• Title/Summary/Keyword: cross -sectional image

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Prediction of Stacking Angles of Fiber-reinforced Composite Materials Using Deep Learning Based on Convolutional Neural Networks (합성곱 신경망 기반의 딥러닝을 이용한 섬유 강화 복합재료의 적층 각도 예측)

  • Hyunsoo Hong;Wonki Kim;Do Yoon Jeon;Kwanho Lee;Seong Su Kim
    • Composites Research
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    • v.36 no.1
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    • pp.48-52
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    • 2023
  • Fiber-reinforced composites have anisotropic material properties, so the mechanical properties of composite structures can vary depending on the stacking sequence. Therefore, it is essential to design the proper stacking sequence of composite structures according to the functional requirements. However, depending on the manufacturing condition or the shape of the structure, there are many cases where the designed stacking angle is out of range, which can affect structural performance. Accordingly, it is important to analyze the stacking angle in order to confirm that the composite structure is correctly fabricated as designed. In this study, the stacking angle was predicted from real cross-sectional images of fiber-reinforced composites using convolutional neural network (CNN)-based deep learning. Carbon fiber-reinforced composite specimens with several stacking angles were fabricated and their cross-sections were photographed on a micro-scale using an optical microscope. The training was performed for a CNN-based deep learning model using the cross-sectional image data of the composite specimens. As a result, the stacking angle can be predicted from the actual cross-sectional image of the fiber-reinforced composite with high accuracy.

CBCT Imaging for Dental Implants (임상가를 위한 특집 2 - 임플란트시술을 위한 CBCT의 활용)

  • An, Seo-Young
    • The Journal of the Korean dental association
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    • v.50 no.4
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    • pp.189-195
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    • 2012
  • Various imaging modalities have been used for dental implant assessment in the different stages of implant treatment. Basic imaging, such as panoramic and periapical radiographs, are generally useful and cost-effective but do not provide the cross-sectional visualization or interactive image analysis that can be obtained with more sophisticated imaging techniques, such as Cone-Beam Computed Tomography(CBCT) imaging. This article includes the applications of CBCT imaging and their diagnostic contribution to presurgical evaluation, treatment planning, and postoperative assessment of dental implants.

혈액정화장치의 현황과 문제점

  • 박한철
    • Journal of Biomedical Engineering Research
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    • v.10 no.2
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    • pp.102-105
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    • 1989
  • In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research.

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The Effect of the Microdefects in Czoscralski Si wafer on Thin Oxide Failures (Thin Oxide 불량에 미치는 Czochralski Si 웨이퍼의 미소결함의 영향)

  • 박진성;이우선;김갑식;문종하;이은구
    • Journal of the Korean Ceramic Society
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    • v.34 no.7
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    • pp.699-702
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    • 1997
  • The cross sectional image of thin oxide failure of MOS device could be observed by Emission Microscope and Focused Ion Beam at the weak point. The oxide failures in low electric field was associated with the presence of a particle or abnormal pattern. The failures occuring at medium field are related to a pit of Si substrate. The pits could be originated from the microdefects of Cz Si wafer.

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Transthoracic Needle Biopsy of Thoracic Lesions (흉부 병터에 대한 경흉부 바늘생검)

  • Song, Jae-Woo
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.3
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    • pp.241-247
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    • 2004
  • In the diagnostic evaluation of thoracic lesions, the image-guided transthoracic needle biopsy was developed, and its role was expanded with the development of cross-sectional detection and characterization of thoracic lesions and advances in biopsy needle design and techniques. Particularly for diagnostic evaluation of solitary pulmonary nodules, transthoracic needle biopsy has emerged as the invasive procedure of choice. This article covers the indication, the pre-procedure preparation, various guidance-modalities and techniques, and complications.

Three Dimensional Dose Planning Using 6MV X-ray and Multiaxial Computed Tomography for Pituitary Adenoma (6MV X-선과 전산화 단층 촬영상을 이용한 뇌하수체 종양 치료계획)

  • Lee, Myung-Za;Choi, Tae-Jin
    • Radiation Oncology Journal
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    • v.3 no.1
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    • pp.59-64
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    • 1985
  • Computation of three dimensional dose distribution using CT image and RT plan was applied to a case of pituitary adenoma. Algorithm was based on two dimensional Tissue Maximun Ratio model extended to the third dimension. The resulting isodose curve of transeverse, coronal and sagittal section was demonstrated. This RT plan allows computation of dose distribution in any arbitarily defined plane in addition to conventional cross sectional view.

