• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.115-120
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• 1996

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.9-15
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• 2005

The polariscope to measure the microscopic stress in CR lens consists of light source polarizer, model, polarizer, CCD, computer, chrome conversion orderly and the principal-stressed difference, (${\sigma}_1-{\sigma}_2$) and the fringe order n were measured by analyzing two components of light wave $E_1$ and $E_2$ following each polarizer's steps. The two-dimensional model could be determined from the fact that the optical axes of sample concide with the principal-stress directions. The bi-refringence acted to a light wave and the phase retardation were in proportion to the principal-stressed difference(${\sigma}_1-{\sigma}_2$) and the intensity of final light wave was proportioned to $sin2({\Delta}/2)$ and when ${\Delta}/2=n{\pi}$ (n=0, 1, 2, ${\ldots}$) the extinction occurs. Photoelastic's image by microscopic stress could analyzed using chrome conversion, and the image showed clearly.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.183-187
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• 2009

The structure of nano-crystalline $MnFe_2O_4$ was determined and refined with electron powder diffraction data employing the Rietveld refinement technique. A nano-crystalline sample (with average crystal size of about 10.9 nm) was characterized by selected area electron diffraction in an energy-filtering transmission electron microscope operated at 120 kV. All reflection intensities were extracted from a digitized image plate using the program ELD and then used in the course of structure refinements employing the program FULLPROF for the Rietveld analysis. The final structure was refined in space group Fd-3m (# 227) with lattice parameters a=8.3413(7) $\AA$. The reliability factors of the refinement are $R_F$=7.98% and $R_B$=3.55%. Comparison of crystallographic data between electron powder diffraction data and reference data resulted in better agreement with ICSD-56121 rather than with ICSD-28517 which assumes an initial structure model.

• Journal of applied mathematics & informatics
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• v.27 no.1_2
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• pp.175-182
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• 2009

Microscopic imaging system often requires the algorithm to adjust location of camera lenses automatically in machine level. An effort to detect the best focal point is naturally interpreted as a mathematical inverse problem [1]. Following Wiener's point of view [2], we interpret the focus level of images as the quantified factor appeared in image degradation model: g = $f{\ast}H+{\eta}$, a standard mathematical model for understanding signal or image degradation process [3]. In this paper we propose a simple, very fast and robust method to compare the degradation parameters among the multiple images given by introducing outlier analysis of histogram.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.18-26
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• 2011

This paper presents a method, Exposure Controlled Temporal Filtering (ECF), applied to visual motion tracking, that can cancel the temporal aliasing of periodic vibrations of cameras and fluctuations in illumination through the control of exposure time. We first present a theoretical analysis of the exposure induced image time integration process and how it samples sensor impingent light that is periodically fluctuating. Based on this analysis we develop a simple method to cancel high frequency vibrations that are temporally aliased onto sampled image sequences and thus to subsequent motion tracking measurements. Simulations and experiments using the 'Center of Gravity' and Normalized Cross-Correlation motion tracking methods were performed on a microscopic motion tracking system to validate the analytical predictions.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.111-114
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• 1996

Mucociliary transport is one of the essential defensive functions of the airway mucosa. In this paper, the objective and quantitative method of measuring CBF(Ciliary Beat Frequency) was developed based on the image processing method. Microscopic ciliary images are acquired through image processing board inside PC, and data necessary for the FFT(Fast Fourier Transform) analysis are extracted. By means of FFT analysis, maximum peak frequencies are found in each divided block of a whole acquired image. Finally using these frequencies, we compose a frequency map showing the spatial distribution of CBF's.

• Applied Microscopy
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• v.38 no.3
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• pp.275-278
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• 2008

Electron tomography (ET) is an electron microscopic technique for obtaining a 3-D image from any electron microscopy specimen and its application in biomedical science has been increased thanks to development of electron microscopy and related technologies during the last decade. There are few researches on ET in Korea during this period. Although the importance of ET has been recognized recently by many researchers, initial approach to electron tomographic research is not easy for beginners. The 4th International Congress on Electron Tomography (4 ICET) was held on Nov $5{\sim}8$, 2006, at San Diego. The program dealt instrumentation, reconstruction algorithm, visualization/quantitative analysis and electron tomographic presentation of biological specimen and nano particles. 1 have summarized oral presentations and analyzed the posters presented on the meeting. Cryo-electron microscopic system was popular system for ET and followed conventional transmission electron microscopic system. Cultured cell line and tissue were most popular specimens analyzed and microorganisms including bacteria and virus also constituted important specimens. This analysis provides a current state of art in ET research and a guide line for practical application of ET and further research strategies.

• Applied Microscopy
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• v.40 no.4
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• pp.267-270
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• 2010

The skin is the largest organ of the integument system whose surface is closely related with many physiological and pathological conditions. Various methods are used to understand the structural and functional status of human skin. We would like to present usefulness of scanning electron microscopic (SEM) observation of skin replica and its significance of training module for a novice. The silicon replicas from several regions of the body (hand, finger, forearm, lip, and face) were casted by applying Exafine$^{(R)}$ mixture. The positive replicas were prepared by applying EPON 812 mixture on negative silicon replicas. Some of the negative silicon replicas were cut with a razor blade and surface profiles were observed. The negative and positive replicas were coated with platinum and were observed under the scanning electron microscope. We could investigate the detailed structures of the human skin surface without any physical damage to the subject. The positive replicas depicted real surface structure of the human skin vividly. The cross sectional view of the negative silicon replicas provided surface profile clearly. The scanning electron microscopic observation of the human skin replicas would be useful to study skin surface structures and to evaluate medical and esthetical applications.

• Journal of Biosystems Engineering
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• v.17 no.2
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• pp.143-155
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• 1992

The aim of this study is to develop a general purpose algorithm for analyzing geometrical features of agricultural products and microscopic particles regardless of their numbers, shapes and positions with a computer vision system. Primarily, boundary informations of an image were obtained by Scan Line Coding and Scan & Chain Coding methods and then with these informations, geometrical features such as area, perimeter, lengths, widths, centroid, major and minor axes, equivalent circle diameter, number of individual objects, etc, were analyzed. The algorithms developed in this study was evaluated with test images consisting of a number of randomly generated ellipsoids or a few synthesized diagrams having different features. The result was successful in terms of accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2529-2543
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• 2019

Scanning electron microscopy (SEM) image can link with the microscopic world through reflecting interaction between electrons and materials. The SEM images are easily subject to blurring distortions during the imaging process. Inspired by the fact that dark channel prior captures the changes to blurred SEM images caused by the blur process, we propose a method to evaluate the SEM images sharpness based on the dark channel prior. A SEM image database is first established with mean opinion score collected as ground truth. For the quality assessment of the SEM image, the dark channel map is generated. Since blurring is typically characterized by the spread of edge, edge of dark channel map is extracted. Then noise is removed by an edge-preserving filter. Finally, the maximum gradient and the average gradient of image are combined to generate the final sharpness score. The experimental results on the SEM blurred image database show that the proposed algorithm outperforms both the existing state-of-the-art image sharpness metrics and the general-purpose no-reference quality metrics.