• 한국의학물리학회지:의학물리
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• 제32권4호
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• pp.145-152
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• 2021

Purpose: During the treatments of cancer patients with a linear accelerator (LINAC) using photon beams with energies ≥8 MV, the components inside the LINAC head get activated through the interaction of photonuclear reaction (γ, n) and neutron capture (n, γ). We used spectroscopy and measured the dose rate for the LINAC in operation after the treatment ended. Methods: We performed spectroscopy and dose rate measurements for three units of LINACs with a portable high-purity Germanium (HPGe) detector and a survey meter. The spectra were obtained after the beams were turned off. Spectroscopy was conducted for 3,600 seconds, and the dose rate was measured three times. We identified the radionuclides for each LINAC. Results: According to gamma spectroscopy results, most of the nuclides were short-lived radionuclides with half-lives of 100 days, except for ⁶⁰Co, ⁶⁵Zn, and ¹⁸¹W nuclides. The dose rate for three LINACs obtained immediately in front of the crosshair was in the range of 0.113 to 0.129 µSv/h. The maximum and minimum dose rates measured on weekends were 0.097 µSv/h and 0.092 µSv/h, respectively. Compared with the differences in weekday data, there was no significant difference between the data measured on Saturday and Sunday. Conclusions: Most of the detected radionuclides had half-lives <100 days, and the dose rate decreased rapidly. For equipment that primarily used energies ≤10 MV, when the equipment was transferred after at least 10 minutes after shutting it down, it is expected that there will be little effect on the workers' exposure.

• Korean Journal of Radiology
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• 제21권1호
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• pp.68-76
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• 2020

Objective: To survey care providers' willingness to use 2-mSv computed tomography (CT) in their usual practice for adolescents and young adults with suspected appendicitis. Materials and Methods: An ethical committee approved this prospective study. We introduced 2-mSv CT in 20 hospitals through a pragmatic clinical trial. At the final phase of the trial, we invited 698 potentially-involved care providers in the survey regarding their willingness to use 2-mSv CT. Multivariable logistic regression analyses were performed to identify factors associated with willingness. Nine months after the completion of the trial patient recruitment, we surveyed whether the hospitals were using 2-mSv CT in usual practice. Results: The analyses included responses from 579 participants (203 attendings and 376 trainees; 221 radiologists, 196 emergency physicians, and 162 surgeons). Regarding the willingness to immediately change their standard practice to 2-mSv CT, 158 (27.3%), 375 (64.8%), and 46 (7.9%) participants responded as "yes" (consistently), "partly" (selectively), and "no", respectively. Willingness varied considerably across the hospitals, but only slightly across the participants' departments or job titles. Willingness was significantly associated with attendings (p = 0.004), intention to maintain the dedicated appendiceal CT protocol (p < 0.001), belief in compelling evidence on the carcinogenic risk of conventional-dose CT radiation (p = 0.028), and hospitals having more than 1000 beds (p = 0.031). Fourteen of the 20 hospitals kept using 2-mSv appendiceal CT in usual practice after the trial. Conclusion: Despite the extensive efforts over the years of this clinical trial, many care providers were willing to use 2-mSv CT selectively or not willing to use.

• 한국치위생학회지
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• 제4권1호
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• pp.49-64
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• 2004

