• Title/Summary/Keyword: Bayesian network

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Design of Time-varying Stochastic Process with Dynamic Bayesian Networks

  • Cho, Hyun-Cheol;Fadali, M.Sami;Lee, Kwon-Soon
    • Journal of Electrical Engineering and Technology
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    • v.2 no.4
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    • pp.543-548
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    • 2007
  • We present a dynamic Bayesian network (DBN) model of a generalized class of nonstationary birth-death processes. The model includes birth and death rate parameters that are randomly selected from a known discrete set of values. We present an on-line algorithm to obtain optimal estimates of the parameters. We provide a simulation of real-time characterization of load traffic estimation using our DBN approach.

Communication Channel Equalization Using Adaptive Neural Net (적응 신경망을 이용한 통신 채널 등화)

  • 김정수;권용광;김민수;이대학;이상윤;김재공
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.1037-1040
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    • 1999
  • This paper investigates a RBF(Radial Basis Function) equalizer for channel equalization. RBF network has an identical structure to the optimal Bayesian symbol-decision equalizer solution. Therefore RBF can be employed to implement the Bayesian equalizer. Proposed algorithm of this paper makes channel states estimation to be unncessary, also makes center number which is needed indivisual channel to be minimum. Bayesian Equalizer has the theorical optimum performance. Proposed Equalizer performance is compared with this Baysian equalizer performance.

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Online Learning Control for Network-induced Time Delay Systems using Reset Control and Probabilistic Prediction Method (네트워크 기반 시간지연 시스템을 위한 리세트 제어 및 확률론적 예측기법을 이용한 온라인 학습제어시스템)

  • Cho, Hyun-Cheol;Sim, Kwang-Yeul;Lee, Kwon-Soon
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.9
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    • pp.929-938
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    • 2009
  • This paper presents a novel control methodology for communication network based nonlinear systems with time delay nature. We construct a nominal nonlinear control law for representing a linear model and a reset control system which is aimed for corrective control strategy to compensate system error due to uncertain time delay through wireless communication network. Next, online neural control approach is proposed for overcoming nonstationary statistical nature in the network topology. Additionally, DBN (Dynamic Bayesian Network) technique is accomplished for modeling of its dynamics in terms of casuality, which is then utilized for estimating prediction of system output. We evaluate superiority and reliability of the proposed control approach through numerical simulation example in which a nonlinear inverted pendulum model is employed as a networked control system.

A Study on the Application of ANN for Surface Roughness Prediction in Side Milling AL6061-T4 by Endmill (AL6061-T4의 측면 엔드밀 가공에서 표면거칠기 예측을 위한 인공신경망 적용에 관한 연구)

  • Chun, Se-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.5
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    • pp.55-60
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    • 2021
  • We applied an artificial neural network (ANN) and evaluated surface roughness prediction in lateral milling using an endmill. The selected workpiece was AL6061-T4 to obtain data of surface roughness measurement based on the spindle speed, feed, and depth of cut. The Bayesian optimization algorithm was applied to the number of nodes and the learning rate of each hidden layer to optimize the neural network. Experimental results show that the neural network applied to optimize using the Expected Improvement(EI) algorithm showed the best performance. Additionally, the predicted values do not exactly match during the neural network evaluation; however, the predicted tendency does march. Moreover, it is found that the neural network can be used to predict the surface roughness in the milling of aluminum alloy.

Protein Secondary Structure Prediction using Multiple Neural Network Likelihood Models

  • Kim, Seong-Gon;Kim, Yong-Gi
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.4
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    • pp.314-318
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    • 2010
  • Predicting Alpha-helicies, Beta-sheets and Turns of a proteins secondary structure is a complex non-linear task that has been approached by several techniques such as Neural Networks, Genetic Algorithms, Decision Trees and other statistical or heuristic methods. This project introduces a new machine learning method by combining Bayesian Inference with offline trained Multilayered Perceptron (MLP) models as the likelihood for secondary structure prediction of proteins. With varying window sizes of neighboring amino acid information, the information is extracted and passed back and forth between the Neural Net and the Bayesian Inference process until the posterior probability of the secondary structure converges.

