다시 유엔사(UNC)를 논하다

장광현(Kwang-Hyun Chang) 대구과학대학교 국방안보연구소 2020 사회융합연구 Vol.4 No.6

ODM과 bismuth를 이용한 수정체와 갑상선 선량 감소 효과 및 영상 화질 평가

이승현(Seung Hyun Lee),오현식(Hyun Sik Oh),김완역(Wan Yuk Kim),장광현(Kwang Hyun Chang) 대한CT영상기술학회 2016 대한CT영상기술학회지 Vol.18 No.2

Purpose : It is to know the method of the limiest dose reduction of lens and Thyroid which is comparative high sensitivity with the implementation of the best images during head and neck exam by using ODM(Organ Dose Modulation, ODM) that is AOBCM(automated organ current modulation) by GE manufacture company, AEC(Automatic exposure control) and bismuth. Materials and Methods : CT equipment is used Discovery CT 750HD(General Electric Medical System, Milwaukee, Wisconsin USA), and Alderson Rando phantom(CNMC Company, USA) is used with attached Radiophoto Luminescent Glass Dosimeter five to head and six to neck for dose measurement using tour methods(AEC, ODM, bismuth, ODM+bismuth) with 10 times scan and acquired average value. Also to evaluate image quality, we used noise and CT number, and to measure linearity and uniformity by using ACR phantom (Model #438, Gamex RMI, USA). Statistic is used MedCalc version 16.1 to have average and standard deviation of all measurement values, and it could be judged statistically when p-value under 0.05 by AVOVA test. Result : The standard by the usage of AEC, the measured dose result shows that lens were ODM 19.2%, bismuth 32.9%, ODM and bismuth 46.7% down, and to Thyroid shows that ODM 31.2%, bismuth 24.9%, ODM and bismuth 56.8% down. To evaluate image quality for noise, lens shows that ODM 7.1 %, bismuth 17.7%, ODM and bismuth 13.3% increase, to Thyroid shows that ODM 10.1 %, bismuth 30.0%, ODM and bismuth 36.9% increase, for CT number values, lens show that ODM 0.3%, bismuth 50.0% and ODM+bismuth 48.8% increase, to Thyroid shows that ODM 1.9% down, bismuth 296.2%, ODM and bismuth 305.8% increase. To evaluate using ACR phantom, for the usage of bismuth, linearity and uniformity were out of tolerance field recommended ACR because of artifact, by ODM case was under tolerance field for ACR recommendation. To judge statistical significance test, as the result of dose, noise and CT number values by ANOVA test, we confirmed that all results were significant with p-value< 0.05. Conclusion : When using ODM, it was known that dose could be reduced over 25% and increased noise, but continued CT number. Also, neck which is lower thickness compared head shows low noise changes and CT number values continuation. Through this result, it is considered that ODM is more effective method for dose reduction and image quality to less thickness area. 목적 : GE사에서 개발한 자동장기기준선량제어장치(automated organ current modulation, AOBCM) 인 ODM(Organ Dose Modulation, ODM)과 자동노출제어장치(Automatic exposure control, AEC), 그리고 비스무스(bismuth)를 이용하여 두경부 검사 시 최고의 영상을 구현하면서 상대적으로 감수성이 높은 장기인 수정체와 갑상선의 선량을 최소로 낮추는 방법을 찾아보고자 한다. 대상 및 방법 : CT장비는 Discovery CT 750HD(General Electric Medical System, Milwaukee, Wisconsin USA)를 사용하였고, 선량측정을 위해 Alderson Rando phantom(CNMC Company, USA)을 이용하여 두부에 5개, 경부에 6개씩 형광유리선량소자를 이용하여 AEC, ODM, bismuth, ODM+bismuth 4가지 방법으로 10회 scan하여 평균값을 구하였다. 또한 화질평가를 위해 noise와 CT number값을 이용하여 평가하였으며, 영상평가를 위해 ACR phantom(Model #438, Gamex RMI, USA)을 사용하여 직선성과 균일성을 측정하였다. 통계는 MedCalc version 16.1을 사용하여 모든 측정치의 평균과 표준편차를 구하였으며, AVOVA로 통계분석 하여 유의확률(p-value)가 0.05 미만일 때 통계적으로 유의하다고 판단하였다. 결과 : AEC를 사용한 경우를 기준으로 선량을 측정한 결과 수정체는 ODM 19.2% bismuth 32.9% ODM과 bismuth 46.7% 감소하였고, 갑상선은 ODM 31.2%, bismuth 24.9%, ODM과 bismuth 56.8% 감소하였다. 화질평가를 위해 측정한 noise값의 경우 수정체는 ODM 7.1%, bismuth 17.7%, ODM+bismuth 13.3% 증가하였고, 갑상선은 ODM 10.1%, bismuth 30.0%, ODM+bismuth 36.9% 증가하였으며, CT number값의 경우 수정체는 ODM 0.3%, bismuth 50.0%, ODM+bismuth 48.8% 증가하였으며, 갑상선은 ODM 1.9% 감소하였고 bismuth 296.2% ODM+bismuth 305.8% 증가하였다. ACR phamtom을 이용한 영상평가에서는 bismuth를 사용하였을 경우 Artifact로 인해 직선성과 균일성 모두 ACR에서 권고하는 허용범위에 속하지 않았으며, ODM을 사용한 경우에는 ACR에서 권고하는 허용범위에 속하였다. 통계적 유의성을 판단하기 위하여 ANOVA test로 각각의 선량, noise, CT number값을 검정한 결과 모든 측정값이 p-value<0.05 미만으로 유의하다고 판단하였다. 결론 : ODM을 사용하였을 경우 선량은 25% 이상을 감소시키면서 noise 값은 증가하지만 CT number값은 유지됨을 알 수 있다. 또한 두부보다 상대적으로 두께가 얇은 경부의 경우 noise값은 변화가 적으면서 CT number값은 유지됨을 알 수 있다. 이를 통해 ODM은 두께가 얇은 부위에 선량감소 및 영상평가에 더욱 효과적이라 사료된다.

