• Title/Summary/Keyword: Fuzzy-Bayesian Theory

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Development of Integrity Assessment Model for Reinforced Concrete Highway Bridges Using Fuzzy Concept (Fuzzy 개념을 이용한 RC도로교의 건전성평가 모델 개발)

  • Na, Ki-Hyun;Park, Ju-Won;Lee, Cheung-Bin;Jung, Chul-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.2
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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.

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Collaborative CRM using Statistical Learning Theory and Bayesian Fuzzy Clustering

  • Jun, Sung-Hae
    • Communications for Statistical Applications and Methods
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    • v.11 no.1
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    • pp.197-211
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    • 2004
  • According to the increase of internet application, the marketing process as well as the research and survey, the education process, and administration of government are very depended on web bases. All kinds of goods and sales which are traded on the internet shopping malls are extremely increased. So, the necessity of automatically intelligent information system is shown, this system manages web site connected users for effective marketing. For the recommendation system which can offer a fit information from numerous web contents to user, we propose an automatic recommendation system which furnish necessary information to connected web user using statistical learning theory and bayesian fuzzy clustering. This system is called collaborative CRM in this paper. The performance of proposed system is compared with the other methods using real data of the existent shopping mall site. This paper shows that the predictive accuracy of the proposed system is improved by comparison with others.

Risk Assessment and Decision-Making of a Listed Enterprise's L/C Settlement Based on Fuzzy Probability and Bayesian Game Theory

  • Cheng, Zhang;Huang, Nanni
    • Journal of Information Processing Systems
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    • v.16 no.2
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    • pp.318-328
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    • 2020
  • Letter of Credit (L/C) is currently a very popular international settlement method frequently used in international trade processes amongst countries around the globe. Compared with other international settlement methods, however, L/C has some obvious shortcomings. Firstly, it is not easy to use due to the sophisticated processes its usage involves. Secondly, it is sometimes accompanied by a few risks and some uncertainty. Thus, highly efficient methods need to be used to assess and control these risks. To begin with, FAHP and KMV methods are used to resolve the problem of incomplete information associated with L/C and then, on this basis, Bayesian game theory is used in order to make more scientific and reasonable decisions with respect to international trade.

Hypotheses testing of Bayes' theorem for fuzzy prior parameters (퍼지 사전 모수에 관한 베이지안 가설검정)

  • Kang Man-Ki;Chio Gue-Tak
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.11a
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    • pp.205-208
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    • 2005
  • We have fuzzy hypotheses testing from Bayesian statistics with ideas from fuzzy sets theory to generalize Bayesian methods both for samples of fuzzy data and for prior distributions with non-precise parameters. Appling the principle of agreement index, the posterior odds ratio in the favor of hypotheses $H_0$ is equal to product of the fuzzy odds ratio and the fuzzy likelihood ratio. If the Posterior odds ratio exceeds the grade judgement, we accept the hypothesis $H_0$ for the degree.

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Fuzzy Theory and Bayesian Update-Based Traffic Prediction and Optimal Path Planning for Car Navigation System using Historical Driving Information (퍼지이론과 베이지안 갱신 기반의 과거 주행정보를 이용한 차량항법 장치의 교통상황 예측과 최적경로 계획)

  • Jung, Sang-Jun;Heo, Yong-Kwan;Jo, Han-Moo;Kim, Jong-Jin;Choi, Sul-Gi
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.11
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    • pp.159-167
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    • 2009
  • The vehicles play a significant role in modern people's life as economy grows. The development of car navigation system(CNS) provides various convenience because it shows the driver where they are and how to get to the destination from the point of source. However, the existing map-based CNS does not consider any environments such as traffic congestion. Given the same starting point and destination, the system always provides the same route and the required time. This paper proposes a path planning method with traffic prediction by applying historical driving information to the Fuzzy theory and Bayesian update. Fuzzy theory classifies the historical driving information into groups of leaving time and speed rate, and the traffic condition of each time zone is calculated by Bayesian update. An ellipse area including starting and destination points is restricted in order to reduce the calculation time. The accuracy and practicality of the proposed scheme are verified by several experiments and comparisons with real navigation.

Reliability and Safety Analysis of Structure System of Retaining Walls (옹벽구조시스템의 신뢰성 및 안전도 해석)

  • Jung, Chul-Won;Yun, Boung-Jo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.3
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    • pp.223-234
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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 structure system, 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 PEM and AFOSM are applied to retaining wall.

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PDC Intelligent control-based theory for structure system dynamics

  • Chen, Tim;Lohnash, Megan;Owens, Emmanuel;Chen, C.Y.J.
    • Smart Structures and Systems
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    • v.25 no.4
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    • pp.401-408
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    • 2020
  • This paper deals with the problem of global stabilization for a class of nonlinear control systems. An effective approach is proposed for controlling the system interaction of structures through a combination of parallel distributed compensation (PDC) intelligent controllers and fuzzy observers. An efficient approximate inference algorithm using expectation propagation and a Bayesian additive model is developed which allows us to predict the total number of control systems, thereby contributing to a more adaptive trajectory for the closed-loop system and that of its corresponding model. The closed-loop fuzzy system can be made as close as desired, so that the behavior of the closed-loop system can be rigorously predicted by establishing that of the closed-loop fuzzy system.

전문가 시스템의 불확실성 추론 방법

  • 이승재
    • 전기의세계
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    • v.39 no.8
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    • pp.7-12
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    • 1990
  • 전문가 시스템에 있어서의 불확실성 정보의 표현 및 처리를 담당하는 주요 추론모델중 Bayesian모델, Certainty Factor 모델 그리고 Dempster-Shafer 모델의 기본이론을 살펴보고자 한다. 이외의 주요 추론 방법으로서 Fuzzy추론 모델이 있는데 이는 판단 지식에 대한 주관적 불확실성과 "매우", "많이" 등의 자연어가 포함하고 있는 불분명성을 체계적이고 효과적으로 다룰 수 있는 Fuzzy Set 이론에 근거한 방법으로서, 불확실성 또는 불명료성을 0에서부터 1 사이의 값을 갖는 membership degree로 표시하며 이를 "MIN"과 "MAX" 함수를 이용한 합성 추론 규칙(Composition Rule of Inference)를 적용하여 처리한다. Fuzzy 추론 모델은 자연어를 포함하는 전문가의 지식 처리에 매우 적합하여 앞으로 그 응용이 높이 기대되는 방법이다. 이외에 Bayesian 모델을 변형 응용한 PROSPECTOR의 Likelyhood Ratio 모델, 정량적 방법인 Theory of Endorsement 모델 등 여러 방법이 있다. 그러나 어느 모델이 더 일반성을 갖고 더 좋은 방법인가 하는 문제에 대하여는 아직 많은 연구가 요구된다. 따라서 이러한 모델들의 전문가 시스템 적용에 있어서는 각 모델의 장단점을 고려하여 주어진 문제 영역에 적합한 모델을 선택하는 것이 바람직하다. 현재 불확실성 처리에 있어서 각 문제에 따른 경험적인 처리에 의존하는 전력 계통 분야의 적용에 있어서도 이러한 실인간 전문가의 추론방법에 근접된 반성을 갖는 불확실성 추론 방버 도입이 요구된다.가의 추론방법에 근접된 반성을 갖는 불확실성 추론 방버 도입이 요구된다.

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