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Quantitative analysis of lumbar multifidus atrophy with low back pain patients using Magnetic Resonance Image (자기공명영상(MRI)을 통한 요통환자의 다열근 위축에 대한 정량적 분석)

  • Yang, Dae-Jung
    • Journal of the Korean Society of Physical Medicine
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    • v.5 no.4
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    • pp.615-621
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    • 2010
  • Purpose : The purpose of this study was to compare chronic LBP patients and asymptomatic subjects on measures of multifidus size (cross-sectional area;CSA, thickness) and symmetry (proportional difference of relatively larger side to smaller side). Methods : Data were obtained from 12 asymptomatic subjects without a prior history of LBP (8 females, 4 males), and a retrospective audit was undertaken of records from 12 chronic low back pain patients (8 females, 4 males). CSA and Thickness of the lumbar multifidus muscles was measured from axial T1-weighted magnetic resonance images(MRI). Results : The results of the analysis showed that chronic LBP patients had significantly smaller multifidus CSA and thickness than asymptomatic subjects at L4-5 vertebral levels(p<.05). The asymmetry between sides was seen at L4- L5 vertebral level in patients with chronic low back pain presentations(p<.05). Conclusions : MRI provided a quantitative measure of change between asymptomatic subjects and chronic low back pain patients of multifidus muscle. MRI identified significant differences in cross-sectional area and thickness and helps to evaluate clinically and plan the treatment modalities of LBP.

A Study on the Shape of the Pattern Milled Using FIB (집속이온빔 연마에 의한 패턴의 형태에 관한 연구)

  • Jung, Won-Chae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.11
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    • pp.679-685
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    • 2014
  • For the measurements of surface shape milled using FIB (focused ion beam), the silicon bulk, $Si_3N_4/Si$, and Al/Si samples are used and observed the shapes milled from different sputtering rates, incident angles of $Ga^+$ ions bombardment, beam current, and target material. These conditions also can be influenced the sputtering rate, raster image, and milled shape. The fundamental ion-solid interactions of FIB milling are discussed and explained using TRIM programs (SRIM, TC, and T-dyn). The damaged layers caused by bombarding of $Ga^+$ ions were observed on the surface of target materials. The simulated results were shown a little bit deviation with the experimental data due to relatively small sputtering rate on the sample surface. The simulation results showed about 10.6% tolerance from the measured data at 200 pA. On the other hand, the improved analytical model of damaged layer was matched well with experimental XTEM (cross-sectional transmission electron microscopy) data.

Single source CVD of epitaxial 3C-SiC on Si(111) without carbonization

  • Lee, Kyung-Won;Yu, Kyu-Sang;Bae, Jung-Wook;Kim, Yun-Soo
    • Journal of Korean Vacuum Science & Technology
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    • v.1 no.1
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    • pp.38-44
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    • 1997
  • Epitaxial growth of SiC films on Si(111) substrates without carbonization was carried out n the temperature range of 900-100$0^{\circ}C$ under high vacuum conditions by single source chemical vapor deposition (CVD) of 1,3-disilabutane (H$_3$SiCH$_2$SiH$_2$$CH_3$). The monocrystalline nature of the films was confirmed by XRD, RHEED and cross-sectional TED. Cross-sectional TEM image indicated that no void exists and the boundary is clear and smooth at the SiC-Si(111) interface. RBS and AES analyses also showed that the films are stoichiometric and homogeneous in depth, From the results, this single source growth techniqe of using 1,3-disilabutane has been found suitable and effective for epitaxial growth of stoichiometric SiC on Si(111) without carbonization at temperatures below 100$0^{\circ}C$.

The effect of mandibular position on measurement in spiral tomography (나선형 단층방사선사진촬영에서 하악골 위치가 측정치에 미치는 영향)

  • Jung Yun-Hoa
    • Imaging Science in Dentistry
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    • v.35 no.2
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    • pp.83-86
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    • 2005
  • Purpose : To evaluate the effect of deviation of mandibular positioning, by changing the mandibular plane inclination, on the measured height and width of mandible in spiral conventional tomography. Materials and Methods : By means of the Scanora multifunctional unit, cross-sectional tomograms were taken from two human dried mandibles at the mandibular angulations: -15 degree, -10 degree, -5 degree, and 0 degree. Twenty-eight sites in two dried mandibles were imaged. One examiner measured the bone heights and widths at selected sites on the images and the actual bone heights were recorded. Results : The bone heights at the four mandibular inclinations overestimated real bone heights and the mean difference between actual heights and image heights on 0 degrees was the smallest (P<0.01). The bone widths on -15 degrees were narrowest and there were significant differences between bone widths measured at the four mandibular inclinations (P<0.001). We found statistically significant differences between both bone heights and widths as measured according to the mandibular plane angle for the posterior region (P<0.01). Conclusion : The use of different mandibular positioning may result in discrepancies in heights and widths when measured from the cross-sectional tomographic images. It is suggested that the mandibular positioning may play a significant role in the measurement of mandibular heights and widths.

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