• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1024-1025
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• 2005

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.480-480
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• 2007

This paper performed the basic study for developing the light therapy equipment for medical treatment. We developed the equipment for medical therapy using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on. Especially, to control the light irradiation frequency, and to control the change of output value, TLC5941 was used. Control stage is divided into 4 step by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and the output of a high brightness LED could be controlled, stage by stage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.394-399
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• 2024

An irradiator is developed using two UVA wavelength ranges of SMD LEDs as a curing light source. This module has dimensions of 545×111×300 mm³ and is equipped with a TIR bar-shaped lens made of PDMS silicone resin. The developed irradiator offers high uniformity, with 89% in the centerline of the horizontal axis direction, for two different wavelength ranges of 365 nm and 385 nm. The radiation intensity from the light source module shows highly directional characteristics, and the irradiator provides a maximum irradiance of 1,634 mW/cm² at a working distance of 50 mm. During the initial 5 minutes of operation, the irradiance experiences a rapid decrease. However, this issue is addressed by optimizing the LED's current reduction characteristics and managing the Transistor's temperature rise in the constant current circuit. After continuous operation for approximately 60 minutes. The highest temperature, near the central part of the irradiating surface, reaches 69.7℃, while the lowest temperature, near the edges, is 41.1℃.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.132-132
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• 2006

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.107-113
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• 1986

It is estimated that the loss of Korean agricultural and fishery products during the storage period is usually more than 20%, and it is difficult to increase agricultural products by a 10% annual rate directly. Therefore, development of food preservation techniques has now become a most important atternative for the indirect increase of such products and for its senitary distribution. Changes eating habits and improved living conditions have accelerated the demand for convenience food production and for this reason it is essential that raw materials at stable, resonable prices and hygienic quality be available the year round. At the end of 1980, the Korean government conceded th economical feasibility of the storage of foods by irradiation and a procedure for preserving food by irradiation on a batch scale was successfully developed by KAERI in 1982. Based on the research results accomplished by the KAERI and on the recommendation on wholesomeness of irradiated food by Joint Committee of FAO/IAEA/WHO in 1980, the approval of wholesomeness of irradiated food was declared by presidential decree in June 1985 and the procedure of permission for individual items is in progress. Korean private firms (Ryung Young Co.) which was technically assisted by KAERI for five years have taken mush interest in the establishment of such facilities in Korea, therefore Ryung Young Co. had proposed for the construction of 500 Kci Co-60 irradiator to the Ministry of Science and Technology in July 1984. The permission of construction has approved by government in May 1985. The commercial irradiator will be constructed as one of the most modernized facilities until May 1987 and that facilities will contribute the propagation of commercial storage of foods and its hygienic quality.

• Progress in Medical Physics
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• v.24 no.3
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• pp.140-144
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• 2013

In this research, the glass dosimeter was calibrated to measure the standard absorbed dose of the Cs-137 irradiator and absorbed dose in a biological sample. Absorbed dose in water for Cs-137 gamma ray was determined by the IAEA TRS-277 protocol. The PTW-TM30013 ion chamber and the PTW-TM41023 water phantom were utilized for measuring absorbed dose and the value was compared with the reading from DoseAce GD-302M glass dosimeter from Asahi Techno Glass Corporation for its calibration. The uncertainty of measurement ($1{\sigma}$) of the calibrated glass dosimeter was 2.7% and this result would be applied to improve the accuracy in measurement of absorbed dose in a biological sample.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.337-344
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• 2018

Food irradiation is important not only in ensuring safety but also improving antioxidant activity of peaches. Our objective was to establish the best irradiation treatment for peaches by calculating dose distribution using Monte Carlo simulation. 3-D geometry and component densities of peaches, extracted from CT scan, were entered into MCNP to obtain simulated dose distribution. Radiation energies for electron beam were 1.35 MeV (low energy) and 10 MeV (high energy). Co (1.25 MeV) and the Husman irradiator, containing three sealed Cs source rods in an annular array, were used for gamma irradiation. At 1.35 MeV electron beam simulation, electrons penetrated well beyond the peach skin, enough for surface treatment for microorganisms and allergens. At 10 MeV electron beam simulation, for top-beam only treatment, doses at the core were the highest and for double beam treatment, the electron energy was absorbed by the entire sample. At Co source, the radiation doses were presented on the whole area. At Cs source, the dose uniformity ratios were 2.78 for one source and 1.48 for three ones at 120 degrees interval. Proper control of irradiation treatment is critical to establish confidence in the irradiation process.

• Progress in Medical Physics
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• v.34 no.3
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• pp.33-39
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• 2023

Purpose: FLASH radiotherapy (RT) using ultra-high dose rate (>40 Gy/s) radiation is being studied worldwide. However, experimental studies such as preclinical studies using small animals are difficult to perform due to the limited availability of irradiation devices and methods for generating a FLASH beam. In this paper, we report the initial dosimetry results of a prototype electron linear accelerator (LINAC)-based irradiation system to perform ultra-high dose rate (UHDR) preclinical experiments. Methods: The present study used the prototype electron LINAC developed by the Research Center of Dongnam Institute of Radiological and Medical Sciences (DIRAMS) in Korea. We investigated the beam current dependence of the depth dose to determine the optimal beam current for preclinical experiments. The dose rate in the UHDR region was measured by film dosimetry. Results: Depth dose measurements showed that the optimal beam current for preclinical experiments was approximately 33 mA, corresponding to a mean energy of 4.4 MeV. Additionally, the average dose rates of 80.4 Gy/s and 162.0 Gy/s at a source-to-phantom surface distance of 30 cm were obtained at pulse repetition frequencies of 100 Hz and 200 Hz, respectively. The dose per pulse and instantaneous dose rate were estimated to be approximately 0.80 Gy and 3.8×10⁵ Gy/s, respectively. Conclusions: Film dosimetry verified the appropriate dose rates to perform FLASH RT preclinical studies using the developed electron-beam irradiator. However, further research on the development of innovative beam monitoring systems and stabilization of the accelerator beam is required.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2065-2069
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• 2014

The DAC-7512E is a 12-bit digital to analog converter that is low power and a single package with internal buffers. The DAC-7512E takes up minimal PCB area for applications of space power electronics design. The spacecraft mass is a crucial point considering spacecraft launch into space. Therefore, we have performed a TID test for the DAC-7512E 12-bit serial input digital to analog converter to reduce the spacecraft mass by using a low-level Gamma-ray irradiator with $Co^{60}$ gamma-ray sources. The irradiation with $Co^{60}$ gamma-rays was carried out at doses from 0 krad to 100 krad to check the error status of the device in terms of current, voltage and bit error status during conversion. The DAC-7512E 12-bit serial digital to analog converter should work properly from 0 krad to 30 krad without any error.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.104-105
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• 1999