LiF:Mg,Cu,Na,Si TL 소자의 선량계적 특성

남영미,김장렬,장시영 대한방사선 방어학회 2001 방사선방어학회지 Vol.26 No.1

최근 개발된 방사선량 측정용 LiF:Mg,Cu,Na,Si TL 소자의 글로우 곡선, 방출스펙트럼, 광자에 대한 선량의존성, 에너지의존성 및 페이딩 등과 같은 물리적 및 선량계적 특성들을 연구하였다. LiF:Mg,Cu,Na,Si TL 소자는 LiF:Mg,Cu,Na,Si TL 분말에 압력을 가한 후 소결하는 방법으로 제조되었다. 방사선에 대한 특성을 알아보기 위하여 광자선 조사는 한국원자력연구소의 X선 발생 장치 및 137Cs γ선 원격조사장치를 이용하였으며, 사용된 광자선 에너지 범위는 20-662keV, 선량 범위는 10-6-102 Gy이었다. 글로우 곡선은 수동형의 TLD 판독장치 (System 310, Teledyne)로 질소를 흘리면서 선형적인 가열률로 측정하였으며, TL 강도는 글로우 곡선을 전체 적분한 면적으로 평가하였다. 5℃·s-1의 선형적인 가열률로 측정한 글로우 곡선은 5개의 피그들로 분리되었으며, 234℃에 나타나는 주피크의 활성화에너지는 2.34 eV, 진동수인자는 1.00×1023이고, 방출스펙트럼은 410nm를 중심으로한 단일한 분포로 나타났다. 선량의존성은 100Gy 이상까지 선형성을 나타내었으며, 137Cs에 대한 저에너지 광자의 상대적인 에너지 반응값은 20% 범위 이내였다. 또한 실온에서 1년간 보관하였을 때, 시간경과에 따른 TL 감도의 감소가 거의 없는 좋은 페이딩 특성을 보였다. Sintered LiF:Mg,Cu,Na,Si thermoluminescence (TL) pellets were developed for application in radiation dosimetry. In the present study, the TL dosimetric properties of LiF:Mg,Cu,Na,Si TL pellets have been investigated for emission spectrum, dose response, energy response, and fading characteristics. LiF:Mg,Cu,Na,Si TL pellets were made by using a sintering process, that is, pressing and heat treatment from TL powders. Photon irradiations for the experiments were carried out using X-ray beams and a 137Cs gamma source at the Korea Atomic Energy Research Institute(KAERI). The average energies and the dose were in the range of 20-662 keV and 10-6- 102 Gy, respectively. The glow curves were measured with a manual type TLD reader(System 310, Teledyne) at a constant nitrogen flux and a linear heating rate. For a constant heating rate of 5℃·s-1, the main dosimetric peak of glow curve appeared at 234℃, the activation energy was 2.34eV and frequency factor was 1.00×1023. TL emission spectrum is appeared at the blue region centered at 410 nm. A linearity of photon dose response was maintained up to 100 Gy. The photon energy responses relative to 137Cs response were within ±20% at overall photon energy region. The fading of TL sensitivity of the pellets stored at the room temperature was not found for one year.