낙동강(한국)의 세 지류에서 포식 윤충류 개체군 동태 및 초식 윤충류 군집에 미치는 영향

김현우 ( Hyun Woo Kim ),장광현 ( Kwang Hyeon Chang ),신운균 ( Woon Kyun Shin ),라긍환 ( Geung Hwan La ),정광석 ( Kwang Seuk Jeong ),주기재 ( Gea Jae Joo ) 한국하천호수학회 2004 생태와 환경 Vol.37 No.4

The herbivorous rotifers community (Brachionus spp.) and population dynamics of the predator rotifer (Asplanchna spp.) in three tributaries (Kumho R., Nam R., and Hwang R.) of the Nakdong River were evaluated on biweekly intervals from Jan. 2001 and Dec. 2002. High abundance of the herbivorous rotifers (peak density: - ca. >1000 Ind. L^(-1)) was observed from two tributaries (Kumho R. and Nam R.) during the spring and fall seasons, respectively. The high peaks of herbivorous rotifers were not evident in one tributary (Hwang R.). Among the herbivorous rotifers, brachionid rotifers (Brachionus spp. consisting of 7 species) were the characteristic rotifer community in this study. Brachionus spp. tended to occur together with the other perennial species, Asplanchna. Asplanchna was also present while two species of B. angularis and B. calyciflorus were highest in density. Subsequently, two populations (B. angularis and B. calyciflorus) rapidly declined, becoming rare after high peaks of Asplanchna occurred, except in one tributary (Hwang R.). We found community shifts in rotifer groups in mid-spring and mid-fall at the study site. The Asplanchna population could be appeared to play an important role in regulating the rotifer community and total plankton biomass in spring and fall at high trophic levels.

보문 : 낙동강 중류지점에서의 동물플랑크톤 동태의 연간 변이 및 특성(낙동강)

김현우 ( Hyun Woo Kim ),장광현 ( Kwang Hyeon Chang ),주기재 ( Gea Jae Joo ) 한국하천호수학회(구 한국육수학회) 2005 생태와 환경 Vol.38 No.3

인터벤션 방사선발생장치에서 입사표면선량률 평가

강병삼(Byung-Sam Kang),장광현(Kwang-Hyun Chang) 대한방사선과학회(구 대한방사선기술학회) 2020 방사선기술과학 Vol.43 No.5

IVR procedures are on the rise, and patient doses are on the rise. It is necessary to evaluate fluoroscopy dose in IVR procedure. Evaluate ESD on IVR equipment as a reference to DRL settings, I would like to present the direction of improvement in the ESD rate test criteria for fluoroscopy dose. The experimental method is measured with 6cc ionization chamber under the 20cm PMMA Phantom. Radiation is subject to abdominal procedure. The average dose rate of the incident surface was 21.6 ± 11.4 mGy/min. The highest dose equipment was 58.5 mGy/min, and there was no equipment exceeding the domestic standard of 100 mGy/min. However, there were five units above 50 mGy/min. To reduce fluoroscopy dose, it is recommended to reduce pulse rate, The dose increases as the image receptor ages. It is recommended to modify the domestic inspection criteria to 50 mGy/min.

