• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.845-853
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• 2014

In this study, we measured the dose reaching the OSLD dosimeter by using the regular lead apron, and air gap apron through 3 experiments, and researched the reductive effect of air gap apron on exposure dose based on the 140 keV gamma ray radiating from $^{99m}technetium$, which is the most commonly used in nuclear medicine. As a result, when the gap between the dosimeter and 0.2mm lead plate is 0 Cm, the average value of 10 dosimeters was 0.515 mSv, and when the gap between the dosimeter and lead plate is 20 Cm, the average value of 10 dosimeters was 0.138 mSv, which shows reductive effect of dose as much as 0.388 mSv. When the gap between the dosimeter and 0.5mm lead plate is 0 Cm, the average value of 10 dosimeters was 0.296 mSv, and when the gap between the dosimeter and lead plate is 20 Cm, the average value of 10 dosimeters was 0.075 mSv, which shows reductive effect of dose as much as 0.221 mSv. As we check the cumulative dosage for 3 days, the lead apron without air layer shows average 0.239 mSv, and the air gap apron shows 0.176 mSv, which is actually reduced by 0.062 mSv. As we check the cumulative dosage for a month, the lead apron without air layer shows 0.59 mSv, and the air gap apron shows 0.54 mSv, which is reduced by 0.05 mSv.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.441-445
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• 2012

X-ray Chest P-A is very important and basic diagnosis examination for pregnant women. For a pregnancy period pregnant women should be treated very carefully not to be exposed to any radiation which might cause harmful damage to women and babies as well. Lead apron is one of the effective methods to protect pregnant women from the X-ray radiation. However, it is difficult to obtain the accurate position of pregnant women during X-ray Chest P-A since conventional lead apron method forces pregnant women to hold the apron by themselves only to make pregnant women very uncomfortable and hard to maintain accurate position during radiation. As a consequence, it is common to get low quality images of X-ray Chest P-A due to the overlap of apex of lung and scapular. In order to fix this problem, we made new design lead apron that allowed pregnant women to be more comfortable to maintain accurate position during X-ray Chest P-A position. Finally, with this new design lead apron, it was possible to get the best optimized images of X-ray Chest P-A of pregnant women by minimizing overlapping apex of lung and scapular.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.247-252
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• 2014

The medical institution has been used electromagnetic radiation of various energy. But researchers are divided on whether using apron for radiation shielding will be effective or not. The purpose of present study was to analyze electromagnetic radiation shielding effect of apron by using Monte carlo simulation. 1 MBq electromagnetic radiation was emitted from 10-500 keV at 10 keV increments in Monte carlo simulation. Then shielded radiation dose difference was confirmed, when 0.25 mmPb shield use for shielding. As a results, shielding ratio was markedly decreased in high energy electromagnetic radiation. The radiation dose was inversely increased with 0.25 mmPb shielding.

• Journal of radiological science and technology
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• v.37 no.2
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• pp.143-150
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• 2014

This study was designated to investigate the bremsstrahlung and radiation dose by beta rays. Radiation attenuation from I-131 treatment ward was analyzed using radio protective apron. Shielding materials which is included lead or water were simulated in Monte Carlo Simulation then the spectrum on interaction was analyzed. The shielding materials were categorized according to the thickness. 0.25mm and 0.5mm thick lead and 0.1mm and 0.2mm thick water shielding materials were configured in Monte Carlo Simulation for this study. Only lead shielding method and water plus lead shielding method were carried. As a results, when 0.5mm thick lead shielding method was performed, the radiation dose was similar to the results with water plus lead shielding method. In case of using 0.25mm thick lead shielding, the shielding effect was somewhat less. However, that shielding method cause dose reduction of about 60% compare with non-shielding material.

• Progress in Medical Physics
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• v.26 no.2
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• pp.93-98
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• 2015

The purpose of this study is to see the usefulness of lead apron for critical organs near the breast under examining. For clinical experiment, 30 female volunteers who agreed to their participation in the experiments, were chosen and divided into two groups, 15 in group A and 15 in group B respectively. group A is to see whether each side of breast under mammography affects to other side glandular on the critical organs is same, because it is not allowed to scan the both breast for same person or to scan repeatedly. Group B is to see the effectiveness of lead apron during the mammography of right breast. Glass dosimeters were placed on the thyroid, the contralateral breast, and lower abdomen where near the breast during examining. The average glandular doses on the surface in mammography of the thyroid gland, the contralateral breast, the lower abdomen were 0.0692 mGy, 0.6790 mGy, and 0.0122 mGy, respectively, which was an extremely low level of glandular dose. In group B, as to the thyroid gland, average dose was decreased from 0.0922 mGy to 0.0158 mGy. The average dose of contralateral breast was decreased from 0.8575 mGy to 0.0286 mGy. The average doses of lower abdomen was decrease 0.0150 mGy to 0.0173 mGy. As to the lower abdomen, dose decreased from 0.0150 mGy before the use of an apron down to 0.0173 mGy after the use. As p-value was under 0.05, statistically significant difference was observed between the two groups. Wearing an apron can have the protective effects on the thyroid gland up to 20 times lower than not wearing one. Besides, it is also necessary to protect the other breast during the examination by wearing one.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.213-217
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• 2014

