한국 연안 퇴적물에서 ^137Cs, ^90Sr 및 Pu 동위원소의 분포

최석원,진현국,김철수,노정환,김창규,노병환 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.2

한국 주변 연안 15개 정점의 퇴적물(0∼20 cm)에서 ^137Cs, ^90Sr, ^239+240Pu 의 농도와 농도비를 조사했다. ^137Cs, ^90Sr, ^238Pu 및^239+240Pu의 평균 방사능 농도는 각각 2.24±0.79 Bq·kg^-1-dry, 0.20±0.04 Bq·kg^-1-dry, 0.009±0.005 Bq·kg^-1-dry 및 0.27±0.17 Bq·kg^-1-dry이다. ^137Cs/^90Sr, ^239+240Pu/^137Cs 및 ^238Pu/229+240Pu의 평균 농도 비와 ^239Pu/240의 평균 원자 비는 각각 11.2±2.9, 0.123±0.053, 0.033±0.01 및 0.218±0.036이다. 퇴적물에서 핵종의 농도 범위와 핵종간의 농도 비는 그 동안 주변국가의 퇴적물에서 조사한 값과 비슷하였다. 퇴적물에서 ^137Cs과 ^239+240Pu의 상관계수는 0.80이다. ^137Cs과 SOM, ^239+240Pu과 점토 함량과의 상관계수는 각각 0.69, 0.67 이다. The concentrations and activity ratios of ^137Cs, ^90Sr, ^238Pu and ^239+240Pu in sediment(0∼20 cm) at 15 coastal stations of Korea were determined. The mean concentrations of ^137Cs, ^90Sr, ^238Pu and ^239+240Pu are 2.24±0.79 Bq·kg^-1-dry, 0.20±0.04 Bq·kg^-1-dry, 0.009±0.005 Bq·kg^-1-dry and 0.27±0.17 Bq·kg^-1-dry, respectively. The mean activity ratios of ^137Cs/^90Sr, ^239+240Pu/^137Cs and ^238Pu/^229+240Pu and atomic ratio of ^240Pu/^239Pu are 11.2±2.9, 0.123±0.053 and 0.033±0.017 and 0.218±0.036, respectively. The concentrations and activity ratios in sediment samples are similar to those reported from neighbouring country in the northern hemisphere. The correlation coefficient of ^137Cs and ^239+240Pu is 0.80. The correlation coefficient of ^137Cs and soil organic matter(SOM), and ^239+240Pu and clay content are 0.69 and 0.67, respectively.

북한이탈주민의 외상 후 스트레스 장애와 자연살해세포 활성

김병창,정성훈,임효덕,최종혁,전정희,전양환 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.5

Objectives : The objective of this study was to evaluate an association between posttraumatic stress disorder (PTSD) and altered immunity m North Korean defectors who were more likely to develop medical conditions and other stress-related psychiatric disorders. Methods : Twenty-four North Korean defectors with PTSD and twenty-two controls without PTSD were recruited from the resettlement and training center for North Korean defectors in South Korea. Peripheral T lymphocyte subsets, natural killer(NK) cells, NK cell activity and plasma hormones (ACTH and cortisol) were obtained from all subjects. We also applied the Hamilton Rating Scale for Depression (HAM-D) and Hamilton Rating Scale for Anxiety (HAM-A) for all subjects. Results : We found NK cell activity was relatively lower than number of NK cells in North Korean defectors with PTSD. Subjects with PTSD had higher HAM-D and HAM-A scores than controls. However, there were no statistical differences in ACTH. cortisol, CD3, CD4, CD8, CD4/CD8 ratio, CD19 and CD56 between the two groups. Conclusion : These findings suggest North Korean defectors with PTSD show higher levels of depression, anxiety and impaired or weak immune function in NK cells.

ECT (European Compression Technic) System 을 사용한 下顎骨 骨折의 治驗例

金晤煥,申曉根,宋采炫,崔秉河,權泰鎬 全北大學校 齒醫學硏究所 1983 전북치대논문집 Vol.1 No.1

The authors in the Dept. of Oral & Maxillo-facial Surgery.J.N.U Hospital could have the following results after treatment of eight mandibular fractures patients with the E.C.T.(European Compression Technic)System. 1. Accurate reduction of the fractured bone. 2. Minimization of the soft tissue injury during operations. 3. No post-operative intermaxillary fixation was necessary. 4. Good recovery of the occlusion.

