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

• Journal of Medicine and Life Science
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• 제16권1호
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• pp.23-26
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• 2019

Total scalp irradiation is a challenging treatment because of unique concave target volume and difficulty with bolus applying. There are few reports about bolus applying methods to the entire scalp in detail. Application of conventional bolus (wax or superflab) is widely used, and it is considered effective. However, the curvature and irregularity of the scalp can produce significant air gap, resulting in inadequate radiation dose distribution. We describe a new method to applying the bolus to the entire scalp. We sutured 1 cm thickness superflab bolus on the thermoplastic mask using cotton string. This method can reduce the air gap between the bolus and scalp and be reproducible.

• 대한두경부종양학회지
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• 제6권1호
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• pp.1-10
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• 1990

This review will be discussed the various causes of radiation failure for head and neck cancers from radiobiologic perspective and also provided a few clinical data to illustrate the basic principle. A knowledge about multiplicity of factors that may underlie failure of radiation treatment is essential for rational application of new treatment strategies. Furthermore, it is important to distinguish causes of failure that can be reduced or minimized by application of conventional treatment from one are potentially remediable by new treatment strategies, and one that are not amenable to some modification of radiotherapeutic approach.

• Radiation Oncology Journal
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• 제34권3호
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• pp.160-167
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• 2016

In oncologic practice, treatment guidelines provide appropriate treatment strategies based on evidence. Currently, many guidelines are used, including those of the European Association for the Study of the Liver and European Organization for Research and Treatment of Cancer (EASL-EORTC), National Comprehensive Cancer Network (NCCN), Asia-Pacific Primary Liver Cancer Expert (APPLE), and Korean Liver Cancer Study Group and National Cancer Centre (KLCSG-NCC). Although radiotherapy is commonly used in clinical practice, some guidelines do not accept it as a standard treatment modality. In this review, we will investigate the clinical practice guidelines currently used, and discuss the application of radiotherapy.

• 대한방사선치료학회지
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• 제3권1호
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• pp.45-50
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• 1989

고 에너지 방사선으로 용적이 적은 표재성 종양 및 부정형의 체표면과 경사진 조사야에 대한 방사선 치료시 종양 용적내에 균등한 선량분포를 얻기 위해서 Wedge filter 기법이 많이 사용되고 있다. 본 연구의 목적은 코발트 $60{\Gamma}$선 치료를 위한 Semi-Universal Wedge filter의 제작과 임의의 조사야에 대한 최적한 출력 및 정확한 조작방법을 기술하고 방사선 치료계획의 최적화를 기하기 위해서 Wedge filter의 임상응용 방법을 제시하고자 한다.

• Journal of Radiation Protection and Research
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• 제41권2호
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• pp.149-154
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• 2016

Background: Any real application of Bayesian inference must acknowledge that both prior distribution and likelihood function have only been specified as more or less convenient approximations to whatever the analyzer's true belief might be. If the inferences from the Bayesian analysis are to be trusted, it is important to determine that they are robust to such variations of prior and likelihood as might also be consistent with the analyzer's stated beliefs. Materials and Methods: The robust Bayesian inference was applied to atmospheric dispersion assessment using Gaussian plume model. The scopes of contaminations were specified as the uncertainties of distribution type and parametric variability. The probabilistic distribution of model parameters was assumed to be contaminated as the symmetric unimodal and unimodal distributions. The distribution of the sector-averaged relative concentrations was then calculated by applying the contaminated priors to the model parameters. Results and Discussion: The sector-averaged concentrations for stability class were compared by applying the symmetric unimodal and unimodal priors, respectively, as the contaminated one based on the class of ${\varepsilon}$-contamination. Though ${\varepsilon}$ was assumed as 10%, the medians reflecting the symmetric unimodal priors were nearly approximated within 10% compared with ones reflecting the plausible ones. However, the medians reflecting the unimodal priors were approximated within 20% for a few downwind distances compared with ones reflecting the plausible ones. Conclusion: The robustness has been answered by estimating how the results of the Bayesian inferences are robust to reasonable variations of the plausible priors. From these robust inferences, it is reasonable to apply the symmetric unimodal priors for analyzing the robustness of the Bayesian inferences.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1449-1455
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• 2022

A radiotracer investigation was carried out in a Thermal Stratification Test Facility (TSTF) with objectives of investigating the dispersion and diffusion of radionuclide and effectiveness of the thermocline to minimize the radionuclide content in the hot water layer. Technetium-99m (^99mTc) as sodium pertechnetate was used as a radiotracer in the investigation. Qualitative analysis showed that a thermocline is formed within the TSTF and is effective in preventing the transport of radionuclide from bottom section to the top section of the facility. It was found that the radiotracer injected at the bottom of the pool took about 17.4 h to disperse from bottom to the top of the facility. The results of the investigation helped in understanding the effectiveness of hot water layer and thus to minimize the pool top radiation levels.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4763-4767
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• 2012

Radiation pneumonitis and pulmonary fibrosis are the main complications with radiotherapy for thoracic neoplasms, directly limiting the efficient dose in clinical application and currently there are few medicines that effectively function as radioprotectants. However, a TLR5 agonist, CBLB502, was confirmed to have protective efficacy against hematopoietic and gastrointestinal radiation syndromes in mice and primates. This study points to a new direction for protection against thoracic radiation-induced pulmonary syndromes and skin injury by CBLB502. We utilized the TUNEL assay, pathological analysis and immunohistochemistry to obtain evidence thatCBLB502 could alleviate the occurrence of radiation pneumonitis and pulmonary fibrosis as well as radiation-induced skin injury. It may thus play a promising role in facilitating clinical radiotherapy of thoracic neoplasms.

• 식품산업과 영양
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• 제11권3호
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• pp.12-20
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• 2006

• 식품과학과 산업
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• 제43권1호
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• pp.70-74
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• 2010