Articles de revues : « Continuous Time Bayesian Network »

1

Stella, F., et Y. Amer. « Continuous time Bayesian network classifiers ». Journal of Biomedical Informatics 45, n^o 6 (décembre 2012) : 1108–19. http://dx.doi.org/10.1016/j.jbi.2012.07.002.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

2

Codecasa, Daniele, et Fabio Stella. « Learning continuous time Bayesian network classifiers ». International Journal of Approximate Reasoning 55, n^o 8 (novembre 2014) : 1728–46. http://dx.doi.org/10.1016/j.ijar.2014.05.005.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

3

Xu, J., et C. R. Shelton. « Intrusion Detection using Continuous Time Bayesian Networks ». Journal of Artificial Intelligence Research 39 (23 décembre 2010) : 745–74. http://dx.doi.org/10.1613/jair.3050.

Texte intégral

Résumé :

Intrusion detection systems (IDSs) fall into two high-level categories: network-based systems (NIDS) that monitor network behaviors, and host-based systems (HIDS) that monitor system calls. In this work, we present a general technique for both systems. We use anomaly detection, which identifies patterns not conforming to a historic norm. In both types of systems, the rates of change vary dramatically over time (due to burstiness) and over components (due to service difference). To efficiently model such systems, we use continuous time Bayesian networks (CTBNs) and avoid specifying a fixed update interval common to discrete-time models. We build generative models from the normal training data, and abnormal behaviors are flagged based on their likelihood under this norm. For NIDS, we construct a hierarchical CTBN model for the network packet traces and use Rao-Blackwellized particle filtering to learn the parameters. We illustrate the power of our method through experiments on detecting real worms and identifying hosts on two publicly available network traces, the MAWI dataset and the LBNL dataset. For HIDS, we develop a novel learning method to deal with the finite resolution of system log file time stamps, without losing the benefits of our continuous time model. We demonstrate the method by detecting intrusions in the DARPA 1998 BSM dataset.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Bhattacharjya, Debarun, Karthikeyan Shanmugam, Tian Gao, Nicholas Mattei, Kush Varshney et Dharmashankar Subramanian. « Event-Driven Continuous Time Bayesian Networks ». Proceedings of the AAAI Conference on Artificial Intelligence 34, n^o 04 (3 avril 2020) : 3259–66. http://dx.doi.org/10.1609/aaai.v34i04.5725.

Texte intégral

Résumé :

We introduce a novel event-driven continuous time Bayesian network (ECTBN) representation to model situations where a system's state variables could be influenced by occurrences of events of various types. In this way, the model parameters and graphical structure capture not only potential “causal” dynamics of system evolution but also the influence of event occurrences that may be interventions. We propose a greedy search procedure for structure learning based on the BIC score for a special class of ECTBNs, showing that it is asymptotically consistent and also effective for limited data. We demonstrate the power of the representation by applying it to model paths out of poverty for clients of CityLink Center, an integrated social service provider in Cincinnati, USA. Here the ECTBN formulation captures the effect of classes/counseling sessions on an individual's life outcome areas such as education, transportation, employment and financial education.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Shelton, C. R., et G. Ciardo. « Tutorial on Structured Continuous-Time Markov Processes ». Journal of Artificial Intelligence Research 51 (23 décembre 2014) : 725–78. http://dx.doi.org/10.1613/jair.4415.

Texte intégral

Résumé :

A continuous-time Markov process (CTMP) is a collection of variables indexed by a continuous quantity, time. It obeys the Markov property that the distribution over a future variable is independent of past variables given the state at the present time. We introduce continuous-time Markov process representations and algorithms for filtering, smoothing, expected sufficient statistics calculations, and model estimation, assuming no prior knowledge of continuous-time processes but some basic knowledge of probability and statistics. We begin by describing "flat" or unstructured Markov processes and then move to structured Markov processes (those arising from state spaces consisting of assignments to variables) including Kronecker, decision-diagram, and continuous-time Bayesian network representations. We provide the first connection between decision-diagrams and continuous-time Bayesian networks.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Sturlaugson, Liessman, et John W. Sheppard. « Sensitivity Analysis of Continuous Time Bayesian Network Reliability Models ». SIAM/ASA Journal on Uncertainty Quantification 3, n^o 1 (janvier 2015) : 346–69. http://dx.doi.org/10.1137/140953848.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

7

Codecasa, Daniele, et Fabio Stella. « Classification and clustering with continuous time Bayesian network models ». Journal of Intelligent Information Systems 45, n^o 2 (22 novembre 2014) : 187–220. http://dx.doi.org/10.1007/s10844-014-0345-0.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

8

Boudali, H., et J. B. Dugan. « A Continuous-Time Bayesian Network Reliability Modeling, and Analysis Framework ». IEEE Transactions on Reliability 55, n^o 1 (mars 2006) : 86–97. http://dx.doi.org/10.1109/tr.2005.859228.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

9

Villa, S., et F. Stella. « A continuous time Bayesian network classifier for intraday FX prediction ». Quantitative Finance 14, n^o 12 (22 avril 2014) : 2079–92. http://dx.doi.org/10.1080/14697688.2014.906811.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

10

Gatti, E., D. Luciani et F. Stella. « A continuous time Bayesian network model for cardiogenic heart failure ». Flexible Services and Manufacturing Journal 24, n^o 4 (8 décembre 2011) : 496–515. http://dx.doi.org/10.1007/s10696-011-9131-2.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

11

Hosoda, Shion, Tsukasa Fukunaga et Michiaki Hamada. « Umibato : estimation of time-varying microbial interaction using continuous-time regression hidden Markov model ». Bioinformatics 37, Supplement_1 (1 juillet 2021) : i16—i24. http://dx.doi.org/10.1093/bioinformatics/btab287.

