• 한국구조물진단유지관리공학회 논문집
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• 제2권2호
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• pp.151-161
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• 1998

In this study, an attempt is made to apply the concept of fuzzy-bayesian theory to the integrity assessment of RC highway bridge, and uncertainty states are represented in terms of fuzzy sets which define several linguistic variables such as "very good", "good", "average", "poor", "very poor", etc. Especially, the concept of fuzzy conditional probability aids to derive a new reliability analysis which includes the subjective assessment of engineers without introducing any additional correction factors. The fuzzy concept are also used as reliability indexes for the condition assessment based on the proposed models, the proposed fuzzy theory-based approach with the results of visual inspection and extensive field load tests are applied to the integrity assessment of a new RC highway bridge, namely, Jichok bridge.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2000년도 하계종합학술대회논문집
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• pp.133-136
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• 2000

The objective of this paper is to present a method for designing robust positioning control systems of a flexible arm using $H_2/H_{\infty}$ and $\mu$ theory. We begin with a description of the flexible arm based on the model identification method and discuss the derivation of the model uncertainty. The validity of the obtained model is confirmed experimentally Next, a robust controller is designed based on the $H_2/H_{\infty}$ and $\mu$ theory by which we can improve robustness of the entire system. On this occasion, we also propose a general plant formation suitable to $H_2/H_{\infty}$ control. Finally, the effectiveness of the proposed design method is verified through experimentation.

• Nuclear Engineering and Technology
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• 제45권6호
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• pp.767-790
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• 2013

MAAP4 is a computer code that can simulate the response of a light water reactor power plant during severe accident sequences, including actions taken as part of accident management. The code quantitatively predicts the evolution of a severe accident starting from full power conditions given a set of system faults and initiating events through events such as core melt, reactor vessel failure, and containment failure. Furthermore, models are included in the code to represent the actions that could mitigate the accident by in-vessel cooling, external cooling of the reactor pressure vessel, or cooling the debris in containment. A key element tied to using a code like MAAP4 is an uncertainty analysis. The purpose of this paper is to present a MAAP4 based analysis to examine the sensitivity of a key parameter, in this case hydrogen production, to a set of model parameters that are related to a Level 2 PRA analysis. The Level 2 analysis examines those sequences that result in core melting and subsequent reactor pressure vessel failure and its impact on the containment. This paper identifies individual contributors and MAAP4 model parameters that statistically influence hydrogen production. Hydrogen generation was chosen because of its direct relationship to oxidation. With greater oxidation, more heat is added to the core region and relocation (core slump) should occur faster. This, in theory, would lead to shorter failure times and subsequent "hotter" debris pool on the containment floor.

• Nuclear Engineering and Technology
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• 제37권3호
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• pp.273-278
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• 2005

Key concepts in South Korean nuclear safety regulation are safety and risk. Nuclear regulation in South Korea has required reactor designs and safeguards that reduce the risk of a major accident to less than one in a million reactor-years-a risk supposedly low enough to be acceptable. To date, in South Korean nuclear safety regulation has involved the establishment of many technical standards to enable administration enforcement. In scientific lawsuits in which the legal issue is the validity of specialized technical standards that are used for judge whether a particular nuclear power plant is to be licensed, the concept of uncertainty law is often raised with regard to what extent the examination and judgment by the judicial power affects a discretion made by the administrative office. In other words, the safety standards for nuclear power plants has been adapted as a form of the scientific technical standards widely under the idea of uncertainty law. Thus, the improvement of nuclear safety regulation in South Korea seems to depend on the rational lawmaking and a reasonable, judicial examination of the scientific standards on nuclear safety.

• The Journal of Asian Finance, Economics and Business
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• 제8권9호
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• pp.23-33
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• 2021

The main objective of this research is to examine the effect of organizational culture, environmental uncertainty, and manager's personnel value on environmental disclosure through the environmental organizational structure of manufacturing companies on the Indonesia Stock Exchange. This research uses the structuration and contingency theory. The sample in this study focused on the level of heads or managers or directors of manufacturing companies listed on the Indonesia Stock Exchange. The research data was obtained through an online questionnaire distributed to heads or managers. The total sample of this study is 161 manufacturing companies. The data comprising of 64 respondents was completed and can be processed. Empirical testing used Structural Equation Modeling (SEM) through Partial Least Square (PLS). The result shows that environmental uncertainty and management personnel value have a positive effect on the environmental organizational structure, as well as the environmental organizational structure has a positive effect on the environmental disclosure. However, organizational culture has no effect on the environmental organizational structure. This research can provide benefits for manufacturing companies. The limitation include the low level of response from the respondents. Also the results cannot be generalized due to its specific focus on the manufacturing companies.

• Geomechanics and Engineering
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• 제36권5호
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• pp.475-487
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• 2024

Many uncertainties affect the stability assessment of rock structures. Some of these factors significantly influence technology decisions. Some of these factors belong to the geological domain, and spatial uncertainty measurements are useful for structural stability analysis. This paper presents an integrated approach to study the stability of rock structures, including spatial factors. This study models two main components: discrete structures (fault zones) and well known geotechnical parameters (rock quality indicators). The geostatistical modeling criterion are used to quantify geographic uncertainty by producing simulated maps and RQD values for multiple equally likely error regions. Slope stability theorem would be demonstrated by modeling local failure zones and RQDs. The approach proided is validated and finally, the slope stability analysis method and fuzzy Laypunov criterion are applied to mining projects with limited measurement data. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage. Simulation results of linear and nonlinear structures show that the proposed method is able to identify structural parameters and their changes due to damage and unknown excitations. Therefore, the goal is believed to achieved in the near future by the ongoing development of AI and fuzzy theory.

