유방촬영용 방사선발생장치의 관전압과 관전류 시험 분석

정홍량(Hong-Ryang Jung),홍동희(Dong-Hee Hong),한범희(Beom-Hui Han) 대한방사선과학회(구 대한방사선기술학회) 2014 방사선기술과학 Vol.37 No.1

유방촬영용 방사선발생장치의 성능 관리 및 품질관리에 적용되는 관전압과 관전류량을 IEC(International Electrotechnical Commission; 국제 전기 기술위원회) 60601-2-45에서 제시한 표준을 근거로 시험하고 분석한 결과 다음과 같은 결론을 얻었다. 관전압에 따른 제조년도별 표준편차 값은 2001∼2010 사이에서 3.15로 가장 크게 나타났고, 관전류량에 따른 제조년도별 표준편차 값은 2000년 이전에서 6.38로 가장 크게 나타났으며, 2011년 이후에 제조된 장치에서는 PAE(Percent Average Error; 백분률표준오차)의 표준편차가 비교적 적게 나타났다. 이는 최근에 제조된 유방촬영용 방사선발생장치의 관전압과 관전류량이 정확한 성능을 유지하고 있음을 알 수 있다. 본 연구결과를 기초자료로 활용하여 유방촬영용 방사선발생장치의 성능 및 품질 관리를 유지하므로 현재 식품의약품안전청의 “진단용 방사선발생장치의 안전관리에 관한 규칙”에서 규정하고 있는 3년 검사주기 동안에 자가 점검으로 방사선발생장치의 방사선에 대한 안전성 확보와 사용하는 X선 장치의 성능을 일관성(constancy) 있게 유지하도록 함으로서 궁극적으로 방사전에 대한 국민피폭선량을 줄일 수 있는 기대효과가 있을 것으로 기대된다. Breast shooting performance management and quality control of the generator is applied to the amount of current IEC(International Electrotechnical Commission) 60601-2-45 tube voltage and tube current are based on standards that were proposed in the analysis of the test results were as follows. Tube voltage according to the value of the standard deviation by year of manufacture from 2001 to 2010 as a 42-3.15 showed the most significant, according to the year of manufacture by tube amperage value of the standard deviation to 6.38 in the pre-2000 showed the most significant, manufactured after 2011 the standard deviation of the devices, the PAE(Percent Average Error) was relatively low. This latest generation device was manufactured in the breast of the tube voltage and tube diagnosed shooting the correct amount of current to maintain the performance that can be seen. The results of this study as the basis for radiography diagnosed breast caused by using the device's performance and maintain quality control, so the current Food and Drug Administration "about the safety of diagnostic radiation generator rule" specified in the test cycle during three years of self-inspection radiation on a radiation generating device ensure safety and performance of the device using a coherent X-ray(constancy) by two ultimately able to keep the radiation dose to the public to reduce the expected effect is expected.

부배열 합성을 이용한 적응적 빔형성기의 구현 및 성능 분석

장윤희(Youn-Hui Jang),홍동희(Dong-Hee Hong),최성희(Seong-Hee Choi) 한국전자파학회 2013 한국전자파학회논문지 Vol.24 No.4

본 논문은 능동형 평면 위상 배열 안테나를 이용한 레이더 시스템에 적용, 구현된 적응적 빔형성기의 시험결과 및 성능을 다룬다. 적응적 빔형성 알고리즘은 이미 많은 문헌 등에서 연구되고 있지만, 실제로 구현된 레이더 시스템에 대한 소개 및 결과는 찾기 어렵다. 여기서는 실시간 디지털 신호 처리까지 구현된 실제 레이더 시스템에 적용된 적응적 빔형성 알고리즘의 결과에 대해 알아본다. 또 일반 평면 위상 배열이 아닌 부배열 합성을 이용한 적응적 빔형성 알고리즘을 구현하였다. 본 알고리즘의 성능은 모델링과 시뮬레이션을 통해 먼저 입증한 다음, 실제 레이더 시스템을 이용한 원전계 시험 결과로 최종 확인한다. In this paper, we present the performance and the experimental results of the adaptive beamformer in the radar system with the planar active array. The study of the adaptive beamformer has already been performed in several literatures, but it is difficult to find the results or examples those are implemented in the actual radar system. Here we employ the adaptive beamformer to the practical radar system with subarray architecture. The performance of beamformer will be demonstrated by modeling and simulation and finally the far-field experimental results.

