X-선 발생장치 시설의 방사선 차폐 해석

문석형,최호신,권석근,육종철 대한방사선 방어학회 1987 방사선방어학회지 Vol.12 No.1

X-선 발생장치 시설에 대한 방사선 차폐해석은 두가지 측면에서 고려된다. 먼저 1차 방사선과 누설방사선에 의한 영향을 고려하여야 하며 본 연구에서는 NCRP-49 및 51에 제시된 방법을 사용하였다. 둘째, 시설의 미로 출입구에서는 산란방사선에 의한 영향이 보다 중요한데, 본연구에서는 이 영향을 평가하기 위하여 Albedo개념을 근거로 한 단순한 방법이 제시되었고, 이를 토대로 계산된 결과를 컴퓨터 코-드(MORSE-CG)의 계산치 및 실측된 결과와 비교하였다. 본 연구에서 제시된 방법에 의한 결과는 미로출입구 안쪽의 경우에 대한 해석에서는 약간의 오차를 보이고 있으나 미로출입구 문바깥에서는 비교적 잘 일치한다. 여기서 출입문바깥의 경우에 대한 해석이 방사선방어 측면에서 보다 중요하다는 관점에서 볼 때 이 방법은 의료용 또는 산업용의 X-선 및 감마선시설의 차폐설계 및 해석이 응용될 수 있을 것이라고 판단된다. Radiation shielding analysis for a 6MeV X-ray facility was carried out. The primary and leakage radiation for the facility can be evaluated based on the methodology in NCRP No. 49 and 51. The present study deals with radiation scattering analysis for the outside and inside door of the facility based on the albedo concept. The calculated dose rates were compared with the results of MORSE-CG code calculation and the measured data, resulting in a good agreement, even though there existed some deviation for the inside door. These results can be utilized to the radiation shielding design of the medical and industrial X and gamma ray facilities, and to the safety evaluation of these facilities.

高等學校 生物敎科書에 取扱된 植物의 分類

文成基,高碩淳 慶星大學校 1992 論文集 Vol.13 No.2

This study was conducted to classify the plants dealt in 14 kinds of biology textbooks used by the high school student in Korea. These books based upon a newly-revised curriculum were written in 1990. The textbooks comprise 7 kinds of high school science book I (vol. I) and 7 kinds of high school biology. The results obtained were as follows 1. The plants dealt in the textbooks were 11 divisions, 102 families, 177 genera, 138 species, 35 sp., and 20 varieties. According to the category of division, the Spermatophyta was made up of 51 families, 114 genera, 110 species, 2sp., and 16 varieties, whereas, Euglenophyta was made up of 1 family, 1 genus, and 1 sp.. The former was dealt the largest numbers and the latter dealt the smallest. 2. In the science textbook Is (vol. I), textbook G dealt with the largest number of plants(55), while textbook B dealt with the smallest ones(27). In the biology textbook 'SA' dealt with the largest number of plants(82), and textbook 'MA' dealt with the smallest ones(46). 3. Among the 14 textbooks, all the books dealt with the plants of rice and bracken, and 13 books dealt with the plants of corn, pine tree, and onion, which were recognized as the most universal plants. All the 7 volumes of science textbook Is(vol. I) dealt with 6 kinds of plants such as bracken, mimosa, soybean, pea, onion, and rice, while the 7 volumes of biology textbooks dealt with 14 kinds of plants, which indicated that biology textbooks dealt with more various kinds of plants than the science textbook Is(vol. I ). 4. In the numbers of plants dealt by textbooks, textbook G dealt with the largest numbers of plant (16), and textbook 'BA' dealt with 12 kinds of plants. While textbook B dealt with the smallest on (3). Textbook 'RA' dealt with a particular plant only once. 5. In the point of dealt plants as experimental materials, onion was dealt the most frequently in the science textbook Is(vol. I), such waterweed, spinach, and soybean were in the biology textbooks. This suggest that biology textbooks dealt more parts of botanical experiment than textbook Is(vol.Ⅰ).

