Investigation on Individual Variation of Organ Doses for Photon External Exposures: A Monte Carlo Simulation Study

이유미,Ji Won Choi,Lior Braunstein,Choonsik Lee,염연수 대한방사선방어학회 2024 방사선방어학회지 Vol.49 No.1

Background: The reference dose coefficients (DCs) of the International Commission on Radiological Protection (ICRP) have been widely used to estimate organ doses of individuals for risk assessments. This approach has been well accepted because individual anatomy data are usually unavailable, although dosimetric uncertainty exists due to the anatomical difference between the reference phantoms and the individuals. We attempted to quantify the individual variation of organ doses for photon external exposures by calculating and comparing organ DCs for 30 individuals against the ICRP reference DCs. Materials and Methods: We acquired computed tomography images from 30 patients in which eight organs (brain, breasts, liver, lungs, skeleton, skin, stomach, and urinary bladder) were segmented using the ImageJ software to create voxel phantoms. The phantoms were implemented into the Monte Carlo N-Particle 6 (MCNP6) code and then irradiated by broad parallel photon beams (10 keV to 10 MeV) at four directions (antero-posterior, postero-anterior, left-lateral, right-lateral) to calculate organ DCs. Results and Discussion: There was significant variation in organ doses due to the difference in anatomy among the individuals, especially in the kilovoltage region (e.g. , <100 keV). For example, the red bone marrow doses at 0.01 MeV varied from 3 to 7 orders of the magnitude depending on the irradiation geometry. In contrast, in the megavoltage region (1–10 MeV), the individual variation of the organ doses was found to be negligibly small (differences <10%). It was also interesting to observe that the organ doses of the ICRP reference phantoms showed good agreement with the mean values of the organ doses among the patients in many cases. Conclusion: The results of this study would be informative to improve insights in individualspecific dosimetry. It should be extended to further studies in terms of many different aspects (e.g. , other particles such as neutrons, other exposures such as internal exposures, and a larger number of individuals/patients) in the future.

In vivo와 in vitro 에서 양극산화 처리한 타이타늄 시편의 상대적인 생체적합성 평가

이유미,이은정,염동선,김도순,이성태,김병일,조현욱,Lee Yu-Mi,Lee Eun-Jung,Yeom Dong-Sun,Kim Do-Soon,Yee Sung-Tae,Kim Byung-Il,Cho Hyun-Wook 한국생명과학회 2006 생명과학회지 Vol.16 No.2

처리하지 않은 타이타늄과 양극 산화 처리한 타이타늄 시편의 생체적합성을 평가하기 위해, 시편을 마우스의 복부 피하 조직에 이식하고 2주 동안 생존시켰다. 그 시편에 대한 복부 피하 결합조직의 반응을 조직학적으로 조사하였다. 시편 주위를 둘러싸는 섬유성 결합조직 막이 관찰되었으며 이 막은 섬유모세포, 섬유세포 및 기타 세포로서 중성호성백혈구, 대식세포, 거대다핵세포 등으로 이루어져 있었다. 시편을 둘러싸는 이 막에 새로이 형성된 혈관이 존재하기도 하였다. 임플란트와 접하는 섬유성 막에 거대다핵세포가 관찰되었다. 섬유성 막에 있는 세포 종류와 막의 두께를 조사하였다. 막에 있는 대부분의 세포는 섬유모세포와 섬유세포이었다. 양극 산화 처리를 하지 않은 타이타늄 시편에 비해 산화 처리를 한 시편을 둘러싸는 섬유성 막의 평균 두께가 더 얇았다. 또한 타이타늄 시편의 생체적합성을 세포 배양법으로 조사하였다. 산화 처리를 한 시편 위에서 배양한 MG-63 세포의 수가 유의하게 증가되었다. 이런 결과들은 in vivo 와 in vitro 실험에서 산화 처리를 한 타이타늄 시편이 생체적합성을 증가시키는데 효과적이라는 것을 말해준다. To evaluate the biocompatibility of untreated and anodized titanium specimens, the specimens were implanted in the subcutaneous tissue of the abdominal region of female mice for two weeks. The reaction of connective tissue to specimens was histologically studied. The implants were encapsulated by fibrous connective. tissue consisting of fibroblast, fibrocyte and other cellss including neutroophil, macrophage and giant multinucleated cell. some newly formed blood vessels were located in the fibrous capsule surrounding the implant. Giant multinucleated cells were observed at the fibrous capsule adjacent to the implant. Kind of cell types and the thickness of fibrous capsules were examined quantitatively. Most of cell types located in the fibrous capsule were fibroblast and fibrocyte. The average thickness of fibrous capsules for the anodized specimens was much thinner than that of the untreated titanium specimen. Biocompatibility of titanium specimens were also studied by using cell culture method. The number of MG-63 cells was significantly increased on the anodized titanium specimens in vitro experiment. Our observations suggest that anodized titanium specimens are more effective for the improvement of biocompatibility in vivo and in vitro.

