independence structure
Profile Graphical Models
Avalos-Pacheco, Alejandra, Lupparelli, Monia, Stingo, Francesco C.
We introduce a novel class of graphical models, termed profile graphical models, that represent, within a single graph, how an external factor influences the dependence structure of a multivariate set of variables. This class is quite general and includes multiple graphs and chain graphs as special cases. Profile graphical models capture the conditional distributions of a multivariate random vector given different levels of a risk factor, and learn how the conditional independence structure among variables may vary across these risk profiles; we formally define this family of models and establish their corresponding Markov properties. We derive key structural and probabilistic properties that underpin a more powerful inferential framework than existing approaches, underscoring that our contribution extends beyond a novel graphical representation.Furthermore, we show that the resulting profile undirected graphical models are independence-compatible with two-block LWF chain graph models.We then develop a Bayesian approach for Gaussian undirected profile graphical models based on continuous spike-and-slab priors to learn shared sparsity structures across different levels of the risk factor. We also design a fast EM algorithm for efficient inference. Inferential properties are explored through simulation studies, including the comparison with competing methods. The practical utility of this class of models is demonstrated through the analysis of protein network data from various subtypes of acute myeloid leukemia. Our results show a more parsimonious network and greater patient heterogeneity than its competitors, highlighting its enhanced ability to capture subject-specific differences.
- Health & Medicine > Therapeutic Area > Oncology > Leukemia (0.88)
- Health & Medicine > Therapeutic Area > Hematology (0.88)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning (0.88)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Uncertainty > Bayesian Inference (0.48)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (0.48)
- Information Technology > Artificial Intelligence > Machine Learning > Performance Analysis > Accuracy (0.46)
Cooperative neural networks (CoNN): Exploiting prior independence structure for improved classification
We propose a new approach, called cooperative neural networks (CoNN), which use a set of cooperatively trained neural networks to capture latent representations that exploit prior given independence structure. The model is more flexible than traditional graphical models based on exponential family distributions, but incorporates more domain specific prior structure than traditional deep networks or variational autoencoders. The framework is very general and can be used to exploit the independence structure of any graphical model. We illustrate the technique by showing that we can transfer the independence structure of the popular Latent Dirichlet Allocation (LDA) model to a cooperative neural network, CoNN-sLDA. Empirical evaluation of CoNN-sLDA on supervised text classification tasks demonstrate that the theoretical advantages of prior independence structure can be realized in practice - we demonstrate a 23 percent reduction in error on the challenging MultiSent data set compared to state-of-the-art.
- North America > Canada > Ontario > Toronto (0.14)
- North America > United States > California (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- Europe > France > Grand Est > Bas-Rhin > Strasbourg (0.04)
- Health & Medicine (0.46)
- Government (0.46)
- North America > United States > Illinois > Cook County > Chicago (0.05)
- Asia > Singapore (0.04)
- Asia > Middle East > Jordan (0.05)
- North America > United States > Georgia > Fulton County > Atlanta (0.04)
- North America > United States > California > Santa Clara County > Palo Alto (0.04)
- North America > Canada > Quebec > Montreal (0.04)
- Information Technology > Artificial Intelligence > Machine Learning > Neural Networks > Deep Learning (1.00)
- Information Technology > Artificial Intelligence > Natural Language > Text Processing (0.94)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (0.46)
Cooperative neural networks (CoNN): Exploiting prior independence structure for improved classification
We propose a new approach, called cooperative neural networks (CoNN), which use a set of cooperatively trained neural networks to capture latent representations that exploit prior given independence structure. The model is more flexible than traditional graphical models based on exponential family distributions, but incorporates more domain specific prior structure than traditional deep networks or variational autoencoders. The framework is very general and can be used to exploit the independence structure of any graphical model. We illustrate the technique by showing that we can transfer the independence structure of the popular Latent Dirichlet Allocation (LDA) model to a cooperative neural network, CoNN-sLDA. Empirical evaluation of CoNN-sLDA on supervised text classification tasks demonstrate that the theoretical advantages of prior independence structure can be realized in practice - we demonstrate a 23 percent reduction in error on the challenging MultiSent data set compared to state-of-the-art.
- North America > United States > Illinois > Cook County > Chicago (0.05)
- Asia > Singapore (0.04)
- Asia > Middle East > Jordan (0.05)
- North America > United States > Georgia > Fulton County > Atlanta (0.04)
- North America > United States > California > Santa Clara County > Palo Alto (0.04)
- North America > Canada > Quebec > Montreal (0.04)
- Information Technology > Artificial Intelligence > Machine Learning > Neural Networks > Deep Learning (1.00)
- Information Technology > Artificial Intelligence > Natural Language > Text Processing (0.94)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (0.46)
Conditional Independence Estimates for the Generalized Nonparanormal
Shah, Ujas, Lladser, Manuel, Morrison, Rebecca
For general non-Gaussian distributions, the covariance and precision matrices do not encode the independence structure of the variables, as they do for the multivariate Gaussian. This paper builds on previous work to show that for a class of non-Gaussian distributions -- those derived from diagonal transformations of a Gaussian -- information about the conditional independence structure can still be inferred from the precision matrix, provided the data meet certain criteria, analogous to the Gaussian case. We call such transformations of the Gaussian as the generalized nonparanormal. The functions that define these transformations are, in a broad sense, arbitrary. We also provide a simple and computationally efficient algorithm that leverages this theory to recover conditional independence structure from the generalized nonparanormal data. The effectiveness of the proposed algorithm is demonstrated via synthetic experiments and applications to real-world data.
- North America > United States > Colorado > Boulder County > Boulder (0.14)
- Europe > United Kingdom > England > Greater Manchester > Rochdale (0.04)
- Europe > Ireland (0.04)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Uncertainty (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning (0.93)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (0.46)
Reviews: Cooperative neural networks (CoNN): Exploiting prior independence structure for improved classification
Summary: The authors propose a new method that combines a latent Dirichlet allocation (LDA) model with a neural network architecture for the application of supervised text classification –– a model that can be trained end-to-end. In particular, they use a network structure to approximate the intractable inference equations that solve the KL-divergence between the LDA posterior and its approximation which is based on marginal distributions. The authors show that an embedding in a Hilbert space can allow for the approximation of the inference equations, and they choose neural networks to parametrize the functional mapping. Finally, based on two applications, the authors demonstrate an incremental advancement over previous models. Clarity: The overall writing is good, especially as it is a very technical paper with many mathematical details.