• Journal of radiological science and technology
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• v.44 no.5
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• pp.481-487
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• 2021

This study was conducted for the purpose of efficient radioactive waste disposal and management. Experiment was evaluated the decontamination efficiencies of the four types decontamination materials(Water, Alcohol, Decontamination Water, Decontamination Gel) with radioactive wastes generated during radio-pharmaceutical production process at Korea Institute Radiological and Medical Sciences(KIRAMS). The radioactive waste sample used in experiment is a lead plate of the fume hood that was disposed in April, 2019. In the experimental method, radioactive waste was measured before and after decontamination using a HPGe semiconductor detector and Gamma survey meter. The measured values before and after decontamination were evaluated for decontamination efficiency as a percentage. As a result, it was confirmed that a lot of specific activity and surface dose rate was removed from the radioactive wastes. In particular, when decontamination water was used, most of the radioactivity of radioactive wastes was removed. Considering these results, if decontamination water is used in decontamination of radioactive waste, decontamination efficiency equivalent to the disposition criteria can be expected with just one decontamination treatment. In addition, in the case of water and alcohol, only on decontamination was effective in approximately 75% and 95%. Otherwise, when decontamination gel was used, it was confirmed that the largest deviation occurred among all experimental results.

• Journal of radiological science and technology
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• v.46 no.2
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• pp.141-149
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• 2023

The Korea Institute of Radiological and Medical Sciences plans to produce ²²⁵Ac, a therapeutic radio-pharmaceutical for precision oncology, such as prostate cancer. Radon, a radioactive gas, is generated by radium, the target material for producing ²²⁵Ac. The radon concentration is expected to be about 2000 Bq·m^-3. High-concentration radon-generating facilities must meet radioactive isotope emission standards by lowering the radon concentration. However, most existing studies concerning radon removal using activated carbon filters measured radon levels at concentrations lower than 1000 Bq·m^-3. This study measured ²²²Rn removal of coconut-based activated carbon filter under a high radon concentration of about 2000 Bq·m^-3. The ²²²Rn removal efficiency of activated carbon impregnated with triethylenediamine was also measured. As a result, the ²²²Rn removal amount of the activated carbon filter showed sufficient removal efficiency in a ²²²Rn concentration environment of about 2000 Bq·m^-3. In addition, despite an expectation of low radon reduction efficiency of Triethylenediamine-impregnated activated carbon, it was difficult to confirm a significant difference in the results. Therefore, it is considered that activated carbon can be used as a radioisotope exhaust filter regardless of whether or not Triethylenediamine is impregnated. The results of this study are expected to be used as primary data when building an air purification system for radiation safety management in facilities with radon concentrations of about 2000 Bq·m^-3.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.63-65
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• 2023

본 논문에서는 FDG-PET 영상을 사용하는 딥러닝 네트워크를 이용하여 직장암 환자의 치료 후 완치를 예측하는 연구를 수행하였다. 직장암은 흔한 악성 종양 중 하나이지만 병리학적으로 완전하게 치료되는 가능성이 매우 낮아, 치료 후의 반응을 예측하고 적절한 치료 방법을 선택하는 것이 중요하다. 따라서 본 연구에서는 FDG-PET 영상에 합성곱 신경망(CNN)모델을 활용하여 딥러닝 네트워크를 구축하고 직장암 환자의 치료반응을 예측하는 연구를 진행하였다. 116명의 직장암 환자의 FDG-PET 영상을 획득하였다. 대상군은 2cm 이상의 종양 크기를 가지는 환자를 대상으로 하였으며 치료 후 완치된 환자는 21명이었다. FDG-PET 영상은 전신 영역과 종양 영역으로 나누어 평가하였다. 딥러닝 네트워크는 2차원 및 3차원 영상입력에 대한 CNN 모델로 구성되었다. 학습된 CNN 모델을 사용하여 직장암의 치료 후 완치를 예측하는 성능을 평가하였다. 학습 결과에서 평균 정확도와 정밀도는 각각 0.854와 0.905로 나타났으며, 모든 CNN 모델과 영상 영역에 따른 성능을 보였다. 테스트 결과에서는 3차원 CNN 모델과 종양 영역만을 이용한 네트워크에서 정확도가 높게 평가됨을 확인하였다. 본 연구에서는 CNN 모델의 입력 영상에 따른 차이와 영상 영역에 따른 딥러닝 네트워크의 성능을 평가하였으며 딥러닝 네트워크 모델을 통해 직장암 치료반응을 예측하고 적절한 치료 방향 결정에 도움이 될 것으로 기대한다.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.1
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• pp.15-20
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• 2019