대학캠퍼스공간에서 여대생이 느끼는 범죄불안감에 관한 연구

이유미,Lee, You-Mi 한국교육시설학회 2013 敎育施設 Vol.20 No.1

This study aims to investigates the female collegian's the fear of crime in university campus. In order to deal with it, the questionnaire survey on the analysis of the female collegian's the fear of crime are conducted in 3 university campuses in Seoul. The results of the 228 questionnaires survey are analyzed in descriptive statistics through SPSS program. This study compares female collegian's the fear with male collegian's one. The result of this are the followings ; 1) The female have the bigger concerns than the male about the crime expected to happen to herself. 2) At night the female are limited in activity than male because of the fear of crime. 3) During day the female have the bigger fear of crime than the male in the space such as stairways and hallways, toilet, and elevator. 4) At night the female have the bigger fear of crime than the male in not only stairways and hallways, toilet, elevator but also pedestrian, green space, recreational space. 5) This study proved the correlation between the collegian's satisfaction about university campus safety and the collegian's satisfaction about university campus environments etc.

산림정보 - 밤이면 잠자는 연꽃 닮은 '물의 요정'

이유미,Lee, Yu-Mi 한국산림경영인협회 2010 山林經營 Vol.197 No.-

우리나라 단독주택 내부의 평면적 구성방식과 입체적 구성방식에 관한 연구

이유미,Lee You-Mi 한국주거학회 2005 한국주거학회 논문집 Vol.16 No.1

This study aims to analyze interior spatial characteristics of Korean single-family house which were designed by architects. For that purpose, plans, pictures and data of Korean single-family 113 houses which appeared in architectural publications from 1998.7 to 2002.6. were collected. The results of this study are the followings; 1) the ratio of southern-facing is higher in living room and master bedroom than in dining room and kitchen; 2) spatial elements of master bedroom are bedroom, bathroom and dressroom, those of dining room and kitchen are dining room, kitchen and multipurpose room and those of family bathroom are bathroom and restroom; 3) the living room does not located in the center of the plan; 4) the ratio of exterior door is higher in kitchen and master bedroom than in dinning room and living room; 5) stairs located in hall, corridor, livingroom etc., 6) there are void spaces in about half of houses which were collected.