This study is designed to conduct a questionnaire research into the safety control and the actual condition of radiography by working with dentistry belonging to university hospitals, dental hospitals and dental clinics for three months ranging from August, 2003 to October, 2003. The researcher came to the following conclusions. 1. The research on the current condition of possessed radiational equipment shows that 61.2 percent of the subjects had one intraoral radiation medicine and that 70.1 percent of the subjects had more than one extraoral radiation medicine and that 37.3 percent of the subjects had more than one digital radiation medicine. 2. Most of intraoral radiography (82.1%) was conducted by dental hygienists, and 7.5 percent of intraoral radiography was conducted by nurse aids. On the other hand, most of extraoral radiography (76.6%) was conducted by dental hygienists and digital radiography was conducted by dental hygienists(60.6%), dentists(32.0%) and radiographer(80.0%). 3. The less-than 1-meter-long distance between cone and the radiographer accounted for 44.8 percent. And the more-than 1.6-meter-long distance accounted for no more than 13.4 percent. The exposure time per standard film which was adjusted to each part accounted for 71.6 percent. Fixing the film on the part of healthy patients accounted for 76.1 percent. Fixing the film of elderly patients and children patients by the radiographer accounted for 43.3 percent. 4. The average daily photographing frequency of standard films stood at six to ten pieces(31.3%), and the average weekly photographing frequency of bitewing films stood at less than one piece(47.8%), and the dentistries where bitewing films were not employed accounted for 25.4%. The subjects whose average weekly photographing freqeuncy of occlusal films stood at less than a piece accounted for 59.7 percent. The dentistries whose average weekly photographing frequency of pediatric films stood at one to five pieces accounted for 41.8 percent. In case of panorama & cephalo, one to five pieces on a weekly average accounted for 36.2 percent. The dentistries whose average daily photographing frequency of digital radiation medicine stood at less than 1 piece accounted for 40.0 percent. 5. The research on the use of protective clothes shows that pregnant ·women only accounted for 31.3 percent. In regard to the use of protective clothes in case of the radiographers fixing films, the cases where no protective clothes were employed accounted for 88.1 percent. The reason was said to he attributable to the trouble related to wearing the clothes(54.2%). 6. The survey on the measurement of exposure dose shows that the cases where no measurement was made accounted for 76.1 percent. As far as the measurement methods of exposure dose was concerned, the employment of film badge accounted for 68.8 percent. The subjects turned out to conduct measurement of exposure dose every third month, which accounted for 43.8 percent. The barriers to the measurement of measurement of exposure dose were attributable to the recognition that a little amount of exposure dose need not be measured(29.9%). 7. The survey on the distinction of radiation rooms and clinic rooms reveals that the cases where radiation rooms exclusively existed accounted for 67.2 percent. 43.3 percent of the subjects turned out to have only one protective garment, and 49.3 percent of the subjects proved to conduct a periodical checkup of radiational equipment. The survey on the examination certificates of radiational generators and protective facilities indicates that 80.6 percent of the subjects had the certificates. The research also shows that the subjects with the marks indicating the radiational areas accounted for 70.1 percent. And trustees turned out to handle developing solutions and fixing solutions.

• 에너지공학
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• 제23권3호
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• pp.13-16
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• 2014

무기단결정을 광 펄스로 여기 한 격자에서 광학이나 음향포논을 이용하여 광 여기 반도체가 서브피코초로 관측하고 있다. 다수의 회절 점으로 결정구조를 파악하는 것으로써 광 여기에 의한 분자결정 구조변화를 관측하는 것이 보고되고 있고 또한 반응이 진행되고 있는 중에 분자구조를 하나하나 영상으로 관측하는 것이 연구되고 있다. 단백질 분자구조의 시간에 따른 변화와 용액 중 분자의 광반응에 따른 구조변화를 파악하고 있는데 이것은 시스템에 따라 펨토 초에서 초 단위까지 다양하고 광범위하게 고도의 시간분해능으로 계측할 수 있는 X선 측정기술이다.

• Journal of Radiation Protection and Research
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• 제45권1호
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• pp.26-34
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• 2020

Background: We examined changes in red ginseng components after different doses of irradiation were applied. We also evaluated what housewives and teachers know about irradiated food, as well as their perceptions of and attitudes toward it. Materials and Methods: General nutrients and unique components of irradiated ginseng were then analyzed. Education on irradiated foods and red ginseng was provided to teachers and housewives on two occasions, and changes in their behaviors were evaluated via a qualitative survey. Results and Discussion: The ideal radiation dose to reduce the number of bacteria without changing the unique components of red ginseng is 7.5 kGy. Notably, after educational seminars on this topic, consumers' knowledge, attitudes toward, and perceptions of irradiated ginseng compared to non-irradiated red ginseng changed significantly. Conclusion: It is necessary to provide consumers with information on irradiated foods to promote the growth of the domestic food industry, and to improve public knowledge of the safety and effects associated with the irradiation of food.

