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다발성 경화증 질환의 자기공명 T2 강조영상에서 단면 두께 변화에 따른 잡음 평가
홍인기(Inki Hong),박민지(Minji Park),강상현(Seong-Hyeon Kang),이영진(Youngjin Lee) 대한방사선과학회(구 대한방사선기술학회) 2021 방사선기술과학 Vol.44 No.4
Magnetic resonance imaging(MRI) uses strong magnetic field to image the cross-section of human body and has excellent image quality with no risk of radiation exposure. Because of above-mentioned advantages, MRI has been widely used in clinical fields. However, the noise generated in MRI degrades the quality of medical images and has a negative effect on quick and accurate diagnosis. In particular, examining a object with a detailed structure such as brain, image quality degradation becomes a problem for diagnosis. Therefore, in this study, we acquired T2 weighted 3D data of multiple sclerosis disease using BrainWeb simulation program, and used quantitative evaluation factors to find appropriate slice thickness among 1, 3, 5, and 7 mm. Coefficient of variation and contrast to noise ratio were calculated to evaluate the noise level, and root mean square error and peak signal to noise ratio were used to evaluate the similarity with the reference image. As a result, the noise level decreased as the slice thickness increased, while the similarity decreased after 5 mm. In conclusion, as the slice thickness increases, the noise is reduced and the image quality is improved. However, since the edge signal is lost due to overlapped signal, it is considered that selecting appropriate slice thickness is necessary.
복합발전 플랜트 안전문화 진단을 위한 시스템 다이내믹스 모델링 및 통합도구 개발 연구
최재우(Jaewoo Choi),엄성인(Sungin Um),홍인기(Inki Hong) 한국가스학회 2017 한국가스학회지 Vol.21 No.3
기업의 안전문화 측정에 있어 다양한 방법들이 시도되고 있으나, 평가방법에 따라 정형화되지 못한 주관적인 기준에 따른 정성적 분석결과를 도출하는 한계를 보인다. 이에, 복합발전 플랜트에 적용할 수 있는 설문지를 개발하고, 이 결과를 기반으로 시스템 다이내믹스 모델을 이용하여 평가결과의 정량화를 하였고, 다양한 시나리오를 통한 시뮬레이션을 실시하여 안전문화 측정과 함께 기업의 미래 안전문화 정책에 기준을 제시 하고자 하였다. Although various methods have been tried to measure the safety culture of firms, they are limited to derive the qualitative analysis results according to the subjective criteria that are not formalized according to the evaluation method. We developed a questionnaire that can be applied to a combined power plant, quantified the evaluation results using the system dynamics model based on the results, and conducted simulation through various scenarios. And to present the criteria for safety cultural policy.