• Title/Summary/Keyword: double contingency

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Structural safety reliability of concrete buildings of HTR-PM in accidental double-ended break of hot gas ducts

  • Guo, Quanquan;Wang, Shaoxu;Chen, Shenggang;Sun, Yunlong
    • Nuclear Engineering and Technology
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    • v.52 no.5
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    • pp.1051-1065
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    • 2020
  • Safety analysis of nuclear power plant (NPP) especially in accident conditions is a basic and necessary issue for applications and commercialization of reactors. Many previous researches and development works have been conducted. However, most achievements focused on the safety reliability of primary pressure system vessels. Few literatures studied the structural safety of huge concrete structures surrounding primary pressure system, especially for the fourth generation NPP which allows existing of through cracks. In this paper, structural safety reliability of concrete structures of HTR-PM in accidental double-ended break of hot gas ducts was studied by Exceedance Probability Method. It was calculated by Monte Carlo approaches applying numerical simulations by Abaqus. Damage parameters were proposed and used to define the property of concrete, which can perfectly describe the crack state of concrete structures. Calculation results indicated that functional failure determined by deterministic safety analysis was decided by the crack resistance capability of containment buildings, whereas the bearing capacity of concrete structures possess a high safety margin. The failure probability of concrete structures during an accident of double-ended break of hot gas ducts will be 31.18%. Adding the consideration the contingency occurrence probability of the accident, probability of functional failure is sufficiently low.

Factors Affecting the Adoption of Innovative Service System in Public Sectors : A Case Study on Implementing Double Entry Bookkeeping With Accrual Basis in Government Accounting System (공공부문의 서비스 혁신 수용에 관한 실증연구 : 중앙정부 및 지방자치단체 회계담당자의 복식부기${\cdot}$발생주의 회계시스템 도입에 관한 사례를 중심으로)

  • Pyun Ho-Bum;Han Kwang-Hyun;Kim Tae Ung
    • Korean Management Science Review
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    • v.22 no.1
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    • pp.103-125
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    • 2005
  • Korean government is planning to adopt double entry bookkeeping with accrual basis in the government accounting system. This paper attempts to identify influencing attitudes of information producers toward the acceptance of the new service system. Several models are introduced, including Luder's Contingency Model, Cheng's Politico-Economic Model of Accounting Policy Choice, Roger's Diffusion of innovation, and Davis's Technology Acceptance Model(TAM). A set of constructs are developed as fellows : information producers' knowledges, experiences, altitudes toward the reform, characteristics of cash based accounting system and new accrual based system, a chief executive officer's willingness to support, availability of supporting systems, and social Influences from external environment. This study also incudes hey factors used in TAM, such as perceived usefulness and ease of use. Survey responses are gathered from accounting officers in government ministries and agencies as well as from local governments. Regression analysis shows that, for information producers, both 'perceived ease of use' and 'perceived usefulness' of the new system are the best explanatory variable for the dependent variable. It has also found that 'perceived usefulness' is explained best by individual characteristics such as knowledge and experiences, quality of current cash based s1n91e entry bookkeeping system, chief executive's support, Positive supporting systems and social influences. The useful guidelines for implementing double-entry bookkeeping system with accrual basis are also provided.

Application and Evaluation of Emergency Rates in Overhead Transmission Lines (가공송전선로의 비상용량 응용과 평가)

  • Kim, Sung Duck
    • Journal of IKEEE
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    • v.18 no.4
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    • pp.442-446
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    • 2014
  • A method for applying emergency ratings to improve the reliability of power supply in ACSR overhead transmission lines is described in this paper. Due to re-regulate power industry, most power companies worldwide as well KEPCO have been searching for only economical strategies without new investment. Power demand was rapidly increasing, however, generation amount did not follow sufficiently. Hence in order to increase the transmission capacity for the existing transmission lines in case of peak load, or contingency in transmission lines, an application method of emergency ratings such as short or long term rating is proposed. If applying long term emergency rating instead of static line rating for the period of a peak load, power transmission can be increased to 10 % or more. Furthermore, it was shown that emergency rating can be effectively used in the contingency of double-circuit transmission lines and/or overload cases.

