• Anatomy & Biological Anthropology
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• v.31 no.4
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• pp.133-142
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• 2018

3D histology is a imaging system for the 3D structural information of cells or tissues. The synchrotron radiation propagation phase contrast micro-CT has been used in 3D imaging methods. However, the simple phase contrast micro-CT did not give sufficient micro-structural information when the specimen contains soft elements, as is the case with many biomedical tissue samples. The purpose of this study is to develop a new technique to enhance the phase contrast effect for soft tissue imaging. Experiments were performed at the imaging beam lines of Pohang Accelerator Laboratory (PAL). The biomedical tissue samples under frozen state was mounted on a computer-controlled precision stage and rotated in $0.18^{\circ}$ increments through $180^{\circ}$. An X-ray shadow of a specimen was converted into a visual image on the surface of a CdWO4 scintillator that was magnified using a microscopic objective lens(X5 or X20) before being captured with a digital CCD camera. 3-dimensional volume images of the specimen were obtained by applying a filtered back-projection algorithm to the projection images using a software package OCTOPUS. Surface reconstruction and volume segmentation and rendering were performed were performed using Amira software. In this study, We found that synchrotron phase contrast imaging of frozen tissue samples has higher contrast power for soft tissue than that of non-frozen samples. In conclusion, synchrotron radiation propagation phase contrast cryo-microCT imaging offers a promising tool for non-destructive high resolution 3D histology.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1864-1866
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• 2001

최근 배전계통에서는 전력공급 신뢰도 향상을 위해서 평상시 및 사고시의 전압/전류를 신속하고, 정확하게 계측할 수 있는 광계측 방식의 적용이 적극적으로 진행되고 있다. 본 논문은 이러한 것을 배경으로 하여 배전용 광 CT 및 PT의 국산화 모델의 선정, 시제품 제작 및 특성시험의 결과에 대해서 기술하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03a
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• pp.310-325
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• 2004

국가전략 6대 분야는 IT(정보기술), BT(생명공학기술), ET(환경기술), NT(극미세기술), ST(우주항공기술) 및 CT(문화기술)로 정부 및 민간부문에서 최근 집중 육성되고 있다. 이중에서 IT는 정보시스템의 계획, 분석, 설계, 구축을 위한 일련의 연결된 형식기법을 통칭하는 용어로 광통신, 디지털방송, 무선통신, 소프트웨어, 차세대 인터넷, 컴퓨터 등을 주요 전략품목으로 삼고 있다. 지반공학에서의 IT는 '계측'이라는 다소 시대에 쳐지는 듯한 용어를 사용하고는 있지만 나름대로 컴퓨터 및 통신기술의 발달과 함께 성장하고 있다.(중략)

• Journal of the Korean Society of Food Culture
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• v.32 no.5
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• pp.453-464
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• 2017

Vegetable soup has been reported to have anti-inflammatory, anti-oxidative and anti-cancer effects. In this study, five kinds of vegetable soup were developed using a new manufacturing process and compositional changes in raw material, and anti-cancer and immuno-stimulatory activities were evaluated. Cytotoxicity tests based on MTT assay revealed that all vegetable soups had strong inhibitory effects against CT26 mouse colon cancer cells, with soups including Solomon's seal being most effective based on comparison of $IC_{50}$ values. Apoptosis in response to vegetable soup was occurred by 3-5 fold on cancer cells compared to normal cells. Mouse splenocytes increased by 266-541% in response to addition of vegetable soup in an in vitro proliferation experiment. In co-culture with splenocytes and CT26 cancer cells, splenocytes increased by more than 280% in every vegetable soup treatment, while cancer cells decreased by about 60% and cytokines such as $IFN- {\gamma}$ and IL-12 were secreted from splenocytes in high levels only in response to vegetable soup including Solomon's seal. In conclusion, all vegetable soups developed in this study had anti-cancer effects, and vegetable soup including Solomon's seal showed the strongest anti-cancer and immuno-stimulatory effects. These results suggest that functionality of vegetable soup could be increased by changes in manufacturing processes and raw materials composition.

• Journal of radiological science and technology
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• v.34 no.4
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• pp.341-349
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• 2011

This study was to measure the patient dose difference between 3D treatment planning CT and 4D respiratory gating CT. Study was performed with each 10 patients who have lung and liver cancer for measured patient exposure dose by using SOMATON SENSATION OPEN(SIMENS, GERMANY). CTDIvol and DLP value was used to analyze patient dose, and actual dose was measured in the location of liver and kidney for abdominal examination and lung, heart and spinal cord for chest examination. Rando phantom were used for the experiment. OSLD was used for in-vitro and in-vivo dosimetry. Increasing overall actual dose in 4D respiratory gated CT-simulation using OSLD increase the dose by 5.5 times for liver cancer patients and 6 times for lung cancer patients. In CT simulation of 10 lung cancer patients, CTDIvol value was increased by 5.7 times and DLP 2.4 times. For liver cancer patients, CTDIvol was risen by 3.8 times and DLP 1.6 times. The accuracy of treatment volume could be increased in 4D CT planning for position change due to the breaths of patient in the radiation therapy. However, patients dose was increased in 4D CT than 3D CT. In conclusion, constant efforts is required to reduce patients dose by reducing scan time and scan range.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1671-1673
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• 2003

