• 제목/요약/키워드: Alternate application

검색결과 90건 처리시간 0.033초

리스크 정보를 활용한 배관 가동중검사 적용 (Application of Risk-Informed Inservice Inspection for Piping in Nuclear Power Plants)

  • 진영복;진석홍;문용식
    • 한국압력기기공학회 논문집
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    • 제7권4호
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    • pp.31-37
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    • 2011
  • Pressurized Water Reactor Owners Group(PWROG) proposed and applied a risk-informed inservice inspection(RI-ISI) program to alternate existing ASME Section XI periodic inspections. The RI-ISI programs enhance overall safety by focusing inspections of piping at high safety significant(HSS) and locations where failure mechanisms are likely to be present, and by improving the effectiveness on inspection of components because the examination methods are based on the postulated failure mode and the configuration of the piping structural element. The RI-ISI programs can reduce NDE, man-rem exposure, costs of engineering analysis, outage duration and chance of complicating plant operations etc. RI-ISI methods of piping inservice inspection were applied on 3 units(KSNP : Korea Standard Nuclear Power Plant) and are scheduled to apply on the other units. In this paper, we compared and showed the results of the 2 units and we concluded that the RI-ISI application could enhance and maintain plant safety and give unquantifiable benefits.

Effect of Bending Test Procedure on the Degradation Behavior of Critical Current in ReBCO Coated Conductor Tapes

  • Shin, H.S.;Dedicatoria, M.J.;Lee, N.J.;Oh, S.S.
    • 한국초전도ㆍ저온공학회논문지
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    • 제11권4호
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    • pp.12-15
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    • 2009
  • The $I_c$ degradation behavior of critical current in differently processed YBCO and SmBCO CC tapes with IBAD template has been investigated. It has been known that the residual strain in the CC tape will influence the shape of the $I_c$-strain window; $I_c$ may show a peak value if there exist a residual strain induced in the tape during manufacturing. The difference of residual strain may be resulted from the adopted different deposition techniques. In this study, bending test of CC tapes has been done using the Goldacker bending test rig which can produce both compressive and tensile bending strain continuously or alternately to the sample. For SmBCO CC tapes, in continuous compressive bending test, $I_c$ showed a minimal increase and did not degrade up to the largest strain that can be applied using the bending rig equivalent to 1.15% based on the sample thickness. However, in the case of alternate application of compressive and tensile bending strain, $I_c$ showed a larger degradation and a lower reversible limit when compared with the case of continuous application of the bending strain. When $I_c$ started to degrade significantly at the tension side, the reversibility ended, also at the compression side which is resulted from the permanent deformation like delamination or cracks that was induced due to tensile bending strain.

Analysis of System Performance Degradation Using Sinusoidally Modulated Signal in Optical Fiber Communication Systems

  • Lee, Jong-Hyung;Han, Dae-Hyun;Park, Byeong-Yoon
    • Journal of the Optical Society of Korea
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    • 제8권2호
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    • pp.59-64
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    • 2004
  • The response of a single-mode fiber to a sinusoidally modulated input has been studied to see its utility in measuring system performance in the presence of fiber nonlinearities. The sinusoidally modulated signal models an alternating bit sequence of ones and zeros in on-off keying. The sinusoidal response of normally dispersive fiber shows a strong correlation with eye-opening penalty (EOP) over a wide range of the nonlinearity parameter N (0.1 < N$^2$< 100). This result implies that the measurement of the sinusoidal response can be an alternate way of measuring EOP without having a long sequence of randomly modulated input bits. But in the anomalous dispersion region, the sinusoidal response has a much more limited range of application to estimate system performance.

Practical Swarm Optimization based Fault-Tolerance Algorithm for the Internet of Things

  • Luo, Shiliang;Cheng, Lianglun;Ren, Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권3호
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    • pp.735-748
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    • 2014
  • The fault-tolerance routing problem is one of the most important issues in the application of the Internet of Things, and has been attracting growing research interests. In order to maintain the communication paths from source sensors to the macronodes, we present a hybrid routing scheme and model, in which alternate paths are created once the previous routing is broken. Then, we propose an improved efficient and intelligent fault-tolerance algorithm (IEIFTA) to provide the fast routing recovery and reconstruct the network topology for path failure in the Internet of Things. In the IEIFTA, mutation direction of the particle is determined by multi-swarm evolution equation, and its diversity is improved by the immune mechanism, which can improve the ability of global search and improve the converging rate of the algorithm. The simulation results indicate that the IEIFTA-based fault-tolerance algorithm outperforms the EARQ algorithm and the SPSOA algorithm due to its ability of fast routing recovery mechanism and prolonging the lifetime of the Internet of Things.

