• Tribology and Lubricants
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• 제36권5호
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• pp.267-273
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• 2020

This study experimentally investigates hydrophobic surfaces fabricated via additive manufacturing. Additive manufacturing, commonly known as 3D printing, is the process of joining materials to fabricate parts from 3D model data, usually in a layer-upon-layer manner. Digital light processing is used to fabricate hydrophobic surfaces in this study. This method uses photo-curable resins and ultraviolet (UV) sources. Moreover, this technique generally has faster shaping speeds and is advantageous for the fabrication of small components because it enables the fabrication of one layer at a time. Two photo-curable resins with different compositions are used to fabricate micro-patterns of hydrophobic surfaces. The resins are composed of a photo-initiator, monomer, and oligomer. Experiments are conducted to determine suitable process conditions for the fabrication of hydrophobic surfaces depending on the type of resin. The most important factors affecting the process conditions are the UV exposure time and slice thickness. The fabrication capability according to the process conditions is evaluated using the side and top views of the micro-patterns observed using a microscope. The micro-patterns are collapsed and intertwined when the exposure time is short because sufficient light (heat) is not applied to cure the photo-curable resin with a given slice thickness. On the other hand, the micro-patterns are attached to each other when the exposure time is prolonged because the over-curing time can cure the periphery of a given shape. When the slice is thicker, the additional curing area is enlarged in each slice owing to the straightness of UV light, and the slice surface becomes rough.

• 치과방사선
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• 제29권1호
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• pp.21-32
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• 1999

Purpose: To evaluate the effect of variable scanning protocols of computed tomography for evaluation of pre-implant site of the mandible through the comparison of the reformatted cross-sectional images of helical CT scans obtained with various imaging parameters versus those of conventional CT scans. Materials and Methods: A dry mandible was imaged using conventional nonoverlapped CT scans with 1 mm slice thickness and helical CT scans with 1 mm slice thickness and pitches of 1.0, 1.5. 2.0, 2.5 and 3.0. All helical images were reconstructed at reconstruction interval of 1 mm. DentaScan reformatted images were obtained to allow standardized visualization of cross-sectional images of the mandible. The reformatted images were reviewed and measured separately by 4 dental radiologists. The image qualities of continuity of cortical outline. trabecular bone structure and visibility of the mandibular canal were evaluated and the distance between anatomic structures were measured by 4 dental radiologists. Results: On image qualities of continuity of cortical outline. trabecular bone structure and visibility of the mandibular canal and in horizontal measurement. there was no statistically significant difference among conventional and helical scans with pitches of 1.0. 1.5 and 2.0. In vertical measurement. there was no statistically significant difference among the conventional and all imaging parameters of helical CT scans with pitches of 1.0, 1.5, 2.0, 2.5 and 3.0. Conclusion: The images of helical CT scans with 1 mm slice thickness and pitches of 1.0, 1.5 and 2.0 are as good as those of conventional CT scans with 1 mm slice thickness for evaluation of predental implant site of the mandible. Considering the radiation dose and patient comfort, helical CT scans with 1 mm slice thickness and pitch of 2.0 is recommended for evaluation of pre-implant site of the mandible.

• Journal of Magnetics
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• 제21권1호
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• pp.115-124
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• 2016

The present study analyzes T1 TSE and T1 slice sel. IR (dark_fluid) signal strength according to the degree of gadolinium contrast agent dilution and analyzes the turbo factors with regard to changes in the maximum and overall signal strength to study correlations between changes and signal-to-noise ratios (SNRs) and compare peak-to-peak SNR (PSNR) enhancement in order to improve the quality of T1-weighted images. Enhancement TR (600 msec) evaluated to determine the T1 TSE turbo factor and obtain the maximum signal strength, T1WI were used sequentially to experiment with turbo factors_1-4. T1 slice sel. IR (dark-fluid) was used to sequentially test turbo factors_2-5 but not turbo factor_1 at a TR (1500 msec) and compare data at an increase in T1 of 900 msec. The T1 TSE was reduced according to the contrast agent concentration. Phantom signal strength increased, whereas turbo factors_1-4 exhibited maximum signal strength at a concentration of 3 mmol, followed by a gradual decrease. In the turbo factors_2-5, the signal strength increased sharply to maximum signal strength at 0.7 mmol, followed by a reduction. T1 TSE had a greater maximum signal strength than did T1 slice sel. IR (dark_fluid). A comparison of SNR found that T1 TSE imaging was superior (33.3 dB) in turbo factor_1 and T1 slice sel. IR (dark_fluid) was highest (33.9 dB) at turbo factor_5. A PSNR comparison analysis was not sufficient to distinguish between the images obtained with both techniques at 30 dB or higher under all experimental conditions.

