• Journal of Periodontal and Implant Science
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• v.43 no.4
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• pp.198-205
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• 2013

Purpose: The aim of this study was to evaluate the surface properties and biological response of an anodized titanium surface by cell proliferation and alkaline phosphatase activity analysis. Methods: Commercial pure titanium (Ti) disks were prepared. The samples were divided into an untreated machined Ti group and anodized Ti group. The anodization of cp-Ti was formed using a constant voltage of 270 V for 60 seconds. The surface properties were evaluated using scanning electron microscopy, X-ray photoelectron spectroscopy, and an image analyzing microscope. The surface roughness was evaluated by atomic force microscopy and a profilometer. The contact angle and surface energy were analyzed. Cell adhesion, cell proliferation, and alkaline phosphatase activity were evaluated using mouse $MC_3T_3-E_1$ cells. Results: The anodized Ti group had a more porous and thicker layer on its surface. The surface roughness of the two groups measured by the profilometer showed no significant difference (P>0.001). The anodized Ti dioxide ($TiO_2$) surface exhibited better corrosion resistance and showed a significantly lower contact angle than the machined Ti surface (P>0.001). Although there was no significant difference in the cell viability between the two groups (P>0.001), the anodized $TiO_2$ surface showed significantly enhanced alkaline phosphatase activity (P<0.001). Conclusions: These results suggest that the surface modification of Ti by anodic oxidation improved the osteogenic response of the osteoblast cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.441-442
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• 2008

For this study, Yttrium aluminum garnet (YAG) particles co-doped with $Ce^{3+}$ and $Eu^{3+}$ were prepared via the combustion process using the 1:1 ratio of metal ions to reagents. The characteristics of the synthesized nano powder were investigated by means of X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and photoluminescence (PL). The various YAG peaks, with the (420) main peak, appeared at all Eu concentrationin XRD patterns. The YAG phase crystallized with results that are in good agreement with the JCPDS diffraction file 33-0040. The SEM image showed that the resulting YAG:Ce,Eu powders had uniform sizes and good homogeneity. The grain size was about 50nm. The photoluminescence spectra of the YAG:Ce,Eu nanoparticles were investigated to determine the energy level of electron transition related to luminescence processes. It was composed a broad band of $Ce^{3+}$ activator into the weak line peak of $Eu^{3+}$ in YAG host. The PL intensity of $Ce^{3+}$ has the wavelengths of 480-650 nm and The PL intensity of $Eu^{3+}$ has main peak at 590nm.

• Spatial Information Research
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• v.1 no.1
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• pp.17-28
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• 1993

In order to minimize vectorizing tasks, which require huge reso¬urces and time and to support the census mapping effectively, the geographic information databases structure has been studied. The steps of the new approach are as follows. : Step 1, Scanning the maps of the whole country and storing the image data in raster format. Step 2, Vectorizing the data of specific items for Census operation such as Enume¬ration District, and then linking to attribute data in the text format. Step 3, Designing the database with a Tile and Multi-layer structure to make a continuous map logically. Step 4, Implement Censlls Mapping System(CMS) for efficient mapping and retrieving. As a consequence of this study, the cost, manpower and time effectiveness was proved and it was confirmed to produce lIseful and high-qual ified maps for the Census. In the future, this system wi II be able to provide many organizations and individuals with the various data based on geographical statistical information.

• Spatial Information Research
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• v.15 no.3
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• pp.323-333
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• 2007

Recently, the South and North Korea have collaborated in the economic cooperation. Success for the cooperation of the South and North Korea has supported the basic and fundamental GIS data building for geographic information (GI) and the land-use of the North Korea. This North Korea GIS project is also vital to facilitate rebuilding and reconnecting socio-economic infrastructures such as reconnecting road and railway networks between the South and North Korea. Thus, this paper emphasizes on the fundamental issues of GIS data building in North Korea area and suggests GI and data establishment methods of the North Korea regions which has not been achieved in GIS research activities in Korea. As the basic GI and data in the North Korea, topographical maps, satellite imageries, and thematic maps were collected and used for surveying of territorial areas of the North Korea. The database of those dataset were built by scanning, image processing, and classifying land-use types. In addition, this paper exacted vector data from the database and included the vector data into the database as other basic GI dataset that enable to analyze quantitative and qualitative territorial land use and development in the North Korea.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.540-545
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• 2008

Since mid 20th century, dental treatments with laser have been introduced and improved a lot. Because early $CO_2$, Nd:YAG, diode, argon, and holmium lasers are used for dealing soft tissue, so it applied just limited field. But, in 1997 the lasers of erbium family that able to dealing soft and hard tissue also were introduced, laser application fields are enlarged. In today, the application fields reach on implantation treatment, so clinicians can use the laser to make holes for implantation, and flap elevation, even though treating peri-implantitis. So our class want to discover the optimal setting of Er:YAG laser when treating peri-implantitis. We observed the surface that initially treated by RBM and TPS passion and laser with varied options of exposure time and power with SEM image. For this we conclude the optimal setting range that does not alter the implant surface structure and report it.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.197-209
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• 2003

A current TV out format is quite different from that of HDTV or PC monitor in encoding techniques. In other words, a conventional analog TV uses interlaced display while HDTV or PC monitor uses Non-interlaced / Progressive-scanned display. In order to encode image signals coming from devices that takes interlaced display format for progressive scanned display, a hardware logic in which scanning and interpolation algorithms are implemented is necessary. The ELA(Edge-Based Line Average) algorithm have been widely used because it provided good characteristics. In this study, the ADI(Adaptive De-interlacing Interpolation) algorithm using to improve the ELA algorithm which shows low quality in vertical edge detections and low efficiency of horizontal edge lines. With the De-interlacing ASIC chip that converts the interlaced Digital YUV to De-interlaced Digital RGB is designed. The VHDL is used for chip design.