객체지향 개념 모델링에서 OCL에 의한 상속성 원리

이지연,최병문,이영환 대전대학교 기초과학연구소 2003 自然科學 Vol.14 No.1

OOA/D에서는 클래스의 일반화와 특수화의 계층구조 사이에서 상속성의 개념이 어디까지 보장되는지 명확한 규칙이 없다. 예를 들어 상위 클래스의 제약조건이 하위 클래스에도 상속되는지, 상위 클래스의 상태 다이어그램이 하위 클래스의 상태 다이어그램에도 상속되는지, 하위 클래스의 행위는 상위 클래스의 행위를 제한시키는 것인지 확장시키는 것인지 등의 문제가 명확하지 않다. 또한 역할과 하위 클래스 설정 문제도 혼동이 일어난다. 본 논문에서는 Liskov의 치환 규칙에 의하여 정적인 면과 동적인 면을 동시에 고려한 상속성 원리를 OCL을 사용하여 정립한다. 이에 따라 역할, 일반화, 특수화, 집합체와 합성에 관한 개념의 가이드라인도 제시한다. There are no explicit rules in OOA/D to indicate whether or not the generalization and specialization hierarchy on a superclass is inherited by its subclasses. For example, we have relevant questions: ls a constraint on a suerclass is inherited by its subclasses? Does subclasses inherit the state diagram of the superclass? Can it refine this state diagram by adding. removing or redefining states, transitions, or events? Can it restrict the behavior of the generalization classes or extend it both? Many methods do not answer these questions. Also concepts of role and subclass are confused in the problem of structure. In this paper, we give an OCL formalization of inheritance by Liskov's Substitution Principle and propose a general guide-lines of concepts of role, generalization, specialization, aggregation, and composition.

위성망에서 효율적인 순방향 에러정정 기법

박태근,김영환,박재현,박현민,최병석 明知大學校 産業技術硏究所 1999 産業技術硏究所論文集 Vol.18 No.-

In this paper, a new method of FEC(Forward Error Correction) using multi-stage Viterbi coder is proposed, with effectively reduce BER in satellite ATM Networks. In terms of structural complexity, proposed multi-stage Viterbi coder simpler than the traditional single-stage coder based on the same BER performances. And, through simulation, proposed coder shows excellent error correction capabilities compared with traditional FEC schemes. Also, we propose a selective FEC mechanism that adaptively changes the number of stages to satisfy the QoS(Quality of Service) requirements. This Selective scheme can be easily implemented using the PLCP(Physical Layer Convergence Protocol) frame structure.

니트섬유강화 복합재료의 기계적 성질에 관한 연구

한길영,이동기,최병기,오환교,신용욱,전수영 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

Using conventional textile techniques such as weaving, braiding, knitting and stitching it is possible to produce a wide range two and three dimensional fiber preforms. However, so far only a limited attention has been given to knitted fabrics in composite industry. This is mainly due to the opinion that knitted fabric reinforced composites posses low mechanical properties owing to their looped fiber architecture. But it is possible to obtain desired mechanical properties by selecting proper knitted fabric structure. In this paper, tensile failure load and displacement of one yarn, four yarns and knitted fabrics of ten yarns of kevlar fiber were determined experimentally in the unidirection. Mechanical properties of plain weft knitted fabrics reinforced composite intrusion beam for car side door application were investigated experimentally, which compared with desire value of American Fedral Motor vehicles Safety Standard (FMVSS) and presented the results.

VOD 서비스에서의 새로운 스트림 할당 기법

이준화,김영환,박재현,박현민,최병석 明知大學校 産業技術硏究所 1999 産業技術硏究所論文集 Vol.18 No.-

Generally, in a VOD(Video On Demand) systems, batching technique is often used to improve throughput. Since subscribers to VOD services tend to renege their requests as the latency becomes large, an optimal stream allocation scheme should consider not only batching size but also renege rate, service latency and fairness between different programs. In this paper, we propose a new stream allocation scheme, which shows improvement in fairness and reduction in renege rate and service latency compared with other well known schemes. When 2 or more streams are available in the VOD server, each streams are allocated based on different program selection policies. Using this approach effectiveness of stream usage can be improved.