Empirical Bayesian Misclassification Analysis on Categorical Data (범주형 자료에서 경험적 베이지안 오분류 분석)

  • 임한승;홍종선;서문섭
    • The Korean Journal of Applied Statistics
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    • v.14 no.1
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    • pp.39-57
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    • 2001
  • Categorical data has sometimes misclassification errors. If this data will be analyzed, then estimated cell probabilities could be biased and the standard Pearson X2 tests may have inflated true type I error rates. On the other hand, if we regard wellclassified data with misclassified one, then we might spend lots of cost and time on adjustment of misclassification. It is a necessary and important step to ask whether categorical data is misclassified before analyzing data. In this paper, when data is misclassified at one of two variables for two-dimensional contingency table and marginal sums of a well-classified variable are fixed. We explore to partition marginal sums into each cells via the concepts of Bound and Collapse of Sebastiani and Ramoni (1997). The double sampling scheme (Tenenbein 1970) is used to obtain informations of misclassification. We propose test statistics in order to solve misclassification problems and examine behaviors of the statistics by simulation studies.

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Evaluation for Lifetime and Thermal Ratings for Aged Overhead Transmission Lines (노후 가공송전선의 수명과 열용량의 평가)

  • Kim, Sung-Duck
    • Journal of IKEEE
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    • v.16 no.1
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    • pp.1-6
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    • 2012
  • Thermal rating or lifetime evaluation for aged overhead transmission line becomes more important concerns with respect to keeping power delivery stable having proper capability. Both load rating and dip/clearance are essential factors to determine transmission capacity. In order to evaluate thermal rating and conductor lifetime for domestic transmission lines with double-circuit, the dip/ground clearance standards as well as the electrical equipment technical standard are examined. Conductor temperature and dip are calculated under the assumption of a contingency, and then, a method to up-rate load capacity is searched. As thermal rating and limit dip for aged conductor are properly evaluated, an improved strategy in order to guarantee the existing power system reliability is presented in this paper.

The study on spatial analysis using the expressional characteristics of surrealism and semiotic approach - Focusing on Greimas' semiotic square - (Surrealism 표현특성과 기호학적 적용방법을 통한 공간분석 연구 - 그레마스의 기호사변형을 중심으로 -)

  • Ham, Bo-A;Lee, Chan
    • Korean Institute of Interior Design Journal
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    • v.18 no.6
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    • pp.44-51
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    • 2009
  • Various and complex cultural phenomena have led to many changes in the space. The concept of unconsciousness, among others, and experimental expression technique and the concepts from surrealism that rather attaches great importance to contingency than intentional attempt have been employed in the space. The abstract expression as expressional characteristics of surrealism makes the space ambiguous through the concept of automatism using the approach of indeterminism and double image expression, and represents the space providing diversity through the dualism. In contrast, objective expression, which was based on depaysement, generates the tension and expresses the dramatic situation in such a way and manner which are intentional, distorted transformed, together with heterogenous meanings aligned through the reversal appeared in the techniques of collage and paranoiac-critical method. However if such space accommodating the expressional characteristics of surrealism is approached as superficial concept in analyzing the human's inner consciousness and imaginary society, expression of the ultimate concept contained in the expressional characteristics of surrealism can hardly be achieved. Hence, the spatial analysis from the semiotic approach, instead of unilateral method aimed to convey the meaning only, which creates the signification, was adopted. The study, as effective approach to the space accommodating the expressional characteristics of surrealism, was intended systematically evaluate the concreteness of understanding and generation of meaning through the semiotic method. Greimas' semiotic square analysis to the space plays the important role in generating the spatial meaning, as well as is needed for objective analysis of the importance of various characteristics and methodology which the space contains through the expressional characteristics of surrealism.

A study on the local development paradigm and strategy in the era of localization (地方化時代의 開發패러다임과 그 開發戰略 硏究)

  • ;;Kang, Hak-Soon;Park, Chan-Suk
    • Journal of the Korean Geographical Society
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    • v.30 no.2
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    • pp.132-145
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    • 1995
  • The Purpose of this study is to integrate two opposite paradigms, (development from above) and (development from below), by means of A. Giddenss (structuration theory) and to provide practical development strategies on the basis of integrated paradigm. The integration of these two opposite paradigms is in fact the internalization of epistemological overcoming of 'dependency', which means the structural transformation of dualistic thinking into monistic thinking that the enlargement of capitalist world-system can be 'development' and it may also be 'dependency'. Therefore the practical main issue of this integrated paradigm results in how peripheral countries should achieve self-reliant and continuous development under the circumstances of dependency. To achieve such development while resisting the growing arrogance of transnational capital, development strategies should be prepared to maker revitalized political community designed to fit a human scale and for the economy to be subordinated to the political will of the community. And at the same time the 'empowerment' of people should be strengthened.

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