• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.151-159
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• 2003

This study presents method for self-calibration of the SEM(Scanning Electron Microscope) stereo image using the standard microprobe with same grid pattern and using parallel and central perspective projection equation. Result showed that parallel projection method is more suitable for standard microprobe. The maximum error of 3D coordinates acquired by this method did not exceed 5 $\mu\textrm{m}$, and DSM(Digital Surface Model) for three dimensional measurement of the rock sample was generated by the digital photogrammetry. This result can be used for quantification of micro scale change of shape and analysis of the micro morphology of rock due to weathering.

• Journal of Environmental Science International
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• v.30 no.3
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• pp.279-287
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• 2021

In this study, the composition and morphology of deposited dust particles with size ranging from a few to tens ㎛ were investigated using SEM/EDX (scanning electron microscopy with energy dispersive x-ray spectrometer). Then deposited dust particles were classified into 8 groups: quartz, aluminosilicates, ca-rich, Fe/Ti oxide, carbon-rich, industrial particle, Fe-rich, and biogenic particle. The sources of deposited dust were high in the order of aluminosilicates 41% > biogenic 18% > Fe-rich 11% > quartz and C-rich 8% > industrial 7% > Fe/Ti oxide 5% > Ca-rich 1%. In particular, the ratio of biogenic particles was relatively high due to influence of pollen. The ratio of carbon-rich was 11% at YM site, 10% at MD site, and 4% at MO site, and the site close to the large emission source was high.

• Applied Microscopy
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• v.52
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• pp.12.1-12.8
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• 2022

The microstructure of diatom frustules found in mud sediments along the coast of Boryeong- city, South Korea, was observed using a scanning electron microscopy (SEM), and the constituent elements of diatoms were analyzed using energy-dispersive X-ray spectroscopy (EDS). Diatom frustules and clay minerals were present in the SEM images of the mud powder. High-magnification SEM images revealed that the surface of the frustules contained identically shaped circular pores, measuring 1 ㎛ in diameter, arranged at regular intervals. This study revealed that the diatom shell fragments in the mud powder ranged in size from 3 to 30 ㎛, with an average thickness of approximately 2.5 ㎛. The elements Si, Al, Fe, K, Na, Mg, and Ti were detected while analyzing the frustule constituents, with Si being the primary component with the highest content.

• Applied Microscopy
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• v.39 no.4
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• pp.349-354
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• 2009

In this paper we have constructed three dimensional images and examined structural failure on thin film transistor (TFT) liquid crystal display (LCD) by using dual-beam focused ion beam (FIB) and IMOD software. Specimen was sectioned with dual-beam focused ion beam. Series of two dimensional images were obtained by scanning electron microscopy. Three dimensional reconstruction was constructed from them by using IMOD software. The short defect between Gate layer and Data layer was found from the result of three dimensional reconstruction. That phenomena made the function of the gate lost and data signal supplied to the electrode though the Drain continuously. That signal made continuous line defect. The result of the three dimensional reconstruction, serial section, SEM imaging by using the FIB will be the foundation of the next advanced study.

• Restorative Dentistry and Endodontics
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• v.29 no.1
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• pp.66-72
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• 2004

All-in-one adhesives were recently developed for reducing the technique sensitivity and chair time, but lots of concerns were made on bondability, longevity, and microleakage. The object of this study was to evaluate microleakage and marginal quality of all-in-one adhesives using electrochemical method and SEM analysis quantitatively. After making Class V cavities, they were bulk filled with Heliomolar(#A1 after surface treatment with three adhesives: Adper Prompt (Group A), One up bond F (Group O), Xeno III (Group X) Electrical conductivity (microamphere, ${\mu}A$) was checked two times: before and after cavity filling. Percentage of leaky margin was estimated from SEM image (${\times}1,000$). The data were statistically analysed: ANOVA and Paired T test for electrical conductivity, Kruskal-Wallis and Mann-Whitney test for marginal quality, Spearman s rho test for checking of relationships between 2 methods. The result were as follows: 1. There was no difference in microleakage between adhesive systems and every specimen showed some of microleakage after filling. 2. Microleakage was reduced about 70% with composite resin filling. 3. Marginal quality was the best in group A. decreasing among groups in the following order: group O, followed by group X. There were significant differences between group A and group X (p=0.015), and between group 0 and group X (p=0.019). 4. There was no relationship between the microleakage measured by electrochemical method and marginal quality measured by SEM analysis. Within the results of this study, there was no difference in microleakage among groups by electrical conductivity. However, significant difference in marginal quality was seen among groups. It was believed that these dissimilar results might be induced because of their own characteristics. Analysis of microleakage needs various methods for accuracy.

