• Journal of Veterinary Clinics
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• v.37 no.1
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• pp.15-22
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• 2020

This study investigated the effectiveness of radiation safety rules in animal hospital and the awareness and behavior of veterinary radiation workers. With the questionnaires, the data was collected from randomly selected veterinarians in animal hospitals and animal medical imaging centers. Collected data were about radiation device, shielding device, regulations, safety management, education, knowledge, behavior and awareness. Frequency, correlation and multiple regression analysis were performed. The medical devices related with radiation in animal hospital were X-ray (59%), CT (15%), fluoroscopy (12%), mobile X-ray (12%) and others (2%). The number of people using radiation shielding device is high. The answers were low on knowing radiation related regulation and receiving radiation protection education. The group with higher knowledge and awareness shows positive correlation with safety behavior. The increase of use of the radiation related medical devices in veterinary hospital causes the increase of radiation exposure risk. This study suggests that radiation safety management system and policies need to be developed to protect radiation workers and give them correct information and consciousness.

• Progress in Medical Physics
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• v.13 no.3
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• pp.114-119
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• 2002

A immobilizing device that is essential for correct lung and lens shielding with homogenous dose distribution in fractionated total body irradiation was developed and it's efficiency was evaluated. The main frame was made of stainless steel bar (5 cm in diameter) to withstand up to 230 cm in height and 100 kg in weight to prevent any injury even in unconsciousness condition. The saddle was designed to adjust the body weight and hight of standing patients. Chest and back supporter were made of 1 cm acryl which could fix the lung block and cassette holder. Leather and sponge pedding were used for head rest to keep patients comfortable. The device was strongly fixed by specially designed bolts on the bottom panel which was made of 1 cm stainless steel and 10 cm thick wooden board. Precise manipulation ($\pm$2 mm) was possible by upper two pulleys and side handles. Average four minutes twenty five seconds were needed for exact setting in fractionated TBI. No significant difference of lung block location on repeated verification films was confirmed and relatively homogeneous dose distribution was measured in rando phantom experiments and patient treatments ($\pm$5%). This immobilizing device was very efficient to keep correct position of patients, which is essential for better result and less complication in fractionated TBI.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.439-448
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• 1993

The B-type gamma knife unit was installed at Kyung-Hee University Hospital in March 1992. The selective beam plugging method can be used to reduce the low percentage isodose profiles of normal sensitive organ and to modify the isodose curves of treatment volume for better shaping of the target volume. For representing the changes of the low percentage isodose profiles, the variations of dose distribution for several cases were discussed in this paper. The film dosimetry was peformed for the evaluation of calculated isodose profiles predicted by KULA dose planning system. The results were verified by RFA-3 automatic densitometry. The clinical application of selective beam shielding method was peformed in 17 patients in 100 patients who have undergone gamma knife radiosurgery for a year. The calculated and the measured isodose profiles for the high percentage regions were well consistent with each other. When the target of pituitary tumor is macro-size, the selective beam shielding method is the most applicable method. When the target size, however, is small, the correct selection of the proper helmet size is very important. All patients were exposed almost about 3~12 Gy for brain stem, and 3~11.2 Gy for optic apparatus. It is recommended that the same or other plugging patterns with multiple isocenters should be used for protection of the radiosensitive normal structures with precise treatment of CNS lesions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.4
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• pp.253-257
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• 2017

Nowadays, it is increasingly important to detect whether cables are live for the operator's safety if there is a sudden power failure. It is especially hard to detect the electrical field of an underground line because of shielding. This paper on detection of live-line states in cables studied the detection characteristics of the change in the magnetic field and axis as the frequency, voltage, and distance at the same load are changed using 3 axes. A search coil type was used as a magnetic field sensor with non-contact. We found that magnetic fields decrease proportionally to the square of the distance and the decrease of rated voltage with load effected to magnetic field. The magnetic field was detected by 3-axis sensors given correct proximity, but appeared as noise components beyond a distance of 2 cm.

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.53-59
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• 1999

The aim of this study is to improve the accuracy of field placement and junction between adjacent fields and block shielding through the use of a computed tomography(CT) simulator and virtual simulation. The information was acquired by assessment of Alderson Rando phantom image using CT simulator (I.Q. Xtra - Picker), determination of each field by virtual fluoroscopy of voxel IQ workstation AcQsim and colored critical structures that were obtained by contouring in virtual simulation. And also using a coronal, sagittal and axial view can determine the field and adjacent field gap correctly without calculation during the procedure. With the treatment planning by using the Helax TMS 4.0, the dose in the junction among the adjacent fields and the spinal cord and cribriform plate of the critical structure was evaluated by the dose volume histogram. The pilot image of coronal and sagittal view took about 2minutes and 26minutes to get 100 images. Image translation to the virtual simulation workstation took about 6minutes. Contouring a critical structure such as cribriform plate, spinal cord using a virtual fluoroscopy were eligible to determine a correct field and shielding. The process took about 20 minutes. As the result of the Helax planning, the dose distribution in adjacent field junction was ideal, and the dose level shows almost 100 percentage in the dose volume histogram of the spinal cord and cribriform plate CT simulation can get a correct therapy area due to enhancement of critical structures such as spinal cord and cribriform plate. In addition, using a Spiral CT scanner can be saved a lot of time to plan a simulation therefore this function can reduce difficulties to keep the patient position without any movements to the patient, physician and radiotherapy technician.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1587-1592
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• 2023