An Application of Bayesian Network for Dynamic System Reliability Assessment (동적시스템의 신뢰도 평가를 위한 베이지안망의 적용)

  • Ahn Sun-Eung;Koo Jung-Mo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.27 no.2
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    • pp.93-101
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    • 2004
  • This paper is intended to assess a dynamic system reliability. Bayesian networks, however, have difficulties in their application for assessing the system reliability especially when the system consists of dependent components and the probability of failure of each component varies over time. Hence, we suggest a method for resolving the difficulties by considering a hoist system composed of two wires. Firstly, we explain the method of calculating the failure probability of the system components. Secondly, we show how to calculate the failure probability of the system for two cases that failure probability of each wire is constant and varying in time, respectively. finally, based on the calculated failure probability of the system, we infer the probability that two interesting events occur.

REVIEW OF VARIOUS DYNAMIC MODELING METHODS AND DEVELOPMENT OF AN INTUITIVE MODELING METHOD FOR DYNAMIC SYSTEMS

  • Shin, Seung-Ki;Seong, Poong-Hyun
    • Nuclear Engineering and Technology
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    • v.40 no.5
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    • pp.375-386
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    • 2008
  • Conventional static reliability analysis methods are inadequate for modeling dynamic interactions between components of a system. Various techniques such as dynamic fault tree, dynamic Bayesian networks, and dynamic reliability block diagrams have been proposed for modeling dynamic systems based on improvement of the conventional modeling methods. In this paper, we review these methods briefly and introduce dynamic nodes to the existing reliability graph with general gates (RGGG) as an intuitive modeling method to model dynamic systems. For a quantitative analysis, we use a discrete-time method to convert an RGGG to an equivalent Bayesian network and develop a software tool for generation of probability tables.

Understanding the genetics of systemic lupus erythematosus using Bayesian statistics and gene network analysis

  • Nam, Seoung Wan;Lee, Kwang Seob;Yang, Jae Won;Ko, Younhee;Eisenhut, Michael;Lee, Keum Hwa;Shin, Jae Il;Kronbichler, Andreas
    • Clinical and Experimental Pediatrics
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    • v.64 no.5
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    • pp.208-222
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    • 2021
  • The publication of genetic epidemiology meta-analyses has increased rapidly, but it has been suggested that many of the statistically significant results are false positive. In addition, most such meta-analyses have been redundant, duplicate, and erroneous, leading to research waste. In addition, since most claimed candidate gene associations were false-positives, correctly interpreting the published results is important. In this review, we emphasize the importance of interpreting the results of genetic epidemiology meta-analyses using Bayesian statistics and gene network analysis, which could be applied in other diseases.

Bayesian Learning for Self Organizing Maps (자기조직화 지도를 위한 베이지안 학습)

  • 전성해;전홍석;황진수
    • The Korean Journal of Applied Statistics
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    • v.15 no.2
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    • pp.251-267
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    • 2002
  • Self Organizing Maps(SOM) by Kohonen is very fast algorithm in neural networks. But it doesn't show sure rules of training results. In this paper, we introduce to Bayesian Learning for Self Organizing Maps(BLSOM) which combines self organizing maps with Bayesian learning. So it supports explanatory power of models and improves prediction. BLSOM has global optima anywhere but SOM has not. This is proved by experiment in this paper.

Fingerprinting Bayesian Algorithm for Indoor Location Determination (실내 측위 결정을 위한 Fingerprinting Bayesian 알고리즘)

  • Lee, Jang-Jae;Kwon, Jang-Woo;Jung, Min-A;Lee, Seong-Ro
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.6B
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    • pp.888-894
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    • 2010
  • For the indoor positioning, wireless fingerprinting is most favorable because fingerprinting is most accurate among the technique for wireless network based indoor positioning which does not require any special equipments dedicated for positioning. The deployment of a fingerprinting method consists of off-line phase and on-line phase and more efficient and accurate methods have been studied. This paper proposes a bayesian algorithm for wireless fingerprinting and indoor location determination using fuzzy clustering with bayesian learning as a statistical learning theory.