일부 소규모 시계조립 사업장의 상지 누적외상성장애의 유병률

장은철,김현주,권영준,박시복,이수진,송재철 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.4

목적 : 단순 반복작업을 하는 시계조립 사업장 근로자를 대상으로 상지 누적외상성장애의 자각증상 유병률과 상지 누적외상성장애 유병률을 파악하고자 하였다. 방 법 : 인구학적 특성, 상지의 자각증상, 사회심리적 요인은 자가 설문지법으로, 인간공학적 특성은 점검표를 이용한 면담법으로 조사하였다. 상지의 자각증상 조사와 사회심리적 요인은 각각, N10SH (1993) 설문지와 Karasek(1979)의 Job strain model을 번역하여 조사하였다. 상지 누적외상성장애 판정은 의사가 작업 현장에서 직접 환자 면담과 이학적 검사를 수행한 후, 연구에서 규정한 증례정의에 의해 수행하였다. 수집된 자료는 x2 teat와 exact test로 단별량 분석을 하였고, 이중 의미있는 변수와 위험 인자로 알려진 변수들로 다중 로지스틱 회귀분석을 시행하였다. 결 과 : 대상자들의 자각증상 유병률은 54.2 %였고, 부위별로는 목 34.9 %, 손/손목 31.3 %, 어깨 30.1 %, 팔/팔꿈치 18.0 %순이었다. 상지 누적외상성장애의 유병률은 45.8 %였고, 근막동통증후군이 26명으로 가장 많았고, De Quervain씨 병 8명, 수부/전완부의 건염 및 건활막영 8명, 수근관 증후군 5명, 이두건염 5명, 척골 신경병증 5명, 내상과 염 4명, 외상과염 2명, 경추 디스크 질환 2명, 흥곽 출구 증후군 1명순으로 나타났다. 단변량 분석시 자각증상 유병률은 작업부서 중 완성 부에서, 상지 누적외상성장애 유병률은 여자와 완성 부에서 통계학적으로 유의하게 높았다. 다중 로지스틱 회귀분석 결과 완성부와 근무긴장도가 높은 군이 상지 누적외상 성장애와 통계학적으로 유의한 결과를 보였다. 결 론 : 이 연구에서 상지 누적외상성장애 유병률은 45.8 %으로서 저강도의 단순 반복작업을 하는 시계조립 사업장 근로자에서도 누적외상성장애의 위험이 있는 것으로 생각된다. 또한, 사회심리적 요인과 작업 부서별 공정 및 환경이 유병률에 영향을 미치는 주요 요인으로 생각되며, 향후 이들에 관한 다양한 연구가 진행되어야 할 것이다. 산업보건 현장에서는 시계조립 사업장과 같이 저 강도의 단순 반복작업을 위주로 하는 사업장에 대한 지속적인 관심과 각 사업장별 위험요인을 파악하여 적절한 예방 및 관리 대책을 세워야 할 것이다. Objectives : The prevalence of cumulative trauma disorders of upper extremities mons watch assembly workers in small-scaled industry was studied. Methods. In 83 workers at five watch assembly factories, symptoms and psychosocial questionnaire, ergonomic Interview, physical examination were conducted. Results : Prevalence of self-reported symptoms was 54.2% and neck 34.9%, wrist/hand 31.3%, shoulder 30.1%, elbow/arm 18.0% by anatomical site. Prevalence of cumulative trauma disorders was 45.8%. Most common disease was myofascial pain syndrome (31.3%). The other diseases were De Quervain disease (9.6%), tenosynovitis/tendinitis at wrist/hand (9.6%), bicipital tendinitis(6.0%), fat. epicondylitis(4.8%), meIn. epicondylitis(2.4%), and cervical disc disease(2.4%). As result of ergonomic interview, repetitiveness was 79(98.8%). There were no differences in the prevalence of self-reported symptoms and cumulative trauma disorders for age, sex, marital status, duration of work In the study, The significant factors of cumulative trauma disorders were occupational task and psychosocial stress in the study. The prevalence of cumulative trauma disorders in high strain group was hlgher (68.4%) than other three groups. The prevalence of self-reported symptoms and cumulative trauma disorders in assembly task was higher (70.0%, 64.0%) than other two tasks. Conclusions : Prevalence of self-reported symptoms was 54.2%, prevalence of cumulative trauma disorders was 45.8% in watch assembly workers. In this study, factor related to self-reported symptoms was occupational task and factors relaxed to cumulative trauma disorders were occupational task and psychosocial stress. This results suggest that differences of ergonomics and environment in occupational task cause differences of prevalence of self-reported symptoms and cumulatlve trauma disorders.

전자상거래를 통한 국내 인터넷 쇼핑몰 업체들의 기대 이득과 경쟁전략

장시영,이정섭 한국경영과학회 2000 經營 科學 Vol.17 No.3

The widespread diffusion of internet has enabled companies to conduct business in quite a different way. Marketing on the internet becomes more important as firms adopt electronic commerce as a means to implement competitive strategies. One hundred and four B2C shopping mall companies responded to an e-mail and web server survey about the anticipated benefits of electronic commerce and related strategies. The survey also asked about improvements in value chain activities and impediments to the implementation of electronic commerce in Korea. The results indicated that Korean shopping mall companies followed differentiation strategy significantly more than the other two strategies. In addition, six benefits factors were drawn from this study - information, productivity, cost savings, customers, management information, and applications. Productivity factor was related to cost leadership strategy, and customers factor was related with cost leadership, differentiation and focus strategies. Several benefits factors were also correlated with value chain activity improvements. The results of this study were compared with those of research conducted in the United States.

