• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권10호
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• pp.693-700
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• 2000

A direct torque control algorithm for 3-level inverter-fed induction motors is presented. Conventional voltage selection methods provoke some problems such as stator flux drooping phenomenon and undersirable torque control appeared especially at the low speed operation. To overcome these problems, a proposed method uses intermediate voltage vectors, which are inherently generated in 3-level inverters. In the proposed algorithm, both subdivision of the basic switching sectors and applications of tntermediated voltages improve the low speed operation characteristics. This algorithm basically considers applications in which direct torque controlled induction motors are fed by 3-level inverters with low switching frequency around 500Hz. An adaptive observer is also employed to bring better responses at the low speed operation, by estimating some state-variables, motor speed and motor parameters which take a deep effect on the performance of the low speed operation. Simulation and experiment results verify effectiveness of the proposed algorithm.

• 방사성폐기물학회지
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• 제9권1호
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• pp.49-62
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• 2011

최근 국제원자력기구와 방사성폐기물 분야 주요 선도국들은 리스크 차등접근법에 따라 방사성폐기물의 분류기준을 세분화하고 있는 추세이며, 이러한 맥락에서 극저준위폐기물을 새로운 방사성폐기물 범주로서 신설하거나 이에 대한 별도의 최적 관리방안을 모색하고 있다. 국제적으로 운영 사례가 점차 증가되고 있는 주요 국가의 극저준위폐기물 전용 공학적 표층매립형 처분시설들은 방사성핵종의 격리 및 지연 성능 측면에서 1960년대 주로 건설된 천층 트렌치형 중 저준위폐기물 처분시설 보다 개선된 것으로 분석되었다. 또한 주요 선도국들의 극저준위폐기물 관리방안은 규제해제 제도, 중 저준위폐기물 처분시설 및 비원자력 폐기물매립장의 활용 가능성, 사회수용성 등에 따라 차이가 있는 것으로 나타났다. 이와 관련하여, 국내에서도 향후 대형 원자력시설의 해체에 대비하여 극저준위폐기물의 최적 관리방안에 관한 종합적인 검토와 논의를 통해 리스크 차등접근법에 따른 최적화된 관리방안을 사전에 수립하고, 이를 국가 방사성폐기물 관리정책 및 관리계획의 틀 내에서 체계적으로 시행할 필요가 있다.

• 한국학교보건학회지
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• 제4권1호
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• pp.116-125
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• 1991

The purposes of this study are to identify the degree of exercise intent and behavior and to determine factors influencing exercise and behavior in middle school students. The subjects for this study were 658 middle school students in Chonbuk area. The data were obtained by questionaire for the period from Nov. 1 to Dec. 20, 1990. The instrument used for the study were included 6 existing scales and 2 scales developed by the researcher for this study. They are: 1) The exercise intent scale to assess the exercise plan even when they had no longer physical education. 2) The current exercise behavior to measure of exercise frequency for 1 week. 3) The scale to measure the level of self -esteem. 4) The scale to measure the level of knowledge about exercise. 5) The scale to measure the level of the perceived ability to make commitment. 6) The scale to measure the level of the perceived benifit of exercise. 7) The scale to measure the level of the perceived athletic ability. 8) The scale to measure the level of the attitude toward physical education. The data were analyzed using frequency, percentage, one way ANOVA, Pearson Coeffecients Correlation and stepwise multiple regression. The following; results were obtained. 1. Exercise intent level was in the intermediate range(mean on five point scale of 3.66, with 1 = definitely no). 2. The current exercise behavior level was relatively low(mean=1.77, with l=less than once per week and 4 = 4 or more times per week). 3. Self -esteem levels were in the intermediate range(mean on five point scale of 2.96, a mean of 5.0 indicate highest level of self-esteem.) 4. The levels of perceived ability to make commitments were in the intermediate range(mean=3.05, with 5.0 as most able). 5. The levels of perceived exercise as benificial were relatively high(mean=3.72, with 5.0 as most benificial). 6. Knowledge levels about exercise were realatively high(mean=3.97, with 5.0 as most knowledgeable). 7. The levels of perceived athletic ability were in intermediate range(mean=3.01, with 5.0 as highest score). 8. The levels of attitudes toward physical education were in the intermediate range(mean=3.29, with 5.0 as most favorable). 9. Among the general characteristic variables, sex, interest sports activities were related to the difference of exercise intent levels. 10. Of the predictor variables analyzed, self - esteem, perceived benifit of exercise, perceived athletic ability, knowledge about exercise and attitude about physical education correlated significantly and positively with exercise intent. Correlations of predictors with current exercise behavior were similiar to exercise intent, exept knowledge about exercise. 11. The stepwise multiple regression analysis shows findings as follows: 1) The most important factor to explain the difference of exercise intent was current exercise behavior. 2) The most improtant factor to explain the difference of current exercise behavior was perceived athletic ability.