자동노출조절장치를 이용한 흉부 방사선검사 시 갑상샘 장기선량 최소화를 위한 새로운 차폐 방법에 관한 연구

주영철(Young-Cheol Joo),홍동희(hong dong hee),한범희(Han Beom Hui) 대한방사선과학회(구 대한방사선기술학회) 2020 방사선기술과학 Vol.43 No.5

The purpose of this study is to investigate the effect of radiation shielding on the thyroid organ dose and image quality during Chest PA examination using automatic exposure control system. This study was conducted in the patient posture and examination conditions such as Chest PA using human model phantom. An experiment without shielding was set as a control group (non) and the cases of using paper coated with a contrast agent (contrast) and bismuth (bismuth) were used as experimental groups. Compared to non-shielded(non), the dose at bismuth increased about 7% in C(cervical vertebrae)5 and C6 and 14% in C7 and contrast showed dose increases of about 17 to 19% in C5 and C6 and about 21% in C7. As a result of the image quality comparison, when measured in the center of the cervical vertebrae, both SNR and CNR in bismuth increased about 40% higher than non, and contrast showed about 8 to 9% improvement. Compared with soft tissues of the cervix, bismuth reduced SNR by about 15% and CNR by about 13%, in contrast, SNR decreased by 11%, and CNR decreased by about 10%. In the Chest PA using AEC, the method of using the shield in front of the collimator has the advantage to observe the anatomical structure of the neck area well compared to the method using the lead. However, the dose at the neck can be increased by 7-21% depending on shielding materials.

100 kg/day 액화수소 제조시설용 Ortho-Para 변환기의 설계 및 성능평가

양성민(Seong Min Yang),박주형(Joo Hyoung Park),이병무(Byeong Moo Lee),김서영(Seo Yong Kim),홍동희(Dong Hui Hong) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.6

This Ortho-Para hydrogen converter was designed for application to actual hydrogen liquefaction facility. The conversion device converts Ortho hydrogen into Para hydrogen after heat exchange of between hydrogen and liquefied nitrogen in a pre-cooler before liquefaction. The performance of this converter was evaluated by the enthalpy change between the inlet line and the out line. The converter is filled with 600 cc by selecting iron oxide(Fe₂O₃) as a catalyst. The conversion rates were compared for each flow range[0.1 to 0.6 m3/min (H₂ @ 293 K, 1 atm)]. Overall, as the flow rate of hydrogen increased, the conversion rate decreased. However, as the flow rate increased, a slight temperature decrease of hydrogen occurred, and there were a section in which the conversion rate increased due to an increase in the equilibrium point of ratio of Para.

100 kg/day 액화수소 제조시설용 Ortho-Para 변환기의 설계 및 성능평가

양성민(Seong Min Yang),박주형(Joo Hyoung Park),이병무(Byeong Moo Lee),김서영(Seo Yong Kim),홍동희(Dong Hui Hong) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.6

This Ortho-Para hydrogen converter was designed for application to actual hydrogen liquefaction facility. The conversion device converts Ortho hydrogen into Para hydrogen after heat exchange of between hydrogen and liquefied nitrogen in a pre-cooler before liquefaction. The performance of this converter was evaluated by the enthalpy change between the inlet line and the out line. The converter is filled with 600 cc by selecting iron oxide(Fe₂O₃) as a catalyst. The conversion rates were compared for each flow range[0.1 to 0.6 m3/min (H₂ @ 293 K, 1 atm)]. Overall, as the flow rate of hydrogen increased, the conversion rate decreased. However, as the flow rate increased, a slight temperature decrease of hydrogen occurred, and there were a section in which the conversion rate increased due to an increase in the equilibrium point of ratio of Para.

100 kg/day 액화수소 제조시설용 Ortho-Para 변환기의 설계 및 성능평가

양성민(Seong Min Yang),박주형(Joo Hyoung Park),이병무(Byeong Moo Lee),김서영(Seo Yong Kim),홍동희(Dong Hui Hong) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.6

This Ortho-Para hydrogen converter was designed for application to actual hydrogen liquefaction facility. The conversion device converts Ortho hydrogen into Para hydrogen after heat exchange of between hydrogen and liquefied nitrogen in a pre-cooler before liquefaction. The performance of this converter was evaluated by the enthalpy change between the inlet line and the out line. The converter is filled with 600 cc by selecting iron oxide(Fe₂O₃) as a catalyst. The conversion rates were compared for each flow range[0.1 to 0.6 m3/min (H₂ @ 293 K, 1 atm)]. Overall, as the flow rate of hydrogen increased, the conversion rate decreased. However, as the flow rate increased, a slight temperature decrease of hydrogen occurred, and there were a section in which the conversion rate increased due to an increase in the equilibrium point of ratio of Para.