조직 구성원이 보유한 형식지와 암묵지의 조직소유인식에 관한 탐색적 연구

장시영,이정섭,오만석 한국경영과학회 2004 經營 科學 Vol.21 No.1

Today's organizations make every effort to achieve effective knowledge management, under the recognition that knowledge is a powerful, competitive weapon. For knowledge management to be successful, however, not only should knowledge be voluntarily offered by organizational members but also the organizational ownership of knowledge be perceived among members. In this regard, this study explores antecedent factors of organizational ownership of knowledge based on the extension of previous studies. The analysis of two hundred and fifty-five survey data indicates that cohesion of department or team, propensity to share, and task interdependence are significantly related to organizational ownership. The relationship turns out to be stronger with tacit knowledge than with explicit knowledge. Some suggestions are proposed for enhancing effective knowledge management.

시스템분석의 주요변수와 시스템성과와의 상관관계 연구 : 분석기간, 사용자참여 및 통제조직을 중심으로

장시영,최중섭 한국경영과학회 1991 經營 科學 Vol.8 No.2

This study investigates the relationship between some control factors of systems analysis and information systems effectiveness. For this purpose, a research model is set up that consists of three independent variables (duration of systems analysis, user involvement, and control organization/mechanism) and a dependent variable (user satisfaction). Data were gathered from thirty-two industry firms in Korea. The results of data analysis indicate that only user involvement is significantly related to the dependent variable. Among independent variables, the existence of the sign-off procedure and auditing organization is associated with the relative duration of systems analysis. Discussions of the results are presented, followed by the suggestions for future research.

비대칭적 관계구조 하에서 C-Commerce 활용수준의 결정요인

최영진,장시영 한국경영과학회 2004 經營 科學 Vol.21 No.2

With enormous changes in market condition, firms try to collaborate with their transaction partners. Recently, the diffusion of the Internet has made it possible for firms to directly collaborate with their partners. Accordingly, the importance of the Collaborative Commerce(C-Commerce) based on the Internet and IT has been emphasized The literature in relational marketing and strategic alliance, however, has focused on the relational characteristics among firms. Therefore, the fundamental objective of this study is to investigate whether C-Commerce can enhance the positive relationships among firms. Based on theoretical and empirical research, some meaningful discussions can be made. First, the asymmetric commitment between buyers and suppliers decreases the C-Commerce utilization. Second, when specific investment is made to facilitate transactions, firms try to trade efficiently and depend on partners in a long-term period.

관상동맥 내 빛간섭단층촬영술을 활용한 관상동맥 내 석회화 병변의 중재시술 후 경과 예측: 전향적 관찰 연구

장지홍,강시혁,조영석,신은석,서정원 순천향대학교 순천향의학연구소 2021 Journal of Soonchunhyang Medical Science Vol.27 No.1

Objective Imaging modalities such as intravascular ultrasonography or computed tomography or angiography have shown limitations in assessing coronary calcification. In this study, we investigated whether quantitative indices of optical coherence tomography (OCT) in calcified lesions are correlated with the late outcome of a coronary stent. Methods We consecutively enrolled patients who had more than grade 2 coronary calcification on fluoroscopy. OCT was performed at baseline, immediately after stenting, and at 9 months after stenting. We analyzed qualitative and quantitative characteristics of plaque, calcification, and stent-related indices. Results All images of 3-time points were available in a total of 10 patients. Calcified lesions were frequently associated with thin cap fibroatheroma (100%), plaque erosion (20%), or rupture (20%) before the procedure. Thrombus was found in 100% of cases in the OCT immediately after stenting. Maximal calcium area before stenting was strongly correlated with late luminal loss assessed by 9-month follow-up OCT (r= 0.766, P= 0.01). Conclusion Preprocedural OCT assessment on calcified coronary lesion may predict high-risk procedure and late stent outcome. Further studies are warranted to confirm these findings.

