• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.50-57
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• 2017

Recently, safety-critical aviation system development programs promoted domestically have been terminated in the middle stage or they have not been put to practical use at the final stage. The program failure may be caused by various factors, but this study focused on imperfect test and evaluation(T&E) procedures. In general, T&E process of a safety-critical system must be distributed throughout the entire life-cycle of the system, have a continuity in phases, and can be implemented in a variety of ways depending on the maturity of the system development and acquisition strategy. This paper aims to present a new strategy by analyzing the domestic and overseas T&E processes to reduce the risk of domestic safety-critical CNS/ATM system development program and increase the success rate of program. First, we discuss the verification and validation techniques for safety-critical systems, analyze the T&E procedures of advanced institutes and the domestic situation, and then compare the domestic and overseas T&E processes to complement the imperfect testing procedure.

• The Korean Journal of Nuclear Medicine
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• v.14 no.2
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• pp.1-9
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• 1980

혈액질환(血液疾患), 특히 용혈성빈혈(溶血性貧血)을 수반(隨伴)한 경우(境遇)에 적혈구(赤血球)의 생성(生成), 파괴과정(破壞過程)을 정확히 파악하는 것은 빈혈(貧血)의 발생기전(發生機轉) 및 병인(病因), 치료(治療), 예후(豫後) 결정(決定)에 매우 중요(重要)하다. 적혈수명측정법(赤血壽命測定法)은 최근(最近) 방사성(放射性)동위원소(同位元素)를 이용(利用)한 방법(方法)이 소개된 이래 널리 시행(施行)되어 왔다. 그러나 그 방법(方法) 및 결과(結果) 해석(解釋)에 표준화(標準化)가 되어 있지 않았던 중 1971년 ICSH (International Committee for Standardization in Hematology)에서 expert panel을 갖고 ICSH 추천 방법(方法)을 발표(發表)하였고, 본지(本誌)에서도 그 내용(內容)을 게재(揭載)한 바 있다. 1980년 ICSH는 전문기관 및 전문가의 협조(協調)를 얻어 다시 expert panal을 갖은 후 1971년에 추진한 적혈구수명측정법(赤血球壽命測定法)의 일부(一部)를 수정(修正)하여 ICSH의 표준방법(標準方法)으로 발표(發表)하였다. 개정(改正)된 표준방법(標準方法)과 1971년 ICSH추친 방법(方法)과의 차이(差異)는 다음과 같다. $^{51}Cr$표지방법중(標識方法中) 참고방법(參考方法)(Reference method)인 ACD법(法)에 수정(修正)을 가하여, ACD solution 구성성분(構成成分)이 차이(差異)가 있으며, 표지(標識)$^{51}Cr$의 양(量)을 체중당(體重當) $1.5{\mu}Ci$에서 $0.5{\mu}Ci$로 제한(制限)시켰다. 투여방법(投與方法)에 대한 언급 특히 투여하는 표지적혈구(標識赤血球)의 용적을 정확하게 측정 하기 위한 방법 4가지를 추가하였고, 검체준비(檢體準備) 과정중(過程中)의 pipet error를 방지(防止)하기위해 일정(一定)한 형태의 pipet을 사용(使用)하며, 1ml의 tuterculin syringe는 사용(使用)하지 않기로 하였다. 또한 결과분석시(結果分析時) 혈구용적(血球容積)의 항정성(恒定性)을 위해 Sodium pertectnetate($^{99m}Tc$)를 이용(利用)해 혈구용적(血球容積)을 반복(反復)해 측정(測定)하도록 하였으며 이때 사용(使用)하는 방사성동위원소(放射性同位元素)는 $^{32}P$ 대신 $^{99m}Tc$로 하였다. 결과해석시(結果解釋時) IgG 항체(抗體) 또는 IgM 항체(抗體)에 따른 차이점(差異點)에 대한 고려가 추가(追加)되었다. ICSH와 국제혈액학회(國際血液學會)에서 수정(修正)된 ICSH 표준방법(標準方法)에 의한 적혈수명측정법(赤血壽命測定法)을 널리 소개(紹介)하여 결과(結果)의 표준화(標準化)를 기하고자 연관잡지(聯관(關)雜誌)에 게재(揭載)할 것을 요청(要請)하였기에 전문(全文)을 본지(本誌)에 소개(紹介)하고자 한다.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.162-167
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• 2015

Although the perfomance indicators of the nuclear power plants in Korea show optimal, it requires detailed analysis and discussion centered on the radiation dose. As analysis methods, analysis on the radiation dose of nuclear power plants over the past five years was assessed by comparing the relevant radiation dose of radiation workers and per capita average annual radiation dose of the world's major nuclear power stations was also analyzed. The radiation workers over the annual radiation dose limit of 50 mSv were not. The contrast ratio of the radiation exposure according to the reactor type was the normal operation of PHWR was 6.2% higher than those of the PWR. This shows the radiation work of PHWR during normal driving operation is much more than those of PWR. According to the Performance Indicators of the World Association of Nuclear Operator, the annual radiation dose per unit in 2013 showed 527 man-mSv of Korea is the best country among the major nuclear power generating states, the world average was 725 man-mSv. The annual per capita radiation dose is about 80% less than 1 mSv of the public dose limit and also the average per capita dose showed a very low level as 0.82 mSv. Workers in related organizations showed 1.07 mSv, the non-destructive inspection agency workers showed 3.87 mSv. The remarkable results were due to radiation reduced program such as development of radiation shielding and radiation protection. In conclusion, the radiation exposured dose of nuclear power plants workers in Korea showed a trend which is ideally reduced. But more are expected to be difficul and the psychological insecurity against the operation of the nuclear power plants is existed to the residents near the nuclear power plants. So the radiation dose reduction policy and radiation dose follow up study of nuclear power plants will be continously excuted.