• Journal of radiological science and technology
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• v.47 no.5
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• pp.395-401
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• 2024

This study aimed to develop a self-directed modular teaching-learning model curriculum for the safe operation of mobile X-ray equipment with designed an educational system using ultrasonic sensors and line tracer sensors. We conducted with radiological science students and clinical radiological technologists. they improved performance in reducing errors during mobile X-ray equipment operation and increased learning satisfaction after repeated practice. The average error rate of driving its decreased through repeated training, and learning satisfaction was rated as excellent. The modular teaching-learning model with sensor-based evaluation system contributed to enhancing practical skills in operating mobile X-ray equipment. Our results demonstrated the effectiveness of self-directed learning for mobile X-ray equipment operation and serves as foundational material for developing future educational programs.

• Progress in Medical Physics
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• v.22 no.1
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• pp.3-11
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• 2011

The purpose of this study was to evaluate feasibility of Vertical Multileaf Collimator for determination of irradiation size using Vertical Multileaf Collimator and lead block to determine 4 different irradiation shape in case of Co-60 gamma-ray and 6 MV X-ray. We chose ion chamber, glass dosimeter and EBT chromic film to compare with Vertical Multileaf Collimator results and lead block results. In case of Co-60 gamma-ray and 6 MV X-ray, the central axis point dose normalized at reference field of lead block with ion chamber results for Vertical Multileaf Collimator were estimated higher than lead block about 5.1%, 4.2%. In case of Co-60 gamma-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 2.2%, 7.8%, 7.2%, 4.0% for reference, circle, triangle, cross field, respectively. In case of 6 MV X-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 6.7%, 6.2%, 3.8%, 6.2% for reference, circle, triangle, cross field, respectively. The results of EBT chromic film, Vertical Multileaf Collimator of penumbra size for all irradiation shape was smaller than lead block of those size that 2.0~3.5 mm for Co-60 gamma-ray, 0.5~1.0 mm for 6 MV X-ray. The results from this study, radiation treatment volume that results in shielding block can be minimized. In addition, during radiation treatment for 2, 3-dimensional radiation therapy using a Vertical Multileaf Collimator of this survey can be used to determine variety of irradiation fields.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.217-223
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• 2022

In this study, images taken using a grid and images taken using Air Gap Technique were evaluated in X-ray chest radiography. Subjective Evaluation The ROC (Receiver Operating Characteristic) evaluation was evaluated by 5 radiologists who had worked for more than 10 years in the radiology department of a university hospital. Objective evaluation SNR (Signal to noise ratio) was evaluated. As a result of the analysis, the Cronbach Alpha value was 0.714, which was significantly higher. In the Air Gap Technique, the distance between the phantom and the subject was set at 20 cm, and the image was taken with a tube voltage of 100 kVp, a tube current and a recording time of 8 mAs. In the ROC (Receiver Operating Characteristic) evaluation, the highest score was obtained with 18 score and an objective evaluation SNR (signal to noise ratio) of 6,149 scored. Also, in the imaging method using a grid, when the distance between the phantom and the constant receptor is 15 cm apart, and the tube voltage is 110 kVp, the tube current and the recording time are taken at 8 mAs, the ROC evaluation score is 19 and the objective evaluation SNR (Signal to noise ratio) is the highest with 6.622 scored. Therefore, if the Air Gap Technique imaging method is used, which overcomes the shortcomings such as delay in reading, increase in patient's exposure dose, and shortening of mechanical lifespan, as well as re-radiography due to the cut-off phenomenon of the grid that appears using the grid, the It is thought that it will be very helpful for chest imaging, including the case of using a portable X-ray imaging device.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.895-908
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• 2018

As modern science is developed and advanced, examination and number of times using radiation are increasing daily. General diagnostic X-ray generator is installed on stationary form, But X-ray generator was developed because patient who is in the intensive care unit, operation room, emergency room can not move to general x-ray room. What we examine patient by x-ray generator is certainly necessary, So patient exposure is inevitable. but reducing radiation exposure is highly important matter about radiation technology, guardian, patient in the same hospital room, nurse etc. For this reason, rule regarding safety control of diagnostic x-ray generator revised for radiation worker, patient and protector proclaim that mobile diagnostic x-ray shield must placed in case of examine different location excluding operation room, emergency room, intensive care unit. But, radiogical technologist is having a lot of difficulties to examine with mobile x-ray generator, diagnostic x-ray shield partition, image plate and lead apron. So, when we use x-ray generator, we manufacture shield tools can be attached to the mobile x-ray generator On behalf of x-ray shield partition and conduct analysis and in comparison to part of body and distribution of dose rate and find way to reduce radiation exposure through distribution of dose rate of patient within the radiogical technologist, medical team. Mobile x-ray generator aimed at SHIMADZU inc. R-20, We manufactured equipment for shielding x-ray scattered x-ray by installing shielding wall from side to side based on support beam on the mobile x-ray generator. Shielding wall when moving can be folded and designed to expand when examine. Experiment measured five times in each by an angle for dose rate of eyes, thyroid, breast, abdomen and gonad on exposure condition of upper and lower extremity, chest, abdomen which is examined many times by mobile x-ray generator. We used dosimeter RSM-100 made by IJRAD and measured a horizontal dose rate by body part. The result of an experiment, shielding decreasing rate of the front and the rear showed 77 ~ 98.7%. Therefore using self-production shielding wall reduce scattered x-ray occurrence rate and confirm can decrease exposure dose consequently. Therefore, through this study, reduction result which is used shielding wall of self-production will be a role of shielding optimization and it could be answer about reduction of medical exposure recommended by ICRP 103.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.859-863
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• 2023

