• Journal of Digital Convergence
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• v.12 no.2
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• pp.555-561
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• 2014

For five diagnostic X-ray generators (DR), four units turned out to be appropriate in tests on the reproducibility of radiation output suggested in the IEC 60601-2-54 standard, but in one unit of the X-ray equipment, an item measured in a combination of 50% of the highest tube voltage of the diagnostic X-ray equipment, the test setting of Group C with authorized output doses between $1{\mu}Gy$ and $5{\mu}Gy$ of mAs turned out to be inappropriate. As a result, the radiation dose to the IEC 60601-2-54 standard for quantification standards proposed by the radiation output from diagnostic X-ray imaging device reproducibility of performance management should be aware that an important evaluation factor.

• The Journal of Korean Society for Radiation Therapy
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• v.3 no.1
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• pp.45-50
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• 1989

Wedge filter are used in high energy radiation therapy to obtain uniform isodose lines at small volume tumor and irregular body surface. The aim of this study is not only to describe the method of construction and setting of semi-universal wedge filter for $^{60}Co$ radiation therapy but also to get the optimum treatment planning by clinical application of wedge filter.

• Journal of the Korean Society of Radiology
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• v.4 no.3
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• pp.5-11
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• 2010

In this paper, we are suggested development of dual-mode detector for dual-energy digital radiography. Design of dual-energy radiography module for commercial BIS (Baggage Inspection System) is used in the spectrum of the X-ray generator and detector for dual-mode features and radiological characteristics were analyzed. BIS suggestl on the image detector module being used to target X-ray tube to simulate X-ray spectrum and simulated spectrum to offer through the new radiographic characteristics of the detector modules were investigated. Using X-ray experiments with an increase in the thickness of the copper filter low energy detector (LED) and high-energy detector (HED) as the difference between the output signal increases. HED, especially in the size of the output signal decreases with increasing thickness of the copper filter was found.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.116-121
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• 2012

DC/DC switching power converters produce DC output voltages from different DC input sources. The converter is used in regenerative braking of DC motors to return energy back in the supply, resulting in energy savings for the systems containing frequent stops. The DC/DC converter is composed of a PWM-IC (pulse width modulation integrated circuit) controller, a MOSFET (metal-oxide semi-conductor field-effect transistor), an inductor, capacitors, and resistors, etc. PWM is applied to control and regulate the total output voltage. In this paper, radiation shows the main influence on the changes in the electrical characteristics of comparator, operational amplifier, etc. in PWM-IC. In the PWM-IC operation, the missing pulses, the changes in pulse width, and the changes of the output waveform are studied by the simulation program with integrated circuit emphasis (SPICE) and compared with experiments.

• Journal of Sensor Science and Technology
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• v.8 no.2
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• pp.95-101
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• 1999

When a metal oxide field effect transistor (MOSFET) is exposed to ionizing radiation, electron/hole pairs are generated in its oxide layer. The slow moving holes of them are trapped in the oxide layer of p-MOSFET and appear as extra charges that change the characteristics of the transistor. The radiation-induced charges directly impact the threshold (turn-on) voltage of the transistor. This paper describes the use of the radiation-induced threshold voltage change as an accumulated radiation dose monitoring sensor. Two kinds of commercial p-type MOSFETS were tested in a Co-60 gamma irradiation facility to see their capabilities as a radiation dosimeter. We found that the transistors showed good linearity in their threshold voltage shift characteristics with radiation dose. The results demonstrate the potential use of commercial p-MOSFETS as inexpensive radiation sensors for the first time.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.681-686
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• 2022

In this study, a scintillation resin for 3D printing was fabricated with 1.0 wt% of PPO organic scintillator, 5.0 wt% of MMA, and commercial acrylic resin. Using the scintillation resin, 3D-shaped plastic scintillator radiation sensors were successfully fabricated quickly and inexpensively with a commercial 3D DLP printer. The 3D printed plastic scintillator has a good dose-output linearity of R-square 0.998 was obtained in the range of 1 to 10 nA of beam current of the 45 MeV proton beam. The developed 3D plastic scintillator has low light output, so there is a limit to its use in low-dose-rate gamma-ray or X-ray dosimetry. However, it was confirmed that the tissue equivalent material could be usefully used for measuring high energy or high dose rates radiation, such as proton beams and ultra-high dose rate beams.

• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.350-356
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• 2000

The optimum composition ratios of primary solute(p-terphenyl) and secondary solute(popop) have been investigated in order to fabricate plastic scintillator with higher light output and less radiation damage. The radiation damage induced by $^{60}Co$ $\gamma$-irradiation depends on mainly the concentration of secondary solute. The spectral range of the luminescence was $400{\sim}450\;nm$, its peak emission appeared at 415 nm. The transmittance and the light output were not changed by radiation damage up to $1{\times}10^4\;Gy$ irradiation with $^{60}Co$ $\gamma$-rays.

• Progress in Medical Physics
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• v.15 no.4
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• pp.237-246
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• 2004

Even though the wedge factor was defined by ICRU, RTPS uses other definition different from the wedge factor to consider the wedge effect to correct dose. Because the factors with different concept are defined in a very different way, replacement of different factor could make severe error of dose and is unacceptable because their values are very different from each other. Radiotherapy machine installed in department includes physical wedges and function of dynamic wedge by upper jaws, and Eclipse and Pinnacle$^{3}$ such as RTPS are used. The wedge factors, relative wedge output factors and wedge field output factors of physical wedges and dynamic wedges were measured by an ionization chamber in water phantom. They are analyzed and compared in according to wedge position, field size, wedge angle, X-ray quality, measurement condition. Wedge factor, relative wedge output factors and wedge field output factors of dynamic wedges comparing physical wedges have an effect of several factors. Main factors effecting to the factors of dynamic wedges were field size and wedge angle. Beam quality of X-ray introduces a few effect to the factors. Because the factors related to wedge and defined with different concepts are different from each other, to reduce dose error it should be input by values proper to RTPS.

• Journal of Radiation Protection and Research
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• v.20 no.3
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• pp.155-162
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• 1995

The state-of-the art of detection and measurements of non-ionizing radiations are reviewed in relation to protection requirements, especially for electromagnetic and ultraviolet radiations. Dosimetric quantities, instruments and considerations needed for measurement are briefly explained. For electromagnetic radiation, the power density levels from various practical sources are summarized for reference uses. Large errors remain in the measurements of non-ionizinf radiations in general. Technical needs of development in measurement and dosimetry of non-ionizing radiations, therefore, are promissing when the increasing public concerns about the adverse health effects of non-ionizing radiations and proliferation of their uses are taken into account.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.387-390
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• 2014

In this paper, we propose to study on the application of the alarm algorithm to the platform of portable radiation detection device based on Coretex-A9 to ensure the safety of user. The analog board transforms sensor's signal and the platform based on Cortex-A9 outputs the results. The radiation detection's alarm is realized to LED and Buzzer to ensure safety of user.