• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.495-496
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• 2008

This paper describes the influence of Ultra-violet irradiation on time to tracking resistance of epoxy insulating materials by use of the inclined plane test. And, the influence of surface degradation was evaluated through several method such as measurement of contact angle, surface roughness, using a scanning electron microscopy. As the 1000 hours of the surface degradation with UV-CON, the flashover time decreases at different rates depending on epoxy resin and silicone rubber specimen. As the duration of the surface degradation with UV-CON is prolonged, the contact angle of epoxy resin decreases at the rate of degradation time, while that of silicone rubber was not exchanged. It is assumed that this phenomenon is related to the decrease in hydrophobicity of the surface of the materials. Also, as to epoxy resin, the decrease of hydrophobicity due to surface degradation with UV-CON is greater than that resulting from surface degradation with WOM. The UV radiation produced chalking and crazing on the surface of the insulating materials specimen.

• Design & Manufacturing
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• v.17 no.2
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• pp.33-41
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• 2023

Metal raw materials and chemical additives, which are raw materials for secondary batteries, are pulverized by the high-speed rotation of the Grinding Disc of the Classifier Separator Mill (CSM). Grinding discs are required to withstand abrasion, corrosion, high-speed rotational force and impact. In order to analyze the stability of domestic and foreign grinding discs, quality tests including surface roughness, surface lubrication, surface state measurement, and surface 3D shape measurement were analyzed. When producing developed products, it shows that excellent products can be produced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.881-894
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• 1999

Cylindrical plunge grinding is widely used for final machining process of precision parts such as automobile, aircraft, measurement units. But in order to make parts which have high precision accuracy and high surface integrity, it is necessary to consider grinding characteristics due to accumulation phenomena of grinding wheel in plunge grinding process. In this study, in order to examine closely plunge grinding process, grinding power, grinding force, real depth of cut are monitored in transient state, steady state and spark out state. As the result, it is shown that grinding power and force are affected by dressing condition, depth of cut and speed ratio and that there exist threshold grinding force and it also affected by dressing condition. Also considered effects of grinding conditions on surface roughness and roundness of workpiece

• Journal of the Korean Vacuum Society
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• v.10 no.3
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• pp.361-367
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• 2001

Recently, Chemical Mechanical Polishing(CMP) has become a leading planarization technique as a method for silicon wafer planarization that can meet the more stringent lithographic requirement of planarity for the future submicron device manufacturing. The SOI(Silicon On Insulator) wafer has received considerable attention as bulk-alternative wafer to improve the performance of semiconductor devices. In this paper, the objective of study is to investigate Material Removal Rate(MRR) and surface micro-roughness effects of slurry and pad in the CMP process. When particle size of slurry is increased, Material Removal rate increase. Surface micro-roughness is greater influenced by pad than by particle size of slurry. As a result of AM measurement, surface micro-roughness was improved from 27 $\AA$ Rms to 0.64 $\AA$Rms.

• Journal of the Korean institute of surface engineering
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• v.38 no.4
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• pp.156-162
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• 2005

Nickel-iron nanocrystalline alloys with different compositions and grain sizes were fabricated by electro-plating for MEMS devices. The iron content of the deposits was changed by varying the nickel/iron ion ratio in the electrolyte. X-ray diffraction (XRD) analysis was applied for measuring the strength of the texture and grain size of the deposits. The nickel/iron atom ratio of the deposits was analyzed by EDS. The hardness of the alloys was evaluated by Vickers hardness indenter. The internal stress of the deposits was measured by Thin Film Stress Measurement using Stoney's formula. Surface morphology and roughness were investigated by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The results of this study revealed that at a grain size of approximately $17\~24$nm the hardness, internal stress and roughness depend strongly on the iron content. With increasing the iron content, the hardness and internal stress of the deposits increased. An excellent correlation between the increase in the internal stress and the loss of (200) texture was found.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.1-7
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• 2015

