• International Journal of Oral Biology
• /
• 제46권4호
• /
• pp.168-175
• /
• 2021

To investigate the perceptions and attitudes of dental hygienists toward radiation safety management in Korea. A total of 800 dental hygienists were randomly selected for an anonymous survey, and 203 of them participated. The questionnaire items included the following: sex, career period, type of installed radiographic equipment, recognition of the diagnostic reference level (DRL), participation in radiation safety education, and attitudes toward radiation protection for both patients and dental hygienists. The participants were divided into two groups according to their years of experience (< 10 years versus ≥ 10 years). The difference between the groups was investigated according to frequency distribution. Fisher's exact test or Pearson's chi-square (𝛘²) test was used as appropriate. A regression analysis was performed to investigate the impact of wearing a thyroid collar for personnel protection during patient radiation exposure. The types of installed radiographic equipment included panoramic radiography (96.1%), cephalometric radiography (76.9%), intraoral radiography (72.9%), and cone-beam computed tomography (69.5%). Significant differences were observed in the learning pathway for the DRL (Fisher's exact test, p < 0.05), satisfaction with radiation safety education (Pearson's 𝛘² test = 5.3975, Pr = 0.02), and use of personnel radiation monitoring systems (Pearson's 𝛘² test = 18.1233, Pr = 0.000) between the groups. Significant differences were also observed in personnel protection using a thyroid collar and patient protection during panoramic radiography (odds ratio = 14.2). Dental hygienists with more than 10 years of experience were more satisfied with radiation safety education and more interested in radiation monitoring. Considering career experience, customized, continuous, and effective radiation safety management education should be provided.

• 대한방사선치료학회지
• /
• 제13권1호
• /
• pp.75-90
• /
• 2001

Although it is presumed that cancer patients take various alternative therapies, the present status is not well recognized. The purpose of this study is to survey alternative therapies used by cancer patients receiving radiation therapy and then, find associated factors of taking alternative therapies. The study subjects were composed of those who receiving radiation therapy in the department of radiation oncology in 5 hospitals located at Extended Busan city and who were on follow-up after medical cure. They were 394 male and female patients over 20 years old. The mean age of the subjects was 53.2 years old and the age ranged from 23 to 83 years old. 188 patients($47.7\%$) used alternative therapies. Total 68 different kinds of alterative therapies were used, average 7.3 kinds per patient were experienced, and average total cost expenditure was 2,830,000 won. Among the alternative therapies, black bean($38.8\%$) was the most commonly used and brown rice($38.3\%$), ganoderm lucidum($37.8\%$), elm tree($33.5\%$), and phellinus linteus($30.8\%$) were followed in order of frequency. However in considering the time, cost and effort spent, phellinus linteus was the first. In terms of cost, phellinus linteus was the highest with average expenditure of 2,740,000 won. Among the motivation of using alternative therapies, expecting auxiliary help for the hospital therapy was the highest ($31.4\%$). About half of users($56.9\%$) of alternative therapies were recommended by their relatives to use alternative therapies. In comparing the characteristics of experienced and unexperienced groups, alternative therapy was experienced significantly more in patients of younger age(p=0.001), in patient of higher educational level(p=0.001), and in patients of higher income(p=0.030) The proportion of using alternative therapies was significantly higher in the group treated with chemotherapy(p=0.005), and in the patients who did not satisfy with radiation therapy(p=0.001). The frequency of drinking was significantly higher tendency in the inexperienced group(p=0.046), There was no significant difference in marital status, job, religion, other disease, surgical operation of the cancer and smoking staus between the two groups. Among the unexperienced group, $34.0\%$ of the patients did not take the alternative therapies because they did not have know]edge for the alternatives, and $22.3\%$ worried about negative effects on hospital-based therapy $58.7\%$ of them were willing to take the alternative therapies if the effects and safety were proven by the government or research institutes. $21.9\%$ of the patients wanted to take the alternatives if they were affordable. $72.3\%$ of the patients was willing to take them if their families recommend, but $27.2\%$ responded they would not take them in any situation. Conclusively, various kinds of alternative therapies which were not proved medically were exposed to patients, In these circumstances, it is required to investigate, study and evaluate the medical effects and safety of the alternative therapies.

