• Title/Summary/Keyword: Magnification ratio

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Uranium Particle Identification with SEM-EDX for Isotopic Analysis by Secondary Ion Mass Spectrometry

  • Esaka, Fumitaka;Magara, Masaaki
    • Mass Spectrometry Letters
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    • v.7 no.2
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    • pp.41-44
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    • 2016
  • Secondary ion mass spectrometry (SIMS) is a promising tool to measure isotope ratios of individual uranium particles in environmental samples for nuclear safeguards. However, the analysis requires prior identification of a small number of uranium particles that coexist with a large number of other particles without uranium. In the present study, this identification was performed by scanning electron microscopy - energy dispersive X-ray analysis with automated particle search mode. The analytical results for an environmental sample taken at a nuclear facility indicated that the observation of backscattered electron images with × 1000 magnification was appropriate to efficiently identify uranium particles. Lower magnification (less than × 500) made it difficult to detect smaller particles of approximately 1 μm diameter. After identification, each particle was manipulated and transferred for subsequent isotope ratio analysis by SIMS. Consequently, the isotope ratios of individual uranium particles were successfully determined without any molecular ion interference. It was demonstrated that the proposed technique provides a powerful tool to measure individual particles not only for nuclear safeguards but also for environmental sciences.

PLANETARY CAUSTIC PERTURBATIONS OF A CLOSE-SEPARATION PLANET ON MICROLENSING

  • Ryu, Yoon-Hyun;Kim, Han-Seek;Chung, Sun-Ju;Kim, Dong-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.77.1-77.1
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    • 2016
  • We investigate the properties and detection conditions for the planetary caustic perturbation of close-separation planets. To find the properties of the planetary caustic perturbation, we construct deviation maps by subtracting the single-lensing magnification of the lens star from the planetary lensing magnification for various lensing parameters. We find that each deviation area of the positive and negative perturbations disappears at the same normalized source radius according to a given deviation threshold regardless of mass ratio but disappears at a different normalized source radius according to the separation. We also estimate the upper limit of the normalized source radius to detect the planetary caustic perturbation. We find simple relations between the upper limit of the normalized source radius and the lensing parameters. From the relations, we obtain an analytic condition for the detection limit of the planet, and which show that we can sufficiently discover a planet with the mass of sub-Earth for typical microlensing events. Therefore, we expect to add the number of low-mass planets in the next-generation microlensing experiments and conclude that our detection condition of the planet can be used as a important criteria for maximal planet detections considering the source type and the photometric accuracy.

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Regularized iterative image resotoration by using method of conjugate gradient with constrain (구속 조건을 사용한 공액 경사법에 의한 정칙화 반복 복원 처리)

  • 김승묵;홍성용;이태홍
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.9
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    • pp.1985-1997
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    • 1997
  • This paper proposed a regularized iterative image restoration by using method of conjugate gradient. Compared with conventional iterative methods, method of conjugate gradient has a merit to converte toward a solution as a super-linear convergence speed. But because of those properties, there are several artifacts like ringing effects and the partial magnification of the noise in the course of restoring the images that are degraded by a defocusing blur and additive noise. So, we proposed the regularized method of conjugate gradient applying constraints. By applying the projectiong constraint and regularization parameter into that method, it is possible to suppress the magnification of the additive noise. As a experimental results, we showed the superior convergence ratio of the proposed mehtod compared with conventional iterative regularized methods.

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Numerical study on RC flat plates subjected to combined axial and transverse load

  • Park, Honggun
    • Structural Engineering and Mechanics
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    • v.8 no.2
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    • pp.137-150
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    • 1999
  • This paper presents a numerical study on the flat plates in deep basements, subjected to floor load and in-plane compressive load due to soil and hydraulic lateral pressure. For nonlinear finite element analysis, a computer program addressing material and geometric nonlinearities is developed. The validity of the numerical model is established by comparison with existing experiments performed on plates simply supported on four edges. The flat plates to be studied are designed according to the Direct Design Method in ACI 318-95. Through numerical study on the effects of different load combinations and loading sequence, the load condition that governs the strength of the flat plates is determined. For plates under the governing load condition, parametric studies are performed to investigate the strength variations with reinforcement ratio, aspect ratio, concrete strength, and slenderness ratio. Based on the numerical results, the floor load magnification factor is proposed.