고체고분자 연료전지의 효과적인 산소확산과 내구성 향상을 위한 카본나노튜브에 담지된 백금 촉매의 합성과 적용

임은자(Eun Ja Lim),장광현(Kwang Hyun Chang),조성훈(Seonghun Cho),박석희(Seok-Hee Park),임성대(Sun-Dae Yim) 한국신재생에너지학회 2015 한국신재생에너지학회 학술대회논문집 Vol.2015 No.11

Dual source CT에서 high pitch chestpain cardiac scan mode를 이용한 angiography 검사의 유용성 평가

이대규(Dae Kyu Lee),이민영(Min Yung Lee),장광현(Kwang Hyun Chang) 대한CT영상기술학회 2015 대한CT영상기술학회지 Vol.17 No.1

목적 : 128 channel dual source computed tomography(이하 DSCT)의 high pitch mode를 이용하여 뇌혈관, 경동맥, 심장혈관을 1초 이하의 scan time 으로 한번에 검사하는 CT protocol 을 연구, 검사하였고 기존의 helical scan mode로 심장혈관을 검사하고, 조영제 추가 주입 후 뇌혈관, 경동맥을 같은 방법으로 검사한 영상을 비교하여 그에 따른 선량감소와 그 유용성을 비교해 보고자 하였다. 대상 및 방법 : 팬텀실험에서는 2개의 128-channel detector의 사용이 가능한 Somatom Definition Flash(Siemens Healthcare, Forchheim, Germany)CT 장비, organ dose 측정을 위해서 Alderson Rando phantom(CNMC Company, USA)을 사용하였다. 선량측정을 위해 형광유리선량계인 Dose Ace(GD-351, 12 mm, FGD-1000 reader, Asahi Techno Glass Cooperation, Shizuoka, Japan)를 사용하였다. 또한 유리 선량계를 주 선속 부위에 속하는 두부, 목, 폐, 심장 부위에 각각 2개씩 위치 organ dose를 측정하였다. 임상조건에서는 2014년 3월 부터 2014년 8월 까지 CCTA를 시행한 환자 210 명을 대상으로 이 중 heart rate가 60 이하인 104 명을 high pitch scan mode 로 검사하였고 106명은 helical scan mode로 검사하였다. Phantom 연구와 동일한 장비를 사용하고 같은 조건으로 나누어 검사 하였으며, 조영 증강을 위해서 이중 조영제주입기(dual flow injector, Stellant, Medrad, Inc, USA)를 사용하였다. 각각의 방법에서 두부, 목, 심장 부위의 CNR,SNR 을 측정하여 비교하였고, 영상은 4단계로 구분하여 2명의 영상의학과 심장판독 전문의가 평가하였다. 선량 평가는 CTDIvol, DLP와 유효선량을 평가하였고, 임상영상평가와 선량평가를 위한 통계학적 분석은 Levene의 등분산 검정을 통하여 정규성 검정을 하였고 통계학적 유의수준은 0.05 미만으로 하였다. 결과 : 1. Phantom 선량평가 : High pitch scan mode가 standard pitch scan mode & helical scan mode 에 비하여 effective dose 는 약 35.7% 정도 감소하였다(p<0.05). 2. 임상 연구 선량평가 : Head ~ coronary 까지 1 scan 으로 high pitch mode 에서 검사한 유효선량 값이 standard pitch & helical scan 로 나뉘어 2 scan 한 선량보다 약 30% 낮았다(p<0.05). 3. 임상영상평가 : 두 검사모드의 정성적 정량적 평가 값에서 모두 유의한 차이를 나타냈다(p<0.05). 결론 : Heart rate가 60대 이하이면서 안정된 환자에게 있어 Chest pain cardiac scan mode 로 검사 시, image quality는 떨어지지 않으면서도 2.5 mSv 이하의 저 선량으로 뇌혈관, 경동맥, 심장혈관을 한번에 검사할 수 있으므로 이는 곧 건강검진 환자나 심장 뇌혈관 질환 환자의 진단에 유용할 것으로 사료된다. Purpose : Using chest pain flash mode of 128 channel dual source computed tomography (below DSCT), we studied and tested one scanning CT protocol with less than 1 second scan time for intra cranial, carotid, and coronary vessel, then examined coronary angiography with helical scan mode, comparing the images that intra and carotid after injecting additional contrast media, following that purposed the dose reduction and usefulness. Materials & Methods: In this phantom test, Somatom Definition Flash (Siemens Healthcare, Forchheim, Germany)CT equipment for two 128-channel detector and Alderson Rando phantom(CNMC Company, USA) was used for the organ dose evaluation. For dose evaluation, Dose Ace (GD-351, 12 mm, FGD-1000 reader, Asahi Techno Glass Cooperation, Shizuoka, Japan) which is fluorescent glass dosimeter was used. Also, organ dose were measured by glass dosimeters positioning each two on head, neck, lungs and heart, belonging to the main flux. The clinical condition tested by high pitch scan mode with 104 patients whose heart rate was under 60 and tested by helical scan mode with 106 patients targeting 210 patients having CCTA from March 2014 to August 2014. Phantom studies using the same equipment and inspection were divided in the same condition, and the double-contrast injector (dual flow injector, Stellant, Medrad, Inc, USA) for enhancement was used. In the way each evaluated, was compared by measuring the head, neck and heart CNR, SNR, and evaluated two reading heart specialist of Radiology, separated by step of 4 images. Statistical analysis for the subjective assessment was used to Mann-Whiteny test of Graphpad Instat ver 3.05 and statistically significant was less than 0.05. CTDIvol, DLP and effective dose were evaluated to dose evaluation, for statistical analysis, normality test was used through equal variance examination, T- test were for analysis, and statistical significance level was done less than 0.05. Results: 1. Phantom dose evaluation: the effective dose of High pitch scan mode decreased about 35.7% (p <0.05) comparing to standard pitch scan mode & helical scan mode. 2. Clinical study dose evaluation: the effective dose value tested high pitch mode with one scan from head to coronary decreased about 30% (p <0.05) which done two scan by standard pitch and helical scan. 3. Clinical image evaluation: Both were significant differences in the two test mode for qualitative and quantitative evaluation value (p <0.05). Conclusion : If Scanning chest pain Flash scan mode for patients whose heart rate is below 60, it is possible that direct one scanning intra cranial, carotid, and coronary angiography exams with less than 2.5 mSv and image quality is equal. So it could be considered to diagnosis for health care and heart- brain vessel disease patients usefully.