Time-encoded imagers (TEI) are important class of instruments to search for potential radioactive sources to prevent illicit transportation and trafficking of nuclear materials and other radioactive sources. The energy of the radiation cannot be known in advance due to the type and shielding of source is unknown in practice. However, the response function of the time-encoded imagers is related to the energy of neutrons or gamma-rays. An improved image reconstruction method based on MLEM was proposed to correct for the energy induced response difference. In this method, the count vector versus time was first smoothed. Then, the preset response function was adaptively corrected according to the measured counts. Finally, the smoothed count vector and corrected response were used in MLEM to reconstruct the source distribution. A one-dimensional dual-particle time-encode imager was developed and used to verify the improved method through imaging an Am-Be neutron source. The improvement of this method was demonstrated by the image reconstruction results. For gamma-ray and neutron images, the angular resolution improved by 17.2% and 7.0%; the contrast-to-noise ratio improved by 58.7% and 14.9%; the signal-to-noise ratio improved by 36.3% and 11.7%, respectively.

• Korean Journal of Digital Imaging in Medicine
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• v.15 no.2
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• pp.13-18
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• 2013

Purpose : Fluoroscopy equipment, depending on the type of changes that occur in the patient's position ESD and study the patient's scatter ray of ESD Practitioners considered a comparative analysis was to evaluate the correct dose. Materials and Methods : HITACHI four overtube type TU-8000 Flat Detector and Under tube C-Arm Philips' Multi Diagnost Eleva with Flat Detector type were measured by. Each devices is a measure of the patient's esd randophantom position in tabel unfors Xi multi funtion then fixed to the abdomen fluoroscopy and 10 seconds, spot was measured three times, practitioners of the incident surface dose by considering the patient's scatter ray of the table for each device in the average human stomach 21cm thickness acrylic phantom ($25cm{\times}25cm$) Place the practitioner position after position randophantom unfors Xi multi funtion in the thyroid and stomach 1 minute by a fixed one-time fluoroscopy and measured. Results : 10 seconds and the patient perspective of the c-arm ESD 1.2 times smaller on the AP and oblique measurements were measured in the 6-13 times smaller. spot positions to changes in the measured three times on the AP of the abdomen, ESD is 18 times smaller c-arm measurements and the oblique measurement was 19-30 times smaller. And 1 minute at practitioners fluoroscopy esd in the thyroid 2.12 times the c-arm, chest 1.75 times less the dose was measured. On the AP, depending on the device, but the lack of dose difference oblique positions of the two devices depending on changes in the area due to changes in both the AP than on the dose increased, the difference in dose between the two devices, the maximum difference was approximately 27 times. Conclusion : Fluoroscopic equipment at the time of inspection in accordance with changes in dose according to the patient and the patient's positions changes, because the area of the scatter ray considering the change of dose measurements be made, and study of the equipment according to the characteristics of the efficiency and the exposure of the patient and practitioner is considered smooth study equipment manufacturers that can be done is to build the system and think that is also important. Various fluoroscopy when you check future changes in many factors of change in dose for the equipment in the laboratory system by considering the scatter ray radiation shielding for the management to take advantage of reckless undertube have been utilized as more exposure Reduction activities can help is considered as the direction.

• Journal of radiological science and technology
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• v.35 no.3
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• pp.219-226
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• 2012

Interventional radiologists are not aware of the potential injury from procedures. The purpose of this study are to evaluate radiation exposure of interventional radiologist from intervention procedures and to develop guideline of the simple methods for decreasing their radiation exposure from intervention procedure. In this study, Dosimeters were used to monitor operator doses of radiation exposure in a broad range of procedures from 20 interventional radiologist during the periods of 3 months. And, we searched protection methods of each interventional radiologist. During TACE procedure, there was using 0.5 mmPb radiation protector decreased average 89.5 % of radiation exposure. Thicker radiation protector provide decreasing radiation exposure. And radiation exposure dose decreased average 47.7 % by using pulse fluoroscopic mode. Therefore, interventional radiologist should wear protective aprons, use active shielding, monitor their doses, and know how to poisoning themselves during the procedure and operate correct of the machines for minimum dose.

• Journal of the Korean earth science society
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• v.38 no.2
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• pp.129-140
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• 2017

Global solar radiation was calculated in this research using ground-base measurement data, meteorological satellite data, and GWNU (Gangneung-Wonju National University) solar radiation model. We also analyzed the accuracy of the GWNU model by comparing the observed solar radiation according to the total cloud cover. Our research was based on the global solar radiation of the GWNU radiation site in 2012, observation data such as temperature and pressure, humidity, aerosol, total ozone amount data from the Ozone Monitoring Instrument (OMI) sensor, and Skyview data used for evaluation of cloud mask and total cloud cover. On a clear day when the total cloud cover was 0 tenth, the calculated global solar radiations using the GWNU model had a high correlation coefficient of 0.98 compared with the observed solar radiation, but root mean square error (RMSE) was relatively high, i.e., $36.62Wm^{-2}$. The Skyview equipment was unable to determine the meteorological condition such as thin clouds, mist, and haze. On a cloudy day, regression equations were used for the radiation model to correct the effect of clouds. The correlation coefficient was 0.92, but the RMSE was high, i.e., $99.50Wm^{-2}$. For more accurate analysis, additional analysis of various elements including shielding of the direct radiation component and cloud optical thickness is required. The results of this study can be useful in the area where the global solar radiation is not observed by calculating the global solar radiation per minute or time.