Texte intégral

Résumé :

Abstract Motivation Accumulating evidence has highlighted the importance of microbial interaction networks. Methods have been developed for estimating microbial interaction networks, of which the generalized Lotka–Volterra equation (gLVE)-based method can estimate a directed interaction network. The previous gLVE-based method for estimating microbial interaction networks did not consider time-varying interactions. Results In this study, we developed unsupervised learning-based microbial interaction inference method using Bayesian estimation (Umibato), a method for estimating time-varying microbial interactions. The Umibato algorithm comprises Gaussian process regression (GPR) and a new Bayesian probabilistic model, the continuous-time regression hidden Markov model (CTRHMM). Growth rates are estimated by GPR, and interaction networks are estimated by CTRHMM. CTRHMM can estimate time-varying interaction networks using interaction states, which are defined as hidden variables. Umibato outperformed the existing methods on synthetic datasets. In addition, it yielded reasonable estimations in experiments on a mouse gut microbiota dataset, thus providing novel insights into the relationship between consumed diets and the gut microbiota. Availability and implementation The C++ and python source codes of the Umibato software are available at https://github.com/shion-h/Umibato. Supplementary information Supplementary data are available at Bioinformatics online.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Perreault, Logan, Monica Thornton, John Sheppard et Joseph DeBruycker. « Disjunctive interaction in continuous time Bayesian networks ». International Journal of Approximate Reasoning 90 (novembre 2017) : 253–71. http://dx.doi.org/10.1016/j.ijar.2017.07.011.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

13

Perreault, Logan, et John Sheppard. « Compact structures for continuous time Bayesian networks ». International Journal of Approximate Reasoning 109 (juin 2019) : 19–41. http://dx.doi.org/10.1016/j.ijar.2019.03.005.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

14

Villa, Simone, et Fabio Stella. « Learning Continuous Time Bayesian Networks in Non-stationary Domains ». Journal of Artificial Intelligence Research 57 (20 septembre 2016) : 1–37. http://dx.doi.org/10.1613/jair.5126.

Texte intégral

Résumé :

Non-stationary continuous time Bayesian networks are introduced. They allow the parents set of each node to change over continuous time. Three settings are developed for learning non-stationary continuous time Bayesian networks from data: known transition times, known number of epochs and unknown number of epochs. A score function for each setting is derived and the corresponding learning algorithm is developed. A set of numerical experiments on synthetic data is used to compare the effectiveness of non-stationary continuous time Bayesian networks to that of non-stationary dynamic Bayesian networks. Furthermore, the performance achieved by non-stationary continuous time Bayesian networks is compared to that achieved by state-of-the-art algorithms on four real-world datasets, namely drosophila, saccharomyces cerevisiae, songbird and macroeconomics.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Acerbi, Enzo, Marcela Hortova-Kohoutkova, Tsokyi Choera, Nancy Keller, Jan Fric, Fabio Stella, Luigina Romani et Teresa Zelante. « Modeling Approaches Reveal New Regulatory Networks in Aspergillus fumigatus Metabolism ». Journal of Fungi 6, n^o 3 (14 juillet 2020) : 108. http://dx.doi.org/10.3390/jof6030108.

Texte intégral

Résumé :

Systems biology approaches are extensively used to model and reverse-engineer gene regulatory networks from experimental data. Indoleamine 2,3-dioxygenases (IDOs)—belonging in the heme dioxygenase family—degrade l-tryptophan to kynurenines. These enzymes are also responsible for the de novo synthesis of nicotinamide adenine dinucleotide (NAD+). As such, they are expressed by a variety of species, including fungi. Interestingly, Aspergillus may degrade l-tryptophan not only via IDO but also via alternative pathways. Deciphering the molecular interactions regulating tryptophan metabolism is particularly critical for novel drug target discovery designed to control pathogen determinants in invasive infections. Using continuous time Bayesian networks over a time-course gene expression dataset, we inferred the global regulatory network controlling l-tryptophan metabolism. The method unravels a possible novel approach to target fungal virulence factors during infection. Furthermore, this study represents the first application of continuous-time Bayesian networks as a gene network reconstruction method in Aspergillus metabolism. The experiment showed that the applied computational approach may improve the understanding of metabolic networks over traditional pathways.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Wei, Xiaohan, Yulai Zhang et Cheng Wang. « Bayesian Network Structure Learning Method Based on Causal Direction Graph for Protein Signaling Networks ». Entropy 24, n^o 10 (24 septembre 2022) : 1351. http://dx.doi.org/10.3390/e24101351.

Texte intégral

Résumé :

Constructing the structure of protein signaling networks by Bayesian network technology is a key issue in the field of bioinformatics. The primitive structure learning algorithms of the Bayesian network take no account of the causal relationships between variables, which is unfortunately important in the application of protein signaling networks. In addition, as a combinatorial optimization problem with a large searching space, the computational complexities of the structure learning algorithms are unsurprisingly high. Therefore, in this paper, the causal directions between any two variables are calculated first and stored in a graph matrix as one of the constraints of structure learning. A continuous optimization problem is constructed next by using the fitting losses of the corresponding structure equations as the target, and the directed acyclic prior is used as another constraint at the same time. Finally, a pruning procedure is developed to keep the result of the continuous optimization problem sparse. Experiments show that the proposed method improves the structure of the Bayesian network compared with the existing methods on both the artificial data and the real data, meanwhile, the computational burdens are also reduced significantly.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Linzner, Dominik, et Heinz Koeppl. « Active learning of continuous-time Bayesian networks through interventions* ». Journal of Statistical Mechanics : Theory and Experiment 2021, n^o 12 (1 décembre 2021) : 124001. http://dx.doi.org/10.1088/1742-5468/ac3908.