대학 캠퍼스 보행자 이동패턴과 보행네트워크간의 상호관련성

이유미,신행우,Lee, Yu-Mi,Shin, Haeng-Woo 한국교육시설학회 2014 敎育施設 Vol.21 No.2

Many Korean university campuses are located on hilly terrain where the hierarchy of the path system is unclear. Therefore, it is difficult to analyze the pedestrian network through space syntax, in which only horizontal direction changes are considered as depths of space. The purpose of this study is to compare pedestrian movement patterns and space syntax analysis in order to find their relevance to each other and the relationship between them. We conducted a survey regarding the most-visited buildings and pathways at S-University, which is located on a hilly area in Seoul. The survey results were compared with the Space Syntax integration map by regression analysis. For the segments where the relationship between pedestrian volume and integration was weak, field observations were conducted. As a result, topographical aspects, functional aspects, and location aspects were observed as the main influential factors. In addition, the research proposes that adding an extra axial line per vertical directional change can potentially compensate for the low relevance of stairs. This study suggests the possibility and the necessity of three-dimensional space syntax programs and emphasizes the importance of campus planning for the pedestrian environment.

십이지장 폐쇄를 동반한 선천성 식도 폐쇄에 대한 고찰

이유미,남소현,김대연,김성철,김인구,Lee, Yu-Mi,Nam, So-Hyun,Kim, Dae-Yeon,Kim, Seong-Chul,Kim, In-Koo 대한소아외과학회 2008 소아외과 Vol.14 No.1

There is significant morbidity and mortality associated with the combination of esophageal atresia (EA) and duodenal atresia (DA). Nevertheless, the management protocol for the combined anomalies is not well defined. The aim of this study is to review our experience with the combined anomalies of EA and DA. From May 1989 to August 2006, seven neonates were diagnosed as EA with DA at Asan Medical Center. In all cases, the type of EA was proximal EA and distal tracheoesophageal fistula (TEF). The diagnosis of DA was made in theprenatal period in 1, at birth in 4, 4 days after birth in 1 (2 days after EA repair) and at postmortem autopsy in 1. Except the one case where DA was missed initially, primary simultaneous repair was attempted. DA repair with gastrostomy followed by EA repair in 2, EA repair followed by DA repair without gastrostomy in 2, and TEF ligation followed by DA repair with gastrostomy in 1. There were two deaths. One baby had a large posterolateral diaphragmatic hernia, and operative repair was not attempted. The other infant who had a TEF ligation and DA repair with gastrostomy expired from cardiac failure due to a large patent ductus arteriosus. Simultaneous repair of EA and DA appears to be an acceptable management approach for the combined anomalies, but more experience would be required for the selection of the primary repair of both anomalies.

공동주택단지에서의 범죄피해경험율과 범죄로부터의 안전성(safety) 평가 지표간의 상관성 분석에 관한 연구

이유미,Lee, You-Mi 한국주거학회 2008 한국주거학회 논문집 Vol.19 No.2

The purpose of this paper is to analyze the correlation analysis between the experienced crime victimization rate and the evaluation indicator of residents' safety of outdoor spaces from crime in multi-family housing. Additionally this paper intend to analyze the correlation analysis between the residents' satisfaction about safety and the evaluation indicator of residents' safety of outdoor spaces. For that purpose, 9 Multi-Family Housing located in the metropolitan area were selected to perform a survey against 349 residents during May 26-29, 2006. The SPSS program was used and the level of satisfaction ranged from 1 to 5. Scale of 5 being most satisfied while 1 being most dissatisfied. The results of this study are the followings; 1) Most occurred crime were auto theft and damages, poster matter theft, housebreaking. 2) The crime rate is higher in outdoor than in indoor. 3) This study proved the correlation between the residents' satisfaction about housing safety and most indicators except the number of households etc. 4) By the results of the correlation coefficient it makes clear that the number of apartment building, the visibility of Green Space, the location of pedestrian etc. have relation with the residents' satisfaction about housing safety.

