• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 추계학술발표회
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• pp.41-41
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• 2017

• 대한전기학회논문지
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• 제31권7호
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• pp.1-10
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• 1982

This paper derives the algorithm to estimate the operating cost, its marginal cost, and the reliability indices for the long term planning of power system. Treating the load duration curve and the system in the stochastic sense takes the place of the inverted load duration curve, effective load duration curve, and the numerical integration in the conventional methods. The time and accuracy of computation are substantially improved due to the fact that all expressions are represented by simple analytic form instead of the existing recursive form.

• 한국정밀공학회지
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• 제29권1호
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• pp.96-102
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• 2012

The current establishment of car engineering plastic piping polyethylene (PE) tube used as bonding state or part of the health or safety of fusion is very important. A part of these fusion methods to determine the soundness of the short-term trials and long-term tests can be largely classified. Typical tests included short-term strength, tensile strength, impact strength, compressive strength, resiliency and compression. Polyethylene (PE) pipes installed in the domestic terms of overall penetration rate of 45% has been used. However, polyethylene (PE) pipes have reliability problems, and these occurs mostly in part by defective welding. Therefore, the test is necessary for safety. Non-destructive methods (ultrasonic testing) are difficult to be used. Therefore, Polyethylene (PE) pipe are used. Fusion of thses materilas is necessary in these field however, its technical, and basic research has not been studied well. In this research, short-term strength of welding parts, its tensile strength, hardness, fatigue, and microstructure have been analyzed to find the optimum process conditions to improve mechanical properties.

• 한국생산제조학회지
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• 제20권5호
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• pp.564-569
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• 2011

The current establishment of city gas piping polyethylene (PE) tube used as bonding state or part of the health or safety of fusion is very important. A part of these fusion methods to determine the soundness of the short-term trials and long-term tests can be largely classified. Typical tests include short-term strength, tensile strength, impact strength, compressive strength, resiliency and compression. Polyethylene (PE) pipes installed in the domestic terms of overall penetration rate of 45% has been used. However, polyethylene (PE) pipes have reliability problems, and these occurs mostly in part by defective welding. Therefore, the test is necessary for safety. Non-destructive methods (ultrasonic testing) are difficult to be used. Therefore, Polypropylene copolymer (PP-C), polypropylene homopolymer (PP-H), and polyethylene (PE) pipe are used. Fusion of these materials is necessary in these field however, its technical, and basic research has not been studied well. In this research, short-term strength of welding parts, its tensile strength, hardness, fatigue, and microstructure have been analyzed to find the optimum process conditions to improve mechanical properties.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4722-4730
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• 2022

This paper introduces a new point depletion-based source term calculation code named BESNA (Bateman Equation Solver for Nuclear Applications), which is aimed to estimate nuclide inventories and source terms from spent nuclear fuels. The BESNA code employs a new modified CE/CM (Constant Extrapolation - Constant Midpoint) predictor-corrector scheme in depletion calculations for improving computational efficiency. In this modified CE/CM scheme, the decay components leading to the large norm of the depletion matrix are excluded in the corrector, and hence the corrector calculation involves only the reaction components, which can be efficiently solved with the Talyor Expansion Method (TEM). The numerical test shows that the new scheme substantially reduces computing time without loss of accuracy in comparison with the conventional scheme using CRAM (Chebyshev Rational Approximation Method), especially when the substep calculations are applied. The depletion calculation and source term estimation capability of BESNA are verified and validated through several problems, where results from BESNA are compared with those calculated by other codes as well as measured data. The analysis results show the computational efficiency of the new modified scheme and the reliability of BESNA in both isotopic predictions and source term estimations.

• 치위생과학회지
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• 제16권1호
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• pp.18-25
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• 2016

이번 연구는 직무착근도의 척도를 국내 실정에 적절하게 적용할 수 있도록 수정 보완하여, 치과위생사의 직무착근도를 평가할 수 있는 도구를 개발하고 타당도와 신뢰도를 평가하고자 시행하였다. 직무착근도 원 도구 25문항을 번역한 후 내용분석 및 내용 타당도 검증을 통하여 8문항을 삭제하고 5문항을 수정하여 총 17문항을 분석하였다. 연구 결과 탐색적 요인분석에 의해 요인 적재량이 0.4 이하인 4개의 문항은 삭제되었으며, 도구의 적합성, 연계, 희생 요인들로부터 추출된 문항들이 새롭게 혼합되어 구성되었다. 치과위생사를 위한 직무착근도의 하위요인으로는 '조직 적합성', '직무 연계성', '직원 관계성'으로 구분되었다. 또한 확인적 요인분석을 통한 모형의 적합도는 대체로 기준을 충족하였다(${\chi}^2=257.394$ [df=62, p<0.001], RMR=0.059, RMSEA=0.107, CFI=0.887, GFI=0.870, AGFI=0.810, NFI=0.857, IFI=0.888, TLI=0.858). 내적일관성을 검증한 결과 Cronbach's ${\alpha}$는 착근도의 하위요인인 조직 적합성 0.866, 직무 연계성 0.916, 직원 관계성 0.669로 나타나 신뢰할 만한 수준의 측정도구임을 나타냈다. 이상의 결과에 따라 치과위생사의 직무착근도 측정도구의 타당도와 신뢰도는 적합하다고 검증되었다. 향후 우리나라 치과 내 조직원들의 이직 및 장기근속에 대한 연구에 활용되어 의료기관의 병원 경영 및 직원 관리에 보탬이 될 것으로 생각된다.