Texte intégral

Résumé :

Abstract We consider the problem of learning structures and parameters of continuous-time Bayesian networks (CTBNs) from time-course data under minimal experimental resources. In practice, the cost of generating experimental data poses a bottleneck, especially in the natural and social sciences. A popular approach to overcome this is Bayesian optimal experimental design (BOED). However, BOED becomes infeasible in high-dimensional settings, as it involves integration over all possible experimental outcomes. We propose a novel criterion for experimental design based on a variational approximation of the expected information gain. We show that for CTBNs, a semi-analytical expression for this criterion can be calculated for structure and parameter learning. By doing so, we can replace sampling over experimental outcomes by solving the CTBNs master-equation, for which scalable approximations exist. This alleviates the computational burden of integrating over possible experimental outcomes in high-dimensions. We employ this framework in order to recommend interventional sequences. In this context, we extend the CTBN model to conditional CTBNs in order to incorporate interventions. We demonstrate the performance of our criterion on synthetic and real-world data.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Sturlaugson, Liessman, et John W. Sheppard. « Uncertain and negative evidence in continuous time Bayesian networks ». International Journal of Approximate Reasoning 70 (mars 2016) : 99–122. http://dx.doi.org/10.1016/j.ijar.2015.12.013.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

19

Badr, Ahmed, Ahmed Yosri, Sonia Hassini et Wael El-Dakhakhni. « Coupled Continuous-Time Markov Chain–Bayesian Network Model for Dam Failure Risk Prediction ». Journal of Infrastructure Systems 27, n^o 4 (décembre 2021) : 04021041. http://dx.doi.org/10.1061/(asce)is.1943-555x.0000649.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

20

Wu, Si, et Shun-ichi Amari. « Computing with Continuous Attractors : Stability and Online Aspects ». Neural Computation 17, n^o 10 (1 octobre 2005) : 2215–39. http://dx.doi.org/10.1162/0899766054615626.

Texte intégral

Résumé :

Two issues concerning the application of continuous attractors in neural systems are investigated: the computational robustness of continuous attractors with respect to input noises and the implementation of Bayesian online decoding. In a perfect mathematical model for continuous attractors, decoding results for stimuli are highly sensitive to input noises, and this sensitivity is the inevitable consequence of the system's neutral stability. To overcome this shortcoming, we modify the conventional network model by including extra dynamical interactions between neurons. These interactions vary according to the biologically plausible Hebbian learning rule and have the computational role of memorizing and propagating stimulus information accumulated with time. As a result, the new network model responds to the history of external inputs over a period of time, and hence becomes insensitive to short-term fluctuations. Also, since dynamical interactions provide a mechanism to convey the prior knowledge of stimulus, that is, the information of the stimulus presented previously, the network effectively implements online Bayesian inference. This study also reveals some interesting behavior in neural population coding, such as the trade-off between decoding stability and the speed of tracking time-varying stimuli, and the relationship between neural tuning width and the tracking speed.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Dui, Hongyan, Jiaying Song et Yun-an Zhang. « Reliability and Service Life Analysis of Airbag Systems ». Mathematics 11, n^o 2 (13 janvier 2023) : 434. http://dx.doi.org/10.3390/math11020434.

Texte intégral

Résumé :

Airbag systems are important to a car’s safety protection system. To further improve the reliability of the system, this paper analyzes the failure mechanism of automotive airbag systems and establishes a dynamic fault tree model. The dynamic fault tree model is transformed into a continuous-time Bayesian network by introducing a unit step function and an impulse function, from which the failure probability of the system is calculated. Finally, the system reliability and average life are calculated and analyzed and compared with the sequential binary decision diagram method. The results show that the method can obtain more accurate system reliability and effectively identify the weak parts of the automotive airbag system, to a certain extent compensating for the lack of computational complexity of dynamic Bayesian networks in solving system reliability problems with continuous failure processes.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Park, Cheol Young, Kathryn Blackmond Laskey, Paulo C. G. Costa et Shou Matsumoto. « Gaussian Mixture Reduction for Time-Constrained Approximate Inference in Hybrid Bayesian Networks ». Applied Sciences 9, n^o 10 (18 mai 2019) : 2055. http://dx.doi.org/10.3390/app9102055.

Texte intégral

Résumé :

Hybrid Bayesian Networks (HBNs), which contain both discrete and continuous variables, arise naturally in many application areas (e.g., image understanding, data fusion, medical diagnosis, fraud detection). This paper concerns inference in an important subclass of HBNs, the conditional Gaussian (CG) networks, in which all continuous random variables have Gaussian distributions and all children of continuous random variables must be continuous. Inference in CG networks can be NP-hard even for special-case structures, such as poly-trees, where inference in discrete Bayesian networks can be performed in polynomial time. Therefore, approximate inference is required. In approximate inference, it is often necessary to trade off accuracy against solution time. This paper presents an extension to the Hybrid Message Passing inference algorithm for general CG networks and an algorithm for optimizing its accuracy given a bound on computation time. The extended algorithm uses Gaussian mixture reduction to prevent an exponential increase in the number of Gaussian mixture components. The trade-off algorithm performs pre-processing to find optimal run-time settings for the extended algorithm. Experimental results for four CG networks compare performance of the extended algorithm with existing algorithms and show the optimal settings for these CG networks.

Styles APA, Harvard, Vancouver, ISO, etc.