정보시스템 전략적 계획을 위한 컴퓨터지원 통계적 접근방법 (A Computer-Aided Statistical Approach to Strategic Information Systems Planning)

  • 김진수;황철언
    • Asia pacific journal of information systems
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    • 제4권2호
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    • pp.188-213
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    • 1994
  • Strategic information systems planning (SISP) remains a critical issue of many organizations and also the top IS concern of chief executives. Therefore, researchers have investigated SISP practices and tried to improve a methodology. Among the various issues of SISP, systematically determining subject database groupings and fully automating the processes are important aspects. This study presents an alternate methodology using a statistical technique, a variable clustering approach, and systematic rules for determining database groupings, which can be fully automated. This methodology provides a strong theoritical justification as well as systematic and simple criteria for database groupings, enhanced interpretability of the output, and would be easy to include in CASE software application.

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원자력발전소 고압전동기 모선 잔류전압 특성 (Motor Bus Residual Voltage Characteristics at Nuclear Power Plant)

  • 변상윤;김순용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.662_663
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    • 2009
  • Motor bus transfer involves the process of transferring a bus that has several critical motors to an alternate source of power when the main normal power source feeding them is interrupted. Bus transfer is a time-critical application in which the transfer progress depends on various parameters such as the type of motor, load on the motor at the time of transfer, inertia of the motor, and the combined open-circuit time constant of various motors present on the bus at the time of transfer. This paper present the result of modeling and simulation of nuclear power motor bus using ETAP(Electrical Transient Analyzing Program) program for motor and motor bus residual voltage decay characteristics.

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Double Sheets Hybrid Compensation for VA LCDs

  • Kang, Liang-Hao;Chen, Li-Fan;Chung, Ming-Shan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.683-686
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    • 2006
  • Accompanied by the demand of thin type TV, the application of the TFT LCD display device is more and more extensive. The key material which influences the optical performance of the TFT LCD is optical film. Due to the rapid development of the big size TFT LCD for the recent years, the supply has been unable to meet the demand for its relative material. Therefore, we bring up a alternate choice-the hybrid compensation film which could not only show well optical performance, but also lessen the quantity of usage in TAC in order to make the optical film free of shortage.

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이종해법의 병용에 관한 연구 (A Study on Combination of Various Numerical Analysis Methods)

  • 임지원;추동욱;한석우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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    • pp.99-103
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    • 2000
  • The finite element method (FEM) is suitable for the analysis of a complicated region that includes nonlinear materials, whereas the boundary element method (BEM) is naturally effective for analyzing a very large region with linear characteristics. Therefore, considering the advantages in both methods, a novel algorithm for the alternate application of the FEM and BEM to magnetic field problems with the open boundary is presented. This approach avoids the disadvantages of the typical numerical methods with the open boundary problem such as a great number of unknown values for the FEM and non-symmetric matrix for the Hybrid FE-BE method. The solution of the overall problems is obtained by iterative calculations accompanied with the new acceleration method.

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A New Hybrid Strategy for the Optimization of Xhemical Processing System

  • Cho, In-Ho;Yoon, En-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.848-855
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    • 1989
  • By structural comparison of process optimization strategies based on Simultaneous Modular Approach, they can be classified into two groups : the Sequential Module Based Approach and the Two-Tier Approach. The Sequential Module Based Approach needs rigorous models and a set of accurate solutions are guranteed. However, it requires large amount of computation time. In the Two-Tier Approach composed of rigorous and simplified models, optimization calculation uses simplified models, therefore comparatively smaller amount of computation time is required but the obtained solutions may not be accurate. These optimization problems were somewhat improved by the alternate application of the two strategies. In this study, improved optimization strategy is suggested, in which Jacobian Matrix is modified to accomodate the strong points of above mentioned strategies. The results of case study show that this approach is superior to the other strategies.

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The improvement of discharge characteristics and lifetime of PDP by MgO deposition on the phosphor

  • Ha, Chang-Hoon;Kim, Jae-Sung;Jeong, Dong-Cheol;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.232-235
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    • 2002
  • An alternate application of MgO film for the improvement of discharge characteristics and life time in an ac plasma display panel (PDP) is suggested. In this research, we deposited MgO on the phosphor to get the same address characteristics irrespective of each phosphor. To avoid the luminance and efficiency degradation by MgO deposition on the phosphor, we optimized the MgO thickness through experiments. The results showed that PDP with MgO coated phosphor has a uniform formative delay in address discharge and improved degradation characteristics.

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