• 한국방사선학회논문지
• /
• 제16권6호
• /
• pp.741-749
• /
• 2022

산업체에서 용접구조물을 파괴 없이 품질을 검증하는 방사선투과검사는 압도적으로 많이 이용되지만, 방사선을 이용함에 따라 많은 안전사항이 요구된다. 방사선투과검사 작업종사자는 검사부재의 이동유무에 따라 감마선조사기인 운반용기에 내장된 Iridium-192 방사선원을 사용시설 내 혹은 사용시설 외의 장소에서 이동시켜 작업을 수행 한다. 일반적인 사용시설은 두꺼운 콘크리트로 외부와 방사선을 전면 차단한 시설이지만, 검사부재의 취급이 용이하지 않은 등의 사유로 천장이 개방된 사용시설이 있다. 일반적인 사용시설은 외부가 모두 차단되어 이론적인 선량 평가 방법을 통하여 건설하여도 무방하지만, 천장이 개방된 경우 스카이샤인효과로 인하여 단순 이론적인 계산 방법으로 방사선 안전성을 평가하는 것은 적합하지 않다. 따라서 본 연구에서는 실제 현장에서 해당 시설의 방사선 안전성을 이온챔버형 방사선측정기와 누적선량계형인 OSLD를 통하여 평가하고, 실제 평가 환경을 몬테카를로 시뮬레이션 코드인 플루카를 이용하여 모델링 및 평가를 하였다. 해당 시설에서 조사방향에 따라 시설 경계의 방사선량은 규제기관에서 정하는 기준을 만족하기 어려웠고, 추가의 방법을 통하여 방사선 안전성을 확보할 수 있었다. 또한, Iridium-192 선원을 이용한 시뮬레이션 결과가 실제 측정값과 유효한 결과임을 확인할 수 있었다.

• 치과방사선
• /
• 제10권1호
• /
• pp.57-61
• /
• 1980

In dental roentgenograph it is of mutual benefit to the patient and the dentist to use the minimum amount of radiation capable of producing roentgenograms with maximum interprtive informations. Recent increases in the number of diagnostic x-ray examinations made in this country have caused attention to be paid to the quantity of radiation delivered to the population and operator. The purposes of this study was to assess the quality of dental x-ray units, the amount of films, the average processing procedures and the radiation protection methods in korea. The results were as following: 1. Most of radiation generating system were used in low voltage such as 60Kvp, 10㎃. 2. High sensitivity films such as 'D' group of Kodak or Rinn were mainly used and average 14.7 films used per weeks. 3. Some dentists practiced visual processing technic in simple dark room, and others used instant films. 4. 68.26% of patient held the film themselves, but 27.30% were assisted by dentists film holding. 5. In radiation protection method, 7.85% of dentists had protection equipments such as protective barrier, 2.73% wore protective apron, 27.9% made it a rules to avoid beam, and 7.51% used to maintain a distance from the radiation source.

• Nuclear Engineering and Technology
• /
• 제49권8호
• /
• pp.1589-1599
• /
• 2017

Field programmable gate arrays (FPGAs) are getting more attention in safety-related and safety-critical application development of nuclear power plant instrumentation and control systems. The high logic density and advancements in architectural features make static random access memory (SRAM)-based FPGAs suitable for complex design implementations. Devices deployed in the nuclear environment face radiation particle strike that causes transient and permanent failures. The major reasons for failures are total ionization dose effects, displacement damage dose effects, and single event effects. Different from the case of space applications, soft errors are the major concern in terrestrial applications. In this article, a review of radiation effects on FPGAs is presented, especially soft errors in SRAM-based FPGAs. Single event upset (SEU) shows a high probability of error in the dependable application development in FPGAs. This survey covers the main sources of radiation and its effects on FPGAs, with emphasis on SEUs as well as on the measurement of radiation upset sensitivity and irradiation experimental results at various facilities. This article also presents a comparison between the major SEU mitigation techniques in the configuration memory and user logics of SRAM-based FPGAs.

• 한국수자원학회논문집
• /
• 제46권3호
• /
• pp.301-314
• /
• 2013

기후변화로 야기될 수 있는 태양복사에너지의 공간적인 불균형은 수자원을 포함한 전반적인 생태 시스템에서의 에너지 불균형을 초래한다. 따라서 정확한 에너지의 흐름을 이해하기 위하여 정량적인 관측을 목적으로 하는 플럭스 타워가 세계 곳곳에 설치되어 운영되고 있다. 국내의 주역에서도 플럭스 타워를 통안 관측이 실시되고 있는 데, 본 연구에서는 이 중 설마천과 청미천 유역의 플럭스 타워의 자료를 대상으로 수문기상 및 생태학적으로 중요한 역할을 하는 에너지원인 하향 단파 및 장파 복사량과 순복사량을 기존의 연구에서 제안된 물리식을 기반으로 계산하고, 산정된 순복사량과 관측 자료를 비교 검증하였다. 이를 통하여 관측이 미흡한 수문기상인자에 대해 기존의 물리적인 방법의 사용 가능성 및 관측 자료의 활용 가능성을 확인하였다.

• The Korean Journal of Pain
• /
• 제26권2호
• /
• pp.142-147
• /
• 2013

Background: Medical doctors who perform C-arm fluoroscopy-guided procedures are exposed to X-ray radiation. Therefore, radiation-protective shields are recommended to protect these doctors from radiation. For the past several years, these protective shields have sometimes been used without regular inspection. The aim of this study was to investigate the degree of damage to radiation-protective shields in the operating room. Methods: This study investigated 98 radiation-protective shields in the operation rooms of Konkuk University Medical Center and Jeju National University Hospital. We examined whether these shields were damaged or not with the unaided eye and by fluoroscopy. Results: There were seventy-one aprons and twenty-seven thyroid protectors in the two university hospitals. Fourteen aprons (19.7%) were damaged, whereas no thyroid protectors (0%) were. Of the twenty-six aprons, which have been used since 2005, eleven (42.3%) were damaged. Of the ten aprons, which have been used since 2008, none (0%) was damaged. Of the twenty-three aprons that have been used since 2009, two (8.7%) of them were damaged. Of the eight aprons used since 2010, one (12.3%) was damaged. Of the four aprons used since 2011, none (0%) of them were damaged. The most common site of damage to the radiation-protective shields was at the waist of the aprons (51%). Conclusions: As a result, aprons that have been used for a long period of time can have a higher risk of damage. Radiation-protective shields should be inspected regularly and exchanged for new products for the safety of medical workers.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.807-814
• /
• 2004

Land seismic reflection survey has been increasingly demanded in various civil engineering works because of its own ability to delineate layers, water table, to detect cavities or fracture zones, to estimate seismic velocities of each layer. However, our shallow subsurface structures are very complex. The relatively thin layer(mostly soil) to the wavelength directly followed by a basic rock with high impedance used to generate complicated surface waves, kind of channel waves with high amplitude that is dominate in entire seismograms and hence the useful reflection events will be almost hopelessly immersed in the undesired surface waves. Thus, it would seem that the use of traditional seismic survey could not be likely to provide in itself a satisfactory information about our exploration targets. This paper hence introduces an efficient measuring strategy illustrating a properly controlled arrangement of the vertical single force sources commonly used, yielding a very sharply elongated form of P-energy with a minimum of S radiation energy, what we call, P-beam source. Abundant experiments of physical modeling showed that in that way the surface waves could be enormously reduced and the reflection events would be additive and thus reinforced. Examples of field data are also illustrated. The contribution of P-beam source will be great in civil engineering area as well as in general geological exploration area.

• 방사성폐기물학회지
• /
• 제21권1호
• /
• pp.95-114
• /
• 2023

During the decades after the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, ambient dose rates have markedly decreased when compared to those at the early state of the accident. Government projects have been continuously conducted by surveying the ambient dose rate and radiocesium distributions. Airborne surveys using crewed helicopters and unmanned aerial vehicles (UAVs) are the best methods for obtaining an overall picture of the distribution. However, ground-based surveys are required for accurate measurements near the population. The differences between these methods include the knowledge of the post depositional behavior of radionuclides in land use. The survey results form the basis for policy decisions such as lifting evacuation zones, decontamination, and other countermeasures. These surveys contain crucial findings regarding post-accident responses. This paper reviews the survey methods of government projects and current situation around the FDNPS. The visualization methods and databases of ambient dose rates are also reviewed to provide information to the population.

• 한국의학물리학회지:의학물리
• /
• 제21권2호
• /
• pp.223-231
• /
• 2010

국내 개설된 방사선종양학과 중 선형가속기 및 근접치료기기가 설치되어 환자치료를 시행하고 있는 총 72개 기관에 대해 설문을 수행하였다. 설문은 선형가속기, 근접치료기기 등의 품질관리 효율성을 파악하기 위해 주기별 품질관리 수행여부, 수행인력 및 주체, 수행 시간을 조사하였다. 선형가속기 및 근접치료기기에 대한 각각의 품질관리 검사 항목에 대한 주기별 수행 여부를 조사하였다. 조사결과 품질관리 검사항목 수에서 미국 및 유럽의 품질관리 지침서와 비교하여 일일 및 주간점검 항목수의 경우는 8~10로서 유사한 결과를 보였으나, 월간과 연간점검 항목 수는 미국 및 유럽의 경우 17~21 항목이었고, 국내의 경우는 15.5로 낮게 나타났다. 또한 국내의 여건은 품질관리를 수행 할 인력 및 시간의 부족과 제한으로 인해 미국 및 유럽의 품질관리 지침서에서 권고하는 소요인력 및 시간과 비교하여 대략 50% 수준의 낮은 수치를 보였다. 따라서 본 연구에서 수집한 국내 방사선종양학과의 품질관리 검사항목 및 실행 주기, 수행 인력 및 수행시간에 관한 현황 조사 결과와 기존에 발표된 미국의학물리학회 TG-40 보고서 및 유럽의 품질관리 지침서를 활용한다면 국내 실정 및 각 기관에 적합한 품질관리 지침서를 수립하는데 유용할 것으로 기대된다.