Medical operations and diagnosis using interventional radiology techniques have been increased. The management and monitoring of occupational radiation exposure to the staff of interventional radiology become important, specially because they stand in close proximity to the patient. The operational radiation protection quantity, Hp(10) which can be obtained from personal dosimeter do not always represent the effective dose to the staff. So, in this study, to estimate the critical organ doses to the staff of interventional radiology, Monte Carlo calculations with mathematical human phantom and dose measurements with personal dosimeters were carried out for the major interventional radiology procedures using C-arm. Results showed that the values of Hp(10) measured by personal dosimeters were higher than critical organ doses which were calculated. And the calculated dose to thyroids was much higher than those of other critical organ doses. For the proper radiation protection of the medical staff of interventional radiology, additional radiation protection for thyroids as well as for whole body shielding like wearing a lead apron should be considered.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.547-553
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• 2017

In the current medical field, lead is widely used as a radiation shield. However, the lead weight is very heavy, so wearing protective clothing such as apron is difficult to wear for long periods of time and there is a problem with the danger of lethal toxicity in humans. Recently, many studies have been conducted to develop substitute materials of lead to resolve these problems. As a substitute materials for lead, barium(Ba) and iodine(I) have excellent shielding ability. But, It has characteristics emitting characteristic X-rays from the energy area near 30 keV. For patients or radiation workers, shielding materials is often made into contact with the human body. Therefore, the characteristic X-rays generated by the shielding material are directly exposured in the human body, which increases the risk of increasing radiation absorbed dose. In this study, we have developed the FLUKA transport code, one of the most suitable elements of radiation transport codes, to remove the characteristic X-rays generated by barium or iodine. We have verified the reliability of the shielding fraction of the structure of the structure shielding by comparing with the MCPDX simulations conducted as a prior study. Using the MCNPX and FLUKA, the double layer shielding structures with the various thickness combination consisting of barium sulphate ($BaSO_4$) and bismuth oxide($Bi_2O_3$) are designed. The accuracy of the type shown in IEC 61331-1 was geometrically identical to the simulation. In addition, the transmission spectrum and absorbed dose of the shielding material for the successive x-rays of 120 kVp spectra were compared with lead. In results, $0.3mm-BaSO_4/0.3mm-Bi_2O_3$ and $0.1mm-BaSO_4/0.5mm-Bi_2O_3$ structures have been absorbed in both 33 keV and 37 keV characteristic X-rays. In addition, for high-energy X-rays greater than 90 keV, the shielding efficiency was shown close to lead. Also, the transport code of the FLUKA's photon transport code was showed cut-off on low-energy X-rays(below 33keV) and is limited to computerized X-rays of the low-energy X-rays. But, In high-energy areas above 40 keV, the relative error with MCNPX was found to be highly reliable within 6 %.

• Korean Security Journal
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• no.51
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• pp.81-100
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• 2017

Recently, Crime patterns in our society are diversifying as followed on the urbanization of population and the influx of immgrants. Existing murder, kidnap, sexual assault, etc. Especially, the crimes such as school violence, dating violence, domestic violence, violent abuse and even social hatred a crime, motiveless crime are spreading into every phase of national life. Due to the social situation, the sharp increase in demand for personal protection, the scale of private security industry has been constantly expanded. Following this trend, the personal protective regulations in Security Industry Act has been revised several times since the it was enacted in 1995. However, despite the fact that the legal and institutional aspects should have been amended and improved systematically according to the industrial development, the regulations adopted initially adopted has been maintained so far, which have resulted in various problems as they could not coincide with the purpose of private security, being divorced from the reality of private security industry and social changes. Especially, in the case of personal protection service and facility security service, the legal requirements of both services are identical with each other in terms. Such legal systems may cause confusion to security businesses and employees, or the police managing and supervising them, regarding the scope and duties of security services. In order to improve such problems, the regulations of permission requirement that the personal protective regulations in Security Industry Act should be revised system. In this study, relevant personal protection provisions prescribed in the Security Industry Act have been reviewed critically in this paper. And also the regulations were review of those personal protection provisions enacted in security industry Act, so that the improvement plan for the personal protection provisions that are apposite to the cases in this country could be suggested in order to amend the current laws and provide real grounds for the law enforcement.

• Sim-seong Yeon-gu
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• v.31 no.1
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• pp.41-94
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• 2016

A Korean fairy tale "The uproot of an archenemy in the underworld" is discussed and interpreted from the perspective of analytical psychology. The essence of the story is as follows; When the three princesses were kidnapped by an archenemy in the underworld, a warrior appeared to save the princesses. He went to the underworld and killed the archenemy with the princesses help. When they tried to come back to the castle, he had difficulties because king's soldiers betrayed him. But a old wise man and a flying horse helped him to come back to the castle. He killed the soldiers that betrayed him and married one of the princesses and got the wealth from the underworld. The kingdom could be prosperous and peace because of the marriage. The psychological meaning of the three princesses were taken by the archenemy is that the archetypal shadow appeared from the unconscious and grasped a part of consciousness and repressed it in unconsciousness. This status could be called the lost of soul. So the warrior ego went through an unconscious trip, saving his anima from the archetypal shadow, and taking her back to consciousness and renewing the collective consciousness. The ego's trip is the individuation process like Shaman in primitive society. This fairy tale has hero motif. It reveals the feature of archetypal shadow. It also shows us man can make conscious with cautious attitude in the individuation process.