23

BOXER, PAUL A. « LEARNING NAIVE PHYSICS BY VISUAL OBSERVATION : USING QUALITATIVE SPATIAL REPRESENTATIONS AND PROBABILISTIC REASONING ». International Journal of Computational Intelligence and Applications 01, n^o 03 (septembre 2001) : 273–85. http://dx.doi.org/10.1142/s146902680100024x.

Texte intégral

Résumé :

Autonomous robots are unsuccessful at operating in complex, unconstrained environments. They lack the ability to learn about the physical behavior of different objects through the use of vision. We combine Bayesian networks and qualitative spatial representation to learn general physical behavior by visual observation. We input training scenarios that allow the system to observe and learn normal physical behavior. The position and velocity of the visible objects are represented as qualitative states. Transitions between these states over time are entered as evidence into a Bayesian network. The network provides probabilities of future transitions to produce predictions of future physical behavior. We use test scenarios to determine how well the approach discriminates between normal and abnormal physical behavior and actively predicts future behavior. We examine the ability of the system to learn three naive physical concepts, "no action at a distance", "solidity" and "movement on continuous paths". We conclude that the combination of qualitative spatial representations and Bayesian network techniques is capable of learning these three rules of naive physics.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Sturlaugson, Liessman, Logan Perreault et John W. Sheppard. « Factored performance functions and decision making in continuous time Bayesian networks ». Journal of Applied Logic 22 (juillet 2017) : 28–45. http://dx.doi.org/10.1016/j.jal.2016.11.030.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

25

Codetta-Raiteri, Daniele. « Applying Generalized Continuous Time Bayesian Networks to a reliability case study ». IFAC-PapersOnLine 48, n^o 21 (2015) : 676–81. http://dx.doi.org/10.1016/j.ifacol.2015.09.605.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

26

Liu, Jianyu, Linxue Zhao et Yanlong Mao. « Bayesian regularized NAR neural network based short-term prediction method of water consumption ». E3S Web of Conferences 118 (2019) : 03024. http://dx.doi.org/10.1051/e3sconf/201911803024.

Texte intégral

Résumé :

With the continuous construction of urban water supply infrastructure, it is extremely urgent to change the management mode of water supply from traditional manual experience to modern and efficient means. The water consumption forecast is the premise of water supply scheduling, and its accuracy also directly affects the effectiveness of water supply scheduling. This paper analyzes the regularity of water consumption time series, establishes a short-term water consumption prediction model based on Bayesian regularized NAR neural network, and compares and evaluates the prediction effect of the model. The verification results show that the Bayesian based NAR neural network prediction model has higher adaptability to the water consumption prediction than the standard BP neural network and the Bayesian regularized BP neural network. The prediction accuracy can more accurately reflect the short-term variation of water consumption.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Beaudry, Eric, Froduald Kabanza et Francois Michaud. « Planning for Concurrent Action Executions Under Action Duration Uncertainty Using Dynamically Generated Bayesian Networks ». Proceedings of the International Conference on Automated Planning and Scheduling 20 (25 mai 2021) : 10–17. http://dx.doi.org/10.1609/icaps.v20i1.13400.

Texte intégral

Résumé :

An interesting class of planning domains, including planning for daily activities of Mars rovers, involves achievement of goals with time constraints and concurrent actions with probabilistic durations. Current probabilistic approaches, which rely on a discrete time model, introduce a blow up in the search state-space when the two factors of action concurrency and action duration uncertainty are combined. Simulation-based and sampling probabilistic planning approaches would cope with this state explosion by avoiding storing all the explored states in memory, but they remain approximate solution approaches. In this paper, we present an alternative approach relying on a continuous time model which avoids the state explosion caused by time stamping in the presence of action concurrency and action duration uncertainty. Time is represented as a continuous random variable. The dependency between state time variables is conveyed by a Bayesian network, which is dynamically generated by a state-based forward-chaining search based on the action descriptions. A generated plan is characterized by a probability of satisfying a goal. The evaluation of this probability is done by making a query the Bayesian network.

Styles APA, Harvard, Vancouver, ISO, etc.

28

WU, CHUNG-HSIEN, JHING-FA WANG, CHAUG-CHING HUANG et JAU-YIEN LEE. « SPEAKER-INDEPENDENT RECOGNITION OF ISOLATED WORDS USING CONCATENATED NEURAL NETWORKS ». International Journal of Pattern Recognition and Artificial Intelligence 05, n^o 05 (décembre 1991) : 693–714. http://dx.doi.org/10.1142/s0218001491000417.

Texte intégral

Résumé :

A speaker-independent isolated word recognizer is proposed. It is obtained by concatenating a Bayesian neural network and a Hopfield time-alignment network. In this system, the Bayesian network outputs the a posteriori probability for each speech frame, and the Hopfield network is then concatenated for time warping. A proposed splitting Learning Vector Quantization (LVQ) algorithm derived from the LBG clustering algorithm and the Kohonen LVQ algorithm is first used to train the Bayesian network. The LVQ2 algorithm is subsequently adopted as a final refinement step. A continuous mixture of Gaussian densities for each frame and multi-templates for each word are employed to characterize each word pattern. Experimental evaluation of this system with four templates/word and five mixtures/frame, using 53 speakers (28 males, 25 females) and isolated words (10 digits and 30 city names) databases, gave average recognition accuracies of 97.3%, for the speaker-trained mode and 95.7% for the speaker-independent mode, respectively. Comparisons with K-means and DTW algorithms show that the integration of the splitting LVQ and LVQ2 algorithms makes this system well suited to speaker-independent isolated word recognition. A cookbook approach for the determination of parameters in the Hopfield time-alignment network is also described.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Bobrowski, Omer, Ron Meir et Yonina C. Eldar. « Bayesian Filtering in Spiking Neural Networks : Noise, Adaptation, and Multisensory Integration ». Neural Computation 21, n^o 5 (mai 2009) : 1277–320. http://dx.doi.org/10.1162/neco.2008.01-08-692.