Standardization of the Recipe for the Korean Traditional Drink "Omigalsu" (오미갈수(五味渴水)의 전통적 조리법 표준화 연구)

  • Han, Eun-Sook
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.3
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    • pp.320-331
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    • 2013
  • Omija, the major material of omigalsu, has liver protective and antioxidant effects, while mung bean has detoxification effects. A series of studies were conducted to standardize the traditional recipe for omigalsu to develop traditional functional drinks made from Omija extract and mung bean juice. Study 1 was designed to determine the optimal conditions for Omija extraction and mung bean juice. A higher water temperature and longer immersion time was associated with higher, free sugar and organic acid contents of omija extract; however, sensory evaluation revealed that the optimal extraction conditions for the highest acceptability, proper taste and red tone were $23^{\circ}C$ and 18 hrs of immersion. Conversely, the pH of the mung bean juice produced by varying the immersion time (5 hr, 11 hr, 17 hr) was found to be neutral, containing small levels of organic acid and free sugar, and showing a yellow tone. The results of the sensory evaluation also showed that the optimal conditions for taste, flavor and yellowness of mung bean juice was 5-hour-long immersion. Study 2 was designed to determine the optimum mixing ratio of omigalsu concentrate. Sensory evaluation revealed that the contents of sugar and total free sugar were highest when the mixing ratio among omija extract, mung bean juice and sugar was 1:1:20%, indicating that these conditions produced the most attractive color and highest overall acceptability. Study 3 was designed to determine the optimum dilution magnification for omigalsu. Sensory evaluation during summer revealed that the omigalsu produced by mixing 54 g of omigalsu concentrate into 200 cc water of $4^{\circ}C$ or $80^{\circ}C$ was most preferred, while during winter. Overall, the optimum dilution magnification for omigalsu was 4.7~5.4.

Adaptive Linear Interpolation Using the New Distance Weight and Local Patterns (새로운 거리 가중치와 지역적 패턴을 고려한 적응적 선형보간법)

  • Kim, Tae-Yang;Jeon, Yeong-Gyun;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.12C
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    • pp.1184-1193
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    • 2006
  • Image interpolation has been widely used and studied in the various fields of image processing. There are many approaches of varying complexity and robustness. In this paper, a new distance weight is proposed for the conventional linear interpolation. In comparison with the conventional linear weight, the new distance weight uses a quadratic or cubic polynomial equation to reflect that the interpolated value should be influenced more by the value of closer pixels in an input image. In this paper, the new adaptive linear (NAL) interpolation, which considers patterns near the interpolated value, is also proposed. This algorithm requires a pattern weight, which is used to determine the ratio of reflection on local patterns, to obtain an interpolated image that exhibits better quality at various magnification factors (MF). In the computer simulation, not only did the NAL interpolation exhibit much lower computational complexity than conventional bicubic interpolation, it also improved peak signal-to-noise ratios (PSNR).

A COMPARISON OF THE APICAL SEALING ABILITY OF OBTURATION TECHNIQUES BY THERMALLY SOFTENED GUTTA PERCHA (열연화시킨 근관충전방법에 따른 근단폐쇄성에 관한 연구)

  • Baek, Seung-Ho
    • Restorative Dentistry and Endodontics
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    • v.23 no.2
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    • pp.607-617
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    • 1998
  • The purpose of this study was to evaluate the apical sealing ability of lateral condensation method, vertical condensation method, and MicroSeal obturation system. Sixty-four extracted anterior teeth were instrumented to #40 using Profile. Three groups of 20 teeth were obturated by lateral condensation technique, vertical condensation technique, and and MicroSeal obturation system. Control group were not obturated. Teeth were immersed in resorcinol-formaldehyde resin for 5 days at $4^{\circ}C$, and the resin was allowed to polymerize completely for 4 days at room temperature. Teeth were ground horizontally at 1,5mm(level 1), 2.5mm(level 2), and 3.5mm(level 3) from the anatomic apex and examined with a stereomicroscope at X40 magnification. The photographs were taken a at X40 magnification of the filling in each level and scanned. The leakage area, which was filled with the resin, was measured at each of the three levels. Each ratio of leakage was evaluated by calculating the ratio of thearea of the resin to the total area of the canal and was analyzed statistically. The results were as followed: 1. Vertical condensation group had significantly higher percentage of the area which was obturated by gutta percha than other two technique at each level. 2. At the level 1, there was the greatest leakage in the lateral condensation group, but there was no statistically significant(P>0.05) 3. At the level 2, there was the least leakage in the MicroSeal group, and the most leakage in the lateral condensation group. There was statistically significant difference between the MicroSeal group and the lateral condensation group(P<0.05). 4. At the level 3, there was least leakage in the vertical condensation group, and the most leakage in the lateral condensation group. There was statistically significant difference between the vertical condensation group and the lateral condensation group(P<0.05).