• Restorative Dentistry and Endodontics
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• v.40 no.3
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• pp.216-222
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• 2015

Objectives: To evaluate the effects of copolymer of acrylic acid and maleic acid (Poly[AA-co-MA]) and calcium hypochlorite ($Ca(OCl)_2$) on root canal dentin using scanning electron microscope (SEM). Materials and Methods: Twenty-four single-rooted teeth were instrumented and the apical and coronal thirds of each root were removed, leaving the 5 mm middle thirds, which were then separated into two pieces longitudinally. The specimens were randomly divided into six groups and subjected to each irrigant for 5 min as follows: G1, $Ca(OCl)_2$; G2, Poly(AA-co-MA); G3, $Ca(OCl)_2$ + Poly(AA-co-MA); G4, sodium hypochlorite (NaOCl); G5, ethylenediaminetetraacetic acid (EDTA); G6, NaOCl+EDTA. The specimens were prepared for SEM evaluation. Smear layer, debris and erosion scores were recorded by two blinded examiners. One image from G3 was analyzed with energy dispersive spectroscopy (EDS) on suspicion of precipitate formation. Data were analyzed using the Kruskal-Wallis and Dunn tests. Results: G1 and G4 showed the presence of debris and smear layer and they were statistically different from G2, G3, G5 and G6 where debris and smear layer were totally removed (p < 0.05). In G1 and G4, erosion evaluation could not be done because of debris and smear layer. G2, G3 and G5 showed no erosion, and there was no significant difference between them. G6 showed severe erosion and was statistically different from G2, G3 and G5 (p < 0.05). EDS microanalysis showed the presence of Na, P, and Ca elements on the surface. Conclusions: Poly(AA-co-MA) is effective in removing the smear layer and debris without causing erosion either alone or with $Ca(OCl)_2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.4
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• pp.212-215
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• 2018

The phase evolution, microstructure, and microwave dielectric properties of $Ba(Mg_{0.5-2x}Y_{2x}W_{0.5-x}Ti_x)O_3$ (x = 0.005~0.05) ceramics sintered at $1,700^{\circ}C$ for 1h were investigated. All compositions exhibited a 1:1 ordered cubic perovskite structure. The field emission scanning electron microscopy image revealed a dense microstructure in all the compositions. As the value of x increased, the lattice parameter, dielectric constant, and quality factor increased. The temperature coefficient of resonant frequency changed from $-19.6ppm/^{\circ}C$ to $-5.9ppm/^{\circ}C$ with increasing x value. The dielectric constant, quality factor, and temperature coefficient of resonant frequency of $Ba(Mg_{0.40}Y_{0.10}W_{0.45}Ti_{0.05})O_3$ were 21.7, 132,685 GHz, and $-5.9ppm/^{\circ}C$, respectively.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.449-452
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• 2008

The building heights of big cities which charged with most space are 3-D information as relative vertical distance from ground control points, but they didn't know the heights using contour with maps as lose of skyline or building heights for downtown, practically continuously developed of many technology methods for implementation of 3-D spatial earth. So, For the view as stereos of variety earth form generated 3-D spatial and made terrain perspective map, 3-D simulated of regional and urban space as aviation images. In this papers, it composited geospatial informations and images by DEM generation, and developed and presented for techniques overlay of CAD data and photos captured at our surroundings uses. Particularly, The airborne LiDAR surveying which are very interesting trend have laser scanning sensor and determine the ground heights through detecting angle and range to the grounds, and then designated 3-D spatial composite and simulation from urban areas. Therefore in this papers are suggested ease selections on the users situation by compare as various simulations that its generation of 3-D spatial image by collective for downtown space and urban sub, and the implementation methods for more accurate, more select for the best images.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.3
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• pp.273-282
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• 2018

Objectives: Dustiness of nanomaterials is considered as exposure index of essential material. Research on dustiness of nanomaterial is needed to control exposure in workplaces. Method: Dustiness measurement using vortex shaker were installed in the laboratory. Nanomaterials, 1 g, was put in the glass test tube and shaked using vortex shaker. Aerosol dispersed was measured using scanning mobility particle sizer(SMPS) and optical particle counter(OPC). Mass concentration using PVC filter and cassette was measured and TEM grid sampling was conducted. Total particle concentration and size distribution were calculated. Image and chemical composition of particles in the air were observed using transmission electron microscopy and energy dispersive X-ray spectrometer. Eleven different test nanomaterials were used in the study. Results: Rank of mass concentration and particle number concentration were coincided in most cases. Rank of nanomateirals with low concentration were not coincided. Two types of fumed silica had the highest mass concentration and particle number concentration. Indium tin oxide, a mixture of indium oxide and tin oxide, had high mass concentration and particle number concentration. Indium oxide had very low mass concentration and particle number concentration. Agglomeration of nanoparticles in the air were observed in TEM analysis and size distribution. In this study, mass concentration and particle number concentration were coincided and two index can be used together. The range of dustiness in particle number concentration were too wide to measure in one method. Conclusion: Particle number concentration ranged from low concentration to high concentration depend on type of nanomaterial, and varied by preparation and amount of nanomaterial used. Further study is needed to measure dustiness of all nanomaterial as one reference method.