• Journal of radiological science and technology
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• v.38 no.4
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• pp.483-489
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• 2015

DICOM (Digital Imaging and Communications in Medicine) standards are generally introduced as de facto and de jure standards in modern medical imaging devices to store and to transmit medical image information. DICOM Dose Structured Report (DICOM dose SR) is implemented to report radiation exposure information in image acquiring process. and DIOCM Modality Performed Procedure Step (DICOM MPPS) is also partly used to report this exposure with the information in its DICOM tag. This article is focused on three type of radiation exposure information of DICOM standards, 1) DICOM dose SR, 2) DICOM MPPS and 3) Radiation Exposure Monitoring(REM) profile by Integrating the Healthcare Enterprise(IHE), to study on radiation exposure reporting. Healthcare facility and its staff of medical imaging related to radiation exposure should have a deep understanding of radiation exposure, and it required a standards to enhance the quality control of medical imaging and the safety of patients and staffs. Staff member have to pay attention on radiation exposures and controling processes from the purchasing stage of X-ray devices.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.447-450
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• 1997

A new technique for the preparation of porous vascular prostheses was investigated. Polyurethane solution (10 to 14wt%) was injected into a mold. After freezing at low temperature $(0^{\circ}C\sim-40^{\circ}C)$, solvent was dissolved out with water at $0^{\circ}C$ to form porous tubes. The average pore size $(<10{\mu}m)$and pore occupation (10% to 51%) were easily changed by changing polyurethane concentration, freezing temperature, and freezing methods. This technique can give a proper pore size $(30\sim60{\mu}m)$ for tissue ingrowth, and suitable compliances for matching with arteries and veins. This method might give a desired compliant graft for artificial implantation with the presently valid medical polymers.

• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.205-214
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• 2016

Objectives: The purpose of the study is to investigate the current status and radiographic safety management in Korea. Methods: A self-reported questionnaire was completed by 200 dental hygienists in Jeonbuk province from September 1, 2014 and October 31, 2014. The questionnaire consisted of general characteristics of the subjects, radiation knowledge, radiation safety management, and radiation exposure anxiety. Data were analyzed using SPSS 18.0 program. Results: Duration of clinical experience(r=0.142) and number of daily radiation shot(r=0.145) showed a positive correlation to radiation safety management, and a nrgative correlation to use of intraoral films and digital devices(r=-0.587). A logistic regression analysis was performed in order to evaluate the influence on radiography knowledge. The results showed that the factors had significant influences on the age group over 41 years old(OR 7.25; 95% CI 1.30-40.43) and those who took a position above team leader(OR 0.23; 95% CI 0.59-0.90). Conclusions: It is very important to have the safety management toward dental intraoral imaging and radiograpgic shot in the dental hygienists. Continuous efforts should be emphasized on radiographic safety management and behavior.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.540-544
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• 2017

In this study, we analyzed the effects of TID(Total Ionizing Dese) and TREE(Transient Radiation Effects on Electronics) on nMOSFET and pMOSFET fabricated by 0.18um CMOS process. The size of nMOSFET and pMOSFET is 100um/1um(W/L). The TID test was conducted up to 1 Mrad(Si) with a gamma-ray(Co-60). During the TID test, the nMOSFET generated leakage current proportional to the applied dose, but that of the pMOSFET was remained in a steady state. The TREE test was conducted at TEST LINAC in Pohang Accelerator Laboratory with a maximum dose-rate of $3.16{\times}10^8rad(si)/s$. In that test nMOESFET generated a large amount of photocurrent at a maximum of $3.16{\times}10^8rad(si)/s$. Whereas, pMOSFETs showed high TREE immunity with a little amount of photocurrent at the same dose rate. Based on the results of this experiment, we will progress the research of the radiation hardening for CMOS unit devices.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.643-649
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• 2018

Recently, together with advancement of domestic aviation industry, overseas tourists using planes have been soared. This study aimed to investigate the risk of diseases for the passengers and flight attendants from the exposed cosmic radiation during the flight by domestic and international literature reviews, as follows. Airliners should develop the program to measure the actual radiation dose and prepare the portable devices for radiation measurement in flight to lower the accumulated dose of cosmic radiation by the attendants. Regulation should be prepared to check the exposed dose during the flight for the passengers by announcement of individual exposed radiation dose which has been provided only to the flight attendants. Passengers and flight attendants should recognize they are exposed to excessive cosmic radiation during the flight and civilians should be protected by the cosmic radiation when they use the flights, which should be prepared by the regulations.