Texte intégral

Résumé :

A key requirement facing organisms acting in uncertain dynamic environments is the real-time estimation and prediction of environmental states, based on which effective actions can be selected. While it is becoming evident that organisms employ exact or approximate Bayesian statistical calculations for these purposes, it is far less clear how these putative computations are implemented by neural networks in a strictly dynamic setting. In this work, we make use of rigorous mathematical results from the theory of continuous time point process filtering and show how optimal real-time state estimation and prediction may be implemented in a general setting using simple recurrent neural networks. The framework is applicable to many situations of common interest, including noisy observations, non-Poisson spike trains (incorporating adaptation), multisensory integration, and state prediction. The optimal network properties are shown to relate to the statistical structure of the environment, and the benefits of adaptation are studied and explicitly demonstrated. Finally, we recover several existing results as appropriate limits of our general setting.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Moura, Márcio das Chagas, et Enrique López Droguett. « A continuous-time semi-markov bayesian belief network model for availability measure estimation of fault tolerant systems ». Pesquisa Operacional 28, n^o 2 (août 2008) : 355–75. http://dx.doi.org/10.1590/s0101-74382008000200011.

Texte intégral

Résumé :

In this work it is proposed a model for the assessment of availability measure of fault tolerant systems based on the integration of continuous time semi-Markov processes and Bayesian belief networks. This integration results in a hybrid stochastic model that is able to represent the dynamic characteristics of a system as well as to deal with cause-effect relationships among external factors such as environmental and operational conditions. The hybrid model also allows for uncertainty propagation on the system availability. It is also proposed a numerical procedure for the solution of the state probability equations of semi-Markov processes described in terms of transition rates. The numerical procedure is based on the application of Laplace transforms that are inverted by the Gauss quadrature method known as Gauss Legendre. The hybrid model and numerical procedure are illustrated by means of an example of application in the context of fault tolerant systems.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Hasan, Samiul, et Satish V. Ukkusuri. « Reconstructing Activity Location Sequences From Incomplete Check-In Data : A Semi-Markov Continuous-Time Bayesian Network Model ». IEEE Transactions on Intelligent Transportation Systems 19, n^o 3 (mars 2018) : 687–98. http://dx.doi.org/10.1109/tits.2017.2700481.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

32

Yin, Ruyang, Jiping Xing, Pengli Mo, Nan Zheng et Zhiyuan Liu. « BO-B&B : A hybrid algorithm based on Bayesian optimization and branch-and-bound for discrete network design problems ». Electronic Research Archive 30, n^o 11 (2022) : 3993–4014. http://dx.doi.org/10.3934/era.2022203.

Texte intégral

Résumé :

<abstract> <p>A discrete network design problem (DNDP) is conventionally formulated as an analytical bi-level programming problem to acquire an optimal network design strategy for an existing traffic network. In recent years, multimodal network design problems have benefited from simulation-based models. The nonconvexity and implicity of bi-level DNDPs make it challenging to obtain an optimal solution, especially for simulation-related models. Bayesian optimization (BO) has been proven to be an effective method for optimizing the costly black-box functions of simulation-based continuous network design problems. However, there are only discrete inputs in DNDPs, which cannot be processed using standard BO algorithms. To address this issue, we develop a hybrid method (BO-B&B) that combines Bayesian optimization and a branch-and-bound algorithm to deal with discrete variables. The proposed algorithm exploits the advantages of the cutting-edge machine-learning parameter-tuning technique and the exact mathematical optimization method, thereby balancing efficiency and accuracy. Our experimental results show that the proposed method outperforms benchmarking discrete optimization heuristics for simulation-based DNDPs in terms of total computational time. Thus, BO-B&B can potentially aid decision makers in mapping practical network design schemes for large-scale networks.</p> </abstract>

Styles APA, Harvard, Vancouver, ISO, etc.

33

Bregoli, Alessandro, Marco Scutari et Fabio Stella. « A constraint-based algorithm for the structural learning of continuous-time Bayesian networks ». International Journal of Approximate Reasoning 138 (novembre 2021) : 105–22. http://dx.doi.org/10.1016/j.ijar.2021.08.005.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

34

Li, Yan-Feng, Jinhua Mi, Yu Liu, Yuan-Jian Yang et Hong-Zhong Huang. « Dynamic fault tree analysis based on continuous-time Bayesian networks under fuzzy numbers ». Proceedings of the Institution of Mechanical Engineers, Part O : Journal of Risk and Reliability 229, n^o 6 (8 juin 2015) : 530–41. http://dx.doi.org/10.1177/1748006x15588446.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

35

Pan, Tie Jun, Lei Na Zheng et Cheng Qing Li. « Lube Intelligent Diagnosis System Combining Bayesian and BP Network Based on IOT Technology ». Advanced Materials Research 490-495 (mars 2012) : 1014–18. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.1014.

Texte intégral

Résumé :

The existing industrial lubrication depend on experience judgment, off-line inspection and regular oil change, whose maintenance requires rich personnel experience and still always have many errors. Line monitoring and quality diagnosis for industrial lube were studied to establish the distributed the online monitoring system based on hierarchical structure, information fusion diagnostic system based on Bayesian network and BP neural network. The filtering system for industrial lube has been developed to achieve unattended, automatic operation purposes, and trialed in the metallurgical industry. The results show monitoring data is stable, reliable, and the problem of high water content of lube in the steel industry is solved. At the same time, lube filtering is transformed from the traditional blind continuous filtering to real-time targeted filtering. In the premise of guaranteeing the lube quality, the system can save electricity more than 30%.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Boudali, Hichem, et Joanne Bechta Dugan. « Corrections on “A Continuous-Time Bayesian Network Reliability Modeling and Analysis Framework&rdquo ; [Mar 06 86-97] ». IEEE Transactions on Reliability 57, n^o 3 (septembre 2008) : 532–33. http://dx.doi.org/10.1109/tr.2008.925796.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

37

Chen, Kevin S. « Optimal Population Coding for Dynamic Input by Nonequilibrium Networks ». Entropy 24, n^o 5 (25 avril 2022) : 598. http://dx.doi.org/10.3390/e24050598.