• Journal of Advanced Marine Engineering and Technology
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• 제38권8호
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• pp.1004-1009
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• 2014

The redundancy allocation problem has usually considered only the component redundancy at the lowest-level for the enhancement of system reliability. A system can be functionally decomposed into system, module, and component levels. Modular redundancy can be more effective than component redundancy at the lowest-level because in modular systems, duplicating a module composed of several components can be easier, and requires less time and skill. We consider a multi-level redundancy allocation problem in which all cases of redundancy for system, module, and component levels are considered. A tabu search of memory-based mechanisms that balances intensification with diversification via the short-term and long-term memory is proposed for its solution. To the best of our knowledge, this is the first attempt to use a tabu search for this problem. Our tabu search algorithm is compared with the previous genetic algorithm for the problem on the new composed test problems as well as the benchmark problems from the literature. Computational results show that the proposed method outstandingly outperforms the genetic algorithm for almost all test problems.

• 센서학회지
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• 제22권4호
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• pp.292-296
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• 2013

The ultrasonic wind sensor that pass through the air, beating the delivery of ultrasonic wind speed increases or decreases by the physical characteristics of the wind speed and the direction of the sensor, the transmission and reception of ultrasonic time difference measured by a two-axis vector wind and wind speed measured by calculating a device that converts the digital signal is Anemometer and wind direction meteorological facilities management, management of the ship sail used for various purposes, including, but used the existing 3-cup (mechanical) anemometer wind rotor caused by mechanical wear parts replacement due to the short-term, the reliability of the product is low, parts replacement, and according to the characteristics caused the car, there is a problem in high maintenance costs. In addition, because the bearings use of the marine environment and the cryogenic environment was constrained. In this study, the excellent long-term reliability, using ultrasonic-type environment that is not constrained to produce wind anemometer located $90^{\circ}$ conformal road using four piezoelectric sensors were fabricated structures, the piezoelectric oscillator circuit produces a rash and receiving transmit and receive speeds the car through the two-axis vector calculation to measure wind velocity processor firmware programming, and its characteristics were tested.

• 콘크리트학회논문집
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• 제19권1호
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• pp.47-56
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• 2007

최근들어 고속도로, 고속철도, 지하철등의 건설이 증가하면서 터널의 건설도 늘어나고 있는 추세이다. 이러한 터널 공사에서 필수적으로 따르는 것이 숏크리트 공정이며 이러한 숏크리트의 시공은 앞으로도 더욱 증가할 추세에 있다. 그러나 숏크리트의 광범위한 시공에도 불구하고 여러 가지 문제점을 내포하고 있는 것이 사실이다. 따라서 본 연구에서는 우리나라 현행 숏크리트의 현황과 문제점을 분석하고, 고품질의 숏크리트 시공을 위하여 실리카퓸 숏크리트의 성능 및 적용성에 대해 분석하였다. 또한 숏크리트의 장기적인 안정성 확보를 위해서는 복합적인 환경조건을 고려한 열화 특성을 파악할 필요가 있다. 본 연구에서는 건습 반복, 동결융해 및 탄산화 등의 열화 인자를 복합적으로 적용한 열화 시험을 수행하였다. 특히, 우수한 강도 증진 효과로 국외에서 많이 사용되고 있는 실리카퓸을 적용하여 혼화재 치환에 따른 숏크리트의 장기 내구 특성을 평가하였다. 복합 열화 시험 결과 실리카퓸을 혼입한 숏크리트는 다른 배합에 비해 가장 양호한 결과를 나타냈고, 실리카퓸은 강도 증진 효과와 함께 강섬유 혼입에 의한 열화 현상을 최소한으로 감소시켜 숏크리트의 장기 내구성을 확보하는데 효과가 있었다.

• 한국기록관리학회지
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• 제1권2호
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• pp.101-119
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• 2001

전자기록물의 정의와 구성요소를 설명하고 보존 개념을 재정립하였다. 전자적인 환경에서 기록물을 장기보존을 위한 접근방법과 요구조건을 논의하였다. 디지털 환경에서의 보존은 신뢰성 있는 진본 기록물 자체에 대한 보존과 접근가능성을 보장하는 것임을 알 수 있었다. 전자기록물을 장기보존하기 위해서는 디지털 환경 변화에 따른 지속적인 변환과 기록물을 생산한 소프트웨어에 독립적인 표준포맷 전략을 선택할 필요가 있다. 그리고 이러한 전략을 통하여 전자기록물의 무결성을 보장할 수 있도록 처리절차와 관련 정보를 메타테이터화 하여야 한다. 전자기록물 보존시스템은 크게 등록처리, 보존처리, 접근처리와 시스템 전체를 관리하는 기록물관리 시스템으로 구성하였다. 또한 보존매체의 선택 기준과 안전 및 재해복구의 개념을 도입하였다.