In this study, simple and portable radiation detection system using X-ray intensifying screen, optical sensor and micro-controller unit for education was proposed. The system was simply composed of detection unit consisting of an optical sensor and intensifying screen, micro-controller unit, and was designed to be suitable for portable. Radiation was measured using developed detection system and absorbed dose dosimeter with changing tube voltage from 50 to 100 kVp. The tube current and SDD were fixed on 100 mAs and 100 cm, and dose were measured repeated ten times at each tube voltage. The response and linearity of the detection system were confirmed using the measured values. It was confirmed that the comparison measurement results of the detection system and absorbed dose dosimeter showed a high correlation(r : 0.998, p<.001). In this results, the feasibility of the detection system with intensifying screen and micro-controller unit based was confirmed, and we considered that the developed detection system could be applied to portable, compact, low cost system for education.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.353-357
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• 2017

In this study, the inclusion phenomena of tetrahydrofuran + 3-hydroxytetrahydrofuran + $CH_4$ clathrate hydrates were explored via thermodynamic and spectroscopic approaches. The phase equilibria of the double hydrates - THF + $CH_4$ and 3-OH THF + $CH_4$ clathrate hydrates - were determined by pressure-temperature trace during hydrate formation and dissociation, and the result revealed that the equilibrium pressures were shifted to lower pressure region compared to pure $CH_4$ hydrate. The powder X-ray diffraction patterns revealed that the double hydrates of THF + 3-OH THF formed structure II type clathrate hydrates with $CH_4$. The dispersive Raman spectra of the double clathrate hydrates also exhibited that $CH_4$ can be trapped in both $5^{12}6^4$ and $5^{12}$ cages whereas THF and 3-OH THF were encaged in $5^{12}6^4$ cage.

• Journal of the Korean Society of Radiology
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• v.7 no.2
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• pp.113-120
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• 2013

Nowadays, the medical system towards patients changes into the medical services. As the human rights are improved and the capitalism is enlarged, the rights and needs of patients are gradually increasing. Also, based on this change, several systems in hospitals are revised according to the convenience and needs of patients. Thus, the cases of mobile portable among examinations are getting augmented. Because the number of mobile portable examinations in patient's room, intensive care unit, operating room and recovery room increases, neighboring patients are unnecessarily exposed to radiation so that the examination is legally regulated. Hospitals have to specify that "In case that the examination is taken out of the operating room, emergency room or intensive care units, the portable medical X-ray protective blocks should be set" in accordance with the standards of radiation protective facility in diagnostic radiological system. Some keep this regulation well, but mostly they do not keep. In this study, we shielded around the Collimator where the radiation is detected and then checked the change of dose regarding that of angles in portable tube and collimator before and after shielding. Moreover, we tried to figure out the effects of shielding on dose according to the distance change between patients' beds. As a result, the neighboring areas around the collimator are affected by the shielding. After shielding, the radiation is blocked 20% more than doing nothing. When doing the portable examination, the exposure doses are increased $0^{\circ}C$, $90^{\circ}C$ and $45^{\circ}C$ in order. At the time when the angle is set, the change of doses around the collimator decline after shielding. In addition, the exposure doses related to the distance of beds are less at 1m than 0.5m. In consideration of the shielding effects, putting the beds as far as possible is the best way to block the radiation, which is close to 100%. Next thing is shielding the collimator and its effect is about 20%, and it is more or less 10% by controlling the angles. When taking the portable examination, it is better to keep the patients and guardians far enough away to reduce the exposure doses. However, in case that the bed is fixed and the patient cannot move, it is suggested to shield around the collimator. Furthermore, $90^{\circ}C$ of collimator and tube is recommended. If it is not possible, the examination should be taken at $0^{\circ}C$ and $45^{\circ}C$ is better to be disallowed. The radiation-related workers should be aware of above results, and apply them to themselves in practice. Also, it is recommended to carry out researches and try hard to figure out the ways of reducing the exposure doses and shielding the radiation effectively.