어류군집과 하천주변 토지이용에 따른 회야강 수계와 인근하천의 건강성 평가

김정희 ( Jeong Hui Kim ),윤주덕 ( Ju Duk Yoon ),조현빈 ( Hyun Bin Jo ),장광현 ( Kwang Hyeon Chang ),장민호 ( Min Ho Jang ) 한국하천호수학회(구 한국육수학회) 2012 생태와 환경 Vol.45 No.4

In this study, to analyze the stream health using fish assemblage and make effective management, we conducted fish monitoring in the Hoeya River basin and neighboring streams. A total of 33 species classified into 12 families were collected from 29 sites in 2007. Dominant species was Zacco platypus (Relative abundance, RA: 24.8%), and subdominant species was Rhynchocypris oxycephalus (RA: 16.2%). Eight Korean endemic species and 4 exotic species were identified. Moreover, two species (Opsariichthys uncirostris amurensis and Hemiculter eigenmanni) were translocated from other basin. To evaluate stream health of the study sites, Index of Biological Integrity (IBI) was applied, based on fish assemblages. Overall, IBI values were "C (Fair)" or "D (Poor)" condition, according to the grade except two sites which recorded "B (Good)". The correlation between land use pattern of surrounding watershed and IBI was analyzed to verify impact of development on stream health using fish assemblage. As a result, when percentage of the developmental groups increased, IBI values were decreased (Pearson correlation, r=-- 0.425, p=0.022). In contrast, increment of percent forest and grass land was positively correlated with IBI (r=0.556, p=0.002). The agricultural group and IBI did not significantly correlate with each other (r=-- 0.231, p=0.333). In this study, we identified a relationship between land use of surrounding watershed and stream health using fish data (i.e. IBI). These results could be provided useful fundamental information to establish management and restoration plan in the Hoeya River basin and other rivers distributed in Korea.

