• Journal of Radiation Protection and Research
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• v.22 no.1
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• pp.1-7
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• 1997

Radiation protection by post-irradiation injection of the ginseng extract in mice was studied. Male ICR mice, 7 weeks old, were orally injected with ginseng extrat(100mg/kg) for 10 days, and with physiologocal saline as the control. Immediately after final injection, mice were whole body irradiated with 5.08Gy(Cs-137 ${\gamma}$-ray, central dose rate : 654Gy/h) which induced Bone marrow death. At 24h after irradiation, micronucleus test and metaphase analysis in bone-marrow were carried, blood cell were counted and the survival rate were carried for 30 days after the irradiation. Stimulated recovery by the extract was observed in thrombocyte count, but that phenomenom was not showed in the erythrocyte and leucocyte counts. The 30-day survival ratio was 5% and 65% for the control and experimental group. Frequencies of micronuclei per 1000 polychromatic erythrocytes were 79.5${\pm}$1.5 in experimental group, 185.9${\pm}$35.8 in control. And Abnormal chromosomes per 50 metaphases were 112 in experimental group and 143 in control.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.93-102
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• 2010

Recently, FRP usage for strengthening RC structures in civil engineering has been increasing. Especially, the use of FRP to strengthen structures against blast loading is growing rapidly. To estimate FRP retrofitting effect under blast loading, blast tests with nine $1,000{\times}1,000{\times}150\;mm$ RC panel specimens, which were retrofitted with carbon fiber reinforced polymer (CFRP), Polyurea, CFRP with Poly-urea and basalt fiber reinforced polymer (BFRP) have been carried out. The applied blast load was generated by the detonation of 15.88 kg ANFO explosive charge at 1.5 m standoff distance. The data acquisitions not only included blast waves of incident pressure, reflected pressure, and impulse, but also included central deflection and strains at steel, concrete, and FRP surfaces. The failure mode of each specimen was observed and compared with a control specimen. From the test results, the blast resistance of each retrofit material was determined. The test results of each retrofit material will provide the basic information for preliminary selection of retrofit material to achieve the target retrofit performance and protection level.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.35-42
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• 2003

Methodology for calculating the organ equivalent doses and the effective doses of pediatric and adult patients undergoing medical X-ray examinations were established. The MIRD-type mathematical phantoms of 4 age groups were constructed with addition of the esophagus to the same phantoms. Two typical examination procedures, chest PA and abdomen AP, were simulated for the pediatric patients as well as the adult as illustrative examples. The results confirmed that patients pick up approximate 0.03 mSv of effective dose from a single chest PA examination, and 0.4 to 1.7 mSv from an abdomen AP examination depending on the ages. For dose calculations where irradiation is made with a limited field, the details of the position, size and shape of the organs and the organ depth from the entrance surface considerably affect the resulting doses. Therefore, it is important to optimize radiation protection by control of X-ray properties and beam examination field. The calculation result, provided in this study, can be used to implement optimization for medical radiation protection.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.18-24
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• 2008

This paper presents the stress and deformation behaviors of 9% nickel steel inner tank in a full containment LNG storage tank using a FE analysis. For an increased strength safety of an inner tank, the tension cable was fastened around the outside wall of an inner tank, which is known as a weak zone for the hydrostatic pressures, cryogenic temperature loads, and other loadings. Based on the FEM computed results between a conventional inner tank and a inner tank with tension cables around the lower part of the side wall of an inner tank, the redesigned inner tank is more safe than that of the conventional tank without a tension cable. The FEM results recommend $3{\sim}4$ steel tension cables with a diameter of 50mm for an increased strength safety of the inner tank, which may decrease the stress concentration and deformation near the lower part of the side wall. Thus the tension cable around the inner tank may be used as an alternative safety device compared to the stiffener and the top girder structures for the increased LNG storage tank, especially.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.860-868
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• 2013

The purpose of this study is to ensure safety by measuring External radiation dose ratio (ERDR) by traits of patients in many ways after administering radiopharmaceutical($^{18}F$-FDG) for PET Torso scan, and to decrease ERDR of those to RI technologist, caretakers, and those who frequently exposed to radiation by arousing attention to radiation dose. Radiopharmaceutical was administered to 80 patients who conducted PET Torso from January to June, 2013. Radiation dose emitted from the patients was measured according to body shape(BMI), water hydration, height, amount of radiation administration. From the moment immediately after the radiopharmaceutical was administered, ERDR was measured by personal traits of patients. The radiation dose increased in proportion to the administered amount of the radiopharmaceutical, and there was no significant difference depending on the body shape of the patients. When water was supplied and the height was normal, the radiation dose was lower compared with the cases where water was not supplied and height was not normal. There is a need for making efforts to minimize the working time through sufficient education and mock training before those who RI technologist with sources of radiation for complying the radiation safety management rule. And they should minimize the ERDR by wearing a protective gear.

• Journal of the Korean Society of Radiology
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• v.5 no.5
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• pp.303-308
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• 2011

Background/Aims : The increasing use of diagnostic and therapeutic interventional radiology calls for greater consideration of radiation exposure risk to radiologist and radiological technician, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a protective grass shield. Methods : A protective grass was following data depth, 0.8 cm; width, 100 cm; length, 100 cm, lead equivalent, 1.6 mmPb. The protective shield was located between the patient and the radiologist. Thirty patients (13 male and 17 female) undergoing interventional radiology between September 2010 and December 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective grass shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. Results : The mean patient age was 69 years. The mean patient height and weight was $159.7{\pm}6.7$ cm and $60.3{\pm}5.9$ kg, respectively. The mean body mass index (BMI) was $20.5{\pm}3.0$ kg/m2. radiologists received $1530.2{\pm}550.0$ mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to $50.3{\pm}85.2$ mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to radiologist and radiological technician was significantly reduced by the use of a protective lead shield (p value <0.0001). The amount of radiation exposure during interventional radiology was related to the patient' BMI (r=0.749, p=0.001). Conclusions : This protective shield grass is effective in protecting radiologist and radiological technician from radiation exposure.

