• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.149-151
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• 2005

A new approach considering CO2 air pollution constraints in the long-term generation mix is proposed under uncertain circumstances. A characteristic feature of the presented approach in this paper is what effects give the air pollution constraints in long term best generation mix. Best generation mix problem is formulated by linear programming with fuel and construction cost minimization with load growth, reliability (reserve margin rate) and air pollutionconstraints. The proposed method accommodates the operation of pumped-storage generator. It was assumed in this study that the construction planning of the hydro power plants is given separately from the other generation plans. The effectiveness of the proposed approach is demonstrated by applying to the best generation mix problem of KEPCO-system, which contains nuclear, coal, LNG, oil and pumped-storage hydro plant multi-years.

• 아동학회지
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• 제22권1호
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• pp.97-107
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• 2001

This study argues the nature of the microgenetic method in respect to child development research and explores its merits and limitations. The microgenetic method focuses on observations that span the entire period from the beginning of developmental change to the time it reaches a relatively stable state. This produces a high density of observations relative to the rate of change in the phenomenon. In this way, observed behavior may be used in intensive trial-by-trial analysis. The microgenetic method is superior to other methods in the possibilities for observing developmental changes as they occur, examining various aspects of change, detecting variability in behavior, and flexibility in application regardless of theoretical perspectives. Limitations of this method include reliability problems due to repeated observations, artificiality relative to the natural situation, inconsistency of short-and long-term change, and demands on children's motivation for participation in research.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1297-1302
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• 2000

A literature review has been carried out to investigate why bridges have collapsed without warning. The reasons behind the collapses have been categorized into short and long term risks. It is thought that permanent monitoring systems which assess structural adequacy are more appropriate to long term risks. From the knowledge of the Korean bridge stock, its current problems and its likely future problems, it was considered that generally the most useful application for a permanent monitoring system is to monitor where chloride-induced corrosion either of the reinforcement or prestressing tendons is possible. A number of permanent monitoring systems currently in use on existing bridges which include some aspect of corrosion detection have been reviewed. The reasons as to why they are being used, what is being measured, what techniques are being used, and if they are deemed successful has been investigated. Based on these findings, and experimental programme has been constructed to investigate the accuracy, reliability and usefulness of various suitable techniques which could be included in a permanent monitoring system.

• Journal of Information Technology Applications and Management
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• 제24권2호
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• pp.81-96
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• 2017

Forecasting long-term mobile service demand is inevitable to establish an effective frequency management policy despite the lack of reliability of forecast results. The statistical forecasting method has limitations in analyzing how the forecasting result changes when the scenario for various drivers such as consumer usage pattern or market structure for mobile communication service is changed. In this study, we propose a dynamic model of the mobile communication service market using system dynamics technique and forecast the future demand for long-term mobile communication subscriber based on the dynamic model, and also experiment on the change pattern of subscriber demand under various scenarios.

• 한국가스학회지
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• 제11권3호
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• pp.40-43
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• 2007

스택의 디자인과 운전조건을 최적화하여 PEMFC stack의 성능을 상당히 증진시킬수 있다. 그러한 결과로, 500시간의 DSS(Daily Start-up & Shutdown) 누적 운전후에 일별 운전성능은 조금의 편차가 있었지만 (0.02-0.9%), 스택의 성능은 거의 변화가 없음을 알 수 있었다. 따라서 PEMFC 시스템의 상용화를 위해서는 스택의 수명 및 운전의 신뢰성을 향상시켜야 한다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.86-89
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• 2004

Recently polymer arresters are being used widely but we don't have appropriate long term characteristics test methods. Therefore we need to develop special test facility to evaluate long term reliability of polymer arresters. It's polymeric housing can be degraded by environmental stress and the interface between housing and inner module can be affected by moisture absorption. This moisture absorption can cause leakage current and tracking in the interface. We developed multi stress accelerated ageing test facility to simulate field conditions including UV, temperature, humidity, voltage, salt fog and rain. In addition, we carried out field exposure test at the outdoor test yard and characteristics analysis of field operated specimens to evaluate accelerating factor of this accelerated aging test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.159-162
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• 1993

A new approach using fuzzy dynamic programming is proposed for the flexible long-term generation mix under uncertain circumstances. A characteristic feature of the presented approach is that not only fuzziness in fuel and construction cost. load growth and reliability but also many constraints of generation mix can easily be taken into account by using fuzzy dynamic programming. The method can accommodate arbitrary shape of membership function as well as the operation of pump-generator. And so more realistic solution can be obtained. The effectiveness of the proposed approach is demonstrated by the best generation mix problem of KEPCO-system which contains nuclear, coal, LNG, oil and pump-generator hydro plant in multi-years.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.812-813
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• 2007

The procurement of generation and transmission/Distribution capacity in vertically-integrated electric industry is sufficient by facility construction in suitable time. However, the introduction of competitive electricity market increase the efficiency of availability for facilities and fuels. As a result, long-term capacity procurement is required for stable demand-supply balance since it is expected to maintain their generation capacity at a minimum for profit maximization. In this paper, a new long-term capacity procurement mechanism is constructed, which is able to assure supplemental contribution in competitive electricity market.

• 대한조선학회논문집
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• 제57권1호
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• pp.1-7
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• 2020

In general, an inspection schedule is established based on the long-term fatigue life during the design stage. However, in the design stage, it is difficult to clearly identify the uncertainty factors affecting long-term fatigue life. In this study, the probabilistic fatigue life assessment was conducted in accordance with the methodology of DNV-GL. Firstly, The initial crack distribution estimated through the initial crack propagation analysis was updated by reflecting the results of crack inspection. Secondly, the updated crack distribution was compared with the initial crack distribution, and the probability of failure was updated with the effect of crack inspection.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.747-757
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• 2019

본 연구는 노인환자가 인식하는 간호사와의 상호작용을 측정하기 위해 개발된 the Korean version of Nurse-Patient Interaction Scale (K-NPIS)을 한국 요양병원에 입원한 노인환자를 대상으로 간호사와의 상호작용을 측정의 신뢰도와 타당도를 검증하려는 목적으로 시행되었다. 진주시, 순천시, 남원시에 소재하는 4개의 요양병원에 입원한 노인환자 202명을 대상으로 신뢰도와 타당도 검증을 실시하였다. 문항분석과 내적일관성 검증을 통해 K-NPIS의 Cronbach α 값은 .96이었다. 전문가들을 통한 내용타당도 검증에서 내용타당도 지수가 0.8 이상으로 확인되었으며, 확인적 요인분석을 거쳐 최종 단일속성으로 구성된 12개 문항 각 10점 척도의 최종 도구가 도출되었으며, 재원기간에 따라 K-NPIS의 점수가 유의하게 차이가 나(p=.042) 판별타당도도 검증되었고, 천장효과나 바닥효과는 나타나지 않았다. 이와 같이 K-NPIS는 신뢰도와 타당도가 높은 도구임이 검증되어 요양병원에서 노인환자를 대상으로 간호사-환자의 상호작용을 측정하는 도구로 사용되는데 적절한 것으로 보이나 장차 준거타당도를 검증할 필요가 있다. K-NPIS는 노인환자가 인식하고 있는 간호사와의 상호작용을 자가보고 형식으로 측정하는 것이므로, 노인환자와의 상호작용을 기반으로 한 돌봄 중재의 성과를 평가하여 간호서비스 질 향상에 기여할 수 있을 것으로 기대된다.