분산 화일 시스템에서의 일치성 유지기법

한문석,엄영익 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1

The replication and caching strategy of files in distributed systems enhances both the performance and scalability of the system by reducing communication overheads between clients and servers. In these distributed environments, consistency control mechanism is needed because shared files can be replicated in serveral servers and be cached in several clients. The consistency control mechanism in conventional distributed systems resolved most of the problems related to the file integrity and persistency of files. In some systems, to increase availability, it is allowed to update the replicas of the same file in several clients. But, in these situation, the file integrity may not be guaranteed and the results of some application programs can be lost.. In this paper, we present the consistency control mechanism that can guarantee the integrity and persistency of files in distributed computing systems.

일본의 해운기업 재무제표 변천 과정에 관한 연구

오문석,정희석 한국해운물류학회 2001 해운물류:이론과실천 Vol.- No.1

현재 우리 나라 해운업계의 심각한 환차손과 이에 연동하여 나타나는 높은 부채비율은 일반 기업회계준칙의 적용이 한 부분을 차지한다고 볼 수 있다. 또한 해운업계에 일반의 기업회계준칙을 폭넓게 적용하고 있지만, 해운업계의 구체적인 실무처리에 있어서는 회계관습을 준용하여 해운기업의 거래관행에 따라 회계처리가 이루어지고 있다. 이런 관점에서 해운업계의 특수한 환경을 고려한 제도적인 보완이 무엇보다 시급한 실정이다. 본고는 제도적인 보완측면에서 해운업계의 재무제표준칙의 필요성을 일본 해운기업의 재무제표준칙을 통해 제시해 보았다.

인벌류우트 기어 호빙 과정에 대한 해석

최석문,이상조,윤영식 연세대학교 산업기술연구소 1991 논문집 Vol.23 No.2

The cutting amount of each tooth in gear hobbing has much influence on the vibration of the hob axis and the wear of tool. In this study, with the simulation of gear hobbing mechanism, cutting parameters such as cutting thickness, cutting are and area moment were calculated. The cutting torque was also obtained by the experiments. The cutting amount of each tooth in the hob can be compared quantitatively by the simulation on the calculated cutting zone, cutting thickness and cutting are. And the cutting torque obtained by the experiments has the same tendency with the area moment calculated by the simulations. The results of this study can be applied to the research on the tool wear, the hob having modified tooth profile and the variation of cutting torque.

강재에 발생한 균열의 형상에 따른 피로강도

임문혁,김문석,김희중 啓明大學校 産業技術硏究所 1997 産業技術硏究所 論文報告集 Vol.20 No.-

It was well known that 70-80% of the fracture of steel plate was due to fatigue fracture. A fatigue behvaior of infinite steel plate was examined in this study. The stress concentration phenomenon around the hole in the steel plate was an important factor for the fatigue fracture. The diameter of the holes existing in the steel plate were varied from 0.1mm up to 0.4mm, and the number of hole was 1 and 3 in this study. It was shown that the stress concentration was exponentially increased as the angle of the crack in the plate was decreased. The initial value of stress concentration was smoothly increased as the diameter of hole was when the hole existed in the steel plate logarithmically decreased as the angle of hole was decreased. As a result of this study, it was found that the fatigue strength decreased extreamly when the small hole occurred in the steel plate. Consequently, greate care for fatigue strength should be excercised in designing steel mumbers.

정보보안 실습을 위한 시스템 구성 방법

서문석 대불대학교 2003 論文集 Vol.9 No.1

The model of system construction for practice room of department of information security is not suggested yet. The students majoring in the security are sharing computers constructed in the same class room with many other students majoring in IT related sciences. So, they don't get the full benefit of the security practies. In this paper, I suggest the system construction scheme consisting of network part, system part, and application program configuration part for the practice room to effectively share computers between students of information securoty and others. I hope that the adaptation of this scheme for construction of computer practice room comes in pretty handy for all students to develop the skill of the computer.