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Quality Improvement Scheme of Interpolated Image using the Characteristics of the Adjacent Pixels (인접 픽셀들의 특성을 이용한 보간 영상의 화질 개선 기법)

  • Jung, Soo-Mok
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.11
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    • pp.95-102
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    • 2011
  • Interpolation schemes are used widely in image magnification. Magnified image generated by interpolation scheme is composed of the known pixels in input image and the interpolated pixels estimated from the known pixels in input image. So, as the interpolated pixels are estimated to have locality which exists in real images, the magnified image is much closer to the real image. In this paper, an efficient interpolation scheme was proposed to provide locality for the interpolated pixels by using the characteristics of adjacent pixels in input image. The quality of magnified image using the proposed scheme was improved. In experiment, PSNR(Peak Signal to Noise Ratio) was used to evaluate the performance of the proposed scheme. The PSNR's of the magnified images generated by the proposed scheme were greater than those of the magnified images generated by the previous interpolation methods.

Evaluation of Validity Thyroid Scintigraphy Using Parallel Hole Collimator (갑상샘 신티그래피 검사 시 평행다공형 조준기 적용의 유효성 평가)

  • Su-Young Park;Ji-Youn Kim;Sung-Min Ahn
    • Journal of the Korean Society of Radiology
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    • v.18 no.1
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    • pp.27-36
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    • 2024
  • In this study, When acquisition thyroid scintigraphy images, a parallel hole collimator was applied, and the difference from the pinhole collimator was quantitatively analyzed under each image acquisition condition. Visual size, resolution, sensitivity, signal to noise ratio (SNR), and contrast to noise ratio (CNR) were evaluated using thyroid phantom and point source. When comparing visual size, it was confirmed that an image similar to the size of the pinhole collimator could be obtained only when a magnification ratio of about 2.00 to 2.09 times when applying a parallel hole collimator. There was no tendency in FWHM(mm) measurement using a point source, and sensitivity was high in the parallel hole collimator. SNR and CNR were high when using a low magnification ratio, matrix size of 128×128, and a parallel hole collimator. In images of similar size to the naked eye, when the matrix size was the same, both SNR and CNR were high in the pinhole collimator. Therefore, when performing a thyroid scintigraphy test, if appropriate conditions are set according to the situation of each hospital and a parallel hole collimator is applied, it can be a good option in terms of equipment utilization and work efficiency.

Epitaxial Layer Growth of p-type 4H-SiC(0001) by the CST Method and Electrical Properties of MESFET Devices with Epitaxially Grown Layers (CST 승화법을 이용한 p-type 4H-SiC(0001) 에픽텍셜층 성장과 이를 이용한 MESFET 소자의 전기적 특성)

  • Lee, Gi-Sub;Park, Chi-Kwon;Lee, Won-Jae;Shin, Byoung-Chul;Nishino, Shigehiro
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.12
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    • pp.1056-1061
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    • 2007
  • A sublimation epitaxial method, referred to as the Closed Space Technique (CST) was adopted to produce thick SiC epitaxial layers for power device applications. In this study, we aimed to systematically investigate surface morphologies and electrical properties of SiC epitaxial layers grown with varying a SiC/Al ratio in a SiC source powder during the sublimation growth using the CST method. The surface morphology was dramatically changed with varying the SiC/Al ratio. When the SiC/Al ratio of 90/1 was used, the step bunching was not observed in this magnification and the ratio of SiC/Al is an optimized range to grow of p-type SiC epitaxial layer. It was confirmed that the acceptor concentration of epitaxial layer was continuously decreased with increasing the SiC/Al ratio. 4H-SiC MESFETs haying a micron-gate length were fabricated using a lithography process and their current-voltage performances were characterized. It was confirmed that the increase of the negative voltage applied on the gate reduced the drain current, showing normal operation of FET device.