• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.198-203
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• 2013

The purpose of this study is to investigate the scattered dose of X-ray at a distance of 30cm from the area to be examined when X-ray field is the most optimized and maximized when X-ray is performed on hand, skull and abdomen. As a result of scattered dose of X-ray on hand, skull and abdomen, first, when X-ray field was the most optimized upon adult X-ray examination, it was $0.08{\mu}Sv$, $4.39{\mu}Sv$ and $5.56{\mu}Sv$, respectively. When x-ray field was maximized, it was $0.58{\mu}Sv$, $33.47{\mu}Sv$ and $35.93{\mu}Sv$, respectively. Second, when X-ray field was the most optimized upon pediatric X-ray examination, it was $0.40{\mu}Sv$, $14.51{\mu}Sv$ and $18.86{\mu}Sv$, respectively. When x-ray field was maximized, it was $2.78{\mu}Sv$, $107.40{\mu}Sv$ and $117.52{\mu}Sv$, respectively(P<0.001). As a result, when the size of X-ray field was decreased down to be necessary and optimal upon X-ray examination, emission of scattered X-ray around specimen is reduced approximately 6-7 times as much as that when it was maximized.

• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.15-22
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• 2006

ln order to manage efficiently many ancient wooden buildings, which have been preserved as cultural properties in Korea, the internal state of wood members should be evaluated exactly and periodically by a NDE (non-destructive evaluation) method. A research project was planned to develop an X-ray CT (computed tomography) system as a NDE method for wood, which could be easily applied in field. This paper includes the first part of this project. First of all, to establish a measuring procedure of wood density using X-ray radiography, the correlation between X-ray intensity and the film brightness was evaluated. Also, initial X-ray intensity was quantified with various radiate conditions controlled by the tube voltage and tube current. And then, the effects of density, annual ring angle, and thickness on the mass attenuation coefficient of wood were examined. Finally, Beer's law was modified with the above results and adopted to calculate the density of wood. As a result of this study, the measuring procedure of wood density was established using a portable soft X-ray device and this procedure was verified with some small wood specimens. This results will he used valuably for the following researches to develop a portable X-ray CT system.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.533-542
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• 2017

In diagnostic radiology, the imaging system has been changed from film/screen to digital system. However, the method for removing scatter radiation such as anti-scatter grid has not kept pace with this change. Therefore, authors have devised the indirect flat panel detector (FPD) system with net-like lead in substrate layer which can remove the scattered radiation. In clinical context, there are many radiographic examinations with angulated incident X-ray. However, our proposed FPD has net-like lead foil so the vertical lead foil to the angulate incident X-ray would have bad effect on its performance. In this study, we identified the effect of vertical/horizontal lead foil component on the novel system's performance and improved the structure of novel system for clinical usage with angulated incident X-ray. Grid exposure factor and image contrast were calculated to investigate various structure of novel system using Monte Carlo simulation software when the incident X-ray was tilted ($0^{\circ}$, $15^{\circ}$, and $30^{\circ}$ from the detector plane). More photons were needed to obtain same image quality in the novel system with vertical lead foil only then the system with horizontal lead foil only. An optimal structure of novel system having different heights of its vertical and horizontal lead foil component showed improved performance compared with the novel system in a previous study. Therefore, the novel system will be useful in a clinical context with the angulated incident X-ray if the height and direction of lead foil in the substrate layer are optimized as the condition of conventional radiography.

• Journal of the Korean Society of Radiology
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• v.13 no.6
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• pp.831-840
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• 2019

The X-ray detector by liquid crystal with front light was proposed and verified by a X-ray image. The proposed detector utilizes the visible light instead of the electric signal by transistor. Therefore, it shows low noise and can be fabricated at low cost. The liquid crystal detector uses the orientation change of the liquid crystal molecule by conductivity change of the photoconductive layer. We can get the X-ray image from the transmitted light through the liquid crystal. The X-ray dose was calibrated from the measured transmittance of the visible light after comparison to the reference transmittance curve of the liquid crystal. The amorphous Se was used for photo con ducting layer and parylene was used for the liquid crystal alignment instead of the conventional alignment layer which needs high-temperature process over 200℃. The proposed X-ray detector can decrease the X-ray dose by high sensitivity which was verified by simulation. After the fabrication of the X-ray detector, the X-ray image was obtained as a function of the bias voltage to the liquid crystal. 10 lines/mm resolution was obtained from the line pattern and we will apply it to the 17inch diagonal liquid crystal X-ray detector with 3π retardation.