• 한국식품과학회지
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• 제34권6호
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• pp.1127-1129
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• 2002

국내에 유통되고 있는 시판 14개사 맥주 중의 biogenic amines의 함량을 조사하였다. 시판 국내 외산 맥주에서 검출된 biogenic amine은 putrescine, cadaverine, tryptamine, ${\beta}-phenylethylamine$, spermine 및 tyramine 등으로 총 6가지 종류가 검출되었으며, 각 제조회사에 따른 함량 차이를 보였다. 검출된 biogenic amines 중 모든 제품에서 SPM이 가장 높은 함량을 보였다. 국내산 맥주 중에는 CAD 및 PHE, 수입산 제품의 경우는 PHE 및 TYR의 함량이 제조사별 유의적 차이를 나타내지 않았다. 따라서 맥주의 화학적 안전성 확보를 위해 지속적인 함량조사가 필요하다.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.4142-4149
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• 2021

In the radiation protection application, the metal-polymer composites have been developed for their radiation shielding properties. In this research, the elastomer composites doped by 10 ㎛ and 100nm size of lead, bismuth and tungsten particles as filler with 30 and 60 wt percentages were prepared. To survey the shielding properties of the polymer composites using gamma-ray emitted from 152Eu and 137Cs sources, the gamma flux was measured by using NaI(Tl) detector, then the linear attenuation coefficient was calculated. Also, the Monte Carlo simulation (MCs) method was used. The results showed a direct relationship between the linear attenuation coefficients of the absorbent and filler ratio. Also, the decrease in the particle size of the shielding material in each weight percentage improved the radiation shielding features. When the dimension of the particles was in the order of nano-size, more attenuation was achieved. At low energies used for medical diagnostic X-ray applications due to the predominance of the photoelectric effect, bismuth and lead were suitable selection as filler.

• 보건의료산업학회지
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• 제13권3호
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• pp.137-147
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• 2019

Objectives: This study aimed to identify the relationship between thoughts and psychological anxiety about nuclear power among Busan residents. Methods: Convenience sampling was used for this cross-sectional survey conducted from February 13 to 14, 2016. A total of 520 residents participated in the study and completed a self-administered questionnaire. Results: We found a significant association between negative thoughts and psychological anxiety about nuclear power. People older than 60 years (odds ratio (OR) 2.53, 95% confidence interval (CI) 1.41-4.54), who feared the possibility of radiation accidents (OR 1.75, 95% CI 1.17-2.62), considered nuclear power plants unsafe (OR 1.94, 95% CI 1.10-3.40), and believed the Gori nuclear power plant in Busan must be shut down (OR 1.84, 95% CI 1.22-2.79), had the highest anxiety about radiation exposure. Conclusions: The authors suggest the need for the formulation of a policy to provide people with precise information on nuclear power to increase their understanding and help eliminate unfounded negative thoughts. Furthermore, policy decisions about nuclear power must be based on social consensus.

• 대한방사선기술학회지:방사선기술과학
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• 제43권6호
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• pp.519-524
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• 2020

This study developed radiation therapy contents based on virtual reality technology and applied them to radiation students. A survey was conducted to analyze the relationship between learning effects and learning satisfaction to students who used virtual reality education videos to analyze their learning performance. 71 students radiology department were classified into two groups one that experienced virtual reality and the other that did not experienced virtual reality. We surveyed between the two groups analyzed self-directed learning, self-learning efficacy and learning satisfaction. As a result, the comparison between the two groups showed no difference between self-directed learning and self-learning efficacy. But the learning satisfaction was significant from 2.64±0.83 to 3.20±0.88 in the problem solving process for groups applying virtual reality contents. Therefore, learning satisfaction has improved experienced group virtual reality content and the materials for virtual reality education can be applied more efficiently in non-face-to-face lectures.

• 대한방사선기술학회지:방사선기술과학
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• 제44권6호
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• pp.679-688
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• 2021

This study is a questionnaire about the lesson environment that radiation major students prefer in a non-face-to-face live online lesson environment for a total of 133 students, 65 second graders and 68 third graders who are enrolled in the department of radiology at a university located in the Seoul metropolitan area. And checked the satisfactory level by grade. The questionnaire consists of three categories: 1st real-time non-face-to-face lectures, 2nd professor lectures, and 3rd corona lectures. A total of 14 questions, with multiple choice and descriptive response methods. As an evaluation method, in the case of a multiple-choice question, the average was calculated using a 5-point Likert scale. As a result of conducting the independent sample T-test of the SPSS program, the response by grade was P > 0.05, and no significant result was shown by the contents of the questionnaire survey of the second grade. As for the lecture method of the department of radiology after the end of Covid-19 virus, it is better to promote face-to-face lessons in radiation training subjects and non-face-to-face real-time education in subjects centered on radiation theory.