• 한국정보과학회논문지:소프트웨어및응용
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• 제28권12호
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• pp.910-920
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• 2001

본 논문은 프로그램 슬라이스에서의 데이타 토큰들의 정보 흐름에 기초하여 프로그램에서의 정보 흐름을 모델링하기 SIF(Slice-based Information Flow Graph)를 개발하였다 다음으로, SIFG에서 의 정보 흐름의 복잡도 측정을 통해서 프로그램의 복잡도를 측정하기 위해 SCM(Slice based Complexity Measure)을 정의하였다. Zuse의 방법에 따라. 본 연구에서는 SIFC에서의 극소 수정(atomic modifica- tion을 통해 SCM이 순서척도가 됨을 보여주었고, 이항 연산 MBSEQ에 대해서 SCM이 가법성을 만족함을 보여주었고, 이항 연산 MBALP 에 대해서는 Zuse의 가법성을 만족하지 않지만 Weyuker의 9번째 공리를 만족함을 보여주었다. 또한 기존 척도들과의 비교를 통해서. SCM이 프로그램 내에서의 제어와 데이타 흐름뿐만 아니라 프로그램의 물리적 크기를 반영하는 측정이 이루어진다는 것을 보여주었다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권7호
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• pp.922-928
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• 2004

본 논문에서는 볼륨데이타에서의 레이블링(labeling)을 위한 알고리즘을 제안하고자한다. 3차원 볼륨은 2차원 슬라이스 데이타의 연속으로 보고 각 슬라이스의 레이블링 정보를 바탕으로 하는 SIL(Slice Information based Labeling)방법을 제안한다. 이는 기존의 알고리즘에 비해 효율적인 메모리 사용이 가능하고 분석하고자 하는 데이타의 특성에 맞는 2차원 레이블링과의 조합이 가능한 장점이 있다. 기존 알고리즘과 제안하는 방법을 3차원 세포영상에서 비교하여 보았으며, SIL을 2차원 레이블링 CCCL(Contour based Connected Component Labeling)과 함께 볼륨데이타에 적용하여 본 결과 기존의 알고리즘 보다 약 2배 빠른 성능을 보였다. 다양한 3차원 레이블링 방법 중 적용되는 영상에 따라 각기 다른 결과를 얻었지만, 3차원 세포영상의 분석에서는 SIL 방법이 우수하다는 결론을 얻었다.

• Natural Product Sciences
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• 제11권3호
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• pp.179-182
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• 2005

We investigated that water extract of Acanthopanax sessiliflorus roots rescued the N-methyl-D-aspartate (NMDA), agonist of glutamate receptor, -induced toxicity in rat organotypic hippocampal slice culture. When the cell death in NMDA only-treated hippocampal slices was set 100%, A. sessiliflorus decreased the cell death to 75.4, 51.6, 48.9, and 40.6% at 1, 10, 50, and $100\;{\mu}g/ml$ treatment, respectively. On the basis of these results, the water extract of A. sessiliflorus roots may be a preventive agent against NMDA-induced cytotoxicity.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2016년도 하계학술대회
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• pp.359-360
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• 2016

본 논문에서는 초고화질의 비디오 실시간 복호화를 위해 HEVC(High Efficiency Video Coding)에서 지원하는 병렬화 기술인 Slice와 Tile 기술을 이용하여 초고해상도 영상에 대한 복호화기 병렬화 성능을 비교한다. Slice와 Tile은 분할 데이터간 의존성이 존재하지 않으므로 분할된 데이터를 다중 스레드에 할당하여 데이터-레벨 병렬화를 수행하였다. 실험 결과에서는 병렬화된 복호화기 성능이 기존 순차 복호화기에 비해 최대 2.08배 고속화 되었고, 분할 데이터 수가 증가하여도 화질 손실이 거의 없는 결과를 보인다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2016년도 하계학술대회
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• pp.378-380
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• 2016

본 논문에서는 UHD (Ultra High Definition) 방송의 비디오 표준인 HEVC 에서 슬라이스 에러가 발생하는 시나리오에 대한 UHD 방송 시험 스트림을 제안한다. 제안 스트림은 개발한 여러 슬라이스 에러 스트림 항목 중 슬라이스 경계를 정의한 slice_segment_address, end_of_slice_segment_flag 신택스의 에러 시나리오에 따라 제작하였으며, 제작된 스트림을 현재 판매되고 있는 UHD 수신기에 재생하여 결과를 확인하였다.

• 한국임상수의학회지
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• 제16권1호
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• pp.75-79
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• 1999

Magnetic resonance imaging (MRI) is an imaging technique used to produce high quality images of the inside of the animal body. MRI is based on the principles of nuclear magnetic resonance (NMR) and started out as a tomographic imaging technique, that is it produced an image of the NMR signal in a thin slice through the animal body. The animal body is primarily fat and water, Fat and water have many hydrogen atoms. Hydrogen nuclei have an NMR signal. For these reasons magnetic resonance imaging primarily images the NMR signal from the hydrogen nuclei. Hydrogen protons, within the body align with the magnetic field. By applying short radio frequency (RF) pulses to a specific anatomical slice, the protons in the slice absorb energy at this resonant frequency causing them to spin perpendicular to the magnetic field. As the protons relax back into alignment with the magnetic field, a signal is received by an RF coil that acts as an antennae. This signal is processed by a computer to produce diagnostic images of the anatomical area of interest.

• 펄프종이기술
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• 제35권5호
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• pp.37-45
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• 2003

To investigate the influence of the design and operating parameters of the headbox on hydrodynamics, a pilot headbox system and pressure monitoring apparatus were constructed. The pilot headbox system consisted of a circulating water reservoir, centrifugal pump, distributor, turbulence generator and slice. The distributor was designed to function as a pressure attenuator. Flow rate to the headbox and MD and CD velocity profiles in the slice zone were monitored using an ultrasonic flowmeter and Pitot tubes, respectively. As the distance from the step diffusor increased, evener CD velocity profile was observed. Wall effect increased with the increase of the velocity. Flow stability in the headbox was evaluated by injecting a dye at the outlet of the distributor. Application of theoretical analysis based on CFD in designing headboxes is briefly discussed.