Background and Objectives : The goal of this study is to present a strategy for improving the self-regulation (SR) ability and facilitating the change of vocal behavior by applying voice therapy using the SR concept to the patients with vocal cord nodule and muscle tension dysphonia. Materials and Method : The subjects were 80 patients and 80 patients who were diagnosed with muscle tension dysphonia and vocal nodules. As a control group, the results were compared among patients with the same dysphonia without using SR strategies. The concept of SR before voice therapy was explained to the patients, and the treatment was divided into three stages according to the goal of voice therapy. The treatment stages consist of 1) skill acquisition, 2) habit formation, and 3) habit changes. voice therapy was performed by applying SR strategies such as goal implementation intentions and a less routine behavior. Patient's dropout rates were measured to compare the adherence of voice therapy. Results : Significant improvement was seen in all groups receiving voice therapy. However, in the group using the SR strategy, the voice analysis results showed a relatively low dropout rate of voice therapy. In the generalization confirmation stage, patients who applied SR concept showed better results. SR strategy did no longer be necessary to maintain newly adopted vocal behavior. Conclusion : The results of this study show that SR is one of the cognitive factors that can have a significant impact on the outcome of voice therapy, and also has a positive impact on the acquisition and generalization of new skills. A better understanding of SR and the development of therapeutic strategies using it will play an important role in solving voice problems in clinical settings.

• Journal of radiological science and technology
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• v.46 no.3
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• pp.219-229
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• 2023

In this study, basic characteristics such as reproducibility, linearity, and directionality of RPL glass dosimeters were evaluated to improve the reliability of dose evaluation through RPL glass dosimeters, and uncertainty elements such as sensitivity by glass element and magazine slot sensitivity were evaluated. Using a mathematical model to calibrate the measured values of the RPL glass dosimeter, the measurement uncertainty was calculated assuming an example. As a result of the characteristic evaluation, the RPL glass dosimeter showed excellent performance with a standard deviation of ±1% (1 SD) for the reproducibility of the reading process, a coefficient of determination for linearity of 0.99997. And the read-out of the RPL glass dosimeter are affected by the circular rotation direction of the glass dosimeter during irradiation, fading according to the period after irradiation, the number of laser pulses of the reader, and response degradation due to repeated reading, it is judged that measurement uncertainty can be reduced by irradiation and reading in consideration of these factors. In addition, it was confirmed that the dose should be determined by calculating the correction factors for the sensitivity of each element and, the sensitivity of each reading magazine slot. It is believed that the reliability of dosimetry using glass dosimeters can be improved by using a mathematical model for correction of glass dosimeter readings and calculating measurement uncertainty.

• Laboratory Medicine Online
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• v.6 no.1
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• pp.25-30
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• 2016

Background: The cell cycle-dependent enzyme thymidine kinase 1 (TK1) is known to increase during cancer cell proliferation and has been reported as a prognostic marker for various hematologic malignancies and solid tumors. This study aimed to determine the reference interval in Korean healthy controls and to evaluate the usefulness of TK1 as a biomarker for aggressive clinical behavior in B-cell lymphoma patients. Methods: We enrolled 72 previously untreated patients with B-cell lymphoma and 143 healthy controls. Serum TK1 levels were measured by chemiluminescence immunoassay ($Liaison^{(R)}$, DiaSorin, USA). We established the reference intervals in healthy controls. The diagnostic performance of serum TK1 was studied using receiver operating characteristic (ROC) analysis, and the correlation between the cutoff level for serum TK1 and clinical characteristics of B-cell lymphoma was evaluated. Results: The reference range (95th percentile) of serum TK1 in healthy controls was 5.4-21.8 U/L. There was a clear difference in TK1 levels between patients with B-cell lymphoma and healthy controls ($40.6{\pm}68.5$ vs. $11.8{\pm}4.4U/L$, P <0.001). The area under the curve of serum TK1 for the diagnosis of B-cell lymphoma was 0.73 (cutoff, 15.2 U/L; sensitivity, 59.7%; specificity, 83.2%). An increased TK1 level (${\geq}15.2U/L$) correlated with the advanced clinical stage (P <0.001), bone marrow involvement (P =0.013), international prognostic index score (P =0.001), lactate dehydrogenase level (P =0.001), low Hb level (<12 g/dL) (P =0.028), and lymphocyte count (P =0.023). Conclusions: The serum TK1 level could serve as a useful biomarker for aggressive clinical behavior in B-cell lymphoma patients.

• The Science & Technology
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• v.35 no.10 s.401
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• pp.93-94
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• 2002

제8회 "원자력안전의 날" 기념행사 개최/원자력 병원, '원자력의 학원' 체제로 출범/제2회 올해의 여성과학기술자상 수상 후보자 공모/청소년들의 과학적 재능을 발휘하는 경진대회 열려 '2002 전국청소년과학경진대회'/부산아시아경기대회의 2002 환경아시아드! '거리의파수꾼(Street leader) 모집'/중소기업 정보화 컨퍼런스 2002 참가기업 모집 '중소기업정보화경영원'

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.387.1-387.1
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.311-311
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• 2002

• 동위원소뉴스
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• no.4 s.40
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• pp.10-11
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• 2000