• Title/Summary/Keyword: 다각주사

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Tomographic Reconstruction of Asymmetric Soot Structure from Multi-angular Scanning (다각 주사법을 이용한 비대칭 매연분포의 재구성)

  • Lee, S.M.;Hwang, J.Y.;Chung, S.H.
    • 한국연소학회:학술대회논문집
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    • 1999.10a
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    • pp.55-61
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    • 1999
  • A convolution algorithm combined with Fourier transformation is applied to the tomographic reconstruction of the asymmetric soot structure to identify the local soot volume fraction distribution. The line of sight integrated data from light extinction measurement with multi-angular scanning form basic information for the deconvolution. Multi-peak following interpolation technique is applied to obtain the effect of increasing number of scanning angles. Measurement of LII signal for the same flame shows the validity of this reconstruction technigue.

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Tomographic Reconstruction of Asymmertic Liquid Spray from Multi-angular Scanning (다각주사법에 대한 비대칭 분무 구조의 토모그래피 재구성)

  • 이충훈;정석호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.177-186
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    • 1996
  • A convolution alogorithm combined with Fourier transformation is applied to the tomographic reconstruction of the asymmetric spray structure to identify the local drop size and volume concentration. The line of sight intergrated data from Malvern particle analyzer with multiangular scanning form a basic information for the deconvolution. Linear interpolation is tested to obtain the effect of increasing number of scanning angles. This transformation method predicts well the structure of asymmetric spray. The tehnique can be extended to other line of sight combustion diagnostics.

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Tomographic Reconstruction of Asymmetric Soot Structure from Multi-angular Scanning (다각 주사법을 이용한 비대칭 매연분포의 재구성)

  • Lee, Sang-Min;Hwang, Jun-Young;Chung, Suk-Ho
    • Journal of the Korean Society of Combustion
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    • v.8 no.3
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    • pp.24-30
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    • 2003
  • A convolution algorithm combined with Fourier transformation has been applied to the tomographic reconstruction of asymmetric soot structure to identify the local soot volume fraction distribution. Line-of-sight integrated data from light extinction measurement with multi-angular scanning formed basic information for the deconvolution. Multi-peak following interpolation technique was applied to obtain the effect of increasing number of scanning angles. Height-by-height reconstructed soot volume fraction distribution was compared with laser-induced incandescence signals.

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A Study on Stability according to the Conservation Environment for Fixative of Korean Mural Painting Layers (한국 흙벽화 채색층 고착제의 보존환경에 따른 안정성 연구)

  • Jin, Byung-hyuk;Wi, Koang-chul
    • Korean Journal of Heritage: History & Science
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    • v.46 no.3
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    • pp.150-171
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    • 2013
  • The most important part of conservation treatment of murals is to preserve them against the risk of a damage by injecting fixative into them when the painting loses its cohesion or powderization of pigments occurred due to occurrence of cracks inside the painting layer. However, studies on the stability of fixative used for painting layers of murals are still insufficient. This study manufactured a mural as a specimen and colored it with four kinds of pigments including oyster shell white, cinnabar, malachite and red clay and applied four kinds of fixative, including, Paraloid $B-72^{(R)}$, Caparol-$binder^{(R)}$, glue and Hydoxypropyl $cellulose^{(R)}$. artificially generated environmental changes in temperature, humidity and ultraviolet rays which may occur after the completion of conservation treatment. Then the changes in physical properties were observed in multifaceted ways such as color stability, contact angle, brilliance, adhesive strength and surface. As a result, this study found that ultraviolet rays and hot?humid environment have a large impact on color stability causing changes in brightness and chroma of all painting layers where the fixative were applied, except for oyster shell white and are considered the main factors of decomposition by accelerating the aging process of fixatives applied. In comparison to the synthetic resins that were also tested in this study, the traditional glue showed satisfactory results in terms of color stability and influence preservation and the hydrophile property. As it showed exceptionally outstanding adhesive strength in all painting layers in the aspect of adhesive strength, it is considered to be highly stabile for the fixation treatment of painting layers of mural.

Usefulness about BSGI (Breast Specific Gamma Imaging) in Breast Cancer Patients (유방암 환자에서 Breast Specific Gamma Imaging (BSGI)의 유용성)

  • Cho, Yong-Gwi;Pyo, Seong-Jae;Kim, Bong-Su;Shin, Chea-Ho;Cho, Jin-Woo;Yeo, Ji-Yeon;Kim, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.92-101
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    • 2009
  • Purpose: Scintimammography is one of the screening tests for the early diagnosis of breast cancer. It has been widely accepted as very useful in assessing masses that have not been detected in breast scanning. This method is highly sensitive and specific with respect to the diagnosis of primary and relapsing breast cancer. It has some difficulties, however, in detecting tumors sized 1 cm and below due to the radioactivity around the breast and the geometrical structure of the equipment. The recent introduction of high-resolution Breast-specific Gamma Imaging (BSGI) has made it possible to more accurately discriminate between malignant and benign tumors than with any other test method. Thus, the possibility of an unnecessary biopsy being performed has decreased. The purpose of this study was to examine the diagnostic capacity of mammography, breast sonography, and scintimammography, which are used for the early diagnosis of known breast cancer, and of BSGI, and to evaluate the skillfulness of radiologists. Materials and Methods: The 53 volunteers participants who had no clinical manifestation of breast cancer underwent the BSGI in February 2009. In the BSGI procedure, scanning images were obtained from the craniocaudal projection (CC) and the mediolateral Oblique projection (MLO), as well as from the additional $80{\times}80$-matrix-sized views at various angles in the Present Time method, 10 minutes after the 25 mCi $^{99m}Tc$-MIBI was injected. Results: The results of the BSGI showed that two participants had masses in their breast tissue. As the results of the diagnosis of four participants were not clear, they were retested and the results of the second test were negative. The results of the clinical screening test for breast cancer showed that the sensitivity of BSGI, scintimammography, mammography, and breast sonography was 86.5%, 77.8%, 85~90%, and 66.7%, respectively, and that their specificity was 92.4%, 84.2%, 20~42%, and 68%, respectively. Conclusion: The autodiagnosis and breast cancer screening test are needed for the early diagnosis of breast cancer. It was not easy, however, to accurately determine the presence of a mass in the breast using the existing breast cancer screening test. The patients with unclear test findings were made to undergo a histologic biopsy for a more accurate diagnosis. It is expected that the BSGI can provide useful information for the early diagnosis of breast cancer and of primary breast cancer, and will reduce the performance of unnecessary biopsies because of its higher sensitivity and specificity than existing breast cancer screening tests.

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