• 전자공학회논문지
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• 제50권6호
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• pp.85-90
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• 2013

본 논문에서는 본 연구실에서 제안된 Dummy Gate Assisted MOSFET을 이용하여 6bit SAR (Successive Approximation Register) ADC를 설계하였으며 이에 대한 대조군으로 Conventional MOSFET으로 동일한 회로를 설계하여 두 회로의 Co-60 Gamma Ray에 의한 누적방사선 영향을 비교 분석해 보았다. 설계된 SAR ADC는 Binary Capacitor DAC과 Dynamic Latch 형태의 Comparator 그리고 Logic으로 구성이 되었으며, 0.35um standard CMOS공정으로 제작되었다. 방사선 조사 후 Conventional MOSFET을 이용한 ADC는 정상동작하지 못하였지만, Dummy Gate Assisted MOSFET을 사용한 ADC는 방사선 조사 후 DNL은 0.7LSB에서 2.0LSB, INL은 1.8LSB에서 3.2LSB로 다소 증가하였으나 정상적인 A/D 변환이 가능하다는 것을 확인하였다.

• 한국식품과학회지
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• 제22권5호
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• pp.509-513
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• 1990

백색종 양송이의 보존기간 연장을 위한 전리에너지 처리가 저장중 버섯의 갈변현상과 색도에 미치는 영향을 조사하였다. 버섯의 갈변현상과 관련된 polyphenol성 화합물은 저장 중 $(9{\pm}1^{\circ}C,\;80{\pm}7%\;RH$, 20일간) 감소하였고 갈변색소는 저장 후 3일경부터 크게 증가하였으며, 이들의 증감현상은 2-3kGy의 감마선 조사로서 유의적으로 감소되었다. 포장된(종이상자와 PE) 버섯의 갓 및 줄기 부위의 표피와 내부조직에 대한 기계적 색도 측정에서 감마선은 처리직후 Hurter L값(백색도)의 감소와 a 및 b값(적색도 및 황색도)의 증가현상을 초래하였으나 저장 후 15일까지 버섯의 변색방지 효과를 뚜렷이 나타내었다. 이 같은 효과는 줄기에 비해 갓 부분에서 높았으며 조사선량(1-3kGy)에도 비례하였다.

• 한국의학물리학회지:의학물리
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• 제23권4호
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• pp.285-291
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• 2012

Si(Li) 검출기를 이용해 한국표준과학연구원에서 보유한 베타선 선원인 $^{147}Pm$, $^{85}Kr$, $^{90}Sr+^{90}Y$ 선원의 순수 베타선 에너지 스펙트럼을 측정하였고 이 측정 스펙트럼에 대한 잔여에너지와 질량충돌저지능비를 산출하였다. 베타선의 잔여에너지는 $^{147}Pm$, $^{85}Kr$, $^{90}Sr+^{90}Y$ 선원에 대하여 각각 0.14, 0.57, 0.93 MeV으로 평가되었고 질량충돌저지능비는 각각 1.123, 1.120, 1.109이었다.

• 방사선산업학회지
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• 제5권1호
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• pp.7-13
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• 2011

The present study has been performed to compare the physiological analysis of monocot model plant (rice) in response to ionizing irradiations (cosmic-ray, gamma-ray, and Ion beam). Ionizing radiations were implanted into monocot model plant (rice) seed. After irradiation, the seeds were planted in the plastic pots for a growth period of one month. Thereafter, the morphological and physiological characteristics including malondealdehyde (MDA) and chlorophyll content, activities of antioxidant enzymes in irradiation samples were investigated. We are confirmed that the activity level of MDA and chlorophyll content were not changed by ionizing irradiation samples. However, the free radical contents were increased in all irradiated plants. And the activities of SOD, POD, and APX were significantly increased by irradiation compared with non-irradiation plant.

• 한국의학물리학회지:의학물리
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• 제33권4호
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• pp.72-79
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• 2022

Purpose: The proficiency test was conducted to assess the performance of the dosimetry audit service provider in the readout practice of the dose delivered to patients in medical institutions. Methods: A certain amount of the absorbed dose to water for the high-energy X-ray from the medical linear accelerator (LINAC) installed in the Korea Research Institute of Standards and Science (KRISS) was delivered to the postal dose audit package given by the dosimetry audit service provider, in which the radio-photoluminescence (RPL) glass dosimeters were mounted. The dosimetry audit service provider read the RPL glass dosimeters and sent the readout dose value with its uncertainty to KRISS. The performance of the dosimetry audit service provider was evaluated based on the E_n number given in ISO/IEC 17043:2010. Results: The evaluated E_n number was -0.954. Based on the ISO/IEC 17043, the performance of the dosimetry service provider is "satisfactory." Conclusions: As part of the conformity assessment, the KRISS performed the proficiency test over the postal dose audit practice run by the dosimetry audit service provider. The proficiency test is in line with confirming the traceability of the medical institutions to the primary standard of absorbed dose to the water of the KRISS and ensuring the confidence of the dosimetry audit service provider.