Effects of Phenytoin and Diazepam on the Seizure Activity in the Cortical Dysplasia Animal Models

Kim, Si-Hyung,Choi, In-Sun,Cho, Jin-Hwa,Park, Eun-Ju,Jang, Il-Sung,Choi, Byung-Ju,Kim, Hyun-Jung,Kim, Young-Jin,Nam, Soon-Hyeun The Korean Academy of Oral Biology 2006 International Journal of Oral Biology Vol.31 No.2

Dysplasia-associated seizure disorders are markedly resistant to pharmacological intervention. Relatively little research has been conducted studying the effects of antiepileptic drugs(AEDs) on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate(MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of AEDs in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injucted control animals. Field potential recordings were used to monitor amplitude and numbers population spikes, and paired pulse inhibition in response to stimulation of commissural pathway. Two commonly used AEDs were tested: diazepam 5, 2.5mg/kg;phenytoin 40, 60mg/kg. Diazepam(DZP) and phenytoin(PHT) reduced the amplitude of population spike in control and MAM-exposed rats. However, the amplitude of population spike was nearly eliminated in control rats as compared to the MAM-exposed rats. Pharmaco-resistance was tested by measuring seizure latencies in awake rats after pilocarpine administration(320mg/kg, i.p.) with and without pretreatment with AEDs. Pre-treatment with PHT 60 mg prolonged seizure latency in control rats, but not in MAM-exposed animals. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard AEDs assessed in vivo. These data suggest that animal model with cortical dysplasia can be used to screen the effects of potential AEDs.

Pastry 마가린 함량과 적층 수에 따른 puff pastry 제조 특성

한장호,김석영,윤여창,이시경 한국응용생명화학회 2003 Applied Biological Chemistry (Appl Biol Chem) Vol.46 No.4

Puff pastry의 제조 공정에서 pastry 마가린 함량과 적층 수의 변화가 제품의 수분 함량, 굽기 손실, 부피, vapor action 등에 미치는 영향을 조사하였다. Pastry 마가린 함량이 90%로 동일하고 적층 수가 27결일 경우 10.8±0.6%의 수분 함량을 나타냈으며, 1024결일 경우 16.7±0.3%로 적층 수가 증가할수록 제품의 수분함량은 증가 하는 경향을 보였다. 적층 수를 256결로 동일하게 하고, pastry 마가린 함량이 50%일 경우는 17.3±0.5%로 나타났으며, 130%에서는 7.5±0.2%로 pastry 마가린 함량이 증가할수록 제품의 수분 함량은 감소하였다. Pastry 마가린 함량을 70%로 동일하게 했을 때 굽기 손실의 변화는 27결일 경우 25.0±0.7%로 나타났으며, 1024결일경우엔 18.8±0.6^로 나타나 적층 수가 증가할수록 제품의 굽기 손실은 감소하는 경향을 보였다. 적층 수를 27결로 동일하게 한 경우에서는 pastry 마가린 함량이 90%일 때 25.4±0.4%의 굽기 손실이 발생하였으며, 110%에서 26.9±0.4%로 굽기 손실이 가장 높게 나타났다. Pastry 마가린 함량이 130%이고 적층수가 81결일 때에 21.87±0.79㎖/g로 최대의 부피를 나타내었다. 또한 vapor action의 크기는 9.15㎜가 pastry 마가린 함량 110%, 적층 수 256결에서 8.25±0.50개로 가장 많이 나타났다. This study was carried out to investigate the effect of pastry margarine content and number of layers on moisture content, baking loss. specific loaf volume and the vapor action in the manufacturing process of puff pastry. As the number of layers of the puff pastry increased the moisture content of the products slightly increased. And the moisture contents of the products decreased, as the pastry margarine contents of the puff pastry increased in the same number of layers. The baking loss of the products tended to decrease as the number of layers increased. On the other hand, as the pastry margarine contents of the puff pastry increased, the baking loss of the product increased. When the pastry margarine content in puff pastries became 130%, 81 layers provided the maximum specific loaf volumes 21.62±0.79 ㎖/g of puff pastries. When 110% of margarine and 256 layers were applied for preparation of puff pastry, the number of vapor action was 8.25±0.50 with the vapor action size of 9-15 ㎜.

본딩 웨이퍼 검사를 위한 모델링 연구

임영환,양시은,장동영,안효석,홍석기 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

본 논문에서는 레이저 빔 투과를 이용한 본딩 웨이퍼 검사 방법을 제안하고 검사 장치를 설계 구현하였다. 1064nm파장에서의 정상웨이퍼를 일정한 비율로 투과하였다. 본딩 불량으로 인한 웨이퍼의 기공은 두께에 따라 투과율이 현저하게 변화하여 기공 부분을 검출하였다. 이러한 기공은 두께의 변화가 있으며 광량의 변화하는 부분이 에어갭으로 인식 카메라로 쉽게 구분이 가능하였다.