• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.301-307
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• 2013

In the present study, space doses generated during X-ray radiography of hand, head, and abdomen, etc. were examined and whether the intensity of space doses of scattering rays is attenuated by the "inverse square law of distance" was figured out. First, the space doses of X-ray with small amounts of generated scattering rays such as hand radiography were mostly attenuated by the "inverse square law of distance" and were not detected at all at a distance of 2m. Second, the space doses of X-ray with large amounts of generated scattering rays such as head or abdomen radiography attenuated in higher rates than the rates under the "inverse square law of distance" at distances ranging from 30cm to 1m from the center of the irradiation field and were attenuated by the "inverse square law of distance" at distances ranging from 1m to 2m. Therefore, in X-ray rooms, the subject should be at least 2m away from the center of the irradiation field in the case of hand radiography and X-ray exposure prevention actions using protective devices are required in the entire spaces of the X-ray rooms in the case of head or abdomen radiography.

• The Journal of the Korean dental association
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• v.13 no.10
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• pp.941-946
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• 1975

치과교정학 분야에 있어서 부정교합자의 다양한 하악골 위치변화에 따른 Hyoid bone 위치변화에 대한 연구는 부족한 감이 있어, 저자등은 Hellman의 치령ⅢA 이후의 부정교합을 가진 남ㆍ녀 97명을 Angle씨 각급 부정교합의 분류에 의해 중심교합위와 안정위시의 두부 X선 사진을 가각 탐득하고 Hyoid bone의 위치변화를 측정하여 다름과 같이 결과를 얻었다. 1. 중심교합위에서의 Cranial base에 대한 Hyoid bone 위치변화에서는 Angle씨 ClassⅢ에서 남ㆍ녀 모두 물징적으로 전방에 위치하며, Mandibular plane에 대한 Hyoid bone위치변화에서는 각급 부정교합사이에 특기할 차이가 없다. 2. 안정위에서의 Hyoid bone위치는 중심교합위에서의 위치와 비슷한 분포를 나타내고 있다. 3. 중심교합위에서는 안정위로싀 위치변화에서 각급 부정교합 똑같이 후ㆍ하방 이동을 나타내고 있다.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.919-927
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• 2018

The purpose of this study was to present simulation training model for general X-ray examinations and to analyze the errors that occur during the simulation training. From 2012 to 2018, a total of 183 students (77 men and 106 women) participated. The simulated X-ray system used computed radiography (CR) system. The contents of simulation training were patient's care, X-ray examinations accuracy, images stability, etc. As a result, it were found that the patient's position setting error, the accuracy error of the X-ray beam central ray, the image receptor's size and setting error, the error of the grid use, the marking error, and the error of X-ray exposure technical factors. It is expected that improved practical general X-ray examinations training of radiographer will be needed, focusing on these errors, so that we could contribute to the health care of the people by providing precise examinations and high quality medical service.

• 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.

• 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.

• Journal of the Korean Society of Radiology
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• v.14 no.6
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• pp.827-832
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• 2020

X-ray equipment, which is frequently used in radiology and treatment, is the most common and most used equipment in clinical practice. Equipment must provide accurate information to patients through continuous quality control. In case of manual quality control measurement, reproducibility may be poor and there may be a problem with reliability of evaluation results. In this study, an automated program was developed and attempted to measure how much the central ray between the focus of the X-ray tube and the variable aperture of the diagnostic X-ray generator used in clinical practice coincides. As a result of the experiment, it succeeded in calculating the coordinates of the two center points, and the distance between the two points was calculated in pixels and applied to the judgment and the automatic judgment value for whether the center line coincidence is within the normal angle or the abnormal angle is presented. The results of this study are considered to be very helpful in the quality control of the X-ray apparatus.