• 제어로봇시스템학회논문지
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• 제17권11호
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• pp.1125-1131
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• 2011

This paper presents a control theoretic approach to realizing fault tolerance in asynchronous sequential circuits. The considered asynchronous circuit is assumed to work in space environment and is subject to faults caused by total ionizing dose (TID) effects. In our setting, TID effects cause permanent changes in state transition characteristics of the asynchronous circuit. Under a certain condition of reachability redundancy, it is possible to design a corrective controller so that the closed-loop system can maintain the normal behavior despite occurrences of TID faults. As a case study, the proposed control scheme is applied to an asynchronous arbiter implemented in FPGA.

• Radiation Oncology Journal
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• 제33권2호
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• pp.66-74
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• 2015

Trace elements play crucial role in the maintenance of genome stability in the cells. Many endogenous defense enzymes are containing trace elements such as superoxide dismutase and metalloproteins. These enzymes are contributing in the detoxification of reactive oxidative species (ROS) induced by ionizing radiation in the cells. Zinc, copper, manganese, and selenium are main trace elements that have protective roles against radiation-induced DNA damages. Trace elements in the free salt forms have protective effect against cell toxicity induced by oxidative stress, metal-complex are more active in the attenuation of ROS particularly through superoxide dismutase mimetic activity. Manganese-complexes in protection of normal cell against radiation without any protective effect on cancer cells are more interesting compounds in this topic. The aim of this paper to review the role of trace elements in protection cells against genotoxicity and side effects induced by ionizing radiation.

• 환경생물
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• 제21권4호
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• pp.321-327
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• 2003

Differences between the principles for the radiological protection of man and the environment are compared. The derived levels of exposure for man and biota recommended by the international agencies with dose rates for chronic radiation producing effects at different levels of biological organization were given in terms of the biological effects. Cytogenetic effects on plants after an exposure to ionizing radiation at low doses alone and in combination with other factors are discussed. A wide range of experimental data were analysed and the general conclusions were extracted to cover the topics such as non-linearity of dose response, synergistic and antagonistic effects of the combined exposure of different factors, radiation-induced genomic instability, and the phenomena of radioadaptation.

• ALGAE
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• 제31권4호
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• pp.403-414
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• 2016

The use of ionizing radiation and radioactive elements is becoming increasingly popular with the rapid developments in nuclear technology, radiotherapy, and radio diagnostic methods. However, ionizing radiation can directly or indirectly cause life-threatening complications such as cancer, radiation burns, and impaired immunity. Environmental contamination with radioactive elements and the depletion of ozone layer also contribute to the increased levels of radiation exposure. Radioprotective natural products have particularly received attention for their potential usefulness in counteracting radiation-induced damage because of their reduced toxicity compared with most drugs currently in use. Moreover, radioprotective substances are used as ingredients in cosmetic formulations in order to provide protection against ultraviolet radiation. Over the past few decades, the exploration of marine algae has revealed the presence of radioprotective phytochemicals, such as phlorotannins, polysaccharides, carotenoids and other compounds. With their promising radioprotective effects, marine algae could be a future source for discovering potential radioprotective substances for development as useful in therapeutics.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.1905-1907
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• 2014

Increasingly it is being realized that despite considerable advancements in therapeutic interventions related to treatment of cancer, satisfactory results are still difficult to achieve. Rapidly accumulating evidence has started to shed light on the fact that cancer cells escape from death via constitutive activation of pro-survival signaling cascades. Cell biology and genetics have extensively enhanced our current understanding of the molecular mechanisms that underlie loss of apoptosis in cancer cells. This review is focused on ionizing radiation mediated restoration of TRAIL mediated apoptosis as evidenced by cell culture and animal model studies. Moreover, we also bring to the limelight radiation induced expression of miRNAs and how miRNAs further control response of cancer cells to radiation.