모 컴퓨터 회사 근로자 건강증진 사업 전개를 위한 수요조사

임현우,안병용,최환석,박정일,김경수,이강숙,김정아,구정완 가톨릭대학산업의학쎈타 산업의학연구소 1997 韓國의 産業醫學 Vol.36 No.4

Before conducting the health promotion program, we surveyed the health risk appraisal(HRA) of 210 workers (186 men and 24 women) in a computer company, for the need assessment, selection of target population, priority setting, and as a standard for comparision after performing the program. The smokers were 115(88.6%), and drinkers (over 1 bottle of Soju per week) were 91(44.8%) in men. Entire women and 148(78.0%) men never or irregularly exercise. Type A personality were 73(39.2%) in men, 8(33.3%) in women, and 26(14.0%) of men and 6(25.0%) of women were high stress risk group. 53(25.2%) of men and 2(8.3%) of women were obese (BMI ≥25kg/m²), and workers who consumed exess of total calory compared with recommendation were 142(76.3%) in men and 18(75%) of women. By the health risk appraisal, it was suggested that smoking cessation program, drinking counselling, exercise prescription, stress management, and weight control program should be conducted effectively for the high risk group.

분산 시스템에서의 스스로 - 안정되는 알고리즘

최병환(Byung Whan Choi),이경희(Kyung Hee Lee),이충세(Chung Sei Rhee) 한국정보과학회 1998 한국정보과학회 학술발표논문집 Vol.25 No.1A

최근 들어 분산 컴퓨터에 대한 중요성이 크게 부각되고 있다. 최근의 네트워크 시스템의 발전과 중요성의 증대에 따라 분산된 시스템들의 응용 설계 등에 대한 연구가 많이 진행되고 있다. 분산 시스템을 구성하고 있는 프로세서에서 오류가 발생했을 때, 이를 교정하기 위한 방법으로서 시스템의 외부의 간섭 없이 스스로 수정작업을 수행한다면 수많은 프로세서가 상호 연결된 분산 시스템에서 최적의 상태를 유지하는데 편리할 것이다. 이러한 특성을 가진 시스템, 즉 시스템이 스스로 오류를 교정하여 안정된 상태를 유지하는 알고리즘을 스스로-안정되는(self-stabilizing) 알고리즘이라 한다. 이 논문에서는 1974년 Dijkstra에 의하여 처음으로 도입된 스스로-안정화하는 알고리즘에 대하여 그 동안 이루어진 연구 방법들을 분석하고 앞으로의 연구방향을 제시한다.

Induction of G1 arrest and apoptosis by schisandrin C isolated from Schizandra chinensis Baill in human leukemia U937 cells.

Park, Cheol,Choi, Young-Whan,Hyun, Sook Kyung,Kwon, Hyun Ju,Hwang, Hye Jin,Kim, Gi-Young,Choi, Byung Tae,Kim, Byung-Woo,Choi, Il-Whan,Moon, Sung-Kwon,Kim, Wun-Jae,Choi, Yung Hyun D.A. Spandidos 2009 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.24 No.4

<P>We isolated two phytochemical lignans, schisandrin and schisandrin C, from Schizandra chinensis Baill and investigated their anti-cancer effects in human leukemia U937 cells. Schisandrin C inhibited cell growth in a dose-dependent manner, which was associated with the induction of G1 arrest of the cell cycle and apoptosis; schisandrin did not inhibit growth. Schisandrin C induced G1 arrest was correlated with down-regulation of cyclin D1, cyclin E, cyclin-dependent kinase (Cdk) 4 and E2Fs expression, inhibition of phosphorylation of retinoblastoma protein (pRB), and up-regulation of the Cdk inhibitor p21(WAF1/CIP1). In addition, schisandrin C-induced apoptosis was associated with down-regulation of expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, proteolytic activation of caspase-3 and -9, and a concomitant degradation of poly(ADP-ribose) polymerase (PARP). Furthermore, schisandrin C-induced apoptosis was significantly inhibited by a caspase-3 specific inhibitor z-DEVD-fmk, indicating an important role for caspase-3 in the schisandrin C mechanism. In summary, growth inhibition by schisandrin C is related to cell cycle arrest at G1 and induction of caspase-3-dependent apoptosis in U937 cells; these findings suggest that schisandrin C may be a useful chemotherapeutic agent.</P>