Texte intégral

Résumé :

The efficient coding hypothesis states that neural response should maximize its information about the external input. Theoretical studies focus on optimal response in single neuron and population code in networks with weak pairwise interactions. However, more biological settings with asymmetric connectivity and the encoding for dynamical stimuli have not been well-characterized. Here, we study the collective response in a kinetic Ising model that encodes the dynamic input. We apply gradient-based method and mean-field approximation to reconstruct networks given the neural code that encodes dynamic input patterns. We measure network asymmetry, decoding performance, and entropy production from networks that generate optimal population code. We analyze how stimulus correlation, time scale, and reliability of the network affect optimal encoding networks. Specifically, we find network dynamics altered by statistics of the dynamic input, identify stimulus encoding strategies, and show optimal effective temperature in the asymmetric networks. We further discuss how this approach connects to the Bayesian framework and continuous recurrent neural networks. Together, these results bridge concepts of nonequilibrium physics with the analyses of dynamics and coding in networks.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Chen, Kevin S. « Optimal Population Coding for Dynamic Input by Nonequilibrium Networks ». Entropy 24, n^o 5 (25 avril 2022) : 598. http://dx.doi.org/10.3390/e24050598.

Texte intégral

Résumé :

The efficient coding hypothesis states that neural response should maximize its information about the external input. Theoretical studies focus on optimal response in single neuron and population code in networks with weak pairwise interactions. However, more biological settings with asymmetric connectivity and the encoding for dynamical stimuli have not been well-characterized. Here, we study the collective response in a kinetic Ising model that encodes the dynamic input. We apply gradient-based method and mean-field approximation to reconstruct networks given the neural code that encodes dynamic input patterns. We measure network asymmetry, decoding performance, and entropy production from networks that generate optimal population code. We analyze how stimulus correlation, time scale, and reliability of the network affect optimal encoding networks. Specifically, we find network dynamics altered by statistics of the dynamic input, identify stimulus encoding strategies, and show optimal effective temperature in the asymmetric networks. We further discuss how this approach connects to the Bayesian framework and continuous recurrent neural networks. Together, these results bridge concepts of nonequilibrium physics with the analyses of dynamics and coding in networks.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Chen, Kevin S. « Optimal Population Coding for Dynamic Input by Nonequilibrium Networks ». Entropy 24, n^o 5 (25 avril 2022) : 598. http://dx.doi.org/10.3390/e24050598.

Texte intégral

Résumé :

The efficient coding hypothesis states that neural response should maximize its information about the external input. Theoretical studies focus on optimal response in single neuron and population code in networks with weak pairwise interactions. However, more biological settings with asymmetric connectivity and the encoding for dynamical stimuli have not been well-characterized. Here, we study the collective response in a kinetic Ising model that encodes the dynamic input. We apply gradient-based method and mean-field approximation to reconstruct networks given the neural code that encodes dynamic input patterns. We measure network asymmetry, decoding performance, and entropy production from networks that generate optimal population code. We analyze how stimulus correlation, time scale, and reliability of the network affect optimal encoding networks. Specifically, we find network dynamics altered by statistics of the dynamic input, identify stimulus encoding strategies, and show optimal effective temperature in the asymmetric networks. We further discuss how this approach connects to the Bayesian framework and continuous recurrent neural networks. Together, these results bridge concepts of nonequilibrium physics with the analyses of dynamics and coding in networks.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Pablo Héctor, Ibargüengoytia-González, Reyes-Ballesteros Alberto, Borunda-Pacheco Mónica et García-López Uriel Alejandro. « Prediction of Wind Power Generation with Modern Artificial Intelli-gence Technology ». Journal of Autonomous Intelligence 4, n^o 2 (25 octobre 2021) : 52. http://dx.doi.org/10.32629/jai.v4i2.501.

Texte intégral

Résumé :

<div><p class="4">In view of the continuous growth of energy demand and interest in environmental protection, the use of clean energy to replace fossil fuels is a global trend. Wind energy is the fastest growing renewable energy in the world in recent years. However, in the case of Mexico, there are still some difficulties in promoting its use in some areas of the national territory. One difficulty is knowing in advance how much energy can be injected into the grid. This paper introduces the development of artificial intelligence technology for wind power generation prediction based on multi-year meteorological information. In particular, the potential application of Bayesian network in these prediction applications is studied in detail. A weather forecasting method based on Dynamic Bayesian network (RBD) is proposed. The forecasting system was tested using meteorological data from the regional wind energy technology center (CERT) of the National Institute of Electricity and Clean Energy (INEEL) in Oaxaca, Mexico. The results are compared with the time series prediction results. The results show that dynamic Bayesian network is a promising wind power generation prediction tool.</p></div>

Styles APA, Harvard, Vancouver, ISO, etc.

41

Zia, Muhammad Azam, Zhongbao Zhang, Guangda Li, Haseeb Ahmad et Sen Su. « Prediction of Rising Venues in Citation Networks ». Journal of Advanced Computational Intelligence and Intelligent Informatics 21, n^o 4 (20 juillet 2017) : 650–58. http://dx.doi.org/10.20965/jaciii.2017.p0650.