Faraday효과를 기본으로 하는 광CT(Optical Current Transformer)는 기존의 CT의 결점을 개선하여 경제적 효과의 증대, 신호제어 시스템의 신속성향상, Digital 계전시스템의 호환성에 크게 기여한다는 점 등 많은 면에서 장점을 가지고 있다. 본 연구에서는 광섬유센서 기술을 응용하고, Faraday 효과의 편광면 회전량을 수광부에서 김출하여 대전류 측정을 위한 광 CT의 동작특성에 대한 실험을 하고자 한다. 실험에 사용찬 광원은 633[nm] He-Ne Laser와 1310[nm] Laser Diode 두 가지로 동일한 시스템으로 구성하여 비교한다. 센싱부의 광섬유는 길이 10[m]의 633[nm] 1310[nm]용 single-mode bare fiber를 전류가 흐르는 케이블에 감아 센싱부를 구성하고, 전류변화에 따른 두 출력값을 측정, 비교하고자 한다.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.3
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• pp.184-193
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• 2016

Purpose: To evaluate marginal leakage of bulk fill flowable composite resin filling with different curing time by using microcomputed tomography technology. Materials and Methods: 30 previously extracted human molars were randomly divided into 6 groups based upon restorative system and different curing time. Class II cavities (vertical slot cavities) were prepared. An individual metallic matrix was used to build up the proximal wall. The SonicFill or SureFil SDR flow was inserted into the preparation by using 1 bulk increment, followed by light polymerization for different curing times. The different exposure times were 20, 40, and 60 seconds. All specimens were submitted to 5,000 thermal cycles for artificial aging. Micro-CT scanning was performed by using SkyScan 1272. One evaluator assessed microleakage of silver nitrated solution at the resin-dentin interface. The 3D image of each leakage around the restoration was reconstructed with CT-Analyser V.1.14.4. The leakage was analyzed with the Mann-Whitney test. Results: Significant differences were observed between the light curing times, but no significant differences were found between the bulk fill composite resins. Increasing in the photoactivation time resulted in greater microleakage in all the experimental groups. Those subjected to 60 seconds of light curing showed higher microleakage means than those exposed for 20 seconds and 40 seconds. Conclusion: Increasing the photoactivation time is factor that may increase marginal microlekage of the bulk fill composite resins. Further, micro-CT can nondestructively detect leakage around the resin composite restoration in three dimensions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.136-142
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• 2005

In this paper, we wrote about the basic experimentation of Optical CT's temperature characteristic to measure high-current in a super-high-voltage electric power equipment which is using Faraday effect. We used the 1310[nm] Laser Diode as the light source and PIN Photodiode as receiver. For the transmission line of light, we used 30[m] single mode fiber which could maintain the state of polarization in the optical fiber. For the experiment, the temperature transformation device make by aluminium. the The range of current was from 400[A] and 1300[A] and the range of temperature was from $-40[^{\circ}C]\;to\;50[^{\circ}C]$. In a same experimental condition, magnitude increased input current increase follow by increasing proportion of input current.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.47-53
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• 2003

In this paper, we described the laboratory layout of the optical CT in connection with the measurement of large current based on Magneto-Optic Effects. It was used He-Ne laser for light source and was used PIN-Photodiode for light receiver. The sensing section was organized by winding optical fiber around conductor on the concept that the rotation angle of polarizing axis by Faraday Effect is proportional to the applied current in to conduction. The optical signal passed through optical fiber sensor was induced to analyzer arranged in the direction of $\theta$ for input polarization, and then analyzed its rotation angle and researched on operating characteristics of optical CT for 60[Hz] AC current measurement from l00[A] to 1000[A] was carried out. In this results, the output signals induced linearly with the current and proved that the intensity is increased with increasing turns of fiber through output differences which in accordance with turns of fiber and we verified that there is not only difference of the output with the medium between electric field and optical fiber, but also the lineality. Measuring the references and output intensities of the optical CT, ratio errors were within $\pm$7%. This confirmed that error rate will be improved by each medium and turns.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.36-42
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• 2003

This paper presents a new current-source PWM inverter based on Buck-boost configuration to interface between photovoltaic system and utility line. Proposed inverter is consisted by two set of buck-boost topology, and the input inductor is designed to be operated on the discontinuous current conduction mode. So high power factor can be achieved without additional input CtUTent controller. As a result, overall system has simple structure, and it can obtain higher ac output rms voltage than the terminal voltage of the photovoltaic system without additional boosting procedure. The operational modes are theoretically analyzed, and then the validity of the proposed system was verified through simulation and experimental results using a prototype.