3차원 뇌자기공명영상을 이용한 강박증의 뇌형태학적 연구

공석원,송인창,한문희,장기현,류인균,권준수 대한신경정신의학회 2000 신경정신의학 Vol.39 No.6

연구 목적 : 강박증의 생물학적 원인으로 전두엽-선조체 회로의 이상이 알려져 있다. 그러나 형태학적 뇌영상을 이용한 기존의 연구는 전두엽과 미상핵의 용적 변화에 대한 일관된 결과가 없었다. 따라서 본 연구에서는 선형변환을 통한 반자동화된 방법을 이용하여 뇌의 각부위에 대한 형태학적 연구를 위하여 시행되었다. 방 법 : DSM-IV의 기준에 의해 진단한 13명의 강박증 환자와 9명의 정상대조군을 대상으로 하였다. 3차원 뇌자기공명영상을 Spoiled gradient-recalled(SPGR)법으로 얻었다. 3차원으로 재구성된 뇌자기공명영상을 Talairach와 Tournoux의 표준화 좌표에 공간적 정위시킨 후 회질과 백직을 반자동화된 방법으로 분리하였다. 죄표에 의거한 뇌엽의 각 부위에 대한 용적 측정을 하고, 미상핵은 수기로 구획한 후 용적측정을 하였다. 전두엽은 Brodman 의 영역에 의거하여 좌표계에 따른 분할을 하여 배외측전두엽, 안와전두엽, 내측전두엽으로 분할 구획하여 용적을 측정하였다. 결 과 : 강박증군에서 전두엽 회질의 용적이 증가되는 경향을 나타내었다. 다른 부위의 회질과 백질 그리고 미상핵의 용적은 차이가 없었다. 편측성에 의한 차이도 없었으며, 임상적 심각도와 상관관계는 관찰되지 않았다. 결 론 : 본 연구에서는 강박증군에서 전두엽의 용적 증가를 관찰할 수 있었으며, 이것은 기존 연구 중 일부에서 전두엽과 미상핵의 용적 감소를 보고했던 것과 차이가 있다. 강박증이 만성화되고 일정기간 이상이지나 구조적 변화가 오기 전까지 오히려 대사와 혈류 증가에 따른 회질 용적 증가가 관찰되는 것이라 생각된다. Objectives: Neurobiological models for obsessive-compulsive disorder(OCD) have consistently Implicated prefrontal-striatal circuits in the pathophysiology of this disorder. But, prior studies have inconsistently found alteration in caudate and frontal lobe volumes in patients with OCD. This study was undertaken in the hope that semi-automated linear transformation methods would elucidate the morphometric differences of various parts of brain between OCD and normal control group. Methods : Thirteen parients meeting the DSM-IV criteria fro OCD, and 9 psychiatrically normal comparison subjects participated in the study. 3-D brain MRIs using Spoiled gradient-recalled(SPGR) sequence were acquired for each subjects. After spatially normalized according to Talairach and Tournoux's coordinates, the gray and white matters were segmented by semi-automated methods using fuzzy algorithm. Each lobal volumes was measured according to Talairach and Tournoux's coordinates, and the region of interests of caudate nuclei was manually traced. The frontal lobe was divided into 3 subregions ; dorsolateral prefrontal cortex, orbital frontal cortex, mesial frontal cortex accoring to the coordinates and Broadman's cytoarchitectonics. Results : Only the volume of left and right frontal gray matter showed a significant difference between OCD and normal subjects. In OCD, the frontal gray matter volume was increased in tendency. There's no difference in laterality and no coorelation with clinical severities. Conclusion : Findings of increased frontal gray matter volumes in patients implicate a structural abnormality of these brain regions in the pathophysiology of OCD. The increased frontl gray matter volumes reflect a epiphenomena due to increased cerebral blood flows and metabolic rates before the structural changes may occur.