Texte intégral

Résumé :

Prediction of rising stars has become a core issue in data mining and social networks. Prediction of rising venues could unveil rapidly emerging research venues in citation network. The aim of this research is to predict the rising venues. First, we presented five effective prediction features along with their mathematical formulations for extracting rising venues. The underlying features are composed by incorporating the citation count, publications, cited to and cited by information at venue level. For prediction purpose, we employ four machine learning algorithms including Bayesian Network, Support Vector Machine, Multilayer Perceptron and Random Forest. Experimental results demonstrate that proposed features set are effective for rising venues prediction. Our empirical analysis spotlights the rising venues that demonstrate the continuous improvement over time and finally become the leading scientific venues.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Codetta-Raiteri, Daniele, et Luigi Portinale. « Generalized Continuous Time Bayesian Networks as a modelling and analysis formalism for dependable systems ». Reliability Engineering & ; System Safety 167 (novembre 2017) : 639–51. http://dx.doi.org/10.1016/j.ress.2017.04.014.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

43

Li, Chunyan. « Urban Planning Design and Evaluation Based on GIS Information and Bayesian Network ». Mathematical Problems in Engineering 2022 (24 août 2022) : 1–10. http://dx.doi.org/10.1155/2022/5963133.

Texte intégral

Résumé :

In recent years, China’s urban construction has set off a climax, with the rapid increase of the number of cities and towns, the increasingly perfect functions of cities and towns, the continuous improvement of the level of urbanization, and the urban landscape changing with each passing day. Under the influence of many factors, urban planning and assessment are facing unprecedented pressure, leading to the inconsistency between the compilation results of planning. Under the guidance of system analysis and system dynamics, this paper designs and develops an urban planning information management system based on GIS (Geographic Information System) and Bayesian network, and then the system is applied to the field of urban planning. In this system, all kinds of data generated by planning are stored in order to realize the standardization of data, and then the urban planning work is guided by the effective management of the result data so as to know the implementation status of urban planning in time and provide the basis for the future planning and implementation.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Ali, Wasiq, Yaan Li, Muhammad Asif Zahoor Raja, Wasim Ullah Khan et Yigang He. « State Estimation of an Underwater Markov Chain Maneuvering Target Using Intelligent Computing ». Entropy 23, n^o 9 (29 août 2021) : 1124. http://dx.doi.org/10.3390/e23091124.

Texte intégral

Résumé :

In this study, an application of deep learning-based neural computing is proposed for efficient real-time state estimation of the Markov chain underwater maneuvering object. The designed intelligent strategy is exploiting the strength of nonlinear autoregressive with an exogenous input (NARX) network model, which has the capability for estimating the dynamics of the systems that follow the discrete-time Markov chain. Nonlinear Bayesian filtering techniques are often applied for underwater maneuvering state estimation applications by following state-space methodology. The robustness and precision of NARX neural network are efficiently investigated for accurate state prediction of the passive Markov chain highly maneuvering underwater target. A continuous coordinated turning trajectory of an underwater maneuvering object is modeled for analyzing the performance of the neural computing paradigm. State estimation modeling is developed in the context of bearings only tracking technology in which the efficiency of the NARX neural network is investigated for ideal and complex ocean environments. Real-time position and velocity of maneuvering object are computed for five different cases by varying standard deviations of white Gaussian measured noise. Sufficient Monte Carlo simulation results validate the competence of NARX neural computing over conventional generalized pseudo-Bayesian filtering algorithms like an interacting multiple model extended Kalman filter and an interacting multiple model unscented Kalman filter.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Yasenjiang, Jiarula, Chenxing Xu, Shengpeng Zhang et Xin Zhang. « Fault Diagnosis and Prediction of Continuous Industrial Processes Based on Hidden Markov Model-Bayesian Network Hybrid Model ». International Journal of Chemical Engineering 2022 (18 novembre 2022) : 1–17. http://dx.doi.org/10.1155/2022/3511073.

Texte intégral

Résumé :

Hidden Markov models (HMMs) have been recently used for fault detection and prediction in continuous industrial processes; however, the expected maximum (EM) algorithm in the HMM has local optimality problems and cannot accurately find the fault root cause variables in complex industrial processes with high-dimensional data and strong variable coupling. To alleviate this problem, a hidden Markov model-Bayesian network (HMM-BN) hybrid model is proposed to alleviate the local optimum problem in the EM algorithm and diagnose the fault root cause variable. Firstly, the model introduces expert empirical knowledge for constructing BN to accurately diagnose the fault root cause variable. Then, the EM algorithm is improved by sequential and parallel learning to alleviate the initial sensitivity and local optimum problems. Finally, the log-likelihood estimates (LL) calculated by the improved hidden Markov model provide empirical evidence for the BN and give fault detection, prediction, and root cause variable detection results based on information about the similar increasing and decreasing patterns of LL for the training data and the online data. Combining the Tennessee Eastman (TE) process and the continuously stirred tank reactor (CSTR) process, the feasibility and effectiveness of the model are verified. The results show that the model can not only find the fault in time but also find the cause of the fault accurately.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Zhang, Qianqian, Jianglei Sun, Jing Zhao, Zilin Xia et Kai Zhang. « Research on the Extraction Method of Book Number Region Based on Bayesian Optimization and Deep Learning ». International Journal of Circuits, Systems and Signal Processing 15 (27 août 2021) : 1150–58. http://dx.doi.org/10.46300/9106.2021.15.125.

