Enamelite 500. 4. Different polishing methods were effective for different composite resins. 5. SEMs of variously finished surfaces supported the profilometer measurements.

• Korean Journal of Optics and Photonics
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• v.6 no.3
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• pp.173-177
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• 1995

The scanning type modulation transfer function (MTF) measurement system of linear charge coupled device (CCD) imagers is fabricated and the MTF of a linear CCD imager is tested. Measured MTF values are very sensitive to small angle knife-edge skew within 1 degree and show different results in several wavelengths. The MTF of the linear CCD imager is measured in different color temperatures of a tungsten filament lamp and the MTF uniformity of ti,t eel) pixels is tested.tested.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.269-269
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• 2013

Redox cycling in between the two working electrodes in an electrochemical cell can lead a great signal enhancement. In this work, we report on a systematic examination of current amplification along with the decrease in the gap distance of a nanogap device which was fabricated by the combination of photo and chemical lithography [1]. The gap distance was controlled by the chemical lithographic process of surfacecatalyzed growth of metallic layer on pre-defined electrodes with wider initial gap. Enhancement of the redox current of ferri/ferrocyanide was observed upon gap distance reduction and the current is amplified about a thousand times in this redox system when the gap distance was decreased from 200 nm to 30 nm. The experimental results were discussed on the basis of the cyclic voltammetry (CV), atomic force microscopy (AFM) and scanning electron microscopy (SEM).

• Korean Journal of Remote Sensing
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• v.14 no.3
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• pp.223-231
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• 1998

Ocean Scanning Multispectral Imager (OSMI) is a payload on the Korean Multi-Purpose SATellite (KOMPSAT) to perform worldwide ocean color monitoring for the study of biological oceanography. The instrument images the ocean surface using a whisk-broom motion with a swath width of 800 km and a ground sample distance (GSD) of less than 1 km over the entire field-of-view (FOV). The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-orbit image data storage. The instrument also performs sun calibration and dark calibration for on-orbit instalment calibration. The OSMI instrument is a multi-spectral imager covering the spectral range from 400 nm to 900 nm using a Charge Coupled Device (CCD) Focal Plane Array (FPA). The ocean colors are monitored using 6 spectral channels that can be selected via ground commands after launch. The instrument performances are fully measured for 8 basic spectral bands centered at 412, 443, 490, 510, 555, 670, 765 and 865 nm during ground characterization of instalment. In addition to the ground calibration, the on-orbit calibration will also be used for the on-orbit band selection. The on-orbit band selection capability can provide great flexibility in ocean color monitoring.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.137-138
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• 2002

The benefits of using DLC coatings on steel in dry sliding are well known. The present study has investigated the effects of using the same materials but in a boundary lubricated environment. Tribological tests were performed using a load-scanning device and a lubricant with an extreme-pressure (EP) additive. XPS and grazing incidence XRD are used for chemical analysis. The chemical composition of the resulting tribofilm is correlated to different friction behaviors and contact loads, and indicates that high loads are beneficial for formation of low friction tribofilm.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.478-480
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• 2009

This experiment implemented a laser projection system that used the 2D MEMS scanner as the driving method for the display device. The 2D MEMS scanner, which can scan the images horizontally and vertically, was applied to drive the projection system using the interlaced scanning method. The laser was directly modulated to implement the grayscale and the images were WVGA resolution quality.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.89.1-89
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• 2001

Measurement of complex surfaces without touching is desirable in several fields. This arises mainly for measurement of complex surfaces including those surfaces that deform during touch. Our research presented in this paper describes the use of a 3D digitizer for scanning 3D objects. The use of such a device, in addition to proper calibration, requires proper scaling in all three dimensions. We propose measurement techniques to measure various aspects of the surface circumference, area and volume. We also present experiments from using a 3D Minolta digitizer for measuring 3D human heads.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.10
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• pp.438-442
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• 2005

Si nanocrystal (Si NC) memory device has several advantages such as better retention, lower operating voltage, reduced punch-through and consequently a smaller cell area, suppressed leakage current. However, the physical and electrical reasons for this behavior are not completely understood but could be related to interface states of Si NCs. In order to find out this effect, we characterized electrical properties of Si NCs embedded in a SiO$_{2}$ layer by scanning probe microscopy (SPM). The Si NCs were generated by the laser ablation method with compressed Si powder and followed by a sharpening oxidation. In this step Si NCs are capped with a thin oxide layer with the thickness of 1$\~$2 nm for isolation and the size control. The size of 51 NCs is in the range of 10$\~$50 m and the density around 10$^{11}$/cm$^{2}$ It also affects the interface states of Si NCs, resulting in the change of electrical properties. Using a conducting tip, the charge was injected directly into each Si NC, and the image contrast change and dC/dV curve shift due to the trapped charges were monitored. The results were compared with C-V characteristics of the conventional MOS capacitor structure.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.192-197
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• 2016

We have surveyed on technical method of fault analysis of semiconductor device. Fault analysis of semiconductor should first be found the places of fault spots. For this process they are generally used the testers; EB(emission beam tester), EM(emission microscope), OBIRCH(optical beam induced resistance change method) and LVP(laser voltage probing) etc. Therefore we have described about physical interpretation and technical method in using scanning electron microscope, transmission electron microscope, focused ion beam tester and Nano prober.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2364-2367
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• 2015

In this study, we fabricated an electrolyte-insulator-metal (EIM) device incorporating a high-k Al₂O₃ sensing membrane using a porous anodic aluminum oxide (AAO) through a two-step anodizing process for pH detection. The structural properties were observed by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction patterns (XRD). Electrochemical measurements taken consisted of capacitance-voltage (C-V), hysteresis voltage and drift rates. The average pore diameter and depth of the AAO membrane with a pore-widening time of 20 min were 123nm and 273.5nm, respectively. At a pore-widening time of 20 min, the EIM device using anodic aluminum oxide exhibited a high sensitivity (56mV/pH), hysteresis voltage (6.2mV) and drift rate (0.25mV/pH).