• Progress in Medical Physics
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• v.27 no.4
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• pp.250-257
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• 2016

The purpose of this study was to compare the patient setup errors of two different immobilization devices (Feet Fix: FF and Leg Fix: LF) for pelvic region radiotherapy in Tomotherapy. Thirty six-patients previously treated with IMRT technique were selected, and divided into two groups based on applied immobilization devices (FF versus LF). We performed a retrospective clinical analysis including the mean, systematic, random variation, 3D-error, and calculated the planning target volume (PTV) margin. In addition, a rotational error (angles, $^{\circ}$) for each patient was analyzed using the automatic image registration. The 3D-errors for the FF and the LF groups were 3.70 mm and 4.26 mm, respectively; the LF group value was 15.1% higher than in the FF group. The treatment margin in the ML, SI, and AP directions were 5.23 mm (6.08 mm), 4.64 mm (6.29 mm), 5.83 mm (8.69 mm) in the FF group (and the LF group), respectively, that the FF group was lower than in the LF group. The percentage in treatment fractions for the FF group (ant the LF group) in greater than 5 mm at ML, SI, and AP direction was 1.7% (3.6%), 3.3% (10.7%), and 5.0% (16.1%), respectively. Two different immobilization devices were affected the patient setup errors due to different fixed location in low extremity. The radiotherapy for the pelvic region by Tomotherapy should be considering variation for the rotational angles including Yaw and Pitch direction that incorrect setup error during the treatment. In addition the choice of an appropriate immobilization device is important because an unalterable rotation angle affects the setup error.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.303-311
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• 2020

Scattering-ray generated during plain radiography can cause secondary exposure to organs and tissues other than the target area. Currently, Shielding devices used to reduce radiation exposure are mostly used for radiation protection of workers, and radiation protection of patients is rarely performed. Therefore, this study intends to evaluate the organ dose by scattered-rays and the effectiveness 3D printing materials as a radiation shielding device during plain radiography through simulation. As a result, the absorbed dose for each organ at the time of examination showed a high effect due to the secondary scattering-ray as the distance from the source was close and the organ closer to the skin surface. The dose reduction effect due to the use of 3D printing shielding devices to protect this showed a higher shielding effect in the case of mixed printing materials compared to plastics.

• Applied Science and Convergence Technology
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• v.23 no.6
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• pp.317-327
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• 2014

In order to develop nano-devices with much lower power consumption for beyond-CMOS applications, the fundamental understanding and precise control of the electronic properties of ultrathin transition metal oxide (TMO) films are strongly required. The metal-insulator transition (MIT) is not only an important issue in solid state physics, but also a useful phenomenon for device applications like switching or memory devices. For potential use in such application, the electronic structures of MIT, observed for TMO nano-structures, have been investigated using a synchrotron radiation angle-resolved photoelectron spectroscopy system combined with a laser molecular beam epitaxy chamber and a scanning photoelectron microscopy system with 70 nm spatial resolution. In this review article, electronic structures revealed by soft X-ray nano-spectroscopy are presented for i) polarity-dependent MIT and thickness-dependent MIT of TMO ultrathin films of $LaAlO_3/SrTiO_3$ and $SrVO_3/SrTiO_3$, respectively, and ii) electric field-induced MIT of TMO nano-structures showing resistance switching behaviors due to interfacial redox reactions and/or filamentary path formation. These electronic structures have been successfully correlated with the electrical properties of nano-structured films and nano-devices.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1219-1229
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• 2016

The present paper reports on a trial to shed further light on the characterization, applications, and operation of radar speed guns or Gunn diodes on different radiation environments of neutron or g fields. To this end, theoretical and experimental investigations of microwave oscillating system for outer-space applications were carried out. Radiation effects on the transient parameters and electrical properties of the proposed devices have been studied in detail with the application of computer programming. Also, the oscillation parameters, power characteristics, and bias current were plotted under the influence of different ${\gamma}$ and neutron irradiation levels. Finally, shelf or oven annealing processes were shown to be satisfactory techniques to recover the initial characteristics of the irradiated devices.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.775-777
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• 2016

In this paper presents an analysis of pulsed radiation effects of unit devices. Unit devices are the nMOSFET, pMOSFET, NPN Transistor and those fabricated by the 0.18um CMOS process. Pulsed radiation test results in nMOSFET, the photocurrent of tens nA was generated in $2.07{\times}10^8rad(si)/s$. For the pMOSFET, a photocurrent generation was not observed in $3{\times}10^8rad(si)/s$. For the NPN transistor, the photocurrent was generated with about 1uA. Therefore, the MOSFET must be used than BJT transistor when radhard IC design.