• Journal of radiological science and technology
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• v.30 no.1
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• pp.7-12
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• 2007

This study examined present conditions of upper-gastrointestinal X-ray fluoroscopy and patient skin dose. The authors elected 21 equipments to check the X-ray equipment and exposure factor of fluoroscopy & spot exposure in university hospitals, hospitals, and clinics where perform upper-gastrointestinal X-ray fluoroscopy more than five times every day in Incheon areas. The amount of patient's skin dose during upper-gastrointestinal X-ray fluoroscopy was measured by ionization chamber.

• Journal of Korea Multimedia Society
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• v.8 no.4
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• pp.482-491
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• 2005

In this paper, we proposed the microcalcification detection algorithm which is based on wavelet transform and automatic thresholding method in the X-ray mammographic images. Digital X-ray imaging system is essential equipment in the field diagnosis and is widely used in the various fields such as chest, fracture of a bone, and dental correction. Especially, digital X-ray mammographic imaging is known as the most important method to diagnose the breast cancer, many researches to develop the imaging system are processing in country. In this paper, we proposed a microcalcifications detection algorithm necessary in the early phase of breast cancer diagnosis and showed that a algorithm could effectively detect microcalfication and could aid diagnosis-radiologist.

• The Journal of Korean Society for Radiation Therapy
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• v.20 no.1
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• pp.31-36
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• 2008

Purpose: X ray irradiates material for dose distribution confirmation through material color variation to evaluate about possibility. Materials and Methods: That is rare earth material to pure KCl and KCl impurity Eu adding 0.5mol% by Czochralski method each single crystal grow and observed color variation of KCl X ray irradiation use of linear accelerator. Results: High energy X ray irradiation KCl:Eu show the blue fluorescence with purple color that pure KCl single crystal can confirm by show was not observed, but was colored violet. Conclusion: Colors variation of KCl founds stable color center from radiation and this color variation will be used usefully to X ray measurement material and phantom.

• Progress in Medical Physics
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• v.13 no.3
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• pp.169-175
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• 2002

The purpose of this study is to verify the usefulness of X-ray simulator which uses a visible light source for further study. We developed a small experimental equipment which is composed of three main components - source, localizer and detector. Cartesian coordinate was set in 3D space, and the position of target was assumed the origin of the coordinate. The light from the source passes directly through the target, and projection image is formed on the screen, which can be taken with the digital camera. Since projection images were acquired behind the screen, they were flipped over right and left. By examining the characters of visual light source and equipments, it could be concluded that developed system was useful for experimental purpose.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.762-763
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• 2010

The X-ray device used for medical treatment is classified into fixed type that is used by installing at the location with the stable power supply and mobile type that can be taken by moving the X-ray device to the location where a patient is. Mobile X-ray device which is typically used in the mobile type of X-ray can be used very usefully beyond the space restriction. However, due to its difficulty to generate high-voltage, it is mainly applied to take hand and foot shootings which only need low output power. In this study, by designing and producing the large volume of mobile X-ray device which doesn't have the limitations on diagnostic areas of the body, the operating characteristics of device according to the loading change was identified.

• Electrical & Electronic Materials
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• v.4 no.1
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• pp.12-18
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• 1991

각종 monomer를 공중합시킨 고분자 필름의 X선 유기 TSC(thermally-stimulated current)를 측정하고 polyethylene(PE)의 절연성능 개선의 관점에서 공중합 monomer의 영향에 대하여 검토하였다. PE의 X선 유기 TSC 피이크는 결정화도가 높을 수록 고온측으로 이동하였다. X선 유기 TSC에서 피이크는 공중합에 의하여 Br 및 F원자가 0.2~0.4eV의 전자 trap이 도입된 것으로 생각된다.