Instance-based weighting filter for superparent one-dependence estimators

Bayesian network model structure based on binary evolutionary algorithm

With the continuous development of new technologies, the scale of training data is also expanding. Machine learning algorithms are gradually beginning to be studied and applied in places where the scale of data is relatively large. Because the current structure of learning algorithms only focus on the identification of dependencies and ignores the direction of dependencies, it causes multiple labeled samples not to identify categories. Multiple labels need to be classified using techniques such as machine learning and then applied to solve the problem. In the environment of more training data, it is very meaningful to explore the structure extension to identify the dependencies between attributes and take into account the direction of dependencies. In this article, Bayesian network structure learning, analysis of the shortcomings of traditional algorithms, and binary evolutionary algorithm are applied to the randomized algorithm to generate the initial population. In the optimization process of the algorithm, it uses a Bayesian network to do a local search and uses a depth-first algorithm to break the loop. Finally, it finds a higher score for the network structure. In the simulation experiment, the classic data sets, ALARM and INSURANCE, are introduced to verify the effectiveness of the algorithm. Compared with NOTEARS and the Expectation-Maximization (EM) algorithm, the weight evaluation index of this article was 4.5% and 7.3% better than other schemes. The clustering effect was improved by 13.5% and 15.2%. The smallest error and the highest accuracy are also better than other schemes. The discussion of Bayesian reasoning in this article has very important theoretical and practical significance. This article further improves the Bayesian network structure and optimizes the performance of the classifier, which plays a very important role in promoting the expansion of the network structure and provides innovative thinking.

Identification of informational and probabilistic independence by adaptive thresholding

The independence assumptions help Bayesian network classifier (BNC), e.g., Naive Bayes (NB), reduce structure complexity and perform surprisingly well in many real-world applications. Semi-naive Bayesian techniques seek to improve the classification performance by relaxing the attribute independence assumption. However, the study of dependence rather than independence has received more attention during the past decade and the validity of independence assumptions needs to be further explored. In this paper, a novel learning technique, called Adaptive Independence Thresholding (AIT), is proposed to automatically identify the informational independence and probabilistic independence. AIT can respectively tune the network topologies of BNC learned from training data and testing instance under the framework of target learning. Zero-one loss, bias, variance and conditional log likelihood are introduced to compare the classification performance in the experimental study. The extensive experimental results on a collection of 36 benchmark datasets from the UCI machine learning repository show that AIT is more effective than other learning techniques (such as structure extension, attribute weighting) and helps make the final BNCs achieve remarkable classification improvements.

From undirected dependence to directed causality: A novel Bayesian learning approach

Bayesian network (BN) is one of the most powerful probabilistic models in the field of uncertain knowledge representation and reasoning. During the past decade, numerous approaches have been proposed to build directed acyclic graph (DAG) as the structural specification of BN. However, for most Bayesian network classifiers (BNCs) the directed edges in DAG substantially represent assertions of conditional independence rather than causal relationships although the learned joint probability distributions may fit data well, thus they cannot be applied to causal reasoning. In this paper, conditional entropy is introduced to measure causal uncertainty due to its asymmetry characteristic, and heuristic search strategy is applied to build Bayesian causal tree (BCT) by identifying significant causalities. The resulting highly scalable topology can represent causal relationship in terms of causal science, and corresponding joint probability can fit training data in terms of data science. Then ensemble learning strategy is applied to build Bayesian causal forest (BCF) with a set of BCTs, each taking different attribute as the root node to represent root cause for causality analysis. Extensive experiments performed on 32 public datasets from the UCI machine learning repository show that BCF achieves outstanding classification performance compared to state-of-the-art single-model BNCs (e.g., CFWNB), ensemble BNCs (e.g., WATAN, IWAODE, WAODE-MI and TAODE) and non-Bayesian learners (e.g., SVM, k-NN, LR).