People are always pursuing the aesthetic feeling relentlessly. But some people have such problems with their hairs like alopecia, cancer chemotherapy, burns, and scalp injury. So the synthetic hair has played a very important role to make up for these deficiencies. But long term use can lead to adverse reactions or uncomfortable feeling. This is primarily caused by its properties differ with human hair. In particular, nanotribological characterizations (roughness, friction force and adhesive force) of synthetic hair surface are dissatisfy with the needs of normal hairs. This paper presents the experiments on nanotribological characterizations measurements of human hairs (coloring hair, permed hair and common hair) in shampooing condition or without shampooing condition. Using atomic force microscopy (AFM) to find out a range of synthetic hair nanotribological characterizations which can correspond with natural hair. The measurements of nanotribological characterizations focus on surface roughness, friction force and adhesive force, and a new design of AFM probe was used for measuring the nanotribological characterizations.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.236-237
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• 2005

To measure surface roughness and smoothness of semiconducting materials in power cable, we have investigated the formation and growth process of carbon black showed by changing the content of carbon black. The specimens were primarily kneaded in material samples of pellet form for 5 minutes on rollers ranging between 70[$^{\circ}C$] and 100[$^{\circ}C$]. Then they were produced as sheets after pressing for 20 minutes at 180[$^{\circ}C$] with a pressure of 200[kg/cm]. The contents of conductive carbon black were the variable, and their contents were 20, 30 and 40[wt%], respectively. The surface roughness and smoothness of specimens were measured by SEM and AFM. From SEM experimental result, carbon black in specimens formed matrix as a particles. Also we showed growth process of carbon black according to an increment of the content of carbon black. From AFM experimental result, surface roughness of specimens decreased according to an increment of the content of carbon black.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.5
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• pp.17-22
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• 2019

In this study, Cermet Reamers for planet carrier was manufactured and the machining characteristics were analyzed through processing experiment. Cermet reamer with ∅14, ∅15, ∅18, and ∅21mm was used and machining characteristics were compared and analyzed by observing tool wear, machining hole dimensions and surface roughness. In the flank wear of the tool, the result is less than 0.2mm, which is the target value for each tool size. The experimental results of the machining hole dimensions show the results of the process control range of 3/100 or less according to the size of the tool. Also, the surface roughness measurement result showed a value of less than $0.5{\mu}m$ in the process control range for each tool size. As a result of observing the experimental results of each ∅, the results satisfied the process standard in both the tool wear, the machining hole dimension and the surface roughness.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.4
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• pp.531-541
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• 1999

The purpose of this study was to compare surface roughness and bone formation around two types of threaded commercially pure titanium implants manufactured by two different companies. The test implants were manufactured by Sumin synthesis dental materials Co. (Avana, Busan, Korea), while the controls were manufactured by Nobel Biocare (MK II, Goteborg, Sweden). To compare bone formation adjacent to newly product implant with $Br{\aa}nemark$ MK II implant, surface roughness was measured by Accurate 1500M and histomorphometric analysis was done. The results were as follows: 1. Measurement of surface roughness showed that Avana implant had a slightly more irregular surface compared with $Br{\aa}nemark$ implant. 2. In the light microscopic studies, no infiltration of inflammatory cells nor the giant cells were observed on both groups. 3. In the light and fluorescent microscopic studies, the amount of osseointegration and the extent and the timing of bone formation were similar. 4. There were no statistically difference between two groups in the average bone to implant con-tacts. Branemark implant; 67% (SD 23%), Avana implant; 70% (SD 16%). Comparing with $Br{\aa}nemark$ implant, Avana implant made of CP grade II titanium showed similar good bone healing, formation and osseointegration.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.94-101
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• 2004

From the Beckmann's reflection model of wave incident, reflected light from a surface is known to have not only specular but also diffuse components. The specular component dominant a surface for a mirror-like surface is distributed on the almost the same area as the spot on the surface, but the diffuse component region dominant f3r a rough surface spreads scattered on the larger areas than the spot. Therefore, statistic parameters from the scattered light distribution are more meaningful in the diffuse region, while the magnitude of rather meaning in the specular region. In usual, there need two sensors to acquire two kinds of information: Photo-detector for light intensity magnitude and image sensor for light intensity distribution. But dual sensor scheme requires a beam splitter usually to feed light to each sensor, and moreover there is not a combination rule to relieve the different sensor characteristics. In this study a new method is proposed for acquisition of the dual information using only an image sensor. Specular region is established on an image area being distinguished from a diffuse component, and laser power is adjusted so that no pixel of the image sensor in the specular region is saturated. Simulation based on the light reflection theory and the experimental results are quite well matched, and thus the proposed method was proved to be very useful for mirror-like surface measurement.