• 한국전자거래학회지
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• 제16권4호
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• pp.241-256
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• 2011

본 연구는 온라인 소비자 리뷰가 제품정보 제공자로서 소비자 구매결정에 미치는 영향에 대해 살펴보았다. 정보이론에서 제시된 엔트로피의 개념을 이용하여, 온라인 소비자 리뷰 안에 존재하는 여러 가지 종류의 제품 정보에 대해 소비자들이 각각 다르게 반응하는 이유를 설명하고자 하였다. 정보 엔트로피는 한 개의 단위 정보가 감소시킬 수 있는 불확실성의 정도를 의미한다. 온라인 소비자 리뷰에는 각각 다른 정도의 엔트로피를 감소시킬 수 있는 여러 가지 정보가 있고 따라서 소비자는 감소되는 엔트로피의 정도에 따라 각각의 정보에 대해 다르게 반응한다. 본 연구에서는 여러 가지 종류의 정보에 따라 감소하는 엔트로피의 양이, 제품 정보 제공의 전후에 따라 제품 속성에 대한 인식된 중요도의 차이로 나타남을 검증하고자 하였다. 이러한 연구 가설들은 총 268명의 온라인 쇼핑몰 이용자에게 실험을 하여 정보제공의 전후에 따른 제품 속성 별 중요도에 분명한 차이가 있음을 보여줌으로써 확인되었다.

• Structural Engineering and Mechanics
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• 제62권4호
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• pp.507-517
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• 2017

Due to the discontinuous nature of uncertainty quantification in conventional evidence theory(ET), the computational cost of reliability analysis based on ET model is very high. A novel ET model based on fuzzy distribution and the corresponding combination rule to synthesize the judgments of experts are put forward in this paper. The intersection and union of membership functions are defined as belief and plausible membership function respectively, and the Murfhy's average combination rule is adopted to combine the basic probability assignment for focal elements. Then the combined membership functions are transformed to the equivalent probability density function by a normalizing factor. Finally, a reliability analysis procedure for structures with the mixture of epistemic and aleatory uncertainties is presented, in which the equivalent normalization method is adopted to solve the upper and lower bound of reliability. The effectiveness of the procedure is demonstrated by a numerical example and an engineering example. The results also show that the reliability interval calculated by the suggested method is almost identical to that solved by conventional method. Moreover, the results indicate that the computational cost of the suggested procedure is much less than that of conventional method. The suggested ET model provides a new way to flexibly represent epistemic uncertainty, and provides an efficiency method to estimate the reliability of structures with the mixture of epistemic and aleatory uncertainties.

• 수산해양기술연구
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• 제31권2호
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• pp.178-189
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• 1995

병렬형 도립진자를 수학적으로 모델링하고 주파수 응답법에 의해 파라미터를 동정하여, $H_\infty$제어이론 중 혼합감도문제에 의거하여 제어계를 설계한 후 응답 시뮬레이션을 한 결과그 응답으로부터 모델링의 불확실성에 대처할 수 있는 강인한 제어계를 구성할 수 있었다. 앞으로 실제 시스템에 대하 s제어들 과제로 남겨두고 있다. 시뮬레이션 응답과는 달리 실제 으답실험에서도 좋은 결과를 얻기 위해서는 여러 가지의 어려움이 있을 것으로 예상된다. 특히 응답 시뮬레이션에서도 나타난 바와 같이 전자가 미소각으로 기울어진 상태에서 제어를 할 경우에도 각 상태의 변동량이 크고, 또한 상당한 제어입력을 요한다. 따라서 센서 잡음에 대한 영향을 충분히 고려할 필요가 있으므로, 노이즈를 많이 발생시키는 PWM방식의 직류모터 구동 드라이버보다는 선형 드라이버를 이용하는 것이 적절할 것으로 예상된다

• 한국의류산업학회지
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• 제7권6호
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• pp.585-593
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• 2005

Diverse and complicated trends of fashion design which were initiated at the latter part of the 20th century have been evolving in the cultural framework of Postmodernism. At this point of time, Poststructuralism, with its aims to interpret and understand modern fashion design, is a new system of thinking that reveals the contradictory aspects of rationalistic Western philosophy and accepts uncertainty and disorder as they exist. The main purpose of this study is to examine the various theoretic systems and characteristic concepts of Poststructuralism, and supply a new cognizance frame to understand the processes of fashion design with free and varied notions of deconstruction and generation, in place of the former systematic and consistent interpretation of meaning. Concerning fashion design, analysis of theories and analysis of contents. By probing and examining deconstruction theory, 'I'-other theory, textual theory, and nomadic thinking, the concepts of cognizance are classified into Nonboundariness, Otherness, and Textualism. The theoretic foundation for this analysis and classification is supplied by Derrida's deconstructional philosophy, Lacan's mental analysis, Bartes's textual theory, Deleuze's change and generation theory, together with other theories of Poststructuralism. In analysis of theories, a cognizance frame is proposed that can categorize the concepts, derived from various theories of Poststructuralism, as traits expressed in fashion design.