• Tribology and Lubricants
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• v.36 no.5
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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.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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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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• v.21 no.1
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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.

• Journal of KIISE:Software and Applications
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• v.28 no.12
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• pp.910-920
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• 2001

We developed a SIFC(Slice-based Information Flow Graph) For modeling the information flow on program on the basis of the information flow of a data tokens on program slices. Then we defined a SCM(Slice-based Complexity Measure) for measuring the program complexity by measuring the complexity of information flow on SIFG, We showed that, according to Zuse's approach, it assumed ordinal scale based on atomic modifications on SIFG and that it was additive to binary operation MBSEQ and that it was not additive to binary operation MBALT but satisfied Weyuker's 9th axiom. Also based on comparison with the existing measures, we showed that SCM could measure not only the control and data flow in program but also the physical size of program.

• Journal of KIISE:Software and Applications
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• v.31 no.7
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• pp.922-928
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• 2004

We propose a new 3 dimensional labeling method based on slice information for the volume data. This method is named SIL (Slice Information based Labeling). Compare to the conventional algorithms, it has advantages that the use of memory is efficient and it Is possible to combine with a variety of 2 dimensional labeling algorithms for finding an appropriate labeling algorithm to its application. In this study, we applied SIL to confocal microscopy images of cervix cancer cell and compared the results of labeling. According to the measurement, we found that the speed of Sd combined with, CCCL (Contour based Connected Component Labeling) is almost 2 times higher than that of other methods. In conclusion, considering that the performance of labeling depends on a kind of image, we obtained that the proposed method provide better result for the confocal microscopy cell volume data.

• Natural Product Sciences
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• v.11 no.3
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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.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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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.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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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.

• Journal of Veterinary Clinics
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• v.16 no.1
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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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.5
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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.