Texte intégral

Résumé :

The continuous development of artificial intelligence technology has promoted the construction of smart libraries and their intelligent services. In the process of intelligent access to books, the extraction of the requested book number region has become an important part of the process. The requested book number is generally affixed to the bottom of the spine of the book, which is small in size, and the height of the book is not always the same, so it’s difficult to identify. By the way, due to the images’ resolution, shooting angle and other practical problems, the difficulty of the extraction work will be increased. To improve the identification accuracy, in this paper, Bayesian Optimization (BO) and one kind of deep neural networks ‘Faster R-CNN’ are combined for the extraction work mentioned above. The data preparation, network training, optimization variable selection, establishment of BO objective function, optimization training, and network parameter evaluation have been introduced in detail. The performance of the designed algorithm has been tested with actual images of book spines taken in the academy library and compared with several other conventional recognition algorithms. The experimental results show that the requested book number region extraction method based on Bayesian optimization and deep neural network is effective and reliable, and its recognition rate can reach 91.82%, which has advantages in both recognition rate and extraction time compared with other algorithms.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Liu, Manxia, Fabio Stella, Arjen Hommersom, Peter J. F. Lucas, Lonneke Boer et Erik Bischoff. « A comparison between discrete and continuous time Bayesian networks in learning from clinical time series data with irregularity ». Artificial Intelligence in Medicine 95 (avril 2019) : 104–17. http://dx.doi.org/10.1016/j.artmed.2018.10.002.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

48

Zaccaria, Valentina, Amare D. Fentaye, Mikael Stenfelt et Konstantinos G. Kyprianidis. « Probabilistic Model for Aero-Engines Fleet Condition Monitoring ». Aerospace 7, n^o 6 (26 mai 2020) : 66. http://dx.doi.org/10.3390/aerospace7060066.

Texte intégral

Résumé :

Since aeronautic transportation is responsible for a rising share of polluting emissions, it is of primary importance to minimize the fuel consumption any time during operations. From this perspective, continuous monitoring of engine performance is essential to implement proper corrective actions and avoid excessive fuel consumption due to engine deterioration. This requires, however, automated systems for diagnostics and decision support, which should be able to handle large amounts of data and ensure reliability in all the multiple conditions the engines of a fleet can be found in. In particular, the proposed solution should be robust to engine-to-engine deviations and different sensors availability scenarios. In this paper, a probabilistic Bayesian network for fault detection and identification is applied to a fleet of engines, simulated by an adaptive performance model. The combination of the performance model and the Bayesian network is also studied and compared to the probabilistic model only. The benefit in the suggested hybrid approach is identified as up to 50% higher accuracy. Sensors unavailability due to manufacturing constraints or sensor faults reduce the accuracy of the physics-based method, whereas the Bayesian model is less affected.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Li, Xi, et Dan Feng Feng. « Bayesian Network Learn Method for Machine Tool Thermal Stability Modeling ». Advanced Materials Research 284-286 (juillet 2011) : 932–35. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.932.

Texte intégral

Résumé :

Maintain the thermal stability of the machine tool is a common problem to achieve intelligent and precise processing control, and its difficulty lies in modeling and real-time compensation. In this paper, considering the correlation of various factors, the correlation of those factors according to experiment data was analysis and optimized, and a dynamic model of thermal error compensation of CNC machine tool based on Bayesian Network theory was found. Moreover, because of the self-learning feature of Bayesian network, the model can be continuously optimized by updating dynamic coefficient, and reflect the changes of processing condition. Finally, the feasibility and validation of this model were proved through the experiment.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Jackson-Blake, Leah A., François Clayer, Sigrid Haande, James E. Sample et S. Jannicke Moe. « Seasonal forecasting of lake water quality and algal bloom risk using a continuous Gaussian Bayesian network ». Hydrology and Earth System Sciences 26, n^o 12 (20 juin 2022) : 3103–24. http://dx.doi.org/10.5194/hess-26-3103-2022.

Texte intégral

Résumé :

Abstract. Freshwater management is challenging, and advance warning that poor water quality was likely, a season ahead, could allow for preventative measures to be put in place. To this end, we developed a Bayesian network (BN) for seasonal lake water quality prediction. BNs have become popular in recent years, but the vast majority are discrete. Here, we developed a Gaussian Bayesian network (GBN), a simple class of continuous BN. The aim was to forecast, in spring, mean total phosphorus (TP) and chlorophyll a (chl a) concentration, mean water colour, and maximum cyanobacteria biovolume for the upcoming growing season (May–October) in Vansjø, a shallow nutrient-rich lake in southeastern Norway. To develop the model, we first identified controls on interannual variability in seasonally aggregated water quality. These variables were then included in a GBN, and conditional probability densities were fit using observations (≤39 years). GBN predictions had R2 values of 0.37 (chl a) to 0.75 (colour) and classification errors of 32 % (TP) to 17 % (cyanobacteria). For all but lake colour, including weather variables did not improve the predictive performance (assessed through cross-validation). Overall, we found the GBN approach to be well suited to seasonal water quality forecasting. It was straightforward to produce probabilistic predictions, including the probability of exceeding management-relevant thresholds. The GBN could be sensibly parameterised using only the observed data, despite the small dataset. Developing a comparable discrete BN was much more subjective and time-consuming. Although low interannual variability and high temporal autocorrelation in the study lake meant the GBN performed only slightly better than a seasonal naïve forecast (where the forecasted value is simply the value observed the previous growing season), we believe that the forecasting approach presented here could be particularly useful in areas with higher sensitivity to catchment nutrient delivery and seasonal climate and for forecasting at shorter (daily or monthly) timescales. Despite the parametric constraints of GBNs, their simplicity, together with the relative accessibility of BN software with GBN handling, means they are a good first choice for BN development with continuous variables.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Continuous Time Bayesian Network »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres