• 한국방사선학회논문지
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• 제8권6호
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• pp.365-369
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• 2014

본 연구는 방사선 이해교육에 대한 유치원 교사들의 인식과 요구를 분석하고, 방사선에 대한 유아교육기관에서의 올바른 이해와 방사선 노출로 인한 유아안전 대책 마련을 위한 기초자료를 제공하는데 의의가 있다. 본 연구에서는 2014년 8월 C시와 G시의 유치원 교사 300명을 대상으로 설문지를 배부하여 회수된 158명의 자료를 분석하였다. 본 연구의 결과는, 첫째, 유치원 교사들의 방사선에 대한 이해수준 낮았으며, 방사선에 대한 이해수준이 낮을수록 방사선의 일반적인 유해성과 피폭유해성에 대한 심리적 불안감은 높은 것으로 나타났다. 둘째, 유치원 교사들의 방사선 이해교육 정도는 낮았으나, 유치원 교사들의 방사선 이해교육의 필요성 및 요구는 높은 것으로 나타났다. 결론적으로 본 연구는 방사선에 대한 올바른 이해를 돕기 위한 교사교육이 시급함을 시사한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2353-2358
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• 2014

Purpose: We aimed to detect the expression of HIF-1${\alpha}$, VEGF, HPSE-1 and CD31 in SKOV3 xenografts in nude mice treated with different doses of ionizing radiation, trying to explore the possible mechanism of hypoxia and radioresistance. Methods: Nude mice bearing SKOV3 xenografts were randomly divided into 4 groups: Group A (control group, no ionizing radiation), Group B (treated with low dose of ionizing radiation: 50cGy), Group C (treated with high dose of ionizing radiation: 300cGy), Group D ( combined ionizing radiation, treated with ionizing radiation from low dose to high dose : 50cGy first and 300cGy after 6h interval). The mRNA levels of HIF-1 and VEGF in each group were detected by real time polymerase chain reaction, while HPSE-1 expression was measured by ELISA. The microvessel density (MVD) and hypoxic cells were determined through immunohistochemical (IHC) staining of CD31 and HIF-1a. Results: Significant differences of HIF-1${\alpha}$ mRNA level could be found among the 4 groups (F=74.164, P<0.001): Group C>Group A>Group D> Group B. The mRNA level of VEGF in Group C was significantly higher than in the other three groups (t=-5.267, P=0.000), while no significant difference was observed among Group A, B and D (t=1.528, 1.588; P=0.205, 0.222). In addition, the MVD was shown to be the highest in Group C (t=6.253, P=0.000), whereas the HPSE-1 level in Group A was lower than in Group B (t=14.066, P=0.000) and higher than in Group C (t=-21.919, P=0.000), and similar with Group D (t=-2.066, P=0.058). Through IHC staining of HIF-1a, the expression of hypoxic cells in Group A was (++), Group B was (+), Group C was (+++) and Group D was (+). Conclusion: Ionizing radiation with lowerdoses might improve tumor hypoxia through inhibiting the expression of HIF-1 and HPSE-1, whereas higherdoses worsen tumor hypoxic conditions by up-regulating HIF-1${\alpha}$, HPSE-1, VEGF and CD31 levels. A protocol of low-dose ionizing radiation followed by a high-dose irradiation might at least partly improve tumor hypoxia and enhance radiosensitivity.

• Journal of Radiation Protection and Research
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• 제48권2호
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• pp.68-76
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• 2023

Background: In the process of discussion on the possibility of using radionuclide-contaminated soil and debris generated by radiation disasters, a strategy for the proper management of radiation exposure protection while considering the source of the contaminated materials is necessary. Materials and Methods: The radiological protection criteria that are likely to be applied to the source-related approach based on the International Commission on Radiological Protection recommendations and the International Atomic Energy Agency safety standards are summarized. We proposed five interpretations of radiation protection to contribute to the promotion of discussion on the possibility of using a part of low-level-radionuclide-contaminated soil and debris in the post-accident rehabilitation. Interpretations I to III are based on the idea of "using a reference level to protect the public in post-accident rehabilitation," whereas IV and V are based on the idea of "using the dose constraint to protect the public in the post-accident rehabilitation when the sources are handled in a planned activity." The former idea is subdivided into three based on the definition of the source, which is managed by the reference level, and the latter idea is divided into two depending on whether or not additional dose from using contaminated materials is deemed acceptable. Results and Discussion: To confirm the applicability of the five interpretations presented, we suggested the concrete values of protection criteria via two feasible cases. In this case study, we proposed radiation protection by the dose constraint based on the Interpretation IV and chose 1 mSv/yr for the public and 20 mSv/yr for workers dealing with radionuclide-contaminated materials. Conclusion: We concretely and systematically demonstrated how the concept of radiation protection can be applied to the process of discussion on the possibility of using radionuclide-contaminated materials within the framework of an international system of protection. This study's findings can provide necessary information to discuss the possibility of using radionuclide-contaminated materials as an alternative option for recovery and reconstruction after a radiation disaster from the viewpoint of radiation protection.

• 환경생물
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• 제21권4호
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• pp.384-391
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• 2003

The induction of chromosome aberrations in Hordeum vulgare germs after irradiation is studied for the dose range of 10 to 1,000 mGy. The relationship between the frequency of aberrant cells and the absorbed dose is shown to be non -linear and has a dose-independent plateau within the range of 56-467 mGy where the level of cytogenetic damage is statistically significantly distinguished from the spontaneous level. The comparison of the goodness of the experimental data fitting with mathematical models of different complexities, using the most common quantitative criteria, demonstrates the benefit of the piecewise linear model over the linear and polynomial ones in approximating the cytogenetical disturbance frequency. The results of our study support the conclusion about indirect mechanism of chromosome aberrations induced by low doses or dose rates mutagenesis.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.172-175
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• 1997

Outline contour is detected firstly to simulate dose distribution in radiation therapy planning system. In this paper, we developed automatic contour detection system using temporal and spatial relationships of image sequences. The low level image analysis involves the use of directional gradient edge operators and Laplacian operator. The High level portion of algorithm uses a knowledge-based strategy that incorporates fuzzy resoning method.

• Journal of Radiation Protection and Research
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• 제29권1호
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• pp.41-48
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• 2004

A safety assessment code, called SAGE (Safety Assessment Groundwater Evaluation), has been developed to describe post-closure radionuclide releases and potential radiological doses for low- and intermediate-level radioactive waste (LILW) disposal in an engineered vault facility in Korea. The conceptual model implemented in the code is focused on the release of radionuclide from a gradually degrading engineered barrier system to an underlying unsaturated zone, thence to a saturated groundwater zone. The radionuclide transport equations are solved by spatially discretizing the disposal system into a series of compartments. Mass transfer between compartments is by diffusion/dispersion and advection. In all compartments, radionuclides ate decayed either as a single-member chain or as multi-member chains. The biosphere is represented as a set of steady-state, radionuclide-specific pathway dose conversion factors that are multiplied by the appropriate release rate from the far field for each pathway. The code has the capability to treat input parameters either deterministically or probabilistically. Parameter input is achieved through a user-friendly Graphical User Interface. An application is presented, which is compared against safety assessment results from the other computer codes, to benchmark the reliability of system-level conceptual modeling of the code.

• Journal of Plant Biology
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• 제12권3호
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• pp.15-25
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• 1969

To investigate the radiation effect of P-32 on the soybean plants, the seeds treated with various levels of P-32 solution were sown and cultured in the pots. The growth of the plants and the contents of the macroelements were observed and the following results were obtained. 1) The linear growth of the plants at the early stage seemed to have been promoted by the low-level P-32 treatemnt. At the later growing stage, however, this difference among treatments were less conspicuous. 2) The plants of high level P-32 application showed some growth damaging symptom at the early growing stage. Later this damage was recorded as the time went on and these plants showed even better growth than the control. As a result at the late growing stage, they ensued highest growth. 3) The plants showed in general more growth at the low activity level than at the high-level at the early growing stage. At the late stage, however, the high-level activity promoted more growth than the low-level. 4) At the early growing stage P-32 treatment produced in general significantly more lower than control. At the later stage, however, this difference was not clearly seen. 5) The P-32 treatment seemed to have stimulated earlier florescence and this tendency was more clearly observable eapecially at the high activity level. 6) The weight of the air-dried seeds tended to be increased through P-32 treatment by 10-45%. This tendency was clearly observed especially at the low-level activity. 7) As for the contents of the various macroelements in the leaves, the nitrogen showed significantly larger contents at the middle level(S1) P-32 treatments. The phosphorous contents showed also highest at the middle levels activity and lower both at the high and low-activity levels. The potassium contents was proved, on the contrary, higher at the low-level activity and lower at the high-level. 8) The nitrogen contents in the stems was found significantly higher than control, except at the low-activity level. The phosphorous showed higher contents at the low-activity level and no significant difference at the high-activity level. As for the contents of potassium, calcium and magnesium, three seemed no significant difference among treatments. However, the magnesium showed somewhat higher content at the low-activity level, whereas the calcium was proved high than control. 9) The inorganic contents in the root showed that N and P in the P-32 treated plant were significantly higher than the control and the K-contents was, on the contrary, significantly higher at the control than the rest of the treatments. As for the calcium and magnesium there showed no difference among all treatments.

• Nuclear Engineering and Technology
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• 제46권4호
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• pp.467-474
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• 2014

The aim of this paper is to describe a relatively recent international agreement on the widely debated concepts of: (i) attributing effects to low dose radiation exposure situations that have occurred in the past and, (ii) inferring radiation risk to situations that are planned to occur in the future. An important global consensus has been recently achieved on these fundamental issues at the level of the highest international intergovernmental body: the General Assembly of the United Nations. The General Assembly has welcomed with appreciation a scientific report on attributing health effects to radiation exposure and inferring risks that had been prepared the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) following a formal request by the General Assembly.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.836-842
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• 2001

The more sophisticated patterns of propagation model is presented in this paper, which includes three different source characteristics. The spherical, cosine and dipole radiation characteristics compared and sound event level and the maximum sound level are calculated by experiment and calculation. It is shown that patterns of propagation has dipole characteristics for low speed range(below about 150km/h) at electric multiple system. We know that push-pull high speed system(maximum speed: 300km/h) has cosine characteristics of noise propagation. For this purpose, We conduct the experiment of noise and know the empirical formula of noise level and radiation coefficient K. This model of simulation is conducted through point source array model at wheel/rail contact point by using program and experimental formula. We can guess prediction of profile, flat and wear of wheel by above modeling in near field.

• 한국군사과학기술학회지
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• 제6권2호
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• pp.20-34
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• 2003

The good sea-keeping capability of the SWATH(Small Waterplane Area Twin Hull) ship has been attractive for research or surveillance vessels. Especially, for the naval ships accomplishing the underwater acoustic missions, it is necessary to access and minimize the underwater radiated noise level generated by the ships. Therefore, acoustic signature management and control are very important topics for these vessels. Underwater radiation pattern in the low frequency range is dominated by the tonals from the vibration of onboard machinery. In this work, the radiated noise level generated by the propulsion machine in the submerged hull is predicted using the transfer function technique and the hull transfer function for the submerged hull is determined by analyzing the longitudinal/circumferential stiffened infinitely long cylindrical shell and considering the empirical database of the previous vessels. It is confirmed that the transfer function technique can give useful information for identifying the noise source and estimating its contribution to the total radiatied noise level.