• 터널과지하공간
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• 제26권5호
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• pp.339-347
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• 2016

스웨덴 포쉬마크 (Forsmark)지역에서는 1988년부터 세계 최초의 동굴식 중저준위 방사성 폐기물 처분장(SFR1)이 운영되고 있다. 4개의 터널 및 1개의 사일로에 용량 $63,000m^3$의 처분공간이 확보되어 연간 $1,000m^3$의 폐기물을 처분할 수 있었지만, 스웨덴 내 12기 중 10기의 원자로의 수명이 연장되고, 나머지 2기의 원자로가 폐쇄되어 추가 폐기물 처분에 대한 요구가 발생하게 되었다. 따라서 6기의 수평터널을 추가로 건설하여 폐기물과 9개의 반응로 용기 처분을 위한 $108,000m^3$의 처분 공간을 확보할 계획으로 스웨덴 방사성폐기물 관리주식회사(SKB)는 SFR3으로의 확장을 위한 허가 신청서를 2014년 정부에 제출하였다. 본 연구에서는 SFR3의 추가 확장 계획에 대해 소개하고, SFR3의 계획 시에 고려된 지질학적, 암반공학 및 암반수리학적인 요소들을 소개하였다.

• 방사성폐기물학회지
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• 제14권4호
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• pp.385-410
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• 2016

경주 방사성폐기물 처분시설은 향후 80만 포장물을 처분할 계획이며 다양한 처분방식 및 관리형태를 가진 복합계가 될 것이다. 본 논문에서는 전체부지 처분용량(80만 포장물) 처분시설의 단계별 개발에 따른 영향을 평가하기 위하여 처분시설 종합개발계획(안)에 따른 예비안전성평가를 수행하였다. 각 시나리오에 대한 안전성평가결과 처분시설의 성능목표치를 만족하였다. 다만, 전체처분시설의 안전성 평가결과에 중준위 방사성폐기물로 인하여 1단계 동굴 처분시설이 가장 크게 영향을 미치므로 처분시설의 안전성 향상을 위하여 처분방사능량제한 설정 등 관리방안이 필요하다. Safety Case 단계별 구축을 통하여 중 저준위 방사성폐기물 처분시설 종합개발 과정에서 인지된 불확실성을 저감하여 안전성을 증진 시킬 수 있을 것으로 판단된다.

• 방사성폐기물학회지
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• 제20권1호
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• pp.127-131
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• 2022

The structural safety of prototype transport and storage containers for very low-level radioactive liquid waste was experimentally estimated for its localization development. Transport containers for radioactive liquid waste have been researched and developed, however, there are no standardized commercial containers for very low-level radioactive waste in Korea. In this study, the structural safety of the designated IP-2 type container capable of transporting and temporarily storing large amounts of very low-level liquid waste, which is generated during the operation and decommissioning of nuclear power plants, was demonstrated. The stacking and drop tests, which were conducted to determine the structural integrity of the container, verified that there was no external leakage of the contents in spite of its structural deformation due to the drop impact. This study shows the effort required for the localization of the technology used in manufacturing transport and storage containers for very low-level radioactive liquid waste, and the additional structural reinforcement of the container in which the commercial intermediate bulk container (IBC) external frame was coupled.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.27-28
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• 2018

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2018년도 공동국제학술발표회
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• pp.102-103
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• 2018

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2007년도 학술논문요약집
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• pp.101-102
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• 2007

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2007년도 학술논문요약집
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• pp.334-335
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• 2007