• The Journal of Advanced Prosthodontics
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• v.7 no.1
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• pp.39-46
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• 2015

PURPOSE. The mechanical and interfacial characterization of laser welded Co-Cr alloy with two different joint designs. MATERIALS AND METHODS. Dumbbell cast specimens (n=30) were divided into 3 groups (R, I, K, n=10). Group R consisted of intact specimens, group I of specimens sectioned with a straight cut, and group K of specimens with a $45^{\circ}$ bevel made at the one welding edge. The microstructure and the elemental distributions of alloy and welding regions were examined by an SEM/EDX analysis and then specimens were loaded in tension up to fracture. The tensile strength (TS) and elongation (${\varepsilon}$) were determined and statistically compared among groups employing 1-way ANOVA, SNK multiple comparison test (${\alpha}$=.05) and Weibull analysis where Weibull modulus m and characteristic strength ${\sigma}_0$ were identified. Fractured surfaces were imaged by a SEM. RESULTS. SEM/EDX analysis showed that cast alloy consists of two phases with differences in mean atomic number contrast, while no mean atomic number was identified for welded regions. EDX analysis revealed an increased Cr and Mo content at the alloy-joint interface. All mechanical properties of group I (TS, ${\varepsilon}$, m and ${\sigma}_0$) were found inferior to R while group K showed intermediated values without significant differences to R and I, apart from elongation with group R. The fractured surfaces of all groups showed extensive dendritic pattern although with a finer structure in the case of welded groups. CONCLUSION. The K shape joint configuration should be preferred over the I, as it demonstrates improved mechanical strength and survival probability.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.487-496
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• 2014

Much research has been actively done so far on the inconvenience of each urban railway station; however, Research is on importance factor analysis on transfer facilities by considering characteristics of railway stations is relatively insufficient. In this study, a novel method of finding causality between transfer facilities(movement, information, comfortability, etc,) in terms of demands and platform types is provided by using SEM(Structural Equation Model). The results of SEM analysis show that a large demand transfer station if combined with island and segregate platform types, has a higher importance factor with respect to information facility, movement facility position and comfortability. In addition, a medium demand transfer station if combined with separate and separate platform types has a higher importance factor with respect to information facility, movement facility and comfortability.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.121-127
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• 2018

The objective of the present study was to investigate the effect of eye movement on cognitive ability using Mini-Mental State Examination for Dementia Screening (MMSE-DS) and the amplitude and latency of P300 from event-related potentials after 55 elderly participants were randomly stratified into the saccadic eye movement (SEM) group and the smooth pursuit eye movement (SPEM) group, and performed eye movement for 4 weeks. As a result, P300 amplitude significantly increased and P300 latency significantly shortened in the SEM and SPEM groups. MMSE-DS showed a significant increase in both groups; upon comparing the groups, the SEM group showed a significant difference in orientation and the SPEM group in attention. In conclusion, it is thought that SEM and SPEM can improve and maintain the cognitive ability of the elderly and may be used as therapeutic tools for dementia prevention and mild dementia.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.111-121
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• 2016

This study provides an approach to perform the double mediation analysis in structural equation models using the R. For this purpose, the study reviews a variety of techniques for mediation analysis, selects the bootstrapping technique as the most suitable way for performing the double mediation analysis and develops an approach for the double mediation analysis in structural equating models with the bootstrapping using the plspm which is the R package for the performing PLS path analysis. This study will be useful for the studies including the double mediation analysis in structural equation modeling, which is not supported by most of SEM packages, also will provide the knowledge base for in-depth analysis through suggesting the new mediation analysis technique using R for the researchers.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.196-204
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• 2012

This study was carried out to develop reliable systems for somatic embryogenesis in oil palm tree (Elaeis guineensis Jacq.), and to verify the somaclonal variants by RAPD analysis. Embryogenic callus was induced successfully on modified half-strength MS medium containing $NaH_2PO_4{\cdot}2H_2O$ and casein. Embryogenic callus was further developed to somatic embryo mass (SEM), which is very hard and bonded tightly each other. Plantlets were proliferated when SEM was cultured on modified MS medium containing half strength $NH_4NO_3$, casein and L-ascorbic acid. Plantlets were transplanted into pots containing artificial soils. When RAPD analysis was conducted using randomly selected 95 in vitro plantlets and 19 random primers, somaclonal variation was detected using BNR35 primer. There was missing band around 1 kb in #22, #28, #35, and #77 plantlets. In addition, bands obtained from #28, #35, and #77 was much stronger than other normal bands. The blast results at NCBI revealed that somaclonal variation observed in this study was related to chloroplast genome of oil palm. The results also revealed that oil palm reproduction system through somatic embryogenesis is quite reliable and early detection of somaclonal variants seem to be possible at in vitro stage by RAPD analysis.