인텔리전트아파트 시스템에 대한 수요자 그룹별 요구 분석 연구

이유미,임미숙,김석경,Lee, You-Mi,Yim, Mi-Sook,Kim, Suk-Kyung 한국주거학회 2007 한국주거학회 논문집 Vol.18 No.5

This study aimed to analyze residential demands on intelligent systems for apartments and suggest space design directions of intelligent apartment complexes. Data collection was done through mail-in surveys by five respondent groups. Outcomes of this study would provide basic data for developing intelligent apartment housing corresponding to the residential characteristics and demands of the five respondent groups. The sample size for the questionnaire survey was 592. The types of the target residents in this study were classified into five categories; nuclear families, dual income families, single households and the handicapped needing special environmental supports, and workers at home who need the new home design with a home office. The primary findings of this study were as follows. 1) For the controllers of intelligent system, nuclear families preferred TV, single households prefer home-pad which is movable and provides access to the internet. Dual income families, the handicapped and workers at home preferred remote control panels. 2) For the desirable space for computer equipment, regardless of the types of target residents, bedroom and living room were preferred. 3) For the desirable space for a home theater system, most of respondent groups preferred living rooms, but many rather wanted to have media rooms only for this system.

A Study on the Function of Oral Medicine as the Secondary Clinic Based on Analysis on Admissive Channel and Case Features

이유미,이정현,임현대,Lee, You-Mee,Lee, Jung-Hyun,Lim, Hyun-Dae Korean Academy of Orofacial Pain and Oral Medicine 2006 Journal of Oral Medicine and Pain Vol.31 No.3

The epidemiological researches on the inpatients hospitalized at the oral medicine ward have been continuously carried out since 1970, and most researches have been performed by centering around the oral medicine wards of college hospitals. Numerous specialists have been produced after the establishment of oral medicine, and they have been active in various fields. As dental clinics have gotten bigger, the function of oral medicine in the secondary clinics is being brought out. As admissive channel, case features, case composition and otherwise have not been researched for a long time, the related researches should be carried out from now on. Hereupon, this study was carried out by targeting the 100 inpatients hospitalized at the oral medicine ward of Sun Hospital located in Daejeon Korea, through questionnaire. As the result, the following results were derived. 1. The ages of the inpatients in Sun Hospital were $29.21{\pm}11.31$ on the average; 71 females' mean average was $29.63{\pm}11.29$ and 29 males' mean average was $28.17{\pm}11.48$. In regard of school career, the patients who finished high-school course or higher accounted for 78%; the patients' school career seemed to be relatively high. The patients who complained of temporomandibular pain accounted for the highest proportion with 65%. In motivation to visit this hospital, internet surfing was 11%, mass media was 10%, acquaintance's introduction was 38%. The patients, who were hospitalized at another hospital due to the same symptom, accounted for 56%. The dental clinics, which made the patients visit this hospital, accounted for 20%. The patients, who were previously aware that the present symptom should be treated by oral medicine, accounted for 38%. The patients, who were not aware of the fact in advance, were 62%. The respondents of 51% answered that they were aware of the fact one month or below before hospitalization. 2. The patients, who complained of craniocervical ache, accounted for 58%; the patients, whose ache aches affect dailylife, were 22%. Continuous ache was 14% and intermittent ache was 68%, and dull pain was 23%. 3. Life variations were compared with each other by using SRRS (Social Readjustment Rating Scale). In consequence, the variation within 3 years indicated a significant difference in the both groups but the variation within 6 months did not indicate any differences. 4. In regard of the questionnaire on the incidents happened for a week, the ache-group was compared with the group free from the ache. As the result, the number of strain arisen for a week, the decrease of favorite works and sudden fear indicated a significant difference. Pleasant feeling and the decrease of interests in looks did not indicate a significant difference, but came close to the significance. 5. In the questionnaire on impatience, the ache-group indicated higher value but there was not a significant difference. 6. In the questionnaire on the symptoms caused by stress, the two groups indicated significant differences in the item of 'the teethridge itches and feels a tooth rising' and 'the occiput or the nape is stiff.' In the item 'the inside of the cheek or the teethridge are widely peeled off, accompanied with ache and hemorrhage', 'the face has acne or pimple' and 'headache frequently attacks', a significant difference was not observed but the two groups came close to the significance.