유기용제에 장기간 폭로된 근로자의 정신의학적 기능과 삶의 질

김석재,강순아,유지숙,국승희,윤진상,문재동,이형영 大韓神經精神醫學會 2000 신경정신의학 Vol.39 No.5

연구목적: 본 연구는 Y공단의 제조공정에서 저농도의 유기용제(solvent)에 장기간 노출된 근로자의 정신의학적 기능과 삶의 질을 평가하고자 하였다. 방법: 총 142명의 남성근로자 중 유기용제에 폭로된 군(이하 폭로군) 82명과 폭로되지 않는 군(이하 비폭로군) 60명에게 간이정신진단검사(Symptom Checklist-90-R, SCL-90-R), 인지 및 정신운동성검사 (Critical Flicker Fusion Threshold. CFFT; Choice Reaction Time, CRT;Compensatory Tracking Task, CTT;Digit-Symbol Substitution, DDS) 및 한국판 스미스클라인 비챰 삶의 질 척도(Korean version of the SmithKline Beecham 'Quality of Life' Scale, KvSBQOL) 등을 적용하였다. 두 군간의 비교는 평가치의 평균에 대해 t-검증을 하였고 또한 연령과 학력을 공변인으로한 공변량분석(ANCOVA)을 하였다. 결과: SCL-90-R의 9개 증상 차원과 3개 전체 지표 점수는 두 군이 각각 정상범위였다. 그러나 신체화 (Somatization, SOM), 우울(Depression, DEP), 적대감(Hostility, HOS), 공포불안(Phobic anx-iety, PHOB)의 증상차원과 전체심도지수(Global Severity Index, GSI), 표출증상합계(Positive Symptom Total, PST)의 전체 지표는 폭로군이 비폭로군보다 유의하게 높았다. 인지 및 정신운동성 검사와 삶의 질은 두 군간에 유의한 차이는 없었다. 결론: 이상의 결과는 유기용제가 허용치 이하일지라도 장기간 폭로되는 경우에는 정신의학적 문제를 다소 일으킬 수 있음을 시사하였다. 중심단어:유기용제·근로자·정신건강·정신운동성 기능·삶의 질. Objectives: The aim of this study was to evaluate the psychiatric function and quality of life of the chemical workers who had been exposed to long-term, low-level organic solvents in the Y industrial complex. Method: A total of 144 male workers, of whom 82 were in the exposed group and 60 in the unexposed-control group, were evaluated by using Symptom Checklist-90-R(SCL-90-R), series of neuropsychological tests(critical flicker fusion threshold, CFFT) ; choice reaction time, CRT ; compensatory tracking task, CTT) ; digit symbol substitution test, DSS), and the Korean version of the SmithKline Beecham Quality Of Life scale(KvSBQOL). For the statistical analyses, comparisons of the means of the two groups were performed for each variable with two-tailed t-test as well as ANCOVA including age and education as covariates. Results: For the SCL-90-R, the nine symptom scales and the three global indices were clinically within normal range in both groups. However, the scores on the symptom scales of 'somatization','depression','hostility' and 'phobic anxiety', and those on the global indices of 'global severity index' and 'positive symptom total', were significantly higher in the exposed group than in the unexposed group. In terms of the neuropsychological function and the quality of life, there wes no significant difference between the two groups. Conclusion: These findings suggested that the long-term eposure to mixed organic solvents, even at the low level below the permissible exposure limit, might induce some psychiatric problems. KEY WORDS: Organic solvent·Worker·Mental health·Psychomotor function·Quality of life.

학습구조차트를 이용한 학습 활동이 수학 학습에 미치는 효과

임석훈,안문자 慶北大學校 師範大學 科學敎育硏究所 2002 科學敎育硏究誌 Vol.26 No.-

Teachers tend to believe that their students may not only fully understand what they have been taught in the classroom by self-studying and solving that problems but also perceive the structural relations in all the contents of learning. What they are studying at school, however, is totally new and strange to them. The relations, in the learning elements and contents, are difficult to understood. The purpose of this study is to show the effects of Professor Saito Noboroo's Climbing Learning Method using Learning Element Structure Chart. This method, in ither words, is the way of making learners form basic concepts and learn the relations of concept with handing out the concrete charts of the conceptional structures which are in teacher's mind. We have ben trying to find out the gradual effects to the Mathematics study after this method was applied to the two modeling classes of second year girls' middle school for six months or so.