• Journal of radiological science and technology
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• v.27 no.3
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• pp.43-50
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• 2004

The effects of ginseng extracts on liver damage induced by high energy x-ray were studied. To one group of ICR male mice were given white(50 mg/kg/day for 7 days, orally) and fermenta ginseng extracts(500 mg/kg/day for 7 days, orally)before irrdiation. To another group were irradiated by 5 Gy dose of high energy x-ray. Contrast group were given with saline(0.1 ml). This study also investigated the effect between MDA, protein content and ginseng extracts on hepatic damage. This study measured the level of MDA(malondialdehyde), protein content in liver tissue. Administrating orally white (50 mg/kg/day for 7 days, orally)and fermenta ginseng extracts(500 mg/kg/day), the level of MDA were generally decreased and the inhibition was increased. And the protein contents were identical with control group. After irradiation, the protein contents were increased and MDA(malondialdehyde) was increased. Therefore, ginseng extracts increased antioxidative enzyme activity. And We know that the antioxidatant effect of extracts from white and fermenta ginseng protect radiation damage by direct antioxidant effect involving SOD, CAT, GPX. It was included that ginsengs can protect against the lipid peroxidation in radiation damage through its antioxidatant properties.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.395-410
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• 2023

Purpose: The purpose of this study was to analyze the current state of drone terrorism response at such critical national facilities and derive improvements, especially to identify problems in laws and systems to effectively utilize the anti-drone system and present directions for improvement. Method: A qualitative research method was used for this study by analyzing a variety of issues not discussed in existing research papers and policy documents through in-depth interviews with subject matter experts. In-depth interviews were conducted based on 12 semi-structured interviews by selecting 16 experts in the field of anti-drone and terrorism in Korea. The interview contents were recorded with the prior consent of the study participants, transcribed back to the Korean file, and problems and improvement measures were derived through coding. For this, the threats and types were analyzed based on the cases of drone terrorism occurring abroad and measures to establish anti-drone system were researched from the perspective of laws and systems by evaluating the possibility of drone terrorism in the Republic of Korea. Result: As a result of the study, improvements to some of the problems that need to be preceded in order to effectively respond to drone terrorism at critical national facilities in the Republic of Korea, have been identified. First, terminologies related to critical national facilities and drone terrorism should be clearly defined and reflected in the Integrated Defense Act and the Terrorism Prevention Act. Second, the current concept of protection of critical national facilities should evolve from the current ground-oriented protection to a three-dimensional protection concept that considers air threats and the Integrated Defense Act should reflect a plan to effectively install the anti-drone system that can materialize the concept. Third, a special law against flying over critical national facilities should be enacted. To this end, legislation should be enacted to expand designated facilities subject to flight restrictions while minimizing the range of no fly zone, but the law should be revised so that the two wings of "drone industry development" and "protection of critical national facilities" can develop in a balanced manner. Fourth, illegal flight response system and related systems should be improved and reestablished. For example, it is necessary to prepare a unified manual for general matters, but thorough preparation should be made by customizing it according to the characteristics of each facility, expanding professional manpower, and enhancing response training. Conclusion: The focus of this study is to present directions for policy and technology development to establish an anti-drone system that can effectively respond to drone terrorism and illegal drones at critical national facilities going forward.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.444-455
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• 2019

The purpose of this research was to analyze technological trends of 「Military Small Giant Venture Tech-Fi Net」 from Defense Technology Information Service via social network analysis. 「Military Small Giant Venture Tech-Fi Net」, which was constituted for their fine technology for application to the military field, registered 847 technologies of 388 companies. In this research, we analyzed 847 technologies for the relations between "Military System" and "Military Technology Category" via centrality measurement, one of the social network analysis methods. The results indicate that the major technologies of domestic military small giant venture companies were "Sensor" and "ICT" for "C4I System" and "Surveillance and Reconnaissance System" and "Platform/Structure" for "Land System", "Aeronautical System" and "Naval Sea System". In contrast, we recognized inadequate technologies, such as "Propellant" and "Material" for "Missile and Ammunition system" and "Sensor" and "ICT" for "Defense System", We hope that our results and method will be conducive to the technological development of Small Giant Venture companies.

• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.96-102
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• 2012

International Commission on Radiological Protection (ICRP) has revised its recommendations concerning the tissue reaction to ionizing radiation in accordance with consideration of the detriment arising from non-cancer effects of radiation on health based on recent epidemiological basis. Particularly, for the lens of the eye, the threshold in absorbed dose revised to be 0.5 Gy, for occupational exposure in planned exposure situation the commission recommended "An equivalent dose limit for the lens of the eye of 20 mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv." To monitor the radiation exposure of radiation worker, TLD is typically provided and the lens of eye dose can be assessed by run of dose calculation algorithm with TL element response data. This study is to assess equivalent dose of the lens of eye using the Harshaw TLD system and its two different dose calculation algorithms. The result provides the Harshaw TLD system showed the assessment of the lens of eye dose with 48.84% error range.