• Radiation Oncology Journal
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• v.25 no.1
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• pp.54-61
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• 2007

[ $\underline{Purpose}$ ]: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on- board imager (OBI). $\underline{Materials\;and\;Methods}$: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed $COM_{OBI}$ with the reference $COM_{CT}$. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. $\underline{Results}$: In the phantom study, the calculated $COM_{CT}$ and $COM_{OBI}$ agreed with $COM_{actual}$ within a millimeter. The algorithm also could localize each seed marker correctly and calculated $COM_{CT}$ and $COM_{OBI}$ for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of $0.1{\pm}2.7{\sim}1.8{\pm}6.6\;mm$ in the AP direction, $0.8{\pm}1.6{\sim}2.0{\pm}2.7\;mm$ in the SI direction and $-0.9{\pm}1.5{\sim}2.8{\pm}3.0\;mm$ in the lateral direction, even though the setup error was quite patient dependent. $\underline{Conclusion}$: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.

• Bulletin of Food Technology
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• v.22 no.2
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• pp.311-320
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• 2009

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.10
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• pp.1770-1778
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• 2001

황토는 대표적인 천연 무기염재의 일종으로서 바람에 의해 운반되어 퇴적된 담황색 내지는 황회색을 띠는 실트질의 퇴적물을 일컫는다. 황토의 구성물질은 주로 석영, 장석, 산화철광물, 깁사이트 등의 여러 가지 점토광물을 포함하는데, 주로 적색을 띠는 것은 소량의 산화철 광물에 기인되는 경우가 많으며 황토를 구성하는 점토광물로는 버미큘라이트, 카오린 광물인 캐올리나이트와 할로이사이트, 일라이트 등이 있다. 본 연구에서는 면직물에 천연 무기염재인 황토를 사용한 염색시에 황토 단독염색과 콩즙 전처리 후 황토염색으로 나누어 염색을 실시하고, 원료 황토와 황토염색 후 면직물에 부착된 성분 간에 차이가 있는지를 확인하기 위해 X선 형광분석(X-ray fluorescence analysis, XRF)을 이용하여 염색 전.후 황토의 성분을 분석하였고, X선 회절분석(X-ray diffraction analysis, XRD)을 이용하여 황토 및 염색 전 후 면직물에 부착된 광물질의 주성분을 분석하였으며, energy dispersive spectrometer (EDS)가 장착된 주사전자현미경을 이용하여 면직물에 부착된 광물의 성분을 조사하였다. 그 결과, 황토로 면직물을 염색하는 경우 면직물에 부착되는 황토의 양과 K/S 값은 거 의 비례하여 증가하는 것으로 나타났다. 황토 염색 후 면직물에 부탁되는 주성분은 주로 SiO$_2$, A1$_2$O$_3$, Fe$_2$O$_3$등인 것으로 나타났으며, X선 회절분석과 EDS분석에 의해 캐올리나이트, 일라이트 등의 점토광물의 형태로 존재하는 것이 확인되었다.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.138-146
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• 2024

Purpose To evaluate whether the image quality of chest radiographs obtained using a camera-type portable X-ray device is appropriate for clinical practice by comparing them with traditional mobile digital X-ray devices. Materials and Methods Eighty-six patients who visited our emergency department and underwent endotracheal intubation, central venous catheterization, or nasogastric tube insertion were included in the study. Two radiologists scored images captured with traditional mobile devices before insertion and those captured with camera-type devices after insertion. Identification of the inserted instruments was evaluated on a 5-point scale, and the overall image quality was evaluated on a total of 20 points scale. Results The identification score of the instruments was 4.67 ± 0.71. The overall image quality score was 19.70 ± 0.72 and 15.02 ± 3.31 (p < 0.001) for the mobile and camera-type devices, respectively. The scores of the camera-type device were significantly lower than those of the mobile device in terms of the detailed items of respiratory motion artifacts, trachea and bronchus, pulmonary vessels, posterior cardiac blood vessels, thoracic intervertebral disc space, subdiaphragmatic vessels, and diaphragm (p = 0.013 for the item of diaphragm, p < 0.001 for the other detailed items). Conclusion Although caution is required for general diagnostic purposes as image quality degrades, a camera-type device can be used to evaluate the inserted instruments in chest radiographs.