한반도 평화통일 과정에서의 한미동맹 관리방안

홍성표 ( Hong Sung-pyo ),최승우 ( Choi Seung-woo ),장광현 ( Chang Kwang-hyun ) 한국군사학회 2018 군사논단 Vol.96 No.-

In terms of human-being’s long history, reunification of Korea has a right reason to be come true, based upon the principle of one nation one state. It is because of that South and North Korea has well preserved common nation character, language, custom, food and culture despite of recent 70-years national division. South Korean people’s opinion is revealed as quite optimistic in a public opinion census on the reunification of Korea. South Korean people expect reunification is born-natural, coming soon with dominant role by the Republic of Korea. South Korean people willingly welcome the burden sharing of the reunification. That means they want to unify the country keenly. Peaceful reunification of Korea is possible when it gets support of international community. Because Korean peninsula has been a focal point of four major powers’ interests. Particularly, the United States of America, China and Russia directly related to the division of Koreas, therefore they will not support the unification unless they are fully confident of their national interests. So, it is required for us to spread out the benefits of the unification to the world. It is also required for persuading other international groups including the European Union, the British Commonwealth, the African Union, the Union of South American Nations, and ASEAN. The ROK-US alliance has been a central axis for the ROK’s security and economic growth for last 70 years. It became a great model of bilateral alliances in the world. The ROK-US alliance has been mutually beneficial for both countries, and has great potential for international cooperations in the future. Based on 70 years accumulated know-how, the ROK and the US should strengthen the alliance further by continuing the development of cooperative measurements for the future. The two countries should pay more attention to their national actors for strengthening the precious alliance by mobilizing all the available contributors not only government organizations but also non-government organizations.

경안천 하류구간에 서식하는 어류의 분포 및 생태특성

이의행 ( Eui Haeng Lee ),김미리내 ( Mi Ri Nae Kim ),김현맥 ( Hyun Mac Kim ),손미선 ( Mi Sun Son ),장광현 ( Kwang Hyeon Chang ),남귀숙 ( Gui Sook Nam ) 한국환경생물학회 2013 환경생물 : 환경생물학회지 Vol.31 No.4

본 연구는 팔당호로 유입되는 경안천 하류구간에서 2010년에 집중강우 전(6월)·후(10월)로 구분하여 어류현장조사 및 생태특성을 분석하였다. 현장조사는 조사지점의 특성에 따라 일각망과 투망을 이용하였으며, 섭식특성은 종별 위내용물 분석을 통해 실시하였다. 현장조사결과, 총 5과 17종 970개체가 출현하였으며, 잉어과가 가장 많은 종(12종)이 출현하였고, 블루길(38%)과 피라미(24%)가 주요 우점종으로 나타났다. 외래도입어종은 3종423개체로 44%의 높은 상대풍부도를 보이는 것으로 나타난 반면, 한국고유종은 4종 98개체로 10%의 상대풍부도를 보였다. 생태지표특성 중 내성도 분석에 따르면, 내성종의 상대풍부도가 97%로 단연 우세하게 나타났으며, 민감종은 1종이 출현하였다. 영양단계 분석에 따르면, 블루길의 우점현상에 의해 충식종의 상대풍부도가 44%로 가장 높게 나타났다. 주요종에 대한 섭식특성은, 우점종으로 나타난 블루길이 치어, 수서곤충, 저서성무척추동물, 동물플랑크톤, 깔따구류(유충), 수초 등을 다양하게 섭식하여, 육식/충식성으로 판단되었으며, 아우점종인 피라미는 지각류가 섭식량의 90% 초과하는 비율을 차지하고 있었다. 향후 본 연구에 안정동위원소 분석을 병행한다면 종별 먹이망 내 정확한 위치파악이 가능할 것으로 사료되었다. Fish field survey, especially fish distribution and their ecological characteristics, was performed in the downstream region of Gyeongan stream during the period of before (June) and after (October) the summer monsoon in 2010. Depending on the characteristics of each site, fyke net or casting net was used for fish sampling. Feeding classification was determined by the analysis of stomach contents. Total number of family and species sampled were 5 and 17, respectively. The dominant family was Cyprinidae (12 species), and relative abundance (RA) of the most dominant species, Lepomis macrochirus and Zacco platypus, was 38% and 24%, respectively. Exotic species and Korean endemic species observed were 3 (423 individuals, RA 44%) and 4 (98 individuals, RA 10%), respectively. Tolerance guild analysis as characteristics of ecological indicators revealed an undoubtedly high percentage (97%), compared to others as reflected by the identification of just one sensitive species. Analysis of trophic guilds showed that L. macrochirus dominated among insectivores (44% RA). The food of L. macrochirus composed of, aquatic insects, benthic invertebrates, zooplankton, Chironomidae, and waterweed. Thus, we determined that L. macrochirus could be classified as insectivores (partially carnivores) in this study. Conversely, Z. platypus consumed Cladocera exclusively, greater than 90% of their feed. We presume that stable isotope analysis would identify the exact position of these species in the food web.